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Pick, Place, Podcast

Advanced Drilling w/ CAM Engineer, Dave Wilcox

May 16, 2022 CircuitHub and Worthington Episode 47
Pick, Place, Podcast
Advanced Drilling w/ CAM Engineer, Dave Wilcox
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Pick, Place, Podcast
Advanced Drilling w/ CAM Engineer, Dave Wilcox
May 16, 2022 Episode 47
CircuitHub and Worthington

We've finally managed to convince CircuitHub CAM Engineer, Dave Wilcox, to come back on the show to continue our series about the intricacies of PCB fabrication.  If you're just tuning in, we recommend you listen to our episodes about Inner Layer Production and PCB Drilling Basics before this one. 

In this episode, we cover some of the finer details of PCB drilling including what the drilling setup physically looks like and tips you can implement to save your PCB fab time.  We also learn that Melissa really needs to work on her email management setup. 

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Show Notes Transcript

We've finally managed to convince CircuitHub CAM Engineer, Dave Wilcox, to come back on the show to continue our series about the intricacies of PCB fabrication.  If you're just tuning in, we recommend you listen to our episodes about Inner Layer Production and PCB Drilling Basics before this one. 

In this episode, we cover some of the finer details of PCB drilling including what the drilling setup physically looks like and tips you can implement to save your PCB fab time.  We also learn that Melissa really needs to work on her email management setup. 

pickplacepodcast.com

Chris:

Welcome to the pick place podcast, a show where we talk about electronics, manufacturing And everything related to getting a circuit board into the world. this is Chris Denny with Worthington,

Melissa:

And this is Melissa Hough with CircuitHub

Chris:

Welcome back Melissa.

Melissa:

welcome back, Chris.

Chris:

So I recently listened to our IPC episode, which I thoroughly enjoyed. I always cringe a little bit listening to my own voice, but I do like to hear how the episodes go. And I thought that was great. I really enjoyed it. I learned a ton.

Melissa:

Yeah, me too

Chris:

so much. we basically, AF after chatting with those folks, we, we've learned so much more about internally just what IPC has to offer and have started to get more documents and do more training with them. And Yeah. so super valuable resource. If you're just listening to this episode and you didn't listen to that one, that's definitely one worth going back to, and, and yeah, making sure you pay attention and take advantage of all the resources they have available. Well, I am thrilled to finally have back our friend, Dave, this week, our in-house cam engineer. It's been a little while it's been a little while, perhaps we can try to catch up with Dave and what we talked about last time and, we can get everybody on board to what we're talking about today. Welcome back, to.

Melissa:

Welcome back, Dave.

Dave:

Thanks for having

Chris:

me. Yeah, of course always. It's it's nice of you to say thanks for having me, but the truth is we, we drag you kicking and screaming into these episodes.

Melissa:

claims he's been remodeling his house, but I think it was just an excuse.

Dave:

I'm sitting in my new office, like I've got a new background,

Melissa:

Fair enough. Fair enough. That is true.

Chris:

true.

Dave:

It's digital behind me I've got a new one.

Chris:

Yeah. it's great. It's just a green screen with us. So, last episode we talked about the, I think it was the inner layer production , and then we started talking about drilling, which was the next step. And drilling was really, I could say drilling was really the last thing we talked about because inner layer production, we produced in one episode and then we cut it and we we did a second episode on drilling. But you, you said something that you should never say in front of Chris Denney, cause you said, this is just the basics. There's so much more to it. And I was like, no, you cannot just do that to me. We need to know so much more Dave. So here we are back. We want to talk about more.

Dave:

yeah, I spent 15 years drilling PCBs, so,

Chris:

my gosh.

Dave:

Yeah, there's a lot can go wrong and there's a lot, you have to take care of

Chris:

it's funny because what I hear from PCB fabs and correct me if I'm wrong, but like the drilling process is almost like the SMT process for an assembler, right? Like, cause it's, it's sorta like the bottleneck it's sorta like where most things can go wrong. It's it. There's a lot of quality control. It's there's a lot, it's sort of the heartbeat of the operation.

Dave:

It can take the longest as well. So, so which is what it becomes a bottleneck. Yeah. You're basically using the same X, Y coordinates in a program and to make a machine and go to that chord, you're putting down a component, drilling a hole, so

Chris:

yeah. Yeah. that's a good way of putting it. It's a good way of putting it, but I meant, I meant it as more of a, like the physicality of it. Obviously it does almost kind of look like a pick and place machine because you see these drills bouncing up and down and everything, but also just in the sense that, because it's kind of the slowest process, it becomes a bit of a bottleneck. And even though the surface Mount assembly process is, is actually very, very fast to like, if you watch these machines run, they are running very, very fast. But because it's doing the majority of every component that needs to go on that board, that it ends up being your bottleneck, right? And so you may have a thousand SMT placements and three through whole placements through hole is going to be a much slower process and going to take much longer. But you only do in three parts versus SMT is trying to do a thousand parts. And that's why SMT ends up being a bottleneck. But is there a correlation like that at all in in a. PCB fabrication where you know, drilling is cause you have to drill thousands of holes. I guess you just have so many you have to make,

Dave:

Yeah. I mean, obviously spool holes, you can, you can drill them quite quickly. You can drill

Chris:

that right?

Dave:

but not the micro holes, but if you're drilling, if you're drilling .4, .5 holes, one millimeter hole, you can, you could drill upwards of a hundred holes a minute, but if you're drilling. Non plated holes. And you do get some, some boards say they got a hundred non plate holes that could take you. They could take two minutes. So because you got slower feeds and speeds, and there's greater distances between the holes. So the travel of the X and Y axis

Chris:

Okay. So that leads me to another question. But I think, I think before I asked that other question, it would probably be better to talk about like the design of these machines and what they're doing. Because in my mind, I always pictured that these machines had like a pick and place head. You had like 10 spindles and, one had a 0.2 millimeter and one had a 0.3 millimeter, one had a 0.4 millimeter and, they would just kind of dance around the board, but it doesn't sound like that. It sounds like maybe you pick up one drill at a time. Is that true?

Dave:

But you might have four heads running at the same time drilling the same drill in the same program. So it's like you got four picker place machines in a row, and they're all doing the same thing at the same time. And then we'll place them the same component at the same time. So, I used a, quite a good two heady machine, which was good enough for our factory. He did everything really. So the two heads, so you could draw two stacks at the same time, but you get these at four, you get to get these modular machines where you can add on a head and you can put one program in a run. Like eight heads all the same time. If you, if you're doing like large volumes of the same board, Not necessarily I had with a single drill, extremely the same drill all the time. And you have some sort of tool you have a barrel system or you have trays, so you can load like a thousand drill bits into the machine. So,

Chris:

literally, maybe, maybe a thousand, that many drill bits in a machine.

Dave:

Yeah.

Chris:

Wow. Holy moly.

Dave:

You have a, you have a drum, which is probably, you can have drums, which are probably a foot and a half to two foot long. And then they got drill bits in all the way around though. So like a hedgehog all spiny with all the coming out.

Chris:

no kidding.

Dave:

and yeah, you program in the machine what drills you've placed, where. And it goes and picks them up.

Chris:

So, these, these these barrels or these trays or nests or whatever you call them, what would be the term you used for this?

Dave:

It depends what machine, what manufacturer machine you buy? So,

Chris:

Okay.

Dave:

I've used one. That's got that, that they'd called it a drum and it, it was a drum and another one use trays. So you you'd feel trays up you'd have 1, 2, 3 or four or five trays.

Chris:

Okay. Interesting. All right. So let's, let's, I'm going to use the term trays only because

Dave:

Yeah, it's easier.

Chris:

I, this, this porcupine thing while it sounds awesome. I, so th these trays are these, do they have like a common sort of Like, okay. Let me put it this way. When I have a when I have a drill set, when I go to the local hardware store and I buy a drill set, the way that these drills are held in, in the drill set is there are holes that match the size of the drill. But I have to imagine if you're holding thousands of drills in these machines, you're not like, oh, this is the tray that can hold the 0.2 fives. This is the tray that can hold the 0.3 is, this is the tray that can hold the 0.4 is they, they must have a common size that goes in the spindle or something.

Dave:

Yeah. You got a turbo shank

Chris:

what a turbo shank.

Dave:

Yes.

Chris:

Oh, that was my band name in high school. Turbo shank

Dave:

still is apparently,

Chris:

Cool. Okay, so you have a turbo

Dave:

yeah, it's, it's one eighth of an inch.

Chris:

Okay.

Dave:

So every drill bit from a 0.1 to a six millimeter has a one eigth turbo shank.

Chris:

And that's what goes up inside the

Dave:

Yeah, so basically all the drills are upside down if you like. So you're, you're looking at the actual drilling drilling piece of the drill if you're looking at that. So to put it upside down.

Chris:

They're putting in upside down now. How, how, how does the head flip them? Like, I don't understand how you, how the head can grab these at this point

Dave:

So then there's a partner machine, which is called a stylus, which we'll go and pick, go pick the drill out of the tray then placed that into the spindle. The spinners got a Collie on there.

Chris:

Yup. Yup.

Dave:

like a normal lave, old fashioned lave mini mini machine. I call it certain size 1.8 or 1.8, one eighth of an inch.

Chris:

Yep.

Dave:

And it will just, just insert it into the. And then, then the college will close. Stylist comes down and it goes away to draw.

Chris:

Interesting. So there's a bit of that stylist acts as a bit of an intermediary to load the different drill bits into the, into the call it. Yeah. And would you, would you load like a bunch of the same drill bit

Dave:

Yes,

Chris:

like w oh, you would?

Dave:

yes. Yeah. You wouldn't change a thousand, so say you can hold a thousand drill bits in these trays. I'm talking, you'll have 40.2 fives. So because you drew it a lot of small holes, you might be drilling, drilling 10,000 holes in a run and, or you might be running machine overnight. Cause you've got an auto loader on it. You're stacking your, your auto loader up with 20 runs. So it'll run 20 cycles automatically. So you make sure you have enough drills, a new machine to cover. So it's basically a soft operation at that point.

Chris:

Yeah.

Dave:

you don't need an operator. So you have to get your drills. You need to, for that run, that you've set up on a machine for your autoloader

Chris:

Okay.

Dave:

drills in there to cover it. So obviously you have hit counts and on each drill.

Chris:

This is what I was going to ask. Yeah. Like how many can you get out of a 0.2, five

Dave:

Up to a thousand, it depends on what you're drilling.

Chris:

really? Wow. Only a thousand. I would expect way more than that.

Dave:

Depends. What if it didn't a lot, if it was an eight layer and you're drilling too high, you're potentially driilling 16 layers a copper.

Chris:

Wow. Yeah. Right, right. Yeah. So that's going to last a lot less long. Can you could, does the software calculate all that for you?

Dave:

no, we have to calculate that.

Chris:

Oh geez. Business opportunity right

Dave:

yeah.

Chris:

Wow. You kidding me. So you have to

Dave:

some might these

Chris:

but you must have, you must have some tables or something you work at and you go, all right. Once, once you've hit this drill, but so many times. And how does is something keeping track of how many times a certain drug that has been used? Are they barcoded or RFID or anything like that?

Dave:

obviously the control for the magazine or you trays. It knows the machine counts, how many times it's it's drilled. So when it hits the limit, it will go and put, put that drill back in the same place, pick up the next new one, place it in, in a spindle and carry on drilling. So, and then it will mark it on your magazine as used or inspired or if it's, or if it's broken or, or whatever. So, yeah. And then, then when you come to replenish that, the tools in the magazine in the morning, you come back in, in the morning, , it's drilled all your panels that have in your Toyota and they come in the morning and you, you replenish the, the used drills. So you replace, what's been used for new drills.

Chris:

okay. Now the, you said you might have 40.2 fives. If it's a larger drill that say, say it's a one millimeter drill bit or something like that, do you just put two or three of them in because they're more robust. They're going to last longer.

Dave:

Obama will draw you, you might get two and a half thousand hits. I have a one little drill.

Chris:

Okay. Yeah. So you do get more.

Dave:

Yeah. So the bigger, the drill, you tend to get that they last longer and they don't drill so many holes, obviously vias. So you'd have less of them, but then again, that is, that is dependent on what you're drilling. You might have a, you have a job that has a lot of one mil holes, so you need more drills. So what you're drilling you put what drills you need in there how many, how many hits you're going to get off, off a one millimeter drill.

Chris:

Okay. Do you do, does it matter, like does the typical fr four respond differently than your Rogers or your Taconic or some of your more exotic materials? It does.

Dave:

Yeah. You, you, you, Rogers is harder. It's a lot

Chris:

is. Okay. your, bits, aren't going to last as long on that stuff. Yeah. Interesting. Have you ever messed around with this Taconic material who've ever seen this?

Dave:

yeah. That's it's horrible to drill

Chris:

har it's horrible to do anything

Dave:

Yeah. It's it's, it's basically a Teflon nonstick, so

Chris:

oh boy. yeah,

Dave:

PTFE. So, yeah, it's horrible. Yeah. It's, it's horrible. It's horrible. It's horrible to cut and rout and to drill.

Chris:

we have one customer. If listeners aren't familiar with Taconic, it's like this. But to me it almost reminds me of like, like a fiberboard it's it's, it's like real, it's like incredibly brittle and fragile and we have to be so careful when we get these boards in the building. They fall apart almost so easily.

Dave:

Yeah. There's different types of content material. Yeah. You get, you get some which are almost plastic.

Chris:

Oh, interesting. No, we haven't seen that. No, this was more of like a fiber material. It's for some crazy RF video broadcasting stuff. And I don't know, it's, it's all complete black arts to me. I have no idea how any of this stuff works, but every time we get the boards, we're like, oh gosh, we actually, they're so fragile that we actually have to take. We, we tell our PCB supplier, send us all of your I'm going to use the wrong term again, underlayment or what, what, what do you, what do you drill into underneath the board? What do you call it? Backend material, send us every piece of backing material that you used to fabricate these boards, because we, we end up using those and we taped down after we're done assembling the boards, We, tape the, assemble the boards down to that backing material and ship them out with it because it's the only way we can ensure that it arrives to our customers safely.

Dave:

We, we use that back, that signed baker board to actually ship the boards to a customer.

Chris:

Yeah. Yup. Yup. But you'll ship like a stack on one backing board. Whereas we wanted one board per backing board. We want every single one to have its own protective. Anyway. We're talking about drilling today, not backing board, so we'll go, we'll steer the ship back on target.

Dave:

We get to the back board in a minute, it's quite important,

Chris:

Okay, well, so let's, so before we do, though, because we were talking about the longevity of the drill, that's one, like I always try to bring this back to, w we love to target the show towards designers and new engineers and people who have learned about this stuff. So we're talking about the challenges that manufacturers have when they're trying to make your product. It sounds to me like with, with how many how long it takes to drill and with with how fragile some of these smaller bits can be. Would you agree that it possibly trying to reduce the number of drills you have in your design and possibly trying to make those drill holes larger? Not extremely large, but larger would have an advantage to your process and potentially reduce costs, increase yields.

Dave:

As, as in the states, bigger is better. Right. Everything's everything's bigger. So

Chris:

see my coffee mug.

Dave:

yeah. So if you could have a big coffee mug, we'll have a big coffee mug. All right.

Chris:

I have a bigger one.

Dave:

So, so the smaller you go, the more difficult is to drill. The more expensive it is to make you board so small tracks, small holes. So you need more small drills to drill the same amount if you had 3000.4 holes as your vias. You probably need two drills to do that. But if you had, if you had the same amount of the holes for a 0.2, you probably need twice as many drills

Chris:

Yeah. There you go. And those drills probably I have to imagine we're talking 15, 20, 30 bucks a piece, each drill.

Dave:

Cheaper than that, you can get them cheaper than that. Yeah. They're cheaper than that. But we used to have a rule of thumb that probably doesn't work. These days prices have changed. A lot but we used to have a rule of thumb.. It was a, a pound of drill, but you get some, but you get some jewels which are like, or 50 cents, if you like, and you get, another drill, which is $3. The bigger, the bigger sizes are, are more expensive, but you can have, you can have 5, 5, 6 millimeter drills in a drill shop for free for four years and only use two of them. Cause it, cause you only drill three holes a month with it. Like,

Chris:

Of course, of course. okay. So, do you ever try to reuse them? Do you re do you sharpen them and reuse them or you just scrap them? Oh, you do?

Dave:

Yep. Yep. Well, yeah, it's important for like keeping costs down so you can we should get 0.2, five stone, anything low on that would be, we couldn't get done. But it's finding the people to do it in the UK that there was only like two places that that could be done. And

Chris:

Oh, so you'd send it out. you, didn't do it in house. You sent it out.

Dave:

that's a separate industry. We, you get after employ someone just to do that all day long

Chris:

yeah,

Dave:

and, you need the machinery to do it, to put the correct, the correct cut and angles back on the drills.

Chris:

It's sorta like, it's sorta like us. We, we, we hire a specialized company to make stencils for us, but there's some shops once they become large enough, they'll have a person in their building and the appropriate equipment and all they do is just make the stencils for the factory.

Dave:

It's like a separate little cottage industry. That's yeah, that,

Chris:

Yup. Exactly. Interesting. Okay. So, Th that I find all that kind of stuff, fascinated about the drilling, but, and then I started to lead into the backing board. It sounded like you wanted to get into the

Dave:

yeah. Well, that's important as well, because like the backing board gives it, obviously it's only drilling into the metal base if you're drilling machine, because that's going to damage the drill. So the exit material, it supports the copper on the bottom side and needs to be strong enough to support a copper up on the side, but not strong enough that it's going to damage the drills.

Chris:

So there's probably like a specific durometer you guys are aiming for.

Dave:

Yeah. So,

Chris:

would that material

Dave:

A drill bit has got a cut and angle and that normally increases with the bigger the drill gets. So it needs to go from, from points of a millimeter to half a millimeter through the bottom of your stack. You can't say, oh, I'll do everything. One miillimeter through the board, because you're on the small Jules, you lose the flute length and you start to strangle, you start to strangle your drills and they snap. So, yeah, if you drill a hole right up to the top of the flute, the swarf in the flutes has got no, no way to exit out the top of

Chris:

this is a debris for those of us in the United States. Swath means debris.

Dave:

Okay. Debris, I will become

Chris:

You're good. You, you, you, you use swath. You swath w we can translate it in our heads. Now we know what you

Dave:

Yeah. So that doesn't get extracted from the hole. The drill bit is an in the hole for the swath go anywhere. So it, it jams in the hole

Chris:

It binds up. Yeah. Interesting. That makes

Dave:

that's basically what we call strangling strangles, the, the top of flute and leaves it in leaves in the material. So you need to make sure you've got enough, enough clearance at the top of your material to, for that to happen. So at the bottom, the exit material is basically there to stop. burs and poor exit holes.

Chris:

Getting a blow out. You could just blow out the copper from the opposite side, probably even right.

Dave:

Well, if,

Chris:

good backing

Dave:

if you get, if you get a Burr

Melissa:

Okay.

Dave:

You've drilled through a piece of aluminium we have a standard hand rule and it all splays out and you've got sharp edge. Well, when you got 4,000 holes in a panel, it's a bit like a cheese they're, if they're burred. And obviously when you're, when you're printed on that later, you need, you need a flat surface and that's not a flat surface. So it's the quality of that whole no burrs clean all of their pre removed. So you've

Chris:

So do you rely on, do you rely on like when you buy the backing material? Whoever's manufacturing this backend material there. They're taking the time to. do all the math and science and everything to figure out, okay, this is the right durometer. This is the right. Like, it has all the right material properties to make your process easy. All you have to do is open a catalog and buy the right stuff. Right. You don't have to go into the science of all this kind of somebody else is doing all that for you.

Dave:

Yeah. But then you get a melamine backed tech board tech board is like a, a brown cardboardy type material, which

Chris:

what we mostly

Dave:

is what you see. The next up next stage up from that is you get a a melamine coated tech board has a white plastic coating on it, which is better for like burrs and things like that. Which what I useed for years. And you can also get specialized backing board, which has like, it's basically lubricated. So when the drill goes in, now it show you your panel. It's lubricating

Chris:

the drill

Dave:

So yeah.

Chris:

potentially helping them to last longer.

Dave:

Yes, last longer. And it makes it more accurate. And the same with natural material, it's the same. You get different types of wrench material.

Chris:

Okay. So it sounds like there's three types of backing material. you might

Dave:

Yeah, especially. So, I mean, if you looking at the basic tech board, you're looking at, say it costs a dollar for a 24 by 10 sheet. And if you look at the specialist stuff, it costs $5. So it's not cost effective, so you need to be sure on what you're going to be used now. So it's only a very specialized product

Chris:

And then what do you call the material on the top? You call that

Dave:

entering material.

Chris:

Yeah. And so what is it, is there different types in different tiers that you use for that as well?

Dave:

yeah, it's, it's normally a a piece of.2 alluminum point to. Allie minium. So it's a

Chris:

Really? That thin that's almost a,

Dave:

Or

Chris:

a foil.

Dave:

you can almost wrap, wrap your Turkey in it if your Turkey sandwiches, Chris,

Chris:

Yeah, seriously.

Dave:

but.

Chris:

I were running theme of the pick place podcast. Chris has

Dave:

so it's, it's not quite Baco foil, but it's alluminum provides a soft landing for your drills when the spindle was coming down. And that, that first point of contact on, on your stack, it's not going to slide the cup is quite strong. It's quite hard. So if you've got a handheld drill, I wanted you to hold any wall and oh, I want to drill a hole there and you just, just, just ran the drill into it. It would slide across your wall.

Chris:

Yes, it will.

Dave:

That can happen without entering material. That is that it's going to happen in a lesser degree. But it will be like that's when he started getting drilled reflection and your vias don't look quite central to your pads when you get your boards back,

Chris:

Yeah, of course. So that's interesting to me because I've always thought whenever. Okay. So when, when you are designing a board, I know that I've talked to other PCB fabs and they've said, Hey, look, your annular rings here are so small. We're we're really going to struggle to hit the target to get that drill just right. I always thought that that was just registration of the drilling against the etching, but it sounds like it could,

Dave:

the drilling, the drilling comes first.

Chris:

Yeah, Yeah. Right. But, but, but it sounds like, so you, you obviously have the registration of the X, Y movement of the drilling machine, but it sounds like there's a third variable. It's not just the X, Y movement of the drilling machine, but it's also the drill head slipping or deflecting from where it's trying to hit to. That's another opportunity for, for, a variable there. So having the larger annular ring you got a bigger target for that drill to hit.

Dave:

yeah. The, the accuracy of a drilling machine you'd like to say we can hit the center of a whole VIN 50 microns.

. Chris:

Okay. That's pretty good.

Dave:

Yeah.

Chris:

50 50 microns. That's that is pretty good, but, but like there's holes that

Dave:

yeah, but, but then again,

Chris:

microns.

Dave:

by PC IPC, three says you must have 50 microns of copper to the whole edge. So if you got a 0.1 hole and you got two 30, I need a ring. got.

Chris:

Then you've got. your 50.

Dave:

The got to have absolute bullseye to, to, to meet IPC three.

Chris:

Yeah, my goodness.

Dave:

you won't get absolute bullseye it's absolutely impossible

Chris:

Yeah. Fascinating.

Dave:

because you think that this material we will move and stretch and shrink. When it goes through wet processes, hot processes, cold processes, it will move in shrink as he goes through the process. And it's not, it's not, you never get a bullseye.

Chris:

Fascinating.

Dave:

might, you might, you might on half your holes, but you're always gonna have a, you always sort of at least a 25 micron movement

Chris:

Yeah. so you want to, okay. So if you, if you want to hit IPC class three and you need to use, for whatever reason, you need to use a a hundred micron hole, try to make your, your the diameter of your copper around that 250 micron. That way there, you got a little extra play.

Dave:

Yeah. Give us, give us something to play with.

Chris:

Yeah, exactly. I know. It's you, I get it because you're, you want to push your designs. You want to make them smaller. You want to, you, you want to get everything to fit, right. And sometimes it's a real challenge to make that work, but be American bigger is better. And unless it's my gut, I would prefer that not to be as big as it is. So, so the entry material, do you have different types of entry material or is it basically just that two thousands?

Dave:

Yeah, you can, you can go. You can have it put into 5, 4, 4 big of drills, but I think it's pretty much common just to go point to.

Chris:

not to thought. I said two thousands foil it's

Dave:

Yeah. Put two millimeters. Yeah. So yeah, again, you can get specialized into materials which are lubricated and stuff like that. So, just to try and get, get a better positional accuracy.

Chris:

Yeah. So sometimes if you get a bad design, you have to start to use these more expensive materials to try to nail it.

Dave:

yeah,

Chris:

So that's going to have an impact in your cost is if your, if your PCB fab has to buy all these, rather than using $1 backing material and 50 cent entry material, they got a, $5 backing material and $10 entry material.

Dave:

yeah, yeah. It can be, it can be the cost of a PCB

Chris:

yeah, yeah.

Dave:

can like, yeah. So yeah. We basically use them. But not on everything. It was a lot for occasional use,

Chris:

Yup.

Dave:

you can't use it all the time. It'd be great if you could, but yeah, it was expensive at the time that the prices may have come down, but it was, there was always more expensive.

Chris:

Yeah. Interesting. Okay. So, you were talking about when you get the the, the drill going through the board and the debris is building up inside of that drill inside that hole. So the, the, the gap between the shaft of the drill and the, the walls of the hole, you're, you've got you've got debris build up and it's starting to bind and jam up and it's starting to grab that drill bit. And then there's a potential for that drill bit breaking and just getting stuck inside of that board. How, how do you, how does the machine know to not carry on? Like, how does it know, like, Hey, something happened here.

Dave:

I tell you back a states the stage the geometry of the drill bit helps with that because we use what we call undercut drills. So the top of the flute is slightly thinner than the bottom. So for example, if you've got, if you've got a one millimeter drill, it'd be one millimeter at the cutting edge and it'd be slightly thinner.

Chris:

Point nine, nine or

Dave:

So swarf has got that, that room to come out now, drilling machines. Most of the machines these days have all the whistles and bells on them. They normally have a broken drill, bit detectors.

Chris:

Okay.

Dave:

So, which is usually Just a light that's passed across the college through the bottom, where the drill sits, you have, you have a light passing through. So as soon as that breaks machine goes, stop,

Chris:

no kid.

Dave:

it can tell you at what point that drill bit broke. So you can go back to that point in your program or find it on your panel.

Chris:

Okay. So, all right, so now I'm not I'm I've got, so this opens up just the enormous number of I'm so sorry, Dave. I got so many questions now. How do you, if you're doing lights out manufacturing and you got to stack a 20 of these that are running on their own overnight, and then you break a drill bit inside of it, what does the machine do? Like is It like done or does it carry on.

Dave:

It detects a broken drill.

Chris:

Yeah,

Dave:

It logs in itself. run it's doing and what hole it broke them in the morning. You can go back and see, all right, this has got broken drills in there. You can go, you can go to the correct stack, pull it out,

Chris:

Yup.

Dave:

find a drill, put it back on and re if you have to re drill the hole, essentially you can go back and drill that hole.

Chris:

Can you really? Yeah. Somewhat. I have to imagine if it's too small, you

Dave:

Sometimes you can't get the drill bit out.

Chris:

Yeah. Yeah. Yeah. Yeah.

Dave:

Yeah.

Chris:

So that would be an X out. You guys, you guys would probably just try to flatten that out and then give it a big old X and

Dave:

Yep.

Chris:

Yeah, Interesting. We, speaking of exiles, sorry, this is a bit of a tangent here, but we we've had we get PCB fabs to ask us, like, do you want this quoted with X outs or without X outs? And so, so for listeners, if you're not familiar, normally when we build your assemblies, we'll get a panel. That'll be like two by five panels. So we'll have 10 PCBs in your panel and we'll, we'll assemble 10 PCBs at the same time. And then we break those out when we deliver them to you that, broken out that way. But occasionally Dave shop Dave Dave's magical PCB fab out in the UK which doesn't exist, but we're going to pretend that exist. They'll, they'll get a broken drill or have an etching issue or something else, and they'll take a Sharpie or they'll do something. And they'll mark that board in the past. With a big X. So it's a big visual indicator to the assembler that says, do not populate this board. There's a problem with this board is not going to work for your customer. And so rather than building 10 of the panel, we're building nine in the panel. That's what we're calling a an X out. And whenever we've had whenever, assemblers do not like X outs, they're a huge pain in the neck. PCB fabs do not like to have to guarantee no X outs. So there's this push pull between the two of us. And so PCB fabs will mitigate their risk of potential X outs by evaluating the design, looking for the number of opportunities where they could have an issue with fabricating that and not meeting the results that we're expecting. And they'll say, okay if, if you need a hundred or if you need a thousand of these, we'd anticipate. Two X outs in this design because it's such an excellent design. And so we're only going to charge a few cents extra to guarantee the PCB assembler. It gets no X outs, but if they look at your design and it has all kinds of problems and you have you, you need 0.1 millimeter hole and you have a 0.2 millimeter copper. So you, you barely have enough room for that hole. We're going to have tons of X outs. We're going to have over a hundred X outs on this thing. We're going to charge, five bucks, extra per PCB to Chris Denny's assembly shop because we know we're going to have to trash tons of these boards. Cause we can't, we can't hit that target.

Dave:

Yeah, it is. It's. It's not to say you can have the smallest PCB say it's a 30 before, even to a piece PCB, but it's so tight. It's got three and a half hour tracking gap and 3 30, 2 rings on, on 0.1, five holes. But then someone like me comes along and puts it in a 30 up. So now it's,

Chris:

Yeah,

Dave:

now it's now it's 200 by 300 and it's at, it's all tight and this it's this very few people that can make a board that size. That's all right. We've had every problem somewhere. So yeah.

Chris:

Right. Without having an X out somewhere. So this is a conversation that the board designers don't probably even realize is taking place in the background is trying to figure out how to manage X outs and deal with scrap and, and so yet another reason to try. Really pay attention to your board design because you'll, you'll, you'll make the PCB fab happy because they're going to have less waste material, right? There's a, you're going to make the assembler happy because they're not going to have to deal with as many X outs. We actually, we had a recent experience with one customer. We've been building the same boards for them. Gosh, I we've probably built 10 rounds of the exact same thing over the years. Maybe more, maybe 20 rounds. I don't know how many times you built these things. And every time our PCB fab would send us loads of X outs, just tons of them. And I was like, oh, you know what, this time I'm going to ask the PCB fab. Like what, why, why do you have so many X outs? It's only a two up panel. Why do you have so many X outs? Well, it turns out the design of this. Was designed with a six mil. Now we're talking Imperial units, sorry to keep switching around. But it was designed with a Smith, six mil trace and gap with six mil trace and gap, which is a very standard size for a one ounce copper board. But this customer was making power supplies. So they needed a two ounce copper board. They had a lot of power they're pushing through all these traces and everything. And then, yeah. And Dave, you immediately, I can see you're going, oh, I know the problem here. The rules that rules are off for too, as soon as you go two ounce, you that six mil rule doesn't really work anymore. You got to go to, you got to go to eight mill now. And so I, I guess this leads me back into our discussion about drill. Is there something like that for, for copper weight or board thickness or material? Is it, do the rules bounce around a little bit based on what you. Your your, your design, I guess

Dave:

Yeah. You've, you've probably heard of aspect ratio

Chris:

Yeah, I have in stencils, but not in a drilling. I

Dave:

it in drilling on a PO in PCB terms. It's basically the ratio between the hole size and the thickness of the panel.

Chris:

Okay.

Dave:

So if you've got a point to drill in at 1.6 board, it's an aspect ratio of eight to one,

Chris:

Okay.

Dave:

Which eight to 10 aspect ratio. Most good PCB manufacturers can cope with when you started going, when you start going over that that's when it starts becoming difficult, it's it then gets difficult to get copper plated in the hole, et cetera, et cetera.

Chris:

So 11 to one, 12 to one you were saying.

Dave:

Yeah. So, on a 2.4, 2.4 thick board, you need to have a minimum hole size put three.

Chris:

great info. I did not know that.

Dave:

because

Chris:

and is that because there's a chance of that binding up and snapping? Is

Dave:

I know that that is I can drill. I can do. 0.2, five hole two up on a 1.6 board so I can drill the hole. It's not, it's not a problem. I can draw you 1.1 hole in at 1.6 boards, the problems come after the drill shop is that you can't get the place in the whole.

Chris:

Oh, it's the plating. Okay.

Dave:

So, depending on your, your, your place in line and the equipment and hat and how you're plating is how, how good you are getting copper down the hall.

Chris:

All right, this is, this is, I feel like this is solid gold here. Trying to target out an eight to one ratio would be anything, anything smaller than eight to one you're golden, anything eight to 10 to one you're you're you're pushing the limits 11 to one. You're you're really pushing the limits at this point. Yeah.

Dave:

Our, our PCB fabs, we use a circuit help. 16 and one, they say they can do that. I haven't tested them out

Chris:

So, so, so our partners, our partners are claiming that they can handle six up to 16 to one ratio and over the. Like it really, really gets challenging. I know that there are there, we do have some partners that do HDI have to imagine that's HDI when you're at 16 to one, you're doing Stuff.

Dave:

building, you're only drilling latter layer on hasty or you're building up lots of layer on you. So you,

Chris:

Oh well, say, say, say that again. What you're you're, building what?

Dave:

it's very virus technology.

Chris:

Oh, okay. Yeah.

Dave:

So, you're, you're drilling one to two to three, three to four, five to six. So, so you're building up a layer of.

Chris:

Yeah, I got

Dave:

So you're not trying to say all the way through the board isn't necessarily the problem.

Chris:

Right. Okay. Understood. Still that's that's quite interesting. So I guess. Th that that aspect ratio is, is, is new to me when it comes to drilling. I know it for stencils, like I said earlier, I know it for census. We have to, we really, really care about aspect ratio and area ratio when it comes to the stencil design. But now will you, I'm curious about this. Will you ever, we, we do this thing in a stencil design because it's, it's a bit less final. I don't know how to put that. Like, if, if your design calls for an area ratio, that's less than 0.6, six, which is the area ratio we can. Listeners designers. Don't, don't worry too much about stencils. We, we have, we have a lot of stuff we can, there's a lot of levers we can pull there. Don't, don't be worrying about your, your stencil apertures median of this area ratio. But we do care about this magic number of 0.6, six area ratio. And if we, if we have a design that falls below that you've got a 0.4 millimeter BGA, for example, we can do special coatings, but we'll also slightly oversize the aperture to get to the 0.6, six ratio. Or in some cases we can go as low as 0.55, but that requires a special coding. But if, if, if we still can't reach that, we'll over, we'll over cut it. So we can get to that 0.4 0.55, but to the end product, does it doesn't really matter a little bit of extra pain. On your board is not going to make a big deal. All you care about is a quality connection and a robust solder joint and not having any bridges or opens or anything, but I don't like w would a drill shop with a cam engineer ever look at an area ratio that's 16 to one and be like, I'm going to open this up a little bit and I'm going to make it 14 to one, but, but then you're changing the design. Right.

Dave:

Yes. Now you, if it, if it meant drilling a 0.3 drew, instead of a 0.25, just to make the aspect ratio eight to one, I'd make that change because

Chris:

Okay.

Dave:

the designers never going to know

Chris:

Yeah. Okay.

Dave:

you because you have a tolerance, you get a tolerance on your drills of plus 0.08 millimeters.

Chris:

Well, that's a great point. Yeah. That's a great point. Cause your, your, yeah, your drill tolerance is already almost there.

Dave:

Yeah. So if you work in, within, within that, like the, the general manufacturing, tolerances, yeah. It's okay. If you're going outside of them. So if you've got to go, if they've, if they've asked for 0.2 virus and you're saying, oh, I want to drill it up. Point three 0.35, then you probably haven't got the space on the board to drill it that much higher, because if designed it with a point 0.2 hole. So yeah, you probably have to have to go back to the customer at that point.

Chris:

Yeah, And say, Hey look, we, we, can, can we change this? Is there something we can do here? Would you, so, so this is good. This is good knowledge for designers because they may have critical hole sizes. There may be certain areas of their board where they have to say, look, look, I understand that sometimes PCB, PCB fabs will change the whole diameter based on their process and to make it more efficient and blah, blah, blah. Just like we talked about. But they could go into their drill drawing and they could say, Hey, location, X location, Y locations. These are critical dimensions. We need you to not change these. And if they don't work, please tell us kind of a thing.

Dave:

Yeah, but that they don't it's and then never will.

Chris:

Yeah,

Dave:

yeah. I've been cynical. I'm sorry, but yeah. Yes, but. We, we shouldn't be changing their design. Anyway. If we change anything on leave the type design of a PCB, then it's normally with the customers the designers say so, so approval was Allie. So yeah, let's say if he's working within, within the, like the confines of of the, of general tolerance in PCB manufacturer. Yeah. I'll make that subtle change, but no, I won't change it. So, I mean, you might have a hold it's supposed to carry like a lot of outreach. If you reduced, if you reduce whole size, especially to, to create more space to make it easier to manufacture, then you're reducing the, the current carrying capacity of that hole. So yeah, don't do that.

Chris:

Nah, no, no. Don't do not do that. I mean, you don't know if That's just a little signal trace or if that's a power trace or something. Yeah.

Dave:

Yeah.

Chris:

Fascinating. So this is, gosh, I, I just, I, every time we talk, Dave, I think to myself about like all these things I never even considered when I was designing boards. And now I'm thinking about like, oh man, did I, did I really do something to make this piece of me? Fab's life awful. You, sometimes you don't know.

Dave:

th th it's it's not no D design doesn't normally make the drilling process difficult. Well, it can, but like, for example, when a board might have 300 holes, but it has 40 drill sizes and you go, man, come on, it's got. It's got, it's got 0.4 0.4, 5.5 0.55, put a six foot 7.75 put eight all the way up. All the way up to two millimeters. He go surely, surely could have grouped someone in together.

Chris:

So I've, I've, I've done this before, but I, I did it for we, we, I will sometimes make evaluation boards, so we might get, for example, I've talked about this, I think before we had these JST can actually, our last episode, the last episode we had you on the show, we talked about these JST connectors and the tolerance specified by the manufacturer by JST. Does this sound familiar to

Dave:

Yeah, it does.

Chris:

Yeah. they have no negative tolerance and only a positive tolerance. Well, w we, we always struggled so much with it. So I went ahead and I designed a little dummy board, a little test board, whatever you want to call it. And I did exactly that. I went 0.7 0.7 5.8 0.8 5.9 0.95. It was probably very annoying to build those boards, but there was a purpose for it.

Dave:

Yeah. If there's, if it's necessary, it's fine. It's it's when you it's, when you, you just put in a lead in a hole and like, it doesn't matter wherever it's put at 6, 5, 6, 6, 12 0.7, like

Chris:

Yeah.

Dave:

group them

Chris:

the truth is using the EDA tools. It's, it's more difficult

Dave:

No,

Chris:

a bunch of random sizes than it is to have all the same size.

Dave:

pulls a footprint out and says, yeah, that's what we need. Yeah.

Chris:

I, I th that we have the same experience. Go ahead.

Dave:

I find that annoying because when you get it in a drill shop, it takes 40, 45 seconds for it to do it all change.

Chris:

Oh, really? It takes that long. No. Okay.

Dave:

So there's, there's 30 minutes already for your drill run, changing tours. It hasn't drilled a whole yet.

Chris:

kidding. That's fascinating. I never even thought about that. That, Yeah, you're looking at. So you could really reasonably consider for every drill size change, your, your you're close to a minute. And so if you can limit the number of drill sizes you're using you, you can reduce the overall manufacturing costs of getting those boards drilled, which again is a bottleneck. So try to do that.

Dave:

because, because on a tall change, it's not just putting down, it's putting down the old drill, the new drill out of the tray, in the spindle. Then it's going to check the depth of that drill to make sure

Chris:

just going to ask.

Dave:

and then, and then it's checking the size.

Chris:

Now. Okay. Well, okay. So speaking of checks and verifications, I remember learning a while ago that a PCB fab we'll drill extra holes that we never get. The assembler never sees these they'll drill, extra holes on the Yeah. On the panel to, and, and they're, they it's the last hole that they drill. Would that, that drill bit to verify that it, it, everything came out the right size or something like that. Right.

Dave:

my opinion, I think that is still a bit of a comfort blanket

Chris:

Okay.

Dave:

because, because you have a Judah machine for someone who has been drilling PCBs for 30 years, right. You, new machines find broke, broken tools, you're not. So, if, if a thought broken cause the machine tells you See what these coupons don't do it. You've got the last hole, the first and last hole. So just drilled the first hole and the short, the last hole. So,

Chris:

the coupon on the side, you're

Dave:

so the operator goes, oh yeah, that's all right. It's drilled the first hole, this drilled the last hole.

Chris:

Yeah.

Dave:

But how many tools is it used in between?

Chris:

Course of course.

Dave:

might use four tools before from the first alter. The last time you might use four different tools,

Chris:

And, and why does it change it? Is it just because they've worn out or is the diameter of the tool changing

Dave:

hit count.

Chris:

pick count. Yeah. But what, what, what about that? Like what does that hit count informed by? Is it, is it because The drills getting,

Dave:

number of holes is drilled. That that's, that, that set.

Chris:

physically happening to the drill that makes you go, you know what? We can, we have to limit the hit count. What's what's going on

Dave:

it's because it's getting blunt.

Chris:

It is getting okay. So it's the sharpness is the dullness of it.

Dave:

So then, then you're getting poor, whole quality.

Chris:

Okay.

Dave:

You're getting, you're getting spirit inside the hole. You're getting debris left in the hole, et cetera.

Chris:

So it's not, it's not that the diameter of it is changing necessarily. It's it's the

Dave:

No, the diameter shouldn't change that much, but you'd have to really like hammer a drill to get it to wear out. So your, your homicides different.

Chris:

It's going to be within that 0.08 tolerance.

Dave:

it should be, but it's the quality of the hole, which is going to affect the quality of the PCB. And

Chris:

And the plating and

Dave:

play plating voids and things like that. So, so you might use four or five drills from first to last hole. you don't know what's broken in between time. Basically what I see is the first drill, but it uses okay. But when it started and the last year was okay when he finished.

Chris:

But everything in between you don't really know.

Dave:

so the Cooper's not telling you anything,

Chris:

Yeah. Yeah. Fascinating. Okay. That's good to know. I wanted to get back to using different drills sizes and and how that can increase costs and everything. Because

Dave:

he comes to curveball.

Chris:

no, it was, I, it was, Yeah. no, it was Oh, okay. I remember now I had, I, I there's an analogy. So when you're, it sounds to me like when you have those different drill sizes and, and you're expressing the frustration, cause you have all the different you have to change that drill and it's going to take 45 to 60 seconds to change that drill and reverify and everything. You would much rather just as much as possible use the same drill size. Well, there's something similar in assembly. I can't tell you, Dave, I can't tell you the number of designs I've seen where you have a 0.1 microfarad capacitor. Okay. Right. But like, like maybe six, seven. I P I think I've seen as many as like 10. Point one microfarad capacitors on the exact same design. And I think to myself, what, what is going on here? Why

Dave:

Yeah,

Chris:

do

Dave:

but they can't be that much differently.

Chris:

They can't be that much different. Now I get, I, I understand there's a, there, there absolutely is a circumstance where, Okay. this, this 0.1 might is, is just, helping out this one little icy. And this 0.1 Mike is, is doing something at, at a higher voltage. This is on a different net that, that operates at a much different voltage and, or potentially more power. And I get that. So it's, it's not a major surprise when we see one or two or excuse me, two or three different 0.1 mix, but I'm talking like they might have like an X five are, thermal temperature, coefficient, and then in the next seven are temperature coefficient, and then they'll have an oh 4 0 2 and then an O 6 0 3 and then in oh five. No, no, no, no, no, no, no, no. What, what is going on here? Like just, just pick one and stick with It. please. So we, we had a, we had a customer come to us recently. It was awesome designer. The kind of guy that I don't know that he does listen to the show, but he's the kind of guy that would, because he really cares about getting his designs to be manufacturable. And he had a great question. He reached out and he said, Hey, look, I can't fit enough. Of these 0.1 mix in oh 4 0 2. He makes these little tiny camera boards really, really tiny cameras for all kinds of applications. I need a ton of 0.1 mix or 0.01 mix or whatever it was for, for my image sensor. You rather me just make all my 0.1 mix these O'Toole because I have to use because I can't fit enough of produce, but I have these other areas where I can fit the 0.1 mix, but I'm going to make those oh 4 0 2. Is, would you rather make them all to. Or would you rather where I need to make the mode 2 0 1 and where I can make them off-road to, for, for our, for our process at the time, now things have changed since then where we've gotten better equipment and better processes. But at the time I said, Hey, look, ma get as many as you can on there. Cause we're going to struggle with the O two O ones. We don't, we don't struggle with the O two O ones anymore. But so now my advice would change now today, I would say just no, just make them all. Oh, two oh ones that way there. I just load one part, one part number. I have to manage one part number. I have to buy one part. I have to load. But because those were very challenging for me. I, at the time I said, please make as many as you can. Oh, 4 0 2. Is there something analogous to, to your process where you might say, okay, if, if you have to use a, a 0.2 or 0.1, five millimeter via in certain areas, please just make them all 0.15. And that way there, I just have to worry about one drill bit. Or would you say no? No, no. Like as much as possible uses few 0.1 fives as you can and make everything else, 0.2 fives or

Dave:

Yeah. users few 0.1, five as possible. Yeah. So, yeah, cause it it's just, it's just, it makes it easier to manufacture.

Chris:

For sure. I

Dave:

Yeah. You can have problems with, we've put 0.1, five holes. But you'd have less of a problem with 0.25. So if you, if you've got room to, to place 0.2, five holes, and then I would say obviously do it.

Chris:

Yeah. good info. Good info. And, and do you think that that's mostly to do well drilling for sure, but also the plating, right. Plating

Dave:

Yes. Yeah,

Chris:

small holes. Yeah.

Dave:

I can drill you. Drill you 0.1 house all day long,

Chris:

all day, All day.

Dave:

all day, the machines, as long as the machines are captain in reasonable condition and looked after they're maintained properly. You can, you can draw 0.1. I was all day,

Chris:

Yup.

Dave:

but I can't play them.

Chris:

Yeah. Well, that's like us. I can play so two oh ones. And now with this new Fuji machines, we'll be able to place oh, 2 0 1 metric, which was oh 8 0 0 4 Imperial really, really small place them all day. No problem. Do you want to design them that way? I'll play some all day. I can't fix them. If I make a mistake, if I make a mistake they're really, really difficult to fix. So please use if you can, and use the smaller ones where you need to. Yeah. So there is a similar analogy. It does, it does kind of line up there to the assembly process as

Dave:

Yeah

Chris:

what, so what else about the, the, the machines, the process, this is the advanced topic. This is the opportunity to get the advanced stuff out the door, or have we shipped it? We have, we touched on everything you wanted to touch on here.

Dave:

no. You say you drilling holes, but we've not talked about the vacuum system yet

Chris:

oh, geez. Vacuum.

Dave:

the TriNet machine.

Chris:

So this, so before you talk about vacuum,

Dave:

we've not, talked

Chris:

were talking about the, oh God. Oh geez. All right. So under, you've got Ms. Material under your board. You've got this material on your board. How is all this stuff being held in the machine? I, that I've never even, we haven't even talked about. Is it just clamps or w what's machine.

Dave:

is a clamp. It's a clump that sits below the bed. So. words, extremities of your drill bed,

Chris:

Okay.

Dave:

and then it will pop up and coming to clamp on onto your stack of boards

Chris:

So does it kind of squeeze the boards? Oh, it does clamp down. It does clamp down.

Dave:

It's also pinned as well like top and bottom pin. So have you have a pin and slot, so you have a hole at the top and the slot along the left, along the left of year, your drill bed. So it's held in, in that axis. So

Chris:

But if you haven't drilled any holes yet, how do you pin it

Dave:

because we have separate machines that look for targets. Look for targets on the panel, sort of helps.

Chris:

okay, so you have a separate machine, these go into just to build the tooling, just to do the tooling holes before they go into the major drilling process. Oh, interesting.

Dave:

every, every manufacturer panel has targets and powerful, powerful idea around the outside, which bits you don't see, or you only see inside, like

Chris:

You're not using our fiducials. You're using your own fiducials, your own targets. Yeah.

Dave:

So th th th they're normally design designed in mind for the machinery you've got, you've got some sort of x-ray machine, and if it finds a holes and drill shelves,

Chris:

Okay. Okay. So now, so you've, you've got him pinned. I've actually seen videos of this done before, where I've seen somebody hammering these pins. What did you ever, is this something that Liz it's just some random shop decided to hammer the

Dave:

We don't normally use a hammer. That's there's there's there's, there's not, there's not so much control. We have a hammer

Chris:

Yeah, no, it looked like they dropped in, it looked like they dropped in like a rod into the panel and then they hammered it into the bed of the, of the drilling machine. Maybe it was a different type of machine,

Dave:

Oh, no, but we used to have a, like a, a hydraulic press if you'd like to, to push pins in, into our panels. But that, that, that was done in a controlled way. It wasn't hammering it. Wasn't hammering them in.

Chris:

All right. All right. So So they're clamped, they're clamped

Dave:

it's important that it's important to pins don't fall out. Of course. So, especially if you've got a loader, which is used the pins to track them onto the machine. So as you brought up, they don't fall out, but yeah, we don't, we don't use hammers.

Chris:

So these pins, these pins are embedded in the panels then.

Dave:

go through to panels. Yeah. There's a hole in the pin disco street.

Chris:

Yep. And then there's a hole in the bed of the drilling

Dave:

There's.

Chris:

drops

Dave:

There's a hole, which is the zero point of your drilling machine,

Chris:

Okay.

Dave:

right in the middle of your bed. And then there's a slot. So w where, if you, if you use an 18 inch panel, 20 it's, 24 inch panel, like it, it doesn't matter that's always the zero point.

Chris:

Gotcha. Yeah. That's another thing probably listeners don't know is that you guys buy your material in very specific sizes, 20 and 24, right.

Dave:

Yeah.

Chris:

Yeah.

Dave:

Yeah. That's that's because the material was made in six foot sheets. So like one foot, two foot, one off foot you can get, get the most what was it? The, the most yield out of a sheet of material?

Chris:

yeah. Yeah. So when you're designing panels for our fabricators, you're, you're you have that in mind, you're taking into consideration how many you can fit within their panel process. Okay. So now we've got the board clamped in the machine and there's a vacuum. What is the vacuum doing

Dave:

At that is taking all the debris away.

Chris:

now? Do you call it now? You called it a vacuum. You didn't call it a Hoover. I'm a little concerned.

Dave:

Well, cause not Hoover. Cause cause a Hoover is a trademark, Chris, as

Chris:

I'm well aware, but I, but I buy, I buy Kirkland brand facial tissue, but I still call it a Kleenex.

Dave:

Yeah. Clinics will be pleased, but yeah,

Chris:

Yes, they would. They've Kirkland. Not so much.

Dave:

It's, it's a vacuum system, so you're taking all that debris away. So like you haven't got an operator station.

Chris:

the swath

Dave:

Swarf

Chris:

swath

Dave:

face swarf.

Chris:

swapped. Yeah, I got it.

Dave:

So yeah, it's taken it all away because you don't want that just drilling because it will make a total mess. If your machine, it, you just have all this, all this dust, basically sitting over the top of your work, but then because that dust ball, then of course drew deflection. Cause if a drill bit comes down and hits a bit of that dusty or debris, it will deflect. So you've got to, you got to clean that off.

Chris:

so is this like, does it have a nozzle sitting like right next to the drill bit? Is that like really close to it? Or how does that

Dave:

So this is the pressure foot, which is probably the most, other than the drill

Chris:

pressure foot.

Dave:

you have a pressure foot, which is basically like a U shaped or round piece that goes around the, the drilling part of the. Okay. So what, when you, when you look at the drilling machine, when it's working, you can't see the drill bit, you only see like a black bit going up and down on the machine.

Chris:

it does. It kind of looks like it has a weird porpoising motion to it.

Dave:

Yeah. That's depression got up and down

Chris:

Yeah, no kidding.

Dave:

that's applying pressure on onto your stack what it's drilling. So it's holding it down then once that comes down, then the drill comes down.

Chris:

Yeah. no kidding. It's just like when you're drilling something in your wall, your wall, I guess you wouldn't have to, the wall is holding itself up, But if you've got a stack of material, you're probably gripping it with your hand or a clamp or something to hold it together. The pressure foot's doing something similar. Yeah.

Dave:

But it's, it's holding the workpiece down and, and so the, the drill bit should always be above. The bottom of the pressure. So if you press it, it's not in the right place. So if you've got your drill bit sticking out of the port where your pressure, then, Then your drill bit is hitting. See? Cause cause the elementary of fall will, it can move up or down.

Chris:

Sure. Yeah.

Dave:

obviously can flip it. It's it's it's not stuck on onto your stack of material so it can move and

Chris:

It's not it's there's no adhesive on it. It's just it's just Laden laying

Dave:

So it's, it's just making sure everything's together. So it drills. And if you press your feet, cause you have like, brushes or solid pressure feet, which are, which wear out there consumable parts. So you probably probably change them once every week or two, so

Chris:

so they're not made of steel. They're like plastic or

Dave:

even those ones were out.

Chris:

yeah. Yeah. Wow. Okay.

Dave:

Yeah. So we had still one, two of our plastic ones. So, but, but they do wear out and or break. They can just break you. It's like, how a thermal looks on a board.

Chris:

Yes.

Dave:

a circle with the two, two ties. The two ties or two are, are open on, on a pressure foot. So you don't have voice, you suck up. It's called a domain of the entry material. So the inter material forms like a dung, then you get birds on, on the top side as well. So,

Chris:

of course. So, so that pressure has to be really flat And just the right amount of pressure.

Dave:

Yep.

Chris:

Yeah, Cause you could crush these things, so there's probably just so many Newtons you're pushing down

Dave:

it doesn't have too much pressure or it needs to be nice and level. Cause it, cause then the pressure can leave marks in your aluminum entry material,

Chris:

Of course,

Dave:

which then a drill bit could deflect off.

Chris:

of course.

Dave:

So it's, it's

Chris:

Didn't even think of that.

Dave:

all sorts of things. Yeah.

Chris:

All sorts of things. Yeah. So, So, would you like, would you start with the smallest because if you do get any marks in your aluminum, it's going to be less of an issue on your larger drill bits to largest. Oh yeah. we did talk about that last time too. You start smallest to largest cause you can always over drill

Dave:

yes.

Chris:

a smaller hole. Yeah. That pressure foot does it also provide a bit of a, maybe it doesn't, but I was going to ask, does it provide a bit of a a space for the vacuum tool to do its job or? It does.

Dave:

So you basically, it's quite simple nothing too technical. You have a hose attachment on the side of the, the pressure.

Chris:

Oh, so it's built into the pressure foot, this, this vacuum hose. Interesting. So you've got little ports around this, this horseshoe shape, because I'm picturing like a horseshoe shaped thing

Dave:

Well, yeah, it can be round, I'll say round ones, but it's it's just, it's, it's a carriage that sits, sits around the bottom of the spindle. So, sorry. I'm talking with my hands is

Chris:

Yeah, I know this. This is a this is a audio medium w theater of the mind here, Dave theater of the

Dave:

So yeah, it, especially it carries to hold CRA credits the pressure up or. On the work slack to hold the drew detectors to hold the vacuum.

Chris:

Oh, So, that's where the light is coming from, that you were talking about earlier to detect if the drill bed broke. Okay.

Dave:

yeah, yeah, Do you want me to sit there all little, little, little wires and little tubes connected to it all around,

Chris:

yeah, no kidding.

Dave:

yeah, that's important. And that the conditioning of your spend is also important. So

Chris:

Yeah.

Dave:

if you have run out, if it's not running true, that's when you get open, real drill, that will will show when, when the machine tries to measure it, it will show us a 1.1, which is start obviously the next size up. So yeah,

Chris:

So, so you have, you, you have a sensor, something that's measuring the run-out of that drill bit before it gets started in the, in the pressure foot, maybe. Yeah.

Dave:

That it's it's it's not in a pressure for it's it's in, it's in the machine. So the machine comes across, it, it drops the drill in there, spins it up to speed and then it can see if it's, if it's moving

Chris:

Oh, so it has a special area that goes to, to measure it. I got

Dave:

Basically that measures the size measures are run out.

Chris:

When it first picks it up, it does this. Yep, Will it do it after every 500 cycles or anything like that, or, yeah.

Dave:

Yep. You can say it to the, through pretty much what you want.

Chris:

Yeah. So maybe if you have kind of a critical drill in your, in your concern that, this is a 0.1 millimeter drill bit, we're worried that this thing will get a big run out. Let's go check it.

Dave:

Yeah.

Chris:

Yeah. And so do you end up in a situation? So I know some of these machines have 2, 3, 4 spindles on them. Do you end up in a situation where you go like, ah, spend a three, that's the one that keeps having to run out on us? Like

Dave:

Switch switch everything off.

Chris:

Yeah. off three. We're only running one, two and four today.

Dave:

Yeah. That, that, that can be okay. It can be tricky. You, you will get away of it if you pay attention to your machine, but if you're not paying attention to your machine, then it will bite you. If you turn all your bits and pieces off.

Chris:

Interesting. I, Dave, I find all this stuff, so fascinating. I, this is, this is a, this is a problem I have in life. I, I find the most mundane things. Absolutely fascinating. And then I can never. You ever get frustrated that you just can't do everything you just can't like you realize you only have limited number of days to, to enjoy life. And there's so many things you want to know about. And this is, is that is all we get.

Dave:

Yeah, I,

Chris:

I could talk about drilling machines forever.

Dave:

I, I like programming my software I might I might little tools I write scripts to do, to do the panel of of little tools that actually scale and my best pieces on.

Chris:

Cool.

Dave:

Maybe we talk about silk screen and how I have to go around it and scale all the

Chris:

That's right.

Dave:

And it was about 10 clicks, a bit, bit, so, more screen to, to get it to the one, one little piece of the silkscreen to, to scale it. I've, I've written a tool where I just drag a window around it and it goes, boom,

Chris:

done. job done.

Dave:

So I'd like doing that sort of stuff, but I realized I will never, ever be as good as the guys we got working in that.

Chris:

Yeah. I hear ya.

Dave:

Yeah. So like for me to go, yeah, I could the Java programming, like I can't the Java programming,

Chris:

Yeah, but to the same extent, I'm sure. They, they could never come down and like, do do the chem engineering the way that you do after

Dave:

but yeah. I don't know,

Chris:

doing it all.

Dave:

but it's just that programming part. When I get something to work, it's working great. It's slight punch the air, but yeah, no, it'd be like

Chris:

All right. Pressure, foot vacuum. Anything else we're missing about this machine we haven't talked about yet?

Dave:

No, that's pretty much it. Yeah. As long as you, as long as you look after machine, then it's all right. So you could run, run like target map tests to check the accuracy of Virginia machine.

Chris:

Yup.

Dave:

you're, you're checking everything at that point. Like your pressure foot, your run out your spindles you hit counts,

Chris:

Yup.

Dave:

sorry. Yeah. So you can, you can do do that once a month or two

Chris:

Okay. Yep. You're doing your calibration and maintenance and all that kind of stuff on it. yeah. Good stuff.

Dave:

So that's when you know, you quote on your website, that you actually can.

Chris:

Yeah,

Dave:

Cause if, if you've gotta spend it, we've run out then like it's amazing what a difference it makes it, it w it would be out to a hundred microns.

Chris:

I believe

Dave:

be everywhere.

Chris:

So, I, I would say key takeaways here from this episode for, for people designing products bigger is better think like an American

Dave:

Yeah.

Chris:

finger's better try to limit the number of drill sizes you use overall. If you can,

Dave:

That's

Chris:

have a standard VSIs and

Dave:

that's probably a P height of mine to set that up. I've had to sit in front of a drilling machine and wait for it to it's nearly finished if somebody got, so you've got 50 holes to drill and it's done it for 15 minutes waiting for you to drill 50 house. But in the previous 15 minutes, just drill 1500,

Chris:

Hey, but no, but no, no joke. Like all those tool changes, they add up each one, each tool chain is going to is going to add costs. I would say make your, make your, your copper diameter. So your annular ring take that into consideration. If we're trying to hit, what did you say? IPC class two. They want at least a 50,000 or 1,050 micron.

Dave:

IP, obviously cost too is pretty much as long as it's not breaking out a hole.

Chris:

Yeah, but three class three is

Dave:

Class three is I'm pretty sure. I haven't got IPC to check

Chris:

you said it was 25 or 50. What did

Dave:

It's it's 50, it's 50 it's 50 microns to 2002 mil.

Chris:

Yeah. Somebody, somebody, if, if, just be aware that this is something to consider, be aware of your endo ring size, and when you go to do your design pay attention to the spec, that's what we have to say about

Dave:

There is a class one w which like,

Chris:

just get out of here with class

Dave:

yeah, in that case you just have to hit the pad somewhere.

Chris:

class class one. So if, if if listeners aren't familiar with the various classes of IPC standards, class three is something that you're doing for typically defense aerospace, some medical, especially if it's life saving medical class two is pretty much everything else. And then class one is like toys. Like something that like, if. It's it only costs a buck 50 in the dollar store anyway, like nobody cares that this thing, but even like your computer mouse, your television remote your keyboard, these are all gonna be class two. These are all class two products. yeah. It's really class one is really intended only for like disposable junk, really think about it. Okay. So, and so the, oh, and the aspect ratio, try to target, if you can an eight to one or a 10 to one aspect ratio.

Dave:

I hate to answer. Yes. So you look at it. I mean, a minimum hole point to in a, in a 1.6 sport standard.

Chris:

Yup.

Dave:

If you go

Chris:

a lot of great tips.

Dave:

you go, you go smaller than 0.2, you need to be asking is my piece of manufacturer capable of that.

Chris:

Well, what if you're doing a 0.6 millimeter board, it's just fine. Right? So it's really the aspect ratio. That's important. Yep. Yeah. Good. don't do a 0.1 0.6 millimeter boards are a pain in the neck to assemble. No, no, it's all good. We we've actually gotten pretty good at handling. We, I think we even do 0.4 millimeter boards now. Um, double-sided does get tricky. So if you have a single-sided board all day, no problem. We can handle single-sided any thickness, not a problem double-sided boards. It gets real tricky to support the bottom side of that board for stencil printing and a pick and place. Reflow all these various processes. And a lot of times you have to, we have to get dedicated tooling. So we, it, there there's a lead time to get the tooling mate designed and made and, and then there's a cost associated with that. So if you do have a need for a thin board, something to be aware of, dedicated tooling might be necessary,

Dave:

Yeah,

Chris:

good stuff. All right. So, I think it's my favorite time of the show then what do you think Melissa is my favorite time?

Melissa:

I think so.

Chris:

Alright I'm prepared for it. I'm ready for it. Our honored guest has deferred. He is deferred to our honored host take it away. Melissa, what do you got Pet peeve of the week.

Melissa:

Pet peeve of the week. So thinking about it, mine possibly might just be a lack of understanding of how GMO works. So we'll find out if it's just a me problem or if other people can relate to this. But I'm the sort of person that'll just let my inbox like fill up and fill out, like I'm really bad at deleting emails. So I'll kind of

Chris:

not worse than my sister. I

Melissa:

okay. So I just put it, put it off until Gmail starts telling me you have like your it's 98% full. Like you're going to stop receiving emails soon if you don't do something about this. So I'm like, okay, I guess I got to do something about it now. So then I started going through my know promotions tab. Unsubscribing to stuff and deleting stuff. So what I, well, I do, maybe there's probably a better way to do this. But all get like, the newsletter at blah, blah, blah.com and just search all of them, like click, select all and delete all of them at once. But my pet peeve is when companies don't use like a specific email for marketing emails. And so it'll be the same email that they send out for all like the newsletters that they have for like the order confirmation.

Chris:

Yes.

Melissa:

And so then I'm like, well, I, if I can't. Yeah. So I can't delete all that because what if I, for whatever reason in the future need to reference that order. So now I can't delete it. So now what do I do

Chris:

Aye.

Melissa:

manually search it? But yeah, that's my

Chris:

There there's. There, there are ways to do that in Gmail,

Melissa:

Yeah. I'm sure there

Chris:

pretty powerful search filters and stuff, but I get you like that's email in general is, is a, is a pet peeve in and of itself.

Melissa:

True. True.

Chris:

I'm I'm quite the opposite from you, Melissa. I am I am an inbox, zero guy. Are you familiar with these psychopaths?

Dave:

Okay.

Chris:

At the end of each day? My inbox has nothing in it.

Melissa:

What, oh my God, that would take me at this point. See, I like, at this point it would just, it would take me, it would be a full-time job.

Chris:

but see, so the reason that the the inbox zero thing, if you're, if you're not familiar with it, you can, you can look it up and there's, there's, there's people that take, I might've been taking some bit too far, but the point is you should have actionable. Like every time you open something, you do something with it. And so you, so you either put it in a to-do folder or you put it in a waiting folder, you put it in a project like you have, you have various folders that you put these things in, or you delete them. Right. Or you just, you just get rid of them right then and there. So that's, that's literally how I do email the way I do emails. I don't, or if you can respond to it within like 30 seconds, just respond to it right then and there just like take care of it, get it done. But if this is going to take you 2, 3, 5 minutes to respond, put it into to Dubin or put it in a project ban or put it, put it in something where you can take action on it later. So every time I opened my email, I, I completely empty my email every single time I open it. But it's because I put it in these various folders. And then once it, once it's at zero, then I go to my to-do folder and that's what I work through. That's what I, that's where I go through and I actually get work done. And I am also a prolific on subscriber. Like if, if an unsubscribed button exists within the email, I'm going to find it and I'm going to click it.

Melissa:

But sometimes you still get the emails. That's what bugs me too.

Chris:

Yeah. Then, then you got to use a Gmail filter to just automatically delete it. Gmail filters are super powerful. Have you ever used Gmail filters?

Melissa:

yeah. Just not enough clearly. Oh, that's another one that email related is when you, you go to unsubscribe to something, but then in order to unsubscribe, they make you like log in first.

Chris:

oh, the worms

Melissa:

Yeah.

Chris:

worse. Straight to jail with those people straight.

Melissa:

I'm like Cause I don't care about you. Like

Chris:

Right. And I never signed up in the first place you bought some email lists. It's you know, here's the thing. Okay. Okay. IPC was just on the show. I love IPC. They're great. They, they, they do the Lord's work, so to speak. We need them. I'm so glad for what they do, but they need to make money. And they've got a lot of data, especially when they offer free trade shows. Like you go to the trade shows. Apex is you don't have to pay for a ticket to go to the, to go to the trade show. But you do have to register. And I registered with my email address and inevitably after apex, the first couple of weeks, especially, but then the first few months after apex, just so much spam because IPC offers a list of. People who attended the show and anybody who wants to pay for this list can pay for it. We've been offered it, right. They come to us and say, Hey, would you like to buy this? Because it's potential customers. I get it. Like, I know how the world works, but it's a huge pain in the neck. It's a huge fan of the neck. And I would just unsubscribe absolutely everything I can. yeah. it is. It is. I will say once I got comfortable with inbox zero and I, I, I got, I got into this, my goodness. in my early twenties. When I first started doing this, it was glorious. I was like, oh, this is, this is the way everything should work. I that's another tip another tip for you if you're, if you're my, my it, the same sort of idea of having a like a collection bin. So I use my inbox is like a collection bin or an inbox, like an old school inbox. Right. That's how it's how work used to be done before emails. Labeled in, and then you pulled something off and you did something with it. And but I remember when I was a child, my mother taught me how to clean my room and, and I would get overwhelmed. Cause I know what to do. You look at all this stuff all around you and you get overwhelmed with it. And I just, little kid just start crying. Cause you don't know how to clean your room. She goes, look, it's very simple, Chris, it's very simple. You have to go to bed at night. Yes. So take all this stuff, pile it on your bed. And, and one at a time, put each thing away, find where it goes, put it away and then it forces you to do it because you need to go to bed.

Melissa:

Or,

Chris:

done.

Melissa:

or pilot on your bed at night. And then when you need to go to bed, throw it on the floor.

Dave:

and then we can go, get Bob. I called she's full of crap.

Chris:

That's good. I like both of those ideas. Those are great. Oh Yeah. But a hundred percent with you there, Melissa, that, that, well, I'll tell you what I think. I think I think CircuitHub handles this a little bit differently. We have very specific email addresses for notifications, important details about billing and issues with your order that comes through a very specific address. And when we do our marketing work and our sales work, we have different addresses individuals typically that do this stuff. Yeah. yeah,

Melissa:

But yeah, I guess it's really, my pet peeve is my lack of email organization, so,

Chris:

It's a prolific problem. I pick, I was saying you can't be worse than my sister because I think my, like last time I looked at my sister's phone, I think she's like, well, over half a million unread emails.

Melissa:

oh, okay. I'm not that bad. I

Chris:

I think, it's half a million. It might be 200,000 or something like that. Yeah,

Dave:

I think I delete most of the emails I get. Just delete, delete, delete, delete.

Chris:

yeah, yeah, yeah. Now for, for listeners who may not know Dave, and I I'm sure you get this too, you probably get just spammed with PCB fabs constantly. Right? Just wanting to make PCBs. Yeah, just constantly. This is, we get more spam from other PCB, assemblers and fabs that want to do business with us than anything else. It's it's just unbelievable. It's like, no, I am the assembler. I don't want you to assemble boards for me. You're a competitor. Why are you emailing me?

Melissa:

Yeah. Yeah. I got one of those. Yeah. Like yesterday, like to wanna like email me if you need a assembly partner. No.

Chris:

We are the assembly partner. Do your research. Don't waste your time on me. It's all good stuff.

Dave:

LinkedIn. I get so many Chinese manufacturers saying, I'll be your friend. I got so many.

Chris:

That's funny. Yeah.

Dave:

I'm also, I'm also a came engineer. Yeah.

Chris:

right? Yeah. Ah, interesting. Yeah. Interesting. Wow. Sorry to hear that. You're dealing with that, Melissa. My recommendation would be to just pay, pay Google their money and get yourself a two terabyte of storage and best problem will go away.

Melissa:

Yeah, that is the easy solution. Throw money at the problem.

Chris:

think it's like, I think it's like two or three bucks a month and I have like, I think I have two terabytes of storage and Yeah, all done.'cause I never delete anything. I archive everything. I delete the spam, right. That I delete. But if it's actually something that I care about, it's archived so I can search for it later. yeah. Take good care of that. Info. Storage is cheap. Knowledge is expensive. We're words of wisdom from Chris Denney. And if you'd like to hear more words of wisdom from Chris Denney contact at pic place, podcast.com. You can also tweet at us. We are at circuit hub. That's how you can get in touch with Melissa and her team and at w assemblies, how you can get in touch with myself and our team. And Dave doesn't want to hear from you.

Dave:

Very busy.

Chris:

if you'd like to hear from Davey, if you have questions for them yeah, just contact a pick place, podcast.com and we'll, we'll be sure to copy him on the, on your email and, and ask away by all means. If you have any questions about any of this kind of stuff, we'd love to hear from listeners. It's, it's been a pleasure chatting with some of you. And we, we really do. I read each and every email, even if I don't respond to them right away. But I have, I've gotten better because now I finally did it, Melissa. I forward all of the contact at pick place podcast to my primary work inbox. And now I respond. So those of you that stopped emailing me because I never responded. You're welcome to email me again because I will respond. All right.

Melissa:

Thanks again, Dave, for coming on the show and agreeing to talk to us about all Chris's very specific questions

Chris:

So, sorry.

Melissa:

and to our listeners. Thanks for listening to the pick place podcast. If you like, what you heard consider following us in your favorite podcast app, and please leave us a review on apple podcasts or wherever you get your podcasts from. Thanks everyone.

Chris:

Thanks so much.