In today's episode Chris, a self proclaimed novice engineer, touches on the layout process and how small decisions can have a significant impact on assembly. We provide some on advice on the best proximity of vias with adjacent pads and plated thru-holes, edge clearance, fiducials, and more.
Useful articles:
https://www.worthingtonassembly.com/blog/2014/12/29/what-are-fiducials-and-why-are-they-useful
https://www.worthingtonassembly.com/blog/2018/6/20/recessing-your-pcb-edge-for-perforated-tabs
pickplacepodcast.com
In today's episode Chris, a self proclaimed novice engineer, touches on the layout process and how small decisions can have a significant impact on assembly. We provide some on advice on the best proximity of vias with adjacent pads and plated thru-holes, edge clearance, fiducials, and more.
Useful articles:
https://www.worthingtonassembly.com/blog/2014/12/29/what-are-fiducials-and-why-are-they-useful
https://www.worthingtonassembly.com/blog/2018/6/20/recessing-your-pcb-edge-for-perforated-tabs
pickplacepodcast.com
Welcome to the Pick, Place, Podcast, the show where we talk and everything related to getting a circuit board into the world. This is Chris Denney with Worthington,
Melissa:and this is Melissa Hough with CircuitHub Welcome back Melissa
Chris:welcome back, melissa. As, uh, as, as you know, things have been crazy again, we're dealing with If you're listening to this and we're going to publish this on Monday, apparently nothing's going to change for like a year and a half, actually
Melissa:kind of funny story about that and well all the shortages in the world. So I just came back from California, visiting my family. And when I was there, I was going on this hike and, uh, you could see the ocean. In Southern California, um, near Huntington beach, but you could
Chris:Don't be creepy.
Melissa:Don't be creepy?
Chris:Yeah. Yeah. Like when you say, wait, where you're from, you're supposed So nobody likes stocks down. Like, oh, I'm going to go for a hike in Huntington beach to find Melissa,
Melissa:I don't actually live in Huntington beach, but you can go there and Um, but you could see all of the boats that just lined Yeah. Yeah. So many of them just lined up. So there might be some parts on there that you're waiting for or
Chris:The craziest, it's just the craziest thing. For example, the reason that part shortage makes our job more like, can you get the part let's just assume we can get the part, right. Not being able to source all of the parts from one or two vendors just significantly buy the amount of time it takes to receive the amount of time it takes to kit. Like it just compounds all these problems. And then the opportunity for error, when, when are the parts going to arrive? Like everything came from Digi-Key and two days and Mouser and three days. But then these guys took six days and it's like, it's just all these You know what I mean?
Melissa:Adding more pieces to the puzzle and adding more unpredictability and yeah.
Chris:And that's that's even if you can get the parts, right? Like, so just let's just assume we can get them. It's it's still madness, but whatever that's what makes the job fun. I guess, if it was easy, everybody would do it.
Melissa:One, one more random fact that I learned. So my cousin works in product design and she was telling me how a shipping$2,000 and now a shipping container, which you can't even really get right now. The same shipping container costs, 14,000.
Chris:Yeah, my goodness. It's funny because my dad and I were thinking about building a I guess we might want to wait on that one for awhile, you know? Wait. Yeah. Yeah. That was going to be a 20, 22 project. Maybe we'll make it a 20, 23 project. We'll see. Yeah. Yeah. Um, but uh, more, more topic of shipping containers. Let's talk about PCB layout.
Melissa:Yes. That's what we're here for.
Chris:I, I am a novice, uh, PCB layout engineer, and I love to dispense, Yes. It's uh, nothing better than, you know, it's like, you should do this. And then everybody who actually does this for a living and is a professional. Like, no you can't. No, no, nobody can do that. But. Uh, I thought maybe we can at least touch on some things that, you know, like Uh, and we have had some in the past with like, um, Dave Wilcox about, But there's just not that much advice out there for assembling a PCB. Right. So like the overall advice we always give is try not to make things too small. Right. That's just like bigger is better. Just, yeah, just don't go crazy. Trying to fit, you know, a little, like we had recently one customer millimeter by 0.8 millimeter BGA with six balls on the bottom of it. I mean, to put that into some context, uh, that is, that is not That's like significantly smaller. And a typical grain of rice with six hours, six separate solder joints on it. Right. And it's like, oh God, you, and they wanted to build like 3000 of these things. And I was like, can you please please research a different package? Like, we'll do it, we'll do it. But you're just asking for, you know, for problems at that point, I No problem. And then there was not a single yield issue, but like, I'm just anyway, but that's, you know, choose, choose larger devices if you can. But this isn't about like component selection. I actually wanted to talk more about the, the design rules you use in the best how it will impact the fabrication of it, but how it will impact the assembly of it. So for example, and let's just get right into it. Let's get into the meat of it with an example right away, vias, believe it or not can have a significant impact on assembly. And now most people think, well, all via what w you know, you don't use vias for So I, I always kind of assume people understand what these terms mean, you And if you're not sure what I'm meaning by a via I'm talking about something or current or whatever it is that you're using it for from the top side of the internal layer, you know, depending on what you're trying to accomplish, but, So it's like a plated through hole, but there's no, like, you're We're just talking about a via, so, okay. Well, most of our audience should probably understand what if he is, but I wanted case, believe it or not, the a poorly laid out via can have a significant So for example, if, if, and the reason I. This is top of my mind recently is because we've been dealing with a lot of these Let's just get an episode of good practice, you know, best And maybe this will be a part one. I don't know. You know, maybe we'll do part two part three. Maybe we'll keep it ongoing. But, um, the proximity of your via to something that you have to solder can say for example, you place a via the most obvious one we can talk about is So you got an oh five and you're like, I'm just going to put a V up right here, Well, you know, you got a big giant hole in the pad now, where do you It's going to just get sucked right down in the hall, but. That like electrically, it's going to work. Like you're going to put that on a work bench and you're going to put that through Um, and it's, and it's going to work on your, on your test bed. And, but then like, you're going to put that out in the field. And if that thing does anything other than sit in a climate controlled room for Like you just don't have enough solder on that part now. Like you've just completely starved the joint of all that solder. Most people know that most people and probably if you're nerdy enough to nodding your head and fanatically, like, yeah, I would never do that. But even some, it was just like, duh. Uh, so like, but even I've seen awesome engine, like, uh, typically like, so And you're like, oh, this is one from Mike. This is one from Melissa. This is one from Jack. And you're like, okay. I, you kind of get familiar with, with how they do their layouts and, and And you're like, oh, Jennifer's, this is going to be great because she always And then every now and then you see some stuff and you're like, So it's like little things that may be, they know don't put a via Don't put a via, even too close to a pad. So what we have had happened to us recently is this company where we've had great success, good yields with them and everything But then they sent us this one board recently, it was a bit more compact really close to some, um, discrete like, 0402, 0603 chips and caps and resistors. And what happened was, it was so close that the fab ended up not being able to So effectively, it's still doing the same thing. The solder paste is still just running into the via. So like, yeah. Try not to get them that close because you you'll still end So my recommendation, and this is not like a minimum, I always Like cozy minimums. I don't know. I use that though, but like, it's like, it's not just the minimum, And so I like to say, keep the like, outside edge of your annular ring feature pad through plated through hole, whatever it might be at least six Because if you leave that much room, then there will definitely be an area Um, but even better than, than, than just like at least leaving some room, If you come to Worthington or, or, you know, set up your rules in Eagle or Altium It defines them as, uh, as all your vias being tented. Now this gets tricky because if you've never actually done this and Eagle or Now I could be wrong, but it used to be not a one button click. It used to be kind of tricky to try to tell the software KiCAD is like, brilliant. Like, there's just like a button. When you go to export your Gerber data, it's like, do you want to tent vias? Yes! It's like so easy to like, make sure your vias are tented in KiCAD. The way they handle that it's brilliant. But, um, in Eagle it's a huge pain in the neck. You have to like go to your DRC, your design rule check tool and you have Like what's the maximum hole size you want covered with solder mask. And so you're like, okay, well what's what size that I use for all my vias. All right. Well, if none of them are bigger than, than 25 mil, then I'm going than, you know, 26 mil or 26 mil and larger leave exposed than anything. It's a huge pain in the neck and Eagle. I don't know why it's such a pain in the neck and Eagle, but it is And I'm not sure about your cadences and your pads and your, your, uh, mentor But if you can, if you can define your vias as being tented, because There's so many reasons that that's useful. Visually. It's just easier to look at. Remember that humans are building these things. So like a person looking at a board, a busy board and having all It can really actually be difficult to kind of like pick out the important Also, it allows you to put a silk screen over the vias because normally you'd have Um, but if you put soldermask down first, then you can typically It'll be a little distorted because that solder mask is going to be perfectly flat It'll be it'll work, you know, especially if you're using it Um, there's, you know, there's all kinds of, there's all kinds Um, there's some disadvantages and, and, you know, we could get into those, but cause I want to have a whole episode where we just talk about vias today. It's just about how it impacts assembly. Um, and, and yeah, if you can, if you can tent all your vias, that is huge. We love tented vias. Please tent your vias. If you tent to your vias, your, your, um, assembly shop is going to be happy. It's gonna make life easy. There's so many, there's so many upsides to assembly to have tented vias. There's going to be no risk of solder bridging. Cause that's the other thing. So let's say, okay, you've done a good job. You've made sure to keep your, your vias six mil from the Um, Uh, but you haven't tented your vias. Well, when we go to do through hole soldering, if we're using an automated we, you know, we have a via really, really close to a plated through We generally try to avoid filling vias with solder if we can. Um, there's a variety of reasons for this because we don't always know if the vias sometimes we'll actually ask like, Hey, do you mind if we fill this via with solder, And so then that's going to limit the size of the nozzle we use for maybe if um, or possibly we could accidentally create a solder bridge between that So even six mil might not be enough, you know, especially if it's near a away from the next, you know, plated through holes so that you definitely Um, but if you, if you tent it, you know, if you cover that via with a soldermask, Cause it's covered in soldermask. Yeah. So this is, this is Chris Denney playing with everybody. Please tent your vias. Please one, one thing that, um, uh, I was, I was talking to Dave previous guest on I said, what size would you recommend people make vias? If they want to make sure that they're tented. And he said, no larger than 0.3 millimeters or 12 mil. Um, if you have it around this size, then it will definitely be filled And, uh, you will have very positive results with that. You can, you can go larger. Certainly we've gone as large as like 30 mil, uh, which is .75 But there's some potential fab defect issues. Like you, you have like, you won't get, you get this weird thing where It just kinda like covers the via. It's still fine, but like PCB fabs, don't like to see that. But at the end of the day, it's, it's not going to really impact the quality So, you know, but if you can try to keep your vias nice and tidy 0.3 millimeter And I'm talking about the actual hole itself. If that wasn't clear, I'm not talking about the annular ring size, I'm If you did it about 0.3 millimeter, you should be in good shape. There that's a pretty small hole. Like, you know, it's kind of a pain to drill holes. That's that size, but it's not like impossible. Like they do that all the time. You know, even down to six mills, I forget where they have It might be like six mill. They have to start using a laser drill. So we're on there, but like at 12 mill, you're still using a steel drill. You're still, you know, So that's vias, let's talk about edge clearance. So, um, normally when you hear, you know, definitions of, oh, you know, what's your And we're talking about copper to the edge of the PCB. Um, let's just talk about copper. Let's not talk about holes here. Um, normally a PCB fab will say, oh, about 0.2, five millimeter or 10 mil, you And that makes sure that, you know, they can put the copper feature down and then And they know they won't damage the copper at the edge. That's, that's kind of the, the clearance you hear from most of them, but that's So what we like to talk about is three millimeters from the edge Right. So you can bury, um, copper traces. You can have ground pours, you can have all that kind of stuff within try not to put any parts within three millimeters of the edge of the PCB. Um, there's, there's an awesome, it's, it's enormous and you have to Is it an IPC spec now? It might not be, I'm trying to think of who publishes it. It might just be SMEMA that publishes it. Boy, this is why I'm the, I'm a novice engineer, not an expert engineer. Um, but anyway, the, the spec is called SMEMA. Don't ask me what it stands for. I have no idea what it spans a stands for SMEMA, and it defines basically how Um, the spec is really written, not for shops like Worthington or CircuitHub Okay, so that, yeah. So when you're making a pick and place machine or a stencil printer, There's going to be other vendors making reflow ovens and conveyors So you want to be able to set up one assembly line and be able So how do you make sure that everybody plays well together And so they wrote a spec and it basically defines like the height of the machine yada, but importantly, it also defines the clamps, the machine clamps that hold So cause you gotta hold a PCB while your stencil printing, gotta hold know, cause otherwise you don't want these things moving around on you. You think about how accurate you need to do all these things. Um, it defines, uh, Uh, the, the, the, the size of the fingers on And that spec is three millimeters. So the edge of the PCB will be covered by three millimeters of clamp. If that makes sense. And if you have any components in the way, then we need to add kind Now this, this three millimeter spec is so it's so poorly known, like nobody machine manufacturers that nobody ever designs their boards with this in mind. Right. It, it is such a problem that we just, we gave up years ago and we We're just not even, we're not even going to consider the three millimeter edge. It's just, it's, it's such a problem. We're just going to add a rails to everything, and we're going We're gonna put our tooling holes on there and we're just going to move on switch their designs, to make sure that we have three millimeters of clearance,
Melissa:but what are the advantages of not having rails
Chris:then you don't need to depanelize the rail. Right. You don't need to remove them from the board. You get a nice clean, routed edge from the PCB fab. Cause they're just gonna you know, use a nice router on the edge. So the rails we tear off, they have these beautiful edges, these beautiful, And we throw them all out. Well, we recycle them obviously, but, uh, uh, we need those in order to handle the clearance that we need so we can eliminate the paneling them altogether, Um, it also eliminates the, the extra stress placed on the Not entirely because we're probably still not going to build your boards. One up are probably still going to build them two up four up six Um, there's uh, I don't know. It's just, there's just it's. It's. Plenty of clearance, you know, nothing we have to worry about when There's just all kinds of good reasons for it. Right. Um, that three millimeter spec, if everybody, if everybody knew about three to the nearest solderable, you know, copper area and fiducials, we would Like we would, we would have no need to, well, no, we still might need to, And so you could still potentially damage it anyway. My point is, uh, that is something that not many people are aware of. And I wanted to get that out there. So people thinking about it and it's like, oh, Hey, you know, if I can do and you've got a good design and it works, and you have one millimeter of Like, like I said, it's such a pervasive problem that we've just, Like we didn't. Don't worry about it, I guess is my point. If you've got a design that works, but if you're designing something from the edge of the PCB, to the nearest solderable feature, then And that'd be pretty nice because what'll happen is let's say, you know, you go cool product and we're building a couple of hundred a month or something like that. And then, and then, you know, somebody picks it up and it goes viral. And all of a sudden you're selling like 2000 a month. Well now though, the added costs of those frames and rails and the paneling process And if you've already designed your board in mind without the need for You know, you've saved yourself, all that money. So it's just kind of like thinking ahead, Uh, so that you don't run future and have to continue to pay for these processes that otherwise Um, it reminds me of, of like the, uh, see if I can find this for the show notes, from, but there's like a, there's like a, a cartoon drawing of, of, uh, uh, an the consumption of, of energy used to use the product and it, and it has a And it's like, which, which one of these things cast the biggest shadow in cost. Right? Is it the, is it the designer? Is it the logistics? Is it the factory? Is it the, the, the use of the product? Well, it's always like 90 percent, you know, the designer They're going to have the biggest impact on the cost and quality Um, and so thinking about these things ahead of time, then it's, you know, significant savings when it comes to manufacturing, you're going to improve So, yeah, that's my point. Think about these things I have the time, but if you haven't, like I
Melissa:But, if every engineer in the world listens to this podcast and starts millimeters, then we might have, we might be able to eliminate rails completely. Is that what you're saying?
Chris:That's right. We could, we could possibly do that. We could possibly do that now. Um, like I said earlier, we have racks that we put these PCBs into
Melissa:And you also redesign the racks.
Chris:Yeah, no, like seriously, at the end of the day, you re you know, you, W you know, you're out like a thousand bucks worth of new racks versus, thousands and thousands and thousands of dollars are wasted on rails. And, uh, depending every year, you know, it's, it's a drop So, yeah, I would be very pleased if all of a sudden, every board showed up the edges, but, but even if they do that and they still don't put copper, uh, We still need to add rails to it because we'd got to add fiduciary.
Melissa:All right. Well that brings you into your next point..
Chris:Yes. Uh, we need fiducials at least at least two fiducials on your board. And if you're not familiar with fiducials, you're not alone. So many PCB designers are not familiar with fiducials. Um, they're basically just a dummy copper feature on the board. Usually like a one millimeter circle. They can be a half millimeter circle, but that's about the I recommend a one again, my cozy recommendations, right? Um, oh, by the way, the three millimeter edge clearance is That's a minimum. My cozy recommendation would be five millimeters, by the way, I meant to, here We got 20 minutes of Chris saying three millimeter and it's not Five millimeters is my actual recommendation. Anyway, I digress. But on your fiducial, I recommend a one millimeter copper feature and then a So kind of like a, if you think about it, your annular ring would have a Half a millimeter or one millimeter. I'm trying to think. No, it would be the annular ring would be about half a millimeter. So your copper circle is one millimeter. And your annular ring of solder mass clearance is, um, half a millimeter. In other words, the total diameter of your solder mask clearance is two millimeters. The total diameter of the copper is one millimeter. And the reason you do that, And a lot of people find this surprising. Why do you, why do you pull the mask away from the fiduciary that's because Uh, very well it's typically mask is very shiny. It has kind of like a, um, a glossy appearance. And when you shine a light down on that with your, your vision systems on the fiducial is, it's going to see all this extra light coming from the mask. And it's going to, I, I don't know where the copper is. I can't tell you. Sorry. You know, and then you're just, yeah, you're, you're Sol you can't move on, but Sort of finish it's it's very dull and doesn't reflect any light at And so you get just this beautiful, nice, bright, copper circle. Your vision systems can lock right on to that thing. And you know, you can be off to the races. So that's why we have that mask clearance on fiducials. I think I have, I think on our website, I have like a whole article all about that. Got this, looking it up real time as we speak. That's always how the pros do it, right? Yeah. I do have a whole article called use fiducials, beautiful. Working with a manufacturer. What are fiducials and why are they useful? So, um, yeah, we'll link to that too. We'll put that in the show notes too.
Melissa:What about if you're using a matte soldermask? Chris: Still, yeah. Still recommend it because, um, matte is still more reflective of matte And the other thing is you may change your mind. You may go, eh, I don't really like the matte green. I want, you know, glossy black, and then it's like, okay, well now, You can't change it. You're stuck with your matte color. You, you can't change it to glossy now because we can't see your fiducials. So yeah, it's just, it's a good idea to do that. And you don't have to, like, you don't have to like put up, put a soak fit one or anything like that with, you know, you don't need to put a Like it's just a dumb feature that we'll know exactly how You'll know exactly what that thing is when they see it, it's, it rings as their salt knows exactly what you're doing with that thing on the board. So, so don't worry about that. Um, we'll make use of it for sure. The other thing is like a lot of people are like, oh, well, aren't you It's like, well, yeah, of course we are. But you know, things happen, you know, like we we've had these situations where rail fiducials in the wrong position, but they put the PCB fiducials in the correct. So we didn't have to get a new stencil made. We were able to just use the PCB fiducials to line up the stencil, um, uh, panels get So we got a four panel, you know, two by two, uh, broken half. Well, we can still build them because now we have fiduciary on the individual PCBs. We can shoot, you know, um, what else, what else? Uh, you know, things happen and having more fiducials is So yeah. Get those on the board. Make Chris happy here. So let's talk about, we had another issue recently with a customer where board goes into like the exact dimensions of their PCB, um, or vice versa. They made their PCB, the exact dimensions of the enclosure. And it was, it was like, oh man, this is, it's just brutal because. First of all, keep in mind that even the best fabs can only hold like a 10th you know, on the edge of the PCB and the larger, the PCB gets the harder it becomes And then when it goes through a reflow of, and it's going to get stretched And then maybe it goes through a wave solder or a selective solder, Or, you know, you put it in a thermal chamber for testing or you like, going to change the size and shape of your PCB, not by a ton, but by enough. And if you're not careful and your enclosure is, you know, you don't You're going to, it's going to be a nightmare. So. You definitely want to give yourself a little bit of wiggle room on the Uh, it doesn't have to be much, it could be a millimeter. It could even be half a millimeter, probably half a Okay. Um, but if you did a millimeter, that's probably, that's probably my cozy uh, you know, limit to, uh, or, you know, expansion of your enclosure or So if you've got, if your enclosure is, is, uh, you know, a hundred If that makes sense. Pretty simple, right? But let's say you've got some, you know, you know, like Chris I've, I'm making a I I've got these critical dimensions that, that I need to make sure are Well, you can always send us, uh, or any cm or any fab, you can send them these are my critical dimensions that you see this line here. And this line here, you must maintain 100 millimeters between these two edges, If you send a drawing and you, you, and you define something as a there that's going to become, there's going to be extra scrutiny and extra It's going to affect how it gets panelized. It's going to affect the way that it gets held in the panel. There's going to be all sorts of things that we do to make sure that Um, it could increase the cost of your design because now maybe we That's less expensive to assemble because we can build more boards at once. Maybe we have to use smaller panels now because we have to So try not to like, ideally you want to give yourself enough wiggle critical dimensions, but if you do just make them clear to us ahead of Cause that was, that was part of the issue we had is we didn't Had we known that ahead of time, we would have, we would And, uh, they, they would have good success. It was, it was a bummer. I felt bad about that situation, but yeah, if you go into it with Uh, also related to the outline of your PCB, try as much as I know this may sound crazy cause you like, you go to Adafruit and flower shapes and you can make you can make almost any shape you want. Like, I'll never forget somebody made a Minnesota Vikings. Uh, you know, if you're not from the United States and Minnesota Vikings are a they have as their logo, this sort of like cartoonish looking Nordic Viking, you And he's all angry looking cause you know, it's football and uh, Like you can make some really awesome shapes, but it's expensive. It's expensive to do that. But when you use a nice rectangular, uh, PCB, we can probably V score it. So if you're not familiar with what the scoring is, it is basically. A or cutting a groove in, in the, uh, panel where two PCBs, but up So, you know, say let's go back to our a hundred millimeter by a And maybe like a three by four panel. Right. So we have 300 by 400 becomes the panel size now. Um, and. That that makes it easier for us. Cause we have to, we, you know, when you move one PCB at a You've got to pay a human to move each one of these PCBs. But when you can move 12 at a time, it's much less expensive, right? It's a lot less manual labor involved. That's why we panelize things. Well, if you cut a V groove into. Uh, into these, when you, when it comes time to separate it V grooves Um, they just, you can snap them in half, just by hand or more commonly, And we'll complete the, the separation of the PCB from each other using And then using this blade, we complete the separation. It looks like, honestly, it looks like, like a pizza slicer. Like that's about the, yeah, I th there's another article we can And we'll be sure to include that in the show notes as well. Um, but if you have kind of like rounded corners or you have some kind of odd or, you know, it fits into kind of a crazy look and enclosure or something. Then we can't use V groups. We can't use V scores. We have to use. What's known as a routed process. So it's literally like a router, um, not, not a computer router, I don't, I grew up, my dad, you know, did a lot of woodworking. So I knew exactly what a router was growing up. But if you're not, it's like a very high speed drill and you have a, of that high-speed drill that cuts, you know, uh, cuts away at material. So when they route a PCB that the super high speed drill is going to edge of your PCB, or, you know, if you've got it round, it's going to walk Okay. When we're putting this 100 millimeter by 100 millimeter circle now. Okay. So we're not using a rectangle anymore. We're using a 100 millimeter diameter diameter circle. We're still want to put that in a three by four panel. We still don't want to handle one board at a time. We want to handle 12 boards at a time, but the only way to do that is to route the Cause they kind of look like, like if a mouse bit, you know, That's kind of what it looks like. So everybody's just always called mouse bites. But anyway, um, they're like a perforated tab that break off the edge of your But the problem is where it's broken off leaves this kind of Um, like we're, we're all the little perforations are you Sticking out. So you don't have a true circle anymore. You still have these annoying little, you know, re you know, remnants of sticking out the edge of the, uh, of the, of the board outline. Well, that can become a problem, because what if your enclosure is, by a hundred millimeter, you know, it's gotta be it's Chris, you know, I gotta make sure this is a perfect circle or whatever. Um, we're, we're going to have problems trying to achieve that because way to solve that is by literally filing them, like, like, like a nail Yes. Manually filing these things away. Um, or we've even like in the worst cases we've, we've used, uh, um, like a belt. You know, very carefully, but use like a benchtop belt sander, and kind It's awful. Like you don't want to pay somebody to do this. Trust me, like, this is just a waste of time. It's a waste of money. Nobody wants to do it. Like, nobody's like, you know what I want to be when I grow up, I want to Right? No, like nobody wants to do that job. Um, I'm grateful for the people that do that job. Uh, and you know, EV I got to tell you, the culture at Weddington assembly that job is, but anybody in the building at Worthington would just be Like, nobody's going to whine about it. Like we just get stuff done. It's, it's awesome. But, but at the end of the day, you know, that that's kind of a waste of time. Like it's a poor design. If you have to take these things off, um, well, I worked with a customer Uh, well, uh, consumer ish, it was for retailers and, um, it, uh, it had and it was really, you know, it was very user facing, so they wanted it to And so they couldn't use a nice rectangle. Like I always recommend they had to have it in this particular shape and them and I'm like, look, guys, this is crazy trying to file off each of And they, they came to us first and they said, Hey, what if we Like, what if we do like a little cutout where you can put those perforated tabs? So once you snap them off, they're not proud of that edge anymore. And it'll fit inside our enclosure. No problem. We won't have these. You know, nubbin sticking out and making it difficult for us And that's the technical term, not just ask Carol she'll, she'll Carol loves to use the word nubbins for little, little Um, everybody knows what they are, as soon as you use the term. You're like, yeah. Oh yeah. It's another one. Of course it is. Um, but yeah, you don't have those things getting in the way. So I have had in my, my, my drafts folder of, of our blogging software, a draft of three years ago about the process to recess the PCBs or recess the edge of Podcast is going to be recorded today. I finally published it today. So it's officially out in the wild. Um, you can find on our website, reassessing your piece would We'll include it in the show notes too. Um, but this is a great way of maintaining sort of those critical dimensions time, you know, not forcing a bunch of manual labor to get it that way. I love it. I just thought it was a brilliant idea. And I, and I, and I just decided to steal it, you know, unreservedly It would be funny if, uh, the original engineer who, who worked with us on this He's talking about my product. If anybody's ever ordered a PCB from OSH park, a fantastic PCB prototyping Um, they, uh, they always send you no matter what. They send you your boards with these perforated tabs. And sometimes they don't even break them off. Sometimes they leave them right on there. At least we have the decency of breaking them off. Um, and, and so if, if you've ever gotten boards from OSH park, you know So make sure to, you know, keep this in mind when you have an odd shape of a PCB it is to just reach out to us ahead of time and say, Hey, I've got an odd shape. I have these critical dimensions. I can't deal with, you know, these perforated tabs, what can we do about it? And it's not as simple as like you just defining where you want the perforated you actually have to, it has to be a collaboration between the designer, All three parties have to be involved in working up this design PCB fab. And then how we, you know, where your perforated tabs are and how many of them It will also have an impact on the fab process, but it will have a significant Because if you only use a couple little tabs and you got a great big giant You might need 3, 4, 5, 6, 7, know, 10 tabs to hold your, So we really need to kinda, you gotta kind of have to go. All right. So here's, here's my rough design. Here's my outline. Let's talk to the F let's talk to the assembly house. What, what panel size works for them? They'll talk to the fab house, the fab house. We'll figure out what panel size works for them. They'll agree on kind of the overall, you know, is it going to be a two by two or And then we'll say, okay, we want to put perforated tabs here. And then you go back to the designer. Can we put perforated tabs here? And you'll say, you can put them here, here and here. But this one you have here. I can't, you know, I, I've got to put my Bluetooth radio, you And so it's like, okay, well, all right. So back to back to the assembly and fab, all right, we got to move this one over. Can we move this one over? And then we go back to the designer? Yes. Okay. Everything looks good and all through once all three parties agree on how to do He can include a drawing too, of the importance of putting the perforated And then he's going to be very happy. Every, you know, boards are going to ship, they're going to be easy to panelize. We're not going to have to spend time filing these things. They're going to fit in the enclosure. Just fine. It's going to be great. So that's, um, it's a cool process. We've had a lot of success with it, with a number of customers over the years and Cool. Yeah, that's really clever.
Chris:I want to have more episodes like this. Just kind of like a quick takes on, you know, layout I think, I think there should be a part one. I agree. And then in like three years we'll have like a part two,
Melissa:well, lots of other advice before that's right. That's right. Yeah. And you mentioned. We also want to take this, take all these tips and, you know, make Yeah. Which I actually just did for the, um, SMT or through whole episode
Chris:Yeah. Yeah. Yeah. More of those we get, you know, we do get requests from time to time I love it. You know, but I'm like driving when I'm listening to it. And then I forget like, oh, did he say three millimeters? Did he say five millimeters? And could, could you, you know, write it down somewhere? Could you, you know, have pictures or notes showing, you know, these easier to talk about it than it is to write it all down, but we got It's um, I'm, I'm glad you're starting to do that. And, uh, you know, get me involved and don't be afraid to just give me
Melissa:Yeah, for sure. All right. I think it's time for the most, the most important part of the show. I'm so excited about this one.
Chris:Now this is, this is low-hanging fruit. I understand. Like, I, I, the reason I love my pet peeve on printers and perforated is because they're like these weird nuance things that nobody ever thinks But this one, lots of people complain about, but I am wholeheartedly that is America's lack of complete adoption of the metric system. Now we've adopted some of the metric system, but not all of it. And it drives me crazy. It's it's just, okay. Let me give you an example. When you go to buy milk at a grocery store here in the United States,
Melissa:A gallon.
Chris:Or quart. Yeah. W which did you, okay. I did not know what a quart of milk was. I did not know. Excuse me. I did not know what a court was for decades. Not until I want to say like maybe a year ago. I probably not even quite a year ago. Did I finally know what a quart measured? Do you know what a quart is?
Melissa:No,
Chris:it's a quarter gallon. That's all it is. See, I'm not alone. I was like, why not call it a quarter? Wait. Right? Why not call it one fourth? Why are you going to call it a quart? Oh, I it's just, I it's a quarter gallon for courts is a gallon it's it's Unless it sounds like you didn't know that either. I I'm certain we're not alone here. There's probably a lot of people that don't know that It's just the
Melissa:size of a small milk that is to me. Right,
Chris:right. You know, it looks okay, but what is okay, Melissa? You, you, you've got, you've got a gallon of milk in your, in your Now you want to get, you know, uh, uh, uh, your partner really likes soda. So we're going to go get him some soda. And, and what size container are you going to buy that soda and Yes. Exactly. And every American listening to this is going to be like, yeah, of course you buy. Yeah. That's what soda comes in, comes in two liter bottle. It's not that we can't adopt the metric system. It's not like there's anything inherently different about Americans. That for whatever reason, we just can't rep wrap our poor little minds around, an hour, it's just like for whatever reason we've refused to, until it And you see, once you get used to a certain unit of measurement, When you buy soda, you buy a two liter bottle of soda. When you buy milk, you buy a gallon of milk. If milk came in a leader, you would just know, oh, this is a liter of milk. This is a two liter thing of milk. Like it's not going to be confusing. It'll be confusing for like a week. And then you'll get used to it. Like we should just. Done just eliminate all the, the English measurement system, What do, what do we even call this thing anymore? I don't know. Antiquated is what we call it.
Melissa:You're just talking about everything. I'm guessing
Chris:for everything. Like, like this whole episode, I kept having to say millimeters. Oh, and mills. Right. And, and, and, and here's the worst part when, cause we have a lot of, we have a When we say a mill to them, to them, it means a millimeter, right. Because what is a mill? A mill is a million or, or really, excuse me, it's not a million. It's a, it's a. Oh, that's even more confusing, but it's millennium thousand, right? That's why it's a mill. Anyway, it's a thousandth of a dimension. So a mill in metric is a millimeter because it is 1000 millimeters in a meter. Of course it makes sense. So when you say, oh, this has to be 10 mil to a person from England, then If you tell an American, this has to be 10 mill, then they're going Completely different dimension, not even close to each other, but So yeah, just it's, it's awful. It's really seriously awful. Uh, and you know what, like. Millions and millions of dollars of mistakes have come out of this where Um, I, before the show, I, I found an article about there was Well, not, I shouldn't call it a disaster. I don't think anybody lost their life from it. But, um, you know, they lost millions of dollars worth of equipment because they didn't do the conversion properly between the standard units and the metric units. Um, there, there was actually a Canadian airline that ran out of fuel one system and didn't yeah, they're like mid air ran out of fuel. I think they landed. Pretty sure they landed, but, um, still, and, and it's like, okay. So I, I, uh, I know Melissa, you, you have traveled and I've, and I've traveled where they they've adopted the metric system, you know, four hours that can be Uh, but I spent three weeks in Australia a couple of years ago. Zero problems adjusting to the metric system. Like within a couple of days, like you got used to, you know, what was a comfortable I got used to buying milk and a particular size. And you know, you know, when you order coffee, you want 300 mils know, that's It's not, but you call it mill. Is that a 300 mil coffee or whatever? Um, it's not hard to adjust to these things. Yeah. In kilometers an hour, a hundred kilometers an hour. It's like, it's easy. It's super easy to get adjusted to. I, and the argument is that everybody makes is, it's like, okay, well now we So that they're nice round numbers. No, you don't. No, you don't. You just start selling it as a 355 milliliter can, which is 12 So it's kind of annoying to say 355 milliliters. So what, so what can we please just, can we please just this. Uh, I'm just so tech, like okay. For example, and a lot of people will say like, oh, well just quit And this just is the way it is. Well, imagine if there was like two different ways of measuring time. Yes. Like, oh yeah. Well, you know, uh, if you go to, if you go to England, they don't measure And it's like, we have standards for a reason. Like, let's like we have a 10 based numbering system. You, there's not a country that uses like a 16 based numbering system except for Um, but like everywhere in the world, we use a 10 base numbering system. Nobody uses anything, but a 10 based numbering system for math and So like this is standards or is it there for a reason? Can we all just get on board? With the metric standard. Oh, that's what it called freedom units. And that's sort of the, that's sorta like the passive aggressive Freedom units. That's the word I was trying to think of earlier because 'Merica and our freedom
Melissa:leave it to America. Yeah. That it would somehow it would turn into like a, a political thing.
Chris:Oh, it's, it's, I'm sure there's some politics behind it. I'm sure there is. I'm sure there is. There's got to be some, you know, a politician, they got paid off by some convert all of my, you know, if I'm going to make a Fox body Mustang, And I don't know, it's just right. Cause wasn't it like the eighties when America decided to convert That's why, like some things like some industries, like soda went Yeah.
Melissa:Well, okay. So I guess that's kind of, I mentioned I had a, like a little tangent off of that. Um, and I think you might've listened to the same thing, but yeah. When the Canadians converted to metric, I think in the sixties or seventies, industry was like, well, now we would have to re redesign all of our tooling and And that's why they started using bags. Cause it's all, it was a lot. Yeah. It was a lot easier to just, you can fill up the bag as And then yeah, he used the bag and said, so they didn't have to make.
Chris:I think I did listen to this and then like people at home, they have like Right. Like they cut the top off. Yeah. And it's just like a thing that like, everybody's like, oh yeah, this is And that's probably like talk about like, eco-friendly like, how awesome is that? You just have this tiny little bag that holds hold your milk, and then over and over rather than buying a new hard container every time. That's brilliant. I love it. Yeah.
Melissa:I think a lot of the provinces have since converted
Chris:I think, I think I was praising them
Melissa:one of the provinces. I think they're still mostly bags.
Chris:That's awesome. I think that's super cool. I love, I sort of love the whole, like the, the idea of like, uh, of like a Um, this is, this is why I, like, I kind of hate water bottles. They got. Individual use water bottles that drives me. No people love them. People love they're convenient. And if like, yeah, if you're on a road trip and you, you forgot to bring a bottle need water, you run into your seven 11 or whatever, and you grab a bottle of water. It's super convenient. I get it. Um, but like, like when, whenever, you know you, I go to somebody's house. Cause I don't do this at my house. Um, but whenever I go to somebody's house and I'm like, ah, I need some like three giant stacks of water bottles you like, is there, is there, is there Like, is there poison in your tab water anyway? Yeah. A metric system go metric system. Let's do it. Let's. I, I, it's not going to be in my lifetime. I doubt it. I doubt it. I wish it was a really do wish. It was. I wonder, you know what, I wonder if like every vehicle sold by 2030 or that they're not going to make, um, internal combustion engines anymore. Uh, if it all becomes electric and like there's the one less Everybody talks about a gallon of gas, right? That's like, that's the sort of thing that everybody points to Again, when people stop buying gallons of gas, will they be more Like I wonder maybe. And then can we start to buy leaders of beer and leaders of what other liquids, well, wine, what do you buy? Wine? 750 milliliter bottle, right? This is not, this is a solved problem. We have. We have to read the world of this ridiculous nonsense of
Melissa:I mean, that would be cool if that did happen in our lifetime. And then when we're seniors, you can tell all the young ones
Chris:I heard a podcast. What's a podcast. Uh, yeah, we'll see. We'll see. All right. I hope everybody enjoyed my, uh, my pet peeve about the metric system. That's that's low hanging fruit. I got to come up with a better one. I got to come up with. If that's that's pretty sad. I can do better than that. Let's be done with the show, Melissa. We're done. I'm done ranting. I've had enough. It's a good day. Good. All right. As always, please reach out to us if you agree that the metric system should United States and what other country, there's another country that uses it. I don't know either way America should adopt it. And if we don't, shouldn't adopt it. Please let us know by contact at pic place, podcast.com. You can email us there, or you can tweet us at CircuitHub or at w assembly and tell
Melissa:Thanks for listening to the pick place podcast. If you liked what you heard, consider following us on your leave us a review on apple podcasts or wherever you get your podcasts.