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

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Full transcript:

[00:00:00] Chris: Welcome to the Pick, Place, Podcast, the show where we talk about electronics, manufacturing and everything related to getting a circuit board into the world. This is Chris Denney with Worthington,

[00:00:18] Melissa: and this is Melissa Hough with CircuitHub

Welcome back Chris

[00:00:22] Chris: welcome back, melissa. As, uh, as, as you know, things have been crazy again, we're dealing with all kinds of, uh, part shortages.

If you're listening to this and we're going to publish this on Monday, August 2nd, uh, nothing has changed and apparently nothing's going to change for like a year and a half, actually

[00:00:41] 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

[00:00:59] Chris: Don't be creepy.

[00:01:01] Melissa: Don't be creepy?

[00:01:02] Chris: Yeah. Yeah. Like when you say, wait, where you're from, you're supposed to say don't be creepy. So nobody likes stocks down. Like, oh, I'm going to go for a hike in Huntington beach to find Melissa,

[00:01:10] Melissa: I don't actually live in Huntington beach, but you can go there and try to find me, but I will not be there.

Um, but you could see all of the boats that just lined up in the ocean containers. Yeah. Yeah. So many of them just lined up. So there might be some parts on there that you're waiting for or something that you're waiting for.

[00:01:33] Chris: The craziest, it's just the craziest thing. For example, the reason that part shortage makes our job more difficult, besides the obvious of 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 adds to the amount of time, it takes to buy the amount of time it takes to receive the amount of time it takes to kit. [00:02:00] 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 sort of compounding problems. You know what I mean?

[00:02:14] Melissa: Adding more pieces to the puzzle and adding more unpredictability and yeah.

[00:02:20] 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.

[00:02:31] Melissa: One, one more random fact that I learned. So my cousin works in product design and she was telling me how a shipping container before COVID used to cost $2,000 and now a shipping container, which you can't even really get right now.

The same shipping container costs, 14,000.

[00:02:50] Chris: Yeah, my goodness. It's funny because my dad and I were thinking about building a workshop out of shipping containers. 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.

[00:03:14] Melissa: Yes. That's what we're here for.

[00:03:16] Chris: I, I am a novice, uh, PCB layout engineer, and I love to dispense, uh, expert advice as a novice. 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 there's tons of advice and we'll, we'll have episodes in the future like this. Uh, and we have had some in the past with like, um, Dave Wilcox about, about, you know, design rules and best practices for [00:04:00] fabricating a PCB.

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 who hit, they wanted to use a 1.4 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 just smaller than a grain of rice. 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 mean, we built a few hundred of them. No problem. And then there was not a single yield issue, but like, I'm just nervous about that kind of stuff 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 practices for your layout, but not just 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 assembly and that's, that's exactly right. So I, I always kind of assume people understand what these terms mean, you know, but maybe not everybody does. And if you're not sure what I'm meaning by a via I'm talking about something that is just [00:06:00] transferring your signal or current or whatever it is that you're using it for from the top side of the PCB to the bottom side, or maybe an internal layer, you know, depending on what you're trying to accomplish, but, uh, but nothing gets added to it, right?

So it's like a plated through hole, but there's no, like, you're not going to put a pin in it. We're just talking about a via, so, okay. Well, most of our audience should probably understand what if he is, but I wanted to get that out of the way, just in case, believe it or not, the a poorly laid out via can have a significant impact on the assembly process.

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 things and I thought, you know what? Let's just get an episode of good practice, you know, best practices and your layout out there. 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 have a pretty significant impact on the assembly process, because let's say for example, you place a via the most obvious one we can talk about is right in the middle of the pad, right? So you got an oh five and you're like, I'm just going to put a V up right here, send the current through the board.

Well, you know, you got a big giant hole in the pad now, where do you think all the solder is going to go? 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 a flying probe machine and yada yada, yada, and everybody's going to be happy.

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 the rest of its life, it's going to fail. 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 [00:08:00] probably if you're nerdy enough to listen to this podcast, you're like 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 you kind of get used to seeing engineers and you get to see their layouts.

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 you know, the good ones, like you see a layout from, from, uh, Jennifer. And you're like, oh, Jennifer's, this is going to be great because she always does a great job with her layout.

And then every now and then you see some stuff and you're like, what in the world is going on here? So it's like little things that may be, they know don't put a via in the pad, but they don't know. 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 work with all the time that they do great layouts, we've had, we've had great success, good yields with them and everything and, and been very happy with them.

But then they sent us this one board recently, it was a bit more compact than normal and they put their vias like 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 fit masking between the via and the past.

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 up with the same problem of, of draining, solder paste into that via. So my recommendation, and this is not like a minimum, I always [00:10:00] like to give recommendations of like, of, of what I call like.

Like cozy minimums. I don't know. I use that though, but like, it's like, it's not just the minimum, it's a minimum with a little fat on it, so it's definitely safe. And so I like to say, keep the like, outside edge of your annular ring of a via and the next closest copper feature pad through plated through hole, whatever it might be at least six mil, at least six mil from each other.

Because if you leave that much room, then there will definitely be an area where we can lay down some soldermask and, and everybody's going to be happy. Um, but even better than, than, than just like at least leaving some room, let us know if we can tent your vias or better yet, you know, export your data.

If you come to Worthington or, or, you know, set up your rules in Eagle or Altium or whatever software you decide to use so that when it defines your mask layer. 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 Altium, I think, well, actually Altium might have a one button click for this.

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 you wanted it to tent vias. 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 to tell it like, okay, what holes do you want covered with via...? Like what's the maximum hole size you want covered with solder mask. And so you're like, okay, well what's what [00:12:00] 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 to say 26 mil, anything bigger 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 a huge pain in the neck in Eagle.

And I'm not sure about your cadences and your pads and your, your, uh, mentor graphics and all these different tools. But if you can, if you can define your vias as being tented, because you don't need them exposed, that's just, that's gravy. 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 those shiny vias all over the place can, can really be distracting. It can really actually be difficult to kind of like pick out the important features of the board you're looking at and make sure that you can see everything. Also, it allows you to put a silk screen over the vias because normally you'd have to trim all those off or you'd have to move your soak screen out of the way.

Um, but if you put soldermask down first, then you can typically get silkscreen on top of it. It'll be a little distorted because that solder mask is going to be perfectly flat on top of the via, but it'll be legible. It'll be it'll work, you know, especially if you're using it for just like a dot or something.

Um, there's, you know, there's all kinds of, there's all kinds of advantages to tenting vias. Um, there's some disadvantages and, and, you know, we could get into those, but maybe, maybe for a separate episode, 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 [00:14:00] 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 next closest copper feature. Um, Uh, but you haven't tented your vias. Well, when we go to do through hole soldering, if we're using an automated through hole soldering process, and we, you know, we have a via really, really close to a plated through hole that we're trying to solder.

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 will be used for testing and yada, yada, yada, usually it's not a big deal, but sometimes we'll actually ask like, Hey, do you mind if we fill this via with solder, but we're going to try to avoid it.

And so then that's going to limit the size of the nozzle we use for maybe if we use a selective soldering process or, um, or possibly we could accidentally create a solder bridge between that via, and that played it through. So even six mil might not be enough, you know, especially if it's near a plated through, well, maybe you want to go 12 mil or 15 mil away from, um, away from the next, you know, plated through holes so that you definitely don't have any solder bridging on it.

Um, but if you, if you tent it, you know, if you cover that via with a soldermask, nobody deal done easy when you know, you're never going to get solder on it. 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 the show expert cam engineer for PCB fab.

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 with solder mask and tented over. And, uh, [00:16:00] 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 millimeter and, and been able to, um, cover those vias with soldermask. But there's some potential fab defect issues. Like you, you have like, you won't get, you get this weird thing where it doesn't actually fill the via.

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 or the functionality of the board. So, you know, but if you can try to keep your vias nice and tidy 0.3 millimeter or 12 mil you'll have good success.

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 talking about the, the physical hole. 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 to start using a laser drill. 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 minimum edge clearance, yada yada yada. 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 know, clearance to the edge of the PCB. And that makes sure that, you know, they can put the copper feature down and then they can route it or they can V score it. 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 for the fab process that does not take into [00:18:00] account the assembly process.

So what we like to talk about is three millimeters from the edge of the PCB, but only the exposed. Right. So you can bury, um, copper traces. You can have ground pours, you can have all that kind of stuff within 10 mil of the edge of the board, but 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 pay for it, but there's an awesome IPC spec, uh, uh, called SMEMA. 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 you handle PCBs, how you handle panels and PCBs throughout an assembly process. Um, the spec is really written, not for shops like Worthington or CircuitHub it's written for a machine manufacturer.

Okay, so that, yeah. So when you're making a pick and place machine or a stencil printer, um, you want to be able to interface with the rest of the assembly line. There's going to be other vendors making reflow ovens and conveyors and SPI machines and all, you know, there's all these machines, right? So you want to be able to set up one assembly line and be able to run the board through the whole thing without any issues.

So how do you make sure that everybody plays well together while you write a spec? And so they wrote a spec and it basically defines like the height of the machine and the conveyor rail size and yada yada, yada, but importantly, it also defines the clamps, the machine clamps that hold the PCBs while they're being processed.

So cause you gotta hold a PCB while your stencil printing, gotta hold it while your pick and place, you know, cause otherwise [00:20:00] 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 a reflow oven, on a wave solder machine, all of these kinds of things.

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 of a frame or rails around the PCB, you know, to hang on to the board. Now this, this three millimeter spec is so it's so poorly known, like nobody knows about this spec, except for 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 just said, Whenever we get boards, we just have to add rails to it, period. 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 to put our fiducials on there.

We're gonna put our tooling holes on there and we're just going to move on because it's impossible to try to, um, you know, you know, get everybody to switch their designs, to make sure that we have three millimeters of clearance, um, you know, to, to make sure that we don't have to have these rails,

[00:21:26] Melissa: but what are the advantages of not having rails

[00:21:29] 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, perfectly routed machined edges. And we throw them all out. Well, we recycle them obviously, but, uh, uh, we need those in order to handle it through our process because we have no idea if you're going to give us the clearance [00:22:00] that we need so we can eliminate the paneling them altogether, that also eliminates the extra material we have to pay for it from the PCB fab.

Um, it also eliminates the, the extra stress placed on the board when we depanel them. 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 up 10 up, something like that. 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 we're, when we're handling them, we're not going to damage anything. There's just all kinds of good reasons for it. Right. Um, that three millimeter spec, if everybody, if everybody knew about three millimeter from the edge of the PCB, to the nearest solderable, you know, copper area and fiducials, we would never put frames and rails on anything.

Like we would, we would have no need to, well, no, we still might need to, because when we put them on the racks, the racks are like 10 millimeters. 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 that, but if you're listening to this and you've got a good design and it works, and you have one millimeter of clearance from, don't worry about it.

Like, like I said, it's such a pervasive problem that we've just, we've just solved it by adding rails and frames to everything at this point. 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 scratch and you can give yourself three millimeters of clearance from the edge of the PCB, to the nearest solderable feature, then great do that for your new designs.

And that'd be pretty nice because what'll happen is let's say, you know, you go from, oh, Hey, you know, it was kind of a cool product and we're building a couple of hundred a [00:24:00] 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 everything that can start to add up. And if you've already designed your board in mind without the need for those frames and rails and the extra, depending time, then there you go. 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 into these sorts of issues in the future and have to continue to pay for these processes that otherwise you wouldn't have to think about. Um, it reminds me of, of like the, uh, see if I can find this for the show notes, but there's this famous sort of, um, um, I don't know where the heck it comes from, but there's like a, there's like a, a cartoon drawing of, of, uh, uh, an engineer or like, you know, a designer, uh, uh, a factory, the logistics process, the consumption of, of energy used to use the product and it, and it has a shadow behind each one of these things.

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 cast the biggest shadow. They're going to have the biggest impact on the cost and quality and longevity of every product.

Um, and so thinking about these things ahead of time, then it's, you know, you're, you're, you're going to have significant savings when it comes to manufacturing, you're going to improve quality, all these kinds of things. So, yeah, that's my point. Think about these things I have the time, but if you haven't, like I said, don't stress about it too much.

[00:25:52] Melissa: But, if every engineer in the world listens to this podcast and starts designing their boards with the three millimeters, then [00:26:00] we might have, we might be able to eliminate rails completely. Is that what you're saying?

[00:26:05] 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 that we'd have to reconsider, but we

[00:26:16] Melissa: And you also redesign the racks.

[00:26:18] Chris: Yeah, no, like seriously, at the end of the day, you re you know, you, you, you get different racks that can handle the three millimeter clearance. W you know, you're out like a thousand bucks worth of new racks versus, you know, how many thousands and thousands and thousands and thousands of dollars are wasted on rails.

And, uh, depending every year, you know, it's, it's a drop in the bucket in comparison. So, yeah, I would be very pleased if all of a sudden, every board showed up with three millimeter edge clearance on the edges, but, but even if they do that and they still don't put copper, uh, fiducials on the board, It doesn't matter.

We still need to add rails to it because we'd got to add fiduciary.

[00:26:54] Melissa: All right. Well that brings you into your next point..

[00:26:58] 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 smallest you can get to be reliable. I recommend a one again, my cozy recommendations, right? Um, oh, by the way, the three millimeter edge clearance is not a cozy recommendation.

That's a minimum. My cozy recommendation would be five millimeters, by the way, I meant to, here we go, three millimeter, three millimeter. We got 20 minutes of Chris saying three millimeter and it's not even my actual recommendation. Five millimeters is my actual recommendation. Anyway, I digress. But on your fiducial, I recommend a one millimeter copper feature and then a two millimeter, uh, you know, kind of outer diameter of the mass clearance.

So kind of like a, if you think about it, your annular ring would [00:28:00] have a length of, I guess, what would that be? 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 lighting will reflect off of mask.

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 your, on your machines, to see where 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 if you pull that mask away, the underlying fiberglass is quite, um, uh, it's like a. Sort of finish it's it's very dull and doesn't reflect any light at all, like very, very little light. 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.

[00:29:51] Melissa: What about if you're using a matte soldermask ?

[00:29:55] Chris: Still, yeah. Still recommend it because, um, [00:30:00] matte is still more reflective of matte soldermask is still more reflective than a, um, than the underlying fiberglass.

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 know, now we've got a problem. 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 screen around it or identify it as fit one or anything like that with, you know, you don't need to put a reference designator on the board. Like it's just a dumb feature that we'll know exactly how to use every assembly house.

You'll know exactly what that thing is when they see it, it's, it rings as clear as a bell, every assembler worth 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 just going to add fiducials to the, um, to the rails of, of the panel.

It's like, well, yeah, of course we are. But you know, things happen, you know, like we we've had these situations where our, um, our census shop put there, the 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 broken, but you still got to build, okay.

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 not going to be a problem. So yeah. Get those on the board.

Make Chris happy here. So [00:32:00] let's talk about, we had another issue recently with a customer where they, they made the enclosure, that their 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 of a millimeter tolerance on the edge, you know, on the edge of the PCB and the larger, the PCB gets the harder it becomes the whole, the, um, that tolerance. And then when it goes through a reflow of, and it's going to get stretched and it's going to shrink back down, so it's going to change even more.

And then maybe it goes through a wave solder or a selective solder, or it goes through reflow twice. Or, you know, you put it in a thermal chamber for testing or you like, there's all kinds of things that are 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 give yourself any wiggle room in your enclosure, you're going to have problems.

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 enclosure where you put this PCB. Uh, it doesn't have to be much, it could be a millimeter. It could even be half a millimeter, probably half a millimeter honestly is even. Okay. Um, but if you did a millimeter, that's probably, that's probably my cozy recommendation of one millimeter, uh, uh, you know, limit to, uh, or, you know, expansion of your enclosure or reduction of your PCB, uh, outline.

So if you've got, if your enclosure is, is, uh, you know, a hundred millimeter by a hundred millimeter, then make your PCB 99 by 99. 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 handheld product or I, you know, it's a, it's a wearable or it's blah blah blah.

I I've got these critical dimensions that, that I need to make sure are within a 10th of a millimeter tolerance. [00:34:00] Well, you can always send us, uh, or any cm or any fab, you can send them a drawing and you can define, like, these are my critical dimensions that you see this line here. And this line here, you must maintain 100 millimeters between these two edges, because otherwise it's not going to fit or, you know, whatever it might be.

If you send a drawing and you, you, and you define something as a critical dimension, will, you know, there that's going to become, there's going to be extra scrutiny and extra care to maintain that dimension. 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 those dimensions are held true. Um, it could increase the cost of your design because now maybe we can't use a, a good size panel. 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 maintain that dimension and.

So try not to like, ideally you want to give yourself enough wiggle room where you don't have to have critical dimensions, but if you do just make them clear to us ahead of time and we'll try to maintain that. Cause that was, that was part of the issue we had is we didn't know that there was these, these critical dimensions on their design.

Had we known that ahead of time, we would have, we would have panelized it differently. 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 giving yourself a little tolerance, no issues, you'll be happy. Uh, also related to the outline of your PCB, try as much as possible to use straight lines.

I know this may sound crazy cause you like, you go to Adafruit and you see all these like super cool 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 popular American football team and there they [00:36:00] have as their logo, this sort of like cartoonish looking Nordic Viking, you know, with this long flowing blonde hair.

And he's all angry looking cause you know, it's football and uh, they made it like they made a PCB in the shape of the Minnesota Viking. 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 against each other in the panel. So, you know, say let's go back to our a hundred millimeter by a hundred millimeter, uh, PCB while we're probably going to build that. 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 time, that's very expensive. 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 are very, very easy to separate. Um, they just, you can snap them in half, just by hand or more commonly, we use a tool and we actually will draw this blade across, uh, the V groove. And we'll complete the, the separation of the PCB from each other using this tool, because a V a V groove is a partial separation of the PCBs.

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 link to, um, related to all this about, um, what that looks like. And we'll be sure to include that in the show notes as well. [00:38:00] Um, but if you have kind of like rounded corners or you have some kind of odd shape, you know, you have around PCB 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, like a wood like wood 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, you have a, uh, a tool at the end 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 cut away and is going to create the edge of your PCB, or, you know, if you've got it round, it's going to walk around and make a big circle for you. 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 PCBs and then add these perforated tabs, which are sometimes called mouse bites.

Cause they kind of look like, like if a mouse bit, you know, just picture a mouse, biting a PCB in the teeth marks left behind. 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 board and leave just the, you know, just that a hundred millimeter circle.

But the problem is where it's broken off leaves this kind of a, uh, what would you call it? Um, like we're, we're all the little perforations are you still got this excess material? Sticking out. So you don't have a true circle anymore. You still have these annoying [00:40:00] little, you know, re you know, remnants of the perforated tabs, and they're 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, you know, a hundred millimeters by a hundred millimeter, you know, it's gotta be it's Chris, you know, here's my critical dimensions. 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 you've got those perforated tabs one way to solve that is by literally filing them, like, like, like a nail file, not two different friends.

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 of, you know, you just take the edge of, of those perforated tabs off. 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 be the guy that runs a belt side here. 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 is amazing because, you know, I, I just explained like how painful that job is, but anybody in the building at Worthington would just be like, yeah, okay, I'll get it done.

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 years and years and years ago, they made really cool consumer product.

Uh, well, uh, consumer ish, it was for retailers and, um, it, uh, it had this really cool looking [00:42:00] enclosure and it was really, you know, it was very user facing, so they wanted it to have a very particular kind of look. And so they couldn't use a nice rectangle. Like I always recommend they had to have it in this particular shape and I, and they're ordering thousands of them and I'm like, look, guys, this is crazy trying to file off each of these we've we've got to do something.

And they, they came to us first and they said, Hey, what if we recess the edge of our PCB, where you put those perforated tabs? 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 to push this into the enclosure. And that's the technical term, not just ask Carol she'll, she'll tell you a little inside joke. Carol loves to use the word nubbins for little, little things that stick out the edge.

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 this article for I kid you not over three years, I started writing this article three years ago about the process to recess the PCBs or recess the edge of the PCB so that you can, you can put a perforated tab in and knowing that this.

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 be edge for perforated tabs. We'll include it in the show notes too. Um, but this is a great way of maintaining sort of those critical dimensions that you need, but also at the same time, you know, not forcing a bunch of manual labor to get it [00:44:00] 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 and recommended out into the world. It would be funny if, uh, the original engineer who, who worked with us on this was listening to this and it was like, I know exactly what he's talking about.

He's talking about my product. If anybody's ever ordered a PCB from OSH park, a fantastic PCB prototyping company, I can't recommend them enough. 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 exactly what I'm talking about with these, with these perforated tabs. So make sure to, you know, keep this in mind when you have an odd shape of a PCB and the best way to kind of deal with 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 tabs and creating the recessed areas you actually have to, it has to be a collaboration between the designer, the assembler and the fab house.

All three parties have to be involved in working up this design because the, uh, the panel design is going to be impacted by the. PCB fab. And then how we, you know, where your perforated tabs are and how many of them there are, is going to have a significant impact on the assembly process. It will also have an impact on the fab process, but it will have a significant impact on the assembly process.

Because if you only use a couple little tabs and you got a great big giant board, it's just going to fall like those tabs, aren't going to hold it in place. You might need 3, 4, 5, 6, 7, know, 10 tabs to hold your, hold your PCB in the panel. [00:46:00] 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 three by four or a two by one or whatever.

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 know, antenna there or something.

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 that recessed area of the edge, then the designer can put those recessed areas.

He can include a drawing too, of the importance of putting the perforated tabs in those recessed areas. 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 yeah, I just, I can't recommend it enough.

[00:47:24] Melissa: Cool. Yeah, that's really clever.

[00:47:27] Chris: I want to have more episodes like this. Just kind of like a quick takes on, you know, layout advice from a novice engineer.

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,

[00:47:42] 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 them into a little cheat sheet type of thing, which I actually did.

Yeah. Which I actually just did for the, [00:48:00] um, SMT or through whole episode that we had to publish that I'll link it in the show notes as well.

[00:48:08] Chris: Yeah. Yeah. Yeah. More of those we get, you know, we do get requests from time to time from people are like, I love it. 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 things it's like, yeah, it's a lot easier to talk about it than it is to write it all down, but we got to do it, you know, you're right. 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 a punch list of stuff you need and, and we'll, we'll put it together.

[00:48:48] 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.

[00:48:58] 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 pull tabs on, uh, on cardboard boxes is because they're like these weird nuance things that nobody ever thinks or complains about, except for me.

But this one, lots of people complain about, but I am wholeheartedly on board with this complaint and 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, what size is the milk container?

[00:49:51] Melissa: A gallon.

[00:49:55] Chris: Or quart. Yeah. W which did you, okay. [00:50:00] 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?

[00:50:20] Melissa: No,

[00:50:21] 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 like, it's such common sense, but for whatever reason, I never knew that.

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 a court is a quarter gallon. It's just the

[00:50:54] Melissa: size of a small milk that is to me. Right,

[00:50:58] 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 cart now at the grocery store.

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 probably like a liter or two? 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, you know, leaders and in kilometers an hour, it's just like for whatever reason we've refused to, until it drives me crazy, it drives me crazy.

And you see, once you get used to a certain unit of measurement, you don't think about it anymore. 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 [00:52:00] 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, the standard measurement. What do, what do we even call this thing anymore? I don't know. Antiquated is what we call it.

[00:52:22] Melissa: You're just talking about everything. I'm guessing

[00:52:25] 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 lot of engineers who work with overseas. 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 they're going to make that 10 millimeter. If you tell an American, this has to be 10 mill, then they're going to make it 10000th of an inch. Completely different dimension, not even close to each other, but you're using the exact same term.

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 people have not converted things properly. Um, I, before the show, I, I found an article about there was a, there was a NASA disaster. 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 calculated something wrong 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 because they measured everything [00:54:00] in 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 myself and we go to these countries where they they've adopted the metric system, you know, four hours that can be in Canada where it's nothing but metric.

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 temperature to be outside and you know how to set your climate control on your car. 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 the other thing, it's a milliliter, right? 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 have to re-engineer our beverage cans. 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 ounces by the way, like, okay. 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 your wining quit your bellyaching. 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 time in 24 hours, they measure time and, uh, you know, like 14 hours.

And it's like, we have standards for a reason. Like, [00:56:00] 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 electrical engineers, which God bless them, but that's how transistors work. 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 counting and all sorts of things. 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 way of saying standard units.

Freedom units.

That's the word I was trying to think of earlier because 'Merica and our freedom

[00:56:46] Melissa: leave it to America. Yeah. That it would somehow it would turn into like a, a political thing.

[00:56:52] 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 lobbyists for GM or who knows, you know, said, I don't want to have to convert all of my, you know, if I'm going to make a Fox body Mustang, it's going to be in English units.

And I don't know, it's just right. Cause wasn't it like the eighties when America decided to convert and then they didn't really convert or they did, but they didn't. That's why, like some things like some industries, like soda went to leaders and then milk was like, Nope, we're still doing gallons. Yeah.

[00:57:29] 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, yeah, they were, they were, the milk industry was like, well, now we would have to re redesign all of our tooling and all the bottles and it'll be expensive.

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 much as like [00:58:00] to the right size. And then yeah, he used the bag and said, so they didn't have to make.

[00:58:05] Chris: I think I did listen to this and then like people at home, they have like containers that they pour the bags into.

Right. Like they cut the top off. Yeah. And it's just like a thing that like, everybody's like, oh yeah, this is my milk container that I, I refill. 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 you reuse your, your hard container over and over rather than buying a new hard container every time.

That's brilliant. I love it. Yeah.

[00:58:33] Melissa: I think a lot of the provinces have since converted back to the jugs or whatever,

[00:58:40] Chris: I think, I think I was praising them

[00:58:42] Melissa: one of the provinces. I think they're still mostly bags.

[00:58:46] 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 refill as opposed to a Virgin container.

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 of water that you can refill and you 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 water like here and they hand me a bottle of water and you look, and they've got like three giant stacks of water bottles you like, is there, is there, is there something wrong with your tap water?

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 [01:00:00] wish it was a really do wish. It was. I wonder, you know what, I wonder if like every vehicle sold by 2030 or whatever, you know, everybody's saying 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 like, cause that's the big thing. Everybody talks about a gallon of gas, right? That's like, that's the sort of thing that everybody points to a gallon of gas, gallon of gas. Again, when people stop buying gallons of gas, will they be more open to buying liters of milk?

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 two, two measurement systems.

[01:00:55] 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 like, oh, when I was your age,

[01:01:04] 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 be adopted wholeheartedly here in the 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 [01:02:00] CircuitHub or at w assembly and tell us how wrong I am about the metric system.

[01:02:05] Melissa: Thanks for listening to the pick place podcast. If you liked what you heard, consider following us on your favorite podcast app, and please leave us a review on apple podcasts or wherever you get your podcasts. .

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