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This episode is dedicated to fiducials which, for those who are unfamiliar with the term, are the small copper dots you may have seen on your bare PCB. We get into the details of what they are, where and why are they are use, and how you can use them in your design.

https://www.worthingtonassembly.com/blog/2014/12/29/what-are-fiducials-and-why-are-they-useful

If you are already using fiducials in your designs tweet us a photo or screenshot of them with the hashtag #fiducialsFTW :)

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Full Transcript:

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

[00:00:19] Melissa: And this is Melissa Hough with CircuitHub.

[00:00:23] Chris: Welcome back, Melissa,

[00:00:24] Melissa: welcome back, Chris,

[00:00:26] Welcome back everyone. We're recording this on Monday at 4:30 of the day that this episode is supposed to be released,

[00:00:34] Chris: That's that is some high quality podcast producing right there.

[00:00:39] Melissa: but we have a very good reason why that is

[00:00:44] Chris: Yeah. I mean,

[00:00:45] Melissa: Something to you Chris...

[00:00:47] Chris: Yeah. I had flooding in my basement, which was fantastic and just totally threw me off and yeah. Still, still have not fixed it.

[00:00:56] Melissa: Really?

[00:00:57] Chris: Well, you know what, the nice thing is. If you're, I know we have international listeners, so I'm going to try to describe this. I have no idea if they have the same sorts of doors outside of the United States, but the brand name is called Bilco and you'll have like a concrete stairway.

[00:01:10] Sometimes the stairs would be made of wood, but you'll have a cutout of concrete from your foundation and then stairs lead down to your basement and they covered the stairs with what they call a Bilco, or sometimes called a bulkhead door. And I left that open all night in the pouring rain and filled up my basement with like a quarter inch of water, which is really very nothing, except for the fact that literally two weeks before this, I had installed a brand new floor in my basement.

[00:01:34] Melissa: yeah, sucks.

[00:01:37] Chris: My wife and I, we bought a house with my parents and they live on one side of a duplex and we live on the other side and yeah, we were going up and down the stairs and packing up the pool, getting the pool closed for the winter and just neither, my dad, nor myself closed the door.

[00:01:52] And it's just, it's killer. Absolutely killer. But the nice thing is, one side of the basement is carpeted and the other side of the basement is a floating floor and the carpet stayed nice and dry. So that's the water. Yeah, the water ran. So I guess if it had gone on the carpet side, that would have been worse.

[00:02:11] Cause we would have had to tear up all the carpet and that would have been awful, but this just went on my side. So we just have to tear up my floor, bleached the heck out of it and get it back down. Oh, well it is what it is. Nobody wants to hear about my floor.

[00:02:25] Melissa: So that's why we're late. And if you've been waiting on October 11th and you're like, where is the new episode of the Pick, Place, Podcast? It will be out tomorrow on Tuesday. Hopefully pending me, editing it in time.

[00:02:38] Chris: yeah, exactly. We had some nice, I didn't get an email, but I just talked to a few people who listened to our last episode and really, really enjoyed it. It was very different for our show, but, people felt the same way we do with the whole, what am I doing?

[00:02:51] Should I be doing this kind of a thing, the whole imposter syndrome. That resonated with a few people I chatted with.

[00:02:58] So I hope you enjoyed that.

[00:02:59] Melissa: We're not alone.

[00:03:01] Chris: Yeah. And, and on, on a technical level, we got a bit of follow-up from, oh probably two, three episodes ago. We had a customer, he reached out to us about, and actually, I don't think he is a customer.

[00:03:12] I think he's. I think he's just yeah. Just all listener. So yeah, a listener I'm so used to people, calling people, customers, well, listener asked all sorts of questions. Some of them very, very specific and maybe we'll get into them on a future episode. But one thing he asked that I thought was interesting is he goes, I'm always struggling to like, okay.

[00:03:31] I want five pieces and then the manufacturer be like, okay, it's $300. All right. Well, how many is, how much is it for seven pieces? And they're like $300. How about 10, $300? How about 11 $300? How about 20? Well, that'll be a $430. It was like, well, can you just tell me the number? You know what I mean?

[00:03:49] Like, can you just tell me the number that $300 gets me.. And they're like, oh yeah, 13, you can get 13. Every manufacturer is going to have something that they call a minimum lot charge. It's more common in PCB fab to talk about minimum lot charge than it is to talk about, than it is for an assembler.

[00:04:07] Worthington doesn't really have a minimum lot charge. I don't think CircuitHub does, in the traditional sense of the word, but when it comes to PCB fab, it's really common to use the term minimum lot charge. If you can remember those three words, minimum lot charge, and you just say, okay, here's my design.

[00:04:26] How many can I get for your minimum lot charge? And that's the question you want to be asking? You'd be surprised how many people don't know that

[00:04:34] Melissa: Yeah. That's a really useful tip.

[00:04:37] Chris: it's super useful. We use it all the time, all the time with our PCB fab suppliers. So remember that one minimum lot charge. That's a free one for you. No charge for that. See what I did there?

[00:04:48] Melissa: I did.

[00:04:49] Chris: Oh boy, this is my jokes are bad, really bad. I don't know why people listen to this. They listened to it to talk about fiducials.

[00:04:57] That's why they listen to the, to the show. They want to hear all about fiducials now, Melissa, why are we talking about fiducials? You want to tell the audience why we're going to talk about fiducials today?

[00:05:07] Melissa: I would love to. So I'm in the process of going back to the beginning of episodes and transcribing all of them.

[00:05:16] Chris: That's a Herculean. Like I can't even, oh my gosh.

[00:05:20] Melissa: It's actually sort of fun in a way. I'm, I'm using a automated tool called Descript. It's really awesome. I recommend

[00:05:29] Chris: getting meta here.

[00:05:31] Melissa: I was going through, I think it was the first full episode and Chris mentioned that he could

[00:05:38] talk for hours about fiducials.

[00:05:41] So I said, Chris, why don't we do that? Well, hopefully not hours, but

[00:05:45] Chris: No, no, not hours. I could, I could I'll limit myself. I'll limit myself.

[00:05:51] I guess we owe the audience a discussion on fiducials. Now. I think I've mentioned this on the show before, and I I'm sorry if I'm boring everybody to tears, but like the first time I heard this term fiducials, I thought it was a joke.

[00:06:03] I was, I don't know, 16, 17 at the time, something like that. And I was helping out in the cam department of of PCB layout company.

[00:06:11] So they didn't actually do any schematic. All they did with it was board layout. That was actually a really cool job. We used to buy the most expensive machines because to run a DRC would take, like, you'd have to run it overnight to run a design rule, check on a design.

[00:06:27] So they would buy the, just the latest and greatest Intel Xeon, just the fastest machines we could buy. We had towers that were like three feet tall. It was so cool. Anyway. But I digress. So he said something about like, oh man don't forget to put fiducials on your board. I was like, what is that a technical term?

[00:06:46] He goes, well, yeah, I think so. I've well, I've only ever heard it here. I'm like, wait, you're serious. That's a real thing. He goes, yeah, fiducials. I was like, I thought that's like the the two by four stretcher that, the old man tells you to get from the truck when you cut the board too short, which was a real experience.

[00:07:02] I have my father, I forget what we were doing. I cut. I cut a two by four, two short he's like, ah, it's all right. Go in the garage. I've got a two by four stretcher. You can just grab that. What? A two by four stretcher?. Yeah. Yeah. You can't miss it. Go in the garage. You'll find it. It's just, ah, it's the meanest joke.

[00:07:17] People love to do that to young people who are don't know any better. That's it's very similar to the wire stretcher. That's another one. If you cut a wire too short or the other one I've heard of the boxing gloves. So when you're painting, if you're painting like a hallway or a huge auditorium or something like that, you're not just using one gallon of paint.

[00:07:37] You're probably going to use 5, 10, 15 gallons of paint, and you want to blend, you want to homogenize all the paint because

[00:07:44] Melissa: Oh, yeah. Yeah.

[00:07:45] Chris: they might not be perfect. Each can is going to be really, really close, but they're not gonna be perfect. So you homogenize them load together. And that process, they call boxing the paint.

[00:07:52] I don't know why they call it boxing the paint. And I remember I was doing this job and this guy goes he goes, oh, go out in the van. You got to grab us the boxing glove so we can box the paint. I'm like, is this like the, the two by four stretcher? And they all just start laughing. Fool me once fool me Anyway, so yeah, fiducials are besides having a very funny name.

[00:08:16] And I have no idea what they come from, I guess like probably relate somewhat related to like what fiduciary means. Right. Isn't it's your fiduciary responsible? It's your responsibility to do this thing properly? Maybe that's what that comes from. I have no idea where this term comes from. Have you ever heard of this term outside of our industry fiducials

[00:08:36] Melissa: I don't think so. I think, I think when I started learning about assembly is when the first time I

[00:08:41] Chris: yeah. Well, anyway, for the uninitiated, they are these typically small dots, small copper dots on your bare PCB. That's typically what you'll see, and if you don't know what they are and you pick up a circuit board and you see them on there, you're probably quite confused.

[00:08:59] And, but here you're going to, it's going to be revealed what they're used for. I had to look up the definition of this and there's lots of definitions, right? But the best one I found for a fiducial was an object placed in a field of view of an imaging center. Which appears in the image produced for use as a point of reference or a measure.

[00:09:19] Now that's a really generic definition of it, but it's so accurate at the same time. Basically these dots are just something that a camera can look at and then measure the distance between the two between two dots and then have an idea of where this object exists in space. So what does that mean as far as getting your board made?

[00:09:46] Right? Let's say you put a circuit board inside of a machine. So you're picturing a machine where, you've got a conveyor, some other clamp holding this board inside the machine, and then you've got to get a pick and place head above it. Let's talk about a pick and place machine first.

[00:09:59] Well, how does the pick and place head know where to put the parts? Right? If you've just put that in by hand, there's no way you're going to put that in the same spot every single time, not accurately enough. Maybe if you're using large parts, you could probably justify it to one corner pretty well, pretty consistently.

[00:10:18] But you know, you're using these tiny, tiny parts. We were talking 0.3 millimeter pitch. BGAs you can't just assume you justified it by hand, accurately enough. So a downward looking camera looking at the board will actually find this small dot understand where that dot is in its physical space.

[00:10:43] You have your motion system is keeping track of its position in the machine. And it's saying, okay, if I turned my motor 16 times to the left and four times up, then that's the center of my first fiducial, right? Obviously it's probably like 16,432 times that it turns to the left and 4,396 times that it turns, it goes up, but you get the idea.

[00:11:03] It creates a marker in space and it says, okay, that's where the board is. But one fiducial only gets you that. It only gets you like the X and Y rough location of where the board is inside the machine. It doesn't tell you if the board is rotated at all. Because if you think about it, you can have it like pretty square, but you're still gonna have a slight rotation.

[00:11:27] And I mean, like slight. So if you have, if you have a small board say, it's only like, I dunno, but a hundred millimeters by a hundred millimeters. It's what roughly like four inches by four inches. The rotation is actually going to make a huge difference, , even that small, I guess if you had a really small board, like a 10 millimeter by 10 millimeter, it wouldn't make any difference.

[00:11:47] But anything larger than any reasonable sized board, you have a small rotation. You're never going to place these fine pitch parts. Right. In these small 0402 0201 and on and on and on. You need to have the rotation. So the first fiducial gets you your first sort of like, okay, where is this thing in space?

[00:12:04] And then your second fiducial, it just creates like a pivot point. And it figures out how much your board is rotated inside the machine. And then it does all this fancy math to recalculate, your placement, orientations, and everything. And that way there you get accurate placements inside your pick and place machine every single time.

[00:12:23] That's a brief sort of like general overview of how fiducials are used. The truth is it's so much more complicated than that. Because you also have to take into consideration how much this board may have shrunk or stretched during its fabrication process.

[00:12:43] When you're fabbing a PCB, you're cutting it to a specific size, but then you're putting it through all of these hot processes. There's a lot of heat involved in making these things and just think about it whenever you heat something up or shrink some cool, something down, you, you, you stretch it or you shrink it.

[00:12:59] Because I'm mechanical by nature, I think of, if you have a nut stuck on a bolt or something like that, you're trying to take your lugs off your car or something in there. If you heat up nut it will swell up, it'll stretch up and it'll make it easier to remove.

[00:13:12] This is kind of just a known thing, right? So the same thing can happen during PCB. Fab is these can stretch and shrink. And so the data that you've given this pick and place machine you'd go, okay, my first part is at one millimeter. My second part is at a hundred millimeters that's, 99 millimeter difference.

[00:13:30] And so that's where you're supposed to place these parts. However, in reality that board might be just a hundredth. Now, probably not a hundredth, a thousandth certainly, or a few thousandths larger, smaller in any direction. And so you need to compensate for that slight stretch and shrink. So that is where a third fiducial comes into the picture.

[00:13:54] So you have, again, just to recap, you ever first one for where it is in space X and Y. You have your second one for the rotation to make sure rotation right. And then the third one, it helps you helps it to calculate even further how much to stretch or shrink the board. The reality is the materials have gotten so good now.

[00:14:18] There's very little stretch and shrink. We still see it, but only on really large boards, like, and after we've put them through our reflow oven, which I believe is significantly more significantly hotter than what the fab goes through. It's either hotter or just like less well-controlled because they always tend to like reshape themselves a little bit after one reflow cycle.

[00:14:41] So if you're doing a double-sided, that's where the third fiducial becomes pretty, pretty handy to compensate for that stretch and that shrink. And the truth is every machine in an assembly process uses these things. Everything your stencil printer uses it. The stencil itself actually uses fiducials.

[00:14:59] So you actually will burn you'll pull the laser out of focus when you're fabricating a stencil and you'll burn it raw. You'll burn the stainless steel rather than cut the stainless steel

[00:15:12] Melissa: Yeah, I've seen that

[00:15:13] Chris: and the reason it's going to have a burn mark on it is because when you put a board into a stencil printer and you have that stencil loaded, you're going to have a camera that looks down at the board and looks up at the stencil and figures out how to rotate either the stencil or the board, depending on the machine.

[00:15:31] So that the two of them match up perfectly and bring, bring those two pieces together for a very accurate print. So. That's where we're gonna use fiducials. We're gonna use them in the sense of printer, the next machine they're going to go into, they're going to go to a solder paste inspection machine.

[00:15:45] That's gotta use fiducial stew to figure out where everything is, so it can do its inspection. That is going to go into a pick and place machine. We already talked about that. Then it might go in an AOI machine before it goes into the reflow oven. After the reflow oven, it's probably going to, it's almost certainly going to go into another AOI machine post reflow.

[00:16:01] There's a lot of selective soldering machines now that use fiducials because, even through whole parts are getting tinier and tinier and more difficult to align. It's just, it's used everywhere. There's x-ray machines that could be using them. There's flying probe machines that could be using them.

[00:16:15] There's a glue dispense machines, solder dispense machines robotic soldering. I could go on and on like almost every machine in an assembly house is going to use fiducials and that's why they become just so critical because you design your workflow around the idea of having these fiducials and when they don't exist, every one of those machines, you have to figure out a way how to tell the machine where this thing is inside of it.

[00:16:48] Right. And if you don't have those, you gotta start to play games. You can get it to work, but you've got to play all kinds of games. Like, for example we get some older designs that don't have fiducials and I'll get into the details of that in a minute. But when w when they don't have them we'll look at like a pad of copper on the board, and then we'll look up at the aperture in the stencil , but you've got to make sure that you choose a pad that doesn't look really similar to something else, because if you just choose like one side of an 0603 pad, you wouldn't want to use something as small as an 0402 pad.

[00:17:21] But if you wanted to look one side of of an 0603 pad, well, if the camera sees the adjacent 0603 pad, it might think that's the fiducial instead, and then lock onto the wrong thing. And then you got yourself a giant mess, it's just it's yeah, it, you can play all kinds of games, but there's all kinds of risks.

[00:17:38] And just whenever, whenever we try to build something that does not have well-executed fiducials it's it's, it is nails on a tree it's worse than nails on a chalkboard. It's like bamboo shoots up my fingernails. It is just the worst. It is so painful.

[00:17:57] Melissa: How often do you see designs with poorly designed fiducials?

[00:18:02] Chris: Well, I'm glad you asked I, I would say wholly nine out of 10 or more, maybe let's say 19 out of 20, let's say fully 95% of everything that we see from our customers don't have fiducials on them at all.

[00:18:21] It's so prevalent that we basically just assume we'll never get fiducials from our customers and we add them ourselves.

[00:18:29] Melissa: Are you adding them to the panels are to the board themselves.

[00:18:33] Chris: It's it gets too complicated to add them to the board itself because we don't know how this product is going to be used. There could be some issue with us putting fiducials on the board itself. We'd like to, we would like to but no, we put them, we'll add like rails around the board top and bottom typically left and right side as well, that will eventually be broken away and recycled at the end of building these because we have to add things like tooling holes and fiducials. Tooling holes, they're less important than they used to be. They're still pretty valuable, but less important than they used to be. And yeah, so we'll add them to that.

[00:19:06] So when you get your product, this whole discussion, you may be so confused cause you're like, what are you talking? I never seen these little dots on my boards and it's because we put them on our panels and and then you never saw them, Some people argue like, oh, can't you just use the holes.

[00:19:23] You got holes on the board drilled they're round, they're roughly the same size as the fiducials. Why don't you just use the holes. Well the truth is when you're fabricating the PCB you're drilling the holes and a totally different process than etching the copper. And so the alignment of the holes to the copper is basically how accurate was the fab process.

[00:19:44] I mean, it's, it's pretty good, but it's not perfect. Whereas the etch it's all done at once. So when you're etching a fiducial and you're etching your 0.3 millimeter pitch BGA, that's all being etched at the exact same time. And so your registration is, theoretically perfect. It's all done at once, so it should be the same.

[00:20:03] It's using the same processes, the same bath. It's the same. Film or whatever, got to get Dave on here to talk

[00:20:08] Melissa: You should know this by now, Chris,

[00:20:10] Chris: I know! The photo resist, film. That's all made at once. Right. And so it, it should in theoretically be perfect.

[00:20:16] And obviously there's reasons why it won't be absolutely perfect, but it will be accurate down to a thousandth of a millimeter. For sure. I, I would not be at all surprised if it's accurate to, within a thousandth of a millimeter and that's all we need. Right. We can get the job done.

[00:20:30] Yeah, that's why there was so much more accurate than just like using a hole or something like that. Now, why do I say that I would like to see fiducials on the individual PCBs themselves. Well, because as Forrest Gump says it happens, like stuff happens in the factory. So yeah, we added them to the rails. I can't tell you how many times I've had some kind of conveyor malfunction. Just completely destroyed the panel.

[00:21:02] Now the boards themselves within the panel are fine because we deliberately put weak points in the panel so that we can separate these boards before we ship them. And so that's what breaks. It's typically not the boards that break it's the panel that breaks. Well, now the panel is broken now, how do I align?

[00:21:18] Okay. So I I've got two individual PCBs now, how do I still build these so that I can get my customer what they need, but now I don't have any fiducials. That's where having fiducials on the boards themselves becomes really handy because then it's like, okay, no problem. We'll just take all this excess material on we'll.

[00:21:37] We'll reprogram our pick and place machine. So it can handle just this one PCB. And, and if we have fids on the board, it's just, life is easy. Life is good. The other thing is when you're programming your machines, you have to teach the machine, okay, here's the overall panel size, here's the fiducials on the panel.

[00:21:57] But then here is where the PCBs are within the panel as they relate to the fiducials. Everything gets programmed off these fiducials. So when we do that, we make mistakes, right? We type a six instead of a five or, or we copy and paste the wrong, or, something, something happens. We, we, we get something wrong.

[00:22:18] If there are fiducials on the individual PCBs, then right at the machine quick and easy, we can make that correction. We can go. Bob programmed, there's no bobs at our company. So I'm pick on the non-existent person, that our company, Bob program, the pickup place, machine wrong.

[00:22:32] But then Bobby, who's running the machine. He can easily correct it and he doesn't have to bug the engineer. He can just, oh, here's the fiducials, boom, I'm on, I'm off and running. So it's just, there's just a lot of reasons for it. It makes life easy. And even sometimes, let me kind of get into another subject and then I'll change my mind about what I was about to say, but let's talk about if you're a designer and you're listening to this and you've gotten the gospel, right. You've heard the good word from Chris. I'm going to use fiducials on my designs. How, how am I going to use them now?

[00:23:07] We have a great article on our website, went into somebody's dot com. And there's there's a section of our website called best practices. So if you go to, if you go to more and then you go to best practices, you'll see this section called know before you order. And you'll see use fiducials and we'll include a link to that in the show notes.

[00:23:27] We like to see that copper dot be one millimeter around, not a ring, right? Just a dot don't, don't, don't be getting fancy with the rings.

[00:23:37] I've seen people try to do that before, don't, don't get crazy. Just give us a nice little one millimeter round dot and pull the mask away from that dot. So that the diameter of the mask keep away is two millimeters. In other words, the ring of no mask around that one millimeter dot has effectively a half millimeter or would it be, yeah, it would be a half millimeter ring around it.

[00:24:03] So sometimes called an annular ring. But we typically talk about annular rings when it comes to copper, but this is like an annular ring of no mask.

[00:24:11] Anyway, one millimeter to a millimeter. So you have, I'm glad you asked or you have a what's great is Melissa, you're not reading over the notes, but like you just, that's a great question.

[00:24:22] Like this is probably something that somebody is asking. I'm not just saying, I'm glad you asked because you're reading the notes. You're not like you're coming up with this on your own. It's great. It's because vision systems are not so great at reflective light, near a fiduciary. So I'm looking for a nice bright piece of copper on a board, one millimeter piece of copper.

[00:24:44] And then if I have all this reflection from a glossy soldermask nearby, I'm never going to see it, especially if you use white or yellow, right. Cause if you like, oh, I like white on my board. And then you put that mask right up against. I'm never going to see it. Never going to see that

[00:24:58] So it's just going to reflect all this light. We're never going to see it, but by pulling that mask away, you get the really dark brown sort of mat te flat light reflecting into the camera. In other words, for all intents and purposes, no light, it almost appears black to a downward looking camera.

[00:25:17] And yeah, you it's makes it super easy to identify those fiducials. And here's what I did. I put it right in my library. I created one. That way there, I can just drop them in. I don't have to create them new every single time. It's just a, in my library, physical feature called one millimeter round fiducial.

[00:25:33] And I just use them in all my designs. So don't, don't get cute. Don't be using squares. Don't be using, all kinds of symbols or something. Apparently back in the day, like it was popular to use like a number symbol or pound sign, hashtag sign, whatever you want to call it.

[00:25:49] That was a popular fiducial back in the day. There was also these things called butterflies, which were these, like they, they, the intent behind them was to make it something so bizarre looking that it could never be confused with something else. Because if you say you have a downward looking camera that can see, 30 millimeters of the board.

[00:26:09] And you put a round little fiducial in one spot, but then you have a BGA with a round little pad nearby. Well guess what? And if it's one millimeter, well guess what the vision system might lock on to your BGA pad rather than your fiducial pad. I think that's why people tried to get cute with using these crazy appearances for their fiducials.

[00:26:34] Don't do that. Please. Don't do that. You're just going to make life difficult for everybody. Just use a nice one millimeter round diameter and we will be happy. Yeah, cause I've seen some advice on the internet where people are like, or you could use this symbol. You could use that.

[00:26:47] So, no, just please. Don't just don't it's just going to make things difficult. When you place them on your board, put them as far apart from each other, as you reasonably can. It, it doesn't really matter. Like as long as they're, roughly near the edges of your board, it really isn't that critical.

[00:27:05] They don't have to be on the same X axis or a Y. None of that matters. None of it matters. Get them on your board somewhere, kinda near the edges, kind of near the corners, if you can, but keep them within about three millimeters of the edge. Because if they're right on the edge, then we might end up covering them with our clamps.

[00:27:23] If we didn't add rails for some reason. a properly designed board would not need rails. If you can make it work, we have some customers that we have I I'll give him a shout out. There's a, there's an open source sprinkler product is, I think he calls it open sprinkler.

[00:27:39] Is it open sprinkler? Yeah, I'm pretty sure it's called open sprinkler and he's a local guy. It's kind of like a side business. He's otherwise a university professor at UMass in Amherst, Massachusetts, but he he designed his boards in such a way that the panel it's a two-by-two panel. So four boards in the panel needs no rails.

[00:28:01] It's got the fiducials, it's got the edge clearances, everything, so we can run them just as is. And when we break them apart, there's zero waste, nothing to recycle. It's awesome. It's super, super cool.

[00:28:11] Melissa: Yeah. You talked about that three episodes ago, I think. Yeah.

[00:28:15] Chris: gosh. Thank you Melissa, for keeping one of us on track, but it's super cool how he's able to do that.

[00:28:22] So there's no waste. But he made sure to keep his fiducials within, I mean, I think he's got them like 10 millimeters in from the edge, something like that. there's no risk of the clamps of the machine covering those fiducials. And we can see them just fine.

[00:28:33] So make them one millimeter, keep them within three millimeters of your edge, keep them roughly near the corners. The other thing you can do, you can add extra fiducials, near critical components. So if you have like, we have a customer with a really expensive, I mean like, like each one is $6,000 FPGA, just, just the, just the FPGA on the board.

[00:28:57] Okay. Is $6,000. Not nothing else. You like, just that one part it's insane. It's some kind of like super high speed wireless communication thing. I don't know what it does. It's it's it's crazy scientific stuff, but anyway, They have fiducials on the corners of that BGA, because you don't want to screw that up.

[00:29:20] Right? Like you, you want that thing placed perfectly. And so we can actually teach our machines that for this component, for these placements, don't use the global fiducials on our rails. Use these regional fiducials right here, these ones, right by this BGA reshoot the fids just before you place this BGA.

[00:29:42] So it places, it like perfectly, there's no issue with stretch or shrink it's going to get done perfectly. It's also kind of handy for a lot of times these expensive devices will have a lot of adjacent support resistors and capacitors and stuff around them.

[00:29:59] And we can assign that whole region to use those fiducials. So if you have a lot of like, 0201s or god help you 01005s we can use we can use those regional fiducials for those really small parts too, so that, that can further help yields and, first pass yields and, just, it can, it can make life a lot easier for us.

[00:30:19] Melissa: So if customers add fiducials, you're also having fiducials on the rails.

[00:30:26] Chris: Yeah. Right.

[00:30:27] Melissa: You would maybe use both?

[00:30:29] Chris: Yeah, potentially. So there's kind of like three classes of, so you have your global fiducials, which are what we're going to add to the rails. have your local fiducials, which are for the individual PCBs. And then you have your regional fiducials, which are used for regions of the board, small sections of the board.

[00:30:46] So it's, it's sorta like a city state nation kind of, if you think of it that way. We will use them very likely because when we position the individual PCB within the panel, if you have fiducials on there, we're going to use those fiducials to position the PCB within the panel.

[00:31:06] Because then if we use those and they become our PCB alignment marks, then if we do break the panel well it's already taught, or if we did mess up how it's positioned in the board well, at least we know exactly what to look for. So we're definitely, if you give us fiducials, they will absolutely be used. There's no question about it. So please, if you put them on the board, know that you're not wasting your time.

[00:31:31] That being said they're not absolutely critical. Right? So we have a customer who makes a really, really tiny board.

[00:31:39] I believe I've mentioned it before. They're used for bird tracking. I think those are like 10 millimeter by 15 millimeters. Something like that. They're crazy. Tiny. Well guess what? No fids on his board. That's okay. That's okay. We're good.

[00:31:54] We're reasonable. Yeah. We don't need them.

[00:31:56] And like I said, most designs we get don't have them anyway. So like we're used to it at this point. But it's one of those things that it's just, the world would be a better place if people put more fiducials and their designs,

[00:32:11] Melissa: an insurance policy, I guess,

[00:32:13] Chris: like an insurance policy. It's like, it's like a free insurance policy.

[00:32:18] Right. It adds zero cost to anything to include them on there. Well, all right. I mean, if somebody's going to get pedantic and they're like, well, my time, time is money it takes me five minutes to add them to it. Yes. Yes. It's going to cost you five minutes to add them to your design, you're going to be saving us a lot of time. Now. All of that being said, there is the possibility that fiducials are going to become a thing of the past.

[00:32:46] Melissa: Okay.

[00:32:49] Chris: We go to trade shows and stuff like that, and look at machines and what's the latest and greatest. The way that fiducials so to speak are being used now they're not even, aligning a board within a machine. The newest vision software is so superior to the old vision software.

[00:33:05] It's hard to even illustrate just how much better. It's like going from, a two wheeled scooter to like a Tesla, like as far as how advanced vision has come from, 30, 40 years ago when fiducials first started getting used in vision systems. Because now what they do is they just basically take a picture of the board and then go, okay, I'm going to look for that region every single time.

[00:33:29] Just some kind of like a pattern matching view of the board. We actually have one machine in our building that that's how it does it now. It doesn't even use fiducials at all. It literally just takes like a 25 millimeter square picture of the board, and then it just looks for that same pattern on the next board.

[00:33:45] And does all of its alignments with like thousands of points of interest. It's yeah, it's super cool. So I think probably 10 years from now, most machines will come with this technology and fiducials will become less important than they used to be. But that doesn't mean you can, you can stop using them, but you know, people will say we will still have legacy machines in our building that use them.

[00:34:09] Like we're probably going to be buying equipment this year that will not have that technology. And we're probably going to have that equipment for 10, 15, maybe 20 years. So, by all means, please continue to put fiducials on your. And you can, you can get cute with them, that people have done creative things with them.

[00:34:26] We have one customer who used it was like project sunflower. And so all of their boards, they had like a dozen different circuit boards that went into this product and it was project sunflower.

[00:34:37] And so on all of their boards, they had a little silkscreen of a sunflower, which was cute. We love to see that kind of stuff. Yeah. If you put artistic things in your boards, we see them, we like them we'll even nickname your boards based on them. We had one customer put like a goofy looking monkey on their board, so we call him the monkey boards.

[00:34:54] Anyway, so, there was a sunflower and guess what he used for the center of the sunflower fiducial,

[00:35:00] Melissa: Ah,

[00:35:02] Chris: it was super cool. And then we've had, we've had other people that had like a little drawing of a Cyclops. And so his eyeball was a fiducial, which is kind of

[00:35:11] Melissa: Oh, that's cute.

[00:35:11] Chris: Yeah. It was cute. It really

[00:35:13] Melissa: It kind of makes everyone's day a little bit.

[00:35:15] Chris: it does. Oh, it's so does like, when we see a neat little things drawn on boards, we love it. Truly. We do it. It just brings a smile to everybody's face. So yeah, like artwork it up, man. Like don't, don't hold back. We see it. Oh, you know what else somebody did one time. They they had a BGA.

[00:35:34] Now, if you're not familiar with these listeners there there's like when you put Ram like the Ram chips themselves. So if you buy Ram for your PC or laptop or whatever really what it is, you're addressing that, that the chips on the board. Yes, you plug a board into your computer, but what your computer is accessing is those chips.

[00:35:55] So those chips will solder on the boards, especially like single board computers and stuff like that. And then you'll have four rows, typically four rows of solder balls on them. And it's really two rows with a space between. So, I dunno if you can picture that, but you got, like two rows of, of all these solder balls and then there's a gap between those two rows.

[00:36:17] Anyway they had a URL in there that if you bought their, yeah. If you bought their product and it was kind of like a Hackster project, somebody who's a hacker and messes around and likes to tinker and recreate things that, that was kind of what the product was. So it's not out of the realm of possibility that somebody might want to desolder this BGA and put on their own if they're really, so they had a URL on there.

[00:36:41] Yes. It was the coolest Easter egg ever. And of course, as a manufacturer, we get to see these silkscreen markings. So we immediately went to the site and like, it took you to a, it was a it was a riddle and if you, responded, they had instructions on what to do. I think you had to email a certain email address or something like that.

[00:37:00] And if you responded with a correct answer to the riddle, you got some kind of a prize, which was kind of neat, but yeah, I couldn't figure out the riddle. I wasn't that smart. Nobody else could either.

[00:37:11] But I thought that was kind of cool. Yeah. Put little Easter eggs on your boards. We love them.

[00:37:14] Melissa: If you have any fun financials on your board, tweet them at us. We'd love to see

[00:37:19] Chris: That'd be cool. Yeah, it would be, it would be neat to see them. And here's one, if you are the proud owner of a design with fiducials on them, just take a picture of that and just be like, we got to start a hashtag for this. We got to like fiducials, FTW fiducials for the win. # fiducialsFTW

[00:37:38] Let's see, we'll get three. I would love to see if I could get three people, take pictures of their boards, of fiducials on them or screenshots of their boards with fiducials on them and tweet at usus fiducials. Hashtag fiducials FTW you would make my day

[00:37:55] Melissa: Definitely will not be a trending hashtag.

[00:38:01] Chris: We'll be right up there with a celebrity of the day.

[00:38:05] All right. That's fiducials. Please use them one millimeter rounds, two millimeter mask, keep aways, put two or three of them on your board. Put them near critical components.

[00:38:17] Or don't either way now, you know what they are.

[00:38:23] All right. All right. Is it time for my favorite part of the show?

[00:38:25] Melissa: I think it is

[00:38:27] Chris: Oh boy. Pet peeve of the week. I'm excited. We should have a little jingle, Melissa just whispering.

[00:38:38] Melissa: the week. We should just do it all in whispers. Make it like an ASMR section.

[00:38:44] Chris: oh God,

[00:38:44] Melissa: I'm just kidding. No. I actually, that, that is a pet peeve for another week is I hate whispering so,

[00:38:54] Chris: Well, okay. So did you watch Loki? Did you watch Loki on Disney plus?

[00:38:58] Melissa: no, I didn't no.

[00:39:00] Chris: Absolutely. Fantastic. I cannot recommend it highly enough. The art design, the music, the acting, the story was super goofy and fun and weird. Just everything about it was so good. I loved every moment of it. My wife did too.

[00:39:16] My wife's not into, and I'm generally not super into superhero stuff. Like I love star wars, but Marvel, like, I don't know it. Like I enjoy it. It's a fun flick. Like all the movies were pretty good. This was, I, I loved Loki so much. I can't recommend it highly enough. But Owen Wilson is is one of the stars of the show and his character.

[00:39:38] Like he, when he gets really emphatic, when it gets really emphatic, he starts a whisper. And that's how he's really getting his point across and like where my wife and I are trying to watch, watch the show. And we have, we have a hot tub and we're trying to watch a show outside and like with the jets and everything and the outside noise.

[00:39:54] And we're like, oh, and please stop whispering. I can't hear you. So yeah. I'm with you there. Whispering. No good speak up. I can't hear ya.

[00:40:10] It was a pet peeve for you.

[00:40:10] Melissa: anyways, today's pet peeve, or at least my pet peeve is not about whispering. It is a poorly thought out packaging for shipping. And of course I have a, I have a

[00:40:22] Chris: Oh, you got to expand on this.

[00:40:23] Yeah, you

[00:40:23] Melissa: I mean, I have a specific incident that happened and I'm sure lots of people have gotten packages where you're just like, it just got thrown into a box. My mom ordered me these I forget the name of them, but like really good quality drinking glasses. And she decided it was cheaper to get a big set. So it was different sizes. it came in this gigantic box, probably like at least a yard wide,

[00:40:53] Chris: Oh my goodness.

[00:40:54] Melissa: it was, it was huge. There were four sets of glasses in there, three of them they were in, The box of glasses was in a cardboard box.

[00:41:04] and they were cocooned in bubble wrap. Great. The other one, the other one was Just the box. of glasses.

[00:41:16] Then they just threw it in there,

[00:41:18] Chris: Oh my gosh.

[00:41:22] Melissa: just threw it in there. Surprisingly on this first shipment, none of them were completely broken. They had some scratches and chips on them, so good quality glasses.

[00:41:32] And then there was no padding for the boxes in the box. So then we asked them to send another one, same exact thing.

[00:41:41] Chris: Ah.

[00:41:41] Melissa: This time one of the glasses Did completely shatter and there is

[00:41:44] Chris: Did you and then you gotta, yeah, you've got to clean that up. And now, did you get enough between the two shipments for

[00:41:52] Melissa: They ended up refunding it completely.

[00:41:53] Chris: Oh, well, so there you go. It's expensive to be cheap, right?

[00:41:58] Melissa: Yeah,

[00:41:58] Chris: That's the answer to that? I think the pet peeve of the week is turning into a packaging its own packaging podcast.

[00:42:05] Melissa: it is .packworld.com We're coming for ya.

[00:42:14] Chris: I love it. That's great.

[00:42:17] Melissa: Alright, but you have a more on topic pet peeve,

[00:42:21] Chris: yeah. And, and I want it, I'm mentioning it as a bit of a preview to to hold myself accountable, to talk about it in the future, because otherwise I'll forget.

[00:42:29] Melissa: oh, I will not forget.

[00:42:31] Chris: but Melissa will not forget. Thank goodness. I read an article today about machine obsolescence specifically as it relates to circuit board manufacturing.

[00:42:42] I think it was mostly about the fab process, but I can speak to the assembly process. I understand why machines go obsolete. I'm not surprised by it. I get the concept of it. I understand, all the fundamental details of, well, there's a chip inside this machine that goes obsolete.

[00:43:01] And then, we can't get, we can't even make circuit boards to support it anymore. So you have to buy this brand new machine and it's like, okay, well, all right, I get it right. I, I like, I, I'm not ignorant of the excuse of it. Like I get that. I also understand that at a certain point, an older machine doesn't have the features.

[00:43:20] Or the speed or the usability of a modern machine. And so at this certain point, it becomes more expensive to keep it and operate it than it does to get a new machine, which will make you more money and be faster and easier to operate and all that kind of good stuff. Like at a fundamental level, I understand the argument, but at a realistic level, I think it's all baloney, right?

[00:43:47] Because that steel is still steel and it's still good and it's still usable and it's still functional. Right? You could come up with a platform that you could continuously update. So you use this TI chip in your design and TI no longer makes the chip and they don't even make the family of chips anymore.

[00:44:06] Okay. So you've got to, you've got to redesign the machine because you can't even get those boards anymore. Well, Why are you redesigning a brand new machine rather than finding a way to repurpose those thousands of machines that you've already sold?

[00:44:24] Melissa: oh yeah, absolutely.

[00:44:26] Chris: Don't get me wrong, you can get into the sort of like the philosophical realm of capitalism and, where we exist in this world today.

[00:44:33] I don't want to get into that sort of subject, but I want to talk about, at some point I want to talk about machine selection. Why does a manufacturer, upgrade their equipment? What are they looking for? What are their needs? Why do they decide on their own to no longer use machines because we've done it.

[00:44:50] Right? So we've, we've obsoleted. I don't know if I want to use obsoleted, but we we've basically recycled two older pick and place machines now. What we did is we took off all the, all the critical components, the motors, the drivers, the the computer, the ver electrical verification, like all these, all these critical elements of, of the products we stripped off.

[00:45:14] And then we hired a company that reclaims steel and metal to come pick up the machine. And they were happy to get it because it was really valuable metal. Actually, I could be wrong, but I want to say a company across the street from us took one of our machines because it was so much good steel that they could use.

[00:45:33] Melissa: Oh, really cool.

[00:45:34] Chris: Yeah. That was kinda cool. Yeah, that was kinda cool. But anyway, but that's like, there was nothing wrong with the frame. The frame was still rock solid and it wasn't twisted or bowed or messed up or cracked, like it was still in great shape. And it's like, okay, well, why not find a way to like retrofit this old equipment and keep it going.

[00:45:53] It's a pet peeve of mine that that's not possible when I feel like it should be possible. Yeah. Yeah. I feel like that should be possible. But anyway, that'll be a fun subject for the future. I can go into more details. Like I can get into specifics cause that's another aspect of what I do is machine selection and technology and looking to the future and how are we going to continue to advance and keep up with, keep up with the times, but also be able to offer greater capabilities to our customers and these sorts of things.

[00:46:20] So I think about machinery quite a bit and it's very expensive and, it's becomes a difficult decision to make when you're, you're about to spend a million dollars, like literally you're asking. To fork over a million dollars on the chance that it will make you $2 million eventually, right.

[00:46:39] That's effectively what you're trying to do. And so I think about these things a lot, and it's something that I've had on my mind for a long time. And then when I read that article today, it sparked this thought in me that that'd be a good pet peeve, but also a good, a good episode, I think, in the future or, or series of episodes.

[00:46:56] Cause I I'd like to talk about I, I haven't really mentioned it very much in the show. I might've dropped hints at it that we're actively shopping for a new pick and place equipment. And I think some of our suppliers listened to the show and I don't want to make them too nervous and get a bunch of phone calls from salespeople. We'll get into the weeds on that. And I hope, I hope listeners find it interesting anyway.

[00:47:19] Melissa: yeah. I wonder if there are any companies out there using that sort of, or exploring using that sort of model.

[00:47:26] Chris: I'd like to think that other industries are doing this. I know that Bridgeport, for example Bridgeport, if you're not familiar, they make, they made just an unbelievable number of machining machines.

[00:47:41] So many of these machines were sold during and around world war one or. It might've been world war one, but I know for sure, world war II, Vietnam, but then they got computerized.

[00:47:50] So like these machines were used for decades and they're still being used to this very day because they were retrofitted with linear scales and computers and motors that could do the same work, but now they were more automated, but it was the same machine. It was the same physical structure and these things were bolted on to keep them up with the times.

[00:48:11] I know just a few years ago we had hired a machinist to cut a bunch of panels for, we had all these aluminum panels and we asked them to cut all these holes and everything for the circuit board that got bolted on. And he used a Bridgeport from probably the 1960s and but it was modern.

[00:48:30] It was computer controlled and he, he, sent a signal over a network to tell it to run and. It's possible. And, and, and I I'd like to talk about the possibilities of that in our industry too, so,

[00:48:43] Melissa: That'd be really fun. yeah.

[00:48:45] Chris: Cool. All right. That's it, Melissa? I think we did it.

[00:48:50] Melissa: Think I think we did.

[00:48:53] Chris: Well, I was, I was excited to talk about this one. I'm sure some people this popped up in their feed and they're like, what really? We're going to talk about fiducials. I hope not. I hope you enjoyed it.

[00:49:03] Melissa: I think there'll be some people that absolutely loved it.

[00:49:05] Chris: I hope so.

[00:49:06] Melissa: That's who our listeners are.

[00:49:08] Chris: That's true. I keep getting feedback. I keep getting feedback. People reach out to me. They call me specifically and they're like, no, no, no, no, no.

[00:49:13] We love it. The weirder, the better we love it. So I hope, I hope you enjoy it. And yeah. Look in the show notes for the link to our article about what are fiducials and why are they useful? And you can get kind of more details as to and, and don't forget to tweet at us. We want to hit, we want to, we want to totally trend that hashtag fiducials FTW, but usually for the win you can tweet at us at CircuitHub or at w assembly.

[00:49:40] And of course you can always email us at contact at pick place, podcast.com.

[00:49:47] Melissa: Thanks for listening to the pick place podcast. If you like what you've heard, consider following us on your favorite podcast app. And please leave us a review on apple podcasts or wherever you get your podcasts from.

[00:49:58] Chris: Thanks so much everybody.

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