Inside a Huge PCB Factory - in China
Circuit, boards are in just about every piece of electronics, in our lives but. How are they made and, why the heck is it so yellow in here today, we're. Gonna find out. Printed. Circuit boards or PCBs, may look really complicated but they're actually pretty simple they're, a bunch of tiny copper wires sandwiched. In between multiple. Layers of fiberglass. Now the wires are, there to connect all of the various integrated, circuits and other electronic, components, in an organized, repeatable, way to make up an electronic circuit today. We're. Gonna see how they're manufactured, I'm, here at the JL CPCB Factory, in play Joe China which, is outside of Schengen and I'm, here with Lilly who's. A technical. Support representative, that talks to engineers, all day long who, sends you design files for, PCB is to have you manufacture, them and so you know everything, about this process and you can answer any question I might ask right. Not. Every question so, you brought someone with you. Great. To have you mr. leo and you can answer any question that Lilly doesn't know the answers yeah. Great. I'm. Really excited to see this process step by step but. First we, need to rewind, a couple hours and go back to your main headquarters in, Shenzhen to see the very first step. So. We're here at your headquarters yeah. And, this is where the first stage in the process happens, right where. The very first thing, when, a when a customer, sends in their file to have a board designs it, happens here this is our, engineering. Department. This. Is where they review the design files to make sure there are no problems yeah. Yeah he's checking where, this fire, is okay for example Reza Sayah is some layer list. Whether. There has a, folder, for the fire weather, yeah whether the shooting fire is there yeah so he's just making sure that the engineer who designed this the customer didn't. Design it in a way that you can't actually manufacture, yeah, so he makes the production file and then he sends that over the Internet to the factory yeah and then the next step happens at the factory yeah right yeah, okay let's go back to the factory and see the exit okay let's go so, this. They're, printing, the design on, to, clear. Film here, Wow. So. These, now we're, gonna go see where they take this film and they, use this they use light to project this image onto, a. Board that, has some photoresist, on it that, will then expose similar, to how you would expose. A photograph, now we've got the design we need to transfer, it onto a copper, circuit board blank but. First we've got to prepare that blank so let's go see where you guys do that oh. I. Have no idea it comes this big so, we have to cut it of course, okay. So this. Is. Your, fr4. Fiberglass, yeah you. Have two coppers, on the top, and the bottom vaminos, yeah. When we remove the copper, then say yellow, yellow, pause that's the so called epithelium. Right what is your fiberglass, so that's your fiberglass, in between and, then the copper. Is our knee sandwich already glued on the outside yeah yep got it and so this, is the. Circuit board before. Anything's, been printed on it this, is the raw raw. Material, yeah that's, really cool so the next step is you cut this down you take these big sheets and you cut it right yeah oh wow. Okay. This, is crazy, this is the original size for this material and. So you're picking this up here and then this is a cutter machine here. So. It starts out as one piece here and it's getting cut down the middle by a song so, what's going on here it looks like it's. Cutting. The edges. So. Maybe man is very smooth got it so. Next what are we gonna see review see how the in in a year it's made of pressed yeah cut it and so these are the wires that run in, the middle of the board where you can't see them yeah okay so we got to put on outfits. This. Is like a proper clean room so we really don't want to damage the the, boards that are being made by right now by like bringing in too much dirt and dust yeah.
Tell. Your boss thank you for, letting us come and see the inside I've never gotten to see this, area. Are. You ready yeah, so we'll go through here. So. These are the boards that we saw yeah, been cut in the other room yeah so they have to load. Back. The joy-filled. On, homicide, and. Sigh okay so when they expose, this material, to light it gets hard and it sticks to the board and, in places where there's no life in where there's black. In the image. This. Disk, will wash off and that. Will protect the copper from. Being, dissolved. By, the alkaline, bath we're gonna see later in the process so now, that the film is on the. Blanks. We. Need to actually apply, the design right, so. She's got books like two films, there sandwich. Together. At. The same time. Oh I, see, and it's doing it behind behind there or, gets it oh I, see there's a light in the corner oh and, you could you can see the design already. So. Why. Are all, the lights of yellow in there. Because. The view, is ligh sensitive. Yeah. So we don't need allies so strong if, it if the lie is strong, then maybe the field will, be exposed, right because, the light is sensitive to blue light or that the film is sensitive to blue light and that, will make it hard and so, the yellow light doesn't affect it I understand. That. This stack of boards is ready to be developed, and they're, gonna feed it through the wall and, so. Then, that will go into the rest of the developing process yeah. Okay, so but I bet we have to take off the bunny suits and go outside to go see that okay. All right let's go all, right here we go this is like an activated, charcoal mask. This, is where we just were and. And, now, the boards are coming through that have been exposed to the light and now, they're going through the developing, process, everywhere. That there's copper, the. Copper is going to get removed so developing, over here where we wash off the excess. Photoresist. And then here is the actual etching process, and this, is like an alkaline, solution that. Removes. The copper chemically, a whole bunch of chemicals, going on here we totally can't see inside, but. When. We come out to this side. Have. A look now, where, there was copper back there there's. The yellow which. Is the fr4, right, that's. The fiberglass and. It's in that in the middle, got. It and so. Underneath this blue is, still the copper that we want to keep so, then it comes around over here then, it's yeah it says here film stripping, so that's removing, the blue now on top of the copper okay so it's a bunch of washing, and removing, oh there. We go the, blue has been removed and it just leaves the copper underneath that it was protecting, and now, we have our designing copper, so that this, is starting to look like a circuit board and.
Then. Drying, it looks like and. Then it's putting a protective, layer in between so they don't scratch each other each one of these now is a finished, inner layer is that right it's. Done, so. Next. You. Need to inspect, the, etching on the inner layer and make sure that everything is okay right this, is, very cool this is an automatic, robotic, inspection. Right you. Guys call this Aoi. Optical. Inspection, and. Then it's scanning it with like a light and a camera. It's. So, fast and so this is comparing, what the board looks like with. What, the design file is supposed to look like and so then when this is done then. This goes to be sandwiched with the with the copper on either side of it let's. Go see that this, is the clip, back we, we, call it CP we. Can see the light here, is its domain the surface may laugh we. Call it round, Tobin that put the PV to it to. Increase. The. Fighting. Boys. Binding, force let me see if I can really explain that a little bit. This. Machine, Witzel. Takes. The smooth surface, and makes, it a little bit more rough yeah so that when you put the prepreg, on there which is sort of like an epoxy glue, that. It can get, into the surface and find more and more strong. So, this is like a like, a sheet of fiberglass but, it's really thin it's flexible, and it, has an epoxy already, already. Impregnated into, it already soaked into the fabric I see and then you're gonna put this here and then we're gonna put another piece of copper and and. The sandwich oh. Wow. This. Is a huge, machine so. This copper, foil is the outside. There's. Only one worker for this whole area, could. Be one person so. That's the bottom topper now the. Prepreg, and the middle and the top. Yep and then, peepee and then another layer of copper and, then one of these metal sheets, one. Big sandwich. This. Is the room we were just in right okay. Oh and, he's about to bring some out right now oh. Oh. These. Are the board's that we just saw being stacked together I'm glad. He told me I would have gotten to run over well, let's go chase that robot cuz that's got the other stack right so, there goes the stack that that, the first stack that we made in, here is the press this is where they come next definitely, no safety rails here you just have to be standing out of the way oh. This. Is where he controls, they, do increase, the temperature. Sometime. Later. And then increase it to 200, I see, so this is the steps it goes through the basic deal is you load this in the furnace. Pressure, and heat up to 200 degrees and. You. Know 27, kgs, of pressure. That. Will melt, the epoxy, in the prepreg and stick. It to both sides and then, and then it comes out here and we can see the finish the finish yeah. Lamination, okay let's go take a look so this is what, it looks like when it's fully laminated, this is the copper wow, that is super thin, this. Is like yeah paper thickness maybe even thinner so inside, that is the inside layer that we etched and now, it's got two pieces of copper foil on the outside now. Now. It's four layer now we need to drill some holes all. The holes yeah, this, is the drill room oh my. God you guys have so many drilling machines underneath. All of this all. Of this stuff is the, circuit boards that we just saw right. And. They're in a standard why they're stacks are like three and, these are all the drill bits here yeah these machines can automatically, change what drill bit they're using yeah they they can drill all different size holes depending, on the design and, they. Just come out here and they they put. The one that they've been using and they pick up a new one and they go back in the kitchen oh it's here it's doing it it's switching heads okay switching bits so, these boards are fully drilled and Louch these.
These Are little, tiny deals there are two kinds of bowls three. Kinds of poles in, a circuit board there RVs, there's. Through-hole, and then, there's just a mechanical, hole right. Yeah, like for putting screws so. So. Those are obvious those are promoting screws and bolts and things through those are these big holes around the outside then, through holes are for putting the, legs of components, through like resistors, capacitors. Right, yeah, and then vias these, vias, are the magic that makes circuit boards work makes multi-layer. Boards work when you've got wires on the top of your board and wires on the bottom of the board the, vias are what connect those two sets of wires together so, you drill a really tiny hole and then, you have to send two late. Copper, in, that hole so that it connects the two yeah, I can't, believe how big this drill operation, is so how many heads is this this is one, two three four five six, heads yeah, so they're all doing the same thing the whole time and. They're all working on their own stacks, of boards which, all have to be perfectly, aligned to each other so next, we'll go see plating, where. Where we actually put copper back in the holes okay. So, this is a copper, plating, process. Where. Every pole, has copper plated, on the inside this. Is a chemical process that I don't fully, understand, if you're a chemist and you, understand this process better than I do leave a comment in the comments and I'll make, sure it gets visible, I'm not sure I fully understand, what all is going on here, but. The. Important takeaway is. That we're putting copper in the holes. So, we talked to mr. Vieau and. It turns out we only saw half the process. This. Is the other half before we it was doing copper plating, but it was just putting a really thin layer. Right. Not thick enough for soldering and for oh you know electricity to flow through. Right. So this is an electroplating, line, but but in. Order to electroplate, you actually need to be able to run electrical current through it and the, first step gave us enough copper to be able to do this and then this will grow. The thickness of the copper in those holes. So. Now we're back in, the dark room. And this time we're putting the traces, on the outside of the board right. Okay so this process is exactly, the same as what we saw for the inside layers so. Let's go ahead and just skip ahead to the next step. So. This is a why again we saw Aoi for. The inner layer. Are. These, machines on any different than the ones downstairs. Same. Exact thing so, this. Is where. You apply the solder mask which, gives circuit boards that unique, green color yeah right so far they've been yellow turning.
Them Green you can do other colors too but green is what, everybody thinks of when they think of soluble. Yeah. It's. Liquid solder mask and. Your, squeegee aiming it on with these sweeties it. Goes back and forth so we're putting it everywhere here, and then in the next step we're gonna remove some of it yeah on, this machine, we're, only soldering, or or only putting solder mask on one side of the board right yeah but we want it on both sides okay. Right. Okay, so. Let's go down here oh I, see so you've got two machines that are exactly the same oh and, you've got you've, got a robot arm that, flips it over in the middle that is, super cool and then, next where do we go we. Have to make. Giant. So, you've got these big industrial dryers. Here, oh I, see, okay so all the board's are vertically, stacked up here yeah, it is, a jointer. That just makes the solder mask kind. Of tacky dry, so that it doesn't run off so. Next, we. Need to go see how we remove, the solder mask off the pads where we don't want it they, cover the, field, on. This, PCB the fil have the openings. For, the. That, means with. Me to remove, these. Films that printed out the same way to put the film as we saw for the traces yeah and, anywhere, there's black. Yes solder mask is gonna be ruined they put black where there are pads or, other things where we don't want Tata mask to, stick yeah, so he's taking boards that have, solder mask everywhere and he's putting the films on, both sides yeah so. I think this. Solder mask is UV. Curable, UV. Light and, so. When you expose this solder mask to UV light it. Makes it hard and. So. What that's what this bright, purple light is over here is a. UV light we're, just hearing the. Solder mask everywhere. That the the film, is clear and, anywhere it's black it's, it's staying uncured, and then. We can wash it off. That's. The washing line in there. This. Is the other side of the clean room where the boards were going into the wall. Come. Out in here and this looks just like the developing, line that, we saw on the in the etching process, right. So it's basically, just water, sprayers, that are moving back and forth and and spraying, off all the excess solder mask right that the solder mask that didn't get hardened by the light so we can see here, the, boards, are, have.
The Solder mask removed, from the pad so we can see the copper pads. That's. Awesome, now it's. Time to put some markings, on these boards this. Is. Your. Silkscreen, process and this, is just. What you would expect this, looks exactly like a t-shirt silkscreen. Yeah, it's a big frame and it's, got a piece of silk stretched in the middle and then. On there. Is the design, from. The design files of where, the. Engineer, has, drawn silkscreen, why do engineers, put a silkscreen on the board. Their. Logos. Maybe. Or. Special. Yeah. So they'll put text that says like what each component is. Alignment. Lines for, where where components, are should be on the board it's, purely for humans, right it has no electrical, purpose but, it's usually for humans to know what goes where how should it be aligned, logos. Part. Numbers things like that and in your life now, this is not the only way you do this you. Have a different machine so. This looks like a giant, inkjet. Printer like. What you would have at home, but. Maybe. With a UV, cured, looks. Like a UV cured. Inkjet. Printer why, do you use, the, old method at all why not do it all with this machine it's, only. The, quantity. It's twice more ah they, think that bitch won it's much. Lower, event, fashi time I understand. So, if they only have a few they, use the slower machine that. Doesn't require making silk screens but, if they're gonna make a lot then. It's worth making a silk screen and they can do it much faster so now we've got all the labels and the outlines, printed, on our board let's. Go see the next step the boards are coming out of the. Ovens that that, finishes the globe strand makes it hard and now. They're coming into surface treatment a service treatment on the copper that makes it easier to solder right. So it makes it perfectly flat and, and. Makes the solder stick better so, there's, a couple different options here, but this one is called hassle, hot. Air service, leveling right. Wow. So. The board is tipping down into the liquid solder. And. Then they pull it out and there's there's hot air blades, that blow. Off all the all the excess you, can tell it. Goes in copper, and it comes out silver. Okay. So. This, looks like the drill machines we saw before we're not drilling holes anymore right. On. One big panel. So. We have to cut out each PCB. According. To the shape the designer. Specified. Drew, these are basically cutting bits that are cutting around the, edges of each circuit board, so. What is this room. Okay. So this is related to what we just saw cutting. Out the profiles but it's a little different. Before. We, go. Our. Tennessee so each of these is a separate board right. But they receive it like this they'll, place all their components, on there in, their pick and place machine or, whatever and. Then, snap, it apart okay. So the V score here this machine makes. That makes that scoring cut so that it's easy to break it he's, getting a stack ready to go into the machine here oh. Wow. That's so fast. We. Have our finished boards we're done right no we have to test whether the. PCB. Is all okay. And. That's. The most important part right we, have to make sure that the things that should connect do connect and the things that shouldn't connect don't, connect so this is your, a testing room if. We, use flying, poke passing, this is one of my favorite machines in a PCB Factory they've, got little tiny. Needles. On the end of these arms, right and those, touch each of the pads on the, circuit board where, a component, is going to be soldered down. So. They're testing the, electrical. Connection, between, two, arbitrary pads, right. And the computer, knows. Where all of the pads should be because, it has the design and, it knows what should connect together and what shouldn't connect together and it, tests all of the combinations, of that one by one yeah, that's, amazing. Finally. Though. We. Have finished, circuit boards here, fully. Tested, wholly, manufactured. And ready to go to the customer yeah. So what's the last step. Packaging. And shipping so. This is a an, example ready, to ship it's got a label on it yeah ready, to go out to the customers once it's all packed up and ready to go it, gets shipped out to the customer so gets packing labels and and, on. Its way and. So how long we've, seen this whole process this is the very last step of shipping out to a customer how, long from, when the customer, submits their design until. It gets shipped out. When. It's, put into production. Is. It maybe four, hours four. Hours not, so, fast. Yeah so, in the u.s. sometimes. Weeks, is typical, or to, wait from the time that you submit your order to the time that it's ready to ship I know you have. Customers. In the US and Europe how long does it typically take for, shipping on top of that. DHL. Shipping three days so you're looking at you, know four days from the time you submit your file to the time you have your boards yeah four days that's pretty darn fast well.
I Think that about does it for this time I really. Enjoyed that I enjoyed seeing the full process I think, I had a couple interesting takeaways, from that I think. The biggest one was just how complex, this process is there, are so many steps and you have so many different boards, so many different designs flowing, through your Factory it's. Amazing, that you guys keep all of this straight that you keep track of whose orders or what and there. Are so many details you have to get right there's there's keeping things aligned, and keeping things clean I'm so, impressed I, hope. You guys enjoyed, this. To her as much as I did I wanted, to thank jlc PCD for sponsoring, this video and making it possible but more importantly I wanted to thank you guys for, giving me such deep. Access to your factory such complete access you, in particular mr. leo have been very accommodating and letting us go into all of the clean rooms and, see all of the different areas it, makes a big difference and Lily, and mr. Leo thank you so much for taking the time to show me around and the rest of your team I really. Appreciate it if, you guys want to learn more about jlc PCB and their capabilities, and, eventually. Order a board. Design and have them manufacture, it you can find a link to their website in the description below, I hope you guys enjoyed this factory tour I want to do a lot more of them this year so, leave, a comment below with what factories, you'd like me to go see and I'll see what I can do but. For now i'm scottie from strange parts if, you enjoyed this video hit that subscribe button down below and hit. That Bell icon next to it if you want to be notified about every video I upload but. For now stay, tuned for more adventures I'll see you next time.