How Is A PCB Manufactured

Have you ever wondered how A PCB is manufactured? one of these standard double-sided PCBs that you take for granted these days. in this case, this is a pcb panel which contains ten individual pcbs. but if you wondered how they actually manufacturer these at the factory?  what equipments use?  what processes are used in? things like that

image

Now, you can actually make your own pcbs at home, it's not that hard but they are not going to be anything like the quality, you can get from a professional pcb manufacturer, they are so cheap these days, it's almost pointless making your own ones at home unless you absolutely need them in like one hour.

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  • you're not going to get the plated through holes
  • you're not going to get the solder mask
  • not going to get the silkscreen component overlay
  • you are not going to get the nice gold pads
  • everything else you are not going to get the v-scoring the routing

everything fantastic that you take for granted on one of these pcbs that you can get for five dollars at one of these prototyping services. if you wait long enough but they are so cheap these days there is actually a lot of steps which goes into manfuacturing a professional quality pcbs like this one, so we will take a look at it.

PCB Manufacturing Show

Thanks to richard brady, from pcb won.net for this video of manufacturing, in this case an old version of my micro current, the video you are going to see is that quite a few years old, i've had it in my archives for a long time, i've only just got around to editing this footage.

film

now pcbs manufacturer have actually upgraded their factory and their processes and technology ,since this video was taken but this video will be a typical example of how sort of you know your traditional pcb manufacturing process works.

before you watch this video it's important to realize that this pcb only have one plated through-hole on , all these other holes here are not plated through and that's important as you will see in this video in this case it's actually a good example this panel, because it combines the routing paths like this with V-scoring which is on edges like that, you can see i done a video on actually our pcb design for manufacturer and it's one of my popular videos it's almost approaching half a million in views now , so click here if you want to have a look at that one i highly recommend it.

anyway, let's get on with the show now!

gerber files and nc drill

the first step here is to actually process the gerber and drill files that you give them, there is various ways that they don this depending on what software they use what machines they have.

everything else so i don't have any video on that, so we will just leave that and we will go straight to generating the film now.  what you see here is the film printing machine i am not sure what model this puppy is.  and this is the film for all the photo image processes.  so the copper layers top and bottom, so you have a  different film there you will have top and bottom silkscreen as well.

if you've got a photo image above silk screen you may not the manufacturer may actually use an inkjet type silkscreen.

silkscreen is an old terminology, when they actually used to use a silk screening process i don't think anyone use that anymore, inkjets are very proper popular now so it can direct print onto pcbs so we are actually going to see a photo image silkscreen or component overlay here today, it's a much better process than the inkjet one you can get much higher resolution, but it's an additional cost and additional steps involved in here.

then of course, we're going to have films for the top and bottom solder mask as well, so we're going to end us with that six different films for this one double sided pcb .

but having said that circuit labs don't use this technique anymore and this is a somewhat older one but lots of places still doesn't generate films don't get me wrong they've got a newer laser direct imaging machine, where they use a laser to scan directly and expose directly both like the copper mask , all these photo image all directly done and with the laser and you can do a way of the film, it's great

so just for completeness i will show you this video i find on youtube from the alba pcb group so i credit to them and this is a nouveau go 800 direct imaging machine, so they take a blank double sided pcb that is already got the photo image of all surface , they clean it with an anti-static out roller.

so there is no charge on there and then they put it in the machine and line it all up and boom it closes. then it takes your twenty thirty ten to thirty seconds there you go to actually use the laser to scan over it and actually image the things so this does away with the film,

here they are just doing the other side so this does away with your traditional film process putting the film over the top lining it up , then exposing it to ultraviolet light, in this case, exposing it to a presumably an ultraviolet laser doing basically the same thing but direct with laser so you don't have to much around with film and the uv exposure  coating that they've got on the pcb is called dry film so this would be like it typically called a dry film process.

they will show you the stats here on the resolution they can get it's pretty amazing

panel file

we are getting away ahead of ourselves, we don't actually expose the board yet we actually drill the plated through holes. so this is a excellent brand machine one of your traditional machines CNC machines to drill these holes in fact the excelon file format , a lot of pcb manufacturers will specify that it just means the drill file whatever before brand cnc machine they use and you will notice here , it's picking up the tool that picks up the different size drill bits you will notice  that there is multiple panels in there, i am not sure how many 10 or something like that stacked in and i know, it take them down like that, and they drill them all at one.

it's just more efficient to drill multple boards all at once and they would have that state those down as well

in the reason why you would dance steak or are pin them all together is so that those boards don't slip in there and i get misaligned when they've being drilled like that and we will see that shortly, here we go.

we will see that they 're taking them off and then they're removing it and the we can see them actually punching out the pins in this thing and then of course they are just going to do a little bit of manual deburring of the holls there

NO WORRIES

and then they are going to put it into electrolysis bath where they do the plated holes so you will notice that this panel doesn't have many holes in that's because my microcurrent just happens to not have any plated through holes on