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How Printed Circuit Boards Are Made 88

An anonymous reader writes "Ever wanted to see how printed circuit boards are made en masse at a professional production house? Well, here you go. The folks over at Base2 Electronics recently got to tour Advanced Circuits, a PCB production house. They took some rather incredible pictures and explained the process along the way."
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How Printed Circuit Boards Are Made

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  • I believe they had an episode containing this a few years back, still entertaining though.
    • by xclr8r ( 658786 )
      This reminds me of those sections of Mr Roger's Neighborhood where they would expose on something that you took for granted and show you how it was manufactured.
  • Ha. We've been an Advanced Circuit customer for years. Stand-up bunch of people.
    • Any suggestions for circuit design companies? low cost, one off devices primarily for development / prototyping?
      (nothing complex; primarily sensing circuits be it pH, ion selective probes, etc)

      Not specifically looking for something to be made right now, but in the future it is a possibility.

      • by Anonymous Coward

        I've used PCB Fab Express [] in the past, their good for 2 - 6 layers nothing with small traces or pitch. Keep to their design rules and it will go well.

        If you ever go further than that, for more complexity or quantity talk with Ben Gonzalez [], he's best PCB guy I've ever worked with. (No I am not him).

      • It's been a few years since I've had anything made, but at the time Olimex [] in Bulgaria seemed to be the cheapest for one-off stuff.
        Places in North America wanted too much cash, and the Chinese outfits weren't worthwhile unless you ordered a bunch of stuff.

        The one exception was.... advanced had a deal for students, not sure if that still exists. (I think it was $33 for a small double sided - normally you need to buy four, but a student could get a single). I'm not a student so it doesn't apply anyway.

      • it's my dad's shop so I'm biased but give it a try!
        • by Anonymous Coward

          We used Sunstone for a custom PCB board in my Sr Design Class at the University of Toledo (a few semesters back). Whats more, I believe they provided the professor with ~$1000/semester to students who need a custom board made.
          Props to your dad, for donating some time/energy/money into helping college students with their projects. If I ever need a custom board made I'll go through him just for that reason.

      • by Fishead ( 658061 )

        Any suggestions for circuit design companies? low cost, one off devices primarily for development / prototyping?
        (nothing complex; primarily sensing circuits be it pH, ion selective probes, etc)

        Not specifically looking for something to be made right now, but in the future it is a possibility.

        Bring the design to my house with a case of beer and a stack of pizza!!!

        I use Eagle Cad (Horrible to learn, yet powerful), print onto glossy magazine paper, iron onto Cu clad (I have a stack of 3"x4"), etch with Ferric Chloride, drill with my dremel, then solder.

        We should have your prototype ready before we run out of beer and pizza.

      • Re: (Score:3, Interesting)

        Welp, speaking of the devil, advance circuits has great rates for all of their capabilities. For 2 layers without soldermask you can get a run for under $50. If that's still too much but you can wait a month or so, Sparkfun runs something called If you only want one board, they will collect other user's boards into one big file and do a run for dirt cheap.
      • Fabrication, or the actual design? For fab, and if you have the time, Batch PCB [] does boards for $2.50 per square inch plus a $10 set-up fee. I did a couple of small simple boards through them earlier this year. Once I passed the automated design rule checks (easy for simple boards), 17-21 days from submission to finished boards in my hands. Production is in China, but the quality was more than good enough for my needs. In both cases, I ordered two copies and received four. Apparently there is some duplication as things are panelized and produced, and they send along the extra copies rather than discarding them. No testing, but all of the boards I received worked.

        They use Gold Phoenix [] for the actual production. If you need enough copies to fill, or even mostly fill, 100 or 150 square inches, it's cheaper to deal with Gold Phoenix directly. Other people have suggested DorkbotPDX []; their prices may end up cheaper, but it appears to take Dorkbot a long time to fill up a panel; BatchPCB seems to fill a panel every couple of days.
    • Heres to that. Their CAM review department would even find shorted traces for me back in grad school when I used to skip the design rule check. The best part is the free popcorn you get with every order.
  • Nice to have some low-level hardware stories once in a while. I used to be a PCB designer so I know it's not a simple process, esp. for the type of hardware people expect these days. It's a shame it's so specialized. (read: not too many jobs anymore in North America, all Far East)
  • by jimmyswimmy ( 749153 ) on Tuesday June 28, 2011 @06:06PM (#36604958)

    I've been to a few smaller PCB fabs a few years ago, before the days of 4PCB and PCBExpress and the like - mail order, nearly overnight, you fit it into their process flow shops. Anyway, this is back when a 4 layer board run was a $2k/2 week kind of deal rather than the $500 or so you can get now (or cheaper if you can wait). Those places were FILTHY and smelled like all kinds of hell. Nasty business. It's amazing how far these guys have come.

    The value is so much better now too. Ten years ago, to get an overnight board we used to mill out two layer boards using a piece of prepreg with copper on either side. A guy would machine off all the copper we didn't want, then drill holes where we needed vias to connect from one side or the other. Then I had to fill the vias with little pieces of wire and solder each side, then stuff the board, then test and debug it; over repeated rework cycles the board would start to peel apart. On top of that, if you get the board hot enough, the vias (wires) would fall out and that was pretty hard to figure out. It was gravity assisted current limit.

    Now, you finish your board design and ship it off to one of these guys. During the time you used to spend getting to square 1 with the milled board, you could order parts and then the board shows up from one of these guys like 4PCB here. A 2 day turn on a 4 layer board is no problem and just a few hundred bucks. The time I spent soldering vias into the milled board cost more than the real PCB I can get now. It's amazing. The way they get the price down is a combination of two things - first, you fit into their process flow, as I mentioned earlier. That means that they don't look at your board, they don't think about your board, they just cram it on a panel with some other guys' boards. If you want slots made in the board, you don't get 'em; if you want internal routs cut out of your board you don't get 'em. You get what their process says it does, and so does everyone else. This leads to the second way they get price down - volume. Lots of guys now order from a couple big shops, rather than these little (pretty dirty, as I mentioned) little mom-n-pop PCB houses. And we all order the same process.

    It's amazing to see how some of these basic market principals have worked in the past ten years, and it has made a huge change in the R&D industry. It's much easier to do a pilot run of a board, it's much easier and cheaper to make a limited run, and since you are risking less you can order more and try things out. Truly awesome for an electrical guy.

    • I luckily managed to completely miss the "bad old days" of crazy-expensive boards, though it's still not "cheap". So far I've managed to get by without the really quick turn times, but I've got a deadline coming up here that may change that.

      For most of my boards though the turn time isn't critical, and many of them are experimental anyway. I can pipeline the wait for PCBs with other stuff, and all is well. However, I end up using the DorkbotPDX group PCB [] order for most everything, because it's cheap and

    • by smellsofbikes ( 890263 ) on Tuesday June 28, 2011 @07:15PM (#36605492) Journal

      I design PCB's for a living, these days. Most board shops I work with have yearly tours/open houses: if you want to see an up-to-date shop see if they're throwing one. It's pretty cool to see. I'm mostly impressed by the electrical test machines: they look like a dozen mechatronic herons madly going after fish.

      When I can wait a bit, I use myropcb [] because if I'm ordering 200 boards the size of postage stamps they're less than a dollar a piece including soldermask and silkscreen on both sides, if I can wait 10 days. (It'd be a lot faster but they tend to go slowly through US customs.) If I'm willing to pay a bit more, I use Circuits West [], who will crank out up to 60 square inch boards for $31, and have had great quality.

      However, the really great thing about milled boards is the turn time -- if you have a mill. I regularly go from hastily drawn schematic to finished, working board in under two hours, if it's a simple design. We can do three revisions of a board in a day, and *then* send it out to get a green board, once we're sure we have something working, and have a tested design ready for large-scale production in three days. We *love* having a PCB plotter in-house. It takes some thinking and experience to lay out good boards for it, but it sure helps productivity.

      While I'm shilling companies that have saved me in crises, Vector Fabrication [] is not the cheapest place to get PCB's, but they'll produce a 30x30 cm 14 layer board with 3 ounce copper in two days.

      • SOB, do you still have my email? if so, flip me yours again.
        • I used to but don't anymore, it doesn't appear. I read your other post in this article and your company will be seeing an RFQ next time I have a big ugly piece of test hardware to get fabricated. Specific questions: do you do conductive fill vias? do you do laser (or whatever technology) blind microvias on the 0.008" size range? and how small a drilled via can you put through a 0.187" thick board? I'm jbump at front range internet.

      • by AmiMoJo ( 196126 )

        As a hobbyist I use Seeed Studio a lot. Very cheap for small boards and about a 1 month lead time from ordering to delivery.

        The biggest problem I have is a lack of good and unrestricted PCB layout software. I mainly use Cadsoft Eagle with a budget license, but there are some fairly severe limits on board size. I do arcade stuff and the JAMMA connectors are longer than the maximum board size my license covers, and the next one up is about $700. A bit high for a hobbyist.

        I tried gEDA and a few others but they

        • At work I use Altium, which is fairly easy to learn but has some weird bugs, draconian licensing, and breathtaking price, and Cadence, which is *not* easy to learn, has the most convoluted, cumbersome, and wretched new-parts-creation system I've ever seen, exostratospheric price, but the best PCB layout I've ever used. It's just dreamy. I also occasionally use OrCAD, which is quite reasonable if not outstanding on all fronts: schematic, layout, and parts creation.

          At home I use gEDA. Schematic works fine,

          • by AmiMoJo ( 196126 )

            I tried KiCad but it seems fairly klunky... It amazes me that we can't come up with a good UI for cad software yet. One of the biggest plus points for Eagle is how well integrated it is, especially the way you can update the schematic and instantly have that reflected on the board.

            • We *have* come up with good UI's: you just pay through the nose for them.

              My favorite nice intertool integration feature of Cadence is that you can open schematic in one window on one monitor, layout on the other monitor, put layout in 'move part' mode, then click on a part in schematic and mouse over to layout and that part is stuck to the cursor, ready to be placed. When you're doing huge boards with repetitive layouts that's an unbelievable time-saver. On Altium, my favorite intertool integration featur

  • See if they can fabricate some circuity to make a webserver that can take a slashdotting...
  • It's great to see how PCB boards are made. I create lots of PCB designs but never get a chance to see how they are actually made. It's refreshing and cool to see that part of the process.

    However, the article partially reads like an advertisement. I've used the mentioned company and their pricing is good when comparing US based PCB fab shops. If they are going to advertise on slashdot, I'll share my experiences with different fabs. I've found the best deals are with non-US companies: http://www.bittel []
    • Have you tried ?
      • Yup. It's still more expensive than shops outside the US. PCBExpress is a division of theirs and is cheaper than sunstone but more expensive than outside the US, but super fast!
    • Most US fab shops don't even look at your boards before building them.

      That's because they have computers to check your boards. Most major board houses have online submission and DRC checks. 4pcb (aka advance circuits) usually gets you the files back within 30 minutes complete with .pdf printouts of each layer along with a quote for every conceivable quantity and delivery schedule. And in case anyone needs some anecdotal evidence, every board house I've used (big and small) has called me at least once to clear up some issues with my boards.

      • My comments were mostly about the automated US based shops that come closer to price parity with non-US based shops. The shops that do DRC checks in the US are expensive and are not price competitive with outside shops that do DRC checks.

        Our setup is automated - your files are processed as sent without design review.

        This quote is from a fully automated pcb fabrication site, pcbexpress. It's super fast and very cheap but the files are made as is without the DRC checks. []. In the end, you will need to choose two items from this list

  • It's interesting to find out that they process things backwards from what one would expect. They apply the resist and use it to protect the places they WILL etch away, then protect the parts they DON'T etch with tin, then remove the resist and then etch.

    Can someone familiar with the process answer why they do this extra step, instead of simply protecting the copper they want to keep with the resist and bypassing the tin-plating step altogether? The only reason I can come up with is that the electroplating

    • Inner layers are processed as you would expect. Etch resist is applied to the areas you want to keep, then copper is etched away. The outerlayers are different. The resist image applied to the board exposes the what you want to keep. It can be considered a "plating resist". The exposed image is then plated with copper (this is where the hole walls get plating) then tin. The resist is then removed. The tin then acts as the etch resist. It's a pain to etch through copper. That is why copper plating i
      • Yes, I understand what they are doing. The question is why apply a resist layer to put down a tin layer, and then remove the resist and then etch the copper? Why not just put down a resist layer directly and etch what the resist doesn't protect? That seems much simpler. "It's a pain to etch through copper" may be true, but that is what happens either way.
        • Why not just put down a resist layer directly and etch what the resist doesn't protect? That seems much simpler.

          More simple, but processing that way wouldn't plate copper in the holes drilled for vias. It sounds like you're forgetting that step.

  • Bah! I call shenanigans! I didn't see a single unicorn, pixie, or elf in those pictures...although that might be a gnome on page 4 pic 2.
  • Board houses CAN do amazing things, however getting straight answers to design rules usually gets a "It depends..." response. Nothing worse for a hardware designer than having to wait until you spit out a GDS file to get surprised about cost of certain process combinations, or incompatibility of certain process options (i.e. getting sold on edge plating or blind vias only to find out the hard way that that results in MUCH worse etch tolerances).

    Most the companies I've dealt with consider their design rules

  • by gary_7vn ( 1193821 ) on Tuesday June 28, 2011 @07:47PM (#36605776) Homepage
    Whatever happened to the good old days when we would construct mnemonic circuits out of "bear skins and stone axes"? Seems logical to me!
    • I remember doing layouts by sticking tape on acetate sheets, cutting the tape tracks with a razor blade - health and safety would not allow that now I imagine.

    • by AmiMoJo ( 196126 )

      Well some of us still build devices without a PCB of any kind. Valve amplifiers are a good example; I am building one from a kit where all components are just soldered leg-to-leg with each other and a few anchor points on the case.

      • I know, and I am in awe of people like you. I was making an obscure reference to an old Star Trek episode, "The City on the Edge of Forever" written by Harlan Ellison, the highest rated original series episode. Spock and Kirk had to go back in time to 1930's earth to rescue McCoy, who had accidentally injected himself with a substance that made him insane. Spock had to repair their tricorder, but wasn't doing well with the tubes etc available. I just checked and I got the quote slightly wrong, "I am endeavo
        • by AmiMoJo ( 196126 )

          Ah yes, I didn't get the quote at first but I did enjoy that episode. Probably one of the earliest sci-fi shows to introduce the concept of not altering the past for fear of changing the future.

  • It starts with a mommy engineer and a daddy EE geek who love each other very much.

  • If you want really cheap boards for prototype purposes, consider these sources:

    Seeed Studio []: these are a total of $10 to $45 for 10 boards, plus a small amount of shipping from China. I get my boards in 1-2 weeks.

    DorkbotPDX []: based in the US, but only sends out batches every few weeks. They charged based on raw square inches.

    And for volume, is really great. Probably over 10x cheaper than Advanced Circuits.

    Of course it's so cheap since it's outsourced, but that's life. Advanced Circuits is ridic

  • I'm surfing slashdot from a PCB shop right now.
  • Nice photos, but where's the popcorn?

    (For those who aren't aware, Advanced Circuits always throws in a free bag of microwave popcorn with every order, as a hook/customer appreciation measure).
  • I recognize this place, made some boards there :) US based PCB fab is more expensive, but quicker and QUALITY. Chinese houses like pcbcart? 6/15 of my boards made with them failed. I even stayed away from their spec limits quite a bit. Half of those that failed did so within a few heat/cool cycles of running (they have FPGA and SDRAM on them, so not THAT much heat). The rest developed electrical shorts that were still there even after I'd completely depopulated the boards. Advanced Circuits? Never have t
  • Back in the day we drew out the traces out on paper in large scale then photographed it. The copper clad board was coated with chemical. We put the film negative on top of the copper board, blasted it with UV then dumped it in a bath. After the copper etch bath etched away the copper (and hopefully you did it right or some of your traces dissolved too) the board was given it a tin bath.

    Now.. GET OFF MY LAWN!

  • Designing a PCB beyond run of the mill, low speed electronics can be reduced to CAD type etch a sketch artwork generation, however, you get beyond a few dozen parts and/or high pin count FPGAs and microprocessors the task of designing such a PCB is very involved and a specialized field. One of the limiting factors is the software used in the design process, the schematic capture, library parts creation, and the layout editor itself and auto route technology. The software for this task can get very expensi
  • I checked out the Advanced circuits site in the link. Their free cad tool has a rather poor library, there doesn't seem to be ANY micro controllers in their library and their own line library can't seem to find common parts either. (Try searching for 2n2222 or 2n3904 and comes up empty!) Even Eagle's free cad tool has a bigger library and lot's of user contributed parts. Only problem with Eagle is that few houses use their file format, though there are ways to make Gerbers from them.

Loose bits sink chips.