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How Printed Circuit Boards Are Made
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."
I believe they had an episode containing this a few years back, still entertaining though.
That's fine and dandy for simple boards, but you won't be building a 7+ layer motherboard with that setup.
I have never had any decent results with toner transfer, but that is my problem ... but you will not be making too small of traces and anything over 2 layers is going to be durn near impossible (unless you make a bunch of boards and glue them together) + solder mask + silk screen + cutting + drilling + though hole plating
your not going to be doing any serious production that way
Ha. We've been an Advanced Circuit customer for years. Stand-up bunch of people.
"Eve of Destruction", it's not just for old hippies anymore...
Sure, as long as you just want to flash a LED... Idiot.
Because that option doesn't scale well? Also, unless you are using surface-mount components, you will also need a 1/16 inch drill bit and a drill to drill the holes for the leads of the parts you will be soldering to the PCB.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
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)
Mostly random stuff.
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.
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.
Just my $0.55 (US inflation, 1774-2008, for $0.02)
See if they can fabricate some circuity to make a webserver that can take a slashdotting...
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).
Bad trolling is bad.
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.bittele.com/PCB_Pricing.asp. Disclaimer, I don't work for this company but I use them all the time. I found them to be the best deal and offer great service. Most US fab shops don't even look at your boards before building them. These guys have extensive capabilities, great prices, and also review your design. The only downside is that the lead-time is not as fast as some of the automated PCB fab shops in the US. But most of the time spent on a board is not on the actual PCB fabrication, it's the assembly that takes a long time. Also, completely automating a prototype assembly isn't exactly feasible: hand placed parts, BGA placements, BGA xrays, setting up hundreds of different parts to be automatically placed on a board, etc. Note, this only applies to prototype PCB and PCBA. Production builds are a different ball-game.
At risk of feeding the troll, I do a helluva lot more that "flash an LED" with my home etched boards. For example, I use a wireless XBee radio to read my power meter and chart my daily usage. Many of the folks at http://www.doityourselfchristmas.com/ do some amazing things with their home etched boards, more that just flashy-blinky lights. So, AC, maybe instead of trolling /. you should go read a book or two, lest you end up demonstrating idiocy to everyone.
I'll finish with this quote from Friedrich Nietzsche:
Anyone who has declared someone else to be an idiot, a bad apple, is annoyed when it turns out in the end that he isn't.
We used a resist pen when i was in school. But we never got to make anything even slightly complicated.
I make my boards nowadays with a sheet of copperclad board and a dremel. After planning things out on paper, I free draw with a pen where I don't want there to be copper, and then use a small hand dremel with a small metal cutting wheel to remove the marked copper.
Perhaps a little barbaric for some people, and I probably really should be wearing at least a basic paper respirator when I do it (but I don't) but it gets the job done and for very small boards like terminating boards with a few discrete parts on them near a connector, it's perfect and even looks good. Beats dead bug any day. Nice and solid construction. When you have to run a long thick coax to an antenna connector, (two physically large parts) and attach a few bits (such as a pin diode, choke, and resistor) in among them where they meet, it makes a good strong physical arrangement. Cables and antennas getting torqued and twisted after installation can't be allowed to tear things up.
And it's a lot faster than etching, I tried that at home a few times and it never went well and took hours. I seemed to have issued with the timing, one time I wouldn't get all the uncovered copper removed, leaving copper speckles all over the place, and the other half the time my traces would be eaten into. My new dremel method takes minutes and doesn't require nasty chemicals, rubber gloves, or fume hoods.
I work for the Department of Redundancy Department.
A new method is needed for hobbyists to make circuit boards. I'm afraid we'll have to figure it out ourselves because industry is totally ignoring us. Conductive paint would be great even if you had to bake it on. I'm not very good at paint making though. A cnc machine is not much more complicated than a printer,why not sell them as cheap? Most hobbyists need the new method to be cheap.
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 step that creates the vias needs a complete circuit to all the vias, and after you etch you lose that. But if you electroplate before etching, you still have that current path.
Isn't the copper that is etched off recovered and used to electroplate? Or is the cost of the copper more than the cost of tin plating, unplating, and recovering the tin?
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 to be semi-secret, even to their customers... If you work with them long enough you get it figured out, but in a high mix business like I was in (every board was a very different stackup with very different requirements) it got to be absolutely frustrating to constantly get surprised, then have to dig up email threads to defend yourself against angry project managers now that the price point blew up or the board has to be completely redesigned despite doing pretty thorough due diligence.
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.
www.sunstone.com it's my dad's shop so I'm biased but give it a try!
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.
The only part that is really difficult for home / hobbyists is the through plating.
Hey KID! Yeah you, get the fuck off my lawn!
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.
Whatever happened to the good old days when we would construct mnemonic circuits out of "bear skins and stone axes"? Seems logical to me!
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 batchpcb.com. If you only want one board, they will collect other user's boards into one big file and do a run for dirt cheap.
It starts with a mommy engineer and a daddy EE geek who love each other very much.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
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, pcbcart.com 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 ridiculously expensive in comparison. Their best price on a prototype run is $33 each, 4 minimum order, plus $30+ shipping. I'd only consider them if I had to get my boards within 5 days and was willing to pay for that.
Not affiliated, just a happy customer.
I'm surfing slashdot from a PCB shop right now.
That's who I use for my two player PCB's and they do a great job with a variety of turn around times. I'd recommend them to anyone interested in having custom high quality PCB's built in small or large quantity
Remember the bad old days when one had to layout the board by hand using "puppets"? Basically various little cutouts one applied to a grid and then hand taped wire runs. Or even better my hand-wrapping days.
speckles = dirt
eaten = too much time
if it takes hours your doing it wrong, I reused the same ferric chloride for the last 4 pcb's I made and even in its weakened state and mostly saturated with copper it only took 20 min
and people mill pcb's all the time =)
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).
On the other hand, you can buy your boards for the expensive American price, and it still won't be the most expensive component in your project.
The determined Real Programmer can write Fortran programs in any language.
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 they failed. Even the PCBs I abused with a rework station never lifted any traces. Even the 0.5mm SMD pads that lifted like paper off the PCBcart boards, they are STILL THERE on the 4pcb/advanced circuits prototype.
I just reworked my design into 4 layers and did another proto from them. No problems either.
If you are a student, you can get on board their 33each (2 layer) and 66each (4layer). Note their shipping charges are a tad high so it works out to about $48 and $88, respectively.
Oh yeah, I wasn't paid by them either, I just am a happy customer. Started using them in high school (thanks Forrest) and now near the end of college they have never let me down.
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.
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!
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.
We partner with well-regarded ISO-9002 certified US based PCB manufacturers and Assemblers to provide you outstanding quality at low prices.
They are a middle man. They send it out. Do yourself a favor and go elsewhere to save money.
I prefer the "u" in honour as it seems to be missing these days.
I worked for a company building (designing/building/manufacturing) SCADA controllers and industrial process controllers. I had built my own printed circuit boards in college, and where I worked, I would draft schematics, layouts, plot the circuit layouts, and send them to a board manufacturer. We would then populate the boards with chips, make any last minute bug fixes if needed (unlike software, bug fixes here involve cutting traces and soldering wire), testing the board and shipping. I always found it funny to hear people talk about 'the circuit board got all wet...surely it must be ruined...' heh.... after populating boards, we would wave solder them (put the circuit board in a machine that sends a ripple ...a wave of solder where the top of the wave just touches the components for a second and solders all components on the board in less than a second... then because we used solder with water soluble flux, we would wash the entire board. We used a Sears Kenmore dishwasher (we didn't use the heat cycle). Of course, since all chips follow Texas Instruments Mach32 test protocol (hermetically sealed, gross leak test, fine leak test, bake and cryogenic freeze tests, high altitude tests, centrifuge tests), there would be no problem washing all chips and getting all that flux off. Never ever had a problem. Hundreds of thousands of circuit boards, millions of chips, hundreds of gallons of water. No problem. "Dude, oh no, you got yer phone all wet, itz probly broken forever man..." NOT!
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 expensive quickly as you move up the chain; these can be $100K plus PC based applications, and only two companies do this, Mentor Graphics and Cadence (yes; there are half dozen minor players). With a small market for this stuff, none of it works as advertized and it can take years to learn the systems and where the land mines are. The learning process itself is daunting, there are no books or college courses really, for high end PCB design and the use of the tools. The software itself has its roots back to the '80s with both companies, and it is obvious that much of it has not been dusted off and seen significant development in decades. There is an open source project or two out there, but the real pros are just too busy cranking out designs to participate. If I were a young computer science student, electronics and graphics guru I think this area is one I would look into; the big guys need some heat and we would all love to see a new player and startup in the high end PCB EDA market. As far as PCB design as a career choice, look elsewhere, these jobs are now going offshore, like everything else in electronics in the USA, we are losing our edge.
Plating? Bah! Luxury!
A piece of wire soldered to both sides!
We both said a lot of things that you are going to regret.
I use Express PCB (http://www.expresspcb.com/) all the time for my prototyping. 3 2-layer boards (3.5" x 2.8") costs about $60. You have to use their CAD program, though, but it's pretty decent.
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.