PCB costs/value for money - Page 1
Forum section: electronics / general

author: peper
author_rank: Contributor
timestamp: October 01, 2010, 01:14:22 pm
content: Hi,If you're having PCBs made for your projects, how many do you normally have made? I understand completely the fact that the per-board price drops significantly as the quantity increases but if it's just your own pet project and it's not something like break-out boards, I would have thought most people would only want one or two.Is the price of a single board not then extremely expensive compared to everything else? When I read various blogs, it always strikes me as odd that someone will design a fairly small, simple circuit that costs maybe a few dollars in parts and then spend probably at least $50 having a PCB made for it. And that will just be for the first prototype.I can understand it if you intend to sell your circuit as a kit as the idea is to make your money back and you'll be having more PCBs made so the per-unit cost comes down anyway but otherwise I find it hard to justify the cost of the board compared to the cost of the parts.I'd be very interested to hear other people's thoughts and their justifications for whichever method they use ("how much is my time worth", "no wife and kids and I want it to look great" etc.).Richard.

author: Simon
author_rank: Unknown
timestamp: October 01, 2010, 02:57:31 pm
content: I make my own prototype PCB's and I'd happily make small runs if need be

author: TopherTheME
author_rank: Regular Contributor
timestamp: October 01, 2010, 04:30:46 pm
content: $50 I think is a bit steep for PCBs. I usually have about 3 made when I do a project at a cost of around $8-$15 each. See this thread for cheap PCB fab:https://www.eevblog.com/forum/index.php?topic=1324.0

author: osmosis321
author_rank: Regular Contributor
timestamp: October 01, 2010, 04:48:07 pm
content: I used to use presensitized PCBs and nasty chemicals but the time/expense/hassle vs quality is so poor I'm outsourcing PCB production these days.I deal with a company that handles the entire order process online. I send them the Gerber files and the quoted price, wait a couple of weeks, and then a delivery guy arrives expecting $30 for his services.They charge per sheet, and however many boards fit on the sheet is what you get. I can't remember the sheet dimensions, but I most recently ordered two sheets, one @ 1oz and one @ 2oz copper thickness, total cost including delivery was approx US$475. One sheet yielded 21 pieces and the other yielded 10.Extras, such as lead-free plating, cost $20/sheet. The product quality is pretty good, far better than anything I can do in my shop.I'll gladly hook anyone up with this company. I think they might even throw me some kind of bone if you tell them I sent you.

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: October 01, 2010, 05:03:27 pm
content: Quote from: osmosis321 on October 01, 2010, 04:48:07 pmDo they cut the boards apart or do you do it yourself?I've tried using a band saw for this with miserable (and dusty!) results. Shearing works pretty well.

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 01, 2010, 09:13:49 pm
content: Etch them yourself unless you want something you can sell or something on a wall.If you really want a PCB, try the Dorkbot group orders. I sent away for boards recently from them. Haven't gotten it back yet to judge quality.$5 per square inch X 3.http://dorkbotpdx.org/wiki/pcb_order

author: DavidDLC
author_rank: Frequent Contributor
timestamp: October 01, 2010, 10:33:32 pm
content: One of my rules is:If the PCB is simple and it's going to be inside a enclosure I do it myself. And of course if I will be using the PCB as development (no enclosure) kit for example then I use companies.But sometimes I also got the PCB fabricated even if it is going to be on enclosure, depends on the "love" I will have for that project !

author: osmosis321
author_rank: Regular Contributor
timestamp: October 01, 2010, 11:30:37 pm
content: Quote from: Jon Chandler on October 01, 2010, 05:03:27 pmThey cut them. Not sure what they use to do it, but it creates a very clean looking edge. Your board needn't be rectangular either, they can cut almost any shape.

author: RayJones
author_rank: Frequent Contributor
timestamp: October 02, 2010, 02:50:15 am
content: They'd be using a router cutter, 2mm or so in a CNC machine to cut the boards out.Reading this thread made me realise the alchemists of old have been done in by ROHS.No longer would they be allowed to attempt turning lead into gold, the irony being gold plating is a ROHS alternative

author: Simon
author_rank: Unknown
timestamp: October 02, 2010, 07:18:33 am
content: Quote from: RayJones on October 02, 2010, 02:50:15 amattempt not metal conversions were done in the past and we still don't know how

author: Unknown
author_rank: Unknown
timestamp: October 02, 2010, 07:23:02 am
content: Quote from: RayJones on October 02, 2010, 02:50:15 amYou do know that RoHS (at least the EU version, don't know about the Chinese version) doesn't forbid any techniques or products, right? The only thing that you're not allowed to do is sell equipment in one of the explicitly mentioned categories (eg. computers or TVs) with significant amounts of restricted substances, so the only problem might be making consumer equipment with your lead turned into gold.

author: osmosis321
author_rank: Regular Contributor
timestamp: October 02, 2010, 04:27:44 pm
content: Forgot to mention that the price includes a silkscreen layer so you can put your company logo on the boards.Some more things to consider when deciding whether or not DIY is the complexity of the design, the package technology of your components and the number of sides of your board. A simple design is a good candidate for DIY. A single-sided design is also good, and surface-mount components work well.Where you'll run into problems is when your design isn't simple, has two sides and uses thru-holes. Then exact alignment of your PCB artwork sides is critical and you'll run into problems you never expected. As an example, I found that both sides of the artwork had to be printed side-by-side instead of top to bottom, because my laserprinter was stretching the image vertically along the page and otherwise I'd have two sides that didn't match.Let's assume you got mad skillz and manage to get the boards etched with matching sides. You're only halfway there, now you've got to drill LOTS of tiny holes. At least you'll need a Dremel(tm) and the stand that converts it into a drill press. You'll need to order the bits because no hardware store carries anything that tiny. The bits are roughly the width of a needle and they cost a couple of dollars apiece -- handle them carefully and try not to drop them, store them in marked containers, and never put any lateral pressure on them or they'll snap in half. That's why you pretty much need the Dremel and the stand, because you can't hand-drill and only a Dremel has a collar that will hold those tiny bits.And after all that, you still end up with something that's only so-so.

author: Simon
author_rank: Unknown
timestamp: October 02, 2010, 04:58:24 pm
content: home made double sided through hole is something I'd not like to attempt you'd need to line the two sides up and accurately drill, errors start to stack up and a hole could miss or go through the side of a pad which would not be nice. Having said that I've seen a very popular video of dual sided, the guy did it by making a pouch out of the two sides of artwork and putting the board inside and securing it. SMD is even easier than through hole as you can forget about the hassle of drilling, it's something I'm looking to take up more and more as i get used to SMD (as the space saving is great too)I use a dremel with the stand and get bits off ebay but the pack of ten for a few pound, I've only done a few board so can't say if the standard bit don't last as long as something more specialized but I've found 0.7mm to be the minimum hole size for through hole (0.5mm won't even do 0.25W resistor leads) so not too special, I've not had one snap yet. You'll want 1mm for larger parts like TO-220 cases

author: Zero999
author_rank: Super Contributor
timestamp: October 02, 2010, 06:38:19 pm
content: One thing you could do is leave one side unetched as the ground plane or make a cut down the centre, giving you two separate power planes. This is good for EMC and will make routing easier as well as avoiding many jumpers.Using both through hole and surface mount components is also another good way to safe space on a single sided PCB.

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 02, 2010, 07:24:10 pm
content: I do double sided every once in a while, but it's pretty rare that I find it necessary or worth the extra effort. I use toner transfer and use the 'pocket method'. I print out both sides on the photo paper, align them by using a light to shine through both pieces of paper and then tape two of the edges to make it stationary. I put the board between and iron it. It's worked pretty well for me. I've also worked out a way to do fairly easy via's using wire, solder paste, and the hot air station.

author: RayJones
author_rank: Frequent Contributor
timestamp: October 02, 2010, 08:26:25 pm
content: "Back when I was a boy" I was regularly making double sided S-100 sized cards with the usual 0.1" pitch DIL packages. (10" x 6" or so).( Damn that was fun building computer board from scratch, I just had to build bigger and better graphics cards! )Double sided really isn't that hard.The best technique I encountered was to use a strip of PCB material along one edge so the negatives were already held apart by the PCB thickness, thus avoiding issues with skewing from top to bottom when you put the actual production board between the negatives.Two decent pieces of glass, clipped together with big arse bulldog clips and you were ready for exposure, well the PCB's anyway.As for 3 layers or more - pass !

author: osmosis321
author_rank: Regular Contributor
timestamp: October 03, 2010, 04:51:36 pm
content: Quote from: TheDirty on October 02, 2010, 07:24:10 pmSounds like your methods are similar to mine. Can you tell me more about this toner transfer process? You iron toner onto a bare copper board and that masks the etchant?Looking at those pics, that's about as good as it gets with DIY.

author: peper
author_rank: Contributor
timestamp: October 03, 2010, 07:22:40 pm
content: Quote from: TopherTheME on October 01, 2010, 04:30:46 pm3 @ $15 is pretty close to $50. I'm not trying to be argumentative here. I'm genuinely interested to know whether I'm missing something obvious, or maybe I'm just a cheapskate!Are your projects usually generic enough that you might realistically want more than one, or is it because the boards you have made aren't tested, so you want to cover yourself?I've not designed too many boards so far and the ones I have done, I etched myself. Also, none of them were boards I'd want more than one of. Whilst it is certainly cheaper to do it yourself (you get over the initial investment very quickly), it's certainly time-consuming and potentially error-prone. Drilling all the holes is also not a huge amount of fun! So I can completely understand paying a (reasonable) premium for not doing it yourself and having lovely looking boards to boot.My current project will need at least three separate PCBs. One large-ish one, and two smaller ones. I've only just started the layout of the larger board, so I don't know yet exactly how big it will be, but as I need two each of the smaller ones, I could image a panel that fits Eagle's size limitation of 100x80mm being about right. At PCBCART, which seems to be quite popular, a single board of that size with 3 individual designs would cost around $100. That, in my eyes, is an awful lot of money for what I'd get. The per-board price drops extremely quickly, of course, but if I don't need more boards, then I've not gained anything by ordering more.BatchPCB would probably be a better bet for this, as by my calculations I'd be paying a bit more than $40 for the same size and I'm not too bothered about the turn-around time (I've been working on the firmware and circuit for over a year now so another month or so isn't going to make much difference. Thanks to two small children, gone are the days of being able to spend entire weekends working on anything!). $40 is more around the price I'm prepared to pay, and even that is a sizeable chunk of the overall cost of the project.Even having several PCB designs made at once doesn't seem to help spread the price much. Quite a few places don't seem to allow more than one design per order. The price jumps quite quickly with PCBCART (100x80 as a single board is about $65). BatchPCB does of course allow multiple designs, but even then you still have to watch it if youdowant a few of each design making as they charge by the square inch.Many blogs I've read either don't mention where they had their boards made or don't explain the justification behind it. Not that I would expect it every time I read a different blog, but I don't think I've ever seen much of an explanation. Even it it's just "I want!".Spending $$$ on a board for a blinking LED project that, while pretty, is probably going to get tossed in a drawer after 5 or 10 minutes doesn't really cut it with me, but maybe that's because I already have enough junk and I'm just tight!Sorry for the long post. Just trying to sort my thoughts and reasoning out!Richard.

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 03, 2010, 08:03:23 pm
content: Quote from: peper on October 03, 2010, 07:22:40 pmI've ordered from BatchPCB before. The DorkbotPDX order that I mentioned earlier is a much better deal, especially if you live in the US. $5 per square inch, but you get three boards for that and no setup fee and no shipping fee in the US. The space/trace limits and drill size are also much better.It's easier for me, since my PCB's are all SMD and always as compressed as they can generally be. I've never gotten anywhere near the Eagle lite board size limit.

author: TopherTheME
author_rank: Regular Contributor
timestamp: October 03, 2010, 11:10:16 pm
content: I think I might try them next time I need some boards made. The only downside I see is time. It looks like it takes nearly a month to fill a panel and have it sent to fab, plus actual fab time. I'm willing to pay a little bit more to get my boards in less time.

author: slburris
author_rank: Frequent Contributor
timestamp: October 04, 2010, 02:06:40 am
content: I find I have to quote specific boards around to several board housesto get the best price -- it seems nobody consistently has the best price.I used to make my own boards, but by the time you coat the board,expose it, develop it, etch it, and drill it, I'm not convinced you savea whole lot of money. I never could drill boards very well, andon large multipin connectors they would never fit right.I tend to use a lot of SMD with 0.65mm and 0.5mm pin spacing, andusually at most 8mil trace/space, so I'll bet the toner transfer methoddoesn't work so well at these feature sizes. And I *really* need thesolder mask for these.I've used:pcbfabexpress.compcbex.combatchpcb.comNone of the boards have had manfacturing issues, but the most professionallooking stuff seems to come back from pcbfabexpress. Don't know why.I've never been able to get the pricesfor pcbcart.com, pcbpool.com, etc.work well for me.Scott

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 04, 2010, 02:10:16 am
content: Quote from: slburris on October 04, 2010, 02:06:40 amYou would lose that bet....and why do you need solder mask? I've never found solder mask necessary and I regularly do QFN's, 0.5mm leaded, and even 0.4mm leaded IC's with no solder mask. I'm definitely not great at soldering, either.

author: slburris
author_rank: Frequent Contributor
timestamp: October 04, 2010, 03:06:29 am
content: Quote from: TheDirty on October 04, 2010, 02:10:16 amMy previous experience is that the toner tends to smear slightly which causes problemswith small sizes.I find the solder mask helpful in avoiding or at least clearing up the solder bridges.I solder 208 TQFPs by hand. Perhaps I need to try skillet reflow or hot air reflow.Never met a 0.4mm leaded package, not sure I would be able to solder that.In any case, I got rid of my ferric chloride and etching tanks long ago. It's mucheasier to send gerbers out and have some boards made, at least for me.Scott

author: Zero999
author_rank: Super Contributor
timestamp: October 04, 2010, 08:02:44 am
content: Quote from: slburris on October 04, 2010, 03:06:29 amIt sounds like the iron is to hot, reduce the temperature until the toner becomes tacky but doesn't melt completely; this requires some experimentation but it's not to hard.

author: peper
author_rank: Contributor
timestamp: October 04, 2010, 09:38:03 am
content: Quote from: slburris on October 04, 2010, 02:06:40 amThat's the impression I'm getting too. It's obvious that it depends on various factors like board size and quantity, but it seems like there's such a variation that you can't just say supplier X is the best value for money on average, so I'll stick with them. Unless, of course, all your boards are always about the same size.QuoteI think it very much depends on how much your time is worth to you. As a hobby, you can only really measure it against what you could be using the time for instead and then weigh that up against the cost to decide whether you're prepared to pay the extra.I've used the toner transfer method for my boards so far and it certainly wasn't 'quick' but that's probably because I haven't done enough boards to have streamlined the process. For drilling the holes I just use a normal drill press with the appropriate bits. I've not had any bits break but then I'm not churning boards out either. I found using drill-aid.ulp in Eagle helped a lot. It makes the actual hole in the pads smaller which helps to keep the bit centred. But I absolutely agree that drilling holes is a pain. One slip up and you've either ruined the board or you've got a fair bit of work to do to work around it.QuoteNearly all my stuff is through-hole. I'd like to use more SMDs but I've just got so many through-hole components lying around that I can't justify throwing them away for the sake of it. Of course, my boards would become smaller and therefore cheaper, which would offset the cost of buying new componentsRichard.

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 04, 2010, 12:12:52 pm
content: Quote from: slburris on October 04, 2010, 03:06:29 amThe biggest failing of Toner Transfer is that there are just too many different types of materials used and different methods for ironing and etching. It makes getting a good repeatable method difficult and either you get it after a few tries or people try several different variations, never seem to get it and give up. I was lucky and got good results after a few tries. I just use photo paper and a regular iron and I get great results quickly and I've been doing it for years now. I've seen a lot of people just get frustrated with it trying to get good results and give up, though.I've done 6mil traces without issue, but I definitely took extra care with them. I'll attach a photo of a 0.4mm lead that I had to do with 6mil traces. This is another 2 sided board that I did. My original plan was to use BatchPCB for this, but 0.4mm leads require a maximum of 7mil traces and BatchPCB's minimum trace/space is 8mil.As for soldering. I use the Sparkfun lazy mans method where I try to solder each pin, but end up with a lot of bridges. I just use some braid and flux to soak up extra solder. I do QFN's with reflow, but anything leaded I still use the soldering iron. It's just easy to tack down corners, run the soldering iron along and then wick it clean.

author: sonicj
author_rank: Frequent Contributor
timestamp: October 05, 2010, 01:04:18 am
content: Quote from: TheDirty on October 04, 2010, 12:12:52 pmgreat job! very inspiring!-sj

author: sonicj
author_rank: Frequent Contributor
timestamp: October 05, 2010, 02:15:36 am
content: anyone tried direct printing?i used to have one of those epson cd printers.... i think an old roommate may have lifted it. =(another thought.... direct to board thermal printing. i had a casio cw-50 that printing great monochrome direct to cd labels! i'm thinking that that printer head on a conveyor type tray would produce excellent results.hmm, i just discovered an interesting fact about thermal printing... tektronix was a solid ink innovator in the mid 80's!http://en.wikipedia.org/wiki/Solid_ink"... The sticks are non-toxic and safe to handle. In the mid 1990s, the president of Tektronix actually ate part of a stick of solid ink, demonstrating that they are safe to handle and presumably, eat. ..."lol!

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 05, 2010, 02:40:17 am
content: Quote from: sonicj on October 05, 2010, 02:15:36 amgreat video! great music! new thing learnt... cut the pcb with paper cutter, thing dont like... alot of cooking (twice), thing to improve... embedded heater inside the printer itself, thing liked... printer stripped naked. i'm going to do that! just wait until i got a printer to waste.

author: sonicj
author_rank: Frequent Contributor
timestamp: October 05, 2010, 03:38:13 am
content: ditto on the tune. the paper cutter was new info for me as well. i was thinking table saw... that looked much easier!the de-cased printer did have a nice lil' ghetto-fab appeal to it.-sj

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: October 05, 2010, 04:25:21 am
content: Quote from: sonicj on October 05, 2010, 02:15:36 amWe used to have a Phasor printer. They hook you with the promise of free black ink. You start by printing just a tiny bit of color but pretty soon, everything is in full color! It doesn't help that the printer driver has no option to default to black ink, and the printer refuses to print when the colors get low. It's really not that expensive to print color, but it's hard to appreciate that when buying ice-cube size blocks of wax for $30 in a 3-pack. And it always put a crimp in the budget when the ink and the maintenance kit both needed replacing at the same time!To be honest, the results are beautiful, and I believe the cost per page blows laser printing away.Jon

author: sonicj
author_rank: Frequent Contributor
timestamp: October 05, 2010, 04:53:14 am
content: interesting! i'll have to keep an eye out for one of those when im on my thrift store adventures. xerox would have a hit on their hands if they produced a scaled down monochrome version with a copper clad hopper! =)-sj

author: sonicj
author_rank: Frequent Contributor
timestamp: October 05, 2010, 05:11:05 am
content: hmm... i have a canon MP600 and it prints direct to cd with the uk cd printer adapter and some firmware trickery. diy tray adaptor:link. cd + tray might be about the same thickness as clad.... hmm...list of direct to cd printers:link

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: October 05, 2010, 05:55:25 am
content: One detail about the Phasor....it has a large ink tank wheremelted inkis kept. It's really designed to stay on and takes 30+ minutes to re-melt the ink. Also, it doesn't like being on and ignored for weeks at a time...somehow the wax can transfer from chamber to chamber (they may have fixed that problem now) and it's a real mess to fix this problem. You have to print a ream or 2 or 5 of solid color pages to clean out the system when this happens.

author: Simon
author_rank: Unknown
timestamp: October 05, 2010, 06:40:41 am
content: again a method of variable results, I'm not sure why you have to heat the board and then bake it, if you can etch a board simply by using a permanent marker on it why all the oven work ?, I still stand by the UV process, really I'm no chemist and no expert and it didn't take me too long to work out a fool proof system

author: TheDirty
author_rank: Frequent Contributor
timestamp: October 05, 2010, 05:58:46 pm
content: The boards I ordered from the Dorkbot group order came today. They look really nice. I left the picture as it is without correction, but the colour of the mask is actually very dark blue and unless the light hits it at an extreme angle it looks like a solid dark mass and you can't see the traces underneath. I'll be ordering some more from here.Picture attached. Front and back.

author: pdunz
author_rank: Newbie
timestamp: October 05, 2010, 11:42:47 pm
content: Quote from: Simon on October 05, 2010, 06:40:41 amIf you are refering to the CD tray printing method - you have to bake (dry) the ink onto the board otherwise it stays wet and once in the etching solution, it becomes a mess and the board is ruined.

author: quantumfall
author_rank: Regular Contributor
timestamp: October 06, 2010, 12:45:49 am
content: Quote from: Simon on October 05, 2010, 06:40:41 amI'd guess its because the ink is dried quicker if the board is hot in the printer, as the copper is non absorbent and the inks are water based not solvent like a marker pen. The second heating probably makes the ink more water proof, etchant proof.