What to do with extra proto PCBs? - Page 1
Forum section: electronics / projects

author: analogo
author_rank: Regular Contributor
timestamp: November 20, 2018, 09:52:29 pm
content: Cheap PCB prototype houses usually send 5 or 10 PCBs per order. But all my order are real one-off "prototypes": I just need one or two PCBs to test if the design is working. If it is, I will move to the next step and design another part of the circuit.Now I have plenty of useless PCBs.What could I do with them? What do you do with your extra PCBs other than throwing them away?

author: Kjelt
author_rank: Super Contributor
timestamp: November 20, 2018, 10:10:28 pm
content: Then why order 5 or 10 if you know in front you will max need two?It is like some people at the all inclusive buffet, they stack their plates full , only eat half and throw the rest away, it is a waste and can easily be prevented.

author: ataradov
author_rank: Super Contributor
timestamp: November 20, 2018, 10:17:41 pm
content: With prototype boards you often have no option but to order 5 or 10. Even if you order fewer, they still send their minimal quantity. Non-standard orders interfere with their flow.I just store them and occasionally use them for prototypes, since they often have footprints that standard prototype boards don't have.I also keep at least one of which for historical record reasons. I eventually want to create a "wall of fame" (or shame, it depends).

author: analogo
author_rank: Regular Contributor
timestamp: November 20, 2018, 10:21:00 pm
content: Quote from: Kjelt on November 20, 2018, 10:10:28 pmWhat? Have you ever ordered from PCBWay or Elecrow? They do not accept orders for less than five boards. Usually you get 6 or 10.Our proto boards are just material to fill panels dedicated to more important and time-sensitive boards. Usually the important boards are ordered in multiples of 5, so we get 5. In the unusual (but not rare) case in which an important board is ordered in multiples of, say, 7 you get 7, and so on.I once asked them to manufacture only two and they said nope, we can't do less than 5. It makes no economic sense to them. Not many friends of the environment in those PCB houses, it seems.

author: ataradov
author_rank: Super Contributor
timestamp: November 20, 2018, 10:53:11 pm
content: Quote from: analogo on November 20, 2018, 10:21:00 pmThere is nothing they can do about it anyway. There is going to be unused hole in the panel anyway. The additional cost of etching a design there is negligible for the environment.

author: m98
author_rank: Frequent Contributor
timestamp: November 20, 2018, 10:58:21 pm
content: I do store them, for documentation, to be able to maybe build a second prototype if the need should arise, as a work reference, and to reuse some functional blocks for some quick and dirty prototypes.

author: sokoloff
author_rank: Super Contributor
timestamp: November 20, 2018, 11:13:31 pm
content: Quote from: analogo on November 20, 2018, 10:21:00 pmThey make your board alongside other boards on a larger panel and all the panels are the same and therefore all the boards are made in the same "depth" (count). It's just like the way we make business cards. If you only need 183 business cards from us, you're going to get 250, because the 131 other orders on that same gang are all getting printed 250 deep.The best the board house could do for you is make them and then throw the "extras" away before shipping, which doesn't do much for the environment. It might save a few grams of fuel that the shipping weight difference would represent.

author: bsudbrink
author_rank: Frequent Contributor
timestamp: November 20, 2018, 11:20:03 pm
content: Give them to a local makerspace or school to teach people to solder on?

author: wraper
author_rank: Unknown
timestamp: November 20, 2018, 11:26:25 pm
content: You attach them to a stencil with double sided adhesive tape to fix PCB in place when applying solder paste.

author: babysitter
author_rank: Frequent Contributor
timestamp: November 20, 2018, 11:26:32 pm
content: Documentation. Training device. Drill or other jig. Evaluation board for the next time you use the same subcircuit again. Give general solder training to somebody. Artwork. If open-sourcable, offer it to people willing to copy it.

author: james_s
author_rank: Super Contributor
timestamp: November 21, 2018, 12:01:49 am
content: I've used them as spacers when applying solder paste, soldering practice, breakout boards for parts of the same package style, reinforcement or shims in various mechanical constructions. More artsy fartsy types could probably find things to build out of them for the cosmetic appearance. Probably the easiest thing to do with them is give them to a school or club that teaches electronics as soldering practice, if anyone even does such a thing anymore.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 21, 2018, 01:12:15 am
content: Or just not make them at all!I make dead-bug protos up to about 100 components per board. Schematic capture and layout take more time than diving in and doing it, plus I learn more in the process, bringing up the circuit a piece at a time.Conversely, if the layout timeisn'ttaking longer than the proto, that's a clear indication that your circuit (or your design method..) is not high enough performance to require an on-board proto, and the solderless breadboard will do fine.If you are dealing with larger circuits than that, you need to reconsider your prototype flow. Break it down into smaller, better-specified subcircuits. (Helps as a design methodology, too!) Get dev boards instead of laying everything out in solder. If it's non-critical in terms of performance, do it on solderless breadboard instead.Alternately, study SPICE simulation or the like -- SPICE is probably harder to get right than a breadboard*, but it's a hell of a lot easier to change out parts in!*It's tricky, because you can easily poke down some components and wires and get a believable result; but, as they say, it takes two to lie: one to tell it, and one to believe it. Mind, it's not that the computer is lying, it's more insidious than that: it's only telling you something about the circuityou'veentered. It is up to you, and only you, to construct a circuit that is realistic and representative, and to check and verify the models used are also realistic. Meanwhile, you have to deal with all the vagaries of a numerical solver: stability, accuracy, speed...Tim

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 21, 2018, 01:23:10 am
content: Quote from: ataradov on November 20, 2018, 10:53:11 pmIn fact, not only that, but I'd expect the setup costs (including materials, processing and waste) are steeply in favor of larger board quantities. That is, while you might not be creating more waste (environmental contamination, say) with a single-board quantity, the amount created by a 10-board run might be, pff, only two or three times greater -- for a tenfold increase in useful end product. That is to say: the economy of scale is STEEP at these quantities, very prohibitive against single-digit levels!As for what to do with them -- meh! The waste is done and gone. The fab has paid for it, in whatever way they do (whether directly and responsibly, or by leaving an ever-more-toxic hazard to future generations..), and that cost is rolled into the price you already paid. (Heh, well, maybe...)If the value of keeping the extras is zero, or even negative, there is only one logical thing to do: throw them out, period!Even at purchased cost, they're hardly, if even, worth posting to anyone else. They're that cheap, which is pretty amazing when you think about it.The greater lesson is to grow a sense of real value of things. Disinterested in, and separate from, the effort you put into them, the connection you may have with them. For something this cheap, even just consideration about it, is literally "penny wise and pound foolish"!(That reminds me, I need to get back to w--...oh.)Tim

author: bloguetronica
author_rank: Frequent Contributor
timestamp: November 21, 2018, 02:02:06 am
content: Quote from: analogo on November 20, 2018, 09:52:29 pmThe "wasteful" line of though doesn't apply here. Most PCB houses drill a stack of 3 to 5 boards at a time. If you want a smaller batch, say, of three PCBs, you can order them from OSH Park. That might be more expensive, though.Kind regards, Samuel Lourenço

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 21, 2018, 02:03:42 am
content: If the design is not confidential, sell them as paperweights/bookmarks/jewelry depending on how big they are.