Electronic – Fast approaches for Soldering / PCB assembly


Our team (three hobbyists now developing our first serious device) is interested in soldering/assembling approximately 200 PCBs. We've already found a low-cost manufacturer for the raw boards, so just the assembly remains.

We'd like to keep the total assembly time and cost reasonably low of course, and therefore are considering various approaches.

The numbers are as follows:

  • 200 single-sided PCBs
  • 5 cm X 5 cm board size
  • 30 capacitors and resistors (0603 size)
  • 5 components QFN / QFP
  • 4 components SOIC / SSOP
  • 1 USB connector
  • 1 SD-card-socket

The raw boards may come bunched/panelized as manufactured but essentially, we want to get, on average, each individual board done in less than 20 minutes ideally.

Which one of the following options would you suggest as best? (given the cost constraint and the desired time per board I stated above):

  • Option A: Hand-place components with tweezers, solder resistors and caps with iron, and solder QFN's with hot-air gun ?
  • Option B: Apply solder paste (possibly using a stencil), hand-place components with tweezers, then use a toaster/reflow oven ?
  • Option C: Get it done entirely by an assembly shop ?

Note: All three of us in the team have roughly around 6 months of consistent experience with the traditional soldering method (tweezer, soldering iron, and hot-air-gun). We don't mind any necessary hand-work at all because we're definitely excited about our board, but it would be good to know we're choosing an efficient approach.

Best Answer

C: definitely the assembly shop, if you have the wallet for it. That's for you to decide. Ask some quotes, and decide if doing it yourself is worth the effort. Since this is a hobby project you may think your time is free, but then it has to stay fun as well, hasn't it?

Just got this in a mailing from DesignSpark: fundraising may get you started to have it done by a shop. Erik raised 313 218 dollar for a 5 000 dollar target.
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Alternatively, B: Again, get a quote for a stencil. Yet, even applying the solder paste manually will take less time than hand soldering, which I would not recommend: the resistors and capacitors are not much of a problem, but the ICs may take quite some time if you want to do it proper, i.e. all pins soldered and no short-circuits.

Not A: it takes too long and it's messy. I would only do it myself if I could use the oven.

Remember that Jobs and the Woz also hand-assembled their first batch of Apple computers :-)