I have been designing and prototyping a PCB for the last couple of months. I'm at the point where I'm extensively testing these boards before going into production. I have come across multiple reliability issues, like a USB or CSI bus not working on multiple PCBs after 2 or 3 weeks. These issues did not show up when I initially powered up the device and tested it with all peripherals connected. So I'm fairly certain that these reliability problems are caused by manufacturing error as I hand assembled these boards and had multiple boards not function correctly during the initial power up. My plan is to have the board house assemble the PCB to eliminate most assembly issues and I have a plan to test these manufactured boards. However, I want validate my design before I drop some money into professional assembly.

What are some common industry standards to validate the PCB layout? I came across this checklist which might be a good start to ensure a good layout, but are there any other steps that I need to take to verify the layout/design?


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The desire is for the design to match the PCB layout and the PCB layout to match the schematic.

The most important thing is to work with the assembly house on ways/practices to avoid errors. The way I do this is I have a mechanical file with all component values and a part number, that way the information can be overlayed on the gerbers and it's easy to check where the physical component goes. The other thing is designators, and making sure they are in readable locations on the board and that the designators in the BOM match the PCB. I also have a note that the 'assembly house' reads in all my files and have been given special instructions to read each note in the file before processing/assembling the board.

I also have a guarantee from the assembly house that they fix all errors if they haven't assembled the boards right, that gives them extra incentive (but adds cost)

The biggest problems with assembly houses that I have experienced are:

  • Backwards components and not following SMT pin indicators

  • Solder joints between parts

  • Leaving out specially marked items on BOM or installing them incorrectly

  • A PCB with a plated through hole that was not tested (and should have been)

Most of the time they get it right, and usually they contact me with assembly questions before the build.

If you're really concerned about a build, make sure you do a prototype run of a few boards and test them before manufacturing 10-1000's of boards. I prototype my boards in house, normally I can turn a board around in 1 day after a PCB manufacturing time of 4-6 days. Sometimes I send out the prototype run for assembly and get 5 done, then release them to manufacturing for order.

I don't really concern myself with all of the industry specifications, because even with all of the ISO and IPC standards the assembly house still makes mistakes, and I don't want to spend 10% of my time reading, I'd rather be designing and fix the mistakes when they show up.

For higher volume designs, every detail matters as even small differences can affect the yeilds of correctly working designs. Things like soldermask size and pad size being off by a few mils can cause a small percentage of the parts to fail in the assembly process (think tombstoning and simmilar SMT failures). Most board houses/assembly houses are more than happy to help with issues or preempt issues through correct design. In the high volume cases work with your fabricators.

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    \$\begingroup\$ If this is volume production (>1K) you might want to ramp up production gradually. For example, if you fab 100 and find there's one IC that often doesn't solder correctly, you can try and tweak the design before the next batch. You don't want to jump in and fab 100K and discover that 50K need reworking (even if somebody else is paying, it will substantially increase production time). You need a batch of 100+ before you really know what the yield stats are like. \$\endgroup\$ Commented Jul 24, 2018 at 22:16

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