I am trying to implement a quality check for our PCBs. We have a pick and place machine and a vapour solder machine. But, unfortunately, even after optical inspection and such, we end up with a lot of tombstones. The worst are the 0201 package passives. They are so small that even after manual inspection, many are assumed to be ok as they are a tiny speck. Is there any documentation that can guide me for a thorough quality check of inhouse PCBs please. I am sure that PCB houses have their own quality checks and protocols. Can anyone share a document that details out the process please. What are the testing and quality control standards implemented by PCB assembly houses ?
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1\$\begingroup\$ Sounds like your fabhouse is not capable of using 0201. Use a different one? \$\endgroup\$– PlasmaHHJul 30, 2015 at 13:53
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1\$\begingroup\$ Aside: Has the PCB designer worked with 0201 packs before? If you're having a lot of tombstoning, you need to look at the PCB itself. Those tiny packages just don't allow you to get away with things you could at 0805 and 0603. \$\endgroup\$– Matt YoungJul 30, 2015 at 13:53
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\$\begingroup\$ @PlasmaHH Tombstoning is more PCB design that manufacturing process, especially at 0201. \$\endgroup\$– Matt YoungJul 30, 2015 at 13:54
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\$\begingroup\$ @MattYoung: I assumed 1) a proper design and c) a fabhouse doing proper rules checks for their capabilities. Probably too much assumptions. \$\endgroup\$– PlasmaHHJul 30, 2015 at 16:43
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We basically do the following things (depending on customer's wishes).
- Automated Optical Inspection (AOI)
- Flying Probe testing (FP)
- In Circuit Testing (ICT)
- Functional Testing
It very much depends on the variety and quantity of products.
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\$\begingroup\$ Could you kindly shed some light on the in circuit testing please. The others look quite expensive to procure unfortunately. \$\endgroup\$ Jul 30, 2015 at 13:53
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1\$\begingroup\$ All of them are expensive to procure up front. This will be an investment you will need to make. Regarding ICT, we use a product from Eschke Elektronik, Berlin (similar to this one: dr-eschke.de/Produkte/CT350_Comet_Td/ct350_comet_td.html). This is basically a freely programmable device where you use an adapter desinged for one specific product. It is especially useful for doing very deep testing for medium to high quantities. There are smaller models available as well, yet I wouldn't recommend it as the first choice system since every product you make will require its own adapter. \$\endgroup\$– Tom L.Jul 30, 2015 at 14:05