Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Inner short

Views: 1935

#80969

Inner short | 29 August, 2018

I ordered 100boards from one China PCB prototype manufacturer,but there was appeared inner short. How can this happen when boards are electrically tested? And how to avoid this?

reply »

#80970

Inner short | 29 August, 2018

I guess these boards only used Fly test. Flying needle test is one of the methods to check the electrical function of PCB (short circuit test). The flight test machine is a system for testing PCB in a manufacturing environment. Instead of using the bed-of-nails interface, which is used in all conventional online test machines, the fly pin test USES four to eight independently controlled probes that move to the components in the test. The unit (UUT,unitundertest) is transported to the test machine through a belt or other UUT transfer system. Then fix the probe contact test pad of the tester. That is not enough for inner layer, you should be choose resistance testing. That is not normal in PCB prototype manufacturer in China. Focob pcb and ALLPCB is a good choice. They will use resistance test in 4plus layers boards.

reply »

#80980

Inner short | 30 August, 2018

You should request 100% Flying probe coverage - will cost you extra. If you have bigger quantities you could consider ICT fixture.

reply »

IPC Certification Training Schedule

IPC Training & Certification - Blackfox