To Fab Shops:

What is the best method to certify/re-certify a pcb fab shop?

How many bad boards should we expect before we consider re-certification?

Where does that responsibility reside.. with QC or the Design group?

We don't require our suppliers to send photoplots to us prior to
shipping boards. We're not sure that they are using all of our
custom apertures that we have defined, especially thermal flashes.
All of our aperture details are outlined in a company document, yet
it would be very easy for a fab shop to substitute thermal flashes
on layers we can't see.

Should purchasing take the blame when new suppliers are not properly
certified?

How long does it take to create a custom aperture on your CAM systems?

Is it so complicated that some shops will substitute apertures?

How do pcb suppliers like to progress through a typical cerfification?

Thanks,