Michael,
Your problem is very real, we perform incoming inspection for printed circuits.
I will not go into many details, but :
Visual inspection is done for each lot on a sample basis, as well as dimensional
testing.
Cross sections for copper thickness in holes and solderability are done following a
skip lot program based on supplier, number of layers, PCB, and supplier history.
We try to order only from suppliers with good history, thus we can widen the intervals
between tests.
New suppliers are tested for each lot for a while, and if successful, they enter the
skip lot.
We are a CM , and do the purchasing too, being totally responsible for the assemblies.
Gaby

Michael Blackburn wrote:

> The company I work for is in the process of moving from inspecting incoming
> pcbs to a "dock to stock" program. Also, we are outsourcing more of our pcb
> assemblies and the feeling is that the CM should be responsible for the
> quality and reliability of the bare board.
>
> Does anyone have feedback about dock to stock programs? What kind of SPC are
> you doing? Is a thourough audit of the board vendor and CM enough? What kind
> of scrap/defect rates are you seeing?
>
> The reason I'm asking about this is because in a recent post about baking
> boards, someone responded that they were doing copper plating thickness
> measurement in the wall of the PTH. We experienced the same problem (blow
> holes) and ended up doing the same test.
>
> I would appreciate any feedback/experiences you might have.
>
> Sincerely,
>
> Mike Blackburn
>
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