[PCB_FORUM] Re: First Article Inspection

Dennis,
 
Ensure vendor doesn't add any information or logo in copper layer. We had bad 
experience in past. Vendor without consulting, added his Logo on top copper 
layer 
that was suppose to be free. The entire lot was of prototype pcb's was rejected 
as it violated minimum required between sub circuits.
 
Trilok Budathoki
GE-India Innovation center
Email: trilok.budathoki@xxxxxx
 
 

-----Original Message-----
From: icu-pcb-forum-bounce@xxxxxxxxxxxxx 
[mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx]On Behalf Of Tom Wood
Sent: Thursday, January 26, 2006 7:18 AM
To: icu-pcb-forum@xxxxxxxxxxxxx
Subject: [PCB_FORUM] Re: First Article Inspection



Dennis,

            I assume that you are saying that the boards are fabricated at a 
subcontractor, and you want to do an incoming inspection before placing 
components onto the boards?  If so, the board should already have been tested 
to make sure it complies with the fab drawing by the fab house.

 

            If that is the case I think your process should involve just a 
couple of steps:

            1.  Make sure that your fab drawing calls out everything that you 
care about, including 100% electrical test, any impedance requirements, and 
compliance to various industry/government specs.

            2.  When the boards arrive, inspect the inspection reports.  Make 
sure that it looks like the testing was actually done.  I.e. the impedance of 
controlled impedance traces should vary slightly from board to board, it 
shouldn't just say "50ohms" straight down the report.  The measured dimensions 
of the board have the same issue.  The tolerance is probably +/-10 mils, if the 
report says that everything is perfect, they probably didn't actually measure 
it.

            3.  Pick a couple tests and spot check them:

                        a.  do a visual inspection looking for soldermask issues

                        b.  do a visual inspection looking for drill breakout 
issues

                        c.  get a Multimeter and check impedance between the 
various plane layers.

 

            My experience is that fab issues come in two flavors: 
cosmetic/outside layer stuff, and buried electrical stuff.  You can't find the 
buried electrical stuff on the bare fab unless you check every net, but you 
already paid the fab house to do that for you.  And the cosmetic outside stuff 
should be easy to spot if you look.

 

Tom
Arira Design, Inc.
408-844-8433 x112 

 


  _____  


From: icu-pcb-forum-bounce@xxxxxxxxxxxxx 
[mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Carrow, Dennis
Sent: Wednesday, January 25, 2006 8:25 AM
To: icu-pcb-forum@xxxxxxxxxxxxx
Subject: [PCB_FORUM] First Article Inspection

 

Hello Everyone,

            I'm at a new company that does its own manufacturing but it appears 
they don't have an inspection group doing a first article inspection on bare 
boards.  I know it should be done but I don't know what to tell them to 
inspect.  The other PWB guy here wants to tell them to inspect to IPC A-600F 
but that doesn't tell them what I think they need to know.  Is there any 
information out there that can help me document what they need to look for?  
Thanks for any advice!

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