Susan,
One cannot "inspect quality into a board". The problems are not with your
supplier's inspection, but with their quality and their process. AOI will
not prevent the quality problems you describe. Visual inspection should be
able to weed these out, but more importantly your supplier should
immediately begin on a program to eliminate the problems in their process
that cause these very basic quality issues.
Rather than having your supplier spend time (and money) figuring out how to
make AOI work, have them spend the time (and money) on their drilling
process and their processes that cause shorts and opens (e.g., the whole
cleaning, resist coat, image, develop, plating, etc. processes). They need
to clean up their act! The quality issues you describe, at the dimensions
you describe, have been dealt with and solved years and years ago.
I realize you have a "good relationship" with this supplier, but there must
be dozens out there who will make the boards right the first time! Time to
get firm with your board supplier.
Patty
Patricia J. Goldman
PPG Industries, Inc.
412-492-5516
[log in to unmask]
-----Original Message-----
From: Susan James [mailto:[log in to unmask]]
Sent: Wednesday, August 18, 1999 12:18 PM
To: [log in to unmask]
Subject: Re: [TN] Board Layout for AOI and LPI
Everyone - Thanks for your responses! To answer your questions:
1. Anne - line width and spacing is 15 mil traces on 25 mil centers. We
have a different supplier for our multi-layer boards who also uses Camtek
inspection stations. They have no problem with the annular ring. I did ask
them for input on our "other" supplier problems and they suggested that the
design rules needed to be changed. They also said the quality of the camera
would influence the results. Maybe this is part of the issue. This vendor
also uses LPI for our multi-layer boards.
2. Ed - yes, the finished hole size is .038. I know the potential for pad
break out is high but we have never had break out issues on these boards.
3. Franklin - you make a good point about whether AOI is worth it on older
boards and, Yu-Shan, I did not know that AOI is usually reserved for inner
layers. The reason we requested AOI and LPI is that we have had some
quality issues with this supplier and see these as a way to help eliminate
the problems. We have a good relationship with this supplier and really are
looking to improve the quality of our bare boards as well as improving the
assembly process in our own facility. This supplier is hand screening our
boards and doing visual inspection. We are seeing things like blown tracks,
shorted tracks, poor drilling, debris in holes, and sometimes dusty boards.
This doesn't happen a lot but we need to prevent it. It's hard for me to
talk to our assemblers about quality when we accept defective boards.
Unfortunately, I have no clout with respect to incoming inspection on
boards. I would like to work this out with the vendor. I'm sure they have
some valid points but I think we do, also. Yes, I agree that partnership is
important and we will be meeting with them next month to discuss all of
this.
Any additional comments would be welcome!
Sue James
Taylor Company
(815) 624-5444
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