Tom,
I worked in various design areas for a fairly large company (IBM). The last
several were spent working on  TBGA designs and they all used via in pad for
the array. All assembly/test was done in house and once the process and
design parameters were defined there were no problems related to that design
feature.

After about 10 years this entire line/process was sold off to become a
separate business and they still continued to produce TBGA products with via
in pad designs.  I believe our original via size was 0.008" and was
eventually reduced to 0.002". 

I'm sure there were a few "patented" processes and tools involved. This was
being done from the mid 90's until 2002 and we shipped a lot of parts
(probably millions) to both internal and external customers during that time
frame and the general design and build process remained fairly constant. 

Scott D. Riley
Technical Design Service
607-658-9322 - Office
607-785-1696 - FAX
www.techdesignservice.com

 

 



-----Original Message-----
From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of Tom
Parkinson
Sent: Friday, June 25, 2004 11:14 AM
To: [log in to unmask]
Subject: [DC] VIA in Pad


We're a CM.  One of our customers is asking us to build a board assembly
that will be using BGAs with VIAs in pads.  They are in the design stages at
this point, and we have some concerns with having a Via in the middle of a
BGA pad.  Anyone have suggestions and/or experience with this??

Thanks


Tom Parkinson - Quality System Manager - CIT
WinTronics, Inc.
Ph: 724-981-5770 Ext. 235
Fax: 724-981-1772
 

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