Fred...

The only strategies available today are the "double-density" BBTesters that give
you an extra pin in the center of the std .100 grid and the "flying probe" type 
testers. Most folks today are using a combination test, flying probe in the high
density area of the PWB and standard BBTester for the remainder of the board. 
Unfortunately, the testers of the world do not have a single solution for high 
volume throughputs.

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______________________________ Reply Separator _________________________________
Subject: Bare Board Test PCBs with BGAs
Author:  [log in to unmask] at internet_gateway
Date:    2/12/96 3:16 PM

Can anyone share successful Bare Board Test strategies and Equipment 
Requirements when 
launching into BGA testing?  For example:  A 19 X 19 array, 1.27 mm pitch, 357 
pin, PBGA with 23 mil diameter NSMD solder pads on 
a board with two signal, one power, and one ground plane.  Can this be done 
using a 100 mil grid BBTester?  Particularly useful would 
be your experience dealing with the obstacles and solutions to unforeseen 
problems.  
     
     
FRED J. PAUL:   [log in to unmask]   FLUKE CORPORATION 
Sr. Process Engineer    POB 9090   M/S 55
PCB Operations     EVERETT, WA 98206
direct: 206 356-5734   fax: 206 356-6070  Corporate: 206 347-6100