Randy

B-24 is a single sided specimen with 4 SIR comb patterns of 16mil lines 
and 20 mil spaces.  This was developed for the CFC alternatives, Phase 3 
program looking at flux based alternatives.

B-25 is double sided with 6 comb patterns (3 on each side) that have 
25/25, 12.5/12.5 and 6.5/6 lines and spaces.  In addition B-25 has a number of
other patterns that were originally used in MIL-P-55110C qualification

For your information as part of the IPC-SM-840C (Solder Mask) 
specification revision, we developed IPC-B-25A which is now available.  
This pattern is a single sided board with 2 B-24 combs, with 1 B-25 
(12.5/12.5) comb, 1 military "Y" pattern, and patterns for solder mask 
tenting and a checkerboard pattern for adhesion testing.

Hope this helps.

Regards
__________________________________________________

David W. Bergman, Technical Director
IPC
2215 Sanders Road
Northbrook, IL  60062-6135
847-509-9700 x340 Phone
847-509-9798 Fax
email  [log in to unmask]
www  http://www.ipc.org

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On Mon, 19 Feb 1996 [log in to unmask] wrote:

> What is the difference between the B-24 and the B-25 coupons?
> 
> Randy Reed
> Merix Corporation
> [log in to unmask]
> 503.359.9300  X4421
> 
>