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id m0sGwgR-0000GoC; Wed, 31 May 95 17:56 CDT |
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Wed, 31 May 1995 16:41:18 -0400 |
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| From [log in to unmask] Fri Apr 26 13: |
51:36 1996 |
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Generally non-functional lands should be included in the pad stack for
multilayer boards. This is primarily a reliability issue. Results from the
IPC small hole round robin program indicated failure in small holes in the
resin rich areas. By leaving the non-functional lands in the stack, you
reduce the resin rich areas around the holes. However, when laminating high
layer count boards, all the lands tend to present a compression problem.
Therefore, it is advisable to remove some of the lands in the stack. It is
suggested to balance the removal in the z-axis.
Gary Ferrari
Tech Circuits
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