Hi Technetters,
For land bond strength, you
have tell me that the forces, 2 kg and 35kg/cm-sq, of IPC-6012A paragraph
3.7.3 are all the load force. But I still don't understand, why is the
unit different? My previous idea is that 2kg is the load force and
35kg/cm-sq is caculated by the formula (4*load force/(pi*(d1*d1-d2*d2)), where
d1 is the diameter of land and d2 is the diameter of hole. Can you tell
me the correct answer by an example? (say, the reading of the pull
force tester is 2.3kg, the diameter of land is 0.14 inch, the diameter of hole
is 0.13 inch, how can I compare the magnitude of 2kg and 35kg/cm-sq
and use the smaller to discribe that the land bond strength is pass or
fail?)
Thanks,
Best Regards,
>Albert Lai
>TEL : 03-3231111 EXT 5381
>FAX:
886-3-3136611 ; 886-3-3235874
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