Hello,

As part of our R&D in the packaging of MEMS devices, we occasionally have
test die sheared off of package substrates to evaluate the strength of
attachment materials (SbPb solder, AuSi solder, SnAg solder, etc.).  This
technique is especially useful since strong, low-stress, low outgasing die
attach is particularly important for many MEMS devices (piezoresistive
sensors, MOEMS mirror arrays, resonators, etc.).  Die shearing is
apparently a common technique in microelectronics packaging
evaluation.  With that said, I have noticed that package shear force is
commonly measured in grams, as opposed to Newtons, the SI unit for
force.  Can anybody explain why?  I have yet to receive a satisfactory
answer for this.

Sincerely,

Robert Dean
Auburn University