On Fri, 07 Jun 1996 17:39:47 -0400 Jarlath McEntee wrote:
>   Have you tried pulling wafers apart? If so do you have any results,
>   numbers, etc?
Yes we have - this is our standard method of assessing bond strength.

Basically we have utilised a puller that is more used to pulling apart steel
wires - hence it is operating at the lower end of its sensitivity, and we have
a fair amount of uncertainty associated with any individual result.

A steel rod is epoxied to each side of the bonded pair (the epoxy has
previously been tested for its bond strength) and cured. The rods are mounted
in the puller and a tensile load applied until the weakest part, the Si-Si
bond, fails. Results are in the low MPa region.

We have been trying to produce a bond using low temperature fusion, and can
produce a bond strength in the 0.5 - 1 MPa range at 200 C. The higher the
temperature, the greater the strength.

Cheers,

Dave Wood.