The use of adhesives with low gas permeability in packaging microcomponents
provides a simple, low-cost alternative to the standard techniques for her
metic packaging. The permeability to helium of various epoxy resin adhesive
s was determined by means of a mass spectrometer in reference specimens of
defined dimensions. The adhesive with the lowest permeability to helium was
chosen to bond an evacuated LIGA gyrometer package (flatpack, volume = 1.4
cm(3)). For comparison, a few packages were closed by laser welding. Subse
quently, the pressure rise in the sealed packages due to gas permeation and
desorption from the walls was measured by the integrated microsensor, and
the permeation rate was determined. The permeation rates of as low as 10(-1
7) m(3)/s achieved in bonded packages are comparable to those measured in l
aser welded packages.