C. Strandman et Y. Backlund, PASSIVE AND FIXED ALIGNMENT OF DEVICES USING FLEXIBLE SILICON ELEMENTS FORMED BY SELECTIVE ETCHING, Journal of micromechanics and microengineering, 8(1), 1998, pp. 39-44
Assembly systems consisting of aligning pits combined with flexible ho
lding elements have been produced for both passive and fixed alignment
of devices such as chips and optical fibres. The free-standing holdin
g elements were fabricated in bulk silicon using the photovoltaic elec
trochemical etch-stop technique. The pits were oriented along the [100
] direction which resulted in square etch profiles and in underetching
of the passivated silicon surface layer. The devices were inserted in
to the pits and positioned towards aligning corners and edges by speci
ally designed tongues. The chips could be positioned with high precisi
on on the wafer, in contrast to the fibres, due to uneven bottom surfa
ces of the grooves. Hence, the alignment method presented here is more
suitable for chip positioning since the lateral position of the chips
does not depend on the pit depth. The presented assembly systems are
well suited for building hybrid microsystems, where different types of
device are assembled onto a micromachined silicon substrate.