Vacuum-assisted selective adhesive imprinting for heterogeneous system integration of MOEMS devices : Automated assembly of miniaturized PM sensor

In this paper we propose the selective adhesive bonding technique using contact imprinting from thin adhesive layers spin-coated on the sacrificial polyethylene foils. The imprinting is assisted with vacuum release of the polymer foil to reduce the pull-off adhesive force and prevent sticking, posing less constraints on the required lifting force. We apply this method in assembly of a highly integrated optical particle counter confronted with several strict assembly requirements, such as selective bonding with small feature size (<; 200 μm), minimal adhesive thicknesses (<; 15μm), precise out-of plane tolerances, low adhesive squeeze-out and hermetically sealed packaging. A successful selective adhesive bonding with ratio of vacuum tool area to adhesive contact area of 1:20 was demonstrated.