Bespoke interconnect technologies for optoelectronic and biomedical products

Two technologies of topical importance in reducing the weight and volume of portable electronic products are (1) the creation of dense interconnects on an ever reducing silicon real-estate and (2) the formation of high aspect ratio through vias in silicon wafer and Printed Circuit Boards (PCBs) to allow interconnections across stacked devices. Whilst still important for biomedical and optoelectronic products, these interconnect technologies must take into account additional requirements which include material bio-compatibility as well as stringent deposition and assembly temperatures, making packaging and assembly highly challenging fields. This paper presents some interconnection technologies developed by the Microsystems Engineering Centre (MISEC) to address the aforementioned challenges in the area of optoelectronic biomedical devices. The use of these technologies for three prototype products, namely an integration optical encoder, a micro UV-LED array, a miniaturised ultrasonic transducer and an LED bonded onto a flexible substrate, are described and preliminary results are presented. A summary of the key findings and future work conclude this article.