By: Norbert Lorenz
Over the past few years the interest in Micro-Electro-Mechanical-Systems (MEMS) and Micro-Optical-Electrical-Mechanical-Systems (MOEMS) from research institutions, industrial firms and the press has risen considerably. Of particular interest are lab-on-a chip devices where many subsystems (ICs and MEMS) are assembled to a functional system for medical and bio-photonic applications. To date the main focus has been on the devices themselves; the research and development of low cost, high reliability assembly and packaging has been rather limited, and as a result current MEMS packaging costs can reach up to 90% of the overall device costs.
MEMS are sensors and actuators on a micro- and nanometre scale incorporating mechanical elements and electronics. They are normally built on a common silicon substrate through microfabrication technology, although alternative technologies using different materials are being increasingly developed. MEMS are commonly known for the realisation of “lab-on-a-chip” devices where many subsystems (ICs and MEMS) are assembled together to make a functional system.
The Heriot-Watt group has demonstrated the feasibility of laser-based glass frit bonding of a range of miniature packages, important for MEMS and related applications. The laser provides localised heat energy, preventing damage to temperature-sensitive materials or dis-assembly of other components of the overall system. Glass frit is an ideal material to use, as it conforms well to the surfaces being joined, provides good hermeticity, and the temperatures required are relatively modest.
The above brief overview was extracted from its original abstract and paper presented at The International Congress on Applications of Lasers & Electro-Optics (ICALEO) in Orlando, FL. To order a copy of the complete proceedings from this conference click here