Vacuum Packaging Technology for Uncooled Infrared Sensor

Abstract We developed vacuum packaging equipment and low‐cost vacuum packaging technology for the mass production of uncooled infrared focal plane arrays (IRFPAs). The equipment consists of two chambers with identical construction. Two‐chamber architecture provides flexibility in the vacuum packaging process, so we can bake the components and achieve getter activation by heating, stem/cap soldering, and cap/window soldering in a series under high‐vacuum conditions. Heaters and component‐holding jigs are designed to assure rapid and uniform heating to 500°C. The batch size is 27 if we choose a 15‐mm diameter TO8 package and can be increased by enlarging the heater area. We also developed a micro‐vacuum gauge to evaluate the vacuum level in encapsulated packages. The operation principle of this vacuum gauge is based on thermal conduction by air molecules. It can be integrated in IRFPA chips since the fabrication process is compatible with that for IRFPAs. We encapsulated the vacuum gauges in TO8 packages with our vacuum packaging equipment, and confirmed that the pressure in fabricated packages is sufficiently low for high‐performance IRFPA operation (≪1 Pa). Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.