Background
Packaging often accounts for the bulk of MEMS/MOEMS (Micro-ElectroMechanical-Systems and Micro-Opto-Electromechanical Systems) costs, particularly when a specific atmosphere is required. Bolometric detectors are very often subject to these types of constraints because the package has to be permeable to infrared radiation while keeping the detectors in a vacuum environment at a stable temperature.
All package parameters, including its lateral dimensions; volume; mass; mechanical strength; and electrical, thermal, and optical properties have an impact on the properties of bolometric detectors or on the properties and operation of any instruments incorporating these detectors. It is therefore critical to develop and optimize packages to yield maximal sensor performance. Although overall performance is a key criterion for military applications, cost and weight can be equally important packaging criteria. Typical examples include unattended ground sensors (UGS) and the instruments used in unmanned aerial vehicles (UAV).
Solution
In order to meet specific MEMS/MOEMS packaging requirements, INO has developed a variety of packaging techniques, including standard packaging and micropackaging, which it has already used for its own uncooled bolometric detectors.
Our patented wafer-level micropackaging technique makes it possible to package bolometric detectors in cavities smaller than the chip itself. This technology is mainly intended for low-cost, high volume applications. Packaging is performed using windows and ceramic spacers. Unlike standard packaging, micropackaging allows for a 65% reduction in footprint and a notable 93% reduction in weight. Metal or ceramic packages can be used in standard packaging techniques.