PORTLAND, Ore. Infrared night vision goggles used by the U.S. military are limited by thermally-generated noise in indium gallium arsenide (InGaAs) infrared sensors.
Nextreme Thermal Solutions Inc. (Durham, N.C.) and infrared sensor maker Princeton Lightwave Inc. (PLI, Cranbury, N..J.) have used thermal bump technology to cool a short-wave infrared InGaAs focal plane array.
|Heat from active electronics in focal plane array chips are channeled by a thermoelectric layer through the copper pillar to the printed circuit board.|
Nextreme's thermal copper pillar technology studs the backside of the focal plane array with solder bumps that help transfer heat from night vision goggles. By incorporating a proprietary nanoscale thermoelectric thin film into each bump, the copper pillars carry heat off the sensor as they transmit signals.
When current passes through the bumps from the array, the end of the thermoelectrically-active structures against the array cools faster than the other end, creating a thermal differential that lowers sensor temperature.
Unlike current sensors, PLI's focal plane array utilizes the 1.6-micron wavelength, which enables the use of laser illuminators that are invisible to current night vision goggles.