Method and apparatus providing focal plane array active thermal control elements

Abstract

A focal plane array (FPA) of infrared (IR) radiation detectors ( ), such as an array of microbolometers, includes an active area ( A) containing a plurality of IR radiation detectors, a readout integrated circuit (ROIC) ( ) that is mechanically and electrically coupled to the active area and, disposed on the ROIC, a plurality of heater elements ( A) that are located and operated so as to provide a substantially uniform thermal distribution across at least the active area. The FPA further includes a plurality of temperature sensors ( B), individual ones of which are spatially associated with one of the heater elements for sensing the temperature in the vicinity of the associated heater element for providing closed loop operation of the associated heater element. In one embodiment pairs of the heater elements and associated temperature sensors are distributed in a substantially uniform manner across at least a top or a bottom surface of the ROIC, while in another embodiment pairs of the heater elements and associated temperature sensors, or only the heater elements, are distributed in accordance with a predetermined thermal profile of the FPA. The plurality of heater elements may each be composed of a silicon resistance, and the plurality of temperature sensors may each be each composed of a silicon temperature sensor.