Precise Thermal Control of CCD Assembly of Space Optical Remote Sensor

One of the most significant requirements driving CCD assemblies design is the operating temperature. In order to avoid unaccepted dark current, CCD need operate between 7 degrees C and 15 degrees C and temperature gradient across the focal plane should be not greater than 1.0 degrees C. These requirements must be achieved by combining active and passive measures. This paper focuses on the precise thermal control design, analysis and test. Because CCD assemblies include focal electronics and movable precise focalizing parts, thermal control must utilize the integrated method to achieve compatible design. Largely using standard and well-proven technologies, this paper also points out some special techniques used. Based on finite difference method and transient energy equations, thermal model of CCD assemblies were built utilizing thermal software and solved for extreme cases. To validate the design, thermal balance test has been done. Analysis and test results have shown that CCD temperature can be controlled between 7.2 degrees C and 13.5 degrees C and temperature gradient was less than 0.5 degrees C. These jobs could give some guidance and reference for the precise thermal control of CCD assembly of other space optical remote-sensor.