Thermal Contact Electronic Packaging in Solar Pointing Space Environment

A thermal design for a solar pointing Space Shuttle mission is presented. The apparatus, which will measure solar flux intensity variations, contains sensors and data acquisition electronics which must be maintained within certain temperature constraints. The thermal design, which utilizes parallel heat flow paths and conduction fins to reject dissipated heat, is shown by finite difference thermal modeling to maintain component temperatures within these constraints. In the thermal modeling, arithmetic nodes are used to represent surface radiosity for radiation heat transfer. Also, the concept of mean fin conduction length and effective fin capacitance are introduced as means of simplifying the model representation of the conduction fins. An experiment was conducted to evaluate the chip/fin contact conductance.