Application and testing of high temperature materials for solenoid coils

Sandia National Laboratories has designed and proven-in two new solenoid coils for a highly-reliable electromechanical switch. Mil-Spec Magnetics Inc., Walnut, CA, manufactured the coils. The new design utilizes two new materials: Liquid Crystal Polymer (Vectra C130) for the bobbin and Thermal Barrier Silicone (VI-SIL, V-658) for the encapsulant. The use of these two new materials solved most of the manufacturing problems inherent in the old Sandia design. The coils are easier to precision wind and more robust for handling, testing, and storage. The coils have some unique weapon related safety requirements. The most severe of these requirements is the 400°C, 1600 V test. The coils must not, and did not, produce any outgassing products to affect the voltage breakdown between contacts in the switch at these temperatures and voltages. Actual coils in switches were tested under these conditions. This paper covers the prove-in of this new coil design