Fast response temperature sensor and method of making

Abstract

A fast response temperature sensing device particularly adapted for use in a rarefied fluid media comprises a body of semiconducting material having a precisely predetermined positive temperature coefficient of resistivity in a selected temperature range. The body has ohmic contact element secured thereto to form a small spreading resistance type of resistor element having precisely predetermined resistance characteristics. Leads are electrically connected to the element for connecting the element in an electrical circuit. The element is encapsulated for shielding the element from the environment in a temperature zone to be monitored; and a vane having greater thermal conductivity than the encapsulating material and having greater heat capacity than the resistor element are secured in heat-transfer relation to the element to extend outside the encapsulating material for rapidly conducting heat to the resistor element from the temperature zone. The temperature sensing device is made by providing a lead frame having leads and a vane, by mounting the resistor element in heat-transfer relation to the vane and in electrically connected relation to the leads, and encapsulating the element and portions of the leads and vane so that the leads extend outside the encapsulating material to be connected in a circuit and the vane extends outside the encapsulating material to receive and conduct heat to the resistor element.