Gas detector

Abstract

Abstract PURPOSE: To permit the gas-sensing element of a gas detector to be readily incorporated in a bridge circuit and to simplify the constitution of the element by forming a cavity in the substrate lower layer, and coating one of two heating units provided on the bridge portions on the cavity with a substance which is inert on a gas to be detected. CONSTITUTION: A portion of a wafer 1 under the upper layer 10 of a heat resisting and electrically insulative substance such as silicon oxide is removed to form a cavity 2, above which two bridge portions 10a and 10b are provided adjacently to each other in the upper layer 10. Then terminals 13a and 13b and heating units 13a' and 13b' are formed of conductive substance on the bridge portions 10a and 10b respectively, and one of the heating units 13a' and 13b' is coated with a substance inert to a gas to be detected such as a SiO 2 film 14. This permits the element to be readily incorporated in a bridge circuit, and enables the constitution of the element to be simplified. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Mitsuteru Kimura

Bibliographic Details