JPS6461638A - Semiconductor pressure sensor - Google Patents

Abstract

PURPOSE:To measure two absolute values of different pressure at the same time by fitting a semiconductor chip which has two pressure sensing diaphragms to a stem which has two through holes and thus forming two pressure application parts. CONSTITUTION:The two pressure sensing diaphragms 6a and 6b are formed on the semiconductor single crystal chip 4. Through holes 16a and 16b, and 17a and 17b are formed in a pedestal 3 formed of a material which has nearly the same coefficient of heat expansion with the chip 4 and the stem 1, and the lower part of the hole 17b serves as a pressure conducting pipe 2. This chip 4 is fitted to the stem 1 through the pedestal 13, and then two pressure application parts are formed and a vacuum chamber 13 is formed at the upper part. The atmospheric pressure is measured by one application part and, for example, air suction manifold pressure is measured by the other, so that the two absolute values of different pressure can be measured at the same time.