Semiconductor type differential pressure measurement apparatus and method for manufacturing the same.

摘要

A semiconductor type differential pressure measurement apparatus comprising a measuring diaphragm whose periphery is fixed and two measuring chambers each having a predetermined spacing along both surfaces of said measuring diaphragm. The apparatus detects differential pressure within the allowable limit of measurement, but when an overpressure is applied, the measuring diaphragm is directly backed up by the wall of the measuring chamber to prevent the diaphragm from being damaged by the overpressure. Accordingly, the apparatus requires no additional protective mechanism against overpressure. The apparatus comprises an additional chamber accompanied by an overhang provided in such a manner that the effective area thereof may be larger than that of the opening of the chamber. Accordingly, the force which is exerted to the joint portion between the silicon substrate and the support substrate upon application of an overpressure can be greatly reduced. Two measuring chambers each having a predetermined spacing are provided along both sides of the measuring diaphragm. Accordingly, the exterior of the semiconductor differential pressure measuring apparatus according to the present invention may be exposed to open air, and thereby no particular pressure-resistant casing is necessary. In further detail, the sensor portion need not be covered with a pressure resistant vessel as in the apparatuses of the conventional type in which the measuring pressure is applied externally to the sensor. The semiconductor type differential pressure measurement apparatus according to the present invention comprises a conductor connection formed by introducing impurities into the joint surface between the silicon substrate and the support substrate, and one end thereof is further connected to a strain detector element. Accordingly, no pressure-resistant hermetic sealing is necessary in extract an electric signal.