| 摘要 |
PURPOSE:To decrease the stress produced in the diaphragm and obtain excellent linearity in a semiconductor diaphragm type sensor by forming the monocrystalline Si diaphragm on which a plurality of piezo-resistor elements are attached, by a thick peripheral fixing portion and a thick central rigid portion surrounded therewith. CONSTITUTION:As the diaphragm 1 constituting the sensor, monocrystalline Si having (110) surface is used. A thick central rigid portion 31 is provided in the center, and a thick peripheral fixing portion is formed surrounding the central rigid portion 31 through a groove pointing to the lower surface. Thus, also the central portion of the diaphragm 1 is formed with a rigid portion. On the surface of the diaphragm 1, a plurality of piezo-resistor elements 5 are formed by diffusing P type impurities so as to be on <111> axes and located at positions 52 and 54 on the fixing portion 3 and positions 51 and 53 on the rigid portion 31. Then, the diaphragm 1 is supported by a support 11 and surrounded by a case 10. Each element 5 is connected through a lead wire 7 to a terminal electrode 8 on a terminal strip 9 provided on the surface of the case 10, to form a bridge circuit. |
