| 摘要 |
PURPOSE:To lessen nonuniformity in an output for a pressure and to reduce nonuniformity in pressure resistance by making a level difference of a movable terminal part of a diaphragm part smaller than a gap in the vicinity of the moveable terminal part between a base part and a movable diaphragm. CONSTITUTION:A sensor is provided with a cavity part 2 formed on one side of a base part 1, a thin-film-shaped diaphragm part 3 covering the cavity part of the base part 1 and formed integrally with an electrode held between insulating films, and a pressure introducing hole 10 so opened on the other side of the base 1 as to communicate with the cavity part 2, and the height of a step of a movable terminal part of the diaphragm part 3 is made smaller than a gap in the vicinity of the movable terminal part between the base part 1 and a movable diaphragm. By this construction, the thin-film diaphragm part 3 is formed to be parallel to the surface of the base 1 and flat, substantially. In other words, a capacitor structure is formed of the upper- side electrode 4 and the base part 1 with the cavity part 2 held there-between. When a pressure is introduced through the pressure introducing hole 10, therefore, the movable part of the diaphragm part 3 is displaced in the vertical direction in accordance with the amount to be measured and the pressure is detected from a change in capacitance. |
