Patent ID: 7111513
Filing Date: 2006-09-26
Classification: B81B,G01C,G01P

Abstract:
1. A physical quantity sensor for detecting a physical quantity, the sensor comprising: a movable portion having a bottom; and a protrusion disposed on the bottom of the movable portion; a fixed electrode; and a substrate for supporting the movable portion movably, wherein the movable portion includes a movable electrode, which faces the fixed electrode in a horizontal direction so that the movable electrode is separated from the fixed electrode by a predetermined distance, wherein the protrusion is provided by a remaining portion, which remains without being etched when the movable portion is prepared by etching, wherein the movable portion is disposed over the substrate with a predetermined clearance therebetween, wherein the protrusion protrudes toward the substrate so that the protrusion prevents the movable portion from adhering to the substrate, wherein the movable portion includes a part, which has a large width compared with other parts of the movable portion, so that the part protrudes from the other parts toward the fixed electrode, wherein the part prevents the movable electrode from adhering to the fixed electrode, wherein the protrusion is disposed on the bottom of the part, and wherein the protrusion is formed simultaneously together with the movable portion in a case where the movable portion is removed from the substrate by etching.