Dynamic semiconductor acceleration sensor for automotive airbag release has two movable electrodes in cruciform arrangement to form condensers

摘要

A dynamic semiconductor sensor has an X-shaped mass section registering dynamic movement in two axes. A dynamic dimensional sensor has a semiconductor substrate (12), a movable electrode (30), first (40,50) and second (60,70) electrodes. The movable electrode has a mass section (31) and electrode sections (32). The mass section contains two rod sections (31a, 31b) in a cruciform arrangement. The first solid electrodes and electrode sections form condensers (CS1, CS2) which register electrode movement in a first direction (X). The second electrodes and electrode sections form second condensers (CS3, CS4) registering movement in a second direction (Y). The movable electrode is constructed such that the ratio of movement in the first direction to that in the second direction is either equal or greater than 1.41.