BOSSED SILICON CAPACITIVE ABSOLUTE PRESSURE SENSOR
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2002-Jan-31
A bossed silicon capacitive absolute pressure sen- sor can be fabricated to provide the following perform- ance and cost advantages: (1) Increase pressure sensitivity For the prior art shown in Figure la, the pressure sensitivity is proportional to LYh: where L is the linear dimension of the diaphragm and h is its thickness. How- ever, there is a limit of improving the sensitivity by SC& ing due to diaphragm buckling caused by internal stress. Both larger L and smaller h increases the likelihood of buckling. The proposed improved design uses smaller thin areas by etching the diaphragm peripherally (Fig- ure lb and 2). Diaphragm bending will be primarily con- centrated on the small thin area, thereby extending the sensitivity limit without causing buckling.