B3.1 - Novel Silicon High Pressure Sensing Element
- Event
- SENSOR+TEST Conferences 2009
2009-05-26 - 2009-05-28
Congress Center Nürnberg - Band
- Proceedings SENSOR 2009, Volume I
- Chapter
- B3 - Micro Sensors
- Author(s)
- P. Heinickel, R. Werthschuetzky - Technische Universität Darmstadt, Darmstadt, Germany
- Pages
- 181 - 186
- DOI
- 10.5162/sensor09/v1/b3.1
- ISBN
- 978-3-9810993-4-8
- Price
- free
Abstract
This paper presents a working principle for a novel piezoresistive high-pressure sensing element for nominal pressure that amounts from 50 MPa to 500 MPa. The novel overload protected sensing element is made of a solid body silicon chip with implanted piezoresistive resistors. A solid body glass substrate is connected to the silicon chip by holohedral anodic bonding. The operating mode of the novel composite element is based on mechanical strain of the silicon chip and the mechanical mismatched substrate caused by the hydrostatic pressure load. As well metrological and analytical investigations as finite element analyses have been done in order to verify the functionality of the novel composite element. The analytical description is predicated on energy conservation within the multilayer compound. On basis of the analytical approach, the improved geometries of the novel composite element enable repeatable measurement results with a normalized sensitivity of Sn = 25µV / V MPa. The measuring is realized within a pressure range up to 100 MPa only, due to the mechanical stability of the electrical feed through. The different investigations yield nearly the same result. The deviations reach values smaller than one percent. Thus, the novel operating mode for measuring high-pressure values is confirmed.