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Browse Prior Art Database

Micromechanical Sensor for and Angular Accelerations

IP.com Disclosure Number: IPCOM000099247D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 4 page(s) / 128K

Publishing Venue

IBM

Related People

Greschner, J: AUTHOR [+2]

Abstract

This article describes a standardized universal sensor which simultaneously senses linear and accelerations, providing extremely accurate values within a variable range.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Micromechanical Sensor for and Angular Accelerations

       This article describes a standardized universal sensor
which simultaneously senses linear and accelerations, providing
extremely accurate values within a variable range.

      For this purpose, the property of silicon micromechanics used

                            (Image Omitted)

 which affords the of complex assemblies
comprising a plurality of designed elements at substantially the same
cost single elements.

      The basic element of the acceleration sensor is shown in 1A-1D.
 A surface 1, coated with an inert compound is suspended from, say,
four carrier arms 2 of boron-doped electrically conductive silicon
above an pit 3 (Figs. 1A and 1B).  The base of etch pit 3 of
a non-conductive silicon oxide layer having a 4 of about 10 mm.  This
layer is applied to the of the silicon wafer after another,
corresponding, pit been etched into silicon wafer from the back side.
 The bottom surface of pit on the back side is provided with a
blanket 5 acting as the counterelectrode, insulated by SiO2/Si3N4
layer, for the gold compound on the front of the assembly.  The two
electrodes are connected by 6 to electronic evaluator means.

      In response to a small linear acceleration (Fig. 1D) in Z-
direction (perpendicular to the silicon wafer), the compound 1 stays
behind, bending the carrier arms 2, the spacing of the electrodes
changing such that it may measured.  (A linear acceleration in one of
the parallel to the wafer surface produces no change in the capacitor
power.)  The deflection the gold compound is proportional to the
linear and is determined by parameters depending upon dimensions, the
material and the design of the sensor.

      In response to an acceleration in the Z-direction, values,
according to Fig. 1, cause the gold 1 to touch the base of pit 3
(limit of measuring preventing damage by impact forces.  For
perpendicular to the Z-direction, the to deflections is greater than
in the Z-direction to the design of the carrier arms 2.  However, to
damage, in particular to the more delicate senso...