Double stop structure for a pressure transducer

• US 6,813,956 B2
• Filed: 04/01/2003
• Issued: 11/09/2004
• Est. Priority Date: 10/24/2001
• Status: Expired due to Term

• Current Assignee: Kulite Semiconductor Products Inc
• Original Assignee: Kulite Semiconductor Products Inc
• Inventors: Kurtz, Anthony D., Ned, Alexander A.
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US10/404,308
• Publication Number:
  US 20040020305A1
• Time in Patent Office: 588 Days
• Field of Search: 737/20, 737/21, 737/26, 737/27, 737/54, 361/283.1, 361/283.2, 361/283.3, 361/283.4, 29/253.5
• US Class Current: 73/754
• CPC Class Codes: G01L 19/0618 Overload protection
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0054 integral with a semiconducting diaphragm

Abstract

A stop member is secured to a piezoresistive semiconductor bossed diaphragm at the peripheral area, and includes a first and second slotted apertures in communication with the central active area, the first and second slotted apertures correspond in location with opposing sides of a central boss. The stop member includes a stop cavity located between the first slotted aperture and the second slotted aperture, and the stop cavity overlies the central boss and is separated therefrom to enable the diaphragm to deflect when a force is applied and to enable the central boss to impinge on the surface of the stop cavity when an excessive force is applied. The first and second slotted apertures permit another force to be applied to the active region of the diaphragm in a direction opposite to the stopped direction. A second stop member is secured to the diaphragm to provide stopping in either direction.

Claims

1. A method of manufacturing a differential pressure transducer, comprising:

fabricating a bossed diaphragm comprising a first substrate composed of silicon, and a second substrate composed of silicon dioxide, said diaphragm including an central active region, and a peripheral non-active region separated by a groove which defines a central boss capable of deflecting;

disposing a plurality of piezoresistive sensing elements on said active region;

forming a plurality of contact areas on said diaphragm that extend from said sensing elements to said peripheral region; and

forming a first stop member including a cavity in the central portion thereof, a plurality of cutout portions of the periphery thereof, and two slotted apertures extending through said stop member, and

forming a second stop member including a cavity in the central portion thereof and two substantially parallel slotted apertures extending through said second stop member, and

placing said first stop member on the bossed surface of said diaphragm to enable said boss to impinge on said stop member for a force in a first direction, and

placing said second stop member on the surface opposite said boss to enable said diaphragm surface opposite said boss to impinge on said stop member for a force in a direction opposite to said first direction.

2. The method according to claim 1 further fabricating a piezoresistive sensor array on said surface of said diaphragm opposite said boss.

3. The method of claim 2, the steps of forming a first and a second stop member further comprising:

forming said first and said second stop members of borosilicate glass.

4. The method of claim 2, further comprising the step of electrostatically bonding said first and said second stop members to said diaphragm.