Shock Resistant Mounting for High G Shock Accelerometer

• US 20120085170A1
• Filed: 10/07/2010
• Published: 04/12/2012
• Est. Priority Date: 10/07/2010
• Status: Abandoned Application

• Current Assignee: Meggitt Incorporated (Amphenol Corporation)
• Original Assignee: Meggitt Incorporated (Amphenol Corporation)
• Inventors: Letterneau, James C.
• Application Number:
  US12/900,075
• Publication Number:
  US 20120085170A1
• Time in Patent Office: Days
• US Class Current: 73/514.33
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/123 by piezo-resistive elements, e.g. semiconductor strain gauges
• CPC Class Codes: G01P 2015/0871 using stopper structures for limiting the travel of the seismic mass

Abstract

A high-g shock accelerometer is provided with an LCC case. A MEMs acceleration sensor is positioned in an interior of the LCC case. The MEMs acceleration sensor has exterior surfaces including top and bottom surfaces and side surfaces. An elastomer is in an adjacent relationship or in contact to a majority of the exterior surfaces and to the interior of the LCC case. The MEMs acceleration sensor with the elastomer attenuates LCC case strain sensitivity while retaining wide band frequency response.

Claims

1. A high-G shock accelerometer, comprising:

an LCC case;

a MEMs acceleration sensor positioned in an interior of the LCC case, the MEMs acceleration sensor having exterior surfaces including top and bottom surfaces, end and side surfaces;

an elastomer adjacent to a majority of the exterior surfaces and to the interior of the LCC case; and

wherein the elastomer provides for a reduction in LCC case strain sensitivity to low levels while maintaining high frequency response.

2. The high-G shock accelerometer of claim 1, wherein the elastomer between the MEMs acceleration sensor and the LCC case has negligible effect on phase and amplitude frequency response.

3. The high-G shock accelerometer of claim 1, wherein the MEMs acceleration sensor in the LCC case has low case strain sensitivity to low levels of strain while maintaining good high frequency response.

4. The high-G shock accelerometer of claim 1, wherein the MEMs acceleration sensor includes a base, a core, a side, a seismic mass positioned in the core, a plurality of piezoresistive strain gages, electrical traces and bonding pads.

5. The high-G shock accelerometer of claim 1, wherein the MEMS acceleration sensor is restrained in the LCC case under high G shocks.

6. The high-G shock accelerometer of claim 1, wherein the MEMS acceleration sensor is restrained in the LCC case under a shock of at least 100 G.

7. The high-G shock accelerometer of claim 1, wherein the MEMS acceleration sensor is restrained in the LCC case under a shock of at least 50,000 G.

8. The high-G shock accelerometer of claim 1, wherein the MEMS acceleration sensor is restrained in the LCC case under a shock of at least 80,000 G.

9. The high-G shock accelerometer of claim 1, wherein the MEMS acceleration sensor is restrained in the LCC case under a shock of at least 300,000 G.

10. The high-G shock accelerometer of claim 1, wherein the elastomer is positioned between at least a majority of a bottom of the LCC case and a bottom of the MEMS acceleration sensor.

11. The high-G shock accelerometer of claim 1, wherein the elastomer provides transmission of both low and high frequency accelerations.

12. The high-G shock accelerometer of claim 11, wherein the elastomer provides transmission of both low and high frequency accelerations of from 0 to 100,000 Hz.

13. The high-G shock accelerometer of claim 11, wherein the elastomer provides transmission of both low and high frequency accelerations of from 1 to 100,000 Hz.

14. The high-G shock accelerometer of claim 11, wherein the elastomer provides transmission of both low and high frequency accelerations of from 10 to 100,000 Hz.

15. The high-G shock accelerometer of claim 1, wherein the MEMs acceleration sensor with the elastomer attenuates LCC case strain sensitivity to high fidelity.

16. The high-G shock accelerometer of claim 1, wherein the elastomer is adjacent to a majority of the bottom and side surfaces.

17. The high-G shock accelerometer of claim 1, wherein the MEMs acceleration die has one axis.

18. The high-G shock accelerometer of claim 1, wherein the MEMs acceleration die has two or three axes.

19. The high-G shock accelerometer of claim 1, wherein the MEMs acceleration die is a dual-stack or tri-stack.

20. The high-G shock accelerometer of claim 19, wherein the dual or tri-stack includes two or three wafers bonded together that are singulated.

21. The high-G shock accelerometer of claim 1, wherein the lid protects the MEMS die and provides a hermetic enclosure.