Acceleration sensing device and method of operation and forming

• US 6,018,998 A
• Filed: 07/18/1998
• Issued: 02/01/2000
• Est. Priority Date: 04/30/1996
• Status: Expired due to Term

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Zunino, Helen M., Koury, Daniel N. Jr.
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Kwok, Helen C.
• Application Number:
  US09/114,193
• Time in Patent Office: 563 Days
• Field of Search: 73/510, 73/511, 73/514.01, 73/514.12, 73/514.16, 73/514.32, 73/514.38, 73/862.381, 73/862.473, 73/862.52, 73/724, 73/754 , 73/504.03, 324/457
• US Class Current: 73/514.16
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/0888 for indicating angular acceleration
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/131 with electrostatic counterbalancing means
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/082 for two degrees of freedom of movement of a single mass

Abstract

A sensor (10) is capable of detecting linear acceleration in the three Cartesian directions and the angular acceleration about three Cartesian axes. The sensor (10) has a conductive layer (32) that is free to move or rotate in any direction. A first, second, and third set of conductors are used to sense and quantify the acceleration of the conductive layer (32). The sensor (10) can also be operated as a closed loop system with the addition of a fourth set of conductors.

Claims

1. A semiconductor device on a support substrate comprising:

a conductive layer that has a first edge, a second edge, a third edge, and a fourth edge, the first edge is opposed to the second edge and the third edge is opposed to the fourth edge, wherein the conductive layer is free to move in a first direction, a second direction, and a third direction, and the first direction, the second direction, and the third direction are orthogonal to each other;

a first conductor under the conductive layer;

a second conductor under the first edge of the conductive layer;

a third conductor under the second edge of the conductive layer;

a fourth conductor under the third edge of the conductive layer;

a fifth conductor under the fourth edge of the conductive layer; and

a sixth conductor overlying the conductive layer and substantially directly over the first conductor.

2. The semiconductor device of claim 1, wherein voltage potentials coupled to the first conductor and the sixth conductor suspends the conductive layer between the first conductor and the sixth conductor.

3. The semiconductor device of claim 1 wherein the second conductor is capacitively coupled to the conductive layer.

4. An integrated circuit comprising the semiconductor device of claim 1.

5. A positional tracking system comprising the semiconductor device of claim 1.

6. An automobile comprising the semiconductor device of claim 1.

7. An apparatus comprising:

a conductive layer that has a first edge, a second edge, a third edge, and a fourth edge, the first edge being opposed to the second edge and the third edge being opposed to the fourth edge, wherein the conductive layer is free to move in a first direction, a second direction, and a third direction, and the first direction, the second direction, and the third direction are orthogonal to each other;

a first conductor under the conductive layer;

a second conductor under the first edge of the conductive layer;

a third conductor under the second edge of the conductive layer;

a fourth conductor under the third edge of the conductive layer;

a fifth conductor under the fourth edge of the conductive layer; and

a sixth conductor overlying the conductive layer and substantially directly over the first conductor.

8. The apparatus of claim 7, wherein a voltage potential placed between the first conductor and the sixth conductor suspends the conductive layer between the first conductor and the sixth conductor.

9. The apparatus of claim 7 wherein the second conductor is capacitively coupled to the conductive layer.