Inertial sensor with dual cavity package and method of fabrication

• US 8,080,925 B2
• Filed: 09/23/2008
• Issued: 12/20/2011
• Est. Priority Date: 09/23/2008
• Status: Active Grant

• Current Assignee: Emcore Corporation
• Original Assignee: Custom Sensors & Technologies Incorporated (Schneider Electric SE)
• Inventors: Berger, William Paul, Collins, Mark Andrew, Frazee, Michael Thomas, Smith, Thad W. (Marc), Anderson, Robert Albert, Knowles, Stuart John, Dragotti, Victor
• Primary Examiner(s): Dougherty, Thomas
• Assistant Examiner(s): Addison, Karen B
• Application Number:
  US12/236,156
• Publication Number:
  US 20100072862A1
• Time in Patent Office: 1,183 Days
• Field of Search: 310/370, 310/344, 310/348, 310/329, 310/311, 734/93, 735/142.9, 735/143.2, 738/041.2
• US Class Current: 310/370
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 7/0058 for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations
• CPC Class Codes: B81C 1/0023 Packaging together an electronic processing unit die and a micromechanical structure die MEMS packages B81B7/0032; MEMS packaging processes B81C1/00261
• CPC Class Codes: G01C 19/5628 Manufacturing; Trimming; Mounting; Housings
• CPC Class Codes: G01C 19/5783 Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 23/057 the leads being parallel to the base
• CPC Class Codes: H01L 2924/1433 Application-specific integrated circuit [ASIC]
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 29/4908 Acoustic transducer

Abstract

Inertial sensor having a body with first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, and leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry.

Claims

1. An inertial sensor, comprising:

a body having a plurality of layers of insulative material bonded together to form first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, and leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry.

2. The inertial sensor of claim 1 wherein the body consists of a stack of ceramic layers laminated together.

3. The inertial sensor of claim 1 including test points which are disposed in the second cavity, connected electrically to the sensing element, and accessible to external test probes.

4. The inertial sensor of claim 1 wherein the sensing element is selected from the group consisting of an angular rate sensing element, an acceleration sensing element, and combinations thereof.

5. The inertial sensor of claim 1 wherein the sensing element is a piezoelectric tuning fork.

6. The inertial sensor of claim 1 including additional interface pads mounted on the outside of the body and connected to the electronic circuitry.

7. The inertial sensor of claim 1 including a lid which covers the cavity on one side of the body and a sealing ring between the body and the lid.

8. The inertial sensor of claim 7 wherein the body is fabricated of ceramic material, the sealing ring and lid are fabricated of a metal alloy, the sealing ring is affixed to the body by brazing, and the lid is hermetically sealed to the ring.

9. The inertial sensor of claim 1 wherein one of the cavities is formed at least in part by a lid having an outer wall spaced from the body and a peripheral side wall between the outer wall and the body.

10. An inertial sensor, comprising:

a body having first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, and leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry, the leads being formed to have at least two inflections and vary in width to make the sensor insensitive to externally applied vibration and shock.

11. An inertial sensor, comprising:

a body having first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, and leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry, each of the leads having a first section that extends laterally from the body, a downwardly curved section extending from the first section, a downwardly and outwardly inclined section extending from the downwardly curved section, an outwardly curved section extending from the downwardly and outwardly inclined section, and a foot section extending outwardly from the outwardly curved section.

12. An inertial sensor, comprising:

a body having first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, and leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry, each of the leads having a first section that extends laterally from the body, an upwardly curved section extending from the first section, a downwardly curved section extending from the upwardly curved section, a downwardly and outwardly inclined section extending from the downwardly curved section, an outwardly curved section extending from the downwardly and outwardly inclined section, and a foot section extending outwardly from the outwardly curved section.

13. An inertial sensor, comprising:

a body having first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, and leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry, each of the leads having an inner end portion near the body, an outer end portion wider than the inner end portion, and a tapered portion between the end portions.

14. An inertial sensor, comprising:

a body having first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, test points which are disposed in the second cavity and connected electrically to the sensing element for testing the sensing element when the first cavity is closed, leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry, and interface pads mounted on the outside of the body for making additional connections with the circuitry.

15. The inertial sensor of claim 14 wherein the leads are formed to have at least two inflections and vary in width to make the sensor insensitive to externally applied vibration and shock.

16. The inertial sensor of claim 14 wherein each of the leads has a first section that extends laterally from the body, a downwardly curved section extending from the first section, a downwardly and outwardly inclined section extending from the downwardly curved section, an outwardly curved section extending from the downwardly and outwardly inclined section, and a foot section extending outwardly from the outwardly curved section.

17. The inertial sensor of claim 14 wherein each of the leads has a first section that extends laterally from the body, an upwardly curved section extending from the first section, a downwardly curved section extending from the upwardly curved section, a downwardly and outwardly inclined section extending from the downwardly curved section, an outwardly curved section extending from the downwardly and outwardly inclined section, and a foot section extending outwardly from the outwardly curved section.

18. The inertial sensor of claim 14 wherein each of the leads has an inner end portion near the body, an outer end portion wider than the inner end portion, and a tapered portion between the end portions.

19. The inertial sensor of claim 14 wherein the leads are formed to have at least two inflections and vary in width to make the sensor insensitive to externally applied vibration and shock.

20. An inertial sensor, comprising:

a body having first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, test points which are disposed in the second cavity and connected electrically to the sensing element for testing the sensing element when the first cavity is closed, leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry, and interface pads mounted on the outside of the body for making additional connections with the circuitry, each of the leads being formed to have at least two inflections and vary in width to make the sensor insensitive to externally applied vibration and shock.