Dynamic quantity sensor

• US 20040238943A1
• Filed: 10/30/2003
• Published: 12/02/2004
• Est. Priority Date: 11/07/2002
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Fujii, Tetsuo
• Application Number:
  US10/695,785
• Publication Number:
  US 20040238943A1
• Time in Patent Office: Days
• US Class Current: 257/704
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding

Abstract

A dynamic quantity sensor includes a sensor board (10) having a movable portion (13) at one surface side thereof and a silicon layer (14) at another surface side thereof. The movable portion (13) is displaced under application of a dynamic quantity. The silicon layer (14) is separated from the movable portion (13) through an insulator (15). The dynamic quantity sensor also includes a circuit board (20) for transmitting/receiving electrical signals to/from the sensor board (20). The circuit board (20) is disposed to confront the one surface of the sensor board (10) through a gap portion (30) and cover the movable portion (13). The sensor board (20) and the circuit board (20) are bonded to each other around the gap portion (30) so that a bonding portion (40) is formed to substantially surround the gap portion (30) and thereby seal the gap portion (30).

Claims

1. A dynamic quantity sensor comprising:

a sensor board including a movable portion at one surface side thereof and a silicon layer at another surface side thereof, wherein the movable portion is displaced under application of a dynamic quantity and the silicon layer is separated from the movable portion by an insulator; and

a circuit board for transmitting to and receiving electrical signals from the sensor board, wherein the circuit board is disposed to confront the one surface of the sensor board through a gap portion and to cover the movable portion, and the sensor board and the circuit board are bonded to each other around the gap portion so that a bonding portion is formed that substantially surrounds the gap portion.

2. The dynamic quantity sensor according to claim 1, wherein the sensor board and the circuit board are sealingly wrapped by mold material.

3. The dynamic quantity sensor according to claim 1, wherein:

a recess portion is formed on a surface of the circuit board facing the sensor board to thereby form the gap portion; and

the bonding portion is formed at sites other than the recess portion on the circuit board.

4. The dynamic quantity sensor according to claim 1, wherein the sensor board is designed to have a plurality of movable portions formed on one surface thereof, and the circuit board covers each of the plurality of movable portions through the gap portion.

5. The dynamic quantity sensor according to claim 1, further comprising a lead frame for transmitting electrical signals to an exterior, wherein the sensor board is bonded to the lead frame on another surface opposite to the one surface of the sensor board facing the circuit board.

6. The dynamic quantity sensor according to claim 1, further comprising a lead frame for transmitting the electrical signals to an exterior, wherein an overhang area that does not face the sensor board and that overhangs from the sensor board is equipped on the surface of the circuit board that faces the sensor board, and the lead frame is bonded to the overhang area on the circuit board.

7. The dynamic quantity sensor according to claim 1, wherein an overhang area that does not face the sensor board and that overhangs from the sensor board is equipped on the surface of the circuit board that faces the sensor board, and a separate board separated from the sensor board is equipped to the overhang area on the circuit board so that the circuit board is supported by the separate board.

8. The dynamic quantity sensor according to claim 1, wherein the sensor board and the circuit board are electrically connected to each other by bonding wires.

9. The dynamic quantity sensor according to claim 1, wherein the sensor board and the circuit board are sealingly wrapped by mold material.

10. The dynamic quantity sensor according to claim 9, wherein the sensor board and the circuit board are sealed by soft material softer than the mold material, and the outside of the soft material is wrapped by the mold material.

11. The dynamic quantity sensor according to claim 10, wherein:

a recess portion is formed on a surface of the circuit board facing the sensor board to thereby form the gap portion; and

the bonding portion is formed at sites other than the recess portion on the circuit board.

12. The dynamic quantity sensor according to claim 10, wherein the sensor board is designed to have a plurality of movable portions formed on one surface thereof, and the circuit board covers each of the plurality of movable portions through the gap portion.

13. The dynamic quantity sensor according to claim 12, wherein a rim portion abutting against the sensor board is formed at a site on the circuit board facing areas other than the area having the plurality of movable portions formed therein on the sensor board.

14. The dynamic quantity sensor according to claim 9, wherein:

a recess portion is formed on a surface of the circuit board facing the sensor board to thereby form the gap portion; and

the bonding portion is formed at sites other than the recess portion on the circuit board.

15. The dynamic quantity sensor according to claim 9, wherein the sensor board is designed to have a plurality of movable portions formed on one surface thereof, and the circuit board covers each of the plurality of movable portions through the gap portion.

16. The dynamic quantity sensor according to claim 15, wherein a rim portion abutting against the sensor board is formed at a site on the circuit board which faces areas other than the area having the plurality of movable portions formed therein on the sensor board.

17. The dynamic quantity sensor according to claim 9, further comprising a lead frame for transmitting the electrical signals to an exterior, wherein an overhang area that does not face the sensor board and that overhangs from the sensor board is equipped on the surface of the circuit board that faces the sensor board, and the lead frame is bonded to the overhang area on the circuit board.

18. The dynamic quantity sensor according to claim 9, wherein an overhang area that does not face the sensor board and that overhangs from the sensor board is equipped on the surface of the circuit board that faces the sensor board, and a separate board separated from the sensor board is equipped to the overhang area on the circuit board so that the circuit board is supported by the separate board.

19. The dynamic quantity sensor according to claim 9, wherein a plurality of sensor boards is bonded to the circuit board.

20. A dynamic quantity sensor comprising:

a sensor board including a movable portion at one surface side thereof, wherein the movable portion is displaced under application of a dynamic quantity; and

a circuit board for transmitting to and receiving electrical signals from the sensor board, wherein the circuit board is disposed so as to confront one surface of the sensor board through a gap portion and to cover the movable portion, and wherein the sensor board and the circuit board are partially bonded to each other around the gap portion.