Physical quantity sensor

• US 20080030205A1
• Filed: 06/12/2007
• Published: 02/07/2008
• Est. Priority Date: 06/13/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Fujii, Tetsuo, Kawasaki, Eishi
• Granted Patent: US 7,540,199 B2
• Time in Patent Office: Days
• US Class Current: 324/661
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 7/02 containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] B81B7/04 takes precedence
• CPC Class Codes: B81C 2203/0118 Bonding a wafer on the substrate, i.e. where the cap consists of another wafer
• 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: 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: H01L 2224/05553 being rectangular
• CPC Class Codes: H01L 2224/05554 being square
• 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 2224/49175 Parallel arrangements
• 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 2924/00014 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 2924/1461 MEMS

Abstract

A physical quantity sensor for detecting a physical quantity includes: a first substrate having a first physical quantity detection element; a second substrate having a second physical quantity detection element, wherein the second substrate contacts the first substrate; and an accommodation space disposed between the first substrate and the second substrate. The first physical quantity detection element is disposed in the accommodation space. The first physical quantity detection element is protected with the first substrate and the second substrate since the first physical quantity detection element is sealed in the accommodation space.

Claims

1. A physical quantity sensor for detecting a physical quantity comprising:

a first substrate having a first physical quantity detection element;

a second substrate having a second physical quantity detection element, wherein the second substrate contacts the first substrate; and

an accommodation space disposed between the first substrate and the second substrate, wherein

the first physical quantity detection element is disposed in the accommodation space.

2. The sensor according to claim 1, wherein

the first physical quantity detection element includes a first movable electrode and a first fixed electrode,

the first movable electrode faces the first fixed electrode so that a capacitance is provided therebetween, and

the capacitance is changeable in accordance with movement of the first movable electrode so that the physical quantity is detected based on capacitance change.

3. The sensor according to claim 1, wherein

the second physical quantity detection element is disposed in the accommodation space.

4. The sensor according to claim 1, wherein

the second physical quantity detection element includes a second movable electrode and a second fixed electrode,

the second movable electrode faces the second fixed electrode so that a capacitance is provided therebetween, and

the capacitance is changeable in accordance with movement of the second movable electrode so that the physical quantity is detected based on capacitance change.

5. The sensor according to claim 1, wherein

the second substrate further includes a through hole electrode, and

the through hole electrode electrically couples between the first physical quantity detection element and the second substrate so that so that a signal is transmitted between first physical quantity detection element and the second substrate.

6. The sensor according to claim 1, wherein

the second substrate further includes a diaphragm, a surface of which is parallel to the second substrate and perpendicular to a physical quantity detection direction,

the second physical quantity detection element is a strain detection element for detecting strain of the diaphragm along with the physical quantity detection direction, and

the physical quantity is detected based on the strain.

7. The sensor according to claim 1, wherein

the second substrate further includes a diaphragm having a second movable electrode,

the diaphragm is parallel to the second substrate and perpendicular to a physical quantity detection direction,

the second physical quantity detection element is provided by the second movable electrode and a second fixed electrode,

the second movable electrode faces the second fixed electrode so that a capacitance is provided therebetween, and

the capacitance is changeable in accordance with movement of the second movable electrode so that the physical quantity is detected based on capacitance change.

8. The sensor according claim 1, wherein

the accommodation space provides a reference pressure chamber for detecting the physical quantity with the second physical quantity detection element.

9. The sensor according to claim 6, wherein

the diaphragm includes a deformation portion and a frame portion,

the deformation portion is deformable in accordance with the pressure,

the frame portion supports the deformation portion,

the frame portion includes a through hole electrode, and

the through hole electrode electrically couples between the first physical quantity detection element and the frame portion so that a signal from the first physical quantity detection element is transmitted to the frame portion.

10. The sensor according to claim 1, wherein

the first physical quantity detection element faces the second physical quantity detection element.

11. The sensor according to claim 1, wherein

the first substrate is bonded to the second substrate with a solder layer,

the first substrate further includes a wiring, and

the solder layer couples between the wiring and the second physical quantity detection element so that a signal from the second physical quantity detection element is transmitted to the wiring.

12. The sensor according to claim 1, wherein

the first substrate further includes a support layer, an insulation layer, a conductive layer and a lower wiring,

the support layer, the insulation layer and the conductive layer are stacked in this order,

the first physical quantity detection element is disposed in the conductive layer,

the lower wiring is sandwiched between the insulation layer and the conductive layer, and

the first physical quantity detection element is coupled with the second substrate through the lower wiring.

13. The sensor according to claim 1, further comprising:

an air-tight ring disposed between the first substrate and the second substrate.

14. The sensor according to claim 1, wherein

the first substrate further includes a first processing circuit and a first wiring, and

the first physical quantity detection element is electrically coupled with the first processing circuit through the first wiring.

15. The sensor according to claim 1, wherein

the second substrate further includes a second processing circuit and a second wiring, and

the second physical quantity detection element is electrically coupled with the second processing circuit through the second wiring.

16. The sensor according to claim 1, wherein

the first physical quantity detection element and the second physical quantity detection element are provided by a semiconductor physical quantity sensor formed by semiconductor process, and

the first physical quantity detection element detects the physical quantity along with a first direction, which is different from a second direction of the second physical quantity detection element.

17. A physical quantity sensor for detecting a physical quantity comprising:

a first substrate having a first physical quantity detection element; and

a second substrate having at least a processing circuit for processing an output signal from the first physical quantity detection element, wherein

the second substrate faces and contacts the first substrate so that an accommodation space is provided between the first substrate and the second substrate.

18. The sensor according to claim 17, wherein

the first physical quantity detection element is disposed in the accommodation space.

19. The sensor according to claim 17, wherein

the processing circuit on the second substrate faces the first substrate.

20. The sensor according to claim 19, wherein

the second substrate further includes a protection film for covering the processing circuit and a second wiring,

the second wiring is embedded in the protection film,

the second wiring is electrically coupled with the processing circuit,

the first substrate further includes a through hole electrode therein, and

the second wiring is electrically coupled with the first physical quantity detection element through the through hole electrode.

21. The sensor according to claim 17, wherein

the processing circuit on the second substrate is opposite to the first substrate.

22. The sensor according to claim 21, wherein

the second substrate further includes a concavity, which is disposed opposite to the processing circuit, and

the accommodation space is provided between the concavity and the first substrate.

23. The sensor according to claim 21, wherein

the second substrate further includes a protection film for covering the processing circuit and a second wiring,

the second wiring is disposed in the protection film,

the second wiring is electrically coupled with the processing circuit,

the first substrate further includes a first through hole electrode and a first wiring,

the second wiring is electrically coupled with the first wiring through the first through hole electrode, and

the first wiring is electrically coupled with the first physical quantity detection element through the first through hole electrode.

24. The sensor according to claim 18, wherein

the first physical quantity detection element includes a first movable electrode and a first fixed electrode,

the first fixed electrode faces the first movable electrode so that a capacitance is provided therebetween, and

the capacitance is changeable in accordance with movement of the first movable electrode so that the physical quantity is detected based on capacitance change.

25. The sensor according to claim 18, wherein

the first substrate further includes a first through hole electrode,

the first physical quantity detection element is electrically coupled with the second substrate through the first through hole electrode so that a signal is transmitted between first physical quantity detection element and the second substrate.

26. The sensor according to claim 18, wherein

the first substrate further includes a support layer, an insulation layer, a conductive layer and a lower wiring,

the support layer, the insulation layer and the conductive layer are stacked in this order,

the first physical quantity detection element is disposed in the conductive layer,

the lower wiring is sandwiched between the insulation layer and the conductive layer, and

the first physical quantity detection element is coupled with the second substrate through the lower wiring.