Dynamic quantity sensor

• US 20080066546A1
• Filed: 08/28/2007
• Published: 03/20/2008
• Est. Priority Date: 09/20/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Katsumata, Takashi
• Granted Patent: US 7,762,134 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

A dynamic quantity sensor includes a base, a sensor chip made of a rectangular board having a corner portion, and a bump. The sensor chip includes a detector, and a plurality of pads. The detector has a movable part, which is displaceable when a dynamic quantity is applied thereto, and detects the dynamic quantity based on a capacitance variation in accordance with a displacement of the movable part. The bump connects the plurality of pads of the sensor chip and the base. The corner portion of the sensor chip is released from the base such that the plurality of pads of the sensor chip is arranged at a location a predetermined distance from the corner portion of the sensor chip.

Claims

1. A dynamic quantity sensor comprising:

a base;

a sensor chip made of a rectangular board having a corner portion, the sensor chip including

a detector having a movable part, which is displaceable when a dynamic quantity is applied thereto, wherein the detector detects the dynamic quantity based on a capacitance variation in accordance with a displacement of the movable part, and

a plurality of pads; and

a bump for electrically and mechanically connecting the plurality of pads of the sensor chip and the base, wherein

the corner portion of the sensor chip is released from the base such that the plurality of pads of the sensor chip is arranged at a location a predetermined distance from the corner portion of the sensor chip.

2. The dynamic quantity sensor according to claim 1, wherein

at least one of the plurality of pads is arranged at an approximately center position of the sensor chip such that the approximately center position of the sensor chip is connected to the base through the bump.

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

the sensor chip has a detector area, in which the detector is disposed, and

at least one of the plurality of pads is arranged in the detector area of the sensor chip.

4. The dynamic quantity sensor according to claim 3, wherein

the detector further has a fixed part opposing to the movable part,

the detector detects the dynamic quantity based on the capacitance variation between the movable part and the fixed part, and

the pad disposed in the detector area of the sensor chip is disposed in a fixed part area of the sensor chip, in which the fixed part is disposed.

5. The dynamic quantity sensor according to claim 4, wherein

the movable part is driven to vibrate in a first direction,

the movable part is detected to vibrate due to a Coliolis force generated in a second direction approximately perpendicular to the first direction, when an angular velocity is applied to the movable part,

the pad disposed in the fixed part area of the sensor chip is one of the plurality of pads, and

the plurality of pads is arranged in the first direction or the second direction.

6. The dynamic quantity sensor according to claim 1, wherein

the plurality of pads is arranged in a cross shape having an approximately center point of the sensor chip as a cross point of the cross shape.

7. The dynamic quantity sensor according to claim 6, wherein

the cross shape extends from the cross point toward each approximately center point of sides of the sensor chip.

8. The dynamic quantity sensor according to claim 1, wherein

the detector is constructed with a first detector and a second detector, which are symmetrical to each other relative to a line for dividing the sensor chip into two equal parts, and

the plurality of pads is arranged in the line.

9. The dynamic quantity sensor according to claim 8, wherein

the movable part is driven to vibrate in a first direction,

the movable part is detected to vibrate due to a Coliolis force generated in a second direction approximately perpendicular to the first direction, when an angular velocity is applied to the movable part,

the plurality of pads arranged in the line is arranged in the second direction.

10. The dynamic quantity sensor according to claim 1, wherein

a part of the plurality of pads is a dummy pad.

11. The dynamic quantity sensor according to claim 1, wherein

the detector and the plurality of pads are arranged on the same face of the sensor chip, and

the sensor chip is connected to the base through the bump such that the detector and the plurality of pads oppose to the base.

12. A dynamic quantity sensor comprising:

a base;

a sensor chip made of a rectangular board having a corner portion, the sensor chip including

a first detector and a second detector, which are symmetrical to each other relative to a first line for dividing the sensor chip into two equal parts, and

a plurality of pads; and

a bump for electrically and mechanically connecting the base and the plurality of pads of the sensor chip, wherein

each of the first and second detectors has a movable part, which is driven to perform a drive vibration in a first direction approximately perpendicular to the first line, and which is detected to perform a detection vibration due to a Coliolis force generated in a second direction approximately parallel to the first line when an angular velocity is applied to the movable part, such that the angular velocity is calculated based on a capacitance variation between the movable part and a fixed part opposing to the movable part,

the plurality of pads is arranged in the first line or a second line for dividing the sensor chip into two equal parts in the first direction,

the plurality of pads arranged in the second line is arranged on the fixed part for detecting the drive vibration or the detection vibration, and

the corner portion of the sensor chip is released from the base.

13. A dynamic quantity sensor comprising:

a base;

a sensor chip made of a rectangular board having a corner portion, the sensor chip including

a detector, which is driven to perform a drive vibration in a first direction, and which is detected to perform a detection vibration due to a Coliolis force generated in a second direction approximately perpendicular to the first direction when an angular velocity is applied to the detector, such that the angular velocity is calculated based on a capacitance variation of the detector,

a plurality of pads; and

a bump for electrically and mechanically connecting the base and the plurality of pads of the sensor chip, wherein

the plurality of pads of the sensor chip is arranged in the first direction or the second direction to be at a location a predetermined distance from the corner portion of the sensor chip.