Package for semiconductor acceleration sensor

• US 7,615,835 B2
• Filed: 06/29/2006
• Issued: 11/10/2009
• Est. Priority Date: 07/27/2005
• Status: Expired due to Fees

• Current Assignee: Oki Semiconductor Company Limited (ROHM Co., Ltd.)
• Original Assignee: Oki Semiconductor Company Limited (ROHM Co., Ltd.)
• Inventors: Takemasa, Kengo
• Primary Examiner(s): Tran; Minh-Loan T
• Assistant Examiner(s): Kuo; W. Wendy
• Application Number:
  US11/427,784
• Publication Number:
  US 20070024409A1
• Time in Patent Office: 1,230 Days
• Field of Search: 257/E21.5, 257/E23.188, 257/E23.194, 257/415, 257/417, 257/701, 257/E23.19
• US Class Current: 257/417
• CPC Class Codes: G01P 1/006 used for thermal compensation
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/123 by piezo-resistive elements, e.g. semiconductor strain gauges
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors

Abstract

A semiconductor device comprises a package having a cavity in the interior thereof, a chip having a semiconductor element, a board having the chip fixed to a first region on the upper face thereof, and an adhesive portion formed in a second region on the bottom face of the board in order to fix the board to a first face of the cavity, the second region being a region on the board other than the region thereof underneath the first region.

Claims

1. A semiconductor device comprising:

a package having a cavity therein, the package having a bottom surface;

a rectangular board having a plurality of sides, wherein the rectangular board is a deformation relief member and has no integrated circuits therein, and wherein the rectangular board has an upper surface;

a chip, having a semiconductor element, which is mounted on the rectangular board, the chip having a bottom surface that is smaller in size than the upper surface of the rectangular board; and

;

an adhesive portion which attaches the rectangular board to the bottom surface of the package so that the rectangular board is disposed in the cavity and spaced apart from the bottom surface of the package, the adhesive portion extending along the sides of the rectangular board but leaving a hollow space in a central region between the sides.

2. The semiconductor device according to claim 1, wherein the package has an inner side with a convex portion disposed below the chip.

3. The semiconductor device according to claim 1, wherein the adhesive portion is comprised of a solidified resin.

4. The semiconductor device according to claim 1, wherein the adhesive portion is comprised of a silicone resin or fluorine resin.

5. The semiconductor device according to claim 1, wherein the board is comprised of a silicon material.

6. The semiconductor device according to claim 1, further comprising:

a first electrode pad on the chip;

a wiring pattern in the package, at least a portion of the wiring pattern being exposed inside the cavity;

a second electrode pad on the bottom face of the package and connected to the wiring pattern; and

a metal wire electrically connecting the first electrode pad and the exposed wiring pattern.

7. The semiconductor device according to claim 1, wherein at least a portion of the package is comprised of a ceramic material.

8. The semiconductor device according to claim 1, wherein the semiconductor element comprises an acceleration sensor.

9. The semiconductor device according to claim 1, wherein

the semiconductor element comprises an acceleration sensor having a fixing portion, a weight portion, and one or more beams, the fixing portion being fixed to the rectangular board, the beams suspending the weight portion from the fixing portion, and the weight portion being movable with respect to the fixing portion.

10. The semiconductor element according to claim 1, wherein the adhesive portion encircles a region of the rectangular board at which the chip is mounted.