Semiconductor acceleration sensor device and method for manufacturing the same

• US 20050279166A1
• Filed: 01/28/2005
• Published: 12/22/2005
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: Oki Semiconductor Company Limited (ROHM Co., Ltd.)
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Shizuno, Yoshinori
• Granted Patent: US 7,568,390 B2
• Time in Patent Office: Days
• US Class Current: 73/493
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• 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 2015/0842 the mass being of clover leaf shape
• 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 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

Although a weight part of an acceleration sensor chip fixed on a die pad is coated with a gelatinous resin part of low elasticity, the weight part is easily displaced by an external acceleration. Thus, an acceleration can be detected with accuracy. Furthermore, long-term reliability equal to those of regular resin packages is ensured because those portions of an acceleration sensor device which are not used for acceleration sensing are sealed with a resin part.

Claims

1. A semiconductor acceleration sensor device comprising:

an acceleration sensor chip that includes;

a weight part,

a support part which flexibly supports the weight part, one end of the support part being connected to the weight part,

a pedestal part surrounding the weight part, an opposite end of the support part being connected to the pedestal part, and

a stress detecting element which detects a stress from deformation caused in the support part due to an acceleration;

an elastic first resin part to coat the weight part and the support part; and

a second resin part to seal the first resin part and the acceleration sensor chip.

2. The semiconductor acceleration sensor device according to claim 1 further comprising:

a die pad which has a first area and a second area, and which also has an upper surface and a lower surface, the second area surrounding the first area, the pedestal part of the acceleration sensor chip being mounted on the second area; and

a through hole which is formed from the upper surface of the first area of the die pad through the lower surface of the first area of the die pad.

3. The semiconductor acceleration sensor device according to claim 2 further comprising a lid part which completely covers the through hole formed in the die pad and which is coated with the second resin part.

4. The semiconductor acceleration sensor device according to claim 2 further comprising:

a conductive part which has a first surface extending outwardly from the second resin part and which is disposed on a periphery of and spaced from the die pad; and

a wire which electrically connects the stress detecting element and the conductive part.

5. The semiconductor acceleration sensor device according to claim 1 further comprising:

a lid part attached to the acceleration sensor chip;

a substrate having a conductive part extending outwardly from the second resin part, the acceleration sensor chip being connected to the substrate via the first resin part;

a bump provided on the substrate and electrically connected to the acceleration sensor chip, the acceleration sensor chip being mounted on the bump.

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

a lid part attached to the acceleration sensor chip;

a substrate having a conductive part extending outwardly from the second resin part;

a semiconductor circuit chip electrically connected to the conductive part of the substrate and mounted on the substrate, the acceleration sensor chip being connected to the semiconductor circuit chip via the first resin part;

a bump provided on the semiconductor circuit chip and electrically connected to the acceleration sensor chip, the acceleration sensor chip being mounted on the bump.

7. A method of manufacturing a semiconductor acceleration sensor device comprising:

preparing an acceleration sensor chip that includes;

a weight part,

a support part which flexibly supports the weight part, one end of the support part being connected to the weight part,

a pedestal part surrounding the weight part, an opposite end of the support part being connected to the pedestal part, and

a stress detecting element which detects a stress from deformation caused in the support part due to an acceleration;

injecting an elastic first resin part to coat the support part and the weight part; and

sealing the first resin part and the acceleration sensor chip with a second resin part.

8. The method of manufacturing a semiconductor acceleration sensor device according to claim 7 further comprising:

preparing a die pad which has a first area and a second area, and which also has an upper surface and a lower surface, the second area surrounding the first area, the pedestal part of the acceleration sensor chip being mounted on the second area, the die pad also having a through hole which is formed from the upper surface of the first area of the die pad through the lower surface of the first area of the die pad;

fixing the pedestal part on the second area of the die pad;

covering the support part and the weight part with the first resin part by injecting the first resin part into the pedestal part via the through hole of the die pad; and

sealing the first resin part, the acceleration sensor chip, and the die pad with the second resin part.

9. The method of manufacturing a semiconductor acceleration sensor device according to claim 8 further comprising:

preparing a lid part which completely covers the through hole formed in the die pad; and

blocking the through hole with the lid part, and sealing the first resin part, the acceleration sensor chip, the die pad, and the lid part with the second resin part.

10. The method of manufacturing a semiconductor acceleration sensor device according to claim 8 further comprising:

preparing a conductive part having a first surface and disposed on a periphery of and spaced from the die pad;

electrically connecting the conductive part and the stress detecting element of the acceleration sensor chip by a wire; and

sealing the first resin part, the acceleration sensor chip, the die pad, the wire, and the conductive part with the second resin part so that the first surface of the conductive part is exposed.

11. The method of manufacturing a semiconductor acceleration sensor device according to claim 7 further comprising:

preparing a substrate having a lid part attached to the acceleration sensor chip, a conductive part extending outwardly from the second resin part, and a bump provided on the substrate and electrically connected to the acceleration sensor chip;

electrically connecting the stress detecting element to the bump by fixing the pedestal part on the bump provided on the substrate;

filling a gap between the pedestal part and the substrate with the first resin part by injecting the first resin part into the pedestal part, and covering the support part and the weight part with the first resin part; and

blocking the pedestal part with the lid part, and sealing the first resin part, the acceleration sensor chip, the lid part, and portions other than the conductive part of the substrate with the second resin part.

12. The method of manufacturing a semiconductor acceleration sensor device according to claim 7 further comprising:

preparing a substrate having a lid part attached to the acceleration sensor chip, and a conductive part extending outwardly from the second resin part;

preparing a semiconductor circuit chip electrically connected to the conductive part of the substrate and mounted on the substrate, the semiconductor circuit chip having a bump provided thereon and electrically connected to the acceleration sensor chip;

fixing the semiconductor circuit chip on the substrate, and electrically connecting the conductive part of the substrate to the semiconductor circuit chip;

electrically connecting the stress detecting element to the bump by fixing the pedestal part on the bump provided on the semiconductor circuit chip;

filling a gap between the pedestal part and the semiconductor circuit chip with the first resin part by injecting the first resin part into the pedestal part, and covering the support part and the weight part with the first resin part; and

blocking the pedestal part with the lid part, and sealing the first resin part, the acceleration sensor chip, the lid part, and portions other than the conductive part of the substrate with the second resin part.

13. The method of manufacturing a semiconductor acceleration sensor device according to claim 7, wherein the support part is coated with the first resin part injected into the pedestal, and the weight part is covered with the first resin part additionally injected into the pedestal part.