Cap attachment structure, semiconductor sensor device and method

Abstract

In an attachment structure, a protective cap is provided with an adhesion layer on its outer peripheral edge part and its internal surface. The protective cap is bonded and fixed to an adherend member through the adhesion layer. This attachment structure can be suitably used for a semiconductor device. Alternatively, in a semiconductor device, a protective cap can be bonded using an adhesive. In this case, an outer peripheral edge part of the protective cap has a first end positioned on its inner rim surface, and a second end positioned on its outer rim surface. Furthermore, the first end protrudes toward a sensor chip more than the second end, and is adjacent to the sensor chip.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Additional objects and advantages of the present invention will be more readily apparent from the following detailed description of preferred embodiments when taken together with the accompanying drawings. In the drawings:

FIG. 1A is a plan view showing a part of a micro device according to a first embodiment of the invention, and FIG. 1B is a cross-sectional view of the part of the micro device taken along line IB-IB in FIG. 1A;

FIGS. 2A to 2C are cross-sectional views showing an attachment process of a protective cap according to the first embodiment;

FIG. 3 is a cross-sectional view of a part of a micro device showing a modification of the first embodiment;

FIG. 4A is a plan view showing a part of a micro device according to a second embodiment of the invention, and FIG. 4B is a cross-sectional view of the part of the micro device taken along line IVB-IVB in FIG. 4A;

FIGS. 5A and 5B are cross-sectional views showing an attachment process of a protective cap according to the second embodiment;

FIG. 6 is a cross-sectional view of a part of a micro device showing a modification of the second embodiment;

FIG. 7 is a cross-sectional view of a semiconductor acceleration sensor according to a third embodiment of the invention;

FIG. 8 is an enlarged cross-sectional view showing a connection part between a sensor chip and a protective cap according to the third embodiment;

FIGS. 9A to 9F are cross-sectional views showing a manufacturing method of the semiconductor acceleration sensor in FIG. 7;

FIG. 10 is a plan view showing a plan configuration of a polyimide base member;

FIG. 11 is a plan view showing a plan configuration of a semiconductor wafer;

FIGS. 12A and 12B are cross-sectional views showing an attachment process of a protective cap to a sensor chip according to the third embodiment;

FIG. 13 is a perspective view showing a state where dicing-cut is curried out with a dicing blade;

FIG. 14 is an enlarged cross-sectional view showing a connection part between a sensor chip and a protective cap of a semiconductor acceleration sensor according to a fourth embodiment of the invention;

FIG. 15 is an enlarged cross-sectional view showing a connection part between a sensor chip and a protective cap of a semiconductor acceleration sensor according to a fifth embodiment of the invention; and

FIG. 16 is an enlarged cross-sectional view showing a connection part between a sensor chip and a protective cap of a semiconductor acceleration sensor according to the other embodiment of the invention.

Claims

1. A cap attachment structure comprising: an adherend member;a protective cap fixed to the adherend member, wherein the protective cap has an outer peripheral edge part and an internal surface for defining an inner space; andan adhesion layer provided on the outer peripheral edge part and the internal surface of the protective cap,wherein the protective cap is bonded and fixed to the adherend member through the adhesion layer.

2. The cap attachment structure according to claim 1, wherein the adhesion layer is made of an adhesive which has at least one property selected from a group comprising a thermo plasticity, a thermosetting, a photo-curing, a chemical reaction-curing, and a solvent evaporation-curing.

3. The cap attachment structure according to claim 2, wherein the adhesive has a photosensitivity.

4. The cap attachment structure according to claim 1, wherein the adhesion layer on the internal surface has an adhesive function, and is provided without being cured.

5. The cap attachment structure according to claim 1, wherein the adhesion layer has an electric conductivity.

6. The cap attachment structure according to claim 1, wherein the protective cap and the adhesion layer are transparent.

7. A cap attachment structure comprising: an adherend member; anda protective cap made of a material having a thermal plasticity, wherein an outer peripheral edge part of the protective cap is attached to an adherend member so that the protective cap is fixed to the adherend member.

8. A cap attachment structure comprising: an adherend member; anda protective cap made of a material having a thermal plasticity, wherein the protective cap is fixed to the adherend member by using the thermal plasticity of the protective cap.

9. The cap attachment structure according to claim 8, wherein the protective cap has an electric conductivity.

10. The cap attachment structure according to claim 8, wherein the protective cap is transparent.

11. The cap attachment structure according to claim 1, wherein the internal surface of the protective cap is uneven to have a concavity and convexity.

12. The cap attachment structure according to claim 1, further comprising: a movable structure arranged on a surface of the adherend member,wherein the protective cap is fixed to the adherend member to cover the movable structure.

13. A semiconductor device comprising: a sensor chip having a sensor structure made of a semiconductor; anda protective cap for covering the sensor structure, the protective cap having a concave part at a position corresponding to that of the sensor structure and an outer peripheral edge part surrounding the concave part; andan adhesive applied to the outer peripheral edge part so that the protective cap is bonded and fixed to the sensor chip through the adhesive,wherein the outer peripheral edge part of the concave part has a first end positioned on an inner rim surface, and a second end positioned on an outer rim surface, andwherein the first end protrudes toward the sensor chip more than the second end, and is adjacent to the sensor chip.

14. The semiconductor device according to claim 13, wherein the outer peripheral edge part has a taper shaped part.

15. The semiconductor device according to claim 14, wherein all the outer peripheral edge part is formed into a taper shape.

16. The semiconductor device according to claim 13, wherein the outer peripheral edge part is formed into a circular arc shape.

17. The semiconductor device according to claim 16, wherein the outer peripheral edge part connects the first end on the inner rim surface and the second end on the outer rim surface.

18. The semiconductor device according to claim 13, wherein the outer peripheral edge part is formed into a stepped shape.

19. A method of manufacturing a semiconductor device, which includes a sensor chip, and a protective cap for covering a sensor structure of the sensor chip, the method comprising:preparing a protective base member, and forming an outer peripheral edge part into a taper or circular arc shape by carrying out an isotropic etching to the protective base member with a first mask material which covers predetermined positions where concave parts will be formed;after removing the first mask material, forming the concave parts by carrying out an etching to the protective base member with a second mask material having openings at the predetermined positions where the concave parts will be formed;preparing a semiconductor wafer in which the sensor structure is formed;applying an adhesive to the outer peripheral edge part;fixing the protective base member and the semiconductor wafer through the adhesive so that the sensor structure and the concave part correspond with each other; anddividing the semiconductor wafer and the protective base member into chip units each of which has the sensor chip and the protective cap.

20. A method of manufacturing a semiconductor device, which includes a sensor chip, and a protective cap for covering the sensor structure of the sensor chip, the method comprising:preparing a protective base member, and forming an outer peripheral edge parts into a stepped shape by removing an area having a predetermined space from predetermined positions where concave parts will be formed;forming the concave parts by carrying out an etching to the protective base member with a mask material having openings at the predetermined positions where the concave parts will be formed;preparing a semiconductor wafer in which the sensor structure is formed;applying an adhesive to the outer peripheral edge part;fixing the protective base member and the semiconductor wafer through the adhesive so that the sensor structure and the concave part correspond with each other; anddividing the semiconductor wafer and the protective base member into chip units each of which has the sensor chip and the protective cap.