Elastic wave device and manufacturing method therefor

1. An elastic wave device comprising:

a piezoelectric substrate including opposing first and second main surfaces;

an interdigital transducer electrode provided on the first main surface;

a wiring electrode provided on the first main surface and electrically connected to the interdigital transducer electrode;

a via hole electrode penetrating the piezoelectric substrate and electrically connected to the wiring electrode;

an external connection terminal provided on the second main surface of the piezoelectric substrate and electrically connected to the via hole electrode;

a cover member defining a hollow space in which the interdigital transducer electrode is sealed, between the first main surface of the piezoelectric substrate and the cover member; and

a heat dissipating member having higher thermal conductivity than the cover member, provided on the wiring electrode, extending from the wiring electrode toward the cover member, and penetrating the cover member.

2. The elastic wave device according to claim 1 , further comprising:

a support layer provided on the piezoelectric substrate and including a cavity defining the hollow space; wherein

the cover member is joined on the support layer.

3. The elastic wave device according to claim 2 , wherein the heat dissipating member penetrating the support layer and the cover member is provided.

4. The elastic wave device according to claim 1 , wherein the heat dissipating member and the via hole electrode are provided at a position at which a portion of the via hole electrode that is joined to the wiring electrode overlaps an end surface of the heat dissipating member that is joined to the wiring electrode, when seen in a plan view.

5. The elastic wave device according to claim 4 , wherein a portion of the heat dissipating member that is joined to the wiring electrode includes the portion of the via hole electrode that is joined to the wiring electrode, when seen in a plan view.

6. The elastic wave device according to claim 1 , further comprising a high-thermal conductivity material portion covering a portion at which the heat dissipating member is exposed, provided on an outer main surface of the cover member at a side opposite to a main surface of the cover member at a side of the hollow space, and having higher thermal conductivity than the cover member.

7. The elastic wave device according to claim 6 , wherein the high-thermal conductivity material portion is defined by an external resin layer.

8. The elastic wave device according to claim 7 , wherein a shield layer made of metal is provided at an outer side portion of the external resin layer.

9. The elastic wave device according to claim 1 , further comprising another electronic component element laminated on an outer main surface of the cover member.

10. The elastic wave device according to claim 9 , wherein the other electronic component element includes another external connection terminal joined to the heat dissipating member.

11. A method for manufacturing the elastic wave device according to claim 1 , the method comprising:

preparing a structure including the piezoelectric substrate, the interdigital transducer electrode provided on the first main surface of the piezoelectric substrate, the wiring electrode provided on the first main surface and electrically connected to the interdigital transducer electrode, the cover member defining the hollow space in which the interdigital transducer electrode is sealed, between the piezoelectric substrate and the first main surface, and the heat dissipating member having higher thermal conductivity than the cover member, provided on the wiring electrode, extending from the wiring electrode toward the cover member, and penetrating the cover member;

applying laser light to the second main surface of the piezoelectric substrate to form a plurality of through holes penetrating from the first main surface toward the second main surface;

forming the via hole electrode by disposing an electrode material in the plurality of through holes; and

forming an external connection terminal on the second main surface of the piezoelectric substrate such that the external connection terminal is electrically connected to the via hole electrode.

12. The method for manufacturing the elastic wave device according to claim 11 , further comprising:

providing a support layer on the piezoelectric substrate and including a cavity defining the hollow space; wherein

the cover member is joined on the support layer.

13. The method for manufacturing the elastic wave device according to claim 12 , wherein the heat dissipating member penetrating the support layer and the cover member is provided.

14. The method for manufacturing the elastic wave device according to claim 11 , wherein the heat dissipating member and the via hole electrode are provided at a position at which a portion of the via hole electrode that is joined to the wiring electrode overlaps an end surface of the heat dissipating member that is joined to the wiring electrode, when seen in a plan view.

15. The method for manufacturing the elastic wave device according to claim 14 , wherein a portion of the heat dissipating member that is joined to the wiring electrode includes the portion of the via hole electrode that is joined to the wiring electrode, when seen in a plan view.

16. The method for manufacturing the elastic wave device according to claim 11 , further comprising:

covering a portion at which the heat dissipating member is exposed with a high-thermal conductivity material portion; wherein

the high-thermal conductivity material portion is provided on an outer main surface of the cover member at a side opposite to a main surface of the cover member at a side of the hollow space, and has higher thermal conductivity than the cover member.

17. The method for manufacturing the elastic wave device according to claim 16 , wherein the high-thermal conductivity material portion is defined by an external resin layer.

18. The method for manufacturing the elastic wave device according to claim 17 , wherein a shield layer made of metal is provided at an outer side portion of the external resin layer.