High-power acoustic device with improved performance

Patent metadata

Field	Value
Publication number	US-10141245-B2
Application number	US-201715685850-A
Country	US
Kind code	B2
Filing date	Aug 24, 2017
Priority date	Aug 24, 2016
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

The present disclosure relates to a high-power acoustic device with improved performance. The disclosed acoustic device includes a substrate, a die-attach material, and an acoustic die. The substrate includes a substrate body and a die pad on a top surface of the substrate body. The die-attach material is a sintered material and applied over the die pad. The acoustic die is coupled to the die pad via the die-attach material. Herein, the acoustic die includes a die body and a metallization structure, which is sandwiched between the die body and the die-attach material.

First claim

What is claimed is:

1. An apparatus comprising:
a substrate comprising a substrate body and a die pad on a top surface of the substrate body;
a die-attach material applied over the die pad, wherein the die-attach material is a sintered material;
an acoustic die coupled to the die pad via the die-attach material, wherein:
the acoustic die includes a plurality of acoustic components, a die body and a metallization structure;
the plurality of acoustic components resides over a top surface of the die body and the metallization structure resides over a bottom surface of the die body; and
the metallization structure is vertically sandwiched between the die body and the die-attach material.

2. The apparatus of claim 1 wherein the metallization structure provides adhesion to the die body, chemical bonding to the die-attach material, and a wetting function that provides an interface between the die body and die-attach material.

3. The apparatus of claim 2 wherein the metallization structure comprises:
a first layer that is in contact with the die body and provides the adhesion to the die body;
a second layer that is in contact with the die-attach material and provides the chemical bonding to the die-attach material; and
a third layer that is sandwiched between the first layer and the second layer and provides the wetting function.

4. The apparatus of claim 3 wherein:
the first layer is formed of Titanium (Ti), Titanium Tungsten (TiW), or Chromium (Cr);
the second layer is formed of gold (Au) or silver (Ag); and
the third layer is formed of TiW, Au, Nickel-Vanadium (NiV), or Nickel (Ni).

5. The apparatus of claim 2 wherein the metallization structure comprises:
a first layer that is in contact with the die body and provides the adhesion to the die body and the wetting function; and
a second layer that is sandwiched between the first layer and the die-attach material and provides the chemical bonding to the die-attach material.

6. The apparatus of claim 2 wherein the metallization structure comprises:
a first layer that is in contact with the die body and provides the adhesion to the die body; and
a second layer sandwiched between the first layer and the die-attach material, wherein the second layer provides the chemical bonding to the die-attach material and the wetting function.

7. The apparatus of claim 2 wherein the metallization structure comprises:
a first layer that is in contact with the die body and provides the adhesion to the die body and the wetting function; and
a second layer sandwiched between the first layer and the die-attach material, wherein the second layer provides the chemical bonding to the die-attach material and the wetting function.

8. The apparatus of claim 2 wherein the metallization structure is formed of at least one of a group consisting of TiW, Ti, Cr, Ni, NiV, Ag, and Au.

9. The apparatus of claim 1 wherein the acoustic die further includes an enclosure coupled to the top surface of the die body to encapsulate the plurality of acoustic components, wherein the enclosure includes a cap and an outer wall extending from the cap to the top surface of the die body.

10. The apparatus of claim 9 wherein:
the substrate further comprises a plurality of wire-contacts on the top surface of the substrate body and surrounding the die pad; and
the acoustic die further comprises a plurality of wires, wherein each of the plurality of wires is outside the enclosure and extends from the top surface of the die body to a corresponding wire-contact on the top surface of the substrate body.

11. The apparatus of claim 1 wherein the substrate body is formed of one of a group consisting of FR-4, BT-NS, PTFE, Rogers RO4003, RO6035, and LCP.

12. The apparatus of claim 1 wherein the substrate body is formed of one of a group consisting of alumina, low temperature co-fired ceramic (LTCC), or high temperature co-fired ceramic (HTCC).

13. The apparatus of claim 1 wherein the substrate is a printed circuit board (PCB).

14. The apparatus of claim 1 wherein the die-attach material is one of a group consisting of sintered silver, sintered copper, and sintered gold.

15. The apparatus of claim 1 wherein the acoustic die is a bulk acoustic wave (BAW) die.

16. The apparatus of claim 1 wherein the acoustic die is a surface acoustic wave (SAW) die.

17. The apparatus of claim 1 wherein the substrate further comprises a heat spreader embedded in the substrate body, wherein the heat spreader is thermally coupled to the die pad and extends from the top surface of the substrate body to a bottom surface of the substrate body.

18. The apparatus of claim 1 wherein the substrate further includes a plurality of thermal vias, wherein each of the plurality of thermal vias is thermally coupled to the die pad and extends from the top surface of the substrate body to a bottom surface of the substrate body.

19. The apparatus of claim 1 further comprising a molding compound formed over the substrate to encapsulate the acoustic die.

Assignees

• Qorvo Us Inc

Inventors

• Railkar Tarak A
• Yee Ian Y
• Galipeau Jeffrey D
• Wu Jason
• Chang Rodolfo E

Classifications

• H10W72/5524

  comprising aluminium [Al] · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W90/754

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title