Acoustic wave device and method of fabricating the same

Patent metadata

Field	Value
Publication number	US-9837980-B2
Application number	US-201414227663-A
Country	US
Kind code	B2
Filing date	Mar 27, 2014
Priority date	May 14, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

An acoustic wave device includes: a substrate; a pad formed on the substrate; a cap formed of an inorganic insulating material and located on the substrate, the cap including a cavity located in a surface of the cap at a substrate side and a penetration hole formed in a location overlapping with the pad; a terminal filling the penetration hole, coupled to the pad on the substrate, and formed of solder; and a functional element formed on an upper surface of the substrate and in the cavity, the functional element exciting an acoustic wave.

First claim

What is claimed is:

1. An acoustic wave device comprising:
a substrate;
a pad formed on the substrate;
a cap formed of an inorganic insulating material, located on the substrate and bonded to the substrate, the cap including a penetration hole formed in a location overlapping with the pad, and defining a cavity between the substrate and the cap;
a terminal filling the penetration hole, coupled to the pad on the substrate, formed of solder, and being surrounded by the cavity in a planar view; and
a functional element formed on an upper surface of the substrate and in the cavity, the functional element exciting an acoustic wave.

2. The acoustic wave device according to claim 1 , wherein
the penetration hole has a tapered shape to taper from an upper surface of the cap toward the cavity.

3. The acoustic wave device according to claim 1 , wherein
the pad includes a protrusion protruding upward from the upper surface of the substrate, and the terminal is bonded to the protrusion.

4. The acoustic wave device according to claim 3 , wherein
the protrusion extends from the upper surface of the substrate to an inside of the penetration hole.

5. The acoustic wave device according to claim 1 , wherein
the terminal protrudes upward from an upper surface of the cap.

6. The acoustic wave device according to claim 1 , further comprising:
a metal layer continuously formed from an upper surface of the cap to a lower surface of the cap through an inner wall of the penetration hole, wherein
the terminal is bonded to the metal layer.

7. The acoustic wave device according to claim 1 , further comprising:
a plated layer covering a surface of the terminal.

8. The acoustic wave device according to claim 1 , wherein
the substrate is a piezoelectric substrate, and
the functional element is an IDT.

9. The acoustic wave device according to claim 8 , wherein
the cap is formed of a piezoelectric substance or sapphire.

10. The acoustic wave device according to claim 1 , wherein
the functional element is a region in which an upper electrode, a piezoelectric thin film, and a lower electrode of a piezoelectric thin film resonator overlap with each other.

11. The acoustic wave device according to claim 10 , wherein
the substrate is formed of silicon; and
the cap is formed of silicon or glass.

12. The acoustic wave device according to claim 1 , wherein
the substrate and the cap are formed of a same material.

Assignees

• Taiyo Yuden Kk

Inventors

• Tajima Motoyuki
• Sakinada Kaoru

Classifications

• H10W90/724

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

• H10W72/012

  of bump connectors, dummy bumps or thermal bumps · CPC title

• Y10T29/49204

  Contact or terminal manufacturing · CPC title

• H01L2924/19105

  Electricity · mapped topic

• H01L2224/11

  Electricity · mapped topic