BULK ACOUSTIC WAVE FILTER DEVICE

• US 20200136585A1
• Filed: 05/08/2019
• Published: 04/30/2020
• Est. Priority Date: 10/25/2018
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: PARK, Jang Ho
• Granted Patent: US 10,892,731 B2
• Time in Patent Office: Days
• CPC Class Codes: H03H 9/02102 of temperature influence cutting angles H03H9/02015
• CPC Class Codes: H03H 9/0514 consisting of mounting pads or bumps
• CPC Class Codes: H03H 9/1014 the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the BAW device
• CPC Class Codes: H03H 9/13 for networks consisting of piezoelectric or electrostrictive materials H03H9/145 takes precedence
• CPC Class Codes: H03H 9/17 having a single resonator crystal tuning forks H03H9/21
• CPC Class Codes: H03H 9/173 Air-gaps
• CPC Class Codes: H03H 9/56 Monolithic crystal filters

Abstract

A bulk acoustic wave filter device includes a substrate including an insulating layer, a resonance portion including a bottom electrode, disposed on the substrate, a piezoelectric layer, disposed above at least a portion of the bottom electrode, and a top electrode disposed above at least a portion of the piezoelectric layer, a wiring portion connected to the resonance portion such that the top electrode or the bottom electrode extends into the wiring portion, a connection electrode connecting the top electrode and the bottom electrode to an external device, and a heat transfer member connecting a portion of at least one of the bottom electrode and the top electrode that is disposed in the wiring portion to the substrate. The resonance portion is provided with a cavity disposed below the bottom electrode, and the heat transfer member is disposed outside of the cavity.

Claims

1. A bulk acoustic wave filter device comprising:

a substrate comprising an insulating layer;

a resonance portion comprising a bottom electrode disposed on the substrate, a piezoelectric layer disposed above at least a portion of the bottom electrode, a top electrode disposed above at least a portion of the piezoelectric layer, and a cavity disposed below the bottom electrode;

a wiring portion connected to the resonance portion such that the top electrode or the bottom electrode extends into the wiring portion;

a connection electrode configured to connect the top electrode and the bottom electrode to an external device; and

a heat transfer member disposed outside of the cavity and connecting a portion of at least one of the bottom electrode and the top electrode that is disposed in the wiring portion to the substrate.

2. The bulk acoustic wave filter device of claim 1, wherein the heat transfer member is disposed between the connection electrode and the cavity.

3. The bulk acoustic wave filter device of claim 1, wherein the heat transfer member is connected to the insulating layer of the substrate or connected to a base of the substrate disposed below the insulating layer.

4. The bulk acoustic wave filter device of claim 1, wherein the heat transfer member comprises a heat conducting material including one or more of molybdenum (Mo), ruthenium (Ru), tungsten (W), iridium (Ir), platinum (Pt), copper (Cu), titanium (Ti), tantalum (Ta), nickel (Ni), chromium (Cr), aluminum (Al), or alloys thereof.

5. The bulk acoustic wave filter device of claim 1, wherein the resonance portion comprises:

a membrane layer that forms the cavity together with the substrate; and

a passivation layer disposed above the top electrode, wherein

the bottom electrode comprises a portion disposed in an upper portion of the cavity;

the piezoelectric layer comprises a portion disposed to cover the bottom electrode;

the top electrode comprises a portion disposed to cover the piezoelectric layer; and

the passivation layer is at least partially disposed in a region in which the bottom electrode and the top electrode do not overlap each other.

6. The bulk acoustic wave filter device of claim 5, wherein the heat transfer member is connected to the bottom electrode and penetrates through the membrane layer.

7. The bulk acoustic wave filter device of claim 6, further comprising:

a first metal pad disposed above the bottom electrode.

8. The bulk acoustic wave filter device of claim 5, wherein the heat transfer member is connected to the top electrode and penetrates through the membrane layer and the piezoelectric layer.

9. The bulk acoustic wave filter device of claim 8, further comprising:

a second metal pad disposed above the top electrode.

10. The bulk acoustic wave filter device of claim 1, wherein the resonance portion comprises:

a membrane layer that forms the cavity together with the substrate; and

an insertion layer disposed to cover at least a portion of the bottom electrode, wherein

the bottom electrode is disposed above the membrane layer;

the insertion layer is disposed to cover at least a portion of the bottom electrode;

the piezoelectric layer is disposed on the bottom electrode to cover the insertion layer; and

the top electrode comprises a portion disposed above the piezoelectric layer.

11. The bulk acoustic wave filter device of claim 10, further comprising:

an etch stop portion disposed to cover the cavity.

12. The bulk acoustic wave filter device of claim 11, further comprising:

a first layer disposed outside of the etch stop portion.

13. The bulk acoustic wave filter device of claim 10, wherein the piezoelectric layer comprises a piezoelectric portion, disposed in a flat portion, and a bent portion disposed in an extending portion that extends from the piezoelectric layer.

14. The bulk acoustic wave filter device of claim 12, wherein the heat transfer member is connected to the bottom electrode and penetrates through the membrane layer and the first layer.

15. The bulk acoustic wave filter device of claim 12, wherein the heat transfer member is connected to the top electrode and penetrates through the piezoelectric layer, the membrane layer, and the first layer.

16. A bulk acoustic wave filter device comprising:

a substrate comprising an insulating layer;

a resonance portion comprising a bottom electrode disposed on the substrate, a piezoelectric layer disposed above at least a portion of the bottom electrode, and a top electrode disposed above at least a portion of the piezoelectric layer;

a wiring portion connected to the resonance portion such that the bottom electrode or the top electrode extends into the wiring portion;

a connection electrode configured to connect the top electrode and the bottom electrode to an external device; and

a heat transfer member connecting a portion of the top electrode or the bottom electrode that extends into the wiring portion to the substrate.

17. A bulk acoustic wave filter device comprising:

a substrate;

a resonance portion comprising a top electrode, a bottom electrode, a piezoelectric layer disposed between the top electrode and the bottom electrode, and a membrane layer disposed between the bottom electrode and the substrate to form a cavity with the substrate;

a first heat transfer member that connects a portion of the top electrode that extends beyond the resonance portion to the substrate; and

a second heat transfer member that connects a portion of the bottom electrode that extends beyond the resonance portion to the substrate.