# US 8,569,936 B2 · Piezoelectric resonator and electrode structure thereof

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- Number: US 8,569,936 B2
- Document ID: US8569936B2
- Status: Granted
- Kind: B2
- Application number: 13/200,980
- Filed: 2011-10-06
- Published: 2012-10-04
- Granted: 2013-10-29
- Earliest claimed: 2011-03-31
- Assignees: Samsung Electro-Mechanics Co., Ltd.
- Applicants: Jang Ho Park
- Inventors: Jang Ho Park
- Web page: https://patentgrep.com/patent/US8569936B2

## CPC

- H03H 9/177: {of the energy-trap type}
- H03H 9/131: {consisting of a multilayered structure}
- H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P)

## Abstract

There are provided a piezoelectric resonator and an electrode structure thereof. The piezoelectric resonator includes: a piezoelectric body oscillated according to an electrical signal; and first and second electrodes each including first and second electrode layers stacked on respective both surfaces of the piezoelectric body, wherein the first electrode layer includes one or more selected from the group consisting of chromium (Cr), nickel (Ni), titanium (Ti), and an alloy including any one thereof, the ratio of the thickness of the first electrode layer to the thickness of the first or second electrode is 3% to 30%; and the second electrode layer includes copper (Cu) or an alloy including copper (Cu), and the ratio of the thickness of the second electrode layer to the thickness of the first or second electrode is 70% to 97%.

## Claims

### Claim 1

A piezoelectric resonator comprising:
a piezoelectric body oscillated according to an electrical signal; and
first and second electrodes each including first and second electrode layers stacked on respective both surfaces of the piezoelectric body,
the first electrode layer including at least one material selected from the group consisting of chromium (Cr), nickel (Ni), titanium (Ti) and alloys thereof, and the ratio of the thickness of the first electrode layer to the thickness of the first or second electrode being 3% to 30%; the second electrode layer including copper (Cu) or an alloy including copper (Cu), and the ratio of the thickness of the second electrode layer to the thickness of the first or second electrode being 70% to 97%.

### Claim 2 (depends on 1)

The piezoelectric resonator of claim 1, wherein the alloy including copper (Cu) includes copper (Cu) and any one selected from the group consisting of gold (Au), manganese (Mn), nickel (Ni), zinc (Zn), aluminum (Al), tin (Sn), lead (Pb), and chromium (Cr).

### Claim 3 (depends on 1)

The piezoelectric resonator of claim 1, wherein an atomic ratio of copper (Cu) to the alloy including copper (Cu) is 30% or less, or 60% or more.

### Claim 4 (depends on 1)

The piezoelectric resonator of claim 1, wherein the atomic ratio of copper (Cu) to the alloy including copper (Cu) is 20% or less.

### Claim 5 (depends on 1)

The piezoelectric resonator of claim 1, wherein the atomic ratio of copper (Cu) to the alloy including copper (Cu) is 90% or more.

### Claim 6 (depends on 1)

The piezoelectric resonator of claim 1, wherein the first and second electrodes have a dual-layered electrode structure including a first layer formed of the first electrode layer and a second layer formed of the second electrode layer.

### Claim 7 (depends on 6)

The piezoelectric resonator of claim 6, wherein the ratio of the thickness of the first layer to the thickness of the first or second electrode is 3% to 15%, and the ratio of the thickness of the second layer to the thickness of the first or second electrode is 85% to 97%.

### Claim 8 (depends on 1)

The piezoelectric resonator of claim 1, wherein the respective first and second electrodes have a structure in which the first and second electrode layers are repeatedly stacked in an alternating manner.

### Claim 9 (depends on 1)

The piezoelectric resonator of claim 1, wherein the first and second electrodes have a quadruple-layered electrode structure including first and third layers constituting the first electrode layer and second and fourth layers constituting the second electrode layer.

### Claim 10 (depends on 9)

The piezoelectric resonator of claim 9, wherein the ratio of the thickness of the second layer to the thickness of the first or second electrode is 17% to 80%, and the ratio of the thickness of the fourth layer to the thickness of the first or second electrode is 17% to 80%.

### Claim 11

A piezoelectric resonator comprising:
a piezoelectric body oscillated according to an electrical signal; and
first and second electrodes each including first and second electrode layers stacked on respective both surfaces of the piezoelectric body,
wherein the first electrode layer including first and third layers including at least one material selected from the group consisting of chromium (Cr), nickel (Ni), titanium (Ti), and alloys thereof, and the ratio of the thickness of the first electrode layer to the thickness of the first or second electrode being 3% to 30%; and the second electrode layer including a second layer including copper (Cu) or an alloy including copper (Cu) and a fourth layer including silver (Ag) or an alloy including silver (Ag), and the ratio of the thickness of the second electrode layer to the thickness of the first or second electrode being 70% to 97%.

### Claim 12

An electrode structure of a piezoelectric resonator, the structure comprising first and second electrode layers stacked on main surfaces of a piezoelectric body,
the first electrode layer including at least one material selected from the group consisting of chromium (Cr), nickel (Ni), titanium (Ti), and alloys thereof, and the ratio of the thickness of the first electrode layer to the overall electrode thickness being 3% to 30%; and the second electrode layer including copper (Cu) or an alloy including copper (Cu), and the ratio of the thickness of the second electrode layer to the overall electrode thickness being 70% to 97%.

### Claim 13 (depends on 12)

The electrode structure of claim 12, wherein the electrode structure is a dual-layered electrode structure including a first layer formed of the first electrode layer and a second layer formed of the second electrode layer.

### Claim 14 (depends on 12)

The electrode structure of claim 12, wherein the electrode structure is a structure in which the first and second electrode layers are repeatedly stacked in an alternating manner.

### Claim 15 (depends on 12)

The electrode structure of claim 12, wherein the electrode structure is a quadruple-layered electrode structure including first and third layers constituting the first electrode layer and second and fourth layers constituting the second electrode layer.

### Claim 16

An electrode structure of a piezoelectric resonator, the electrode structure comprising first and second electrode layers stacked on main surfaces of a piezoelectric body,
the first electrode layer including first and third layers including at least one material selected from the group consisting of chromium (Cr), nickel (Ni), titanium (Ti), and alloys thereof, and the ratio of the thickness of the first electrode layer to the overall electrode thickness being 3% to 30%; and the second electrode layer including a second layer including copper (Cu) or an alloy including copper (Cu) and a fourth layer including silver (Ag) or an alloy including silver (Ag), and the ratio of the thickness of the second electrode layer to the overall electrode thickness being 70% to 97%.