# US 11,029,274 B2 · Humidity sensor and manufacturing method thereof

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- Number: US 11,029,274 B2
- Document ID: US11029274B2
- Status: Granted
- Kind: B2
- Application number: 16/691,628
- Filed: 2019-11-22
- Published: 2021-03-04
- Granted: 2021-06-08
- Earliest claimed: 2019-08-29
- Assignees: Interface Technology (ChengDu) Co., Ltd.; Interface Optoelectronics (Shenzhen) Co., Ltd.; General Interface Solution Limited
- Applicants: Interface Technology (ChengDu) Co., Ltd.; Interface Optoelectronics (ShenZhen) Co., Ltd.; General Interface Solution Limited
- Inventors: Yu-Chieh Tu
- Web page: https://patentgrep.com/patent/US11029274B2

## CPC

- G01N 27/226: {Construction of measuring vessels; Electrodes therefor}
- G01N 27/223: {for determining moisture content, e.g. humidity (rain detectors on vehicle windows B60S1/0825)}
- G01N 27/121: {for determining moisture content, e.g. humidity, of the fluid (moisture content of the tested material G01N27/048)}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

The invention provides a humidity sensor and a manufacturing method thereof. The humidity sensor comprises a substrate, an electrode structure, and a humidity sensing structure. The electrode structure is disposed on the substrate. The humidity sensing structure is disposed on the electrode structure. The humidity sensing structure includes a first humidity sensing layer and a second humidity sensing layer. The first humidity sensing layer is in direct contact with the electrode structure and has a first oxygen vacancy number. The second humidity sensing layer is disposed on the first humidity sensing layer and has a second oxygen vacancy number. The second oxygen vacancy number is greater than the first oxygen vacancy number.

## Claims

### Claim 1

A humidity sensor, comprising:
a substrate;
an electrode structure disposed on the substrate; and
a humidity sensing structure disposed on the electrode structure, wherein the humidity sensing structure comprises:
a first humidity sensing layer directly contacting the electrode structure and having a first oxygen vacancy number; and
a second humidity sensing layer disposed on the first humidity sensing layer and having a second oxygen vacancy number, wherein the second oxygen vacancy number is greater than the first oxygen vacancy number.

### Claim 2 (depends on 1)

The humidity sensor of claim 1, wherein the humidity sensing structure further comprises a third humidity sensing layer disposed on the second humidity sensing layer, the third humidity sensing layer has a third oxygen vacancy number greater than the second oxygen vacancy number.

### Claim 3 (depends on 1)

The humidity sensor of claim 1, wherein the first humidity sensing layer and the second humidity sensing layer each comprises a perovskite-type oxide material with an ABO3 structure.

### Claim 4 (depends on 1)

The humidity sensor of claim 1, wherein the electrode structure comprises an interdigital structure.

### Claim 5

A method of manufacturing humidity sensor, comprising steps of:
providing a substrate and an electrode structure, wherein the electrode structure is located on the substrate; and
forming a humidity sensing structure on the electrode structure, comprising:
forming a first humidity sensing layer at a first sintering temperature, wherein the first humidity sensing layer is in direct contact with the electrode structure and has a first oxygen vacancy number; and
forming a second humidity sensing layer on the first humidity sensing layer at a second sintering temperature, wherein the second sintering temperature is lower than the first sintering temperature, such that a second oxygen vacancy number of the second humidity sensing layer is greater than the first oxygen vacancy number.

### Claim 6 (depends on 5)

The method of claim 5, further comprising steps of:
forming a third humidity sensing layer on the second humidity sensing layer at a third sintering temperature, wherein the third sintering temperature is lower than the second sintering temperature, such that a third oxygen vacancy number of the third humidity sensing layer is greater than the second oxygen vacancy number.

### Claim 7 (depends on 5)

The method of claim 5, wherein the first humidity sensing layer and the second humidity sensing layer each comprises a perovskite-type oxide material with an ABO3 structure.

### Claim 8 (depends on 5)

The method of claim 5, wherein the first sintering temperature ranges from 300° C. to 700° C.

### Claim 9 (depends on 5)

The method of claim 5, wherein the second sintering temperature ranges from 200° C. to 600° C.

### Claim 10 (depends on 5)

The method of claim 5, wherein the third sintering temperature ranges from 100° C. to 500° C.