# US 5,703,668 A · Liquid crystal display device and method of forming the same

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- Number: US 5,703,668 A
- Document ID: US5703668A
- Status: Granted
- Kind: A
- Application number: 08/616,092
- Filed: 1996-03-15
- Granted: 1997-12-30
- Earliest claimed: 1995-11-25
- Assignees: LG Electronics Inc.
- Inventors: Woo-Sup Shin
- Web page: https://patentgrep.com/patent/US5703668A

## CPC

- G02F 1/136209: {Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element}
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

A liquid crystal display device includes a substrate, a thin film transistor including a gate line, a source electrode, and a drain electrode formed on the substrate, a first protective layer formed on the thin film transistor, a black matrix pattern formed on the first protective layer, a second protective layer covering the black matrix pattern, and a pixel electrode connected to the drain electrode of the thin film transistor, wherein the first protective layer is selectively removed using the black matrix pattern as a mask to expose the pixel electrode, and wherein the second protective layer is formed using a shadow mask.

## Claims

### Claim 1

A light blocking device in a liquid crystal display device, the liquid crystal display device having a plurality of pixel electrodes, a plurality of data lines formed on a substrate, and areas not overlapping with the plurality of pixel electrodes and the plurality of data lines, a remaining region being defined as a portion of the non-overlapping areas, the light blocking device comprising:
a first protective layer, covering at least the remaining region, and being of a first size; and
a black matrix covering an area of a second size on the first protective layer;
wherein the first size equals the second size.

### Claim 2 (depends on 1)

A light blocking device as in claim 1, wherein:
the first protective layer also at least partially covers the plurality of pixel electrodes.

### Claim 3 (depends on 1)

A light blocking device as in claim 1, wherein:
the first protective layer also at least partially covers the plurality of data lines.

### Claim 4 (depends on 3)

A light blocking device as in claim 3, wherein:
the first protective layer completely covers the plurality of data lines.

### Claim 5 (depends on 1)

A light blocking device as in claim 1, wherein the non-overlapping areas include a plurality of thin film transistors.

### Claim 6 (depends on 1)

A light blocking device as in claim 1, wherein the black matrix includes a black resin.

### Claim 7 (depends on 6)

A light blocking device as in claim 6, wherein the black resin has at least one of the following qualities:
heat resistant up to about 250.degree. C., under 50% transmission of light, and a coating thickness of about 1.5 .mu.m.

### Claim 8 (depends on 1)

A light blocking device as in claim 1, further comprising:
a second protective layer formed on the black matrix using a shadow mask.

### Claim 9 (depends on 8)

A light blocking device as in claim 8, wherein at least one of the first protective layer and the second protective layer is one of a silicon oxide layer (SiOx) and a silicon nitride layer (SiNx).

### Claim 10

A method of forming a black matrix in a liquid crystal display device, the liquid crystal display device having a plurality of pixel electrodes, a plurality of data lines formed on a substrate, and areas not overlapping with the plurality of pixel electrodes and the plurality of data lines, a remaining region being defined as a portion of the non-overlapping areas, the method comprising the steps of:
a) forming a first protective layer on at least the remaining region;
b) forming a black matrix layer on the first protective layer;
c) selectively removing portions of the black matrix layer and portions of the first protective layer, wherein a black matrix is formed when the portions of the black matrix layer are selectively removed; and
d) forming a second protective layer on the black matrix, the step d) including the step of using a shadow mask to selectively control where the second protective layer is formed.

### Claim 11 (depends on 10)

A method as in claim 10, wherein the step a) includes:
forming the first protective layer on at least one of the plurality of data lines and the plurality of electrodes.

### Claim 12 (depends on 11)

A method as in claim 11, wherein:
the step c) exposes the plurality of pixel electrodes.

### Claim 13 (depends on 10)

A method as in claim 10, wherein the step c) includes:
c1) selectively removing the portions of the black matrix layer to form a black matrix; and
c2) selectively removing, after the step c1), the portions of the first protective layer.

### Claim 14 (depends on 13)

A method as in claim 13, wherein the step c) includes:
c3) using the black matrix as a mask for the step c2).

### Claim 15 (depends on 10)

A method as in claim 10, wherein the step c) includes:
c1) etching the black matrix layer and the first protective layer.

### Claim 16 (depends on 10)

A method as in claim 10, wherein the non-overlapping areas include a plurality of thin film transistors.

### Claim 17 (depends on 10)

A method as in claim 10, wherein:
the black matrix layer includes a black resin.

### Claim 18 (depends on 17)

A method as in claim 17, wherein the black resin has at least one of the following qualities:
heat resistant up to about 250.degree. C., under 50% transmission of light, and a coating thickness of about 1.5 .mu.m.

### Claim 19 (depends on 10)

A method as in claim 10, wherein at least one of the first protective layer and the second protective layer is one of a silicon oxide layer and a silicon nitride layer.

### Claim 20

A liquid crystal display device comprising:
a plurality of data lines formed on a substrate;
a plurality of pixel electrodes formed between the plurality of data lines;
a plurality of remaining areas not overlapping with the plurality of pixel electrodes and the plurality of data lines;
a first protective layer, covering at least a portion of the plurality of remaining areas, and being of a first size;
a black matrix covering an area of a second size on the first protective layer;
wherein the first size equals the second size.

### Claim 21 (depends on 20)

A device as in claim 20, further comprising:
a second protective layer formed on the black matrix using a shadow mask.

### Claim 22 (depends on 20)

A device in claim 20, wherein the plurality of remaining areas include a plurality of thin film transistors.

### Claim 23 (depends on 20)

A device as in claim 20, wherein:
the first protective layer also at least partially covers the plurality of pixel electrodes.

### Claim 24 (depends on 20)

A device as in claim 20, wherein:
the first protective layer also at least partially covers the plurality of data lines.

### Claim 25 (depends on 20)

A device as in claim 20, wherein the black matrix includes a black resin having at least one of the following qualities:
heat resistant up to about 250.degree. C., under 50% transmission of light, and a coating thickness of about 1.5 .mu.m.

### Claim 26 (depends on 20)

A device as in claim 20, wherein at least one of the first protective layer and the second protective layer is one of a silicon oxide layer and a silicon nitride layer.