Liquid crystal display substrate, method of manufacturing the same, and liquid crystal display device having the same

• US 7,599,026 B2
• Filed: 08/30/2007
• Issued: 10/06/2009
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation, Fujitsu Limited
• Inventors: Tanaka, Yoshinori, Misaki, Katsunori, Doi, Seiji
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): Chung; David Y
• Application Number:
  US11/897,481
• Publication Number:
  US 20080002086A1
• Time in Patent Office: 768 Days
• Field of Search: 349/38, 349/39, 349/110, 349/113, 349/114
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element

Abstract

A liquid crystal display substrate with multiple pixel areas each having in at least a portion thereof a reflection area and a wrinkled resin layer formed with a positive light-sensitive resin in the reflection area. The wrinkled resin layer has in at least a portion thereof a wrinkled surface and a reflection electrode. The wrinkled resin layer also includes a light shielding portion, formed as an underlayer, for shielding light incident from the substrate'"'"'s back surface side, wherein at least part of the light shielding portion is formed in a same layer with the same material as a drain electrode and a source electrode of a thin film transistor and a storage capacitor electrode, to shield a large proportion of an under area of the wrinkled resin layer from light along with the drain electrode, the source electrode and the storage capacitor electrode.

Claims

1. A liquid crystal display substrate comprising:

a plurality of pixel areas each having in at least a portion thereof a reflection area reflecting light incident from a front surface side of the substrate;

a wrinkled resin layer formed with a positive light-sensitive resin in the reflection area, the wrinkled resin layer having in at least a portion thereof a wrinkled surface;

a reflection electrode formed with a light reflection material on the wrinkled resin layer, the reflection electrode having a wrinkled surface following the surface of the wrinkled resin layer;

a light shielding portion formed as an underlayer of the wrinkled resin layer, the light shielding portion shielding light incident from a back surface side of the substrate; and

a thin film transistor formed in each of the pixel areas,

wherein at least a portion of the light shielding portion is formed in a same layer with the same material as a drain electrode and a source electrode of the thin film transistor and a storage capacitor electrode, to shield a large proportion of an under area of the wrinkled resin layer from light along with the drain electrode, the source electrode and the storage capacitor electrode.

2. A liquid crystal display substrate as claimed in claim 1, wherein the light shielding portion is electrically separated from the drain electrode and the source electrode.

3. A liquid crystal display substrate comprising:

a plurality of pixel areas each having at least a portion thereof a reflection area reflecting light incident from a front surface side of the substrate;

a wrinkled resin layer formed with a positive light-sensitive resin in the reflection area, the wrinkled resin layer having at least a portion thereof a wrinkled surface;

a reflection electrode formed with a light reflection material on the wrinkled resin layer, the reflection electrode having a wrinkled surface following the surface of the wrinkled resin layer;

a light shielding portion formed as an underlayer of the wrinkled resin layer, the light shielding portion shielding light incident from a back surface side of the substrate; and

a thin film transistor formed in each of the pixel areas,

wherein at least a portion of the light shielding portion is formed in a same layer with the same material as an active semiconductor layer of the thin film transistor, to shield a large proportion of an area of the under area of the wrinkled resin layer from light, along with a storage capacitor electrode.

4. A liquid crystal display substrate as claimed in claim 3, wherein the light shielding portion is electrically separated from the active semiconductor layer.

5. A method of manufacturing a liquid crystal display substrate having a reflection area reflecting light incident from a front surface side of a substrate, and a transparent area transmitting light incident from a back surface side of the substrate, in each of the pixel areas, the method comprising the steps of:

forming a first electroconductive film having light transmittance and a second electroconductive film having light shielding capability in this order on the substrate;

forming a light shielding portion in the reflection area and an electroconductive layer having a predetermined shape in the transmission area by patterning the first and second electroconductive films;

forming an insulating film on the light shielding portion and the electroconductive layer;

exposing the electroconductive layer by removing the insulating film in the transmission area;

forming a transparent electrode by removing the second electroconductive film of the exposed electroconductive layer;

forming a resin layer having a predetermined shape on the insulating film in the reflection area;

forming a wrinkled resin layer having wrinkled unevenness on at least a portion of a surface thereof by curing and heat treating a surface of the resin layer; and

forming a reflection electrode on the wrinkled resin layer.

6. A method of manufacturing a liquid crystal display substrate as claimed in claim 5, wherein a gate electrode of a thin film transistor is formed simultaneously with forming the light shielding portion and the electroconductive layer.

7. A method of manufacturing a liquid crystal display substrate as claimed in claim 5, wherein the step of forming a wrinkled resin layer comprises a step of exposing the resin layer from a back surface side of the substrate before heat treatment so as to prevent the wrinkled unevenness from being formed on the resin layer in an area having no light shielding portion formed.