High aperture LCD with insulating color filters overlapping bus lines on active substrate

• US 6,365,916 B1
• Filed: 07/16/1999
• Issued: 04/02/2002
• Est. Priority Date: 06/06/1995
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: den Boer, Willem, Zhong, John Z. Z.
• Primary Examiner(s): Lee, Eddie
• Assistant Examiner(s): Wilson, Allan R.
• Application Number:
  US09/356,302
• Time in Patent Office: 991 Days
• Field of Search: 257/59, 257/72, 257/89, 257/440, 349/138, 349/106
• US Class Current: 257/59
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2202/42 Materials having a particular dielectric constant
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 29/66765 Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• CPC Class Codes: H01L 29/78636 with supplementary region or layer for improving the flatness of the device

Abstract

A high aperture active matrix liquid crystal display (AMLCD) includes pixel electrodes in respective pixels which overlap adjacent address lines. The color filters are formed on the active substrate in a manner such that the filters also overlap the address lines and function as an insulating layer between the pixel electrodes and address lines in the areas of overlap. Accordingly, line-pixel capacitances are reduced and the resulting AMLCD is easier to manufacture. The total number of process step in manufacturing is reduced, and plate-to-plate (active to passive plate) alignment is much easier and less important.

Claims

1. A color liquid crystal display including color filters, the liquid crystal display comprising:

first and second substrates;

a liquid crystal layer sandwiched between said first and second substrates;

first and second colored pixels, said first pixel including a first pixel electrode, a first insulating color filter, and a first switching element, and said second pixel including a second pixel electrode, a second insulating color filter, and a second switching element, wherein said first and second color filters are differently colored;

said first pixel electrode overlapping at least one address line in communication with said first switching element, and said second pixel electrode overlapping at least one address line in communication with said second switching element, so as to define a high aperture display, said overlapping by said first and second pixel electrodes forming areas of overlap;

said first color filter being at least partially disposed in an area of overlap formed by said first pixel electrode and said first color filter having a dielectric constant of less than about 5.0 and a first contact hole defined therein that allows said first pixel electrode to be in electrical communication with said first switching element; and

said second color filter being at least partially disposed in an area of overlap formed by said second pixel electrode, and said second color filter having an dielectric constant of less than about 5.0 and a contact hole defined therein that allows said second pixel electrode to be in electrical communication with said second switching element.

2. The display of claim 1, wherein each of said first and second color filters comprises photo-imageable material.

3. The display of claim 2, wherein each of said first and second color filters comprises a negative resist.

4. The display of claim 1, wherein each of said first and second color filters has a refractive index of from about 1.5 to 2.0.

5. The display of claim 1, wherein each of said first and second color filters has a thickness of from about 1.5-2.5 μ

m, and wherein the pixel aperture ratio of the display is at least about 68%.

6. A liquid crystal display device comprising:

a substrate having a pixel region;

first and second address lines defining the pixel region;

a switching device having an electrode on the substrate;

a first color filter on the switching device and the substrate, the first color filter covering the pixel region, the first color filter having a contact hole adjacent a portion of the switching device;

a pixel electrode contacting the electrode of the switching device through the contact hole; and

a second color filter adjacent the first color filter and partially overlapping the first address line, the second color filter being spaced from the first color filter.

7. The liquid crystal display device according to claim 6, wherein the second color filter is spaced from the first color filter by about 0.5 μ

m to 2.0 μ

m.

8. The liquid crystal display device according to claim 6, wherein the second color filter is spaced from the first color filter by more than 0.5 μ

m.

9. A liquid crystal display device comprising:

a first substrate having first, second and third pixel regions;

address lines defining the first, second and third pixel regions;

first, second and third thin film transistors in corresponding first, second and third pixel regions on the substrate, each of the first, second and third thin film transistors having a gate electrode, a source electrode and a drain electrode;

first, second and third color filters covering corresponding first, second and third thin film transistors and the corresponding first, second and third pixel regions, the first second and third color filters each having a contact hole adjacent one of the source and drain electrodes of a corresponding one of the first, second and third thin film transistors; and

first, second and third pixel electrodes contacting corresponding first, second and third thin film transistors through the contact hole of each of the first, second and third color filters,

wherein the first, second and third color filters are spaced from each other.

10. The liquid crystal display device according to claim 9, wherein the first, second and third color filters are spaced from each other by about 0.5 μ

m to 2.0 μ

m.

11. The liquid crystal display device according to claim 9, wherein the first, second and third color filters are spaced from each other by more than 0.5 μ

m.