JP2007156009A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein the external light entering from a display region reaches a liquid crystal driver IC to cause malfunction of a COG package, having the liquid crystal driver IC as a bare chip connected directly to a glass substrate. <P>SOLUTION: By installing a groove formed in the glass substrate between the LCD driver IC and display region, external light is prevented from entering into the LCD driver IC from the display region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a COG (chip on glass) type liquid crystal display device mounted on various electric products, and more particularly to a liquid crystal display device capable of reliably shielding light from a bare chip type liquid crystal driver.

  In general, since an IC uses a silicon substrate, it has a photoconductive effect on light. When the semiconductor crystal is irradiated with light due to the photoconductive effect, carriers (electrons or holes) are excited in proportion to the amount of incident light, and the conductivity increases. Therefore, when light is irradiated onto a specific circuit (especially a high impedance circuit), signal charges in the circuit leak, and IC characteristics change, resulting in malfunction.

  Therefore, generally, an IC has a structure that blocks light that reaches a bare chip after being packaged, and solves the above problem.

  However, in recent electrical products, with the downsizing and cost reduction, the mounting method of the liquid crystal driver of the liquid crystal display device to be used has shifted to the COG (chip on glass) system in which the bare chip is mounted on the glass substrate as it is. It is necessary to block the light that reaches it.

As a conventional technique for blocking light reaching the bare chip, there is a technique in which an upper portion of a liquid crystal driver IC is sealed with a colored sealant (see, for example, JP-A-10-41514). Further, there is a liquid crystal driver IC in which a light shielding sheet is disposed on the opposite surface to the glass substrate (see, for example, JP-A-6-112371)
Japanese Patent Laid-Open No. 10-41514 JP-A-6-112371

  Although both the front and back surfaces of the liquid crystal driver IC can be shielded from light by the prior art, the following problems still remain.

  That is, outside light from the surface opposite to the periphery of the chip mounting surface of the liquid crystal driver IC can be blocked by the conventional technique, but the display area of the liquid crystal display device cannot be blocked. Therefore, external light enters from the display area of the liquid crystal display device and reaches the bare chip mounting surface, which may cause the bare chip to malfunction.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a liquid crystal display device that can more reliably prevent a malfunction of a bare chip due to external light.

  According to the present invention, the object is to provide a liquid crystal display device in which a driver IC as a bare chip is mounted on a transparent substrate on which a transparent electrode is formed, and a groove is formed between the driver IC on the transparent substrate and the display area. Is achieved by forming.

  As described above, according to the present invention, it is possible to prevent external light entering the driver IC from the display area of the liquid crystal display device, and it is possible to further prevent the malfunction of the bare chip by implementing it together with the light shielding technique for the driver IC according to the prior art. It can be surely prevented.

  FIG. 1 is a schematic cross-sectional view of a conventional liquid crystal display panel portion. A liquid crystal layer 103 is formed between the first transparent electrode substrate 101 and the second transparent electrode substrate 102 on which the transparent electrodes are formed. Generally, ITO is used for the transparent electrode and glass material is used for the substrate. The transparent electrodes formed on the first transparent electrode substrate 101 and the second transparent electrode substrate 102 and the liquid crystal driver IC 104 are connected via an anisotropic conductive material 105 (generally called ACF) to drive the liquid crystal driver IC 104. Thus, dynamic display is possible by controlling the liquid crystal layer 103 sandwiched between ITO.

  Reference numeral 106 denotes a sealing material for sealing the liquid crystal driver IC 104, which is colored with carbon or the like and shields external light 108 from the upper surface of the liquid crystal driver IC 104. A light shielding sheet 107 is attached to the second transparent electrode substrate 102 on the opposite surface of the liquid crystal driver IC 104 and shields the external light 109 from the lower surface of the liquid crystal driver IC 104.

  110 is external light entering the display area of the liquid crystal display panel. Then, a part of the external light 110 reaches the mounting surface of the liquid crystal driver IC 104 via the second transparent electrode substrate 102 like the external light 111, causing a problem that causes the liquid crystal driver IC 104 to malfunction.

  FIG. 2 is a schematic cross-sectional view of the liquid crystal display panel portion according to Embodiment 1 of the present invention.

  Reference numeral 120 denotes a groove provided in the second transparent electrode substrate 102 between the liquid crystal driver IC 104 and the display area 121 of the liquid crystal display panel. Hereinafter, 120 is referred to as a light shielding groove. In FIG. 2, the light shielding groove 120 is filled with the sealing material 106. Even if the light shielding groove 120 is not filled with the sealing material 106, the external light 111 is reflected in the light shielding groove 120, thereby preventing external light to the liquid crystal driver IC 104. There is an effect.

  In FIG. 2, the light shielding groove 120 penetrates the second transparent electrode substrate 102, but it is sufficient that the amount of external light entering the liquid crystal driver IC 104 can be reduced without penetration.

  FIG. 3 is a perspective view of the liquid crystal display panel portion according to the first embodiment of the present invention.

  The light shielding groove 120 is formed between the liquid crystal driver IC 104 and the display area 121 of the liquid crystal display panel. The light shielding groove 120 is formed in the horizontal direction with respect to the liquid crystal driver IC 104 and the display area 121 of the liquid crystal display panel, thereby preventing external light from entering the liquid crystal driver IC 104 from the display area 121 of the liquid crystal display panel. Yes.

  The light shielding groove 120 may be formed by any method such as processing performed by applying thermal distortion using laser light, chemical processing such as etching, or mechanical processing.

  The first transparent electrode substrate 101 and the second transparent electrode substrate 102 may be made of a transparent resin such as an acrylic resin.

  FIG. 4 is a schematic cross-sectional view of a liquid crystal display panel portion according to the second embodiment of the present invention.

  Reference numeral 130 denotes a plurality of small grooves provided in the second transparent electrode substrate 102 between the liquid crystal driver IC 104 and the display area 121 of the liquid crystal display panel. Hereinafter, 130 is referred to as a diffusion region. Although the diffusion region 130 is represented as a large groove in FIG. 4, the diffusion region 130 forms a certain region where light is not totally reflected on the second transparent electrode substrate 102 between the liquid crystal driver IC 104 and the display region 121 of the liquid crystal display panel. As long as it is possible, it may actually be a lot of small scratches made of a file.

  By providing the diffusion region 130 in this manner, since the external light that enters the display region of the liquid crystal display panel and repeats total reflection and diffuses toward the liquid crystal driver IC 104 is diffused in the diffusion region 130, the external light reaching the liquid crystal driver IC 104 is greatly reduced. Can be made.

  In FIG. 4, the diffusion regions 130 are formed on both surfaces of the second transparent electrode substrate 102, but the diffusion regions 130 may be formed on only one of the upper surface and the lower surface of the second transparent electrode substrate 102.

Schematic cross-sectional view of a conventional liquid crystal display panel Typical sectional drawing of the liquid crystal display panel part in Embodiment 1 of this invention The perspective view of the liquid crystal display panel part in Embodiment 1 of this invention Typical sectional drawing of the liquid crystal display panel part in Embodiment 2 of this invention

Explanation of symbols

101 first transparent electrode substrate 102 second transparent electrode substrate 103 liquid crystal layer 104 liquid crystal driver IC
105 Anisotropic Conductive Material (ACF)
106 Sealant 107 Light-shielding sheet 108 External light from the upper surface of the liquid crystal driver IC 109 External light from the lower surface of the liquid crystal driver IC 110 External light that enters the display area of the liquid crystal display panel 111 External light that reaches the liquid crystal driver IC by 110 110 external light 120 light shielding groove 121 display area of liquid crystal display panel 130 diffusion area

Claims (4)

  A liquid crystal display device in which a bare chip for driving a liquid crystal is mounted on a transparent substrate on which a transparent electrode is formed, wherein a groove is formed between the bare chip on the transparent substrate and a display area. Display device.   The liquid crystal display device according to claim 1, wherein a groove formed between the bare chip and the display area on the transparent substrate is formed in a horizontal direction with respect to the bare chip and the display area.   The liquid crystal display device according to claim 1, wherein a light shielding member is filled in a groove formed between the bare chip and the display region on the transparent substrate.   In a liquid crystal display device in which a bare chip for driving a liquid crystal is mounted on a transparent substrate on which a transparent electrode is formed, an area for diffusing light is formed between the bare chip on the transparent substrate and the display area. A characteristic liquid crystal display device.

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