Liquid crystal display device

Abstract

To realize a structure which can secure high reliability and low reflectance while reducing manufacturing costs for a display region of an IPS type liquid crystal display device.SOLUTION: In a liquid crystal display device, a display region 140 is formed in a portion where a counter substrate 200 overlaps a TFT substrate 100 and a terminal region 150 is formed in a portion where the counter substrate 200 does not overlap the TFT substrate 100. A side of the counter substrate 200 that is adjacent to the terminal region 150 extends in a first direction, a terminal 10 for reference potential which is connected to a reference potential and a terminal wiring are formed in the terminal region 150, and an upper polarizing plate 50 on which a driver IC 80 is mounted and which has a transparent conductive adhesive material 40 is pasted to the counter substrate 200, as well as extends in a direction perpendicular to the first direction to cover a portion of the terminal region 150. The terminal 10 for reference potential electrically connects to the transparent conductive adhesive material 40 of the upper polarizing plate 50 via a conductive member 20, and the upper polarizing plate 50 covers the driver IC 80.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal display device, and more particularly to a shield structure on the surface of a display area. [Background technology]

[0002] Liquid crystal display devices consist of a TFT substrate on which pixels, each of which has a pixel electrode and a thin film transistor (TFT), are formed in a matrix, and an opposing substrate is placed opposite the TFT substrate, with liquid crystal sandwiched between the TFT substrate and the opposing substrate. Images are formed by controlling the light transmittance of each pixel using liquid crystal molecules. Liquid crystal display devices are flat and lightweight, which has led to a wide range of applications in a variety of fields.

[0003] The viewing angle is a problem for LCDs, but IPS (In Plane Switching) LCDs have an excellent viewing angle. However, a feature of IPS is that the opposing substrate, which faces the TFT substrate, does not have an electrode. Therefore, in order to shield the inside of the LCD panel, a conductive film is formed on the surface of the opposing substrate and connected to a reference potential, thereby shielding the inside of the LCD panel.

[0004] Patent document 1 describes a configuration in which a polarizing plate having a conductive adhesive is attached to the surface of an opposing substrate, the sides of the conductive adhesive are connected to conductive resin placed on the sides of the liquid crystal display panel and the backlight, and the conductive resin is connected to the metal frame of the backlight, thereby shielding the surface of the opposing substrate.

[0005] Patent document 2 describes a configuration in which a polarizing plate having a transparent conductive film formed on the front side of a polarizing plate that is attached to an opposing substrate, a portion of the polarizing plate with the conductive film attached extends to a flexible wiring board, and a portion of this flexible wiring board is connected to a reference potential terminal formed on the flexible wiring board using copper foil or the like.

[0006] Cited Document 3 describes a configuration in which a conductive film is formed on the upper surface of the opposing substrate, and the periphery of this transparent conductive film and a reference potential terminal formed on a TFT substrate or the like are formed by coating on the side of the liquid crystal display panel and then connected with a solidified conductive resin.

[0007] Patent document 4 describes a configuration in which a polarizing plate having a conductive adhesive material is attached to the surface of an opposing substrate, the polarizing plate extends toward the terminal side, and is connected to a reference potential terminal formed on a TFT substrate by a conductive member. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2021-089334 [Patent Document 2] Japanese Patent Application Publication No. 2014-098825 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-170200 [Patent Document 4] Japanese Patent Application Publication No. 2019-184721 Summary of the Invention [Problem to be solved by the invention]

[0009] In IPS-type liquid crystal display devices (hereafter simply referred to as liquid crystal display devices unless otherwise specified), a transparent conductive film of ITO (Indium Tin Oxide) is formed on the surface of the opposing substrate by sputtering to shield the inside of the liquid crystal display panel, and this transparent conductive film is connected to a reference potential terminal formed on the TFT substrate. However, forming the ITO film on the opposing substrate by sputtering is costly. Also, although ITO is a transparent conductive film, it does absorb a certain amount of light.

[0010] To address this issue, a technique has been proposed in which the adhesive used to attach the polarizer to the opposing substrate is made conductive to provide a shielding function. However, the configuration in which the conductive adhesive formed on the polarizer is connected to the reference potential terminal formed on the TFT substrate may not be sufficiently reliable.

[0011] Furthermore, the terminal area of ​​an LCD panel contains driver ICs and various wiring, and noise can be emitted from these structures. Until now, no measures have been taken to prevent noise emission from this terminal area.

[0012] The present invention aims to realize a configuration in which a polarizing plate is attached to an opposing substrate via a conductive adhesive to shield the inside of a liquid crystal display panel, in which the conductive adhesive and a reference potential terminal formed on a TFT substrate are connected with high reliability, and also to realize a configuration in which noise radiation from the terminal area of ​​the liquid crystal display panel is prevented. [Means for solving the problem]

[0013] The present invention overcomes the above problems, and the main specific means are as follows.

[0014] (1) A liquid crystal display device in which a display area is formed in a portion where a counter substrate overlaps a TFT substrate, and a terminal area is formed in a portion of the TFT substrate where the counter substrate does not overlap, wherein an edge of the counter substrate adjacent to the terminal area extends in a first direction, a reference potential terminal and terminal wiring connected to a reference potential are formed in the terminal area, and a driver IC is mounted on the counter substrate, and an upper polarizer having a transparent conductive adhesive is attached to the counter substrate and extends in a direction perpendicular to the first direction to cover a part of the terminal area, the reference potential terminal is electrically connected to the transparent conductive adhesive of the upper polarizer via a conductive member, and the upper polarizer covers the driver IC.

[0015] (2) A liquid crystal display device in which a display region is formed in a portion where a counter substrate overlaps a TFT substrate, and a terminal region is formed in a portion of the TFT substrate where the counter substrate does not overlap, wherein an edge of the counter substrate adjacent to the terminal region extends in a first direction, a reference potential terminal connected to a reference potential and terminal wiring are formed in the terminal region, an upper polarizing plate having a transparent conductive adhesive is attached to the counter substrate and extends in a direction perpendicular to the first direction to cover a portion of the terminal region, the reference potential terminal is electrically connected to the transparent conductive adhesive of the upper polarizing plate via a conductive member, an organic insulating film is present on the terminal wiring, and the conductive member is present between the organic insulating film and the transparent conductive adhesive of the upper polarizing plate, and the conductive member is formed continuously from the first edge side to the second edge side of the terminal region when viewed in the first direction. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view of a liquid crystal display device that does not use the present invention. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] 2 is a cross-sectional view of FIG. 1 taken along line B-B. [Figure 4] FIG. 2 is a cross-sectional view of a display area of ​​a liquid crystal display device. [Figure 5] FIG. 2 is a plan view showing a first process of the first embodiment. [Figure 6] 6 is a cross-sectional view taken along CC in FIG. 5. [Figure 7] FIG. 10 is a plan view showing a second process of the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view taken along the line DD in FIG. 7. [Figure 9] FIG. 10 is a plan view showing a third process of the first embodiment. [Figure 10] 1 is a plan view of a liquid crystal display device according to a first embodiment. [Figure 11] 11 is a cross-sectional view of FIG. 10 taken along E-E axis. [Figure 12] FIG. 11 is a cross-sectional view of FIG. 10 taken along the line F-F. [Figure 13] 11 is a cross-sectional view of FIG. [Figure 14] FIG. 10 is a plan view of a liquid crystal display device according to a second embodiment. [Figure 15] FIG. 15 is a cross-sectional view of FIG. 14 . [Figure 16] FIG. 15 is a cross-sectional view of FIG. 14 . [Figure 17] FIG. 10 is a plan view of another liquid crystal display device according to the second embodiment. [Figure 18] 18 is a cross-sectional view of FIG. 17 . [Figure 19] FIG. 10 is a cross-sectional view illustrating a problem to be solved in a third embodiment. [Figure 20] FIG. 10 is a cross-sectional view showing a first form of the third embodiment. [Figure 21] FIG. 10 is a cross-sectional view showing a second embodiment of the third embodiment. [Figure 22] FIG. 10 is a cross-sectional view showing a third form of the third embodiment. [Figure 23] FIG. 10 is a plan view of a liquid crystal display device according to a fourth embodiment. [Figure 24] 10 is a process flowchart for manufacturing a liquid crystal display device according to Example 5. DETAILED DESCRIPTION OF THE INVENTION

[0017] Fig. 1 is a plan view of a typical liquid crystal display device. In Fig. 1, a TFT substrate 100 and a counter substrate 200 are bonded with a sealant 160, and liquid crystal is sealed inside. An upper polarizing plate 50 is attached to the upper side of the counter substrate 200. In Fig. 1, the upper polarizing plate 50 is formed to be slightly smaller than the counter substrate 200 in a plan view. A display area 140 exists in the area where the TFT substrate 100 and the counter substrate 200 overlap.

[0018] In the display area 140, scanning signal lines 1 extend in the horizontal direction (x direction) and are arranged in the vertical direction (y direction). Video signal lines 2 extend in the vertical direction and are arranged in the horizontal direction. Pixels 3 are formed in the area surrounded by the scanning signal lines 1 and the video signal lines 2.

[0019] The TFT substrate 100 is formed larger than the counter substrate 200, and the portion where the TFT substrate 100 and the counter substrate 200 do not overlap forms a terminal area 150. A driver IC 80 that drives the liquid crystal display device is mounted in the terminal area 150, and a flexible wiring substrate 90 that supplies power and signals to the liquid crystal display device is connected to it. Since liquid crystal does not emit light itself, a backlight is provided on the back of the liquid crystal display panel.

[0020] The upper polarizer 50 is attached to the counter substrate via a transparent conductive adhesive formed on its back side. This transparent conductive adhesive covers the entire surface of the counter substrate 200, thereby electrically shielding the interior of the liquid crystal display panel. However, to achieve this shielding, the transparent conductive adhesive must be connected to a reference potential. For this purpose, a reference potential terminal 10 is formed on the TFT substrate 100, and the transparent conductive adhesive and the reference potential terminal 10 are connected with a conductive paste 30 such as silver paste.

[0021] Fig. 2 is a cross-sectional view taken along the line AA in Fig. 1. In Fig. 2, a TFT substrate 100 and a counter substrate 200 are bonded together using a sealant, and liquid crystal is sandwiched between the TFT substrate 100 and the counter substrate 200. A driver IC 80 is mounted in a terminal region 150, and a flexible wiring substrate 90 is connected to it. A lower polarizing plate 60 is bonded to the lower side of the TFT substrate 100 via an adhesive material 70. This adhesive material 70 does not need to be conductive. An upper polarizing plate 50 is bonded to the upper side of the counter substrate 200 via a transparent conductive adhesive material 40. The transparent conductive adhesive material 40 serves to electrically shield the liquid crystal display panel.

[0022] 3 is a cross-sectional view taken along the line BB in FIG. 1, and is a cross-sectional view of the vicinity of a reference potential terminal 10 for connecting the transparent conductive adhesive material 40 to a reference potential. In FIG. 3, the reference potential terminal 10 connected to a reference potential is formed on the TFT substrate 100. The side surface of the transparent conductive adhesive material 40 and the reference potential terminal 10 are connected by a conductive paste 30 such as silver paste.

[0023] 3, the connection between the reference potential terminal 10 and the transparent conductive adhesive material 40 relies on the contact between the side surface of the transparent conductive adhesive material 40 and the conductive paste 30, which makes it difficult to increase the contact area, resulting in problems with the reliability of the connection and also in a tendency for the connection resistance to increase.

[0024] The present invention realizes a highly reliable connection structure between the transparent conductive adhesive material 40 that bonds the upper polarizer 50 and the counter substrate 200 and the reference potential terminal 10 formed on the TFT substrate 100. In the present invention, a special structure is formed in the terminal region 150, but since the structure of the terminal region 150 is formed simultaneously with the formation of the display region 140, the cross-sectional structure of the display region 140 will be described first.

[0025] Fig. 4 is a cross-sectional view of an IPS liquid crystal display device. In Fig. 4, a light-shielding film 101 is formed of metal on a TFT substrate 100, and an underlying film 102 is formed thereon of an SiO film and an SiN film. A semiconductor film 103 is formed on the underlying film 102. The semiconductor film 103 is formed of, for example, an oxide semiconductor or a polysilicon semiconductor.

[0026] A gate insulating film 104 is formed to cover the semiconductor film 103, and a gate electrode 105 is formed thereon. The gate electrode 105 is connected to a scanning signal line 1. An interlayer insulating film 106 is formed to cover the gate electrode 105. A drain electrode 107 and a source electrode 108 are formed on the interlayer insulating film 106. The drain electrode 107 is connected to a video signal line 2, and is connected to the drain region of the semiconductor film 103 via a through hole. The source electrode 108 is connected to the source region of the semiconductor film 103 via a through hole.

[0027] 4, an organic passivation film 109 is formed to cover the drain electrode 107, the source electrode 108, etc. The organic passivation film 109 also serves as a planarization film, and is formed to a thickness of about 2 to 4 μm in order to reduce stray capacitance. A common electrode 110 is formed in a planar shape on the organic passivation film 109 using ITO or the like. A capacitive insulating film 111 is formed on the common electrode 110 using SiN or the like, and a pixel electrode 112 having, for example, a comb-like shape is formed on top of the capacitive insulating film 111 using ITO or the like.

[0028] The pixel electrode 112 is connected to the source electrode 108 via a through-hole 1091 formed in the organic passivation film 109. An alignment film 113 is formed covering the pixel electrode 112. This is for initially aligning the liquid crystal molecules 301. A counter substrate 200 is disposed opposite the TFT substrate 100, with a liquid crystal layer 300 sandwiched between them. A black matrix 202 and a color filter 201 are disposed on the counter substrate 200, and an overcoat film 203 is disposed on the color filter 201 and the black matrix 202. An alignment film 204 is formed on the overcoat film 203.

[0029] In Figure 4, when a voltage based on a video signal is applied to the pixel electrode 112, electric lines of force are generated as shown in the figure, causing the liquid crystal molecules 301 to rotate and changing the transmittance of the liquid crystal layer 300. An image is formed by changing the transmittance for each pixel. Since the liquid crystal molecules 301 can only control polarized light, as shown in Figure 4, a lower polarizer 60 is attached to the TFT substrate 100, and only specific polarized light from the backlight is allowed to pass. Then, an upper polarizer 50 is attached to the counter substrate 200 and analyzed.

[0030] 4, no electrodes are formed on the counter substrate 200, so it cannot shield against external noise. Conventionally, ITO was sputtered onto the surface of the counter substrate 200, and this ITO film was used to shield the inside of the liquid crystal display panel, but the cost of ITO sputtering and the increase in reflectance caused by the ITO posed problems.

[0031] Therefore, a technique has been developed in which an upper polarizing plate 50 having a conductive transparent conductive adhesive material 40 is attached to the counter substrate 200 and connected to a reference potential, thereby providing a shielding effect. This method makes it possible to omit the step of forming an ITO film on the counter substrate 200.

[0032] In addition to conductivity, the important characteristic of the conductive adhesive material 40 is that it must have low light reflectance. The light reflectance of the conductive adhesive material 40 configured as described above can be made lower than that of ITO. Note that, since various electrodes are present on the TFT substrate 100 side, there is no need to place a shield electrode outside the TFT substrate 100. Therefore, in FIG. 4, the adhesive material 70 used to attach the lower polarizer 60 to the TFT substrate does not need to be conductive.

[0033] In order to provide a shielding effect to the transparent conductive adhesive material 40 to which the upper polarizer 50 is attached, it is necessary to connect the transparent conductive adhesive material 40 to a reference potential. Specifically, the upper polarizer 50 and the transparent conductive adhesive material 40 that attaches it are formed on the surface of the counter substrate 200, and it is necessary to connect this transparent conductive adhesive material 40 to the reference potential terminal 10 formed on the TFT substrate 100. The present invention realizes a highly reliable connection structure between the transparent conductive adhesive material 40 of the upper polarizer 50 and the reference potential terminal 10 of the TFT substrate 100. [Example]

[0034] The configuration of Example 1 of the present invention will be described with reference to Figs. 5 to 13. Fig. 10 is a plan view of a liquid crystal display device showing the configuration of Example 1. That is, an upper polarizer 50 having a transparent conductive adhesive material 40 is extended to an area covering a reference potential terminal 10 of a TFT substrate 100, and the reference potential terminal 10 and the transparent conductive adhesive material 40 of the upper polarizer 50 are connected by a conductive member 20. As the conductive member 20, various conductive adhesive materials, heat-curable or ultraviolet-curable conductive adhesive materials, etc. can be used. In this embodiment, first, a case where a conductive adhesive material is used as the conductive member 20 will be described.

[0035] FIG. 5 is a plan view showing the state in which the reference potential terminals 10 are formed in the terminal region 150. The configuration of the reference potential terminals 10 will be explained later, but they are configured such that a terminal metal made of metal is covered with an oxide conductive film such as ITO. Two reference potential terminals 10 are formed in the terminal region 150. FIG. 6 is a cross-sectional view taken along CC in FIG. 5. Detailed layer configuration is omitted in FIG. 6.

[0036] The terminal region 150 is formed simultaneously with the structure of the display region 140 described in Fig. 4. Fig. 7 is a plan view showing a state in which a conductive member (conductive adhesive material) 20 having approximately the same size as the reference potential terminal 10 is attached to cover the reference potential terminal 10. In Fig. 7, the driver IC 80 is thermocompression bonded to the terminal formed in the terminal region 150 via an ACF (Anisotropic Conductive Film). It does not matter whether the conductive member 20 is attached first or the driver IC 80 is thermocompression bonded first.

[0037] Fig. 8 is a cross-sectional view taken along the line DD of Fig. 7. In Fig. 8, a conductive member 20 is attached onto the reference potential terminal 10. This conductive member 20 and the transparent conductive adhesive material 40 of the upper polarizer 50 are electrically connected. Since the upper polarizer 50 is made of a relatively hard material, the conductive member 20 must be formed thick to prevent bending stress from occurring in the upper polarizer 50. Note that the lower polarizer is omitted from the cross-sectional views in Fig. 8 and subsequent figures.

[0038] It is best to use the same material as the transparent conductive adhesive 40 of the upper polarizer 50 as the material for the conductive member 20. This is because it provides the highest adhesive reliability. Quality control of the material is also easy. For example, an acrylic resin, which is conductive in itself, can be used as the conductive member (conductive adhesive) 20. There are also acrylic adhesives with conductive particles dispersed in them. For example, metal particles such as silver, nickel, aluminum, and copper can be used as the conductive particles. Note that since the conductive member 20 is present in the terminal region 150, it does not need to be transparent. Therefore, in addition to metal particles, carbon particles such as graphite can also be used as the conductive particles in the adhesive.

[0039] 8, the space between the opposing substrate 200 or the sealing material 160 and the reference potential terminal 10 can be used as a space for terminal wiring. Also, the area outside the reference potential terminal 10 can be used as an area for an inspection terminal, for example.

[0040] Fig. 9 is a cross-sectional view showing a state in which a polarizing plate 50 is attached to the configuration of Fig. 8. Fig. 9 is a portion corresponding to the DD cross section of Fig. 7. In Fig. 9, after the upper polarizing plate 50 is attached, in order to prevent excessive bending stress from occurring in the upper polarizing plate 50 or to prevent peeling stress from occurring between the upper polarizing plate 50 and the conductive member 20, it is necessary to increase the thickness of the conductive member 20.

[0041] Specifically, the height h of the TFT substrate 100 from the glass surface is equal to or greater than the thickness of the transparent conductive adhesive material 40 of the upper polarizer 50 and equal to or less than the thickness of the counter substrate 200. In the present invention, as shown in FIGS. 10 and 12 , the upper polarizer 50 is disposed so as to cover the driver IC 80. Therefore, it is preferable that the height h be equal to or less than the height of the driver IC 80 from the substrate 100. Even if it is difficult to dispose such a thick conductive member 20, it is preferable that the height h of the TFT substrate 100 from the glass surface be equal to or greater than half the thickness of the counter substrate 200.

[0042] FIG. 10 is a plan view of a liquid crystal display device according to the present invention formed in this manner. In FIG. 10, the upper polarizer 50 extends to the terminal region 150, covering not only the counter substrate 200 but also the reference potential terminal 10 and the driver IC 80. The transparent conductive adhesive material 40 of the upper polarizer 50 is electrically connected to the reference potential terminal 10 and the conductive member 20 and acts as a shielding material for the entire counter substrate 200. In FIG. 10, the conductive member 20 and the transparent conductive adhesive material 40 are in surface contact, ensuring a sufficient contact area and high reliability of conduction. In FIG. 10, the outer edge of the conductive member 20 or the reference potential terminal 10 in the y direction coincides with the outer edge of the upper polarizer 50 in the y direction.

[0043] Another feature of Figure 10 is that the transparent conductive adhesive material 40 of the upper polarizer 50 covers the driver IC 80. The driver IC 80 generates scanning signals and clock signals with relatively large amplitudes. In other words, the driver IC 80 can be a noise source. In the configuration of Figure 10, covering the driver IC 80 with the transparent conductive adhesive material 40 of the upper polarizer 50 can shield noise from the driver IC 80.

[0044] Fig. 11 is an E-E cross-sectional view of Fig. 10. The configuration of Fig. 11 is the same as that described in Fig. 8 and Fig. 9. In Fig. 11, there is a space between the counter substrate 200 and the reference potential terminal 10, and many terminal wirings are often formed in this area. Some of these terminal wirings may be a source of noise, but this noise is shielded by the transparent conductive adhesive material 40 of the upper polarizer 50.

[0045] Fig. 12 is an FF cross-sectional view of Fig. 10. In Fig. 12, the driver IC 80 is connected to the terminal area 150 via an ACF 81. The upper polarizer 50 extends from the counter substrate 200 to the terminal area 150 and covers the driver IC 80. The transparent conductive adhesive material 40 of the upper polarizer 50 is adhered to the upper surface of the driver IC 80. The transparent conductive adhesive material 40 can be adhered to the driver IC 80 with the same strength as that of the counter substrate 200. Since the height of the driver IC 80 is approximately the same as that of the counter substrate 200, no height adjustment member is particularly necessary.

[0046] Noise from the driver IC 80 can be shielded by the transparent conductive adhesive material 40 connected to a reference potential. In Fig. 12, the edge of the driver IC is located inside the edge of the upper polarizer 50, but this is to more reliably shield noise from the driver IC 80. However, the edge of the driver IC 80 and the edge of the upper polarizer 50 may be aligned.

[0047] 12, the flexible wiring board 90 is connected to terminals formed in the terminal area 150 at the end of the terminal area 150 via ACF 91. The upper polarizing plate 50 is configured not to cover the portion to which the flexible wiring board 90 is connected, so the flexible wiring board 90 can be connected after adhering the upper polarizing plate 50. However, if necessary, depending on the relationship with the thermocompression bonding device for the driver IC 80, flexible wiring board 90, etc., the upper polarizing plate 50 can be connected after the flexible wiring board 90 is connected.

[0048] Fig. 13 is a cross-sectional view taken along line GG in Fig. 10. In Fig. 13, an upper polarizing plate 50 and a transparent conductive adhesive material 40 cover a terminal region 150 like a canopy. Many terminal wirings are formed in the terminal region 150, but noise from these wirings is shielded by the transparent conductive adhesive material 40 connected to a reference potential.

[0049] As described above, according to the first embodiment, the inside of the liquid crystal display panel can be reliably shielded by the transparent conductive adhesive material 40 of the upper polarizing plate 50. In addition, it is possible to shield noise from the driver IC 80 in the terminal area 150 and from the terminal wiring. [Example]

[0050] FIG. 14 is a plan view of a liquid crystal display device according to Example 2. FIG. 14 differs from FIG. 10 of Example 1 in that the area of ​​the conductive member 20 covering the reference potential terminal 10 is larger. In FIG. 10 of Example 1, the area of ​​the conductive member 20 is approximately the same as the area of ​​the reference potential terminal. In the configuration of FIG. 10, the transparent conductive adhesive material 40 of the upper polarizer 50 and the conductive member 20 are in surface contact, but the adhesive strength may not be sufficient. Furthermore, in the structure of Example 1, as shown in FIG. 13, the tip of the canopy portion of the upper polarizer 50 is unstable, and there is a risk that the upper polarizer 50 will peel off from this point.

[0051] In Example 2 shown in Fig. 14, the area of ​​the conductive member 20 is made considerably larger than the area of ​​the reference potential terminal 10, thereby further reducing the risk of peeling off of the upper polarizer 50. "Considerably larger" specifically means that in Fig. 14, the width of the conductive member 20 in the x direction of the conductive member 20, i.e., in the extension direction of the side adjacent to the terminal region of the counter substrate in a plan view, is at least two times, preferably at least three times, and more preferably at least five times the width of the reference potential terminal 10. Furthermore, in the y direction of the conductive member 20, i.e., in the direction perpendicular to the extension direction of the side adjacent to the terminal region 150 of the counter substrate 200, the conductive member 20 has a width sufficient to cover the area between the end of the counter substrate 200 and the reference potential terminal 10.

[0052] FIG. 15 is a cross-sectional view taken along line H-H of FIG. 14. In FIG. 15, unlike FIG. 11 of Example 1, the conductive member 20 covers the edge of the upper polarizer 50 and the area from the edge of the reference potential terminal 10 to the edge of the counter substrate 200. This increases the bonding area between the upper polarizer 50 and the conductive member 20, improving the reliability of the bonding. FIG. 16 is a cross-sectional view taken along line II of FIG. 14. In FIG. 16, unlike FIG. 13 of Example 1, the conductive member 20 covers the area from the edge of the upper polarizer 50 to the edge of the counter substrate 200. This allows the upper polarizer 50 to be stably fixed all the way to the edge.

[0053] Fig. 17 is a plan view of a liquid crystal display device showing a second form of Example 2. Fig. 17 differs from Fig. 14 in that a conductive member 20 is present in the entire area between the upper polarizer 50 and the terminal area 150, except for the area where the driver IC 80 is arranged. Fig. 18 is a cross-sectional view taken along the line JJ in Fig. 17. As shown in Fig. 18, a conductive member 20 is present between the driver IC 80 and the end of the counter substrate 200.

[0054] The driver IC 80 is connected via the ACF 81, but since the ACF 81 is not conductive in the lateral direction, even if the conductive member 20 and the ACF 81 come into contact, there is no problem with insulation as long as they do not come into contact with the bumps of the driver IC 80. In Fig. 18, the upper polarizer 50 protrudes like a canopy outside the driver IC 80, but this is to more effectively shield the driver IC 80, and this canopy is not necessary.

[0055] As described above, according to the second embodiment, it is possible to improve the adhesive strength between the transparent conductive adhesive material 40 of the upper polarizing plate 50 and the conductive member 20, thereby reliably shielding the inside of the liquid crystal display panel. It is also possible to shield noise from the driver IC 80 and terminal wiring in the terminal region 150. [Example]

[0056] FIG. 19 is a detailed cross-sectional view of the terminal region 150. FIG. 19 corresponds to the HH cross-sectional view of FIG. 14. In FIG. 19, the reference potential terminal 10 is formed by a terminal metal 11 and a protective conductive film 14 made of ITO that covers it. The terminal metal 11 is made of the metal of either the light-shielding film, gate electrode, or drain / source electrode. The ITO for the protective conductive film 14 is made of either the ITO that constitutes the common electrode or the ITO that constitutes the pixel electrode, or both.

[0057] As shown in FIG. 19 , many wirings 15 exist in the terminal region 150. To protect these wirings 15, inorganic insulating films such as SiO and SiN are used as the protective insulating film 12. These inorganic insulating films are also used in the display region and have excellent moisture-proofing properties. These inorganic insulating films are formed simultaneously with the formation of the underlayer 102, gate insulating film 104, interlayer insulating film 106, or capacitor insulating film 111, as described in FIG. 4 . The inorganic insulating film to be used depends on the metal used for the terminal metal 11: the light-shielding film 101, gate electrode 105, or drain / source electrodes 107 and 108. In either case, these inorganic insulating films are very thin, typically less than 200 nm. This results in a large stray capacitance, indicated by C1, between the terminal wirings 15 and the conductive member 20. The presence of this large stray capacitance can cause delays in signal writing, etc.

[0058] FIG. 20 is a cross-sectional view of the terminal region 150 showing Example 3. FIG. 20 corresponds to the HH cross-sectional view of FIG. 14. In FIG. 20, the organic passivation film 109 formed in the display region 140 is also formed in the terminal region 150 so as to cover the terminal wiring 15. The organic passivation film 109 is formed with a thickness of 2 to 4 μm, for example, from an acrylic resin. This allows the distance between the terminal wiring 15 and the conductive member 20 to be increased, thereby reducing the stray capacitance C2. Therefore, even if the area where the conductive member 20 is formed is expanded, as in Example 2, an increase in stray capacitance can be prevented.

[0059] FIG. 21 is a cross-sectional view of a terminal portion showing embodiment 2 of example 3. FIG. 21 corresponds to the H-H cross-sectional view of FIG. 14. The organic passivation film 109 may swell due to absorption of moisture in the atmosphere, which may lead to peeling. FIG. 21 shows a configuration to prevent this, in which the surface of the organic passivation film 109 is covered with a second protective film 111. In this case, the second protective film 111 serves as a capacitive insulating film 111. This prevents the organic passivation film 109 from peeling due to swelling, etc.

[0060] FIG. 22 is a cross-sectional view of the terminal region 150 illustrating Example 3 of Example 3. FIG. 22 corresponds to the H-H cross-sectional view of FIG. 14. The operation of FIG. 22 is similar to that described in Embodiments 1 and 2. A feature of FIG. 22 is the edge of the counter substrate 200. The counter substrate 200 needs to have a portion corresponding to the terminal region 150 of the TFT substrate 100 removed. This is achieved by scribing a portion of the counter substrate 200. However, the presence of the sealant 160 can make it difficult to remove the end material of the counter substrate 200. FIG. 22 shows an example in which a spacer 170 and an organic passivation film 109 are disposed at the edge of the counter substrate 200 to facilitate separation of the end material of the counter substrate 200. The spacer 170 extends in a bank-like manner in the direction perpendicular to the plane of the drawing.

[0061] 22, the sealant 160 is formed on the organic passivation film 109 and the capacitive insulating film 111 inside the spacer 170. The organic passivation film 109 is separated into three regions: the inside of the seal portion, the seal portion, and the terminal region 150. This structure makes it possible to prevent moisture from penetrating into the liquid crystal display panel through the organic passivation film 109. Furthermore, it is possible to easily separate the end material of the counter substrate 200, and to reliably shield the display region 140. [Example]

[0062] Fig. 23 is a plan view showing a fourth embodiment of the present invention. Fig. 23 shows a case where a driver IC 80 is arranged on a flexible wiring substrate 90 in order to reduce the area of ​​the terminal region 150. A feature of Fig. 23 is that a conductive member 20 is formed on the entire surface of the upper polarizer 50 extending into the terminal region 150. Therefore, the upper polarizer 50 is stably adhered in the terminal region 150, and it is possible to prevent poor conductivity between the reference potential terminal 10 and the transparent conductive adhesive material 40 of the upper polarizer 50 and peeling at the edge of the upper polarizer.

[0063] 23, as explained in FIGS. 20 to 22 of Example 3, an organic passivation film 109 is formed in the terminal region 150. This makes it possible to suppress an increase in stray capacitance between the conductive member 20 and the terminal wiring 15. The KK cross section in FIG. 23 is the same as the cross section shown in FIGS. 20 to 22, except for the length of extension of the upper polarizer 50 to the terminal region 150. [Example]

[0064] In Examples 1 to 4, a conductive adhesive material is used as the conductive member. A conductive adhesive material can also be used as the conductive member. Since there are a relatively large number of types of conductive adhesive material, the advantage of using a conductive adhesive material is that the most suitable material can be selected from a wide range of materials.

[0065] Conductive adhesives include resins that are conductive in themselves, as well as resins that have conductive particles such as metal or carbon dispersed within them. Resins that can be used include epoxy, acrylic, silicone, and urethane. These conductive adhesives with dispersed conductive particles are often initially liquids with high viscosity, but their volume shrinks during the thermal curing process, causing the conductive particles to come into contact with each other and exhibit the same conductivity.

[0066] Figure 24 shows an example of a process chart for forming such a conductive adhesive in the terminal area. In Figure 24, first, the adhesive is applied to the terminal area using a dispenser or screen printing, etc. The conductive adhesive is then dried. After that, an upper polarizer having a transparent conductive adhesive is attached. The conductive adhesive is then cured by heat or ultraviolet light, thereby bonding the reference potential terminal formed on the TFT substrate to the upper polarizer and establishing electrical continuity.

[0067] In the case of the conductive adhesive material, the formation range in plan view is the same as in the case of the conductive adhesive material described in Examples 1 to 4. [Explanation of symbols]

[0068] 1...scanning signal line, 2...video signal line, 3...pixel, 10...reference potential terminal, 11...terminal metal, 12...protective insulating film, 13...protective insulating film, 14...protective ITO, 15...terminal wiring, 20...conductive member, 30...conductive paste, 40...transparent conductive adhesive, 50...upper polarizer, 60...lower polarizer, 70...adhesive, 80...driver IC, 81...ACF, 90...flexible wiring board, 91...ACF, 100...TFT substrate, 101...light-shielding film, 102...undercoat film, 103...semiconductor film, 104...gate insulating film, 105...gate electrode, 106...interlayer insulating film, 107...drain electrode, 108...source electrode, 109...organic passivation film, 110...common electrode, 111...capacitive insulating film, 112...pixel electrode, 113...alignment film, 140...display area, 150...terminal area, 160...sealing material, 170...spacer, 200...opposing substrate, 201...color filter, 202...black matrix, 203...overcoat film, 204...alignment film, 300...liquid crystal, 301...liquid crystal molecule

Claims

1. A liquid crystal display device in which a display area is formed in a portion where a counter substrate overlaps a TFT substrate, and a terminal area is formed in a portion of the TFT substrate where the counter substrate does not overlap, a side of the opposing substrate adjacent to the terminal region extends in a first direction; In the terminal area, a reference potential terminal connected to a reference potential and a terminal wiring are formed, and a driver IC is mounted thereon; A conductive transparent acrylic resin adhesive layer is formed on the entire surface of the upper polarizing plate, the upper polarizing plate is attached to the opposing substrate by the conductive transparent acrylic resin adhesive layer, and extends in a direction perpendicular to the first direction to cover a part of the terminal area; the reference potential terminal is electrically connected to the conductive transparent acrylic resin adhesive layer via a conductive member; The liquid crystal display device is characterized in that the upper polarizing plate and the conductive transparent acrylic resin adhesive layer cover the driver IC.

2. 2. The liquid crystal display device according to claim 1, wherein the width of the conductive member in the first direction is at least twice the width of the reference potential terminal in the first direction.

3. 2. The liquid crystal display device according to claim 1, wherein the width of the conductive member in the first direction is at least three times the width of the reference potential terminal in the first direction.

4. 2. The liquid crystal display device according to claim 1, wherein the conductive member is formed continuously from a first side to a second side of the terminal region when viewed in the first direction in the terminal region.

5. 2. The liquid crystal display device according to claim 1, wherein an organic insulating film is present on the terminal wiring, and the conductive member is present between the organic insulating film and the conductive transparent acrylic resin adhesive layer of the upper polarizer.

6. 6. The liquid crystal display device according to claim 5, wherein the organic insulating film is made of the same material as an organic passivation film formed on the TFT substrate in the display region.

7. 7. The liquid crystal display device according to claim 6, wherein the organic insulating film has a thickness of 2 [mu]m or more.

8. 6. The liquid crystal display device according to claim 5, wherein an inorganic insulating film is formed to cover the surface of the organic insulating film.

Images