JP2006133813A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance reliability of a reflection electrode, brightness and production yield of a liquid crystal display. <P>SOLUTION: In the liquid crystal display having a pair of transparent substrates disposed opposite to each other via a liquid crystal layer, a plurality of scanning wires and a plurality of signal wires wired in a direction crossing the scanning wires and thin film transistors in the vicinity of the respective crossing parts thereof which are provided on one substrate, a protective film formed so as to cover the thin film transistors and the signal wires and pixel electrodes formed on the upper part of the protective film to be connected to source electrodes of the thin film transistors and composed of a material having high light reflection efficiency to incident light from the surface thereof, regularly disposed linear fine recessed parts or projecting parts and irregularly disposed recessed parts or projecting parts straddling the linear recessed parts or the projecting parts are formed on the protective film formed under the pixel electrodes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device, and more particularly to an active matrix liquid crystal display device such as a thin film transistor (TFT) type having a reflective electrode.

  There are two types of liquid crystal display devices: a transmissive liquid crystal display device that displays an image by switching transmission and blocking of light from a backlight with a liquid crystal panel, and a reflective liquid crystal display device that reflects and uses light incident from the surroundings. .

  The transmissive liquid crystal display device has the disadvantages that the power consumption of the backlight is large and the visibility is lowered by the external light, so that it is not the best as a display device for a portable information terminal mainly used outdoors.

  On the other hand, reflective liquid crystal display devices are widely used for display devices for portable information terminals because they have low power consumption and are thin and light.

  In order to improve the brightness and contrast, irregularities are irregularly formed on the reflective electrode surface of the reflective liquid crystal display device so as to increase the reflection efficiency of external light. Is disclosed.

The fine irregularities are formed of a resin under the reflective electrode for easy shape control.
JP-A-6-75238

  However, the adhesion between the resin and the metal is weak, and the reflective electrode is partially peeled off from the resin, causing a problem of a decrease in reflection efficiency.

  Increasing the unevenness density can improve the adhesion between the resin and the metal, but there is a limitation to irregularly arrange the unevenness to improve the scattering characteristics of incident light, which is insufficient for strengthening the adhesion. is there.

  An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a liquid crystal display device using an electrode that strongly adheres a resin and a metal in a reflective pixel electrode portion and reflects outside light without reflection.

  Representative means for solving the problems provided by the present application are as follows.

  (Means 1) Having a transparent substrate and the other substrate disposed opposite to the transparent substrate with a liquid crystal layer interposed therebetween, a plurality of scanning wirings on the other substrate and wired in a direction crossing the scanning wirings A plurality of signal wirings, a thin film transistor provided in the vicinity of each intersection, a protective film formed to cover the thin film transistor and the signal wiring, and a source electrode of the thin film transistor formed on the protective film. Liquid crystal display device having pixel electrodes connected to each other, wherein the pixel electrodes are made of a material having light reflectivity, and a plurality of thin linear recesses are formed in a region under the pixel electrodes of the protective film Alternatively, the first region in which the convex portion is formed and the second region in which the concave portion or the convex portion is disposed between the first region, and the thin linear concave portion in the first region. Or the width of the convex part is almost A law, the width of the second region is larger than the regular width.

  (Means 2) A transparent substrate and the other substrate disposed opposite to the transparent substrate with a liquid crystal layer interposed therebetween, and a plurality of scanning wirings on the other substrate and wired in a direction crossing the scanning wirings A plurality of signal wirings, a thin film transistor provided in the vicinity of each intersection, a protective film formed to cover the thin film transistor and the signal wiring, and a source electrode of the thin film transistor formed on the protective film. Liquid crystal display device having pixel electrodes connected to each other, wherein the pixel electrodes are made of a material having light reflectivity, and a plurality of thin linear recesses are formed in a region under the pixel electrodes of the protective film Or a first region in which a convex portion is formed and a second region in which a concave portion or a convex portion is formed between the first regions, and the thin linear concave portion in the first region or The width of the convex part is almost It is regular and the second region is irregularly arranged.

  (Means 3) A transparent substrate and the other substrate disposed opposite to the transparent substrate with a liquid crystal layer interposed therebetween. A plurality of scanning wirings are arranged on the other substrate in a direction crossing the scanning wirings. A plurality of signal wirings, a thin film transistor provided in the vicinity of each intersection, a protective film formed to cover the thin film transistor and the signal wiring, and a source electrode of the thin film transistor formed on the protective film In a liquid crystal display device having pixel electrodes electrically connected through holes, at least a part of the contact hole is formed into a wave shape when viewed in plan.

  Further, the means 3 has a plurality of linear recesses or projections arranged almost regularly in a region below the pixel electrode of the protective film, and the corrugated shape is the plurality of linear recesses or projections. It is configured to have almost the same regularity as the convex portion.

  Further, in the means 3 or 4, the corrugated shape is formed on or adjacent to an extension line of the plurality of linearly arranged concave portions or convex portions arranged almost regularly.

  Further, in the means 1 to 5, the interval between the linear recesses or projections arranged almost regularly is arranged so that an error is within 50%.

  Further, in the means 1 to 5, the intervals between the linearly arranged concave or convex portions arranged almost regularly are arranged so as to have an error within 10%.

  Further, the means 1 to 5 are arranged such that the period of the linearly arranged concave or convex portions arranged almost regularly is 1 μm to 6 μm.

  Furthermore, the means 1 to 5 are arranged so that the depth of the concave portions or the height of the convex portions arranged almost regularly is 0.001 μm to 1 μm.

  (Means 4) Applying a photosensitive resin and exposing the resin using a mask in which a linear light shielding pattern and a linear opening pattern are regularly arranged; There is a step of exposing the resin using a regularly arranged mask, and the resin is developed with an alkaline solution to form a pattern.

  (Means 5) Applying a photosensitive resin and using a mask having regularly arranged linear light shielding patterns and linear opening patterns and irregularly arranged dots or strips of light shielding patterns Then, the resin is developed with an alkaline solution to form a pattern.

  According to the present invention, the adhesion strength between the pixel electrode and the protective film can be improved, and a liquid crystal display device with high reliability and high reflectance can be realized. Further, by having both the regular part and the irregular part, it is possible to realize a liquid crystal display device having an electrode that reflects external light without reflection.

  In addition, since the contact hole portion is corrugated, even if a stress causes peeling to one side of the contact hole, it can be prevented from spreading to the entire side, so the rate of connection failure can be greatly reduced and high A liquid crystal display device having reliability can be realized.

  Further means of the present invention will become apparent in the following description.

  According to the present invention, the adhesion strength between the pixel electrode and the protective film can be improved, and a liquid crystal display device with high reliability and high reflectance can be realized. Further, by having both the regular part and the irregular part, it is possible to realize a liquid crystal display device having an electrode that reflects external light without reflection. In addition, since the contact hole portion is corrugated, even if a stress causes peeling to one side of the contact hole, it can be prevented from spreading to the entire side, so the rate of connection failure can be greatly reduced and high A liquid crystal display device having reliability can be realized. In production, the yield can be improved.

  Embodiments of a liquid crystal display device and a manufacturing method thereof according to the present invention will be described below with reference to the drawings.

  FIG. 1 is an overall equivalent circuit diagram showing an embodiment of a liquid crystal display device according to the present invention. This figure is an equivalent circuit, but is drawn corresponding to the actual geometric arrangement.

  In FIG. 1, there is a pair of transparent substrates SUB1 and SUB2 arranged to face each other via a liquid crystal, and the liquid crystal is sealed by a sealing material SE that also serves to fix the other transparent substrate SUB2 to one transparent substrate SUB1.

  The liquid crystal side surface of the one transparent substrate SUB1 surrounded by the sealing material SE and the gate signal line GL extending in the X direction and provided in the Y direction and extending in the Y direction and provided in the X direction. The drain signal line DL is formed.

  A region surrounded by each gate signal line GL and each drain signal line DL constitutes a pixel region, and a matrix aggregate of these pixel regions constitutes a liquid crystal display unit AR.

  In each pixel region, a thin film transistor TFT that is operated by a scanning signal from the gate signal line GL on one side and a pixel electrode PX1 to which a video signal from the drain signal line DL on one side is supplied via the thin film transistor TFT are formed. Has been.

  The pixel electrode PX1 generates an electric field between the pixel electrode PX1 and the opposing transparent electrode PX2 formed on the transparent substrate SUB2, and the light transmittance of the liquid crystal is controlled by the electric field.

  One end of each of the gate signal lines GL extends beyond the seal material SE, and the extending end constitutes a terminal to which the output terminal of the vertical signal driving circuit V is connected.

  The input terminal of the vertical scanning drive circuit V receives a signal from a printed circuit board disposed outside the liquid crystal display panel.

  The vertical scanning drive circuit V is composed of a plurality of semiconductor devices, and a plurality of gate signal lines GL adjacent to each other are grouped, and one semiconductor device is assigned to each group.

  Similarly, one end of each of the drain signal lines DL extends beyond the seal material SE, and the extending end constitutes a terminal to which the output terminal of the video signal driving circuit He is connected. .

  The input terminal of the video signal drive circuit He is adapted to receive a signal from a printed circuit board arranged outside the liquid crystal display panel.

  This video signal drive circuit He is also composed of a plurality of semiconductor devices, and a plurality of adjacent drain signal lines DL are grouped, and one semiconductor device is assigned to each group.

  One of the gate signal lines GL is sequentially selected by a scanning signal from the vertical scanning circuit V.

  Further, a video signal is supplied to each of the drain signal lines DL by the video signal driving circuit He in accordance with the selection timing of the gate signal line GL.

  FIG. 2 is a plan view showing the configuration in the pixel region (the unevenness of the surface of the pixel electrode PX1 is not shown), and a cross-sectional view taken along line AA in FIG. 3 is a cross-sectional view taken along line BB in FIG. Is shown in FIG.

  The cross-sectional structures of the region RE1 in FIG. 3 and the region RE2 in FIG. 4 are the same in the region RE shown in FIG. 2, and the same cross-sectional structure is obtained in the line AA or BB shown in FIG. It is not limited to a sectional view.

  On the surface of the transparent substrate SUB1 on the liquid crystal side, first, a pair (one not shown) of gate signal lines GL extending in the X direction and provided side by side in the Y direction is formed.

  These gate signal lines GL surround a rectangular area together with a pair of drain signal lines (one not shown) to be described later, and this area is configured as a pixel area.

  Thus, an insulating film GI made of, for example, SiN is formed on the SUB surface of the transparent substrate on which the gate signal line GL is formed so as to cover the gate signal line GL.

  The insulating film GI functions as an interlayer insulating film for the gate signal line GL in a drain signal line DL formation region described later, and functions as a gate insulating film in a thin film transistor TFT formation region described later. In the region where the capacitor element Cadd is formed, the capacitor element Cadd has a function as a dielectric.

  A semiconductor layer AS made of, for example, amorphous Si is formed on the surface of the insulating film GI so as to overlap a part of the gate signal line GL.

  The semiconductor layer AS may be polycrystalline Si.

  This semiconductor layer AS is that of the thin film transistor TFT, and by forming a drain electrode SD1 and a source electrode SD2 on the upper surface thereof, an MIS type transistor having an inverted stagger structure having a part of the gate signal line GL as a gate electrode is formed. can do.

  Here, the drain electrode SD1 and the source electrode SD2 are formed simultaneously with the formation of the drain signal line DL.

  That is, a drain signal line extending in the Y direction is formed, and a part of the drain signal line extends to the upper surface of the semiconductor layer AS to form the drain electrode SD1, and the drain electrode SD1 and the channel of the thin film transistor TFT are formed. A source electrode SD2 is formed separated by a long distance.

  The source electrode SD2 extends slightly from the semiconductor layer AS surface to the upper surface of the insulating film GI on the pixel region side, and a contact portion for connection with a pixel electrode PX described later is formed.

  Note that a thin layer doped with a high concentration impurity is formed at the interface between the semiconductor layer AS and the drain electrode SD1 and the source electrode SD2, and this layer functions as a contact layer.

  For example, when the semiconductor AS layer is formed, the contact layer has a high-concentration impurity layer already formed on the surface thereof, and the pattern of the drain electrode SD1 and the source electrode SD2 formed on the upper surface is used as a mask to expose the contact layer. It can be formed by etching impurities.

  Thus, the protective film PC is formed on the surface of the transparent substrate on which the thin film transistor TFT, the drain signal line DL, the drain electrode SD1, and the source electrode SD2 are formed.

  In this case, the protective film PC plays a role of avoiding the direct contact of the thin film transistor TFT with the liquid crystal LC and preventing the characteristic deterioration of the thin film transistor TFT.

  Furthermore, by forming an inorganic insulating film made of silicon nitride (SiNx) between the semiconductor layer AS of the thin film transistor TFT and the protective film PC, it is possible to improve the reliability of preventing the deterioration of characteristics of the thin film transistor TFT.

  Further, the protective film PC is a base for a pixel electrode PX1 described later, and is a layer for forming irregularities on the surface of the pixel electrode PX1.

  In the present invention, the positive photosensitive polymer resin is used for the protective film PC. However, the unevenness can be formed even by using a negative photosensitive polymer resin.

  FIG. 5 is a plan view of a mask for forming irregularities on the surface of the protective film PC used in the present invention. FIG. 6 is a cross-sectional view taken along the line CC of FIG. 6, and FIG. 6 is a cross-sectional view taken along the line DD of FIG. This is shown in FIG.

  The cross-sectional structures of the region RE3 in FIG. 6 and the region RE4 in FIG. 7 are the same cross-sectional structures as long as they are within the region surrounded by the light shielding pattern SH3 shown in FIG. 5, and the CC line shown in FIG. Or it is not restricted to sectional drawing in the DD line.

  In FIG. 6, the light shielding pattern SH is formed on the mask substrate QU with a material having a low light transmittance, for example, chromium (Cr). The opening pattern KA1 and the opening pattern CHX represent locations where there is no chromium on the mask substrate QU.

  In the region RE3 where the mask is provided, they are regularly arranged with a period of the sum LX of the width W1 of the linear light shielding pattern SH1 and the width D1 of the linear opening pattern KA1.

  In this embodiment, the LX is 2 μm.

  On the other hand, in FIG. 7, the light shielding pattern SH2 formed on the mask substrate QU is irregularly arranged in the region RE4 where the mask is provided.

  In this case, the light shielding pattern SH2 is preferably circular in plan view, but may be a polygon such as a quadrangle or an octagon.

  Further, the opening pattern CHX formed on the mask substrate QU is a pattern for forming a contact hole CH that electrically connects a pixel electrode PX1 described later and the source electrode SD2 of the thin film transistor TFT. In the figure, the opening pattern CHX is hatched for easy understanding, but is an area through which light is transmitted in the same manner as the opening pattern KA1.

Exposure of the light mask is transmitted through the irradiating the protective film PC as described above, the opening patterns and 200 mJ / cm ² in place of CHX, utilizing diffraction and interference of light at the location of the opening pattern KA1 40 mJ / cm ² It is said.

  After the exposure as described above, a pattern is formed on the protective film PC by developing with an alkaline solution.

  Further, if necessary, the protective film PC may be baked.

  A pixel electrode PX1 made of, for example, aluminum (Al) is formed on the protective film PC on the SUB1 surface of the transparent substrate on which the protective film PC is thus formed.

  The pixel electrode PX1 may be made of a material having high light reflection efficiency with respect to incident light. Molybdenum (Mo), titanium (Ti), tantalum (Ta), tungsten (W), chromium (Cr), silver (Ag) A metal such as

  Although not shown, an alignment film for initial alignment of liquid crystal molecules is formed on the surface (interface) in contact with the liquid crystal LC of the active matrix substrate.

  On the surface on the SUB 1 obtained as described above, irregularities CO1 regularly arranged with a period L in the region RE1 are formed, and irregularities CO2 irregularly arranged in the region RE2 are formed. It is formed.

  The unevenness height of the unevenness CO1 may be 0.001 μm to 1 μm, and is 0.4 μm in this embodiment.

  The unevenness CO1 is regularly formed with a period L, and is 2 μm in this embodiment.

  On the other hand, if the average height of irregularly arranged unevenness CO2 is in the range of 0.1 to 2 μm in the region RE of FIG. 2, incident light can be scattered, and in this embodiment, 0.7 μm. It is said.

  Further, the average interval between the vertices of the adjacent concave and convex portions CO2 may be 10 μm to 30 μm, and in this embodiment, it is 15 μm.

  FIG. 14 is an enlarged view of a region E in the vicinity of the contact hole CH in FIG.

  The contact hole CH in the present embodiment has a quadrangular shape, strictly speaking, a shape with rounded corners.

  The contact hole CH is not limited to the shape as described above, and may be circular or elliptical.

  The adhesion between the pixel electrode PX1 and the protective film PC is increased by the anchor effect because the surface area increases due to the presence of regular irregularities CO1 on the surface of the protective film PC.

  FIG. 8 is a diagram showing the adhesion strength between the pixel electrode PX1 and the protective film PC. The irregularly arranged density shown on the horizontal axis in the figure indicates the value obtained by dividing the number of vertices of the convex portion by the pixel area. For example, the irregularly arranged density is irregularly arranged in the pixel area of 16000 μm2. In the case where there are 160 vertices, the number of protrusions is 0, 01 / μm2. The density of irregularly arranged irregularities in the practical range is 0.005 / μm 2 to 0.015 / μm 2 considering the diffusibility of incident light. Therefore, the structure of the present invention having the regular unevenness CO1 shows that the adhesion strength between the pixel electrode PX1 and the protective film PC is stronger than the conventional structure in the practical range.

  In addition, since there are irregularly arranged irregularities CO2, the reflection efficiency of external light is high.

  In the second embodiment, the adhesion strength between the pixel electrode PX1 and the protective film PC in the contact hole CH is stronger than that in the first embodiment.

  FIG. 15 shows an enlarged view of a region E in the vicinity of the contact hole CH in FIG.

  Due to the presence of a wave shape in plan view in a partial region of the contact hole CH, the contact area between the pixel electrode PX1 and the protective film PC increases, and the pixel electrode PX1 and the protective film PC of the contact hole CH are caused by the anchor effect. The adhesion of becomes stronger.

  Therefore, a decrease in reflectance due to peeling of the pixel electrode PX1 is prevented.

  Also, the perimeter of the contact hole in plan view increases. As a result, the probability of disconnection at the contact hole portion can be reduced by increasing the perimeter, and the corrugated shape prevents the stress from spreading to the entire side even if the stress causes peeling to one side of the contact hole. Therefore, the rate of connection failure can be greatly reduced, and high reliability can be realized.

  In Example 3, the adhesion strength between the pixel electrode PX1 and the protective film PC in the contact hole CH is stronger than that in Example 1.

  16 and 17 show enlarged views of a region E in the vicinity of the contact hole CH in FIG.

  Due to the presence of the corrugated shape in the region of the contact hole CH in plan view, the contact area between the pixel electrode PX1 and the protective film PC increases, and the adhesion between the pixel electrode PX1 and the protective film PC in the contact hole CH is caused by the anchor effect. Become stronger.

  Therefore, a decrease in reflectance due to peeling of the pixel electrode PX1 is prevented.

  Also, the perimeter of the contact hole in plan view increases. As a result, the probability of disconnection at the contact hole portion can be reduced by increasing the perimeter, and the corrugated shape prevents the stress from spreading to the entire side even if the stress causes peeling to one side of the contact hole. Therefore, the rate of connection failure can be greatly reduced, and high reliability can be realized.

  In Example 4, in order to enhance the adhesion between the pixel electrode PX1 and the protective film PC and increase the reflection efficiency of the external light as compared with Example 1, linear irregularities are regularly arranged on irregularly arranged irregularities. A shape is formed.

  9 is a cross-sectional view taken along the line AA in FIG. 2 and corresponds to FIG.

  In order to obtain the surface shape as shown in FIG. 9, a protective film PC made of a photosensitive resin is applied after the drain electrode SD1 and the source electrode SD2 of the thin film transistor TFT are formed, and exposure is performed using a mask shown in FIG. Development is performed with an alkali solution through a step of exposing at an amount of 200 mJ / cm 2 and a step of exposing at an exposure amount of 40 mJ / cm 2 using a mask shown in FIG.

  Further, if necessary, the protective film PC may be baked.

  In this case, unevenness can be formed even if the order of use of the mask of FIG. 10 and the mask of FIG. 11 is changed.

  10 and 11 are plan views of masks for forming irregularities on the surface of the protective film PC used in the present invention, and a sectional view taken along line JJ in FIG. 10 is taken along line II in FIG. 12 and FIG. A cross-sectional view is shown in FIG.

  The cross-sectional structure of the region RE6 in FIG. 12 is the same as that of the region surrounded by the light shielding pattern SH3 shown in FIG. 10, and is limited to the cross-sectional view taken along the line JJ shown in FIG. is not. Similarly, the cross-sectional structure of the region RE7 in FIG. 13 is the same as that of the region surrounded by the light shielding pattern SH6 shown in FIG. 11, and the cross-sectional view taken along the line II shown in FIG. It is not limited to.

  In the region RE6 where the mask is shown in FIG. 12, there is a linear light shielding pattern SH4 and an opening pattern KA2, which are regularly arranged at a period of the sum XX of the width WX1 of the light shielding pattern SH4 and the width DX1 of the opening pattern KA2. .

  In the present embodiment, the XX is 2 μm.

  On the other hand, in the mask of FIG. 11, the light shielding pattern SH5 formed on the QU is irregularly arranged in the region RE7 where the mask is present.

  In this case, the light shielding pattern SH5 is preferably circular in plan view, but may be a polygon such as a quadrangle or an octagon.

  Next, a pixel electrode PX1 made of, for example, aluminum (Al) is formed on the protective film PC on the surface of the transparent substrate SUB1 on which the protective film PC is formed.

  Although not shown, an alignment film for initial alignment of liquid crystal molecules is formed on the surface (interface) in contact with the liquid crystal LC of the active matrix substrate.

  In the region RE6, the surface on the SUB 1 obtained as described above has a regular irregularity CO3 with a period X on irregular irregularities CO4 drawn irregularly drawn with thick dotted lines in the figure. It is a shape that is arranged.

  In this embodiment, the period X is 2 μm. The uneven height of the unevenness CO3 may be 0.001 μm to 1 μm, and in this embodiment is 0.001 μm to 1 μm.

On the other hand, the average height of the irregularly arranged irregularities CO4 can scatter incident light within the range of 0.1 to 2 μm in the region RE of FIG. 2. In this embodiment, the average height is 0.7 μm. It is said.

  Further, the contact hole CH has a wave shape in plan view.

  FIG. 18 is a diagram showing the adhesion strength between the pixel electrode PX1 and the protective film PC in this embodiment.

  The adhesion between the pixel electrode PX1 and the protective film PC is increased by the anchor effect because the surface area increases due to the presence of regular irregularities CO3 on the surface of the protective film PC.

  Similarly, in the contact hole CH having a wave shape with a period S in plan view, the adhesion between the pixel electrode PX1 and the protective film PC increases in surface area and is enhanced by the anchor effect.

  In addition, since there are irregularly arranged irregularities CO3, the reflection efficiency of external light is high.

  Also, the perimeter of the contact hole in plan view increases. As a result, the probability of disconnection at the contact hole portion can be reduced by increasing the perimeter, and the corrugated shape prevents the stress from spreading to the entire side even if the stress causes peeling to one side of the contact hole. Therefore, the rate of connection failure can be greatly reduced, and high reliability can be realized.

1 is an overall equivalent circuit showing an embodiment of a liquid crystal display device according to the present invention. It is a top view which shows one Example of the pixel of the liquid crystal display device by this invention. It is sectional drawing of the AA line of FIG. 2 in one Example. It is sectional drawing of the BB line of FIG. 2 in one Example. It is explanatory drawing of the photomask for forming the pixel electrode surface shape of FIG.3 and FIG.4. It is sectional drawing in the CC line of FIG. It is sectional drawing in the DD line | wire of FIG. It is the graph which compared the adhesion strength of resin which is a pixel electrode and pixel electrode base with the Example of this invention conventionally. It is sectional drawing of the AA line of FIG. 2 in another Example. It is explanatory drawing of the photomask for forming the pixel electrode surface shape of FIG. 9 in another Example. It is explanatory drawing of the photomask for forming the pixel electrode surface shape of FIG. 9 in another Example. It is sectional drawing in the JJ line of FIG. It is sectional drawing in the II line | wire of FIG. FIG. 3 is an enlarged plan view of an E region in FIG. 2 in one embodiment. It is an enlarged plan view of E area | region of FIG. 2 in another Example. It is an enlarged plan view of E area | region of FIG. 2 in another Example. It is an enlarged plan view of E area | region of FIG. 2 in another Example. It is the graph which compared the adhesion strength of resin which is a pixel electrode and pixel electrode base with the other Example of this invention conventionally.

Explanation of symbols

SUB ... transparent substrate, GL ... gate signal line, DL ... drain signal line, AS ... semiconductor layer, TFT ... thin film transistor, PX ... pixel electrode, GI ... insulating film, PS ... protective film, LC ... liquid crystal, CH ... contact hole, QU: Transparent substrate, KA: Opening pattern in mask, SH: Shading pattern in mask, SD: Source / drain electrode, CO: Uneven shape on pixel surface.

Claims (3)

A transparent substrate and the other substrate disposed opposite to the transparent substrate across the liquid crystal layer, a plurality of scanning wirings on the other substrate, and a plurality of signals wired in a direction intersecting the scanning wirings Wiring, a thin film transistor provided near each intersection, a protective film formed so as to cover the thin film transistor and the signal wiring, and a source electrode of the thin film transistor formed on the protective film via a contact hole In a liquid crystal display device having electrically connected pixel electrodes,
A liquid crystal display device, wherein at least a part of the contact hole has a wave shape when seen in a plan view.   The protective film has a plurality of linear recesses or projections arranged almost regularly in a region below the pixel electrode of the protective film, and the corrugated shape is substantially the same as the plurality of linear recesses or projections The liquid crystal display device according to claim 1, having the regularity of: The said waveform shape is formed in the extended line of the said some linear recessed part or convex part arrange | positioned substantially regularly, or the place which adjoins, The one of Claim 1 or 2 characterized by the above-mentioned. Liquid crystal display device.

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