JP2005084231A - Liquid crystal display and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display which is inexpensive and has satisfactory display quality and to provide its manufacturing method, wherein increase of the number of manufacturing steps is suppressed. <P>SOLUTION: The liquid crystal display is so constituted that a liquid crystal layer 300 is interposed between an array substrate 100 and a counter substrate 200. The array substrate 100 is provided with a color filter layer 24(R, G, B) consisting of a plurality of colored resin layers respectively colored in a plurality of colors, an over coating layer 25 covering the surface of the color filter layer 24(R, G, B) and columnar spacers 31 disposed on the color filter layer 24(R, G, B), formed integrally with the over coating layer 25 and forming a gap for holding the liquid crystal layer 300 between the array substrate 100 and the counter substrate 200. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly to an active matrix type color liquid crystal display device including a color filter layer and a manufacturing method thereof.

  Since the liquid crystal display device has features such as light weight, thinness, and low power consumption, it is applied to various fields such as OA equipment, information terminals, watches, and televisions. In particular, a liquid crystal display device having a thin film transistor, that is, a TFT, is applied as a monitor that displays data including a large amount of information, such as a portable television or a computer, because of its high responsiveness.

  A generally used liquid crystal display device is configured by sandwiching a liquid crystal layer between two glass substrates having electrodes. These two substrates are fixed around the periphery with an adhesive applied except for the liquid crystal sealing port. In addition, the liquid crystal display device for color display is arranged from a colored resin layer arranged for each pixel of one of the two glass substrates and colored red (R), green (G), and blue (B). The color filter layer is provided.

  Recently, in liquid crystal display devices, demands such as an increase in screen size and an improvement in display quality are increasing. In such a demand for further performance improvement, one of the factors hindering this is a problem of flatness of the surface of the color filter layer. That is, the colored resin layers of the respective colors forming the color filter layer are overlapped at the respective end portions, and the film thickness at such portions increases.

  As described above, there is a slight step in the color filter layer, and the gap for sandwiching the liquid crystal layer changes, and the arrangement of liquid crystal molecules is disturbed around the step, and the contrast is increased. This is a factor that degrades display performance. However, it is difficult to form the surface of the color filter layer completely flat.

Therefore, a method of flattening by arranging a transparent overcoat layer on the color filter layer has been proposed (see, for example, Patent Document 1).
JP 7-294720 A

  However, the method of disposing the overcoat layer as described above has a problem that the number of manufacturing steps is increased and the manufacturing cost is increased.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an inexpensive liquid crystal display device having a good display quality and a method for manufacturing the same, suppressing an increase in the number of manufacturing steps.

A liquid crystal display device according to a first aspect of the present invention provides:
A liquid crystal layer is sandwiched between the first substrate and the second substrate,
The first substrate is
A color filter layer comprising a plurality of colored resin layers colored in a plurality of colors, and
An overcoat layer covering the surface of the color filter layer;
A spacer disposed on the color filter layer and formed integrally with the overcoat layer, and forming a gap for sandwiching a liquid crystal layer between the first substrate and the second substrate;
It is provided with.

A method of manufacturing a liquid crystal display device according to the second aspect of the present invention includes:
A method of manufacturing a liquid crystal display device configured by sandwiching a liquid crystal layer between a first substrate and a second substrate,
In the first substrate,
Forming a color filter layer comprising a plurality of colored resin layers colored in a plurality of colors,
Applying a light-sensitive photosensitive resin material to the entire surface of the color filter layer,
Exposing the photosensitive resin material at a first exposure amount corresponding to a region for forming an overcoat layer;
Exposing the photosensitive resin material in a second exposure amount different from the first exposure amount corresponding to a region for forming a spacer;
Developing the photosensitive resin material;
From the first film thickness that forms a gap for sandwiching a liquid crystal layer between the first substrate and the second substrate, and the overcoat layer having a first film thickness covering the surface of the color filter layer. The spacer having the thick second film thickness is integrally formed.

  According to the present invention, an increase in the number of manufacturing steps can be suppressed, and an inexpensive liquid crystal display device with good display quality and a manufacturing method thereof can be provided.

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

  As shown in FIGS. 1 and 2, a liquid crystal display device according to this embodiment, for example, an active matrix liquid crystal display device 1, includes a transmissive liquid crystal panel 10 and a drive circuit that supplies a drive signal to the liquid crystal panel 10. A substrate 500 and a backlight unit 800 that illuminates the liquid crystal panel 10 from the back side are provided. The liquid crystal panel 100 and the drive circuit board 500 are electrically connected via a flexible wiring board 950. The flexible wiring board 950 is electrically connected to the liquid crystal panel 100 and the drive circuit board 500 by an anisotropic conductive film (ACF) or the like.

  The liquid crystal panel 10 includes an array substrate (first substrate) 100, a counter substrate (second substrate) 200 disposed to face the array substrate 100, and a liquid crystal layer 300 held between the array substrate 100 and the counter substrate 200. And have. The array substrate 100 and the counter substrate 200 are bonded together by a seal member 106 while forming a predetermined gap for sandwiching the liquid crystal layer 300. The liquid crystal layer 300 is composed of a liquid crystal composition sealed between the array substrate 100 and the counter substrate 200.

  In such a liquid crystal display panel 10, a display area 102 for displaying an image is composed of a plurality of pixels PX (R, G, B) arranged in an m × n matrix. The display area 102 is defined on the inner side surrounded by the sealing material 106.

  In the display region 102, the array substrate 100 is formed on a light-transmissive insulating substrate 11 such as a glass substrate, a plurality of scanning lines Y, a plurality of signal lines X, a plurality of switching elements 121, and a color filter layer 24 (R , G, B), an overcoat layer 25, a plurality of pixel electrodes 151, a plurality of columnar spacers 31, an alignment film 13A, and the like. In the peripheral area 104 defined around the display area 102, the array substrate 100 includes a light shielding layer SP and the like.

  That is, the m scanning lines Y are arranged along the row direction of the pixel electrodes 151. The n signal lines X are arranged so as to be orthogonal to the m scanning lines Y, and are arranged along the column direction of the pixel electrodes 151. The m × n switching elements 121 are arranged in the vicinity of the intersection of the scanning line Y and the signal line X, and are configured by an n-channel thin film transistor, that is, a pixel TFT having a polysilicon semiconductor layer.

  The color filter layer 24 (R, G, B) is composed of a plurality of colored resin layers colored red (R), green (G), and blue (B), and each color of red, green, and blue Transmits component light. The color filter layer 24 (R, G, B) is disposed so as to cover the switching element 121 for each of the corresponding color pixels PXR, PXG, PXB.

  Each colored resin layer is disposed so as to be superimposed on a light-shielding wiring portion (for example, signal line X, scanning line Y, auxiliary capacitance element). For example, in the example shown in FIG. 4, each colored resin layer 24 (R, G, B) is formed in a stripe shape along the extending direction of the signal line X. In the case of such a layout, the color filter layers are arranged such that the end portions of the colored resin layers 24 (R, G, B) of the respective colors are superimposed on each other on the signal line X.

  In the case of a layout in which the colored resin layers 24 (R, G, B) are formed in stripes along the extending direction of the scanning lines Y, the colored resin layers 24 (R, G, B) of the respective colors. Are arranged so as to overlap each other on the scanning line Y or on the auxiliary capacitive element parallel to the scanning line Y. In the case of a layout in which the colored resin layers 24 (R, G, and B) are randomly arranged or staggered for each pixel, the colored resin of each color on the signal line X and the scanning line Y or the auxiliary capacitance element. The ends of the layers 24 (R, G, B) are arranged so as to overlap each other.

  The overcoat layer 25 is disposed so as to cover the surface of the color filter layer 24 (R, G, B). The columnar spacer 31 is disposed on the color filter layer 24 (R, G, B) so as to be positioned on the light-shielding wiring portion, and sandwiches the liquid crystal layer 300 between the array substrate 100 and the counter substrate 200. Forming a gap. The overcoat layer 25 and the columnar spacer 31 are integrally formed in the same process by the same resin material having light transmittance.

  The light shielding layer SP is arranged in a frame shape along the periphery of the effective display area 102. The light blocking layer SP is formed of a colored resin, for example, a black resin material, in order to block light transmission. The alignment film 13 </ b> A is disposed so as to cover the entire plurality of pixel electrodes 151 and the overcoat layer 25. The alignment film 13A aligns liquid crystal molecules contained in the liquid crystal layer 300 in a predetermined direction with respect to the array substrate 100.

  The m × n pixel electrodes 151 are arranged in a matrix for each pixel PX on the overcoat layer 25. These pixel electrodes 151 are formed of a light-transmitting conductive member such as ITO (indium tin oxide). Each pixel electrode 151 is electrically connected to the corresponding pixel TFT 121 through a contact hole 26 penetrating the color filter layer 24 (R, G, B) and the overcoat layer 25.

  Each pixel TFT 121 has a semiconductor layer 112 formed of a polysilicon film, as shown in FIG. 3 in more detail. The semiconductor layer 112 is disposed on the undercoating layer 60 disposed on the glass substrate 11, and has a drain region 112D and a source region 112S formed by doping impurities on both sides of the channel region 112C. Yes.

  The gate electrode 63 of the pixel TFT 121 is formed integrally with the scanning line Y, for example, and is disposed to face the channel region 112 </ b> C of the semiconductor layer 112 with the gate insulating film 62 interposed therebetween. The drain electrode 88 of the pixel TFT 121 is formed integrally with the signal line X, for example, and is electrically connected to the drain region 112D of the semiconductor layer 112 through a contact hole 77 that penetrates the gate insulating film 62 and the interlayer insulating film 76. It is formed by. The source electrode 89 of the pixel TFT 121 is formed by being electrically connected to the source region 112 </ b> S of the semiconductor layer 112 through a contact hole 78 that penetrates the gate insulating film 62 and the interlayer insulating film 76.

  The source electrode 89 is disposed on the color filter layer 24 (R, G, B) and the color filter layer 24 (R, G, B) covering the interlayer insulating film 76, the drain electrode 88, and the source electrode 89. The pixel electrode 151 is electrically connected through a contact hole 26 formed in the overcoat layer 25. Thereby, the pixel TFT 121 is connected to the scanning line Y and the signal line X, is turned on by the drive signal from the scanning line Y, and applies the signal voltage from the signal line X to the pixel electrode 151.

  The pixel electrode 151 is electrically connected to an auxiliary capacitor element that forms an auxiliary capacitor C electrically parallel to the liquid crystal capacitor CL. That is, the auxiliary capacitance electrode 61 is formed of a polysilicon film in the same layer as the semiconductor layer 121 and is configured to have the same potential as the pixel electrode 151. At least a part of the auxiliary capacitance line 52 is disposed opposite to the auxiliary capacitance electrode 61 via the gate insulating film 62 and is set to a predetermined potential.

  Wiring portions such as the signal lines X, the scanning lines Y, and the auxiliary capacitance lines 52 are formed of a light-shielding low resistance material such as aluminum or molybdenum-tungsten. In this embodiment, the scanning lines Y and the auxiliary capacitance lines 52 arranged substantially parallel to each other are formed of molybdenum-tungsten. Further, the signal line X, the drain electrode 88, and the source electrode 89 are mainly formed of aluminum.

  On the other hand, in the display region 102, the counter substrate 200 includes a counter electrode 204 formed on a light-transmitting insulating substrate 21 such as a glass substrate, an alignment film 13B covering the counter electrode 204, and the like. The counter electrode 204 is formed of a light transmissive conductive member such as ITO. The counter electrode 204 is disposed in common for all the pixels PX (R, G, B) and faces all the m × n pixel electrodes 151 through the liquid crystal layer 300. The alignment film 13 </ b> B aligns liquid crystal molecules included in the liquid crystal layer 300 in a predetermined direction with respect to the counter substrate 200.

  In the peripheral region 104, the array substrate 100 has a scanning line driving circuit 18 including a driving TFT for driving the scanning line Y, a signal line driving circuit 19 including a driving TFT for driving the signal line X, and the like. The driving TFTs included in the scanning line driving circuit 18 and the signal line driving circuit 19 are composed of an n-channel thin film transistor and a p-channel thin film transistor having a polysilicon semiconductor layer.

  A polarizing plate PL1 and a polarizing plate PL2 are provided on the outer surfaces of the array substrate 100 and the counter substrate 200 in the liquid crystal display panel 10, respectively. The deflecting plates PL1 and PL2 are arranged, for example, so that their polarization axes are orthogonal to each other.

Next, a first manufacturing method of the liquid crystal display panel 10 having the above-described structure will be described.
In the manufacturing process of the array substrate 100, first, after forming the undercoating layer 60 on the glass substrate 11, the polysilicon semiconductor layer 112 such as the pixel TFT 121 and the auxiliary capacitance electrode 61 are formed. Subsequently, after forming the gate insulating film 62, various wiring portions such as the scanning line Y, the auxiliary capacitance line 52, and the gate electrode 63 integrated with the scanning line Y are formed.

  Subsequently, using the gate electrode 63 as a mask, an impurity is implanted into the polysilicon semiconductor layer 112 to form a drain region 112D and a source region 112S on both sides of the channel region 112C, and then the entire substrate is annealed to activate the impurity. To do. Subsequently, after forming the interlayer insulating film 76, the signal line X is formed, and the drain electrode 88, the source electrode 89, and the contact electrode 80 of the pixel TFT 121 are formed integrally with the signal line X.

Subsequently, a color filter layer 24 (R, G, B) of a color corresponding to each color pixel is formed. That is, an ultraviolet curable acrylic resin material CR-2000 (manufactured by Fuji Film Ohlin Co., Ltd.) in which a red pigment is dispersed is applied to the entire surface of the substrate by a spinner. Then, this resin material is exposed at a wavelength of 365 nm and an exposure amount of 100 mJ / cm ² through a photomask that irradiates light to a portion corresponding to the red pixel. The resin material is developed with a 1% aqueous solution of KOH for 20 seconds, further washed with water, and then baked. As a result, a red color filter layer 24R having a film thickness of about 3 μm is formed.

  Subsequently, by repeating the same process, a green color filter layer 24G having a film thickness of about 3 μm made of an ultraviolet curable acrylic resin material CG-2000 (Fuji Film Aurin Co., Ltd.) in which a green pigment is dispersed, blue A blue color filter layer 24B having a film thickness of about 3 μm made of an ultraviolet curable acrylic resin material CB-2000 (manufactured by Fuji Film Orin Co., Ltd.) in which the above pigment is dispersed is formed.

Subsequently, the overcoat layer 25 and the columnar spacer 31 are integrally formed on the color filter layer 24 (R, G, B).
That is, as shown in FIG. 5A, first, a photosensitive resin material having optical transparency is applied to the entire surface of the color filter layer 24 (R, G, B). Here, a UV curable acrylic resin material NN600 (manufactured by JSR Corporation) 25A is applied to the entire surface by a spinner and dried in an environment of 90 ° C. for 10 minutes. This resin material 25A is a negative type that crosslinks and insolubilizes with light, and as shown in FIG. 6, the film thickness after development tends to increase as the exposure dose increases.

  Subsequently, as illustrated in FIG. 5B, the resin material 25 </ b> A is exposed with the first exposure amount corresponding to the region 25 </ b> B where the columnar spacer is formed. At this time, the resin material 25A is exposed using the first photomask 410 having the first transmittance in a pattern corresponding to the columnar spacer.

The first photomask 410 applied here is obtained by forming a light-shielding mask pattern 412 such as chromium on a light-transmitting transparent substrate 411. The first photomask 410 has a pattern 413 corresponding to a columnar spacer. The transmittance is almost 100%, and the transmittance in the other portion 412 is almost 0%. In this embodiment, the region 25B where the columnar spacer is formed is exposed through the first photomask 410 at a wavelength of 365 nm and a first exposure amount of about 40 mJ / cm ² .

  Subsequently, as shown in FIG. 5C, the resin material 25A is exposed at a second exposure amount different from the first transmittance corresponding to the region 25C where the overcoat layer is formed. At this time, the resin material 25A is exposed using the second photomask 420 having the second transmittance in a pattern corresponding to the overcoat layer.

  The second photomask 420 applied here is obtained by forming a light-shielding mask pattern 422 such as chromium on a light-transmitting transparent substrate 421. The second photomask 420 is a pattern 423 corresponding to an overcoat layer. 2 The transmittance is approximately 100%, and the transmittance in the other portion 422 is approximately 0%.

Since the second film thickness of the columnar spacer needs to be thicker than the first film thickness of the overcoat layer, the second exposure is performed when the resin material 25A to be exposed is a negative type having the characteristics shown in FIG. The amount is set smaller than the first exposure amount. In this embodiment, the region 25C where the overcoat layer is to be formed is exposed through the second photomask 420 at a wavelength of 365 nm with a second exposure amount of about 10 mJ / cm ² .

  Subsequently, as shown in FIG. 5D, the resin material 25A is developed with an alkaline aqueous solution having a pH of 11.5, then further washed with water and baked in an environment of 200 ° C. for 60 minutes. Thereby, the overcoat layer 25 having a film thickness of about 1 μm (first film thickness) and the columnar spacer 31 having a height of about 4 μm (second film thickness) are simultaneously formed integrally. In the example shown in FIGS. 5A to 5D, the region 25C for forming the columnar spacer is exposed after the region 25B for forming the overcoat layer is first exposed. The process and the process shown in (c) may be reversed.

Subsequently, ITO is formed to a thickness of 1500 angstrom by sputtering or the like, and the pixel electrode 151 is formed by patterning. Subsequently, for example, a black ultraviolet curable acrylic resin resist NN700 (manufactured by JSR Corporation) is applied to the entire surface of the substrate by a spinner. Thereafter, the resist film is dried at 90 ° C. for 10 minutes, and then exposed using a photomask having a predetermined pattern shape at a wavelength of 365 nm and an exposure amount of 300 mJ / cm ² . The resist film is developed with an alkaline aqueous solution having a pH of 11.5 and baked at 200 ° C. for 60 minutes. Thereby, the light shielding layer SP is formed along the periphery of the display region 102.

Subsequently, AL-3046 (manufactured by JSR Co., Ltd.) as an alignment film material is applied to the entire surface of the substrate with a film thickness of 800 angstroms and baked to form an alignment film 13A.
Thereby, the array substrate 100 is manufactured.

On the other hand, in the manufacturing process of the counter substrate 200, first, an ITO film is formed on the glass substrate 21 with a film thickness of 1500 Å by sputtering or the like, and the counter electrode 204 is formed by patterning. Thereafter, AL-3046 (manufactured by JSR Co., Ltd.) is applied over the entire substrate in a film thickness of 800 angstroms and baked to form the alignment film 13B.
Thereby, the counter substrate 200 is manufactured.

  In the manufacturing process of the liquid crystal display panel 10, the seal member 106 is printed and applied along the outer edge of the counter substrate 200 leaving the liquid crystal inlet, and further, an electrode transfer material for applying a voltage from the array substrate 100 to the counter electrode 200. Is formed on the electrode transition electrode around the seal member 106. Subsequently, the array substrate 100 and the counter substrate 200 are arranged so that the alignment film 13A of the array substrate 100 and the alignment film 13B of the counter substrate 200 face each other, and the sealing member 106 is cured by heating to cure the two substrates. to paste together. Subsequently, a liquid crystal composition such as ZLI-1565 (made by MERCK) having positive dielectric anisotropy is injected from a liquid crystal injection port, and the liquid crystal injection port is sealed with an ultraviolet curable resin or the like. 300 is formed. Further, the deflection plate PL1 is provided on the outer surface of the array substrate 100, and the deflection plate PL2 is provided on the outer surface of the counter substrate 200.

  An active matrix type color liquid crystal display panel is manufactured by the manufacturing method as described above. When the color liquid crystal display device manufactured in this way was lit and displayed, it was confirmed that display defects due to the disorder of the alignment of liquid crystal molecules did not occur and the display quality was excellent.

  According to the liquid crystal display device manufactured by the above-described manufacturing method, by arranging the overcoat layer on the color filter layer, it is possible to absorb the step due to the overlap at the end of the colored resin layer and to contact the liquid crystal layer. It is possible to flatten the alignment film. Thereby, the gap for sandwiching the liquid crystal layer is made uniform, and the disorder of the arrangement of the liquid crystal molecules can be suppressed, and the display performance can be improved.

  In addition, by integrally forming the overcoat layer and the columnar spacer, it is not necessary to separately increase the manufacturing process for forming the overcoat layer. That is, by simultaneously forming the overcoat layer using the same photosensitive resin material in the manufacturing process for forming the columnar spacer, it is possible to suppress the increase in the number of manufacturing processes and to reduce the manufacturing cost. . Therefore, an inexpensive liquid crystal display device with excellent display quality can be provided.

  At this time, the overcoat layer and the columnar spacer are formed of a light-sensitive photosensitive resin material. The film thickness of such a photosensitive resin material can be easily controlled by controlling the exposure amount. For this reason, it is possible to simultaneously form overcoat layers and columnar spacers having different thicknesses by controlling the exposure amount to the photosensitive resin material corresponding to the respective regions where the overcoat layer and the columnar spacers are formed. It is.

  In addition, the overcoat layer 25 should just be the film thickness in which the colored resin layer in the opening part periphery can be flattened. That is, when the overcoat layer 25 has a film thickness of less than 1 μm, it may not be possible to sufficiently flatten it. When the film thickness exceeds 1.5 μm, the light transmitted through the colored resin layer may not be transmitted. The rate may be reduced and the brightness or contrast may be reduced. For this reason, the overcoat layer 25 is desirably formed to a thickness of about 1 to 1.5 μm, although it depends on the thickness of the colored resin layer.

  Next, a second manufacturing method of the liquid crystal display panel 10 having the above structure will be described. Note that the second manufacturing method is different only in the manufacturing process of the overcoat layer 25 and the columnar spacer 31, and the other processes are substantially the same as the first manufacturing method, and thus the description thereof is omitted.

  That is, as shown in FIG. 7A, a photosensitive resin material having optical transparency is applied to the entire surface of the color filter layer 24 (R, G, B) as in the first manufacturing method.

Subsequently, as shown in FIG. 7B, the entire resin material 25A is collectively exposed. At this time, the resin material 25A is exposed at an exposure amount necessary to form a thin film thickness. In this embodiment, the resin material 25A is exposed at a wavelength of 365 nm, for example, with an exposure amount (about 10 mJ / cm ² ) necessary for forming an overcoat layer.

  Subsequently, the resin material 25A is exposed at a predetermined exposure amount corresponding to the region where the overcoat layer or the columnar spacer is to be formed. At this time, the resin material 25A is exposed using a photomask 430 having a pattern corresponding to the overcoat layer or the columnar spacer.

In this embodiment, as shown in FIG. 7C, the resin material 25A is exposed corresponding to the region 25B where the columnar spacer is formed. The photomask 430 applied here is obtained by forming a light-shielding mask pattern 432 on a light-transmitting transparent substrate 431. The transmittance of the pattern 433 corresponding to the columnar spacer is almost 100%. Yes, the transmittance in the other portion 432 is almost 0%. Through such a photomask 430, the region 25B where the columnar spacer is to be formed is exposed at a wavelength of 365 nm with an exposure amount of about 30 mJ / cm ² .

  Subsequently, as shown in FIG. 7D, the resin material 25A is developed with an alkaline aqueous solution having a pH of 11.5, further washed with water, and baked in an environment of 200 ° C. for 60 minutes. Thereby, the overcoat layer 25 having a film thickness of about 1 μm (first film thickness) and the columnar spacer 31 having a height of about 4 μm (second film thickness) are simultaneously formed integrally. Note that the process shown in FIG. 7B and the process shown in FIG. 7C may be reversed.

  Even in such a second manufacturing method, like the first manufacturing method described above, an increase in the number of manufacturing steps can be suppressed, and a liquid crystal display device that is inexpensive and excellent in display quality can be provided. . In addition, since only one type of photomask for forming the overcoat layer and the columnar spacer is prepared, the manufacturing cost can be further reduced.

  Next, a third manufacturing method of the liquid crystal display panel 10 having the above-described structure will be described. In the third manufacturing method, only the manufacturing process of the overcoat layer 25 and the columnar spacer 31 is different, and the other processes are substantially the same as those of the first manufacturing method, and thus the description thereof is omitted.

  That is, as shown in FIG. 8A, a photosensitive resin material having optical transparency is applied to the entire surface of the color filter layer 24 (R, G, B) as in the first manufacturing method.

  Subsequently, as illustrated in FIG. 8B, the entire resin material 25 </ b> A is collectively exposed using a photomask 440. The photomask 440 applied here has different transmittances in patterns corresponding to the overcoat layer and the columnar spacer, respectively. That is, the photomask 440 is obtained by forming a mask pattern 442 corresponding to a columnar spacer and a mask pattern 443 corresponding to an overcoat layer on a transparent substrate 441 having light transmittance. And the mask pattern 443 has the second transmittance.

  At this time, in order to collectively expose the resin material 25A, the mask pattern corresponding to the thin film thickness is set to have a lower transmittance than the mask pattern corresponding to the thick film thickness. Thereby, the area | region which forms a thin film thickness is exposed by the exposure amount lower than the area | region which forms a thick film thickness.

In this embodiment, the first transmittance is approximately 100%, while the second transmittance is set to approximately 25%. When the resin material 25A is collectively exposed through such a photomask 440 at a wavelength of 365 nm, the region 25B where the columnar spacer is to be formed is exposed with an exposure amount of about 40 mJ / cm ^{2 and} an overcoat layer is formed. The region 25B is exposed with an exposure amount of about 10 mJ / cm ² .

  Subsequently, as shown in FIG. 8C, the resin material 25A is developed with an alkaline aqueous solution having a pH of 11.5, further washed with water, and baked in an environment of 200 ° C. for 60 minutes. Thereby, the overcoat layer 25 having a film thickness of about 1 μm (first film thickness) and the columnar spacer 31 having a height of about 4 μm (second film thickness) are simultaneously formed integrally.

  In such a third manufacturing method, as in the first manufacturing method described above, an increase in the number of manufacturing steps can be suppressed, and a liquid crystal display device that is inexpensive and excellent in display quality can be provided. . In addition, since only one type of photomask for forming the overcoat layer and the columnar spacer is prepared, the manufacturing cost can be further reduced. Furthermore, since the exposure process for forming the overcoat layer and the columnar spacers may be performed once, the number of manufacturing processes can be further reduced, and the cost can be reduced.

  In the above-described embodiment, a so-called COA (color filter on array) structure in which the color filter layer 24 (R, G, B) is provided on the array substrate 100 side has been described. However, the color filter layer 24 (R , G, B) may be provided on the counter substrate 200 side.

  That is, as shown in FIG. 9, in the display area 102, the array substrate 100 covers the switching element 121 and the switching element 121 arranged on the insulating substrate 11 in the vicinity of the intersection of the scanning line and the signal line. The insulating layer 23 disposed, the pixel electrode 151 disposed on the insulating layer 23, the alignment film 13A disposed so as to cover the pixel electrode 151, and the like are provided.

  The counter substrate 200 includes a color filter layer 24 (R, G, B), an overcoat layer 25 disposed on the color filter layer 24 (R, G, B), and a color filter layer 24 (R, G, B). The columnar spacer 31 disposed on the overcoat layer 25 and the counter electrode 204 disposed on the overcoat layer 25, the alignment film 13B disposed so as to cover the counter electrode 204, and the display region 102 The light shielding layer SP etc. which were arrange | positioned in frame shape along the outer periphery are provided.

Even in the liquid crystal display panel having such a structure, the first to third manufacturing methods can be applied to form the color filter layer, the overcoat layer, and the columnar spacer, and the same effects as described above can be obtained. It goes without saying that it is obtained.
Further, in the above-described embodiment, the photosensitive resin material for forming the overcoat layer and the columnar spacer has been described as an example in which a negative type is applied. However, a positive type that is decomposed by light and becomes soluble in a solvent. May be applied. In contrast to the negative type resin material, the positive type resin material tends to decrease the film thickness after development as the exposure amount increases. Therefore, it goes without saying that the first exposure amount for forming the columnar spacer is set to be smaller than the second exposure amount for forming the overcoat layer.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

FIG. 1 schematically shows a configuration of a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the structure of a liquid crystal display panel applicable to the liquid crystal display device shown in FIG. FIG. 3 is a cross-sectional view schematically showing the structure of the array substrate in the liquid crystal display panel shown in FIG. FIG. 4 is a schematic cross-sectional view for explaining the overlapping state of the colored resin layers constituting the color filter layer. FIGS. 5A to 5D are views for explaining a first manufacturing method for forming an overcoat layer and a columnar spacer. FIG. 6 is a diagram showing the relationship between the exposure amount and the film thickness after development in a negative type resin material. FIGS. 7A to 7D are views for explaining the second manufacturing method for forming the overcoat layer and the columnar spacers. FIGS. 8A to 8C are views for explaining a third manufacturing method for forming the overcoat layer and the columnar spacer. FIG. 9 is a cross-sectional view schematically showing the structure of another liquid crystal display panel applicable to the liquid crystal display device shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 10 ... Liquid crystal display panel, 23 ... Insulating layer, 24 (R, G, B) ... Color filter layer, 25 ... Overcoat layer, 31 ... Columnar spacer, 100 ... Array substrate, 121 ... Thin-film transistor ( Switching element), 151 ... pixel electrode, 200 ... counter substrate, 204 ... counter electrode, 300 ... liquid crystal layer, PX (R, G, B) ... (red, green, blue) pixel, X ... signal line, Y ... scanning line

Claims (7)

A liquid crystal layer is sandwiched between the first substrate and the second substrate,
The first substrate is
A color filter layer comprising a plurality of colored resin layers colored in a plurality of colors, and
An overcoat layer covering the surface of the color filter layer;
A spacer disposed on the color filter layer and formed integrally with the overcoat layer, and forming a gap for sandwiching a liquid crystal layer between the first substrate and the second substrate;
A liquid crystal display device comprising: The first substrate further includes a scanning line arranged in a row direction, a signal line arranged in a column direction, a switching element disposed in the vicinity of an intersection of the scanning line and the signal line, and the over substrate. A pixel electrode arranged in a matrix for each pixel on the coat layer,
The color filter layer is disposed by overlapping a colored resin layer of each color assigned to each pixel so as to cover the switching element on the signal line,
2. The liquid crystal display device according to claim 1, wherein the color filter layer and the overcoat layer have a contact hole for electrically connecting the pixel electrode and each switching element.   The liquid crystal display device according to claim 1, wherein the first substrate further includes a counter electrode disposed on the overcoat layer. In a method for manufacturing a liquid crystal display device configured by sandwiching a liquid crystal layer between a first substrate and a second substrate,
In the first substrate,
Forming a color filter layer comprising a plurality of colored resin layers colored in a plurality of colors,
Applying a light-sensitive photosensitive resin material to the entire surface of the color filter layer,
Exposing the photosensitive resin material at a first exposure amount corresponding to a region for forming a spacer;
Exposing the photosensitive resin material at a second exposure amount different from the first exposure amount corresponding to a region for forming an overcoat layer;
Developing the photosensitive resin material;
From the first film thickness that forms a gap for sandwiching a liquid crystal layer between the first substrate and the second substrate, and the overcoat layer having a first film thickness covering the surface of the color filter layer. A manufacturing method of a liquid crystal display device, wherein the spacer having a thick second film thickness is integrally formed. Exposing the photosensitive resin material using a first photomask having a first transmittance in a pattern corresponding to the spacer;
5. The method for manufacturing a liquid crystal display device according to claim 4, wherein the photosensitive resin material is exposed using a second photomask having a second transmittance in a pattern corresponding to the overcoat layer. Exposing the entire photosensitive resin material;
5. The method of manufacturing a liquid crystal display device according to claim 4, wherein the photosensitive resin material is exposed using a photomask having a pattern corresponding to the overcoat layer or the spacer.   5. The liquid crystal display device according to claim 4, wherein the photosensitive resin material is collectively exposed using a photomask having different transmittances in patterns corresponding to the overcoat layer and the spacer, respectively. Production method.

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