JP2008233476A - Photosensitive resin composition, black matrix and method for manufacturing therefor, transistor array substrate and method for manufacturing therefor, and color filter substrate and method for manufacturing therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain high OD (optical density), while maintaining patterning accuracy. <P>SOLUTION: The present invention provides a photosensitive resin composition containing a material, having chromic characteristics in a positive or negative photoresist. The OD of the photosensitive resin composition can be varied, by heating, irradiation with light or the like. Thus, by increasing the OD by heating or irradiating with light after patterning, a black matrix with higher OD, while maintaining high patterning accuracy, can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition for forming a light-shielding film, a black matrix using the photosensitive resin composition and a manufacturing method thereof, a transistor array substrate using the black matrix and a manufacturing method thereof, and the black matrix. The present invention relates to a color filter substrate using the above and a manufacturing method thereof.

  A TFT-type liquid crystal display device using TFT (Thin Film Transistor) includes a thin film transistor array substrate (hereinafter referred to as TFT array substrate), a color filter substrate including a black matrix (hereinafter referred to as BM) and a color filter, The liquid crystal is enclosed between and. Then, by controlling the electric field strength applied between the pixel electrode in each pixel region on the TFT array substrate side and the common electrode on the color filter substrate side, the alignment state of the liquid crystal in each pixel region is changed to transmit light. The image is displayed by changing the rate.

  In the liquid crystal display device, it is required to improve the ratio of the display area to the entire display screen of the TFT type liquid crystal display device, that is, the aperture ratio. Reduction of the light shielding area by various wirings, the TFT array substrate and the color Studies such as reduction of the light-shielding area corresponding to the margin by improving the bonding accuracy with the filter substrate have been made. Among them, as a method for improving the bonding accuracy between the TFT array substrate and the color filter substrate in recent years, for example, an active matrix type liquid crystal display device disclosed in Japanese Patent Laid-Open No. 4-253028 (Patent Document 1). As described above, a structure (CF on Array structure) in which the color filter layer and the BM portion are integrally formed on the TFT array substrate has been proposed.

  On the other hand, in order for such a liquid crystal display device to maintain a high-contrast image, the color purity of the color filter material is improved and the optical density (hereinafter referred to as OD) of the BM is set to prevent color mixing. Need to be high. The BM includes a metal thin film BM typified by chromium and a resin BM. However, in recent years, the cost has been shifted to a resin BM containing a pigment such as carbon black from the viewpoint of environmental safety.

  The resin BM is formed by applying a solution of the photosensitive resin composition to form a thin film (hereinafter referred to as a resist film), and then forming it into a desired shape by an exposure / development process. Here, the resist film is classified into a positive type and a negative type according to the exposure characteristics. For example, as a positive type black resist, there is a resist composition disclosed in, for example, JP-A-7-261015 (Patent Document 2).

  After the application, the positive resist film becomes soluble in an alkaline solution and is peeled off by cleaving molecules only at the exposed portion of the resin. On the other hand, in the negative resist film, the polymerization is started at the place where the light hits, so that the part not exposed to the light is peeled off. In any case, in order to ensure the patterning accuracy, it is necessary to allow light to reach the lower part (bottom part) of the resist film. However, in the case of the above-described BM that requires a high OD value, it is a big problem to allow light to reach the bottom of the resist film.

  In the past, development of the resin BM centered on the negative type that can cause the reaction to proceed to the lower part by exposing the resist film to the surface. As an example for high OD, for example, as described in “Resist composition containing a dye for black matrix” disclosed in Patent Document 2, the above-mentioned carbon black is coated with a resin to improve dispersibility. A method for increasing the content of carbon black contained in the resin BM has been proposed.

  However, the “resist composition containing a dye for black matrix” disclosed in the above-mentioned conventional Patent Document 2 has the following problems. That is, in consideration of the active matrix liquid crystal display device having the CF on Array structure disclosed in Patent Document 1, it is necessary to form a structure such as wiring on the resin BM. Therefore, as BM characteristics, in addition to the above-described increase in OD, further improvement in patterning accuracy of the upper surface and reduction in dielectric constant are required. However, the conventional negative-type resin BM cannot theoretically perform multi-tone patterning, and cannot cope with the patterning of the upper part of the resin BM required in the CF on Array structure. There is.

On the other hand, in the case of the resin BM of the positive type BM, as described above, as the OD is increased, the lower part of the resist film cannot be exposed, so that there is a problem that the patterning accuracy is remarkably lowered. .
Japanese Patent Laid-Open No. 4-253028 JP-A-7-261015

  Accordingly, an object of the present invention is to provide a photosensitive resin composition capable of increasing the OD while maintaining patterning accuracy, a BM using the photosensitive resin composition, a manufacturing method thereof, and a transistor array substrate using the BM And a manufacturing method thereof, and a color filter substrate using the BM and a manufacturing method thereof.

In order to solve the above problems, a photosensitive resin composition for forming a light-shielding film according to the present invention comprises:
A positive photosensitive resin composition containing an alkali-soluble novolak resin and a naphthoquinonediazide group-containing compound is mixed with a compound having chromic characteristics.

  According to the above configuration, since a mixture of a positive photosensitive resin composition having exposure characteristics and a compound having chromism characteristics is used as the photosensitive resin composition for forming a light shielding film, the photosensitive resin composition is applied. Then, the patterning accuracy of the resist film formed by drying can be increased by performing the patterning of the resist film in a state where the compound having the chromic characteristics does not exhibit the chromic characteristics (that is, the OD value is low). Furthermore, the OD value of the resist film can be increased by causing the compound having the chromism characteristics to exhibit the chromism characteristics.

  Therefore, according to the present invention, it is possible to provide a photosensitive resin composition for forming a light shielding film capable of achieving a high OD while maintaining a high patterning accuracy.

Further, the photosensitive resin composition for forming a light shielding film of the present invention is
A negative photosensitive resin composition containing a polymer binder, a photopolymerizable monomer, a photopolymerization initiator, and a light-shielding pigment is mixed with a compound having chromic characteristics.

  According to the above configuration, since a negative photosensitive resin composition having exposure characteristics and a compound having chromism characteristics are used as the photosensitive resin composition for forming a light shielding film, the photosensitive resin composition is applied. Then, the patterning accuracy of the resist film formed by drying can be increased by performing the patterning of the resist film in a state where the compound having the chromic characteristics does not exhibit the chromic characteristics (that is, the OD value is low). Furthermore, the OD value of the resist film can be increased by causing the compound having the chromism characteristics to exhibit the chromism characteristics.

  Therefore, according to the present invention, it is possible to provide a photosensitive resin composition for forming a light shielding film capable of achieving a high OD while maintaining a high patterning accuracy.

In the photosensitive resin composition of one embodiment,
The compound having the chromic property is a thermochromic material.

  According to this embodiment, the chromism characteristics of the compound having the chromism characteristics can be controlled by temperature. Therefore, the OD value of the resist film obtained by applying and drying the photosensitive resin composition can be easily controlled by controlling the heating temperature of the resist film.

The BM of the present invention is
The photosensitive resin composition for forming the light-shielding film is characterized in that it is patterned by being irradiated with actinic rays and developed, and further blackened by a physical stimulus.

  According to the above configuration, this BM is irradiated with actinic rays and developed on a photosensitive resin composition for forming a light shielding film capable of achieving a high OD while maintaining high patterning accuracy. It is obtained by patterning and blackening by applying a physical stimulus. Therefore, it has a target shape and a high OD value.

Moreover, the manufacturing method of BM of this invention is as follows.
After coating the photosensitive resin composition for forming the light shielding film on the substrate, it is dried.
After selectively irradiating the photosensitive resin composition applied on the substrate with actinic rays, a pattern is formed by developing with an alkaline aqueous solution,
The patterned photosensitive resin composition is blackened by applying a physical stimulus.

  According to the above configuration, the pattern is formed by selectively irradiating with active light and developing the photosensitive resin composition for forming a light shielding film capable of achieving high OD while maintaining high patterning accuracy. It is formed and blackened by further physical stimulation. Therefore, a BM exhibiting a high OD value can be formed with high patterning accuracy.

The transistor array substrate of the present invention is
A plurality of pixel electrodes formed in a matrix on a substrate;
Gate lines arranged extending in one direction between the pixel electrodes,
A source line arranged extending in the other direction between the pixel electrodes;
A gate electrode connected to the gate line, a source electrode connected to the source line, and a drain electrode connected to the pixel electrode are arranged at intersections of the gate lines and the source lines. A plurality of transistors having,
The BM is disposed above each transistor and at least an upper part of a wiring including each gate line, and between each pixel electrode and a wiring including at least each gate line and each source line. It is a feature.

  According to the above configuration, the upper part of each transistor and the upper part of the wiring including at least each gate line and the wiring including at least each gate line and each source line and each pixel electrode are formed with high patterning accuracy. In addition, a BM exhibiting a high OD value is provided. Accordingly, a high OD value is provided between the upper portion of each of the transistors, the upper portion of the wiring including at least each of the gate lines, and between the wiring including at least each of the gate lines and the source lines and the pixel electrodes. The light can be reliably shielded by the BM. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

The color filter substrate of the present invention is
A plurality of color filters formed in a matrix on the substrate;
A common electrode formed on the entire surface of each color filter,
The BM is disposed between the color filters.

  According to the above configuration, the BM that is molded with high patterning accuracy and exhibits a high OD value is disposed between the color filters. Therefore, the color filters can be reliably shielded from light by the BM having a high OD value. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

In addition, the manufacturing method of the transistor array substrate of the present invention,
A metal film is formed over the substrate, a gate line and a source line, a gate electrode connected to the gate line, a transistor having a source electrode and a drain electrode connected to the source line, and a drain electrode Forming a pattern of connected drain lines,
According to the method of manufacturing the BM, the transistor, the gate line, and the drain line are disposed above, between the gate line and the pixel electrode formation region, and between the drain line and the pixel electrode formation region. To form a BM that is patterned and blackened,
A pixel electrode is formed in the pixel electrode formation region by forming a conductive transparent film and performing patterning.

  According to the above configuration, the upper part of the transistor, the gate line and the drain line, between the gate line and the pixel electrode, and between the drain line and the pixel electrode are molded with high patterning accuracy. A BM exhibiting a high OD value is provided. Therefore, the BM having a high OD value is surely connected between the transistor, the gate line and the drain line, between the gate line and the pixel electrode, and between the drain line and the pixel electrode. Can be shielded from light. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

In addition, the manufacturing method of the transistor array substrate of the present invention,
A metal film is formed on the substrate, and a pattern of a gate line, a transistor having a gate electrode, a source electrode, and a drain electrode connected to the gate line, and a drain line connected to the drain electrode is formed. Forming,
According to the method of manufacturing the BM, the transistor, the gate line, and the drain line are disposed above, between the gate line and the pixel electrode formation region, and between the drain line and the pixel electrode formation region. A BM that is patterned and blackened so that a groove for forming an upper source line and a hole for connecting a source electrode are formed on the surface.
Filling the groove and the hole on the BM surface with metal to form an upper source line connected to the source electrode;
A pixel electrode is formed in the pixel electrode formation region by forming a conductive transparent film and performing patterning.

  According to the above configuration, the upper part of the transistor, the gate line and the drain line, between the gate line and the pixel electrode, and between the drain line and the pixel electrode are molded with high patterning accuracy. A BM exhibiting a high OD value is provided. Therefore, the upper part of the transistor, the gate line and the drain line, between the gate line and the pixel electrode, and between the drain line and the pixel electrode are surely secured by a BM having a high OD value. Can be shielded from light. Further, since the BM is formed with high patterning accuracy, a multi-level tone exposure is performed at the time of formation, so that a groove for forming an upper source line and a hole for connecting a source electrode are formed on the surface of the BM. Can be patterned. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

In addition, the manufacturing method of the color filter substrate of the present invention,
On the substrate, a BM that is patterned into a frame shape and blackened by the BM manufacturing method is formed.
A color filter is formed by applying pigment ink in the BM,
A counter electrode made of a conductive transparent film is formed on the entire surface.

  According to the above configuration, the color filter is surrounded with the BM that is molded with high patterning accuracy and exhibits a high OD value. Therefore, the periphery of the color filter can be reliably shielded from light by the BM having a high OD value. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

  As is clear from the above, since the photosensitive resin composition for forming a light shielding film of the present invention is a mixture of a photosensitive resin composition having exposure characteristics and a compound having chromism characteristics, The patterning of the resist film formed by applying and drying the photosensitive resin composition is performed in a state in which the compound having the chromic property does not exhibit the chromic property (that is, the OD value is low), thereby increasing the patterning accuracy. Can do. Furthermore, the OD value of the resist film can be increased by causing the compound having the chromism characteristics to exhibit the chromism characteristics.

  Therefore, according to the present invention, it is possible to provide a photosensitive resin composition for forming a light-shielding film capable of achieving a high OD while maintaining patterning accuracy.

  In addition, the BM of the present invention and the manufacturing method thereof perform irradiation and development of actinic rays on a photosensitive resin composition for forming a light shielding film capable of achieving a high OD while maintaining patterning accuracy. BM is obtained by patterning and blackening by applying a physical stimulus. Therefore, the BM has a desired shape and a high OD value.

  In addition, the transistor array substrate of the present invention has high patterning accuracy at the upper part of each transistor and the upper part of the wiring including at least each gate line and between the wiring including at least each gate line and each source line and each pixel electrode. And a BM exhibiting a high OD value is disposed, so that the upper part of each of the transistors, the upper part of the wiring including at least each of the gate lines, and at least each of the gate lines and the source lines are arranged. It is possible to reliably shield light between the included wiring and each pixel electrode by the BM having a high OD value. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

  In addition, since the color filter substrate of the present invention is formed with high patterning accuracy between the color filters and the BM exhibiting a high OD value is disposed, the high OD is provided between the color filters. The BM having a value can be surely shielded from light. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

  The transistor array substrate manufacturing method according to the present invention provides high patterning on the tops of transistors, gate lines and drain lines, between the gate lines and the pixel electrodes, and between the drain lines and the pixel electrodes. Since a BM that is molded with high accuracy and exhibits a high OD value is disposed, the upper portion of the transistor, the gate line and the drain line, between the gate line and the pixel electrode, the drain line and the above The light shielding between the pixel electrode and the pixel electrode can be ensured by the BM having a high OD value. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

  The transistor array substrate manufacturing method according to the present invention provides high patterning on the tops of transistors, gate lines and drain lines, between the gate lines and the pixel electrodes, and between the drain lines and the pixel electrodes. Since a BM that is molded with high accuracy and exhibits a high OD value is disposed, the upper portion of the transistor, the gate line and the drain line, between the gate line and the pixel electrode, the drain line and the above The light shielding between the pixel electrode and the pixel electrode can be ensured by the BM having a high OD value. Further, since the BM is formed with high patterning accuracy, a multi-level tone exposure is performed at the time of formation, so that a groove for forming an upper source line and a hole for connecting a source electrode are formed on the surface of the BM. Can be patterned. Further, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

  In the color filter substrate manufacturing method of the present invention, the periphery of the color filter is surrounded by a BM that is formed with high patterning accuracy and exhibits a high OD value. Therefore, the periphery of the color filter can be reliably shielded from light by the BM having a high OD value. Furthermore, since the BM is formed with high patterning accuracy, the alignment margin of the photomask during patterning can be reduced, and the aperture ratio can be improved accordingly.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  First, the material definition will be described. The “material” in the present invention is composed of two materials, a material having exposure characteristics and a material having chromism characteristics by heating or light irradiation.

  Here, the “chromism characteristics” are classified according to factors causing color change, such as light, heat, electric field, solvent, pressure, solvent vapor, ion addition, solution pH, and the like. Among these, considering the BM manufacturing method, a material that is particularly effective in the present embodiment is a material that exhibits chromism characteristics due to light, heat, and an electric field.

  The chromism property due to light is a property in which the color changes due to a cis-trans structure change or bond change caused by light (mainly ultraviolet light). Specific materials include spiropyran compounds, indolinospiropyran compounds, fulgide compounds, pyran compounds, spirooxazine compounds, spironaphthoxazine compounds, spirophenanthrooxazine compounds, diarylethene compounds, chromene compounds, and thio compounds thereof. Examples thereof include organic materials such as stilbene derivatives and azo compounds.

  The heat chromism property is a property in which the molecular orientation is changed by heating or the reaction is advanced by liquefaction by heating, resulting in a change in color. Specifically, metal oxide materials, or leuco dyes, salicylidene anilines, polythiophene derivatives, tetrahalogeno complexes, ethylenediamine derivative complexes, dinitrodiammine copper complexes, 1,4-diazacyclooctane complexes, hexamethylene Organic materials, such as a tetramine complex and a saltyl aldehyde complex, are mentioned.

  In addition, the chromism property due to an electric field is a property in which, when an electric field is applied to a material, an oxidation-reduction reaction occurs and the color changes due to cationization or anionization. Specific examples include polymer materials such as polythiophene, polypyrrole, polyaniline, polyethylenedioxythiophene and derivatives thereof.

  Next, the material having the above exposure characteristics may be either a positive type or a negative type. However, in consideration of improving the workability of the BM upper surface, a composition including a material having a positive type exposure characteristic is included. Is more effective. Specifically, as the positive type material, a general material composed of a novolac resin and a naphthoquinone diazide compound can be applied. Moreover, even if it is a negative type material, the general material comprised from a polymer binder, a photopolymerizable monomer, a photoinitiator, and a light-shielding pigment can be applied.

  Next, the definition of the mixed material will be described. The composition in this invention is formed by mixing the material having the above-mentioned exposure characteristics and the material having chromism characteristics. Here, the optimal mixing ratio of materials having chromic characteristics varies depending on the material, but considering the fact that the color after change becomes clearer, the color that appears after irradiation with heat or light affects the state before irradiation. It is preferable that the concentration is higher within the range not giving the above. Specifically, the range up to 30% by weight is particularly preferable.

  Next, the substrate definition will be described. A general substrate can be selected, and a glass, a plastic substrate, or the like can be selected. Moreover, you may select what formed the insulating film or the metal film on the said board | substrate.

  Next, the BM manufacturing method using the said photosensitive resin composition is demonstrated. The BM in this invention is formed through (1) a solution coating process, (2) a drying process, (3) an exposure / development process, and (4) a heat treatment process.

  First, the above-mentioned “solution coating process” is performed by, for example, a material having the above-described exposure characteristics and chromism on a substrate by a general method such as a spin coating method, a bar coating method, an LB method, a dip coating method, and an ink jet method. It is a step of applying a resin composition formed by mixing a material having characteristics. Here, the coating film thickness is set to be, for example, 0.5 μm to 5 μm after drying.

  Further, the “drying step” is a step of removing the solvent by leaving it at room temperature for several hours to several days, or by heating it with a hot air heater, an infrared heater, a hot plate, etc. for several minutes to several hours. . Here, about the temperature to heat, the grade which reaction of a chromic material does not advance is preferable, for example, is a temperature range of room temperature-100 degreeC.

Also, the "exposure and development step", the coating film through a photomask or the like, the active energy rays such as ultraviolet rays or excimer laser beam, the range of the irradiation energy dose 100mJ / cm ² ~2000mJ / cm ² To expose. Then, it is the process of developing to a desired pattern, for example using alkaline solutions, such as 1 mass%-10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution. A general thing can be applied about the exposure apparatus and developer used in that case.

  Further, the “heat treatment step” is to improve the durability of the resist pattern by heating the substrate on which the pattern is formed with a hot air heater, an infrared heater, a hot plate or the like for several minutes to several hours, This is a process for causing a color change. Here, the heating temperature can be selected according to the color change temperature of the chromic material, and is, for example, 50 ° C. to 200 ° C.

  More specifically, the BM manufacturing method is appropriately selected and used as follows, for example, depending on the characteristics of the chromic material included in the composition.

First, as a BM manufacturing method using a photosensitive resin composition containing a photochromic material, for example,
In the “exposure / development process” in (3) above, after exposure and development by incidence of ultraviolet light having a wavelength necessary for patterning, in the “heat treatment process” in (4), it is necessary for color change. A method of injecting ultraviolet light of a wavelength.
In the “exposure / development step” in (3) and the “heat treatment step” in (4), the temperature is raised after exposure and development are performed by irradiating ultraviolet light while suppressing color change by heating. In this method, heat treatment is performed, and ultraviolet light is further irradiated while returning the substrate to room temperature.
Can be applied.

  The former method is particularly useful when the wavelength of ultraviolet light necessary for exposure is longer than the wavelength necessary for color change. On the other hand, the latter method is useful for a material (T-type) capable of returning a color change caused by ultraviolet light by heat.

  In addition, as a BM manufacturing method using a photosensitive resin composition containing a thermochromic material or an electrochromic material, a method of changing color by heating or energizing in the “heat treatment step” of the above (4) is applied. be able to.

-1st Embodiment FIG. 1: is a longitudinal cross-sectional view of the board | substrate which shows the procedure in the BM manufacturing method using the photosensitive resin composition of this Embodiment. The photosensitive resin composition in the present embodiment is a leuco dye / positive black resist in which a positive black resist is mixed with a leuco dye.

  First, as the photosensitive resin composition, 5% leuco dye (manufactured by Yamamoto Kasei Co., Ltd.) was added to 1% by weight of carbon black mixed in a novolak positive black resist (JAS-100: manufactured by JSR Corporation). A mixture of bisphenol A, which is a developer, so that the molar ratio of bisphenol and leuco dye is 1: 2 is used.

  Subsequently, BM is manufactured according to the following procedure. First, as shown to Fig.1 (a), after apply | coating the photosensitive resin composition 2 mentioned above by the spin coat method on the glass substrate 1, it dries at 80 degreeC for 5 minutes, and forms a coating film. Next, as shown in FIG. 1 (b), a semi-transparent region (transmittance 40%) 4 is disposed in the center (upper part) of the photosensitive resin composition 2, and on both sides of the semi-transparent region 4. A light-shielding region 5 is arranged, and a three-tone photomask 3 in which both sides of the light-shielding region 5 are all transmissive regions 6 is arranged, exposed as indicated by a white arrow by a normal lithography technique, and developed using an alkaline aqueous solution To do.

  By doing so, as shown in FIG. 1C, the photosensitive resin composition 2 has a region corresponding to the light shielding region 5 of the three-tone photomask 3 of the photosensitive resin composition 2 before the exposure. The region corresponding to the translucent region 4 of the three-tone photomask 3 is formed in a shape that is recessed to a depth corresponding to the transmittance while maintaining the height. Thereafter, heat treatment is performed at 200 ° C. for 10 minutes to cause the leuco dye in the photosensitive resin composition 2 and the bisphenol A to react with each other to blacken, thereby forming BM7 as shown in FIG.

When the light shielding rate of BM7 obtained in this way was measured, the OD value was “2.5”, and the resistance value was 2.1 × 10 ¹¹ Ω / □. The BM 7 formed on the glass substrate 1 was excellent without pinholes or color unevenness. Further, in FIG. 1D, an unexposed portion 8 shielded by the light shielding region 5 of the three-tone photomask 3 and a semi-exposed portion 9 exposed through the semitransparent region 4 of the three-tone photomask 3. The film thickness was measured. As a result, the respective film thicknesses were 1.1 μm and 0.6 μm, and it was confirmed that exposure of two gradations was achieved.

[Comparative Example 1: BM formation 1 using positive type black resist]
As the photosensitive resin composition, as in the case of the first embodiment, a material in which 1% by weight of carbon black was mixed in a novolak positive black resist was used. And like the case of the said 1st Embodiment, after apply | coating the said photosensitive resin composition on a glass substrate with a spin coat method, it dries at 80 degreeC for 5 minute (s). Then, BM is formed by sequentially performing exposure by a normal lithography technique, development with an alkaline solution, and heat treatment at 200 ° C. for 10 minutes. When the light shielding rate of the BM thus obtained was measured, the OD value was “0.6”, and a sufficient light shielding rate could not be obtained.

[Comparative Example 2: BM formation 2 using positive type black resist]
A BM was formed in the same manner as in Comparative Example 1 except that the amount of carbon black mixed with the novolac positive black resist was 10 wt%. When the light shielding rate of the BM thus obtained was measured, the OD value was “2.8”, and a sufficient light shielding rate could be obtained. However, a pattern (see FIG. 1 (d)) of the half-exposed portion and the unexposed portion could not be formed.

  As described above, in the present embodiment, a novolac positive black resist mixed with 1% by weight of carbon black is used as the material having the above exposure characteristics, and 5% by weight of the leuco dye is used as the thermochromic material. Bisphenol A is used as a developer, and a mixture of a novolac positive black resist mixed with the carbon black, a leuco dye, and bisphenol A is used as the photosensitive resin composition 2.

  And after apply | coating the said photosensitive resin composition 2 on the said glass substrate 1, it is made to dry for 5 minutes at 80 degreeC which is the temperature which the reaction of the said leuco pigment | dye does not advance, and the coating film (resist film) is formed. . Therefore, the formed resist film is not blackened, and light can sufficiently reach the lower part of the resist film at the time of exposure by lithography using the next three-tone photomask 3. FIG. As shown in c), two-tone exposure can be achieved.

  Thereafter, the photosensitive resin composition 2 patterned with high accuracy by the above-described two-tone exposure and development is subjected to a heat treatment at 200 ° C. for 10 minutes, which is a temperature at which the reaction of the leuco dye can sufficiently proceed. By doing so, the leuco dye and the bisphenol A are reacted to cause blackening. Therefore, the light shielding rate of the obtained BM7 is “2.5” in OD value, and a sufficient light shielding rate can be obtained.

  Thus, by using a mixture of the material having the above exposure characteristics and the thermochromic material as the photosensitive resin composition 2, the resist film is patterned in a state where the OD value is low, thereby increasing the patterning accuracy. Thereafter, it becomes possible to increase the OD value by heating. Therefore, according to the present embodiment, it is possible to obtain the BM 7 having a high OD while maintaining a high patterning accuracy.

Further, by using a positive black resist as the material having the above exposure characteristics, it is possible to perform multi-tone exposure and to obtain a high resistance value of 2.1 × 10 ¹¹ Ω / □. Therefore, according to the present embodiment, it is possible to realize an active matrix liquid crystal display device having the “CF on Array structure”.

Second Embodiment The present embodiment relates to a method for forming a TFT array substrate and a liquid crystal panel using the leuco dye / positive type black resist by using the BM manufacturing method in the first embodiment.

  FIG. 2 is a plan view of the TFT array substrate formed according to the present embodiment. 3 (a) is a cross-sectional view taken along the line AA 'in FIG. 2, FIG. 3 (b) is a cross-sectional view taken along the line BB' in FIG. 2, and FIG. It is CC 'arrow sectional drawing in. Hereinafter, the present embodiment will be described with reference to FIGS. In addition, examples other than the BM formation in the present embodiment are shown as examples, and are not limited to the present embodiment.

(Board preparation)
First, a metal film such as aluminum is formed on the glass substrate 11 by sputtering, and the gate line 12 and the common electrode 13 are formed by photolithography. Next, a lower insulating film 14 made of silicon nitride or the like is formed, and a semiconductor film (a-Si, n + a-Si) is formed on the lower insulating film 14 by a plasma CVD (Chemical Vapor Deposition) method. After the film formation, a pattern of the semiconductor film 15 is formed by photolithography. Thereafter, after a metal film such as aluminum is formed, a pattern of the source electrode 16, the drain electrode 17, and the drain line 18 is formed by photolithography. Thereafter, the substrate before BM formation is formed by forming a pattern of the protective film 19 made of silicon nitride.

(BM formation)
FIG. 4 is a cross-sectional view of the TFT array substrate when the main BM is formed. That is, FIG. 4A is a view corresponding to FIG. 3A when the BM is formed. FIG. 4B corresponds to FIG. 3B when the BM is formed. FIG. 4C corresponds to FIG. 3C when the BM is formed.

  First, the same photosensitive resin composition solution as in the first embodiment is applied to the substrate before BM formation formed in the above-mentioned “substrate preparation” using a coater, and dried at 80 ° C. for 5 minutes. A coating film 20 ′ is formed. Subsequently, as shown in FIG. 4, the region 21a corresponding to the pixel portion and the connection portion is totally transmissive, and the region 21b and the region 21c corresponding to the upper source wiring formation portion are 60% transmittance and 20% transmittance. The four-tone exposure is performed using the four-tone photomask 21 in which the region 21d corresponding to the other portion is shielded from light. After that, development is performed with an alkaline solution.

  As a result, a patterned upper insulating film 20 is formed as shown in FIG. FIG. 5A is a view corresponding to FIG. 3A after BM formation. FIG. 5B is a view corresponding to FIG. 3B after BM formation. FIG. 5C is a view corresponding to FIG. 3C after BM formation. Thereafter, by performing heat treatment at 200 ° C. for 10 minutes, the upper insulating film 20 is blackened to form a BM as in the case of the first embodiment.

(TFT array substrate and liquid crystal panel formation)
First, the protective film 19 is dry-etched using the blackened pattern of the upper insulating film 20 as a mask, and then metal ink is applied to the groove portions (the connection portions) 22 and 23 by an ink jet method to obtain an upper source. Line 24 is formed. Further, the color filter (R) 25, the color filter (G) 26, and the color filter (B) 27 are formed by applying pigment ink to the pixel portion by an ink jet method.

  Thereafter, an overcoat film 28 made of a photosensitive resin is applied to partition and form the connection portion 30 between the drain line 18 and the pixel electrode 29, as shown in FIG. On the other hand, exposure and dry etching are performed. After that, by forming a conductive transparent film such as ITO (Indium Tin Oxide) and patterning the conductive transparent film by a photolithography method or the like, as shown in FIG. 29 is formed.

  Through the above steps, the TFT array substrate is formed.

  On the other hand, a counter electrode substrate (not shown) in which a counter electrode (not shown) made of a conductive transparent film such as ITO is formed on the entire surface of another glass substrate (not shown) is formed. Then, the counter electrode substrate and the TFT array substrate are bonded together so that the counter electrode and the pixel electrode 29 face each other. Thereafter, a liquid crystal panel is formed by injecting liquid crystal between the counter electrode substrate and the TFT array substrate.

  The liquid crystal panel produced as described above has no leakage of current and can reproduce a uniform display image.

  As described above, in the present embodiment, the TFTs constituting the TFT array substrate, the insulating films that cover the upper portions of the gate lines 12 and the drain lines 18, and shield the light, and the gate lines 12 and the pixels. Between each electrode 29, between each upper source line 24 and each pixel electrode 29, between each drain line 18 and each pixel electrode 29, and between each upper source line 24 and each drain line 18. The insulating film that is disposed and shields light and prevents color mixing is formed by the BM that is formed by the BM manufacturing method in the first embodiment and that achieves high OD while maintaining high patterning accuracy. Therefore, the TFT, each gate line 12 and each drain line 18 can be reliably covered and shielded from light, and can be reliably shielded by being disposed between each wiring and each pixel electrode 29.

  Furthermore, the alignment margin of the four-tone photomask 24 when patterning the BM can be reduced, and the aperture ratio can be improved accordingly.

  In this embodiment, a case where a TFT array substrate having the above “CF on Array structure” is formed by performing multi-tone exposure using a positive black resist as a material having the above exposure characteristics will be described. ing. However, the present invention is not limited to this, when the source line is formed on the substrate, when the pixel electrode is directly connected to the drain electrode of the TFT without going through the drain line, when there is no color filter, etc. Needless to say, the present invention can also be applied to various TFT array substrates.

Third embodiment [Reference example]
First, a reference example will be described. Using “COLOR MOSAIC CK (manufactured by Fuji Film)” as the photosensitive resin composition, a BM was formed by the same method as in the present embodiment described below. In this case, the light shielding rate of the produced BM was “3.5” in terms of OD value, and the resistance value was 2.8 × 10 ¹² Ω / □.

  Next, this embodiment will be described. The present embodiment relates to a method of forming a BM, a color filter substrate, and a liquid crystal panel using the leuco dye / negative black resist by using the BM manufacturing method in the first embodiment.

  As the above-mentioned photosensitive resin composition, 15% by weight of leuco dye is mixed in “COLOR MOSAIC CK (manufactured by Fuji Film)”, then citric acid as a developer is mixed with a molar ratio of citric acid and leuco dye of 1 : 3 mixed to be used.

  First, the said photosensitive resin composition is apply | coated on a glass substrate using a coater, and it is made to dry for 5 minutes at 80 degreeC. The dry film thickness is 1.5 μm. Then, after performing exposure and development using a negative mask, heat treatment is performed at 200 ° C. for 10 minutes to form a BM that is patterned into a frame shape and blackened.

When the shading rate of the BM thus obtained was measured, the OD value was “4.5”, and the resistance value was 2.1 × 10 ¹² Ω / □. As compared with the above [Reference Example], it was confirmed that the BM according to the present embodiment can improve the light shielding rate while maintaining a high resistance. The BM formed on the substrate was excellent without pinholes or color unevenness. Further, after forming color filters R, G, and B by applying pigment ink in the frame of the BM, a counter electrode made of a conductive transparent film such as ITO is formed on the entire surface to form the color filter substrate. The

  Subsequently, the TFT array substrate formed according to the conventional forming method and the formed color filter substrate are bonded together with the pixel electrode of the TFT array substrate and the counter electrode of the color filter substrate facing each other. After that, a liquid crystal panel is formed by injecting liquid crystal.

  The liquid crystal panel produced as described above has no leakage of current and can reproduce a uniform display image.

  As described above, in the present embodiment, the insulating film that surrounds each of the color filters R, G, and B constituting the color filter substrate in a frame shape to shield the light and prevent color mixing is as follows. Forming.

  That is, a negative black resist was used as the material having the exposure characteristics, a leuco dye was used as the thermochromic material, citric acid was used as a developer, and the negative black resist, leuco dye and citric acid were mixed. A thing is used as a photosensitive resin composition. And after apply | coating the said photosensitive resin composition on a glass substrate, it is made to dry for 5 minutes at 80 degreeC which is the temperature which the reaction of the said leuco dye does not advance, and the coating film (resist film) is formed. Therefore, the formed coating film is not blackened, and light can sufficiently reach the lower part of the coating film at the time of exposure using the next negative mask, so that high patterning accuracy can be obtained.

  Thereafter, the resist film patterned with high accuracy is subjected to a heat treatment at 200 ° C., which is a temperature at which the reaction of the leuco dye can sufficiently proceed, for 10 minutes, whereby the leuco dye and the citric acid are obtained. To make it black. Therefore, the light shielding rate of the light shielding film made of the obtained BM is “2.5” in OD value, and a sufficient light shielding rate can be obtained.

  In this way, since the light shielding film that shields the surroundings of the color filters R, G, B is formed by the BM that can increase the OD while maintaining the patterning accuracy, each of the color filters R, G, B The surroundings can be reliably shielded from light. Further, the alignment margin of the negative mask when patterning the resist film can be reduced, and the aperture ratio can be improved accordingly.

It is a longitudinal cross-sectional view which shows the procedure in the BM manufacturing method using the photosensitive resin composition of this invention. It is a top view of the TFT array substrate formed using the BM manufacturing method shown in FIG. It is sectional drawing in FIG. It is sectional drawing of the TFT array substrate at the time of BM formation. It is sectional drawing of the TFT array substrate after BM formation.

Explanation of symbols

1,11 ... Glass substrate,
2 ... photosensitive resin composition,
3 ... 3 gradation photomask,
4 ... translucent area,
5, 21d ... light shielding area,
6, 21a ... Total transmission region,
7 ... BM,
8 ... unexposed part,
9: Half-exposure part,
12 ... Gate line,
13 ... Common electrode,
14 ... Lower insulating film,
15 ... Semiconductor film,
16 ... Source electrode,
17 ... drain electrode,
18 ... drain wire,
19 ... Protective film,
20 '... coating film of photosensitive resin composition solution,
20 ... upper insulating film,
21 ... 4 gradation photomask,
21b ... 60% transmittance region,
21c ... transmittance 20% region,
22, 23 ... Groove portion (connection portion),
24 ... upper source line,
25 ... Color filter (R),
26 Color filter (G),
27. Color filter (B),
28 ... overcoat film,
29 ... pixel electrode,
30: Connection point between the drain line and the pixel electrode.

Claims (10)

A photosensitive resin composition for forming a light-shielding film, wherein a positive photosensitive resin composition containing an alkali-soluble novolak resin and a naphthoquinonediazide group-containing compound is mixed with a compound having chromic properties. A photosensitive resin for forming a light-shielding film, characterized in that a negative photosensitive resin composition containing a polymer binder, a photopolymerizable monomer, a photopolymerization initiator, and a light-shielding pigment is mixed with a compound having chromic characteristics. Composition. In the photosensitive resin composition of Claim 1 or Claim 2,
The photosensitive resin composition for forming a light-shielding film, wherein the compound having the chromic property is a thermochromic material. The photosensitive resin composition for forming a light-shielding film according to claim 1 or 2 is patterned by irradiation with active light and development, and further blackened by applying a physical stimulus. A black matrix characterized by comprising. The photosensitive resin composition for forming a light-shielding film according to claim 1 or 2 is applied on a substrate and then dried.
After selectively irradiating the photosensitive resin composition applied on the substrate with actinic rays, a pattern is formed by developing with an alkaline aqueous solution,
A method for producing a black matrix, wherein the patterned photosensitive resin composition is blackened by applying a physical stimulus. A plurality of pixel electrodes formed in a matrix on a substrate;
Gate lines arranged extending in one direction between the pixel electrodes,
A source line arranged extending in the other direction between the pixel electrodes;
A gate electrode connected to the gate line, a source electrode connected to the source line, and a drain electrode connected to the pixel electrode are arranged at intersections of the gate lines and the source lines. A plurality of transistors having,
5. The black matrix according to claim 4, wherein an upper portion of each of the transistors and an upper portion of a wiring including at least each of the gate lines, and a wiring including at least each of the gate lines and each of the source lines and each of the pixel electrodes are disposed. A transistor array substrate characterized by comprising: A plurality of color filters formed in a matrix on the substrate;
A common electrode formed on the entire surface of each color filter,
5. A color filter substrate, wherein the black matrix according to claim 4 is disposed between the color filters. A metal film is formed over the substrate, a gate line and a source line, a gate electrode connected to the gate line, a transistor having a source electrode and a drain electrode connected to the source line, and a drain electrode Forming a pattern of connected drain lines,
6. The method of manufacturing a black matrix according to claim 5, wherein the transistor, the gate line and the drain line, the space between the gate line and the pixel electrode formation region, the drain line and the pixel electrode formation region, And a black matrix that is patterned to be disposed and blackened,
A method of manufacturing a transistor array substrate, comprising forming a transparent electrode film and patterning to form a pixel electrode in the pixel electrode formation region. A metal film is formed on the substrate, and a pattern of a gate line, a transistor having a gate electrode, a source electrode, and a drain electrode connected to the gate line, and a drain line connected to the drain electrode is formed. Forming,
6. The method of manufacturing a black matrix according to claim 5, wherein the transistor, the gate line and the drain line, the space between the gate line and the pixel electrode formation region, the drain line and the pixel electrode formation region, And a black matrix which is patterned and blackened so that a groove for forming an upper source line and a hole for connecting a source electrode are formed on the surface. Form the
Filling the grooves and holes on the black matrix surface with metal to form an upper source line connected to the source electrode;
A method of manufacturing a transistor array substrate, comprising forming a transparent electrode film and patterning to form a pixel electrode in the pixel electrode formation region. A black matrix that is patterned into a frame shape and blackened by the black matrix manufacturing method according to claim 5 is formed on the substrate,
A color filter is formed by applying a pigment ink in the black matrix,
A method of manufacturing a color filter substrate, comprising forming a counter electrode made of a conductive transparent film over the entire surface.

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