JP2009211005A - Color filter and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter that can increase a compressive displacement per unit load in a low load region and decrease a compressive displacement per unit load in a high load region when a load is applied to a spacer, and to provide a method for manufacturing the color filter. <P>SOLUTION: The color filter 10 includes a color filter substrate 11 and a spacer 20 formed on the color filter substrate 11. The spacer 20 includes a black layer 22 for the spacer as the lowest layer, a blue layer 25 for the spacer, a red layer 26 for the spacer, a green layer 27 for the spacer and an overcoat layer 28 as an uppermost layer. The overcoat layer 28 has an upper part 30 covering the green layer 27 for the spacer as an uppermost layer, and the upper part 30 has an arc-like perpendicular cross section. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lateral electric field (IPS) driving color filter and a method of manufacturing the same, and particularly when a load is applied to the spacer from the outside, the compressive displacement per unit load in the low load region is increased to increase the load. The present invention relates to a color filter capable of reducing a compressive displacement per unit load in a region and a manufacturing method thereof.

  Conventionally, a color liquid crystal display device has been used as a flat display. In such a liquid crystal display device, a color filter and a thin film transistor (TFT) substrate face each other with a predetermined gap, and a liquid crystal material is injected into the gap to form a liquid crystal layer. In order to maintain the distance between the TFT substrate and the color filter facing each other, a spacer is provided between them, thereby maintaining the thickness of the liquid crystal layer between them uniformly in the plane.

  In particular, in a color filter used in a lateral electric field (IPS) type liquid crystal display device, for example, as shown in FIGS. 6A and 6B, a black matrix layer 102 is provided on a color filter substrate 101, and this black matrix layer is provided. A colored layer 103 and a protective film 104 are sequentially stacked on the layer 102. Thereafter, a columnar resin spacer 105 is provided on the protective film 104 with a photoresist, whereby the color filter 100 is manufactured. The resin spacer 105 keeps the distance between the thin film transistor (TFT) substrate and the color filter 100.

  On the other hand, in order to omit the step of providing the columnar resin spacer 105 with a photoresist, a spacer formed by laminating three colored layers 113, 114, and 115 as shown in FIGS. A color filter 110 having 111 is also known. That is, in FIGS. 7A and 7B, the first colored layer 113 is provided on the color filter substrate 117 and the black matrix layer 112, and the second colored layer 114 and the third colored layer 115 are provided on the first colored layer 113. A protective film 116 is formed on the third colored layer 115 by sequentially laminating. A laminate including the first colored layer 113, the second colored layer 114, and the third colored layer 115 formed in this manner is used as the spacer 111.

FIG. 8 shows an enlarged view of the spacer 111 of the color filter 110 shown in FIGS. As shown in FIG. 8, the spacer 111 has a side part shape having a tapered surface close to vertical.
Japanese Patent Laid-Open No. 10-082909 JP-A-10-104606 JP 2001-117103 A

  FIG. 9 shows the relationship between the compression load and the compression displacement when a load is applied in the vertical direction from the outside to the conventional spacers shown in FIGS. 6 (a), 6 (b) and 7 (a), 7 (b). It is a graph to show. As shown in FIG. 9, the conventional spacer has a relatively small compressive displacement per unit load in the low load region.

  In general, when a load is applied to the spacer in the vertical direction from the outside, it is preferable that the compression displacement per unit load of the spacer is large (that is, soft) in the low load region. This is because it is easy to adjust the distance between a substrate such as a thin film transistor (TFT) and a color filter when manufacturing a liquid crystal display device. In contrast, in general, in a high load region, it is preferable that the compression displacement per unit load of the spacer is small (that is, hard). This is because the liquid crystal layer disposed between the TFT substrate and the color filter is protected when an impact or the like is applied when the liquid crystal display device is used.

  However, when the conventional spacers shown in FIGS. 6A and 6B and FIGS. 7A and 7B are used, if the material of the spacer is changed to increase the compressive displacement per unit load in the low load region. In addition, the compressive displacement per unit load in the high load region also increases. Conversely, if the compressive displacement per unit load of the spacer in the low load region is reduced, the compressive displacement per unit load in the high load region also tends to be reduced. Therefore, even if the material constituting the spacer is changed, it is possible to simultaneously increase the compression displacement per unit load in the low load region and reduce the compression displacement per unit load in the high load region. It is extremely difficult.

  The present invention has been made in consideration of such points, and increases the compressive displacement per unit load of the spacer in the low load region and reduces the compressive displacement per unit load of the spacer in the high load region. It is an object of the present invention to provide a color filter that can be used and a method for manufacturing the same.

  The present invention provides a color filter, comprising a color filter substrate, a black matrix layer, a blue layer, a red layer, and a green layer formed on the color filter substrate, and a spacer formed on the color filter substrate, The lowermost spacer black layer, the spacer blue layer formed on the spacer black layer, the spacer red layer, the spacer green layer, and the uppermost overcoat layer, the overcoat layer is A color filter having an upper portion covering the uppermost layer among the blue layer for spacer, the red layer for spacer, and the green layer for spacer, and the upper portion of the overcoat layer has an arc-shaped vertical section It is.

  The present invention provides a process for forming a spacer black layer on a color filter substrate and forming a spacer blue layer, a spacer red layer, and a spacer green layer on the spacer black layer in a method for manufacturing a color filter. Applying the overcoat resist material onto the spacer blue layer, the spacer red layer, and the spacer green layer, and curing the overcoat resist material by post-baking the overcoat resist material. And a step of forming an overcoat layer that covers the uppermost layer of the spacer blue layer, the spacer red layer, and the spacer green layer and has an upper portion having an arc-shaped vertical cross section by causing heat flow. A method for producing a color filter characterized by

  In the present invention, a black matrix layer, a blue layer, a red layer, and a green layer are formed on a color filter substrate simultaneously with a corresponding spacer black layer, spacer blue layer, spacer red layer, and spacer green layer. And a color filter manufacturing method.

  The present invention is a method for producing a color filter, wherein in the step of forming an overcoat layer, the overcoat resist material is cured and heat-flowed at a temperature of 150 ° C. to 200 ° C.

  The present invention is a method for producing a color filter, wherein a step of drying the overcoat resist material under reduced pressure is provided after the step of applying the overcoat resist material.

  In the present invention, the overcoat resist material is made of a UV curable resin, and after the step of drying the overcoat resist material under reduced pressure, the overcoat resist material made of the UV curable resin is exposed and developed to form a desired pattern. A process for producing a color filter, characterized in that a process is provided.

  In the present invention, the overcoat resist material is composed of a thermosetting resin, and in the step of applying the overcoat resist material, the overcoat resist material is applied in a desired pattern and the overcoat layer is formed. An overcoat resist material made of a thermosetting resin is thermally cured.

  As described above, according to the present invention, the upper portion of the overcoat layer has an arc-shaped vertical cross section. Therefore, when a load is applied to the spacer from the outside, the spacer and the TFT substrate and the like are placed in a low load region. The contact area is reduced, and the compressive displacement per unit load of the spacer can be increased. On the other hand, in the high load region, the contact area between the spacer and the TFT substrate is increased, and the compressive displacement per unit load of the spacer can be reduced.

  According to the present invention, when manufacturing a color filter, an overcoat layer is formed by a step of post-baking a resist material for overcoat without providing a step of pre-baking. Thereby, since both the effect | action of hardening and a heat flow can be produced with respect to the resist material for overcoat, a circular-arc-shaped vertical cross section can be reliably formed in the upper part of an overcoat layer.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a color filter according to the present embodiment, and FIG. 2 is a cross-sectional view (cross-sectional view taken along the line II-II in FIG. 1) showing the color filter according to the present embodiment. FIG. 3 is a detailed enlarged view showing an upper part of the overcoat layer of the spacer, and FIGS. 4A to 4G are schematic process diagrams showing a method for manufacturing a color filter according to the present embodiment. FIG. 5 is a graph showing the relationship between the compression load and the compression displacement when the spacer is compressed.

Configuration of Color Filter First, an outline of a color filter will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the color filter 10 includes a color filter substrate 11, a black matrix layer 12 formed on the color filter substrate 11, a blue layer 15 and a red layer formed on the color filter substrate 11, respectively. 16 and the green layer 17, and a spacer 20 formed on the color filter substrate 11. A transparent protective layer 18 that covers the blue layer 15, the red layer 16, and the green layer 17 is formed on the blue layer 15, the red layer 16, and the green layer 17.

  Among these, as the color filter substrate 11, a flexible material such as a non-flexible material such as quartz glass, Pyrex (registered trademark) glass, or a synthetic quartz plate, or a flexible material such as a transparent resin film or an optical resin plate. Can be used.

  The black matrix layer 12 is provided between the display pixel portion including the blue layer 15, the red layer 16, and the green layer 17 and outside the region where the blue layer 15, the red layer 16, and the green layer 17 are formed. Yes. Such a black matrix layer 12 is formed by forming a metal thin film such as chromium by sputtering, vacuum deposition or the like, and patterning this thin film, a polyimide resin containing light shielding particles such as carbon fine particles, Forming a resin layer of acrylic resin, epoxy resin, etc., patterning this resin layer, forming a photosensitive resin layer containing light shielding particles such as carbon fine particles, metal oxide, etc. Any of those formed by patterning the resin layer may be used.

  On the other hand, the blue layer 15, the red layer 16, and the green layer 17 are colored layers that are colored blue, red, and green, respectively, and are photosensitive resins or non-photosensitive resins such as acrylic, polyvinyl alcohol, and polyimide. It is made up of.

  Further, the protective layer 18 is formed by curing an overcoat resist material 18A made of a UV curable resin or a thermosetting resin, as will be described later. The protective layer 18 is provided to flatten the surface of the color filter 10 and to prevent the components contained in the blue layer 15, the red layer 16, and the green layer 17 from eluting into the liquid crystal layer. . The thickness of the protective layer 18 can be set in consideration of the light transmittance of the material used, the surface state of the color filter 10, and the like, and can be set, for example, in the range of 0.1 to 3.0 μm. Such a protective layer 18 is formed so as to cover at least a portion of the blue layer 15, the red layer 16, and the green layer 17 that comes into contact with the liquid crystal layer when the color filter 10 is bonded to the TFT substrate.

  The spacer 20 is provided to form an interval between the color filter 10 and the TFT substrate when the color filter 10 is bonded to the TFT substrate. The spacer 20 has a certain height so as to protrude from the protective layer 18 in a range of about 2 to 10 μm. The amount of protrusion can be set as appropriate from the thickness required for the liquid crystal layer of the liquid crystal display device. In addition, the formation density of the spacers 20 can be appropriately set in consideration of the thickness unevenness of the liquid crystal layer, the aperture ratio, the shape, material, and the like of the spacers 20.

  As shown in FIG. 2, the spacer 20 includes a spacer black layer 22 on the lowermost layer (that is, the color filter substrate 11 side), a spacer red layer 26 formed on the spacer black layer 22 in sequence, and a spacer blue layer. 25, the spacer green layer 27, and the uppermost overcoat layer 28. The spacer black layer 22, the spacer blue layer 25, the spacer red layer 26, the spacer green layer 27, and the overcoat layer 28 constituting the spacer 20 are respectively the black matrix layer 12, the blue layer 15, and the red described above. It corresponds to the layer 16, the green layer 17, and the protective layer 18, and is formed simultaneously with these corresponding layers. That is, the spacer black layer 22, the spacer blue layer 25, the spacer red layer 26, the spacer green layer 27, and the overcoat layer 28 are respectively the black matrix layer 12, the blue layer 15, the red layer 16, the green layer 17, And corresponding to the protective layer 18. The spacer black layer 22, the spacer green layer 25, the spacer red layer 26, the spacer green layer 27, and the overcoat layer 28 include the corresponding black matrix layer 12, blue layer 15, red layer 16, green layer 17 and It consists of the same material as the protective layer 18.

  Further, the overcoat layer 28 has an upper portion 30 that covers the spacer green layer 27 that is the uppermost layer among the spacer red layer 26, the spacer blue layer 25, and the spacer green layer 27.

  As shown in FIG. 2, the upper portion 30 of the overcoat layer 28 has an arcuate vertical cross section. That is, as shown in FIG. 3, the upper portion 30 of the overcoat layer 28 has an arc-shaped vertical section that is gently inclined downward from the upper end. Here, FIG. 3 is an enlarged view showing the upper portion 30 of the overcoat layer 28 of the spacer 20, and is an enlarged view of about 10 times in the vertical direction with respect to the horizontal direction in FIG. Further, the horizontal section of the upper portion 30 has a substantially circular shape, and the diameter of the arc-shaped horizontal section gradually increases from the upper end of the upper portion 30 downward. The horizontal section of the upper portion 30 of the overcoat layer 28 is not limited to a substantially circular shape, and may be an elliptical shape, a rectangular shape, or the like.

  In FIG. 2, each colored layer is laminated in the order of the red layer 16 (the spacer red layer 26), the blue layer 15 (the spacer blue layer 25), and the green layer 17 (the spacer green layer 27) from the bottom layer. However, the order of laminating the colored layers is not limited.

Manufacturing Method of Color Filter Next, a manufacturing method of the color filter 10 shown in FIGS. 1 and 2 will be described with reference to FIGS.

  First, as shown in FIG. 4A, a color filter substrate 11 is prepared.

  Next, the black matrix layer 12 is formed on the color filter substrate 11. At the same time when the black matrix layer 12 is formed, the spacer black layer 22 is formed on the color filter substrate 11 (FIG. 4B).

  During this time, first, a light shielding layer made of a metal thin film such as chromium formed by sputtering, vacuum deposition, or the like, a resin layer containing light shielding particles such as carbon fine particles, and the like is formed on the color filter substrate 11. A photosensitive resist layer is formed using a positive or negative photosensitive resist. Next, the photosensitive resist layer is exposed and developed through a photomask for black matrix, the exposed light-shielding layer is etched, and then the remaining photosensitive resist layer is removed to form the black matrix layer 12. .

  Next, a red layer 16, a blue layer 15, and a green layer 17 are sequentially formed on the color filter substrate 11 (FIGS. 4C to 4E). At this time, the spacer red layer 26, the spacer blue layer 25, and the spacer green layer 27 are simultaneously formed on the spacer black layer 22.

  During this time, first, a color sensitive material is formed to a predetermined thickness on the color filter substrate 11 on which the black matrix layer 12 is formed by means of a spin coater, a roll coater, etc., and then each of exposure, development, and processing is performed. Perform the process. The same process is repeated for the red layer 16, the blue layer 15, and the green layer 17. At this time, a photosensitive positive resist is further applied onto the colored photosensitive material, exposure and development are performed to leave a necessary portion pattern, and the same steps are repeated for the red layer 16, the blue layer 15, and the green layer 17. A portion to be a predetermined coloring pixel and a portion to be a spacer red layer 26, a spacer blue layer 25, and a spacer green layer 27 corresponding to the red layer 16, the blue layer 15, and the green layer 17, respectively. Form.

  Subsequently, an overcoat resist material is formed on the black matrix layer 12, the blue layer 15, the red layer 16, and the green layer 17, the spacer black layer 22, the spacer blue layer 25, the spacer red layer 26, and the spacer green layer 27. 18A is applied using a known means such as a spin coater or a roll coater (FIG. 4 (f)).

  Next, the overcoat resist material 18A applied in this manner is dried under reduced pressure.

  The overcoat resist material 18A applied in this way is made of UV (ultraviolet) curable resin or thermosetting resin as described above.

  When the overcoat resist material 18A is made of UV curable resin, the overcoat resist material 18A is exposed and developed without a pre-baking step after the step of drying the overcoat resist material 18A under reduced pressure. A desired pattern is formed. At this time, the overcoat resist material 18A is exposed through a photomask and then developed. Thereby, unnecessary portions (for example, the outer peripheral portion of the protective layer 18 and the like) excluding a desired pattern including the protective layer 18 and the overcoat layer 28 described later are removed. Examples of such UV curable resins include UV curable acrylic resins.

  On the other hand, when the overcoat resist material 18A is made of a thermosetting resin, the overcoat resist material 18A is previously applied in the above-described application process so as to have a desired pattern, for example, a pattern excluding the outer peripheral portion of the protective layer 18. Keep it. Next, the overcoat resist material 18A is dried under reduced pressure, and then the overcoat layer 28 is formed by a post-bake process described later without a pre-bake process (FIG. 4G). In addition, as such a thermosetting resin, thermosetting resins, such as a phenol resin, a melamine resin, an epoxy resin, and a xylene resin, are mentioned.

  Thereafter, the overcoat resist material 18A is post-baked to cure the overcoat resist material 18A and to cause heat flow. As a result, the protective layer 18 is formed from the overcoat resist material 18A. Further, an overcoat layer 28 that covers the uppermost spacer green layer 27 and has an upper portion 30 having an arc-shaped vertical cross section is formed (FIG. 4G).

  In the step of forming the overcoat layer 28 by post-baking the overcoat resist material 18A, the temperature at which the overcoat resist material 18A is cured and heat-flowed is set to 150 ° C. to 200 ° C. In this manner, after the overcoat resist material 18A is dried under reduced pressure, the overcoat resist material 18A is post-baked at a relatively high temperature without a pre-baking step. Thereby, not only the overcoat resist material 18A can be cured, but also the overcoat resist material 18A can be heat-flowed. By such an action of the heat flow, when the overcoat layer 28 is cured, the vertical section of the upper portion 30 can be formed into an arc shape.

  If the post-baking temperature is less than 150 ° C., the overcoat resist material 18A can be cured but cannot be sufficiently heat-flowed, and the vertical section of the upper portion 30 of the overcoat layer 28 has an arc shape. I can't do it. For example, in a normal prebaking process, the resist material is heated at a temperature of about 80 ° C. to 120 ° C. in order to volatilize the solvent in the resist material. In this case, the above-described heat flow cannot be applied to the resist material. On the other hand, when the post-baking temperature exceeds 200 ° C., the performance of the overcoat resist material 18A is adversely affected.

  Next, the operation of the present embodiment when a load is applied to the spacer 20 will be described.

  In the manufacturing process of the liquid crystal display device, the TFT substrate 40 is placed on the spacer 20 of the color filter 10 (see the phantom line in FIG. 2). In this manufacturing process, the distance between the TFT substrate 40 and the color filter 10 is generally adjusted. In the present embodiment, since the upper portion 30 of the overcoat layer 28 of the spacer 20 has an arcuate vertical cross section, the contact area between the TFT substrate 40 and the spacer 20 is relatively small. Therefore, the upper end of the spacer 20 can be compressed and deformed only by applying a small load from the TFT substrate 40 to the spacer 20, and the distance between the TFT substrate 40 and the color filter 10 can be easily adjusted.

  On the other hand, an impact or the like is applied to the manufactured liquid crystal display device, and a high load is assumed to be applied to the spacer 20 in the vertical direction. In this case, since the upper portion 30 of the overcoat layer 28 of the spacer 20 has an arcuate vertical cross section, the contact area between the TFT substrate 40 and the spacer 20 is relatively large. Therefore, even if a high load is applied between the TFT substrate 40 and the spacer 20 in the vertical direction, the spacer 20 is not easily deformed, and the strength of the TFT substrate 40 and the color filter 10 is increased. The liquid crystal layer in between can be protected.

  FIG. 5 is a graph showing the relationship between the compression load and the compression displacement when the spacer 20 is compressed. As shown in FIG. 5, the spacer 20 according to the present embodiment is less in comparison with the conventional spacers shown in FIGS. 6A, 7 </ b> B, and 7 </ b> A, 7 </ b> B when a load is applied. The change of the compressive displacement per unit load of the spacer 20 in the load region is large (that is, the slope of the graph is steep). On the other hand, in the high load region, the change of the compressive displacement per unit load of the spacer 20 is small compared with the conventional spacer (that is, the slope of the graph is gentle).

  As described above, according to the present embodiment, the upper portion 30 of the overcoat layer 28 has an arcuate vertical cross section. Therefore, when a load is applied to the spacer 20 from the outside, the contact of the spacer 20 in the low load region. The compression displacement per unit load of the spacer 20 can be increased by reducing the area. On the other hand, in the high load region, the contact area of the spacer 20 can be increased to reduce the compressive displacement per unit load of the spacer.

  Further, according to the present embodiment, when the color filter 10 is manufactured, the overcoat layer 28 is formed by post-baking the overcoat resist material 18A without providing a pre-baking step. At this time, both the curing and the heat flow are caused to act on the overcoat resist material 18A, so that the upper portion 30 of the overcoat layer 28 can have an arcuate vertical cross section. In addition, since the pre-baking step can be omitted, the manufacturing process of the color filter 10 can be simplified compared to the prior art.

The top view which shows the color filter by one embodiment of this invention. Sectional drawing which shows the color filter by one embodiment of this invention (II-II sectional view taken on the line of FIG. 1). The detailed enlarged view which shows the upper part of the overcoat layer of a spacer. FIG. 3 is a schematic process diagram illustrating a method for manufacturing a color filter according to an embodiment of the present invention. The graph which shows the relationship between the compression load at the time of compressing a spacer, and compression displacement. The top view and sectional drawing which show the conventional color filter (conventional example 1). The top view and sectional drawing which show the conventional color filter (conventional example 2). The detailed enlarged view which shows the conventional spacer. The graph which shows the relationship between the compression load at the time of compressing the conventional spacer, and compression displacement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Color filter 11 Color filter board | substrate 12 Black matrix layer 15 Blue layer 16 Red layer 17 Green layer 18 Protective layer 18A Overcoat resist material 20 Spacer 22 Spacer black layer 25 Spacer blue layer 26 Spacer red layer 27 Spacer green Layer 28 Overcoat layer 30 Upper part 40 TFT substrate

Claims (7)

In the color filter,
A color filter substrate;
A black matrix layer, a blue layer, a red layer, and a green layer formed on the color filter substrate;
A spacer formed on the color filter substrate,
The spacer has a lowermost spacer black layer, a spacer blue layer formed on the spacer black layer, a spacer red layer, a spacer green layer, and an uppermost overcoat layer.
The overcoat layer has an upper portion that covers the uppermost layer of the spacer blue layer, the spacer red layer, and the spacer green layer,
A color filter, wherein an upper portion of the overcoat layer has an arcuate vertical cross section. In the manufacturing method of the color filter of Claim 1,
Forming a spacer black layer on the color filter substrate, and forming a spacer blue layer, a spacer red layer, and a spacer green layer on the spacer black layer;
Applying a resist material for overcoat on the spacer blue layer, the spacer red layer, and the spacer green layer;
By post-baking the overcoat resist material, the overcoat resist material is cured and heat-flowed to cover the uppermost layer of the spacer blue layer, spacer red layer, and spacer green layer, and in an arc shape. And a step of forming an overcoat layer having an upper portion having a vertical cross section.   A black matrix layer, a blue layer, a red layer, and a green layer are formed on the color filter substrate simultaneously with the corresponding spacer black layer, spacer blue layer, spacer red layer, and spacer green layer. The method for producing a color filter according to claim 2.   4. The method for producing a color filter according to claim 2, wherein in the step of forming the overcoat layer, the overcoat resist material is cured and heat-flowed at a temperature of 150 to 200.degree.   5. The method for producing a color filter according to claim 2, further comprising a step of drying the overcoat resist material under reduced pressure after the step of applying the overcoat resist material. The overcoat resist material consists of UV curable resin,
6. The step of forming a desired pattern by exposing and developing the overcoat resist material made of a UV curable resin after the step of drying the overcoat resist material under reduced pressure is provided. A method for producing a color filter. The overcoat resist material consists of a thermosetting resin,
In the step of applying the resist material for overcoat, the resist material for overcoat is applied in a desired pattern, and in the step of forming the overcoat layer, the resist material for overcoat made of a thermosetting resin is thermally cured. The method for producing a color filter according to claim 5, wherein:

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