JP2010085796A - Liquid crystal display device, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with a spacer that is manufactured by a simple process. <P>SOLUTION: A pair of substrates 10 and 20 are disposed so as to face each other with a spacer 30 therebetween, and liquid crystal is filled between the substrates 10 and 20. The spacer 30 includes a composite material having solid particles 30c mixed in an elastic resin material and includes a first spacer 30a having a first compression modulus and a second spacer 30b comprising a resin material and having a second compression modulus different from the first compression modulus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device in which a spacer having elasticity is provided between a pair of substrates, and a manufacturing method thereof.

  Patent Document 1 discloses a liquid crystal display device in which a spacer composed of a plurality of layers having different hardness is provided between a pair of substrates. The upper layer of the spacer of this liquid crystal display device is configured with solid eyes, and the lower layer is configured with soft eyes. For this reason, when a pressing force is applied to the liquid crystal display device, the hard portion of the upper layer resists this, and the deformation in the thickness direction of the liquid crystal display device is suppressed, and the occurrence of color unevenness is suppressed. On the other hand, when the liquid crystal expands and contracts due to a temperature change, the soft layer in the lower layer is deformed to follow the change in the distance between the substrates accompanying the expansion and contraction of the liquid crystal, thereby suppressing the generation of vacuum bubbles.

JP 2005-345666 A

  The spacer disclosed in Patent Document 1 is formed by patterning a photosensitive resin applied to the TFT side substrate by applying a photolithography process. However, in the configuration disclosed in Patent Document 1, since the types of the upper layer photosensitive resin and the lower layer photosensitive resin are different, it is necessary to form the upper layer and the lower layer of the spacer in separate steps. That is, it is necessary to repeat the photolithography process twice. Therefore, there is a problem that the manufacturing process becomes complicated.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal display device including a spacer that can be manufactured by a relatively simple process, and a manufacturing method thereof.

  The liquid crystal display device according to the present invention is a liquid crystal display device in which a pair of substrates each having an electrode formed on each surface facing each other are disposed to face each other via a spacer, and a liquid crystal layer is disposed between the pair of substrates. The spacer is composed of a composite material in which solid particles are mixed in a resin material having elasticity, and includes a first spacer having a first compression elastic modulus, and at least the first compression elastic modulus including the resin material. And a second spacer having a different second compression modulus.

  For example, the first spacer is formed from a composite material in which solid particles are mixed in a resin material, and the second spacer is formed only from the same resin material as the resin material forming the first spacer. Has been.

  For example, the first spacer is formed of a first composite material composed of a resin material having elasticity and solid particles mixed in the resin material at a first ratio, and the second spacer. Is composed of the same resin material as the resin material forming the first spacer, and solid particles mixed in the resin material at a second ratio different from the first ratio. Formed from a composite material.

  For example, the first spacer and the second spacer are stacked on each other between the pair of substrates.

  For example, the first spacer and the second spacer are disposed adjacent to each other in parallel between the pair of substrates.

  For example, the solid particles are configured by mixing a plurality of different materials.

  In the method for manufacturing a liquid crystal display device according to the present invention, a pair of substrates each having an electrode formed on each surface facing each other are arranged to face each other via a spacer for defining a distance between the substrates, and the pair of substrates is arranged. In a method of manufacturing a liquid crystal display device in which a liquid crystal layer is disposed, a composite material for forming a first spacer in which solid particles are mixed in a photosensitive resin material is applied to the upper surface of one substrate. A first layer coating step for forming a first coating film; a first layer pre-baking step for prebaking the first coating film; and a second spacer for forming a second spacer including the photosensitive resin material. A second layer coating step of applying a resin material on the upper surface of the first coating film to form a second coating film; a second layer pre-baking step of pre-baking the second coating layer; and a pre-baked first layer 1 coating layer and The unnecessary part of the second coating film is removed using a photolithography process, the first coating layer remaining on the one substrate, and the second coating film are baked to form the one And a fixing step of fixing to the substrate.

  For example, in the first layer coating step, a composite material for forming a first spacer in which solid particles are mixed at a predetermined first ratio in a photosensitive resin material is formed on the upper surface of one substrate. The second layer coating step includes a second spacer obtained by mixing solid particles in the photosensitive resin material at a second ratio different from the first ratio. It is characterized by comprising a step of applying a composite material to be formed on the upper surface of the first coating film.

  According to the present invention, a liquid crystal display device including a plurality of spacers having different compression elastic moduli can be manufactured by a relatively simple process.

  Hereinafter, a liquid crystal display device 100 according to the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross-sectional structure of a liquid crystal display device 100 according to the present embodiment.

  As shown in FIG. 1, the liquid crystal display device 100 includes a pair of substrates 10 and 20 disposed opposite to each other, a spacer 30 disposed between the substrates 10 and 20, and a seal between the pair of substrates 10 and 20. And a stopped liquid crystal layer 40.

  The substrates 10 and 20 are each composed of a light-transmitting substrate such as glass or resin.

  On the substrate 10, pixel electrodes 11 and switching elements 12 connected to the pixel electrodes 11 are arranged in a matrix. The pixel electrode 11 is made of, for example, ITO (Indium Tin Oxide) or the like, and the switching element 12 is made of a TFT (Thin Film Transistor) or the like. Further, an alignment film 13 is formed so as to cover them.

  On the other hand, on the substrate 20, a color filter 22, an alignment film 23, and the like are sequentially formed on the common electrode 21.

  A plurality of spacers 30 are disposed between the substrate 10 and the substrate 20, and a plurality of spacers 30 are disposed in a non-display area, that is, an area where the pixel electrode 11 does not exist. Each spacer 30 as a whole is formed in a cylindrical shape having a length substantially equal to the gap length, and is formed by laminating a first spacer 30a and a second spacer 30b.

  The first spacer 30a is made of a composite material in which solid particles 30 are mixed with a resin material having elasticity, and has a first compression elastic modulus. The second spacer 30b is made of the same resin material as that of the first spacer 30a, does not include the solid particles 30c, and has a second compressive elastic modulus smaller than the first compressive elastic modulus. Have.

  As shown in FIG. 1, the first spacer 30a is disposed on the substrate 10 (more precisely, the alignment film 13), the second spacer 30b is laminated on the first spacer 30a, and the counter substrate 20 ( More precisely, it is fixed to the alignment film 23).

  The first spacer 30a is based on a photosensitive resin material mainly composed of, for example, an ethylene-vinyl acetate copolymer, an ethylene-vinyl chloride copolymer, an ethylene vinyl copolymer, polystyrene, a polyvinyl chloride resin, or the like. A solid material 30c is mixed with the base material.

  The solid particles 30 c are harder than the base material of the first spacer 30 a and have a diameter of about 1/20 to 1/3 of the diameter of the spacer 30. The solid particles 30c can be selected from an organic material, an inorganic material, an organic-inorganic composite material, or the like. Examples of organic materials include acrylic polymers and diene polymer rubber latex, inorganic materials include silicon oxide, germanium oxide, titanium oxide, aluminum oxide, and organic-inorganic composite materials. And a silicone-based composite material in which an organic material such as an acrylic polymer and silicone are combined. Further, the solid particles 30c may be constituted by one kind of material, or may be constituted by mixing or combining a plurality of materials.

  Since the 1st spacer 30a is comprised from the mixture of the base material and the harder solid particle 30c, if the mixing ratio (content rate) of the solid particle 30c with respect to the said base material is enlarged, the 1st spacer 30a. The compression elastic modulus of the liquid crystal display device 100 is set to an appropriate compression elastic modulus by adjusting the mixing ratio.

  The second spacer 30b is made of the same resin material as that of the first spacer 30a and does not contain the solid particles 30c. Therefore, the compression elastic modulus of the second spacer 30b is smaller than the compression elastic modulus of the first spacer 30a. That is, the second spacer 30 b is softer than the first spacer 3.

Next, a method for forming the spacer 30 will be described with reference to FIGS.
First, the substrate 10 on which the pixel electrode 11, the active element 12, and the alignment film 13 are formed is prepared.

  Next, the solid particles 30c are mixed with a photosensitive resin material at a predetermined weight ratio, for example, 1/20 to 1/2, and sufficiently mixed to produce a composite material. As shown in FIG. 3B, the first coating film 41 is formed by coating on the alignment film 13. In addition, what is necessary is just to use various well-known methods, such as spin coating, immersion, printing, dispensing, or a roll coater, for application | coating. The thickness of the coating film of the composite material is such that the thickness after baking is the same as the thickness of the first spacer 30 a of the spacer 30.

  Next, the composite material applied to the substrate 10 is pre-baked. Note that the pre-baking is performed by using various known methods such as drying the substrate 10 by heating from the lower surface, vacuum drying, freeze drying, spray drying, or the like.

  Subsequently, the photosensitive resin is applied on the upper surface of the coating film 41 as shown in FIG. 3C to form a second coating film 42. The above-mentioned method can be used for application. The thickness of the second coating film 42 is such that the thickness after baking is equal to the second spacer 30 b of the spacer 30.

  Thereafter, the resin material is pre-baked at, for example, room temperature to 120 ° C.

  Next, the first and second coating films 41 and 42 are patterned by a photolithography process to form an uncured spacer 30 at a predetermined position on the substrate 10.

  First, a photomask 51 is disposed on the first and second coating films 41 and 42 as shown in FIG. The photomask 51 includes a planar circular opening 51 a at a position where the spacer 30 is formed.

  Subsequently, as shown in FIG. 4A, the mask pattern, that is, the planar shape of the spacer 30 is transferred to the first and second coating films 41 and 42 by irradiation with ultraviolet light or the like.

  Next, the substrate 10 is immersed in a predetermined developer, and unnecessary portions of the first and second coating films 41 and 42, that is, other than the predetermined pattern transferred to the first and second coating films 41 and 42, are obtained. The part (unexposed part) is formed as shown in FIG. 4B, for example.

  Subsequently, the substrates 10 and 20 are baked, for example, at 200 to 250 ° C. to form the spacers 30 at predetermined positions.

  On the other hand, a common electrode 21, a color filter 22, and an alignment film 23 are sequentially formed on the substrate 20. Subsequently, the substrate 10 on which the spacers 30 are formed and the counter substrate 20 on which the common electrode 22 and the like are formed are bonded via a sealing material to form a liquid crystal cell. At this time, the gap length is maintained at an appropriate value by the spacer 30.

Subsequently, the liquid crystal cell is filled with liquid crystal, and the inlet is sealed.
Then, a polarizing plate etc. are arrange | positioned on an outer surface, and the liquid crystal display device 100 is completed.

  According to this manufacturing method, the base materials of the first and second coating films 41 and 42 are the same spacer material, and the first spacer 30a and the spacer 30b are separated by a common exposure process and a development process. Can be formed.

  In addition, since the spacer 30 includes the first spacer 30a having high elasticity and the second spacer 30b having low elasticity, even if a pressing force is applied to the substrates 10 and 20, as shown in FIG. Since the first spacer 30a receives this and resists deformation, variation in the thickness of the liquid crystal layer 40 can be suppressed, and color unevenness can be prevented. Further, as shown in FIG. 6, even if the volume of the liquid crystal layer 40 contracts or expands due to a change in temperature, the second spacer 30b is deformed and follows this, so that the generation of vacuum bubbles can be suppressed. .

  In this embodiment, the solid particles 30c are contained only in the first spacer 30a and the solid particles 30c are not contained in the second spacer 30b. However, the present invention is not limited to this. For example, as shown in FIG. 7, the solid particles 30c are contained in the second spacer 30b at a lower content than the first spacer 30a so that a desired compressive elastic modulus can be obtained individually and as a whole. Good.

  Further, in the embodiment of the present invention, an example in which the spacer 30 has two layers is given, but the present invention is not limited to this. For example, as shown in FIG. 8, different resin materials may be laminated in three or more layers, and the content of the solid particles 30 c in each layer may be changed to obtain desired elasticity as a whole and individually.

  In the embodiment of the present invention, an example in which the first and second spacers 30a and 30b are stacked is shown, but the present invention is not limited to this, and as shown in FIG. 30a and the second spacer 30b may be disposed adjacent to each other in parallel between the substrates 10 and 20.

It is sectional drawing of the liquid crystal display device which concerns on embodiment of this invention. It is a figure which shows the spacer which concerns on embodiment of this invention. (A)-(c) is a figure explaining the method of forming a spacer. (A), (b) is a figure explaining the method of forming a spacer. It is a figure which shows the effect | action of the said liquid crystal display device. It is a figure which shows another effect | action of the said liquid crystal display device. It is a figure which shows the modification of the spacer of a two-layer structure. It is a figure which shows the spacer of a three-layer structure. It is a figure which shows the structure which has arrange | positioned the spacer in parallel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Substrate, 11 ... Pixel electrode, 12 ... Active element, 13 ... Alignment film, 20 ... Substrate 21 ... Counter electrode, 22 ... Color filter, 23 ... Alignment film, 30 ... spacer, 30a ... first spacer, 30b ... second spacer, 30c ... solid particles, 40 ... liquid crystal layer, 41 ... first coating Film, 42 ... second coating film, 51 ... photomask, 100 ... liquid crystal display device

Claims (8)

In a liquid crystal display device in which a pair of substrates each having an electrode formed on each surface facing each other are disposed to face each other via a spacer, and a liquid crystal layer is disposed between the pair of substrates.
The spacer is made of a composite material in which solid particles are mixed with an elastic resin material, and includes at least the first spacer having the first compression elastic modulus and the first compression elastic modulus. And a second spacer having a second compressive elastic modulus different from that of the liquid crystal display device. The first spacer is formed from a composite material in which solid particles are mixed in a resin material, and the second spacer is formed only from the same resin material as the resin material forming the first spacer. The liquid crystal display device according to claim 1, wherein: The first spacer is formed of a first composite material including a resin material having elasticity and solid particles mixed in the resin material at a first ratio,
The second spacer is composed of the same resin material as that forming the first spacer, and solid particles mixed in the resin material at a second ratio different from the first ratio. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is formed from a second composite material. 4. The liquid crystal display device according to claim 1, wherein the first spacer and the second spacer are stacked on each other between the pair of substrates. 5. 4. The liquid crystal display according to claim 1, wherein the first spacer and the second spacer are arranged adjacent to each other in parallel between the pair of substrates. 5. apparatus. The liquid crystal display device according to any one of claims 1 to 3, wherein the solid particles are configured by mixing a plurality of different materials. Manufacture of a liquid crystal display device in which a pair of substrates each having an electrode formed on each surface facing each other are arranged to face each other via a spacer for defining a distance between the substrates, and a liquid crystal layer is arranged between the pair of substrates. In the method
A first layer coating step in which a composite material for forming a first spacer in which solid particles are mixed in a photosensitive resin material is coated on the upper surface of one substrate to form a first coating film;
A first layer pre-baking step of pre-baking the first coating film;
A second layer coating step including a resin material having photosensitivity and applying a resin material for forming a second spacer on the upper surface of the first coating film to form a second coating film;
A second layer pre-baking step of pre-baking the second coating layer;
A photolithography process for removing unnecessary portions of the pre-baked first coating layer and the second coating film by using a photolithography process;
A method for manufacturing a liquid crystal display device, comprising: a first coating layer remaining on the one substrate; and a fixing step of baking and fixing the second coating film to the one substrate. In the first layer coating step, a composite material for forming a first spacer in which solid particles are mixed in a photosensitive resin material at a predetermined first ratio is coated on the upper surface of one substrate. The process consists of
In the second layer coating step, a composite material for forming a second spacer in which solid particles are mixed in the photosensitive resin material at a second ratio different from the first ratio is used. The method for manufacturing a liquid crystal display device according to claim 7, comprising a step of applying to the upper surface of the first coating film.

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