JP2010145756A - Liquid crystal display element and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display element in which a change in an interval between substrates is reduced against external force applied to the liquid crystal display element and to provide a manufacturing method of the liquid crystal display element. <P>SOLUTION: Columnar spacers 109 formed at a height lower than a gap between a TFT substrate 101 and a counter substrate 102 and granular spacers 108 each of which is buried in each columnar spacer 109 and has a diameter larger than the height of the columnar spacer 109 to specify the layer thickness of liquid crystal sealed between the TFT substrate 101 and the counter substrate 102 are arranged between both the substrates 101, 102. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display element, and more particularly, to a liquid crystal display element provided with a spacer that is sandwiched between two substrates and regulates the distance between the substrates, and a method for manufacturing the same.

  The liquid crystal display device has a structure in which liquid crystal is supported between two glass substrates, and a spacer is provided between the two glass substrates in order to keep the distance between the two glass substrates at a predetermined size. It is pinched. A liquid crystal display device using spherical plastic beads for this spacer is also known (for example, Patent Document 1).

Japanese Patent Laid-Open No. 7-114033

  Plastic beads have elasticity, and if plastic beads are used as spacers, they can follow the change in volume of liquid crystal due to temperature changes. However, when an external force that presses the surface of the glass substrate is applied, there is a problem that the glass substrate is deformed according to the elasticity of the plastic beads and the substrate interval is changed.

  The present invention has been made in view of such a background, and provides a liquid crystal display element in which a change in a substrate interval is reduced with respect to an external force applied to the liquid crystal display element, and a method for manufacturing the same.

In order to solve the above problems, a liquid crystal display element according to the first aspect of the present invention provides:
A first substrate on which a transparent electrode is formed;
A second substrate disposed opposite to the surface of the first substrate on which the transparent electrode is formed, and a plurality of pixel electrodes, a thin film transistor connected to each pixel electrode, and a wiring connected to the thin film transistor; A substrate of
Liquid crystal sealed between the inner surface of the first substrate and the inner surface of the second substrate;
The first substrate or the second substrate is disposed between the first substrate and the second substrate, and is lower than a predetermined gap between the inner surface of the first substrate and the inner surface of the second substrate. Columnar spacers formed at a height that abuts against the inner surface of the first substrate and the inner surface of the second substrate when the second substrate is deformed;
Liquid crystal embedded in the columnar spacer and sealed between the first substrate and the second substrate in contact with the inner surface of the first substrate and the inner surface of the second substrate. A particulate spacer having a diameter larger than the height of the columnar spacer, in order to define the layer thickness to a predetermined thickness;
It is characterized by providing.

  The particulate spacer is composed of, for example, a bead spacer made of plastic, and is in contact with the inner surface of the first substrate and the inner surface of the second substrate corresponding to the thin film transistor.

  Alternatively, the particulate spacer is composed of a bead spacer made of plastic, and is in contact with the inner surface of the first substrate and the inner surface of the second substrate corresponding to the wiring.

Moreover, the manufacturing method of the liquid crystal display element of the present invention according to the second aspect of the present invention includes:
The first substrate and the second substrate on which electrodes are respectively formed are arranged to face each other via a spacer portion that defines a gap between the first substrate and the second substrate. In a liquid crystal display element manufacturing method for manufacturing a liquid crystal display element by enclosing a liquid crystal,
The step of forming the spacer portion includes
A resin layer forming step of forming a resin layer for forming columnar spacers on one of the first substrate and the second substrate;
The liquid crystal layer having a diameter larger than the thickness of the resin layer on the resin layer, and the thickness of the liquid crystal sealed between the first substrate and the second substrate is defined to a predetermined thickness. For dispersing the particulate spacers for embedding in the resin layer,
A step of fixing the resin layer to a shape corresponding to the columnar spacer, and fixing the particulate spacer to the substrate;
A columnar spacer forming step of forming a columnar spacer having a height lower than the diameter of the particulate spacer by removing unnecessary portions other than the portion corresponding to the columnar spacer of the resin layer;
Having
It is characterized by that.

  For example, the resin layer is made of a photosensitive resin, and the spacer fixing step includes a curing step of covering the resin layer with a light shielding mask having a predetermined light shielding pattern and curing the resin layer by irradiating ultraviolet rays. And a step of removing an uncured portion of the resin layer after execution of the curing step.

A method for manufacturing a liquid crystal display element according to the third aspect of the present invention is as follows.
The first substrate and the second substrate on which electrodes are respectively formed are arranged to face each other via a spacer portion that defines a gap between the first substrate and the second substrate. In a method for manufacturing a liquid crystal display element in which liquid crystal is sealed to manufacture a liquid crystal display element,
The step of forming the spacer portion includes
A resin application step of applying a resin for forming a columnar spacer at a predetermined position on one of the first substrate and the second substrate;
A predetermined thickness of a liquid crystal layer having a diameter larger than the applied resin layer thickness on the applied uncured resin and sealed between the first substrate and the second substrate. Scattering the particulate spacer for prescribing, and a spacer dispersing step of embedding the particulate spacer in the resin,
A columnar spacer forming step of curing the resin and fixing the particulate spacer to the first substrate, and forming a columnar spacer having a height lower than the diameter of the particulate spacer;
An unnecessary bead removing step of cleaning the substrate on which the particulate spacers are dispersed and removing the granular spacers not fixed by the columnar spacers;
It is characterized by having.

  The resin coating step is performed by, for example, applying a resin to a desired position on the one substrate using an inkjet apparatus.

  According to the present invention, since the spacer portion is composed of the columnar spacer and the particulate spacer, the change in the substrate interval due to the external force applied to the liquid crystal display element is reduced, and the quality of the image displayed by the liquid crystal display element is improved. To do.

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

(Embodiment 1)
FIG. 1 is a cross-sectional view of the liquid crystal display element according to the first embodiment.
As shown in the figure, the liquid crystal display element 1 of Embodiment 1 includes a pair of transparent substrates 101 and 102 disposed opposite to each other, a liquid crystal 107 sealed in a gap between the transparent substrates 101 and 102, and both transparent It consists of a particulate spacer 108 and a columnar spacer 109 disposed between the substrates 101 and 102.

  A plurality of pixel electrodes 103 and a plurality of thin film transistors 110 are formed on the inner surface of the transparent substrate 101 (hereinafter referred to as the TFT substrate 101) facing the transparent substrate 102.

The pixel electrodes 103 are formed on the inner surface of the TFT substrate 101 so as to be arranged in the row direction and the column direction. The thin film transistors 110 are arranged corresponding to the pixel electrodes 103 and connected to the corresponding pixel electrodes 103.
Although not shown, a plurality of scanning lines (gate lines) for supplying gate signals to the thin film transistors 110 in each row and a plurality of signals for supplying data signals to the thin film transistors 110 in each column are provided on the inner surface of the TFT substrate 101. Lines (data lines) are provided.

  Further, an alignment film is disposed on the TFT substrate 101 so as to cover these members. The surface of the alignment film in contact with the liquid crystal 107 is subjected to an alignment process for aligning liquid crystal molecules. The alignment film is not shown because it is extremely thin.

  On the inner surface of the transparent substrate 102 (hereinafter referred to as the counter substrate 102) facing the TFT substrate 101, a single film-like transparent electrode 106 (hereinafter referred to as the counter electrode) facing the array region of the plurality of pixel electrodes 103. Is provided. Each region where the pixel electrode 103 faces the counter electrode 106 forms a pixel.

On the inner surface of the counter substrate 102, a light shielding film 105 for shielding the peripheral region of the pixel and a color filter 104 of three colors of red, green, and blue are formed so as to correspond to each of the plurality of pixels. . The counter electrode 106 is formed on the color filter 104.
Further, an alignment film is disposed on the counter electrode 106. The surface of the alignment film in contact with the liquid crystal 107 is subjected to an alignment process for aligning liquid crystal molecules. The alignment film is not shown because it is extremely thin.

  The light shielding film 105 is disposed at a position facing the corresponding thin film transistor 110 of the corresponding TFT substrate 101. Each color filter 104 is disposed at a position facing the corresponding pixel electrode 103 of the TFT substrate 101.

  The columnar spacer 109 is formed between the TFT substrate 101 and the counter substrate 102 at a position corresponding to the thin film transistor 110 formed on the TFT substrate 101 and the light shielding film 105 formed on the counter substrate 102. The columnar spacers 109 are the inner surface (more precisely, the alignment film) of the TFT substrate 101 on which the thin film transistor 110, the pixel electrode 103, and the like are formed, and the inner surface (more precisely, the alignment film) on which the counter electrode 106 is formed. ), And when at least one of the TFT substrate 101 and the counter substrate 102 is deformed by an external pressure, the inner surfaces of the TFT substrate 101 and the counter substrate 102 (more precisely, an alignment film) It is formed in the height which contacts. The columnar spacer 109 is formed on the counter electrode 106 (more precisely, on the alignment film) of the counter substrate 102 with a photo-curing resin or a thermosetting resin.

  Part of the particulate spacer 108 is embedded in the columnar spacer 109. The particulate spacer 108 is in contact with the inner surfaces (more precisely, the alignment film) of the TFT substrate 101 and the counter substrate 102, and has a predetermined value for the thickness of the liquid crystal 107 sealed between the TFT substrate 101 and the counter substrate 102. It is composed of bead spacers formed of a spherical plastic having elasticity having a diameter larger than the height of the columnar spacer 109. For example, the particulate spacer 108 is in contact with the counter electrode 106 (more precisely, the alignment film) of the counter substrate 102 and the upper surface (more precisely, the alignment film) of the thin film transistor 110 formed on the TFT substrate 101. The distance between the inner surfaces of the TFT substrate 101 and the counter substrate 102 is defined so that the gap between the electrode 106 and the pixel electrode 103 is a predetermined liquid crystal layer thickness, for example, 4 to 5 microns.

  FIG. 1 shows the case where one particulate spacer 108 is arranged so as to be embedded in one columnar spacer 109, but the diameter of the particulate spacer 108 is as small as the thickness of the liquid crystal layer. A plurality of particulate spacers 108 may be embedded in one columnar spacer 109.

The liquid crystal display element 1 of this embodiment is disposed between the TFT substrate 101 and the counter substrate 102 and is lower than a predetermined gap between the TFT substrate 101 and the counter substrate 102, and one of the TFT substrate 101 and the counter substrate 102. Alternatively, when both of them are deformed by an external force, the columnar spacer 109 formed at a height to be in contact with the inner surfaces of the TFT substrate 101 and the counter substrate 102 and the columnar spacer 109 are disposed so as to be embedded. Particles having a diameter larger than the height of the columnar spacer 109 for defining the layer thickness of the liquid crystal 107 which is in contact with the inner surface of the 102 and sealed between the TFT substrate 101 and the counter substrate 102 to a predetermined thickness Shaped spacer 108.

  Therefore, when no external force is applied to either the TFT substrate 101 or the counter substrate 102, the particulate spacer 108 contacts the inner surfaces (more precisely, the alignment film) of the TFT substrate 101 and the counter substrate 102, and the liquid crystal The layer is defined to a predetermined thickness. When an observer or the like presses one or both of the substrates 101 and 102 with a finger or the like, the particulate spacer 108 is deformed by its elasticity and the substrate gap becomes narrow, and the columnar spacer 109 becomes the both substrates 101 and 102. The inner surface of the substrate (more precisely, the alignment film) is brought into contact with and supports between the two substrates 101 and 102. Therefore, the change in the substrate interval (the thickness of the liquid crystal layer) when an external pressure is applied to the substrates 101 and 102 can be reduced, and the display stability is improved.

  Further, in the liquid crystal display element 1 of this embodiment, the particulate spacer 108 is made of a bead spacer formed of plastic, and is formed on the inner surface of the counter substrate 102 and the inner surface of the substrate corresponding to the thin film transistor 110 formed on the TFT substrate 101. Since the particles are in contact with each other and the particulate spacers 108 are not arranged in the pixels, the display quality is improved.

  In Embodiment 1, the particulate spacer 108 and the columnar spacer 109 formed on the counter electrode 106 of the counter substrate 102 are arranged at positions corresponding to the thin film transistors 110 formed on the TFT substrate 101. However, the present invention is described above. It is not limited to the embodiment. However, it is desirable to arrange at a position where visual recognition is difficult. For example, the particulate spacers 108 and the columnar spacers 109 may be arranged at positions where they are in contact with the scanning lines or signal lines of the thin film transistor 110 formed on the TFT substrate 101.

  FIG. 2 shows a second embodiment in which the particulate spacers 108 and the columnar spacers 109 are brought into contact with the scanning lines formed on the TFT substrate 101. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals.

  Between the pixel electrodes 103 on the TFT substrate 101, a plurality of scanning lines 111 for supplying a scanning signal for turning on or off the thin film transistor 110 to the thin film transistors 110 in the corresponding row is provided.

  A particulate spacer 108 and a columnar spacer 109 are arranged at a position corresponding to the scanning line 111 of the counter electrode 106 of the counter substrate 102, and a gap between the counter electrode 106 and the pixel electrode 103 is set to a predetermined liquid crystal layer thickness. It stipulates that

Also in this embodiment, when an observer presses one or both of the substrates 101 and 102 with a finger or the like, the particulate spacer 108 is deformed by its elasticity, and the columnar spacer 109 is changed to the both substrates 101 and 102. The two substrates 101 and 102 are supported by contacting the inner surface of the substrate. Accordingly, the change in the substrate interval can be reduced, and the display stability is improved.
Further, since the particulate spacer 108 and the columnar spacer 109 are not arranged in the pixel, display quality is improved.

  Next, a manufacturing method of the spacer portion formed by embedding the particulate spacer 108 in the columnar spacer 109 will be described with reference to FIG.

First, the light shielding film 105 is formed on the counter substrate 102, and then the color filter 104 is formed. Further, the counter electrode 106 is formed of ITO or the like, an alignment film is formed, and an alignment process is performed to form the substrate 202.
Next, as shown in FIG. 3A, a photosensitive resin 201 is dropped on the substrate 202. Next, spin coating is performed to form a photosensitive resin layer 203 having a uniform thickness as shown in FIG. Note that means for forming the photosensitive resin layer 203 on the substrate 202 is not limited to spin coating. A known coating method such as slit coating or roll coating can also be selected.

  Next, particulate spacers 108 made of bead spacers are dispersed on the uncured photosensitive resin layer 203. Further, the dispersed particulate spacers 108 are pressed into the photosensitive resin layer 203 as shown in FIG. Subsequently, the photosensitive resin layer 203 is dried and cured to fix the particulate spacers 108 on the substrate 202 (FIG. 3D).

  Next, a mask on which a pattern that shields light other than the region where the columnar spacer 109 is to be formed is prepared. For example, in the first embodiment, a mask on which a light-shielding pattern is formed except for a portion corresponding to the thin film transistor 110 of the TFT substrate 101 (a position where the columnar spacer 109 is to be formed) is prepared. In the second embodiment, a mask on which a light-shielding pattern is formed except for a portion corresponding to the scanning line 111 of the TFT substrate 101 (a position where the columnar spacer 109 is to be formed) is prepared.

  Subsequently, the photosensitive resin layer 203 is covered with a prepared mask, and the photosensitive resin layer 203 is irradiated with ultraviolet rays. By this ultraviolet irradiation, a portion of the photocurable resin corresponding to the columnar spacer 109 of the photosensitive resin layer 203 is polymerized and cured. Thereafter, as shown in FIG. 3E, by removing the uncured photosensitive resin layer 203, a spacer portion in which the particulate spacer 108 is embedded in the columnar spacer 109 is formed.

  Although the case where the spacer portion is formed on the counter substrate 102 has been described, the present invention is not limited to this, and the spacer portion may be formed on the TFT substrate 101 on which a thin film transistor or the like is formed.

  According to the spacer part manufacturing method described above, the step of forming the spacer part is to form the resin layer 203 for forming the columnar spacer on one of the transparent substrates 101 and 102. Particles for defining the layer thickness of the liquid crystal 107 having a diameter larger than the layer thickness of the resin layer on the resin layer 203 and sealed between the transparent substrates 101 and 102 to a predetermined thickness in the layer forming step A spacer spraying step of spraying the spacers 108 and embedding them in the resin layer 203; a spacer fixing step of fixing the particulate spacers 108 to the substrate by curing the resin layer 203 into a shape corresponding to the columnar spacers 109; The columnar spacer is formed by removing unnecessary portions other than the portion corresponding to the columnar spacer 109 and forming the columnar spacer 109 having a diameter smaller than that of the particulate spacer 108. Because it has an extent, it is possible to form the spacer portion by a simple process.

  Further, in the step of forming the spacer portion described above, the resin layer 203 is made of a photosensitive resin, and in the spacer fixing step, the resin layer 203 is covered with a light shielding mask having a predetermined light shielding pattern and irradiated with ultraviolet rays, and the resin layer 203 203 includes a step of curing 203, and the unnecessary resin layer removing step includes a step of removing uncured resin of the resin layer 203. For this reason, the spacer portion can be formed by a simple process.

  Next, another manufacturing method for manufacturing the spacer portion in which the particulate spacer 108 is embedded in the columnar spacer 109 will be described with reference to FIG.

  In this manufacturing method, a substrate 202 having a light shielding film 105, a color filter 104, and a counter electrode 106 formed on a transparent substrate 102 is prepared. Next, as shown in FIG. 4A, an adhesive resin 302 is applied on the substrate 202 from a nozzle 301 of the ink jet apparatus to a portion corresponding to the columnar spacer 109 on the substrate 202. That is, the resin 302 is applied in a shape for forming the columnar spacer 109 on the thin film transistor 110 or the scanning line 111 for each pixel. Since the inkjet apparatus is controlled by a computer (not shown), the resin 302 can be applied to the programmed position on the substrate 202.

  Particulate spacers 108 made of bead spacers are dispersed on the substrate 202 on which the resin 302 is applied. Next, as shown in FIG. 4B, the dispersed particulate spacers 108 are embedded in the columnar spacers 109. Then, the resin 302 is dried and cured, and then the substrate 202 is washed to remove excess particulate spacers 108 (particulate spacers 108 not fixed to the substrate 202). As shown, a spacer portion in which the particulate spacer 108 is embedded in the columnar spacer 109 is formed.

  Although the case where the spacer portion is formed on the counter substrate 102 has been described, the present invention is not limited to this, and the spacer portion may be formed on the TFT substrate 101.

  According to the other manufacturing method of the spacer portion described above, the step of forming the spacer portion forms the columnar spacer at a predetermined position on one of the one transparent substrate 101 and the other transparent substrate 102. A resin coating step of applying a resin 302 for the purpose of performing the process, and a layer of liquid crystal 107 having a diameter larger than the thickness of the resin layer on the applied uncured resin 302 and sealed between the transparent substrates 101 and 102 Dispersing the particulate spacers 108 for defining the thickness to a predetermined thickness, embedding the particulate spacers dispersed in the resin, curing the resin, and the particulate spacers on the first substrate The columnar spacer forming step of fixing and forming a columnar spacer having a height lower than the diameter of the particulate spacer, and cleaning the substrate on which the particulate spacer is dispersed, And a required bead removal step of removing the particulate spacers are not constant. Therefore, the spacer portion can be formed by a simple process.

  In addition, since the resin application process is performed by applying the resin to a desired position of the one substrate using an inkjet apparatus, the spacer portion can be formed by a simple process.

  Although an example in which an alignment film is formed on the entire surface of the TFT substrate 101 and the counter substrate 102 has been shown, for example, an alignment film is disposed only on the pixel electrode 103 and the counter electrode 106, or only on one substrate side. A film may be arranged.

It is sectional drawing which shows the liquid crystal display element of Embodiment 1 of this invention. It is sectional drawing which shows the liquid crystal display element of Embodiment 2 of this invention. It is a schematic process drawing which shows the manufacturing method of the spacer part in a liquid crystal display element. It is a schematic process drawing which shows the other manufacturing method of the spacer part in a liquid crystal display element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display element, 101 ... Transparent substrate (TFT substrate), 102 ... Transparent substrate (counter substrate), 103 ... Pixel electrode, 104 ... Color filter, 105 ... Light shielding film 106 ... Counter electrode, 107 ... Liquid crystal, 108 ... Particulate spacer, 109 ... Columnar spacer, 110 ... Thin film transistor, 111 ... Scanning line, 201 ... Photosensitive resin, 203 ... photosensitive resin layer, 301 ... nozzle, 302 ... resin,

Claims (7)

A first substrate on which a transparent electrode is formed;
A second substrate disposed opposite to the surface of the first substrate on which the transparent electrode is formed, and a plurality of pixel electrodes, a thin film transistor connected to each pixel electrode, and a wiring connected to the thin film transistor; A substrate of
Liquid crystal sealed between the inner surface of the first substrate and the inner surface of the second substrate;
The first substrate or the second substrate is disposed between the first substrate and the second substrate, and is lower than a predetermined gap between the inner surface of the first substrate and the inner surface of the second substrate. Columnar spacers formed at a height that abuts against the inner surface of the first substrate and the inner surface of the second substrate when the second substrate is deformed;
A thickness of a liquid crystal layer that is partly embedded inside the columnar spacer, has a diameter larger than the height of the columnar spacer, and is sealed between the first substrate and the second substrate. To a predetermined thickness, particulate spacers that contact the inner surface of the first substrate and the inner surface of the second substrate,
A liquid crystal display element comprising:   2. The particulate spacer is formed of a bead spacer made of plastic, and is in contact with an inner surface of the first substrate and an inner surface of the second substrate corresponding to the thin film transistor. A liquid crystal display element according to 1.   2. The particulate spacer is composed of a bead spacer formed of plastic, and is in contact with an inner surface of the first substrate and an inner surface of the second substrate corresponding to the wiring. A liquid crystal display element according to 1. The first substrate and the second substrate on which electrodes are respectively formed are arranged to face each other via a spacer portion that defines a gap between the first substrate and the second substrate, and the gap is defined between the first substrate and the second substrate. In a method for manufacturing a liquid crystal display element in which liquid crystal is sealed to manufacture a liquid crystal display element,
The step of forming the spacer portion includes
A resin layer forming step of forming a resin layer for forming columnar spacers on one of the first substrate and the second substrate;
The liquid crystal layer having a diameter larger than the thickness of the resin layer on the resin layer, and the thickness of the liquid crystal sealed between the first substrate and the second substrate is defined to a predetermined thickness. For dispersing the particulate spacers for embedding in the resin layer,
A step of fixing the resin layer to a shape corresponding to the columnar spacer, and fixing the particulate spacer to the substrate;
A columnar spacer forming step of removing a columnar spacer having a height lower than the diameter of the particulate spacer by removing unnecessary portions other than the portion corresponding to the columnar spacer of the resin layer;
Having
A method for producing a liquid crystal display element. The resin layer is composed of a photosensitive resin,
The spacer fixing step includes a curing step of covering the resin layer with a light-shielding mask having a predetermined light-shielding pattern and irradiating ultraviolet rays to cure the resin layer, and after performing the curing step, the resin layer is uncured Removing the portion, and
The method for producing a liquid crystal display element according to claim 4. The first substrate and the second substrate on which electrodes are respectively formed are arranged to face each other via a spacer portion that defines a gap between the first substrate and the second substrate, and the gap is defined between the first substrate and the second substrate. In a method for manufacturing a liquid crystal display element in which liquid crystal is sealed to manufacture a liquid crystal display element,
The step of forming the spacer portion includes
A resin application step of applying a resin for forming a columnar spacer at a predetermined position on one of the first substrate and the second substrate;
A predetermined thickness of a liquid crystal layer having a diameter larger than the applied resin layer thickness on the applied uncured resin and sealed between the first substrate and the second substrate. Scattering the particulate spacer for prescribing, and a spacer dispersing step of embedding the particulate spacer in the resin,
A columnar spacer forming step of curing the resin and fixing the particulate spacer to the first substrate, and forming a columnar spacer having a height lower than the diameter of the particulate spacer;
An unnecessary bead removing step of cleaning the substrate on which the particulate spacers are dispersed and removing the particulate spacers not fixed by the columnar spacers;
A method for producing a liquid crystal display element, comprising:   The method for manufacturing a liquid crystal display element according to claim 6, wherein the resin application step is performed by applying a resin to a desired position of the one substrate using an inkjet device.

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