JP2018159817A - Manufacturing method of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method capable of preventing a display defect of a flexible liquid crystal display device.SOLUTION: The manufacturing method of a liquid crystal display device includes: a first substrate forming step which includes a first step to form a first flexible substrate which includes a first area formed of a first flexible material and a second area which does not contain the first flexible material; a second substrate forming step including a second step to form the second flexible substrate formed of second flexible material; and a substrate bonding step of bonding the first substrate prepared in the first substrate forming step and the second substrate prepared in the second substrate forming step.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method for manufacturing a liquid crystal display device.

  In general, a method of manufacturing a liquid crystal display device includes a step of manufacturing a thin film transistor substrate, a step of manufacturing a color filter substrate, a step of bonding the two substrates, and a step of bonding the two substrates, and then forming the thin film transistor substrate. And a step of exposing a terminal portion for connecting an electronic circuit. In the step of exposing the terminal portion, a process of removing a portion of the color filter substrate that overlaps the terminal portion in plan view is performed. In a conventional method for manufacturing a liquid crystal display device, the above portion is removed by cutting a glass substrate constituting a color filter substrate with a cutter or the like (see, for example, Patent Document 1).

JP 2004-118135 A

  By the way, in a liquid crystal display device having flexibility proposed in recent years, a flexible substrate made of a flexible material (for example, a polyimide resin material) is included instead of a glass substrate. Flexible material In the step of exposing the terminal part, when cutting only the glass substrate, it can be made relatively simple by scratching the substrate surface with a cutter, but when the flexible material is formed on the back surface of the glass substrate In this case, it is necessary to make a scratch for cutting the flexible material, and a process of deeply inserting a cutter blade into the flexible material and a process of cutting the flexible material with laser light are required. However, if such a process is performed, the terminal portion disposed under the flexible material may be damaged or disconnected, resulting in a display failure.

  This invention is made | formed in view of the said subject, The objective is to provide the manufacturing method which can prevent the display defect of the liquid crystal display device which has flexibility.

  In order to solve the above-described problem, a method of manufacturing a liquid crystal display device according to the present invention includes a first flexible substrate, a flexible first substrate, and a second flexible substrate disposed opposite to the first substrate. A method for manufacturing a liquid crystal display device, comprising: a second substrate having flexibility, and a liquid crystal layer disposed between the first substrate and the second substrate, wherein the first substrate is made of a first flexible material. A first substrate manufacturing step including a first step of forming the first flexible substrate including a region and a second region not including the first flexible material; and forming the second flexible substrate made of the second flexible material. A second substrate manufacturing step including a second step, a first substrate manufactured in the first substrate manufacturing step, and a second substrate manufactured in the second substrate manufacturing step. A substrate bonding process that, characterized in that it comprises a.

  In the method for manufacturing a liquid crystal display device according to the present invention, the second substrate includes a terminal portion for connecting an electronic component, and the first substrate and the second substrate are bonded together in plan view. The second region may overlap the terminal portion.

  In the method for manufacturing a liquid crystal display device according to the present invention, in the first step, the first flexible material is applied to a first portion corresponding to the first region of the first glass substrate, and the first glass substrate is coated with the first flexible material. A step of not applying the first flexible material to the second portion corresponding to the second region may be included.

  In the method of manufacturing a liquid crystal display device according to the present invention, the first step includes hydrophobizing the entire surface of the first glass substrate and hydrophilizing the second portion corresponding to the second region of the first glass substrate. And a step of applying the first flexible material to the entire surface of the hydrophobized and hydrophilized first glass substrate.

  In the method for manufacturing a liquid crystal display device according to the present invention, the first step includes a step of forming a metal material on a portion of the first glass substrate corresponding to the second region, and the step of forming the metal material. A step of applying the first flexible material to the entire surface of one glass substrate and a step of removing the metal material and the first flexible material applied on the metal material by wet etching may be included.

  In the method for manufacturing a liquid crystal display device according to the present invention, after bonding the first substrate and the second substrate, a cutting step of cutting the first substrate in the second region, and after the cutting step, A peeling step of peeling the first glass substrate from the first flexible substrate.

  According to the method for manufacturing a liquid crystal display device according to the present invention, it is possible to prevent display defects of a flexible liquid crystal display device.

(A) is a top view which shows schematic structure of the liquid crystal display device which concerns on this embodiment, (b) is AA 'sectional drawing of (a). It is a top view which shows schematic structure of the display area of the display panel which concerns on this embodiment. It is a top view which shows the structure of the pixel of the display panel which concerns on this embodiment. It is BB 'sectional drawing of FIG. It is CC 'sectional drawing of FIG. (A) is a top view which shows the state after the board | substrate bonding process in the manufacturing method of the liquid crystal display device which concerns on this embodiment, (b) is DD 'sectional drawing of (a). It is a figure for demonstrating the exposure process in the manufacturing method of the liquid crystal display device which concerns on this embodiment. It is a figure for demonstrating the peeling process in the manufacturing method of the liquid crystal display device which concerns on this embodiment. It is a figure for demonstrating the other formation method of the flexible substrate in the manufacturing method of the liquid crystal display device which concerns on this embodiment. It is a figure for demonstrating the other formation method of the flexible substrate in the manufacturing method of the liquid crystal display device which concerns on this embodiment. It is a figure for demonstrating the other formation method of the flexible substrate in the manufacturing method of the liquid crystal display device which concerns on this embodiment. It is a figure for demonstrating the other formation method of the flexible substrate in the manufacturing method of the liquid crystal display device which concerns on this embodiment.

  An embodiment of the present invention will be described below with reference to the drawings. In the embodiment of the present invention, a COG (Chip On Glass) type liquid crystal display device is taken as an example, but the present invention is not limited to this. For example, a COF (Chip On Film) type or TCP (Tape Carrier Package) type liquid crystal display device is used. It may be.

  FIG. 1 is a plan view and a cross-sectional view illustrating a schematic configuration of the liquid crystal display device according to the present embodiment. The liquid crystal display device 1 includes a display panel 10, a source driver IC 20, a gate driver IC 30, and a backlight (not shown). The display panel 10 includes a thin film transistor substrate 100 (TFT substrate), a color filter substrate 200 (CF substrate), and a liquid crystal layer 300 sandwiched between both substrates. The display panel 10 includes a display area 10a for displaying an image and a non-display area 10b around the display area 10a. The source driver IC 20 and the gate driver IC 30 are mounted on the thin film transistor substrate 100. The number of source driver ICs 20 and gate driver ICs 30 is not limited.

  FIG.1 (b) is AA 'sectional drawing of Fig.1 (a). The thin film transistor substrate 100 includes a flexible substrate 110 formed of a flexible material, a TFT element layer 120 formed on the display surface side of the flexible substrate 110, and a polarizing plate 130 formed on the back side of the flexible substrate 110. It is out. In the non-display area 10 b of the TFT element layer 120, a terminal portion 31 and a source driver IC 20 and a gate driver IC 30 that are electrically connected to the terminal portion 31 are provided. The color filter substrate 200 includes a flexible substrate 210 formed of a flexible material, a CF element layer 220 formed on the back side of the flexible substrate 210, and a polarizing plate 230 formed on the display surface side of the flexible substrate 210. Contains. A liquid crystal layer 300 is disposed between the thin film transistor substrate 100 and the color filter substrate 200, and a sealing material 310 is formed around the liquid crystal layer 300.

  FIG. 2 is a plan view (equivalent circuit diagram) showing a schematic configuration of the display region 10 a in the display panel 10. The display panel 10 is provided with a plurality of source lines 11 extending in a first direction (for example, a column direction) and a plurality of gate lines 12 extending in a second direction (for example, a row direction). At each intersection of each source line 11 and each gate line 12, a thin film transistor 13 (TFT) is provided. Each source line 11 is electrically connected to a source driver IC 20 (see FIG. 1), and each gate line 12 is electrically connected to a gate driver IC 30 (see FIG. 1).

  In the display panel 10, a plurality of pixels 14 are arranged in a matrix (row direction and column direction) corresponding to each intersection of each source line 11 and each gate line 12. The thin film transistor substrate 100 is provided with a plurality of pixel electrodes 15 arranged for each pixel 14 and a common electrode 16 common to the plurality of pixels 14.

  Each source line 11 is supplied with a data signal (data voltage) from the source driver IC 20, and each gate line 12 is supplied with a gate signal (gate on voltage, gate off voltage) from the gate driver IC 30. A common voltage Vcom is supplied to the common electrode 16 from a common driver (not shown). When an on voltage (gate on voltage) of the gate signal is supplied to the gate line 12, the thin film transistor 13 connected to the gate line 12 is turned on, and the data voltage is supplied to the pixel electrode via the source line 11 connected to the thin film transistor 13. 15 is supplied. An electric field is generated by the difference between the data voltage supplied to the pixel electrode 15 and the common voltage Vcom supplied to the common electrode 16. The liquid crystal is driven by this electric field, and the image display is performed by controlling the light transmittance of the backlight. In the case of performing color display, a desired data voltage is applied to each source line 11 connected to the pixel electrode 15 of each pixel 14 corresponding to red, green, and blue formed by a striped color filter. Realized by supplying.

  FIG. 3 is a plan view showing the configuration of the pixel 14. 4 is a cross-sectional view taken along the line BB ′ of FIG. 3, and FIG. 5 is a cross-sectional view taken along the line CC ′ of FIG. A specific configuration of the display panel 10 will be described with reference to FIGS.

  In FIG. 3, a region defined by two adjacent source lines 11 and two adjacent gate lines 12 corresponds to one pixel 14. Each pixel 14 is provided with a thin film transistor 13. The thin film transistor 13 includes a semiconductor layer 17 formed on the insulating film 121 (see FIG. 4), and a drain electrode 18 and a source electrode 19 formed on the semiconductor layer 17 (see FIG. 3). . The drain electrode 18 is electrically connected to the source line 11, and the source electrode 19 is electrically connected to the pixel electrode 15 through the through hole 21.

  Each pixel 14 is formed with a pixel electrode 15 made of a transparent conductive film such as ITO. The pixel electrode 15 has a plurality of openings (slits) and is formed in a stripe shape. In common with each pixel 14, one common electrode 16 made of a transparent conductive film such as ITO is formed over the entire display area. In the common electrode 16, an opening for electrically connecting the pixel electrode 15 and the source electrode 19 is formed in a region overlapping the through hole 21 and the source electrode 19 of the thin film transistor 13.

  As shown in FIGS. 4 and 5, the display panel 10 includes a thin film transistor substrate 100 (second substrate) disposed on the back side, a color filter substrate 200 (first substrate) disposed on the display surface side, and a thin film transistor. And a liquid crystal layer 300 sandwiched between the substrate 100 and the color filter substrate 200.

  In the thin film transistor substrate 100, gate lines 12 (FIG. 5) are formed on the display surface side of the flexible substrate 110, and an insulating film 121 is formed so as to cover the gate lines 12. A source line 11 (FIG. 4) is formed on the insulating film 121, and an insulating film 122 is formed so as to cover the source line 11. A common electrode 16 is formed on the insulating film 122, and an insulating film 123 is formed so as to cover the common electrode 16. A pixel electrode 15 is formed on the insulating film 123, and an alignment film 124 is formed so as to cover the pixel electrode 15. A polarizing plate 130 is formed on the back side of the flexible substrate 110.

  In the color filter substrate 200, a black matrix 222 and a color filter 221 (for example, a red color filter 221r, a green color filter 221g, and a blue color filter 221b) are formed on the back side of the flexible substrate 210, and an overcoat layer is formed so as to cover them. 223 is formed. An alignment film 224 is formed on the overcoat layer 223. A polarizing plate 230 is formed on the display surface side of the flexible substrate 210.

  Liquid crystal 301 is sealed in the liquid crystal layer 300. The liquid crystal 301 may be a negative liquid crystal having a negative dielectric anisotropy or a positive liquid crystal having a positive dielectric anisotropy.

  The alignment films 124 and 224 may be alignment films that have been subjected to a rubbing alignment process, or may be optical alignment films that have been subjected to a photo-alignment process.

  The stacked structure of each part constituting the pixel 14 is not limited to the structure shown in FIGS. 4 and 5, and a known structure can be applied. Further, as described above, the liquid crystal display device 1 has an IPS (In Plane Switching) system configuration. The configuration of the liquid crystal display device 1 is not limited to the above configuration.

  Next, a method for manufacturing the liquid crystal display device 1 will be described. The manufacturing method of the liquid crystal display device 1 includes a thin film transistor substrate manufacturing process (second substrate manufacturing process) for manufacturing the thin film transistor substrate 100 (second substrate) and a color filter substrate manufacturing process for manufacturing the color filter substrate 200 (first substrate). (First substrate manufacturing process), a substrate bonding process for bonding the thin film transistor substrate 100 and the color filter substrate 200, a cutting process for cutting each display panel 10 (liquid crystal cell), and electronic components (source driver IC 20 and gate driver). IC 30) including an exposure process for exposing the terminal portion 31 and a peeling process for peeling the underlying glass substrate.

  FIG. 6A is a plan view showing a state after the substrate bonding step, and FIG. 6B is a cross-sectional view taken along the line DD ′ of FIG. In the example shown in FIG. 6, a process of manufacturing nine display panels 10 is shown.

  In the thin film transistor substrate manufacturing process, first, an absorption film that absorbs laser light is formed on the entire surface of the glass substrate 101 (mother glass) to form a release layer (not shown). Next, a flexible material whose main component is polyimide resin or the like is applied to the entire surface of the release layer and baked to form the flexible substrate 110 (second step). Next, the TFT element layer 120 is formed on the flexible substrate 110. The TFT element layer 120 includes the respective constituent members (source line 11, gate line 12, thin film transistor 13, pixel electrode 15, common electrode 16 and the like) shown in FIGS. Next, the terminal portion 31 is formed in the non-display area 10b (see FIG. 1) on the TFT element layer 120. Thus, the thin film transistor substrate 100 is manufactured. Note that the peeling layer may be omitted from the thin film transistor substrate 100.

  In the color filter substrate manufacturing process, first, an absorption film that absorbs laser light is formed on the entire surface of the glass substrate 201 (mother glass) to form a release layer (not shown). Next, in the entire surface of the release layer, a flexible resin mainly composed of a polyimide-based resin or the like is formed in a region excluding a region (non-formation region 211) that overlaps the terminal portion 31 in plan view when the thin film transistor substrate 100 is bonded. The material is applied and baked to form the flexible substrate 210 (first step). For example, by controlling the location where the flexible material is applied using an ink jet method or a linear coater, the portion (first portion) corresponding to the region excluding the region overlapping the terminal portion 31 in the glass substrate 201 including the release layer is flexible. The material is applied, and a process in which the flexible material is not applied to the portion (second portion) corresponding to the region overlapping the terminal portion 31 in the glass substrate 201 is executed. Thereby, the flexible substrate 210 including the region (first region) made of the flexible material and the non-formed region 211 (second region) not including the flexible material is formed. Next, the CF element layer 220 is formed on the flexible substrate 210. The CF element layer 220 includes the respective constituent members (color filter 221, black matrix 222, etc.) shown in FIGS. 4 and 5. As described above, the color filter substrate 200 is manufactured. In the color filter substrate 200, the release layer may be omitted.

  In the substrate bonding step, first, the sealing material 310 is applied on the color filter substrate 200 manufactured through the color filter substrate manufacturing step, and the display region 10a of the thin film transistor substrate 100 manufactured through the thin film transistor substrate manufacturing step (FIG. 1). Liquid crystal 301 is dropped. Next, the thin film transistor substrate 100 and the color filter substrate 200 are bonded together, and the sealing material 310 is cured by irradiating ultraviolet rays.

  In the cutting step, the display panel 10 (liquid crystal cell) is cut after the substrate bonding step. In the example shown in FIG. 6, it cut | disconnects with a cutter etc. along the cutting line CL1, and it divides | segments into the nine display panels 10. FIG.

  FIG. 7 is a diagram for explaining the exposure process. In the exposure process, as shown in FIG. 7A, in order to remove the portion of the color filter substrate 200 that overlaps the terminal portion 31 in plan view, the non-formation region 211 is colored along the cutting line CL2 with a cutter or the like. The filter substrate 200 is cut (cutting step). FIG. 7B shows a state in which a part of the color filter substrate 200 is cut. Thereby, as shown in FIG.7 (c), the terminal part 31 can be exposed. Thereafter, an electronic component (for example, a gate driver IC 30) is mounted on the terminal portion 31.

  FIG. 8 is a diagram for explaining the peeling process. In the peeling step, as shown in FIG. 8A, the peeling layer between the glass substrate 201 and the flexible substrate 210 is irradiated with laser light (excimer laser) to crystallize the peeling layer. The flexible substrate 210 is peeled from the release layer due to the structural change during crystallization. Similarly, the release layer between the glass substrate 101 and the flexible substrate 110 is irradiated with laser light to crystallize the release layer. The flexible substrate 110 is peeled from the peeling layer due to the structural change during crystallization. After the glass substrates 101 and 201 are peeled off (see FIG. 8B), polarizing plates 130 and 230 are attached (see FIG. 8C). Even when there is no release layer, it is possible to release the glass substrate from the flexible substrate by optimizing the laser irradiation conditions due to a difference in volume expansion due to a temperature change between the glass substrate and the flexible substrate.

  The liquid crystal display device 1 is manufactured through the above steps. According to the above manufacturing method, in particular, the flexible substrate 210 of the color filter substrate 200 includes the non-formation region 211 where no flexible material is formed, and the non-formation region 211 is disposed at a position overlapping the terminal portion 31 of the thin film transistor substrate 100. Is done. For this reason, when exposing the terminal part 31, the color filter substrate 200 can be cut | disconnected in the part (non-formation area | region 211) where a flexible material does not exist. Thereby, the terminal part 31 can be easily exposed without damaging the terminal part 31. That is, display defects of the liquid crystal display device 1 can be prevented.

  The present invention is not limited to the above configuration. In particular, the method of forming the flexible substrate 210 including the non-formation region 211 in the manufacturing process of the color filter substrate 200 is not limited to the above method. 9 and 10 are diagrams for explaining another method for forming the flexible substrate 210. FIG. First, the entire surface of the glass substrate 201 is hydrophobized by, for example, HMDS (Hexamethyldisilazane) treatment (see FIG. 9A). Next, the region (non-formation region 211) that overlaps the terminal portion 31 in plan view when the thin film transistor substrate 100 is bonded is hydrophilized (see FIG. 9B). The treatment for hydrophilization is not limited. For example, after applying TMAH (tetramethylammonium hydroxide) as a positive photoresist developer by an inkjet method, it may be washed with water, or a hydrophilic coating agent may be applied by an inkjet method. It may be applied, UV ozone treatment may be performed using a desired mask, or atmospheric pressure plasma treatment may be performed. Next, a flexible material is applied to the entire surface of the glass substrate 201 that has been subjected to a hydrophobic treatment and a hydrophilic treatment (see FIG. 10). Thereby, the flexible material almost does not exist in the portion subjected to the hydrophilic treatment, and the flexible substrate 210 including the non-formation region 211 is formed.

  11 and 12 are diagrams for explaining another method of forming the flexible substrate 210. FIG. First, after a metal material such as Mo is formed on the glass substrate 201 by sputtering, a process such as etching is performed, and when the thin film transistor substrate 100 is bonded, a region that overlaps the terminal portion 31 in a plan view (non-formation) Patterning is performed so that the region 211) remains (see FIG. 11A). Next, a flexible material is applied and baked on the entire surface of the glass substrate 201 containing the patterned metal material (see FIG. 11B). Next, the patterned metal material and the upper flexible material are simultaneously removed by wet etching (see FIG. 12). Thereby, the flexible substrate 210 including the non-formation region 211 is formed. In addition, the patterned metal material and the flexible material on the upper part cannot be removed at the same time, and only the metal material may be removed and the flexible material may remain. In that case, you may cut | disconnect the baked flexible material using a cutter along a metal material pattern before a wet etching process.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to said each embodiment, The form suitably changed by those skilled in the art from said each embodiment within the range which does not deviate from the meaning of this invention. Needless to say, it is included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 Liquid crystal display device, 10 Display panel, 10a Display area, 10b Non-display area, 11 Source line, 12 Gate line, 13 Thin-film transistor, 14 pixel, 15 Pixel electrode, 16 Common electrode, 20 Source driver IC, 30 Gate driver IC, 31 terminal portion, 40 display panel, 100 thin film transistor substrate, 200 color filter substrate, 300 liquid crystal layer, 101, 201 glass substrate, 110, 210 flexible substrate, 120 TFT element layer, 211 non-formation region, 220 CF element layer, 310 seal Wood.

Claims (6)

A first substrate having a first flexible substrate and having flexibility, a second substrate having a second flexible substrate disposed opposite to the first substrate and having flexibility, the first substrate and the second substrate A liquid crystal display device comprising a liquid crystal layer disposed between
A first substrate manufacturing step including a first step of forming the first flexible substrate including a first region made of a first flexible material and a second region not including the first flexible material;
A second substrate manufacturing step including a second step of forming the second flexible substrate made of a second flexible material;
A substrate bonding step of bonding the first substrate manufactured in the first substrate manufacturing step and the second substrate manufactured in the second substrate manufacturing step;
A method of manufacturing a liquid crystal display device comprising: The second substrate includes a terminal portion for connecting an electronic component,
When the first substrate and the second substrate are bonded together, the second region overlaps the terminal portion in plan view.
The method for manufacturing a liquid crystal display device according to claim 1. In the first step, the first flexible material is applied to a first portion corresponding to the first region in the first glass substrate, and a second portion corresponding to the second region in the first glass substrate is applied. Including a step of not applying the first flexible material,
The method for manufacturing a liquid crystal display device according to claim 1. The first step includes the step of hydrophobizing the entire surface of the first glass substrate, the step of hydrophilizing the second portion corresponding to the second region in the first glass substrate, and the hydrophobization and the hydrophilization. Applying the first flexible material to the entire surface of the first glass substrate.
The method for manufacturing a liquid crystal display device according to claim 1. The first step includes forming a metal material on a portion of the first glass substrate corresponding to the second region, and applying the first flexible material on the entire surface of the first glass substrate on which the metal material has been formed. Applying and removing the metal material and the first flexible material applied on the metal material by wet etching,
The method for manufacturing a liquid crystal display device according to claim 1. A cutting step of cutting the first substrate in the second region after bonding the first substrate and the second substrate;
After the cutting step, a peeling step of peeling the first glass substrate from the first flexible substrate;
The method for manufacturing a liquid crystal display device according to claim 3, further comprising:

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