JP2008203619A - Method for manufacturing liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid crystal display panel in which a plastic substrate having good flatness can be obtained after the plastic substrate is arranged of a glass substrate and is subjected to various kinds of processing. <P>SOLUTION: This method includes steps of: bonding the first plastic substrate (3) onto a glass substrate (1); forming a patterned transparent electrode (4) onto the first plastic substrate; forming an alignment layer (6) onto the first plastic substrate; forming a sealing material (7) on the first plastic substrate; superposing a second plastic substrate (l1) via the sealing material onto the first plastic substrate; peeling the glass substrate from the first plastic substrate superposed with the second plastic substrate thereby forming the cell (30) for the liquid crystal display panel; and forming the cell for the liquid crystal display. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid crystal display panel, and more particularly to a method for manufacturing a liquid crystal display panel using a plastic substrate.

  A manufacturing method of a liquid crystal display panel using a plastic substrate as a liquid crystal display panel substrate is known (for example, Patent Document 1). In Patent Document 1, since a plastic substrate alone is insufficient in strength, the plastic substrate may be bent by various processes, resulting in poor accuracy. Therefore, the plastic substrate is attached to the glass substrate via an adhesive layer. After that, various treatments (formation of transparent electrode, formation of alignment film, rubbing treatment, baking process, etc.) are performed on the plastic substrate, and after that, the adhesive strength of the adhesive layer is reduced by irradiating ultraviolet rays etc. The substrate is peeled off.

  The reason for using such an adhesive layer whose adhesive strength is weakened by ultraviolet rays is that the glass substrate and the plastic substrate are strongly bonded due to high temperature in the baking process or the like, and it becomes difficult to peel off. .

JP 7-325297 A (2nd page)

  However, the use of an adhesive layer whose adhesive strength is weakened by ultraviolet rays and the need for a process of irradiating with ultraviolet rays have resulted in increased costs and increased process steps, which is not preferable.

  Furthermore, since the glass substrate and the plastic substrate have different expansion rates, when the baking process is performed with the glass substrate and the plastic substrate adhered, only the plastic substrate expands significantly, causing deflection and undulation. There is a problem that a plastic substrate with good flatness cannot be obtained.

  Therefore, the present invention provides a method for manufacturing a liquid crystal display panel that can easily and easily peel a glass substrate from a plastic substrate after a plastic substrate is placed on the glass substrate and subjected to various treatments. Objective.

  It is another object of the present invention to provide a method of manufacturing a liquid crystal display panel that can obtain a plastic substrate with good flatness after a plastic substrate is placed on a glass substrate and subjected to various treatments.

  In order to achieve the above object, in the first method for manufacturing a liquid crystal display panel according to the present invention, a first plastic substrate is adhered to a glass substrate with an adhesive layer, and is patterned on the first plastic substrate. A transparent electrode is formed, an alignment film is formed on the first plastic substrate, a sealing material is formed on the first plastic substrate, and the second plastic is formed on the first plastic substrate via the sealing material. A step of forming a liquid crystal display panel cell by stacking the substrates, peeling the glass substrate from the first plastic substrate on which the second plastic substrate is stacked, and firing the liquid crystal display cell; To do.

  In order to achieve the above object, in the second method for manufacturing a liquid crystal display panel according to the present invention, a first plastic substrate is adhered to a glass substrate with an adhesive layer, and a pattern is formed on the first plastic substrate. Forming a transparent electrode, forming an alignment film on the first plastic substrate, forming a sealing material on the first plastic substrate, peeling the glass substrate from the first plastic substrate, A liquid crystal display panel cell is formed by overlaying a second plastic substrate on a peeled first plastic substrate with a sealant interposed therebetween, and the liquid crystal display cell is baked.

  Furthermore, in the liquid crystal display panel according to the present invention, it is preferable that all processes from the first plastic substrate to the step of peeling the glass substrate are performed at a low temperature, particularly 60 ° C. or less.

  Furthermore, the liquid crystal display panel according to the present invention preferably further includes a step of injecting a liquid crystal material into a space defined by the first plastic substrate, the second plastic substrate, and the sealing material and sealing.

  In the method for manufacturing a liquid crystal display panel according to the present invention, since various processes are performed on a plastic substrate disposed on a rigid glass substrate, the flatness of the plastic substrate can be ensured and the patterning accuracy of the transparent electrode can be ensured. It became possible to raise.

  Further, in the method for manufacturing a liquid crystal display panel according to the present invention, the plastic is peeled off from the glass substrate before the baking step, and thus it is possible to obtain a plastic substrate with good flatness.

  Furthermore, in the method for manufacturing a liquid crystal display panel according to the present invention, the steps until the plastic is peeled off from the glass substrate are all performed at a low temperature of 60 ° C. or lower. 2 and 12 can peel the glass substrate relatively easily. Therefore, the plastic substrate is hardly damaged, bent and strained when the glass substrate is peeled off.

  A method for manufacturing a liquid crystal display panel according to the present invention will be described below with reference to the drawings.

  1 to 4 are views for explaining a method of manufacturing the first liquid crystal display panel according to the present invention. It should be noted that FIGS. 1 to 4 are all cross-sectional views and show a part of an actual intermediate material for explanation, and the scale is different from the actual one.

  FIG. 1A shows a first plastic substrate 3 having a first transparent electrode layer 4 disposed on a first glass substrate 1 via a first adhesive layer 2. The first glass substrate 1 has a rectangular shape of 400 × 300 mm, and the first first plastic substrate 3 is pulled out from the roll and cut into a size that fits the first glass substrate 1. It is stuck on the glass substrate 1 by the first adhesive layer 2. A fine adhesive material was used as the first adhesive layer 2. In addition, the magnitude | size of the 1st glass substrate 1 is an example, Comprising: It is not limited to this. Further, about 30 liquid crystal display panel cells 30 are formed on one glass substrate at a time.

  The first plastic substrate 3 was formed of polycarbonate resin and had a thickness of 100 μm. However, the first plastic substrate 3 is not limited to this, and may be a modified acrylic resin, polymethacrylic resin, polyethersulfone resin, polyethylene terephthalate resin, norboltene resin, and the thickness is 50 μm to It is preferable that it is 250 micrometers.

  The first transparent electrode layer 4 was made of ITO and formed on the first plastic substrate 3 to a thickness of about 0.03 μm by sputtering.

  FIG.1 (b) has shown the application | coating process of the 1st positive photosensitive resist layer by the roll coater 40 after the process of Fig.1 (a). The application method is not limited to this, and for example, a spinner method may be used. As the positive photosensitive resist, ZPP1700 was used, and the first positive photosensitive resist layer 5 was formed so as to have a thickness of 1.5 μm. After the first positive photosensitive resist layer 5 was applied, the pressure was reduced (0.8 to 1.0 Torr) for 20 seconds, followed by drying at atmospheric pressure.

  FIG. 1C shows a pre-baking process of the first positive photosensitive resist layer 5 after the process of FIG. The pre-baking process is performed to evaporate the residual solvent of the first positive photosensitive resist layer 5 and strengthen the adhesion with the first transparent electrode layer 4, and is heated on a hot plate at a temperature of 60 ° C. for 3 minutes. Was done.

  FIG. 1D shows an exposure processing step using the photomask 41 after the step of FIG. The photomask 41 corresponding to the shape of the desired transparent electrode and the first plastic substrate 3 are arranged so that the alignment marks coincide with each other, and exposure is performed from the photomask 41 side. 1 positive photosensitive resist layer 5 was modified so as to be easily eroded by the developer. In the exposure, ultraviolet rays were irradiated at an intensity of 100 mJ.

  FIG. 2A shows a developing process of the first positive photosensitive resist layer 5 after the process of FIG. Using a 0.7% aqueous solution of potassium hydroxide as a developing solution, treatment was performed at a water temperature of 25 ° C. for 1 minute, and the first positive photosensitive resist layer 5 at a location not exposed in FIG. Removed.

  FIG. 2B shows an etching process of the first transparent electrode layer 4 after the process of FIG. A first transparent electrode at a location where the first positive photosensitive resist layer 5 does not remain, using a 4% aqueous solution of hydrobromic acid as an etching solution, treated at a water temperature of 25 ° C. for 1 minute. Layer 4 was removed.

  FIG. 2C shows a process of removing the remaining first positive photosensitive resist layer 5 after the process of FIG. Using a 2% aqueous solution of potassium hydroxide as a removal solution, treatment was performed at a water temperature of 25 ° C. for 2 minutes.

  FIG. 2D shows a cleaning process after the process of FIG. The solution adhering during the development process, the etching process, and the removal process was washed with pure water from the nozzle 42, and then the pure water was removed with an air knife (not shown) and dried. A desired patterned first transparent electrode layer 4 was formed on the first plastic substrate 3 by the steps of FIGS. 1 (a) to 2 (d).

  FIG. 3A shows an alignment film coating step after the step of FIG. A first alignment film 6 was applied on the first plastic substrate 3 on which the first transparent electrode layer 4 was formed by using an polyimide as a material and an offset printing method.

  FIG. 3B shows a heating process of the first alignment film 6 after the process of FIG. The heating process of the first alignment film 6 was performed to cure the alignment film, and the treatment was performed in an oven at 60 ° C. for 20 minutes.

  FIG. 3C shows a rubbing treatment process of the first alignment film 6 after the process of FIG. In the rubbing process, the rotation speed of the roll 43 was set to 1000 rpm, and the feeding speed of the plastic substrate 3 was set to 25 mm / sec and passed once.

FIG. 3D shows a sealing material forming process and a gap material spraying process after the process of FIG. A thermosetting adhesive that cures at about 120 ° C. is formed by seal printing on the plastic substrate 3 that has been subjected to the rubbing treatment, and the gap material 8 is spread by a spreader (not shown). did. As the gap material 8, plastic beads having a spherical diameter of about 7 μm were used and sprayed at about 150 pieces / mm ² . Note that the sealing material and the gap material are examples, and the present invention is not limited thereto. As the gap material, plastic beads or silica beads having a spherical diameter of 7 to 10 μm can be used, and the application amount is 50 to 50. The number is preferably 200 / mm ² .

  4 (a) shows one side 10 manufactured by the steps from FIG. 1 (a) to FIG. 3 (d) after the step of FIG. 3 (d), and FIG. 1 (a) to FIG. 3 (c). The process of superimposing the other side 20 manufactured by the process up to FIG. The other side 20 manufactured by the steps from FIG. 1A to FIG. 3C includes a second glass substrate 11, a second adhesive layer 12, a second plastic substrate 13, and a second transparent electrode. The layer 14 and the second alignment film 16 are included. In the step shown in FIG. 4A, one side 10 and the other side 20 are overlapped by a dedicated overlayer (not shown) in accordance with the alignment marks of the first and second glass substrates. .

FIG. 4B shows a pre-baking process step with the one side 10 and the other side 20 which are overlapped after the step of FIG. In order to cure the sealing material 7 to some extent, the one side 10 and the other side 20 are sandwiched between airbags (not shown), and a predetermined pressure (0.4 to 1.2 kg / cm ² ) is applied, Heated in an oven (not shown) at 60 ° C. for about 2 hours.

  FIG.4 (c) shows the peeling process of the glass substrate after the process of FIG.4 (b). The first and second glass substrates 1 and 11 were peeled off by a dedicated peeler (not shown) to form a cell 30 of a liquid crystal display panel.

  Since all the steps from FIG. 1A to FIG. 4B are performed at a low temperature of 60 ° C. or lower, the first and second adhesive layers 2 and 12 are cured and firmly fixed. Since it does not adhere to the 1st and 2nd glass substrates 1 and 11, it becomes possible to peel a glass substrate comparatively easily. Therefore, the plastic substrate is hardly damaged, bent and strained when the glass substrate is peeled off.

  Moreover, since all the processes from FIG. 1A to FIG. 4B are performed at a low temperature of 60 ° C. or less, the plastic substrate based on the difference in expansion coefficient between the glass substrate and the plastic substrate is used. The plastic substrate can be processed with high accuracy without causing deflection or distortion.

  Thereafter, the cell 30 of the liquid crystal display panel was step-baked in an oven at 60 ° C. for 4 hours and subsequently in an oven at 120 ° C. for 2 hours, and then gradually cooled for 5 hours to complete the liquid crystal display panel cell 30. .

  Then, it is cut into cell units (since about 30 liquid crystal display panel cells are formed on one glass substrate at a time), the first and second plastic substrates 3 and 13 and the sealing material Liquid crystal is injected into the space defined by 7 from the opening (injection port) of the sealing material 7, the opening is sealed with the sealing material, a polarizing plate and a protective layer are further mounted, electric wiring and IC chip Was installed to make a liquid crystal display panel.

  FIG. 5 is a diagram for explaining a method of manufacturing the second liquid crystal display panel according to the present invention. It should be noted that FIG. 5 is all a cross-sectional view and shows a part of an actual intermediate material for the purpose of explanation, and the scale is different from the actual one.

  Fig.5 (a) shows the peeling process of the glass substrate after the process of FIG.3 (d). The first glass substrate 1 is peeled off by a dedicated peeler (not shown) to form one side 50 of the liquid crystal display panel cell 30. Since the process of performing various treatments on the first glass substrate 1 is the same as the process shown in FIGS. 1A to 3D, description thereof is omitted.

  FIG.5 (b) shows the peeling process of the glass substrate after the process of FIG.3 (c). A second glass substrate 11 different from the first glass substrate 1 shown in FIG. 5A is peeled off by a dedicated peeling device (not shown), and the other side 60 of the liquid crystal display panel cell 30 is removed. Create Since the process of performing various treatments on the second glass substrate 11 is the same as the process shown in FIGS. 1A to 3C, description thereof is omitted. In addition, the other side 60 of the liquid crystal display panel cell 30 includes a second adhesive layer 12, a second plastic substrate 13, a second transparent electrode layer 14, and a second alignment film 16.

  In the steps of FIGS. 5A and 5B, the steps from FIGS. 1A to 3D are all performed at a low temperature of 60 ° C. or lower. Since the adhesive layers 2 and 12 are cured and do not adhere firmly to the first and second glass substrates 1 and 11, the glass substrate can be peeled relatively easily. Therefore, the plastic substrate is hardly damaged, bent and strained when the glass substrate is peeled off. In addition, since all the steps from FIG. 1A to FIG. 3D are performed at a low temperature of 60 ° C. or less, the plastic substrate based on the difference in expansion coefficient between the glass substrate and the plastic substrate is used. The plastic substrate can be processed with high accuracy without causing deflection or distortion.

  FIG. 5C shows a process of superposing one side 50 of the liquid crystal display panel cell 30 by the process of FIG. 5A and the other side 60 by the process of FIG. 5B. In the step of FIG. 5 (c), superposition is performed by a dedicated superposing machine (not shown) in accordance with the alignment marks of the first and second plastic substrates 3 and 13.

FIG. 5 (d) shows a pressure firing process of the liquid crystal display panel cell after the process of FIG. 5 (c). In order to cure with the sealing material 7, both sides of the liquid crystal display panel cell 30 are sandwiched between airbags (not shown), a predetermined pressure (0.4 to 1.2 kg / cm ² ) is applied, and the liquid crystal display panel The cell 30 is subjected to step baking in an oven at 60 ° C. for 4 hours, then in an oven at 120 ° C. for 2 hours, and then gradually cooled for 5 hours to complete the liquid crystal display panel cell 30.

  After that, it is cut into cell units (because about 30 liquid crystal display panel cells are formed on one glass substrate at a time), and liquid crystal is injected from the opening (injection port) of the sealing material 7. Then, the opening was sealed with a sealing material, a polarizing plate and a protective layer were further mounted, and electrical wiring and an IC chip were mounted to obtain a liquid crystal display panel.

  In the first manufacturing method described above, since the sealing material needs to be cured to some extent in order to peel off the glass substrate, the glass substrate is peeled off after the pre-baking treatment step (see FIG. 4B) (see FIG. 4). 4 (c)). Further, in order to completely cure the sealing material 7 thereafter, step baking was performed because there is a possibility that the plastic substrate which is processed at a high temperature from the beginning may be damaged. On the other hand, in the second manufacturing method, since the plastic substrates after the glass substrates are peeled are overlapped, the prebaking process step (see FIG. 4B) in the first manufacturing method is not necessary.

  In the first and second manufacturing methods described above, in most of the steps, various treatments are performed with a plastic substrate placed on a glass substrate, and manufacturing for a liquid crystal display panel using a conventional glass substrate is performed. The line can be used as it is, and there is an advantage that it is not necessary to make a large amount of capital investment when the first and second manufacturing methods described above are performed.

It is the 1st figure for explaining the process concerning the 1st manufacturing method concerning the present invention. It is the 2nd figure for explaining the process concerning the 1st manufacturing method concerning the present invention. It is the 3rd figure for explaining the process concerning the 1st manufacturing method concerning the present invention. It is the 4th figure for explaining the process concerning the 1st manufacturing method concerning the present invention. It is a figure for demonstrating the process which concerns on the 2nd manufacturing method which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st glass substrate 2 1st adhesion layer 3 1st plastic layer 4 1st transparent electrode layer 6 1st orientation layer 7 Seal material 8 Gap material 11 2nd glass substrate 12 2nd adhesion layer 13 Second plastic layer 14 Second transparent electrode layer 16 Second alignment layer 30 Cell for liquid crystal display panel

Claims (4)

A method of manufacturing a liquid crystal display panel,
A first plastic substrate is adhered to the glass substrate with an adhesive layer,
Forming a patterned transparent electrode on the first plastic substrate;
Forming an alignment layer on the first plastic substrate;
Forming a sealing material on the first plastic substrate;
Overlaying the second plastic substrate on the first plastic substrate via the sealing material,
Forming a cell for a liquid crystal display panel by peeling the glass substrate from the first plastic substrate on which the second plastic substrate is overlaid;
Firing the liquid crystal display cell;
A process for producing a liquid crystal display panel, comprising a step. A method of manufacturing a liquid crystal display panel,
A first plastic substrate is adhered to the glass substrate with an adhesive layer,
Forming a patterned transparent electrode on the first plastic substrate;
Forming an alignment layer on the first plastic substrate;
Forming a sealing material on the first plastic substrate;
Peeling the glass substrate from the first plastic substrate;
Forming a cell for a liquid crystal display panel by superimposing a second plastic substrate on the first plastic substrate from which the glass substrate has been peeled through the sealing material;
Firing the liquid crystal display cell;
A process for producing a liquid crystal display panel, comprising a step.   The manufacturing method of the liquid crystal display panel of Claim 1 or 2 which processes by the low temperature all processes from the said 1st plastic substrate to the process of peeling the said glass substrate.   4. The method according to claim 1, further comprising a step of injecting and sealing a liquid crystal material into a space defined by the first plastic substrate, the second plastic substrate, and a sealing material. A method for manufacturing a liquid crystal display panel.

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