JP2010054761A - 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 that can prevent the panel from bloating and causes no damage at the exhausting in a cell of the liquid crystal display panel in a vacuum injection method. <P>SOLUTION: The method for manufacturing the liquid crystal display panel in which a first substrate 1 and a second substrate 2 disposed facing each other are joined through a sealing material 3, and a liquid crystal 5 is injected in a region surrounded by the first substrate 1, the second substrate 2 and the sealing material 3, and has: a step (a) in which a dummy substrate 50 is attached sandwiching the joined first substrate 1 and the second substrate 2; a step (b) in which the liquid crystal 5 is injected into the region surrounded by the first substrate 1, the second substrate 2 and the sealing material 3 by a vacuum injection method after step (a); and a step (c) in which the dummy substrate 50 is removed from the first substrate 1 and the second substrate 2 after step (b). <P>COPYRIGHT: (C)2010,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 in which liquid crystal is injected using a vacuum injection method.

  Conventionally, in a method for manufacturing a liquid crystal display panel, a vacuum injection method is known as one of methods for injecting liquid crystal into a display panel. In this vacuum injection method, first, a liquid crystal display panel is placed in a vacuum chamber of a liquid crystal injection device, the vacuum chamber is decompressed, and air in the liquid crystal panel is exhausted and removed. Next, an inlet provided in advance in the liquid crystal display panel is immersed in the liquid crystal, and the vacuum chamber is returned to atmospheric pressure. In this method, the liquid crystal is injected into the liquid crystal display panel by utilizing the pressure difference between the liquid crystal panel and the vacuum chamber. A technique related to a manufacturing method of a liquid crystal display panel in which liquid crystal is injected using this vacuum injection method is disclosed in Patent Document 1 below.

JP-A-11-326924

  However, when liquid crystal is injected by the conventional vacuum injection method described above using thin panels of about 0.3 mm or less on the TFT substrate and the color filter substrate, the pressure in the chamber and panel cell during decompression in the liquid crystal injection process Due to the difference, the panel expands, resulting in the destruction of the panel, resulting in a problem that the yield is very poor. The reason why this panel expands is considered to be as follows. When the inside of a liquid crystal display panel cell composed of a TFT substrate and a color filter substrate is evacuated, the gap of the liquid crystal display panel cell is at most about 4 to 5 microns. In addition, the degree of vacuum in the chamber and the liquid crystal display panel cell eventually becomes the same degree of vacuum, but the degree of vacuum in the chamber is higher than that in the panel cell during the evacuation process. Expands.

  Therefore, the present invention has been made to solve such a problem, and obtains a method of manufacturing a liquid crystal display panel that prevents expansion of the panel and does not cause breakage when the liquid crystal display panel is evacuated in the vacuum injection method. For the purpose.

  In the method for manufacturing a liquid crystal display panel according to the present invention, a first substrate and a second substrate which are arranged to face each other are bonded together via a sealing material, and the first substrate, the second substrate, and the sealing material are bonded together. A method of manufacturing a liquid crystal display panel in which liquid crystal is injected into a region surrounded by (a) a dummy substrate is pasted so as to sandwich the first substrate and the second substrate pasted together (B) after the step (a), injecting liquid crystal into a region surrounded by the first substrate, the second substrate and the sealing material by a vacuum injection method; Removing the dummy substrate from the first substrate and the second substrate after the step (b).

  According to the method for manufacturing a liquid crystal display panel of the present invention, by attaching a dummy substrate to both sides of the display panel, it is possible to prevent damage due to expansion of the display panel during exhaust in the cells of the liquid crystal display panel. It is possible to provide a method for manufacturing a liquid crystal display panel having excellent properties.

  First, a general method for manufacturing a liquid crystal display panel will be described as a premise of the method for manufacturing a liquid crystal display panel of the present invention. FIG. 7 is a view showing the upper surface (a) and the side surface (b) of the final form of the liquid crystal display panel that has flowed in the panel assembly line. The liquid crystal display panel includes a TFT substrate 1 in which a TFT (thin film transistor) is formed on a glass substrate by a method such as sputtering, and a color filter substrate in which a color material is formed on the glass substrate for color display of the liquid crystal panel. 2 and a sealing material 3 that joins the TFT substrate 1 and the color filter substrate 2 to each other. When the TFT substrate 1 and the color filter substrate 2 are bonded together by the sealing material 3, a gap 4 for injecting liquid crystal is provided between the substrates.

  In the liquid crystal display panel, liquid crystal 5 is injected into a region surrounded by the TFT substrate 1, the color filter substrate 2 and the sealing material 3. The liquid crystal display panel displays an image on the display area 6 by increasing or decreasing the light transmittance by utilizing the characteristic that the direction of liquid crystal molecules changes by applying a voltage. The liquid crystal display panel further includes a sealing material 7 for sealing the injected liquid crystal 5 and a mounting terminal 8 for inputting an electrical signal for displaying the liquid crystal display panel.

  8 to 10 are diagrams showing a general method for manufacturing a liquid crystal display panel. FIG. 8 is a diagram showing a process of attaching the TFT substrate 1 and the color filter substrate 2. First, an alignment film (not shown) for aligning liquid crystal molecules in a certain direction is applied to the display areas 6 of the film formation surfaces 1a to 1f on the TFT substrate 1 in which TFTs are formed on a glass substrate. Similarly, an alignment film (not shown) for aligning liquid crystal molecules in a certain direction is applied to the display area 6 of the color filter substrate 2. Thereafter, a rubbing process is performed by rubbing a cylindrical drum wound with a cloth on the surface of the TFT substrate 1 and the color filter substrate 2 on which the alignment film is applied to form grooves in the alignment film. By performing the rubbing process, after the liquid crystal 5 is injected (see FIG. 10 described later), the liquid crystal molecules can be aligned in a certain direction.

  Next, sealing materials 3a to 3f for joining the TFT substrate 1 and the color filter substrate 2 are applied using a technique such as printing. After applying the sealing materials 3a to 3f, spacers for regulating the gap 4 are sprayed on the TFT substrate 1 (not shown). After the spacers are dispersed, the TFT substrate 1 and the color filter substrate 2 are aligned and temporarily fixed, and an ultraviolet curable resin is applied to the TFT substrate 1 as the temporary fixing material 30. Next, the sealing materials 3a to 3f are heated at about 180 ° C., and then thermally cured to bond the TFT substrate 1 and the color filter substrate 2 together.

  FIG. 9 is a diagram showing a process of separating the bonded TFT substrate 1 and the color filter substrate 2 into a panel form. In order to make the bonded substrate shown in FIG. 8 into a panel form, the substrate is scribed and broken at positions A-A ′ to J-J ′ using a carbide foil to be separated into a panel form.

  FIG. 10 shows a vacuum injection process for injecting the liquid crystal 5 into the liquid crystal display panel. The display panel cut in FIG. 9 is placed in a vacuum liquid crystal injection apparatus chamber 100 (hereinafter referred to as chamber 100), the inside of the chamber 100 of the liquid crystal injection apparatus is depressurized, and the inside of the panel cell is evacuated. Next, the panel inlet 200 is immersed in the liquid crystal 5 contained in the liquid crystal dish 70, and the inside of the chamber 100 is returned to atmospheric pressure. Due to the pressure difference between the liquid crystal panel and the chamber 100, the liquid crystal 5 is injected into the liquid crystal display panel.

  However, as described above, when liquid crystal is injected into the TFT substrate 1 and the color filter substrate 2 using thin panels of about 0.3 mm or less, the chamber 100 at the time of decompression in the vacuum chamber 100 when the liquid crystal 5 is injected. Due to the pressure difference between the inside and the panel cell, the panel may expand and break.

  Therefore, in the embodiment of the present invention, a method for manufacturing a liquid crystal display device that prevents expansion of the panel and does not cause breakage when the inside of the cell of the liquid crystal display panel is exhausted in the vacuum injection method will be described. In each figure, the same code | symbol is abbreviate | omitted description as the same or substantially the same structure.

<Embodiment 1>
FIG. 1 is a diagram showing an upper surface (a) and a side surface (b) of the final form of the liquid crystal display panel in the present embodiment that has flowed in the panel assembly line. The liquid crystal display panel in the present embodiment is a color TFT liquid crystal display panel, which is the same as the general liquid crystal display panel shown in FIG.

  2 to 6 are views showing a method of manufacturing the liquid crystal display panel in the present embodiment. FIG. 2 is a diagram showing a process of attaching the TFT substrate 1 and the color filter substrate 2. Since this process is the same as the process shown in FIG.

  FIG. 3 is a diagram showing a process of reducing the thickness of the TFT substrate 1 and the color filter substrate 2. First, as shown in FIG. 2, after the TFT substrate 1 and the color filter substrate 2 are bonded with the sealing material 3, the outer peripheral side of the substrate is sealed with the sealing material 40. After sealing, the thickness of each substrate is reduced to about 0.2 mm using etching or loose abrasive grains.

  FIG. 4 is a diagram showing a process of separating the bonded TFT substrate 1 and the color filter substrate 2 into a panel form. Since this process is the same as the process shown in FIG.

  FIG. 5 is a diagram showing a process of attaching the dummy substrate 50 so as to sandwich the liquid crystal display panel. As shown in the figure, a glass substrate 50 having a substrate thickness W = 0.3 mm or more is applied as a dummy substrate 50 to the surface of the TFT substrate 1 and the color filter substrate 2 with a tape 60 (in this embodiment, for example, Yoshioka Corporation (Use Kapton tape 60). Desirably, the thickness W of the glass substrate 50 may be 0.5 mm, and sufficient strength can be obtained when the display panel is sandwiched.

  The kapton tape 60 is affixed at the position h from the front end, avoiding the front end of the inlet 200 of the panel. The dimension h is about 5.0 mm, and the liquid crystal 5 can be prevented from creeping up when the liquid crystal is injected by keeping a gap from the injection port. In this embodiment, the Kapton tape 60 is attached to a total of six locations on the surfaces of the TFT substrate 1 and the color filter substrate 2, two on each side and two on the opposite side of the injection port 200. Thereby, it is possible to prevent the positional deviation between the display panel and the dummy substrate 50. The pasting position may be another position as long as no positional deviation occurs between the TFT substrate 1 and the color filter substrate 2 and the dummy substrate 50.

  FIG. 6 is a diagram showing a vacuum injection process for injecting the liquid crystal 5 into the liquid crystal display panel. In FIG. 5, the display panel to which the dummy substrate 50 is attached is placed in the vacuum liquid crystal injection apparatus chamber 100, the pressure in the chamber 100 of the liquid crystal injector is reduced, and the panel cell is evacuated. Next, the panel inlet 200 is immersed in the liquid crystal 5 contained in the liquid crystal dish 70, and the chamber 100 is returned to atmospheric pressure. The liquid crystal 5 is injected into the liquid crystal display panel due to the pressure difference between the liquid crystal panel and the vacuum chamber 100. Next, after injecting the liquid crystal 5, the injection port 200 is sealed with the sealing material 7, and the glass substrate 50 is peeled off from the panel to obtain the liquid crystal display panel shown in FIG.

  As described above, when evacuation is performed in the vacuum chamber 100, the interior of the chamber 100 and the liquid crystal display panel cell finally have the same degree of vacuum. However, in the evacuation process, the vacuum in the chamber 100 is smaller than that in the panel cell. High degree. Therefore, in the past, the panel cell expanded due to this, and the substrate was sometimes damaged. However, the expansion of the panel cell can be suppressed by attaching the glass substrate as the dummy substrate 50 as in the present embodiment. And damage to the liquid crystal display panel can be prevented.

  As described above, according to the method for manufacturing a liquid crystal display panel of the present invention, the dummy substrate 50 is attached to both sides of the display panel, thereby preventing damage due to expansion of the display panel when the liquid crystal display panel cell is exhausted. Can do. Accordingly, it is possible to provide a method for manufacturing a liquid crystal display panel which can be injected without inferior to the conventional injection time in a thick panel state, has excellent mass productivity, and has improved yield.

  In the present embodiment, the glass substrate is used as the dummy substrate 50. However, an acrylic substrate or the like may be used as long as it can reinforce the strength of the substrate.

It is the top view and side view which showed the liquid crystal display panel in embodiment of this invention. It is the figure which showed the manufacturing method of the liquid crystal display panel in embodiment of this invention. It is the figure which showed the manufacturing method of the liquid crystal display panel in embodiment of this invention. It is the figure which showed the manufacturing method of the liquid crystal display panel in embodiment of this invention. It is the figure which showed the manufacturing method of the liquid crystal display panel in embodiment of this invention. It is the figure which showed the manufacturing method of the liquid crystal display panel in embodiment of this invention. It is the top view and side view which showed the conventional liquid crystal display panel. It is the figure which showed the manufacturing method of the conventional liquid crystal display panel. It is the figure which showed the manufacturing method of the conventional liquid crystal display panel. It is the figure which showed the manufacturing method of the conventional liquid crystal display panel.

Explanation of symbols

  1 TFT substrate, 2 color filter substrate, 3 sealing material, 4 gap, 5 liquid crystal, 6 display area, 7 sealing material, 8 mounting terminal, 30 temporary fixing material, 40 sealing material, 50 dummy substrate, 60 tape, 100 Vacuum liquid crystal injector chamber, 200 inlet.

Claims (7)

The first substrate and the second substrate which are arranged to face each other are bonded to each other through a sealing material, and liquid crystal is injected into a region surrounded by the first substrate, the second substrate, and the sealing material. A method of manufacturing a liquid crystal display panel,
(A) a step of attaching a dummy substrate so as to sandwich the first substrate and the second substrate bonded together;
(B) after the step (a), injecting liquid crystal into the region surrounded by the first substrate, the second substrate, and the sealing material by a vacuum injection method;
(C) After the step (b), a step of removing the dummy substrate from the first substrate and the second substrate.   The method of manufacturing a liquid crystal display panel according to claim 1, wherein the step (a) includes a step of attaching the dummy substrate at a predetermined interval from an injection port for injecting liquid crystal.   The method of manufacturing a liquid crystal display panel according to claim 1, wherein the step (a) includes a step of attaching the dummy substrate using a tape.   The method for manufacturing a liquid crystal display panel according to claim 1, wherein the step (a) includes a step of attaching a dummy substrate thicker than the first substrate and the second substrate.   (D) The manufacturing method of the liquid crystal display panel according to any one of claims 1 to 4, further comprising a step of reducing the thicknesses of the first substrate and the second substrate before the step (a). .   6. The method of manufacturing a liquid crystal display panel according to claim 5, wherein the step (d) includes a step of reducing the thicknesses of the first substrate and the second substrate using etching or loose abrasive grains.   The method for manufacturing a liquid crystal display panel according to claim 1, wherein the first substrate is a TFT substrate and the second substrate is a color filter substrate.

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