JP2008139641A - Liquid crystal display panel and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a leak of a liquid crystal material in a liquid crystal injection port. <P>SOLUTION: A thin liquid crystal display panel 30 is equipped with: a TFT substrate 10 and a CF substrate 20 which are disposed opposite to each other; a liquid crystal layer 15 provided between the TFT substrate 10 and CF substrate 20; a seal material 16 which is provided so as to surround the liquid crystal layer 15 between the TFT substrate 10 and CF substrate 20 and has the liquid crystal injection port 16a for injecting the liquid crystal material constituting the liquid crystal layer 15; and a sealing material 17 provided so as to close the liquid crystal injection port 16a, wherein the CF substrate 20 has a through hole H reaching the liquid crystal injection port 16a, and the through hole H is filled with the sealing material 17. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display panel and a manufacturing method thereof, and more particularly to a thin liquid crystal display panel.

  Since the liquid crystal display panel is thin and lightweight, it has been used in various fields. In this liquid crystal display panel, for example, a TFT substrate in which a thin film transistor (hereinafter referred to as “TFT”) is formed on a glass substrate, and a color filter (hereinafter referred to as “CF”) layer is formed on another glass substrate. After bonding the CF substrate to the frame-shaped sealing material having an injection port for injecting the liquid crystal material, and injecting the liquid crystal material into the space surrounded by the sealing material between the bonded substrates, It is manufactured by sealing the inlet with a UV curable resin or the like. Here, in the liquid crystal display panel, if bubbles or the like are mixed in the space surrounded by the sealing material, the electro-optical characteristics in the liquid crystal layer composed of the liquid crystal material and the like become poor. It is necessary to improve.

For example, in Patent Document 1, a liquid crystal injection hole is formed in a frame-shaped sealing material that joins a first and second glass substrates with a predetermined gap, and both glass substrates corresponding to the liquid crystal injection holes are formed. Each end face part and the end face parts on both sides of the end face part are formed on a slope whose facing interval gradually narrows toward the liquid crystal injection hole, and there is sufficient in the facing part of each inclined end face part formed in this deep shape. A liquid crystal element is disclosed in which an amount of a sealing material (sealing material) is injected and the liquid crystal injection hole is filled without a gap. According to this, since the pair of substrate end surface portions corresponding to the liquid crystal injection holes are formed on the inclined surface, the sealing material can be sufficiently applied to the inclined end surface portion enlarged by inclining the end surface and applied. It is described that the problem that the sealing material protrudes from the substrate can be prevented, and as a result, it is possible to promote the reduction in size and thickness of the product on which the liquid crystal element is mounted and to seal the liquid crystal with high reliability over a long period of time. ing.
JP 2006-234859 A

  In recent years, in the liquid crystal display panel, for example, the TFT substrate and the CF substrate are formed to have thicknesses of about 0.3 mm and about 0.1 mm, respectively, and the thickness reduction is rapidly progressing.

  FIG. 5 is a plan view of a conventional thinned liquid crystal display panel 130. 6 is a schematic plan view in which a region C in FIG. 5 is enlarged. FIG. 7 is a schematic cross-sectional view taken along line VII-VII in FIG.

  As shown in FIG. 5, the liquid crystal display panel 130 includes a TFT substrate 110 and a CF substrate 120 that is disposed to face the TFT substrate 110 and has a light shielding layer 121 around the display region D. Here, as shown in FIG. 6, the TFT substrate 110 and the CF substrate 120 are provided on the light shielding layer 121 and bonded together via a frame-shaped sealing material 116 having a liquid crystal injection port 116 a. In the liquid crystal display panel 130, as shown in FIGS. 6 and 7, the liquid crystal material 115 is sealed between the TFT substrate 110 and the CF substrate 120 by a sealing material 116 and a sealing material 117.

  By the way, in the liquid crystal display panel 130, as described above, since the thinning is advanced, for example, as shown in FIG. 7, the CF substrate 120 having a simpler structure than the TFT substrate 110 is formed thinner. A lot is happening. Therefore, even if a UV curable resin is applied to the end face where the liquid crystal injection hole 116a of the liquid crystal display panel 130 is disposed in order to form the sealing material 117, the surface area of the end face of the CF substrate 120 is the surface area of the end face of the TFT substrate. Therefore, the UV curable resin constituting the sealing material 117 is sufficiently in contact with the end surface on the TFT substrate 110 side, but may not be in contact with the end surface on the CF substrate 120 side. . Then, as shown in the photograph of FIG. 8, since the bubbles 118 are sandwiched between the sealing material 116 and the sealing material 117, the bubbles 118 are mixed in the liquid crystal material 115 or the liquid crystal material 115 to be sealed. There is a concern that the air leaks outside through the bubbles 118.

  The present invention has been made in view of such points, and an object thereof is to suppress leakage of the liquid crystal material at the liquid crystal injection port.

  In order to achieve the above object, according to the present invention, a through hole reaching the liquid crystal injection port is formed in at least one of the first substrate and the second substrate, and the through hole is filled with a sealing material. is there.

  Specifically, a liquid crystal display panel according to the present invention includes a first substrate and a second substrate disposed to face each other, a liquid crystal layer provided between the first substrate and the second substrate, and the first substrate. And a sealing material provided between the second substrate and the second substrate so as to surround the liquid crystal layer and for injecting a liquid crystal material constituting the liquid crystal layer, and so as to block the liquid crystal injection port A thin liquid crystal display panel provided with a provided sealing material, wherein at least one of the first substrate and the second substrate is formed with a through hole reaching the liquid crystal injection port. The sealing material is filled.

  According to said structure, the sealing material which plugs the liquid-crystal injection hole for inject | pouring the liquid-crystal material which comprises a liquid-crystal layer was apply | coated from the side surface of a 1st board | substrate and a 2nd board | substrate, a 1st board | substrate, and a 1st board | substrate. That is, both of the two substrates are filled with through holes formed in at least one of the two substrates. For this reason, the liquid crystal injection port can be reliably closed by the sealing material, and thus leakage of the liquid crystal material at the liquid crystal injection port is suppressed.

  The through hole may be provided so as to reach at least one of both end portions along the width direction of the liquid crystal injection port.

  According to the above configuration, since the sealing material is difficult to spread and bubbles are easily generated at both ends along the width direction of the liquid crystal injection port that hits the boundary between the sealing material and the sealing material, a through-hole is formed in the portion. It is possible to reliably close the liquid crystal injection port by forming the liquid crystal and filling the sealing material through the through hole.

  The through hole may be provided in a thinner one of the first substrate and the second substrate.

  According to said structure, since it becomes easy to form a through-hole in a board | substrate, the effect of this invention is show | played effectively.

  The thinner substrate may be a color filter substrate on which a color filter layer is formed.

  According to the above configuration, the color filter substrate generally has a simpler configuration than the TFT substrate, and is easily reduced in thickness, so that the operational effects of the present invention are effectively achieved.

  Also, the method for manufacturing a liquid crystal display panel according to the present invention includes a liquid crystal injection port for injecting a liquid crystal material provided around the display region, the first substrate and the second substrate each having a display region formed thereon. A bonding process for preparing a bonded body by bonding through a sealing material on which a liquid crystal is formed, and a liquid crystal injection process for injecting a liquid crystal material from the liquid crystal injection port into the bonded body manufactured in the bonding process And a sealing step for sealing the liquid crystal material by applying a sealing material on the side surface of the bonded body into which the liquid crystal material has been injected in the liquid crystal injection step so as to close the liquid crystal injection port. A method for manufacturing a liquid crystal display panel, comprising: a through hole forming step of forming a through hole reaching the liquid crystal injection port in at least one of the first substrate and the second substrate in the bonded body produced in the bonding step. In the sealing step, characterized by filling the sealing material in the through hole formed in the through hole forming step.

  According to the above method, in the sealing step, the sealing material for closing the liquid crystal inlet for injecting the liquid crystal material constituting the liquid crystal layer is applied from the side surfaces of the first substrate and the second substrate, and the first It is filled through a through hole formed in at least one of the first substrate and the second substrate. For this reason, the liquid crystal injection port can be reliably closed by the sealing material, and thus leakage of the liquid crystal material at the liquid crystal injection port is suppressed.

  You may provide the etching process of etching the outer surface of the bonding body produced at the said bonding process, and thinning at least one of the said 1st board | substrate and a 2nd board | substrate.

  According to the above method, since at least one of the glass substrates constituting the first substrate and the second substrate is thinned in the etching step, the effect of the present invention is specifically exhibited.

  According to the present invention, since the through hole reaching the liquid crystal injection port is formed in at least one of the first substrate and the second substrate, and the through hole is filled with the sealing material, the liquid crystal material leaks from the liquid crystal injection port. Can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment.

  FIG. 1 is a plan view of a liquid crystal display panel 30 according to an embodiment of the present invention. 2 is a schematic plan view in which the region A in FIG. 1 is enlarged, and FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG.

  As shown in FIGS. 1 to 3, the liquid crystal display panel 30 includes a TFT substrate 10 that is a first substrate, a CF substrate 20 that is a second substrate disposed to face the TFT substrate 10, a TFT substrate 10, A seal provided in a frame shape so as to join the liquid crystal layer 15 provided between the CF substrate 20 and the TFT substrate 10 and the CF substrate 20 and surround the liquid crystal layer 15 between the TFT substrate 10 and the CF substrate 20. And a material 16.

  The TFT substrate 10 includes a plurality of gate lines (not shown) provided so as to extend in parallel with each other, and a plurality of source lines (not shown) provided so as to extend in parallel with each other in a direction orthogonal to each gate line. A plurality of TFTs (not shown) provided at intersections of the gate lines and the source lines, and a plurality of pixel electrodes (not shown) provided for each pixel which is the minimum unit of the image. Yes.

  The TFT is provided on a glass substrate, a gate electrode which is a portion protruding to the side of the gate line, a gate insulating film provided so as to cover the gate electrode, and a gate electrode on the gate insulating film And a source layer and a drain electrode provided so as to face each other on the semiconductor layer. Here, the source electrode is a portion protruding to the side of the source line. The drain electrode is electrically connected to the pixel electrode.

  As shown in FIGS. 1 to 3, the CF substrate 20 includes a glass substrate 19, a CF layer 21 provided on the glass substrate 19, a light shielding layer 21 c provided in a frame shape around the CF layer 21, A common electrode (not shown) provided on the CF layer 21.

  The CF layer 21 corresponds to each pixel electrode on the TFT substrate 10, for example, a plurality of colored layers 21 a colored in red, green, or blue, and a black matrix 21 b provided between the colored layers 21 a It has.

  In the TFT substrate 10 and the CF substrate 20, as shown in FIG. 1, each pixel electrode and each colored layer 21a constitute pixels which are the minimum unit of an image, and by arranging these pixels in a matrix, A display area D is configured.

  The sealing material 16 is disposed so as to overlap the light shielding layer 21c on the CF substrate 20, and has a liquid crystal injection port 16a for injecting the liquid crystal material (15) constituting the liquid crystal layer 15 as shown in FIG. ing.

  Further, as shown in FIGS. 1 to 3, the CF substrate 20 is provided with through holes H reaching the liquid crystal injection port 16 a at positions corresponding to both end portions along the width direction of the liquid crystal injection port 16 a. The through hole H is filled with a sealing material 17 as shown in FIG. The sealing material 17 is integrated with the TFT substrate 10 and the CF substrate 20 applied to the side surfaces (lower end surfaces in FIG. 1) of the TFT substrate 10 and the CF substrate 20. The through hole H may be formed at one of both end portions along the width direction of the liquid crystal injection port 16a, or may be formed at a corresponding position on the TFT substrate 10 side.

  The liquid crystal layer 15 is made of a nematic liquid crystal material having electro-optical characteristics.

  In the liquid crystal display panel 30 configured as described above, in each pixel, when the gate signal is sent from the gate line to the gate electrode and the TFT is turned on, the source signal is sent from the source line to the source electrode, and the semiconductor A predetermined charge is written into the pixel electrode through the layer and the drain electrode. At this time, a potential difference is generated between each pixel electrode of the TFT substrate 10 and the common electrode of the CF substrate 20, and a predetermined voltage is applied to the liquid crystal layer 15. In the liquid crystal display device 30, an image is displayed by adjusting the light transmittance of the liquid crystal layer 15 by changing the alignment state of the liquid crystal layer 15 according to the magnitude of the voltage applied to the liquid crystal layer 15.

  Next, a method for manufacturing the liquid crystal display panel 30 of the present embodiment will be described. The manufacturing method of this embodiment includes a TFT substrate manufacturing process, a CF substrate manufacturing process, a bonding process, an etching process, a through-hole forming process, a liquid crystal injection process, and a sealing process.

<TFT substrate manufacturing process>
First, a metal film of aluminum or the like is formed on the entire glass substrate having a thickness of about 0.7 mm by a sputtering method with a thickness of about 1500 mm, and then patterned by photolithography to form gate lines and gate electrodes. Form.

  Subsequently, a silicon nitride film or the like is formed to a thickness of about 4000 mm on the entire substrate on which the gate line and the gate electrode are formed by a CVD (Chemical Vapor Deposition) method to form a gate insulating film.

  Further, an intrinsic amorphous silicon film and an n + amorphous silicon film doped with phosphorus are continuously formed on the entire substrate on which the gate insulating film is formed by a CVD method at a thickness of about 1500 mm and 400 mm, respectively. Thereafter, patterning in an island shape on the gate electrode by photolithography is performed to form a semiconductor layer composed of an intrinsic amorphous silicon layer and an n + amorphous silicon layer.

  Then, a metal film such as titanium is formed on the entire substrate on which the semiconductor layer is formed by a sputtering method with a thickness of about 1500 mm, and then patterned by photolithography to form a source line, a source electrode, and a drain electrode. To do.

  Subsequently, by etching the n + amorphous silicon layer of the semiconductor layer using the source electrode and the drain electrode as a mask, the channel portion is patterned to form a TFT.

  Furthermore, an organic insulating film such as a photosensitive acrylic resin is formed with a thickness of about 3 μm on the entire substrate on which the TFT is formed by using a spin coating method, and then a contact hole is formed on the drain electrode by photolithography. A protective insulating film is formed by patterning.

  Then, an ITO (Indium Tin Oxide) film having a thickness of about 1000 mm is formed on the entire substrate on the protective insulating film by a sputtering method, and then patterned by photolithography to form a pixel electrode.

  Finally, a polyimide resin is applied with a thickness of about 500 mm on the entire substrate on which the pixel electrodes are formed by a printing method, and then a rubbing process is performed to form an alignment film.

  As described above, the TFT substrate 10 having the alignment film formed on the surface can be manufactured.

<CF substrate manufacturing process>
First, for example, a chromium thin film having a thickness of about 1000 mm is formed on the entire substrate of a glass substrate (19) having a thickness of about 0.7 mm by sputtering, and then patterned by photolithography to form a grid-like black A matrix 21b and a frame-shaped light shielding layer 21c are formed.

  Subsequently, for example, a photosensitive resist material colored in red, green, or blue is applied to each of the lattices of the black matrix 21b with a thickness of about 1 to 3 μm, and then selected by patterning by photolithography. The colored layer 21a is formed. Further, the same process is repeated for the other two colors to form the CF layer 21 including the colored layers 21a and the black matrix 21b.

  Further, a common electrode is formed on the CF layer 21 by sputtering, for example, by forming an ITO film with a thickness of about 1000 mm.

  Finally, a polyimide resin is applied to the entire substrate on which the common electrode is formed with a thickness of about 500 mm by a printing method, and then a rubbing process is performed to form an alignment film.

  As described above, the CF substrate 20 having the alignment film formed on the surface can be manufactured.

<Lamination process>
First, for example, by applying a thermosetting epoxy resin or the like with a thickness of 1 μm to 3 μm to the position overlapping with the light shielding layer 21c by a screen printing method on the CF substrate 20 manufactured in the CF substrate manufacturing step, The sealing material 16 is formed. Here, as shown in FIG. 4, for example, the width X of the sealing material 16 is 0.5 mm to 1.0 mm, and the width of the liquid crystal injection port 16 a is 3.0 mm. Further, the sealing material 16 has a frame shape having a long side length of about 50 mm and a short side length of about 40 mm, for example. FIG. 4 is a schematic plan view in which a region B in FIG. 2 is enlarged.

  Subsequently, for example, the inside of the sealing material 16 of the CF substrate 20 on which the sealing material 16 is formed has a diameter corresponding to the thickness of the liquid crystal layer 15 and is made of plastic beads or ceramic beads such as silica. Scatter spacers.

  Furthermore, after the CF substrate 20 on which the spacers are dispersed and the TFT substrate 10 manufactured in the TFT substrate manufacturing process are bonded together, the sealing material 16 is cured by heating, and the TFT substrate 10 and the CF substrate 20 are bonded. A bonded body (25) is produced by bonding.

<Etching process>
The outer surface of each glass substrate (19) constituting the TFT substrate 10 and the CF substrate 20 is etched by immersing the bonded body (25) produced in the bonding step in an etching solution, so that the thin wall of each glass substrate is etched. To do. Here, since the thickness of the thinned bonding body (25) is 0.05 mm to 0.5 mm, and preferably 0.3 mm to 0.4 mm, for example, the TFT substrate 10 is 0.3 mm. The CF substrate 20 is thinned to 0.1 mm. In this embodiment, the outer surfaces of both the TFT substrate 10 and the CF substrate 20 are etched to reduce the thickness. However, in the present invention, one outer surface of the TFT substrate 10 and the CF substrate 20 is etched to reduce the thickness. May be performed.

<Through hole formation process>
First, after the photosensitive resin is applied to the surface of the bonded body (25) thinned in the etching step on the CF substrate 20 side, the photosensitive resin is patterned so that a region for forming the through hole H is exposed. Then, a photoresist is formed.

  Subsequently, the CF substrate 20 is subjected to a sand blasting process in which an abrasive having a particle size of 40 μm to 80 μm is sprayed with compressed air on the bonded body 25 on which the photoresist is formed, which is made of alumina or silicon carbide. As shown in FIG. 4, a through hole H having a diameter D of 0.1 mm is formed. Here, in the sandblasting, fine holes are formed with an accuracy of φ30 μm ± 5 μm. Note that the cross-sectional shape of the through-hole H is not limited to the circular shape, but may be a polygonal shape such as a rectangle.

<Liquid crystal injection process>
After the photoresist is peeled off and washed on the bonded body 25 in which the through hole H is formed in the through hole forming step, the liquid crystal material 15 is transferred from the liquid crystal injection port 16a to the TFT substrate 10 and the CF substrate by a decompression method. Inject between 20.

<Sealing process>
First, the excessively attached liquid crystal material 15 is removed with a cleaning liquid such as a surfactant with respect to the bonded body 25 into which the liquid crystal material 15 has been injected in the liquid crystal injection step.

  Subsequently, a UV curable acrylic resin (viscosity at 20 ° C. of 12000 mPa · s to 25000 mPa · s) is applied to the end face of the bonded body 25 with a brush or the like so as to block the liquid crystal injection port 16a, and a dispenser or the like. By filling the through hole H with the acrylic resin.

Finally, the liquid crystal injection port 16 a is irradiated with UV light (for example, 3 J / cm ² ) to cure the sealing material 17 and seal the liquid crystal material 15.

  The liquid crystal display panel 30 can be manufactured as described above.

  As described above, according to the liquid crystal display panel 30 and the manufacturing method thereof according to the present embodiment, the sealing material 17 that closes the liquid crystal injection port 16a for injecting the liquid crystal material constituting the liquid crystal layer 15 in the sealing process. Is applied from the side surfaces of the TFT substrate 10 and the CF substrate 20 and is filled through the through holes H formed in the CF substrate 20. Therefore, since the liquid crystal injection port 16a can be reliably closed by the sealing material 17, leakage of the liquid crystal material 15 at the liquid crystal injection port 16a can be suppressed.

  Further, according to the liquid crystal display panel 30 and the manufacturing method thereof according to the present embodiment, the sealing material 117 is distributed as shown in FIG. Since the through holes H are formed at both ends along the width direction of the liquid crystal injection port 16a, which are difficult to generate bubbles 118, the sealing material 17 is sufficiently filled through the through holes H. The liquid crystal injection port 16a can be reliably closed.

  As described above, the present invention is useful for a thin liquid crystal display panel because the liquid crystal material leakage at the liquid crystal inlet can be suppressed even if each glass substrate constituting the liquid crystal display panel is thinned. It is.

It is a top view of the liquid crystal display panel 30 which concerns on embodiment of this invention. It is the plane schematic diagram which expanded the area | region A in FIG. It is a cross-sectional schematic diagram along the III-III line in FIG. It is the plane schematic diagram which expanded the area | region B in FIG. It is a top view of the conventional liquid crystal display panel. It is the plane schematic diagram which expanded the area | region C in FIG. It is a cross-sectional schematic diagram along the VII-VII line in FIG. It is a microscope observation photograph of the edge part of the liquid-crystal injection hole 116a.

Explanation of symbols

D Display area H Through hole 10 TFT substrate (first substrate)
15 Liquid crystal layer (Liquid crystal material)
16 Sealing material 16a Liquid crystal injection port 17 Sealing material 20 CF substrate (second substrate)
21 Color filter layer 25 Bonded body 30 Liquid crystal display panel

Claims (6)

A first substrate and a second substrate disposed to face each other;
A liquid crystal layer provided between the first substrate and the second substrate;
A sealing material provided so as to surround the liquid crystal layer between the first substrate and the second substrate and having a liquid crystal injection port for injecting a liquid crystal material constituting the liquid crystal layer;
A thin liquid crystal display panel provided with a sealing material provided to close the liquid crystal injection port,
A through hole reaching the liquid crystal injection port is formed in at least one of the first substrate and the second substrate,
The liquid crystal display panel, wherein the through hole is filled with the sealing material. The liquid crystal display panel according to claim 1,
The liquid crystal display panel, wherein the through hole is provided to reach at least one of both end portions along the width direction of the liquid crystal injection port. The liquid crystal display panel according to claim 1,
The liquid crystal display panel, wherein the through hole is provided in a thinner one of the first substrate and the second substrate. The liquid crystal display panel according to claim 3,
The liquid crystal display panel, wherein the thinner substrate is a color filter substrate on which a color filter layer is formed. Each of the first substrate and the second substrate on which the display area is formed is bonded through a sealing material provided around the display area and having a liquid crystal injection port for injecting a liquid crystal material. A bonding step for producing a bonded body;
A liquid crystal injection step of injecting a liquid crystal material from the liquid crystal injection port into the bonded body produced in the bonding step;
A thin liquid crystal display comprising: a sealing step for sealing the liquid crystal material by applying a sealing material to the side surface of the bonded body into which the liquid crystal material is injected in the liquid crystal injection step so as to close the liquid crystal injection port A method of manufacturing a panel,
A through hole forming step of forming a through hole reaching the liquid crystal injection port in at least one of the first substrate and the second substrate in the bonded body produced in the bonding step,
In the sealing step, the sealing material is filled in the through hole formed in the through hole forming step. In the manufacturing method of the liquid crystal display panel described in Claim 5,
A method of manufacturing a liquid crystal display panel, comprising: an etching step of etching an outer surface of the bonded body produced in the bonding step to thin at least one of the first substrate and the second substrate.