JPH09127527A - Production of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly pressurize transparent substrates. SOLUTION: This process comprises placing two sheets of the transparent substrates 52 superposed on each other by means of sealing materials via a lower fluid enclosing member 25 on a lower pressurizing plate 21, placing an upper pressurizing plate 22 via an upper fluid enclosing member 2 on the transparent substrate 52 and placing a spring receiving plate 23 via a spring member 29 on this upper pressurizing plate 22. The upper pressurizing plate 22 is pressed downward by the energizing force of the spring member two sheets of the transparent substrates 52 are pressurized via the fluid sealing members 25, 26 from above and below and, therefore, even if the lower pressurizing plate 21 and the upper pressurizing plate 22 are deflected and the pressure acted from the outer side is made nonuniform, the always specified internal pressure of the fluid sealing member members 25, 26 is attained and the uniform pressurization of the transparent substrates 52 is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device.

[0002]

2. Description of the Related Art Generally, a liquid crystal display device is formed by bonding two transparent substrates, each having a transparent electrode formed on each of the opposite surfaces, with a spacer interposed between them.
The structure is such that liquid crystal is sealed between both transparent substrates inside the sealing material.

By the way, in the case of bonding two transparent substrates with a sealing material in the manufacture of such a liquid crystal display device, as shown in FIGS. 9 and 10, for example, first, the guide shafts 1 are provided at the four corners. Lower pressure plate 2 in which
A lower glass plate 3, a lower release sheet 4, two transparent substrates 5 superposed with a spacer interposed with a sealing material, an upper release sheet 6, and an upper glass plate 7 are sequentially mounted on the upper surface of Place. In this case, if necessary, they are repeatedly placed in the same order. Next, the guide shafts 1 are inserted into the guide holes 9 at the four corners of the upper pressure plate 8, the upper pressure plate 8 is placed on the upper surface of the uppermost upper glass plate 7, and then the four corners of the spring receiving plate 10 are placed. The guide shaft 1 is inserted into each of the guide holes 11, the spring receiving plate 10 is placed on a large number of spring members 12 arranged in a lattice on the upper surface of the upper pressure plate 8, and then the fixing plate 1 is placed.
The guide shaft 1 corresponding to the notched recesses 14 at both ends of the spring receiving plate 3 is inserted into the pressure receiving portion 15 provided at the central portion of the upper surface of the spring receiving plate 10 and the pressing screw 1 screwed into the central portion of the fixing plate 13.
An upper limit stopper 1 that abuts the lower ends of the fixed plates 6 and guides the guide shafts 1 on both ends of the fixed plate 13 to the upper limit position of the fixed plate 13.
7 is attached. Then, when the push-in screw 16 is screwed in to press the pressure receiving portion 15, the spring receiving plate 10 is pressed downward according to the screwing amount, and the upper pressure plate 8 is pressed downward via the many spring members 12. As a result, the biasing force of the spring member 12 acts between the spring receiving plate 10 and the upper pressure plate 8 to press the upper pressure plate 8 to the lower pressure plate 2 side with a predetermined pressure. In the following, although not shown, the two transparent substrates 5 are pressed at room temperature for a predetermined time so that the two transparent substrates 5 are blended together, and then the pressing jig is placed in an oven and heated at a predetermined temperature for a predetermined time. As a result, the sealing material is hardened, so that the two transparent substrates 5 can be bonded together via the sealing material with the spacer interposed.

[0004]

However, in the conventional method for manufacturing such a liquid crystal display device, the lower end portions of the four guide shafts 1 are fixed to the four corners of the lower pressure plate 2 respectively, and the predetermined pressure 2 is set. Since the upper ends of the guide shafts 1 of the book are fixed to both ends of the fixed plate 13 by the upper limit stoppers 17, the push-in screws 16 are screwed in to press the spring receiving plate 10 downward, and the spring member 12 moves downward. When the side pressure plate 8 is pressed downward, the fixing plate 13 is pressed upward by the stress of the spring member 12, whereby the guide shaft 1 is pulled upward, and the outer peripheral portion of the lower pressure plate 2 is bent upward. Sometimes. Further, the push-in screws 16 are arranged above the central portion of the spring receiving plate 10, the spring members 12 are arranged on the lower surface of the spring receiving plate 10 in a grid pattern, and the transparent substrate 5 is below the substantially central portion of the upper pressing plate 8. Therefore, when the push-in screw 16 is screwed in to press the spring receiving plate 10 downward, and the upper pressing plate 8 is pressed downward via the spring member 12, the outer peripheral portion of the spring receiving plate 10 moves to the outside of the spring member 12. The stress may bend upward, and the outer peripheral portion of the upper pressure plate 8 may bend downward due to the stress of the spring member 12. In this way, the outer peripheral portion of the lower pressure plate 2 bends upward,
If the outer peripheral portion of the upper pressure plate 8 bends downward, the transparent substrate 5 cannot be uniformly pressed, and the pressing force is concentrated on the outer peripheral portion of the transparent substrate 5. The object of the present invention is to
It is to be able to uniformly press the transparent substrate.

[0005]

According to the first aspect of the present invention,
When manufacturing a liquid crystal display device in which two transparent substrates are bonded together via a sealing material and liquid crystal is sealed between the both transparent substrates inside the sealing material, the two transparent substrates are sealed with each other. One of the two transparent substrates is placed outside the other transparent substrate, and the other transparent substrate is placed outside of the other transparent substrate. By heating while applying pressure from the outside of the transparent substrate via both the fluid sealing members, the both transparent substrates are bonded together via the sealing material. According to a second aspect of the present invention, when manufacturing a liquid crystal display device in which liquid crystal is enclosed in a liquid crystal cell formed by bonding two transparent substrates with a sealing material interposed therebetween, one transparent substrate of the liquid crystal cell is used. One fluid sealing member is arranged on the outer side of the liquid crystal, and another fluid sealing member is arranged on the other side of the other transparent substrate, and the liquid crystal cell is held in a state of being pressurized from the outside through the both fluid sealing members. Meanwhile, the liquid crystal is injected into the liquid crystal cell.

According to the first aspect of the present invention, since the two transparent substrates are pressed from the outside through the fluid sealing member, the internal pressure of the fluid sealing member is always constant even if the pressure applied from the outside is uneven. It becomes uniform, and the transparent substrate can be uniformly pressed. According to the invention described in claim 2, since the liquid crystal cell is held in a state of being pressurized from the outside through both the fluid sealing members, even if the pressure applied from the outside is uneven, the internal pressure of the fluid sealing member is It is always uniform, and the transparent substrate can be uniformly pressed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a sectional view of a pressure jig used in this embodiment, and FIG. 2 shows a plan view of the pressure jig. This pressing jig includes a lower pressing plate 21, an upper pressing plate 22, and a spring receiving plate 23.
And a fixed plate 24 and two fluid sealing members 25 and 26. The lower pressure plate 21 is made of metal or the like in a square shape, and guide shafts 27 are provided upright at four corners. A lower fluid sealing member 25 is attached to the upper surface of the lower pressure plate 21. The upper pressure plate 22 is made of metal or the like in a square shape, and guide holes 28 to be inserted into the guide shaft 27 are formed at four corners. An upper fluid sealing member 26 is attached to the lower surface of the upper pressure plate 22. A large number of spring members 29 are arranged in a grid pattern on the upper surface of the upper pressure plate 22. In this case, the spring member 29 is a coil spring having a spring constant of about 0.98 kg / mm. The spring receiving plate 23 is made of metal or the like in a square shape, and the guide holes 30 to be inserted into the guide shaft 27 are formed at the four corners. At the center of the upper surface of the spring receiving plate 23, there is provided a pressure receiving portion 33 in which a sphere 32 is rotatably fitted on the pedestal 31. The fixing plate 24 is formed of metal or the like into a substantially rectangular shape, and notch recesses 34 to be inserted into the guide shaft 27 are formed at both ends. A push screw 35 is screwed into the central portion of the fixed plate 24. Further, the guide shafts 27 on both ends of the fixed plate 24 are provided with upper limit stoppers 36 that regulate the upper limit position of the fixed plate 24. It should be noted that stopper springs 38 that come into contact with the screws 37 screwed into the upper pressure plate 22 to regulate the gap between the spring pressure plate 22 and the upper pressure plate 22 are screwed into the predetermined two positions of the spring pressure plate 23 so that the upper surface of the spring pressure plate 23 can be secured. Is provided with a handle portion 39.

As shown in FIG. 3, the fluid sealing members 25 and 26 have a structure in which a fluid 42 is sealed inside a flexible bag 41. The bag 41 has a high tensile strength,
It is made of a resin, such as polyethylene, which has a low elongation and does not easily transmit the vapor or air of the fluid 42 to be enclosed. The fluid 42 has a low compressibility and is made of a material that does not easily corrode the bag 41, such as water. FIG. 4 (A)-
(C) shows a manufacturing process of such fluid sealing members 25, 26. Referring to this figure, the structure of the fluid sealing members 25 and 26 will be described together with the manufacturing method. First, as shown in FIG. 4 (A), a resin film is formed into a cylindrical shape and the lower end portion is sealed. The bag 41 is prepared, and the inner portion of the right side of the bag 41 is sealed parallel to the right side, and then the bag 41 is filled with a predetermined amount of fluid 42. Next, as shown in FIG. 4 (B), the inside of the upper side of the bag 41 is sealed in parallel with the upper side so that air does not enter, so that the fluid 42 is enclosed in the bag 41, and then the upper side and When the unnecessary portion outside the seal portion on the right side is cut along the alternate long and short dash line, the fluid sealing members 25 and 26 are obtained as shown in FIG. 4 (C).

In order to bond two transparent substrates with a sealing material using this pressure jig, as shown in FIG. 1, first, the transparent plates were bonded to the upper surface of the lower pressure plate 21. The upper surface of the lower fluid sealing member 25 was overlapped with the lower release sheet 51 and the spacer with the seal material interposed therebetween.
The transparent substrate 52 and the upper release sheet 53 are sequentially placed. In this case, if necessary, they are repeatedly placed in the same order. Next, the guide shaft 27 is inserted into each guide hole 28 of the upper pressure plate 22, the upper pressure plate 22 is placed on the upper surface of the uppermost upper release sheet 53 via the upper fluid sealing member 26, and then the spring. The guide shaft 27 is inserted into each guide hole 30 of the receiving plate 23, the spring receiving plate 23 is placed on a large number of spring members 29 arranged on the upper surface of the upper pressure plate 22, and then the notch recesses of the fixing plate 24. 34, the guide shaft 27 corresponding to 34 is inserted, the lower end of the push screw 35 is brought into contact with the ball 32 of the pressure receiving portion 33, and the upper limit stopper 36 is attached to the guide shaft 27 on both ends of the fixed plate 24. The upper limit position of the fixed plate 24 is regulated. Next, the push-in screw 35 is screwed into the pressure receiving portion 3
When 3 is pressed, the spring receiving plate 23 is pressed downward according to the screwing amount, and the upper pressure plate 22 is pressed downward via the spring member 29. As a result, the urging force of the spring member 29 acts between the spring receiving plate 23 and the upper pressure plate 22 to press the upper pressure plate 22 toward the lower pressure plate 21 side with a predetermined pressure. The pressure in this case is 1.0 to 1.5 kg / c
m ² . In the following, although not shown, after pressurizing the two transparent substrates 52 at room temperature for a predetermined time so that the two transparent substrates 52 fit together, they are put in an oven together with a pressing jig and heated at a predetermined temperature for a predetermined time. As a result, the sealing material is cured, so that the two transparent substrates 52 can be bonded to each other with the spacer interposed therebetween.

As described above, in the method of manufacturing the liquid crystal display device, the two transparent substrates 52 are placed on the fluid sealing member 2 from above and below.
Since the pressure is applied via 5, 26, even if the lower pressure plate 21 and the upper pressure plate 22 are bent and the pressure applied from the outside becomes non-uniform, the internal pressure of the fluid sealing members 25, 26 is always uniform and transparent. The substrate 52 can be pressed uniformly. Therefore, the gap (gap) between the two transparent substrates 52 bonded together via the sealing material becomes uniform, and it is possible to prevent deterioration of display quality. Also, two transparent substrates 5
Since 2 is pressed from above and below via the fluid sealing members 25 and 26, even if the parallelism and flatness of the upper surface of the lower pressure plate 21 and the lower surface of the upper pressure plate 22 are not good, uniform pressure can be applied.

In the first embodiment, the fluid sealing members 25 and 26 are attached to the upper surface of the lower pressure plate 21 and the lower surface of the upper pressure plate 22, but the invention is not limited to this.
It may be placed on the upper surface of 1 and the upper surface of the uppermost upper release sheet 53, or may be attached to the lower surface of the lower release sheet 51 and the upper surface of the upper release sheet 53.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 shows a sectional view of a cell holding jig used in this embodiment, and FIG. 6 shows a plan view of the cell holding jig. This cell holding jig includes a jig body 61, a right side pressure plate 62, a left side pressure plate 63, a fixing plate 64, and two fluid sealing members 65 and 66.
And The jig body 61 is formed in a square shape from metal or the like. The right pressure plate 62 is formed in a square shape from metal or the like, and is provided at the right end portion of the jig body 61.
Guide shafts 67 are provided horizontally at four corners of the right pressure plate 62. A right fluid sealing member 65 is attached to the left surface of the right pressure plate 62. The left pressure plate 63 is formed in a square shape from metal or the like, has four corners penetrated by the guide shaft 67, and is provided so as to be horizontally movable along the guide shaft 67 while facing the right pressure plate 62. A left side fluid sealing member 66 is attached to the right side surface of the left side pressure plate 63. The fixing plate 64 is made of metal or the like and has a rectangular shape. The fixing plate 64 is provided at the left end of the jig body 61 so as to face the pressing plates 62 and 63, and the left ends of the guide shafts 67 are attached to the four corners. A nut member 68 is screwed between the fixed plate 64 on the outer peripheral portion of each guide shaft 67 and the left pressure plate 63, and a left spring receiving member 69 is interposed between the nut member 68 and the left pressure plate 63.
The right side spring receiving member 70 is provided on the left surface of the left pressure plate 63, and the spring member 71 for urging the spring receiving members 69 and 70 is provided between the spring receiving members 69 and 70. in this case,
The spring member 71 is composed of a coil spring having a spring constant of about 0.98 kg / mm. A handle 72 is provided on the upper surfaces of the fixed plate 64 and the right pressure plate 62.

FIG. 7 is a plan view showing the fluid sealing members 65 and 66. In this figure, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The fluid sealing members 65 and 66 cover the outside of the fluid sealing members 25 and 26 described in the first embodiment with a flexible outer bag 73, and the fluid is filled inside the doubled bags 41 and 73. It has a structure in which 42 is enclosed. Similar to the inner bag 41, the outer bag 73 has a high tensile strength, a small elongation, and is made of a resin, such as polyethylene, which does not easily transmit the vapor or air of the fluid 42 to be enclosed. FIGS. 8A to 8C show the manufacturing process of such fluid sealing members 65 and 66. Referring to these figures, the structure of the fluid sealing members 65 and 66 will be described together with the manufacturing method.
As shown in (A), the fluid sealing members 25 and 26 described in the first embodiment are put in the outer bag 73. Next, FIG.
As shown in (B), the fluid sealing member 2 in the outer bag 73.
Seal the outer parts of the upper and right sides of 5, 26,
Then, unnecessary portions outside the seal portion on the upper side and the right side are cut along the alternate long and short dash line to obtain the fluid sealing members 65 and 66 as shown in FIG. 8C.

To inject a liquid crystal into a liquid crystal cell using this cell holding jig, first, as shown in FIG.
Right release sheet 74, 2 between both fluid sealing members 65, 66
A liquid crystal cell 75 and a left release sheet 76, which are formed by sticking together a transparent substrate with a spacer interposed therebetween with a spacer in between, are sequentially held. In this case, if necessary, hold in the same order repeatedly. Further, the liquid crystal cell 75 holds the liquid crystal inlet (not shown) downward. Next, when the left spring receiving member 69 is moved rightward by screwing in the nut member 68, the left spring receiving member 69 presses the left pressure plate 63 toward the right pressure plate 62 side via the spring member 71. As a result, the urging force of the spring member 71 acts between the spring receiving members 69 and 70, and the left pressure plate 63 is moved to the right pressure plate 62.
Side is pressurized with a predetermined pressure, and in this state both pressure plates 62,
The liquid crystal cell 7 is sandwiched between 63 and both fluid sealing members 65 and 66.
Hold 5. The pressure in this case is 0.1-0.2 kg /
It is about cm ² . Although not shown, the cell holding jig together with the cell holding jig is put in a vacuum chamber to evacuate the vacuum chamber, and then the liquid crystal injection port of the liquid crystal cell 75 is inserted into the liquid crystal in the liquid crystal dish arranged in the vacuum chamber. The liquid crystal can be injected into the liquid crystal cell 75 through the liquid crystal injection port by immersing the liquid crystal into the liquid crystal cell 75 and then bringing the vacuum chamber to the atmospheric pressure.

As described above, according to this method of manufacturing a liquid crystal display device, the liquid crystal cell 75 is provided with the both fluid sealing members 6 from the outside.
Since the pressure is maintained via the pressures 5 and 66, even if the right pressure plate 62 or the left pressure plate 63 bends and the pressure applied from the outside becomes uneven, the internal pressures of the fluid sealing members 65 and 66 are always kept. It becomes uniform, and both transparent substrates of the liquid crystal cell 75 can be uniformly pressed. Therefore, even if the space between the transparent substrates of the liquid crystal cell 75 is widened in whole or in part, the space between the transparent substrates can be reduced by uniformly pressing both transparent substrates. Can be made uniform at intervals of, and deterioration of display quality can be prevented. Further, the fluid sealing members 65 and 66 are the bags 41 and 7.
Since 3 is doubled, even if it is used in a vacuum state, the fluid 42 evaporates, and the decrease in the fluid 42 due to the vapor passing through the double bags 41 and 73 and leaking to the outside is small. Moreover, even if the inner bag 41 is damaged, the fluid 42 inside does not easily leak out. Further, the fluid sealing members 65 and 66 are the bags 41 and 7.
Since 3 is doubled, pinholes and tears of the bags 41 and 73 can be confirmed. That is, for example, the fluid sealing member 6
When 5 and 66 are put in a vacuum tank and kept in a vacuum state of about 1 Torr for about 10 minutes, the inner bag 41 and the outer bag 73 expand due to evaporation of the enclosed fluid 42 or expansion of the internal air. However, if there are pinholes or tears, steam or air leaks from these pinholes or tears, making it difficult for them to swell, and pinholes or tears can be confirmed by looking at the degree of swelling of the fluid sealing members 65, 66.

In the second embodiment, the bags 41 and 7 are
Although the number 3 is doubled to prevent the fluid 42 from leaking due to evaporation, the invention is not limited to this, and the bags 41 and 73 may be formed of a material having low air permeability such as an aluminum vapor deposition material or an acrylic resin-based barrier coat material. May be.

[0017]

As described above, according to the first aspect of the present invention, since two transparent substrates are pressed from the outside through the fluid sealing member, the pressure applied from the outside is not uniform. Also, the internal pressure of the fluid sealing member is always uniform, and the transparent substrate can be uniformly pressed. According to the invention described in claim 2, since the liquid crystal cell is held in a state of being pressurized from the outside through both the fluid sealing members, even if the pressure applied from the outside is uneven, the internal pressure of the fluid sealing member is It is always uniform, and the transparent substrate can be uniformly pressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a pressure jig used in a first embodiment of the present invention.

FIG. 2 is a plan view showing the pressure jig.

FIG. 3 is a plan view showing a fluid sealing member of the pressure jig.

4A to 4C are schematic views showing a manufacturing process of the fluid sealing member.

FIG. 5 is a sectional view showing a cell holding jig used in a second embodiment of the present invention.

FIG. 6 is a plan view showing the cell holding jig.

FIG. 7 is a plan view showing a fluid sealing member of the cell holding jig.

8A to 8C are schematic views showing a manufacturing process of the fluid sealing member.

FIG. 9 is a cross-sectional view showing a conventional pressing jig.

FIG. 10 is a plan view showing the pressure jig.

[Explanation of symbols]

 21 Lower Pressure Plate 22 Upper Pressure Plate 25, 26 Fluid Sealing Member 41 Bag 42 Fluid 52 Transparent Substrate

Claims (4)

[Claims] 1. When manufacturing a liquid crystal display device in which two transparent substrates are bonded together via a sealing material and liquid crystal is sealed between the both transparent substrates inside the sealing material, The transparent substrates are overlapped with each other with the sealing material interposed therebetween, and one fluid sealing member, in which a fluid is sealed in a flexible bag, is arranged outside one of the two transparent substrates. , Another fluid encapsulating member, in which a fluid is enclosed in a flexible bag, is disposed on the outside of the other transparent substrate, and heating is performed from the outside of the both transparent substrates via the both fluid encapsulating members while applying pressure. By doing so, the both transparent substrates are bonded together via the sealing material, and the method for manufacturing a liquid crystal display device. 2. When manufacturing a liquid crystal display device in which liquid crystal is sealed in a liquid crystal cell, which is formed by bonding two transparent substrates together with a sealing material interposed therebetween, the liquid crystal cell is provided on the outside of one transparent substrate of the liquid crystal cell. A fluid sealing member having a fluid sealed inside a flexible bag is arranged, and another fluid sealing member having a fluid sealed inside a flexible bag outside the other transparent substrate. And a liquid crystal is injected into the liquid crystal cell while the liquid crystal cell is held under pressure from the outside through the fluid sealing members, and a method for manufacturing a liquid crystal display device. 3. The method for manufacturing a liquid crystal display device according to claim 1, wherein the bag is made of a film member. 4. The method of manufacturing a liquid crystal display device according to claim 3, wherein the film member is formed by laminating or bonding a plurality of resin films.