JP2002365641A - Manufacturing method for liquid crystal display substrate and integrally manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously perform the operation for uniformly scattering spacers on the surface of at least one substrate of a liquid crystal display element and the operation for heating the uniformly scattered spacers and the substrate to adhesively fix the substrate and the spacers by the thermal melt- sticking function of an adhesive with which the spacers are like to be coated in the same device and for a short time. SOLUTION: The integrally manufacturing device for the liquid crystal display substrate is characteristically provided with a stage for scattering the spacers 5 as well as a stage for heating the substrate on which the spacers 5 are disposed to hold the temperature thereof uniformly and at a prescribed temperature for the purpose of thermally melt-sticking the adhesive to the outer peripheral part of the spacers and reliably fixing the substrate 1 and the spacers 5 to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a liquid crystal display device in which a liquid crystal layer and a spacer are sandwiched between two opposing substrates and sealed with a sealing material. A method of manufacturing a liquid crystal display substrate, in which spacers are scattered on a substrate having an alignment film and a transparent electrode on one of the inner surfaces for maintaining an interval between two upper and lower substrates, and the spacers are bonded and fixed to the substrates. The present invention relates to a manufacturing integrated device.

[0002]

2. Description of the Related Art In recent years, liquid crystal elements have been required to have larger areas and higher definition as display devices for computers and televisions. The present invention relates to a method and an apparatus for manufacturing a liquid crystal display device in which a liquid crystal layer and a spacer are sandwiched between two conventionally facing substrates and sealed with a sealing material. Examples of the disposing step include a wet spraying method, a dry spraying method, and an intermediate spraying method between wet and dry, which is called an intermediate semi-dry method. In the dry spraying method, spraying is performed with compressed air or an inert gas at a predetermined distance from the nozzle to the substrate together with the spacer and the gas. In addition, the wet spraying method generally disperses the spacers uniformly in an organic solvent such as ethyl alcohol and freon, and sprays a mixed solution of the solvent and the spacers via a gas from a nozzle,
In general, a method is used in which the solvent evaporates from the coexistence state of the spacer and the solvent during the spraying and only the spacer adheres to the substrate. The semi-dry method is an intermediate method between the wet method and the dry method, and details are omitted. In recent years, in order to increase the area of liquid crystal display devices, it is necessary to more reliably fix the spacers scattered on the substrate surface to the substrate, because the spacers may peel off or fall off from the substrate due to transportation in a later process. When the liquid crystal display device moves, it may appear as color unevenness or linear color unevenness in a screen, or a markedly different color point (hereinafter referred to as a point defect), which may be a defect. Such defects greatly affect the area of the liquid crystal display device as well as the size of the liquid crystal display device, and are a serious factor in lowering the yield as a product. Conventionally, after the spacer dispersing step, separately heat the spacer and the substrate simultaneously in the air, heat-bond the adhesive resin applied as if coating the spacer, and perform a heat treatment for bonding and fixing to the substrate. It is common to provide a step for performing. In this step, the substrate on which the spacers are scattered is held at a predetermined temperature for a certain period of time, and the adhesive applied to the outer peripheral portion is melted by heat so as to cover the spacers, thereby securely fixing the substrate and the spacers. The purpose is to perform a heat treatment.

[0003]

As a conventional method, at least one of the upper and lower substrates has an alignment film and an inner surface of a substrate having a transparent electrode. It is necessary to process, carry in every single substrate, carry out spacer spraying, and then carry out, saying that with the movement, the spread spacers are placed on the horizontal substrate mainly by gravity and electrostatic force. It is not just fixed by adhesive. Next, in a separate heating furnace, the substrate on which the spacers have been sprayed is heated to a predetermined temperature, the adhesive resin coated on the spacers is heat-welded, and a temperature of 120 to 180 ° C. is applied for bonding and fixing the substrate and the spacers. A heat treatment is performed so as to maintain a predetermined time within a range, for example, 5 minutes or more. However, when separate independent devices are used to perform the spacer dispersing step and the heat treatment step for heat bonding as described above, a loading or unloading operation occurs for each substrate, and the state after the spacer is dispersed. In this case, the spacers were only in contact with the surface of the substrate, and the spacers were moved and aggregated due to the influence of wind generated during the transfer of the substrate, vibration of the substrate transfer means, and the like. Sometimes the spacers, which should have been evenly scattered, are peeled off or dropped from the substrate, causing non-uniformity of the scattered density in the surface of the substrate, and turning on the liquid crystal display element after assembly after subsequent bonding When this is done, the spacing between the substrates (hereinafter referred to as the cell gap) is varied due to the spacers, causing color unevenness in the pixel plane, and linear irregularities due to the non-uniformity of the spacers. Appears as uneven color or point defects,
This significantly deteriorates the image quality of the liquid crystal display element and causes a reduction in the production yield.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and as an object, a spacer is scattered on one of an opposing substrate having an alignment film and a transparent electrode. Heat treatment for heating and holding the substrate at a predetermined temperature to bond and fix the spacer to the substrate can be processed efficiently, and the spacer is moved or aggregated due to the influence of the wind accompanying the substrate transfer, the vibration and external force during the transfer. Liquid crystal display devices with a large cell area, uniform cell gaps, and excellent image quality without color unevenness, linear defects, and point defects. An apparatus for manufacturing is provided.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a method of disposing a spacer for maintaining a space between two substrates by disposing the substrate on a substrate support disposed outside a spraying chamber. Conveying means for conveying into the spraying chamber, spacer spraying means for spraying a spacer coated on the outer periphery with an adhesive, and supporting means for supporting the substrate by pushing up detachable heat insulating pins above the support. A heating means for moving the substrate to a holding position and raising the temperature to a predetermined temperature while holding the substrate in a non-contact manner, and a cooling means having a temperature control function after retracting the heater. Means for solidifying the adhesive by removing the heat-insulating pins from the cooling plate and contacting the substrate with the cooling plate to cool the substrate heated to a predetermined temperature; and pushing up the heat-insulating pins again. Manufacturing the substrate by using an integrated apparatus for manufacturing a liquid crystal display substrate, wherein the retracted support is advanced, the substrate is supported again, and the substrate is carried out outside the room. All issues are solved.

Further, by connecting an ultrasonic vibrator to the substrate support and moving it at the time of spraying the spacers, it is possible to spray finer spacers.

Further, the temperature control zone management of the heater plate enables the temperature distribution of the substrate to be finer.

[0008]

Embodiments of the present invention will be described below in detail. FIG. 1 shows a schematic cross-sectional view of an apparatus for manufacturing a liquid crystal display substrate of the present invention. The first embodiment will be described below using a specific example. As shown in FIG. 1, the integrated apparatus for manufacturing a liquid crystal display substrate according to the present invention includes a spacer spraying chamber 10 and a heating chamber 20. The spacer 5 is a resin spacer having an adhesive material, and has an average particle diameter of 3.7 to 5.0 mainly composed of a heat-resistant resin applied so as to cover an outer peripheral portion of the sphere with an adhesive material having a heat melting property at 120 ° C. or higher. 7
A μm spherical one was used. As an example of the used spacer, preferably, Soliostar (manufactured by Nippon Shokubai Co., Ltd.) was used. A glass substrate 1 having an alignment film and a transparent electrode while spraying a solution obtained by dispersing a spacer 5 having such characteristics (hereinafter referred to as an adhesive spacer) in isopropyl alcohol from a spray nozzle 4 by the above-mentioned known wet spraying method. Has an effect of being able to be sprayed at a dispersion density of 100 to 300 particles / mm ² . The glass substrate 1 has a width of 55 in the present invention.
0, 670 mm in height, and 0.7 mm in thickness. Heat-resistant support pins 2 (hereinafter referred to as heat-resistant pins) are arranged below the substrate 1, and FIG. Although shown, it is supported at 12 points as shown in the figure. Examples of the material of the heat-resistant pin 2 include a heat-resistant resin such as a polyimide resin and a Teflon (registered trademark) resin, and titanium (6).
4 titanium) or stainless steel (SUS304). Although the number of support points increases or decreases depending on the substrate size as the supporting position, the pitch P between the heat-resistant pins shown in FIG. 2 is preferably 100 to 250 mm, and the glass substrate is allowed to be bent at a high temperature. In order to achieve a certain value or less, the maximum is desirably 250 mm or less, and most desirably, the pitch is 120 mm. As shown in FIG. 1, a cooling plate for contacting and cooling at the time of cooling is arranged below the heat-resistant pin 2, and when the spacer spraying step is completed, the cooling plate is then sprayed as shown in a schematic sectional view of FIG. 160 to adhere the spacer 5 to the glass substrate 1
The glass substrate is placed between the heaters 21 and 22 that have been waiting in the heating chamber 20 for heating to about 180 ° C., and the substrate 1 and the support are placed while the cooling plate 3 is kept stationary in the spray chamber 10. 101 is characterized in that the heating chamber 20 and the spraying chamber 10 are alternately moved to carry out the above two steps.

The glass substrate 1 and the spacer 5 are simultaneously heated by heaters 21 and 22 arranged so as to sandwich the glass substrate 1 from at least two directions, and the adhesive material coated on the spacer is heated to 120 ° C. After melting as described above, the substrate 1 and the substrate support 31 are moved in the arrangement shown in FIG.
When the temperature control is performed and the cooling plate 3 is again placed on the cooling plate 3 maintained at a constant temperature, the heat-resistant pins 2 receive the substrate 1 and the heat-resistant pins 2 go down, and the cooling plate 3 and the substrate 1 come into contact with each other. , And the spacer 5 is completely fixed to the glass substrate 1.

As described above, according to the present invention, it is possible to instantaneously switch the heating step and the cooling step of the substrate from the step of spraying the spacer, and the step of heating the spacer and the glass substrate in a shorter time, It is characterized in that a cooling action can be performed, the spacer can be securely fixed to the substrate, the image quality of the liquid crystal display element is large, the defect is high in quality, and high productivity can be expected.

Further, in the embodiment of the present invention, while having the structure of the present invention, the heat-resistant pins 2 for supporting the substrate and the cooling plate for promoting the cooling action are arranged, and these are kept stationary. This is a liquid crystal display substrate manufacturing integrated device characterized by instantly switching from spacer spraying to glass substrate heating to glass substrate cooling by moving the spacer spraying chamber 10 and the heating chamber 20.

As another embodiment of the present invention, as shown in a schematic sectional view in FIG. 4, in addition to the same configuration as in the above-described embodiment, in the main body of the cooling plate 3 holding the substrate, ultrasonic vibration is applied. An apparatus for manufacturing a liquid crystal display device, characterized in that a vibrator 6 capable of vibrating a support is connected.
As a result of confirming the effect of the present invention at a frequency of 6 to 19.6 kHz as the frequency of the vibrator 6, it is possible to vibrate at present, preferably 11 to 14 kHz, and more preferably 2 to 12 as shown in Table 1. The frequency in the range of 78 to 120 kHz was the frequency with the smallest number of aggregations in which more than one spacer overlapped. Also, it was confirmed that the number of agglomerated spacers was clearly higher in the case without vibration as in case 8 of (Table 1) than in the case with vibration. As described above, by using the third aspect of the present invention, it is possible to reduce the aggregation of the spacers that degrade the image quality of the liquid crystal display element, and to provide a high quality liquid crystal display device with a large area and few defects. is there.

Further, the present invention has the above-described structure,
As shown in FIG. 5, the heat-resistant pins 2 for supporting the substrate are made operable, and in order to promote the cooling action from the above-described substrate heating step, as shown in FIG. However, the heat-resistant pins 2 move up and down, the heating step is completed, and the heat-resistant pins 2 are buried in the cooling plate 3 having the temperature control function, and the cooling plate and the glass substrate 1 come into contact with each other. A liquid crystal display manufacturing apparatus characterized in that cooling can be performed while being controlled at a predetermined temperature. Further, as shown in FIG. 5B, the cooling plate 3 is made of heat-resistant alumina or zirconia ceramics or stainless steel (SUS316L), and in the above-mentioned heating step, the heat-resistant pins 2 project from the plate 3. Fig. 5 (a)
It becomes a form like the following. The gap between the heat-resistant pin 2 and the glass substrate 1 varies depending on the design of the heater that is arranged so as to be sandwiched, but is preferably about 10 to 50 mm because heat radiation does not affect the temperature accuracy, Most preferably, it is about 20 mm from the viewpoint of machining and temperature accuracy. Further, the temperature control mechanism 7 of the cooling plate 3 can greatly reduce the cooling time, particularly in the temperature range from about 50 ° C. or lower to room temperature, and can shorten the processing time in the cooling step, resulting in high productivity. This is a manufacturing apparatus for a liquid crystal display device capable of manufacturing a liquid crystal display element with excellent image quality.

Further, the present invention relates to the heaters 21 and 22 in the heating chamber 20 shown in FIG. 1 while having the above-described structure of the present invention. As a specific example, each heater is locally divided into two parts. Although not limited to this, in the present invention, as an example, it is divided into two as shown in FIG. 6, and each of the divided heaters 21a and 21b has a function 23 capable of controlling the temperature independently. Similarly heater 2
2a and 22b have the same configuration. By adopting such a configuration, the temperature of the glass substrate 1 is locally controlled, so that the width is 550 m and 670 m when the heater is not divided.
Temperature variation 170 ° C ± 4.8 ° C within the glass substrate surface of m
However, the in-plane temperature variation could be reduced to ± 2.2 ° C. by the two-piece heater of the present invention. As described above, it is needless to say that the temperature can be more accurately maintained by further dividing the heater into three parts at the front, rear, and center. According to such an invention, the temperature in the glass substrate surface can be maintained with high accuracy, so that the bonding performance with the substrate due to the molten form of the spacer can be made more uniform. It is possible to provide a manufacturing apparatus capable of manufacturing a liquid crystal display device with less high quality.

[0015]

The following effects can be obtained by the above-described method and apparatus for manufacturing a liquid crystal display substrate of the present invention.

(1) A series of processes from spacer spraying to heating to cooling can be processed by a single device, and a device having a small structure can increase productivity per area.
In addition, an efficient liquid crystal display device having a high production capacity per unit time can be manufactured.

(2) In melting the adhesive spacer and bonding it to the glass substrate, a function capable of precisely controlling the temperature even in the cooling step of the glass substrate due to the small in-plane temperature variation of the substrate. To manufacture a liquid crystal display element having excellent image quality without deteriorating the image quality such as color unevenness, linear defects, and point defects even in a large area and high detail liquid crystal display element. Can be. Table 1 shows an example of the results of the aggregation of the spacers.

[0018]

[Table 1]

(3) The number of agglomerations of the spacers can be reduced by performing the ultrasonic vibration in the spacer dispersing step, and the image quality defect of the liquid crystal display element caused by the spacer can be achieved without deteriorating the image quality of the liquid crystal display element. It is possible to manufacture a high-quality liquid crystal display device with less noise.

(4) Since the spacer dispersing step, the heating step, and the cooling step are switched while moving, the heating and cooling operations of the substrate can be instantaneously switched, and the spacer can be fixed to the substrate in a shorter time. It is characterized in that it is possible to provide a manufacturing apparatus of a liquid crystal display device which can perform a heat treatment of a substrate in a short time in a high quality, can use energy with high efficiency, and can increase productivity.

(5) The quality of spacers can be improved by controlling the temperature of the heater plate and controlling the temperature of the heater plate so that the substrate can be heated more finely.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an integrated apparatus for manufacturing a liquid crystal display substrate of the present invention.

FIG. 2 is a plan view illustrating a cooling plate and heat-resistant pins on a glass substrate.

FIG. 3 is a schematic sectional view of an integrated apparatus for manufacturing a liquid crystal display substrate for explaining one embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view showing one embodiment of an integrated manufacturing apparatus for a liquid crystal display substrate according to the present invention.

5A is a diagram showing a state where a glass substrate is cooled by a cooling plate of the present invention; FIG. 5B is a diagram showing a state where a glass substrate is held by a heat insulating pin of the present invention;

FIG. 6 is a detailed sectional view of individual control of the heater of the present invention.

FIG. 7 is a perspective view showing a substrate support.

FIG. 8 is a sectional view of a support.

FIG. 9 is a perspective view showing a state where a heat insulating pin is installed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Heat-resistant pin 3 Cooling plate 4 Spray nozzle 5 Adhesive spacer 6 Ultrasonic vibrator 7 Temperature control mechanism 10 Spacer dispersion room 20 Heating room 21 Upper heater 21 (a) One-division control heater part of upper heater 21 (b) One-part control heater part of upper heater 22 Lower heater 22 (a) One-part control heater part of lower heater 22 (b) One-part control heater part of lower heater 23 Local control means of heater 101 Support

Claims (4)

[Claims] 1. A method for manufacturing a liquid crystal substrate in which a substrate is bonded to an inside of a substrate having an alignment film and a transparent electrode on at least one of two substrates, and processed inside the substrate having the alignment film and the transparent electrode. A manufacturing method, wherein
A transfer step of transferring the substrate to the substrate support disposed outside the spray chamber for spraying a spacer for maintaining a space between two substrates, and transferring the substrate into the spacer spray chamber; A spacer spraying step for spraying, a supporting step for supporting the substrate by pushing up a detachable heat insulating pin above the support, and moving to a holding position of the substrate,
A heating step with an upper and lower heater for raising the temperature to a predetermined temperature while being held in a non-contact manner, and after retracting the heater, removing the heat insulating pin to a cooling plate which can be cooled by cooling means having a temperature control function, Contacting the substrate with the cooling plate to cool the substrate heated to a predetermined temperature to solidify the adhesive; pushing up the heat-insulating pins again to advance the retracted support to advance the support; A method of manufacturing a liquid crystal display substrate, wherein the substrate is supported again and the substrate is carried out of the room. 2. The method for manufacturing a liquid crystal display substrate according to claim 1, wherein an ultrasonic vibrator is directly connected to the glass substrate according to claim 1 to perform the spacer spraying step. 3. The method for manufacturing a liquid crystal display substrate according to claim 1, wherein each of the upper and lower heaters according to claim 1 is locally divided, and the temperature can be independently controlled. 4. A liquid crystal substrate manufacturing apparatus in which at least one of two substrates has an alignment film and a transparent electrode and is bonded to the inside of the substrate having an alignment film and a transparent electrode, the inside of the substrate having the alignment film and the transparent electrode is processed. A manufacturing apparatus for processing, wherein
Transport means for transferring the substrate to the substrate support disposed outside the spray chamber for spraying a spacer for maintaining a spacing between two substrates, and transporting the substrate into the spacer spray chamber; and Spacer dispersing means for dispersing, and supporting means for supporting the substrate by pushing up a detachable insulating pin above the support, and moving to a holding position of the substrate,
Remove the heat-insulating pins from the heating means with the upper and lower heaters for raising the temperature to a predetermined temperature while holding it in a non-contact manner, and a cooling plate having a temperature control function capable of cooling by the cooling means after retracting the heater. Means for solidifying the adhesive by cooling the substrate heated to a predetermined temperature by bringing the base into contact with the cooling plate, and pushing up the heat-insulating pins again to advance the retreated support. An integrated apparatus for manufacturing a liquid crystal display substrate, wherein the substrate is supported again and the substrate is carried out of the room.