JP2005215050A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for easily processing a very thin type liquid crystal display device without wasting materials, the liquid crystal display device being characterized in that liquid crystal is charged in a sealed space which is surrounded with a seal material and formed by arranging two substrates opposite each other and a circuit of a driving part for liquid crystal is exposed on an outside substrate in the liquid crystal sealed area. <P>SOLUTION: When a surface of a substrate is made thin by machining, the circuit 5 of the driving part is previously coated with a protecting film material 6, which is removed after the thinning machining. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a liquid crystal display device manufactured through thinning processing such as polishing, grinding, and sandblasting.

  In a liquid crystal display device used as a display terminal such as a personal computer, a television, and other various business displays, a component incorporating a color filter (hereinafter referred to as CF) and an array substrate (hereinafter referred to as TFT) is a cell. Called. FIG. 7 shows an example of a liquid crystal display device in a simplified manner, in which substrates 1 and 2 made of two rectangular glass plates are arranged to face each other with the sealing material 3 therebetween and facing each other. The liquid crystal 4 is sealed in a very thin sealed space formed between the substrates (a gap having a thickness of 3 to 5 μm) and surrounded by the sealing material 3.

  The sealing material 3 is in a state in which a linear body is formed in a frame shape, and liquid crystal is sealed inside a rectangle surrounded by the sealing material 3. Therefore, the inside of the sealing material 3 is a liquid crystal sealing region. A wiring pattern (not shown) for controlling the state of the liquid crystal 4 is arranged in a matrix on the inner surface of the driving substrate 2 in the liquid crystal sealing region, and this wiring pattern is a driving circuit composed of switching elements. Is connected to the circuit 5 of the unit (driver).

  The substrate 2 is generally formed with two L-shaped edges out of the four sides outwardly from the substrate 1 and is formed larger than the substrate 1, and the driving portion is formed on the inner surface portion of the stepped portion. The circuit 5 is exposed and provided. When the image signal generation unit is connected via a terminal provided in the circuit 5 of the drive unit and an image signal is input from the image signal generation unit, the wiring pattern has a state in which liquid crystal is transmitted at the pixel level and light is transmitted. It works to switch to a state that does not allow light to pass.

  In the case of a color liquid crystal display device, the substrate 1 is called CF, and the substrate 2 is called TFT. For such a liquid crystal device, the driving unit 5 is driven by a display signal while light from a backlight (not shown) is applied from the substrate 2 side through a plate-like deflecting plate provided behind the substrate 2. Since the liquid crystal 4 thus made passes through or does not pass the backlight at the pixel level, a color image according to the image signal can be recognized when viewed from the substrate 1 side (see, for example, Patent Document 2).

  The cell tends to be thinner to reduce the weight of the product. Compared to the substrate thickness of about 1.1 mm in the early days, the cell has become increasingly thinner to 0.7 mm and 0.5 mm in recent years. Tend to.

  In order to make the cell extremely thin, it is essential to make the substrates 1 and 2 thin, and there are chemical etching and mechanical processing as thin processing methods. As the machining, mechanical polishing and mechanical grinding are mainly employed. In the chemical etching method, hydrofluoric acid is mainly used to dissolve the surfaces of the substrates 1 and 2 to make them thinner. In mechanical polishing, both sides or one side of a cell are processed using loose abrasive grains to reduce the thickness. In mechanical grinding, each cell surface is thinned with a fixed grindstone. When the thickness is reduced by machining, a product with high thickness accuracy is obtained, and it is also popular in terms of environmental measures and safety.

  In manufacturing the liquid crystal display device, it is necessary to form a substrate wiring pattern in the liquid crystal sealing region on the substrate 2 and to provide the drive circuit 5 outside the liquid crystal sealing region.

  The thinning process of the cell may be performed before the liquid crystal 4 is injected into the liquid crystal sealing region, or may be performed after the liquid crystal 4 is injected. In the chemical etching method, since the substrates 1 and 2 are immersed in the etching solution, the hydrofluoric acid contained in the etching solution corrodes the terminal of the circuit 5 of the driving unit. For this reason, it can be performed only in the state before liquid crystal injection.

  On the other hand, machining can be performed before or after liquid crystal injection, but what is performed after liquid crystal injection is to effectively use mother glass, simplify the cell process, It is advantageous from the viewpoint.

  In the machining method, water or polishing liquid is applied to the workpiece. On the other hand, the circuit 5 of the driving unit is exposed to the outside, and a metal that is easily corroded by water or polishing liquid is used for the terminal. For this reason, the metal part of a drive part will be corroded if it does not protect the drive part 5 with a certain protective material also in machining.

  Therefore, in machining after injecting liquid crystal into the liquid crystal sealing region, it is necessary to take measures to protect the circuit 5 of the driving unit from physical and chemical damage before processing. As countermeasures for protecting the drive circuit 5 from physical and chemical damage, resist coating, tape sticking, and the like are conceivable. However, in resist coating, the apparatus cost is high and the time required for peeling is long. However, the tape sticking has problems from the viewpoints of work cost, yield, and quality, such as an expensive tape material and high apparatus cost.

  As another countermeasure for protecting the drive circuit 5 from physical and chemical damage, as shown in FIG. 10, substrates 10 and 20 formed in advance with a larger area than the original substrates 1 and 2 are used. A method of assembling a basic configuration of a liquid crystal display device, and forming another protective seal 30 on the outside of the main seal 3 so as to surround the circuit 5 of the driving unit in advance, and cutting and removing it after processing. Has been done.

  In other words, the circuit 5 of the driving unit is disposed between the sealing material 3 and the protective seal 30 by surrounding the outside of the circuit 5 of the driving unit for liquid crystal and providing the protective seal 30 a little larger outside the sealing material 3. Seal.

  As a result, the liquid crystal 4 is double protected by the sealing material 3 and the protective seal 30. Then, the liquid crystal display device is processed into a desired thickness by a machine (a polishing machine or the like). In this way, even when exposed to water or polishing liquid, the circuit 5 of the drive unit is protected by the protective seal 30 and therefore is not corroded and impurities do not enter the liquid crystal 4.

  Thus, after machining the substrates 10 and 20 to a predetermined thickness, as shown in FIG. 10, the cut line AA and the cut line that pass through the position where the protective seal 30 can be removed while leaving the circuit 5 of the drive unit. By cutting the end portion of the substrate 10 along BB, a liquid crystal display device as shown in FIG. 7 can be obtained.

  However, this method also has problems. It is necessary to provide a protective seal 30 or a process for cutting the substrate, so that a time loss occurs and a part of the cut substrate is not directly reflected in the product. Is to be wasted.

  In addition, a technique is disclosed in which a pattern that surrounds the periphery of a portion where wiring is to be cut is provided, and laser cutting is performed within a sub-seal surrounded by the pattern (Patent Document 3). However, the wiring part in the sub seal in this method is irrelevant to the driver and cannot be used as a driver terminal exposed to the outside.

JP-A-5-249422 JP-A-5-249423 JP 2003-5205 A JP-A-7-56185

  The subject of this invention is providing the technique which can process an ultra-thin liquid crystal display device easily, without wasting material.

The present invention has the following configuration in order to achieve the above object.
(1). Liquid crystal is sealed in a liquid crystal sealing region formed by surrounding two sealing substrates while being surrounded by a sealing material, and a circuit of a liquid crystal driving unit is exposed on a substrate outside the liquid crystal sealing region. In the manufacturing method of the liquid crystal display device, when the surface of the substrate is thinned by machining, a protective film material is applied and covered in advance on the driving unit, and the protective film material is removed after the thinning process ( Claim 1).
(2) In the method for producing a liquid crystal display device according to (1), the protective film material contains at least 10 to 30 vol% of a styrene-based thermoplastic elastomer and 1 to 10 percent vol% of a hydrogen terpene resin as main components. Used (Claim 2).
(3) In the method for producing a liquid crystal display device according to (1), the protective film material contains at least 10 to 30 vol% of a styrene-based thermoplastic elastomer and 1 to 10 percent vol% of a hydrogen terpene resin as a main component, and the rest Consists of a mixed solvent and a dye (claim 3).
(4) In the method for manufacturing a liquid crystal display device according to any one of (1) to (3), the protective film material is a liquid crystal driving unit provided inside one substrate and outside the liquid crystal sealing region. By covering the circuit and reaching the edge of the other opposing substrate, it is formed in a substantially triangular prism shape.

  In the first aspect of the present invention, since the liquid crystal driving section is previously covered with a protective member, the driving section is protected from erosion and contaminants during processing, and the processing is performed by machining such as polishing, grinding, sandblasting, etc. With high-speed machining, high-speed and high-precision machining is possible.

  In the second aspect of the present invention, the protective material having the predetermined component ratio according to the second aspect can obtain material characteristics that are strong against external force during processing and have good peelability after processing.

  In the invention described in claim 3, the application workability is improved by the mixed solvent, and the application location can be clearly identified and the unpainted portion can be prevented by containing the dye.

  In the invention according to claim 4, by forming the protective member in a substantially triangular shape extending from the drive unit to the edge of the substrate, it is possible to increase the strength of the protective member by expanding the bonding area and resist external force during processing. it can.

In carrying out the present invention, the following procedure is followed.
First Step As shown in FIGS. 1 and 4, a wiring pattern is provided in the liquid crystal sealing region formed by the substrates 1 and 2 and the sealing material 3, and the drive circuit 5 is also installed. A liquid crystal display device in which the liquid crystal 4 is sealed in the liquid crystal sealing region is prepared.

Second Step As shown in FIG. 5, using the dispensing container 7 in which the protective film material 6 is put, the protective film material 6 is applied to the place where the driving part 5 is located by the dispensing method or the spray method, The circuit 5 is covered with a protective film material 6 (Claim 1). FIG. 2 shows a state in which the circuit 5 of the driving unit is covered with the protective film material 6. In the case of application by a spray method, the viscosity is lowered by increasing the ratio of the mixed solvent as compared with the case of the dispense method.

  In the case of the dispensing method, coating is performed so as to cover the circuit 5 of the driving unit along the frame portion of the cell using an ordinary dispensing device. The coating amount is determined by optimizing the coating pressure, the coating speed (nozzle moving speed), and the nozzle diameter, but is finely adjusted by the frame width and the thickness of the substrate 1 (color filter CF). It is important to take care that the protective film agent 6 does not overflow the upper surface of the substrate 1 (color filter CF) and does not sag from the end surface of the substrate 2 (TFT). In the case of the dispensing method, it is possible to cope with various cells having different outer sizes by simply changing the dispensing application program.

  When the substrate 1 (color filter CF) is extremely thin, it is necessary to control the coating thickness to be thinner. In this case, the solvent concentration is optimized and spray coating is performed.

  If applied in this manner, the circuit 5 of the liquid crystal driving unit is covered with the protective member 6 in advance, and thus the circuit 5 of the driving unit is protected from erosion and contamination during thin processing of the substrate.

  In the case of performing mechanical polishing, mechanical grinding, sandblasting as thin processing, when the liquid poured into the workpiece touches the drive unit 5, Cl, Na in the liquid causes Al, Mo, etc. of the circuit 5 of the drive unit Although the metal is corroded, the corrosion is not caused by covering with the protective member 6. In addition, when machining is performed by machining, the strength is increased by the protective member 5, so that high-speed and high-precision machining is possible.

  The protective film material 6 contains at least 10 to 30 vol% of a styrene-based thermoplastic elastomer and 1 to 10 percent vol% of a hydrogen terpene resin as main components (Claim 2). The protective material with such a component ratio is strong against compression external force, shear external force, etc. at the time of processing, and has a material characteristic that it is easily peeled off when peeled after processing. The processing after processing is also easy.

  Furthermore, the protective film agent 6 is not peeled off or absorbed during machining, and the circuit 5 of the drive unit is not corroded by moisture intrusion into the interface between the protective film agent 6 and the terminal of the circuit 5 of the drive unit.

More specifically, a protective film material comprising at least 10 to 30 vol% of a styrene-based thermoplastic elastomer and 1 to 10 percent vol% of a hydrogen terpene resin as a main component and the remainder consisting of a mixed solvent and a dye is applied (invoice) Item 3).
According to such a protective film material, an appropriate coating viscosity can be obtained with a mixed solvent, so that the coating workability is improved.

  Although a volatile solvent, xylene and toluene, was used as the mixed solvent in this example, it passes the current regulations, and drying after application can be completed in a short time. Curing is completed in 3 hours under a normal working environment of 20 ° C. and 50% RH. By appropriately selecting the color of the dye, it is possible to clearly identify the application site and prevent unpainted areas.

As shown in FIG. 2, the liquid crystal driving unit provided inside the one substrate 2 (on the extension of the surface facing the substrate 1) and outside the liquid crystal enclosing region defined by the sealing material 3. A protective film material 6 is formed in a substantially triangular prism shape by covering the circuit 5 and reaching the edge of the other substrate 1 facing the substrate 2 (claim 4). By forming the protection member 6 in a substantially triangular shape from the circuit 5 of the drive unit to the edge of the substrate 1, the adhesion area can be increased to increase the strength of the protection member 5 and resist external forces during processing. Therefore, even a wide glass substrate can be processed thinly.

Third Step After the substrate is thinned, the protective film material 6 is removed (claim 1). Since the protective film agent 6 is made of the material having the above-described component ratio, the protective film agent 6 is rich in releasability and can be easily peeled off using tweezers as shown in FIG. The protective film agent 6 after peeling is environmentally friendly and safe.

  In the above example, the case where the circuit 5 of the driving unit is installed in the portion corresponding to the two L-shaped sides of the substrates 1 and 2 and the protective film 6 is formed in the portion corresponding to the two L-shaped sides will be described. did.

  The present invention is not limited to this. For example, as shown in FIG. 8, the circuit 5 of the driving unit is installed only in a portion corresponding to one side of the substrates 1 and 2, and corresponds to the one side portion. A protective film 6 is formed at the site.

  In addition, as shown in FIG. 9, when the circuit 5 of the drive unit is installed at the site corresponding to the four sides of the substrates 1 and 2, the protective film 6 is formed at the site corresponding to the four sides. However, although not shown, when the circuit 5 of Kudo is installed in a portion corresponding to three of the four sides, the protective film 6 is formed on the three sides.

It is sectional drawing explaining the structure of the liquid crystal image forming apparatus suitable for implementation of this invention. It is sectional drawing of the state which apply | coated the protective film material to the circuit of the drive part. It is sectional drawing of the state which peeled the protective film material from the circuit of the drive part. It is the perspective view explaining the structure of the liquid crystal image forming apparatus suitable for implementation of this invention. It is the perspective view explaining a mode that the protective film material is apply | coated to the circuit of a drive part. It is a perspective view of the state which applied the protective film material to the circuit of the drive part. It is sectional drawing of a liquid crystal display device. It is the perspective view explaining the structure of the liquid crystal image forming apparatus suitable for implementation of this invention. It is the perspective view explaining the structure of the liquid crystal image forming apparatus suitable for implementation of this invention. It is sectional drawing of the liquid crystal display device concerning a prior art.

Explanation of symbols

1, 2 Substrate 3 Sealing material 4 Liquid crystal 5 Drive circuit 6 Protective film material 7 Dispensing container

Claims (4)

Liquid crystal is sealed in a liquid crystal sealing region formed by surrounding two sealing substrates while being surrounded by a sealing material, and a circuit of a liquid crystal driving unit is exposed on a substrate outside the liquid crystal sealing region. In the manufacturing method of the liquid crystal display device,
When the surface of the substrate is thinned by machining, a protective film material is coated and covered in advance on the circuit of the driving unit, and the protective film material is removed after the thinning process. Manufacturing method. In the manufacturing method of the liquid crystal display device of Claim 1,
The method for producing a liquid crystal display device, wherein the protective film material contains at least 10 to 30 vol% of a styrene-based thermoplastic elastomer and 1 to 10 percent vol% of a hydrogen terpene resin as main components. In the manufacturing method of the liquid crystal display device of Claim 1,
The protective film material includes at least 10 to 30 vol% of a styrenic thermoplastic elastomer and 1 to 10 percent vol% of hydrogen terpene resin as main components, and the rest is composed of a mixed solvent and a dye. The manufacturing method. In the manufacturing method of the liquid crystal display device in any one of Claims 1 thru | or 3,
The protective film material is substantially triangular by covering the circuit of the liquid crystal driving unit provided inside the one substrate and outside the liquid crystal sealing region, and reaching the edge of the opposite substrate. A method of manufacturing a liquid crystal display device, characterized by being formed in a columnar shape.

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