JPH10282508A - Production of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a liquid crystal display device with which liquid crystal gap control is facilitated, image quality is improved and a cost is reduced. SOLUTION: A liquid crystal drive substrate 1 formed with circuits and pixel parts 4 consisting of polysilicon thin-film transistors and a counter substrate 2 formed with counter electrodes are superposed to face each other and thereafter, the respective substrates are divided, by which individual liquid crystal panel parts are formed. A plurality of sealants 9 are first applied on the inside surface of the liquid crystal driving substrate 1 or the counter substrate 2 in the state of forming liquid crystal injection ports 9a and outer peripheral sealants 10 are applied in the state of enclosing the outermost peripheral of a region where the liquid crystal sealants 9 line up. Next, these substrates 1, 2 are superposed on each other via the liquid crystal sealants 9 and the outer peripheral sealants 10. The respective outside surfaces of the substrates 1, 2 are optically polished in the state of superposing the substrates on each other and, thereafter, the substrates 1, 2 are broken and divided by a half cut dicing treatment, by which the plural liquid crystal panel parts are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a liquid crystal display device having a plurality of liquid crystal driving circuits and pixel openings formed thereon, and a counter substrate having a plurality of counter electrodes formed thereon.
The present invention relates to a method for manufacturing a liquid crystal display device in which individual substrates are divided to form individual liquid crystal panel components.

[0002]

2. Description of the Related Art As a method of manufacturing a liquid crystal display device, there are conventionally known a so-called single-assembly method in which a substrate is divided and then superposed, and a so-called surface-assembly method in which a substrate is superposed and divided. There is. In the single unit assembling method, first, a liquid crystal driving circuit and a liquid crystal thin film transistor in a pixel opening are formed in a matrix on a glass substrate (hereinafter simply referred to as a TFT), and the individual substrates are formed by dicing or the like. An alignment film is applied, rubbed and washed on the divided liquid crystal driving substrate, and a common agent is applied. In addition, a counter electrode, a color filter, and the like are formed on another glass substrate, and an individual substrate, that is, a single divided counter substrate is coated with an alignment film, rubbed, and washed by dicing or the like. afterwards,
A liquid crystal panel component is formed by applying a sealant to the counter substrate and superposing the two on each other.

On the other hand, in the surface assembling method, first, a plurality of TFTs are formed on a glass substrate before being divided, and an alignment film is applied, rubbed, washed, and a common agent is applied.
Further, the other glass substrate before division is coated with a counter electrode, a color filter and an alignment film, rubbed, washed, and coated with a sealant. Next, the respective glass substrates are overlapped with each other, and then divided to form individual liquid crystal panel components.

[0004]

By the way, in such a manufacturing method, the substrate on which the TFT is formed, that is, the liquid crystal driving substrate, is subjected to various processes by semiconductor technology for forming the TFT, for example, lithography and CV.
Processing by semiconductor technology such as D, etching, and sputtering is performed. Among such processes, in particular, in a film forming process by CVD, sputtering, or the like, a TFT on a substrate is usually used.
A film is formed not only on the formation surface, but also on the glass surface (outer surface) on the opposite side, and furthermore, the above-described processing causes scratches and stains on the outer surface.

In particular, when the liquid crystal driving substrate is a substrate on which a polycrystalline silicon thin film transistor is formed (hereinafter, simply referred to as a poly-Si TFT substrate), an insulating film and a semiconductor film are often continuously formed by plasma CVD. For this reason, a TFT constituting thin film such as polysilicon or PSG (phosphorus silicate glass) is formed on the outer surface.
Thus, when the liquid crystal driving substrate is a poly-Si TFT substrate, particularly when the finally formed liquid crystal display device is of a transmission type, the film formed on the outer surface is unnecessary, and this reduces light transmission. It must be removed in the middle of the process because it will be damaged.

[0006] However, when the film formed on the outer surface is removed in this manner, the poly-S
The concave warpage due to the compressive stress of the TFT constituent thin film formed on the iTFT base becomes large, and adverse effects such as lithography accuracy and non-uniformity of liquid crystal gap in superposition are caused in subsequent steps. When the concave warpage of the poly-Si TFT substrate becomes large, it becomes difficult to control the liquid crystal gap when the poly-Si TFT substrate is superimposed on the counter substrate, resulting in deterioration of image quality such as reduction of light transmittance and reduction of contrast.

Further, if the outer surface is scratched or stained by various processes after removing the film formed on the outer surface, this leads to poor image quality. Therefore, in the past, after quality screening, the obtained defective liquid crystal panel parts were optically polished one by one to remove scratches and dirt on the outer surface. However, this resulted in an increase in man-hours, which contributed to an increase in cost. Has become.

On the other hand, the substrate on which the counter electrode and the color filter are to be formed, that is, the opposite substrate is also subjected to various treatments by the semiconductor process technology as in the case of the liquid crystal driving substrate. Resist stains, scratches, and the like occur on the outer surface. Therefore, the outer surface of this opposing substrate is optically polished while the inner surface is protected in the final step to remove resist stains and flaws. However, the number of steps increases the cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal display device that can easily control a liquid crystal gap to improve image quality and reduce costs. An object of the present invention is to provide a method for manufacturing a display device.

[0010]

According to a method of manufacturing a liquid crystal display device of the present invention, a liquid crystal driving circuit comprising a polycrystalline silicon thin film transistor and a liquid crystal driving substrate having a plurality of pixel openings formed therein, and a counter substrate having a plurality of counter electrodes formed thereon. When the individual liquid crystal panel components are formed by dividing each substrate after superimposing and superimposing, first, the liquid crystal is placed in a state where a liquid crystal injection port is formed on the inner surface of the liquid crystal driving substrate or the opposite substrate. A plurality of sealants are applied, an outer periphery sealant is applied so as to surround an outermost periphery of a region where a plurality of liquid crystal sealants are arranged, and a common agent is applied to a predetermined position of the liquid crystal driving base. A state in which the driving substrate and the opposing substrate are overlapped with each other via the liquid crystal sealing agent and the outer peripheral sealing agent, and then the liquid crystal driving substrate and the opposing substrate are overlapped. The method of solving the above problem is to optically polish the outer surface of each of the substrates, and then divide the liquid crystal driving substrate and the opposite substrate by half-cut dicing and breaking to form a plurality of liquid crystal panel components. did.

According to this manufacturing method, the outer periphery sealing agent is applied so as to surround the outermost periphery of the region where the liquid crystal sealing agents are arranged, and the liquid crystal driving base and the opposing base are overlapped. It is not necessary to protect the inner surface of each substrate at the time of the half-cut dicing process, and it is also possible to prevent water used in these processes from entering the region where the liquid crystal sealant is arranged. Further, prior to optically polishing the outer surfaces of the respective substrates, that is, before the liquid crystal driving substrate has a large concave warp, the liquid crystal driving substrate and the opposing substrate are overlapped with a sealant interposed therebetween. The liquid crystal gap between the base and the opposing base can be easily controlled.

In addition, a laminated film made of polysilicon, PSG, or the like having a lower resistance than quartz glass remains on the outer surface of the liquid crystal driving substrate until the two substrates are overlapped and optically polished. Even in a rubbing process or the like in a cell manufacturing process, it is hard to receive electrostatic damage. Furthermore, after the liquid crystal driving substrate and the opposing substrate are overlapped with each other via the sealant, the outer surfaces of the respective substrates are optically polished, so that the outer surface of the liquid crystal driving substrate and the outer surface of the opposing substrate can be simultaneously processed, Therefore, the number of steps can be reduced. In addition, when the scratch on the outer surface is several μm, optical polishing may be performed. However, when the scratch is as deep as about 10 μm, it is preferable to perform optical polishing after lapping from the viewpoint of reducing the number of steps.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a reflection type liquid crystal display device according to the present invention will be described in detail. 1 (a) to 1 (d),
FIGS. 2A to 2D are views for explaining the first embodiment of the present invention. In these figures, reference numeral 1 denotes a liquid crystal driving base, and 2 denotes a counter base. First, as shown in FIG. 1A, for example, a quartz glass plate 3 having a diameter of, for example, 8 inches and a thickness of about 0.8 mm is prepared, and a plurality of surfaces (inner surfaces) are formed on one surface (inner surface) by a known semiconductor technology. A liquid crystal driving circuit composed of a poly-Si TFT and a pixel opening portion are formed to form a circuit / pixel portion 4.
Is manufactured to obtain the liquid crystal driving base 1. At this time, a thin film constituting the TFT is formed on the surface (outer surface) of the quartz glass plate 3 on the side opposite to the circuit / pixel portion 4.

Subsequently, a probe test called a pellet check is performed on the liquid crystal driving circuit in the circuit / pixel section 4 to check the electrical performance, and pass / fail judgment is made by a function check. The circuit / pixel section 4 of the liquid crystal driving base 1
An alignment film (not shown) made of polyimide or the like is formed on the side surface (inner surface), and a rubbing process is performed thereon. Thereafter, this is washed to prepare for a later superposition step. Here, even with such washing, usually the quartz glass plate 3
The TFT constituent thin film formed on the outer surface of the quartz glass plate 3 is not removed, and the outer surface of the quartz glass plate 3 is scratched by a photoresist coater, a chuck jig, or the like during processing such as TFT formation or rubbing. . The locations where these TFT constituent thin films and flaws are formed are indicated by reference numeral 5 in FIG.

In addition, as shown in FIG. 1B, for example, as shown in FIG.
A transparent crystallized glass plate 6 having a thickness of about 3 mm is prepared, and a counter electrode (not shown) made of a color filter (not shown) or ITO, and a chrome pattern for a black mask are provided on one surface (inner surface) thereof. The opposing element portion 7 is manufactured by forming the above-mentioned components, and thereby the opposing base 2 is obtained. At this time, the transparent crystallized glass plate 6 is stained with colored resist on the surface (outer surface) on the side opposite to the opposing element portion 7.

Subsequently, the quality of the manufactured opposing element portion 7 is determined, and an alignment film (not shown) made of polyimide or the like is formed on the surface (inner surface) on the side of the opposing element portion 7, and a rubbing process is performed thereon. Is applied. Thereafter, this is washed to prepare for a later superposition step. Here, even with such cleaning, the resist stain formed on the outer surface of the transparent crystallized glass plate 6 is not removed, as in the case of the liquid crystal driving base 1, and the color filter formation, the rubbing treatment, etc. During the processing, the outer surface of the transparent crystallized glass plate 6 may be scratched by a photoresist coater or a chuck jig. The spots where these colored resist stains and scratches are formed are indicated by reference numeral 8 in FIG.

After the liquid crystal driving base 1 and the opposing base 2 are prepared in this way, as shown in FIG. 1C, the liquid crystal injection port 9 is provided on the inner surface of the liquid crystal driving base 1 or the opposing base 2.
A plurality of liquid crystal sealants 9 are applied in a state where a is formed, and an outer peripheral sealant 10 is applied so as to surround the outermost periphery of a region where these liquid crystal sealants 9 are arranged. Further, a common agent (not shown) is applied to a predetermined position of the liquid crystal driving base 1. Subsequently, the liquid crystal driving base 1 and the opposing base 2 are
As shown in (d), they are superposed via the liquid crystal sealant 9 and the outer peripheral sealant 10.

Next, the outer surface of the liquid crystal driving substrate 1 and the outer surface of the opposing substrate 2 thus superimposed are simultaneously optically polished using an abrasive mainly composed of cerium oxide, as shown in FIG.
As shown in FIG. 5, a portion 5 where a TFT constituting thin film or a scratch is formed
And the portion 8 where the resist stains and flaws are formed are simultaneously removed. At this time, since the liquid crystal sealant 9 is surrounded by the outer peripheral sealant 10 between the liquid crystal drive base 1 and the opposing base 2, water flowing on the optically polished surface or the like is not filled with the liquid crystal sealant 9.
Does not penetrate into the area where is lined up.

Next, the liquid crystal driving base 1 and the opposing base 2 in the superposed state are divided into a single liquid crystal panel. The division processing includes a scribe break as shown in FIG. 2B and a half-cut dicing as shown in FIG. 2C. In the case of half-cut dicing, as shown in FIG. 2C, an uncut portion 11 having a thickness of about 100 to 200 μm is formed so that cutting water does not enter. And furthermore, it is desirable to remove it because it hinders later liquid crystal injection and sealing. However, such uncut 1
The removal of 1 may be performed only on the liquid crystal injection port side. Next, the liquid crystal 12 is injected into the liquid crystal sealant 9 between the liquid crystal driving substrate 1a and the opposing substrate 2a in the same manner as in the related art, and the liquid crystal 12 is further sealed. A liquid crystal panel component 13 is obtained as shown in FIG.

In such a manufacturing method, the outer peripheral sealant 1 is placed so as to surround the outermost periphery of the region where the liquid crystal sealants 9 are arranged.
0, and the liquid crystal driving base 1 and the opposing base 2 are overlapped, so that it is not necessary to protect the inner surfaces of the bases 1 and 2 at the time of the subsequent optical polishing processing or the single-piece division processing. In addition, it is possible to prevent water used for these treatments from entering a region where the liquid crystal sealant 9 is lined up, thereby facilitating the process and
The yield and quality of the obtained liquid crystal display device can be improved. Before the outer surfaces of the substrates 1 and 2 are optically polished, the liquid crystal driving substrate 1 and the opposing substrate 2 in a state of small concave warp are overlapped with the sealing agents 9 and 10 therebetween. It is possible to easily control the liquid crystal gap between the driving base and the opposing base.

Until the substrates 1 and 2 are superimposed and optically polished, a laminated film composed of a TFT constituting thin film such as polysilicon or PSG having a lower resistance than quartz glass is formed on the outer surface of the liquid crystal driving substrate 1. , It is difficult to receive electrostatic damage even in, for example, a rubbing process in a cell manufacturing process, and therefore, the electrostatic damage can be suppressed. Further, after the liquid crystal driving base 1 and the opposing base 2 are overlapped with each other via the sealants 9 and 10, the outer surfaces of the bases 1 and 2 are optically polished. The outer surface and the outer surface can be processed at the same time, so that the man-hour can be reduced and the cost can be reduced as compared with the conventional case.

In the above embodiment, the outer surface of the liquid crystal driving base 1 and the outer surface of the opposing base 2 are optically polished at the same time. You may. That is, in general, in the case of lapping, the level of unevenness on the surface becomes optically problematic, so that optical polishing is required. Further, only wrapping may be performed according to a required image quality level.

[0023]

As described above, in the method of manufacturing a liquid crystal display device according to the present invention, an outer peripheral sealant is applied to a state surrounding an outermost periphery of a region where liquid crystal sealants are arranged, and a liquid crystal driving substrate and an opposing substrate are overlapped. By doing so, it is not necessary to protect the inner surface of each substrate during the subsequent optical polishing process or the half-cut dicing division process, and water used for these processes is deposited in the area where the liquid crystal sealant is lined up. Since the intrusion is also prevented, the process can be facilitated, and the yield and quality of the obtained liquid crystal display device can be improved. Further, prior to optically polishing the outer surfaces of the respective substrates, that is, before the liquid crystal driving substrate has a large concave warp, the liquid crystal driving substrate and the opposing substrate are overlapped with a sealant interposed therebetween. The liquid crystal gap between the base and the opposing base can be easily controlled, thereby improving the image quality of the obtained liquid crystal display device.

Further, a laminated film made of polysilicon, PSG, or the like having a lower resistance than quartz glass is necessarily left on the outer surface of the liquid crystal driving substrate until the two substrates are overlapped and optically polished. Even in the rubbing process in the cell manufacturing process, it is hard to receive electrostatic damage,
Therefore, yield and quality can be improved by suppressing electrostatic damage, and capital investment and management man-hours for static electricity countermeasures such as an ionizer used in conventional processes can be reduced. Further, after the liquid crystal driving substrate and the opposing substrate are overlapped with a sealant interposed therebetween, the outer surfaces of the respective substrates are optically polished. Thus, man-hours can be reduced and costs can be reduced.

[Brief description of the drawings]

FIGS. 1A to 1D are side sectional views of a main part for describing a manufacturing method of the present invention in the order of steps.

FIGS. 2 (a) to 2 (d) are views for explaining the manufacturing method of the present invention in the order of steps, and are main-portion side sectional views for explaining steps subsequent to the step shown in FIG. 1; .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Liquid crystal drive base | substrate 2 Opposite base | substrate 4 Circuit / pixel part 9 Liquid crystal sealant 10 Peripheral sealant 13 Liquid crystal panel components

Claims (2)

[Claims] 1. A liquid crystal driving circuit comprising a polycrystalline silicon thin film transistor and a liquid crystal driving substrate having a plurality of pixel openings formed thereon are opposed to a counter substrate having a plurality of counter electrodes formed thereon. A method for manufacturing a liquid crystal display device for forming individual liquid crystal panel components by first applying a plurality of liquid crystal sealants to the inner surface of the liquid crystal driving base or the opposing base in a state where a liquid crystal injection port is formed. Applying an outer peripheral sealant to a state surrounding the outermost periphery of a region where a plurality of liquid crystal sealants are arranged, and applying a common agent to a predetermined position of the liquid crystal drive base; Are interposed via the liquid crystal sealant and the outer peripheral sealant. Then, in a state where the liquid crystal drive base and the opposing base are superposed, the outer surface of each base is Wherein the liquid crystal driving base and the opposing base are divided by half-cut dicing and breaking to form a plurality of liquid crystal panel components. 2. The method for manufacturing a liquid crystal display device according to claim 1, wherein the optical polishing of the outer surfaces of the liquid crystal driving substrate and the opposing substrate is performed simultaneously on both substrates.