JP2008216522A - Method of manufacturing electrooptical device and electrooptical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electrooptical device hardly broken against an impact and the like by removing a crack generated at a surface of a substrate to suppress breakage of a substrate and to provide the electrooptical device. <P>SOLUTION: The method of manufacturing the electrooptical device comprises: a first thinning step (S2) for thinning a pair of substrate formed by sticking two substrates 11 and 12 for a plurality of electrooptical devices to each other; a single product forming step (S3) for cutting the pair of substrates which are thinned and forming single products of the plurality of electrooptical devices 21a; and a second thinning step (S5) for thinning the pair of substrates of each electrooptical device 21a to be the single product. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an electro-optical device manufacturing method and an electro-optical device, and more particularly, to an electro-optical device manufacturing method and an electro-optical device that are not easily broken by an impact or the like.

Conventionally, a display device such as a liquid crystal display device is known as an electro-optical device. For example,
The liquid crystal display device is configured by bonding two substrates. Display devices such as liquid crystal display devices are widely used by being mounted on electronic devices such as mobile phones.
In recent years, with the reduction in size or thickness of electronic devices, there has been a demand for thinner display devices.

Usually, for example, when reducing the thickness of a liquid crystal display device, a thin liquid crystal display device is manufactured by mechanically polishing the surface of the glass substrate to thin each glass substrate. But,
When polishing accuracy cannot be obtained, there is a problem that it is difficult to uniformly polish the surface of the glass substrate.
Therefore, a method has been proposed in which a surface corresponding to a partition of each liquid crystal display element is thinned by etching on a pair of glass substrates having an area corresponding to a plurality of liquid crystal display elements (for example,
Patent Document 1). And after etching the surface of the pair of glass substrates, it is divided into a single liquid crystal display device.
Japanese Patent Laid-Open No. 4-116619

However, in the method according to the proposal, after thinning the glass substrate of each liquid crystal display element in a so-called large plate state, the liquid crystal display element is converted into individual liquid crystal display elements from the state of the large glass substrate. There is a process of conversion. For this reason, when the glass substrate is transported by a roller or a robot or supported by pins, there is a risk that the surface of the large glass substrate may be scratched. Furthermore, there is a possibility that the glass substrate surface may be scratched even when it is placed on a mounting table or the like due to the glass powder generated during the cutting process for making a single product.

Scratches on the substrate surface of a thin liquid crystal display device cause cracks in the substrate due to impact or the like. For example, when an electronic device equipped with a liquid crystal display device falls, scratches become the starting point of cracking due to impact when it hits the ground, etc., and the substrate of the liquid crystal display device inside the electronic device breaks There is. In particular, the thinner the liquid crystal display device is, the more the substrate is required to be thinner. Even a small scratch may cause the substrate to crack.

Accordingly, the present invention has been made in view of such problems, and removes scratches generated on the surface of the substrate, suppresses the occurrence of cracks in the substrate, and is an electro-optical device that is difficult to crack against impacts and the like. It is an object to provide a manufacturing method and an electro-optical device.

The method for manufacturing an electro-optical device according to the present invention includes a first thinning step of thinning a pair of substrates on which two substrates for a plurality of electro-optical devices are bonded, and the pair of thinned substrates. A step of cutting and dividing the plurality of electro-optical devices into single products, and a second thinning step of thinning a pair of substrates of each of the electro-optical devices made into single products.
According to such a configuration, it is possible to provide an electro-optical device that is difficult to break against an impact or the like.

In the electro-optical device manufacturing method of the present invention, it is desirable that the thinning in the second thinning step is thinning by chemical etching.
According to such a configuration, not only the scratches after the single product process can be removed, but also the scratches remaining in the first thinning process can be removed. The part can also be smoothed.

Further, in the electro-optical device manufacturing method of the present invention, in the second thinning step, after protecting the terminal portion for connection with an external circuit of each electro-optical device made into a single product with a protective material, It is desirable to perform the chemical etching.
According to such a configuration, chemical etching can be performed without affecting the terminal portion.

In the electro-optical device manufacturing method of the present invention, it is preferable that the thinning in the first thinning step is thinning by mechanical polishing.
According to such a configuration, when the polishing accuracy can be achieved in mechanical polishing, the variation in the overall plate thickness can be reduced.

In the electro-optical device manufacturing method of the present invention, it is preferable that the thinning in the first thinning step is thinning by chemical etching.
According to such a configuration, when the first thinning step is chemical etching, the same processing is performed, so that the lead time can be shortened and the cost can be reduced.

The electro-optical device of the present invention is an electro-optical device manufactured by the manufacturing method of the present invention.

According to such a configuration, it is possible to realize an electro-optical device that is difficult to break against an impact or the like.

Embodiments of the present invention will be described below with reference to the drawings.
First, based on FIG. 1, the structure of the electro-optical device manufacturing method according to the present embodiment will be described.
FIG. 1 is a diagram for explaining a process according to the method of manufacturing the electro-optical device according to the present embodiment. A method for manufacturing a liquid crystal display device will be described below with reference to FIG.

FIG. 2 is a diagram for explaining the bonding of two substrates 11 and 12 constituting a plurality of liquid crystal display devices. The substrate 11 has a plurality of liquid crystal display device formation regions arranged therein, and is one of the two substrates constituting the liquid crystal display device. Therefore, the substrate 11 is a large substrate (also referred to as a so-called mother substrate) that serves as one of the substrates of the plurality of liquid crystal display devices. The substrate 11 is, for example, a glass substrate that is an element substrate such as a so-called TFT substrate of a liquid crystal display device. The substrate 12 is a glass substrate serving as a counter substrate which is the other of the two substrates. The substrate 12 on the counter substrate side is also a large substrate.

Each of these substrates 11 and 12 has a rectangular or circular shape when viewed in plan, that is, when viewed from a direction orthogonal to the surface of the substrate (when viewed in plan).
Hereinafter, the case where each board | substrate 11 and 12 is a rectangle is demonstrated. In FIG. 1, a small rectangle 13 indicates a portion corresponding to each liquid crystal display device.
Large substrates 11 and 12 as shown in FIG. 2 are bonded together (step S1). In this bonding, a frame-shaped sealing material (illustrated) surrounding liquid crystal (display area) provided on the opposing surface of one large plate of the substrate 11 or the substrate 12 corresponding to the formation area of each liquid crystal display device. And a sealing material (not shown) provided on the outer periphery of the large plate to surround the formation area of the plurality of liquid crystal display devices and prevent the etching solution such as hydrofluoric acid from entering between the large plates in the subsequent chemical etching. ), The two large plates 15 and 25 are bonded together. A liquid crystal is sealed between the two substrates, thereby forming an assembly including a pair of substrates for a plurality of liquid crystal display devices.
The aggregate is transported or the like for processing in a later step, and scratches may be formed on the outer surface of the glass substrate of the aggregate during the transport or the like.

FIG. 3 is a schematic cross-sectional view for explaining scratches formed in the aggregate. As shown in FIG. 3, here, scratches 22 are formed on the surface of the aggregate 21 on the substrate 12 side. Scratch 2
2 is made by a roller, a robot or the like at the time of conveyance in the manufacturing process, or a pin for supporting.

Next, a first thinning process is performed (step S2). FIG. 4 is a diagram for explaining the first thinning process. Here, the thinning process is performed by chemical etching.
FIG. 4 is a diagram for explaining the chemical etching process. By immersing the aggregate 21 in a tank 32 in which a hydrofluoric acid-based solution 31 is stored, the two glass substrates 11 and 12 of the aggregate 21 are thinned. The aggregate 21 is immersed in the solution 31 in a state where there are no bubbles or the like in the solution 31 in the tank 32 (in other words, in a state where the solution 31 is stationary).
This is because if the assembly 21 is immersed in the solution 31 in a state where the solution 31 is not stationary in the tank 32, the etching may not be performed uniformly. As shown in FIG. 4, the outer surfaces of the glass substrates 11 and 12 are etched by immersing the aggregate 21 in a stationary hydrofluoric acid-based solution 31. Depending on the length of time the assembly 21 is immersed in the solution 31,
The degree of thinning changes. Therefore, the etching amount of the substrate can be controlled by controlling the time.

Here, as an example, the thickness of each of the substrates 11 and 12 is 0.5 mm, but is etched to 0.3 mm by this thinning.

This etching may remove all scratches on the surface of each substrate, but some scratches may remain. FIG. 5 is a schematic cross-sectional view for explaining scratches remaining after chemical etching.

As shown in FIG. 5, some of the scratches on the substrate surface generated after the bonding are changed to semi-hollow recesses 23. This is because of the angular recess 22 caused by chemical etching.
It is because the surface of is melted.

In order to divide the aggregate 21 chemically etched in the large plate state into individual liquid crystal display devices, a single product process is performed (step S3).
In the single product process, the pair of substrates 11 and 12 of the assembly 21 are placed on a predetermined table,
A scribing break, that is, a cutting process is performed by a scribing device or the like.

The individual liquid crystal display devices 21 a are obtained from the aggregate 21 by the single product process. Each of the scribe-breaked liquid crystal display devices 21a has a substrate 11a larger than the substrate 12a, and the substrate 11a is provided with a portion (extension portion) protruding from the substrate 12a. The surface of the partial substrate 12a side has a terminal portion 14a provided with a plurality of terminals, a drive circuit and the like for connection with other circuit devices and the like. FIG. 6 shows the liquid crystal display device 2
It is typical sectional drawing for demonstrating 1a. FIG. 7 is a schematic perspective view for explaining the liquid crystal display device 21a.

As shown in FIGS. 6 and 7, the liquid crystal display device 21 a includes one substrate, here the element substrate 1.
A terminal portion 14a is provided on the surface on the 1a side. In other words, the terminal portion 14a is exposed at an extension portion of one substrate of the liquid crystal display device 21a from the other substrate.

In the single product process, the aggregate 21 is transported by a roller, a robot, or the like, or when the aggregate 21 is placed on the table by the glass powder generated during the cutting process for single product, or each liquid crystal display device 21a is When moving from the table, scratches 24 are attached to the glass substrate surface of each liquid crystal display device 21a. For example, if glass powder generated at the time of cutting exists between the substrates 11 and 12 and the table, the substrates 11 and 12 at the time of conveyance, gripping, or movement.
And scratches 24 due to friction between the table and the table.

Next, a protective material application process is performed in which a protective material is applied and coated on the terminal portion 14a for connection with an external device (step S4). FIG. 8 is a schematic perspective view for explaining a process of applying a protective material to the terminal portion 14a for connection with an external device.
The protective material 41 is provided on the surface of the terminal portion 14a on which the terminals and the like are formed by, for example, applying a liquid protective material by dropping or the like and covering the formation region of the plurality of terminal portions 14a. The terminal portion 14a is covered. The protective material 41 is made of a resin such as an epoxy resin, and is a material that protects the terminal portion 14a in the next thinning process.

Then, the second thinning process is performed on the liquid crystal display device 21a in a state where the terminal portion 14a is protected by the protective material 41 (step S5). In the second thinning step, a thinning process by chemical etching is performed.

FIG. 9 is a diagram for explaining the chemical etching process in the second thinning step. The liquid crystal display device 21a divided and divided into a tank 32 in which a hydrofluoric acid-based solution 31 is stored.
The two glass substrates 11a and 12a of the liquid crystal display device 21a are subjected to a thinning process. Also in the second thinning step, the aggregate 21 is immersed while the solution 31 in the tank 32 is stationary. Also in FIG. 9, the degree of thinning by etching changes according to the length of time during which the liquid crystal display device 21 a is immersed in the solution 31. Therefore, the etching amount of the substrate can be controlled by controlling the time.

For example, the thickness of each of the substrates 11a and 12a was 0.3 mm, but by this thinning, the substrate is etched by several μm to 10 μm. Therefore, the solution immersion time for chemical etching in the second thinning step is shorter than the solution immersion time for chemical etching in the first thinning step.

Therefore, since the outer surfaces of the two glass substrates 11a and 12a of the liquid crystal display device 21a are etched in the second thinning step while protecting the terminal portion 14a with the protective material 41, the terminal portion 14a is chemically treated. Etching solution in etching (hydrofluoric acid based solution)
The scratches on the substrate surface are removed while preventing damage caused by the intrusion of the substrate.

The hemispherical depression 23 remaining in the first thinning step is left in the second thinning step in a state as it is or in a state where there is a scratch attached in the steps after the single itemization step (S3). (S5) may be performed and removed.

In addition, since the second thinning process is chemical etching, the liquid crystal display device 21 that has been made into a single product is used.
Since the end surface portion, which is a cut surface portion of a, is also etched and becomes smooth, it is more difficult to break against impact or the like.

When the second thinning process is finished, the liquid crystal display device 21a is washed and dried, and then a protective material peeling process for removing the protective material 41 is performed (step S6). FIG. 10 is a schematic perspective view for explaining a protective material peeling process. The protective material 41 can be peeled off by, for example, irradiating with ultraviolet rays (UV), but other methods may be used.

FIG. 11 is a schematic cross-sectional view of the liquid crystal display device from which scratches on the surface of the glass substrate have been removed and the protective material has been peeled off by the second thinning step. FIG. 11 shows a liquid crystal display device 21a having substrates 11a and 12a from which the surfaces of the substrates 11a and 12a are etched and the protective material 41 is peeled off.
Indicates. Compared with the liquid crystal display device 21a in FIG. 6, the scratches are removed in the substrates 11a and 12a in FIG.

In addition, the liquid crystal which is an electro-optical material is sealed from a liquid crystal sealing port of each liquid crystal display device in a state of a plurality of liquid crystal display devices as shown in FIG. And enclosed in each liquid crystal display device. Alternatively, as shown in FIG. 7, after being separated into individual liquid crystal display devices, the liquid crystal is sealed from the liquid crystal sealing port of each liquid crystal display device, and the sealing port is sealed with a sealing material. You may make it enclose in a display apparatus.

Furthermore, in the case of the drop bonding method in which the liquid crystal is provided with a frame-shaped sealing material on the surface on the counter substrate side and the liquid crystal is dropped inside the sealing material to bond the counter substrate side and the element substrate side, FIG. By dropping the liquid crystal in such a large plate state, the liquid crystal is sealed in each liquid crystal display device.

As described above, in the method of manufacturing the electro-optical device according to the present embodiment, the first thinning step is performed on the large-plate assembly 21 in which the two substrates are bonded together. Aggregate 21
The second thinning step is performed in a state in which the terminal portion 14a of the liquid crystal display device 21a that has been separated into pieces is covered and protected by the protective material 41. Therefore, in the assembly cutting step, it is possible to obtain an electro-optical device in which scratches on the glass surface of each substrate are removed and the occurrence of cracks in the substrate is suppressed without affecting the terminal portion by chemical etching. it can. As a result, it is possible to realize an electro-optical device that is difficult to break against an impact or the like.

In particular, since the second thinning step is performed by chemical etching, it is possible to remove a scratch that becomes a base point of cracking of the substrate, and as a result, the substrate is hardly cracked against an impact such as dropping. A display device can be obtained. Depending on the shape of the scratch on the substrate surface,
When a glass substrate is cracked, it tends to be the starting point of cracking, but the shape of the scratch is difficult to become the starting point of cracking by chemical etching.

In the first thinning step, thinning may be performed by mechanical polishing (mechanical polishing). In the case where the thinning of the substrate can be performed accurately and uniformly by mechanical polishing, the variation in the thickness of the entire aggregate 21 can be reduced.
Furthermore, when both the first thinning step and the second thinning step are performed by chemical etching as in the above-described embodiment, since both are the same processing, the lead time is shortened and the cost is reduced. Can be achieved.

Further, the electro-optical device of the present invention is an active matrix type liquid crystal display device (for example, T
The present invention can be similarly applied not only to a liquid crystal display panel provided with FT (thin film transistor) and TFD (thin film diode) as a switching element) but also to a passive matrix liquid crystal display device. In addition to liquid crystal display panels, electroluminescence devices,
Organic electroluminescence devices, plasma display devices, electrophoretic display devices, devices using electroluminescent elements (Field Emission Display and Surface-Conduction El
The present invention can be similarly applied to various electro-optical devices such as an ectron-emission display.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

FIG. 10 is a diagram for explaining a process according to the method for manufacturing the electro-optical device according to the embodiment of the invention. The figure for demonstrating bonding of the two board | substrate of embodiment of this invention. The typical sectional view for explaining the crack formed in the aggregate. The figure for demonstrating the process of the chemical etching of a 1st thinning process. A typical sectional view for explaining a crack which remained after chemical etching. FIG. 3 is a schematic cross-sectional view for explaining a liquid crystal display device. The typical perspective view for demonstrating a liquid crystal display device. The typical perspective view for demonstrating the process which apply | coats a protective material to a terminal part. The figure for demonstrating the process of the chemical etching of a 2nd thin plate process. The typical perspective view for demonstrating the peeling process of a protective material. FIG. 6 is a schematic cross-sectional view of a liquid crystal display device from which a protective material has been peeled off after a second thinning step.

Explanation of symbols

11, 11a, 12, 12a Substrate, 14a Terminal portion, 21 Assembly, 21a Liquid crystal display device, 22, 23, 24 Scratches, 31 Solution, 32 tanks, 41 Protective material

Claims (6)

A first thinning step of thinning a pair of substrates on which two substrates for a plurality of electro-optical devices are bonded;
Cutting the pair of thinned substrates to separate the plurality of electro-optical devices into single products; and
A second thinning step of thinning a pair of substrates of each electro-optic device made into a single product;
A method for manufacturing an electro-optical device. The method of manufacturing an electro-optical device according to claim 1, wherein the thinning in the second thinning step is thinning by chemical etching. 3. The chemical etching is performed in the second thinning step after a terminal portion for connection with an external circuit of each electro-optical device that has been made into a single product is protected by a protective material. A method for manufacturing the electro-optical device according to claim 1. 4. The method of manufacturing an electro-optical device according to claim 1, wherein the thinning in the first thinning step is thinning by mechanical polishing. The method of manufacturing an electro-optical device according to claim 1, wherein the thinning in the first thinning step is thinning by chemical etching. An electro-optical device manufactured by the method according to claim 1.

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