JPH05289038A - Manufacture of element substrate and liquid crystal display device - Google Patents

Abstract

PURPOSE:To prevent cutting dust of a substrate and a supporting tape from adhering to the surface of a base body, and to improve the manufacture yield of the element substrate by covering the surface of the base body with the supporting tape, in a cutting process for the base body. CONSTITUTION:According to this method, plural element substrates 14 are manufactured by cutting a base body 10 in which plural elements are formed on the surface, and also, a cutting mark is put in a prescribed position, this method contains a process for sticking a supporting tape 12 for supporting the base body 10 to the surface of the base body 10, and a process for cutting the base body 10, and also, cutting a part of the supporting tape 12, and separating it to each element substrate 14. Moreover, this method contains a process for separating each element substrate by giving a shock to the base body 10 from the supporting tape side. Accordingly, since the surface of the base body 10 is protected by the supporting tape 12 until it is cut to each element substrate 14, it can be prevented surely that dust adheres to the surface of the base body 10. Also, since a cutting mark is put in a prescribed position of the base body 10, the base body 10 can be cut exactly to a prescribed shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an element substrate,
The present invention also relates to a method for manufacturing a liquid crystal display device to which the method for manufacturing the element substrate is applied.

[0002]

2. Description of the Related Art Usually, a substrate on which individual semiconductor elements, liquid crystal driving elements or counter electrodes are formed (hereinafter, simply referred to as
The element substrate is also a semiconductor element, a liquid crystal driving element, a counter electrode, or the like (hereinafter, also simply referred to as an element or the like).
After forming a plurality of on the surface of one substrate, cut the substrate,
Manufactured by separating. The substrate is made of, for example, quartz glass or general glass. In this specification, a substrate on which a plurality of elements and the like are formed is referred to as a base.

As shown in FIG. 4, a conventional substrate cutting method is performed in the following procedure. That is, on the back surface of the base body 10,
A support tape 12 that supports the substrate is attached (see FIG. 4A). A thermosetting adhesive or an ultraviolet curable adhesive is applied to the support tape 12. Then
The substrate 10 is cut in the thickness direction, and the support tape 12 is further cut in the thickness direction (see FIG. 4B). Normal,
The cutting is performed using a dicing device. Then, the support tape 12 is stretched and separated into individual element substrates 14 (see FIG. 4C).

Alternatively, a method of sticking an adhesive tape using an adhesive agent of an adhesive agent of an ultraviolet curable type on the surface of a substrate, dicing it, and then irradiating ultraviolet rays to cure the adhesive agent is disclosed in Japanese Patent Publication No. No. 23324 is known.

A method of manufacturing a liquid crystal display device includes a multi-cavity method and a single-cavity method. In the multi-chamfering method, a first substrate in which a plurality of liquid crystal driving elements are formed on a substrate made of glass or the like and a second substrate in which a plurality of counter electrodes are formed on a substrate made of glass or the like are prepared. Then, these substrates are stacked, a plurality of liquid crystal display devices are manufactured at a time, and then a cutting process is performed to separate the substrates into individual liquid crystal display devices. Further, in the single-piece fabrication method, the first substrate in which a plurality of liquid crystal driving elements are formed on a substrate made of glass or the like is cut to manufacture individual liquid crystal driving element substrates. Similarly, the second base body, in which a plurality of counter electrodes are formed on a substrate made of glass or the like, is cut to manufacture individual counter electrode element substrates. Then, these non-defective element substrates are overlapped with each other to manufacture a liquid crystal display device.

The manufacturing yield when a plurality of liquid crystal driving elements are formed on a substrate made of glass or the like and the manufacturing yield when a plurality of counter electrodes are formed on a substrate made of glass or the like are low. Therefore, the multi-chambering method in which a plurality of liquid crystal display devices are manufactured at one time by stacking these substrates on each other has a problem that the manufacturing yield of the liquid crystal display device is further reduced. Further, due to the variation in the flatness of the first base and the second base, it is difficult to obtain a uniform gap over the whole when the two bases are superposed, and if the gap is forcibly adjusted by hot pressing. There is a problem that the spacer inserted between the two substrates causes damage to the liquid crystal driving element or the counter electrode. Therefore, in order to manufacture a liquid crystal display device having a small area with high yield and high quality, the single-piece manufacturing method is desirable.

[0007]

In the normal substrate cutting method shown in FIG. 4, the surface 10A of the substrate is cut when the substrate is cut.
Is not protected. Therefore, the cutting waste such as silicon or glass or the cutting waste of the support tape (hereinafter collectively referred to as dust) generated during the cutting of the base adheres to the surface of the base. Dust adhering to the surface of the substrate cannot be completely removed in the step of washing the substrate with water. As a result, disconnection / short-circuit failure or bonding failure of the wiring formed on the element or the like occurs. Further, when dust adheres to the surface of the CCD element or the linear sensor, pixel defects such as black scratches occur in that portion.

Further, as a measure against electrostatic breakdown of the element or the like when the substrate is cut, CO ₂ is mixed into pure water so that the specific resistance of pure water is several M.
However, if CO ₂ is mixed in, pure water will be acidified, and the life of the cutting blade of the dicing device will be shortened, and a CO ₂ generator will be required.

In the case of manufacturing a liquid crystal display device by the single-piece manufacturing method described above, in manufacturing a liquid crystal driving element substrate or a counter electrode substrate, the liquid crystal driving element substrate or the counter electrode is attached to the surface of the element substrate. During the rubbing process of the alignment film, the dust may scratch the thin film transistor (TFT) part of the liquid crystal driving element, the pixel display part, or the counter electrode, and further, the wiring may be scratched or broken. However, there is a problem in that the manufacturing yield and the quality are deteriorated.

Further, when manufacturing a liquid crystal display device by the multi-chamfering method, it is necessary to stack two substrates to manufacture a plurality of liquid crystal display devices at a time and then perform a cutting process. There are problems that the manufacturing yield and the quality of the liquid crystal display device are deteriorated due to chipping of the substrate, cracking of the substrate, deterioration of airtightness, and the like.

In the dicing method disclosed in Japanese Examined Patent Publication No. 23324/1990, since the adhesive tape is attached to the surface of the substrate, the above problem caused by the cutting residue of the substrate can be solved when the substrate is cut. is there. However, as is clear from FIG. 4 of Japanese Patent Publication No. 23324/1990,
After cutting, the adhesive tape is peeled off from the substrate, the substrate is split, and the substrate is separated into individual semiconductor element substrates. At this time, a crushed slag of the substrate is generated, and there is a problem that the surface of the semiconductor element substrate is contaminated by the crushed slag.

Therefore, an object of the present invention is to reliably prevent dust from adhering to the surface of the substrate until it is cut and separated into individual element substrates, and it is possible to accurately cut the substrate into a predetermined shape. Another object of the present invention is to provide a method for manufacturing an element substrate and a method for manufacturing a liquid crystal display device.

[0013]

The above-mentioned object includes a plurality of elements formed on the surface, and the plurality of elements are formed by cutting a substrate having cutting marks at predetermined positions, including the following steps. This can be achieved by the method for manufacturing an element substrate according to the first aspect of the present invention for manufacturing the element substrate.
That is, (a) a step of attaching a support tape supporting the base to the surface of the base (b) cutting the base, and further cutting a part of the support tape,
Process of separating into individual element substrates

The element means a semiconductor element, a liquid crystal driving element, a counter electrode, or the like. The substrate can be made of a transparent material such as quartz glass or general glass. The base means a substrate on which a plurality of elements and the like are formed. The element substrate means a substrate obtained by cutting and separating a substrate on which such an element is formed.

Further, the above-mentioned object is to manufacture a plurality of element substrates by cutting a substrate having a plurality of elements formed on its surface and having cutting marks at predetermined positions, including the following steps. Can be achieved by the method for manufacturing an element substrate according to the second aspect of the present invention. That is, (a) a step of attaching a support tape supporting the base to the surface of the base (b) a step of cutting a part of the base from the back surface of the base (c) an impact is applied to the base from the side of the support tape to Process of separating into element substrate

The adhesive used for the supporting tape is a thermosetting type,
Various adhesives such as pressure-sensitive adhesives and ultraviolet curable adhesives can be used, but ultraviolet curable adhesives are most preferable. In a preferred aspect of the method for manufacturing an element substrate according to the first and second aspects of the present invention, the supporting tape comprises a film and an ultraviolet curable adhesive, and the supporting tape is irradiated with ultraviolet rays after the separating step to form a supporting tape. Cure the adhesive.

Further, the above object can be achieved by a method for manufacturing a liquid crystal display device according to the third aspect of the present invention, which includes the following steps. That is, (a) a step of producing a substrate by forming a plurality of liquid crystal driving elements or counter electrodes and cutting marks at predetermined positions on the surface of the substrate (b) a step of attaching a support tape to the surface of the substrate (C) Cutting the base, and further cutting a part of the support tape,
Process of separating into individual liquid crystal drive element substrates or counter electrode substrates

Further, the above object can be achieved by a method for manufacturing a liquid crystal display device according to a fourth aspect of the present invention, which includes the following steps. That is, (a) a step of producing a substrate by forming a plurality of liquid crystal driving elements or counter electrodes and cutting marks at predetermined positions on the surface of the substrate (b) a step of attaching a support tape to the surface of the substrate (C) A step of cutting a part of the substrate from the back surface of the substrate (D) A step of applying an impact to the substrate from the side of the supporting tape to separate it into individual liquid crystal driving element substrates or counter electrode substrates

The adhesive used for the support tape is a thermosetting type,
Various adhesives such as pressure-sensitive adhesives and ultraviolet curable adhesives can be used, but ultraviolet curable adhesives are most preferable. In a preferred aspect of the method for manufacturing a liquid crystal display device according to the third and fourth aspects of the present invention, the support tape comprises a film and an ultraviolet curable adhesive, and the support tape is irradiated with ultraviolet rays after the separation step to support the support tape. Cure the adhesive on the tape.

[0020]

In the method of the present invention, the surface of the substrate is protected by the supporting tape until it is cut and separated into individual element substrates. Therefore, it is possible to reliably prevent dust from adhering to the surface of the substrate. Moreover, since the cutting mark is provided at a predetermined position on the base body, the base body can be accurately cut into a predetermined shape.

[0021]

EXAMPLES Referring to FIGS. 1 to 3, a liquid crystal driving element is formed by cutting a substrate having a plurality of liquid crystal driving elements formed on a glass substrate. Taking an example of manufacturing individual element substrates,
The present invention will be described. 1 to 3 are schematic partial cross-sectional views of a substrate, a liquid crystal driving element, and the like.

(Example-1) Example-1 is characterized by including a step of cutting the substrate and further cutting a part of the supporting tape to separate the individual element substrates. [Step-10] First, a plurality of liquid crystal driving elements are formed on the surface of a glass substrate. Specifically, as shown in the schematic partial sectional view of FIG. 2, a first polysilicon layer 22 having a thickness of about 50 nm is formed on a substrate 20 made of glass by a conventional plasma CVD method. Then, a gate oxide film 24 having a thickness of about 50 nm is formed thereon by the conventional plasma CVD method. Further, a second polysilicon layer having a thickness of about 400 nm is formed thereon by the conventional plasma CVD method. Next, the second polysilicon layer is patterned by a conventional method to form the gate electrode region 26.

Then, the first polysilicon layer 22 is ion-implanted to form the source / drain regions 30 and 32. After that, as a protective film on the surface of the substrate 20, about 30 by the conventional plasma CVD method and pattern forming method.
A Si ₃ N ₄ layer 28 having a thickness of nm is formed. Then, a first insulating layer 34 of, eg, PSG and having a thickness of 500 nm is formed on the entire surface by a conventional atmospheric pressure CVD method. Then, an opening is formed in the first insulating layer 34 and the gate oxide film 24 on the source region by photolithography and etching.

After that, the opening and the first insulating layer 3 are formed.
The wiring 36 is formed by depositing aluminum having a thickness of 500 nm on the substrate 4 by sputtering and patterning the aluminum. Further, a dicing alignment mark is formed at a predetermined position. Then, a second insulating layer 38 made of PSG and having a thickness of 500 nm is deposited on the entire surface by atmospheric pressure CVD. In this way, a plurality of thin film transistors are formed on the surface of the substrate. Then, the second insulating layer 38 on the drain region, the first insulating layer 38,
An opening is formed in the insulating layer 34 and the gate oxide film 24 of FIG. 2 by the photolithography method and the etching method, and a thickness of 15 is formed on the opening and the second insulating layer 38 by the sputtering method.
Since the ITO film 40 having a thickness of 0 nm is formed and the ITO film 40 is used as a drive electrode of the liquid crystal display device, the ITO film 40 is patterned by the conventional photolithography method and etching method. In this way, the base body 1 in which the plurality of elements for driving liquid crystal are formed on the substrate 20 made of glass
Create 0.

[Step-20] Next, based on the conventional method, a polyimide-based alignment film material having a thickness of about 80 to 100 nm is applied to the surface of the substrate 10 by a spin coat method or a roll coater method, and the alignment is performed. After baking the film material, rubbing treatment is performed to form the alignment film 42.

[Step-30] Next, the surface 1 of the substrate 10
The support tape 12 is attached to OA (see FIG. 1A). The support tape 12 is composed of a film base material made of polyolefin or PVC and an ultraviolet curable adhesive. It is important to select the support tape so that the adhesive does not remain on the surface of the substrate when it is peeled off from the substrate 10 later. Generally, the harder the adhesive, the less adhesive remains on the surface of the substrate when the support tape is peeled off from the substrate. That is, when the support tape is attached to the surface of the base, it is preferable that the adhesive of the support tape has a hardness that does not penetrate into a fine pattern portion such as an element formed on the base. As the support tape, for example, SP-525 manufactured by Furukawa Electric Co., Ltd.
M, SP-594M, SP-45M, UC-3446P
Alternatively, S-107V manufactured by Bando Kagaku Co., U-10D manufactured by Nitto Denko Corporation, and D608 manufactured by Linlac Co., Ltd. can be used. The thickness of the support tape is 80-10
It is preferably about 0 μm.

[Step-40] After that, while reading the cutting mark formed on the front surface of the base 10 using a normal dicing device, the base 10 is completely removed from the back surface 10B side in the thickness direction. Then, the support tape 12 is partially cut in the thickness direction (see FIG. 1B). It is desirable to cut the support tape 12 by about 30 to 40 μm in the thickness direction. At the time of cutting, since the surface 10A of the base is covered with the support tape 12, it is possible to prevent the cutting waste of the substrate and the dust of the cutting waste of the support tape from adhering to the surface 10A of the base. Since the substrate is glass, the substrate can be cut while reading the cutting mark formed on the surface of the substrate from the back surface of the substrate, and the substrate can be accurately cut into a desired shape. In this way, the element substrate 14 including the individual liquid crystal driving elements is cut and separated from the base body 10 on which the plurality of liquid crystal driving elements are formed.

[Step-50] Next, if necessary, the support tape 12 is stretched (see FIG. 1C), and then the support tape 12 is irradiated with ultraviolet rays in an amount of 300 to 500 mJ / cm 2.
Irradiation is performed for about ² to cure the ultraviolet curable adhesive of the support tape and reduce the adhesive force between the support tape 12 and the substrate 10. Then, the support tape 12 is peeled off from the surface of the substrate 10. Before UV irradiation, 500-1000g / 25
Since the adhesive strength of the ultraviolet curable adhesive, which is about mm, decreases to about 20 to 30 g / 25 mm after the irradiation with ultraviolet rays,
The support tape 12 can be easily peeled off from the surface of the substrate 10. Dust of a few microns level adhered to the alignment film during the rubbing treatment adheres to the adhesive of the support tape and is removed when the support tape is peeled off. Therefore, it is not necessary to remove dust on the alignment film by cleaning, and the alignment film can be prevented from being deteriorated by cleaning.

[Step-60] Next, the liquid crystal display device is completed based on the conventional method for manufacturing a liquid crystal display device.

The formation of the alignment film including the rubbing treatment can be performed in [Step-60] instead of the above-mentioned [Step-20].

Example-2 Next, Example-2 will be described. Example-2 is characterized by including a step of cutting a part of the base from the back surface of the base and a step of separating the individual element substrates by applying an impact to the base from the supporting tape side. [Step-100] First, on the surface of the substrate made of glass,
An element including a plurality of liquid crystal driving elements is formed. This step is the same as [Step-10] in Example-1, and the description thereof will be omitted.

[Step-110] Next, based on a conventional method, a polyimide-based alignment film material having a thickness of about 80 to 100 nm is applied to the surface of the substrate 10 by a spin coat method or a roll coater method, and the alignment is performed. After firing the film material, rubbing treatment is performed to form an alignment film.

[Step-120] Next, the support tape 12 is attached to the surface 10A of the substrate 10 ((A) of FIG. 3).
reference). The support tape 12 is polyolefin or PVC.
And a UV-curable adhesive. As the supporting tape, the supporting tape exemplified in Example-1 can be used.

[Step-130] After that, while reading the cutting mark formed on the front surface of the base 10 with a cemented carbide roll cutter or a diamond cutter using an ordinary scribing device, from the back surface 10B side of the base 10. Base 1
A part of 0 is cut in the thickness direction (see FIG. 3B). The cut amount is preferably about 0.1 to 0.2 mm. Since the surface 10A of the substrate is covered with the support tape 12 when the substrate is partially cut, it is possible to prevent dust, which is a cutting waste of the substrate, from adhering to the surface of the substrate. Since the base is cut while reading the cutting marks formed on the base, the base can be cut accurately into a desired shape.

[Step-140] Next, the back surface of the substrate is placed on a support base, and a shock is applied to the substrate 10 by a breaker 16 along a line partially cut from the support tape 12 side, so that a plurality of liquid crystals are formed. From the base body 10 on which the driving element is formed,
The element substrate 14 composed of individual liquid crystal driving elements is cut and separated (see FIG. 3C). Since a shock is applied to the base 10 from the supporting tape 12 side, damage to the base 10 is reduced. In addition, the surface of the substrate is the support tape 12
Since it is covered with, it is possible to prevent dust from the substrate from adhering to the surface of the substrate.

[Step-150] Then, if necessary,
After stretching the support tape 12, the support tape 12 is attached to the base 1
Peel from the surface of 0. This step is the same as [Step-50] of Example-1, and description thereof will be omitted. Dust of a few microns level adhered to the alignment film during the rubbing treatment adheres to the adhesive of the support tape and is removed when the support tape is peeled off. Therefore, it is not necessary to remove dust on the alignment film by cleaning, and the alignment film can be prevented from being deteriorated by cleaning.

[Step-160] Then, the liquid crystal display device is completed based on the conventional method for manufacturing a liquid crystal display device.

It is also possible to perform the formation of the alignment film and the rubbing treatment in [step-160] instead of the above-mentioned [step-110].

A color filter is formed on a glass substrate,
Then, the ITO film is sputtered to form a plurality of counter electrodes on the substrate by a photolithography method and an etching method, and then by [Step-20] to [Step-60] of the above-described Example-1, or Example 2 [Step-
110] to [Step-160], individual counter electrode substrates can be manufactured.

The present invention has been described above based on the preferred embodiments, but the present invention is not limited to the above embodiments. The liquid crystal display device can be configured by a simple matrix system in addition to the active matrix system described in the embodiments.

[0041]

In the manufacturing method of the present invention, the surface of the substrate is covered with the supporting tape in the step of cutting the substrate. Therefore, the cutting residue of the substrate or the supporting tape does not adhere to the surface of the base body, so that it is possible to improve the manufacturing yield of the element substrate and the reliability of the element and the like. Also,
Since dust on the substrate surface is removed when the support tape is peeled off,
It is possible to improve the manufacturing yield of element substrates and the reliability of elements and the like. Moreover, reduction of clean work,
It is possible to reduce capital investment in clean rooms and manufacturing equipment. Further, the CO ₂ generator for preventing electrostatic breakdown, which is required in the conventional method, becomes unnecessary.

Further, since the base is cut while reading the cutting mark attached to the base, the base can be cut into a predetermined shape accurately.

[Brief description of drawings]

FIG. 1 is a diagram illustrating each step of the method of the present invention.

FIG. 2 is a schematic partial cross-sectional view of a liquid crystal driving element.

FIG. 3 is a diagram illustrating each step of another method of the present invention.

FIG. 4 is a diagram illustrating each step of a conventional substrate cutting method.

[Explanation of symbols]

 10 Base 12 Support Tape 14 Element Substrate 20 Substrate 26 Gate Electrode Region 30, 32 Source / Drain Region 34 First Insulating Layer 36 Wiring 38 Second Insulating Layer 40 ITO Film 42 Alignment Film

Claims (5)

[Claims] 1. A method of manufacturing a plurality of element substrates by cutting a base body having a plurality of elements formed on the surface and having cutting marks at predetermined positions, the method comprising: (a) a surface of the base body. To a step of attaching a support tape for supporting the substrate, and (b) cutting the substrate, further cutting a part of the support tape,
A method of manufacturing an element substrate, comprising a step of separating into individual element substrates. 2. A method of manufacturing a plurality of element substrates by cutting a base body having a plurality of elements formed on the surface and having cutting marks at predetermined positions, comprising: (a) a surface of the base body. Then, a step of adhering a support tape for supporting the substrate, (b) a step of cutting a part of the substrate from the back surface of the substrate, and (c) a shock from the supporting tape side to the substrate to apply it to each element substrate. And a step of separating the element substrate. 3. The support tape comprises a film and an ultraviolet curable adhesive, and the adhesive of the support tape is cured by irradiating the support tape with ultraviolet rays after the separating step. The method for manufacturing the element substrate according to claim 2. 4. A step of producing a substrate by forming a plurality of liquid crystal driving elements or counter electrodes and cutting marks at predetermined positions on the surface of the substrate, and (b) supporting on the surface of the substrate. A step of adhering the tape, and (c) cutting the substrate, and further cutting a part of the support tape,
A method of manufacturing a liquid crystal display device, comprising a step of separating each of the liquid crystal driving element substrate or the counter electrode substrate. 5. A step of producing a substrate by forming a plurality of liquid crystal driving elements or counter electrodes and cutting marks at predetermined positions on the surface of the substrate, and (b) supporting on the surface of the substrate. A step of attaching a tape, (c) a step of cutting a part of the base from the back surface of the base, and (d) a shock is applied to the base from the side of the supporting tape to form an individual liquid crystal drive element substrate or counter electrode substrate. A method of manufacturing a liquid crystal display device, comprising: a step of separating.