JP2001355058A - Substrate deposited with transparent electrically conductive film and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evade the generation of the defect of display by remarkably reducing the coating weight of foreign matters onto a transparent electrically conductive film as possible and thereby to improve the yield. SOLUTION: The upper face of a glass substrate 1 is deposited with a colored layer 2 as a color filter of R(red).G(green) B(blue), the upper face of the colored layer 2 is deposited with a protective film 3 (overcoat layer) composed of an acrylic resin or the like, and the upper face is further deposited with at ITO film 4 whose circumferential edge parts are tapered so as to have a prescribed angle θ of <=70 deg. with the glass substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate with a transparent conductive film and a method of manufacturing the same, and more particularly, to a color liquid crystal display and an electroluminescence (hereinafter referred to as "electroluminescence").
The present invention relates to a substrate with a transparent conductive film used as an electrode of a display or the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a substrate with a transparent conductive film used as an electrode of a liquid crystal display or an EL display has an R surface on a glass substrate 101 as shown in FIG.
(Red), G (green), and blue (B) colored layers 102 are laminated, and the colored layers 102 are covered with a protective film 103. The surface of the protective film 103 is further coated with indium tin oxide (indium tin oxide). : Hereinafter referred to as “ITO”).

When the substrate with a transparent conductive film is used, for example, as a liquid crystal display element, a large number of TFT elements are separately formed on another glass substrate, and the transparent conductive film 104 is interposed via a liquid crystal layer. And the TFT element are arranged so as to face each other, and an image is displayed by driving the TFT element and applying a voltage to the liquid crystal layer.

That is, by applying a voltage to the liquid crystal layer, T
The surface of the glass substrate 101 facing the FT element is preferably at zero potential for stable image display. However, if the transparent conductive film 104 is not formed, the surface of the glass substrate 101 which is electrically insulative is surely formed. Therefore, it is difficult to make the potential zero, and the voltage applied to the liquid crystal layer becomes unstable, and the image display may also become unstable. Therefore, conventionally, the transparent conductive film 1 is formed on the glass substrate 101 so as to cover the entire colored layer 102 which is a display area of the glass substrate 101.
04 are laminated, thereby preventing the glass substrate 101 from being charged and stabilizing the surface potential of the glass substrate 101.

[0005] In addition, this type of substrate with a transparent conductive film comprises:
It is manufactured by performing a so-called “multi-panning” in which a plurality of substrates with a transparent conductive film are obtained from a large-sized glass plate.

That is, a coloring layer 102 and a protective film 103 are sequentially formed at predetermined positions on a single large-sized glass plate, and then a metal thin plate having an opening 105 as shown in FIG. A mask (hereinafter, referred to as a “metal mask”) 106 is placed on a glass plate, a predetermined sputtering process is performed thereon, and a transparent conductive film 104 made of ITO is laminated on the protective film 103 (mask evaporation). By appropriately cutting the plate, a plurality of substrates with a transparent conductive film are obtained from one large-sized glass plate, whereby a large number of liquid crystal display elements are manufactured in one continuous process.

[0007]

However, in the conventional substrate with a transparent conductive film, the transparent conductive film 104 is formed on the protective film 103 by mask evaporation as described above. Opening 105
Has a shape in which a hole is simply provided. When mask deposition is performed using the metal mask 106, as shown in part A of FIG. Since it is substantially vertical and has a shape that is pointed outward, foreign matter such as dust caused by static electricity easily adheres to the peripheral edge during the manufacturing process of the liquid crystal display element, and this foreign matter adheres. There is a problem that display defects are easily generated.

That is, although the assembling work of the liquid crystal display element is performed in a so-called clean room, since the assembling work needs to be performed in a dry atmosphere with low humidity, the glass surface of the electrically insulating glass substrate 1 is exposed. Static electricity is likely to be generated in the portion, and foreign matter such as minute dust floating in the air is likely to adhere to the surface of the transparent conductive film 104 which is an electrode, and the transparent conductive film 104 has a sharp portion. In such a case, the electric field concentrates on the pointed portion, so that foreign matter is intensively attached to the pointed portion.

However, in the conventional substrate with a transparent conductive film, the peripheral edge (A
Portion) has a pointed shape, so that the foreign matter tends to adhere to the peripheral edge portion (portion A). If foreign matter adheres to the peripheral edge portion (part A) during a series of manufacturing steps of the liquid crystal display element, it adversely affects the alignment of the liquid crystal, and therefore, the probability of manufacturing a product that can cause display defects increases,
As a result, there is a problem that the product yield is reduced.

Also, in the case of an EL display or the like, when foreign matter adheres to the sharp portion of such a transparent conductive film,
There is a problem in that the probability that the sharp portion becomes a bright spot and a product causing display failure is manufactured increases, which leads to a reduction in product yield.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing problems, and it is possible to significantly reduce the amount of foreign matter adhering to a transparent conductive film to thereby prevent display defects from occurring, thereby improving the product yield. It is an object of the present invention to provide a substrate with a transparent conductive film and a method for manufacturing the same.

[0012]

[MEANS FOR SOLVING THE PROBLEMS] Liquid crystal display and EL
The substrate with a transparent conductive film used for a display element such as a display is manufactured in an atmosphere having a good air cleanliness in order to avoid the attachment of foreign matter such as fine dust as described above, Since the operation is performed in a dry atmosphere, the operation is performed in an environment where charging due to electrostatic force easily occurs.

That is, since this type of display element is manufactured in an environment in which electrification easily occurs in a dry atmosphere even when the air cleanliness is extremely good, the substrate with the transparent conductive film for floating dust in the air is produced. There is a limit to reducing the adhesion to metal.

In view of such circumstances, the present inventors have conducted intensive studies focusing on the shape of the transparent conductive film. As a result, the angle between the transparent conductive film and the transparent substrate is tapered to a predetermined angle or less. By forming the transparent conductive film on the transparent substrate, it has been found that the concentration of an electric field on the peripheral edge of the transparent conductive film can be avoided and the adhesion of foreign substances to the transparent conductive film can be drastically reduced. Was.

The present invention has been made based on such findings, and a substrate with a transparent conductive film according to the present invention is a substrate with a transparent conductive film having a transparent conductive film formed on the surface of the transparent substrate. The transparent conductive film is formed on the surface of the transparent substrate so that an angle formed between the transparent substrate and the transparent conductive film has a tapered shape of a predetermined angle or less.

Specifically, it is preferable that the predetermined angle is equal to or less than 70 °.
By setting as follows, the peripheral edge of the transparent conductive film can be prevented from exhibiting a sharp shape, and it is possible to prevent the electric field concentration at the peripheral edge from occurring. Etc. can be prevented from adhering.

Further, as described above, in order to make the angle between the transparent substrate and the transparent conductive film into a tapered shape of a predetermined angle or less, a conventional mask vapor deposition is performed to form the transparent conductive film on the glass substrate. In this method, a part of the opening of the metal mask is expanded more than the other part to form an expanded part having a predetermined size in the opening of the metal mask, and the metal mask having the expanded part is used. It is preferable to perform mask vapor deposition.

Therefore, in the method of manufacturing a substrate with a transparent conductive film according to the present invention, a metal member having an opening is placed on the surface of the transparent substrate, and the metal member is used as a mask to correspond to the opening. After forming a transparent conductive film on a transparent substrate, removing the metal member from the transparent substrate, and cutting the transparent substrate, a plurality of substrates with a transparent conductive film are manufactured from one transparent substrate. In the method for manufacturing a substrate with a transparent conductive film, a part of the opening of the metal member is expanded more than another part to form an expanded part, and the expanded part is formed on the transparent substrate so as to face the transparent part. And the transparent conductive film is formed on the surface of the transparent substrate.

According to the manufacturing method, as described above, the transparent conductive film having a tapered shape having a predetermined angle or less can be formed on the transparent substrate, and the adhesion of foreign substances to the transparent conductive film can be drastically reduced. Thus, a substrate with a transparent conductive film can be manufactured.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a substrate with a transparent conductive film according to the present invention.

In FIG. 1, reference numeral 1 denotes a rectangular glass substrate made of alkali glass or the like, and R (red), G (green), and B (blue) color filters are provided on the upper surface of the glass substrate 1. A colored layer 2 is formed, and a protective film 3 (overcoat layer) made of acrylic resin, epoxy resin, polyimide resin, or the like is formed on the upper surface of the colored layer 2, and a transparent conductive film is formed on the upper surface of the protective film 3. An ITO film 4 as a film is laminated.

As shown in FIG. 2, the ITO film 4 is formed in a tapered shape so that the angle formed with the glass substrate 1 has a predetermined angle θ of 30 ° to 70 °.

The ITO film 4 is formed in a tapered shape at a predetermined angle θ with respect to the glass substrate 1 and the predetermined angle θ is set at 30 ° to 70 ° for the following reasons.

By forming the ITO film 4 and the glass substrate 1 in a tapered shape so that the angle between the ITO film 4 and the glass substrate 1 has a predetermined angle θ, the peripheral edge 5 of the ITO film 4 does not have an outwardly sharp shape. The shape becomes smooth, so that the electric field can be prevented from being concentrated on the peripheral edge portion 5, whereby foreign matter such as minute floating dust in the air can be prevented from adhering.

That is, when the predetermined angle θ exceeds 70 °, the predetermined angle θ formed between the glass substrate 1 and the ITO film 4 becomes large, and becomes close to a right angle.
Has a sharp shape, electric field concentration occurs, and minute floating dust due to electrostatic force easily adheres to the peripheral edge portion 5, so that display defects easily occur and the product yield can be improved. Can not.

On the other hand, when the predetermined angle θ is less than 30 °,
Since the ITO film 4 becomes excessively large and the surface area of the ITO film 4 itself increases, the size of the display element itself increases.

Therefore, in the present embodiment, the predetermined angle θ is set to 30 ° to 70 ° as described above.

Next, a method of manufacturing the substrate with a transparent conductive film will be described.

FIG. 3 is a manufacturing process diagram showing a method for manufacturing a substrate with a transparent conductive film according to the present invention. In this embodiment, four substrates with a transparent conductive film are formed from a large square glass plate. Manufacturing.

First, using a resin material containing a dye or pigment in a known photosensitive resin matrix, a known photolithography method is used, as shown in FIG. A colored layer 2 having a thickness of about 1 μm is formed.

Next, as shown in FIG. 3B, a polymer resin is applied to the surface of the colored layer 2 and dried, thereby forming a protective film 3 having a thickness of about 1 μm.

As a material for the protective film, for example, an acrylic resin, an epoxy resin, or a polyimide resin can be used.

Next, as shown in FIG. 3C, a metal mask 7 made of stainless steel is placed on the glass plate 6.

As shown in FIG. 4, the metal mask 7 is provided with an opening 8 having a supply port size D at a position corresponding to the portion of the ITO film 4 laminated on the protective film 3. In addition, a part of the opening 8 is expanded more than the other part to form an expanded part 8a. That is, the opening 8 has an opening height L, and is located below the opening 8 (the glass plate 6).
Side), an expanded portion 8a having an expanded width W and an expanded height H
Is formed in a part of the opening 8 to provide a desired predetermined angle θ in a film forming process described later.
Is formed.

In order to form the ITO film at a predetermined angle θ in the range of 30 ° to 70 °, the expansion width W, the expansion height H, and the opening height L are expressed by the following formulas (Eq. 1) ~
It is preferable to set so as to be within the range of Expression (3).

W ≧ 0.2 mm (1) H ≧ 0.05 mm (2) L ≧ 0.1 mm (3) That is, from the viewpoint of improving the product yield, the product yield needs to be 80% or more. However, when the expansion width W, the expansion height H, and the opening height L are set so as not to satisfy the above formulas (1) to (3), the predetermined angle θ exceeds 70 °. As a result, the peripheral edge portion 5 has a sharp shape, so that foreign matter is easily attached to the peripheral edge portion 5, display defects are likely to occur, and the product yield is reduced to 80% or less, thereby improving the product yield. Can not.

Therefore, in the present embodiment, the respective dimensions are set so that the above-mentioned widening width W, widening height H, and opening height L fall within the ranges of equations (1) to (3). did.

After the metal mask 7 is placed at a predetermined position on the glass plate 6 in this manner, as shown in FIG. 3D, by a sputtering method, an electron vapor deposition method, an ion plating method or the like. ITO film 4 is deposited,
Next, the metal mask 7 is removed, and an ITO film 4 is formed on the glass plate 6 as shown in FIG.

Next, the glass plate 6 on which the ITO film 4 is formed is cut along a broken line 10 shown in FIG. The attached substrate is manufactured.

FIG. 6 shows a case where the substrate with the transparent conductive film is incorporated in a liquid crystal display device.

That is, the substrate 10 with the transparent conductive film and the glass substrate 12 on which a plurality of TFT elements 11 are formed are arranged so that the TFT elements 11 and the ITO film 4 are opposed to each other. The end of the glass substrate 1 and the end of the glass substrate 12 are adhered with an epoxy resin 13, and a space is defined by the glass substrate 1, the glass substrate 12, and the epoxy resin 13, and an STN (Super Twiste
d Nematic) or the like.

In the liquid crystal display element, a voltage is applied to the liquid crystal 14 by driving the TFT element 12, whereby an image is displayed.

In this embodiment, the ITO film 4 is formed on the glass substrate 1 so as to have a taper angle of 30 ° to 70 ° with respect to the glass substrate 1.
The peripheral edge 5 of the film 4 does not have a sharp shape, and therefore, no electric field concentration occurs due to the electrostatic force at the peripheral edge 5, and as a result, the peripheral edge 5 floats in the air even during the manufacturing process. It is possible to prevent foreign substances such as dust from being concentrated on the peripheral edge portion 5 of the ITO film 4 and to reduce the production of liquid crystal display elements with display defects, thereby improving the product yield. Can be done.

[0045]

Next, embodiments of the present invention will be described specifically.

The inventor of the present invention has determined that the dimensions (the width W, the height H, and the height L) of the opening 8 are different.
Using 100 types of metal masks 7, 100 substrates each having a transparent conductive film were manufactured, and the product yield was evaluated from the state of adhesion of foreign substances.

That is, first, a resin material containing a dye and a pigment is used as an acrylic resin as a photosensitive resin, and a large-size glass plate 6 is applied by applying a well-known photolithography method.
A coloring layer 2 having a film thickness of 1 μm as a color filter is laminated at the predetermined positions (four places) on the upper side, whereby the coloring layers 2 which are arranged so that the R, G, and B dye film patterns are sequentially and repeatedly arranged. Formed.

Next, the surface of the colored layer 2 was coated with an acrylic resin, and heated to a temperature of 150 ° C. to dry the acrylic resin, thereby forming a protective film 3 having a thickness of 1 μm.

Next, a metal mask 7 is placed on the glass plate 6 so that the opening 8 is formed on the protective film 3 and a sputtering process is performed under the following sputtering conditions. To remove the film thickness 1
A test piece having a 50 nm ITO film 4 was prepared. [Sputtering conditions] Target: In ₂ O ₃ sputtering gas containing 10 wt% SnO ₂ : Ar + O ₂ (however, O ₂ : 1.0 vol)
l%) Gas pressure of sputtering gas: 4 × 10 ⁻¹ Pa (3 × 1
0 ^-3 Torr) Supply power: 1000 W Substrate temperature of glass substrate: 250 ° C. And 10 kinds of test pieces obtained in this way, 100 pieces each (Example of the present invention: 4 kinds, Comparative example: 6 kinds)
Was left standing vertically on a glass holder for 10 hours in a room under a liquid crystal display element manufacturing environment having a relative humidity of 30%, a temperature of 22 ° C., and an air cleanliness of 1000 for dust or the like attached to the test piece. Foreign matter was visually observed and 1
The product yield was calculated for each test piece, with the test piece in which more than one foreign substance was visually recognized as a defective product and the test piece in which no foreign substance was adhered as a non-defective product.

Table 1 shows the experimental results. In the table, 〇 indicates that the product yield was 80% or more, and △ indicates that the product yield was 5%.
0% to 80%, and x indicates that the product yield is 50% or less.

[0051]

[Table 1]

As is clear from Table 1, Comparative Example 1
Uses a metal mask (conventional product) not provided with the expanded portion 8a, so that the glass substrate 1 (glass plate 6)
And the ITO film 4 have a large predetermined angle θ of 82.2 °, and the peripheral edge 5 of the ITO film 4 has a sharpened shape. Adhesion to the end was confirmed, and the product yield was 50% or less.

In Comparative Example 2, since the expansion width W and the expansion height H were as small as 0.1 mm and 0.04 mm, respectively, the inflow of ITO as a film forming material into the expansion section 8a was small. Therefore, the predetermined angle θ is as large as 79.3 °, and therefore, as in Comparative Example 1, it is confirmed that foreign matter adheres to the peripheral edge 5 in many test pieces, and the product yield is 50% or less. Was.

In Comparative Example 3, although the enlarged portion 8a was provided in the opening 8 of the metal mask 7, the size of each portion was small. Therefore, the predetermined angle θ is also smaller than 76.
Although the product yield was as large as 8 °, and the product yield was slightly improved as compared with Comparative Examples 1 and 2, the foreign matter was found to be less in the peripheral edge 5 in many test pieces.
Has been confirmed, and the product yield is 50% to 80%.
%Met.

In Comparative Example 4, the predetermined angle θ was 72.0 ° because the width W of the expansion was small, and in Comparative Example 5, the predetermined angle θ was small because the width W and the height H of the expansion were small. θ is 73.3 °, and the product yield is 50
% To 80%.

In Comparative Example 6, the expansion width W and the supply port height L were good, but the expansion height H was 0.04 mm.
Therefore, the predetermined angle is 74.0 ° and the desired predetermined angle θ (≦ 70 °) cannot be obtained, and the product yield is 5
0% to 80%.

On the other hand, each of the test pieces of Examples 1 to 4 had dimensions within the ranges of Expressions (1) to (3) described in [Embodiment of the Invention]. Therefore, the predetermined angle θ was also in the range of 30 ° to 70 °, and no adherence of foreign matter to the ITO film 4 in each test piece was visually recognized, and a good product yield of 80% or more was obtained.

[0058]

As described in detail above, the substrate with a transparent conductive film according to the present invention is a substrate with a transparent conductive film having a transparent conductive film formed on the surface of a transparent substrate. Since the transparent conductive film is formed on the surface of the transparent substrate so as to have a tapered shape having a predetermined angle (≦ 70 °) or less, the peripheral edge of the transparent conductive film has a sharp shape. Therefore, it is possible to avoid the occurrence of electric field concentration at the peripheral edge, and to prevent the attachment of foreign substances such as floating dust in the air, thereby obtaining a product in which a display defect or the like occurs. Product yield can be avoided as much as possible and the product yield can be improved.

Further, in the method of manufacturing a substrate with a transparent conductive film according to the present invention, a metal member having an opening is placed on the surface of a transparent substrate, and the metal member is used as a mask to correspond to the opening. After forming a transparent conductive film on a transparent substrate, removing the metal member from the transparent substrate, and cutting the transparent substrate, a plurality of substrates with a transparent conductive film are manufactured from one transparent substrate. In the method for manufacturing a substrate with a transparent conductive film, a part of the opening of the metal member is expanded more than another part to form an expanded part, and the expanded part is formed on the transparent substrate so as to face the transparent part. The transparent conductive film is formed on the surface of the transparent substrate by disposing the transparent conductive film on the surface of the transparent substrate. A group with a transparent conductive film that can drastically reduce adhesion It can be produced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a substrate with a transparent conductive film according to the present invention.

FIG. 2 is a sectional view of a main part of FIG.

FIG. 3 is a manufacturing process diagram showing a method for manufacturing a substrate with a transparent conductive film according to the present invention.

FIG. 4 is a cross-sectional view of a metal mask used in the manufacturing method.

FIG. 5 is a plan view of a large-sized glass plate on which an ITO film is laminated by the manufacturing method of FIG. 3;

FIG. 6 is a cross-sectional view showing a state where the substrate with a transparent conductive film of the present invention is incorporated in a liquid crystal display device.

FIG. 7 is a cross-sectional view showing a conventional example of a substrate with a transparent conductive film.

FIG. 8 is a sectional view showing a conventional example of a metal mask.

[Explanation of symbols]

 Reference Signs List 1 glass substrate (transparent substrate) 4 ITO film (transparent conductive film) 7 metal mask (metal member) 8 opening 8a expanding part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 33/10 H05B 33/10 33/28 33/28 F-term (Reference) 2H048 BA45 BA48 BB06 BB37 BB44 2H091 FA02Y FC02 GA03 LA07 LA30 2H092 HA04 MA21 NA13 NA29 PA08 3K007 AB18 BB06 CA01 CB01 FA01 4K029 AA09 AA24 BA50 BB01 BC09 BD00 CA05 HA03

Claims (3)

[Claims] 1. A substrate with a transparent conductive film having a transparent conductive film formed on a surface of a transparent substrate, wherein the angle between the transparent substrate and the transparent conductive film has a tapered shape of a predetermined angle or less. A substrate with a transparent conductive film, wherein a film is formed on a surface of the transparent substrate. 2. The substrate with a transparent conductive film according to claim 1, wherein the predetermined angle is 70 ° or less. 3. A metal member having an opening is placed on the surface of a transparent substrate, and a transparent conductive film is formed on the transparent substrate corresponding to the opening using the metal member as a mask. A method for manufacturing a substrate with a transparent conductive film, wherein a plurality of substrates with a transparent conductive film are manufactured from one transparent substrate by cutting the transparent substrate after removing the member from the transparent substrate. A part of the opening of the member is expanded more than the other part to form an expanded part, and the expanded part is disposed on the transparent substrate so as to face the transparent substrate, and the transparent conductive film is formed on the surface of the transparent substrate. A method for producing a substrate with a transparent conductive film, characterized by forming a film.