JP2000105548A - Electrode substrate for display panel and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode substrate for a display panel and manufacture thereof, which substrate can excellently secure the property of supplying a current between a built-in auxiliary electrode and a transparent electrode while excellently securing the flatness of the inner surface of the electrode substrate by contriving the formation of the built-in auxiliary electrode. SOLUTION: In an auxiliary electrode formation process S2, a plurality of stripe-like auxiliary electrodes 12 are formed with a metallic material on the inner surface of a transparent substrate 11. In a planarization film material deposition process S3 a glass paste film is formed by applying a glass paste on the inner surface of the transparent substrate 11 so as to embed the individual auxiliary electrodes 12. In a polishing process S4, the forward end surface of each the auxiliary electrodes 12 is polished to be exposed as an exposed surface 12a. In a transparent electrode formation process S6, a stripe-like transparent electrode 14 is formed on the exposed surface 12 of each the auxiliary electrodes 12, along the longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode substrate for various display panels such as a liquid crystal panel and an electroluminescence panel, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, for example, in a matrix-driven transmission type liquid crystal panel, it is considered that the magnitude of each wiring resistance of a plurality of transparent electrodes of an electrode substrate greatly affects the display performance and manufacturing cost of the liquid crystal panel. Then, a stacked auxiliary electrode structure in which an auxiliary electrode made of an opaque metal material is stacked on each transparent electrode is adopted.

[0003]

In the above liquid crystal panel, the wiring resistance of each transparent electrode is further reduced by increasing the width and height of each auxiliary electrode. It is necessary to increase the cross-sectional area of the electrode. However, when the width of each auxiliary electrode is increased, each of the auxiliary electrodes is opaque, so that the aperture ratio in the display area of the liquid crystal panel is reduced. As a result, the brightness of the liquid crystal panel decreases. In addition, when the height of each auxiliary electrode is increased, the flatness of the inner surface of the electrode substrate is deteriorated, so that the distance between the two electrode substrates becomes uneven. As a result, display unevenness of the liquid crystal panel is caused.

Therefore, in recent years, an “embedded electrode structure” in which each auxiliary electrode is embedded in a glass substrate of an electrode substrate and a corresponding transparent electrode is formed thereon has been adopted. According to the "buried electrode structure", the height of each auxiliary electrode can be sufficiently secured inside the glass substrate without deteriorating the flatness of the inner surface of the electrode substrate. Therefore, in principle, it is possible to reduce the wiring resistance of each transparent electrode without lowering the aperture ratio of the liquid crystal panel.

Here, as a method of manufacturing the “embedded electrode structure”, there is a method in which a plurality of grooves are formed in a glass substrate by shot blasting, etching, or the like, and a conductive paste material is embedded in each of the grooves. When a non-fired type is used as the conductive paste, the conductive paste contains an organic binder, and thus has a high specific resistance. Therefore, a sufficient effect of reducing the wiring resistance of each transparent electrode cannot be expected. Also,
When a baking type is used as the conductive paste, the conductive paste shrinks due to the combustion of the organic binder. For this reason, it is difficult to ensure good flatness of the inner surface of the electrode substrate.

On the other hand, an electrode substrate adopting an "embedded electrode structure" and aiming at flattening the inner surface of the electrode substrate is disclosed in Japanese Patent Application Laid-Open No. 9-189917. This electrode substrate has a structure in which a resin layer is buried flat between the auxiliary electrodes formed on the inner surface of the glass substrate. Here, this structure is formed as follows.

That is, the fluid resin material is interposed between the flat inner surface of the mold substrate and the inner surface of the glass substrate on which the auxiliary electrodes are formed. Then, the fluid resin material interposed in this way is pressed and spread while pressing the mold substrate and the glass substrate by a pair of rollers to form a resin layer, and then cured. Next, the glass substrate and the cured resin layer are separated from the mold substrate. As a result, a structure in which the resin layer is embedded between the auxiliary electrodes as described above is formed. This means that the inner surface of the electrode substrate can be made flat by transfer using the mold substrate.

However, in the process of pressing and spreading by the pair of rollers as described above, each auxiliary electrode has an exposed surface to be electrically contacted with each corresponding transparent electrode. Due to the above pressing and spreading, the exposed area of the exposed surface becomes insufficient, and the hardening treatment of the fluid resin material is performed while the exposed surface is partially covered with the fluid resin material.

Therefore, when the glass substrate and the cured resin layer are separated from the mold substrate as described above, the exposed surface of the auxiliary electrode remains partially covered with the cured resin layer. Even if a transparent electrode is formed on the exposed surface of such an auxiliary electrode, a problem arises in that electrical conductivity between the two electrodes, that is, the auxiliary electrode and the transparent electrode, is poor. On the other hand, in order to ensure good conductivity between the auxiliary electrode and the transparent electrode described above, the flatness of the exposed surface of the auxiliary electrode needs to be roughened to 200 ° or more by setting the surface roughness to Ra. In this case, the distance between the two electrode substrates becomes non-uniform, which causes display unevenness on the liquid crystal panel.

In order to cope with the above, the present invention devises a method of forming a buried auxiliary electrode structure, and while ensuring the flatness of the inner surface of the electrode substrate, the auxiliary electrode and the buried auxiliary electrode structure. An object of the present invention is to provide an electrode substrate for a display panel and a method for manufacturing the same, which ensure good conductivity between the electrode and the transparent electrode.

[0011]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a plurality of stripe-shaped auxiliary electrodes (1) are formed on the inner surface of a substrate (11) using a metal material.
(2) forming an auxiliary electrode (S1, S2, R1 to R3), and forming a material film by applying a flattening film forming material to the inner surface of the substrate so as to bury each auxiliary electrode (S3, R4); a polishing step (S4, R5) of polishing the surface of the material film so as to expose the tip end surface of each auxiliary electrode as an exposed surface (12a); Main electrode forming steps (S5, S6, R
6, R7, U5, U6).

In this way, the material film is formed by applying the flattening film forming material to the inner surface of the substrate so as to bury each auxiliary electrode, and to form the material film such that the tip end surface of each auxiliary electrode is exposed as an exposed surface. Is polished, the exposed surface of each auxiliary electrode is uniformly exposed, and the exposed surface and the surface of each flattening film are on the same plane. For this reason, it is possible to ensure not only good electrical conductivity between the auxiliary electrode and the transparent electrode, but also good flatness of the inner surface of the electrode substrate.

Here, according to the second aspect of the present invention,
In the first aspect of the present invention, in the material film forming step, a low-melting glass paste is used as a material for forming a planarizing film, and the low-melting glass paste is fired at a predetermined temperature to form a material film. Accordingly, when the main electrode is formed on each auxiliary electrode by, for example, ITO, it can be performed at a high temperature.

According to a third aspect of the present invention, in the first or second aspect, in the auxiliary electrode forming step, a photosensitive Ag paste is used as a metal material,
This Ag paste is applied to the inner surface of the substrate, and each auxiliary electrode is formed by a patterning process using a photolithography method. This simplifies the formation process by patterning each auxiliary electrode as compared with the case where a non-photosensitive paste is used as the metal material.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, in the auxiliary electrode forming step, Cu and Ni are used as the metal material and Ni is not present on the inner surface of the substrate. A Ni film is formed by electrolytic plating, and a Cu film is formed by electrolytic plating of Cu on the Ni film using the Ni film as a base electrode. Each of the Cu film and the Ni film is patterned by photolithography to form an auxiliary electrode. Form. As described above, even when the auxiliary electrode is formed using Cu and Ni, the same operation and effect as those of the first or second aspect of the invention can be achieved.

According to the fifth aspect of the present invention, the auxiliary electrode forming step (S11, S21, R1) for forming a plurality of stripe-shaped auxiliary electrodes on the inner surface of the substrate with a metal material.
1 to R31) and a stripe-shaped flattening film formed of a flattening film forming material having a higher hardness than the metal material on the inner surface of the substrate along the space between the auxiliary electrodes so that the tip surface of each auxiliary electrode protrudes. Film forming step (S
31, R41), a polishing step (S41, R51) of polishing the tip surface of each auxiliary electrode until it matches the surface of each planarization film to form an exposed surface, and a longitudinal direction on the exposed surface of each auxiliary electrode. Main electrode forming steps of forming stripe-shaped main electrodes along the lines (S5, S6, R6, R7, U5, U6)
A method for manufacturing a display panel electrode substrate comprising:

As described above, the stripe-shaped flattening material is formed on the inner surface of the substrate along the space between the auxiliary electrodes such that the tip end surface of each auxiliary electrode protrudes by the flattening film forming material having a higher hardness than the metal material. Since the film is formed and the exposed surface is formed by polishing the tip surface of each auxiliary electrode until it coincides with the surface of each flattening film, the function and effect of the invention described in claim 1 can be achieved. As compared with the case of the first aspect, the polishing amount can be reduced and the flatness of the inner surface of the electrode substrate can be more favorably secured.

According to the invention of claim 6, an auxiliary electrode / flattening film forming step (T1) of alternately forming a plurality of auxiliary electrodes and flattening films in stripes on the inner surface of the substrate (11). To T5) and a main electrode forming step (T7, T8) of forming a striped main electrode (14) along the longitudinal direction on the exposed surface of each auxiliary electrode. The auxiliary electrode / flattening film forming step is a base electrode forming step (T1, T2) for forming a plurality of striped base electrodes (h, i) on the inner surface of the substrate.
T2), a material film forming step (T3) of forming a material film (j) by applying a flattening film forming material on the inner surface of the substrate so as to cover the respective base electrodes, and applying the respective base electrodes to the material film. An opening / flattening film forming step (T4) of forming a stripe-shaped opening so as to face each other and forming a flattening film between the respective openings, and forming the respective openings in the respective openings on the respective base electrodes. A conductive member forming step of forming a stripe-shaped conductive member by filling a conductive metal material by electroplating so as to protrude from each part, and a tip end surface of each conductive member coincides with a surface of each flattening film. Polishing step (T) in which each conductive member having the exposed surface is formed as an auxiliary electrode together with its underlying electrode.
6) is provided.

As described above, the stripe-shaped openings are formed in the material film so as to face the respective base electrodes, and the flattening films are respectively formed between the respective openings. A striped conductive member is formed by filling a conductive metal material by electroplating so as to protrude from each opening, and the leading end surface of each conductive member is polished until it matches the surface of each flattening film. The same operation and effect as those of the invention described in claim 5 can be achieved even if it is formed as.

According to the seventh aspect of the present invention, the substrate (11), auxiliary electrodes and flattening films alternately formed in a plurality of stripes on the inner surface of the substrate, and exposure of each auxiliary electrode. A display panel electrode substrate comprising a main electrode (14) formed in a stripe shape along a longitudinal direction of the substrate, wherein the plurality of auxiliary electrodes are each a stripe-shaped base electrode provided on an inner surface of the substrate. (I) for a display panel, comprising: a conductive member (k1) formed by electroplating a conductive metal material on the base electrode between the flattened films on both sides of the base electrode among the plurality of flattened films. An electrode substrate is provided. According to this, it is possible to provide a display panel electrode substrate suitable for manufacturing according to the invention described in claim 6.

Further, the manufacturing method according to claim 1 and claim 5 was further studied diligently. As a result, a low-melting glass paste was used as a material for forming a flattening film, and ITO was used as a material for forming a main electrode in a main electrode forming step. (Indi
um Tin Oxide) has been found to cause the following problems. That is, a transparent ITO film is formed on the exposed surface of the material film and each auxiliary electrode by sputtering, and then patterned in a stripe shape by etching using an etchant (aqua regia) to form a main electrode. However, at the time of patterning, the low-melting glass (such as lead glass) becomes cloudy and melts due to the etchant.

To solve such a problem, a transparent electrode material which can be etched on a low-melting glass and an etchant thereof have not been known. Further, there is a lift-off method as a patterning method not based on etching, but it is difficult to realize the method due to a problem of foreign matter mixing due to a resist material used for patterning and an increase in cost.

Therefore, as a result of investigation on the problem of the clouding of the low melting point glass, the problem was found that the acid resistance of the base (low melting point glass such as lead glass) was extremely low, and the problem was caused by an etching solution (aqua regia). It has been found that the reason is that the etching rate is higher than the etching rate of the material to be patterned (sputtered ITO).

As a result of intensive studies on the material for forming the main electrode to be patterned and the etching solution to avoid the above-mentioned problem, it has been found that the material for forming the main electrode having lower acid resistance and higher etching rate than the low-melting glass as the base material is I
It has been found that ZO (Indium Zinc Oxide) or an organic acid ITO may be used, and an etchant diluted with an organic solvent may be used as an etchant with low attack on low melting point glass. Claims 8 to 11
The described invention has been made based on this finding.

That is, according to the eighth aspect of the present invention, in the first or fifth aspect of the present invention, a low-melting glass paste is used as a material for forming a flattening film, and in the main electrode forming step (U5, U6). IZO or organic acid ITO is used as a main electrode forming material for forming the main electrode (14), and after forming a material film and a covering film (m) covering the exposed surface of each auxiliary electrode with the main electrode forming material, The main electrode is formed by etching the cover film with an etchant obtained by diluting an acid with an organic solvent. This allows
It is possible to provide a manufacturing method which has the same effect as the invention of claim 1 or claim 5 and appropriately prevents the problem of cloudiness and melting of the low melting point glass.

Further, during the investigation, it was found that the low-melting glass reacts sensitively to the moisture in the etching solution and becomes cloudy. As a result of the examination, as in the invention according to claim 9, the amount of water contained as an etching solution is 2
%, It was found that the problem of cloudiness and melting of the low-melting glass can be more suitably prevented.

Here, specifically, hydrochloric acid or chlorosulfonic acid can be used as an acid of the etching solution, and n-butanol or iso-propanol can be used as an organic solvent of the etching solution.

[0028]

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

(First Embodiment) FIG. 1 shows an example in which the present invention is applied to a liquid crystal panel which is one embodiment of a display panel. This liquid crystal panel includes a lower electrode substrate 10 and an upper electrode substrate 20.
Between 0 and 20, a smectic liquid crystal is provided with a plurality of spacers via a band-shaped seal. In addition,
The lower electrode substrate 10 is a scanning electrode electrode substrate, and the upper electrode substrate 20 is a signal electrode side electrode substrate.

The lower electrode substrate 10 has a plurality of opaque striped auxiliary electrodes 12, a plurality of transparent striped flattening films 13, a plurality of striped transparent electrodes 14, a transparent insulating film on the inner surface of a transparent substrate 11. And a transparent alignment film are sequentially formed. Here, the transparent substrate 11 is formed of a glass plate having a thickness of about 1 mm made of a soda-lime glass material or the like. It is desirable that both surfaces of the glass plate 11 have high parallelism by polishing.

Each auxiliary electrode 12 and each flattening film 13 are formed alternately and in parallel with each other on the inner surface of the transparent substrate 11, and each auxiliary electrode 12 is formed as shown in FIG. The exposed surface 12a, which is the leading end surface, is in uniform contact with the back surface of the corresponding transparent electrode 14. Thereby, each auxiliary electrode 12 lowers the wiring resistance value of the corresponding transparent electrode 14. In the present embodiment, the forming material of each auxiliary electrode 13 is as follows.
It is desirable that the material be a metal material, have a low resistance value, and have good adhesion to the glass plate as the transparent electrode 11.

Each flattening film 13 has the same height as the height of each auxiliary electrode 12 from the inner surface of the transparent substrate 11, and the material for forming each flattening film 13 is, for example, glass. A paste (paste that becomes a transparent glass by being cured by baking), a monomer liquid of a photocurable transparent resin, or the like is used. Each transparent electrode 14 is formed on the exposed surface 12a of each corresponding auxiliary electrode 12 along its longitudinal direction.
Note that ITO is used as a material for forming each transparent electrode 14.

On the other hand, the upper electrode substrate 20 is
A plurality of stripe-shaped transparent electrodes 22, a transparent insulating film and an alignment film are sequentially formed on the inner surface of the substrate. In addition,
The plurality of transparent electrodes 25 are arranged so as to extend at a right angle to the plurality of transparent electrodes 12, and form a plurality of matrix-shaped pixels together with the smectic liquid crystal.

Next, a method of manufacturing the lower electrode substrate 10 of the liquid crystal panel thus configured will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 2A shows an auxiliary electrode material film forming step S1. In this step, a photosensitive silver paste is formed as a silver paste film on the inner surface of the transparent substrate 11 by coating by a printing method, as indicated by a symbol a in FIG. The thickness of the silver paste film is a thickness required for reducing the wiring resistance of each transparent electrode 14 after the main firing of the film. After the film formation, the silver paste film a is pre-baked at a temperature of 80 ° C. and dried.

Next, an auxiliary electrode forming step S2 (FIG. 2)
In (b), the silver paste film a is developed and exposed by a photolithography method, patterned, and baked to form a plurality of stripe-shaped auxiliary electrodes 12. At this time, if the photosensitive silver paste is a low-temperature firing type containing low melting point glass, firing can be performed at 470 ° C. Such low-temperature baking is effective for suppressing the amount of warpage and shrinkage of the glass substrate as the transparent substrate 11.

The next flattening film material forming step S3 (FIG. 2)
In (c), the glass paste is applied as shown in FIG.
As shown by reference numeral b in (c), a glass paste film is formed on the inner surface of the transparent substrate 11 by application by screen printing. However, the thickness of the glass paste film b is set to a thickness sufficient to embed each auxiliary electrode 12 in the glass paste film b, as exemplified in FIG.

After the formation of the glass paste film b as described above, the glass paste film b is fired. Since the polishing step S4 described later is performed after such firing, even if the glass paste film b shrinks during firing, the auxiliary electrode 12
No deformation or the like occurs. Here, if a low melting point type of Bi or Pb is used as the glass paste, it can be fired at 530 ° C. Such low-temperature baking is effective for suppressing the amount of warpage and shrinkage of the glass plate as the transparent substrate 11.

Next, a polishing step S4 (see FIG. 2D)
The polishing of the glass paste film b is performed as follows using a head-fixed tape polishing machine 30 as shown in FIG. Here, the feed speed of the table 31 of the tape polishing machine 30 is 300 mm / min, and the winding speed of the polishing tape 32 by the roller 33 is 1200 mm / min.
Minutes. The polishing tape 32 is made of silicon carbide N
O. A polishing tape of 600 is employed.

First, the transparent substrate 11 is sandwiched between the upper surface of the table 31 and the tape portion 32a of the polishing tape 32 located between the rollers 34 and 35 so that the glass paste film b is positioned on the upper side (FIG. 3 (a)). At this time, the glass paste film b is applied on the upper surface of the table 31 by a roller 35 with a load of 40 kgf and a tape portion 32.
Pressed through a. The roller 35 is made of rubber having a rubber hardness of 60.

In such a state, as described above,
Arrow A shown on the table 31 at a feed rate of 300 mm / min.
, And the polishing tape 32 is wound up by the roller 33 at a winding speed of 1200 mm / min.

As a result, the glass paste film b is polished at its surface b1 (see FIG. 2C) by the polishing tape 32 at the tape portion 32a. The polishing at this time can be performed smoothly without damaging the glass paste film b since the roller 35 is formed of rubber having the above rubber hardness. In addition, the amount of polishing is set to an amount sufficient to expose the tip end surface of each auxiliary electrode 12 as an exposed surface.

With such polishing, when the surface b1 of the glass paste film b reaches the same surface as the exposed surface 12a of each auxiliary electrode 12, the polishing by the tape polishing machine 30 is stopped. As a result, the glass paste film b is formed as a plurality of stripe-shaped planarizing films 13, and the exposed surfaces 12a of the auxiliary electrodes 12 are uniformly exposed as illustrated in FIG.

In other words, the tape polishing machine 3 as described above
By polishing with 0, the surface 13a of each flattening film 13 is evenly planarized on the same plane as the exposed surface 12a of each auxiliary electrode 12, and the exposed surface 12a of each auxiliary electrode 12 is uniformly exposed. You.

The polishing of the glass paste film b is performed by using a belt polishing machine 40 shown in FIG. 3B or a head vibration type tape polishing machine 50 shown in FIG. May be performed.

Here, both rollers 4 of the belt polishing machine 40
The speed of the polishing belt 43 according to 1, 42, that is, the belt speed is 400 m / min. The feed speed of the belt polisher 40 to the transparent substrate 11 by each upper feed roller 44 and each lower feed roller 45 is 1 m / min. The polishing belt 43 is made of aluminum oxide NO.
A 1000 abrasive belt is employed. In addition,
The roller 41 is formed of rubber having a rubber hardness of 35.

According to such a belt polishing machine 40, the transparent substrate 11 is fed by the upper feed rollers 44 and the lower feed rollers 45 at the feed speed in the direction of arrow C in the figure.
Further, while the polishing belt 43 is wound up by the two rollers 41 and 42 in the direction of arrow D in the drawing at the above-mentioned winding speed, the respective flattening films 13 of the transparent substrate 11 are formed by the polishing belt 43 under the above rubber hardness of the roller 41. In the same manner as described above, flattening is performed smoothly.

As a result, the same operation and effect as in the case of polishing by the tape polishing machine 30 can be achieved. When the polishing is performed by the belt polishing machine 40, since there is a large difference between the feeding speed of the transparent substrate 11 and the winding speed of the polishing belt 43, the polishing is performed while spraying water on the polishing surface and cooling.

On the other hand, the feed speed of the table 51 of the head vibration type tape polishing machine 50 is 50 mm / min.
The feed speed of the polishing tape 52 by No. 3 is 50 m / sec. As the polishing tape 52, diamond NO. 60
0 is used as the polishing tape. The roller 53 is moved in the direction indicated by a double arrow F in FIG.
(The direction orthogonal to the moving direction of the roller 53), and the frequency of the roller 53 is 450 cpm. The roller 53 is formed of rubber having a rubber hardness of 60.

According to such a tape polishing machine 50, the polishing tape 52 is fed in the direction of the arrow G shown in the figure at the above-mentioned feed speed while the table 51 is fed in the direction of the arrow E in the figure at the above-mentioned feed speed. Is vibrated in the direction F in the figure at the above frequency, and the respective flattening films 13 of the transparent substrate 11 are smoothly flattened by the polishing tape 52 under the above rubber hardness of the roller 53 in the same manner as described above. As a result, the same operation and effect as in the case of polishing by the tape polishing machine 30 can be achieved.

After the polishing step S4 is completed as described above, in the transparent electrode material forming step S5 (see FIG. 2E), ITO is applied to the exposed surface 12a of each auxiliary electrode 12 and the flattening film 13. ITO on the surface 13a by sputtering
The film is formed as a film c.

The heat resistant temperature of the transparent substrate 11 is 580 ° C.
Therefore, instead of the above-described sputtering, a film may be formed by printing ITO which requires firing at about 400 ° C. Here, the printed ITO is formed by screen printing an organic acid ITO paste on the exposed surface 12 of each auxiliary electrode 12.
The printed ITO film may be formed by printing and applying a film on the surface 13a of each of the flattening films 13a and 13a, and firing the printed ITO film at about 400 ° C. to form the ITO film c. Thereby, the ITO film c can be formed at a lower cost than in the case of sputtering.

Next, a transparent electrode forming step S6 (FIG. 2)
2 (f), the ITO film c is developed and exposed by photolithography and patterned to form a plurality of striped transparent electrodes 14 as illustrated in FIG. 2 (f). Here, each transparent electrode 14 has
Each is formed so as to cover the entire exposed surface 12a of each corresponding auxiliary electrode 12 and to cover a part of each surface of the planarizing film 13 on both sides thereof.

In this case, as described above, the exposed surface 12a of each auxiliary electrode 12 is on the same plane as the surface 13a of each flattening film 13 and is uniformly exposed by the above polishing. Is the exposed surface 12a of each corresponding auxiliary electrode 12.
Can be uniformly adhered. Thereby, good electrical conductivity between each transparent electrode 14 and each corresponding auxiliary electrode 12 can be secured.

Thereafter, an insulating film forming step S7 (FIG. 2G)
2), a transparent insulating film material is applied by printing to the surface 13a of each planarizing film 13 via each transparent electrode 14 to form an insulating film (see reference numeral d in FIG. 2G). Next, in an alignment film forming step S8 (see FIG. 2 (h)), a transparent alignment film material (for example, polyimide) is formed on the insulating film d as an alignment film (see reference numeral e in FIG. 2 (h)). I do. Thus, the manufacture of the lower electrode substrate 10 is completed.

In the lower electrode substrate 10 manufactured as described above, as described above, the exposed surface of each auxiliary electrode 12 and the surface of each flattening film 13 are both planarized in the same plane. Even if such a lower electrode substrate 10 is superposed on the upper electrode substrate 20 via a seal and a spacer to form a liquid crystal panel, the distance between the two electrode substrates 10 and 20 is uniform. As a result, the occurrence of display unevenness of the liquid crystal panel can be favorably prevented. Since the lower electrode substrate 10 has a structure in which the auxiliary electrode 12 is embedded between the planarizing films 13, the planarizing film 13 and the auxiliary electrode 1 are formed.
By adjusting the height of 2, the wiring resistance of the transparent electrode 14 can be reduced, so that the aperture ratio of the display area as the liquid crystal panel does not decrease.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention. The lower electrode substrate of the liquid crystal panel in the second embodiment is different from the lower electrode substrate 10 of the liquid crystal panel described in the first embodiment in that a plurality of stripe auxiliary electrodes 12 are used instead of the plurality of stripe auxiliary electrodes 12. The electrode 15 (see FIGS. 4C to 4G) is provided. FIGS. 4C to 4G show an example of the plurality of stripe-shaped auxiliary electrodes 15.
Other configurations are the same as those in the first embodiment.

Next, a method of manufacturing the lower electrode substrate of the liquid crystal panel thus configured will be described with reference to FIG.
First, in a Ni electroless plating step R1 of FIG. 4A, Ni is plated on the inner surface of the transparent substrate 11 described in the first embodiment by an electroless plating method to form a Ni film f.

Next, a Cu electric field plating step R shown in FIG.
2, the Ni film f was used as an electrode on the Ni film f
u is plated by an electric field plating method to form a stacked Cu film g. As described above, the Cu film g was formed on the Ni film f because the Cu film g was directly formed on the glass substrate as the transparent substrate 11 by the electroplating method. In consideration of insufficient adhesion to the glass substrate, a Ni film f made of Ni having good adhesion to the glass substrate is effectively used as a base electrode.

Next, an auxiliary electrode forming step R3 (FIG. 4)
(C), the Cu film g laminated and formed as described above.
The Ni film f is etched by a photolithography method to form a plurality of stripe-shaped auxiliary electrodes 15. FIG. 4C shows an example of the auxiliary electrode 15.

In the following flattening film material forming step R4 shown in FIG. 4D, the glass paste film b is formed by the same processing as the flattening film material forming step S3 described in the first embodiment. Is formed on the inner surface of the transparent substrate 11 in such a thickness that the auxiliary electrodes 15 are sufficiently embedded in the glass paste film b.

Thereafter, a polishing step R5 shown in FIG.
Then, the glass paste film b is polished by the same processing as the polishing step S4 described in the first embodiment. As a result, the glass paste film b is formed as a plurality of stripe-shaped flattening films 13 as in the first embodiment, and the exposed surface 15a (the tip surface of the Cu film g) of each auxiliary electrode 15 is formed as shown in FIG. As shown in (e), it is uniformly exposed. In other words, the surface 13a of each planarization film 13 is evenly planarized on the same plane as the exposed surface 15a of each auxiliary electrode 15, and the exposed surface 15a of each auxiliary electrode 15 is uniformly exposed. .

After such a polishing treatment, in the transparent electrode material forming step R6 shown in FIG. 4F, the ITO is formed by the same processing as the transparent electrode material forming step S5 described in the first embodiment. The film c is formed on the exposed surface 15a of each auxiliary electrode 15 and the surface 13a of each flattening film 13.

Next, in a transparent electrode forming step R7 shown in FIG. 4G, a plurality of stripe-shaped transparent electrodes 14 are formed by patterning in the same manner as in the transparent electrode forming step S6 described in the first embodiment. I do. Here, each transparent electrode 14 is formed on its back surface so as to cover the entire exposed surface 15a of each corresponding auxiliary electrode 15 and to cover a part of each surface of the flattening film 13 on both sides thereof. .

In this case, as described above, each planarizing film 13
Is flattened, and the exposed surface 15a of each auxiliary electrode 15 is
Are located on the same plane as the surface 13a of each flattening film 13 and are uniformly exposed by the above polishing.
Can uniformly contact with the corresponding exposed surface 15a of each auxiliary electrode 15. Thereby, good electrical conductivity between each transparent electrode 14 and each corresponding auxiliary electrode 15 can be secured.

After the transparent electrode forming step R7,
The processes of the insulating film forming step S7 and the alignment film forming step S8 described in the first embodiment are performed in the same manner, and the manufacture of the lower electrode substrate in the second embodiment is completed.

When the liquid crystal panel is constructed by overlapping the lower electrode substrate thus manufactured with the upper electrode substrate 20 in the same manner as in the first embodiment, the distance between the two electrode substrates is uniform. Become. As a result, the occurrence of display unevenness of the liquid crystal panel can be favorably prevented. Other functions and effects are the same as those of the first embodiment.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention. In the third embodiment, the lower electrode substrate of the liquid crystal panel (corresponding to the lower electrode substrate 10 described in the first embodiment) has a flat silver paste, which is a material for forming the auxiliary electrodes 12, having a flat hardness. Utilizing that the hardness is much lower than the hardness of the glass paste which is the material for forming the oxide film 13, it is manufactured as follows.

When the silver paste and the glass paste were fired, the hardness of the silver paste was 16.7, and the hardness of the glass paste was 212.4. Therefore, it can be seen that the hardness of the silver paste is significantly lower than the hardness of the glass paste.
The hardness was measured using a 115 ° triangular pyramid indenter with a DUH-201S type hardness measuring device manufactured by Shimadzu Corporation.
gf with a load.

First, in the auxiliary electrode material forming step S11 shown in FIG. 5A, the photosensitive material is formed by substantially the same processing as the auxiliary electrode material forming step S1 described in the first embodiment. A silver paste is formed as a silver paste film a1 on the inner surface of the transparent substrate 11, then calcined and dried. However, in the third embodiment, the thickness of the silver paste film a1 is
The thickness is sufficiently larger than the thickness of the silver paste film a described in the first embodiment.

Next, in the silver paste film portion forming step S21 shown in FIG. 5B, the silver paste film a1 is formed by the same processing as the auxiliary electrode forming step S2 described in the first embodiment. Each silver paste film portion a2 having the same width as the auxiliary electrode 12 is patterned and formed. In addition,
FIG. 5B shows an example of the silver paste film part a2.

After such patterning, FIG.
In the flattening film material forming step S31 shown in (c),
Flattening film material forming step S3 described in the first embodiment
By substantially the same process as above, a glass paste is formed on the inner surface of the transparent substrate 11 as a plurality of stripe-shaped glass paste films b1 instead of the glass paste film b.
In this case, the thickness of each glass paste film b1 is smaller than the thickness of the silver paste film a1, and is equal to the height of the auxiliary electrode 12 described in the first embodiment.

In the following polishing step S41 shown in FIG. 5D, unlike the polishing step S4 described in the first embodiment, the polishing of each silver paste film portion a2 is performed according to the first embodiment. This is performed using the fixed head tape polishing machine 30 described above. That is, each of the silver paste film portions a2 is polished at its leading end surface by the polishing tape 32 at the tape portion 32a. Along with this, the front end surface of each silver paste film part a2 becomes the surface of each glass paste film b1, that is, each auxiliary electrode 12a.
When it reaches the same plane as the exposed surface 12a, the tape polishing machine 30
Is stopped.

Thus, each silver paste film portion a2 is formed as each auxiliary electrode 12, and the exposed surface 1 of each auxiliary electrode 12 is formed.
2a is uniformly exposed as illustrated in FIG. 5D. At this time, the surface of each glass paste film b1 is slightly polished for flattening to become each flattening film 13.

As described above, the third embodiment differs from the first embodiment in that the hardness of each silver paste film portion a2 is significantly lower than the hardness of each glass paste film b1. After forming the silver paste film portion a2 thicker than each glass paste film b1, each silver paste film portion a2 is polished. As a result, the third embodiment can achieve the following specific effects as compared with the first embodiment.

In the first embodiment, as described above, the glass paste film b is polished instead of the auxiliary electrodes 12, but the glass paste film b has a high hardness, so that the glass paste film b is easily broken during polishing. Therefore, if the glass paste film b is polished with fine abrasive grains in order to prevent this cracking, it takes a long time to remove unnecessary portions of the glass paste film b by polishing.

On the other hand, if the glass paste film b is polished with coarse abrasive particles, unnecessary portions of the glass paste film b can be removed by polishing in a short time, but there are streaks and cracks on the polished surface of the glass paste film b. And disconnection of the auxiliary electrode. For this reason, even when the finishing process is performed, the flatness of the flattening film 13 cannot be sufficiently secured.

On the other hand, in the third embodiment, as described above, each glass paste film b1 (glass paste film b
), Rather than the respective silver paste film portions a2 (the above first paste material) having significantly lower hardness than the respective glass paste films b1.
(Corresponding to each auxiliary electrode 12 in the embodiment). Therefore, the silver paste film portion a2 can be polished smoothly and satisfactorily in a short period of time without causing breakage of the glass paste film b1 or disconnection of the auxiliary electrode 12, etc., while reducing the abrasive grains. it can.

In the first embodiment, the glass paste film b is formed with a thickness such that the auxiliary electrode 12 is embedded therein. For this reason, the removal amount of the glass paste film b is large, and as a result, the removal by polishing is not easily performed in combination with the high hardness of the glass paste film b. Then, the surface of the planarizing film 13 is roughened, so that leveling by the ITO is difficult at the time of forming the ITO, and the resist adhesion at the time of etching the ITO is poor, so that the patterning process cannot be performed well.

On the other hand, in the third embodiment, as described above, each silver paste film portion a2 is replaced with each glass paste film b.
Since each silver paste film portion a2 is polished after being formed thicker than 1, the amount of polishing is considerably smaller than when the glass paste film b is polished as in the first embodiment. Therefore, the polishing time of the third embodiment can be reduced as compared with the case of the first embodiment.

Further, in the third embodiment, as described above, since each silver paste film portion a2 is polished, the polishing can be performed smoothly. Therefore, the patterning of the ITO film can be favorably performed without causing the surface of the flattening film 13 to be rough.

In the third embodiment, as described above, when forming each glass paste film b1 on the inner surface of the transparent substrate 11 in the flattening film material forming step S31, as described above, Unlike this, as shown in FIG. 5C, the glass paste film b11 is formed unnecessarily on the tip end surface of the silver paste film part a2.

However, the auxiliary electrode material film forming step S11
In the above, the silver paste becomes porous when the binder is preliminarily fired, so that the glass paste film b11 formed as described above becomes porous and is absorbed by the silver paste film part a2. Therefore, the glass paste film b
11 becomes thinner. Therefore, the subsequent polishing step S4
1 can further reduce the amount of polishing.

In the first embodiment, when the glass paste film portion on each auxiliary electrode is to be entirely removed, the portion of each auxiliary electrode exposed at the initial stage is formed by the glass paste film and the silver paste film. Due to the difference in hardness between the portions, the silver paste film is excessively shaved while it takes time to remove the glass paste film in a portion other than the exposed portion. Therefore, the exposed surface of the auxiliary electrode has a concave shape with respect to the surface of the glass paste film.

On the other hand, if the polishing of the glass paste film is completed early, the glass paste film portion on the auxiliary electrode cannot be completely removed. On the other hand, in the third embodiment, as described above, unlike the first embodiment, each silver paste film portion a
2 is polished, the surface of each glass paste film b1 having a higher hardness than each of the silver paste film portions a2 serves as a stopper for the polishing amount. Therefore, the exposed surface of the auxiliary electrode is not excessively shaved and does not become concave with respect to the surface of the glass paste film.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention. In the fourth embodiment, the lower electrode substrate of the liquid crystal panel (corresponding to the lower electrode substrate described in the second embodiment) has a hardness of a Ni film and a Cu film, which are materials for forming the auxiliary electrodes 15, respectively. Utilizing the fact that the hardness of the glass paste which is the material for forming each flattening film 13 is significantly lower than that of the glass paste, it is manufactured as follows.

In the Ni electroless plating step R11 shown in FIG. 6A, Ni is electrolessly plated on the inner surface of the transparent substrate 11 by the same processing as the Ni electroless plating step R1 in the second embodiment. A Ni film f is formed by plating by a method.

Next, in a Cu electric field plating step R21 shown in FIG. 6B, a Cu film g1 is formed on the Ni film f by substantially the same processing as the Cu electric field plating step R2 in the second embodiment. Electroplating is formed. However, the fourth
In the embodiment, the sum of the thickness of the Cu film g1 and the thickness of the Ni film f is the same as the thickness of the silver paste film a1 described in the third embodiment. The reason why the Cu film g1 is formed on the Ni film f is that the insufficient adhesion between the Cu film g1 and the transparent substrate 11 is caused by the Ni film as in the case of the second embodiment. This is to prevent by f.

Next, in the Ni.Cu film portion forming step R31 shown in FIG. 6C, the Ni film f and the Ni film f are formed by the same process as the silver paste film portion forming step S21 described in the third embodiment. The Cu film g1 is patterned and formed as a Ni.Cu film portion having the same width as each auxiliary electrode 15.

After such patterning, FIG.
In the flattening film material forming step R41 shown in (d), the glass paste is converted into a plurality of striped glass paste films b1 by the same processing as the flattening film material forming step S31 described in the third embodiment. Is formed on the inner surface of the transparent substrate 11.

Thereafter, a polishing step R5 shown in FIG.
1, the polishing step S4 described in the third embodiment.
The Ni / Cu film portions are polished by the same processing as in step 1. Thus, each of the polished Ni and Cu film portions is formed as each of the auxiliary electrodes 15 (see FIG. 4). Thereby, the same operation and effect as in the third embodiment can be achieved.

Here, in the flattening film material forming step R41, each glass paste film b2 is formed on the inner surface of the transparent substrate 11.
Is formed, a Cu film g is formed as shown in FIG.
Even if the glass paste film b3 is thinly and unnecessarily formed on the front end surface of the substrate 1, the glass paste film b3 can be easily polished and removed in the subsequent polishing step R51. No problem.

(Fifth Embodiment) FIG. 7 shows a fifth embodiment of the present invention. In the lower electrode substrate according to the fifth embodiment, the hardness of the silver paste, which is a material for forming each auxiliary electrode (corresponding to each auxiliary electrode 15) on the lower electrode substrate, is equal to each flattening film (each flattening film 13). Using the fact that the hardness is significantly lower than the hardness of the glass paste as the forming material of (corresponding to), it is manufactured as follows.

In the Ni electroless plating step T1 shown in FIG. 7A, a film of about 100 nm is formed on the inner surface of the transparent substrate 11 by the same processing as the Ni electroless plating step R1 in the second embodiment. A thick Ni film h is formed. It should be noted that instead of this Ni film h, a Cr film was formed on the transparent substrate 11.
May be formed on the inner surface.

Next, in a Ni film patterning step T2 shown in FIG. 7B, a plurality of stripe-shaped Ni film portions i are formed by patterning the Ni film h by photolithography. Next, in a flattening film material forming step T3 shown in FIG. 7C, a photosensitive glass paste is applied to the inner surface of the transparent substrate 11, a glass paste film j is formed, and baked.

Then, in a flattening film material film formation patterning step T4 shown in FIG. 7D, the glass paste film j is exposed and developed by photolithography.
In the glass paste film j, a stripe-shaped opening j1 having a trapezoidal cross section is formed on each Ni film portion i. As a result, the glass paste film j is formed as a plurality of stripe-shaped flattening films j2 (corresponding to the plurality of flattening films 13) between the openings j1. Each Ni film portion i is exposed to the outside through each opening j1.

However, when forming each opening j1, exposure and
By selecting the developing condition, each of the openings j1 is formed as shown in FIG.
As shown in the example, the divergent shape extends upward in the figure. Thereby, it is possible to prevent disconnection of the later-described ITO film formation. After the exposure and development, each Ni film portion i is finally baked.

Next, in a Cu electric field plating step T5 shown in FIG. 7E, Cu is plated on each Ni film part i by an electric field plating method using the Ni film part i as a base electrode.
The u film part k is formed. Here, the thickness of each Cu film portion k is
Each opening j1 is larger than the depth.

Thereafter, a polishing step T6 shown in FIG.
In the above, each Cu film portion k is polished in the same manner as in the polishing step R51 of the fourth embodiment, so that the polished Cu film portion k1
Form as This polished Cu film portion k1 and Ni film portion i
Constitute the auxiliary electrode. Here, the surface of each polished Cu film portion k1 is the same as the surface of each flattening film j2 and is uniformly exposed.

Next, in a transparent electrode material forming step T7 shown in FIG. 7G, an ITO film c is formed in the same manner as in the third embodiment, and a transparent electrode forming step shown in FIG. At T7, each transparent electrode 14 is formed in the same manner as in the third embodiment. Even when the lower electrode substrate is manufactured in this manner, the same operation and effect as those of the fourth embodiment (see FIG. 6) can be achieved.

(Sixth Embodiment) FIG. 8 shows a method of manufacturing an electrode substrate for a display panel according to the present embodiment. This manufacturing method shows a method for manufacturing the lower electrode substrate 10 of the liquid crystal panel shown in FIG. 1 above, and the same parts as those in FIG. 2 are denoted by the same reference numerals in FIG. To simplify. In the present embodiment, a plurality of stripe-shaped transparent electrodes (main electrodes in the present invention) 14 are formed of IZO (Indium Zi).
nc Oxide) is different from the above embodiments. Hereinafter, the present embodiment will be described in the order of the manufacturing process.

First, in the auxiliary electrode material forming step S1 shown in FIG. 8A, a photosensitive silver paste is applied on the inner surface of a transparent substrate 11 such as a glass substrate by a printing method to form a silver paste film a. Form a film. In this example, the printed film thickness of the silver paste film a can be about 10 μm. After the above film formation,
The silver paste film a is pre-baked at a temperature of 80 ° C. and dried.

Next, an auxiliary electrode forming step S2 (FIG. 8)
In (b), the silver paste film a is developed (patterned) and baked at, for example, about 570 ° C. to form a plurality of stripe-shaped auxiliary electrodes 12. The auxiliary electrode (silver paste) 12 that has been finally fired contracts to a thickness of about 5 μm in this example. In the next flattening film material forming step S3 (see FIG. 8C), a low melting point type glass paste (low melting point glass paste, transparent lead glass in this example) as shown in the first embodiment. Is printed on the inner surface of the transparent substrate 11 and temporarily baked (80 ° C. in this example) to obtain a glass paste film b.
As a film.

After forming the glass paste film b in this step S3, main firing (550 ° C. in this example) is performed. At this time, the lead glass is melted, and the porous auxiliary electrode (silver wiring) 12
In the following polishing process S4 (FIG. 8)
(See (d)), a polishing process is performed in the same manner as in the first embodiment, and the surface b1 of the glass paste film b and each auxiliary electrode 1
2 and the same exposed surface 12a.

As a result, the glass paste film b is formed as a plurality of stripe-shaped flattening films 13 and
The exposed surface 12a of each auxiliary electrode 12 is uniformly exposed as illustrated in FIG. Steps S1 to here
Step S4 is the same as in the first embodiment, but in this embodiment, a transparent electrode material film forming step U5 and a transparent electrode forming step U6 to be performed next are different from those in the first embodiment.

First, in the transparent electrode material forming step U5 shown in FIG. 8E, IZO (ID-IXO (trade name) manufactured by Idemitsu Kosan Co., Ltd.) is used as a main electrode forming material. The IZO film (in the present invention) is formed by sputtering this IZO on the exposed surface 12a of each auxiliary electrode 12 and the surface 13a of each flattening film (material film) 13 so as to have a predetermined thickness (500 Å in this example). The film is formed as a covering film m.

Next, in a transparent electrode forming step U6 shown in FIG. 8F, the transparent electrode 14 is formed by etching with an etching solution obtained by diluting an acid with an organic solvent. In this example, the IZO film m which becomes the transparent electrode 14 is formed of a photosensitive resist material.
Mask the surface of. Next, n is used as an etchant.
Using a mixture of 99% butanol and 1% 35% hydrochloric acid, immersing it at a liquid temperature of 25 ° C. for about 3 minutes to pattern the IZO film m to form the transparent electrode 14. Here, if the liquid temperature is set to 30 ° C. or higher or a small amount of water is mixed in the etching liquid, the surface of the lead glass, which is the flattening film 13, becomes locally clouded or dug in, so care must be taken. Also, an unnecessarily long time (for example, 10 minutes or more)
If the substrate is immersed, the lead glass may be attacked.

Thereafter, similarly to the first embodiment, an insulating film forming step S7 (see FIG. 8G) is performed to form an insulating film d for preventing short circuit between the upper and lower electrode substrates 10, 20. . Here, in this example, the insulating film d can be formed by forming a film of tantalum oxide by sputtering or forming a film of an organic Ti (organic titanium) -based material by a sol-gel method. Further, similarly to the first embodiment, in the alignment film forming step S8 (see FIG. 8H), the insulating film d is printed by a method such as printing a transparent alignment film material (eg, polyimide) by an offset method. An alignment film e is formed thereon. Thus, the manufacture of the lower electrode substrate 10 is completed.

In the present embodiment, in the transparent electrode material forming step U5 and the transparent electrode forming step U6, I
After forming the IZO film m by ZO, this IZO film m
Is etched with an etching solution obtained by diluting an acid with an organic solvent to form a transparent electrode 14 as a main electrode. The grounds for adopting such a method will be described below.

The transparent electrode material forming step S5 and the transparent electrode forming step S6 (FIG. 2E and FIG.
In (f), ITO is formed as a material of the transparent electrode 14 by sputtering or printing. And
In order to form the transparent electrode 14, the surface of the ITO film c serving as an electrode is masked with a photosensitive resist material, and patterned with a common ITO etching solution such as a mixed solution of hydrochloric acid and ferric chloride, aqua regia, and the like. Is peeled off.

However, in this method, as described above,
The flattening film 13 which is a low melting point glass (for example, lead glass) is clouded and melted by a general ITO etching solution. Actually, although a 20% oxalic acid solution which is relatively weakly acidic among the ITO etching solutions was tried, the flattening film 1 was used.
The lead glass No. 3 became cloudy. As described above, since the low-melting glass was found to have low acid resistance, Au (gold), ZnO (zinc oxide), and the like were also examined as transparent electrode materials that can be patterned with an etchant having a lower acidity than ITO. .

However, although Au can be etched with an aqueous solution of KI (potassium iodide), it is difficult to use it for an electrode substrate for a display panel because its transmittance is low even if it is deposited at a film thickness of 500 Å or less. Was. ZnO can be patterned with a weakly acidic aqueous solution of 1% acetic acid. However, when ZnO is formed by an ion plating method, it reacts with the lead glass as the flattening film 13 and changes color to black. I knew I couldn't.

Then, next, IZO was selected as a material for forming the transparent electrode 14 (material for forming the main electrode), and this IZO was selected.
Was formed to a film thickness of 1500 angstroms by sputtering, and an acceptable transmittance was secured. However, in the oxalic acid aqueous solution, which is an etchant for IZO, lead glass is discolored as described above. Therefore, etching with a 1% aqueous solution of acetic acid, which is an extremely weak acid, results in a solution temperature of 70 ° C.
Patterning was possible in 5 minutes, but the lead glass became cloudy.

From these results, the low-melting glass (such as lead glass) used as the flattening film 13 is easily discolored by the reaction with the transparent electrode forming material, is weak to acid, and reacts with the moisture in the etching solution. The material was found to be easily turbid. Therefore, it is necessary to select a transparent electrode material that does not react with the low-melting glass and that can be etched with weak acidity, and that the etching solution be weakly acidic and contain as little moisture as possible.

Therefore, as a result of examining various combinations, it was found that IZO may be used as a material for forming a transparent electrode, and a solution obtained by diluting a trace amount of an acid with an organic solvent may be used as an etching solution. Specifically, as an etchant,
As described above, a mixture of 1% of 35% hydrochloric acid with respect to 99% of n-butanol may be used. In the case of this mixed system,
If 35% hydrochloric acid exceeds 3%, the lead glass becomes cloudy.

In addition, other etchants such as i
97% so-propanol and 3% hydrochloric acid, is
Even when using 97% of o-propanol and 3% of chlorosulfonic acid, IZO can be etched without attacking the low-melting glass (such as lead glass) which is the flattening film 13. Further, it was also found that those containing 2% or less of water in these specific etching solutions are preferable for preventing clouding of the low-melting glass. The above is the grounds for adopting the etching method of the present embodiment.

Such an etching method, that is, the steps U5 and U6 are applicable to the second, third, and fourth embodiments also when a low-melting glass paste is used as a material for forming a flattening film. . According to the present embodiment, in addition to obtaining the same effects as those of the above-described first to fourth embodiments, a manufacturing method for appropriately preventing the above-described problem of white turbidity and melting of the low melting point glass is provided. Can be provided.

According to the study of the present inventors, it is possible to use a paste of an organic acid ITO that can be screen-printed or spin-coated as a material for forming the transparent electrode 14 instead of IZO. In this case, the organic acid I
Attention must be paid to the fact that the etching time becomes longer depending on the film quality that changes depending on the TO baking conditions and the like, and as a result, the lead glass surface of the flattening film 13 may be attacked.

(Other Embodiments) In practicing the present invention, the present invention is applied not only to the transmission type liquid crystal panel electrode substrate described in each of the above embodiments but also to the reflection type liquid crystal panel electrode substrate. You may. Further, in carrying out the present invention, the present invention is not limited to the matrix driving type liquid crystal panel electrode substrate described in each of the above embodiments, and may be applied to various driving type liquid crystal panel electrode substrates. Good.

In the practice of the present invention, the liquid crystal of the liquid crystal panel is not limited to a smectic liquid crystal, but may be various types of liquid crystal. In practicing the present invention,
The present invention is not limited to a liquid crystal panel, and may be applied to various types of display panel electrode substrates such as an electroluminescence panel.

The present specification includes the following problems, means for solving the problems, and another invention having effects achieved by the means. Although the embodiment of the present invention is based on the above-described sixth embodiment using the manufacturing method of FIG. 2, it is needless to say that the method of forming the transparent electrode in the above-described second to fifth embodiments, Can be applied to other embodiments.

Problem: When a substrate of a display panel (for example, a flat display panel such as a liquid crystal display panel, a plasma display panel, and an EL panel) is made of low-cost glass such as lead glass, the low-melting glass is used. A transparent conductive film composed of ITO (indium / tin oxide) or IZO (indium / zinc oxide) is formed on the surface of the substrate made of, and the conductive film is striped using a normal etching solution (for example, aqua regia). The present inventor has found that when an electrode is formed by patterning in the shape of a glass, the low melting point glass becomes cloudy and dissolves by the etching solution.

As a result of close examination, the melting of the low melting point glass is caused by the fact that the acid resistance of the low melting point glass is extremely low, and the etching rate by the etching solution is higher than the etching rate of the conductive film. Further, it was found that the cloudiness of the low-melting glass was caused by moisture in the etching solution.

As a result of intensive studies, the present inventor has used a transparent conductive film made of a material having a lower acid resistance and a higher etching rate than the low-melting glass, and also made the etching solution have an aggressiveness to the low-melting glass. It has been found that by using a low etching solution in which an acid is diluted with an organic solution, clouding and dissolution of the low-melting glass by the etching solution can be avoided.

Means for solving the problem: The following structure is provided to achieve the above-mentioned problem. That is, (1) a transparent conductive film made of a material having a lower acid resistance and a higher etching rate than the low melting glass is formed on the low melting glass, and an etching solution obtained by diluting an acid with an organic solvent is used. (2) In the above (1), the organic solvent is an alcohol, and (3) the above (1), wherein the transparent conductive film is patterned by etching. (1) or (2), wherein the acid is hydrochloric acid or chlorosulfonic acid; (4) in (2), the alcohol is n-butanol or iso-propanol; ) The above (1)-
(4) The etching method according to any one of (1) to (5), wherein the amount of water contained in the etching solution is within 2%. (7) In the etching method, wherein the low-melting glass is mainly composed of lead glass, (7) In any one of (1) to (6), the low-melting glass is a substrate constituting a display panel An etching method,
(8) In any one of (1) to (7), the transparent conductive film is made of an organic acid ITO or IZO.

Effects: The effects of the above configurations (1) to (8) are as follows. That is, according to (1) to (8), the transparent conductive film formed on the surface of the low-melting glass is patterned with the etching solution having the above-described specific configuration, thereby avoiding clouding and dissolution of the low-melting glass. Can be. Therefore, for example, when the low-melting glass is used as a substrate of a display panel, the low-melting glass substrate does not become cloudy, and various performances as a display panel, for example, light transmittance is reduced. Disappears.

Further, it was found that the low-melting glass became cloudy due to the moisture in the etching solution. For this reason, (2)-
As described in (5), by using an etchant having a water content of 2% or less (including 0%), it is possible to favorably prevent the low-melting glass from becoming cloudy.

It is to be noted that hydrochloric acid or chlorosulfonic acid is preferable as the acid which is an effective component of the etching solution. Also,
The alcohol of the organic solvent is n-butanol or iso.
-Propanol is preferred, the alcohol having a water content of 2
Easy to adjust within%.

The transparent conductive film is preferably made of IZO or organic acid ITO. IZO is usually formed by sputtering, but since it has a high etching rate, it can be etched even with the above-mentioned etching solution. On the contrary,
When a film formed by ordinary sputtering is used as ITO, the crystal structure is strong and etching is difficult, so it is preferable to use an organic acid ITO that can be formed by coating and heat treatment.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a liquid crystal panel according to the present invention.

FIGS. 2A to 2H are process diagrams showing a method for manufacturing the lower electrode substrate of the liquid crystal panel.

FIGS. 3A to 3C are schematic diagrams each showing a polishing machine for polishing a glass paste film.

FIG. 4 is a main part manufacturing process diagram of a lower electrode substrate according to a second embodiment of the present invention.

FIG. 5 is a main part manufacturing process diagram of a lower electrode substrate according to a third embodiment of the present invention.

FIG. 6 is a main part manufacturing process diagram of a lower electrode substrate showing a fourth embodiment of the present invention.

FIG. 7 is a main part manufacturing process diagram of a lower electrode substrate showing a fifth embodiment of the present invention.

FIG. 8 is a main part manufacturing process diagram of a lower electrode substrate showing a sixth embodiment of the present invention.

[Explanation of symbols]

11: transparent substrate, 12, 15 ... auxiliary electrode, 12a, 15
a: exposed surface, 13: flattening film, 14: transparent electrode, R1,
R11, T1 ... Ni electroless plating step, R2, R21 ...
Cu electroplating step, R3, S2 ... auxiliary electrode forming step,
R31: Ni / Cu film portion forming step, R4, S3, S3
1, T3: flattening film material forming step, R5, S4, S4
1, R51: polishing step, R6, S5, U5: transparent electrode material film forming step, R7, S6, U6: transparent electrode forming step, S
1, S11: auxiliary electrode material forming step, S21: silver paste film forming step, T2: Ni film patterning step, T4 ...
Flattening film material deposition patterning step.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akinari Fukaya 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Hiromichi Kato 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Co., Ltd. Inside DENSO (72) Inventor Kazushige Suematsu 1-1-1, Showa-cho, Kariya, Aichi Prefecture Inside DENSO Corporation

Claims (11)

[Claims] An auxiliary electrode forming step (S1, S2, R1 to R3) for forming a plurality of stripe-shaped auxiliary electrodes (12) from a metal material on an inner surface of a substrate (11); A material film forming step (S3, R4) of forming a material film by coating the inner surface of the substrate so as to embed each auxiliary electrode, and exposing a tip end surface of each auxiliary electrode as an exposed surface (12a). A polishing step of polishing the surface of the material film (S
4, R5) and a main electrode forming step (S5, S6, R6, R7, U5, U6) of forming a striped main electrode (14) on the exposed surface of each auxiliary electrode along its longitudinal direction. The manufacturing method of the electrode substrate for display panels provided. 2. In the material film forming step, a low melting point glass paste is used as the flattening film forming material, and the low melting point glass paste is fired at a predetermined temperature to form the material film. The method for manufacturing an electrode substrate for a display panel according to claim 1. 3. In the auxiliary electrode forming step, a photosensitive Ag paste is used as the metal material, and the Ag paste is applied to the inner surface of the substrate, and the auxiliary electrodes are formed by a patterning process using a photolithography method. 3. The method of manufacturing an electrode substrate for a display panel according to claim 1, wherein: 4. In the auxiliary electrode forming step, Cu and Ni are used as the metal material, and the Ni is formed as an Ni film on the inner surface of the substrate by electroless plating. Are formed on the Ni film by electroplating to form a Cu film.
The method for manufacturing an electrode substrate for a display panel according to claim 1, wherein the auxiliary electrodes are formed by patterning a film by a photolithography method. 5. An auxiliary electrode forming step (S1) for forming a plurality of stripe-shaped auxiliary electrodes on the inner surface of a substrate using a metal material.
1, S21, R11 to R31), and a flattening film forming material having a higher hardness than the metal material on the inner surface of the substrate along the space between the auxiliary electrodes so that the tip end surfaces of the auxiliary electrodes protrude. Film forming step (S31, R4)
1) and a polishing step of polishing an end surface of each of the auxiliary electrodes until the front surface of each auxiliary electrode coincides with the surface of each of the flattening films to form an exposed surface (S41,
R51) and a main electrode forming step (S) of forming a stripe-shaped main electrode on the exposed surface of each auxiliary electrode along the longitudinal direction thereof.
5, S6, R6, R7, U5, U6). 6. An auxiliary electrode / flattening film forming step (T1 to T5) of alternately forming a plurality of auxiliary electrodes and flattening films in a stripe pattern on the inner surface of the substrate (11), and exposing each of the auxiliary electrodes. A main electrode forming step (T7, T8) of forming a main electrode (14) in the form of a stripe along the longitudinal direction on the surface, wherein the auxiliary electrode and the flattening film are provided. Forming a plurality of stripe-shaped base electrodes (h,
(i) forming a base electrode forming step (T1, T2); and forming a material film (j) by coating a flattening film forming material on the inner surface of the substrate so as to cover each base electrode. A step (T3), an opening / flattening film forming step (T4) of forming a stripe-shaped opening in the material film so as to face each of the base electrodes and forming a flattening film between the openings. And (T5) a conductive member forming step of forming a stripe-shaped conductive member by filling a conductive metal material by electroplating into each of the openings so as to protrude from each of the openings on each of the base electrodes. The tip surface of each conductive member is polished until it matches the surface of each planarizing film to form an exposed surface, and each conductive member having the exposed surface is formed as an auxiliary electrode together with its base electrode. Laboratory A method for manufacturing an electrode substrate for a display panel, comprising a polishing step (T6). 7. A substrate (11), auxiliary electrodes and flattening films alternately formed in a plurality of stripes on the inner surface of the substrate, and stripes are formed along the longitudinal direction on the exposed surface of each of the auxiliary electrodes. A main electrode (14) formed on the display panel, wherein the plurality of auxiliary electrodes are each a stripe-shaped base electrode (i) provided on an inner surface of the substrate; An electrode substrate for a display panel, comprising: a conductive member (k1) formed by electroplating a conductive metal material on the underlying electrode between the planarizing films on both sides of the underlying electrode in the planarizing film. 8. A main electrode forming material for forming the main electrode (14) using IZO or organic acid ITO in the main electrode forming step (U5, U6) using a low melting point glass paste as the flattening film forming material. After forming a covering film (m) covering the material film and the exposed surface of each of the auxiliary electrodes with this main electrode forming material, the covering film is etched with an etching solution obtained by diluting an acid with an organic solvent. 6. The method according to claim 1, wherein the main electrode is formed.
3. The method for producing an electrode substrate for a display panel according to item 1. 9. The method for manufacturing an electrode substrate for a display panel according to claim 8, wherein the etching solution has a water content of 2% or less. 10. The method according to claim 8, wherein hydrochloric acid or chlorosulfonic acid is used as an acid of the etching solution. 11. The method according to claim 8, wherein n-butanol or iso-propanol is used as an organic solvent of the etching solution.
5. A method for manufacturing an electrode substrate for a display panel according to any one of the above.