JPH1078589A - Wiring board, liquid crystal element having the wiring board and production of the wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the delay of voltage waveforms, to reduce the thickness and weight of a liquid crystal panel and to reduce the cost thereof. SOLUTION: This liquid crystal panel is provided with metallic wirings 23 in addition to transparent electrodes 25 and, therefore, the resistance value of the electrodes may be lowered and the delay of the voltage waveforms may be prevented. The metallic wirings 23 are formed by an inexpensive method, by which the cost of the liquid crystal panel itself is reduced. Further, the metallic wirings 23 are formed by a plating method and, therefore, the use of a resin as a translucent base material 21 is possible. Consequently, the lightweight and thin liquid crystal panel is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-resistance wiring board, a liquid crystal device having the wiring board, and a method of manufacturing the wiring board.

[0002]

2. Description of the Related Art Hitherto, liquid crystal devices using liquid crystals have been used in various fields. As one example, the structure of a liquid crystal panel for displaying information will be briefly described with reference to FIG.

As shown in FIG. 1A, the liquid crystal panel P ₁ includes a pair of wiring boards 1 arranged at a predetermined distance from each other, and these wiring boards 1 are bonded by a sealing member 2. The ferroelectric liquid crystal 3 is held in the internal gap.

The wiring substrate 1 has a glass substrate 5 as a light-transmitting base material, and ITO transparent electrodes 6 for driving liquid crystal are formed in a stripe shape on the surface of the glass substrate 5 (these substrates). the transparent electrode 6 of, constitutes the simple matrix in the state where the liquid crystal panel P ₁ is assembled). In addition, these transparent electrodes 6 are 500-5000５００.
It is formed in a stripe shape by a patterning process (see FIG. 1B). A dielectric film 7 for preventing short circuit is formed on the surface of these transparent electrodes 6 by silicon oxide, titanium oxide, or the like.
It is formed to a thickness of about 000 mm, and an alignment film layer 9 is formed on the surface thereof with a polyimide resin or the like.

[0005] Incidentally, the strength in the dielectric liquid 3, generally chiral smectic liquid crystal (SmC *, SmH *) so used, but showing the orientation of liquid crystal molecular long axis is twisted in the bulk state, cells of the liquid crystal panel P ₁ Reduce the thickness (1-3 μm
Degree), the twist of the long axis of the liquid crystal molecules is eliminated (P213-P234, NA CLAR).
K et al, MCLC 1983, Vol. 94).

By the way, such a liquid crystal panel P ₁
The electrodes are driven by applying a voltage to the opposing transparent electrodes 6, 6, but since the liquid crystal 3 interposed between the transparent electrodes 6, 6 becomes a capacitive load in an electric circuit, a voltage waveform is generated. Propagation delay easily occurred. Particularly, in the case of the liquid crystal panel P ₁ using a ferroelectric liquid crystal 3, cell thickness and 1 to 2 [mu] m, TN
Thinner than one third to one fifth of a liquid crystal device
Even when the same wiring board 1 was used, the propagation delay of the voltage waveform was remarkable as compared with the TN type liquid crystal element. In recent years, high definition of liquid crystal panels has been desired. For this purpose, it is necessary to avoid this propagation delay, and research and development of liquid crystal panels have been changing. That is, A. In the case of the liquid crystal panel having the above-described configuration, the delay of the voltage waveform was not solved because the resistance value of the ITO transparent electrode was high. B. A method of providing a metal wire having a low resistance value on the surface of the transparent electrode was also conceived, but the metal wire could not be thickened due to various restrictions, and the delay of the voltage waveform could not be eliminated. C. Here, setting the thickness of the metal wiring to a predetermined value or more is indispensable for increasing the driving frequency,
This has been confirmed by experiments performed by the present inventors. D. Instead of attaching metal wiring to the surface of the transparent electrode,
If the method is arranged between the glass substrate and the transparent electrode (the back surface of the transparent electrode), the thickness of the metal wiring can be increased without restriction, and the delay of the voltage waveform can be eliminated.

Hereinafter, the above A to D will be described in detail. A. Reasons why delay of voltage waveform cannot be eliminated only by transparent electrode (without using metal wiring) The resistance value of transparent electrode 6 described above is a sheet resistance of 20 to 4
00Ω, 200 × 10 ^{-8 to} 4000 × 10 in volume resistance
^-8 Ωm and a metal material (for example, 3.0 ×
10 ⁻⁸ Ωm), and the transparent electrode 6 must be thickened in order to avoid the delay of the voltage waveform. In this case, the transmittance is reduced and the transparent electrode 6 is recognized. As a result, there is a problem that the display quality is deteriorated. Therefore, it has been difficult to avoid delay of the voltage waveform while maintaining good display quality. B. The reason why the delay of the voltage waveform cannot be eliminated by the method in which the metal wiring is provided on the surface of the transparent electrode On the other hand, as a method of avoiding the delay of the voltage waveform, chromium (volume resistance = 15 × 10 ⁻⁸ Ωm) and molybdenum (volume resistance = A method is conceivable in which a metal wiring having a low resistivity such as 6.0 × 10 ⁻⁸ Ωm) is provided on the surface of the transparent electrode 6 (the surface on which the liquid crystal 3 is injected).

However, even if such a metal wiring is provided, it is difficult to form a thick metal wiring for various reasons, and there is a limit in avoiding delay of a voltage waveform. Hereinafter, the reason why the thickness of the metal wiring is restricted will be described. (1) The metal wirings are arranged so as to face each other in the gap between the transparent electrodes (cell thickness). However, due to dimensional restrictions, the metal wirings must be less than half the cell thickness. Specifically, the cell thickness is as thin as about 1.1 μm, and the maximum thickness of the metal wiring is 550 nm.

Therefore, although a metal wire having a low resistance value is used in addition to the transparent electrode, the effect of reducing the resistance value by the metal wire is not so large, and there is a limit in avoiding the delay of the voltage waveform. (2) On the other hand, also in the case of forming the metal wiring in this way, as described with reference to FIG. 1, the metal wiring is covered with the alignment film layer 9 and the liquid crystal molecules are fixed by the alignment film layer 9. They need to be ordered.

However, in such a case, there is a problem that unevenness due to the metal wiring is generated in the alignment film layer 9, and an optical difference is generated between the concave portion and the convex portion, thereby deteriorating the display quality. . In addition, there is also a problem that the electric field response changes and crosstalk easily occurs. Further, there is a problem that the rubbing treatment of the alignment film layer 9 cannot be performed uniformly due to the unevenness due to the metal wiring, so that the alignment state is not uniform, and optical differences and crosstalk also occur. Such a problem was remarkable in a liquid crystal panel in which the pixel size was reduced for higher definition. In order to avoid such a problem, the thickness of the metal wiring must be equal to or less than a predetermined value (actually, equal to or less than 250 nm).
Therefore, even if the metal wiring is used, the delay of the voltage waveform cannot be avoided. C. Relationship Between Thickness of Metal Wiring and Driving Frequency By the way, it is necessary to increase the driving frequency in order to increase the definition of the liquid crystal panel. The relationship between the thickness of the metal wiring and the driving frequency will be described with reference to FIG. . Note that FIG.
Indicates the “thickness of metal wiring−” in a 21-inch diagonal panel.
The relationship between "waveform delay amount-drive frequency" is shown.
Here, LQ-1802 (manufactured by Hitachi Chemical Co., Ltd.) was used as the alignment film layer 9, and the rubbing direction was the same when the liquid crystal panel was assembled. Further, an Al-Si-Cu alloy was used as the metal wiring.

Now, when a liquid crystal material having a spontaneous polarization of 7 nc / cm ² is used and the cell thickness is set to about 1 μm, as is apparent from FIG. Assuming that the rise time between 90% is 1), the delay amount was 0.56 at the film thickness of 348 nm.
When this relationship is expressed by a drive frequency of 2048 scanning lines (one frame scanning frequency), a power supply is connected to both ends of one scanning line (expressed as both-side mounting).
However, it can be seen that the drive frequency can be increased as the amount of delay is smaller, although the power supply is connected to one side and the power supply is connected to one side (expressed as one-sided mounting).

In addition, the spontaneous polarization is set to 1 for high-speed driving.
00 nc / cm ² , the cell thickness is about 2 μm, and the rounding of the waveform is reduced. In order to increase the driving frequency to 15 Hz or more, when Al-Si-Cu is used for both-side mounting, 629 nm is used. Thickness is required, 22 for single-sided mounting
A film thickness of 76 nm is required. This can be alleviated by changing the type of metal. However, even when Cu is used, it is 387 nm for both-side mounting and 131 for single-side mounting.
A film thickness of 0 nm is required, but in any case 250 nm
Must be exceeded. In other words, as described above, the thickness of the metal wiring must be 250 nm or less in order to prevent the occurrence of optical differences and crosstalk (see B (2) above). The frequency could not be increased, and it was difficult to respond to high definition.

Since the cost of the power supply IC is twice as large between the two-sided mounting and the one-sided mounting described above, which causes a great difference in the product strength, the single-sided mounting is desirable as the configuration of the liquid crystal element. D. Method of Forming Metal Wiring on Backside of Transparent Electrode By the way, to solve the above problems (1) and (2), a wiring board 10 as shown in FIG. 3 (h) has been proposed.

The wiring substrate 10 includes a transparent glass substrate 11 as a light-transmitting substrate.
1 has a stripe-shaped metal wiring (first electrode) 1
2 are formed in large numbers. These metal wirings 12 are arranged with a predetermined gap therebetween, and the gap is filled with a UV curing resin 13. The resin 13 forms a smooth surface together with the metal wires 12, and a large number of transparent electrodes (second electrodes) 15 are formed on the formed smooth surface along the metal wires 12. ing.

In the wiring board 10, since the metal wiring 12 is disposed on the back side of the transparent electrode 15 (on the side of the glass substrate 11), the thickness of the metal wiring 12 can be freely set, and the above (1) ( Problems such as 2) are solved.

Next, a method of manufacturing such a wiring board 10 will be briefly described with reference to FIGS.

First, a thick metal layer is formed on the surface of a glass substrate 11 by a sputtering method or the like, and the metal layer is patterned by a photolithography method or the like to form a large number of stripe-shaped metal wirings 12 (FIG. 1). (a)).
Then, a UV curable resin 13 is provided on the surface on which the metal wiring 12 is formed.
Is dropped (see FIG. 3 (b)), and a smooth mold 16 having a smooth surface is overlapped (see FIGS. 3 (c) and 3 (d)). This allows
The gap between the metal wires 12 is filled with the UV curing resin 13, and the resin 13 forms a smooth surface together with the metal wires 12. The UV curable resin 13 is cured by irradiating it with ultraviolet rays (see FIG. 7 (e)), and then the smoothing mold 16 is peeled off (see FIGS. (F) and (g)). Further, a transparent electrode 15 is formed by a predetermined method (see FIG.
(h)).

[0018]

In the conventional manufacturing method, the metal wiring 12 is formed on the surface of the glass substrate 11, and then the steps of applying and curing the UV curing resin 13 are performed. The wiring 12 was easily peeled or disconnected. As a result, the manufacturing yield of the liquid crystal panel has been reduced, and image defects due to the peeling of the metal wiring 12 have occurred.

Further, in the conventional manufacturing method, the metal wiring 12 is formed by using a vacuum film forming method or an etching method. However, there is a problem that an expensive apparatus is required and the manufacturing cost of the liquid crystal panel is increased. Was.

Accordingly, an object of the present invention is to provide an inexpensive wiring board, a liquid crystal device having the wiring board, and a method for manufacturing the wiring board.

Another object of the present invention is to provide a method for manufacturing a wiring board which prevents peeling and disconnection of the first electrode.

Still another object of the present invention is to provide a thin and lightweight wiring board and a liquid crystal device provided with the wiring board.

Still another object of the present invention is to provide a wiring board and a liquid crystal device provided with the wiring board, which use a thin and lightweight resin base material while preventing clouding and deformation. It is assumed that.

Another object of the present invention is to provide a wiring board for preventing a delay of a voltage waveform and a liquid crystal device provided with the wiring board.

Another object of the present invention is to provide a liquid crystal element free of optical difference and crosstalk.

Still another object of the present invention is to provide a liquid crystal device having good display quality.

[0027]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a light-transmitting base material that transmits light.
The wiring substrate, comprising: a plurality of first electrodes supported by the light-transmitting substrate; and a plurality of second electrodes formed to be electrically connected to the first electrodes. Base material,
While being formed of resin, the surface thereof has a plurality of recesses, the first electrode is disposed in the plurality of recesses so as to form a substantially flat surface with a portion other than the recesses, and
The second electrode is formed on the flat surface so as to be electrically connected to each first electrode.

Further, the present invention comprises a pair of wiring boards arranged at a predetermined distance from each other, and a liquid crystal arranged in a gap between these wiring boards, and the wiring board has a light transmitting property of transmitting light. A liquid crystal element comprising a transparent substrate, a plurality of first electrodes supported by the transparent substrate, and a second electrode formed along the first electrode, wherein the transparent substrate has a surface And the first electrode is disposed in the plurality of recesses so as to form a substantially flat surface with a portion other than the recess, and the second electrode is provided in each first electrode. Formed on the flat surface to be electrically connected,
It is characterized by the following.

Further, the present invention provides a step of molding a light-transmitting base material having a plurality of concave portions on the surface and transmitting light.
To form a substantially flat surface with the portion other than the concave portion,
Forming a first electrode in the recess and forming a second electrode on the flat surface so as to be electrically connected to each first electrode.

Since the translucent substrate is formed of a resin, the thickness and weight of the wiring board and the liquid crystal element can be reduced. In addition, since the first electrode is formed in the concave portion of the translucent substrate, an inexpensive plating method can be used, and the manufacturing cost can be reduced.

[0031]

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

First, a first embodiment of the present invention will be described with reference to FIG.

The liquid crystal element P _{2 according} to the present embodiment is similar to that of FIG.
Two wiring boards 20 shown in (f) are provided. These two wiring boards 20, 20 are arranged at a predetermined distance, similarly to the wiring boards 1, 1 shown in FIG. 1, and a liquid crystal 3 is arranged in a gap between these wiring boards 20, 20. ing.

Each wiring substrate 20 has a light-transmitting base material 21 made of resin which transmits light, and the light-transmitting base material 21 has a large number of concave portions 21a on the surface. The base layer 22 and the first electrode 23 are buried in these recesses 21 a, and the first electrode 23 is formed on the flat portion 2 of the translucent substrate 21.
1b (a portion other than the concave portion 21a; see FIG. 3E) and a substantially flat surface. The underlayer 22 is made of the first
It plays a role in enhancing the adhesion between the electrode 23 and the light-transmitting substrate 21. The second electrode 25 is provided on this flat surface.
The first electrodes 23 are formed along the first electrodes 23.
Is electrically connected to Note that a dielectric film 7 for preventing short circuit is formed on the surface of the second electrode 25, and an alignment film layer 9 is further formed on the surface (not shown).

The light-transmitting substrate 21 may be any plate-shaped, smooth and transparent resin substrate, for example, acrylic resin, polycarbonate resin, epoxy resin, phenol resin, urea resin, melamine resin, polyethylene resin. For example, a polypropylene resin, a polyamide resin, a polyacetal resin, a fluorine resin, a vinyl chloride resin, a polystyrene resin, a polyphenylene oxide resin, a polysulfone resin, a polyphenylene sulfide resin, and a methylpentene resin may be used.

The underlayer 22 may be of any type as long as it has conductivity. For example, Pd, Ag,
A metal such as Au or Pt may be used.

Further, Cu, Cr,
Metals such as Mo, Ni, Au, Ag, and Pt, and alloys of these metals may be used.

Next, a method for manufacturing the liquid crystal element (wiring board) according to the present embodiment will be described with reference to FIGS.

First, as described above, the light-transmissive substrate 21 having the concave portions 21a is formed (see FIG. 1A). The molding method may be any method, for example, using casting molding, compression molding, transfer molding, injection molding, extrusion molding, blow molding, calendar molding, vacuum molding, air pressure molding, powder molding, paste molding, lamination molding, or the like. The recess 21a may be formed by using a mold or the like processed into the pattern shape of the first electrode.

Next, a photosensitive resin 26 is applied to the surface of the translucent substrate 21 (see FIG. 3B). For this application, a spinner, a roll coat, printing, spraying or the like is used. After that, the photosensitive resin 26 is dried, exposed and developed, so that the photosensitive resin 26 remains only on the flat portion 21b. The photosensitive resin 26 may be any resin that can be easily patterned and easily removed. Examples thereof include a photoresist, a deep UV resist, an EB resist, and an X-ray resist.

Further, the light-transmissive substrate 2
1 and dirt attached to the surface of the photosensitive resin 26 are removed.
As a method of the degreasing treatment, a solvent treatment, emulsification degreasing (emulsion degreasing), alkali degreasing, electrolytic degreasing, mechanical degreasing, or the like may be used.

Next, an underlayer 22 is formed (see FIG. 3C). As a method for forming the underlayer 22, a plating method or an evaporation method may be used. Further, the thickness of the underlayer 22 is
It is sufficient that the thickness is such that the first electrode 23 can be plated on the surface thereof.
It is preferably in the range of -500 °. Since the underlayer 22 has such a thickness, its resistance value is sufficiently high, and there is no fear of short circuit even when the liquid crystal element is driven. However, this underlayer 22 is appropriately divided by using a laser or a photolithography method. do it,
The first electrodes adjacent to each other may not be electrically connected.

Next, the photosensitive resin 26 is dissolved with a dissolving solution,
The underlayer 22 is left only in the concave portion 21a (see FIG. 3D).
As the solution, a solvent, an alkaline solution, a dedicated stripping solution, or the like may be used.

Thereafter, the first electrode 23 is formed in the concave portion 21a of the translucent substrate 21 by a plating method (see FIG. 3E). In addition, as a plating method of the first electrode 23, electroless plating (chemical plating), electric field plating, or the like may be used, but electroless plating excellent in film thickness uniformity is preferable.

Further, the light-transmitting substrate 21 and the first electrode 2
A second electrode 25 made of ITO or the like is formed on the flat surface formed by 3 (see FIG. 2F).

Next, the effect of the present embodiment will be described.

According to the present embodiment, the first electrode 23
Since they are arranged so as to be electrically connected to each second electrode 25, the resistance value of the electrodes is reduced. Therefore, it is possible to obtain a liquid crystal element in which the delay of the voltage waveform as described in the conventional example is eliminated, the inversion of the liquid crystal molecules is uniform, and the liquid crystal element can cope with high definition.

According to the present embodiment, the first electrode 2
3 is arranged in a state of being embedded in the concave portion 21a of the translucent substrate 21, and since the second electrode 25 is formed on the surface thereof, the alignment film layer 9 does not have excessive unevenness. Good quality images can be obtained without occurrence of optical difference or crosstalk. In other words, the first electrode 23 can be made thicker without worrying about image defects, so that the resistance of the electrode can be reduced and the delay of the voltage waveform can be more reliably prevented. Incidentally, when the inventor actually measured the resistance value,
It was 300Ω or less.

Further, according to the present embodiment, since the first electrode 23 is provided for lowering the resistance, it is not necessary to form the second electrode 25 thick. Therefore, the transmittance of the second electrode 25 does not decrease and the second electrode 25 is not recognized,
Accordingly, the display quality does not deteriorate.

Further, since the translucent base 21 is formed of a resin, the liquid crystal element can be made thinner and lighter.

Further, since the base layer 22 for improving the adhesiveness between the light-transmitting substrate 21 and the first electrode 23 is formed between the recess 21a and the first electrode 23, the first electrode 23 is peeled off. Is reduced, and as a result, the production yield of the liquid crystal element is reduced,
The occurrence of image defects due to the separation of the first electrode 23 and the like is prevented.

Further, when the metal wiring 12 is formed by a plating method in the conventional manufacturing method, the metal wiring 1
2 and the substrate 11, the smooth plate 16
In the step of peeling off, there is a possibility that peeling or disconnection of the metal wiring 12 may occur. However, in the present embodiment, since there is no such a peeling step, there is no need to worry about peeling of the first electrode 23, etc.
It is possible to prevent the occurrence of image defects due to the separation of the electrode 23 and the like.
Further, since the first electrode 23 is formed by an inexpensive plating method, the manufacturing cost of the liquid crystal element can be reduced. Further, with the use of such a plating method, it is possible to avoid white turbidity and deformation of the translucent substrate 21.

Next, a second embodiment of the present invention will be described with reference to FIG.

The wiring board 30 according to the present embodiment is similar to that shown in FIG.
As shown in (c), a transparent substrate 21 having the same shape as in the first embodiment is provided, and a color filter 32 is formed on a flat portion 21b. Further, the translucent substrate 21
The base layer 22 and the first electrode 31 are arranged in the concave portion 21a, and the first electrode 31 forms a substantially flat surface together with the color filter 32. The second electrode 25 is formed on this flat surface.

Next, a method of manufacturing the wiring board 30 will be briefly described.

First, a light-transmissive substrate 21 having a concave portion 21a on its surface is formed.

Next, a color filter 32 is formed on the flat portion 21b of the translucent substrate 21. The color filter 3
As a method for forming 2, a photolithography method, a printing method, a sublimation method, an inkjet method, or the like may be used.

Further, an underlayer 22 is formed in the concave portion 21a of the translucent substrate 21 (see FIG. 6A).

Thereafter, the first electrode 31 is formed in the recess 21a (see FIG. 3B).

Further, the second electrodes 25 are formed so as to be electrically connected to the respective first electrodes 31 (see FIG. 3C).

According to the present embodiment, a color liquid crystal element having the same effect as that of the first embodiment can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIG.

The wiring board 50 according to the present embodiment is similar to the wiring board shown in FIG.
As shown in (c), a transparent substrate 21 having the same shape as in the first embodiment is provided, and a color filter 32 is formed on a flat portion 21b. The surface of the color filter 32 is covered with a protective layer 51. In addition, the underlayer 22 is formed in the concave portion 21a of the translucent substrate 21.
And the first electrode 31 are arranged.
Forms a substantially flat surface together with the protective layer 51. The second electrode 25 is formed on this flat surface.

Next, a method for manufacturing the wiring board 50 will be briefly described.

First, a light-transmissive substrate 21 having a concave portion 21a on the surface is formed.

Next, a color filter 32 is formed on the flat portion 21b of the translucent substrate 21. The color filter 3
As a method for forming 2, a photolithography method, a printing method, a sublimation method, an inkjet method, or the like may be used. Further, a protective layer 51 is formed on the surface of the color filter 32, and an underlayer 22 is formed in the concave portion 21a (see FIG. 7A).

After that, the first electrode 31 is formed in the recess 21a (see FIG. 3B).

Further, the second electrodes 25 are formed so as to be electrically connected to the respective first electrodes 31 (see FIG. 3C).

According to this embodiment, the same effects as those of the first and second embodiments can be obtained, and the color filter 32 can be protected from an acidic or alkaline degreasing solution or plating solution. Decolorization of the filter 32 can be prevented.

[0070]

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

First, the first embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

In this embodiment, first, a transparent resin substrate (translucent base material) 21 having a concave portion 21a is formed (see FIG. 1A). In this molding, an acrylic monomer (methyl methacrylate) and a polymerization initiator (benzoyl peroxide) are injected into a predetermined mold to cause polymerization. Thereafter, the mold is released to obtain a transparent resin substrate 21 made of an acrylic resin. In the present embodiment, the dimensions of the transparent resin substrate 21 are 300 × 310 × 0.2 mm, the pitch of the concave portions 21a is 320 μm, the width of the concave portions 21a is 20 μm, and the depth of the concave portions 21a is 2 μm.

Next, a positive resist (OFPR-800: manufactured by Tokyo Ohka Co., Ltd.) as a photosensitive resin is applied to the surface of the transparent resin substrate 21 to a thickness of 1 μm using a spinner, and this is applied at a temperature of 90 ° C. for 30 minutes. Prebaked for minutes. Thereafter, exposure was performed only on the concave portion 21a through a photomask, development and rinsing were performed, and post-baking was performed at a temperature of 100 ° C. for 30 minutes. Thus, the photosensitive resin 26 is formed in a portion other than the concave portion 21a (see FIG. 2B).

Thereafter, the surface of the substrate 21 was washed with a neutral detergent, and further subjected to an alkali degreasing treatment.

Next, using a Pd solution, a chemical plating treatment was carried out at room temperature for 1 minute to form a Pd film having a thickness of 20 ° on the entire surface of the substrate (see FIG. 3C). Thereafter, the photosensitive resin 26 is dissolved using a stripper for exclusive use of a positive resist, and the concave portion 2 is removed.
The Pd film (underlayer 22) was left only on 1a (see FIG. 3D).

Thereafter, a metal wiring (first electrode) 23 is formed in the concave portion 21a of the transparent resin substrate 21 by plating (see FIG. 7E). In this embodiment, the metal wiring 23 has a three-layer structure by performing three-layer metal plating.

Specifically, a Ni solution was used at 80 ° C. for 2 hours.
2,000 minutes of chemical plating
An i film was formed. Then, after washing with water and drying, 100 ° C
At 30 ° C. for 30 minutes. Further, after a treatment with diluted hydrochloric acid at room temperature for 1 minute, a chemical plating treatment is performed at 80 ° C. for 30 minutes using a Cu solution,
A Cu film having a thickness of 00 ° was formed. Thereafter, washing was performed with water. Further, using a Ni solution, a chemical plating treatment was carried out at a temperature of 80 ° C. for 2 minutes to form a 2000-nm thick Ni on the Cu film.

Further, a transparent electrode (second electrode) 25 was formed on the flat surface formed by the transparent resin substrate 21 and the metal wiring 23 (see FIG. 1F). In this embodiment, the pitch of the transparent electrodes 25 is set to 320 μm,
The electrode width was 300 μm.

Next, the effect of this embodiment will be described.

According to this embodiment, since the metal wiring 23 is arranged so as to be electrically connected to each transparent electrode 25, the resistance value of the electrode is reduced. Therefore, it is possible to obtain a liquid crystal panel in which the delay of the voltage waveform as described in the conventional example is eliminated, the inversion of the liquid crystal molecules is uniform, and the definition is compatible.

Further, according to the present embodiment, the metal wiring 23 is disposed in a state of being embedded in the concave portion 21a of the transparent resin substrate 21, and the transparent electrode 25 is formed on the surface thereof. 9 does not have excessive unevenness, does not have optical difference or crosstalk, and can obtain an image of good quality. In other words, the thickness of the metal wiring 23 can be increased without worrying about image defects, so that the resistance of the electrode can be reduced and the delay of the voltage waveform can be more reliably prevented. Incidentally, when the inventor actually measured the resistance value,
It was 300Ω or less.

Further, according to the present embodiment, since the metal wiring 23 is provided to reduce the resistance, it is not necessary to form the transparent electrode 25 thick. Therefore, the transmittance of the transparent electrode 25 does not decrease and the transparent electrode 25 is not recognized, and the display quality does not deteriorate accordingly.

Further, since the transparent resin substrate 21 is formed of resin, the liquid crystal panel can be made thinner and lighter.

Since the underlayer 22 for improving the adhesion between the transparent resin substrate 21 and the metal wiring 23 is formed between the recess 21a and the metal wiring 23, the peeling of the metal wiring 23 is reduced. As a result, a reduction in the production yield of the liquid crystal panel and the occurrence of image defects due to peeling of the metal wiring 23 and the like are prevented.

Further, when the metal wiring 12 is formed by a plating method in the conventional manufacturing method, the metal wiring 1
2 and the substrate 11, the smooth plate 16
In the step of peeling off, there is a possibility that peeling or disconnection of the metal wiring 12 may occur. However, in the present embodiment, since there is no such a peeling step, there is no fear of peeling of the metal wiring 23 and the like. Can be prevented. Further, since the metal wiring 23 is formed by an inexpensive plating method, the manufacturing cost of the liquid crystal panel can be reduced. Further, with the use of such a plating method, cloudiness or deformation of the transparent resin substrate 21 can be avoided. Note that the present inventor has proposed the metal wiring 23.
Microscopic observation was performed in the state in which was formed, but no disconnection or peeling of the metal wiring 23 or clouding or deformation of the transparent resin substrate 21 was observed at all.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the above embodiment, the plating for forming the metal wiring 23 was performed after the photosensitive resin 26 was dissolved, but in this embodiment, as shown in FIG.
At the stage of plating the metal wiring 23, the photosensitive resin 26 and the like were left, and thereafter, the photosensitive resin 26 was removed.

According to this embodiment, the same effects as in the first embodiment can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIG.

In the present embodiment, a pigment-based color filter (manufactured by Ube Industries, Ltd.) 32 was formed on the flat portion 21b of the transparent resin substrate 21 to a thickness of 1 μm by photolithographic etching.

Next, the effect of this embodiment will be described.

According to this embodiment, it is possible to obtain a color liquid crystal panel having the same effects as in the first embodiment.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

In this embodiment, a pigment-based color filter (manufactured by Ube Industries, Ltd.) 32 was formed on the flat portion 21b of the transparent resin substrate 21 to a thickness of 1 μm by a photolithographic etching method. Further, on the surface of the color filter 32, a photosensitive polyamide-based transparent coating agent (manufactured by Ube Industries, Ltd.) was applied and patterned to a thickness of 0.5 μm as a protective layer 51.

Next, the effect of this embodiment will be described.

According to the present embodiment, the above-described first and third
The same effect as that of the embodiment can be obtained, and the color filter 32 can be protected from an acidic or alkaline degreasing solution or plating solution, and the color filter 32 can be prevented from being decolorized.

[0097]

As described above, according to the present invention,
Since the first electrodes are arranged so as to be electrically connected to the respective second electrodes, the resistance value of the electrodes is reduced. Therefore, it is possible to obtain a liquid crystal element in which the delay of the voltage waveform as described in the conventional example is eliminated, the inversion of the liquid crystal molecules is uniform, and the liquid crystal element can cope with high definition.

Further, according to the present invention, the first electrode is disposed so as to be embedded in the concave portion of the light-transmitting substrate, and the second electrode is formed on the surface thereof. Even if the thickness is increased, the cell thickness does not become non-uniform, and there is no occurrence of optical difference and crosstalk, and an image of good quality can be obtained. In other words, there is no need to worry about image defects.
Since the electrodes can be made thicker, the resistance of the electrodes can be reduced,
The delay of the voltage waveform can be more reliably prevented.

Further, according to the present invention, since the first electrode is provided for reducing the resistance, it is not necessary to form the second electrode thick. Therefore, the transmittance of the second electrode decreases and the second electrode
The electrodes are not recognized, and the display quality is not deteriorated accordingly.

Further, since the light-transmitting substrate is formed of a resin, the liquid crystal element can be made thinner and lighter.

Further, between the concave portion and the first electrode,
In the case where an underlayer that enhances the adhesion between the light-transmissive substrate and the first electrode is formed, the separation of the first electrode is reduced, and as a result, the production yield of the liquid crystal element is reduced, and The occurrence of image defects due to peeling of the image is prevented.

Further, when a color filter is disposed between the light-transmitting substrate and the second electrode, a color liquid crystal element having the various effects described above can be obtained.

Further, when a protective layer is disposed between the color filter and the second electrode so as to cover the color filter, the color filter can be protected from various chemicals, and decolorization of the color filter can be prevented. it can.

In the case where the first electrode is formed by plating, even if the light-transmitting substrate is formed of resin as described above, the substrate may become cloudy or deformed. Nothing to do. Furthermore, with the use of inexpensive plating methods,
The manufacturing cost of the liquid crystal element can be reduced.

[Brief description of the drawings]

1A and 1B are diagrams for explaining the structure of a conventional liquid crystal panel, wherein FIG. 1A is a cross-sectional view of the liquid crystal panel, and FIG. 1B is a plan view for explaining the shape of a transparent electrode.

FIG. 2 is a chart for explaining a relationship between a thickness of a metal wiring and a driving frequency.

FIG. 3 is a view for explaining a conventional method for manufacturing a wiring board.

FIG. 4 is a diagram for explaining the method for manufacturing the wiring board according to the first embodiment.

FIG. 5 is a view showing a modification of the method of manufacturing the wiring board according to the first embodiment;

FIG. 6 is a diagram for explaining a method for manufacturing a wiring board according to the second embodiment.

FIG. 7 is a diagram for explaining a method of manufacturing a wiring board according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Wiring board 21 Transparent resin substrate (translucent base material) 21a Depression 22 Underlayer 23 Metal wiring (1st electrode) 25 Transparent electrode (2nd electrode) 30 Wiring board 31 Metal wiring (1st electrode) 32 Color filter 50 Wiring board 51 Protective layer

Claims (11)

[Claims] 1. A light-transmitting substrate that transmits light, a plurality of first electrodes supported by the light-transmitting substrate, and a plurality of electrodes formed to be electrically connected to each of the first electrodes. Wherein the light-transmitting substrate is formed of a resin and has a plurality of recesses on its surface, and the first electrode has a portion other than the recesses. And the second electrode is formed on the flat surface so as to form an almost flat surface, and the second electrode is electrically connected to each of the first electrodes. Characteristic wiring board. 2. The method according to claim 1, further comprising: forming a base layer between the recess and the first electrode, the base layer increasing the adhesion between the light-transmissive substrate and the first electrode. Wiring board. 3. The method according to claim 1, wherein the underlayer is made of Pd, Ag, Au, Pt.
The wiring board according to claim 1, wherein the wiring board is formed of a metal such as the above. 4. The method according to claim 1, wherein the first electrode is made of Cu, Cr, Mo, N
4. The wiring board according to claim 1, wherein the wiring board is formed of a metal such as i, Au, Ag, Pt, or an alloy of these metals. 5. A light-transmitting base material comprising: a pair of wiring boards arranged at a predetermined distance from each other; and a liquid crystal arranged in a gap between these wiring boards, wherein said wiring board transmits light.
In a liquid crystal element including a plurality of first electrodes supported by the translucent substrate and a second electrode formed along the first electrode, the translucent substrate includes a plurality of concave portions on a surface thereof. And the first electrode is disposed in the plurality of recesses so as to form a substantially flat surface with a portion other than the recesses, and the second electrode is electrically connected to each first electrode. A liquid crystal element formed on the flat surface so as to be formed. 6. At least one of the pair of wiring boards includes a color filter disposed between the light-transmissive base material and the second electrode, and the color filter includes The liquid crystal device according to claim 5, wherein a substantially flat surface is formed together with one electrode, and the second electrode is formed on the flat surface. 7. A color filter provided between at least one of the pair of wiring substrates and the light-transmissive substrate and the second electrode, and the color filter covering the color filter. A protective layer disposed between the filter and the second electrode, wherein the protective layer forms a substantially flat surface together with the first electrode, and the second electrode is formed on the flat surface. The liquid crystal element according to claim 5, wherein the liquid crystal element is formed. 8. A step of forming a light-transmitting substrate having a plurality of recesses on its surface and transmitting light, and forming a substantially flat surface with portions other than the recesses.
Forming a first electrode in the concave portion; and forming a second electrode on the flat surface so as to be electrically connected to each of the first electrodes. 9. A step of forming a light-transmitting substrate having a plurality of recesses on the surface and transmitting light, a step of forming a first electrode in the recesses, and a step of forming the first electrode in a portion other than the recesses. Forming a color filter so as to form a substantially flat surface together with the electrodes; and forming a second electrode on the flat surface so as to be electrically connected to each of the first electrodes. Substrate manufacturing method. 10. A step of forming a light-transmitting substrate having a plurality of recesses on the surface and transmitting light, a step of forming a first electrode in the recesses, and forming a color filter in portions other than the recesses. Forming a protective layer on the surface of the color filter so as to form a substantially flat surface together with the first electrode; and connecting the second electrode to each of the first electrodes. Forming a wiring substrate on the flat surface. 11. The method according to claim 8, wherein the first electrode is formed by a plating method.