JPH0124236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improved conductive film and a method for manufacturing the same.

[Prior art]

In recent years, there has been a rapid increase in demand for digital display devices such as liquid crystal displays, touch pen type handwriting input devices, facsimile devices, and the like.
High conductivity can be applied to the connectors of input/output parts of these home devices, such as the connection of electrode extraction parts of liquid crystal display devices and electrochromic display devices, the input of touch pens, the output extraction of image sensors in facsimiles, etc. in arbitrary patterns. There is a need for an inexpensive film that has the following characteristics.

Furthermore, if films with anisotropy in conductivity, such as films with conductivity only in the thickness direction or films with conductivity only in one dimension, can be produced at low cost, we can expect a variety of new applications in the future. .

Conventionally, conductive polymer films have been produced by mixing various thermoplastic resins with conductive fillers and molding them into films, and by vapor depositing and spraying conductive materials onto the surface of the polymer film. Painted or plated materials have been used. Although it is easy to obtain a uniformly conductive film with any of these films, in order to obtain a film that has conductivity only in the desired pattern, it is necessary to perform some kind of pattern forming process on the film. be.

On the other hand, unlike such composite systems with metals and carbon, conductive polymer materials in which the polymer material itself is electrically conductive are attracting attention because of their high electrical conductivity. However, even with these materials, it is difficult to impart conductivity in a pattern.

[Purpose of the invention]

An object of the present invention is to provide a film having conductive portions in a desired pattern shape and a method for manufacturing the same.

[Structure of the invention]

To summarize the present invention, the first aspect of the present invention relates to a film having conductivity in a pattern, which comprises: a polymer film formed on an electrode having conductive portions in a desired pattern; It is characterized in that it includes a metal material formed by electrolytic plating on an electrode with a polymer film.

Further, a second invention of the present invention relates to a method for manufacturing the above-mentioned film, which includes a step of forming a polymer film on an electrode having a conductive portion in a desired pattern shape, and an electrode with the polymer film. The present invention is characterized in that it includes each step of forming a metal material by electrolytic plating.

Furthermore, a third invention of the present invention is an invention relating to another patterned conductive film,
Includes a polymer film formed on an electrode having conductive sites in a desired pattern shape, and an aromatic polymer material formed by electrolytic polymerization of an aromatic compound on the electrode with the polymer film. It is characterized by

Furthermore, a fourth invention of the present invention relates to a method for manufacturing the film according to the third invention, which comprises a step of forming a polymer film on an electrode having a conductive portion in a desired pattern shape; It is characterized in that it includes each step of forming an aromatic polymer material by electrolytic polymerization of an aromatic compound on the electrode with the polymer film.

It is well known that conductive metal foil or conductive polymer film can be obtained on electrodes by using electrolytic plating of metals or electrolytic polymerization of aromatic compounds. At that time, if a conductive part and an insulating part are provided in a desired pattern on the electrode surface by some means, and such an electrode is used for electrolytic plating of metal materials or electrolytic polymerization of aromatic compounds,
Metal foil or conductive polymer film can be formed only on the conductive pattern portion. However, with this method, it is difficult to isolate the obtained metal foil or conductive polymer film from the electrode, and in particular, it is impossible to isolate isolated conductive parts or thin wire parts as a film at all. be.

However, the present inventors found that coating a thermoplastic polymer film on the electrode during electrolytic plating or electrolytic oxidation polymerization insulates the electrode surface, but under appropriate reaction conditions. It was discovered that electrolytic plating and electrolytic oxidative polymerization proceed. The film obtained in this way has a metal material produced by electrolytic plating or a conductive polymer material produced by electrolytic polymerization dispersed in an insulating polymer film, and the entire film or only one side of the film is dispersed. Make it conductive.

When obtaining a conductive film using this method, if the electrode is provided with a pattern of conductive parts and insulating parts as described above, the part of the insulating polymer film in contact with the conductive part of the electrode becomes conductive. The portion of the insulating polymer film in contact with the insulating portion of the electrode remains insulating.

In this way, the film as a whole is easy to isolate from the electrode. Once a pattern is formed on the electrode surface, the film can be peeled off and used repeatedly. Furthermore, by forming the electrode into a drum shape, a continuous pattern-like conductive film can be obtained and the cost of the film can be reduced.

In addition, in electrolytic plating or electrolytic polymerization of aromatic compounds on electrodes coated with an insulating film, depending on the polymerization conditions, there are cases where the entire film is made conductive, and cases where the entire film is made conductive.
It is possible to select a case in which only one side of the film, that is, only the side that was in contact with the electrode surface, is made conductive.
One of the parameters of such polymerization conditions is the resistance of the electrode; using an electrode substrate with low resistance makes it easier to make the entire film conductive, and conversely, using a substrate with high resistance makes it easier to make the entire film conductive. is difficult, and only one side tends to be conductive. Taking advantage of this feature, if an electrode substrate is used in which a pattern is formed with relatively low and high resistance areas, the film surface in contact with the back electrode surface will become conductive as a whole, but the electrolyte on the surface will The film can be made conductive only on the surface that is in contact with the pattern corresponding to the low resistance pattern.

Such electrodes can be fabricated on a suitable conductive surface using conventional photolithography techniques. As the material for the electrode surface, noble metals such as gold, platinum, and palladium, or conductive metal oxides such as tin oxide and indium oxide can be used for both electrolytic plating and electrolytic polymerization. Also, other metal substrates can be used for electrolytic plating. A resist material is coated on the surface of such an electrode, and a pattern is exposed on the resist layer using a photomask having a desired pattern.
After development, the substrate is processed. FIG. 1 shows a schematic diagram of the structure of one example of a patterned electrode according to the present invention.
In FIG. 1, reference numeral 1 indicates an insulating substrate, 2 a patterned conductor layer, 3 the entire conductor layer, and 4 a patterned insulator. When processing the board, the first
By directly etching the electrode conductor layer as shown in Figure a,
Electrodes can be patterned. Although this method is also effective, direct patterning may cause inconveniences such as electric field concentration at the edges of the pattern and the inability to conduct electricity to isolated patterns. Therefore, if the entire conductor layer is patterned with an insulator as shown in FIG. 1b, electrolytic plating or electrolytic polymerization will proceed uniformly over the entire electrode surface.

The resist material itself can be used as such an insulator, but the resist pattern tends to peel off when the film is repeatedly made and peeled off.
Does not withstand repeated use. For this reason, insulating oxides such as SiO and SiO ₂ with high adhesion, Si ₃ N ₄ , BN
It is preferable to use nitrides such as Metals that can be electrolytically plated include copper, nickel, platinum, gold,
Examples include rhodium, silver, ruthenium, palladium, indium, and aluminum.

On the other hand, polymer films that can be made conductive by electrolytic plating include polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, carbomethoxycellulose, methylcellulose, polymethylmethacrylate, and various copolymers of these. Various types of polymer films can be used. Furthermore, films prepared by blending plasticizers, stabilizers, solvents, ultraviolet absorbers, antifogging agents, pigments, dyes, etc. with these polymer films can also be used.

In order to obtain a conductive metal-containing polymer film, it is necessary to select the type of polymer film and the composition of the electrolytic plating solution. That is, an electrolytic plating solution that did not dissolve the film but had a fairly good affinity for the polymer film type gave good results. This is presumed to be because the polymer film swells to some extent in the electrolytic plating solution, metal ions can diffuse into the polymer film, and the electrolytic plating reaction progresses at the electrode interface.

Therefore, the type of polymer film is not limited to any type as long as it swells in the electrolytic plating solution used. However, since electrolytic plating solutions generally contain water-based solvents as their main component, polymer films that easily swell in water can be easily made conductive, but even hydrophobic polymer films can be made conductive by mixing water with dimethylformamide, dimethyl sulfoxide, N-
By mixing organic solvents such as methylpyrrolidone, tetrahydrofuran, ethylene glycol, and diesters of diethylene glycol, electrolytically plated metals can be mixed into a wide range of polymer films to make them highly conductive.

In addition, aromatic compounds that can be electrolytically oxidized and polymerized include pyrrole, 3-methylpyrrole, N-methylpyrrole, thiophene, furan, phenol, thiophenol, selenophene, tellurophene, biphenyl, azulene, p-terphenyl, o-terphenyl, p-quarter Phenyl, 2-hydroxybiphenyl, diphenyl sulfide, 2-
(α-thienyl)thiophene, 2-(α-thienyl)furan, 2-(2-pyrrolyl)pyrrole, 2
-(2-pyrrolyl)thiophene, 2-phenylthiophene, α-thienyl phenyl ether, β-
Furyl-α-thienylselenide, 2-(2-pyrrolyl)selenophene, 2-(2-selenienyl)
Aromatic compounds such as tellurofene, N-vinylcarbazole, N-ethynylcarbazole, methylazulene, and pyrene can be used. Various substituted butadiene compounds, which are not aromatic compounds, can also be used.

Furthermore, various compounds such as organic quaternary ammonium salts, inorganic salts, protonic acids, and esters can be used as electrolytes during electrolytic polymerization. Although acetonitrile-based solvents are usually used, any solvent can be selected as long as it is capable of electrolytically polymerizing aromatic compounds and dissolves a suitable electrolyte.

On the other hand, polymer films that can be made conductive by electrolytic polymerization include polyvinyl chloride resins, that is, polyvinyl chloride, vinyl chloride and various vinyl esters, vinyl ethers, acrylic acid and its esters, methacrylic acid and its esters. , maleic acid and its esters, fumaric acid and its esters, maleic anhydride, aromatic vinyl compounds including styrene, halogenated vinylidene compounds, copolymers with monomers such as acrylonitrile, methacrylonitrile, and propylene. Can be used. In addition, vinylidene chloride and various vinyl esters, vinyl ethers, acrylonitrile,
Copolymers of methacrylonitrile, vinyl chloride, etc.
Furthermore, polyethylene and copolymers of ethylene and the various monomers mentioned above can also be used. Depending on the purpose, polyethylene terephthalate and various rubbers can also be used.

Furthermore, films prepared by blending plasticizers, heat stabilizers, lubricants, ultraviolet absorbers, antifogging agents, pigments, dyes, etc. with the above resins can also be used.

A typical example of the method of the present invention is shown in FIG. That is, FIG. 2 is a manufacturing process diagram of a typical example of the method of the present invention. In FIG. 2, reference numeral 1 denotes an insulating substrate, 3 a full-surface conductor layer, 4 a patterned insulator, 5 a polymer film, 6 a conductive portion, and 7 an insulating portion.

(a) A conductor layer 3 is provided on an insulating substrate 1, and an insulator 4 is formed on this in a desired pattern using lithography technology.
is formed and used as an electrode substrate.

(b) Casting, calendar molding,
The polymer film 5 is coated by an appropriate method such as spin coating or a doctor blade method.

(c) Form a plating layer or an electrolytically polymerized aromatic polymer material only on the conductive part of the electrode by passing a current in an electrolytic plating solution or an electrolytic polymerization solution (6 is a conductive part, 7 is an insulating part) .

(d) Peel off the film from the electrode substrate.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, and there are infinite combinations of the present invention by changing the pattern shape, the insulating film material, the structure of the conductive film, etc. Therefore, the present invention is not limited to these examples.

Example 1 After 100 Å thick chromium and 700 Å thick gold were deposited on a glass substrate, 700 Å thick indium oxide was formed by sputtering. A lattice pattern was formed as follows on the conductive substrate having the indium oxide layer thus obtained as the surface. First, photoresist AZ-1350J (manufactured by Shipley) was spin-coated to a thickness of 2 μm, and then 0.1 mm thick was coated using a photomask.
A one-dimensional grid pattern of 0.1 mm lines and 0.1 mm spaces was exposed and developed. After depositing SiO to a thickness of 2000 Å on this layer, lift-off was carried out in methyl ethyl ketone to create an SiO pattern, which is an insulating layer with a width of 0.1 mm, at a pitch of 0.2 μm on the indium oxide surface.

On this substrate, polyvinyl alcohol (molecular weight
9000 (alcoholization rate: 80%) was cast to create a polyvinyl alcohol film with a thickness of 10 μm.

Using the substrate coated with this film as a negative electrode and a mesh platinum electrode as a positive electrode, gold plating was performed in a gold plating liquid Neutronex 309 (manufactured by Nippon Electroplating Engineers) containing gold sulfite ions. After gold plating at a constant voltage of 1.5V for 7 minutes, the film was washed with water and dried, and gold precipitation was observed. The film could be easily peeled off from the electrode substrate. When the electrical conductivity of the obtained film was measured, it showed a high conductivity of 10.5 S/cm in the direction parallel to the electrode grid, but 10 ^-8 S/cm in the direction perpendicular to the grid. It showed the following insulation properties.

Example 2 A 20 μm thick film was formed on the same substrate as in Example 1 from a solution of polyvinyl chloride (molecular weight 70,000) in methyl ethyl ketone by the casting method. This film-coated substrate was added to a mixed solvent of acetonitrile-methyl ethyl ketone (1:1) at 0.3
When a platinum-plated titanium mesh is immersed as a counter electrode in an electrolytic solution containing 1 mole of tetraethylammonium paratoluene sulfonate and 1 mole of pyrrole, and electropolymerization of pyrrole is carried out at a voltage of 3.0 V for 10 minutes, a black color appears. Precipitation of polypyrrole was observed. The resulting film could be peeled off more easily than the electrode, and its electrical conductivity was measured in a direction parallel to the electrode grid.
It showed high conductivity of 4.5S/cm. On the other hand, in the direction perpendicular to the lattice, the insulating property was less than 10 ^-13 S/cm, and a highly anisotropic conductive film was obtained.

Example 3 After 100 Å of chromium and 700 Å of platinum were deposited on a glass substrate, 500 Å of indium tin oxide was deposited by sputtering to obtain a conductive substrate. On top of this, photoresist AZ-1350J was spin-coated to a thickness of 2 μm, and a photomask was used to coat the photoresist AZ-1350J.
A two-dimensional grid pattern with a pitch of 50 μm was exposed and developed. After depositing 2000 Å of SiO on this, lift-off was performed in methyl ethyl ketone.

In this way, a two-dimensional lattice pattern of insulating SiO was formed on the surface of conductive indium tin oxide. On this surface, conductive patterns isolated at 50 μm intervals were obtained. A vinylidene chloride-vinyl chloride (75:25) copolymer film was coated onto this substrate by a casting method to a thickness of 15 μm. This film-coated substrate was combined with a platinum-plated titanium mesh electrode and thiophene (1 mol/
), immersed in an acetonitrile-tetrahydrofuran (2:1) solution containing tetraethylammonium perchlorate (0.3 mol/) for 10 minutes.
Electrolytic polymerization of thiophene was performed at 4.0V. As a result, the formation of green polythiophene was observed.
When this film was peeled off from the electrode substrate and the electrical conductivity was measured, it was found that on the film surface it was 10 ^-12 S/
The electrical conductivity in the thickness direction was 1.5 S/cm, although the insulating property was less than cm. In this way, a film having conductivity only in the thickness direction was obtained.

Example 4 After 100 Å of chromium and 1000 Å of gold were deposited on a glass substrate, 2000 Å of indium tin oxide was deposited. On top of this, photoresist AZ-1350J was spin-coated to a thickness of 2 μm, and a photomask was used to coat the photoresist AZ-1350J.
A one-dimensional grid pattern of 50 μm lines and 50 μm spaces was exposed and developed. After this, using a parallel plate reactive ion etching device, CBrF ₃ was used as an etching gas at a gas pressure of 20 mtorr and a flow rate.
Indium under the condition of 20SCCM, power 100W
The tin oxide layer was etched to 1200 Å. When the remaining AZ resist was removed using a plasma assher device, an electrode substrate was obtained in which 800 Å and 2000 Å thick indium tin oxide layers were arranged on gold in a one-dimensional lattice pattern every 50 μm.

A polyvinyl chloride film (molecular weight 70,000) with a thickness of 20 μm was formed on this electrode substrate by a casting method. When the obtained film-attached electrode substrate was subjected to electrolytic polymerization of pyrrole under the same conditions as in Example 2,
Formation of polypyrrole occurred over the entire surface of the film. This film can be easily peeled off from the electrode substrate, and when its electrical conductivity was measured, the electrical conductivity of the back side that was in contact with the electrode substrate surface was 12S/cm in the direction parallel to the one-dimensional grid, and 12S/cm in the direction parallel to the one-dimensional grid, and direction is
It showed high conductivity in both directions at 8.5S/cm. On the other hand, on the surface that was in contact with the electrolytic solution, the insulation properties were 6.8 S/cm in the direction parallel to the lattice and 10 ^-12 S/cm or less in the direction perpendicular to the lattice. In this way, by forming a lattice pattern on the electrode surface using conductors with different specific resistances and appropriately selecting the electrolytic polymerization conditions, one side can have full conductivity and the other side can have anisotropic conductivity in the pattern. A sticky film was created.

〔Effect of the invention〕

As explained above, according to the present invention, an electrode having conductive sites in a desired pattern is used, a polymer film is coated on the electrode, and then electrolytic plating of metal materials or electrolytic polymerization of aromatic compounds is carried out. Since it is possible to obtain a polymer film that has conductivity in the pattern shape of the conductive sites on the electrode, it has the advantage that it is possible to easily produce films that have conductivity in various anisotropic shapes or in special circuit shapes. .

These films can be used in various industrial fields, such as patterned conductive layers for input of various flat input devices, input terminals of display elements, and output terminals of image sensors.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the structure of one example of a patterned electrode according to the present invention, and FIG. 2 is a manufacturing process diagram of a typical example of the method of the present invention. 1: Insulating substrate, 2: Patterned conductor layer,
3: Full-surface conductor layer, 4: Patterned insulator,
5: Polymer film, 6: Conductive part, 7: Insulating part.

Claims (1)

[Scope of Claims] 1. Features include a polymer film formed on an electrode having conductive parts in a desired pattern shape, and a metal material formed by electrolytic plating on the electrode with the polymer film. A film that has conductivity in a pattern. 2. It is characterized by including the steps of forming a polymer film on an electrode having a conductive portion in a desired pattern shape, and forming a metal material by electrolytic plating on the electrode with the polymer film. A method for manufacturing a film having conductivity in a pattern. 3. Includes a polymer film formed on an electrode having conductive sites in a desired pattern shape, and an aromatic polymer material formed by electrolytic polymerization of an aromatic compound on the electrode with the polymer film. A film having conductivity in a pattern. 4 Each step of forming a polymer film on an electrode having conductive sites in a desired pattern shape, and forming an aromatic polymer material by electrolytic polymerization of an aromatic compound on the electrode with the polymer film. 1. A method for producing a film having conductivity in a pattern, the method comprising: