JPS622689A - Formation of wiring pattern - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention uses a solution of a heat-resistant aromatic polymer having a photosensitive group to coat an aromatic polyimide film as a substrate.
After forming the photo-cured layer of the aromatic polymer from which the portion corresponding to the wiring pattern has been removed, this photo-cured layer is used to form a wiring pattern consisting of thin conductive metal wiring by vapor deposition or sputtering. , relates to a method of forming on the aromatic polyimide film,
It can be applied to the production of various electronic material parts.

[Conventional technology]

Conventionally, various methods have been known for forming a conductive metal wiring pattern on an insulating support base line or film (patterning method), but recently, methods for forming conductive metal wiring patterns on an insulating support base line or film, etc. have been known. , by closely overlapping the cut-out masks of the wiring pattern parts, on the surface of the substrate,
A buttering method has been proposed in which a conductive metal wiring pattern is formed by performing plating, spuckling, vapor deposition, etc., and then removing the mask layer and the metal layer on the mask layer by peeling off the mask or the like.

Furthermore, a photosensitive film made of a photosensitive polymer is further laminated on a metal layer such as Cu attached to the film, and then the photosensitive film is irradiated with light to form a portion corresponding to a wiring pattern. After photocuring and developing the photosensitive film, covering the portion corresponding to the wiring pattern with a photocuring layer, and removing the photosensitive film other than the portion corresponding to the wiring pattern to expose the metal layer,
A method has also been proposed in which a conductive metal wiring pattern is formed by removing the exposed portion of the metal layer by etching and then removing the photocured layer.

[Problem that the invention seeks to solve]

In the method using a mask, an expensive mask with a wiring pattern cut out of a metal plate or glass plate by a complicated process such as etching is used as a heat-resistant mask. With masks, it is extremely difficult to form a large number of particularly fine wiring patterns with good reproducibility, and since these masks are quite thick and rigid, they are It is difficult to fix the wire in close contact with a support substrate, etc., and it is difficult to form a precise wiring pattern in a patterning process such as sputtering or vapor deposition. Furthermore, since the manufacturing process of the above mask is complicated and expensive, it is necessary to reuse it during patterning, and in order to reuse it, a process of removing the metal layer attached to the mask and regenerating it is necessary. However, various problems have arisen in the process.

Furthermore, in the method of laminating photosensitive films made of photosensitive polymers, the process is complicated, and the solvent used for etching the metal layer is strong, so there is a risk that the base film may be attacked. Furthermore, there were other problems such as etching being complicated and troublesome.

Therefore, an object of the present invention is to provide a method that can easily form a fine wiring pattern made of thin conductive metal wiring on a film without causing the above-mentioned problems. .

[Means for solving problems]

As a result of repeated research to achieve the above object, the present inventors used a solution of a heat-resistant aromatic polymer having a photosensitive group to form a pattern corresponding to a wiring pattern on an aromatic polyimide film as a substrate. After forming the photocured layer of the aromatic polymer from which portions have been removed, depositing or sputtering a metal onto the surface of the polyimide film, and then removing the photocured layer and the Group 41 layer thereon. It was discovered that a fine wiring pattern can be easily formed on the aromatic polyimide film with extremely good reproducibility.

The present invention was made based on the above findings, and involves coating an aromatic polyimide film with a solution of a heat-resistant aromatic polymer having a photosensitive group, drying the solution, and applying the above-mentioned aromatic polymer onto the polyimide film. A laminated film on which a photosensitive layer is formed is created, and then light is irradiated onto the photosensitive layer of the laminated film through a positive film in which the portion corresponding to the wiring pattern is made opaque, thereby forming a layer corresponding to the wiring pattern. The above-mentioned photosensitive layer is photocured except for the portions corresponding to the wiring pattern, and then the unphotocured portions of the photosensitive layer are removed by developing the photosensitive layer, and the portions other than those corresponding to the wiring pattern are photocured. Then, the partially covered polyimide film is covered with a metal thin film by sputtering or sputtering to form a thin metal film on the partially covered polyimide film. The present invention provides a method for forming a wiring pattern, characterized in that the photocured layer and the metal layer on the photocured layer are removed.

The method for forming a wiring pattern according to the present invention will be described in detail below.

The heat-resistant aromatic polymer having a photosensitive group used in the present invention can be photocrosslinked by irradiation with energy rays (light rays).
The polymer main chain has a photosensitive group containing a carbon-carbon unsaturated group that undergoes photocuring, and the upper limit of the operating temperature is approximately 200°C.
It is an organic solvent-soluble aromatic polymer having heat resistance, preferably 250° C. or higher, and preferred examples of such an aromatic polymer include the following aromatic polyamides and aromatic polyimides.

A dicarboxylic acid component containing about 70 mol% or more of aromatic dicarboxylic acids and an aromatic diamine component containing at least 30 mol%, preferably 40 mol% or more of an aromatic diamine compound having a photosensitive group in an organic polar solvent. An organic solvent-soluble aromatic polyamide having a photosensitive group and consisting of a homopolymer or copolymer obtained by polymerizing with.

A tetracarboxylic acid component containing about 70 mol% or more of aromatic tetracarboxylic acids and an aromatic diamine component similar to the aromatic diamine component used in the production of the aromatic polyamide are polymerized in an organic polar solvent. An organic solvent-soluble aromatic polyimide having a photosensitive group and consisting of the resulting homopolymer or copolymer.

To explain the above aromatic polyamide in more detail,
Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 4.4°-dicarboxy-biphenyl, 4,4°-dicarboxy-diphenylmethane, 4,4
Aromatic dicarboxylic acids such as °-dicarboxy-diphenyl ether and their acid halides (especially acid chlorides)
can be preferably mentioned.

In addition to the above-mentioned aromatic dicarboxylic acids, the dicarboxylic acid component used in the production of the aromatic polyamide includes, for example,
A part of alicyclic or aliphatic dicarboxylic acids may be used in combination.

In addition, aromatic diamine compounds containing a photosensitive group include:
For example, 3,5-diaminobenzoic acid ethyl (meth)acrylate, 2,4-diaminobenzoic acid ethyl (meth)acrylate, 3,5-diaminobenzoic acid glycidyl (meth)acrylate, 2.4- Diaminobenzoic acid glycidyl (meth)acrylate ester, 3゜5-diaminobenzoic acid cinnamic ester, 2,4-
benzoic acid esters such as diaminobenzoic acid cinnamic ester; benzyl acrylate-814-acrylamide-3 such as 3,5-diaminobenzyl (meth)acrylate;
4°-diaminodiphenyl ether, 2-acrylamide-3,4°-diaminodiphenyl ether, 4-cinnamamide-3°4″-diaminodiphenyl ether,
3.4'-diacrylamide-3', 4-diaminodiphenyl ether, 3,4''-dicinnamamide-3'.

4-diaminodiphenyl ether, 4-methyl-2゛-
diphenyl ethers such as carboxyethyl methacrylate ester-3,4''-diaminodiphenyl ether;
and 4.4'-diaminochalcone, 3,3'-diaminochalcone, 4'-methyl-3', 4-diaminochalcone, 4'-methoxy-3', 4-diaminochalcone, 3
Chalcone such as ゛-methyl-3,5-diaminochalcone can be mentioned.

The aromatic diamine component used in the production of the aromatic polyamide may contain, in addition to the above-mentioned aromatic diamine compound having a photosensitive group, an aromatic diamine compound having no photosensitive group.

Examples of aromatic diamine compounds that do not have this photosensitive group include phenylenediamine, metaphenylenediamine, 2.4-diaminotoluene, 4.4°-diaminodiphenyl ether, 4.4''-diaminodiphenylmethane, 0- Diamine compounds such as tolidine, 1,4-bis(4-aminophenoxy)benzene, 2,2″-bis(4-aminophenoxyphenyl)propane, 0-)lysine sulfone, and 9,9-bis(4-amino Diamine compounds containing a ketone group such as phenyl)-10-anthrone, 1,5-diaminoanthraquinone, 3.3°-diaminohensiphenone, and 1-dimethylamino-4-(5,5-diaminohendiyl)-naphthalene. can be mentioned. Among these, aromatic diamine compounds having ketone groups in particular have sensitizing properties, so polyamides obtained from aromatic diamine components having ketone groups can be This is preferable because the sensitivity to

The aromatic polyamide contains the dicarboxylic acid component and
Using approximately equal moles of the above aromatic diamine component,
Polymerization conditions similar to known polymerization methods (e.g., in an organic polar solvent, a polymerization temperature of about 100' C or less, about 0.1 to 50
(polymerization time, etc.).

The aromatic polyamide has a logarithmic viscosity [concentration; 0°5 g/
100ml (N-methyl-2-pyrrolidone; NMP
), 11 constant temperature; measured at a temperature of 30°C] is about 0.1 to
4.0, particularly preferably within the range of about 0.2 to 3.0.

Next, to explain the aromatic polyimide in more detail, the aromatic tetracarboxylic acids include 2.3.3
Aromatic tetracarboxylic acids such as ', 4''- or 3.3°, 4,4'-biphenyltetracarboxylic acid, 3.3', 4°4'-hensiphenotetracarboxylic acid, or acid dianhydrides thereof etc., and esters, salts, etc. of the above-mentioned aromatic tetracarboxylic acids may also be used.

The above-mentioned aromatic polyimide is obtained by polymerizing the tetracarboxylic acid component and the aromatic diamine component using approximately equal moles and using substantially the same polymerization method and polymerization conditions as in the case of the above-mentioned aromatic polyamide.

The aromatic polyimide has a logarithmic viscosity [concentration; 0°5 g/
100ml (N-methyl-2-pyrrolidone; NMP
), measurement temperature: 30℃] is approximately 0.0
It is preferably within the range of about 8 to 2, particularly about 0.15 to 1.0.

Examples of the aromatic polyamide and aromatic polyimide include N,N-dimethylformamide and N.

It is soluble in organic solvents such as N-dimethylaceamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylene phosphoramide, and diglyme, and is uniformly dissolved in the organic solvent at a concentration of about 1 to 40% by market weight. It can be melted into

Further, the aromatic polyimide film used as the substrate in the present invention is, for example, 2.3.3", 4" - 3.3".
', 4,4"-biphenyltetracarboxylic acid, 3.3'
, obtained by polymerizing an aromatic tetracarboxylic acid such as 4.4″-benzophenonetetracarboxylic acid or its acid dianhydride and an aromatic diamine compound that does not have a photosensitive group in a medium. It is made of an organic solvent-insoluble aromatic polyimide that does not have a photosensitive group.Although its thickness is not particularly limited, it is usually 1 to 200 μm, preferably 5 to 150 μm.

Next, a preferred embodiment of the wiring pattern forming method of the present invention will be described.

First, an organic solvent solution of the above-mentioned heat-resistant aromatic polymer having a photosensitive group is prepared, and this solution is applied to the above-mentioned aromatic polyimide film as the substrate, dried, and the above-mentioned aromatic polymer is applied onto the polyimide film. A laminated film on which a photosensitive layer made of a group polymer is formed is prepared.

The solution of the aromatic polymer can be prepared by, for example, adding the organic solvent-soluble aromatic polyamide or aromatic polyimide having a photosensitive group to N,N-dimethylformamide,
N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylene phosphoramide, diglyme, etc. in a solvent at a concentration of about 1 to 40% by weight, preferably 3 to 30% by weight. All you have to do is melt it. Also, the rotational viscosity (25
C) is preferably about 0.5 to 1000 voids, particularly about 1 to 500 voids.

Examples of the aromatic polymer solution include Michler's ketone, hengeine, benzoin methyl ether, benzine ethyl ether, 2-tert-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, 4,4"- Bis(diethyl?mino)benzophenone, acetophenone, benzophenone, thioxanthone,
Methylthioxanthone, chlorthioxanthone, 1.5
- It is preferable to incorporate a photopolymerization initiator such as acenaphthene, hensyl ketal, and anthranilic acid trimethylaminobenzoate, and monomers having a hydroxy group (
Photopolymerizable monomers such as meth)acrylate compounds, poly(meth)acrylate compounds, N-vinyl-2-1pyrrolidone, or hydroquinone, 2,6-ditertiary-butyl-4-methylphenol (BHT) , methyl ether hydroquinone, benzoate, benzoquinone, 4-hydroxymethyl-2,6-ditertiary-butylphenol, and other thermal polymerization inhibitors, as well as methyl N,N-dimethylanthranilate, ortho- or var.
- A sensitizer such as ethyl dimethylbenzoate may be blended.

The above aromatic polymer f6 liquid contains aromatic polymer 10
With respect to 0 part of electric charge, about 0.5 to 150 parts by weight of the previously combined monomer, about 0.01 to 5 parts by weight of thermal polymerization inhibitor, or about 0.01 to 15 parts of light It is preferable that a polymerization initiator is blended.

The solution of the aromatic polymer can be applied to the substrate using, for example, a spin coating machine. The coating film is dried using a hot air dryer or the like at 100°C or less for 1 to 60 minutes, especially for 10 minutes.
It is preferable to carry out the treatment for about 30 minutes. At this time, the thickness of the photosensitive layer (coated film after drying) is preferably about 1 to 150 .mu.m, particularly preferably 2 to 100 .mu.m.

Next, a positive film whose portion corresponding to the wiring pattern is made opaque is closely attached to the photosensitive layer of the laminated film formed as described above, and visible light, ultraviolet rays, electron beams, and X-rays are transmitted through the positive film. The photosensitive layer is photocured (crosslinked) and made insolubilized by irradiating it with an energy beam (light beam) such as a wire, except for the portion corresponding to the wiring pattern F.

Subsequently, the photosensitive layer was heated to about 0.~100% in a suitable developer.
The uncured portion of the photosensitive layer is eluted and removed by development, such as by immersion at a temperature of .degree.

Examples of the above-mentioned developing solution include those exemplified as the solvent used for preparing the solution of the aromatic polymer, as well as 1.
Solvents such as 1.1-trichloroethane, methyl cellosolve, T-butyrolactone, and cyclohexanone can also be used.

Further, during the development, it is appropriate to apply ultrasonic waves to the developer.

This film is then heated in a hot oven for approximately 100 to 40
It is preferable to heat-treat at 0°C, particularly at 150-300°C for 10-120 minutes.

In this way, a partially covered polyimide film is obtained in which the portion other than the portion corresponding to the wiring pattern is covered with the photocured layer (the photocured portion of the photosensitive layer), and the portion corresponding to the wiring pattern is exposed.

Thereafter, the partially coated polyimide film is preferably heated to a temperature of about 200° C. or higher, particularly preferably about 250° C.
Conductive metals (including alloys) are deposited or coated at a temperature of ~400°C, preferably with a thickness of approximately 1~400°C.
A thin film of the metal of 150 .mu.m, particularly preferably 2 to 100 .mu.m, is formed on the partially coated polyimide film.

In the above vapor deposition or sputtering, since the photocured layer of the aromatic polymer constituting the partially covered polyimide film and the aromatic polyimide film suitably have flexibility, heat resistance, etc., conventionally known methods can be used. Alternatively, the device can be used as is.

Finally, the photocured layer of the partially covered polyimide film is eluted by dissolving and washing with a solvent or the like, and the gold gS layer thereon is removed together with the photocured layer, and the aromatic polyimide film formed on the aromatic polyimide film is A wiring pattern consisting of the thin layer wiring of the above metal is obtained.

The solvent used for elution of the photocured layer includes an alkaline solution such as an aqueous alkaline solution, an organic solvent used for preparing the aromatic polymer solution, hydrazine, and an organic amine such as trimethylamine, triethylamine, pyridine, and ethanolamine. Alternatively, a mixture thereof can be mentioned.

〔Example〕

Example 1 (Production of photosensitive aromatic polyamide) After replacing the gas in the flask by passing dry nitrogen gas into a three-neck flask, 3 g of lithium chloride and 31.71 g of 3,5-diaminobenzoic acid ethyl methacrylate were added.
4g of N-methyl-2-pyrrolidone (N
240 ml of MP) was added and melted. After dissolving, cool to 3°C and add 24.36 terephthalic acid dichloride while stirring.
Added 4g.

At this time, heat generation occurred and the temperature of the solution rose to 34°C.

After stirring this in ice water for 30 minutes, stirring was continued for 1 hour at room temperature to cause a polymerization reaction.

Next, 300 ml of NMP was added to the reaction solution to dilute it, and then added to a mixed solution of 6 f methanol and 61 l water to precipitate aromatic polyamide.

The precipitate was collected by filtration and dried to obtain 42.01 g of white aromatic polyamide powder.

Logarithmic viscosity (concentration; 0, 5
g/100ml solvent, solvent, NMP, measurement temperature; 3
0°C) was 1.73.

(Preparation of aromatic polymer solution) 30 g of aromatic polyamide powder obtained as described above
To the solution were added 150 g of NMP as an organic solvent, 1.2 g of Michler's ketone as a photopolymerization initiator, and 0.15 g of hydroquinone and 0.15 g of methyl ether hydroquinone as thermal polymerization inhibitors, and stirred well to form a uniform viscous solution. After that, the mixture was filtered under pressure to remove fine dust and the like, thereby preparing a photosensitive aromatic polyamide solution with 150 voids.

(Patterning) 30μ-thick aromatic polyimide film (3゜3'
, 4.4°-biphenyltetracarboxylic dianhydride and 4
An outer frame (spacer) with a height of about 250 μm was provided along the upper periphery of the 4°-diaminodiphenyl ether (obtained by polymerizing 4°-diaminodiphenyl ether and Pour the aromatic polyamide solution and apply it to a uniform thickness using a bar coater to form a thin film with an average thickness of about 250 μm, and dry the thin film in a hot air dryer at 70°C for 2 hours. A laminated film was prepared in which a 30 μm thick photosensitive layer was formed on the aromatic polyimide film.

On the photosensitive layer of the above laminated film, a line width of 0.1 mm,
Using a positive film with a wiring pattern in which lines of length 21 are drawn back and forth five times at intervals of 0.5 mm, the film is overlaid and closely adhered, and a light source of an ultra-high pressure mercury lamp placed on top of the film is used. IJ/c is applied to the photosensitive layer through the above positive film.
The photosensitive layer was photocured by irradiating light with an intensity of sA to produce a photocured film having an uncured portion corresponding to a wiring pattern.

Next, the photocured film was developed in an NMP solvent for 3 minutes while applying ultrasonic waves.
After eluating and removing the non-photocured portion (portion corresponding to the wiring pattern), the portions other than the portion corresponding to the wiring pattern are heated at 150°C for 30 minutes to form a photocured layer of the aromatic polyamide (thermal decomposition starts). A partially covered polyimide film was obtained in which the polyimide film was covered at a temperature of 300° C. or higher, and the portion corresponding to the wiring board was exposed.

After that, the partially covered polyimide film was applied using a magnetron sputtering device (manufactured by Nikkei Anelva ■, 5
PF-312 type) at a predetermined position, and sputtering of aluminum is performed at about 300° C. under an argon atmosphere and under reduced pressure to form an aluminum layer on the partially covered polyimide film, and finally, The film with the aluminum layer formed thereon is taken out from the sputtering device, and the photocured layer and the aluminum layer thereon are removed by eluting the photocured layer with an alkaline aqueous solution, and the aluminum layer formed on the aromatic polyimide film is removed. In addition, a wiring pattern consisting of aluminum thin layer wiring with a thickness of about 1 μM was obtained.

〔Effect of the invention〕

The method for forming a wiring pattern of the present invention uses a solution of a heat-resistant aromatic polymer having a photosensitive group, and applies the above-mentioned aromatic polymer onto an aromatic polyimide film as a base, from which a portion corresponding to the wiring pattern has been removed. After forming a photo-cured layer, a wiring pattern consisting of a thin layer of conductive metal is formed on the aromatic polyimide film by vapor deposition or sputtering using this photo-cured layer. Since the photo-cured layer formed on the substrate functions as a mask, it is not necessary to separately manufacture a mask and overlay the mask on the substrate, and the photo-cured layer has extremely excellent heat resistance and chemical resistance,
Because of its mechanical strength and flexibility, patterning processes such as vapor deposition or sputtering, which are performed under heating at fairly high temperatures, can be performed without any problems, making it easy to create detailed wiring patterns with excellent reproducibility. Furthermore, the metal layer other than the wiring pattern portion can be easily removed by dissolving the photocured layer with a solvent, eliminating the need for complicated and troublesome processes such as etching the metal layer. The solvent used to elute the photocured layer is weaker than the solvent normally used for etching metal layers, so there is no danger of it corroding the base film, and it has various excellent effects. be.

Claims (1)

[Scope of Claims] A solution of a heat-resistant aromatic polymer having a photosensitive group is applied to an aromatic polyimide film and dried to form a photosensitive layer made of the aromatic polymer on the polyimide film. Next, the photosensitive layer of the laminated film is irradiated with light through a positive film in which the portion corresponding to the wiring pattern is made opaque, and the photosensitive layer is opaque except for the portion corresponding to the wiring pattern. The photosensitive layer is photocured, and then the photosensitive layer is developed to remove the unphotocured portion of the photosensitive layer, so that the photocured layer covers areas other than the portions corresponding to the wiring pattern, and the wiring pattern is covered with the photocured layer. forming a partially covered polyimide film with the corresponding portion exposed; then vapor depositing or sputtering on the partially covered polyimide film to form a thin metal film on the partially covered polyimide film; and finally, A method for forming a wiring pattern, comprising removing the photocured layer and the metal layer on the photocured layer.