JP2751125B2 - Evaporated film circuit board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a vapor-deposited film circuit board excellent in adhesion and insulating properties.

(Prior art) In general, when a vapor-deposited film circuit board is manufactured by a vapor deposition method, a heat-resistant and smooth insulating coating film is formed on the surface of a substrate such as an aluminum plate, and the vapor-deposited film circuit is formed on the surface. The method of forming is adopted. The insulating coating film on which the vapor-deposited film is formed is usually as thin as 200 μm or less, and it is not preferable to raise the curing temperature to 200 ° C. or higher. In particular, the smoothness of the insulating coating film is required.

Conventionally, condensed cyclized polyimide resin has been used as the resin for this insulating coating film. However, it takes a long time at a temperature of 300 ° C. or more to cyclize (harden) this resin. However, the coating film formed has a disadvantage that water in the air is extremely easily adsorbed. When this polyimide resin is cured at a temperature of 200 ° C. or lower, the insulation failure between the vapor deposition film circuit and the substrate tends to occur in the moisture absorption test, which has been one of the causes of lowering the reliability.

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances, and has been made in order to solve the drawbacks, and has excellent adhesion, insulating properties, smoothness, and moisture resistance as an insulating coating film, and An object of the present invention is to provide a vapor-deposited film circuit board that can be manufactured with good workability by light curing.

[Constitution of the Invention] (Means for Solving the Problems) The present inventors have conducted intensive studies to achieve the above object, and as a result, the above object is achieved by using a novel polyimide resin described later. Thus, the present invention has been completed.

That is, the present invention provides: (A) (a) a compound having an imide group and an epoxy group represented by the following general formula: (Where R is (B) a polyimide resin reacted with phenylenediacrylic acid, and (B) a heat-resistant photosensitive composition containing a sensitizer and a photoinitiator as essential components. A vapor-deposited film circuit board comprising a circuit formed by vapor-depositing a film.

 Hereinafter, the present invention will be described in detail.

The polyimide resin (A) used in the present invention is obtained by reacting (a) a compound having an imide group and an epoxy group with (b) phenylenediacrylic acid. The compound having an imide group and an epoxy group used here is a compound having the following general formula.

(Where R is In addition, (b) phenylenediacrylic acid has the following structural formula.

The polyimide resin is subjected to an addition reaction of (a) a compound having an imide group and an epoxy group and (b) phenylenediacrylic acid in an organic solvent at a temperature of 150 to 200 ° C. for 3 to 12 hours. can get. At this time, it is preferable to use a basic reaction catalyst such as a tertiary amine. This reaction may use a solvent if necessary.
Such solvents include N-methyl-2-pyrrolidone,
Examples thereof include dimethylacetamide, dimethylformamide, dioxane, and diglyme, and these can be used alone or in combination of two or more.

The (B) sensitizer and photoinitiator used in the present invention include:
Benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin phenyl ether, and other benzoin alkyl ethers, benzoin thioethers, benzophenone, acetophenone, 2-ethyl-anthraquinone, decyl chloride, thioxanthone, and the like. These can be used in combination.

The heat-resistant photosensitive composition of the present invention contains a polyimide resin, a sensitizer and a photoinitiator as essential components, but within a range not contrary to the purpose of the present invention, and if necessary, a thermal polymerization inhibitor and an inorganic filler. Agents, coloring agents and the like can be added and blended. Examples of the thermal polymerization inhibitor include p-methoxyphenol, hydroquinone, 2,6-di-tert-butyl-4-methylphenol, methyl ether hydroquinone, benzoate, benzoquinone, and 4-hydroxymethyl-2,6.
-Di-t-butylphenol and the like, which may be used alone or in combination of two or more. The mixing ratio of the thermal polymerization inhibitor can be 0.05 to 2.0 parts by weight per 100 parts by weight of the heat-resistant photosensitive composition. As the inorganic filler,
Examples include silica, magnesium carbonate, calcium carbonate, sodium sulfate, talc, bentonite, and the like, and examples of the colorant include phthalocyanine green.

The heat-resistant photosensitive composition of the present invention is soluble in an organic solvent,
When used as an insulating protective film forming material, 5-40
%, Preferably 15 to 30% by weight (photosensitive resin solution).

Examples of the organic solvent include N, N-dimethylsulfoxide, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, Examples include diglyme, hexamethylenephosphamide, γ-butyllactone, cyclohexanone, and the like, and these can be used alone or as a mixture of two or more.

Next, a method for manufacturing a vapor deposition film circuit board using a photosensitive resin liquid will be described. Photosensitive resin liquid is applied to resin substrate, metal substrate,
On a substrate surface such as a ceramic substrate, spin coating is performed by using screen printing or a spinner to form a coating layer having a thickness of 7 to 10 μm.
m to form a smooth and uniform coating film. This is dried by heating at a temperature of 100 ° C. for 30 minutes, and then light-cured with a 250 W high-pressure mercury lamp. A vapor deposition film circuit was formed on the insulating coating film.
First, a conductive film is deposited on an insulating coating film by vacuum deposition, then a resist pattern of a circuit is formed by a photographic method, and then an unnecessary portion of the conductive film is etched to produce a vapor-deposited film circuit board. Can be. The vapor-deposited film circuit board thus manufactured is suitable for various load cells and thermal heads.

(Action) The present invention provides a compound having an imide group and an epoxy group,
The object can be achieved by using a specific polyimide resin obtained by an addition reaction with phenylenediacrylic acid having a photopolymerizable unsaturated group. That is, it is not necessary that the cyclization (curing) be performed by heating at a temperature of 300 ° C. or more for a long time, and the imide group already cyclized and the unsaturated group photopolymerizable with respect to the epoxy group are used. Since a polyimide resin having the following properties is used, an insulating coating film having excellent smoothness can be easily obtained by short-time heating at about 100 ° C. and light irradiation. Further, since the film is completely cured by heating at 100 ° C. and light, the adhesion between the substrate and the vapor-deposited film circuit is good, and the insulation characteristics can be improved.

(Examples) Next, the present invention will be described specifically with reference to examples. In the following Examples and Comparative Examples, “parts” means “parts by weight”.

Example 1 After replacing the inside of a flask with dry nitrogen in a three-necked flask, 27.50 parts of a compound having an imide group and an epoxy group derived from benzophenonetetracarboxylic anhydride and 6.97 parts of phenylenediacrylic acid were added to triethylamine.
Add 0.03 parts. After heating the temperature in the flask to 150 ° C,
The temperature was raised to 250 ° C. at a temperature increase rate of 0 ° C./one hour, and the reaction was stirred at 200 ° C. for 4 hours while suppressing the heat generation due to the reaction.
After the reaction is completed, add diglyme to the flask and cool down.
This was poured into a mixed solution of methanol and water to precipitate a polyimide resin. The precipitate was dried to obtain 34.0 g of a brown polyimide resin powder. 20 parts of this polyimide resin powder was dissolved in 80 parts of diglyme, and 2 parts of benzoin isopropyl ether as a photoinitiator was added and blended to prepare a varnish (A) of a heat-resistant photosensitive composition.

Example 2 After replacing the inside of the three-necked flask with dry nitrogen through nitrogen, 0.03 part of triethylamine was added to 23.93 parts of a compound having an imide group and an epoxy group derived from pyromellitic anhydride and 6.97 parts of phenylenediacrylic acid. . After heating the flask to a temperature of 150 ° C., the temperature was raised to 200 ° C. at a heating rate of 20 ° C./one hour, and the reaction was allowed to stir for 4 hours while suppressing heat generation due to the reaction. Next, after the reaction was completed, diglyme was added and the mixture was cooled, and the mixture was poured into a mixed solution of methanol and water to precipitate a polyimide resin. The precipitate was dried to obtain 29.83 g of a brown polyimide resin powder. 20 parts of this polyimide resin powder was dissolved in 80 parts of diglyme, and 2 parts of benzoin isopropyl ether as a photoinitiator was added and blended to produce a varnish (B) of a heat-resistant photosensitive composition.

Example 3 After replacing the inside of a three-necked flask with dry nitrogen through a flask, 26.88 parts of a compound having an imide group and an epoxy group derived from 4,4'-oxydiphthalic anhydride and 6.97 parts of phenylenediacrylic acid were added to 0.03 parts of triethylamine. Parts were added. After heating the flask to a temperature of 150 ° C, 20 ° C / 1
The temperature was raised to 200 ° C. at a rate of temperature increase over time, and the reaction was allowed to proceed with stirring at 200 ° C. for 4 hours while suppressing heat generation due to the reaction. Next, after the reaction was completed, diglyme was added and the mixture was cooled, and the mixture was poured into a mixed solution of methanol and water to precipitate a polyimide resin. The precipitate is dried and brown polyimide resin powder
33.0 g was obtained. 20 parts of this polyimide resin powder was dissolved in 80 parts of diglyme, and 2 parts of benzoin isopropyl ether as a photoinitiator was added and blended to prepare a varnish (C) of a heat-resistant photosensitive composition.

Comparative Example 4,4'-diaminodiphenyl ether and pyromellitic dianhydride were reacted in an equivalent amount in N, N-dimethylacetamide to obtain a polyamic acid varnish (D) having a resin content of 17% by weight.
Was manufactured.

Varnishes (A) manufactured in Examples 1 to 3 and Comparative Example
(D) is spin-coated at 2000 rpm on a 2 mm-thick aluminum plate, heated at 100 ° C. for 30 minutes, then spin-coated again at 2000 rpm, and dried by heating at 100 ° C. for 1 hour. After that, (A) to (C) were light-cured with a 250 W high-pressure mercury lamp, and (D) was heat-cured at 270 ° C. for 4 hours to obtain a film having a thickness of 21 mm.
A substrate having a μm insulating coating was prepared. Next, on each insulating coating surface, nickel,
Layers of chromium, titanium, and copper were overlaid, and a circuit resist pattern was formed on the surface by photolithography. Thereafter, unnecessary portions were etched to produce a vapor-deposited film circuit board. Various tests were conducted on these circuit boards for adhesion, insulation resistance, dielectric constant, dielectric loss tangent, and curability. The results are shown in Table 1. The results of the examples were all excellent, and the effects of the present invention could be confirmed.

[Effects of the Invention] As is clear from the above description and the results in Table 1,
The vapor-deposited film circuit board of the present invention has excellent adhesion, insulation properties, smoothness, and moisture resistance as an insulating coating film, and can be manufactured by photocuring with good workability at a low temperature in a short time. For example, a highly reliable product can be obtained.

Claims (1)

(57) [Claims] (A) (a) a compound having an imide group and an epoxy group represented by the following general formula: (Where R is (B) a polyimide resin reacted with phenylenediacrylic acid, and (B) a heat-resistant photosensitive composition containing a sensitizer and a photoinitiator as essential components. A vapor-deposited film circuit board comprising a circuit formed by vapor-depositing a film.