TWI494401B - Adhesive resin composition, coverlay film and circuit board - Google Patents

Description

Resin resin composition, cover film and circuit substrate

The present invention relates to an adhesive resin composition useful as an adhesive in a circuit board such as a flexible printed circuit board, and use thereof.

In recent years, with the advancement of miniaturization, weight reduction, and space saving of electronic equipment, flexible circuit boards (FPC: flexible printed sheets) which are thin, lightweight, flexible, and have excellent durability against repeated bending have been added. There is a need for circuits called flexible printed circuit boards. Since the FPC can be assembled in a three-dimensional and high-density space even in a restricted space, for example, it is not only a wiring of a movable part of an electronic device such as an HDD, a DVD, or a mobile phone, but also a component such as a cable or a connector. Its use continues to expand.

A cover film is used for the purpose of protecting the wiring portion in the FPC. The cover film is formed by laminating a film for a cover film made of a synthetic resin such as a polyimide resin and an adhesive. In the production of the FPC, for example, a film for a cover film is adhered to a circuit board via a pressure-sensitive adhesive layer by a method such as hot pressing. The subsequent layer is required to have high adhesion to both the circuit wiring pattern of the copper wiring and the like and the film for the cover film. As a binder for such a cover film, there is a proposal for a binder resin composition for a printed circuit board which is excellent in heat resistance and the like under low-temperature hot pressing conditions (for example, Patent Document 1). It is blended in a mixed resin of a polyimide resin and an epoxy resin having a siloxane unit, and is selected from a phosphate ester, a phthalate ester, a polyester, and One or more plasticizers in the fatty acid ester system.

In addition, the film for a cover film is improved in heat resistance, non-curing property, and adhesion as a protective film, and improves compatibility with an epoxy resin-based adhesive. A resin composition obtained by blending a soluble polyimine oxime, an epoxy resin, and a flat talc is proposed (for example, Patent Document 2). Further, in the same manner as the film for a cover film, there is also proposed a resin composition containing a polyalkylenimine oxime having an acid group and a polyamidoxime containing a terminal epoxy group and talc. The non-crimping property of the protective film (for example, Patent Document 3).

[Reference technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 10-212468

[Patent Document 2] Japanese Patent Laid-Open No. Hei 7-304950

[Patent Document 3] Japanese Patent Publication No. 2009-167260

However, in an automotive electronic device using an FPC, since it is placed in a high-temperature environment that is repeated at about 150 ° C, the adhesion between the cover film and the wiring of the FPC is lowered during a long period of time, and wiring protection is generated. Will greatly reduce the problem. With the expansion of the use of FPC, it is not limited to automotive electronic equipment, and it is expected that the use of FPC in the same severe temperature environment will increase in the future. Therefore, for FPC used in a high-temperature environment, research measures are strongly demanded for the reduction of the adhesion force of the cover film.

Accordingly, an object of the present invention is to provide an adhesive resin composition which is an adhesive layer which does not reduce the adhesion of a wiring layer and a cover film even when placed in a high-temperature environment.

As a result of examining the above-mentioned problems, the present inventors have found that copper in copper wiring is oxidized due to long-term use in a high-temperature environment, and causes a decrease in adhesion force. For example, oxidation of copper can be suppressed. The present invention can be completed by maintaining excellent adhesion for a long period of time even in a high temperature environment. That is, the adhesive resin composition of the present invention contains the following components (a) and (b); (a) a polyimine containing the constituent units represented by the following general formulas (1) and (2); 100 parts by weight of a polysiloxane (b) containing 5 to 200 parts by weight of a plate-like inorganic filler having an average particle diameter in the range of 2 to 25 μm.

Wherein Ar represents a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ represents a divalent diamine fluorinated alkane residue derived from a diamine siloxane, and R ₂ represents an aromatic group. The diamine-derived divalent aromatic diamine residue, m and n each represent a molar ratio of the constituent units, m is in the range of 0.75 to 1.0, and n is in the range of 0 to 0.25. ]

In the adhesive resin composition of the present invention, the particle size distribution of the inorganic filler is represented by a number, and is preferably 60% or more in a particle diameter of 10 μm or less, and preferably 10% or less in a particle diameter of 20 μm or more.

Further, in the adhesive resin composition of the present invention, the polyamidofluorene alkane is preferably synthesized by using a diamine sulfoxane represented by the following general formula (3) as a raw material. In this case, among the total diamine components of the raw material, the molar ratio of the diamine oxime of the general formula (3) is preferably 80 mol% or more.

[wherein R ₃ and R ₄ each represent a divalent organic group which may contain an oxygen atom, and R ₅ to R ₈ each represent a hydrocarbon group having 1 to 6 carbon atoms, and m ₁ of the average number of repeats is 1 to 20. ]

The adhesive resin composition of the present invention is preferably an adhesive for a cover film which serves as a wiring portion for protecting a circuit board.

The cover film of the present invention is a cover film obtained by laminating an adhesive layer and a film for a cover film, and the adhesive layer is formed by using any of the above-described adhesive resin compositions.

The circuit board of the present invention includes a base material, a wiring layer formed on the base material, and the cover film covering the wiring layer. In the air, the peel strength between the wiring layer and the film layer for the cover film after the long-term heat resistance test at 150 ° C for 1,000 hours is preferably 0.2 kN/m or more.

In the adhesive resin composition of the present invention, an adhesive layer can be formed, and even if it is placed in a high-temperature environment, oxidation of the metal wiring layer can be prevented without lowering the adhesion to the metal wiring layer. Therefore, the peeling strength of the cover film of the adhesive layer formed by the adhesive resin composition of the present invention can be improved, and the reliability of the circuit board using the cover film can be improved.

[polyimine oxime]

The adhesive resin composition of the present invention contains, as the component (a), a polyamidopentaoxane containing the structural units represented by the above general formulas (1) and (2). The polyamidooxane is a thermoplastic resin, and the bases in the general formulae (1) and (2) are tetravalent aromatic groups derived from an aromatic tetracarboxylic anhydride, and the radical R ₁ is an aromatic diamine. A derivatized divalent diaminocarbamethoxy residue, the base R ₂ being a divalent aromatic diamine residue derived from an aromatic diamine. The constituent unit represented by the formula (1) in the resin is present in the range of from 75 to 100 mol%, desirably in the range of from 80 to 100 mol%. The diaminomethoxyoxane residue is a group of a siloxane coupling (Si-O-Si) having an amine group removed by a diamine siloxane, and by increasing the ratio of the siloxane coupling Even if the plasticizer is not blended, sufficient flexibility can be imparted to the adhesive layer, and the curling of the cover film can be suppressed. Therefore, in the present invention, the m value in the formula (1) is set to 0.75 or more. When the m value is less than 0.75, the effect of suppressing the warping cannot be sufficiently obtained. Further, it is also conceivable to reduce the yttrium bond site of the polyamidofluorene by the increase in the siloxane linkage, and to reduce the hardening shrinkage. Thus, the value of n in the formula (2) is set to be in the range of 0 to 0.25, and desirably in the range of 0 to 0.2. Further, the viscosity of the solution state of the adhesive resin composition can be lowered by the increase in the ratio of the siloxane coupling ratio. Therefore, for example, when a soft inorganic filler such as talc is used, when the adhesive composition is applied in a solution state, it is advantageous to easily form a plate-like inorganic filler in a layer form (the surface portion of the inorganic filler is The coated surfaces are arranged in a nearly parallel state.

Examples of the group Ar include a group represented by the following formula (4) or formula (5).

[In the formula (5), W represents a single bond, a divalent hydrocarbon group having 1 to 15 carbon atoms, -O-, -S-, -CO-, -SO-, -SO ₂ -, -NH- or -CONH-Selected 2 valence base. ]

In particular, the base Ar is a single bond in the formula (4) or the formula (5) in order to suppress the amount of the polar group contained in the polyimine oxyalkylene molecule and to improve the adhesion. The group represented by a divalent hydrocarbon group having 1 to 15 carbon atoms, -O-, -S-, -CO-, or -SO ₂ - is preferable, and W in the formula (4) or the formula (5) is a single bond. The knot is more preferably a group represented by a divalent hydrocarbon group having 1 to 15 carbon atoms or a -CO- group.

Further, the constituent units represented by the above general formulas (1) and (2) may be present in a single polymer or may be a constituent unit of the copolymer. When a copolymer having a plurality of constituent units is present, it may be a block copolymer (in the case where a block copolymer is called a block copolymer), or may be a random copolymer.

Since the polyimine resin is generally produced by reacting an acid anhydride with a diamine, a specific example of the polyimide resin is understood from the description of the acid anhydride and the diamine. In the above general formulas (1) and (2), the group Ar can be said to be a residue of an acid anhydride, and the group R ₁ and the group R ₂ can be said to be residues of a diamine, so that an ideal polyimine resin can be an acid anhydride and two Amine to illustrate. However, the polyimine resin is not limited to the resin obtained from the acid anhydride and the diamine described herein.

Examples of the acid anhydride having a residue of the group Ar include, for example, pyromellitic anhydride (benzoic anhydride), 3,3', 4,4'-biphenyltetracarboxylic dianhydride, and 3 , 3', 4, 4'-diphenyl sulfone tetracorboxylic acid anhydride, 4,4'-oxydiphthalic dianhydride ( 4,4'-oxydiphthalic anhydrie) is preferred. Further, as an acid anhydride, 2,2',3,3'-, 2,3,3',4'- or 3,3',4,4'-benzophenone tetracarboxylic acid can be cited. Acid dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3',3,4 '-Diphenyl ether tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, 3,3',4,4'-, 2,3,3",4"- or 2 , 2", 3, 3"-p-terphenylphenyltetracarboxylic dianhydride, 2,2-bis(2,3- or 3,4-dicarboxyphenyl)propane dianhydride, bis(2,3- or 3,4-Dicarboxyphenyl)methane dianhydride, bis(2,3- or 3,4-dicarboxyphenyl)ruthenium anhydride, 1,1'-bis(2,3- or 3,4-di Carboxyphenyl)ethane dianhydride, for example 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene tetracarboxylic dianhydride, 2,3 6,6-decyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane dianhydride, 2,3,5,6-cyclohexanedianhydride, 2, 3,6,7-naphthyltetracarboxylic dianhydride, 1,2,5,6-naphthyltetracarboxylic dianhydride, 1,4,5,8-naphthyltetracarboxylic dianhydride, 4,8- Dimethyl-1,2,3,5,6,7-hexahydronaphthalenyl-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthyl-1 , 4,5,8-tetracarboxylic dianhydride, 2,3,6,7-(or 1,4,5,8-)tetrachloronaphthyl-1,4,5,8- (or 2,3 ,6,7-)tetracarboxylic acid Anhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene-tetracarboxylic dianhydride, ring Pentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5 - tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, etc. .

Further, the group R ₂ may be a group represented by the following formulas (6) to (8).

[In the formulae (6) to (8), R _g is independently a monovalent hydrocarbon group or an alcoholoxy group having a carbon number of 1 to 6, and z represents a single bond, a divalent hydrocarbon group selected from a carbon number of 1 to 15, and - A divalent group of O-, -S-, -CO-, -SO-, -SO ₂ -, -NH- or -CONH-, and n ₁ is an integer representing 0 to 4 individually. ]

In particular, as the radical R ₂ , in order to suppress the amount of the polar group contained in the molecule of the polyfluorene imine, the adhesion is improved, and z in the formula (8) is a single bond, and the carbon number is 1. The divalent hydrocarbon group to 15 and the group in which n ₁ is 0 are ideal.

The diamine having a residue of the base R ₂ may, for example, be 4,4'-diaminodiphenyl ether or 2'-methoxy-4,4'-diaminobenzimidamide, 1 , 4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2'-bis[4-(4-aminophenoxy)benzene Propane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diamine Benzobenzidine, 2,2-bis-[4-(3-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]anthracene, bis[4 -(3-Aminophenoxy)phenyl]anthracene, bis[4-(4-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy)]biphenyl, double [1-(4-Aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(4-aminophenoxy)]methane, double [4-(3-Aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl Ether, bis[4-(4-aminophenoxy)]diphenyl ketone, bis[4-(3-aminophenoxy)]diphenyl ketone, bis[4,4-(4- Aminophenoxy)]benzimidanilide, bis[4,4-(3-aminophenoxy)]benzamide, 9,9-bis[4-(4-aminophenoxy) Phenyl]fluorene, 9,9-bis[4-(3-amine Phenoxy)phenylbutyrene], 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis[4-(3-aminophenoxy) Phenyl]hexafluoropropane, 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-2,6-dimethylaniline (xylidine), 4,4'-methylene Base-2,6-diethylaniline, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminodiphenylethane , 3,3'-diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodi Phenylsulfide, 3,3'-diaminodiphenylsulfide, 4,4'-diaminodiphenylphosphonium, 3,3'-diaminodiphenylphosphonium, 4,4'-diamine Diphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, benzidine, 3,3'-diaminobiphenyl, 3 , 3'-Dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4"-diamino-p-terphenyl, 3,3"-diamine Base-p-terphenyl, m-phenylene diamine, p-phenylenediamine, 2,6-diaminopyridine, 1,4-bis(4-aminophenoxy)benzene , 1,3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylene bis(1-A) Ethylamine], bismethylamine, 4,4'-[1,3-phenylene bis(1-methylethylidene)]dimethylamine, bis(p-aminocyclohexyl)methane, double (pair) -β-Amino-tertiary butylphenyl)ether, bis(p-β-methyl-δ-aminopentyl)benzene, p-bis(2-methyl-4-aminopentyl)benzene, pair Bis(1,1-dimethyl-5-aminopentyl)benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis(β-aminotridecyl) Toluene, 2,4-diaminotoluene, m-xylylene-2,5-diamine, p-xylylene-2,5-diamine, m-xylylene diamine, P-xylylene diamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, Piperazine and the like.

Further, examples of the group R _{1 include} a group represented by the following formula (3a).

Wherein R ₃ and R ₄ each represent a divalent organic group which may also contain an oxygen atom, R ₅ to R ₈ are a hydrocarbon group each having a carbon number of 1 to 6, and m ₁ of the average repeat number is 1 to 20 . ]

In particular, as the group R ₁ , in order to impart solubility to the polyimine, R ₃ and R ₄ in the formula (3a) are each a divalent hydrocarbon group, and R ₅ to R ₈ are each a carbon number of 1 to 6. The hydrocarbon group, which has an average repeat number of m ₁ of 5 to 15, is desirable.

In order to improve the long-term heat resistance, the aromatic tetracarboxylic anhydride and the aromatic diamine which are raw materials are preferably those having a small polar group. Therefore, the aromatic tetracarboxylic anhydride and the aromatic diamine are preferably compounds having a P value of 1.0 or less calculated according to the following formulas (i) and (ii). In particular, the P value of the aromatic diamine is preferably 0.7 or less, more preferably 0.6 or less. The P value is an index indicating the amount of polar groups contained in the molecule.

P value of aromatic tetracarboxylic anhydride = (A1/B1) × 100 ... (i)

P value of aromatic diamine = (A2 / B2) × 100 ... (ii)

[here,

A1 = (the number of polar groups in the base Ar) × (the number of moles of the base Ar)

A2 = (number of polar groups in the group R ₂₎ × (number of moles of group R ₂₎

B1 = (molecular weight in the base Ar) × (the number of moles of the base Ar)

B2 = (molecular weight in the base R ₂ ) × (the number of moles of the radical R ₂ )]

The polar groups on which the above-mentioned P value is calculated are divided into three groups by the magnitude of the electric dipole moment. The first group is -X (X represents a halogen atom), -OH, -SH, -O-, -S-, -SO-, -NH-, -CO-, -CN, -P=O, -PO- These are calculated by counting each number as a polar base. The second group is -SO ₂ -, -CONH-, and these are calculated by counting the respective numbers as two polar groups. The third group is -SO ₃ H, which is calculated as three polar groups.

In order to control the above P value to a low value, as an aromatic tetracarboxylic anhydride suitable for preparing a precursor of a polyimide, for example, 3,3',4,4'-biphenyltetracarboxylate Acid dianhydride (BPDA), 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride ( DSDA), pyrethic acid dianhydride (PMDA), and the like. Among the particularly desirable acid anhydrides, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride (BTDA) )Wait. These aromatic tetracarboxylic anhydrides may be blended in combination of two or more kinds.

Further, in order to control the above-mentioned P value to a low value, as an aromatic diamine suitable for preparing a precursor of polyfluorene oxime oxane, for example, 2,2-bis(4-amino group) Phenoxyphenyl)propane (BAPP), 2,2-divinyl-4,4'-diaminobiphenyl (VAB), 2,2'-dimethyl-4,4'-diamino Biphenyl (m-TB), 2,2'-diethyl-4,4'-diaminobiphenyl, 2,2',6,6'-tetramethyl-4,4'-diamino Biphenyl, 2,2'-diphenyl-4,4'-diaminobiphenyl, 9,9-bis(4-aminophenyl)anthracene, and the like. Among them, as a particularly desirable diamine, 2,2-bis(4-aminophenoxyphenyl)propane (BAPP) and 2,2'-divinyl-4,4'-diamino group are mentioned. Biphenyl (VAB), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), and the like. These aromatic diamines may be blended in combination of two or more kinds.

In the precursor of the preparation of the polyimine oxime, the diamine oxirane which is one of the raw materials, the diamine oxirane represented by the above general formula (3) can be mentioned. The use of a diamine siloxane to introduce a siloxane chain into a polyamidiamine oxime can impart fluidity at the time of heat pressing of the adhesive resin composition of the present invention, and can be improved on printed circuit wiring. Filling. A specific example of the diamino sulfoxane represented by the general formula (3) is preferably a diamine oxirane represented by the following formulas (9) to (13), wherein the formula (9) or the formula (10) The aliphatic diamine oxirane shown is preferred. These diamino siloxanes may be blended in combination of two or more kinds. Further, when two or more kinds of diamino sulfoxanes are combined and blended, the aliphatic diamine oxime represented by the formula (9) or the formula (10) is added to 100 parts by weight of the total siloxane diamine. It is preferred that the alkane is blended in an amount of 90 parts by weight or more. Further, in the formula (3) and the formula (9) to the formula (13), the m _{1 of the} average number of repetitions is in the range of 1 to 20, and preferably in the range of 5 to 15. m is ₁ to 1 hours as the time of filling of the adhesive decrease, then the more than 20 may be lowered.

The acid anhydride and the diamine may be used alone or in combination of two or more. Further, an acid anhydride or a diamine other than the above may be used in combination.

Polyimine oxime having a structural unit represented by the general formulas (1) and (2), wherein the aromatic tetracarboxylic anhydride, the diamine sulfoxane and the aromatic diamine are reacted in a solvent to form a precursor The resin can be produced by heating the closed loop after the resin. For example, the acid anhydride component and the diamine component are dissolved in an organic solvent at a slight molar ratio, and stirred at a temperature in the range of 0 to 100 ° C for 30 minutes to 24 hours to cause polymerization, thereby obtaining a polyimine oxide. The precursor of the alkane is a polyamine. When reacting, the reaction components are dissolved so that the precursor formed is in the range of 5 to 30% by weight in the organic solvent, desirably in the range of 10 to 20% by weight. Examples of the organic solvent used in the polymerization include N,N-dimethylformamide, N,N-dimethylacetamide (DMAC), N-methyl-2-pyrrolidone, and 2-butanone. , dimethyl hydrazine, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme, and the like. These solvents may be used in combination of two or more kinds, and aromatic hydrocarbons such as xylene or toluene may be used in combination.

The precursors synthesized are generally preferred for use as a reaction solvent solution, but may be concentrated, diluted, or substituted for other organic solvents as needed. Further, the precursor is generally excellent in solvent solubility, and thus is advantageous for use. The method of imidizing the precursor hydrazine is not particularly limited. For example, in the above solvent, heat treatment such as heating at a temperature of from 80 to 400 ° C for 1 to 24 hours may be suitably employed.

In the preparation of the adhesive resin composition of the present invention, the mixing ratio of the acid anhydride component and the diamine component as the raw material is not particularly limited. For example, the molar ratio of the acid anhydride component to the diamine component is The terminal substituent of the amine oxane is set to be an amine group (that is, the acid anhydride group is blocked with a diamine), and the viewpoint of suppressing the polarity of the polyamidino oxirane is that the acid anhydride component: the diamine component is 1.000. :1.001 to 1.0:1.2 is ideal.

Further, the polyimine oxime having the constituent units represented by the above formulas (1) and (2) is a reaction obtained by a reaction of an aromatic tetracarboxylic anhydride, a diamine siloxane, and an aromatic diamine. Imine structure. In order to maintain the adhesion to the wiring layer, the structure of the complete yttrium imidization is most desirable. The ruthenium imidization ratio was measured by a Fourier transform infrared spectrophotometer (available from FT/IR620 manufactured by JASCO Corporation), and the infrared absorption spectrum of the polyimide film was measured by a single reflection ATR method to be around 1015 cm ^-1 . The benzene ring absorber was calculated based on the absorbance of the C=O stretching of the quinone imine group derived from 1780 cm ^-1 . Further, a part of the polyimine oxime may be a proline, and the unreacted proline sites (-CONH- and -COOH) are regarded as polar groups, and in the calculation of the P value described later, The proline was calculated as a substituent having four polar groups (two for -CONH- and two for -COOH).

[Inorganic Filler]

The component (b) of the adhesive resin composition of the present invention is a plate-like inorganic filler containing an average particle diameter in the range of 2 to 25 μm. These inorganic fillers use a plate-like substance in order to impart sufficient gas barrier properties to the adhesive layer. Here, the term "plate shape" means that the flat shape, the flat shape, the flake shape, the scale shape, etc. are used, and the thickness of the inorganic filler is much smaller than the long diameter or the short diameter of the plane portion (ideally at 1/). 2 or less) substances. In particular, it is preferred to use a scaly inorganic filler. From another point of view, the term "plate shape" means that the ratio of the major axis to the thickness of the filler particles (long diameter/thickness) is preferably 5 or more, more preferably 10 or more, and more preferably 15 or more. . Further, the relationship between the long diameter and the average particle diameter of the plate-like inorganic filler is preferably a long diameter ≧ average particle diameter of > 0.4 × a long diameter, and preferably a long diameter ≧ average particle diameter ≧ 0.5 × a long diameter. Further, the long diameter (or short diameter) and the thickness of the filler particles in the present invention, and the ratio of the long diameter to the thickness are average values when the filling of arbitrary 10 particles is measured by a stereoscopic microscope. When the shape of the inorganic filler is not a plate shape, for example, in a spherical shape, the gas barrier property of the adhesive layer is lowered, and oxidation of the wiring layer proceeds, and the strength is sometimes lowered.

As the inorganic filler, for example, an insulating inorganic filler using talc, mica, sericite, clay, kaolin or the like is preferable.

The inorganic filler has an average particle diameter calculated by a laser diffraction method in the range of 2 to 25 μm, and is preferably in the range of 5 to 20 μm. Here, the particle size of the inorganic filler is based on the average of the long diameters of the particles. When the average particle diameter exceeds the above upper limit value, the surface of the adhesive layer tends to be rough, and when it is less than the above lower limit, the effect of suppressing oxygen permeation is not easily obtained.

In addition, the particle size distribution of the inorganic filler is preferably 60% or more, more preferably 65% or more, and preferably 10% or less of the particle diameter of 20 μm or more. When the inorganic filler having a particle diameter of 10 μm or less is less than 60%, when the adhesive resin composition is formed into a film, the filler does not form a layer, and protrusions appear on the surface of the film, which causes the film surface to be rough. Further, when the inorganic filler having a particle diameter of 20 μm or more exceeds 10%, protrusions are formed on the surface of the film, which causes the surface of the film to be rough. For example, when a film of 15 μm or less is produced, it tends to have a rough surface.

Further, the frequency distribution of the particle diameter of the inorganic filler is preferably 0.1 to 100 μm, and more preferably 0.5 to 70 μm. When the frequency distribution exceeds the above upper limit value, the surface of the adhesive layer tends to be rough. When the lower limit is not reached, the effect of suppressing oxygen permeation is not easily obtained.

The compounding amount of the inorganic filler is 5 to 200 parts by weight, preferably 10 to 150 parts by weight, more preferably 30 to 100 parts by weight, and more preferably 40% by weight based on 100 parts by weight of the polyimine oxime. Up to 80 parts by weight. When the amount of the inorganic filler is less than 5 parts by weight based on 100 parts by weight of the polyimine oxime, the effect of blending is not obtained, and the effect of suppressing oxygen permeation cannot be obtained. In addition, when the amount of the inorganic filler is more than 200 parts by weight based on 100 parts by weight of the polyimine oxime, the adhesive layer becomes weak, and as a result, the strength is lowered due to aggregation failure of the adhesive layer. The apparent adhesion will be significantly reduced. Further, although the inorganic filler in the present invention uses a plate-like substance, an inorganic filler which is not a plate shape may be used in combination. When a non-plate-shaped inorganic filler is used in combination, the total amount of the inorganic filler (the total of the plate shape and other shapes) is preferably not more than 200 parts by weight based on 100 parts by weight of the polyamidoxime.

When the adhesive resin composition of the present invention is used for the formation of the adhesive layer of the cover film, in order to exhibit particularly excellent effects, for example, the acid anhydride component and the diamine component of the raw material are used in combination of the following A to C. Ideal.

A) Aromatic tetracarboxylic anhydride: from 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 3,3',4,4'-benzophenone tetracarboxylic dianhydride ( At least one or more selected by BTDA);

B) a diamino methoxy oxane: a diamino methoxy oxane represented by the above formula (9) or (10) (the weight average molecular weight is preferably in the range of 230 to 1,000);

C) Aromatic diamine: 2,2-bis(4-aminophenoxyphenyl)propane (BAPP).

In addition, the blending ratio is such that, in view of the solubility of the polyimine oxime, the low warpage property of the cover film, and the flexibility, the component B: the component C is based on 100% by mole of the component A. It is set to 75 to 100 mol%: 25 to 0 mol% is ideal, 80 to 90 mol%: 20 to 10 mol% is desirable, and it is desirable to be 80 to 85 mol%: 20 to 15 mol%.

The A to C component is blended at the above ratio, and the inorganic filler is blended, and the adhesion of the obtained polyimide film as the adhesive layer of the adhesive layer can be extremely excellent. More specifically, the peel strength of the copper wiring layer after a long-term heat resistance test at 150 ° C for 1,000 hours in the atmosphere may be 0.20 kN/m or more. This extremely high peel strength, which was impossible in the conventional cover film, was first realized by the present invention. In addition, the blending ratio of the component B with respect to the total diamine component is 75 mol% or more, and it is possible to impart excellent solvent solubility to the polyimine oxime, and further, the coating film can be prevented without blending a plasticizer. Upturned.

Further, in the adhesive resin composition of the present invention, in addition to the inorganic filler of the component (a), the inorganic filler of the component (b), any component may be appropriately blended as needed, for example. Other resin components such as epoxy resin, plasticizer, hardening accelerator, coupling agent, pigment, viscosity adjuster, and the like. However, in order to maintain excellent adhesion under high-temperature use conditions, it is preferable that the resin component in the adhesive resin composition is entirely composed of the polyimine oxime of the above component (a). Further, since the plasticizer contains a compound having a large amount of a polar group, it promotes the diffusion of copper from the copper wiring and reduces the adhesion. Therefore, it is preferable to use a plasticizer as much as possible. Further, as described above, in the adhesive resin composition of the present invention, even if the general formula (3) diamine oxirane molar ratio in the total diamine component of the raw material is set to 75 mol% or more, even Full flexibility can be obtained without adding a plasticizer, and the curling of the cover film can be prevented. Therefore, when a plasticizer is to be used, it is desirable to blend it within a range that does not impair the effects of the present invention.

When the adhesive composition of the present invention is blended with an optional component, for example, the total amount of the optional components is preferably from 1 to 10 parts by weight, based on 100 parts by weight of the polyamidoxime oxime. It is more desirable to be 7 parts by weight.

In addition, when the adhesive resin composition of the present invention having the above-mentioned essential components and optional components is used as an adhesive for a cover film or the like, the adhesive force can be maintained in a high-temperature environment, and the following mathematical formula is used. The P value calculated by the formula (iii) is preferably 0.7 or less, more preferably 0.6 or less.

P={(A1+A2+An)/(B1+B2+Bn)}×100 ...(iii)

[here:

An = (the number of polar groups in an arbitrary component) × (the number of moles of an arbitrary component)

Bn = (molecular weight in an arbitrary component) × (mole of arbitrary components)

In the formula, A1, A2, B1, and B2 have the same meanings as described above, and An and Bn are added for each arbitrary component. Further, the number of polar groups is calculated in the same manner as in the case of the aforementioned P value.

The P value is an index indicating the amount of the polar group contained in the composition containing the polyamidiamine oxirane, and the larger the P value, the polar group contained in the composition containing the polyamidiamine siloxane. The greater the amount. When used as an adhesive for a cover film, the polar group contained in the adhesive layer becomes a cause of diffusion of copper in the copper wiring. That is, when a large amount of polar groups are contained in the adhesive layer, copper of the copper wiring spreads over a wide range of the adhesive layer between the reverse heating. As a result, the adhesion force of the adhesive layer is weakened, and the cover film is easily peeled off. In the adhesive resin composition of the present invention, since the P value is 0.7 or less (preferably 0.6), the amount of the polar group contained in the composition is reduced, and the decrease in the adhesion force can be suppressed. Further, when the P value is calculated, the polar group contained in the group Ar (aromatic tetracarboxylic anhydride residue) and the group R ₂ (aromatic diamine residue) of the polyfluorinated amidoxane is used as a reference. The reason is that the amount of the polar group contained in the base R and the base R ₂ determines the polarity of the entire polyamidopentaoxane which is the main component of the adhesive. Therefore, the polar group contained in the diamine oxirane residue and the polar group participating in the quinone imine bond are not considered in calculating the P value.

The adhesive resin composition of the present invention is prepared by mixing and stirring the polyimine oxime of the component (a) and the inorganic filler of the component (b).

When the adhesive resin composition of the present invention obtained as described above forms an adhesive layer, it has excellent flexibility and thermoplasticity, for example, as a FPC, a rigid flex board, or the like. The adhesive for the cover film of the wiring portion has desirable characteristics. When the adhesive layer of the cover film is used as a cover layer for the cover film, the adhesive resin composition of the present invention is applied as a solution on one surface of the cover film, and then heat-treated at a temperature of 60 to 200 ° C, for example. A cover film of the present invention having a film layer for a cover film and an adhesive layer is formed. Further, the adhesive resin composition of the present invention is applied in a solution state on an arbitrary substrate, for example, dried at a temperature of 80 to 180 ° C, and then peeled off to form an adhesive film, and the adhesive film is as described above. The film for a cover film is hot-pressed, and the cover film of the present invention having a film layer for a cover film and an adhesive layer can also be formed.

The film for a cover film of the cover film of the present invention is not limited, but a polyimide film such as a polyimide resin, a polyether quinone resin or a polyamide amide resin can be used. A resin film, a polyamine-based resin film, a polyester resin, or the like. Among them, a polyimide film having excellent heat resistance is particularly preferable. The thickness of the film layer for a cover film is not particularly limited, and is preferably, for example, 5 μm or more and 10 μm or less. Further, the thickness of the adhesive layer is not particularly limited, but is preferably, for example, 25 μm or more and 50 μm or less.

Further, when the adhesive resin composition of the present invention is formed into a film, for example, it can also be used as a bonding sheet of a multilayer FPC. When used as a bonding sheet, the adhesive resin composition of the present invention may be applied in a solution state on any substrate film, for example, after drying at a temperature of 80 to 180 ° C, and then peeling off. The film may be used as a bonding sheet as it is, or the adhesive film may be used in a layered state with any of the substrate films.

Further, the cover film or the adhesive sheet may have a form in which the release material is bonded to the adhesive surface to form a release layer. The material of the release profile is not particularly limited as long as it can be peeled off without damaging the cover film or the adhesive sheet, but for example, polyethylene terephthalate (PET), A resin film such as polyethylene or polypropylene is used, or these resin films are laminated on paper.

The method of forming the adhesive resin composition of the present invention as the adhesive layer may be formed by coating the adhesive resin composition in a solution state, and is not particularly limited, and for example, a double roll (comma) may be used. A coater such as a coater, a die coater, a knife coater, or a lip coater is applied. When the adhesive layer is formed by coating, the plate-shaped inorganic filler may be formed into a layer shape (a state in which the surface portion of the inorganic filler is slightly parallel to the coated surface) without special work.

The circuit board of the present invention is not particularly limited as long as it has the cover film or the adhesive sheet obtained as described above. For example, a preferred embodiment of the circuit board of the present invention includes at least a wiring layer made of a base material, a metal such as copper formed in a predetermined pattern on the base material, and a cover film of the present invention covering the wiring layer. The substrate to be used as the circuit board is not particularly limited. However, in the FPC, it is preferable to use the same material as the film for the cover film, and it is preferable to use a substrate made of a polyimide resin.

Since the circuit board of the present invention uses the cover film of the present invention, an adhesive layer having excellent flexibility and thermoplasticity is filled between the wirings, and high adhesion of the cover film and the wiring layer can be obtained. Further, the use of the adhesive composition of the present invention containing the inorganic filler to form an adhesive layer can impart excellent gas barrier properties to the adhesive layer. In short, an inorganic filler exists in the adhesive layer close to the wiring layer, and even if oxygen permeates the covering body, it can be blocked before the wiring layer. Further, the adhesive layer formed of the adhesive resin composition of the present invention containing a flexible polyimine oxime is adhered to the wiring layer by tightly filling the wiring, thereby improving the adhesive layer. The gas barrier property further suppresses the oxidation of the wiring layer most reliably. Moreover, the diffusion of copper from the wiring layer into the adhesive layer can also be suppressed due to the filler present in the adhesive layer. Therefore, excellent adhesion can be maintained for a long period of time even if it is used repeatedly in a high temperature environment. More specifically, after a long-term heat resistance test at 150 ° C for 1,000 hours in the atmosphere, the peel strength between the wiring layer and the film layer for the cover film can be maintained at 0.2 kN/m or more. In particular, by selecting the group Ar, the group R ₁ and the group R ₂ in the general formulae (1) and (2), an extremely high peel strength of 0.35 kN/m or more can be obtained. In addition, when the compounding ratio of the diamine sulfoxane of the total diamine component of the raw material is 75 mol% or more, excellent solubility can be obtained, and the coating film can be prevented from being warped even if the plasticizer is not blended. .

Further, the circuit board of the present invention can also be configured as a multilayer circuit board. In this case, not only the cover film but also the adhesive film obtained from the adhesive resin composition of the present invention can be used for the cover sheet.

The production of the circuit board of the present invention is not particularly limited. For example, a metal foil film of a metal laminated plate such as a copper-clad laminate is subjected to circuit processing on a predetermined pattern by chemical etching or the like, and then the circuit is processed. The necessary portion of the upper layer is covered with a film laminate, and for example, a method of hot pressing using a hot press device or the like can be exemplified. In this case, the pressing condition is not particularly limited. For example, the pressing temperature is preferably 130° C. or higher and 200° C. or lower, and the pressure is preferably 0.1 MPa or more and 4 MPa or less.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. Further, in the following examples, various measurements and evaluations were carried out as described below unless otherwise specified.

[Measurement of average particle size]

The average particle diameter was measured by a laser diffraction type particle size distribution measuring apparatus (manufactured by Shimadzu Corporation, SALD-2000J).

[Measurement of strength]

Next, the strength was obtained by placing the adhesive surface of the test piece cut into a width of 10 mm and having a length of 100 mm on a shiny surface of a copper foil (35 μm thick) (removing the rust preventive metal), and heatd at 180 ° C, 4 MPa, and 60 minutes. After the press, the tensile tester (Strograph-M1, manufactured by Toyo Seiki Co., Ltd.) was peeled off at a speed of 50 mm/min in a direction of 180°. The force at the time of peeling is taken as the strength. In the present experiment, when the strength was 0.2 kN/m or more, it was judged as "OK", and when it was 0.35 kN/m or more, it was judged as "good".

[Measurement of Weight Average Molecular Weight]

The weight average molecular weight was measured by a gel permeation chromatography machine (manufactured by Tosoh Corporation, HLC-8220GPC). The standard material is polystyrene, and the developing solvent is N,N-dimethylacetamide.

[Method of evaluation of warping]

The evaluation of the tilt is performed by the method described below. The polyimine adhesive was applied onto a Kapton film having a thickness of 25 μm to have a thickness of 35 μm after drying. In this state, the Kapton film was placed underneath, and the average height of the four corners of the film was measured. The average value of the height of the four corners of the film was regarded as "good", and when it was more than 5 mm, it was regarded as "poor".

The code used in this example is the following compound.

BTDA: 3,3',4,4'-benzophenone tetracarboxylic dianhydride

(Polar base of BTDA: 1, P value = 0.56)

BAPP: 2,2-bis(4-aminophenoxyphenyl)propane

(Polar base of BAPP: 2, P value = 0.53)

PSX-A: diamine oxirane represented by the above formula (9)

(However, the average value of the number of m ₁ is in the range of 1 to 20, and the weight average molecular weight is 740.)

[Example 1]

In a 1000 ml separable flask, 9.89 g of BAPP (0.0240 mol), 71.30 g of PSX-A (0.0964 mol), 168 g of N-methyl-2-pyrrolidone and 112 g of xylene were added. Further, 38.66 g of BTDA (0.120 mol) was placed in a separable flask, and stirred at room temperature for 2 hours to obtain a polyamidonic acid solution. The polyamic acid solution was heated to 190 ° C, heated for 20 hours, and stirred to obtain a ruthenium imidized polyimine solution. At this time, the molar % of the diamine siloxane component relative to the total amine component was 80% (m value = 0.8). In addition, the "m value" indicates the presence of a molar ratio (the same applies hereinafter) of the structural unit represented by the above general formula (1) contained in the obtained polyimide resin. Further, the index P value indicating the amount of the polar group contained in the obtained polyimide resin was 0.55.

In this solution, 60 g of talc (manufactured by Nippon Talc Co., Ltd., trade name: MICRO ACE K-1, shape: scaly; average long diameter: 7.0 μm; average short diameter: 5.8 μm; long diameter and thickness Ratio: 15 or more; average particle diameter: 6.6 μm; median diameter: 0.5 μm, maximum frequency: 8.7 μm; cumulative particle amount of particle diameter 10 μm or less: 77%; cumulative particle amount of particle diameter of 20 μm or more: 5 %), stirring for another hour to obtain a polyimine solution a.

The obtained polyimine solution a was coated on one side of a polyimide film (manufactured by DuPont, trade name: Kapton ENS, length × width × thickness = 200 mm × 300 nm × 25 μm), and dried at 80 ° C for 15 minutes. A cover film 1 having an adhesive layer thickness of 35 μm was formed. This cover film 1 was placed on a copper foil having a surface on which the rust-preventive metal layer was removed, and pressurized at a temperature of 180 ° C, a pressure of 4 MPa, and a time of 60 minutes to obtain Sample 1. The adhesive strength of the cover film after hardening of the layer and the copper foil was 0.56 kN/m. Moreover, there is no problem with the cover film tilting.

Next, the evaluation sample 1 was subjected to heat treatment at 150 ° C for 1,000 hours in the atmosphere in an oven. The adhesion strength between the treated copper foil and the cover film was measured and found to be 0.52 kN/m. The peeling surface at this time is in the adhesive layer, and aggregation failure of the adhesive layer occurs. The measured bond strength is a value which is destroyed by agglomeration in the adhesive layer.

Further, a printed circuit board in which a circuit (wiring width/wiring interval (L/S) = 25 μm / 25 μm) was formed on both sides of a polyimide film, and the cover film 1 obtained in Example 1 was placed on a printed substrate. The circuit surface was pressurized at a temperature of 180 ° C, a pressure of 4 MPa, and a time of 60 minutes to obtain a wiring board 1 having a cover film.

[Embodiment 2]

The film 2 was obtained after the same procedure as in Example 1 was carried out except that the talc 60g blended in Example 1 was changed to 84 g, and the sample 2 was evaluated. The adhesion strength between the cover film after hardening of the layer and the copper foil was 0.41 kN/m. Moreover, there is no problem in the curling of the cover film.

Next, the evaluation sample 2 was subjected to heat treatment at 150 ° C for 1,000 hours in the atmosphere in an oven. The adhesion strength between the treated copper foil and the cover film was measured and found to be 0.35 kN/m. The peeling surface at this time is caused by aggregation failure of the adhesive layer in the adhesive layer. The measured bond strength is a value which is destroyed by agglomeration in the adhesive layer.

Further, in the same manner as in the first embodiment, a printed circuit board having a circuit (wiring width/wiring interval (L/S) = 25 μm / 25 μm) was prepared, and the cover film 2 obtained in Example 2 was placed on the circuit surface of the printed substrate. Pressurization is performed to obtain a wiring board 2 having a cover film.

Comparative example 1

In addition to the talc 60g blended in Example 1, it was blended with 60 g of heavy calcium carbonate (manufactured by Takehara Chemical Industry Co., Ltd., trade name: SL-300, shape: granular; average particle diameter: 5.7 μm) The same procedure as in Example 1 was carried out to obtain a polyimine solution, and a film was obtained, and the sample was evaluated. The adhesion strength between the cover film after hardening of the layer and the copper foil was 0.66 kN/m. Moreover, there is no problem in the curling of the cover film.

Next, the above evaluation sample was subjected to heat treatment at 150 ° C for 1,000 hours in an atmosphere in an oven. The adhesion strength between the treated copper foil and the cover film was measured and found to be 0.16 kN/m. The peeling surface at this time is an interface between the adhesive layer and the copper foil, and interface peeling occurs. The measured bond strength is a value which is peeled off by this interface.

Comparative example 2

In addition to the talc 60g blended in Example 1, it was blended with 84 g of heavy calcium carbonate (manufactured by Takehara Chemical Industry Co., Ltd., trade name: SL-300, shape: granular; average particle diameter: 5.7 μm) The same procedure as in Example 1 was carried out to obtain a polyimine solution, and a film was obtained, and the sample was evaluated. The adhesion strength between the cover film after hardening of the layer and the copper foil was 0.62 kN/m. Moreover, there is no problem in the curling of the cover film.

Next, the above evaluation sample was subjected to heat treatment at 150 ° C for 1,000 hours in an atmosphere in an oven. The adhesion strength between the treated copper foil and the cover film was measured and found to be 0.13 kN/m. The peeling surface at this time is an interface between the adhesive layer and the copper foil, and interface peeling occurs. The measured bond strength is a value which is peeled off by this interface.

Comparative example 3

In addition to 60 g of talc blended in Example 1, it was changed to blend with 60 g of cerium oxide (manufactured by Micron Co., Ltd., trade name: SP30, shape: spherical shape; average particle diameter: 2.7 μm), and the others were carried out. In the same manner as in Example 1, a polyimine solution was obtained, and a film was obtained, and the sample was evaluated. The adhesion strength between the cover film after hardening of the layer and the copper foil was 0.59 kN/m. Moreover, there is no problem in the curling of the cover film.

Next, the above evaluation sample was subjected to heat treatment at 150 ° C for 1,000 hours in an atmosphere in an oven. When the adhesive strength between the copper foil after the treatment and the cover film was measured, 0.18 kN/m was obtained. The peeling surface at this time is the interface between the adhesive layer and the copper foil, and there is interface peeling. The measured bond strength is a value which is peeled off by this interface.

Comparative example 4

In addition to the talc 60g blended in Example 1, it was blended with 84 g of cerium oxide (manufactured by Micron Co., Ltd., trade name: SP30, shape: spherical shape; average particle diameter: 2.7 μm), and the others were carried out. In the same manner as in Example 1, a polyimine solution was obtained, and a film was obtained, and the sample was evaluated. The adhesion strength between the cover film after hardening of the layer and the copper foil was 0.35 kN/m. Moreover, there is no problem in the curling of the cover film.

Next, the above evaluation sample was subjected to heat treatment at 150 ° C for 1,000 hours in an atmosphere in an oven. When the adhesive strength between the copper foil after the treatment and the cover film was measured, 0.19 kN/m was obtained. The peeling surface at this time is the interface between the adhesive layer and the copper foil, and there is interface peeling. The measured bond strength is a value which is peeled off by this interface.

Comparative Example 5

In a 1000 ml separable flask were added 15.35 g of BAPP (0.0374 mol), 64.53 g of PSX-A (0.0872 mol), 168 g of N-methyl-2-pyrrolidone and 112 g of xylene. Further, 40.14 g of BTDA (0.1246 mol) was placed in a separable flask, and stirred at room temperature for 2 hours to obtain a polyamidonic acid solution. The polyamic acid solution was heated to 190 ° C, heated for 20 hours, and stirred to obtain a ruthenium imidized polyimine solution. At this time, the molar % of the diamine siloxane component relative to the total amine component was 70% (m value = 0.7).

60 g of the talc used in Example 1 was blended in this solution, and stirred for further 1 hour to obtain a polyimine solution.

The obtained polyimine solution was coated on one surface of a polyimide film (manufactured by DuPont, trade name: Kapton ENS, length × width × thickness = 200 mm × 300 nm × 25 μm), and dried at 80 ° C for 15 minutes. A cover film having an adhesive layer thickness of 35 μm was formed. This cover film was placed on a copper foil having a surface on which the rust-preventive metal layer was removed, and pressurized at a temperature of 180 ° C, a pressure of 4 MPa, and a time of 60 minutes to obtain a sample. The adhesive strength between the cover film after hardening of the layer and the copper foil was 0.56 kN/m. Also, the cover film is overturned rather than satisfactory.

Next, the above evaluation sample was subjected to heat treatment at 150 ° C for 1,000 hours in an atmosphere in an oven. When the adhesive strength between the copper foil after the treatment and the cover film was measured, 0.20 kN/m was obtained. The peeling surface at this time is the interface between the adhesive layer and the copper foil, and there is interface peeling. The measured bond strength is a value which is peeled off by this interface.

The above results are shown in the first table. In the first table, the strength 1 is the adhesion strength between the copper foil and the cover film after curing, and the strength 2 is the between the copper foil and the cover film after heat treatment at 150 ° C for 1,000 hours in the air. Then the intensity. Example of using a polyimine oxime having a structural unit represented by the general formulas (1) and (2) and a plate-like inorganic filler having an average particle diameter of 2 to 25 μm at a predetermined ratio After the heat treatment at 150 ° C for 1,000 hours, the adhesive composition of 1 and 2 hardly decreased the strength of the cover film, and it was confirmed that excellent adhesion was obtained. On the other hand, in Comparative Examples 1 to 4 in which granular calcium carbonate or spherical cerium oxide was used as the inorganic filler, the adhesion of the coating film after the heat treatment was greatly lowered. This is because the gas barrier property of the granular or spherical inorganic filler is insufficient, and thus it can be considered that the copper foil of the sample is evaluated for oxidation and the force is lowered. Further, the blending ratio of the diamine heoxane in the diamine component of the raw material was Comparative Example 5 as low as 0.70, and the coating film was warped.

The embodiments of the present invention have been described in detail above for illustrative purposes, but the present invention is not limited by the embodiments described above. Various changes can be made by those skilled in the art without departing from the scope of the invention, and modifications thereof are also included in the scope of the invention. For example, in the above-described embodiment, the use of the adhesive resin composition of the present invention is, for example, a cover film or a bonded sheet of a circuit board such as FPC. However, the adhesive resin composition is used in other applications than the above, and may be used as Tape forming automated bonding (TAB), chip size package (CSP), and the like are used in the formation of a resin.

Claims (8)

An adhesive resin composition containing the following components (a) and (b); (a) a structural unit represented by the following general formulas (1) and (2): Wherein Ar represents a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ represents a divalent diamine fluorinated alkane residue derived from a diamine siloxane, and R ₂ represents an aromatic group. a diamine-derived divalent aromatic diamine residue, m and n each represent a molar ratio of the structural unit, m is in the range of 0.75 to 1.0, and n is in the range of 0 to 0.25,] The aromatic tetracarboxylic anhydride and the aromatic diamine are compounds having a P value of 1.0 or less calculated according to the following formulas (i) and (ii), wherein the P value is represented by 100 parts by weight of the base oxane. The index of the amount of the polar group contained in the molecule, the P value of the aromatic tetracarboxylic anhydride = (A1/B1) × 100 (i) The P value of the aromatic diamine = (A2 / B2) × 100 (ii) ) wherein the number A1 = (number of polar groups Ar groups) × (number of moles of the group Ar) A2 = (polar group in the group R ₂₎ × (number of moles of group R ₂₎ Bl = (molecular weight in the base Ar) × (the molar number of the base Ar) B2 = (the molecular weight in the radical R ₂ ) × (the number of moles of the radical R ₂ ), the number of the aforementioned polar groups, -X [X represents a halogen Atom], -OH, -SH, -O-, -S-, -SO-, -NH-, -CO-, -CN, -P=O, -PO- are each counted as 1,SO ₂ - ,-CONH- Not counted as 2, -SO ₃ H counts as 3; (b) containing 5 to 200 parts by weight average particle diameter of plate-like inorganic filler in the range 2 to 25μm. The adhesive resin composition according to the first aspect of the invention, wherein the particle size distribution of the inorganic filler is 60% or more in a particle diameter of 10 μm or less and 10% or less in a particle diameter of 20 μm or more. The adhesive resin composition according to the first or second aspect of the invention, wherein the polyfluorinated fluorinated alkane is a raw material of the following formula (3): Synthesizer, [wherein R ₃ and R ₄ each represent a divalent organic group which may contain an oxygen atom, and R ₅ to R ₈ each represent a hydrocarbon group having 1 to 6 carbon atoms, and the average number of reversals m ₁ is 1 to 20]. The adhesive resin composition according to claim 3, wherein the molar ratio of the diamine sulfoxane of the above general formula (3) in the total diamine component of the raw material is 80 mol% or more. The composition of the adhesive resin as described in item 1 or 2 of the patent application scope The material is an adhesive for protecting the cover film of the circuit board wiring portion. A cover film which is formed by laminating an adhesive layer and a film for a cover film, wherein the adhesive layer is an adhesive resin composition according to any one of claims 1 to 5. Formed by. A circuit board comprising a substrate, a wiring layer formed on the substrate, and a cover film according to claim 6 covering the wiring layer. The circuit board according to the seventh aspect of the invention is characterized in that the peeling strength between the wiring layer and the film layer for the cover film after the long-term heat resistance test at 150 ° C for 1,000 hours in the air is 0.2 kN/m or more. .