TWI875715B - Resin film, cover film, circuit board, copper foil with resin, metal-clad laminate, multi-layer circuit board, polyimide and adhesive resin composition - Google Patents

Abstract

The present invention provides a resin film, a polyimide, an adhesive resin composition and a use thereof, which can cope with the high frequency of electronic devices by improving dielectric properties and have dielectric properties with suppressed humidity dependence. The resin film contains a polyimide obtained by reacting a tetracarboxylic anhydride component with a diamine component as a resin component, wherein the diamine component contains a dimer diamine composition having a dimer diamine as a main component in an amount of 40 mol% or more relative to the total diamine components.

Description

Resin film, cover film, circuit board, copper foil with resin, metal-clad laminate, multi-layer circuit board, polyimide and adhesive resin composition

The present invention relates to a polyimide useful as an adhesive in a circuit board such as a printed wiring board and its use.

In recent years, with the development of miniaturization, lightness and space saving of electronic equipment, the demand for flexible printed circuits (FPC) that are thin, light, flexible and have excellent durability even after repeated bending has increased. FPC can be installed three-dimensionally and at high density in a limited space, so its use is gradually expanding in the wiring of movable parts of electronic equipment such as hard disk drives (HDD), digital video disks (DVD), and mobile phones, or in parts such as cables and connectors.

In addition to the above-mentioned high density, the performance of equipment has also been developed, so it is also necessary to cope with the high frequency of transmission signals. In information processing or information communication, in order to transmit and process large amounts of information, efforts are being made to increase the transmission frequency, and printed circuit board materials are required to reduce transmission losses by thinning the insulation layer and improving the dielectric properties of the insulation layer. In the future, FPCs or adhesives that cope with high frequencies will be needed, and reducing transmission losses will become important.

As a technology related to an adhesive layer having polyimide as a main component, it is proposed to apply a crosslinked polyimide resin obtained by reacting a polyimide with an amino compound having at least two primary amino groups as functional groups, wherein the polyimide is made of a diamine compound derived from an aliphatic diamine such as dimer acid (dimer fatty acid) as a raw material in an adhesive layer of a coating film (for example, Patent Document 1). In addition, it is proposed to apply a resin composition using a thermosetting resin such as the polyimide and an epoxy resin and a crosslinking agent in a copper-clad laminate (for example, Patent Document 2). However, Patent Documents 1 and 2 do not consider the influence of by-products other than dimer diamine derived from dimer acid contained in the raw material at all.

It is known that dimer acid is a dimerized fatty acid obtained by using natural fatty acids such as soybean oil fatty acid, tall oil fatty acid, rapeseed oil fatty acid, and oleic acid, linoleic acid, linolenic acid, erucic acid, etc., which are purified from these acids, and performing a Diels-Alder reaction. Polyacid compounds derived from dimer acid can be obtained as a composition of fatty acids or trimerized or higher fatty acids as raw materials (for example, Patent Document 3). [Prior Art Document]

[Patent Documents] [Patent Document 1] Japanese Patent Publication No. 2013-1730 [Patent Document 2] Japanese Patent Publication No. 2017-119361 [Patent Document 3] Japanese Patent Publication No. 2017-137375

[Problem to be solved by the invention] As a method for controlling the physical properties of a resin containing polyimide as a main component, it is important to control the molecular weight of a polyamic acid or polyimide which is a precursor of the polyimide. However, when dimer diamine is used as a raw material, it is used in a state containing byproducts other than dimer diamine derived from dimer acid. Such byproducts not only make it difficult to control the molecular weight of the polyimide, but also affect the dielectric properties or humidity dependence thereof in a wide range of frequencies.

The purpose of the present invention is to provide a resin film and polyimide having dielectric properties with suppressed humidity dependence that can cope with the high frequency of electronic devices by improving dielectric properties. [Technical means for solving the problem]

The resin film of the present invention contains polyimide as a resin component, wherein the polyimide is formed by reacting a tetracarboxylic anhydride component with a diamine component, wherein the diamine component contains a dimer diamine composition having as a main component a dimer diamine in which the two terminal carboxylic acid groups of the dimer acid are substituted with a primary aminomethyl group or an amino group, at a concentration of 40 mol% or more relative to the total diamine components. Furthermore, the resin film of the present invention satisfies the following constitutions I and II.

Configuration I: Based on the following mathematical formula (i) E ₁ =√ε ₁ ×Tanδ ₁ ･･･(i) [here, ε ₁ represents the dielectric constant at 10 GHz measured by a Split Post Dielectric Resonator (SPDR) after humidification at constant temperature and humidity conditions of 23°C and 50%RH (normal state) for 24 hours, and Tanδ ₁ represents the dielectric loss tangent at 10 GHz measured by an SPDR after humidification at constant temperature and humidity conditions of 23°C and 50%RH for 24 hours], it is calculated that the E ₁ value, which is an indicator of dielectric properties at 10 GHz after humidification at constant temperature and humidity conditions of 23°C and 50%RH for 24 hours, is 0.010 or less.

Configuration II: Based on the following mathematical formula (ii) E ₂ =√ε ₂ ×Tanδ ₂ ･･･(ii) [here, ε ₂ represents the dielectric constant at 10 GHz measured by SPDR after water absorption at 23°C for 24 hours, and Tanδ ₂ represents the dielectric loss tangent at 10 GHz measured by SPDR after water absorption at 23°C for 24 hours], the E ₂ value, which is an index representing the dielectric properties at 10 GHz after water absorption at 23°C for 24 hours, is calculated, and the ratio of the E ₂ value to the E ₁ value (E ₂ /E ₁ ) is in the range of 3.0 to 1.0.

In mathematical formula (i) and mathematical formula (ii), “√ε _１ ” and “√ε _２ ” respectively refer to the square roots of “ε _１ ” and “ε _２ ”.

The covering film of the present invention is laminated with an adhesive layer and a covering film material layer, wherein the adhesive layer includes the resin film.

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.

The resin-coated copper foil of the present invention is laminated with an adhesive layer and the copper foil, wherein the adhesive layer contains the resin film.

The metal-clad laminate of the present invention comprises an insulating resin layer, an adhesive layer laminated on at least one side of the insulating resin layer, and a metal layer laminated on the insulating resin layer via the adhesive layer, wherein the adhesive layer comprises the resin film.

The multilayer circuit board of the present invention comprises a laminate including a plurality of laminated insulating resin layers, and one or more conductive circuit layers embedded in the laminate. In the multilayer circuit board of the present invention, at least one of the plurality of insulating resin layers is formed by an adhesive layer having adhesiveness and covering the conductive circuit layer, and the adhesive layer comprises the resin film.

The polyimide of the present invention is formed by reacting a tetracarboxylic anhydride component with a diamine component, wherein the diamine component contains a dimer diamine composition as a main component, wherein the two terminal carboxylic acid groups of the dimer acid are substituted with primary aminomethyl or amino groups, at a content of 40 mol% or more relative to the total diamine components. In the polyimide of the present invention, the component (c) among the following components (a) to (c) is 2% or less in terms of the area percentage of the chromatogram obtained by measuring the dimer diamine composition using colloid permeation chromatography; (a) dimer diamine; (b) a monoamine compound obtained by substituting the terminal carboxylic acid group of a monoacid compound having a carbon number in the range of 10 to 40 with a primary aminomethyl group or an amino group; (c) an amine compound obtained by substituting the terminal carboxylic acid group of a polyacid compound having a carbon number in the range of 41 to 80 with a primary aminomethyl group or an amino group (except the dimer diamine).

The polyimide of the present invention may contain 50 mol% or more of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) relative to the total amount of the tetracarboxylic anhydride component.

The adhesive resin composition of the present invention comprises the following (A) component and (B) component: (A) the polyimide, and (B) an amino compound having at least two primary amino groups as functional groups, and the (B) component is contained in such a manner that the primary amino groups are in a total amount within a range of 0.004 mol to 1.5 mol relative to 1 mol of the ketone group of the BTDA residue derived from the BTDA in the (A) component. [Effect of the Invention]

The resin film and polyimide of the present invention control the content of amine compounds other than dimer diamine in the dimer diamine composition, so the humidity dependence of the dielectric properties is low and the stability is excellent. Therefore, the resin film and polyimide of the present invention can be particularly preferably used in circuit substrates such as FPC in electronic devices requiring high-speed signal transmission.

The following describes the implementation of the present invention.

<Resin film> The resin film of the present embodiment is formed by filming with a resin component as the main component. In order to impart excellent high-frequency characteristics and stability relative to humidity, the resin film of the present embodiment contains a polyimide formed by reacting a tetracarboxylic anhydride component with a diamine component as the resin component, wherein the diamine component contains a dimer diamine composition in which the two terminal carboxylic acid groups of the dimer acid are substituted with primary aminomethyl or amino groups in an amount of 40 mol% or more relative to the total diamine components. Furthermore, the resin film of the present embodiment may also contain any component other than the resin component, such as a filler.

(Dielectric properties) In the resin film of the present embodiment, the dielectric constant at 10 GHz measured by a separate dielectric resonator (SPDR) after humidification at a constant temperature and humidity of 23°C and 50%RH for 24 hours (normal state) is calculated based on the following formula (i) E ₁ =√ε ₁ ×Tanδ ₁ ･･･(i) [Here, ε ₁ represents the dielectric constant at 10 GHz measured by a separate dielectric resonator (SPDR) after humidification at a constant temperature and humidity of 23°C and 50%RH for 24 hours, and Tanδ ₁ represents the dielectric loss tangent at 10 GHz measured by an SPDR after humidification at a constant temperature and humidity of 23°C and 50%RH for 24 hours], which is an index representing the dielectric properties at 10 GHz after humidification at a constant temperature and humidity of 23°C and 50%RH for 24 hours. _{The E1} value is 0.010 or less, preferably 0.009 or less, and more preferably 0.008 or less. If the _E1 value exceeds the upper limit, when used in a circuit board such as an FPC, it is easy to cause a loss of electrical signals in the transmission path of high-frequency signals.

(Dielectric constant) In the resin film of the present embodiment, in order to ensure impedance matching when used in a circuit board such as an FPC and to reduce the loss of electric signals, the dielectric constant (ε ₁ ) at 10 GHz after humidification for 24 hours under constant temperature and humidity conditions of 23°C and 50%RH is preferably 3.2 or less, and more preferably 3.0 or less. If the dielectric constant exceeds 3.2, when used in a circuit board such as an FPC, it is easy to cause disadvantages such as loss of electric signals in the transmission path of high-frequency signals.

(Dielectric loss tangent) In addition, in the resin film of the present embodiment, in order to reduce the loss of electrical signals when used in a circuit board such as an FPC, the dielectric loss tangent ( _Tanδ1 ) at 10 GHz after humidification for 24 hours under constant temperature and humidity conditions of 23°C and 50%RH is preferably less than 0.005, and more preferably less than 0.004. If this dielectric loss tangent is greater than 0.005, when used in a circuit board such as an FPC, it is easy to cause disadvantages such as loss of electrical signals in the transmission path of high-frequency signals.

(Moisture absorption dependence) In the resin film of the present embodiment, in order to reduce the loss of electric signals when dry and wet or to ensure impedance matching when used in a circuit board such as an FPC, the ratio of _{the E2} value _to the E1 value calculated based on the above formula (i) is calculated based on the following formula (ii) _E2 =√ε2 ×Tanδ2 ･･･(ii) [where _ε2 represents the dielectric constant at 10 GHz measured by SPDR after absorbing water at 23°C for ₂₄ hours, and _Tanδ2 represents the dielectric loss tangent at 10 GHz measured by SPDR after absorbing water at _{23 °} C for 24 hours _] . ) is in the range of 3.0 to 1.0, preferably in the range of 2.5 to 1.0, and more preferably in the range of 2.2 to 1.0. If E ₂ /E ₁ exceeds the upper limit, when used in a circuit board such as an FPC, the dielectric constant and dielectric loss tangent will increase when wet, and it is easy to cause undesirable conditions such as loss of electrical signals in the transmission path of high-frequency signals.

(Moisture absorption rate) In addition, in the resin film of the present embodiment, in order to reduce the influence of humidity when used in a circuit substrate such as an FPC, the moisture absorption rate of the resin film is preferably less than 0.5 mass%, and more preferably less than 0.3 mass%. Here, "moisture absorption rate" refers to the moisture absorption rate after more than 24 hours under constant temperature and humidity conditions of 23°C and 50%RH (the same meaning in this manual). If the moisture absorption rate of the resin film exceeds 0.5 mass%, it is easily affected by humidity when used in a circuit substrate such as an FPC, and it is easy to cause adverse conditions such as changes in the transmission speed of high-frequency signals. That is, if the moisture absorption rate of the resin film exceeds the above range, it is easy to absorb water with a high dielectric constant, which will cause an increase in the dielectric constant and the dielectric loss tangent, and it is easy to cause disadvantages such as loss of electrical signals in the transmission path of high-frequency signals.

(Storage modulus) The resin film of the present embodiment may have a temperature domain in the range of 40°C to 250°C in which the storage modulus decreases at a steep rate as the temperature rises. The properties of such a resin film are believed to be a major factor in, for example, alleviating internal stress during hot pressing and maintaining dimensional stability after circuit processing. The resin film preferably has a storage modulus of 5×10 ⁷ [Pa] or less at the upper limit temperature of the temperature domain. By setting such a storage modulus, hot pressing can be performed below 250°C even at the upper limit of the temperature range, thereby ensuring adhesion and suppressing dimensional changes after circuit processing. Furthermore, the resin film of the present embodiment has high thermal expansion but low elasticity, so even if the coefficient of thermal expansion (CTE) exceeds 30 ppm/K, it can alleviate the internal stress generated during lamination.

(Glass transition temperature) In the resin film of this embodiment, the glass transition temperature (Tg) is preferably below 250°C, and more preferably within the range of above 40°C and below 200°C. By setting the Tg of the resin film below 250°C, heat pressing can be performed at a low temperature, thereby relieving the internal stress generated during lamination and suppressing dimensional changes after circuit processing. If the Tg of the resin film exceeds 250°C, the bonding temperature becomes high, which may damage the dimensional stability after circuit processing.

(Thickness) The thickness of the resin film of the present embodiment is preferably, for example, in the range of 5 μm or more and 125 μm or less, and more preferably in the range of 8 μm or more and 100 μm or less. If the thickness of the resin film is less than 5 μm, there is a possibility that wrinkles or other undesirable conditions may occur during the transportation of the resin film during production, etc. On the other hand, if the thickness of the resin film exceeds 125 μm, there is a possibility that the productivity of the resin film may decrease.

<Polyimide> The polyimide of the present embodiment is obtained by imidizing a precursor polyamide obtained by reacting a tetracarboxylic anhydride component with a diamine component, wherein the diamine component contains a dimer diamine composition as a main component, wherein the two terminal carboxylic acid groups of the dimer acid are substituted with primary aminomethyl or amino groups, in an amount of 40 mol% or more relative to the total diamine components.

(Tetracarboxylic anhydride component) The tetracarboxylic anhydride used in the polyimide of the present embodiment may include tetracarboxylic anhydride commonly used in thermoplastic polyimide without particular limitation, but preferably contains 90 mol% or more of tetracarboxylic anhydride represented by the following general formula (1) relative to the total tetracarboxylic anhydride components. It is preferred that the tetracarboxylic anhydride represented by the following general formula (1) is contained in an amount of 90 mol% or more relative to the total tetracarboxylic anhydride components, because it is easy to achieve a balance between the softness and heat resistance of the polyimide. If the total amount of tetracarboxylic anhydride represented by the following general formula (1) is less than 90 mol%, the solvent solubility of the polyimide tends to decrease.

[Chemistry 1]

In the general formula (1), X represents a single bond or a divalent group selected from the following formulae.

[Chemistry 2]

In the above formula, Z represents -C ₆ H ₄ -, -(CH ₂ )n- or -CH ₂ -CH(-OC(=O)-CH ₃ )-CH ₂ -, and n represents an integer of 1-20.

In addition, "thermoplastic polyimide" is generally a polyimide whose glass transition temperature (Tg) can be clearly confirmed, but in the present invention, it refers to a polyimide having a storage elastic modulus of 1.0×10 ⁸ Pa or more at 30°C and a storage elastic modulus of less than 3.0×10 ⁷ Pa at 300°C as measured using a dynamic viscoelasticity measuring device (dynamic thermomechanical analyzer (DMA)). In addition, "non-thermoplastic polyimide" is generally a polyimide that does not soften or show adhesiveness even when heated, but in the present invention, it refers to a polyimide having a storage elastic modulus of 1.0×10 ⁹ Pa or more at 30°C and a storage elastic modulus of 3.0×10 ⁸ Pa or more at 300°C as measured using a dynamic viscoelasticity analyzer (DMA).

Examples of the tetracarboxylic anhydride represented by the general formula (1) include 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenylsulfonatetetracarboxylic dianhydride (DSDA), 4,4'-oxydiphthalic anhydride (ODPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA), p-phenylenebis(trimellitic acid monoester anhydride) (TAHQ), and ethylene glycol bis(trimellitic acid monoester anhydride) (TMEG). Among these, when 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) is used, the adhesion of the polyimide can be improved, and the ketone group present in the molecular skeleton reacts with the amino group of the component (B) described later to form a C=N bond, which easily exhibits the effect of improving heat resistance. From this point of view, it is preferable to contain BTDA in an amount of preferably 50 mol% or more, more preferably 60 mol% or more, relative to the total tetracarboxylic anhydride component.

The polyimide of the present embodiment may contain tetracarboxylic acid residues derived from an acid anhydride other than the tetracarboxylic acid anhydride represented by the general formula (1) as long as the effect of the invention is not impaired. Such tetracarboxylic acid residues are not particularly limited, and examples thereof include pyromellitic acid dianhydride, 2,3',3,4'-biphenyl tetracarboxylic acid dianhydride, 2,2',3,3'-benzophenone tetracarboxylic acid dianhydride or 2,3,3',4'-benzophenone tetracarboxylic acid dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic acid dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, 3,3'',4,4''-p-terphenyl tetracarboxylic acid dianhydride, 2,3,3'',4''-p-terphenyl tetracarboxylic acid dianhydride or 2,2'',3,3''-p-terphenyl tetracarboxylic acid dianhydride, 2,2-bis(2, bis(2,3-dicarboxyphenyl)-propane dianhydride or 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride or bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)sulfonate dianhydride or bis(3,4-dicarboxyphenyl)sulfonate dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride or 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-phenanthrene-tetracarboxylic dianhydride, 1,2,6,7-phenanthrene-tetracarboxylic dianhydride or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic Acid dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-(or 1,4,5,8-)tetrachloronaphthalene-1,4,5,8-(or 2,3 Tetracarboxylic acid residues derived from aromatic tetracarboxylic acid dianhydrides such as 2,6,7-tetracarboxylic acid dianhydride, 2,3,8,9-perylene-tetracarboxylic acid dianhydride, 3,4,9,10-perylene-tetracarboxylic acid dianhydride, 4,5,10,11-perylene-tetracarboxylic acid dianhydride or 5,6,11,12-perylene-tetracarboxylic acid dianhydride, cyclopentane-1,2,3,4-tetracarboxylic acid dianhydride, pyrazine-2,3,5,6-tetracarboxylic acid dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic acid dianhydride, thiophene-2,3,4,5-tetracarboxylic acid dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, and ethylene glycol bis(trimellitic acid)anhydride.

(Diamine component) The polyimide of this embodiment contains a dimer diamine composition in an amount of 40 mol% or more, preferably 60 mol% or more, relative to the total diamine components. By containing the dimer diamine composition in the above amount, the dielectric properties of the polyimide can be improved, the heat pressing properties can be improved by lowering the glass transition temperature (lowering Tg) of the polyimide, and the internal stress can be relieved by lowering the elastic modulus.

(Dimer diamine composition) The dimer diamine composition contains the following component (a), and the amounts of component (b) and component (c) are controlled.

(a) Dimer diamine: The dimer diamine of component (a) is a diamine in which the two terminal carboxylic acid groups (-COOH) of the dimer acid are replaced by primary aminomethyl groups ( _-CH2 - _NH2 ) or amino groups ( _-NH2 ). Dimer acid is a known dibasic acid obtained by the intermolecular polymerization reaction of unsaturated fatty acids. Its industrial production process is roughly standardized in the industry. It is obtained by dimerizing unsaturated fatty acids with 11 to 22 carbon atoms using clay catalysts or the like. The main component of industrially available dimer acid is a dibasic acid with 36 carbon atoms obtained by dimerizing an unsaturated fatty acid with 18 carbon atoms, such as oleic acid, linoleic acid, or linolenic acid, and may contain any amount of monomeric acid (with 18 carbon atoms), trimer acid (with 54 carbon atoms), or other polymerized fatty acids with 20 to 54 carbon atoms, depending on the degree of purification. In addition, double bonds remain after the dimerization reaction, but in the present invention, dimer acids also include compounds whose unsaturation is reduced by further hydrogenation. (a) Component dimer diamine can be defined as a diamine compound obtained by substituting the terminal carboxylic acid group of a dibasic acid compound with a carbon number in the range of 18 to 54, preferably in the range of 22 to 44, with a primary aminomethyl group or amino group.

The dimer diamine composition preferably has a dimer diamine content of component (a) increased to 96% by weight or more, preferably 97% by weight or more, and more preferably 98% by weight or more by using a purification method such as molecular distillation. By setting the dimer diamine content of component (a) to 96% by weight or more, the expansion of the molecular weight distribution of the polyimide can be suppressed. Furthermore, if technically feasible, it is most preferred that the dimer diamine composition is entirely (100% by weight) composed of dimer diamine of component (a).

(b) A monoamine compound obtained by substituting the terminal carboxylic acid group of a monoacid compound having a carbon number in the range of 10 to 40 with a primary aminomethyl group or an amino group; The monoacid compound having a carbon number in the range of 10 to 40 is a mixture of a monobasic unsaturated fatty acid having a carbon number in the range of 10 to 20 derived from a raw material of dimer acid and a monoacid compound having a carbon number in the range of 21 to 40 which is a by-product in the production of dimer acid. The monoamine compound is obtained by substituting the terminal carboxylic acid group of these monoacid compounds with a primary aminomethyl group or an amino group.

The monoamine compound (b) is a component that suppresses the increase in molecular weight of polyimide. During the polymerization of polyamic acid or polyimide, the monofunctional amino group of the monoamine compound reacts with the terminal anhydride group of the polyamic acid or polyimide, thereby blocking the terminal anhydride group and suppressing the increase in molecular weight of the polyamic acid or polyimide.

(c) Amine compounds obtained by substituting the terminal carboxylic acid group of a polyacid compound having a carbon number in the range of 41 to 80 with a primary aminomethyl group or an amino group (except the dimer diamine); The polyacid compound having a carbon number in the range of 41 to 80 is a polyacid compound having a carbon number in the range of 41 to 80 as a by-product when producing dimer acid, i.e., a tribasic acid compound having a carbon number in the range of 41 to 80 as a main component. In addition, polymerized fatty acids other than dimer acid having a carbon number of 41 to 80 may also be included. The amine compounds are obtained by substituting the terminal carboxylic acid group of these polyacid compounds with a primary aminomethyl group or an amino group.

(c) The amine compound is a component that promotes the increase in the molecular weight of polyimide. The trifunctional or higher amino group, which is mainly a triamine derived from trimer acid, reacts with the terminal anhydride group of polyamic acid or polyimide to rapidly increase the molecular weight of polyimide. In addition, amine compounds derived from polymerized fatty acids other than dimer acid having 41 to 80 carbon atoms also increase the molecular weight of polyimide and cause the gelation of polyamic acid or polyimide.

The dimer diamine composition is quantitatively determined by using gel permeation chromatography (GPC) to determine each component. In order to easily confirm the peak start, peak top, and peak end of each component of the dimer diamine composition, a sample treated with acetic anhydride and pyridine is used, and cyclohexanone is used as an internal standard. Using the sample prepared in this way, each component is quantitatively determined by using the area percentage of the GPC chromatogram. The peak start and peak end of each component are used as the minimum value of each peak curve and used as a reference to calculate the area percentage of the chromatogram.

In the dimer diamine composition used in the present invention, the total content of component (b) and component (c) is 4% or less, preferably less than 4%, in terms of area percentage of a chromatogram obtained by GPC measurement. By setting the total content of component (b) and component (c) to 4% or less, the expansion of the molecular weight distribution of the polyimide can be suppressed.

In addition, the area percentage of the chromatogram of the component (b) is preferably 3% or less, more preferably 2% or less, and further preferably 1% or less. By setting it within such a range, the decrease in the molecular weight of the polyimide can be suppressed, and the range of the molar ratio of the tetracarboxylic anhydride component and the diamine component can be expanded. Furthermore, the component (b) may not be included in the dimer diamine composition.

In addition, the area percentage of the chromatogram of the component (c) is 2% or less, preferably 1.8% or less, and more preferably 1.5% or less. By setting it within such a range, the rapid increase of the molecular weight of the polyimide can be suppressed, and the increase of the dielectric loss tangent of the resin film in a wide frequency range can be suppressed. Furthermore, the component (c) may not be included in the dimer diamine composition.

When the ratio (b/c) of the area percentage of the chromatogram of the component (b) to the component (c) is 1 or more, the molar ratio of the tetracarboxylic anhydride component to the diamine component (tetracarboxylic anhydride component/diamine component) is preferably set to 0.97 or more and less than 1.0. By setting such a molar ratio, the molecular weight of the polyimide can be more easily controlled.

When the ratio (b/c) of the area percentage of the component (b) to the component (c) in the chromatogram is less than 1, the molar ratio of the tetracarboxylic anhydride component to the diamine component (tetracarboxylic anhydride component/diamine component) is preferably set to 0.97 or more and 1.1 or less. By setting such a molar ratio, the molecular weight of the polyimide can be more easily controlled.

The weight average molecular weight of polyimide is preferably in the range of 10,000 to 200,000, and within this range, the weight average molecular weight of polyimide can be easily controlled. In addition, when used as an adhesive for FPC, for example, the weight average molecular weight of polyimide is more preferably in the range of 20,000 to 150,000, and further preferably in the range of 40,000 to 150,000. When the weight average molecular weight of polyimide is less than 20,000, the flow resistance tends to deteriorate. On the other hand, if the weight average molecular weight of the polyimide exceeds 150,000, the viscosity increases excessively and the polyimide becomes insoluble in the solvent, which tends to cause defects such as uneven thickness and streaks in the adhesive layer during coating.

The dimer diamine composition used in the present invention is preferably purified to reduce components other than the dimer diamine. There is no particular limitation on the purification method, and known methods such as distillation or precipitation purification are preferred. The dimer diamine composition before purification can be obtained in the form of commercial products, for example, PRIAMINE 1073 (trade name) manufactured by Croda Japan, PRIAMINE 1074 (trade name) manufactured by Croda Japan, PRIAMINE 1075 (trade name) manufactured by Croda Japan, etc.

As diamine compounds other than the dimer diamine used in the polyimide, aromatic diamine compounds and aliphatic diamine compounds can be cited. Specific examples of these compounds include 1,4-diaminobenzene (p-PDA; p-phenylenediamine), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), 2,2'-n-propyl-4,4'-diaminobiphenyl (m-NPB), 4-aminophenyl-4'-aminobenzoate (APAB), 2,2-bis-[4-(3-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy)phenyl]methane , bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)]benzophenone, 9,9-bis[4-(3-aminophenoxy)phenyl]fluorene, 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine (Xylidine), 4,4'-methylenedi-2,6-diethylaniline, 3,3'-diaminobiphenyl ethane, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, bis(p-aminocyclohexyl)methane, bis(p-β-amino-tert-butylphenyl) ether, bis(p-β-methyl-δ-aminopentyl)benzene, p-bis(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4 -bis(β-amino-tert-butyl)toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-phenylenediamine, p-phenylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, 2'-methoxy-4,4'-diaminobenzanilide, 4,4'-diaminobenzanilide, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 6-amino-2-(4-aminophenoxy)benzoxazole, 1,3-bis(3-aminophenoxy)benzene and other diamine compounds.

Polyimide can be produced as follows: the tetracarboxylic anhydride component and the diamine component are reacted in a solvent to generate polyamide, and then the polyamide is heated for ring closure. For example, the tetracarboxylic anhydride component and the diamine component are dissolved in an organic solvent in approximately equimolar amounts, and the polymerization reaction is carried out by stirring for 30 minutes to 24 hours at a temperature in the range of 0°C to 100°C, thereby obtaining polyamide as a precursor of polyimide. During the reaction, the reaction components are dissolved in a manner such that the generated precursor is in the range of 5% by weight to 50% by weight, preferably in the range of 10% by weight to 40% by weight in the organic solvent. Examples of organic solvents used in the polymerization reaction include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), 2-butanone, dimethyl sulfoxide (DMSO), hexamethylphosphatamide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), methanol, ethanol, benzyl alcohol, cresol, etc. These solvents may be used in combination of two or more, and aromatic hydrocarbons such as xylene and toluene may also be used in combination. The amount of the organic solvent used is not particularly limited, but is preferably adjusted so that the concentration of the polyamide solution obtained by the polymerization reaction becomes about 5 wt % to 50 wt %.

The synthesized polyamine is usually advantageously used as a reaction solvent solution, and can be concentrated, diluted or replaced with other organic solvents as needed. In addition, polyamine is generally excellent in solvent solubility, so it is advantageously used. The viscosity of the polyamine solution is preferably in the range of 500 cps to 100,000 cps. If it deviates from the above range, it is easy to produce defects such as uneven thickness and streaks in the film when applying it using a coating machine.

The method for imidizing polyamic acid to form polyimide is not particularly limited, and for example, a heat treatment such as heating in the solvent at a temperature condition in the range of 80°C to 400°C for 1 hour to 24 hours can be preferably adopted. In addition, the temperature can be heated at a fixed temperature condition or the temperature can be changed in the middle of the step.

By selecting the types of the tetracarboxylic anhydride component and the diamine component in the polyimide of the present embodiment, or by using two or more tetracarboxylic anhydride components or diamine components, their respective molar ratios can be controlled to control dielectric properties, thermal expansion coefficient, tensile elastic modulus, glass transition temperature, etc. In addition, when the polyimide of the present embodiment has a plurality of structural units of polyimide, they may exist as blocks or randomly, preferably randomly.

The imide group concentration of the polyimide of the present embodiment is preferably 22 wt% or less, more preferably 20 wt% or less. Here, "imide group concentration" refers to the value obtained by dividing the molecular weight of the imide group (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. If the imide group concentration exceeds 22 wt%, the molecular weight of the resin itself becomes small, and the low hygroscopicity is also deteriorated due to the increase of polar groups, and the Tg and elastic modulus increase.

The polyimide of this embodiment is preferably a completely imidized structure. However, a part of the polyimide may be amide. The imidization rate can be measured by using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation) and using the attenuated total reflection (ATR) method to measure the infrared absorption spectrum of the polyimide film, and using the benzene ring absorber near 1015 cm ^-1 as a reference, and calculating it from the absorbance of the C=O stretching of the imide group at 1780 cm ^-1 .

<Adhesive resin composition> The adhesive resin composition of the present embodiment comprises: as component (A), the polyimide containing BTDA residues derived from BTDA in an amount of preferably 50 mol% or more, more preferably 60 mol% or more relative to all tetracarboxylic acid residues, and as component (B), an amino compound having at least two primary amino groups as functional groups. In the present invention, "BTDA residues" refer to tetravalent groups derived from BTDA.

(Amino compound) In the adhesive resin composition of the present embodiment, as the component (B), the amino compound having at least two primary amino groups as functional groups may be exemplified by dihydrazide compounds, aromatic diamines, aliphatic amines, etc. Among these, dihydrazide compounds are preferred. Aliphatic amines other than dihydrazide compounds are prone to form cross-linked structures even outdoors, so there is a concern about the storage stability of the varnish. On the other hand, aromatic diamines need to be made at a high temperature in order to form a cross-linked structure. In this way, when a dihydrazide compound is used, both the storage stability of the varnish and the shortening of the curing time can be taken into account. Preferred examples of the dihydrazide compound include oxalic acid dihydrazide, malonate dihydrazide, succinate dihydrazide, glutarate dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diethylene glycol, The present invention also includes dihydrazide compounds such as hydrazide of tartrate, hydrazide of apple acid, hydrazide of o-phthalate, hydrazide of isophthalate, hydrazide of terephthalate, hydrazide of 2,6-naphthoic acid, hydrazide of 4,4-diphenylhydrazide, hydrazide of 1,4-naphthoic acid, hydrazide of 2,6-pyridinediacid, and hydrazide of itaconic acid. The above dihydrazide compounds may be used alone or in combination of two or more.

Furthermore, the amino compounds such as (I) dihydrazide compounds, (II) aromatic diamines, and (III) aliphatic amines may be used in combination of two or more, for example, a combination of (I) and (II), a combination of (I) and (III), or a combination of (I), (II), and (III).

In addition, from the viewpoint of making the network structure formed by crosslinking of the amino compound of component (B) denser, the molecular weight (weight average molecular weight when the amino compound is an oligomer) of the amino compound of component (B) used in the present invention is preferably 5,000 or less, more preferably 90 to 2,000, and further preferably 100 to 1,500. Among these, amino compounds having a molecular weight of 100 to 1,000 are particularly preferred. If the molecular weight of the amino compound is less than 90, there is a tendency that only one amino group of the amino compound forms a C=N bond with the ketone group of the polyimide resin, and the surrounding of the remaining amino group becomes larger in volume stereographically, so that the remaining amino group is less likely to form a C=N bond.

When the ketone group of the BTDA residue is crosslinked with the amino compound, the amino compound is added to the resin solution containing the (A) component to cause the ketone group in the polyimide to undergo a condensation reaction with the primary amino group of the amino compound. Through this condensation reaction, the resin solution is cured to form a cured product. In this case, the amount of the amino compound added may be such that the total amount of the primary amino group is 0.004 mol to 1.5 mol, preferably 0.005 mol to 1.2 mol, more preferably 0.03 mol to 0.9 mol, and most preferably 0.04 mol to 0.6 mol, per 1 mol of the ketone group. If the amount of the amino compound added is less than 0.004 mol of the total primary amino group per 1 mol of the keto group, crosslinking of the amino compound is insufficient, and thus heat resistance after curing tends to be difficult to exhibit. If the amount of the amino compound added exceeds 1.5 mol, unreacted amino compounds act as thermoplastics, and heat resistance as an adhesive layer tends to decrease.

The conditions for the crosslinking condensation reaction are not particularly limited as long as the ketone group in the (A) component polyimide reacts with the primary amino group in the (B) component amino compound to form an imine bond (C=N bond). The temperature of the heat condensation is preferably in the range of 120°C to 220°C, more preferably in the range of 140°C to 200°C, for the purpose of releasing water generated by the condensation to the outside of the system or simplifying the condensation step when the heat condensation reaction is performed after the synthesis of the (A) component polyimide. The reaction time is preferably about 30 minutes to 24 hours. The end point of the reaction can be confirmed, for example, by measuring the infrared absorption spectrum using a Fourier transform infrared spectrophotometer (commercially available product: FT/IR620, manufactured by JASCO Corporation) and by the decrease or disappearance of the absorption peak derived from the ketone group in the polyimide resin at around 1670 cm ^-1 and the appearance of the absorption peak derived from the imine group at around 1635 cm ^-1 .

The ketone group of the polyimide component (A) and the primary amino group of the amino compound component (B) can be condensed by heating, for example, by the following methods: (1) a method in which the amino compound component (B) is added and heated after the synthesis (imidization) of the polyimide component (A); (2) a method in which an excess amount of the amino compound is added as a diamine component, and after the synthesis (imidization) of the polyimide component (A), the remaining amino compound that does not participate in the imidization or amidation is heated together with the polyimide as the (B) component; or (3) a method in which the composition of the polyimide component (A) to which the amino compound component (B) is added is processed into a predetermined shape (for example, after being coated on an arbitrary substrate or formed into a film).

In order to impart heat resistance to the polyimide component (A), the formation of imide bonds in the formation of the cross-linked structure has been described, but the present invention is not limited thereto. As a method for curing the polyimide component (A), for example, epoxy resins, epoxy resin curing agents, active ester compounds, benzoxazine resins, cyanate resins, maleimide, activated ester resins, resins having a phenyl ether skeleton or a styrene skeleton having an unsaturated bond, etc. may be mixed and cured. Here, the active ester compound is one that functions as a curing agent for epoxy resins and has active esters.

In addition, in the adhesive resin composition of the present embodiment, in addition to the polyimide component (A) and the amino compound component (B), the inorganic filler component (C) is preferably contained as an optional component. Furthermore, as required, other resin components such as plasticizers, epoxy resins, fluororesins, olefin resins, hardening accelerators, coupling agents, fillers, pigments, solvents, flame retardants, etc. can be appropriately formulated as other optional components. However, some plasticizers contain a large amount of polar groups, and there is a concern that they will promote the diffusion of copper from copper wiring, so it is preferred not to use plasticizers as much as possible.

The adhesive resin composition of this embodiment has excellent flexibility and thermoplasticity when used to form an adhesive layer, and has satisfactory properties as an adhesive for covering films for protecting wiring parts such as FPCs, rigid and flexible circuit boards.

<Coating film> The covering film of the present embodiment includes an adhesive layer including the resin film or the adhesive resin composition and a covering film material layer. The covering film material is not particularly limited, and for example, polyimide resin films such as polyimide resin, polyetherimide resin, polyamideimide resin, or polyamide resin films, polyester resin films, etc. can be used. Among these, polyimide resin films with excellent heat resistance are preferably used. The thickness of the covering film material layer is not particularly limited, and for example, it is preferably 5 μm or more and 100 μm or less. The thickness of the adhesive layer is not particularly limited, but is preferably, for example, 10 μm or more and 50 μm or less.

Furthermore, the covering film material may contain a black pigment in order to effectively exhibit light-shielding properties, concealing properties, design properties, etc., and may also contain an arbitrary component such as a matte pigment for suppressing surface gloss within a range that does not impair the effect of improving dielectric properties.

The covering film of the present embodiment can be manufactured, for example, by the following exemplified method. First, as a first method, an adhesive resin composition serving as an adhesive layer is applied to one side of a covering film material in a solution state (e.g., a varnish state containing a solvent), and then the adhesive resin composition is heat-pressed at a temperature of, for example, 60°C to 220°C, thereby forming a covering film having a covering film material layer and an adhesive layer.

In addition, as a second method, an adhesive resin composition for an adhesive layer is applied to an arbitrary substrate in a solution state (e.g., a varnish state containing a solvent), and after drying at a temperature of, for example, 80°C to 180°C, the adhesive resin composition is peeled off to form a resin film for an adhesive layer, and the resin film is heat-pressed with a film material for covering at a temperature of, for example, 60°C to 220°C to form a covering film of the present embodiment. Furthermore, the adhesive layer can also be used as follows, that is, an adhesive resin composition is applied to an arbitrary substrate in a solution state by, for example, screen printing to form a coating film, and the coating film is dried at a temperature of, for example, 80°C to 180°C to form a film for use.

<Circuit board> The circuit board of this embodiment includes a substrate, a wiring layer formed on the substrate, and the covering film covering the wiring layer. The substrate of the circuit board is not particularly limited. In the case of an FPC, it is preferred to use the same material as the covering film material, and it is more preferred to use a substrate made of a polyimide resin.

<Copper foil with resin> The copper foil with resin of this embodiment includes an adhesive layer including the resin film or the adhesive resin composition and copper foil.

The thickness of the adhesive layer is preferably, for example, in the range of 0.1 μm to 125 μm, more preferably in the range of 0.3 μm to 100 μm. If the thickness of the adhesive layer is less than the lower limit, there may be problems such as failure to ensure sufficient adhesion. On the other hand, if the thickness of the adhesive layer exceeds the upper limit, there may be disadvantages such as decreased dimensional stability. In addition, from the perspective of low dielectric constant and low dielectric loss tangent, the thickness of the adhesive layer is preferably set to 3 μm or more.

In the resin copper foil of the present embodiment, the material of the copper foil is preferably copper or copper alloy as the main component. The thickness of the copper foil is preferably 35 μm or less, and more preferably in the range of 5 μm to 25 μm. From the perspective of production stability and handling, the lower limit of the thickness of the copper foil is preferably 5 μm. Furthermore, the copper foil may be a rolled copper foil or an electrolytic copper foil. In addition, a commercially available copper foil may be used as the copper foil.

The resin copper foil of this embodiment can be prepared, for example, by preparing a resin film, sputter-plating a metal to form a shielding layer, and then forming a copper layer by, for example, copper plating. It can also be prepared by laminating using a method such as hot pressing with a copper foil.

Furthermore, the resin-coated copper foil of the present embodiment can also be prepared by casting a coating liquid for forming a resin layer on the copper foil, drying the coating film, and then heat treating the film.

<Metal-clad pressed sheet> The metal-clad pressed sheet of the present embodiment is a so-called three-layer metal-clad pressed sheet having an insulating resin layer, an adhesive layer including the resin film or the adhesive resin composition laminated on at least one side of the insulating resin layer, and a metal layer laminated on the insulating resin layer via the adhesive layer. In the three-layer metal-clad laminate, the adhesive layer can be provided on one side or both sides of the insulating resin layer, and the metal layer can be provided on one side or both sides of the insulating resin layer via the adhesive layer. That is, the metal-clad laminate of the present embodiment can be a single-sided metal-clad laminate or a double-sided metal-clad laminate. By etching the metal layer of the metal-clad laminate of the present embodiment to perform wiring circuit processing, a single-sided FPC or a double-sided FPC can be manufactured.

The insulating resin layer is not particularly limited as long as it includes a resin having electrical insulation, and examples thereof include polyimide, epoxy resin, phenolic resin, polyethylene, polypropylene, polytetrafluoroethylene, silicone, ETFE, etc., preferably polyimide. The polyimide layer constituting the insulating resin layer may be a single layer or a multi-layer, and preferably includes a non-thermoplastic polyimide layer.

The thickness of the insulating resin layer is preferably, for example, in the range of 1 μm to 125 μm, more preferably in the range of 5 μm to 100 μm. If the thickness of the insulating resin layer is less than the lower limit, there may be problems such as failure to ensure sufficient electrical insulation. On the other hand, if the thickness of the insulating resin layer exceeds the upper limit, there may be problems such as warping of the metal-clad pressed plate. In addition, the ratio of the thickness of the insulating resin layer to the thickness of the adhesive layer (thickness of the insulating resin layer/thickness of the adhesive layer) is preferably in the range of 0.5 to 2.0. By setting such a ratio, warping of the metal-clad laminate can be suppressed.

The insulating resin layer may contain a filler as necessary. Examples of fillers include silicon dioxide, aluminum oxide, magnesium oxide, curium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, and metal salts of organic phosphonic acids. These may be used alone or in combination of two or more.

The thickness of the adhesive layer is preferably, for example, in the range of 0.1 μm to 125 μm, more preferably in the range of 0.3 μm to 100 μm. In the three-layer metal-clad laminate of the present embodiment, if the thickness of the adhesive layer is less than the lower limit, there may be problems such as failure to ensure sufficient adhesion. On the other hand, if the thickness of the adhesive layer exceeds the upper limit, there may be undesirable conditions such as decreased dimensional stability. In addition, from the perspective of lowering the dielectric constant and dielectric loss tangent of the insulating layer as a whole of the laminate of the insulating resin layer and the adhesive layer, the thickness of the adhesive layer is preferably set to be greater than 3 μm.

The material of the metal layer in the metal-clad press plate of the present embodiment is not particularly limited, and examples thereof include: copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, magnesium, manganese, and alloys thereof, etc. Among them, copper or copper alloys are particularly preferred.

The thickness of the metal layer is not particularly limited. For example, when copper foil is used as the metal layer, it is preferably 35 μm or less, and more preferably in the range of 5 μm to 25 μm. From the perspective of production stability and handling, the lower limit of the thickness of the copper foil is preferably 5 μm. Furthermore, when copper foil is used, it can be a rolled copper foil or an electrolytic copper foil. In addition, as the copper foil, a commercially available copper foil can be used.

When copper foil is used as the metal layer, the copper foil preferably includes a base copper foil and a rust-proofing layer formed on the surface of the base copper foil on the side where the adhesive layer (or insulating resin layer) is formed. In addition to the rust-proofing, the surface of the copper foil may be subjected to a surface treatment such as siding, aluminum alcoholate, aluminum chelate, silane coupling agent, etc. for the purpose of improving the adhesive force.

<Multi-layer circuit substrate> The multi-layer circuit substrate of the present embodiment includes a laminate including a plurality of laminated insulating resin layers, and one or more conductive circuit layers embedded in the laminate, wherein at least one of the plurality of insulating resin layers is formed by an adhesive layer having adhesiveness and covering the conductive circuit layer, and the adhesive layer includes the resin film or the adhesive resin composition.

The multilayer circuit substrate of the present embodiment has at least two insulating resin layers and at least two conductive circuit layers, at least one of which is a conductive circuit layer covered by an adhesive layer. The adhesive layer covering the conductive circuit layer may partially cover the surface of the conductive circuit layer or cover the entire surface of the conductive circuit layer. In addition, the multilayer circuit substrate of the present embodiment may also arbitrarily have a conductive circuit layer exposed to the surface of the multilayer circuit substrate. In addition, it may also have an interlayer connecting electrode (via electrode) connected to the conductive circuit layer.

The conductive circuit layer is formed with a conductive circuit in a predetermined pattern on one or both sides of the insulating resin layer. The conductive circuit may be formed in a pattern on the surface of the insulating resin layer or in an embedded (embedded) pattern.

Examples The following examples are given to explain the features of the present invention in more detail. However, the scope of the present invention is not limited to the examples. In the following examples, unless otherwise specified, various measurements and evaluations are performed in accordance with the following contents.

[Determination of amine value] Weigh about 2 g of the dimer diamine composition into a 200 mL to 250 mL Erlenmeyer flask, use phenolphthalein as an indicator, add 0.1 mol/L ethanolic potassium hydroxide solution until the solution turns light pink, and dissolve it in about 100 mL of neutralized butanol. Add 3 to 7 drops of phenolphthalein solution, and titrate with 0.1 mol/L ethanolic potassium hydroxide solution while stirring until the sample solution turns light pink. Add 5 drops of bromophenol blue solution, and titrate with 0.2 mol/L hydrochloric acid/isopropanol solution while stirring until the sample solution turns yellow. The amine value is calculated by the following formula (1). Amine value = {(V ₂ ×C ₂ )-(V ₁ ×C ₁ )}×M _KOH /m ･･･（1） Here, the amine value is a value expressed in mg-KOH/g, and M _KOH is the molecular weight of potassium hydroxide, 56.1. In addition, V and C are the volume and concentration of the solution used in the titration, respectively, and the subscripts 1 and 2 represent 0.1 mol/L ethanolic potassium hydroxide solution and 0.2 mol/L hydrochloric acid/isopropanol solution, respectively. In addition, m is the sample weight expressed in grams.

[Measurement of weight average molecular weight (Mw) of polyimide] The weight average molecular weight was measured by gel permeation chromatograph (manufactured by TOSOH Co., Ltd., using HLC-8220GPC). Polystyrene was used as a standard substance, and tetrahydrofuran (THF) was used as a developing solvent.

[GPC and calculation of area percentage of chromatogram] For GPC, 20 mg of the dimer diamine composition was added to 100 mg of the solution prepared previously with 200 μL of acetic anhydride, 200 μL of pyridine and 2 mL of THF, and the solution was diluted with 10 mL of THF (containing 1000 ppm of cyclohexanone) to prepare the sample. The prepared sample was measured using the TSK-gel G2000HXL and G1000HXL columns, flow rate of 1 mL/min, column (oven) temperature of 40°C, and injection volume of 50 μL using the HLC-8220 GPC manufactured by Tosoh Corporation. Note that cyclohexanone was used as a standard substance to correct the elution time.

At this time, the retention time of the peak top of the main peak of cyclohexanone was used as the retention time. The components (a) to (c) were detected under the following conditions: (a) the component represented by the main peak; (b) the component represented by the GPC peak detected at a later time based on the minimum value on the time side of the retention time of the main peak; (c) the component represented by the GPC peak detected at an earlier time based on the minimum value on the time side of the retention time of the main peak.

[Evaluation of Dielectric Properties] The resin sheet (cured resin sheet) was left at 23°C and 50% humidity for 24 hours using a vector network analyzer (Agilent Technologies, trade name: vector network analyzer E8363C) and SPDR resonator, and the dielectric constant (ε ₁ ) and dielectric loss tangent (Tanδ ₁ ) at a frequency of 10 GHz were measured. E ₁ , an index representing the dielectric properties of the resin laminate, was calculated based on the above-mentioned mathematical formula (i). In addition, after absorbing water at 23°C for 24 hours, the dielectric constant (ε ₂ ) and dielectric loss tangent (Tanδ ₂ ) of the resin sheet (cured resin sheet) at a frequency of 10 GHz were measured. E ₂ , an index representing the dielectric properties of the resin laminate, was calculated based on the mathematical formula (ii).

[Measurement of moisture absorption rate] Prepare 2 test pieces of resin sheets (resin sheets after hardening) (width 4 cm × length 25 cm) and dry them at 80℃ for 1 hour. Immediately after drying, place them in a constant temperature and humidity chamber at 23℃/50%RH and leave them for more than 24 hours. Calculate the moisture absorption rate (weight %) based on the weight change before and after using the following formula. Moisture absorption rate (weight %) = [(weight after moisture absorption - weight after drying) / weight after drying] × 100

[Glass transition temperature (Tg) and storage elastic modulus] The glass transition temperature (Tg) and storage elastic modulus were measured for a 5 mm × 20 mm resin sheet (resin sheet after curing) using a dynamic viscoelasticity measuring device (DMA: manufactured by Dubm, trade name: E4000F) from 30°C to 400°C at a heating rate of 4°C/min and a frequency of 11 Hz. The temperature at which the elastic modulus change (tanδ) was the largest was defined as the glass transition temperature.

[Tensile modulus] The tensile modulus is measured using the following procedure. First, a test piece (width 12.7 mm × length 127 mm) is prepared from a resin sheet (resin sheet after curing) using a tension tester (Tensilon manufactured by Orientec). Using this test piece, a tensile test is performed at 50 mm/min to determine the tensile modulus at 25°C.

[Warp evaluation method] Warp evaluation is performed using the following method. Polyimide adhesive is applied to a 25 μm thick Kapton film or a 12 μm thick copper foil so that the thickness after drying is 25 μm. In this state, the Kapton film and copper foil are placed so that the bottom surface is the bottom surface, and the average height of the warp at the four corners of the film is measured. If it is less than 5 mm, it is set as "good", and if it exceeds 5 mm, it is set as "unacceptable".

The ellipsis used in this example represents the following compounds. BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride (manufactured by Evonik, trade name: BTDA Ultra Pure) BisDA: 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic dianhydride (manufactured by SABIC Innovative Plastics Japan LLC., trade name: BisDA-1000) BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride ODPA: 4,4'-oxydiphthalic anhydride DDA1: Distilled and purified from PRIAMINE 1075 manufactured by Croda Japan Co., Ltd. (component a: 98.2% by weight, component b: 0%, component c: 1.9%, amine value: 206 mg KOH/g) DDA2: PRIAMINE 1075 manufactured by Croda Japan Co., Ltd., which was purified by distillation (component a: 99.2% by weight, component b: 0%, component c: 0.8%, amine value: 210 mg KOH/g) N-12: dodecanedioic acid dihydrazide NMP: N-methyl-2-pyrrolidone APB: 1,3-bis(3-aminophenoxy)benzene BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl]propane In addition, in the above-mentioned DDA1 and DDA2, the [%] of the component b and the component c refers to the area percentage of the chromatogram in the GPC measurement. In addition, the molecular weight of DDA1 and DDA2 is calculated by the following formula (1). Molecular weight = 56.1 × 2 × 1000 / amine value (1)

[Example 1] In a 1000 ml separable flask, 55.51 g of BTDA (0.1721 mol), 94.49 g of DDA1 (0.1735 mol), 210 g of NMP and 140 g of xylene were placed and mixed thoroughly at 40°C for 1 hour to prepare a polyamide solution. The polyamide solution was heated to 190°C, stirred for 10 hours, and 125 g of xylene was added to prepare a polyimide solution 1 (solid content: 30% by weight, weight average molecular weight: 82,900) after imidization.

[Example 2 to Example 12] Polyimide solutions 2 to 12 were prepared in the same manner as in Example 1 except that the raw material compositions were set as shown in Table 1.

[Table 1]

As shown in Table 1, in Examples 1 to 12, polyimide having a weight average molecular weight in the range of 40,000 to 150,000 was obtained.

[Example 13] In 169.49 g (50 g in the form of solid components) of the polyimide solution 1 obtained in Example 1, 2.7 g of N-12 (0.0105 mol; primary amino groups are equivalent to 0.35 mol per 1 mol of ketone groups of BTDA) was mixed, 6.0 g of NMP was added for dilution, and the mixture was stirred for 1 hour to obtain an adhesive resin composition 1.

The obtained adhesive resin composition 1 was applied to one side of a release PET film (manufactured by Dongshan Film Co., Ltd., trade name: HY-S05, length × width × thickness = 200 mm × 300 mm × 25 μm), dried at 80°C for 15 minutes, and the adhesive layer was peeled off from the release PET film to prepare a resin film 1 having a thickness of 25 μm. This resin film 1 was heated in an oven at a temperature of 160°C for 2 hours to obtain an evaluation sample 1. The evaluation results of various properties are shown in Table 2.

[Example 14 to Example 24] Except that polyimide solution 2 to polyimide solution 1 were used instead of polyimide solution 1, adhesive resin composition 2 to adhesive resin composition 12 and resin film 2 to resin film 12 were prepared in the same manner as in Example 13, and evaluation samples 2 to evaluation samples 12 were obtained. The evaluation results of various properties are shown in Table 2.

[Table 2]

[Example 25] The adhesive resin composition 1 obtained in Example 13 was applied to one side of a polyimide film (manufactured by Dupont, trade name: Kapton 100EN-S, ε1=3.5, tanδ1=0.012, length×width×thickness=200 mm×300 mm×25 μm), and dried at 80°C for 15 minutes to obtain a coating film 1 having an adhesive layer thickness of 25 μm. The warping state of the obtained coating film was "good".

[Example 26 to Example 36] Coating films 2 to 12 were prepared in the same manner as in Example 25 except that adhesive resin composition 2 to 12 were used instead of adhesive resin composition 1. The warping conditions of the obtained covering films 2 to 12 were all "good".

[Example 37] The adhesive resin composition 1 obtained in Example 13 was applied to one side of an electrolytic copper foil having a thickness of 12 μm, and dried at 80°C for 15 minutes to obtain a resin-coated copper foil 1 having an adhesive layer thickness of 25 μm. The warp state of the obtained resin-coated copper foil 1 was "good".

[Example 38] The adhesive resin composition 4 obtained in Example 16 was applied to one side of an electrolytic copper foil having a thickness of 12 μm, and dried at 80°C for 30 minutes to obtain a resin-coated copper foil 2 having an adhesive layer having a thickness of 50 μm.

[Example 39] An adhesive resin composition 4 is applied to the resin surface of the resin-coated copper foil 2 obtained in Example 38, and dried at 80°C for 30 minutes to obtain a resin-coated copper foil 3 having an adhesive layer with a total thickness of 100 μm.

[Example 40] The adhesive resin composition 1 obtained in Example 13 was applied to one side of a release PET film (manufactured by Dongshan Film Co., Ltd., trade name: HY-S05, length × width × thickness = 200 mm × 300 mm × 25 μm), dried at 80°C for 30 minutes, and the adhesive layer was peeled off from the release PET film, thereby obtaining a resin film 1' having a thickness of 50 μm. On an electrolytic copper foil having a thickness of 12 μm, a resin film 1', a polyimide film (manufactured by Dupont, trade name: Kapton 100-EN, thickness 25 μm, ε1=3.6, tanδ1=0.084), a resin film 1' and an electrolytic copper foil having a thickness of 12 μm are laminated in sequence, and pressed for 2 minutes using a vacuum lamination press at a temperature of 160°C and a pressure of 0.8 MPa, and then heat treated at 160°C for 4 hours to obtain a copper-clad laminate 1.

[Example 41] The adhesive resin composition 1 obtained in Example 13 was applied to one side of a polyimide film (manufactured by Dupont, trade name: Kapton 50EN, ε1=3.6, tanδ1=0.086, length×width×thickness=200 mm×300 mm×12 μm), and dried at 80°C for 15 minutes to prepare a covering film 1' with an adhesive layer thickness of 25 μm. On an electrolytic copper foil having a thickness of 12 μm, a coating film 1' is laminated in such a manner that the adhesive resin composition 1 side is in contact with the copper foil, and the lamination is performed for 2 minutes at a temperature of 160°C and a pressure of 0.8 MPa using a vacuum lamination press, and then heat-treated at 160°C for 2 hours to obtain a copper-clad laminated plate 2.

[Example 42] On a rolled copper foil having a thickness of 12 μm, the resin film 1 (thickness: 25 μm) obtained in Example 13 is laminated, and the covering film 1' obtained in Example 41 is laminated in such a manner that the polyimide film side is in contact with the resin film 1, and then the resin film 1 (thickness: 25 μm) and the rolled copper foil having a thickness of 12 μm are laminated in sequence, and the laminated copper foil is laminated for 2 minutes at a temperature of 160°C and a pressure of 0.8 MPa using a vacuum laminating press, and then heat-treated at 160°C for 2 hours to obtain a copper-clad laminated plate 3.

[Example 43] Prepare two sheets of the resin-coated copper foil 3 obtained in Example 39, laminate a polyimide film (manufactured by Dupont, trade name: Kapton 200-EN, thickness 50 μm, ε1=3.6, tanδ1=0.084) on the adhesive resin composition 4 side of one of the resin-coated copper foils 3, and laminate the other resin-coated copper foil 3 in such a way that the adhesive resin composition 4 side is in contact with the polyimide film, and use a vacuum laminating press at a temperature of 160°C and a pressure of 0.8 MPa, pressed for 5 minutes, and then heat treated at 160°C for 4 hours to obtain a copper-clad pressed plate 4.

[Example 44] The adhesive resin composition 1 obtained in Example 13 was applied to the polyimide side of a single-sided copper-clad pressboard (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: Espanex FC12-25-00UEJ, length × width × thickness = 200 mm × 300 mm × 25 μm), and dried at 80°C for 30 minutes to obtain an adhesive-attached copper-clad pressboard 1 having an adhesive layer thickness of 50 μm. On the adhesive resin composition 1 side of the copper-clad pressed plate 1 with an adhesive, a single-sided copper-clad pressed plate (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: Espanex FC12-25-00UEJ) was laminated in a polyimide-bonded manner, and pressed for 120 minutes at a temperature of 160° C. and a pressure of 4.0 MPa using a small precision press machine to obtain a copper-clad pressed plate 5.

[Example 45] The copper-clad pressed plates 1 with adhesive obtained in Example 44 were laminated with the adhesive resin composition 1 sides touching each other, and pressed for 120 minutes at a temperature of 160°C and a pressure of 4.0 MPa using a small precision press to obtain a copper-clad pressed plate 6.

[Example 46] The resin film 4 (thickness 25 μm) obtained in Example 16 was laminated on the polyimide side of a single-sided copper-clad press plate (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: Espanex FC12-25-00UEJ), and the single-sided copper-clad press plate (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: Espanex FC12-25-00UEJ) was laminated in such a way that the polyimide side and the resin film 4 were in contact, using a small precision press machine at a temperature of 160°C and a pressure of 4.0 MPa for 120 minutes to obtain the copper-clad pressed plate 7.

[Example 47] The adhesive resin composition 1 obtained in Example 13 was applied to one side of a release PET film (manufactured by Dongshan Film Co., Ltd., trade name: HY-S05, length × width × thickness = 200 mm × 300 mm × 25 μm), dried at 80°C for 15 minutes, and the adhesive layer was peeled off from the release PET film, thereby obtaining a resin film 1'' having a thickness of 15 μm. A resin film 1'' was laminated on the polyimide side of a single-sided copper-clad pressed plate (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: ESPANEX FC12-25-00UEJ), and the single-sided copper-clad pressed plate (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: ESPANEX FC12-25-00UEJ) was laminated in such a manner that the polyimide side and the resin film 1'' were in contact, and pressed for 120 minutes at a temperature of 160°C and a pressure of 4.0 MPa using a small precision press machine, thereby obtaining a copper-clad pressed plate 8.

[Example 48] A double-sided copper-clad laminate (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: Espanex FB12-25-00UEY) is prepared, and a circuit is processed by etching on the copper foil on one side thereof to prepare a wiring board 1 having a conductive circuit layer formed thereon. At the same time, the copper foil on one side of the double-sided copper-clad laminate (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: Espanex FB12-25-00UEY) is removed by etching to prepare a copper-clad laminate 9. The resin film 1 obtained in Example 13 was sandwiched between the surface on the conductive circuit layer side of the wiring board 1 and the surface on the insulating base layer side of the copper-clad laminate 9, and they were hot-pressed at a temperature of 160°C and a pressure of 4.0 MPa for 120 minutes in a laminated state to prepare a multilayer circuit board 1.

[Example 49] A copper-clad laminate 10 is prepared with a liquid crystal polymer film (manufactured by Kuraray Co., Ltd., trade name: CT-Z, thickness: 50 μm, CTE: 18 ppm/K, thermal deformation temperature: 300°C, dielectric constant: 3.40, dielectric loss tangent: 0.0022) as an insulating substrate and copper foil (electrolytic copper foil, thickness: 9 μm, surface roughness Rz: 2.0 μm) provided on both sides thereof, and a circuit is processed by etching the copper foil on one side thereof to prepare a wiring board 2 having a conductive circuit layer formed thereon. At the same time, the copper foil on one side of the copper-clad laminate 10 is etched away to prepare a copper-clad laminate 10'. The resin film 1 obtained in Example 13 was sandwiched between the surface on the conductive circuit layer side of the wiring substrate 2 and the surface on the insulating base material layer side of the copper-clad laminate 10', and they were hot-pressed at a temperature of 160°C and a pressure of 4.0 MPa for 120 minutes in a laminated state to prepare a multilayer circuit substrate 2.

[Example 50] The adhesive resin composition 1 side of the covering film 1' obtained in Example 41 was laminated with a mold release PET film (manufactured by Dongshan Film Co., Ltd., trade name: HY-S05) in a contact manner, and the film was laminated for 2 minutes at a temperature of 160°C and a pressure of 0.8 MPa using a vacuum laminating press. Thereafter, the adhesive resin composition 1 obtained in Example 13 was applied to the polyimide film side of the covering film 1' in a manner such that the thickness after drying was 25 μm, and dried at 80°C for 15 minutes. Furthermore, a demolding PET film (manufactured by Dongshan Film Co., Ltd., trade name: HY-S05) was laminated on one side of the dried adhesive resin composition 1 in a contacting manner, and pressed for 2 minutes at a temperature of 160°C and a pressure of 0.8 MPa using a vacuum laminating press to prepare a polyimide adhesive layer laminate 1 having an adhesive layer on both sides of the polyimide film.

Although the embodiments of the present invention have been described in detail for the purpose of illustration, the present invention is not limited to the embodiments described above and various modifications are possible.

without.

without

Claims (9)

A resin film, characterized in that it contains polyimide as a resin component, wherein the polyimide is obtained by reacting a tetracarboxylic anhydride component with a diamine component, the diamine component contains 40 mol% or more of a dimer diamine composition relative to the total diamine component, the dimer diamine composition mainly comprising a dimer diamine in which both terminal carboxylic acid groups of a dimer acid are substituted with primary aminomethyl groups or amino groups, and the resin film satisfies the following configurations I and II: Configuration I: Based on the following mathematical formula (i), the _E1 value, which is an index of dielectric properties at 10 GHz after humidification for 24 hours under constant temperature and humidity conditions of 23°C and 50%RH, is calculated to be 0.010 or less,

In mathematical formula (i), ε ₁ represents the dielectric constant at 10 GHz measured by a separate dielectric resonator under constant temperature and humidity conditions of 23° C. and 50% RH, that is, after humidification for 24 hours under normal conditions, and Tanδ ₁ represents the dielectric loss tangent at 10 GHz measured by a separate dielectric resonator under constant temperature and humidity conditions of 23° C. and 50% RH after humidification for 24 hours; Composition II: Based on the following mathematical formula (ii), the ratio of the E ₂ value to the E ₁ value, that is, E ₂ /E _1, which is an index of dielectric properties at 10 _GHz after water absorption at 23° C. for 24 hours, is calculated to be within the range of 3.0 to 1.0,

In the mathematical formula (ii), _ε2 represents the dielectric constant at 10 GHz measured by a separate dielectric resonator after absorbing water at 23°C for 24 hours, and Tanδ ₂ represents the dielectric loss tangent at 10 GHz measured by a split dielectric resonator after absorbing water at 23° C. for 24 hours, wherein in the polyimide, the component c of the following components a to c is 2% or less, and the component a is 96% or more, based on the area percentage of the chromatogram obtained by measuring the dimer diamine composition using colloid permeation chromatography; component a: dimer diamine; component b: a monoamine compound obtained by replacing the terminal carboxylic acid group of a monobasic acid compound having a carbon number in the range of 10 to 40 with a primary aminomethyl group or an amino group; component c: a polybasic acid compound having a carbon number in the range of 41 to 80 having a alkyl group An amine compound in which the terminal carboxylic acid group of the compound is substituted with a primary aminomethyl group or an amino group, wherein, excluding the dimer diamine, when the ratio b/c of the area percentage of the component b to the component c in the chromatogram is 1 or more, the molar ratio of the tetracarboxylic anhydride component to the diamine component, i.e., the tetracarboxylic anhydride component/diamine component, is 0.97 or more and less than 1.0, and when the ratio b/c of the area percentage of the component b to the component c in the chromatogram is less than 1, the molar ratio of the tetracarboxylic anhydride component to the diamine component, i.e., the tetracarboxylic anhydride component/diamine component, is 0.97 or more and less than 1.008. A covering film characterized by laminating an adhesive layer and a covering film material layer, wherein the adhesive layer comprises a resin film as described in item 1 of the patent application scope. A circuit substrate includes a substrate, a wiring layer formed on the substrate, and a covering film as described in item 2 of the patent application scope covering the wiring layer. A copper foil with resin, characterized in that an adhesive layer is laminated with the copper foil, wherein the adhesive layer comprises a resin film as described in item 1 of the patent application scope. A metal-clad laminated plate, characterized in that it has an insulating resin layer, an adhesive layer pressed on at least one side of the insulating resin layer, and a metal layer pressed on the insulating resin layer via the adhesive layer, wherein the adhesive layer includes the resin film as described in item 1 of the patent application scope. A multi-layer circuit substrate, characterized in that it includes a laminate including a plurality of laminated insulating resin layers, and one or more conductive circuit layers embedded in the laminate, wherein at least one of the plurality of insulating resin layers is formed by an adhesive layer having adhesiveness and covering the conductive circuit layer, and the adhesive layer includes the resin film as described in item 1 of the patent application scope. A polyimide, characterized in that it is obtained by reacting a tetracarboxylic anhydride component with a diamine component, wherein the diamine component contains 40 mol% or more of a dimer diamine composition relative to the total diamine component, the dimer diamine composition having as a main component a dimer diamine in which two terminal carboxylic acid groups of a dimer acid are substituted with primary aminomethyl groups or amino groups, and in terms of area percentage of a chromatogram obtained by measuring the dimer diamine composition using colloid permeation chromatography, the component c of the following components a to c is 2% or less, and the component a is 96% or more; component a: dimer diamine; component b: a compound obtained by replacing the terminal carboxylic acid groups of a monobasic acid compound having a carbon number in the range of 10 to 40 with primary aminomethyl groups or amino groups. ; component c: an amine compound obtained by substituting the terminal carboxylic acid group of a polyacid compound having a carbon number in the range of 41 to 80 with a primary aminomethyl or amino group, wherein, excluding the dimer diamine, when the ratio b/c of the area percentage of the component b to the component c in the chromatogram is 1 or more, the molar ratio of the tetracarboxylic anhydride component to the diamine component, i.e., the tetracarboxylic anhydride component/diamine component, is 0.97 or more and less than 1.0, and when the ratio b/c of the area percentage of the component b to the component c in the chromatogram is less than 1, the molar ratio of the tetracarboxylic anhydride component to the diamine component, i.e., the tetracarboxylic anhydride component/diamine component, is 0.97 or more and less than 1.008. The polyimide as described in item 7 of the patent application is characterized in that it contains 50 mol% or more of 3,3',4,4'-benzophenone tetracarboxylic dianhydride relative to the total amount of the tetracarboxylic anhydride component. An adhesive resin composition, characterized in that it comprises the following components A and B: Component A: polyimide as described in item 8 of the patent application, and Component B: an amino compound having at least two primary amino groups as functional groups, and the component B is contained in a manner such that the primary amino groups are in a total range of 0.004 mol to 1.5 mol relative to 1 mol of the ketone group of the 3,3',4,4'-benzophenonetetracarboxylic dianhydride residue derived from the 3,3',4,4'-benzophenonetetracarboxylic dianhydride in the component A.