KR20220091354A - Polyimide composition, adhesive film, laminate, coverlay film, copper foil with resin, metal-crad laminate and circuit board - Google Patents

Abstract

(assignment)
The present invention provides a polyimide composition capable of forming a resin film having both a low dielectric loss tangent and excellent adhesion by using a thermoplastic polyimide.
(Solution)
This invention contains (A) thermoplastic polyimide and (B) polystyrene elastomer resin whose acid value is 10 mgKOH/g or less, and content of (B) component with respect to 100 weight part of (A) component is 10 weight part It relates to a polyimide composition in the range of 100 parts by weight or less, and the thermoplastic resin layer obtained by filming this polyimide composition is controlled at 23° C. and 50% RH under constant temperature and humidity conditions for 24 hours, followed by split post dielectric. The dielectric loss tangent (Tanδ) at 10 GHz measured by the resonator (SPDR) is 0.0020 or less.

Description

POLYIMIDE COMPOSITION, ADHESIVE FILM, LAMINATE, COVERLAY FILM, COPPER FOIL WITH RESIN, METAL-CRAD LAMINATE AND CIRCUIT BOARD}

The present invention relates to a polyimide composition useful as an adhesive in a circuit board such as a printed wiring board, a resin film, a laminate, a coverlay film, a copper foil with resin, a metal clad laminate, and a circuit board.

Recently, with the progress of miniaturization, weight reduction, and space saving of electronic devices, the demand for flexible printed circuits (FPC) is increasing, which is thin, light, flexible, and has excellent durability even after repeated bending. . Since FPC is three-dimensional and can be mounted at high density even in a limited space, its use is expanding to wiring of movable parts of electronic devices such as HDD, DVD, and mobile phone, and parts such as cables and connectors.

In addition to the above-mentioned densification, as the performance of devices progresses, it is also necessary to cope with the increase in the frequency of transmission signals. In information processing and information communication, measures are being taken to increase the transmission frequency in order to transmit and process large-capacity information. A reduction in loss is required. Thereafter, with respect to the insulating layer (including the adhesive layer) constituting the FPC, further reduction of transmission loss and response to high frequency will be required. Regarding the improvement of the dielectric properties of printed circuit board materials, an adhesive composition containing an acid-modified polystyrene elastomer resin, a carbodiimide resin, and an epoxy resin has been proposed (for example, Patent Document 1). However, in Patent Document 1, when the acid value of the acid-modified polystyrene elastomer resin is low, compatibility with other components is lowered and adhesive strength is not expressed. Moreover, although it relates to the adhesive agent for fixing to a support body when grinding|polishing a semiconductor wafer, the adhesive composition containing acid-modified polystyrene elastomer resin is proposed (for example, patent document 2).

By the way, the crosslinked polyimide resin obtained by reacting a thermoplastic polyimide using a diamine compound derived from an aliphatic diamine such as dimer acid (dimer fatty acid) as a raw material with an amino compound having at least two primary amino groups as functional groups is covered. Application to the adhesive layer of a lay film is proposed (for example, patent document 3). The Example of Patent Document 3 also discloses mixing of flaky talc with a thermoplastic polyimide composition using an aliphatic diamine as a raw material. Here, the dimer acid is, for example, a Diels-Alder reaction using natural fatty acids such as soybean oil fatty acid, tall oil fatty acid, and rapeseed oil fatty acid, and oleic acid, linoleic acid, linolenic acid, erucic acid, and the like, which are purified therefrom. It is a dimerized fatty acid obtained by making it, and it is known that a polybasic acid compound derived from a dimer acid is obtained as a composition of a fatty acid as a raw material or a fatty acid more than trimerized (for example, patent document 4).

Japanese Patent No. 6705456 Publication International Publication No. WO2013/153904 Japanese Patent No. 5777944 Publication Japanese Patent Laid-Open No. 2017-137375

Thermoplastic polyimide using aliphatic diamine as a raw material is a resin material useful as an adhesive because it is soluble in a solvent, has excellent adhesion, and has good handling properties. In addition to being satisfied, low dielectric dissipation tangent is more and more required.

Accordingly, it is an object of the present invention to provide a polyimide composition capable of forming a resin film having both a low dielectric loss tangent and excellent adhesion using a thermoplastic polyimide.

The polyimide composition of this invention is following (A) component and (B) component;

(A) a thermoplastic polyimide, and

(B) polystyrene elastomer resin having an acid value of 10 mgKOH/g or less

While containing, content of the said (B) component with respect to 100 weight part of the said (A) component exists in the range of 10 weight part or more and 100 weight part or less.

The polyimide composition of this invention may exist in the range whose content rate of the styrene unit in the said (B) component is 10 weight% or more and 65 weight% or less.

In the polyimide composition of the present invention, the thermoplastic polyimide may be formed by reacting a tetracarboxylic anhydride component with a diamine component, or may contain 40 mol% or more of an aliphatic diamine with respect to the diamine component.

The polyimide composition of the present invention may be a dimer diamine composition in which the aliphatic diamine contains, as a main component, dimer diamine in which two terminal carboxylic acid groups of dimer acid are substituted with primary aminomethyl groups or amino groups.

The polyimide composition of the present invention may further contain an amino compound having at least two primary amino groups as a functional group.

The resin film of the present invention is a resin film comprising a thermoplastic resin layer,

The said thermoplastic resin layer is following (A) component and (B) component;

(A) a thermoplastic polyimide, and

(B) polystyrene elastomer resin having an acid value of 10 mgKOH/g or less

It is characterized in that the content of the component (B) with respect to 100 parts by weight of the component (A) is in the range of 10 parts by weight or more and 100 parts by weight or less.

In the resin film of the present invention, the thermoplastic resin layer is subjected to a dielectric loss tangent ( Tanδ) may be 0.0020 or less.

The laminate of the present invention is a laminate comprising a substrate and an adhesive layer laminated on at least one surface of the substrate, wherein the adhesive layer is made of the resin film.

The coverlay film of the present invention is a coverlay film comprising a film material layer for a coverlay and an adhesive layer laminated on the film material layer for the coverlay, wherein the adhesive layer is made of the resin film.

The copper foil with resin of this invention is copper foil with resin which laminated|stacked the adhesive bond layer and copper foil, and said adhesive bond layer consists of the said resin film, It is characterized by the above-mentioned.

The metal clad laminate of the present invention is a metal clad laminate comprising an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, wherein at least one of the insulating resin layers is made of the resin film. .

The circuit board of the present invention is formed by wiring the metal layer of the metal clad laminate.

Since the polyimide composition of the present invention contains a thermoplastic polyimide and a polystyrene elastomer resin having a specific acid value, a resin film having practically sufficient peel strength and excellent adhesion while maintaining a low dielectric loss tangent can be formed. . Accordingly, the polyimide composition and the resin film of the present invention can be particularly suitably used as a material for circuit boards such as FPC in, for example, electronic devices requiring high-speed signal transmission. In addition, by improving the dielectric properties of the resin film, it becomes possible to apply the direct conversion method to the receiver. In addition, since the peel strength of the resin film can be improved, it is a highly reliable, low-k adhesive that can be applied to electronic devices of all structures.

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described.

[Polyimide composition]

The polyimide composition which concerns on 1 Embodiment of this invention is following (A) component and (B) component;

(A) a thermoplastic polyimide, and

(B) polystyrene elastomer resin having an acid value of 10 mgKOH/g or less

contains

<Component (A): Thermoplastic polyimide>

(A) The thermoplastic polyimide of component is a thermoplastic polyimide which has solvent solubility, and imidates the polyamic acid which is a precursor obtained by making a tetracarboxylic-acid anhydride component and a diamine component react. In addition, "thermoplastic polyimide" is a polyimide that is generally softened by heating and solidified by cooling, and this can be repeated, and the glass transition temperature (Tg) can be clearly confirmed, In the present invention, it means a polyimide that can clearly confirm the glass transition temperature in a temperature range of less than 150 ℃. In addition, from the viewpoint of thermocompression bonding properties at low temperatures, it is preferable that the polyimide is a polyimide that can clearly confirm the glass transition temperature in a temperature range of less than 100 ° C. A polyimide having a storage modulus of 1.0×10 ⁸ Pa or more and a storage modulus of less than 3.0×10 ⁷ Pa at a glass transition temperature of +30°C is more preferable. In addition, "non-thermoplastic polyimide" is a polyimide that generally does not show softening or adhesion even when heated, but in the present invention, the storage modulus at 30°C measured using a dynamic viscoelasticity measuring device (DMA) is 1.0 It is x10 ⁹ Pa or more, and the storage modulus in 300 degreeC refers to the polyimide 3.0 x 10 ⁸ Pa or more.

(Tetracarboxylic acid anhydride component)

The thermoplastic polyimide of component (A) may contain, without particular limitation, a tetracarboxylic acid residue derived from a tetracarboxylic acid anhydride generally used for thermoplastic polyimide, but with respect to all tetracarboxylic acid residues, the following general formula (1) It is preferable to contain 90 mol% or more in total of the tetracarboxylic acid residue derived from the tetracarboxylic acid anhydride represented by. By containing 90 mol% or more of tetracarboxylic acid residues derived from tetracarboxylic acid anhydride represented by the following general formula (1) in total with respect to all tetracarboxylic acid residues, it is easy to achieve both flexibility and heat resistance of the polyimide, and it is preferable. When the total of the tetracarboxylic acid residues derived from the tetracarboxylic acid anhydride represented by the following general formula (1) is less than 90 mol%, the solvent solubility of the polyimide tends to decrease.

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

In the above formula, Z represents —C ₆ H ₄ —, —(CH ₂ )n— or —CH ₂ —CH(—O—C(=O)—CH ₃ )—CH ₂ —, and n is 1 An integer of ∼20 is represented.

Examples of the tetracarboxylic anhydride represented by the general formula (1) include 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride (BTDA), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'-oxydiphthalic anhydride (ODPA), 4,4'-(hexafluoroiso Propylidene) diphthalic anhydride (6FDA), 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), p-phenylene bis (trimellitic acid monoester acid anhydride) ) (TAHQ), ethylene glycol bisanhydro trimellitate (TMEG), etc. are mentioned. Among these, in the case of using 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), the adhesiveness of the polyimide can be improved, and the ketone group present in the molecular skeleton and crosslinking described later. The amino group of the amino compound for formation may react to form a C=N bond, and the effect of improving heat resistance is likely to be exhibited. From such a viewpoint, the content of tetravalent tetracarboxylic acid residues (BTDA residues) derived from BTDA is preferably 50 mol% or more, more preferably 60 mol% or more, based on all tetracarboxylic acid residues.

(A) The thermoplastic polyimide of component can contain the tetracarboxylic-acid residue derived from acid anhydrides other than the tetracarboxylic-acid anhydride represented by the said General formula (1) in the range which does not impair the effect of invention. Although there is no particular limitation on the tetracarboxylic acid residue as such, for example, pyromellitic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'- or 2,3,3',4'-benzophenone tetracarboxylic 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-terphenyltetracarboxylic dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl)-propanedianhydride, bis(2,3- or 3,4-dicarboxyphenyl)methandianhydride, bis(2,3- or 3,4-di Carboxyphenyl) sulfonic anhydride, 1,1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride, 1,2,7,8-, 1,2,6,7- or 1, 2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropanedianhydride, 2 ,3,5,6-cyclohexanedianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetra Carboxylic acid dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic acid dianhydride, 2,6- 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 ,6,7-)tetracarboxylic dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene-tetra Carboxylic acid dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic acid Aromatic esters such as anhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, and 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride and tetracarboxylic acid residues derived from tetracarboxylic dianhydride.

(diamine component)

(A) As for the thermoplastic polyimide of component, as a raw material, Preferably it is 40 mol% or more of aliphatic diamine with respect to all the diamine components, It is good to use the diamine component containing more preferably 60 mol% or more. That is, the thermoplastic polyimide of (A) component preferably contains 40 mol% or more of the diamine residues derived from an aliphatic diamine with respect to all the diamine residues, More preferably, it is good to contain 60 mol% or more. By containing the diamine residue derived from an aliphatic diamine in the above amount, the dielectric properties of the polyimide are improved, and the thermocompression bonding properties are improved and the modulus of elasticity is lowered by lowering the glass transition temperature of the polyimide (lower Tg). Internal stress caused by fire can be relieved. When the diamine residue derived from an aliphatic diamine is less than 40 mol% based on the total diamine residue, the effect of improving dielectric loss tangent and thermocompression bonding characteristics may not be sufficiently obtained. Here, as the aliphatic diamine, for example, a dimer diamine composition mainly comprising dimer diamine in which two terminal carboxylic acid groups of dimer acid are substituted with primary aminomethyl groups or amino groups, hexamethylenediamine, dodecanediamine, cyclohexanediamine , polyoxyalkyleneamine, 4,4-diaminodicyclohexylmethane, etc. can be used, and a dimerdiamine composition is particularly preferred.

(dimerdiamine composition)

While the dimerdiamine composition contains the following component (a) as a main component, the quantity of a component (b) and a component (c) is controlled.

(a) dimerdiamine;

(a) The dimerdiamine of component means a diamine in which two terminal carboxylic acid groups (-COOH) of dimer acid are substituted with a primary aminomethyl group (-CH ₂ -NH ₂ ) or an amino group (-NH ₂ ) do. Dimer acid is a known dibasic acid obtained by intermolecular polymerization of unsaturated fatty acids, and its industrial production process is almost standardized in the industry, and is obtained by dimerizing unsaturated fatty acids having 11 to 22 carbon atoms with a clay catalyst or the like. The industrially obtained dimer acid is mainly composed of a dibasic acid having 36 carbon atoms obtained by dimerizing an unsaturated fatty acid having 18 carbon atoms such as oleic acid, linoleic acid, and linolenic acid. It contains an acid (54 carbon atoms) and other polymerized fatty acids having 20 to 54 carbon atoms. Moreover, although a double bond remains after dimerization reaction, in this invention, what was made to carry out hydrogenation reaction to reduce unsaturation shall also be contained in dimer acid. (a) The dimer diamine of component is defined as a diamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a dibasic acid compound within the range of 18 to 54 carbon atoms, preferably within the range of 22 to 44 carbon atoms. can do.

As a characteristic of dimerdiamine, the characteristic derived from the backbone of a dimer acid can be provided. That is, since dimerdiamine is an aliphatic macromolecule having a molecular weight of about 560 to 620, it is possible to increase the molar volume of the molecule to relatively reduce the polar group of the polyimide. Such characteristics of dimer acid type diamine are considered to contribute to improving dielectric properties by reducing the relative dielectric constant and dielectric loss tangent while suppressing a decrease in the heat resistance of the polyimide. In addition, since it has two freely moving minor chains having 7 to 9 carbon atoms and two chain aliphatic amino groups having a length close to 18 carbon atoms, flexibility can be imparted to the polyimide. However, it is considered that polyimide can have a non-target chemical structure or a non-planar chemical structure, so that it is possible to achieve low dielectric constant and low dielectric loss tangent of polyimide.

As the dimer diamine composition, the dimer diamine content of component (a) is increased to 96% by weight or more, preferably 97% by weight or more, more preferably 98% by weight or more by a purification method such as molecular distillation. . (a) By making dimerdiamine content of a component into 96 weight% or more, the diffusion of molecular weight distribution of a polyimide can be suppressed. Also, if technically possible, it is best that all (100% by weight) of the dimerdiamine composition is composed of the dimerdiamine of component (a).

(b) a monoamine compound obtained by substituting a terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms with a primary aminomethyl group or an amino group;

Monobasic acid compounds in the range of 10 to 40 carbon atoms are monobasic unsaturated fatty acids in the range of 10 to 20 carbon atoms derived from the raw material of dimer acid, and by-products in the production of dimer acid in the range of 21 to 40 carbon atoms. It is a mixture of monobasic acid compounds in The monoamine compound is obtained by substituting a terminal carboxylic acid group of these monobasic acid compounds with a primary aminomethyl group or an amino group.

(b) The monoamine compound of a component is a component which suppresses the molecular weight increase of a polyimide. During polymerization of polyamic acid or polyimide, the monofunctional amino group of the monoamine compound reacts with the terminal acid anhydride group of the polyamic acid or polyimide, whereby the terminal acid anhydride group is sealed and the polyamic acid or polyimide It suppresses the increase in the molecular weight of the mid.

(c) an amine compound obtained by substituting a terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms with a primary aminomethyl group or an amino group (however, the dimerdiamine is excluded);

The polybasic acid compound having a hydrocarbon group in the range of 41 to 80 carbon atoms is a polybasic acid compound mainly comprising a tribasic acid compound in the range of 41 to 80 carbon atoms, which is a by-product during the production of dimer acid. Moreover, polymerized fatty acids other than a C41-C80 dimer acid may be included. The amine compound is obtained by substituting a terminal carboxylic acid group of these polybasic acid compounds with a primary aminomethyl group or an amino group.

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

In the dimerdiamine composition, when each component is quantified by measurement using gel permeation chromatography (GPC), the peak start, peak top and peak end of each component of the dimerdiamine composition can be easily identified. , A sample in which the dimerdiamine composition was treated with acetic anhydride and pyridine is used, and cyclohexanone is used as an internal standard. Using the sample thus prepared, each component is quantified by area percent of the chromatogram of GPC. The peak start and peak end of each component are taken as the minimum value of each peak curve, and the area percent of the chromatogram can be calculated based on this.

Further, in the dimerdiamine composition used in the present invention, the total of the components (b) and (c) is 4% or less, preferably less than 4%, in terms of area percent of the chromatogram obtained by GPC measurement. By making the sum total of a component (b) and a component (c) into 4 % or less, the diffusion of molecular weight distribution of a polyimide can be suppressed.

Moreover, as for the area percent of the chromatogram of (b) component, Preferably it is 3 % or less, More preferably, it is 2 % or less, More preferably, 1 % or less is good. By setting it as such a range, the fall of the molecular weight of a polyimide can be suppressed and the range of the molar ratio of the input amount of a tetracarboxylic anhydride component and a diamine component can be broadened. In addition, (b) component does not need to be contained in dimerdiamine composition.

Moreover, the area percent of the chromatogram of (c)component is 2 % or less, Preferably it is 1.8 % or less, More preferably, 1.5 % or less is good. By setting it as such a range, the rapid increase of the molecular weight of polyimide can be suppressed and also the raise of the dielectric loss tangent in the frequency range of a resin film can be suppressed. In addition, (c) component does not need to be contained in the dimer diamine composition.

In addition, when the ratio (b/c) of the area percent in the chromatograms of the components (b) and (c) is 1 or more, the molar ratio of the tetracarboxylic anhydride component and the diamine component (tetracarboxylic anhydride component/diamine component) is preferably Preferably, it is good to set it as 0.97 or more and less than 1.0, and control of the molecular weight of a polyimide becomes easier by setting it as such a molar ratio.

In addition, when the ratio (b/c) of the area percent of the chromatograms of the components (b) and (c) is less than 1, the molar ratio of the tetracarboxylic anhydride component and the diamine component (tetracarboxylic acid anhydride component/diamine component) is, Preferably, it is good to set it as 0.97 or more and 1.1 or less, and control of the molecular weight of a polyimide becomes easier by setting it as such a molar ratio.

As for the weight average molecular weight of a polyimide, the inside of the range of 10,000-200,000 is preferable, for example. Further, for example, when applied as an adhesive for FPC, the weight average molecular weight of the polyimide is more preferably in the range of 20,000 to 150,000, still more preferably in the range of 40,000 to 150,000. When the weight average molecular weight of the polyimide is less than 20,000, the flow resistance tends to deteriorate. On the other hand, if the weight average molecular weight of polyimide is more than 150,000, the viscosity increases excessively and becomes insoluble in solvents.

It is preferable to refine|purify a dimer diamine composition in order to reduce components other than dimer diamine of (a) component. Although it does not restrict|limit especially as a purification method, Well-known methods, such as a distillation method and precipitation purification, are preferable. The dimerdiamine composition before purification can be obtained as a commercial item, for example, Croda Japan (Croda Japan K.K.) PRIAMINE 1073 (brand name), PRIAMINE 1074 (brand name), PRIAMINE 1075 (brand name), etc. are mentioned.

As diamine compounds other than the aliphatic diamine used for a polyimide, an aromatic diamine compound is mentioned. Specific examples thereof include 1,4-diaminobenzene (p-PDA; paraphenylenediamine), 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-k Silidine, 4,4'-methylene-2,6-diethylaniline, 3,3'-diaminodiphenylethane, 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-t-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-t-butyl)toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine , p-xylylenediamine, 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 and diamine compounds such as -(4-aminophenoxy)benzoxazole and 1,3-bis(3-aminophenoxy)benzene.

The polyimide can be produced by reacting the above tetracarboxylic acid anhydride component and the diamine component in a solvent to produce polyamic acid and then heating and ring closure. For example, polyamic acid, a precursor of polyimide, is obtained by dissolving a tetracarboxylic anhydride component and a diamine component in approximately equimolar amounts in an organic solvent, stirring at a temperature within the range of 0 to 100° C. for 30 minutes to 24 hours, and polymerization. In the reaction, the reactant components are dissolved in the organic solvent so that the resulting precursor is in the range of 5 to 50% by weight, preferably in the range of 10 to 40% by weight. Examples of the organic solvent used for the polymerization reaction include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, and N-methyl-2-pi. Rollidone (NMP), 2-butanone, dimethyl sulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diglyme , triglyme, methanol, ethanol, benzyl alcohol, cresol, and the like. Two or more of these solvents may be used in combination, and an aromatic hydrocarbon such as xylene or toluene may also be used in combination. In addition, the amount of the organic solvent used is not particularly limited, but it is preferable to adjust the amount to be used so that the concentration of the polyamic acid solution obtained by the polymerization reaction is about 5 to 50% by weight.

The synthesized polyamic acid is usually advantageously used as a reaction solvent, but may be concentrated, diluted or substituted with another organic solvent if necessary. In addition, polyamic acids are generally used advantageously because of their excellent solvent solubility. It is preferable that the viscosity of the solution of polyamic acid exists in the range of 500 cps - 100,000 cps. If it is out of this range, defects such as thickness unevenness and streaks are likely to occur in the film during application by a coater or the like.

The method for imidizing polyamic acid to form polyimide is not particularly limited, and for example, heat treatment such as heating in the solvent at a temperature within the range of 80 to 400° C. for 1 to 24 hours is preferably employed. do. In addition, the temperature may be heated under a constant temperature condition, and it is also possible to change the temperature in the middle of the process.

In the thermoplastic polyimide of component (A), by selecting the types of the tetracarboxylic acid anhydride component and the diamine component, or each molar ratio in the case of applying two or more types of tetracarboxylic acid anhydride component or diamine component, dielectric properties, coefficient of thermal expansion , tensile modulus of elasticity, glass transition temperature, etc. can be controlled. Moreover, the thermoplastic polyimide of (A) component WHEREIN: When providing two or more structural units of a polyimide, even if it exists in a block, although it may exist at random, it is preferable to exist at random.

(A) The imide group density|concentration of the thermoplastic polyimide of a component becomes like this. Preferably it is 22 weight% or less, More preferably, 20 weight% or less is good. Here, "imide group concentration" means the value obtained by dividing the molecular weight of the imide group moiety (—(CO) ₂ —N—) in the polyimide by the molecular weight of the entire structure of the polyimide. When the concentration of the imide group exceeds 22% by weight, the molecular weight of the resin itself decreases, and the low hygroscopicity also deteriorates due to an increase in the polar group, and the Tg and the tensile modulus of elasticity increase.

(A) As for the thermoplastic polyimide of component, the most preferable structure imidated completely. However, a part of polyimide may be made into amic acid. The imidation rate was determined by measuring the infrared absorption spectrum of the polyimide thin film by a single reflection ATR method using a Fourier transform infrared spectrophotometer (commercial product: manufactured by JASCO Corporation, trade name: FT/IR620). By doing so, it can be calculated from the absorbance of C=O stretching derived from an imide group of 1780 cm ^-1 on the basis of the benzene ring absorber in the vicinity of 1015 cm ^-1 .

<(B) component: polystyrene elastomer resin>

(B) Polystyrene elastomer resin of component is a copolymer of styrene or its derivative(s), and a conjugated diene compound, Comprising: The hydrogenated substance is included. Although it does not specifically limit as styrene or its derivative(s) here, Styrene, methylstyrene, butylstyrene, divinylbenzene, vinyltoluene, etc. are illustrated. Moreover, although it does not specifically limit as a conjugated diene compound, Butadiene, isoprene, 1, 3- pentadiene, etc. are illustrated.

Moreover, it is preferable that the polystyrene elastomer resin is hydrogenated. When hydrogen is added, stability to heat is further improved, decomposition and deterioration such as polymerization are less likely to occur, aliphatic properties are enhanced, and compatibility with the thermoplastic polyimide of component (A) is increased.

(B) A block structure may be sufficient as the copolymerization structure of polystyrene elastomer resin of component, and a random structure may be sufficient as it. Preferred specific examples of the polystyrene elastomer resin are styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene-butylene-styrene block copolymer (SBBS), and styrene-ethylene-butylene-styrene block copolymer (SEBS). ), a styrene-ethylene-propylene-styrene block copolymer (SEPS), and a styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), but are not limited thereto.

(B) The acid value of the polystyrene elastomer resin of component is 10 mgKOH/g or less, 1 mgKOH/g or less is preferable, and it is more preferable that it is 0 mgKOH/g. By blending the polystyrene elastomer resin having an acid value of 10 mgKOH/g or less in the polyimide composition, the dielectric loss tangent when the resin film is formed can be reduced and good peel strength can be maintained. On the other hand, when the acid value exceeds 10 mgKOH/g, dielectric properties deteriorate due to an increase in polar groups, and compatibility with component (A) deteriorates, thereby reducing adhesion when a resin film is formed. Therefore, the acid value is so good that it is low, and the thing which is not acid-modified (that is, the thing whose acid value is 0 mgKOH/g) is most suitable as (B) component of this invention. In this invention, since it becomes possible to express the outstanding adhesiveness when the thermoplastic polyimide of (A) component contains the residue derived from an aliphatic diamine, it is not acid-modified (that is, the property related to aliphatic is strong). Even when a polystyrene elastomer resin is used, the decrease in adhesive strength as feared in Patent Document 1 can be avoided.

(B) As for the polystyrene elastomer resin of component, it is preferable that the content rate of a styrene unit [ _-CH2CH ( _C6H5 )-] exists _in the range of 10 weight% or more and 65 weight% or less, 20 weight% or more and 65 weight% It is more preferable to exist in the range of % or less, and it is most preferable to exist in the range of 30 weight% or more and 60 weight% or less. When the content of styrene units in the polystyrene elastomer resin is less than 10% by weight, the elastic modulus of the resin decreases and the handling property as a film deteriorates, and when it becomes higher than 65% by weight, the resin becomes rigid and used as an adhesive In addition to this difficulty, since the rubber component in the polystyrene elastomer resin decreases, the dielectric properties deteriorate.

In addition, since the ratio of aromatic rings in the resin film is increased by making the content of the styrene unit within the above range, via holes (through holes) and blinds by laser processing in the process of manufacturing a circuit board using the resin film In the case of forming the via hole, it becomes possible to increase the absorbency in the ultraviolet region, and the laser processability can be further improved.

(B) It is preferable to exist in the range of 50,000-300,000, for example, and, as for the weight average molecular weight of polystyrene elastomer resin of component, the inside of the range of 80,000-270,000 is more preferable. When the weight average molecular weight of component (B) is lower than the above range, the effect of improving the dielectric properties may be lowered. Conversely, if the weight average molecular weight of component (B) is high, the viscosity of the polyimide composition may increase, making it difficult to prepare a resin film.

(B) As polystyrene elastomer resin of component, if an acid value is 10 mgKOH/g or less, a commercial item can be selected suitably and can be used. As such commercially available polystyrene elastomer resins, for example, A1535HU (trade name), G1652MU (trade name), G1726VS (trade name), G1645VS (trade name), FG1901GT (trade name), G1650MU (trade name), manufactured by Kraton Corporation, G1654HU (trade name), G1730VO (trade name), MD1653MO (trade name), etc. can be preferably used.

[Amount]

Content of (B) component with respect to 100 weight part of (A) component in a polyimide composition exists in the range of 10 weight part or more and 100 weight part or less, The inside of the range of 20 weight part or more and 90 weight part or less is preferable, The inside of the range of 30 weight part or more and 80 weight part or less is more preferable. If content of (B) component with respect to 100 weight part of (A) component is less than 10 weight part, the effect of reducing a dielectric loss tangent may not fully be expressed. On the other hand, when the weight ratio of component (B) exceeds 100 parts by weight, the adhesiveness when the resin film is formed is lowered, and the solid content concentration in the polyimide composition is too high to increase the viscosity, so handling properties are lowered. have.

[Optional Ingredients]

When the thermoplastic polyimide of component (A) has a ketone group, an amino compound having the ketone group and at least two primary amino groups as functional groups (in this specification, described as "amino compound for crosslinking formation") A crosslinked structure can be formed by reacting the amino group of (in some cases) to form a C=N bond. By forming the crosslinked structure, the heat resistance of the thermoplastic polyimide forming the adhesive layer can be improved. Therefore, the polyimide composition of this embodiment may contain the amino compound for crosslinking formation as an optional component.

Preferable examples of tetracarboxylic anhydride for forming a polyimide having a ketone group include 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA). Examples of the diamine compound include and aromatic diamines such as 4,4'-bis(3-aminophenoxy)benzophenone (BABP) and 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene (BABB). For the purpose of forming a crosslinked structure, the polyimide composition of the present embodiment, in particular, contains preferably 50 mol% or more, more preferably 60 mol% or more of BTDA residues derived from BTDA with respect to all tetracarboxylic acid residues ( It is preferable to contain the thermoplastic polyimide of A) component and the amino compound for crosslinking formation.

Examples of the amino compound for crosslinking include (I) dihydrazide compounds, (II) aromatic diamines, (III) aliphatic amines, and the like. Among these, a dihydrazide compound is preferable. Aliphatic amines other than dihydrazide compounds tend to form a crosslinked structure even at room temperature, and there is concern about storage stability of the varnish. Thus, when a dihydrazide compound is used, the storage stability of a varnish and shortening of hardening time can be made compatible. As the dihydrazide compound, for example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, and azelaic acid dihydrazide. Zide, sebacic acid dihydrazide, dodecane diacid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartrate dihydrazide, malic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide Zide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4-bisbenzene dihydrazide, 1,4-naphthoic acid dihydrazide, 2,6-pyridine diacid dihydrazide, itacone Dihydrazide compounds, such as acid dihydrazide, are preferable. The above dihydrazide compounds may be used independently, and it is also possible to mix and use 2 or more types.

Further, amino compounds such as (I) dihydrazide compound, (II) aromatic diamine, and (III) aliphatic amine include, for example, a combination of (I) and (II), a combination of (I) and (III), Like a combination of (I), (II) and (III), it is also possible to use a combination of two or more types beyond categories.

In addition, from the viewpoint of making the network-like structure formed by crosslinking with the amino compound for crosslinking more dense, the amino compound for crosslinking used in the present invention has a molecular weight (when the amino compound for crosslinking is an oligomer) , weight average molecular weight) is preferably 5,000 or less, more preferably 90 to 2,000, still more preferably 100 to 1,500. Among these, amino compounds for crosslinking having a molecular weight of 100 to 1,000 are particularly preferable. When the molecular weight of the amino compound for crosslinking is less than 90, one amino group of the amino compound for crosslinking only forms a C=N bond with the ketone group of the polyimide resin, and the periphery of the other amino group sterically swells, so the rest The amino group tends to be difficult to form a C=N bond.

When crosslinking the ketone group in the thermoplastic polyimide of component (A) and the amino compound for crosslinking, the amino compound for crosslinking is added to the resin solution containing the component (A) to form crosslinking with the ketone group in the thermoplastic polyimide Condensation reaction of the primary amino group of the amino compound for use. By this condensation reaction, the resin solution is cured to become a cured product. In this case, the amount of the amino compound for crosslinking is 0.004 mol to 1.5 mol in total, preferably 0.005 mol to 1.2 mol, more preferably 0.03 mol to 0.9 mol, and most preferably, the primary amino group per 1 mol of the ketone group. Preferably, it can be set as 0.04 mol to 0.6 mol. With the addition amount of the amino compound for crosslinking so that the total of the primary amino groups is less than 0.004 mol with respect to 1 mol of the ketone group, the crosslinking by the amino compound for crosslinking is not sufficient, so heat resistance after curing tends to be difficult to be expressed. , when the amount of the amino compound for crosslinking exceeds 1.5 mol, the unreacted amino compound for crosslinking acts as a thermoplastic and tends to decrease the heat resistance as an adhesive layer.

The conditions of the condensation reaction for crosslinking are conditions under which the ketone group in the thermoplastic polyimide of component (A) reacts with the primary amino group of the amino compound for crosslinking to form an imine bond (C=N bond). , is not particularly limited. The temperature of the heating condensation is to release the water generated by the condensation to the outside of the system, or to simplify the condensation process in the case where the heating condensation reaction is continued after the synthesis of the thermoplastic polyimide of component (A). For these reasons, for example, the inside of the range of 120-220 degreeC is preferable, and the inside of the range of 140-200 degreeC is more preferable. The reaction time is preferably about 30 minutes to 24 hours. The end point of the reaction is, for example, by measuring the infrared absorption spectrum using a Fourier transform infrared spectrophotometer (commercially available product: FT/IR620 manufactured by Nippon Spectroscopy Co., Ltd.), the ketone in the polyimide resin in the vicinity of 1670 cm ^-1 It can be confirmed by the decrease or disappearance of the absorption peak derived from the group, and the appearance of the absorption peak derived from the imine group in the vicinity of 1635 cm ^-1 .

Heat condensation of the ketone group of the thermoplastic polyimide of component (A) and the primary amino group of the amino compound for crosslinking is, for example,

(1) The method of adding and heating the amino compound for crosslinking formation following the synthesis|combination (imidization) of the thermoplastic polyimide of (A) component;

(2) Prepare an excess amount of an amino compound as a diamine component in advance, continue to the synthesis (imidization) of the thermoplastic polyimide of component (A), and crosslink the remaining amino compounds not involved in imidation or amidation a method of heating together with a thermoplastic polyimide using as an amino compound for use, or

(3) A method of heating a polyimide composition to which an amino compound for crosslinking has been added, after processing it into a predetermined shape (for example, after coating on an arbitrary substrate or forming into a film)

etc. can be carried out.

Although the formation of an imine bond has been described as the formation of a crosslinked structure for imparting heat resistance to the thermoplastic polyimide of component (A), it is not limited thereto. As a curing method of the thermoplastic polyimide of component (A), for example, an epoxy resin , an epoxy resin curing agent, maleimide, activated ester resin, or a compound having an unsaturated bond, such as a resin having a styrene skeleton, may be blended and cured.

In the polyimide composition of the present embodiment, as an optional component, inorganic fillers, organic fillers, plasticizers, curing accelerators, coupling agents, pigments, flame retardants, etc. may be further appropriately blended as optional components within a range that does not impair the effects of the invention. have. Here, as the inorganic filler, for example, silicon dioxide, aluminum oxide, beryllium oxide, niobium oxide, titanium oxide, magnesium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, magnesium fluoride, potassium silicate fluoride, phosphinic acid A metal salt etc. are mentioned. These can be used 1 type or in mixture of 2 or more types. Moreover, you may mix|blend other resin components, such as an epoxy resin, a fluororesin, and an olefin resin, as an optional component, for example.

Moreover, the polyimide composition of this embodiment can contain solvents, such as an organic solvent. The thermoplastic polyimide of component (A) has solvent solubility, and the polystyrene elastomer resin of component (B) also exhibits good solubility in aromatic hydrocarbon solvents such as xylene and toluene. The polyimide composition can be prepared as a polyimide solution (varnish) containing a solvent. Examples of the organic solvent include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, and N-methyl-2-pyrrolidone (NMP). , 2-butanone, dimethylsulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme, cresol, etc. It is preferable to use the mixed solvent which mixed 1 type, 2 or more types, and the said aromatic hydrocarbon type solvent in arbitrary ratios.

Although it does not restrict|limit especially as content of a solvent, It is preferable to adjust and use it so that the density|concentration of a polyamic acid or polyimide will be about 5 to 30 weight%.

[viscosity]

The viscosity of the polyimide composition is preferably within the range of 3000 cps to 100000 cps, for example, in the range of 3000 cps to 100000 cps, as a viscosity range in which it is easy to form a coating film of uniform thickness by improving handling properties when the polyimide composition is applied, and 5000 cps to 50000 cps It is more preferable to be within the range of If the viscosity is out of the above range, defects such as thickness unevenness and streaks are likely to occur in the film during coating by a coater or the like.

[Preparation of polyimide composition]

A polyimide composition can be prepared, for example by mix|blending and mixing a polystyrene elastomer resin with the resin solution of the thermoplastic polyimide produced using arbitrary solvents. At this time, in order to uniformly mix the thermoplastic polyimide and the polystyrene elastomer resin, the polystyrene elastomer resin may be mixed in a state of being dissolved in a solvent, or a solvent exhibiting high solubility in the polystyrene elastomer resin may be added.

The polyimide composition of the present embodiment has excellent flexibility and thermoplasticity when an adhesive layer is formed using the polyimide composition. Therefore, for example, in FPC, rigid-flex circuit boards, etc., it has characteristics suitable for uses, such as an adhesive for a coverlay film which protects the material of an adhesive bond layer, and a wiring part.

[Resin Film]

The resin film of this embodiment is a resin film consisting of a single layer or a plurality of layers including a thermoplastic resin layer, wherein the thermoplastic resin layer contains the solid content of the polyimide composition (residue excluding the solvent). It is made into a film using the main component. That is, a thermoplastic resin layer is (A) component and (B) component;

(A) a thermoplastic polyimide, and

(B) polystyrene elastomer resin having an acid value of 10 mgKOH/g or less

While containing, content of the said (B) component with respect to 100 weight part of the said (A) component exists in the range of 10 weight part or more and 100 weight part or less. The resin film of this embodiment has the excellent high frequency characteristic and the outstanding adhesiveness (especially peeling strength).

The resin film of the present embodiment is not particularly limited as long as it is a film of an insulating resin containing the above-mentioned thermoplastic resin layer, and may be a film (sheet) made of only an insulating resin, copper foil, glass plate, polyimide-based A film of an insulating resin laminated on a substrate such as a resin sheet such as a film, a polyamide-based film, or a polyester-based film may be used.

(relative permittivity)

The resin film of this embodiment, for example, in order to ensure impedance matching when used for circuit boards such as FPC and to reduce electric signal loss, control humidity for 24 hours under constant temperature and humidity conditions of 23°C and 50%RH. The relative dielectric constant (ε) at 10 GHz after the conversion is preferably 3.3 or less, more preferably 3.1 or less. When the relative permittivity exceeds 3.3, problems such as electric signal loss on the transmission path of high-frequency signals tend to occur when used for circuit boards such as FPC.

(Dielectric loss tangent)

In addition, the resin film of this embodiment, for example, in order to reduce the loss of electric signals when used for circuit boards such as FPC, 23 ℃, 50% RH constant temperature and humidity conditions for 24 hours after 24 hours of temperature control The dielectric loss tangent (Tanδ) in this is preferably 0.0020 or less, and more preferably 0.0018 or less. When this dielectric loss tangent exceeds 0.0020, when it is used for circuit boards, such as an FPC, it becomes easy to produce problems, such as electric signal loss on the transmission path of a high frequency signal.

(Glass Transition Temperature)

As for the resin film of this embodiment, it is preferable that a glass transition temperature (Tg) is 250 degrees C or less, and it is more preferable that it exists in the range of 40 degreeC or more and 200 degrees C or less. By setting the Tg of the resin film to 250° C. or less, thermocompression bonding at a low temperature is possible, so that internal stress generated during lamination can be relieved, and dimensional change after circuit processing can be suppressed. When the Tg of the resin film exceeds 250 DEG C, the bonding temperature becomes high and there is a risk of impairing the dimensional stability after circuit processing.

(thickness)

The thickness of the resin film of this embodiment is, for example, preferably 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 fear that problems such as wrinkles may occur during conveyance in the production of a resin film, etc., and on the other hand, if the thickness of the resin film exceeds 125 μm, the There is a possibility that productivity may fall.

(Tensile modulus)

The resin film of this embodiment preferably has a tensile modulus of 0.1 GPa to 3.0 GPa, and 0.2 GPa to 2.0 GPa, from the viewpoints of reduction of wrinkle generation, prevention of bubble entrainment during lamination, handling properties, and the like. I prefer

(Maximum Elongation)

The resin film of this embodiment preferably has a maximum elongation in the range of 30% to 200% from the viewpoint of bendability and crack prevention when applied as an insulating resin layer of FPC, and is in the range of 60% to 160% I prefer

Since the resin film of this embodiment has a low dielectric loss tangent and excellent adhesiveness, an adhesive layer in a coverlay film, an adhesive layer in a circuit board, a multilayer circuit board, a copper foil with resin, a bond ply, a bonding sheet It is useful as

[Laminate]

A laminate according to one embodiment of the present invention includes a substrate and an adhesive layer laminated on at least one surface of the substrate, and the adhesive layer is made of the resin film. In addition, the laminated body may contain arbitrary layers other than the above. As a base material in a laminated body, base materials of inorganic materials, such as copper foil and a glass plate, and base materials of resin materials, such as a polyimide-type film, a polyamide-type film, and a polyester film, are mentioned, for example.

As a preferable aspect of a laminated body, a coverlay film, copper foil with resin, etc. are mentioned.

[Coverlay Film]

The coverlay film, which is one aspect of the laminate, includes a film material layer for coverlay as a base material, and an adhesive layer laminated on one side of the film material layer for coverlay, and the adhesive layer is made of the resin film . Moreover, the coverlay film may contain the arbitrary layers other than the above.

Although the material of the film material layer for the coverlay is not particularly limited, for example, polyimide-based films such as polyimide resins, polyetherimide resins, and polyamideimide resins, polyamide-based films, polyester-based films, etc. may be used. can Among these, it is preferable to use a polyimide-based film having excellent heat resistance. In addition, the film material for a coverlay may contain a black pigment in order to effectively express light-shielding properties, hiding properties, design properties, etc., and a matting pigment that suppresses the gloss of the surface within a range that does not impair the improvement effect of dielectric properties (delustering pigment) may include an optional component.

Although the thickness of the film material layer for coverlays is not specifically limited, For example, the inside of the range of 5 micrometers or more and 100 micrometers or less is preferable.

Moreover, although the thickness of an adhesive bond layer is not specifically limited, For example, the inside of the range of 10 micrometers or more and 75 micrometers or less is preferable.

The coverlay film of this embodiment can be manufactured by the method illustrated below.

First, as a first method, a varnish-like polyimide composition containing a solvent is applied to one side of a film material layer for a coverlay, and then dried at a temperature of, for example, 80 to 180° C. to make an adhesive. By forming a layer, the coverlay film provided with the film material layer for coverlays and an adhesive bond layer can be formed.

Further, as a second method, a resin film for an adhesive layer is formed by applying a varnish-like polyimide composition containing a solvent on an arbitrary substrate, drying it at a temperature of, for example, 80 to 180° C., and then peeling it. A coverlay film can be formed by thermocompression bonding a resin film and the film material layer for coverlays at the temperature of 60-220 degreeC, for example.

[Copper foil with resin]

The copper foil with resin which is another aspect of a laminated body laminates|stacks an adhesive bond layer on at least one side of the copper foil as a base material, Comprising: The adhesive bond layer consists of the said resin film. Moreover, the copper foil with resin of this embodiment may contain the arbitrary layers other than the above.

It is preferable to exist in the range of 2-125 micrometers, for example, and, as for the thickness of the adhesive bond layer in copper foil with resin, the inside of the range of 2-100 micrometers is more preferable. When the thickness of the adhesive layer does not reach the lower limit, there are cases in which a problem such as not being able to ensure sufficient adhesiveness occurs. On the other hand, when the thickness of the adhesive layer exceeds the upper limit, problems such as a decrease in dimensional stability arise. Further, from the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent, it is preferable that the thickness of the adhesive layer be 3 µm or more.

It is preferable that the material of the copper foil in copper foil with resin has copper or a copper alloy as a main component. The thickness of copper foil becomes like this. Preferably it is 35 micrometers or less, More preferably, the inside of the range of 5-25 micrometers is good. It is preferable that the lower limit of the thickness of copper foil shall be 5 micrometers from a viewpoint of production stability and handling property. In addition, rolled copper foil may be sufficient as copper foil, and electrodeposited copper foil may be sufficient as it. Moreover, as copper foil, commercially available copper foil can be used.

The resin-coated copper foil may be prepared by, for example, sputtering a metal on a resin film to form a seed layer and then forming a copper layer by, for example, copper plating, or by heating the resin film and copper foil. You may prepare by laminating by methods, such as crimping|compression-bonding. Moreover, since copper foil with resin forms an adhesive bond layer on copper foil, after casting the coating liquid of a polyimide composition, drying it and setting it as a coating film, you may perform required heat processing and may prepare it.

[Metal clad laminate]

(First aspect)

A metal clad laminate according to one embodiment of the present invention includes an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, and at least one of the insulating resin layers is made of the resin film. In addition, the metal foil laminated board of this embodiment may contain arbitrary layers other than the above.

(Second aspect)

A metal clad laminate according to another embodiment of the present invention includes, for example, 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 with the adhesive layer interposed therebetween. A so-called three-layer metal clad laminate provided with an adhesive layer made of the above resin film. In addition, the three-layer metal clad laminate may contain arbitrary layers other than the above. In the three-layer metal clad laminate, the adhesive layer may be formed on one or both sides of the insulating resin layer, and the metal layer may be formed on one or both sides of the insulating resin layer with the adhesive layer interposed therebetween. That is, the three-layer metal clad laminate may be a single-sided metal clad laminate or a double-sided metal clad laminate. A single-sided FPC or a double-sided FPC can be manufactured by performing wiring circuit processing by etching the metal layer of the three-layer metal clad laminate.

The insulating resin layer in the three-layer metal clad laminate is not particularly limited as long as it is composed of a resin having electrical insulation properties, and for example, polyimide, epoxy resin, phenol resin, polyethylene, polypropylene, polytetrafluoroethylene, Although silicone, ethylene-tetrafluoroethylene (ETFE), etc. are mentioned, It is preferable that it is comprised by polyimide. The polyimide layer constituting the insulating resin layer may be a single layer or a plurality of layers, but it is preferable to include a non-thermoplastic polyimide layer.

The thickness of the insulating resin layer in the three-layer metal clad laminate is, for example, preferably in the range of 1 to 125 µm, more preferably in the range of 5 to 100 µm. If the thickness of the insulating resin layer does not reach the lower limit, there may be problems such as not being able to guarantee sufficient electrical insulation. On the other hand, when the thickness of the insulating resin layer exceeds the above upper limit, there arises a problem such as a tendency for warpage of the metal clad laminate to occur.

It is preferable to exist in the range of 0.1-125 micrometers, for example, and, as for the thickness of the adhesive bond layer in a three-layer metal clad laminated board, the inside of the range of 0.3-100 micrometers is more preferable. In the three-layer metal clad laminate of the present embodiment, if the thickness of the adhesive layer does not reach the lower limit, there may be problems such as not being able to ensure sufficient adhesiveness. On the other hand, when the thickness of the adhesive layer exceeds the upper limit, problems such as a decrease in dimensional stability arise. In addition, from the viewpoint of reducing the dielectric constant of the entire insulating layer, which is a laminate of the insulating resin layer and the adhesive layer, and reducing the dielectric loss tangent, the thickness of the adhesive layer is preferably 3 µm or more.

Further, 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, for example, preferably within the range of 0.1 to 3.0, more preferably within the range of 0.15 to 2.0. By setting it as such a ratio, the curvature of a three-layer metal clad laminated board can be suppressed. Moreover, the insulating resin layer may contain a filler as needed. Examples of the filler include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, and metal salts of organic phosphinic acid. These can be used 1 type or in mixture of 2 or more types.

[circuit board]

A circuit board according to an embodiment of the present invention is formed by wiring the metal layer of the metal clad laminate according to any one of the above embodiments. A circuit board such as an FPC can be manufactured by processing one or more metal layers of the metal clad laminate into a pattern by a normal method to form a wiring layer (conductor circuit layer). Moreover, the circuit board may be equipped with the coverlay film which coat|covers the wiring layer.

(Example)

Examples are shown below, and the characteristics of the present invention will be described more specifically. However, the scope of the present invention is not limited to the Examples. In addition, in the following examples, various measurements and evaluations are based on the following unless otherwise indicated.

[Measurement of weight average molecular weight (Mw) of polyimide]

The weight average molecular weight was measured by a gel permeation chromatograph (Tosoh Corporation, trade name: HLC-8220GPC was used). Polystyrene was used as a standard material, and tetrahydrofuran (THF) was used as a developing solvent.

[Measurement of storage modulus]

It was measured using a dynamic viscoelasticity measuring device (DMA: manufactured by TA Instruments, trade name: RSA-G2).

[Evaluation of genetic characteristics]

Using a Vector Network Analyzer (Agilent Technologies, Inc. product, trade name; Vector Network Analyzer E8363C) and an SPDR resonator, the polyimide film (polyimide film after curing) was subjected to temperature; 23℃, humidity; After leaving it to stand under the condition of 50%RH for 24 hours, the dielectric constant (epsilon) and dielectric loss tangent (Tanδ) in a frequency of 10 GHz were measured.

[Glass Transition Temperature (Tg)]

temperature ; 160°C, pressure; 3.5 MPa, time ; The adhesive sheet pressed under the conditions of 60 minutes was cut into a test piece having a size of 5 mm x 20 mm, and using a dynamic viscoelasticity measuring device (DMA: TA Instruments product, trade name: RSA-G2), from 30 ° C. to 200 ° C. Measurement was performed at a temperature increase rate of 4°C/min and a frequency of 11 Hz, and the temperature at which the change in elastic modulus (tan δ) becomes the maximum was set as the glass transition temperature.

[Tensile modulus and maximum elongation]

Using a tension tester (manufactured by ORIENTEC CORPORATION, Tensilon), a tensile test of 50 mm/min was performed on a specimen of a resin film (width: 12.7 mm, length: 127 mm), 25 The tensile modulus and maximum elongation at °C were calculated.

[Solder heat resistance test (dry)]

Double-sided copper clad laminate (NIPPON STEEL Chemical & Material Co., Ltd. product, trade name; ESPANEX MB12-25-12UEG) One copper foil surface and an adhesive sheet are laminated|stacked in the form which pinches|interposed between copper foil, and temperature; 160°C, pressure; 3.5 MPa, time ; Pressed under the conditions of 60 minutes. After drying this copper foil-attached test piece at 135°C/60 minutes, it was immersed in a solder bath set at each evaluation temperature from 260°C to 300°C in units of 10°C for 10 seconds, and the adhesion state was observed. , the presence or absence of defects such as foaming, blistering, and peeling was confirmed. In judgment, the case where a defect was not confirmed at 280 degreeC was made into (good) (good), and the case where the defect was confirmed was made into x (poor).

[Solder heat resistance test (moisture absorption)]

Copper foil on one side of a double-sided copper clad laminate (Nitetsu Chemical & Materials Co., Ltd. product, trade name; Espanex MB12-25-12UEG) is removed by etching, and the copper foil side of the other side and an adhesive sheet are placed between the copper foils. and temperature ; 160°C, pressure; 3.5 MPa, time ; Pressed under the conditions of 60 minutes. 40 degreeC, relative humidity; this test piece with copper foil; After standing at 90%RH for 72 hours, it is immersed for 10 seconds in a solder bath set at each evaluation temperature from 240°C to 300°C in units of 10°C, and the adhesion state is observed, foaming, blistering, peeling, etc. The presence or absence of defects was confirmed. In judgment, the case where a defect was not confirmed at 260 degreeC was made into (good) (good), and the case where defect was confirmed was made into x (poor).

[Measurement of Peel Strength]

Width of double-sided copper clad laminate (Nitetsu Chemical & Materials Co., Ltd. product, trade name; Espanex MB12-25-12UEG); 50 mm, length; After cutting to 100 mm, an adhesive sheet is placed on the copper foil side of the sample from which the copper foil on one side has been removed by etching, and a polyimide film (DU PONT-TORAY CO., LTD.) is placed on this adhesive sheet. A brand name: Kapton 50EN-S) was further laminated, and temperature; 160°C, pressure; 3.5 MPa, time ; It pressed on the conditions for 60 minutes, and the laminated body was prepared. This laminate was cut into a width of 5 mm to be a test piece, and the test piece was tested using a tensile tester (manufactured by Toyo Seiki Seisaku-sho, Ltd., trade name; STROGRAPH VE). Peel strength was determined by measuring the peel strength of the adhesive layer and the copper foil when pulled at a speed of 50 mm/min in the 180° direction.

[Evaluation method of film retention]

The adhesive sheet was cut out into a test piece having a width of 20 mm and a length of 20 mm, folded along a diagonal line to make a mark, and then unfolded to observe the state of the film. At this time, the thing with no cracks in the test piece even after folding and unfolding was made into "good|favorableness", and the thing which cracked even partly was made into "impossible".

[Method for evaluating film defects]

Polyimide varnish was applied to one side of a PET film subjected to release treatment, dried at 100° C. for 5 minutes, dried at 120° C. for 10 minutes, and the state of the peeled film was observed. At this time, the thing with no scratches (scratches), etc. resulting from the poor solubility of an aggregate or elastomer resin was made into "good|favorableness", and a thing with a scratch was made into "impossible".

[acid value]

The acid value is the number of mg of potassium hydroxide (KOH) required to neutralize 1 g of the sample. This is measured, for example, by the following method. First, precisely measure the sample, put it in a 250 mL flask, add 50 mL of ethanol or an equal volume mixture of ethanol and ether, heat to dissolve, and titrate with 0.1 N potassium hydroxide solution while shaking as needed ( Indicator: phenolphthalein). The end point of the titration is the point at which the pink color of the solution lasts for 30 seconds. Next, a blank test is performed in the same way to correct, and the value of the acid value is calculated by the following formula.

Acid value = [Consumption of 0.1N potassium hydroxide solution (mL) × 5.611] / [Amount of sample (g)]

The symbol used in this Example shows the following compounds.

BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride

DDA: Croda Japan product, trade name ; What distilled and purified PRIAMINE 1075 ((a) component; 99.2 weight%, (b) component; 0%, (c) component; 0.8%, amine value: 210 mgKOH/g)

N-12: dodecane diacid dihydrazide

NMP: N-methyl-2-pyrrolidone

Elastomer resin 1: Krayton product, trade name; A1535HU (hydrogenated polystyrene elastomer resin, styrene unit content ratio 58% by weight, specific gravity: 0.96, no acid value)

Elastomer resin 2: Krayton product, trade name; G1652MU (Hydrogenated polystyrene elastomer resin, styrene unit content ratio 30% by weight, specific gravity: 0.91, no acid value)

Elastomer resin 3: Kraton product, trade name; G1726VS (hydrogenated polystyrene elastomer resin, styrene unit content ratio 30 wt%, specific gravity: 0.91, no acid value)

Elastomer resin 4: Kraton product, trade name; G1645VS (Hydrogenated polystyrene elastomer resin, styrene unit content ratio 13% by weight, specific gravity: 0.89, no acid value)

Elastomer resin 5: Creighton product, trade name; FG1901GT (Hydrogenated polystyrene elastomer resin, styrene unit content ratio 30 wt%, specific gravity: 0.91, acid value 10 mgKOH/g)

Elastomer resin 6: Asahi Kasei Corp. product, trade name; Tuftec M1913 (hydrogenated polystyrene elastomer resin, styrene unit content ratio 30 wt%, specific gravity: 0.91, acid value 11 mgKOH/g)

Elastomer resin 7: Asahi Kasei Co., Ltd. product, trade name; Toughtech M1943 (hydrogenated polystyrene elastomer resin, styrene unit content ratio 20% by weight, specific gravity: 0.91, acid value 11 mgKOH/g)

In addition, in said DDA, "%" of (a) component, (b) component, and (c)component means the area percent of the chromatogram in a GPC measurement. In addition, the molecular weight of DDA was computed by following formula (1).

Molecular weight = 56.1 x 2 x 1000 / amine value … (One)

(Synthesis Example 1)

In a 1000ml separable flask, 55.51 g of BTDA (0.1721 mol), 94.49 g of DDA (0.1735 mol), 210 g of NMP and 140 g of xylene were put, and mixed well at 40° C. for 1 hour to prepare a polyamic acid solution. . This polyamic acid solution was heated to 190 ° C., heated and stirred for 10 hours, and imidized by adding 125 g of xylene. Polyimide solution 1 (solid content: 31 wt%, weight average molecular weight: 80,900, thermoplastic polyi mid) was prepared.

[Example 1]

To 100 g of the polyimide solution 1 prepared in Synthesis Example 1, 1.12 g of N-12 and 7.8 g of the elastomer resin 1 were blended, and xylene was added to dilute and stirred so that the solid content was 27 wt%, to obtain polyimide varnish 1a. prepared.

[Examples 2 to 8]

Polyimide varnishes 2a to 8a were prepared in the same manner as in Example 1 except that elastomer resins 1, 2, 3, 4, and 5 were used and the blending amount was changed as shown in Table 1.

(Comparative Examples 1 and 2)

Polyimide varnishes 9a and 10a were prepared in the same manner as in Example 1 except that elastomer resins 6 and 7 were used and the blending amount was changed as shown in Table 1 and the solid content concentration of the polyimide varnish was changed to 31 wt%. did

(Comparative Example 3)

Polyimide varnish 11a was prepared in the same manner as in Example 1 except that no elastomer was used and the solid content concentration of the polyimide varnish was set to 31 wt%.

In Tables 1 and 2, the formulations of Examples 1 to 8 and Comparative Examples 1 to 3 are shown.

[Example 9]

The polyimide varnish 1a prepared in Example 1 was applied to one side of a release-treated PET film, dried at 100° C. for 5 minutes, dried at 120° C. for 10 minutes and peeled off, thereby adhesive sheet 1b (thickness: 25 μm) was prepared.

Various evaluation results of the adhesive sheet 1b are as follows.

relative permittivity ; 2.5, dielectric loss tangent ; 0.0018, tensile modulus; 0.3 GPa, maximum elongation; 136%, Tg; 41°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.5 kN/m, film defect; Good

[Example 10]

An adhesive sheet 2b was prepared in the same manner as in Example 9 using the polyimide varnish 2a.

Various evaluation results of the adhesive sheet 2b are as follows.

relative permittivity ; 2.5, dielectric loss tangent ; 0.0015, tensile modulus; 0.3 GPa, maximum elongation; 195%, Tg; 43°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.4 kN/m, film defect; Good

[Example 11]

An adhesive sheet 3b was prepared in the same manner as in Example 9 using the polyimide varnish 3a.

Various evaluation results of the adhesive sheet 3b are as follows.

relative permittivity ; 2.5, dielectric loss tangent ; 0.0013, tensile modulus; 0.3 GPa, maximum elongation; 230%, Tg; 42°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.3 kN/m, film defect; Good

[Example 12]

An adhesive sheet 4b was prepared in the same manner as in Example 9 using the polyimide varnish 4a.

Various evaluation results of the adhesive sheet 4b are as follows.

relative permittivity ; 2.6, dielectric loss tangent ; 0.0018, tensile modulus; 0.4 GPa, maximum elongation; 118%, Tg; 40°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.5 kN/m, film defect; Good

[Example 13]

An adhesive sheet 5b was prepared in the same manner as in Example 9 using the polyimide varnish 5a.

Various evaluation results of the adhesive sheet 5b are as follows.

relative permittivity ; 2.8, dielectric loss tangent ; 0.0017, tensile modulus; 0.3 GPa, maximum elongation; 144%, Tg; 40°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.6 kN/m, film defect; Good

[Example 14]

An adhesive sheet 6b was prepared in the same manner as in Example 9 using the polyimide varnish 6a.

Various evaluation results of the adhesive sheet 6b are as follows.

relative permittivity ; 2.6, dielectric loss tangent ; 0.0018, tensile modulus; 0.3 GPa, maximum elongation; 103%, Tg; 42°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.4 kN/m, film defect; Good

[Example 15]

An adhesive sheet 7b was prepared in the same manner as in Example 9 using the polyimide varnish 7a.

Various evaluation results of the adhesive sheet 7b are as follows.

relative permittivity ; 2.6, dielectric loss tangent ; 0.0020, tensile modulus; 0.2 GPa, maximum elongation; 103%, Tg; 41°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.4 kN/m, film defect; Good

[Example 16]

An adhesive sheet 8b was prepared in the same manner as in Example 9 using the polyimide varnish 8a.

Various evaluation results of the adhesive sheet 8b are as follows.

relative permittivity ; 2.6, dielectric loss tangent ; 0.0019, tensile modulus; 0.3 GPa, maximum elongation; 122%, Tg; 41°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.2 kN/m, film defect; Good

(Comparative Example 4)

An adhesive sheet 9b was prepared in the same manner as in Example 9 using the polyimide varnish 9a.

Various evaluation results of the adhesive sheet 9b are as follows.

relative permittivity ; 2.8, dielectric loss tangent ; 0.0022, tensile modulus; 0.3 GPa, maximum elongation; 201%, Tg; 43°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ×, peel strength; 1.6 kN/m, film defect; impossible

(Comparative Example 5)

An adhesive sheet 10b was prepared in the same manner as in Example 9 using the polyimide varnish 10a.

Various evaluation results of the adhesive sheet 10b are as follows.

relative permittivity ; 2.8, dielectric loss tangent ; 0.0022, tensile modulus; 0.2 GPa, maximum elongation; 185%, Tg; 41°C, film retention; Good, solder heat resistance test (dry) ; ○, Solder heat resistance test (moisture absorption); ○, Peel strength; 1.4 kN/m, film defect; impossible

(Comparative Example 6)

An adhesive sheet 11b was prepared in the same manner as in Example 9 using the polyimide varnish 11a.

Various evaluation results of the adhesive sheet 11b are as follows.

relative permittivity ; 2.6, dielectric loss tangent ; 0.0021, tensile modulus; 0.5 GPa, maximum elongation; 119%, Tg; 44°C, film retention; Good, solder heat resistance test (dry) ; ×, Solder heat resistance test (moisture absorption) ; ×, peel strength; 1.0 kN/m, film defect; Good

Table 3 summarizes the above results.

From Table 3, compared with the adhesive sheets 9b and 10b of Comparative Examples 4 and 5, the adhesive sheets 1b to 8b of Examples 9 to 16 to which the elastomer resin 1 and the elastomer resin 2, 3, 4, and 5 were added had a dielectric loss tangent. It is 0.0020 or less, and it has confirmed that high peeling strength can be obtained and there is no defect of a film. From these results, the adhesive sheet as a resin film according to the present embodiment can be expected to reduce transmission loss in a high frequency band of, for example, about 10 to 20 GHz, and has excellent peel strength while maintaining flexibility and film retainability. It could be confirmed that the

As shown in each of the above examples, by adding a hydrogenated polystyrene elastomer resin having an acid value of 10 mgKOH/g or less to a polyimide using an aliphatic diamine as a raw material, a clear improvement in dielectric properties was observed, and an improvement in peel strength was also seen. could

In addition, it was also confirmed that the adhesive sheet obtained in each Example maintained its shape as a film by using a hydrogenated polystyrene elastomer resin having an acid value of 10 mgKOH/g or less in a compounding amount within the practical range.

From the above results, it has been confirmed that the resin film according to the present embodiment is suitably used as a material for circuit boards such as high-frequency compatible FPC.

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

Claims (12)

following (A) component and (B) component;
(A) a thermoplastic polyimide, and
(B) polystyrene elastomer resin having an acid value of 10 mgKOH/g or less
While containing, the content of the component (B) with respect to 100 parts by weight of the component (A) is in the range of 10 parts by weight or more and 100 parts by weight or less.
According to claim 1,
The polyimide composition in which the content rate of the styrene unit in the said (B) component exists in the range of 10 weight% or more and 65 weight% or less.
3. The method of claim 1 or 2,
The said thermoplastic polyimide is made by making a tetracarboxylic-acid anhydride component and a diamine component react, Comprising: The polyimide composition containing 40 mol% or more of aliphatic diamines with respect to the said diamine component.
4. The method of claim 3,
The polyimide composition, wherein the aliphatic diamine is a dimer diamine composition mainly comprising dimer diamine in which two terminal carboxylic acid groups of dimer acid are substituted with primary aminomethyl groups or amino groups.
3. The method of claim 1 or 2,
The polyimide composition further containing the amino compound which has at least two primary amino groups as a functional group.
As a resin film comprising a thermoplastic resin layer,
The said thermoplastic resin layer is following (A) component and (B) component;
(A) a thermoplastic polyimide, and
(B) polystyrene elastomer resin having an acid value of 10 mgKOH/g or less
In addition to containing, the content of the component (B) with respect to 100 parts by weight of the component (A) is in the range of 10 parts by weight or more and 100 parts by weight or less.
7. The method of claim 6,
The thermoplastic resin layer has a dielectric loss tangent (Tanδ) at 10 GHz measured by a split post dielectric resonator (SPDR) of 0.0020 after humidity control for 24 hours under a constant temperature and humidity condition of 23°C and 50% RH. The following resin film.
A laminate comprising a substrate and an adhesive layer laminated on at least one surface of the substrate,
The said adhesive layer is laminated body, characterized in that it consists of the resin film of Claim 6.
A coverlay film comprising: a film material layer for a coverlay; and an adhesive layer laminated on the film material layer for a coverlay;
The adhesive layer is a coverlay film, characterized in that consisting of the resin film of claim 6.
A copper foil with a resin in which an adhesive layer and a copper foil are laminated,
The said adhesive layer consists of the resin film of Claim 6, The resin-coated copper foil characterized by the above-mentioned.
A metal foil laminate comprising an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer,
At least one layer of the insulating resin layer is a metal clad laminate, characterized in that it consists of the resin film of claim 6.
A circuit board formed by wiring the metal layer of the metal clad laminate of claim 11 .