TW202010634A - Laminated board with metal-coated layer, adhesive sheet, adhesive polyimide resin composition and circuit substrate having adhesive layer with excellent adhesion, dielectric constant, small dielectric dissipation factor and capable of reducing transmission loss even for high-frequency transmission - Google Patents

Abstract

The present invention provides a laminated board with metal-coated layer and a circuit substrate. The laminated board with metal-coated layer includes an adhesive layer with excellent adhesion, dielectric constant and small dielectric dissipation factor, and capable of reducing transmission loss even for high-frequency transmission. For the laminated board with metal-coated layer having an insulation resin layer, an adhesive layer laminated on a surface of at least one side of the insulation resin layer, and a metal layer insulating the adhesive layer and laminated on the insulation resin layer, the adhesive layer contains polyimide with tetracarboxylic residues and diamine residues, wherein the polyimide contains more than 50 mole fractions of diamine residues with respect to 100 mole fractions of diamine residues, in which the diamine residues are derived from dimer acid type diamine by replacing the two end carboxyl groups of dimer acid with primary amino-methyl or amino.

Description

Metal-clad laminate, adhesive sheet, adhesive polyimide resin composition and circuit board

The invention relates to a metal-clad laminated board, an adhesive sheet, an adhesive polyimide resin composition and a circuit board.

In recent years, with the progress of miniaturization, weight reduction, and space saving of electronic devices, flexible printed wiring boards (FPC; Flexible Printed Circuits) that are thin and lightweight, have flexibility, and have excellent durability even when repeatedly bent ) Needs to increase. FPC can realize three-dimensional and high-density packaging even in a limited space. Therefore, it is used in electronics such as hard disk drives (HDD), digital video disks (DVD), and smart phones. The wiring of moving parts of equipment, or cables, connectors and other parts are expanding.

In addition to the above-mentioned high-density, the high-performance of the equipment is progressing, so it is also necessary to cope with the high-frequency transmission signal. When the transmission loss in the transmission path is large when a high-frequency signal is transmitted, there are disadvantages such as loss of an electrical signal or a longer delay time of the signal. Therefore, in the future, it is also important in FPC to reduce transmission loss. In order to cope with high frequency, the following FPC is used, which uses a liquid crystal polymer characterized by a low dielectric constant and a low dielectric loss tangent as a dielectric layer. However, although the liquid crystal polymer is excellent in dielectric properties, there is still room for improvement in heat resistance or adhesion to the metal layer.

Metal-clad laminates that are used as circuit board materials for FPCs and the like are known in which a metal layer subjected to wiring and an insulating resin layer are bonded via an adhesive layer using an adhesive resin (three-layer metal-clad laminate) Board) (for example, Patent Document 1). It is considered that in terms of realizing the use of such a three-layer metal-clad laminate in a circuit board for high-frequency signal transmission, it is important to improve the dielectric properties of the adhesive layer.

In addition, as a technology related to an adhesive layer mainly composed of polyimide, it is proposed to use a crosslinked polyimide resin as an adhesive layer for a coverlay film. The polyimide resin is obtained by reacting a polyimide starting from a diamine compound derived from an aliphatic diamine such as dimer acid and an amino compound having at least two primary amino groups as functional groups (for example, a patent Literature 2). The cross-linked polyimide resin of Patent Document 2 has the following advantages: it does not generate volatile components containing a cyclic silicone compound, has excellent solder heat resistance, and is not exposed even in a use environment repeatedly exposed to high temperatures Will reduce the adhesion between the wiring layer and the cover film. However, Patent Document 2 does not study the application possibility in high-frequency signal transmission or the application in the adhesive layer in the three-layer metal-clad laminate. [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication WO2016/031960 [Patent Document 2] Japanese Patent No. 5777944

[Problems to be Solved by the Invention] An object of the present invention is to provide a metal-clad laminate and a circuit board including excellent adhesion, low dielectric constant and dielectric loss tangent, and high-frequency transmission It can also reduce the transmission loss of the adhesive layer. [Technical means to solve the problem]

The inventors of the present invention conducted intensive studies and found that by using polyimide for the adhesion layer that bears the adhesion function of the wiring layer and the insulating resin layer in the circuit board, and for the polyimide By controlling the type and amount of the monomers of the raw materials, excellent adhesion can be maintained, low dielectric constant and low dielectric loss tangent can be achieved, and the present invention has been completed.

The metal-clad laminate of the present invention includes an insulating resin layer, an adhesive layer laminated on at least one side of the insulating resin layer, and a layer laminated on the insulating resin layer via the adhesive layer Metal layer. The adhesive layer in the metal-clad laminate of the present invention has a polyimide containing a tetracarboxylic acid residue and a diamine residue. Moreover, the polyimide is characterized in that it contains 50 mol parts or more of the diamine acid residues and the two terminal carboxylic acid groups of the dimer acid are substituted with primary carbamic acid by 100 mol parts. A diamine residue derived from a dimer acid diamine derived from a group or an amino group.

In the metal-clad laminate of the present invention, the polyimide may contain a total of 90 mole parts or more of the following general formula (1) and/or 100 mole parts of the tetracarboxylic acid residue. Or a tetracarboxylic acid residue derived from the tetracarboxylic anhydride represented by the general formula (2).

[Chemical 1]

In the general formula (1), X represents a single bond or a divalent group selected from the following formulas; in the general formula (2), the cyclic portion represented by Y represents the formation of a 4-membered ring, 5-membered ring, or 6 Cyclic saturated hydrocarbon group in the member ring, 7 member ring or 8 member ring.

[Chem 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 the metal-clad laminate of the present invention, the polyimide may be contained in the range of 50 mole parts or more and 99 mole parts or less with respect to 100 mole parts of the diamine residue. A diamine residue derived from a dimer acid type diamine, and may contain the one represented by the following general formula (B1) to general formula (B7) in the range of 1 mol or more and 50 mol or less A diamine residue derived from at least one diamine compound in the diamine compound.

[Chemical 3]

In formula (B1) to formula (B7), R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents a group selected from -O-, -S-, -CO-, -SO-, -SO ₂ -, -COO-, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or -CONH-, a divalent group, n ₁ independently represents an integer of 0 to 4 . Among them, the part that repeats with the formula (B2) is removed from the formula (B3), and the part that repeats with the formula (B4) is removed from the formula (B5).

In the metal-clad laminate of the present invention, the metal layer may include copper foil, and the surface of the copper foil that is in contact with the adhesive layer may be subjected to rust prevention treatment.

In the circuit board of the present invention, the metal layer of any metal-clad laminate is processed into wiring.

The adhesive sheet of the present invention is an adhesive layer having an insulating resin layer, a layer laminated on at least one side of the insulating resin layer, and a layer laminated on the insulating resin layer via the adhesive layer The adhesive sheet for forming the adhesive layer in the metal-clad laminate of the metal layer. The adhesive sheet of the present invention has a polyimide containing a tetracarboxylic acid residue and a diamine residue. Moreover, the polyimide is characterized in that it contains 50 mol parts or more of the diamine acid residues and the two terminal carboxylic acid groups of the dimer acid are substituted with primary carbamic acid by 100 mol parts. A diamine residue derived from a dimer acid diamine derived from a group or an amino group.

In the adhesive sheet of the present invention, the polyimide may contain a total of 90 mole parts or more of the general formula (1) and/or more than 100 mole parts of the tetracarboxylic acid residue. The tetracarboxylic acid residue derived from the tetracarboxylic anhydride represented by the general formula (2).

In the adhesive sheet of the present invention, the polyimide may be contained in the range of 50 mole parts or more and 99 mole parts or less with respect to 100 mole parts of the diamine residue. A diamine residue derived from a polyacid type diamine, and may contain a diamine represented by the general formula (B1) to the general formula (B7) within a range of 1 mol or more and 50 mol or less A diamine residue derived from at least one diamine compound in the amine compound.

The adhesive polyimide resin composition of the present invention is an adhesive layer having an insulating resin layer, a layer laminated on at least one side of the insulating resin layer, and is laminated on the adhesive layer The composition for forming the adhesive layer in the metal-clad laminate of the metal layer on the insulating resin layer. The adhesive polyimide resin composition of the present invention contains a polyimide containing a tetracarboxylic acid residue and a diamine residue. Moreover, the polyimide is characterized in that it contains 50 mol parts or more of the diamine acid residues and the two terminal carboxylic acid groups of the dimer acid are substituted with primary carbamic acid by 100 mol parts. A diamine residue derived from a dimer acid diamine derived from a group or an amino group.

In the adhesive polyimide resin composition of the present invention, the polyimide may contain a total of 90 mole parts or more based on 100 mole parts of the tetracarboxylic acid residue. The tetracarboxylic acid residue derived from the tetracarboxylic anhydride represented by the formula (1) and/or the general formula (2).

In the adhesive polyimide resin composition of the present invention, the polyimide may be more than 50 mol parts and less than 99 mol parts relative to 100 mol parts of the diamine residue The diamine residue derived from the dimer acid type diamine is contained within the range, and may be selected from the general formula (B1) to the general formula within a range of 1 mol part or more and 50 mol part or less (B7) A diamine residue derived from at least one of the diamine compounds represented by (B7). [Effect of invention]

The metal-clad laminate of the present invention uses polyimide into which specific tetracarboxylic acid residues and diamine residues are introduced to form an adhesive layer, thereby ensuring adhesion and ensuring low dielectric constant and low Dielectric loss is tangent. By using the metal-clad laminate of the present invention, for example, it can also be applied to circuit boards and the like that transmit high-frequency signals above 10 GHz. Therefore, the circuit board can improve reliability and yield.

The embodiment of the present invention will be described in detail.

[Metal-clad laminate] The metal-clad laminate of this embodiment includes an insulating resin layer, an adhesive layer laminated on at least one surface of the insulating resin layer, and a dielectric resin layer laminated on the insulating resin via the adhesive layer The metal layer on the layer is a so-called three-layer metal-clad laminate. With regard to the three-layer metal-clad laminate, the adhesive layer only needs to be provided on one side or both sides of the insulating resin layer, and the metal layer only needs to be provided on one side or both sides of the insulating resin layer via the adhesive layer. That is, the metal-clad laminate of this embodiment 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 etching or the like and performing wiring circuit processing on the metal layer of the metal-clad laminate of this embodiment.

<Insulating resin layer> The insulating resin layer is not particularly limited as long as it contains a resin having electrical insulation properties, and examples include polyimide, epoxy resin, phenol resin, polyethylene, polypropylene, and polytetrafluoroethylene. , Silicone, Ethylene tetrafluoroethylene (ETFE), etc., preferably containing polyimide. The polyimide layer constituting the insulating resin layer may be a single layer or multiple layers, and preferably contains a non-thermoplastic polyimide layer. Here, the “non-thermoplastic polyimide” is generally polyimide that does not show adhesiveness even when it is softened by heating. In the present invention, it is referred to the use of a dynamic viscoelasticity measuring device (dynamic thermomechanical analyzer (Dynamic Thermomechanical Analyzer ( Dynamic thermomechanical analyzer (DMA)) Polyimide with a storage elastic modulus at 30°C of 1.0×10 ⁹ Pa or more and a storage elastic modulus at 300°C of 3.0×10 ⁸ Pa or more.

Polyimide is produced by polyimidization of a polyamic acid which is a precursor obtained by reacting a specific acid anhydride with a diamine compound. Therefore, non-thermoplastic polyacrylic acid is understood by explaining the acid anhydride and the diamine compound Specific examples of amines (the same applies to the thermoplastic polyimide forming the adhesive layer described later). In addition, the polyimide in the present invention includes polyimide, imide, polybenzimidazole, polyimide, polyether imide, polysilicon in addition to the so-called polyimide Oxalimide and other compounds having an amide imide group in the structure.

(Acid anhydride) Examples of the acid anhydride used in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer include 3,3',4,4'-biphenyltetracarboxylic dianhydride and homobenzene Tetracarboxylic dianhydride, 1,4-phenylene bis(trimellitic acid monoester) dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, 4,4'-oxygen Diphthalic anhydride, 2,3,3,4-biphenyltetracarboxylic dianhydride, 2,2,3,3-benzophenone tetracarboxylic dianhydride, 2,3,3,4 -Benzophenone tetracarboxylic dianhydride or 3,3,4,4-benzophenone tetracarboxylic dianhydride, 2,3,3,4-diphenyl ether tetracarboxylic dianhydride, bis(2 ,3-dicarboxyphenyl)ether dianhydride, 3,3,4,4-p-terphenylphenyltetracarboxylic dianhydride, 2,3,3,4-p-terphenylphenyltetracarboxylic dianhydride or 2, 2,3,3-p-terphenylphenyltetracarboxylic dianhydride, 2,2-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)methane dianhydride Or bis(3,4-dicarboxyphenyl) 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 Acid dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane Alkane dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic 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 2,3,6,7-)tetracarboxylic dianhydride, 2,3,8,9-perylene-tetracarboxylic dianhydride, 3,4,9 ,10-perylene-tetracarboxylic dianhydride, 4,5,10,11-perylene-tetracarboxylic dianhydride or 5,6,11,12-perylene-tetracarboxylic dianhydride, cyclopentane-1,2 ,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3 ,4,5-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, 2,2-bis[4-(3,4-dicarboxy Phenoxy)phenyl]propane dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, p-phenylene bis (trimellitic acid monoester anhydride), ethylene glycol bis Acid dianhydride such as trimellitic anhydride.

(Diamine compound) Examples of the diamine compound used in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer include an aromatic diamine compound or an aliphatic diamine compound. Specific examples of these 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]benzene, 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-aminobenzene Oxy)phenyl]hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 3,3'-dimethyl-4,4'diamino Benzene, 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-2,6-dimethylaniline, 4,4'-methylene-2,6-diethyl Aniline, 3,3'-diaminodiphenylethane, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3-diamino-p-terphenyl, 4 ,4-[1,4-Phenylenebis(1-methylethylene)]bisaniline, 4,4-[1,3-Phenylenebis(1-methylethylene)]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-xylylenediamine, p-xylylene Amine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, pyrazine, 2-methoxy-4,4-diamino Benzoylaniline, 4,4-diaminobenzylanilide, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 6-amino-2-(4-aminobenzene Oxygen) benzoxazole, 1,3-bis (3-aminophenoxy) benzene, dimer acid two terminal carboxylic acid groups are substituted with a primary aminomethyl or amino group dimer acid type two Diamine compounds such as amines.

By selecting the type of the acid anhydride and diamine compound among non-thermoplastic polyimides, or the respective molar ratios when two or more acid anhydrides and diamine compounds are applied, the thermal expansion coefficient, storage elastic modulus, Tensile elastic modulus, etc. In addition, in the case where the non-thermoplastic polyimide has a plurality of structural units of polyimide, it may exist in the form of a block or may exist randomly. From the viewpoint of suppressing in-plane deviation, it is preferable For random existence.

The thickness of the insulating resin layer is, for example, preferably within a range of 1 μm to 125 μm, and more preferably within a range of 5 μm to 50 μm. If the thickness of the insulating resin layer is less than the lower limit, problems such as insufficient electrical insulation may not be guaranteed. On the other hand, if the thickness of the insulating resin layer exceeds the upper limit, defects such as warpage of the metal-clad laminate are likely to occur. 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. With such a ratio, the warpage of the metal-clad laminate can be suppressed.

The non-thermoplastic polyimide layer constituting the insulating resin layer has low thermal expansion, and the coefficient of thermal expansion (Coefficient Of Thermal Expansion, CTE) is preferably in the range of 10 ppm/K or more and 30 ppm/K or less, and more preferably 10 ppm/ Within the range of K or more and 25 ppm/K or less. If the CTE is less than 10 ppm/K, or exceeds 30 ppm/K, warpage occurs, or dimensional stability decreases. By appropriately changing the combination, thickness, drying and curing conditions of the raw materials used, a polyimide layer having a desired CTE can be produced.

When the insulating resin layer is applied to a circuit board, for example, in order to suppress the deterioration of dielectric loss, the dielectric loss tangent (Tanδ) at 10 GHz may be 0.02 or less, more preferably 0.0005 or more and 0.01 or less, and Preferably, it is in the range of 0.001 or more and 0.008 or less. If the dielectric loss tangent of the insulating resin layer at 10 GHz exceeds 0.02, when it is used in a circuit board such as an FPC, it is easy to cause defects such as loss of electrical signals in the transmission path of high-frequency signals. On the other hand, the lower limit of the dielectric loss tangent of the insulating resin layer at 10 GHz is not particularly limited, and physical property control of the insulating resin layer as a circuit board can be considered.

When the insulating resin layer is applied as an insulating layer of a circuit board, for example, in order to ensure impedance matching, the entire insulating layer preferably has a dielectric constant at 10 GHz of 4.0 or less. If the dielectric constant of the insulating resin layer at 10 GHz exceeds 4.0, when it is used in a circuit board such as an FPC, the dielectric loss of the insulating resin layer deteriorates and an electrical signal is easily generated on the transmission path of the high-frequency signal Loss and other bad conditions.

The insulating resin layer may contain filler as necessary. 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 alone or in combination of two or more.

<Adhesive layer> The adhesive layer contains a polyimide containing a tetracarboxylic acid residue derived from a tetracarboxylic anhydride and a diamine residue derived from a diamine compound, and preferably contains a thermoplastic polyimide. Here, the "thermoplastic polyimide" is usually a polyimide whose glass transition temperature (Tg) can be clearly confirmed. In the present invention, the storage elastic modulus at 30°C measured using DMA is Polyimide having 1.0×10 ⁸ Pa or more and a storage elastic modulus at 300° C. of less than 3.0×10 ⁷ Pa. In the present invention, the term "tetracarboxylic acid residue" refers to a tetravalent group derived from tetracarboxylic dianhydride, and the term "diamine residue" refers to a divalent group derived from a diamine compound.

(Tetracarboxylic acid residue) The thermoplastic polyimide forming the adhesive layer preferably contains a total of 90 mole parts or more based on 100 mole parts of the tetracarboxylic acid residue, which is represented by the following general formula (1) and// Or a tetracarboxylic acid residue derived from the tetracarboxylic acid anhydride represented by the general formula (2) (hereinafter sometimes referred to as "tetracarboxylic acid residue (1)" and "tetracarboxylic acid residue (2)"). In the present invention, by containing a total of 90 mole parts or more of tetracarboxylic acid residues (1) and/or tetracarboxylic acid residues (2) relative to 100 mole parts of tetracarboxylic acid residues, The thermoplastic polyimide of the adhesive layer imparts solubility to the solvent, and it is easy to achieve the coexistence of the flexibility and heat resistance of the thermoplastic polyimide, which is preferable. If the total of tetracarboxylic acid residues (1) and/or tetracarboxylic acid residues (2) is less than 90 mole parts, the solvent solubility of the thermoplastic polyimide tends to decrease.

[Chemical 4]

In the general formula (1), X represents a single bond or a divalent group selected from the following formulas; in the general formula (2), the cyclic portion represented by Y represents the formation of a 4-membered ring, 5-membered ring, or 6 Cyclic saturated hydrocarbon group in the member ring, 7 member ring or 8 member ring.

[Chem 5]

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 .

Examples of the tetracarboxylic dianhydride used to derive the tetracarboxylic acid residue (1) include: 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3,4 ,4-benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride ( ODPA), 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane di Anhydride (BPADA), p-phenylene bis (trimellitic acid monoester anhydride), etc.

In addition, examples of the tetracarboxylic dianhydride used to derive the tetracarboxylic acid residue (2) include, for example, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4- Cyclopentane tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 1,2,4,5-cycloheptane tetracarboxylic dianhydride, 1,2,5,6 -Cyclooctane tetracarboxylic dianhydride, etc.

The thermoplastic polyimide forming the adhesive layer may contain a tetracarboxylic acid residue derived from an acid anhydride other than the tetracarboxylic anhydride represented by the general formula (1) or the general formula (2) within the range that does not impair the effect of the invention. Examples of the acid anhydride residues other than the tetracarboxylic acid residue (1) or the tetracarboxylic acid residue (2) include the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer in the insulating resin layer. The acid anhydride used is exemplified by the residue of the acid anhydride.

(Diamine residue) The thermoplastic polyimide forming the adhesive layer is within a range of 50 mole parts or more, for example, 50 mole parts or more and 99 mole parts or less with respect to 100 mole parts of the diamine residue. It is preferable that the dimer acid type diamine residue derived from the dimer acid type diamine is contained within a range of 80 mole parts or more, for example, 80 mole parts or more and 99 mole parts or less. By containing the dimer acid type diamine residue in the stated amount, the dielectric properties of the adhesive layer can be improved, and the required flexibility of the adhesive layer can be ensured. If the dimer acid type diamine residue is less than 50 mole parts with respect to 100 mole parts of the diamine residue, the adhesion layer between the insulating resin layer and the metal layer may not be sufficiently obtained The adhesiveness may also cause warpage of the metal-clad laminate.

Here, the dimer acid type diamine means that the two terminal carboxylic acid groups (-COOH) of the dimer acid are substituted with a primary aminomethyl group (-CH ₂ -NH ₂ ) or an amino group (-NH ₂ ). The resulting diamine. Dimer acid is a known dibasic acid obtained by intermolecular polymerization of unsaturated fatty acids. Its industrial manufacturing process has been roughly standardized in the industry, and it can be used for clays with a number of 11-22 Saturated fatty acids are obtained by dimerization. The dimer acid obtained industrially is mainly composed of dibasic acids of carbon number 36 obtained by dimerizing unsaturated fatty acids having carbon number 18 such as oleic acid or linoleic acid, and is contained according to the degree of purification Any amount of monomeric acid (carbon number 18), trimer acid (carbon number 54), and other polymeric fatty acids with carbon number 20-54. In the present invention, the dimer acid is preferably a compound that uses molecular distillation to increase the dimer acid content to 90% by weight or more. In addition, double bonds remain after the dimerization reaction. However, in the present invention, the dimer acid also includes a compound that further undergoes a hydrogenation reaction to reduce unsaturation.

As a characteristic of the dimer acid type diamine, the polyimide can be given a characteristic derived from a skeleton of the dimer acid. That is, the dimer acid type diamine is a macromolecular aliphatic having a molecular weight of about 560 to 620, so it can increase the molar volume of the molecule and relatively reduce the polar group of the polyimide. It is considered that the characteristics of this dimer acid type diamine contribute to suppressing the decrease in the heat resistance of polyimide and reducing the dielectric constant and the dielectric loss tangent to improve the dielectric properties. In addition, because it contains two freely-moving hydrophobic chains with a carbon number of 7 to 9, and two chain-like aliphatic amino groups with a length close to the carbon number of 18, it not only imparts flexibility to the polyimide, but can also polymerize Acetylene imide is an asymmetric chemical structure or a non-planar chemical structure, and therefore it is considered that the dielectric constant of polyimide can be reduced and the dielectric loss tangent can be reduced.

The dimer acid type diamine is commercially available, and examples thereof include: PRIAMINE 1073 (trade name) manufactured by CRODA Japan, and CRODA Japan manufactured by CRODA Japan. PRIAMINE 1074 (trade name), CRODA Japan's PRIAMINE 1075 (trade name), Cognis Japan's Versamine 551 (trade name), Versamine 552 (trade name) manufactured by Cognis Japan, etc.

In addition, the thermoplastic polyimide forming the adhesive layer is preferably contained in the range of 1 mole part or more and 50 mole parts or less in total with respect to 100 mole parts of all diamine components. The diamine residue derived from at least one diamine compound among the diamine compounds represented by (B1) to general formula (B7) is more preferably contained in the range of 1 mole part or more and 20 mole parts or less. Since the diamine compound represented by the general formula (B1) to the general formula (B7) contains a molecular structure having flexibility, the use of at least one diamine compound selected from these within the range can improve the polymerization The flexibility of the imidate molecular chain imparts thermoplasticity. If the total amount of diamine (B1) to diamine (B7) exceeds 50 mol parts with respect to 100 mol parts of all diamine components, the solvent solubility of polyimide may become low, if it is less than 1 In the case of moles, the flexibility of the polyimide is insufficient, and the workability at high temperatures sometimes decreases.

[化6]

In formula (B1) to formula (B7), R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents a group selected from -O-, -S-, -CO-, -SO-, -SO ₂ -, -COO-, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or -CONH-, a divalent group, n ₁ independently represents an integer of 0 to 4 . Among them, the part that repeats with the formula (B2) is removed from the formula (B3), and the part that repeats with the formula (B4) is removed from the formula (B5). Furthermore, in formula (B1) to formula (B7), the hydrogen atoms in the two amino groups at the terminal may be substituted, for example, it may be -NR ₂ R ₃ (here, R ₂ and R ₃ independently mean an alkyl group Etc.).

The diamine represented by formula (B1) (hereinafter sometimes referred to as "diamine (B1)") is an aromatic diamine having two benzene rings. It is believed that the diamine (B1) is in the meta position by the amino group directly bonded to at least one benzene ring and the divalent linking group A, while the polyimide molecular chain has increased degrees of freedom and has high flexibility , Thereby contributing to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B1), the thermoplasticity of polyimide is improved. Here, the linking group A is preferably -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -CO-, -SO ₂ -, -S-, -COO-.

Examples of the diamine (B1) include 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenylpropane, 3,3′-diaminodiphenylsulfide, and 3, 3'-diaminodiphenyl ether, 3,3-diaminodiphenyl ether, 3,4-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 3,4'-di Aminodiphenylpropane, 3,4'-diaminodiphenylsulfide, 3,3'-diaminobenzophenone, (3,3'-bisamino)diphenylamine, etc.

The diamine represented by the formula (B2) (hereinafter sometimes referred to as "diamine (B2)") is an aromatic diamine having three benzene rings. It is believed that the diamine (B2) is located in the meta position by the amino group directly bonded to at least one benzene ring and the divalent linking group A, while the polyimide molecular chain has increased degrees of freedom and has high flexibility , Thereby contributing to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B2), the thermoplasticity of polyimide is improved. Here, the linking group A is preferably -O-.

Examples of the diamine (B2) include 1,4-bis(3-aminophenoxy)benzene, 3-[4-(4-aminophenoxy)phenoxy]aniline, and 3-[3- (4-Aminophenoxy)phenoxy]aniline and the like.

The diamine represented by the formula (B3) (hereinafter sometimes referred to as "diamine (B3)") is an aromatic diamine having three benzene rings. It is believed that the diamine (B3) is in a meta position with two divalent linking groups A directly bonded to a benzene ring, and the polyimide molecular chain has increased degrees of freedom and high flexibility , Thereby contributing to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B3), the thermoplasticity of polyimide is improved. Here, the linking group A is preferably -O-.

Examples of the diamine (B3) include 1,3-bis(4-aminophenoxy)benzene (TPE-R), 1,3-bis(3-aminophenoxy)benzene (APB), 4 ,4-[2-methyl-(1,3-phenylene)bisoxy]bisaniline, 4,4-[4-methyl-(1,3-phenylene)bisoxy]bisaniline , 4,4-[5-methyl-(1,3-phenylene) bisoxy] bisaniline and so on.

The diamine represented by formula (B4) (hereinafter sometimes referred to as "diamine (B4)") is an aromatic diamine having four benzene rings. It is believed that the diamine (B4) has a high flexibility by the amino group directly bonded to at least one benzene ring and the divalent linking group A, thereby contributing to the flexibility of the molecular chain of the polyimide Improvement. Therefore, by using diamine (B4), the thermoplasticity of polyimide is improved. Here, the linking group A is preferably -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ -, -CO-, and -CONH-.

Examples of the diamine (B4) include bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]propane, and bis[4-(3 -Aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]shen, bis[4-(3-aminophenoxy)]benzophenone, bis[4, 4-(3-Aminophenoxy)] aniline and the like.

The diamine represented by formula (B5) (hereinafter sometimes referred to as "diamine (B5)") is an aromatic diamine having four benzene rings. It is believed that the diamine (B5) is located in the meta position with two divalent linking groups A directly bonded to at least one benzene ring, and the polyimide molecular chain has increased degrees of freedom and high bending Properties, thereby contributing to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B5), the thermoplasticity of polyimide is improved. Here, the linking group A is preferably -O-.

Examples of the diamine (B5) include 4-[3-[4-(4-aminophenoxy)phenoxy]phenoxy]aniline, 4,4'-[oxybis(3,1-sub Phenyloxy)] bisaniline and so on.

The diamine represented by formula (B6) (hereinafter sometimes referred to as "diamine (B6)") is an aromatic diamine having four benzene rings. It is considered that the diamine (B6) has high flexibility by having at least two ether bonds, and thus contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B6), the thermoplasticity of polyimide is improved. Here, the linking group A is preferably -C(CH ₃ ) ₂ -, -O-, -SO ₂ -, and -CO-.

Examples of the diamine (B6) include 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) and bis[4-(4-aminophenoxy)phenyl] Ether (BAPE), bis[4-(4-aminophenoxy)phenyl] sulfone (BAPS), bis[4-(4-aminophenoxy)phenyl] ketone (BAPK), etc.

The diamine represented by the formula (B7) (hereinafter sometimes referred to as "diamine (B7)") is an aromatic diamine having four benzene rings. It is considered that the diamine (B7) has a highly flexible divalent linking group A on both sides of the diphenyl skeleton, and thus contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B7), the thermoplasticity of polyimide is improved. Here, the linking group A is preferably -O-.

Examples of the diamine (B7) include bis[4-(3-aminophenoxy)]biphenyl and bis[4-(4-aminophenoxy)]biphenyl.

The thermoplastic polyimide forming the adhesive layer may contain diamine residues derived from the diamine acid diamine and diamine compounds other than diamine (B1) to diamine (B7) within the range that does not impair the effect of the invention. base. Examples of the diamine residue derived from the diamine acid diamine and diamine compounds other than diamine (B1) to diamine (B7) include non-thermoplastic polyacrylic acid that constitutes the insulating resin layer Residues of the diamine compound exemplified as the diamine compound used in the non-thermoplastic polyimide of the amine layer.

When the types of the tetracarboxylic acid residues and diamine residues are selected in the thermoplastic polyimide forming the adhesive layer, or when two or more kinds of tetracarboxylic acid residues or diamine residues are applied, The molar ratio can control the thermal expansion coefficient, tensile elastic modulus, glass transition temperature, etc. In addition, when the thermoplastic polyimide has a plurality of structural units of polyimide, it may be present in the form of a block or may be present randomly, and is preferably present randomly.

The concentration of the amide imide group of the thermoplastic polyimide is preferably 33% by weight or less. Here, the "acid imide group concentration" refers to a value obtained by dividing the molecular weight of the imide group portion (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. . If the concentration of the amide imide group exceeds 33% by weight, the molecular weight of the resin itself becomes small, and the low hygroscopicity also deteriorates due to the increase in polar groups. In this embodiment, by selecting the combination of the diamine compounds to control the orientation of the molecules in the thermoplastic polyimide, the increase in CTE accompanying the decrease in the concentration of the amide imide group is suppressed, thereby ensuring low moisture absorption . In addition, if the hygroscopicity of the polyimide becomes high, it is the main cause of the deterioration of the dielectric properties of the polyimide film. Therefore, ensuring low hygroscopicity can prevent the increase in dielectric constant and dielectric loss tangent. It is therefore preferred.

The weight average molecular weight of the thermoplastic polyimide is, for example, preferably in the range of 10,000 to 400,000, and more preferably in the range of 20,000 to 350,000. If the weight-average molecular weight is less than 10,000, the strength of the adhesive layer will decrease and it will tend to be brittle. On the other hand, if the weight average molecular weight exceeds 400,000, the viscosity is excessively increased, and there is a tendency for defects such as uneven thickness of the adhesive layer and streaks to easily occur during the coating operation.

The thermoplastic polyimide forming the adhesive layer is interposed between, for example, the insulating resin layer and the wiring layer of the circuit board. Therefore, in order to suppress the diffusion of copper, the most fully imidized structure is most preferred. Among them, a part of polyimide can also be amide acid. Regarding its imidate ratio, a Fourier transform infrared spectrophotometer (commercially available product: FT/IR620 manufactured by Nippon Spectroscopy) and primary reflection ATR (Attenuated Total Reflectance) can be used The infrared absorption spectrum of the polyimide film was measured by the method, and it was calculated based on the benzene ring absorber in the vicinity of 1015 cm ^-1 and based on the absorbance of 1780 cm ^-1 C=O expansion and contraction derived from the amide imide group.

(Cross-linked formation) When the thermoplastic polyimide forming the adhesive layer has a ketone group, the ketone group reacts with an amino group of an amino compound having at least two primary amino groups as functional groups to form a C=N bond , Thereby forming a cross-linked structure. By forming a cross-linked structure, the heat resistance of the thermoplastic polyimide forming the adhesive layer can be improved. Examples of preferred tetracarboxylic anhydrides for forming a thermoplastic polyimide having a ketone group include 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), and preferred diamine compounds are, for example. Examples include 4,4'-bis(3-aminophenoxy)benzophenone (BABP), 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene (BABB), etc. Aromatic diamine.

Examples of the amino compound that can be used for crosslinking of the thermoplastic polyimide forming the adhesive layer include dihydrazine compounds, aromatic diamines, and aliphatic amines. Among these, dihydrazide compounds are preferred. Compared with the case of using other amino compounds, the dihydrazide compound can shorten the hardening time after crosslinking. As the dihydrazide compound, for example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide are preferred , Suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide Hydrazine, dihydrazide tartrate, dihydrazide malate, dihydrazide phthalate, dihydrazide isophthalate, dihydrazide terephthalate, 2,6-naphthoic acid dihydrazide, 4, 4-Diphenylhydrazine, 1,4-naphthoic acid dihydrazide, 2,6-pyridinedicarboxylic acid dihydrazide, itaconic acid dihydrazide and other dihydrazide compounds. The above dihydrazide compounds may be used alone or in combination of two or more.

<Manufacture of Adhesive Layer> The thermoplastic polyimide forming the adhesive layer can be produced by reacting the tetracarboxylic dianhydride and the diamine compound in a solvent to form polyamic acid, and then heating and ring-closing . For example, the tetracarboxylic dianhydride and the diamine compound are dissolved in an organic solvent at approximately the same molarity, and stirred at a temperature in the range of 0°C to 100°C for 30 minutes to 24 hours to perform a polymerization reaction, thereby obtaining as Polyamide, the precursor of polyimide. During the reaction, the reaction component is dissolved so that the produced precursor is in the range of 5% to 50% by weight in the organic solvent, preferably in the range of 10% to 40% by weight. Examples of the organic solvent used in the polymerization reaction include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N,N-diethylacetamide. Amine, N-methyl-2-pyrrolidone (NMP), 2-butanone, dimethyl sulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclic Hexanone, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), cresol, etc. Two or more of these solvents may be used in combination, and aromatic hydrocarbons such as xylene and toluene may be used in combination. In addition, the amount of use of such an organic solvent is not particularly limited, but it is preferably adjusted to a concentration of 5 to 50% by weight of the polyamide solution obtained by the polymerization reaction.

The synthesized polyamic acid is usually advantageously used as a reaction solvent solution, and may be concentrated, diluted or replaced with other organic solvents as necessary. In addition, polyamic acid is generally excellent in solvent solubility, so it is advantageously used. The viscosity of the solution of polyamic acid is preferably in the range of 500 cps to 100,000 cps. If it deviates from the above range, defects such as uneven thickness and streaks may easily occur in the film during the coating operation by a coating machine or the like.

The method for forming the thermoplastic polyimide by imidizing the polyimide to form a thermoplastic polyimide is not particularly limited. For example, temperature conditions in the range of 80°C to 400°C in the solvent can be suitably used for 1 hour to 24 hours. Perform heat treatment.

When cross-linking the thermoplastic polyimide obtained as described above, the amino compound is added to a resin solution containing a thermoplastic polyimide having a ketone group, and the ketone in the thermoplastic polyimide is added The group undergoes a condensation reaction with the primary amino group of the amino compound. By the condensation reaction, the resin solution hardens to become a hardened product. In this case, the addition amount of the amino compound may be 0.004 moles to 1.5 moles, preferably 0.005 moles to 1.2 moles, more preferably 0.03 moles to a total of 1 mole of keto groups. The amino compound is added in a manner of 0.9 moles, most preferably 0.04 moles to 0.5 moles. The addition amount of the amino compound whose primary amino group is less than 0.004 mol in total with respect to 1 mol of the keto group is insufficient due to insufficient crosslinking of the thermoplastic polyimide using the amino compound, so there is a difficulty in showing the heat resistance of the adhesive layer after curing If the amount of the amino compound added exceeds 1.5 moles, the unreacted amino compound acts as a thermoplastic agent, and the heat resistance of the adhesive layer tends to decrease.

The conditions of the condensation reaction for crosslinking formation are not particularly limited if the ketone group in the thermoplastic polyimide reacts with the primary amino group of the amino compound to form an imine bond (C=N bond). Regarding the temperature of the heating condensation, for the reason that the water generated by the condensation is released out of the system, or the heating condensation reaction is carried out after the synthesis of the thermoplastic polyimide and the condensation step is simplified, etc. For example, it is preferably in the range of 120°C to 220°C, and more preferably in the range of 140°C to 200°C. The reaction time is preferably about 30 minutes to 24 hours. For example, the end point of the reaction can be measured by using a Fourier transform infrared spectrophotometer (commercially available product: FT/IR620 manufactured by Nippon Spectroscopy), using 1670 cm ⁻ The absorption peak derived from the ketone group in the polyimide resin in the vicinity of ¹ decreased or disappeared, and the absorption peak derived from the imine group in the vicinity of 1635 cm ^-1 appeared to be confirmed.

The heating and condensation of the ketone group of the thermoplastic polyimide and the primary amino group of the amino compound can be performed by, for example, the following method: (a) synthesis of the thermoplastic polyimide (amidation), followed by addition of the amino compound and heating Method; (b) Put an excess of amino compound as a diamine component in advance and synthesize (polyimidize) the thermoplastic polyimide, followed by the residual amino compound that has not participated in the amide imidization or amide imidization A method of heating the thermoplastic polyimide; or (c) after processing the composition of the thermoplastic polyimide added with an amino compound (the adhesive polyimide resin composition described later) into a predetermined shape (for example, coating On any substrate or after forming into a film) heating method.

(Thickness of Adhesive Layer) The thickness of the adhesive layer is, for example, preferably in the range of 0.1 μm to 100 μm, and more preferably in the range of 0.3 μm to 50 μm. In the three-layer metal-clad laminate of this embodiment, if the thickness of the adhesive layer is less than the lower limit, problems such as insufficient adhesiveness may not be guaranteed. On the other hand, if the thickness of the adhesive layer exceeds the upper limit, problems such as a decrease in dimensional stability may occur. In addition, from the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent of the entire insulating layer of the laminate of the insulating resin layer and the adhesive layer, the thickness of the adhesive layer is preferably 3 μm or more.

(CTE of adhesive layer) The thermoplastic polyimide forming the adhesive layer is highly thermally expandable, and the CTE is preferably 35 ppm/K or more, more preferably 35 ppm/K or more and 80 ppm/K or less, and It is preferably in the range of 35 ppm/K or more and 70 ppm/K or less. By appropriately changing the combination, thickness, drying and curing conditions of the raw materials used, a polyimide layer having a desired CTE can be produced.

(Dielectric loss tangent of the adhesive layer) When the adhesive layer is applied to a circuit board, for example, in order to suppress the deterioration of the dielectric loss, the dielectric loss tangent (Tanδ) at 10 GHz may be 0.004 or less, more preferably 0.001 or more and 0.004 or less, and more preferably 0.002 or more and 0.003 or less. If the dielectric loss tangent of the adhesive layer at 10 GHz exceeds 0.004, when it is used in a circuit board such as an FPC, it is easy to cause problems such as loss of electrical signals in the transmission path of high-frequency signals. On the other hand, the lower limit of the dielectric loss tangent of the adhesive layer at 10 GHz is not particularly limited.

(Dielectric Constant of Adhesive Layer) When the adhesive layer is applied as an insulating layer of a circuit board, for example, in order to ensure impedance matching, the dielectric constant at 10 GHz is preferably 4.0 or less. If the dielectric constant of the adhesive layer at 10 GHz exceeds 4.0, when it is used in a circuit board such as an FPC, the dielectric loss of the adhesive layer deteriorates, and an electrical signal is easily generated on the transmission path of the high-frequency signal Loss and other bad conditions.

(Filler) The adhesive layer may contain filler if necessary. 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 alone or in combination of two or more.

<Metal layer> The material of the metal layer in the metal-clad laminate of this embodiment is not particularly limited, and examples thereof include copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, and zirconium , Tantalum, titanium, lead, magnesium, manganese and their alloys. Among them, copper or copper alloy is particularly preferable. In addition, the material of the wiring layer in the circuit board of this embodiment described later is also the same as the metal layer.

The thickness of the metal layer is not particularly limited. For example, when copper foil is used as the metal layer, the thickness may be preferably 35 μm or less, and more preferably in the range of 5 μm to 25 μm. From the viewpoint 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 may be rolled copper foil or electrolytic copper foil. In addition, commercially available copper foil can also be used for copper foil.

(Anti-rust treatment) As the metal layer of this embodiment, when a copper foil is used, the copper foil preferably includes a base material copper foil and an adhesive layer (or insulation) formed in the base material copper foil Resin layer) forms a rust-proof treatment layer on the surface of the surface side. The rust prevention treatment can suppress the reduction in the bonding strength between the copper foil and the adhesive layer during the wiring process of the metal-clad laminate, and the resistance to the etching chemical solution. The base material copper foil may be any of electrolytic copper foil and rolled copper foil. The thickness of such a base material copper foil is not particularly limited as long as the thickness of the copper foil used in a general copper-clad laminate is in view of the flexibility of the copper-clad laminate, preferably 70 μm the following. If the thickness exceeds 70 μm, the use of the obtained copper-clad laminate is limited, which is not preferable. In addition, when a copper-clad laminate is used as the flexible copper-clad laminate, the thickness of the base material copper foil is preferably in the range of 5 μm to 35 μm. If the thickness of the base material copper foil is less than 5 μm, wrinkles or the like are likely to occur during manufacturing, and there is a tendency to cost a thin copper foil during manufacturing. On the other hand, if the thickness exceeds 35 μm, it is obtained by use In the case of a copper-clad laminate, there is an integrated circuit (IC) that drives a liquid crystal display that is a display part of a personal computer, mobile phone, or portable information terminal (PDA (Personal Digital Assistant)) Thinning or miniaturization of package substrates and the like tends to be insufficient.

From the viewpoint of improving the adhesion strength (peel strength) or chemical resistance between the copper foil and the adhesive layer, the base material copper foil is preferably a copper foil subjected to a roughening treatment on the surface . Further, from the viewpoints described above, and the viewpoints of reducing the bendability and conductor loss of the obtained copper-clad laminate, the ten-point average roughness (Rz) of the base material copper foil is preferably 1.5 μm or less, and more preferably It is in the range of 0.1 μm to 1.0 μm.

The anticorrosive treatment layer of the present invention is a layer having anticorrosive properties formed on the surface of the base material copper foil on the side where the adhesive layer is formed. In the present invention, by forming such a rust prevention treatment layer on the base material copper foil, sufficient rust resistance can be imparted to the base material copper foil, and the adhesion layer and the copper foil can be improved Bonding strength. The thickness of such a rust-preventive treatment layer is preferably in the range of 10 nm to 50 nm, for example. If the thickness is less than the lower limit, there is a tendency that the surface of the base metal copper foil cannot be uniformly covered, and it is difficult to obtain a sufficient rust prevention effect. The solubility (etchability) tends to be insufficient.

The anti-rust treatment layer preferably includes a plating treatment layer containing zinc and a chromate treatment layer. With regard to such a treatment layer, the surface of the base material copper foil is subjected to a plating treatment using a plating solution containing a zinc compound, thereby forming a zinc plating treatment layer, and further including a chromate treatment layer can further improve the prevention Rust effect and adhesion to the adhesive layer. The chromate treatment layer may be formed by performing immersion or electrolytic chromate treatment using a chromate treatment agent containing chromium oxide or the like on the surface of the rust prevention treatment layer.

In addition, the zinc content in the anti-rust treatment layer is preferably 0.01 mg/dm ² or more. If the zinc content is less than the lower limit, there is a tendency that the anticorrosive treatment layer has insufficient solubility (etchability) in the copper etchant, and the anticorrosive treatment layer is sticky due to thermal degradation during the production of the copper-clad laminate. The bonding strength between the bonding layer and the copper foil is insufficient. In addition, from the viewpoint of further improving the etchability of the rust prevention treatment layer and the adhesion strength between the adhesion layer and the copper foil, the zinc content is more preferably in the range of 0.01 mg/dm ² to 1.5 mg/dm ² .

Furthermore, metals other than zinc may be contained in the rust-preventive treatment layer. Examples of metals other than zinc include nickel, cobalt, and molybdenum. For example, the nickel content in the anti-rust treatment layer is preferably 0.1 mg/dm ² or more. If the nickel content is less than the lower limit, there is a tendency that the rust prevention effect on the surface of the copper foil is insufficient, and discoloration of the surface of the copper foil is likely to occur after heating or in a high temperature or high humidity environment. In addition, from the viewpoint of sufficiently preventing copper from the base material copper foil from diffusing to the rust-preventive treatment layer or the adhesion layer, the nickel content is more preferably in the range of 0.1 mg/dm ² to 3 mg/dm ² .

Nickel is an infinite proportional solid solution with respect to copper and can be made into an alloy state, or nickel is easily diffused with respect to copper and is easy to make into an alloy state. Compared with copper alone, this state has a larger resistance, in other words, the conductivity becomes smaller. According to this situation, if a large amount of nickel is contained in the rust prevention treatment layer, the resistance of copper alloyed with nickel increases. As a result, the resistance of the signal wiring utilizing surface effects increases and the loss during signal transmission becomes larger. From such a viewpoint, in the copper-clad laminate of the present embodiment, for example, in the case of a circuit board for performing high-frequency transmission of 10 GHz in the step, it is preferable to suppress the amount of nickel to 0.01 mg/ dm ² or less.

When the amount of nickel in the rust prevention treatment layer is suppressed to 0.01 mg/dm ² or less, it is preferable that the rust prevention treatment layer contains at least cobalt and molybdenum. Regarding such a rust-preventive treatment layer, nickel is preferably 0.01 mg/dm ² or less, cobalt is in the range of 0.01 mg/dm ² to 0.5 mg/dm ² and molybdenum is 0.01 mg/dm ² to 0.5 mg/dm ² Within the range of 0.1 mg/dm ² to 0.7 mg/dm ² and the total amount of cobalt and molybdenum elements (Co+Mo) is controlled. By setting within such a range, the etching residue of the resin portion between the wirings during the wiring process of the copper-clad laminate can be suppressed, the resistance to etching chemical liquid can be suppressed from being reduced, and the copper foil and the resin can be suppressed. Reduced bonding strength and long-term reliability.

In addition, the copper foil used in the copper-clad laminate according to the present embodiment may be subjected to, for example, an exterior board (siding) or aluminum alcoholization on the surface of the copper foil for the purpose of improving adhesion in addition to the above-mentioned rust prevention treatment. Surface treatment of metal, aluminum chelate, silane coupling agent, etc.

<Manufacturing method of metal-clad laminate> The metal-clad laminate can be prepared, for example, by preparing a resin film laminated with an adhesive layer and an insulating resin layer, and sputtering a metal on the adhesive layer side to form a seed layer Then, a metal layer is formed by, for example, plating.

In addition, the metal-clad laminate can be prepared by preparing a resin film laminated with an adhesive layer and an insulating resin layer, and laminating metal foil such as copper foil on the adhesive layer side by a method such as thermocompression bonding.

Furthermore, the metal-clad laminate can be prepared by casting a coating solution for forming an adhesive layer on a metal foil such as copper foil, drying it, forming a coating film, and casting the coating film The coating liquid for forming the insulating resin layer is dried to form a coating film, and then heat-treated in batches. In this case, as the coating liquid for forming the adhesive layer, an adhesive polyimide resin composition (described later) or a polyimide as a precursor of the thermoplastic polyimide forming the adhesive layer can be used Amino acid solution. In addition, the thermoplastic polyimide forming the adhesive layer can be formed by crosslinking by the above method.

[Circuit board] The metal-clad laminate of this embodiment is mainly useful as a circuit board material such as an FPC and a rigid-flex circuit board. That is, the metal layer of the metal-clad laminate according to this embodiment can be processed into a pattern to form a wiring layer by a common method, thereby manufacturing an FPC according to an embodiment of the present invention.

[Adhesive sheet] The adhesive sheet of the present embodiment is an adhesive layer having an insulating resin layer, a layer laminated on at least one side of the insulating resin layer, and is laminated on the substrate via the adhesive layer The adhesive sheet for forming the adhesive layer in the metal-clad laminate of the metal layer on the insulating resin layer. The adhesive sheet is formed by forming the thermoplastic polyimide forming the adhesive layer into a sheet shape. That is, the thermoplastic polyimide forming the adhesive sheet contains a predetermined amount of tetracarboxylic acid residues and diamine residues as in the adhesive layer.

The adhesive sheet may be in a state of being laminated on any base material such as copper foil, glass plate, polyimide-based film, polyamide-based film, and polyester-based film. The thickness, thermal expansion coefficient, dielectric loss tangent, and dielectric constant of the adhesive sheet are based on the adhesive layer. In addition, the adhesive sheet may contain arbitrary components such as fillers.

Examples of the method of manufacturing the adhesive sheet of the present embodiment include: [1] A support substrate is coated with a solution of polyamic acid, dried, and heat-treated to be imidized, and then the self-supporting substrate The method of peeling off and manufacturing the adhesive sheet; [2] After applying the solution of polyamic acid to the supporting substrate and drying it, peeling off the gel film of polyamic acid from the supporting substrate, and performing heat treatment Amination to produce an adhesive sheet; [3] Applying a solution of an adhesive polyimide resin composition (described later) to a supporting substrate and drying it, peeling off the supporting substrate to produce an adhesive sheet Methods. Furthermore, the thermoplastic polyimide constituting the adhesive sheet can be formed by crosslinking by the above method.

The method of applying the polyimide solution (or polyamic acid solution) on the supporting substrate is not particularly limited, and for example, it can be applied by a coating machine such as a corner wheel, die, blade, die lip, or the like. The manufactured adhesive sheet is preferably formed by applying a polyimide solution that has been subjected to imidization in a polyamic acid solution to a supporting base material and drying it. The polyimide of the present embodiment is soluble in a solvent. Therefore, polyimide can be imidized in a solution state and used directly as a coating solution of polyimide, which is advantageous.

The adhesive sheet obtained as described above has excellent flexibility and dielectric properties (low dielectric constant and low dielectric loss tangent) when it is used to form an adhesive layer of a circuit board, for example, as FPC, An adhesive layer such as a rigid flexible circuit board has preferable characteristics.

[Adhesive Polyimide Resin Composition] The adhesive polyimide resin composition of this embodiment is adhered to a surface having an insulating resin layer and laminated on at least one side of the insulating resin layer A layer and a metal-clad laminate laminated on the insulating resin layer via the adhesion layer to form the adhesion layer. The adhesive polyimide resin composition contains a polyimide containing a tetracarboxylic acid residue and a diamine residue, and is more than 50 mol parts relative to 100 mol parts of the diamine residue. For example, in the range of 50 mol parts or more and 99 mol parts or less, preferably 80 mol parts or more, for example, 80 mol parts or more and 99 mol parts or less, the two terminal carboxylic acids composed of dimer acid are contained A diamine residue derived from a dimer acid diamine formed by substitution of a primary aminomethyl group or an amino group, and containing more than 90 mole parts from 100 mole parts of the tetracarboxylic acid residue The tetracarboxylic acid residue derived from the tetracarboxylic anhydride represented by the general formula (1) and/or general formula (2).

In addition, the adhesive polyimide resin composition preferably contains two selected from the general formula (B1) to the general formula (B7) in the range of 1 mol or more and 50 mol or less. A diamine residue derived from at least one diamine compound in the amine compound.

The adhesive polyimide resin composition of this embodiment is solvent-soluble and may contain an organic solvent as an optional component. Preferred organic solvents include, for example, N,N-dimethylformamide, N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, 2-butanone, dimethanone Methyl sulfoxide, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, etc. These solvents may be used in combination of two or more kinds, and in addition, aromatic hydrocarbons such as xylene and toluene may be used in combination.

The adhesive polyimide resin composition of this embodiment can be further suitably formulated with an amino compound, inorganic filler, plasticizer, epoxy resin, etc. having at least two primary amino groups used as functional groups in the crosslink formation Other resin components, hardening accelerators, coupling agents, fillers, pigments, solvents, flame retardants, etc. are other optional components.

The adhesive polyimide resin composition obtained as described above has excellent flexibility and dielectric properties (low dielectric constant and low dielectric) when it is used to form an adhesive layer or adhesive sheet Loss tangent), for example, can be preferably used as a material for forming an adhesive layer such as an FPC or a rigid-flex circuit board.

[Examples] Hereinafter, the present invention will be described more specifically using examples, but the present invention is not limited by these examples. In the following examples, unless otherwise specified, various measurements and evaluations are in accordance with the following.

[Measurement of Thermal Expansion Coefficient (CTE)] A polyimide film with a size of 3 mm×20 mm was used with a thermomechanical analyzer (manufactured by Bruker, trade name: 4000SA), and a constant load was applied while applying a load of 5.0 g. The temperature rising rate was increased from 30°C to 300°C, and after maintaining at the temperature for 10 minutes, cooling was performed at a rate of 5°C/min to obtain the average coefficient of thermal expansion (coefficient of thermal expansion) from 250°C to 100°C.

[Measurement of Surface Roughness of Copper Foil] The surface roughness of copper foil was manufactured using Atomic Force Microscope (AFM) (Bruker AXS), trade name: Dimension Icon Needle microscope (Scanning Probe Microscope, SPM), probe (made by Bruker AXS (Bruker AXS), trade name: TESPA (NCHV), tip radius of curvature 10 nm, spring constant 42 N/m), in tap mode ( tapping mode) The range of 80 μm×80 μm on the surface of the copper foil is measured, and the ten-point average roughness (Rzjis) is determined.

[Measurement of metal elements on the surface of copper foil subjected to metal precipitation treatment] After masking the back surface of the analysis surface of the copper foil, the analysis surface was dissolved with 1N-nitric acid, and the volume was fixed to 100 mL, using platinum Elmer (PerkinElmer ) The company's inductively coupled plasma luminescence spectrometer (inductively coupled plasma atomic emission spectrometer (inductively coupled plasma atomic emission spectrometer (ICP-AES))) Optima (Optima) 4300 for measurement.

[Evaluation method of warpage] The evaluation of warpage was performed by the following method. The 10 cm×10 cm film was placed, and the average height of the four corners of the film was measured, and “10” or less was considered “good”, and “10” or more was considered “impossible”.

[Measurement of Dielectric Constant (Dk) and Dielectric Loss Tangent (Df)] Dielectric constant and dielectric loss tangent were measured using a cavity resonator perturbation method permittivity evaluation device (manufactured by Agilent, trade name) : Vector Network Analyzer (E8363C) and split post dielectric resonator (SPDR resonator), measuring resin sheets at a frequency of 10 GHz (or laminated resin sheets on insulating resin layers Insulation layer) dielectric constant and dielectric loss tangent. In addition, the resin sheet (or the insulating layer which laminated|stacked the resin sheet to the insulating resin layer) used for measurement was left for 24 hours under the conditions of temperature: 24 degreeC-26 degreeC, and humidity: 45%-55%.

[Evaluation method of laser processability] Evaluation of laser processability was performed by the following method. Bottom through-hole processing was carried out by irradiating UV-YAG and third-harmonic 355 nm laser light at a frequency of 60 kHz and an intensity of 1.0 W, and the case where no depression or undercut was generated in the adhesive layer was evaluated as "Possible", and evaluation of the occurrence of depressions or undercuts in the adhesive layer as "impossible".

[Measurement of Peel Strength] The measurement of peel strength is performed by the following method. The measurement was performed using a tensile tester (manufactured by Toyo Seiki Co., Ltd., Strograph VE) on an insulating resin layer with a test piece width of 5 mm at a speed of 50 mm/min in the direction of 90° of the adhesive layer. Peel strength during stretching. In addition, a peel strength of 0.9 kN/m or more was evaluated as "good", a peel strength of 0.4 kN/m or more and less than 0.9 kN/m was evaluated as "OK", and a peel strength of less than 0.4 kN/m was evaluated as " Not possible".

The abbreviations used in this example indicate the following compounds. BTDA: 3,3',4,4'-benzophenone tetracarboxylic dianhydride BPDA: 3,3',4,4'-diphenyltetracarboxylic dianhydride 6FDA: 4,4'-(six Fluoroisopropylidene) diphthalic anhydride BPADA: 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride PMDA: pyromellitic dianhydride APB: 1 ,3-bis(3-aminophenoxy)benzene BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl]propane DDA: aliphatic diamine with 36 carbon atoms (Japan Heda ( Made by CRODA Japan Co., Ltd., trade name: PRIAMINE 1074, amine value: 210 mgKOH/g, mixture of dimer diamine with ring structure and chain structure, content of dimer component : 95% by weight or more) m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl ODPA: 4,4'-oxydiphthalic anhydride (alias: 5,5' -Oxybis-1,3-isobenzofurandione) N-12: dodecanedioic acid dihydrazide NMP: N-methyl-2-pyrrolidone DMAc: N,N-dimethylacetamide

(Synthesis Example 1) <Preparation of resin solution for adhesive layer> In a 1000 ml separable flask, 56.18 g of BTDA (0.174 mol), 93.82 g of DDA (0.176 mol), 210 g of NMP and 140 g of xylene were mixed well at 40°C for 1 hour to prepare a polyamic acid solution. The polyamic acid solution was heated to 190°C, heated and stirred for 4 hours, and 140 g of xylene was added to prepare a polyimide solution 1 (solid content: 30% by weight, viscosity: 5,100) cps, weight average molecular weight: 66,100).

(Synthesis Example 2 to Synthesis Example 10) <Preparation of resin solution for adhesive layer> Polyimide solution 2 to polyimide were prepared in the same manner as in Synthesis Example 1 except that the raw material composition shown in Table 1 was used. Solution 10.

[Table 1]

(Synthesis Example 11) <Preparation of resin solution for adhesive layer> 1.1 g of N-12 (0.004) was prepared for 100 g (30 g in terms of solid content) of the polyimide solution 1 prepared in Synthesis Example 1 Mohr), and add and dilute 0.1 g of NMP and 10 g of xylene, and further stir for 1 hour, thereby preparing polyimide solution 11.

(Synthesis Example 12 to Synthesis Example 17) <Preparation of Resin Solution for Adhesive Layer> A polyimide solution 5 to a polyimide solution 10 shown in Table 2 were used to prepare a polymer in the same manner as Synthesis Example 11. Amidimide solution 12 ~ polyimide solution 17.

[Table 2]

(Synthesis Example 18) <Preparation of polyimide film for insulating resin layer> Under a nitrogen gas flow, 2.196 g of DDA (0.0041 mole) and 16.367 g of m-TB were put into a 300 ml separable flask (0.0771 mol) and 212.5 g of DMAc, and stirred and dissolved at room temperature. Secondly, after adding 4.776 g of BPDA (0.0162 mol) and 14.161 g of PMDA (0.0649 mol), stirring was continued at room temperature for 3 hours and polymerization was performed to prepare a polyamic acid solution P (viscosity: 26,000 cps ).

After the polyamic acid solution P was uniformly applied to the copper foil (surface roughness Rz: 2.1 μm) so that the thickness after hardening was about 25 μm, the solvent was removed by heating and drying at 120°C. Furthermore, a stepwise heat treatment is performed from 120°C to 360°C, and the imidization is completed to prepare the metal-clad laminate P. The metal foil laminate P was etched and removed using an aqueous solution of ferric chloride to prepare a polyimide film P (CTE: 20 ppm/K, DK: 2.95, Df: 0.0041).

(Preparation Example 1) <Preparation of resin sheet for adhesive layer> Polyimide solution 1 was applied to one side of a polyethylene terephthalate (PET) film subjected to release treatment, And after drying at 80 degreeC for 15 minutes, it peeled off and the resin sheet 1a (thickness: 25 micrometers) was prepared. Table 3 shows the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 1a.

(Preparation Example 2 to Preparation Example 7) <Preparation of Resin Sheet for Adhesive Layer> Using Polyimide Solution 1 and in the same manner as Preparation Example 1, Resin Sheet 1b to Resin Sheet 1g were prepared with the thickness of the resin sheet changed. Table 3 shows the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 1b to the resin sheet 1g.

[table 3]

(Production Example 8 to Production Example 16) <Preparation of Resin Sheet for Adhesive Layer> A resin sheet 2a to a thickness of 25 μm was prepared in the same manner as in Production Example 1 except that the polyimide solution shown in Table 4 was used. Resin sheet 10a. The dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 2a to the resin sheet 10a are shown in Table 4.

[Table 4]

(Preparation Example 17) <Preparation of copper foil with rust prevention treatment> Prepare an electrolytic copper foil (thickness: 12 μm, MD direction (longitudinal direction (Machine Direction); flow direction of long copper foil) on the resin layer side) Roughness Rz: 0.3 μm). After roughening the surface of the copper foil, a plating treatment (metal precipitation treatment) containing a predetermined amount of cobalt and molybdenum is performed, followed by galvanizing and chromate treatment in this order to prepare copper foil 1 (Ni: 0.01 mg/dm ² or less, Co: 0.23 mg/dm ² , Mo: 0.36 mg/dm ² , Zn: 0.11 mg/dm ² , Cr: 0.14 mg/dm ² ).

[Example 1] A resin sheet 1a (thickness: 25 μm, Dk: 2.4, Df: 0.0020) was placed on a copper foil 1 (surface roughness Rz: 0.3 μm), and a polyimide film 1 was laminated thereon (Toray dupont), trade name: Kapton EN-S, thickness: 25 μm, CTE: 16 ppm/K, Dk: 3.79, Df: 0.0126), at a temperature of 170 The vacuum lamination was performed under the conditions of 0° C., a pressure of 0.85 MPa, and a time of 1 minute, and then heated in an oven at a temperature of 160° C. and a time of 1 hour to prepare a copper-clad laminate 1. The evaluation results of the copper-clad laminate 1 are shown in Table 5.

[Example 2] A copper-clad laminate 2 was prepared in the same manner as in Example 1 except that 1 g of resin sheet (thickness: 50 μm, Dk: 2.4, Df: 0.0020) was used instead of the resin sheet 1a. The evaluation results of the copper-clad laminate 2 are shown in Table 5.

[Example 3] A resin sheet 1g was used instead of the resin sheet 1a, and a liquid crystal polymer film 3 was used instead of the polyimide film 1 (manufactured by KURARAY), trade name: CT-Z, thickness: 50 μm , CTE: 18 ppm/K, Dk: 3.40, Df: 0.0022), except that the copper-clad laminate 3 was prepared in the same manner as in Example 1. The evaluation results of the copper-clad laminate 3 are shown in Table 5.

Table 5 summarizes the results of Examples 1 to 3.

[table 5]

[Example 4] Polyimide solution 1 was coated on one side of the polyimide film P prepared in Synthesis Example 18, and dried at 80°C for 15 minutes to prepare an insulating film 4 (thickness of the adhesive layer) : 3 μm). Vacuum lamination was carried out under the conditions of a temperature of 170° C., a pressure of 0.85 MPa, and a time of 1 minute in a state where the adhesion layer of the insulating film 4 was superimposed on the rust-proof surface of the copper foil 1, and then, in an oven Heating was carried out under conditions of a temperature of 160° C. and a time of 1 hour, thereby preparing a copper-clad laminate 4. The evaluation results of the copper-clad laminate 4 are shown in Table 6.

[Example 5] A copper-clad laminate 5 was prepared in the same manner as in Example 4 except that the thickness of the adhesive layer was 1 μm. The evaluation results of the copper-clad laminate 5 are shown in Table 6.

[Example 6] A copper-clad laminate 6 was prepared in the same manner as in Example 4 except that the thickness of the adhesive layer was 0.3 μm. Table 6 shows the evaluation results of the copper-clad laminate 6.

Table 6 summarizes the results of Examples 4 to 6.

[Table 6]

[Example 7] Polyimide solution 1 was coated on the polyimide film surface of the copper-clad laminate 4 prepared in Example 4, and dried at 80°C for 15 minutes, and the thickness of the adhesive layer It was set to 3 μm, and then the rust-proof surface of the copper foil 1 was superimposed on the adhesion layer, and vacuum lamination was performed under the conditions of a temperature of 170° C., a pressure of 0.85 MPa, and a time of 1 minute, and then, in an oven Heating was performed at a temperature of 160° C. for a period of 1 hour to prepare a copper-clad laminate 7. The evaluation results of the copper-clad laminate 7 are shown in Table 7.

[Example 8] A copper-clad laminate 8 was prepared in the same manner as in Example 7 except that the thickness of the adhesive layer was 1 μm. The evaluation results of the copper-clad laminate 8 are shown in Table 7.

[Example 9] A copper-clad laminate 9 was prepared in the same manner as in Example 7 except that the thickness of the adhesive layer was 0.3 μm. The evaluation results of the copper-clad laminate 9 are shown in Table 7.

Table 7 summarizes the results of Examples 7 to 9.

[Table 7]

[Example 10] The polyimide solution 1 was coated on one side of the polyimide film 1 and dried at 80°C for 15 minutes to prepare an insulating film 5 (thickness of adhesive layer: 12 μm). Vacuum lamination was performed under the condition of a temperature of 170° C., a pressure of 0.85 MPa, and a time of 1 minute with the adhesion layer of the insulating film 5 superimposed on the rust-proof surface of the copper foil 1, and then, in an oven Heating was performed under the conditions of a temperature of 160° C. and a time of 1 hour, thereby preparing a copper-clad laminate 10. The evaluation results of the copper-clad laminate 10 are shown in Table 8.

[Example 11] Polyimide solution 1 was coated on the rust-proof surface side of copper foil 1, and dried at 80°C for 15 minutes to prepare copper foil-attached film 6 (adhesion layer thickness: 5 μm) ). The bonding layer of the film 6 with copper foil and the polyimide film 2 (manufactured by Toray Dupont), trade name: Kapton EN, thickness: 5 μm, CTE: 16 ppm /K, Dk: 3.70, Df: 0.0076) In a superimposed state, vacuum lamination was carried out under the conditions of a temperature of 170° C., a pressure of 0.85 MPa, and a time of 1 minute. Thereafter, the temperature was 160° C. for 1 hour in an oven. Heating is carried out under conditions to prepare the copper-clad laminate 11. The evaluation results of the copper-clad laminate 11 are shown in Table 8.

[Example 12] A polyimide solution 13 was coated on the polyimide film surface of the copper-clad laminate 4 prepared in Example 4, and dried at 80°C for 15 minutes, and the thickness of the adhesive layer It was set to 25 μm, and then the rust-proof surface of the copper foil 1 was superimposed on the adhesion layer, and vacuum lamination was performed under the conditions of a temperature of 170° C., a pressure of 0.85 MPa, and a time of 1 minute, and then, in an oven Heating was carried out at a temperature of 160° C. for a period of 1 hour to prepare a copper-clad laminate 12. The evaluation results of the copper-clad laminate 12 are shown in Table 8.

[Example 13] A polyimide solution 16 was coated on the polyimide film surface of the copper-clad laminate 4 prepared in Example 4, and dried at 80°C for 15 minutes, and the thickness of the adhesive layer It was set to 25 μm, and then the rust-proof surface of the copper foil 1 was superimposed on the adhesion layer, and vacuum lamination was performed under the conditions of a temperature of 170° C., a pressure of 0.85 MPa, and a time of 1 minute, and then, in an oven Heating was carried out at a temperature of 160° C. for a period of 1 hour to prepare a copper-clad laminate 13. The evaluation results of the copper-clad laminate 13 are shown in Table 8.

[Table 8]

(Synthesis Example 19 to Synthesis Example 21) <Preparation of Resin Solution for Adhesive Layer> A polyimide solution 19 to polyimide was prepared in the same manner as in Synthesis Example 1 except that the raw material composition shown in Table 9 was used. Solution 21.

[Table 9]

(Production Example 18 to Production Example 20) <Preparation of Resin Sheet for Adhesive Layer> A resin sheet 18a to a thickness of 25 μm was prepared in the same manner as in Production Example 1, except that the polyimide solution shown in Table 10 was used. Resin sheet 20a. Table 10 shows the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 18a to the resin sheet 20a.

[Table 10]

(Comparative Example 1) A polyimide solution 19 was coated on one side of the polyimide film 1 and dried at 80°C for 15 minutes to prepare an insulating film 7 (thickness of adhesive layer: 12 μm). Vacuum lamination was performed under the conditions of a temperature of 170° C., a pressure of 0.85 MPa, and a time of 1 minute in a state where the adhesion layer of the insulating film 7 was superimposed on the rust-proof surface of the copper foil 1, and then, in an oven Heating was carried out under conditions of a temperature of 160° C. and a time of 1 hour, thereby preparing a copper-clad laminate 18. The evaluation results of the copper-clad laminate 18 are shown in Table 11.

(Comparative Example 2) A copper-clad laminate 19 was prepared in the same manner as Comparative Example 1, except that the polyimide solution 20 was used. The evaluation results of the copper-clad laminate 19 are shown in Table 11.

(Comparative Example 3) A copper-clad laminate 20 was prepared in the same manner as Comparative Example 1, except that the polyimide solution 21 was used. The evaluation results of the copper-clad laminate 20 are shown in Table 11.

[Table 11]

In the above, the embodiment of the present invention has been described in detail for the purpose of illustration, but the present invention is not restricted by the above-mentioned embodiment, and various modifications can be made.

Claims (11)

A metal-clad laminate having an insulating resin layer, an adhesive layer laminated on at least one side of the insulating resin layer, and a metal laminated on the insulating resin layer via the adhesive layer Layer, the metal-clad laminate is characterized in that the adhesive layer has a polyimide containing a tetracarboxylic acid residue and a diamine residue, and the polyimide relative to the diamine residue It contains 100 mol parts and contains 50 mol parts or more of diamine residues derived from a dimer acid type diamine in which two terminal carboxylic acid groups of the dimer acid are substituted with primary aminomethyl groups or amino groups. The metal-clad laminate as described in item 1 of the patent application range, wherein the polyimide contains a total of 90 mole parts or more based on 100 mole parts of the tetracarboxylic acid residues by the following general formula (1) and/or the tetracarboxylic acid residue derived from the tetracarboxylic anhydride represented by the general formula (2),

In the general formula (1), X represents a single bond or a divalent group selected from the following formulas; in the general formula (2), the cyclic portion represented by Y represents the formation of a 4-membered ring, 5-membered ring, or 6 Cyclic saturated hydrocarbon group in the member ring, 7 member ring or 8 member ring,

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 . The metal-clad laminate according to item 1 or 2 of the patent application scope, wherein the polyimide is at least 50 mol parts and 99 mol parts relative to 100 mol parts of the diamine residue The diamine residue derived from the dimer acid type diamine is contained within the range of 1 part or less, and is selected from the following general formula (B1) to within the range of 1 mol part or more and 50 mol part or less A diamine residue derived from at least one diamine compound of the diamine compounds represented by the general formula (B7),

In formula (B1) to formula (B7), R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents a group selected from -O-, -S-, -CO-, -SO-, -SO ₂ -, -COO-, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or -CONH-, a divalent group, n ₁ independently represents an integer of 0 to 4 ; Where, from formula (B3), the part that repeats with formula (B2) is removed, and from formula (B5), the part that repeats with formula (B4) is removed. The metal-clad laminate according to item 1 or 2 of the patent application scope, wherein the metal layer includes copper foil, and the surface of the copper foil that is in contact with the adhesion layer is subjected to rust prevention treatment . A circuit board formed by processing the metal layer of the metal-clad laminate according to any one of the first to fourth patent application ranges into wiring. An adhesive sheet comprising an insulating resin layer, an adhesive layer laminated on at least one side of the insulating resin layer, and a layer laminated on the insulating resin layer via the adhesive layer The metal-clad laminate is used to form the adhesive layer. The adhesive sheet is characterized in that the adhesive sheet has a polyimide containing a tetracarboxylic acid residue and a diamine residue. The polyimide contains 50 mole parts or more of two moles of dimer acid with two terminal carboxylic acid groups substituted with primary aminomethyl or amino groups with respect to 100 mole parts of the diamine residue Diamine residue derived from polyacid type diamine. The adhesive sheet according to item 6 of the patent application scope, wherein the polyimide contains a total of 90 mol parts or more with respect to 100 mol parts of the tetracarboxylic acid residue by the following general formula ( 1) and/or the tetracarboxylic acid residue derived from the tetracarboxylic anhydride represented by the general formula (2),

In the general formula (1), X represents a single bond or a divalent group selected from the following formulas; in the general formula (2), the cyclic portion represented by Y represents the formation of a 4-membered ring, 5-membered ring, or 6 Cyclic saturated hydrocarbon group in the member ring, 7 member ring or 8 member ring,

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 . The adhesive sheet according to item 6 or item 7 of the patent application scope, wherein the polyimide is at least 50 mol parts and 99 mol parts relative to 100 mol parts of the diamine residue The following range contains diamine residues derived from the dimer acid type diamine, and within the range of 1 mol part or more and 50 mol part or less within a range selected from the following general formula (B1) to A diamine residue derived from at least one diamine compound of the diamine compounds represented by formula (B7),

In formula (B1) to formula (B7), R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents a group selected from -O-, -S-, -CO-, -SO-, -SO ₂ -, -COO-, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or -CONH-, a divalent group, n ₁ independently represents an integer of 0 to 4 ; Where, from formula (B3), the part that repeats with formula (B2) is removed, and from formula (B5), the part that repeats with formula (B4) is removed. An adhesive polyimide resin composition comprising an insulating resin layer, an adhesive layer laminated on at least one side of the insulating resin layer, and a layer interposed therebetween The metal-clad laminate of the metal layer on the insulating resin layer is used to form the adhesive layer. The adhesive polyimide resin composition is characterized in that: the adhesive polyimide resin The composition contains a polyimide containing a tetracarboxylic acid residue and a diamine residue, and the polyimide contains 50 mole parts or more of dimerized monomers with respect to 100 mole parts of the diamine residue. A diamine residue derived from a dimer acid diamine formed by substitution of two terminal carboxylic acid groups of an acid with a primary aminomethyl group or an amino group. The adhesive polyimide resin composition as described in item 9 of the patent application range, wherein the polyimide contains a total of 90 mol parts or more with respect to 100 mol parts of the tetracarboxylic acid residue The tetracarboxylic acid residue derived from the tetracarboxylic anhydride represented by the following general formula (1) and/or general formula (2),

In the general formula (1), X represents a single bond or a divalent group selected from the following formulas; in the general formula (2), the cyclic portion represented by Y represents the formation of a 4-membered ring, 5-membered ring, or 6 Cyclic saturated hydrocarbon group in the member ring, 7 member ring or 8 member ring,

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 . The adhesive polyimide resin composition according to item 9 or 10 of the patent application scope, wherein the polyimide is at 50 mol relative to 100 mol of the diamine residue A diamine residue derived from the dimer acid type diamine is contained in a range of more than 99 parts by moles and less than 1 mole and less than 50 parts by moles selected from the following Diamine residue derived from at least one diamine compound among the diamine compounds represented by general formula (B1) to general formula (B7),

In formula (B1) to formula (B7), R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents a group selected from -O-, -S-, -CO-, -SO-, -SO ₂ -, -COO-, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or -CONH-, a divalent group, n ₁ independently represents an integer of 0 to 4 ; Where, from formula (B3), the part that repeats with formula (B2) is removed, and from formula (B5), the part that repeats with formula (B4) is removed.