JP7093282B2 - Metal-clad laminate and circuit board - Google Patents

Description

The present invention relates to a metal-clad laminate and a circuit board useful as electronic components.

In recent years, with the progress of miniaturization, weight reduction, and space saving of electronic devices, a flexible printed wiring board (FPC) that is thin and lightweight, has flexibility, and has excellent durability even after repeated bending. The demand for Circuits) is increasing. Since FPC can be mounted three-dimensionally and at high density even in a limited space, its use is expanded to, for example, wiring of moving parts of electronic devices such as HDDs, DVDs, and smartphones, and parts such as cables and connectors. I'm doing it.

In addition to the above-mentioned high density, the high performance of the equipment has advanced, so it is also necessary to cope with the high frequency of the transmission signal. When transmitting a high-frequency signal, if the transmission loss in the transmission path is large, inconveniences such as loss of an electric signal and long delay time of the signal occur. Therefore, it will be important to reduce transmission loss in FPC in the future. In order to support high-frequency signal transmission, instead of polyimide, which is widely used as an FPC material, a material having a liquid crystal polymer having a lower dielectric constant and a lower dielectric loss tangent as a dielectric layer is used. However, although the liquid crystal polymer has excellent dielectric properties, there is room for improvement in heat resistance and adhesiveness to the metal layer.

Fluorine-based resins are also known as polymers showing low dielectric constant and low dielectric loss tangent. For example, as an FPC material capable of supporting high-frequency signal transmission and having excellent adhesiveness, a polyimide adhesive film having a thermoplastic polyimide layer and a highly heat-resistant polyimide layer is bonded to both sides of a fluororesin layer, respectively. (Patent Document 1). Since the insulating film of Patent Document 1 uses a fluororesin, it is excellent in terms of dielectric properties, but has a problem in dimensional stability. Especially when it is applied to FPC, before and after circuit processing by etching. There is a concern that the dimensional change will be large. Therefore, it is difficult to increase the thickness of the fluororesin and increase the thickness ratio.

It has also been proposed to manufacture a double-sided copper-clad laminate having an insulating resin layer having a thickness of 50 μm or more by laminating the polyimide resin surfaces of two single-sided copper-clad laminates (for example, Patent Documents 2 and 3). ). However, in Patent Documents 2 and 3, the correspondence to high frequency transmission is not considered, and the configuration of the polyimide when the thick insulating resin layer is adopted is not considered.

Japanese Unexamined Patent Publication No. 2017-24265 Japanese Patent No. 5886027 Japanese Patent No. 6031396

The present invention provides a metal-clad laminate and a circuit board in which the thickness of the insulating resin layer is sufficiently secured, the dimensional stability is excellent, and it is possible to cope with high-frequency transmission accompanying the high performance of electronic devices. be.

The metal-clad laminate of the present invention is a metal-clad laminate comprising a resin laminate including a plurality of polyimide layers and a metal layer laminated on at least one surface of the resin laminate. In the metal-clad laminate of the present invention, the resin laminate contains at least three non-thermoplastic polyimide layers composed of non-thermoplastic polyimide and at least four thermoplastic polyimide layers composed of thermoplastic polyimide. .. The outermost layer of the resin laminate in the metal-clad laminate of the present invention is composed of the thermoplastic polyimide layer, and the non-thermoplastic polyimide layer is laminated via the thermoplastic polyimide layer, and the non-thermoplastic polyimide layer is laminated. The thermoplastic polyimide contains tetracarboxylic acid residues and diamine residues, and 20 diamine residues derived from the diamine compound represented by the following general formula (1) are contained in 100 mol parts of all diamine residues. It is more than a molar part.

In the formula (1), the linking group Z represents a single bond or —COO—, and Y is a monovalent hydrocarbon group having 1 to 3 carbon atoms or 1 carbon number which may be independently substituted with a halogen element or a phenyl group. It represents an alkoxy group of 3 to 3 or a perfluoroalkyl group or an alkenyl group having 1 to 3 carbon atoms, n represents an integer of 0 to 2, and p and q independently represent an integer of 0 to 4.

In the metal-clad laminate of the present invention, the non-thermoplastic polyimide constituting at least two non-thermoplastic polyimide layers of the non-thermoplastic polyimide layer has the above-mentioned general formula (1) with respect to 100 mol parts of all diamine residues. ), 70 mol parts or more and 98 mol parts or less of the diamine residue derived from the diamine compound in which Y is a monovalent hydrocarbon group or an alkoxy group having 1 to 3 carbon atoms and n is an integer of 1 or 2. The diamine residue derived from the diamine compound represented by the following general formulas (C1) to (C4) may be contained in the range of 2 to 15 mol parts.

In the formulas (C1) to (C4), R ₂ independently represents a monovalent hydrocarbon group, an alkoxy group or an alkylthio group having 1 to 6 carbon atoms, and the linking group A'is independently -O-, -SO ₂ . -, -CH _2- or -C (CH ₃ ) _2- Represents a divalent group selected from 2-, and the linking group X1 is independently -CH _2- , -O-CH ₂ --O-, -O-C ₂ H ₄ -O-, -O-C ₃ H ₆ -O-, -O-C ₄ H ₈ -O-, -O-C ₅ H ₁₀ -O-, -O-CH ₂ -C (CH ₃ ) ₂ -CH ₂ -O-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- or -SO _2- , n ₃ independently indicates an integer of 1 to 4, and n ₄ independently. Indicates an integer from 0 to 4, but in the formula (C3), the linking group A'is -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- or -SO _2- . When not included, any one of n ₄ is 1 or more.

In the metal-clad laminate of the present invention, the non-thermoplastic polyimide constituting at least two non-thermoplastic polyimide layers of the non-thermoplastic polyimide is 3,3'with respect to 100 mol parts of all tetracarboxylic acid residues. , 4,4'-Biphenyltetracarboxylic acid dianhydride (BPDA) and 1,4-phenylenebis (trimeritic acid monoester) dianhydride (TAHQ) derived from at least one tetracarboxylic acid residue. Within 30-60 mol parts, tetracarboxylic acid residues derived from at least one of pyromellitic acid dianhydride (PMDA) and 2,3,6,7-naphthalenetetracarboxylic acid dianhydride (NTCDA). May be contained in the range of 40 to 70 mol parts.

In the metal-clad laminate of the present invention, the non-thermoplastic polyimide constituting at least three non-thermoplastic polyimide layers of the non-thermoplastic polyimide layer has the above-mentioned general formula (1) with respect to 100 mol parts of all diamine residues. ), In addition to containing 70 mol parts or more of a diamine residue derived from a diamine compound in which Y is a monovalent hydrocarbon group or an alkoxy group having 1 to 3 carbon atoms and n is an integer of 1 or 2. The diamine residue derived from the diamine compound represented by the general formulas (C1) to (C4) may be contained in the range of 2 to 15 mol parts.

In the metal-clad laminate of the present invention, the non-thermoplastic polyimide constituting at least three non-thermoplastic polyimide layers of the non-thermoplastic polyimide layer is 3,3 with respect to 100 mol parts of all tetracarboxylic acid residues. ', 4,4'-Tetracarboxylic acid residues derived from at least one of biphenyltetracarboxylic acid dianhydride (BPDA) and 1,4-phenylenebis (trimeritic acid monoester) dianhydride (TAHQ). In the range of 30-60 mol parts, the tetracarboxylic acid residue derived from at least one of pyromellitic acid dianhydride (PMDA) and 2,3,6,7-naphthalenetetracarboxylic acid dianhydride (NTCDA). The group may be contained in the range of 40 to 70 mol parts.

In the metal-clad laminate of the present invention, the thermoplastic polyimide constituting the thermoplastic polyimide layer of the outermost layer of the resin laminate contains a tetracarboxylic acid residue and a diamine residue, and the total amount of the diamine residue is 100 mol. On the other hand, the diamine residue derived from at least one diamine compound selected from the diamine compounds represented by the following general formulas (B1) to (B7) may be 60 mol parts or more.

In the formulas (B1) to (B7), R ₁ independently represents a monovalent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms, and the linking group A is independently -O-, -S-, -CO-. , -SO-, -SO _2- , -COO, -CH _2- , -C (CH ₃ ) _2- , NH- or -CONH- indicates a divalent group, and n ₁ is independently 0 to 0 to Indicates an integer of 4. However, the formula (B3) that overlaps with the formula (B2) is excluded, and the formula (B5) that overlaps with the formula (B4) is excluded.

In the metal-clad laminate of the present invention, the imide group concentration of the non-thermoplastic polyimide and the thermoplastic polyimide may be 33% or less.

In the metal-clad laminate of the present invention, the total thickness of the resin laminate is in the range of 25 to 180 μm, and the total thickness of the non-thermoplastic polyimide layer is relative to the total thickness of the resin laminate. It may be in the range of 50 to 97%.

In the metal-clad laminate of the present invention, the resin laminate may have a layer structure symmetrical in the thickness direction with respect to the center in the thickness direction thereof.

The circuit board of the present invention is formed by processing the metal layer of any of the above metal-clad laminates into a wiring circuit.

The metal-clad laminate of the present invention has a sufficient thickness and can ensure dimensional stability. Further, when applied to a circuit board or the like that transmits a high frequency signal of 10 GHz or more, it is possible to reduce the transmission loss. Therefore, it is possible to improve reliability and yield in the circuit board.

It is explanatory drawing of the target for position measurement used for measuring the dimensional change rate after etching. It is explanatory drawing of the evaluation sample used for the measurement of the dimensional change rate after etching.

Hereinafter, embodiments of the present invention will be described.

[Metal-clad laminate]
The metal-clad laminate of the present embodiment includes a resin laminate including a plurality of polyimide layers, and a metal layer laminated on at least one surface of the resin laminate.

<Resin laminate>
The resin laminate includes at least three non-thermoplastic polyimide layers made of non-thermoplastic polyimide and at least four thermoplastic polyimide layers made of thermoplastic polyimide. The outermost layer of the resin laminate is composed of a thermoplastic polyimide layer, and the non-thermoplastic polyimide layer is laminated via the thermoplastic polyimide layer.
Here, the thermoplastic polyimide is generally a polyimide in which the glass transition temperature (Tg) can be clearly confirmed, but in the present invention, it is measured at 30 ° C. using a dynamic viscoelastic modulus measuring device (DMA). A polyimide having a storage elastic modulus of 1.0 × 10 ⁹ Pa or more and a storage elastic modulus of less than 1.0 × 10 ⁸ Pa at 300 ° C. The non-thermoplastic polyimide is generally a polyimide that does not soften or show adhesiveness even when heated, but in the present invention, it is measured at 30 ° C. using a dynamic elastic modulus measuring device (DMA). A polyimide having a storage elastic modulus of 1.0 × 10 ⁹ Pa or more and a storage elastic modulus of 1.0 × 10 ⁸ Pa or more at 300 ° C.
The resin laminate may have any resin layer other than the thermoplastic polyimide layer and the non-thermoplastic polyimide layer.

The total thickness of the resin laminate is preferably in the range of 25 to 180 μm, more preferably in the range of 40 to 180 μm, and further preferably in the range of 50 to 160 μm. If the total thickness of the resin laminate is less than 25 μm, sufficient high-frequency transmission characteristics may not be obtained, and if it exceeds 180 μm, problems may occur in dimensional stability, flexibility, and the like.

Further, the resin laminate means the thickness of the non-thermoplastic polyimide layer with respect to the total thickness of the resin laminate (when the resin laminate contains a plurality of non-thermoplastic polyimide layers, it means the total thickness of the plurality of layers. The ratio is preferably in the range of 50 to 97%, preferably in the range of 70 to 97%, and more preferably in the range of 75 to 95%. By controlling the ratio of the thickness of the non-thermoplastic polyimide layer to the total thickness of the resin laminate within the above range, a circuit board such as an FPC having excellent high frequency transmission characteristics can be manufactured. If the ratio of the thickness of the non-thermoplastic polyimide layer to the total thickness of the resin laminate is less than 50%, the ratio of the non-thermoplastic polyimide layer in the insulating resin layer becomes too small, resulting in warpage and deterioration of dimensional stability. If it exceeds 97%, the thermoplastic polyimide layer becomes thin, so that the adhesion reliability between the resin laminate and the metal layer tends to decrease.

<Non-thermoplastic polyimide layer>
The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer contains a tetracarboxylic acid residue and a diamine residue. By including at least three non-thermoplastic polyimide layers, it is possible to prevent warpage and deterioration of dimensional stability even when the thickness of the resin laminate is increased, for example. From such a viewpoint, it is preferable to have a layer structure symmetrical in the thickness direction with respect to the center in the thickness direction of the resin laminate. Further, by having two or more, more preferably three or more non-thermoplastic polyimide layers composed of non-thermoplastic polyimide formed of a specific monomer described later, the dimensional stability of the resin laminate can be improved. The security and dielectric properties can be improved.
In the present invention, the tetracarboxylic acid residue represents a tetravalent group derived from tetracarboxylic acid dianhydride, and the diamine residue is a divalent group derived from a diamine compound. Represents that. Further, in the present invention, the "diamine compound" may be substituted with hydrogen atoms in the two terminal amino groups, for example, -NR ₃ R ₄ (where R ₃ and R ₄ are independently. It may be any substituent (meaning any substituent such as an alkyl group).

(Diamine residue)
The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer has 100 mol parts of all diamine residues as diamine residues derived from the diamine compound represented by the following general formula (1). Is preferably contained in an amount of 20 mol parts or more, preferably 70 to 95 mol parts, and more preferably 80 to 90 mol parts.

In the general formula (1), the linking group Z represents a single bond or —COO—, and Y may be independently substituted with a halogen element or a phenyl group, and is a monovalent hydrocarbon group having 1 to 3 carbon atoms or a carbon number of carbon atoms. It represents an alkoxy group of 1 to 3 or a perfluoroalkyl group or an alkenyl group having 1 to 3 carbon atoms, n represents an integer of 0 to 2, and p and q independently represent an integer of 0 to 4. "Independently" means that, in the above formula (1), a plurality of substituents Y, integers p, and q may be the same or different.

The diamine residue derived from the diamine compound represented by the general formula (1) (hereinafter, may be referred to as “diamine residue (1)”) easily forms an ordered structure and enhances dimensional stability. Can be done.

Examples of the diamine (1) include 1,4-diaminobenzene (p-PDA; paraphenylenediamine), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), 2,2'-. Examples thereof include n-propyl-4,4'-diaminobiphenyl (m-NPB) and 4-aminophenyl-4'-aminobenzoate (APAB).

Further, in order to improve the dielectric properties of the resin laminate, as the diamine residue contained in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer, Y has 1 to 3 carbon atoms in the general formula (1). A diamine residue derived from a diamine compound (hereinafter, may be referred to as "diamine (A1)") which is a monovalent hydrocarbon group or an alkoxy group and in which n is an integer of 1 or 2 is preferable.

The diamine residue derived from the diamine (A1) (hereinafter, may be referred to as "diamine residue (A1)") is an aromatic diamine having two or three benzene rings. Since the diamine residue (A1) has a rigid structure, it has an action of imparting an ordered structure to the entire polymer. Therefore, a polyimide having low gas permeability and low hygroscopicity can be obtained, and the water content inside the molecular chain can be reduced, so that the dielectric loss tangent can be lowered. Here, as the linking group Z, a single bond is preferable.

The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer contains the diamine residue (A1) in an amount of preferably 70 mol parts or more, more preferably 70 to 90 mol parts, based on 100 mol parts of the total diamine residues. It is preferably contained within the range, more preferably within the range of 80 to 90 mol parts. By containing the diamine residue (A1) in an amount within the above range, the rigid structure derived from the monomer facilitates the formation of an ordered structure in the entire polymer, has low gas permeability, low moisture absorption, and low dielectric loss tangent. Non-thermoplastic polyimide is easily obtained. On the other hand, if the diamine residue (A1) exceeds 90 mol parts, the elongation of the film may decrease.

Further, the non-thermoplastic polyimide preferably contains a diamine residue derived from a diamine compound represented by the general formulas (C1) to (C4). Since the diamines (C1) to (C4) have bulky substituents and flexible sites, flexibility can be imparted to the polyimide. Further, since the diamines (C1) to (C4) can improve the gas permeability, they have an effect of suppressing foaming during the production of the metal-clad laminate. From this point of view, the diamine residue derived from one or more diamine compounds selected from diamines (C1) to (C4) is within the range of 2 to 15 mol parts with respect to 100 mol parts of all diamine residues. It is preferable to contain in. If the number of diamine residues derived from diamines (C1) to (C4) is less than 2 mol, foaming may occur when a metal-clad laminate is manufactured. Further, when the diamine residue derived from the diamines (C1) to (C4) exceeds 15 mol parts, the orientation of the molecule is lowered and it becomes difficult to reduce the CTE.

In the above formulas (C1) to (C4), R ₂ independently represents a monovalent hydrocarbon group, an alkoxy group or an alkylthio group having 1 to 6 carbon atoms, and the linking group A'is independently -O-, -SO. A _divalent group selected from 2-, -CH _2- or -C (CH ₃ ) _2- , preferably a divalent group selected from -O-, -CH _2- or -C (CH ₃ ) _2- . Independently, the linking group X1 is -CH _2- , -O-CH ₂ --O-, -O-C ₂ H ₄ -O-, -O-C ₃ H ₆ -O-, -O-C ₄ H ₈ -O-, -O-C ₅ H ₁₀ -O-, -O-CH ₂ -C (CH ₃ ) ₂ -CH ₂ -O-, -C (CH ₃ ) _2- , -C (CF ₃ ) ) ₂ -or -SO _2- , n ₃ independently indicates an integer of 1 to 4, n ₄ independently indicates an integer of 0 to 4, but in the formula (C3), the linking group A'is When -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- or -SO _2- is not included, any one of n4 is ₁ or more. However, when n ₃ = 0, it is assumed that the two amino groups in the formula (C1) are not in the para position. Here, "independently" means a plurality of linking groups A', a plurality of linking groups X1, and a plurality of substituents R in one of the above formulas (C1) to (C4) or in two or more. It means that _two or a plurality of _n3 and _n4 may be the same or different. In the above formulas (C1) to (C4), the hydrogen atom in the two terminal amino groups may be substituted, for example, -NR ₃ R ₄ (here, R ₃ and R ₄ are independently. It may mean any substituent such as an alkyl group).

Examples of the aromatic diamine represented by the general formula (C1) include 2,6-diamino-3,5-diethyltoluene and 2,4-diamino-3,5-diethyltoluene.

Examples of the aromatic diamine represented by the general formula (C2) include 2,4-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane and bis (4-amino-3-ethyl-5-. Methylphenyl) methane and the like can be mentioned.

Examples of the aromatic diamine represented by the general formula (C3) include 1,3-bis [2- (4-aminophenyl) -2-propyl] benzene, 1,4-bis [2- (4-amino)]. Phenyl) -2-propyl] benzene, 1,4 bis (4-aminophenoxy) -2,5-di-tert-butylbenzene and the like can be mentioned.

Examples of the aromatic diamine represented by the general formula (C4) include 2,2-bis [4- (4-aminophenoxy) phenyl] propane.

As described above, the non-thermoplastic polyimide contains 70 mol or more, preferably 70 to 90 mol, of the diamine residue derived from the diamine (A1) with respect to 100 mol of the total diamine residue. , Diamine residues derived from diamines (C1) to (C4) may be controlled to be contained in the range of 2 to 15 mol parts.

Examples of other diamine residues contained in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer include 2,2-bis- [4- (3-aminophenoxy) phenyl] propane and 2,2-bis [. 4- (4-Aminophenoxy) Phenyl] Hexafluoropropane, 2,2-bis [4- (2-Trifluoro-4-aminophenoxy) Phenyl] Hexafluoropropane, 1,4-bis (4-Aminophenoxy) 2,3,6-trimethyl-benzene, 1,4-bis (4-aminophenoxymethyl) propane, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) methane, 1,4-bis (4-aminophenoxy) ethane, 1,4-bis (4-aminophenoxy) Propane, 1,4-bis (4-aminophenoxy) butane, 1,4-bis (4-aminophenoxy) pentane, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-amino) Phenyl phenyl] sulfone, bis [4- (3-aminophenoxy) biphenyl, bis [1- (3-aminophenoxy)] biphenyl, bis [4- (3-aminophenoxy) phenyl] methane, 1,4-bis (4-Aminophenoxy) 2-Phenyl-benzene, 1,4-bis (2-trifluoromethyl-4-aminophenoxy) benzene, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4- (3-aminophenoxy) phenyl] ether 3-Aminophenoxy)] benzophenone, 9,9-bis [4- (3-aminophenoxy) phenyl] fluorene, 2,2-bis- [4- (3-aminophenoxy) phenyl] hexafluoropropane, 3,3 '-Dimethyl-4,4'-diaminobiphenyl, 4,4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 3,3'-Diaminodiphenylethane, 2-trifluoromethyl-4,4'-diaminodiphenyl ether, 2,2'-ditrifluoromethyl-4,4'-diaminodiphenyl ether, 3,3'-diaminobiphenyl, 3, 3'-Dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 4,4'-[1,3- Phenyllen Bis (1-methylethylidene)] bisaniline, bis (p-aminocyclohexyl) methane, bis (p-β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminopentyl) benzene, p -Bis (2-methyl-4-aminopentyl) benzene, p-bis (1,1-dimethyl-5-aminopentyl) benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis (β-Amino-t-butyl) Toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylene diamine, p-xylylene diamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, 2'-methoxy-4,4'-diaminobenzanilide, 4,4' -Diamine residues derived from aromatic diamine compounds such as diaminobenzanilide, 6-amino-2- (4-aminophenoxy) benzoxazole, and the two terminal carboxylic acid groups of dimer acid are primary aminomethyl groups or Examples thereof include diamine residues derived from an aliphatic diamine compound such as a dimer acid type diamine substituted with an amino group.

(Tetracarboxylic acid residue)
The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer has 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride (BPDA) and 1,4-phenylenebis (tri) as tetracarboxylic acid residues. Merit Acid Monoester) Tetracarboxylic acid residues derived from at least one of the dianhydride (TAHQ) and pyromellitic acid dianhydride (PMDA) and 2,3,6,7-naphthalenetetracarboxylic acid dianhydride. It preferably contains a tetracarboxylic acid residue derived from at least one of (NTCDA).

The tetracarboxylic acid residue derived from BPDA (hereinafter, also referred to as “BPDA residue”) and the tetracarboxylic acid residue derived from TAHQ (hereinafter, also referred to as “TAHQ residue”) are ordered of the polymer. It is easy to form a structure, and it is possible to reduce the dielectric positive contact and moisture absorption by suppressing the movement of molecules. However, on the other hand, the BPDA residue can impart the self-supporting property of the gel film as the polyamic acid of the polyimide precursor, but it increases the CTE after imidization and lowers the glass transition temperature to lower the heat resistance. It becomes a tendency.

From this point of view, the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer preferably contains 30 mol parts or more of the total of BPDA residues and TAHQ residues with respect to 100 mol parts of all tetracarboxylic acid residues. The content is controlled to be contained within the range of 60 mol parts or less, more preferably 40 mol parts or more and 50 mol parts or less. If the total of BPDA residues and TAHQ residues is less than 30 mol parts, the formation of the ordered structure of the polymer is insufficient, the hygroscopicity is lowered, and the reduction of the dielectric loss tangent is insufficient, and 60 mol parts is used. If it exceeds the limit, the CTE may increase and the heat resistance may decrease.

Further, a tetracarboxylic acid residue derived from pyromellitic acid dianhydride (hereinafter, also referred to as “PMDA residue”) and a tetra derived from 2,3,6,7-naphthalenetetracarboxylic acid dianhydride. Since the carboxylic acid residue (hereinafter, also referred to as “NTCDA residue”) has rigidity, it enhances in-plane orientation, suppresses CTE to a low level, controls in-plane retardation (RO), and controls the glass transition temperature. It is a residue that plays a role in controlling. On the other hand, since PMDA residues have a small molecular weight, if the amount is too large, the imide group concentration of the polymer will increase, the polar groups will increase, and the hygroscopicity will increase, and the water content inside the molecular chain will increase. Due to the influence, the dielectric positive contact increases. In addition, the NTCDA residue tends to make the film brittle due to the highly rigid naphthalene skeleton, and tends to increase the elastic modulus.
Therefore, in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer, the total of PMDA residues and NTCDA residues is preferably 40 mol parts or more and 70 mol parts or less with respect to 100 mol parts of all tetracarboxylic acid residues. It is contained in the range of 50 mol parts or more, more preferably 60 mol parts or less, and more preferably 50 to 55 mol parts or less. If the total of PMDA residues and NTCDA residues is less than 40 mol parts, CTE may increase or heat resistance may decrease, and if it exceeds 70 mol parts, the imide group concentration of the polymer becomes high and the polarity There is a risk that the number of groups will increase and the low moisture absorption property will be impaired, the dielectric adduct will increase, and the film will become brittle and the self-supporting property of the film will decrease.

Further, the total of at least one of BPDA residue and TAHQ residue and at least one of PMDA residue and NTCDA residue is 80 mol parts or more, preferably 90 parts or more with respect to 100 mol parts of all tetracarboxylic acid residues. It should be more than a molar part.

Further, the molar ratio of at least one BPDA residue and TAHQ residue to at least one PMDA residue and NTCDA residue {(BPDA residue + TAHQ residue) / (PMDA residue + NTCDA residue)} is 0. Within the range of 4 or more and 1.5 or less, preferably within the range of 0.6 or more and 1.3 or less, more preferably within the range of 0.8 or more and 1.2 or less, and control the formation of the ordered structure of CTE and the polymer. It is good to do.

Since PMDA and NTCDA have a rigid skeleton, it is possible to control the in-plane orientation of molecules in polyimide as compared with other general acid anhydride components, and suppress the coefficient of thermal expansion (CTE) and glass. It has the effect of improving the transition temperature (Tg). Further, since BPDA and TAHQ have a larger molecular weight than PMDA, the imide group concentration is lowered by increasing the charging ratio, which is effective in lowering the dielectric loss tangent and the hygroscopicity. On the other hand, when the charging ratio of BPDA and TAHQ increases, the in-plane orientation of the molecules in the polyimide decreases, which leads to an increase in CTE. Furthermore, the formation of an ordered structure in the molecule progresses, and the haze value increases. From this point of view, the total amount of PMDA and NTCDA charged is in the range of 40 to 70 mol parts, preferably in the range of 50 to 60 mol parts, with respect to 100 mol parts of the total acid anhydride component of the raw material. More preferably, it is in the range of 50 to 55 mol parts. If the total amount of PMDA and NTCDA charged is less than 40 mol parts with respect to 100 mol parts of the total acid anhydride component of the raw material, the in-plane orientation of the molecule deteriorates, it becomes difficult to reduce the CTE, and Tg. The heat resistance and dimensional stability of the film during heating are reduced due to the decrease in the pressure. On the other hand, when the total amount of PMDA and NTCDA charged exceeds 70 mol parts, the hygroscopicity deteriorates due to the increase in the imide group concentration, and the elastic modulus tends to increase.

Further, BPDA and TAHQ are effective in suppressing molecular motion, reducing the dielectric loss tangent by lowering the imide group concentration, and lowering the moisture absorption rate, but increase the CTE as a polyimide film after imidization. From this point of view, the total amount of BPDA and TAHQ charged is in the range of 30 to 60 mol parts, preferably in the range of 40 to 50 mol parts, with respect to 100 mol parts of the total acid anhydride component of the raw material. More preferably, it is in the range of 40 to 45 mol parts.

Examples of the tetracarboxylic acid residue other than the BPDA residue, TAHQ residue, PMDA residue, and NTCDA residue contained in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer are 3,3', 4 , 4'-Diphenylsulfonate tetracarboxylic acid dianhydride, 4,4'-oxydiphthalic acid anhydride, 2,3', 3,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3,3' -2,3,3', 4'-or 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride, 2,3', 3,4'-diphenyl ether tetracarboxylic acid dianhydride, bis (2,3-Dicarboxyphenyl) Ethereal dianhydride, 3,3'', 4,4''-, 2,3,3'', 4''-or 2,2'',3,3' '-p-Terphenyltetracarboxylic acid dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3- or 3.4-di) Carboxyphenyl) methane dianhydride, bis (2,3- or 3,4-dicarboxyphenyl) sulfonate dianhydride, 1,1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride 1,2,7,8-,1,2,6,7- or 1,2,9,10-phenanthrene-tetracarboxylic acid dianhydride, 2,3,6,7-anthracene tetracarboxylic acid dian Anhydrous, 2,2-bis (3,4-dicarboxyphenyl) tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 1,2,5,6-naphthalene tetracarboxylic acid dianhydride Anhydrous 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetra Carboxylic acid dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 2,3,6,7-(or 1,4,5,8) -) Tetrachloronaphthalene-1,4,5,8-(or 2,3,6,7-) Tetracarboxylic acid dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11-or 5,6,11,12-perylene-tetracarboxylic acid dianhydride, cyclopentane-1,2,3,4-tetracarboxylic acid dianhydride, pyrazine-2,3, 5,6-Tetracarboxylic acid dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic acid dianhydride, thiophene-2,3,4,5-tetracarboxylic acid dianhydride, 4,4'- Bis (2,3-Jika) Luboxyphenoxy) Examples thereof include tetracarboxylic acid residues derived from aromatic tetracarboxylic acid dianhydrides such as diphenylmethane dianhydride and ethylene glycol bisamhydrotrimeritate.

In non-thermoplastic polyimide, thermal expansion is performed by selecting the types of the tetracarboxylic acid residue and the diamine residue and the molar ratio of each when two or more kinds of tetracarboxylic acid residues or diamine residues are applied. The coefficient, storage elastic modulus, tensile elastic modulus, etc. can be controlled. Further, in the non-thermoplastic polyimide, when the polyimide has a plurality of structural units, it may exist as a block or may exist at random.

It is preferable to use both the tetracarboxylic acid residue and the diamine residue contained in the non-thermoplastic polyimide as an aromatic group because the dimensional accuracy of the polyimide film in a high temperature environment can be improved.

The imide group concentration of the non-thermoplastic polyimide is preferably 33% or less, more preferably 32% or less. Here, the "imide group concentration" means a value obtained by dividing the molecular weight of the imide base portion (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. When the imide group concentration exceeds 33%, the molecular weight of the resin itself becomes small, and the decrease in the polar groups also deteriorates the low hygroscopicity. By selecting the combination of the acid anhydride and the diamine compound, the orientation of the molecules in the non-thermoplastic polyimide is controlled, thereby suppressing the increase in CTE due to the decrease in the imide group concentration and ensuring low moisture absorption. ing.

The weight average molecular weight of the non-thermoplastic polyimide is preferably in the range of, for example, 10,000 to 400,000, and more preferably in the range of 50,000 to 350,000. If the weight average molecular weight is less than 10,000, the strength of the film is lowered and the film tends to be brittle. On the other hand, when the weight average molecular weight exceeds 400,000, the viscosity is excessively increased, and defects such as film thickness unevenness and streaks tend to occur easily during the coating work.

The thickness of the non-thermoplastic polyimide layer is preferably in the range of 6 μm or more and 100 μm or less, preferably 9 μm or more, from the viewpoint of ensuring the function as a base layer and transportability during manufacturing and coating with the thermoplastic polyimide. The range of 50 μm or less is more preferable. If the thickness of the non-thermoplastic polyimide layer is less than the above lower limit value, the electrical insulation and handleability are insufficient, and if it exceeds the upper limit value, the productivity is lowered.

From the viewpoint of heat resistance, the non-thermoplastic polyimide layer preferably has a glass transition temperature (Tg) of 280 ° C. or higher.

Further, from the viewpoint of suppressing warpage, the coefficient of thermal expansion of the non-thermoplastic polyimide layer is in the range of 1 pm / K or more and 30 ppm / K or less, preferably in the range of 1 ppm / K or more and 25 ppm / K or less, more preferably 15 ppm. It is preferably in the range of / K or more and 25 ppm / K or less.

Further, the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer may contain, as optional components, other curing resin components such as a plasticizer and an epoxy resin, a curing agent, a curing accelerator, a coupling agent, a filler and a solvent. , Flame retardant and the like can be appropriately blended. However, it is preferable not to use a plasticizer as much as possible because some plasticizers contain a large amount of polar groups, which may promote the diffusion of copper from copper wiring.

<Thermoplastic polyimide layer>
The thermoplastic polyimide layer is composed of a thermoplastic polyimide containing a tetracarboxylic acid residue and a diamine residue, and has a function as an adhesive layer between the non-thermoplastic polyimide layers in the resin laminate. Further, since it has a function as an adhesive layer with a metal layer, it is located on the outermost layer of the resin laminate, and is further formed by forming a thermoplastic polyimide layer composed of a thermoplastic polyimide formed of a specific monomer described later. Adhesion can be improved even for low-roughness copper foil, gas permeability can be reduced, and excellent long-term heat-resistant adhesiveness can be provided. The thermoplastic polyimide constituting the thermoplastic polyimide layer has high expandability, and in order to obtain a suitable adhesive layer, the glass transition temperature (Tg) is preferably, for example, 360 ° C. or lower, preferably 200 to 320 ° C. Those within the range are more preferable.

(Tetracarboxylic acid residue)
As the tetracarboxylic acid residue used in the thermoplastic polyimide constituting the thermoplastic polyimide layer, the same one as exemplified as the tetracarboxylic acid residue in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer shall be used. Can be done.

(Diamine residue)
As the diamine residue contained in the thermoplastic polyimide constituting the thermoplastic polyimide layer, a diamine residue derived from the diamine compounds represented by the general formulas (B1) to (B7) is preferable.

In the formulas (B1) to (B7), R ₁ independently represents a monovalent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms, and the linking group A is independently -O-, -S-, -CO-. , -SO-, -SO _2- , -COO-, -CH _2- , -C (CH ₃ ) _2- , -NH- or -CONH- indicates a divalent group, n ₁ is independent. Indicates an integer from 0 to 4. However, the formula (B3) that overlaps with the formula (B2) is excluded, and the formula (B5) that overlaps with the formula (B4) is excluded. Here, "independently" means that, in one of the above formulas (B1) to (B7), or in two or more, a plurality of linking groups A, a plurality of _R1s , or a plurality of _n1s are the same. But it means that it can be different.

The diamine represented by the formula (B1) (hereinafter, may be referred to as "diamine (B1)") is an aromatic diamine having two benzene rings. This diamine (B1) has a high degree of flexibility due to an increase in the degree of freedom of the polyimide molecular chain by having an amino group directly connected to at least one benzene ring and a divalent linking group A at the meta position. It is considered that this contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B1) enhances the thermoplasticity of the polyimide. Here, as the linking group A, —O—, —CH _2- , —C (CH ₃ ) _2- , —CO−, _—SO2- , —S— are preferable.

Examples of the diamine (B1) include 3,3'-diaminodiphenylmethane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, and 3,3'-diamino. Diphenyl ether, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylpropane, 3,4'-diaminodiphenylsulfide, 3,3'-diaminobenzophenone, (3,3'- Bisamino) diphenylamine and the like can be mentioned.

The diamine represented by the formula (B2) (hereinafter, may be referred to as "diamine (B2)") is an aromatic diamine having three benzene rings. This diamine (B2) has a high degree of flexibility due to an increase in the degree of freedom of the polyimide molecular chain by having an amino group directly connected to at least one benzene ring and a divalent linking group A at the meta position. It is considered that this contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B2) enhances the thermoplasticity of the polyimide. Here, —O— is preferable as the linking group A.

Examples of the diamine (B2) include 1,4-bis (3-aminophenoxy) benzene, 3- [4- (4-aminophenoxy) phenoxy] benzeneamine, and 3- [3- (4-aminophenoxy) phenoxy]. Benzene amine and the like can be mentioned.

The diamine represented by the formula (B3) (hereinafter, may be referred to as "diamine (B3)") is an aromatic diamine having three benzene rings. This diamine (B3) has two divalent linking groups A directly linked to one benzene ring at the meta position of each other, so that the degree of freedom of the polyimide molecular chain is increased and it has high flexibility. Therefore, it is considered that it contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B3) enhances the thermoplasticity of the polyimide. Here, —O— is preferable as the linking group A.

Examples of the diamine (B3) include 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,3-bis (3-aminophenoxy) benzene (APB), and 4,4'-[2- [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 the like can be mentioned.

The diamine represented by the formula (B4) (hereinafter, may be referred to as "diamine (B4)") is an aromatic diamine having four benzene rings. This diamine (B4) has high flexibility because the amino group directly linked to at least one benzene ring and the divalent linking group A are in the meta position, and it improves the flexibility of the polyimide molecular chain. It is thought to contribute. Therefore, the use of diamine (B4) enhances the thermoplasticity of the polyimide. Here, as the linking group A, -O-, -CH _2- , -C (CH ₃ ) _2- , -SO _2- , -CO-, and -CONH- are preferable.

Diamines (B4) include bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] ether, and bis. Examples thereof include [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy)] benzophenone, and bis [4,4'-(3-aminophenoxy)] benzanilide.

The diamine represented by the formula (B5) (hereinafter, may be referred to as "diamine (B5)") is an aromatic diamine having four benzene rings. This diamine (B5) has two divalent linking groups A directly linked to at least one benzene ring at the meta position of each other, so that the degree of freedom of the polyimide molecular chain is increased and the diamine has high flexibility. It is considered that this contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B5) enhances the thermoplasticity of the polyimide. Here, —O— is preferable as the linking group A.

Examples of the diamine (B5) include 4- [3- [4- (4-aminophenoxy) phenoxy] phenoxy] aniline, 4,4'-[oxybis (3,1-phenyleneoxy)] bisaniline and the like. ..

The diamine represented by the formula (B6) (hereinafter, may be referred to as "diamine (B6)") is an aromatic diamine having four benzene rings. This diamine (B6) has high flexibility by having at least two ether bonds, and is considered to contribute to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B6) enhances the thermoplasticity of the polyimide. Here, as the linking group A, -C (CH ₃ ) _2- , -O-, -SO _2- , and -CO- are preferable.

Examples of the diamine (B6) include 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), bis [4- (4-aminophenoxy) phenyl] ether (BAPE), and bis [4). -(4-Aminophenoxy) phenyl] sulfone (BAPS), bis [4- (4-aminophenoxy) phenyl] ketone (BADK) and the like can be mentioned.

The diamine represented by the formula (B7) (hereinafter, may be referred to as “diamine (B7)”) is an aromatic diamine having four benzene rings. Since this diamine (B7) has a highly flexible divalent linking group A on both sides of the diphenyl skeleton, it is considered to contribute to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B7) enhances the thermoplasticity of the polyimide. Here, —O— is preferable as the linking group A.

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

The thermoplastic polyimide constituting the thermoplastic polyimide layer contains 60 diamine residues derived from at least one diamine compound selected from diamine (B1) to diamine (B7) for 100 mol parts of all diamine residues. It may be contained in a molar portion or more, preferably in a range of 60 mol parts or more and 99 mol parts or less, and more preferably in a range of 70 mol parts or more and 95 mol parts or less. Since diamines (B1) to diamines (B7) have a molecular structure having flexibility, the flexibility of the polyimide molecular chain is improved by using at least one diamine compound selected from these in an amount within the above range. And can impart thermoplasticity. If the total amount of diamine (B1) to diamine (B7) is less than 60 mol parts with respect to 100 mol parts of the total diamine component, sufficient thermoplasticity cannot be obtained due to insufficient flexibility of the polyimide resin.

Further, as the diamine residue contained in the thermoplastic polyimide constituting the thermoplastic polyimide layer, the diamine residue (A1) is also preferable. The diamine (A1) and the diamine (A1) are as described in the description of the non-thermoplastic polyimide. Since the diamine residue (A1) has a rigid structure and has an action of imparting an ordered structure to the entire polymer, it is possible to reduce dielectric loss tangent and hygroscopicity by suppressing the movement of the molecule. Further, by using it as a raw material for thermoplastic polyimide, a polyimide having low gas permeability and excellent long-term heat-resistant adhesiveness can be obtained.

The thermoplastic polyimide constituting the thermoplastic polyimide layer contains a diamine residue (A1) in a range of preferably 1 mol part or more and 40 mol parts or less, more preferably 5 mol parts or more and 30 mol parts or less. You may. By including the diamine residue (A1) in an amount within the above range, the rigid structure derived from the monomer forms an ordered structure in the entire polymer, so that the gas permeability and hygroscopicity are low while being thermoplastic. A polyimide having excellent long-term heat-resistant adhesiveness can be obtained.

The thermoplastic polyimide constituting the thermoplastic polyimide layer can contain diamine residues derived from diamine compounds other than diamines (A1) and (B1) to (B7) as long as the effects of the invention are not impaired.

In the thermoplastic polyimide, the coefficient of thermal expansion is selected by selecting the types of the tetracarboxylic acid residue and the diamine residue and the molar ratio of each when two or more kinds of the tetracarboxylic acid residue or the diamine residue are applied. , Tensile modulus, glass transition temperature, etc. can be controlled. Further, in the thermoplastic polyimide, when a plurality of structural units of the polyimide are present, it may exist as a block or randomly, but it is preferable that it exists randomly.

By using both the tetracarboxylic acid residue and the diamine residue contained in the thermoplastic polyimide as an aromatic group, the dimensional accuracy of the polyimide film in a high temperature environment can be improved.

The imide group concentration of the thermoplastic polyimide is preferably 33% or less, more preferably 32% or less. Here, the "imide group concentration" means a value obtained by dividing the molecular weight of the imide base portion (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. When the imide group concentration exceeds 33%, the molecular weight of the resin itself becomes small, and the decrease in the polar groups also deteriorates the low hygroscopicity. By controlling the orientation of the molecules in the thermoplastic polyimide by selecting the combination of the diamine compounds, the increase in CTE accompanying the decrease in the imide group concentration is suppressed, and low hygroscopicity is ensured.

The weight average molecular weight of the thermoplastic polyimide is preferably in the range of, for example, 10,000 to 400,000, and more preferably in the range of 50,000 to 350,000. If the weight average molecular weight is less than 10,000, the strength of the film is lowered and the film tends to be brittle. On the other hand, when the weight average molecular weight exceeds 400,000, the viscosity is excessively increased, and defects such as film thickness unevenness and streaks tend to occur easily during the coating work.

Since the thermoplastic polyimide constituting the thermoplastic polyimide layer is, for example, an adhesive layer in the insulating resin of the circuit board, a completely imidized structure is most preferable in order to suppress the diffusion of copper. However, a part of the polyimide may be an amic acid. The imidization rate is around 1015 cm ^-1 by measuring the infrared absorption spectrum of the polyimide thin film by the single reflection ATR method using a Fourier transform infrared spectrophotometer (commercially available: FT / IR620 manufactured by Nippon Spectroscopy). It is calculated from the absorbance of C = O expansion and contraction derived from the imide group of 1780 cm ^-1 based on the benzene ring absorber of.

The thickness of the thermoplastic polyimide layer is preferably in the range of 1 μm or more and 10 μm or less, and more preferably in the range of 1 μm or more and 5 μm or less, from the viewpoint of ensuring the adhesive function. If the thickness of the thermoplastic polyimide layer is less than the above lower limit value, the adhesiveness becomes insufficient, and if it exceeds the upper limit value, the dimensional stability tends to deteriorate.

From the viewpoint of suppressing warpage, the thermoplastic polyimide layer has a coefficient of thermal expansion in the range of 30 ppm / K or more, preferably in the range of 30 ppm / K or more and 100 ppm / K or less, and more preferably in the range of 30 ppm / K or more and 80 ppm / K or less. It should be inside.

In addition to polyimide, the resin used for the thermoplastic polyimide layer includes, as optional components, other curing resin components such as plasticizers and epoxy resins, curing agents, curing accelerators, inorganic fillers, coupling agents, and fillings. Agents, solvents, flame retardants and the like can be appropriately blended. However, it is preferable not to use a plasticizer as much as possible because some plasticizers contain a large amount of polar groups, which may promote the diffusion of copper from copper wiring.

(Synthesis of polyimide)
The polyimide constituting the resin laminate can be produced by reacting the acid anhydride and diamine in a solvent to form a precursor resin and then heating and closing the ring. For example, the acid anhydride component and the diamine component are dissolved in an organic solvent in approximately equimolar amounts, and the mixture is stirred at a temperature in the range of 0 to 100 ° C. for 30 minutes to 24 hours to carry out a polymerization reaction to obtain a polyimide precursor. Polyamic acid is obtained. In the reaction, the reaction components are dissolved in the organic solvent so that the precursor to be produced is in the range of 5 to 30% by weight, preferably in the range of 10 to 20% by weight. Examples of the organic solvent used in the polymerization reaction include N, N-dimethylformamide, N, N-dimethylacetamide (DMAC), N-methyl-2-pyrrolidone, 2-butanone, dimethylshoxide, dimethyl sulfate, cyclohexanone, and dioxane. , Tetrahydrofuran, diglyme, triglyme and the like. Two or more of these solvents can be used in combination, and aromatic hydrocarbons such as xylene and toluene can be used in combination. The amount of such an organic solvent used is not particularly limited, but the amount used is such that the concentration of the polyamic acid solution (polyimide precursor solution) obtained by the polymerization reaction is about 5 to 30% by weight. It is preferable to adjust to the above.

In the synthesis of polyimide, the acid anhydride and the diamine may be used alone or in combination of two or more. Thermal expansion, adhesiveness, glass transition temperature, etc. can be controlled by selecting the types of acid anhydride and diamine and the molar ratio of each when two or more types of acid anhydride or diamine are used. ..

The synthesized precursor is usually advantageous for use as a reaction solvent solution, but can be concentrated, diluted or replaced with other organic solvents as needed. In addition, precursors are generally excellent in solvent solubility and are therefore used advantageously. The method for imidizing the precursor is not particularly limited, and for example, a heat treatment such as heating in the solvent under a temperature condition in the range of 80 to 400 ° C. for 1 to 24 hours is preferably adopted.

<Metal layer>
As the metal layer, a metal foil can be preferably used. The material of the metal foil is not particularly limited, but for example, copper, stainless steel, iron, nickel, berylium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, magnesium, manganese and alloys thereof. And so on. Of these, copper or a copper alloy is particularly preferable. The copper foil may be rolled copper foil or electrolytic copper foil.

The surface of the metal foil used as the metal layer may be surface-treated, for example, by rust-preventive treatment, siding, aluminum alcoholate, aluminum chelate, silane coupling agent, or the like.

In the metal-clad laminate of the present embodiment, for example, the thickness of the metal layer when used for manufacturing FPC is preferably in the range of 3 to 50 μm, more preferably in the range of 5 to 30 μm, but in the circuit pattern. The range of 5 to 20 μm is most preferable in order to reduce the line width. The thickness of the metal layer is preferably thick from the viewpoint of suppressing an increase in conductor loss in high-frequency transmission, but on the other hand, if the thickness becomes too large, it becomes difficult to apply it to miniaturization and the flexibility decreases. When the circuit is processed, the adhesiveness between the wiring layer and the insulating resin layer may be impaired. Considering such a trade-off relationship, the thickness of the metal layer may be within the above range.

Further, from the viewpoint of achieving both high-frequency transmission characteristics and adhesiveness to the resin laminate, the ten-point average roughness (Rz) of the surface of the metal layer in contact with the thermoplastic polyimide layer is 1.2 μm or less, which is 0.05. It is preferably in the range of about 1.0 μm. From the same viewpoint, the arithmetic mean height (Ra) of the surface of the metal layer in contact with the thermoplastic polyimide layer is preferably 0.2 μm or less.

In the metal-clad laminate of the present embodiment, a commercially available copper foil can be used as the metal layer. Specific examples thereof include copper foil CF-T49A-DS-HD (trade name) manufactured by Fukuda Metal Leaf Powder Industry Co., Ltd., copper foil TQ-M4-VSP (trade name) manufactured by Mitsui Mining & Smelting Co., Ltd., and JX Metal Co., Ltd. Examples thereof include copper foil GHY5-HA-V2 (trade name) and BHY (X) -HA-V2 (trade name) manufactured by the same company.

<Manufacturing method of metal-clad laminate>
The metal-clad laminate can be manufactured by, for example, the following method 1, method 2 or method 3.
[Method 1]
The polyimide sheet to be the intermediate layer (B) is the second insulation of the first insulating resin layer (P1) of the first single-sided metal-clad laminate (C1) and the second single-sided metal-clad laminate (C2). A method in which the resin layer (P2) is placed between the resin layer (P2), bonded, and thermocompression bonded.
[Method 2]
The solution of the polyamic acid to be the intermediate layer (B) is applied to the first insulating resin layer (P1) of the first single-sided metal-clad laminate (C1) or the second of the second single-sided metal-clad laminate (C2). A method of applying and drying to one or both of the insulating resin layers (P2) of the above to a predetermined thickness, and then attaching the side of the coating film to thermocompression bonding.
[Method 3]
After applying a polyamic acid solution on the metal layer and drying it, imidize it to form a polyimide layer to prepare a single-sided metal-clad laminate, and then bond the metal layer to the insulating resin layer of the single-sided metal-clad laminate. , How to heat crimp.

The polyimide sheet used in Method 1 is, for example, (1) a method in which a solution of polyamic acid is applied to an arbitrary supporting base material, dried, heat-treated to imidize, and then peeled off from the supporting base material to obtain a polyimide sheet. (2) A method of applying a polyamic acid solution to an arbitrary supporting base material, drying it, peeling the polyamic acid gel film from the supporting base material, and heat-treating it to imidize it into a polyimide sheet. (3) Supporting group It can be manufactured by a method of applying the above-mentioned adhesive polyimide solution to a material, drying it, and then peeling it off from a supporting base material to form a polyimide sheet.
Further, in the above, the method of applying the polyimide solution (or the polyamic acid solution) on the supporting base material or the insulating resin layer is not particularly limited, and for example, the polyimide solution may be applied with a coater such as a comma, a die, a knife, or a lip. Is possible.

The metal-clad laminate (C) of the present embodiment obtained as described above is subjected to wiring circuit processing by etching the first metal layer (M1) and / or the second metal layer (M2). Thereby, a circuit board such as a single-sided FPC or a double-sided FPC can be manufactured.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In the following examples, various measurements and evaluations are as follows unless otherwise specified.

[Measurement of viscosity]
The viscosity at 25 ° C. was measured using an E-type viscometer (manufactured by Brookfield, trade name; DV-II + Pro). The rotation speed was set so that the torque was 10% to 90%, and 2 minutes after the start of the measurement, the value when the viscosity became stable was read.

[Measurement of glass transition temperature (Tg)]
A polyimide film having a size of 5 mm × 20 mm was heated from 30 ° C. to 400 ° C. at a heating rate of 4 ° C./min using a dynamic viscoelasticity measuring device (DMA: UBM Co., Ltd., trade name; E4000F). The measurement was performed at a frequency of 11 Hz, and the temperature at which the elastic modulus change (tan δ) was maximized was defined as the glass transition temperature. “Thermoplastic” means that the storage elastic modulus at 30 ° C. measured using DMA is 1.0 × 10 ⁹ Pa or more and the storage elastic modulus at 300 ° C. is less than 3.0 × 10 ⁸ Pa. 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 was defined as “non-thermoplastic”.

[Measurement of coefficient of thermal expansion (CTE)]
A polyimide film having a size of 3 mm × 20 mm was heated from 30 ° C. to 265 ° C. at a constant heating rate while applying a load of 5.0 g using a thermomechanical analyzer (manufactured by Bruker, trade name; 4000SA). Further, after holding at that temperature for 10 minutes, the mixture was cooled at a rate of 5 ° C./min to obtain an average coefficient of thermal expansion (coefficient of thermal expansion) from 250 ° C. to 100 ° C.

[Measurement of hygroscopicity]
Two test pieces of polyimide film (width 4 cm × length 25 cm) were prepared and dried at 80 ° C. for 1 hour. Immediately after drying, the mixture was placed in a constant temperature and humidity chamber at 23 ° C./50% RH and allowed to stand for 24 hours or more, and the weight change before and after that was calculated by the following formula.
Hygroscopicity (% by weight) = [(Weight after moisture absorption-Weight after drying) / Weight after drying] x 100

[Measurement of surface roughness of copper foil]
1) Measurement of root mean square roughness (Rq) Using a stylus type surface roughness meter (manufactured by Kosaka Laboratory Co., Ltd., trade name; surfcoder ET-3000), Force; 100 μN, Speed; 20 μm, Range; 800 μm. Obtained according to the measurement conditions. The surface roughness was calculated by a method based on JIS-B0601: 2001.
2) Measurement of Arithmetic Mean Height (Ra) Using a stylus type surface roughness meter (manufactured by Kosaka Laboratory Co., Ltd., trade name; surfcoder ET-3000), Force; 100 μN, Speed; 20 μm, Range; 800 μm. Obtained according to the measurement conditions. The surface roughness was calculated by a method based on JIS-B0601: 1994.
3) Measurement of 10-point average roughness (Rz) Using a stylus type surface roughness meter (manufactured by Kosaka Laboratory Co., Ltd., trade name; Surfcoder ET-3000), Force; 100 μN, Speed; 20 μm, Range; 800 μm It was obtained according to the measurement conditions of. The surface roughness was calculated by a method based on JIS-B0601: 1994.

[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, dissolve the analysis surface with 1N-nitric acid, set the volume to 100 mL, and then measure using an inductively coupled plasma emission spectrophotometer (ICP-AES) Optima 4300 manufactured by PerkinElmer. did.

[Measurement of permittivity and dielectric loss tangent]
The dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet at a predetermined frequency were measured using a vector network analyzer (manufactured by Agilent, trade name E8633C) and a split post dielectric resonator (SPDR resonator). The material used for the measurement was left for 24 hours under the conditions of temperature; 24-26 ° C. and humidity; 45-55%.

[Calculation of imide group concentration]
The imide group concentration was defined as the value obtained by dividing the molecular weight of the imide base (-(CO) ₂ -N-) by the molecular weight of the entire polyimide structure.

[Measurement of dimensional change rate]
A metal-clad laminate having a size of 80 mm × 80 mm was prepared. After providing a dry film resist on the metal layer of this laminated plate, it is exposed and developed, and as shown in FIG. 1, 5 points are formed at intervals of 50 mm in the vertical direction (MD) and the horizontal direction (TD), respectively. Sixteen resist patterns having a diameter of 1 mm were formed so as to be measurable, and a position measurement target was prepared.
After measuring the distance between the targets of the resist pattern in the position measurement target in an atmosphere of temperature; 23 ± 2 ° C. and relative humidity; 50 ± 5%, the exposed part of the metal layer of the resist pattern opening is etched. It was removed by (etching liquid temperature; 40 ° C. or lower, etching time; within 10 minutes), and as shown in FIG. 2, an evaluation sample having 16 metal layer residual points was prepared. This evaluation sample was allowed to stand in an atmosphere of temperature; 23 ± 2 ° C. and relative humidity; 50 ± 5% for 24 ± 4 hours, and then the distance between the residual points of the metal layer was measured. The dimensional change rate for each of the five normal conditions in the vertical direction and the horizontal direction is calculated, and the average value of each is used as the dimensional change rate after etching.
Next, the evaluation sample was heat-treated in an oven at 120 ° C. for 1 hour, and the distance between the remaining metal layer points was measured thereafter. The dimensional change rate after heating is calculated at each of the five locations in the vertical direction and the horizontal direction, and the average value of each is used as the dimensional change rate after heating.
Each dimensional change rate was calculated by the following formula.
Dimensional change rate after etching (%) = (BA) / A × 100
A; Distance between targets after resist development B; Distance between remaining metal layer points after metal layer etching Dimensional change rate after heating (%) = (CB) / B x 100
B; Distance between the remaining points of the metal layer after etching the metal layer C; Distance between the remaining points of the metal layer after heating

The abbreviations used in the synthetic examples indicate the following compounds.
BTDA: 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride PMDA: pyromellitic acid dianhydride BPDA: 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride DSDA: 3,, 3', 4,4'-Diphenylsulfone tetracarboxylic acid dianhydride DAPE: 4,4'-diaminodiphenyl ether p-PDA: p-phenylenediamine BAPP: 2,2-bis [4- (4-aminophenoxy) phenyl ] Propane m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl TPE-R: 1,3-bis (4-aminophenoxy) benzeneDMAc: N, N-dimethylacetamide

The copper foil used in Examples and Reference Examples shows the following copper foil.
Copper foil 1: Electrolytic copper foil, thickness; 12 μm, Rz; 0.5 μm, Ra; 0.1 μm, Rq; 0.2 μm, maximum roughening height of roughening treatment; 0.25 μm, Ni; 0 .01 mg / dm ² , Zn; 0.11 mg / dm ² , Cr; 0.14 mg / dm ² , Co; 0.36 mg / dm ² , Mo; 0.23 mg / dm ² )

(Synthesis Example 1)
312 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. 14.67 g of DAPE (0.073 mol) was dissolved in this reaction vessel with stirring in the vessel. Next, 23.13 g of BTDA (0.072 mol) was added. Then, stirring was continued for 3 hours to prepare a resin solution a (solution viscosity; 2,960 mPa · s) of polyamic acid.

Next, a resin solution a of polyamic acid was uniformly applied to one side (Rz; 2.1 μm) of an electrolytic copper foil having a thickness of 12 μm so that the cured thickness would be about 25 μm, and then heated and dried at 120 ° C. The solvent was removed. Further, a stepwise heat treatment from 120 ° C. to 360 ° C. was performed within 30 minutes to complete the imidization. The copper foil was removed by etching with an aqueous solution of ferric chloride to prepare a polyimide film a (thermoplastic, Tg; 283 ° C., CTE; 53 ppm / K, moisture absorption rate; 1.3% by weight).

(Synthesis Example 2)
312 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. 0.6.60 g of a spherical filler (silica, average particle size 1.2 μm, manufactured by Admatex, “SE4050”) was added to this reaction vessel, and the mixture was dispersed by an ultrasonic disperser for 3 hours. 14.67 g of DAPE (0.073 mol) was dissolved in this solution in a container with stirring. Next, 23.13 g of BTDA (0.072 mol) was added. Then, stirring was continued for 3 hours to prepare a resin solution b of polyamic acid (solution viscosity; 3,160 mPa · s, silica content; 10% by volume).

(Synthesis Example 3)
308 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. 27.14 g of BAPP (0.066 mol) was dissolved in this reaction vessel with stirring in the vessel. Next, 14.86 g of PMDA (0.068 mol) was added. Then, stirring was continued for 3 hours to prepare a resin solution c (solution viscosity; 2,850 mPa · s) of polyamic acid.

A polyimide film c (thermoplastic, Tg; 312 ° C., CTE; 55 ppm / K, moisture absorption rate; 0.5% by weight) was prepared using the resin solution c of polyamic acid in the same manner as in Synthesis Example 1.

(Synthesis Example 4)
250 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. 2.561 g of p-PDA (0.0237 mol) and 16.813 g of DAPE (0.0840 mol) were dissolved in this reaction vessel with stirring in the vessel. Next, 18.501 g of PMDA (0.0848 mol) and 6.239 g of BPDA (0.0212 mol) were added. Then, stirring was continued for 3 hours to prepare a resin solution d (solution viscosity; 29,500 mPa · s) of polyamic acid.

Polyimide film d (non-thermoplastic, Tg; 375 ° C., CTE; 17 ppm / K, moisture absorption, similar to Synthesis Example 1 except that the thickness after curing was set to about 50 μm using the resin solution d of polyamic acid. Rate; 0.9% by weight) was prepared.

(Synthesis Example 5)
255 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. 22.13 g of TPE-R (0.076 mol) was dissolved in this reaction vessel with stirring in the vessel. Next, 16.17 g of DSDA (0.047 mol) and 6.78 g of PMDA (0.031 mol) were added. Then, stirring was continued for 2 hours to prepare a resin solution e (solution viscosity; 2,640 mPa · s) of polyamic acid.

A polyimide film e (thermoplastic, Tg; 277 ° C., CTE; 61 ppm / K, hygroscopicity; 0.9% by weight) was prepared using the resin solution e of polyamic acid in the same manner as in Synthesis Example 1.

(Synthesis Example 6)
200 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. 1.335 g of m-TB (0.0063 mol) and 10.414 g of TPE-R (0.0356 mol) were dissolved in this reaction vessel with stirring in the vessel. Next, 0.932 g of PMDA (0.0043 mol) and 11.319 g of BPDA (0.0385 mol) were added. Then, stirring was continued for 2 hours to prepare a resin solution f (solution viscosity 1,420 mPa · s) of polyamic acid.

A polyimide film f (thermoplastic, Tg; 256 ° C., CTE; 52 ppm / K, hygroscopicity; 0.4% by weight) was prepared using the resin solution f of polyamic acid in the same manner as in Synthesis Example 1.

(Synthesis Example 7)
250 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. 12.323 g of m-TB (0.0580 mol) and 1.886 g of TPE-R (0.0064 mol) were dissolved in this reaction vessel with stirring in the vessel. Next, 8.314 g of PMDA (0.0381 mol) and 7.477 g of BPDA (0.0254 mol) were added. Then, stirring was continued for 3 hours to prepare a resin solution g (solution viscosity; 31,500 mPa · s) of polyamic acid.

Polyimide film g (non-thermoplastic, Tg; 342 ° C., CTE; 16 ppm / K, moisture absorption, similar to Synthesis Example 1 except that the thickness after curing was set to about 50 μm using the resin solution g of polyamic acid. Rate; 0.6% by weight) was prepared.

(Synthesis Example 8)
250 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. 21.218 g of DAPE (0.1063 mol) was dissolved in this reaction vessel with stirring in the vessel. Next, 22.834 g of PMDA (0.1047 mol) was added. Then, stirring was continued for 3 hours to prepare a resin solution h (solution viscosity; 26,500 mPa · s) of polyamic acid.

Polyimide film h (non-thermoplastic, Tg; 394 ° C., CTE; 43 ppm / K, moisture absorption, similar to Synthesis Example 1 except that the thickness after curing was set to about 50 μm using the resin solution h of polyamic acid. Rate; 1.2% by weight) was prepared.

(Production Example 1)
<Preparation of single-sided metal-clad laminate>
The resin solution f was uniformly applied to the surface of the copper foil 1 so that the thickness after curing was about 2 to 3 μm, and then dried by heating at 120 ° C. to remove the solvent. Next, the resin solution g was uniformly applied onto the resin solution g so as to have a thickness of about 21 μm after curing, and then heat-dried at 120 ° C. to remove the solvent. Further, the resin solution a was uniformly applied thereto so as to have a thickness of about 2 to 3 μm after curing, and then heat-dried at 120 ° C. to remove the solvent. In this way, after forming the three polyamic acid layers, a stepwise heat treatment is performed from 120 ° C. to 360 ° C. to complete imidization, and a single-sided copper-clad laminate 1A having a polyimide layer thickness of 25 μm is prepared. did.

(Production Example 2)
<Preparation of single-sided metal-clad laminate>
The resin solution f was uniformly applied to the surface of the copper foil 1 so that the thickness after curing was about 2 to 3 μm, and then dried by heating at 120 ° C. to remove the solvent. Next, the resin solution g was uniformly applied onto the resin solution g so as to have a thickness of about 21 μm after curing, and then heat-dried at 120 ° C. to remove the solvent. Further, the resin solution b was uniformly applied onto the resin solution b so as to have a thickness of about 2 to 3 μm after curing, and then dried by heating at 120 ° C. to remove the solvent. In this way, after forming the three polyamic acid layers, a stepwise heat treatment is performed from 120 ° C. to 360 ° C. to complete imidization, and a single-sided copper-clad laminate 2A having a polyimide layer thickness of 25 μm is prepared. did.

(Production Example 3)
<Preparation of single-sided metal-clad laminate>
The resin solution f was uniformly applied to the surface of the copper foil 1 so that the thickness after curing was about 2 to 3 μm, and then dried by heating at 120 ° C. to remove the solvent. Next, the resin solution g was uniformly applied onto the resin solution g so as to have a thickness of about 21 μm after curing, and then heat-dried at 120 ° C. to remove the solvent. Further, the resin solution c was uniformly applied onto the resin solution c so as to have a thickness of about 2 to 3 μm after curing, and then dried by heating at 120 ° C. to remove the solvent. In this way, after forming the three polyamic acid layers, a stepwise heat treatment is performed from 120 ° C. to 360 ° C. to complete imidization, and a single-sided copper-clad laminate 3A having a polyimide layer thickness of 25 μm is prepared. did.

(Production Example 4)
<Preparation of single-sided metal-clad laminate>
The resin solution f was uniformly applied to the surface of the copper foil 1 so that the thickness after curing was about 2 to 3 μm, and then dried by heating at 120 ° C. to remove the solvent. Next, the resin solution g was uniformly applied onto the resin solution g so as to have a thickness of about 21 μm after curing, and then heat-dried at 120 ° C. to remove the solvent. Further, the resin solution e was uniformly applied onto the resin solution e so as to have a thickness of about 2 to 3 μm after curing, and then dried by heating at 120 ° C. to remove the solvent. In this way, after forming the three polyamic acid layers, a stepwise heat treatment is performed from 120 ° C. to 360 ° C. to complete imidization, and a single-sided copper-clad laminate 4A having a polyimide layer thickness of 25 μm is prepared. did.

(Production Example 5)
<Preparation of single-sided metal-clad laminate>
The resin solution f was uniformly applied to the surface of the copper foil 1 so that the thickness after curing was about 2 to 3 μm, and then dried by heating at 120 ° C. to remove the solvent. Next, the resin solution g was uniformly applied onto the resin solution g so as to have a thickness of about 21 μm after curing, and then heat-dried at 120 ° C. to remove the solvent. Further, the resin solution f was uniformly applied onto the resin solution f so as to have a thickness of about 2 to 3 μm after curing, and then dried by heating at 120 ° C. to remove the solvent. In this way, after forming the three polyamic acid layers, a stepwise heat treatment is performed from 120 ° C. to 360 ° C. to complete imidization, and a single-sided copper-clad laminate 5A having a polyimide layer thickness of 25 μm is prepared. did.

(Production Example 6)
<Preparation of polyimide film>
The copper foil layer of the single-sided metal-clad laminate 5A was removed by etching with an aqueous solution of ferric chloride to obtain a polyimide film 5B (thickness; 25 μm, CTE; 23 ppm / K, Dk; 3.4, Df; 0.0032). Prepared.

(Production Example 7)
<Preparation of single-sided metal-clad laminate>
The resin solution f was uniformly applied to the surface of the copper foil 1 so that the thickness after curing was about 2 to 3 μm, and then dried by heating at 120 ° C. to remove the solvent. Next, the resin solution g was uniformly applied onto the resin solution g so as to have a thickness of about 46 μm after curing, and then heat-dried at 120 ° C. to remove the solvent. Further, the resin solution f was uniformly applied onto the resin solution f so as to have a thickness of about 2 to 3 μm after curing, and then dried by heating at 120 ° C. to remove the solvent. In this way, after forming the three polyamic acid layers, a stepwise heat treatment is performed from 120 ° C. to 360 ° C. to complete imidization, and a single-sided copper-clad laminate 6A having a polyimide layer thickness of 50 μm is prepared. did.

(Production Example 8)
<Preparation of polyimide film>
The copper foil layer of the single-sided metal-clad laminate 6A was removed by etching with an aqueous solution of ferric chloride to obtain a polyimide film 6B (thickness; 50 μm, CTE; 24 ppm / K, Dk; 3.4, Df; 0.0033). Prepared.

[Example 1]
Two single-sided copper-clad laminates 5A and one polyimide film d are prepared, and the surface of the single-sided copper-clad laminate 5A on the insulating resin layer side is laminated on the polyimide film d, and the single-sided copper-clad laminate 5A and the polyimide film are laminated. d, the single-sided copper-clad laminate 5A was laminated in this order, and crimped by applying a pressure of 6.8 MPa at 320 ° C. for 30 minutes. The polyimide layer had a thickness of 100 μm and was a non-thermoplastic polyimide layer (resin) for the entire resin laminate. A double-sided copper-clad laminate 1 having a thickness ratio of 92% of the polyimide layer formed by the solution d and the resin solution g) was prepared. The evaluation results of the double-sided copper-clad laminate 1 are as follows.
Dimensional change rate after etching in the MD direction (longitudinal direction); 0.04%
Dimensional change rate after etching in the TD direction (width direction); 0.04%
Dimensional change rate after heating in MD direction (longitudinal direction); -0.05%
Dimensional change rate after heating in the TD direction (width direction); -0.04%
The double-sided copper-clad laminate 1 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 1 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 1 were 3.4 and 0.0066, respectively. The results of these evaluations are shown in Table 1.

[Example 2]
Two single-sided copper-clad laminates 5A and two polyimide films 5B are prepared, and the surface of the single-sided copper-clad laminate 5A on the insulating resin layer side is laminated on the polyimide film 5B, and the single-sided copper-clad laminate 5A and the polyimide film are laminated. 5B, polyimide film 5B, and single-sided copper-clad laminate 5A were laminated in this order and pressure-bonded at 320 ° C. for 30 minutes with a pressure of 6.8 MPa. A double-sided copper-clad laminate 2 having a thickness ratio of the thermoplastic polyimide layer (polyimide layer formed by the resin solution g) of 84% was prepared. The evaluation results of the double-sided copper-clad laminate 2 are as follows.
Dimensional change rate after etching in the MD direction (longitudinal direction); 0.00%
Dimensional change rate after etching in the TD direction (width direction); 0.00%
Dimensional change rate after heating in MD direction (longitudinal direction); -0.07%
Dimensional change rate after heating in the TD direction (width direction); -0.08%
The double-sided copper-clad laminate 2 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 2 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 2 were 3.4 and 0.0032, respectively. The results of these evaluations are shown in Table 1.

[Reference Example 1]
Two single-sided copper-clad laminates 5A and one polyimide film h are prepared, and the surface of the single-sided copper-clad laminate 5A on the insulating resin layer side is laminated on the polyimide film h, and the single-sided copper-clad laminate 5A and the polyimide film are laminated. h, the single-sided copper-clad laminate 5A was laminated in this order, and pressure-bonded at 320 ° C. for 30 minutes with a pressure of 6.8 MPa. The thickness of the resin laminate was 100 μm and the non-thermoplastic polyimide layer for the entire resin laminate ( A double-sided copper-clad laminate 3 having a thickness ratio of 92% of the resin solution g and the polyimide layer formed by the resin solution h) was prepared. The evaluation results of the double-sided copper-clad laminate 3 are as follows.
Dimensional change rate after etching in the MD direction (longitudinal direction); -0.03%
Dimensional change rate after etching in the TD direction (width direction); -0.02%
Dimensional change rate after heating in MD direction (longitudinal direction); -0.14%
Dimensional change rate after heating in the TD direction (width direction); -0.14%
The dimensional change rate after heating of the double-sided copper-clad laminate was a large value exceeding ± 0.1%. The Dk and Df (10 GHz) of the resin laminate 3 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 3 were 3.5 and 0.0093, respectively. The results of these evaluations are shown in Table 1.

[Reference Example 2]
Two single-sided copper-clad laminates 5A and one fluororesin film (manufactured by Asahi Glass Co., Ltd., trade name; adhesive perfluororesin EA-2000, thickness; 50 μm, Tg; none) were prepared, and the single-sided copper-clad laminate 5A was prepared. The surface on the insulating resin layer side is laminated on the fluororesin film, and the single-sided copper-clad laminate 5A, the fluororesin film, and the single-sided copper-clad laminate 5A are laminated in this order, and a pressure of 3.5 MPa is applied at 320 ° C. for 5 minutes. By crimping, a double-sided copper-clad laminate 4 having a resin laminate thickness of 100 μm was prepared. The evaluation results of the double-sided copper-clad laminate 4 are as follows.
Dimensional change rate after etching in the MD direction (longitudinal direction); -0.13%
Dimensional change rate after etching in the TD direction (width direction); -0.15%
Dimensional change rate after heating in MD direction (longitudinal direction); -0.18%
Dimensional change rate after heating in the TD direction (width direction); -0.19%
The dimensional change rate after etching and the dimensional change rate after heating of the double-sided copper-clad laminate became large values exceeding ± 0.1%. The Dk and Df (10 GHz) of the resin laminate 4 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 4 were 2.9 and 0.0025, respectively. The results of these evaluations are shown in Table 1.

[Example 3]
Similar to Example 1, the thickness of the resin laminate is 100 μm, and the non-thermoplastic polyimide layer (formed by the resin solution g) with respect to the entire resin laminate is formed, except that the polyimide film g is used instead of the polyimide film d. A double-sided copper-clad laminate 5 having a thickness ratio of 92% was adjusted. The double-sided copper-clad laminate 5 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 5 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 5 were 3.4 and 0.0033, respectively.

[Example 4]
Similar to Example 2, the thickness of the resin laminate is 100 μm, and the non-thermoplastic polyimide layer for the entire resin laminate is used, except that the single-sided copper-clad laminate 1A is used instead of the single-sided copper-clad laminate 5A. A double-sided copper-clad laminate 6 having a thickness ratio of 84% (polyimide layer formed of the resin solution g) was adjusted. The double-sided copper-clad laminate 6 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 6 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 6 were 3.4 and 0.0038, respectively.

[Example 5]
Similar to Example 2, the thickness of the resin laminate is 100 μm, and the non-thermoplastic polyimide layer for the entire resin laminate is used, except that the single-sided copper-clad laminate 2A is used instead of the single-sided copper-clad laminate 5A. A double-sided copper-clad laminate 7 having a thickness ratio of 84% (polyimide layer formed of the resin solution g) was adjusted. The double-sided copper-clad laminate 7 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 7 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 7 were 3.4 and 0.0039, respectively.

[Example 6]
Similar to Example 2, the thickness of the resin laminate was 100 μm, and the resin laminate was used as a whole, except that the single-sided copper-clad laminate 3A was used instead of the single-sided copper-clad laminate 5A and crimped at 380 ° C. A double-sided copper-clad laminate 8 having a thickness ratio of a non-thermoplastic polyimide layer (polyimide layer formed by the resin solution g) of 84% was adjusted. The double-sided copper-clad laminate 8 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 8 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 8 were 3.3 and 0.0034, respectively.

[Example 7]
Similar to Example 2, the thickness of the resin laminate is 100 μm, and the non-thermoplastic polyimide layer for the entire resin laminate is used, except that the single-sided copper-clad laminate 4A is used instead of the single-sided copper-clad laminate 5A. A double-sided copper-clad laminate 9 having a thickness ratio of 84% (polyimide layer formed of the resin solution g) was adjusted. The double-sided copper-clad laminate 9 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 9 (thickness; 100 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 9 were 3.4 and 0.0041, respectively.

[Example 8]
Similar to Example 2, the thickness of the resin laminate is 75 μm, and the non-thermoplastic polyimide layer for the entire resin laminate is used, except that one polyimide film 5B is used instead of the two polyimide films 5B. A double-sided copper-clad laminate 10 having a thickness ratio of 84% (polyimide layer formed of the resin solution g) was adjusted. The double-sided copper-clad laminate 10 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 10 (thickness; 75 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 10 were 3.4 and 0.0032, respectively.

[Example 9]
Similar to Example 8, the resin laminate has a thickness of 150 μm and is a resin laminate, except that the single-sided copper-clad laminate 6A and the polyimide film 6B are used instead of the single-sided copper-clad laminate 5A and the polyimide film 5B. The double-sided copper-clad laminate 11 having a thickness ratio of the non-thermoplastic polyimide layer (polyimide layer formed by the resin solution g) of 92% to the whole was adjusted. The double-sided copper-clad laminate 11 did not warp, and there was no problem in dimensional change. The Dk and Df (10 GHz) of the resin laminate 11 (thickness; 150 μm) prepared by etching and removing the copper foil layer in the double-sided copper-clad laminate 11 were 3.4 and 0.0033, respectively.

Although the embodiments of the present invention have been described in detail for the purpose of illustration, the present invention is not limited to the above embodiments and can be modified in various ways.

Claims (10)

A metal-clad laminate comprising a resin laminate including a plurality of polyimide layers and a metal layer laminated on at least one surface of the resin laminate.
The resin laminate includes at least three non-thermoplastic polyimide layers made of non-thermoplastic polyimide and at least four thermoplastic polyimide layers made of thermoplastic polyimide.
The outermost layer of the resin laminate is made of the thermoplastic polyimide layer.
The non-thermoplastic polyimide layer is laminated via the thermoplastic polyimide layer.
The non-thermoplastic polyimide contains a tetracarboxylic acid residue and a diamine residue, and a diamine residue derived from a diamine compound represented by the following general formula (1) with respect to 100 mol parts of all diamine residues. A metal-clad laminate characterized by having a portion of 20 mol or more.

[In the formula (1), the linking group Z represents a single bond or —COO—, and Y may be independently substituted with a halogen element or a phenyl group, and is a monovalent hydrocarbon group having 1 to 3 carbon atoms or a carbon number of carbon atoms. It represents an alkoxy group of 1 to 3 or a perfluoroalkyl group or an alkenyl group having 1 to 3 carbon atoms, n represents an integer of 0 to 2, and p and q independently represent an integer of 0 to 4. ] In the non-thermal polyimide constituting at least two non-thermal polyimide layers of the non-thermal polyimide layer, Y has 1 to 1 carbon atoms in the general formula (1) with respect to 100 mol parts of all diamine residues. It contains a diamine residue derived from a diamine compound which is a monovalent hydrocarbon group or an alkoxy group of 3 and n is an integer of 1 or 2, in the range of 70 mol parts or more and 98 mol parts or less, and is described below. The metal-clad laminate according to claim 1, wherein the diamine residue derived from the diamine compound represented by the general formulas (C1) to (C4) is contained in the range of 2 to 15 mol parts.

[In the formulas (C1) to (C4), R ₂ independently represents a monovalent hydrocarbon group, an alkoxy group or an alkylthio group having 1 to 6 carbon atoms, and the linking group A'is independently -O-, -SO. A _divalent group selected from 2-, -CH _2- or -C (CH ₃ ) _2- , and the linking group X1 is independently -CH _2- , -O-CH ₂ -O-, -OC. ₂ H ₄ -O-, -O-C ₃ H ₆ -O-, -O-C ₄ H ₈ -O-, -O-C ₅ H ₁₀ -O-, -O-CH ₂ -C (CH ₃ ) ) ₂ -CH ₂ -O-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- or -SO _2- , n ₃ independently indicates an integer of 1 to 4, and n ₄ is. Independently, an integer of 0 to 4 is shown, but in the formula (C3), the linking group A'is -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- or -SO _2-- . If is not included, any one of n ₄ is 1 or more. ] The non-thermoplastic polyimide constituting at least two non-thermoplastic polyimide layers of the non-thermal polyimide has 3,3', 4,4'-biphenyltetracarboxylic acid with respect to 100 mol of all tetracarboxylic acid residues. Within 30-60 mol parts of tetracarboxylic acid residues derived from at least one of acid dianhydride (BPDA) and 1,4-phenylenebis (trimeritic acid monoester) dianhydride (TAHQ). Within 40-70 mol parts of tetracarboxylic acid residues derived from at least one of pyromellitic acid dianhydride (PMDA) and 2,3,6,7-naphthalenetetracarboxylic acid dianhydride (NTCDA). The metal-clad laminate according to claim 1 or 2, wherein the metal-clad laminate is contained in 1. In the non-thermoplastic polyimide constituting at least three non-thermoplastic polyimide layers of the non-thermoplastic polyimide layer, Y has 1 to 1 carbon atoms in the general formula (1) with respect to 100 mol parts of all diamine residues. It contains 70 mol parts or more of a diamine residue derived from a diamine compound which is a monovalent hydrocarbon group or an alkoxy group of 3 and n is an integer of 1 or 2, and has the above general formulas (C1) to (C4). The metal-clad laminate according to any one of claims 1 to 3, wherein the diamine residue derived from the diamine compound represented by) is contained in the range of 2 to 15 mol parts. The non-thermoplastic polyimide constituting at least three non-thermoplastic polyimide layers of the non-thermoplastic polyimide layer is 3,3', 4,4'-biphenyltetra with respect to 100 mol parts of all tetracarboxylic acid residues. Within 30-60 mol parts of tetracarboxylic acid residues derived from at least one of carboxylic acid dianhydride (BPDA) and 1,4-phenylenebis (trimellitic acid monoester) dianhydride (TAHQ). , 40-70 mol parts of tetracarboxylic acid residues derived from at least one of pyromellitic acid dianhydride (PMDA) and 2,3,6,7-naphthalenetetracarboxylic acid dianhydride (NTCDA). The metal-clad laminate according to any one of claims 1 to 4, wherein the metal-clad laminate is contained therein. The thermoplastic polyimide constituting the thermoplastic polyimide layer of the outermost layer of the resin laminate contains a tetracarboxylic acid residue and a diamine residue, and has the following general formula with respect to 100 mol parts of the total amount of the diamine residue. The item according to any one of claims 1 to 5, wherein the diamine residue derived from at least one diamine compound selected from the diamine compounds represented by B1) to (B7) is 60 mol parts or more. The described metal-clad laminate.

[In the formulas (B1) to (B7), R ₁ independently represents a monovalent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms, and the linking group A is independently -O-, -S-, -CO. -, -SO-, -SO _2- , -COO, -CH _2- , -C (CH ₃ ) _2- , NH- or -CONH- indicates a divalent group selected from, n ₁ is 0 independently. Indicates an integer of ~ 4. However, the formula (B3) that overlaps with the formula (B2) is excluded, and the formula (B5) that overlaps with the formula (B4) is excluded. ] The metal-clad laminate according to any one of claims 1 to 6, wherein both the non-thermoplastic polyimide and the thermoplastic polyimide have an imide group concentration of 33% or less. The total thickness of the resin laminate is in the range of 25 to 180 μm, and the total thickness of the non-thermoplastic polyimide layer is in the range of 50 to 97% with respect to the total thickness of the resin laminate. The metal-clad laminate according to any one of claims 1 to 7, wherein the metal-clad laminate is characterized by the above. The metal-clad laminate according to any one of claims 1 to 8, wherein the resin laminate has a layer structure symmetrical with respect to the center in the thickness direction. A circuit board obtained by processing the metal layer of the metal-clad laminate according to any one of claims 1 to 9 into a wiring circuit.

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