JP5890764B2 - Copper-clad laminate and circuit board - Google Patents

Description

  The present invention relates to a copper-clad laminate that can be used for manufacturing flexible printed wiring boards and the like, and a circuit board using the same.

  In recent years, with the progress of downsizing, weight reduction, and space saving of electronic devices, flexible printed wiring boards (FPCs) that are thin, light, flexible, and have excellent durability even after repeated bending are used. The demand for Circuits) is increasing. FPC can be mounted three-dimensionally and densely in a limited space. For example, it can be used for wiring of movable parts of electronic devices such as HDDs, DVDs, mobile phones, and parts such as cables and connectors. It is expanding.

  From the viewpoint of reducing the weight of automobiles, the use of FPC is increasing in various parts, such as around the engine of an automobile (specifically, engine, intake manifold, alternator, radiator, etc.), gearbox, transmission, etc. ing.

  Polyimide esters and polyimides are often used for the insulating resin serving as a base material for FPC, but the amount of heat-resistant polyimide is overwhelmingly large. On the other hand, copper foil is generally used as the conductive material because of its excellent conductivity.

Regarding the metal foil used for FPC, in patent document 1, in order to raise the peeling strength of the polyimide layer and copper foil in a polyimide metal laminated board, the adhesion amount of zinc of the surface which contacts the polyimide layer of copper foil is 0.07 mg / It has been proposed to use one that is dm ² or less.

Moreover, in patent document 2, the metal precipitation process which deposits at least nickel, zinc, and cobalt and the process by a coupling agent are given to the surface of copper foil whose surface roughness Rz is 0.3-1.0 micrometer. Has been proposed. In this patent document 2, the surface of the copper foil subjected to the metal deposition treatment is supposed to have nickel 5 to 15 μg / cm ² , zinc 1 to 5 μg / cm ² , and cobalt 0.1 to 5 μg / cm ² .

Japanese Patent No. 3664708 JP 2011-66431 A

  In addition to being repeatedly exposed to high-temperature environments, automobile FPCs have a feature that there are many opportunities to come into contact with oil (for example, engine oil, transmission oil, etc.). However, while FPC is repeatedly exposed to oil, there is a problem that the adhesion between the resin layer and the wiring layer is lowered, and the wiring layer is easily peeled off. Therefore, the copper clad laminate (CCL) used for automotive FPC has a copper foil and resin layer in a high temperature environment and oil adhesion environment in addition to the characteristics required for general electrical and electronic equipment. It is required that high adhesion can be maintained.

  Accordingly, an object of the present invention is to provide a laminate and a circuit board in which the adhesive strength between a copper foil and a resin layer is unlikely to deteriorate even in a use environment that is repeatedly exposed to high temperatures and oil components.

  As described above, when a circuit board such as an FPC is repeatedly placed in a high temperature environment and an oil adhesion environment, the adhesive force between the wiring layer and the resin layer decreases. As a result of investigating the mechanism of this decrease in adhesive strength, it was estimated that the sulfur component contained in the oil was the cause. Specifically, the sulfur compound derived from oil enters the interface between the copper wiring and the insulating layer, where copper and the sulfur compound react to form a brittle copper sulfide layer. Since cohesive failure occurs in the fragile layer, the adhesive force between the copper foil and the insulating layer is reduced. Further investigation was made on the decrease in adhesive strength (decrease in oil resistance) caused by such a mechanism. When cobalt element is present on the surface of the copper foil by rust prevention treatment, cobalt having high reactivity with the sulfur compound is present. The possibility of triggering the formation of the copper sulfide layer was estimated. Therefore, the present invention has found that the oil resistance of the copper clad laminate and the circuit board can be improved by controlling the amount of cobalt element present on the surface of the copper foil.

That is, the copper clad laminate of the present invention has an insulating layer and a copper foil laminated on at least one surface of the insulating layer, and is used in an oil containing a sulfur-containing organic compound. is there. This copper-clad laminate is characterized in that the amount of cobalt element adhering to the surface of the copper foil in contact with the insulating layer is 2 mg / dm ² or less.

In the copper clad laminate of the present invention, the insulating layer comprises the following components (A) and (B);
(A) a polyamic acid having a weight average molecular weight in the range of 10,000 to 150,000,
And (B) an acrylic compound,
The polyamic acid composition containing 0.1 to 60 parts by weight of the component (B) with respect to 100 parts by weight of the component (A) is heat-treated and imidized. It may include a resin layer of a polyimide composition.

In the copper clad laminate of the present invention, the component (A) has a radical polymerizable unsaturated bond amount of 3 mmol or less per 1 g of weight,
The component (B) may have a value of [number of (meth) acryloyl groups in one molecule / molecular weight] of 0.001 or more.

  The copper clad laminate of the present invention may be one in which the resin layer of the polyimide composition is laminated in contact with the copper foil.

  In the copper clad laminate of the present invention, the insulating layer is a thermoplastic polyimide obtained by heat-treating and imidizing a polyamic acid obtained by a reaction between an aromatic diamine and an aromatic tetracarboxylic dianhydride, The aromatic diamine contains an aromatic diamine having a radical polymerizable unsaturated bond within the range of 2 to 6 carbon atoms, and the amount of the radical polymerizable unsaturated bond within the range of 2 to 6 carbon atoms. However, it may include a thermoplastic polyimide resin layer in a range of 0.096 mmol to 3 mmol per 1 g of the polyamic acid.

  The copper clad laminate of the present invention may be one in which the thermoplastic polyimide resin layer is laminated in contact with the copper foil.

The circuit board of this invention has an insulating layer and the copper wiring layer formed on the said insulating layer, and is used in the oil containing a sulfur containing organic compound. In this circuit board, the copper wiring layer is characterized in that the amount of cobalt element adhering to the surface in contact with the insulating layer is 2 mg / dm ² or less.

In the circuit board of the present invention, the insulating layer includes the following components (A) and (B):
(A) a polyamic acid having a weight average molecular weight in the range of 10,000 to 150,000,
And (B) an acrylic compound,
The polyamic acid composition containing 0.1 to 60 parts by weight of the component (B) with respect to 100 parts by weight of the component (A) is heat-treated and imidized. It may include a resin layer of a polyimide composition.

In the circuit board of the present invention, the component (A) has a radical polymerizable unsaturated bond amount of 3 mmol or less per 1 g of weight,
The component (B) may have a value of [number of (meth) acryloyl groups in one molecule / molecular weight] of 0.001 or more.

  The circuit board of the present invention may be one in which a resin layer of the polyimide composition is laminated in contact with the copper wiring layer.

  In the circuit board of the present invention, the insulating layer is a thermoplastic polyimide obtained by heat-treating and imidizing a polyamic acid obtained by a reaction between an aromatic diamine and an aromatic tetracarboxylic dianhydride, The group diamine contains an aromatic diamine having a radical polymerizable unsaturated bond within the range of 2 to 6 carbon atoms, and the amount of the radical polymerizable unsaturated bond within the range of 2 to 6 carbon atoms is It may contain a resin layer of thermoplastic polyimide in the range of 0.096 mmol to 3 mmol per g of the polyamic acid.

  The circuit board of the present invention may be formed by laminating the thermoplastic polyimide resin layer in contact with the copper foil.

  Even if the copper clad laminate and the circuit board of the present invention are repeatedly placed in a high temperature environment and an oil adhesion environment, the adhesive force between the copper foil and the resin layer does not decrease. Therefore, the reliability of the electronic component can be improved by using the laminate or the circuit board of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail.

[Copper-clad laminate and circuit board]
The copper clad laminate of the present embodiment has an insulating layer and a copper foil laminated on at least one surface of the insulating layer, and is used in oil containing a sulfur-containing organic compound. Moreover, the circuit board of this Embodiment has an insulating layer and the copper wiring layer formed on the said insulating layer, and is used in the oil containing a sulfur containing organic compound.

[Copper foil, copper wiring layer]
In the copper clad laminate and the circuit board of the present embodiment, the copper foil and the copper wiring layer have an amount of cobalt element adhering to the surface in contact with the insulating layer of 2 mg / dm ² or less, preferably 1 mg / dm ² or less. More preferably, it is 0.5 mg / dm ² or less. The smaller the amount of cobalt element on the surfaces of the copper foil and the copper wiring layer, the better, and it is most preferable that the cobalt element is not substantially contained. When the amount of cobalt element exceeds ² mg / dm ² , cobalt is highly reactive with the sulfur compound, and thus triggers the formation of a copper sulfide layer and causes a decrease in the adhesion between the copper foil and the insulating layer. . In addition, a copper alloy can also be used for copper foil.

As copper foil whose amount of cobalt element on the surface is 2 mg / dm ² or less, for example, commercially available products such as electrolytic copper foil F1-WS, F2-WS manufactured by Furukawa Circuit Foil, electrolytic copper foil HLB manufactured by Nippon Electrolytic Co., Ltd. are used. it can.

The copper foil used for the copper clad laminate and the circuit board of the present embodiment may be subjected to rust prevention treatment. As the antirust treatment, for example, nickel treatment, chromate treatment, zinc or zinc alloy film formation treatment, a combination of these treatments, and the like can be performed. Moreover, as an organic rust prevention process, you may perform the process by benzotriazole or its derivative (s), for example. Here, nickel and chromium have a low reactivity with a sulfur compound due to a dense oxide film formed on the metal surface, while cobalt and zinc have a high reactivity with a sulfur compound. From this viewpoint, the total amount of cobalt element and zinc element is preferably 2 mg / dm ² or less, more preferably 1 mg / dm ² or less, more preferably, it is 0.5 mg / dm ² or less.

  Although the thickness of the copper foil used for the copper clad laminated body and circuit board of this Embodiment is not specifically limited, For example, it can be in the range of 8-200 micrometers.

[Insulation layer]
As the insulating layer, for example, a resin such as polyimide or epoxy resin can be used. Among these, polyimide having excellent heat resistance is preferable. Moreover, in this Embodiment, it is preferable to use the polyimide which has a function which traps a sulfur containing organic compound as a polyimide. Then, two preferable aspects are illustrated and demonstrated about the polyimide which has a function which traps a sulfur containing organic compound.

(First aspect)
As a 1st aspect of the polyimide which has a function which traps a sulfur containing organic compound, following component (A) and (B);
(A) a polyamic acid having a weight average molecular weight in the range of 10,000 to 150,000,
And (B) an acrylic compound,
The polyamic acid composition containing 0.1 to 60 parts by weight of the component (B) with respect to 100 parts by weight of the component (A) is heat-treated and imidized. A polyimide composition can be used.

<(A) component; polyamic acid>
In the first embodiment, the polyamic acid of component (A) is a polyimide precursor. Therefore, the precursor polyamic acid and the imidized polyimide will be described together.

  In the first embodiment, as the polyimide, for example, an aromatic polyimide, an aliphatic polyimide, a polyamideimide, a polybenzimidazole, a polyimide ester, a polyetherimide, a polysiloxaneimide, and the like, a heat resistance made of a polymer having an imide group in the structure. Resins can be mentioned.

For example, when applied as a base material for a circuit board, polyimide having low thermal expansion can be suitably used as the polyimide. Specifically, the coefficient of linear thermal expansion (CTE) is in the range of 1 × 10 ⁻⁶ to 30 × 10 ⁻⁶ (1 / K), preferably 1 × 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K ), More preferably 15 × 10 ^{−6 to} 25 × 10 ⁻⁶ (1 / K). When such a polyimide is applied as a base material of a circuit board, it is advantageous because warpage as a circuit board can be suppressed. However, polyimide exceeding the linear thermal expansion coefficient can also be used, and in that case, adhesion to the copper foil can be improved.

As the low thermal expansion polyimide, a polyimide having a structural unit represented by the general formula (1) is preferable. In General Formula (1), Ar ₁ represents a tetravalent aromatic group represented by Formula (2) or Formula (3), and Ar ₂ represents a divalent group represented by Formula (4) or Formula (5). R ₁ independently represents a monovalent hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group, and X and Y independently represent a single bond or a divalent hydrocarbon having 1 to 15 carbon atoms. A divalent group selected from a group, O, S, CO, SO, SO ₂ or CONH, n ₁ independently represents an integer of 0 to 4, q represents an abundance ratio of structural units, and 0. A value of 1 to 1.0.

  The structural unit may be present in the homopolymer or may be present as a structural unit of the copolymer. In the case of a copolymer having a plurality of structural units, it may exist as a block copolymer or a random copolymer. Among polyimides having such a structural unit, a polyimide that can be suitably used is a non-thermoplastic polyimide.

Since polyimide is generally produced by reacting a diamine and an acid anhydride, a specific example of the polyimide can be understood by explaining the diamine and the acid anhydride. In the above general formula (1), Ar ₂ can be referred to as a diamine residue, and Ar ₁ can be referred to as an acid anhydride residue. Therefore, a preferred polyimide will be described using a diamine and an acid anhydride. However, the non-thermoplastic polyimide is not limited to those obtained from the diamine and acid anhydride described herein.

  Examples of acid anhydrides include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 4, A preferred example is 4'-oxydiphthalic anhydride. Moreover, 2,2 ', 3,3'-, 2,3,3', 4'- or 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,3 ', 3,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2,3 ', 3,4'-diphenyl ether tetracarboxylic dianhydride Bis (2,3-dicarboxyphenyl) ether dianhydride and the like are also preferred. In addition, 3,3``, 4,4 ''-, 2,3,3 '', 4 ''-or 2,2 '', 3,3 ''-p-terphenyltetra Carboxylic dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3- or 3.4-dicarboxyphenyl) methane dianhydride, bis Preferred examples include (2,3- or 3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride and the like.

  Examples of other acid anhydrides include 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6, 7-anthracenetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 2,3,6, 7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1, 2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetra Carboxylic 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 dianhydride, cyclo Pentane-1,2,3,4-te Tracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5 -Tetracarboxylic dianhydride, 4,4'-bis (2,3-dicarboxyphenoxy) diphenylmethane dianhydride and the like.

  Diamines include 4,4'-diaminodiphenyl ether, 2'-methoxy-4,4'-diaminobenzanilide, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) Benzene, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl 4,4′-diaminobenzanilide and the like are preferred. Diamines include 2,2-bis- [4- (3-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, and bis [4- (3-aminophenoxy) phenyl. ] Sulfone, bis [4- (4-aminophenoxy)] biphenyl, bis [4- (3-aminophenoxy) biphenyl, bis [1- (4-aminophenoxy)] biphenyl, bis [1- (3-aminophenoxy) )] Biphenyl, bis [4- (4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy)] benzophenone, bis [4- (3-aminophenoxy)] benzophenone, bis [4,4 '-(4-aminophenoxy)] Ben Anilide, bis [4,4 '-(3-aminophenoxy)] benzanilide, 9,9-bis [4- (4-aminophenoxy) phenyl] fluorene, 9,9-bis [4- (3-aminophenoxy) Preferred examples include phenyl] fluorene and the like.

  Examples of other diamines include 2,2-bis- [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis- [4- (3-aminophenoxy) phenyl] hexafluoropropane, 4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 4,4'-diaminodiphenylpropane, 3,3'- Diaminodiphenylpropane, 4,4'-diaminodiphenylethane, 3,3'-diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3 '-Diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,3-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether Ter, benzidine, 3,3'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4 ''-diamino-p-terphenyl, 3, 3 ''-diamino-p-terphenyl, m-phenylenediamine, p-phenylenediamine, 2,6-diaminopyridine, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-amino) Phenoxy) benzene, 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 4,4'-[1,3-phenylenebis (1-methylethylidene)] bisaniline, bis (p- Aminocyclohexyl) methane, bis (p-β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminopentyl) benzene, p-bis (2-methyl-4-aminopentyl) benzene, p-bis (1,1-dimethyl-5-aminopentyl) benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene 2,4-bis (β-amino-t-butyl) toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p -Xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine and the like.

  Each of acid anhydrides and diamines can be used alone or in combination of two or more. Further, other acid anhydrides or diamines not included in the general formula (1) can be used together with the acid anhydrides or diamines. In this case, acid anhydrides not included in the general formula (1) Alternatively, the proportion of diamine used is 90 mol% or less, preferably 50 mol% or less. Controlling thermal expansion, adhesiveness, glass transition temperature (Tg), etc. by selecting the type of acid anhydride or diamine, or the molar ratio of each of two or more acid anhydrides or diamines. be able to.

A thermoplastic polyimide can also be used as the polyimide. Thermoplastic polyimide can be suitably used, for example, when applied as an adhesive layer between a wiring layer and an insulating layer of a circuit board. As the polyamic acid used for the precursor of the thermoplastic polyimide, a polyamic acid having a structural unit represented by the general formula (6) is preferable. In General Formula (6), Ar ₃ represents a divalent aromatic group represented by Formula (7), Formula (8), or Formula (9), and Ar ₄ represents Formula (10) or Formula (11). Represents a tetravalent aromatic group, R ₂ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and V and W independently represent a single bond or 1 to 15 carbon atoms. A divalent hydrocarbon group, a divalent group selected from O, S, CO, SO ₂ or CONH, m ₁ independently represents an integer of 0 to 4, and p represents a molar ratio of constituent units; The value of 0.1 to 1.0.

In the general formula (6), Ar ₃ can be referred to as a diamine residue, and Ar ₄ can be referred to as an acid anhydride residue. Therefore, a preferred thermoplastic polyimide will be described using a diamine and an acid anhydride. However, the thermoplastic polyimide is not limited to those obtained from the diamine and acid anhydride described herein.

  Examples of diamines suitably used for forming thermoplastic polyimides include 4,4'-diaminodiphenyl ether, 2'-methoxy-4,4'-diaminobenzanilide, 1,4-bis (4-aminophenoxy). Benzene, 1,3-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3, 3'-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide and the like. In addition, the diamine mentioned by description of the said non-thermoplastic polyimide can be mentioned.

  Examples of the acid anhydride suitably used for forming the thermoplastic polyimide include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4 Examples include '-diphenylsulfonetetracarboxylic dianhydride and 4,4'-oxydiphthalic anhydride. In addition, the acid anhydrides mentioned in the description of the non-thermoplastic polyimide can be given.

  As the diamine and the acid anhydride that are preferably used for forming the thermoplastic polyimide, only one of them may be used, or two or more of them may be used in combination. In addition, diamines and acid anhydrides other than those described above can be used in combination.

  In the polyamic acid which is a precursor of the thermoplastic polyimide, the structural unit represented by the formula (6) may be present in the homopolymer or as a structural unit of the copolymer. In the case of a copolymer having a plurality of structural units, it may exist as a block copolymer or a random copolymer. There are a plurality of structural units represented by formula (6), but they may be one type or two or more types. Advantageously, the main component is the structural unit represented by the formula (6), and the precursor preferably contains 60 mol% or more, more preferably 80 mol% or more.

  The polyimide can be formed by imidizing (curing) the polyamic acid that is a precursor thereof. The synthesis of polyamic acid, which is a precursor of low thermal expansion or thermoplastic polyimide, can be performed by reacting the acid anhydride and diamine in a solvent. Examples of the solvent to be used include N, N-dimethylacetamide (DMAc), n-methylpyrrolidinone, 2-butanone, diglyme, xylene and the like, and these may be used alone or in combination of two or more. it can. In the synthesis of the polyamic acid, the molar ratio of acid anhydride to diamine (number of moles of acid anhydride / number of moles of diamine) is preferably greater than 1. By adding the acid anhydride excessively, the polyamic acid can have a structure having no amine terminal, and the reactivity with the acrylic compound can be suppressed.

  The polyamic acid (A) is used as a polyamic acid solution. Usually, it is advantageous to use as a reaction solvent solution, but if necessary, it can be concentrated, diluted or replaced with another organic solvent. In addition, since the polyamic acid of component (A) is generally excellent in solvent solubility, it can be easily mixed with an acrylic compound.

  Moreover, since the polyamic acid of (A) component suppresses reaction with an acrylic compound, what does not contain a radically polymerizable unsaturated bond in the molecular skeleton, or its content is preferable. Specifically, the amount of the radical polymerizable unsaturated bond present per 1 g of the polyamic acid is preferably 3 mmol or less, more preferably 2.5 mmol or less. Thus, since the acrylic compound can be prevented from being consumed by reacting with the polyamic acid by keeping the amount of radically polymerizable unsaturated bonds contained in the polyamic acid low, the acrylic compound is trapped with a sulfur compound. It can function effectively as a means. Here, examples of the functional group having a radical polymerizable unsaturated bond include a monovalent organic group having a (meth) acryl group, a vinyl group, or an allyl group at a terminal or a side chain.

  Further, in the polyamic acid, the combination of the acid anhydride and the diamine for suppressing the amount of the radical polymerizable unsaturated bond present per 1 g of weight to 3 mmol / g or less is not particularly limited. Examples of acid anhydrides include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2 ', 3,3'-, 2,3,3', 4'- or 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2'-bis [4- ( 4-Aminophenoxy) phenyl] propane, 4,4′-diaminodiphenyl ether.

  As the polyamic acid solution, commercially available products can be suitably used. For example, U-Varnish-A (trade name) and U-Varnish-S (trade name) which are non-thermoplastic polyamic acid varnishes manufactured by Ube Industries, Ltd. ), Thermoplastic Polyamic Acid Varnish SPI-200N (trade name), SPI-300N (trade name), SPI-1000G (trade name) manufactured by Nippon Steel Chemical Co., Ltd., Toray Nice # 3000 (trade name) manufactured by Toray Industries, Inc. Product name).

  The (A) component polyamic acid preferably has a weight average molecular weight of 10,000 or more from the viewpoint of suppressing the reaction with the acrylic compound by reducing the number of amine terminals that can act as a nucleophile. Within the range of ˜150,000 is preferred. In addition, by setting the weight average molecular weight to 10,000 or more, the effect of lowering the mobility of the molecular chain and lowering the nucleophilicity at the amine terminal can be expected.

<(B) component; acrylic compound>
In the first aspect, the acrylic compound acts as a trap means for capturing the sulfur-containing organic compound. Acrylic compounds include methacrylic compounds. As the acrylic compound, those having no sulfur-containing group that sulfidizes (oxidizes) a metal are preferable. More specifically, it is preferable not to include a functional group that acts as an oxidizing agent (sulfurizes) on a metal, such as a thiol group. However, sulfur-containing groups such as —SO ₂ — in the main chain may be used because they do not have a function as an oxidizing agent.

  As the acrylic compound, for example, an acrylic compound having a value of [number of (meth) acryloyl groups in one molecule / molecular weight] of 0.001 or more, preferably 0.003 or more is preferable. When the above value is less than 0.001, the amount of the acrylic compound necessary for exhibiting the effects of the invention increases, and the heat resistance and other characteristics inherent to the polyimide may be reduced. From such a viewpoint, as the acrylic compound, a polyfunctional acrylic compound having a plurality of (meth) acryloyl groups in the molecule is preferable.

  Specific examples of the acrylic compound include, for example, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acryloyl phosphate, 2-methoxyethoxyethyl acrylate, 2-ethoxyethoxyethyl acrylate, tetrahydrofur Freel acrylate, phenoxyethyl acrylate, isodecyl acrylate, stearyl acrylate, lauryl acrylate, glycidyl acrylate, allyl acrylate, ethoxy acrylate, methoxy acrylate, N, N′-dimethylaminoethyl acrylate, benzyl acrylate, 2-hydroxyethyl acryloyl phosphate, Dicyclopentadienyl acrylate, dicyclopentadiene ether Monoacrylates such as acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-butanediol diacrylate, diethylene glycol diacrylate , Neopentyl glycol diacrylate, polyethylene glycol 200 diacrylate, polyethylene glycol 400 diacrylate, polyethylene glycol 600 diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, hydroxypivalate ester neopentyl glycol diacrylate, triethylene glycol diacrylate Bis (acryloxyethoxy) bisphenol A, bis (acrylo Ciethoxy) tetrabromobisphenol A, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypenta It is possible to use polyfunctional acrylates such as acrylate. Among the acrylic compounds exemplified above, an acrylic compound having two or more functional groups is preferable. For example, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, pentaerythritol tetraacrylate, Examples include dipentaerythritol hexaacrylate and dipentaerythritol monohydroxypentaacrylate.

  A commercially available product can be preferably used as the acrylic compound. Examples of commercially available products include KAYARAD D-310, D-330, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120, DN-0075, DN-2475, SR- manufactured by Nippon Kayaku Co., Ltd. 295, SR-355, SR-399E, SR-494, SR-9041, SR-368, SR-415, SR-444, SR-454, SR-492, SR-499, SR-502, SR-9020, SR-9035, SR-111, SR-212, SR-213, SR-230, SR-259, SR-268, SR-272, SR-344, SR-349, SR-601, SR-602, SR- 610, SR-9003, PET-30, T-1420, GPO-303, TC-120S, HDDA, NPGDA, TPG A, PEG400DA, MANDA, HX-220, HX-620, R-551, R-712, R-167, R-526, R-551, R-712, R-604, R-684, TMPTA, THE- 330, TPA-320, TPA-330, KS-HDDA, KS-TPGDA, KS-TMPTA, Toronsei Co., Ltd. Aronix M-400, M-404, M-408, M-450, M-305, M- 309, M-310, M-315, M-320, M-350, M-360, M-208, M-210, M-215, M-220, M-225, M-233, M-240, M-245, M-260, M-270, M-1100, M-1200, M-1210, M-1310, M-1600, M-221, M-203, TO-924, TO- 1270, TO-1231, TO-595, TO-756, TO-1343, TO-902, TO-904, TO-905, TO-1330, Kyoeisha Chemical Co., Ltd. light acrylate PE-4A, DPE-6A, DTMP -4A, Osaka Organic Chemical Co., Ltd. PhSEA, Biscote # 802, and the like.

  The polyamic acid composition contains the acrylic compound (B) within a range of 0.1 to 60 parts by weight with respect to 100 parts by weight of the polyamic acid (A). The range is more preferable, and the range of 1 to 10 parts by weight is most preferable. When the blending ratio of the acrylic compound is less than 0.1 parts by weight with respect to 100 parts by weight of the polyamic acid, the effect of trapping the sulfur compound cannot be sufficiently obtained. When the blending ratio of the acrylic compound exceeds 60 parts by weight, the polymerization reaction between the acrylic compounds is likely to occur, and the effect of trapping the sulfur compound derived from the oil component may be reduced.

  Further, the polyamic acid composition can further contain a solvent. Examples of the solvent include N, N-dimethylacetamide (DMAc), n-methylpyrrolidinone, 2-butanone, diglyme, xylene and the like, and these can be used alone or in combination.

  The polyamic acid composition is prepared by charging and mixing the polyamic acid of component (A) and the acrylic compound of component (B) at the above blending ratio. In preparing the polyamic acid composition, it is preferable to use a solvent if necessary.

  The polyimide composition is obtained by heat-treating the polyamic acid composition to imidize the polyamic acid of component (A). The imidization method is not particularly limited, and for example, heat treatment such as heating for 1 to 60 minutes under a temperature condition in the range of 80 to 400 ° C. is suitably employed.

  In the polyimide composition, the acrylic compound is considered to exist in a non-bonded state in the polyimide. Here, the “non-bonded state” means that the functional group of the acrylic compound does not form a bond with the polyimide, and the acrylic compound maintains the state at the time of blending. However, it is not necessary for the total amount of the acrylic compound mixed in the polyamic acid to maintain a non-bonded state in the polyimide, and there may be an acrylic compound that forms a bond with the polyimide. From such a viewpoint, for example, when the polyamic acid of component (A) does not contain a radical polymerizable unsaturated bond in its molecular skeleton, the amount of the acrylic compound is present per 1 g of the polyamic acid composition ( The amount of the (meth) acryloyl group is preferably 0.096 mmol or more and 3.0 mmol or less, more preferably 0.15 mmol or more and 2.5 mmol or less. If the amount of (meth) acryloyl groups present per 1 g of weight is less than 0.096 mmol, the effect of trapping sulfur compounds may not be sufficiently obtained. If it exceeds 3.0 mmol, the polyimide composition is used as a resin layer. There is a possibility that the oil resistance of the used laminate or circuit board is lowered.

(Second aspect)
The thermoplastic polyimide according to the second embodiment is a thermoplastic polyimide obtained by heat-treating and imidizing a polyamic acid obtained by a reaction between an aromatic diamine and an aromatic tetracarboxylic dianhydride. Here, the aromatic diamine contains an aromatic diamine having a radical polymerizable unsaturated bond in the range of 2 to 6 carbon atoms, and the amount of the radical polymerizable unsaturated bond is 0 per 1 g of the polyamic acid. Within the range of 0.096 mmol to 3 mmol.

  The metal-clad laminate and circuit board produced using the thermoplastic polyimide of the second aspect are immersed in 150 ° C. oil containing a sulfur compound, and after 1000 hours or more have passed, the metal layer and the resin layer A high adhesive force can be maintained. Thus, in the second embodiment, the radical polymerizable unsaturated bond in the thermoplastic polyimide acts as a trap means for capturing the sulfur compound.

  Examples of the polyimide constituting the thermoplastic polyimide of the second aspect include a heat resistant resin made of a polymer having an imide group in the structure such as polyimide, polyamideimide, polybenzimidazole, polyimide ester, polyetherimide, and the like. it can.

As a precursor used for the thermoplastic polyimide of the second aspect, a polyamic acid having a structural unit represented by the general formula (6) is preferable. In particular, in the second aspect, in the general formula (6), R ₂ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and at least one of R ₂ has 2 carbon atoms. Those having a radical polymerizable unsaturated bond in the range of ˜6 are used.

（式中、Ｘは単結合、ＣＨ_２、Ｃ（ＣＨ_３）_２及びＳＯ_２から選択されるいずれかを示し、Ｒ_３、Ｒ_４は炭素数２〜６の範囲内のラジカル重合性の不飽和結合を有する１価の有機基を示す。） The thermoplastic polyimide of the second aspect has excellent heat resistance by using an aromatic diamine as the raw material diamine. In order to introduce a radically polymerizable unsaturated bond having 2 to 6 carbon atoms into the thermoplastic polyimide, the diamine is preferably an aromatic diamine represented by the following general formula (12).

(In the formula, X represents any one selected from a single bond, CH ₂ , C (CH ₃ ) _2, and SO ₂ , and R ₃ and R ₄ represent a radical polymerizable non-carbon within a range of 2 to 6 carbon atoms. Indicates a monovalent organic group having a saturated bond.)

In the formula (12), R ₃ and R ₄ represent a monovalent organic group having a radical polymerizable unsaturated bond, but are monovalent having a (meth) acryl group, a vinyl group or an allyl group at the terminal or side chain. The organic group is preferably, and more preferably a group represented by CH═CH—R ₅ —. Here, R ₅ represents a direct bond and an alkylene group having 1 to 4 carbon atoms, but R ₅ is a direct bond (that is, R ₃ and R _{4 in} formula (12) are vinyl groups). Is preferable in terms of reactivity. Specific examples of such a compound of formula (12) include 2,2′-divinyl-4,4′-diamino-biphenyl.

  Examples of aromatic diamines other than diamines having a radical polymerizable unsaturated bond in the range of 2 to 6 carbon atoms include, for example, 4,4′-diaminodiphenyl ether, 2′-methoxy-4,4′-diaminobenz. Anilide, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2 ' -Dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide and the like.

  Examples of the acid anhydride suitably used for forming the thermoplastic polyimide include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4 ′. -Diphenylsulfone tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride.

  Each of the diamine and acid anhydride may be used alone or in combination of two or more. In addition, diamines and acid anhydrides other than those described above can be used in combination.

  Further, the amount of the radically polymerizable unsaturated bond having 2 to 6 carbon atoms present per 1 g of the polyamic acid is preferably in the range of 0.096 mmol to 3 mmol, and in the range of 0.15 mmol to 2 mmol. It is more preferable that If the amount of the radically polymerizable unsaturated bond having 2 to 6 carbon atoms present per 1 g of the polyamic acid is less than 0.096 mmol, the effect of trapping the sulfur compound may not be sufficiently obtained, and the amount exceeds 3 mmol. Then, the polymerization reaction between the unsaturated bonds is likely to occur, and the effect of trapping the sulfur compound derived from the oil component may be reduced.

  Polyamide acid can be synthesized by reacting the acid anhydride and diamine in a solvent. Examples of the solvent to be used include N, N-dimethylacetamide (DMAc), n-methylpyrrolidinone, 2-butanone, diglyme, xylene and the like, and these may be used alone or in combination of two or more. it can. In the synthesis of the polyamic acid, the molar ratio of acid anhydride to diamine (number of moles of acid anhydride / number of moles of diamine) is preferably greater than 1. By adding an acid anhydride in excess, it becomes possible for the polyamic acid to have a structure having no amine terminal, and to suppress the reactivity with a radical polymerizable unsaturated bond within the range of 2 to 6 carbon atoms. be able to.

  The synthesized polyamic acid is used as a polyamic acid solution. Usually, it is advantageous to use as a reaction solvent solution, but if necessary, it can be concentrated, diluted or replaced with another organic solvent. Moreover, the polyamic acid which is a precursor is generally easy to form a solution having excellent solvent solubility.

  Thermoplastic polyimide is prepared by imidizing (curing) polyamic acid. The imidization method is not particularly limited, and for example, heat treatment such as heating for 1 to 60 minutes under a temperature condition in the range of 80 to 400 ° C. is suitably employed.

  The weight average molecular weight of the polyamic acid which is a precursor of the thermoplastic polyimide is 10,000 or more from the viewpoint of suppressing reaction with a radical polymerizable unsaturated bond by reducing the number of amine terminals that can act as a nucleophile. It is preferable that it is within the range of 50,000 to 300,000, and most preferably within the range of 50,000 to 150,000. In addition, by setting the weight average molecular weight to 10,000 or more, the effect of lowering the mobility of the molecular chain and lowering the nucleophilicity at the amine terminal can be expected.

  The polyamic acid composition of the second embodiment is a mixture of a polyamic acid having a radical polymerizable unsaturated bond within the range of 2 to 6 carbon atoms and a solvent. Examples of the solvent include N, N-dimethylacetamide (DMAc), n-methylpyrrolidinone, 2-butanone, diglyme, xylene and the like, and these may be used alone or in combination of two or more thereof. it can.

  In the laminate and the circuit board of this embodiment, the resin layer of the polyimide composition is preferably used by being laminated in contact with the copper foil (including the wiring layer). The laminated body and circuit board of the present embodiment are immersed in a 150 ° C. oil containing a sulfur-containing organic compound as shown in the examples below, and for example, after 250 hours or more have elapsed, the copper foil and the resin layer High adhesive strength can be maintained between the two.

  Although the thickness of the insulating layer in the copper clad laminated body and circuit board of this Embodiment is not specifically limited, For example, it can be in the range of 3-100 micrometers.

[How to use the circuit board]
In the method of using the circuit board according to the present embodiment, the circuit board is used in oil containing a sulfur-containing organic compound. Here, examples of the oil containing a sulfur-containing organic compound include engine oil and transmission oil. Examples of the sulfur-containing organic compound include thiol compounds such as benzothiazole. The operating temperature of the circuit board of the present embodiment in the oil is, for example, about room temperature to about 200 ° C.

[Laminate and Circuit Board Manufacturing Method]
In the present embodiment, the method for producing the circuit board is not limited except that a copper foil having an amount of cobalt element adhering to the surface in contact with the insulating layer is 2 mg / dm ² or less. For example, a method (subtractive method) may be used in which a laminate composed of a polyimide resin layer and a copper foil is prepared and the copper foil is etched to form a wiring.

  The laminated body used for the subtractive method may be prepared by, for example, preparing a resin film made of polyimide and laminating a copper foil thereon by a method such as thermocompression bonding. Further, a resin solution may be cast on a copper foil, dried to form a coating film, and then heat treated and imidized to form a resin layer to prepare a laminate.

  Hereinafter, the method for manufacturing the circuit board according to the present embodiment will be specifically described with reference to a case where the cast method and the subtractive method are typically combined and the insulating layer is polyimide.

First, the production of the laminate
(1) A step of applying a polyamic acid-containing resin solution on a copper foil to form a coating film;
(2) heat-treating the coating film to imidize the polyamic acid to form a polyimide resin layer.
In addition to the steps (1) and (2) above, the manufacture of the circuit board
(3) The process of patterning the copper foil of a laminated body and forming a wiring layer can be included.

(1) The process of apply | coating the resin solution containing a polyamic acid on copper foil, and forming a coating film:
The copper foil as the substrate can be used in the form of a cut sheet, a roll, or an endless belt. In order to obtain productivity, it is efficient to use a roll-like or endless belt-like form so that continuous production is possible. Furthermore, the copper foil is preferably in the form of a roll that is formed in a long shape from the viewpoint of expressing the effect of improving the accuracy of the wiring pattern on the circuit board.

  The coating film can be formed by applying a polyamic acid solution directly on the copper foil and then drying. The method of applying is not particularly limited, and it is possible to apply with a coater such as a comma, die, knife, lip or the like.

  The polyimide resin layer may be a single layer or a plurality of layers. In the case where a plurality of polyimide layers are used, other precursors can be sequentially applied on the precursor layers made of different components. When the precursor layer is composed of three or more layers, the precursor having the same configuration may be used twice or more. The thickness of the precursor layer (after drying) may be in the range of 3 to 100 μm, preferably in the range of 3 to 50 μm. In the method of the present embodiment in which the polyamic acid solution is applied, the thickness of the coating film can be freely adjusted.

  When a plurality of polyimide resin layers are used, it is preferable to form the precursor layer so that the polyimide resin layer in contact with the copper foil becomes a thermoplastic polyimide resin layer. By using thermoplastic polyimide, the adhesion to the copper foil can be improved. Such a thermoplastic polyimide preferably has a glass transition temperature (Tg) of 350 ° C. or lower, more preferably 200 to 320 ° C.

  It is also possible to once imidize a single layer or a plurality of precursor layers into a single layer or a plurality of polyimide layers, and further form a precursor layer thereon.

(2) A process of forming a polyimide resin layer by heat-treating the coating film and imidizing the polyamic acid:
The imidization method is not particularly limited, and for example, heat treatment such as heating for 1 to 60 minutes under a temperature condition in the range of 80 to 400 ° C. is suitably employed. In order to suppress the oxidation of the copper foil, heat treatment in a low oxygen atmosphere is preferable. Specifically, it is performed in an inert gas atmosphere such as nitrogen or a rare gas, in a reducing gas atmosphere such as hydrogen, or in a vacuum. Is preferred. By the heat treatment, the polyamic acid in the coating film is imidized to form polyimide. In this way, a laminate having a polyimide resin layer (single layer or multiple layers) and a copper foil can be produced.

(3) A step of patterning the copper foil of the obtained laminate to form a wiring layer:
In this step, the copper foil is etched into a predetermined shape to form a pattern and processed into a wiring layer. Etching can be performed by any method using, for example, photolithography.

  In the above description, only the characteristic steps of the circuit board manufacturing method of the present embodiment have been described. That is, when manufacturing a circuit board, processes other than the above normally performed, for example, processes such as through-hole processing in a previous process, terminal plating in a subsequent process, and external processing can be performed according to a conventional method.

As described above, in the present embodiment, by using a copper foil in which the amount of cobalt element adhering to the surface in contact with the insulating layer is 2 mg / dm ² or less, it is repeatedly placed in a high temperature environment and an oil adhesion environment. A laminated body in which the adhesive force between the copper foil and the resin layer is not reduced can be formed. Moreover, the reliability of a circuit board can be improved by using the said copper foil. The circuit board of the present embodiment is preferably used for applications such as FPC in equipment used in high-temperature environments where oil is likely to adhere, such as automobile engines, intake manifolds, alternators, radiators, gearboxes, and transmissions. it can.

[Example]
EXAMPLES 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 adhesive strength]
The adhesive strength was obtained by cutting an evaluation sample cut into a width of 10 mm and a length of 100 mm with a copper foil at a rate of 50 mm / min in the 180 ° direction using a tensile tester (Toyo Seiki Co., Ltd., Strograph-M1). The force when peeling between the polyimides was taken as the adhesive strength.

[Measurement of sulfur concentration]
The sulfur concentration (hereinafter sometimes referred to as “S concentration”) is determined by an energy dispersive X-ray fluorescence spectrometer (EDX) analysis of the peeled surface on the copper foil side after peeling between copper and polyimide of the evaluation sample. ,Obtained.

Abbreviations used in Examples and the like indicate the following compounds.
BAPP: 2,2-bis (4-aminophenoxyphenyl) propane VAB: 2,2′-divinyl-4,4′-diaminobiphenyl m-TB: 2,2′-dimethyl-4,4′-diaminobiphenyl TPE -R: 1,3'-bisaminophenoxybenzene PMDA: pyromellitic dianhydride BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride DMAc: N, N-dimethylacetamide

Synthesis Examples 1-1 to 1-2:
In order to synthesize the polyamic acids A and B, the diamine shown in Table 1 was dissolved in the solvent DMAc with stirring in a 200 ml separable flask under a nitrogen stream. Subsequently, the tetracarboxylic dianhydride shown in Table 1 was added. Thereafter, the solution was stirred at room temperature for 5 hours to conduct a polymerization reaction, and kept for a whole day and night. A viscous polyamic acid solution was obtained, and it was confirmed that a polyamic acid having a high degree of polymerization was produced. Table 1 shows the solid content and solution viscosity of the obtained solutions of polyamic acids A and B (hereinafter referred to as polyamic acid solutions A and B).

Reference Example 1-1
Equivalent to 5 parts by weight of acrylic compound (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYARAD PET-30) with respect to 100 parts by weight of the solid content of the polyamic acid solution A obtained in Synthesis Example 1-1 (0 as acryloyl group) 0.656 g / .56 mmol / g) was mixed and stirred at room temperature for 2 hours to prepare a polyamic acid composition 1-1. Polyamic acid composition on copper foil A (Co amount; 2.68 mg / dm ² , Zn amount; 0.13 mg / dm ² , Cr amount; 0.08 mg / dm ² , Ni amount; 0.76 mg / dm ² ) 1-1 was applied so that the thickness after curing was 2 μm, dried by heating at 130 ° C. to remove the solvent, and then the thickness after curing the polyamic acid solution B obtained in Synthesis Example 1-2 thereon Was applied to a thickness of 21 μm and dried by heating at 125 ° C. to remove the solvent. Furthermore, the polyamic acid solution A was applied thereon so that the thickness after curing was 2 μm, and the solvent was removed by heating and drying at 125 ° C. Thereafter, stepwise heat treatment is performed at 130 ° C., 145 ° C., 160 ° C., 210 ° C., 280 ° C., 320 ° C., and 360 ° C. for 1 to 15 minutes each to form a wiring board comprising three polyimide layers on the copper foil. A laminated body 1-1 was produced. The thickness of the polyimide layer on the copper foil is 2 μm / 21 μm / 2 μm in order from the copper foil side. After cutting the wiring board laminate 1-1 to 10 cm × 3 cm, the copper foil is etched so that the copper foil has a size of 9 cm × 2 cm, and a 10 cm × 3 cm coverlay (Nippon Steel Chemical Co., Ltd.) is formed on the copper foil side. Manufactured, product name; Espanex SPC) was subjected to thermocompression bonding to produce Evaluation Sample 1-1. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of the evaluation sample 1-1 was 1.3 kN / m. The polyimide obtained by imidizing the polyamic acid solution A is thermoplastic, and the polyimide obtained by imidizing the polyamic acid B is non-thermoplastic.

  Next, the evaluation sample 1-1 was heat-treated in an oven for automatic transmission oil (trade name: ATF M-III) manufactured by Mazda Co. at 150 ° C. for 250 hours. It was 0.82 kN / m when the adhesive strength (adhesion strength 2) between the copper foil and polyimide after heat processing was measured. At this time, the S concentration on the peeled surface on the copper foil side was 0.4%. And it was 0.18 kN / m when the adhesive strength (adhesion strength 3) between the copper foil and polyimide after heat processing for 1000 hours at 150 degreeC in oil was measured. The results are shown in Table 2.

Reference Example 1-2
The same method as in Reference Example 1-1, except that 1.25 g of an acrylic compound corresponding to 10 parts by weight (1.17 mmol / g as an acryloyl group) was mixed with 100 parts by weight of the solid content of the polyamic acid solution A After obtaining the polyamic acid composition 1-2, a laminate 1-2 for a wiring board was obtained, and an evaluation sample 1-2 was obtained. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of the evaluation sample 1-2 was 1.3 kN / m. Moreover, the adhesive strength (adhesive strength 2) between the copper foil and the polyimide after heat treatment at 150 ° C. for 250 hours in an oil for automatic transmission (trade name; ATF M-III) manufactured by Mazda Co. was 0.56 kN / m. . At this time, the S concentration on the peeled surface on the copper foil side was 5%. And it was 0.11 kN / m when the adhesive strength (adhesion strength 3) between the copper foil and polyimide after heat processing for 1000 hours at 150 degreeC was measured. The results are shown in Table 2.

Reference Example 1-3
The same method as in Reference Example 1-1, except that 2.50 g of an acrylic compound corresponding to 20 parts by weight (2.34 mmol / g as an acryloyl group) was mixed with 100 parts by weight of the solid content of the polyamic acid solution A. After obtaining the polyamic acid composition 1-3, a laminate 1-3 for a wiring board was obtained, and an evaluation sample 1-3 was obtained. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of Evaluation Sample 1-3 was 1.3 kN / m. Moreover, the adhesive strength (adhesive strength 2) between the copper foil and the polyimide after heat treatment at 150 ° C. for 250 hours in an oil for automatic transmission (trade name; ATF M-III) manufactured by Mazda Co. was 0.5 kN / m. . At this time, the S concentration on the peeled surface on the copper foil side was 5%. And when 150 degreeC and the adhesive strength (adhesion strength 3) between the copper foil and polyimide after 1000-hour heat processing were measured, it was 0 kN / m. The results are shown in Table 2.

Example 1
Copper foil 1 (Co amount; 0mg / ^dm 2, Zn amount; 0.04mg / ^dm 2, Cr amount; 0.10mg / ^dm 2, Ni content; 0.22mg / dm ²⁾ curing the polyamic acid solution A on After coating to a thickness of 2 μm and drying by heating at 130 ° C., the thickness after curing of the polyamic acid solution B obtained in Synthesis Example 1-2 is 21 μm. And then dried by heating at 125 ° C. to remove the solvent. Furthermore, the polyamic acid solution A was applied thereon so that the thickness after curing was 2 μm, and the solvent was removed by heating and drying at 125 ° C. Thereafter, stepwise heat treatment is performed at 130 ° C., 145 ° C., 160 ° C., 210 ° C., 280 ° C., 320 ° C., and 360 ° C. for 1 to 15 minutes each to form a wiring board composed of three polyimide layers on the copper foil. A laminated body 1-4 was prepared. And the evaluation sample 1-4 was obtained from the laminated body 1-4 for wiring boards similarly to the reference example 1-1. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of the evaluation sample 1-4 exceeded 2 kN / m. Moreover, the adhesive strength (adhesive strength 2) between the copper foil and the polyimide after heat treatment at 150 ° C. for 250 hours in an oil for automatic transmission (trade name: ATF M-III) manufactured by Mazda Corporation exceeded 2 kN / m. And when the adhesive strength (adhesion strength 3) between the copper foil and polyimide after heat processing for 1000 hours at 150 degreeC was measured, it was over 2 kN / m. The results are shown in Table 3.

Example 2
Instead of the copper foil 1 of Example 1, the copper foil 2 (Co amount 0 mg / dm ² , Zn amount; 0.08 mg / dm ² , Cr amount; 0.10 mg / dm ² , Ni amount; 0.13 mg / dm) ^A laminate 1-5 for a wiring board was produced in the same manner as in Example 1 except that ² ) was used. And the evaluation sample 1-5 was obtained from the laminated body 1-5 for wiring boards similarly to the reference example 1-1. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of Evaluation Sample 1-5 was 1.4 kN / m. Moreover, the adhesive strength (adhesive strength 2) between the copper foil and the polyimide after heat treatment at 150 ° C. for 250 hours in an oil for automatic transmission (trade name; ATF M-III) manufactured by Mazda was 1.4 kN / m. . At this time, the S concentration on the peeled surface on the copper foil side was 0%. And when 150 degreeC and the adhesive strength (adhesion strength 3) between the copper foil and polyimide after 1000-hour heat processing were measured, it was 1.4 kN / m. The results are shown in Table 3.

Example 3
Instead of the copper foil 1 of Example 1, the copper foil 3 (Co amount 0.42 mg / ^dm 2, Zn amount; 0.10mg / ^dm 2, Cr amount; 0.05mg / ^dm 2, Ni content; 0.43 mg / Dm ² ) A wiring board laminate 1-6 was prepared in the same manner as in Example 1 except that the following was used. And the evaluation sample 1-6 was obtained from the laminated body 1-6 for wiring boards similarly to the reference example 1-1. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of the evaluation sample 1-6 exceeded 2 kN / m. Moreover, the adhesive strength (adhesive strength 2) between the copper foil and the polyimide after heat treatment at 150 ° C. for 250 hours in an oil for automatic transmission (trade name: ATF M-III) manufactured by Mazda Corporation exceeded 2 kN / m. And when the adhesive strength (adhesion strength 3) between the copper foil and polyimide after heat processing for 1000 hours at 150 degreeC was measured, it was over 2 kN / m. The results are shown in Table 3.

Comparative Example 1
A wiring board laminate 1-7 was prepared in the same manner as in Example 1 except that the copper foil A was used in place of the copper foil 1 of Example 1. And the evaluation sample 1-7 was obtained from the laminated body 1-7 for wiring boards similarly to the reference example 1-1. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of Evaluation Sample 1-7 was 1.3 kN / m. Moreover, the adhesive strength (adhesive strength 2) between the copper foil and the polyimide after heat treatment at 150 ° C. for 250 hours in an oil for automatic transmission (trade name; ATF M-III) manufactured by Mazda was 0.12 kN / m. . At this time, the S concentration on the peeled surface on the copper foil side was 7%. And when 150 degreeC and the adhesive strength (adhesion strength 3) between the copper foil and polyimide after 1000-hour heat processing were measured, it was 0 kN / m. The results are shown in Table 3.

In Examples 1 to 3, by using copper foils 1 to 3 having a small amount of Co, compared with Comparative Example 1 using a copper foil A having a Co amount exceeding ² mg / dm ² , in oil at 150 ° C. As a result of the long-term oil resistance test, the oil resistance was clearly improved.

Synthesis Example 2-1 Under a nitrogen stream, 15.67 g of BAPP (0.0382 mol), 0.47 g of VAB having a vinyl group (0.0020 mol), and 100 g of DMAc were charged into a 300 ml separable flask. And dissolved by stirring at room temperature. Next, 8.27 g of PMDA (0.0379 mol) and 0.59 g of BPDA (0.00199 mol) were added, and the solution was stirred at room temperature for 5 hours to carry out a polymerization reaction to obtain a polyamic acid solution a. It was.

Synthesis Examples 2-2 to 2-5
A polyamic acid solution b, c, d, e was prepared in the same manner as in Synthesis Example 2-1, except that the raw material composition shown in Table 4 was used.

Reference Example 2-1
The polyamic acid solution a polymerized in Synthesis Example 2-1 was applied onto the copper foil A so that the thickness after curing was 2 μm, dried by heating at 130 ° C., and then the synthesis example 2- The polyamic acid solution e obtained in 5 was applied so that the thickness after curing was 21 μm, and dried by heating at 125 ° C. to remove the solvent. Furthermore, the polyamic acid solution d obtained in Synthesis Example 2-4 was applied thereon so that the thickness after curing was 2 μm, and the solvent was removed by heating and drying at 125 ° C. Thereafter, a stepwise heat treatment is performed at 130 ° C., 145 ° C., 160 ° C., 210 ° C., 280 ° C., 320 ° C., and 360 ° C. for 1 to 15 minutes each to form a wiring board composed of three polyimide layers on the copper foil. The laminated body 2-1 for manufacture was produced. The thickness of the polyimide layer on the copper foil is 2 μm / 21 μm / 2 μm in order from the copper foil side. Next, after cutting the wiring board laminate 2-1 into 10 cm × 3 cm, the copper foil is etched so that the copper foil has a size of 9 cm × 2 cm, and a 10 cm × 3 cm coverlay (Nippon Steel) is formed on the copper foil side. A sample manufactured by Kagaku Co., Ltd., trade name: Espanex SPC) was thermocompression bonded to produce Evaluation Sample 2-1. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of the evaluation sample 2-1 was 1.3 kN / m.

  Next, heat treatment was performed on the evaluation sample 2-1 in an oven for automatic transmission oil (trade name: ATF M-III) manufactured by Mazda at 150 ° C. for 250 hours. It was 0.30 kN / m when the adhesive strength (adhesive strength 2) between the copper foil and polyimide after heat processing was measured. At this time, the S concentration on the peeled surface on the copper foil side was 5%. And it was 0.05 kN / m when the adhesive strength (adhesive strength 3) between the copper foil and polyimide after heat processing for 1000 hours at 150 degreeC was measured. The results are shown in Table 5.

Reference Example 2-2
A laminate for wiring board 2- in the same manner as in Reference Example 2-1, except that the polyamic acid solution b polymerized in Synthesis Example 2-2 was applied onto the copper foil A so that the thickness after curing was 2 μm. After obtaining 2, evaluation sample 2-2 was obtained. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of the evaluation sample 2-2 was 1.3 kN / m. Moreover, the adhesive strength (adhesive strength 2) between the copper foil and the polyimide after heat treatment at 150 ° C. for 250 hours in an oil for automatic transmission (trade name; ATF M-III) manufactured by Mazda was 0.76 kN / m. . At this time, the S concentration on the peeled surface on the copper foil side was 1%. And it was 0.18 kN / m when the adhesive strength (adhesion strength 3) between the copper foil and polyimide after heat processing for 1000 hours at 150 degreeC was measured. The results are shown in Table 5.

Reference Example 2-3
A laminate 2 for a wiring board 2 in the same manner as in Reference Example 2-1, except that the polyamic acid solution c polymerized in Synthesis Example 2-3 was applied onto the copper foil A so that the thickness after curing was 2 μm. After obtaining 3, evaluation sample 2-3 was obtained. The adhesive strength (adhesive strength 1) between the copper foil and polyimide of Evaluation Sample 2-3 was 1.3 kN / m. Moreover, the adhesive strength (adhesive strength 2) between the copper foil and the polyimide after heat treatment at 150 ° C. for 250 hours in an oil for automatic transmission (trade name; ATF M-III) manufactured by Mazda was 0.55 kN / m. . At this time, the S concentration on the peeled surface on the copper foil side was 5%. And it was 0.05 kN / m when the adhesive strength (adhesive strength 3) between the copper foil and polyimide after heat processing for 1000 hours at 150 degreeC was measured. The results are shown in Table 5.

  As mentioned above, although embodiment of this invention was described in detail for the purpose of illustration, this invention is not restrict | limited to the said embodiment. For example, in the above-described embodiment, the substrate of the circuit board such as FPC is given as an example of the use of the polyimide of the present invention, but other uses such as a coverlay film main body or cover that covers the wiring layer of the circuit board. It can also be used for adhesive layers in lay film adhesive layers, tape automated bonding (TAB), chip size packages (CSP), and the like.

Claims (12)

An insulating layer made of polyimide, and a copper foil laminated on at least one surface of the insulating layer, and a copper-clad laminate used in oil containing a sulfur-containing organic compound,
The copper clad laminate is characterized in that the amount of cobalt element attached to the surface of the copper foil in contact with the insulating layer is 2 mg / dm ² or less. A copper clad laminate used in an oil containing an insulating layer and a copper foil laminated on at least one surface of the insulating layer, and containing a sulfur-containing organic compound,
The amount of cobalt element adhering to the surface in contact with the insulating layer in the copper foil is 2 mg / dm ² or less,
The insulating layer comprises the following components (A) and (B):
(A) a polyamic acid having a weight average molecular weight in the range of 10,000 to 150,000,
And (B) an acrylic compound,
The polyamic acid composition containing 0.1 to 60 parts by weight of the component (B) with respect to 100 parts by weight of the component (A) is heat-treated and imidized. A copper-clad laminate comprising a resin layer of a polyimide composition. In the component (A), the amount of radically polymerizable unsaturated bonds present per 1 g of weight is 3 mmol or less,
The copper-clad laminate according to claim 2 , wherein the component (B) has a value of [number of (meth) acryloyl groups in one molecule / molecular weight] of 0.001 or more.   The copper clad laminate according to claim 2 or 3, wherein a resin layer of the polyimide composition is laminated in contact with the copper foil. The insulating layer is a thermoplastic polyimide obtained by heat-treating and imidizing a polyamic acid obtained by a reaction between an aromatic diamine and an aromatic tetracarboxylic dianhydride, wherein the aromatic diamine has 2 carbon atoms. An aromatic diamine having a radically polymerizable unsaturated bond in the range of ˜6, and the amount of the radically polymerizable unsaturated bond in the range of 2 to 6 carbon atoms is 0 per gram of the polyamic acid. copper clad laminate according to claim 1 or 2 comprising a resin layer of thermoplastic polyimide is in the range of .096Mmol～3mmol.   The copper clad laminate according to claim 5, wherein the thermoplastic polyimide resin layer is laminated in contact with the copper foil. A circuit board having an insulating layer made of polyimide and a copper wiring layer formed on the insulating layer, and used in oil containing a sulfur-containing organic compound,
The circuit board, wherein the copper wiring layer has an amount of cobalt element adhering to a surface in contact with the insulating layer of 2 mg / dm ² or less. A circuit board having an insulating layer and a copper wiring layer formed on the insulating layer, and used in oil containing a sulfur-containing organic compound,
In the copper wiring layer, the amount of cobalt element attached to the surface in contact with the insulating layer is 2 mg / dm ² or less,
The insulating layer comprises the following components (A) and (B):
(A) a polyamic acid having a weight average molecular weight in the range of 10,000 to 150,000,
And (B) an acrylic compound,
The polyamic acid composition containing 0.1 to 60 parts by weight of the component (B) with respect to 100 parts by weight of the component (A) is heat-treated and imidized. A circuit board comprising a resin layer of a polyimide composition. In the component (A), the amount of radically polymerizable unsaturated bonds present per 1 g of weight is 3 mmol or less,
The circuit board according to claim 8 , wherein the component (B) has a value of [number of (meth) acryloyl groups in one molecule / molecular weight] of 0.001 or more.   The circuit board according to claim 8 or 9, wherein a resin layer of the polyimide composition is laminated in contact with the copper wiring layer. The insulating layer is a thermoplastic polyimide obtained by heat-treating and imidizing a polyamic acid obtained by a reaction between an aromatic diamine and an aromatic tetracarboxylic dianhydride, wherein the aromatic diamine has 2 carbon atoms. An aromatic diamine having a radically polymerizable unsaturated bond in the range of ˜6, and the amount of the radically polymerizable unsaturated bond in the range of 2 to 6 carbon atoms is 0 per gram of the polyamic acid. The circuit board according to claim 7 or 8 , comprising a resin layer of thermoplastic polyimide in a range of 0.096 mmol to 3 mmol. The circuit board according to claim 11, wherein the thermoplastic polyimide resin layer is laminated in contact with the copper wiring layer.