JP2002361792A - Laminated body of polyimide/metal foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide/metal foil laminated body in which not only curl is remarkably suppressed for the body to be smoothed, but also adhesive properties, heat resistance and strength are remarkably excellent, to provide a flexible printed wiring base with high quality and high reliability, and to improve productivity of the printed wiring base with high quality and high reliability. SOLUTION: The polyimide/metal foil laminated body (1) comprising: a polyimide layer comprising a polyimide with a repeating unit of chemical formula (I); and a metal foil layer (wherein in the chemical formula (I), R is a methyl group or an ethyl group and Z is a tetravalent aromatic group which may be substituted or at least one group selected from a group of chemical formula (II)) is provided. In addition, the flexible printed wiring base (2) comprising the polyimide/metal foil laminated body (1) is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide / metal foil laminate widely used for electronic materials and a method for producing the same. Among them, especially curl,
The present invention relates to a polyimide / metal foil laminate excellent in adhesion, heat resistance and strength, and a method for producing the same.

[0002]

2. Description of the Related Art A flexible printed wiring board is one of the major applications of a polyimide / metal foil laminate. As a method of manufacturing a flexible printed wiring board, a method of bonding a film of polyimide or the like to a copper foil via an adhesive, or applying a precursor solution of polyimide or the like to the copper foil and drying the copper foil is adopted. When a flexible printed wiring board is manufactured in this manner, curling, warping, and the like occur due to differences in thermal behavior of materials, and there has been a problem that circuit patterning cannot be performed. Conventionally, it has been difficult to manufacture a flexible printed circuit board that suppresses curl only by the properties of a single resin and is excellent in adhesiveness, heat resistance, and strength.
Therefore, a technique for smoothing the curled base material by heat treatment (Japanese Patent Application Laid-Open No. 56-23791), a method of forming a resin layer having high linear expansion on a copper foil, and further forming a resin layer having low linear expansion on it. A technique of forming a resin layer, controlling the thickness of each resin layer, and forming a multilayer to reduce curl (Japanese Patent Application Laid-Open No. 8-250
No. 860) has been developed.

[0003] However, these methods require post-processing for smoothing every time heating is performed in the process, and increase in the number of processes is unavoidable. It was not satisfactory. As described above,
A problem remains in producing a polyimide / metal foil laminate excellent in adhesiveness, heat resistance and strength while suppressing curling.

On the other hand, a polyimide having a repeating unit represented by the chemical formula (III) (Formula 5) is disclosed in JP-B-56-45.
It is a known substance as shown in JP-A-87.
However, there was no finding that this substance is useful as a polyimide for a flexible printed wiring board, or that it was suitable for producing a polyimide / metal foil laminate in which curling was suppressed.

Embedded image

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to produce and provide a polyimide / metal foil laminate which suppresses curling and has excellent adhesiveness, heat resistance and strength.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that 3,3'-dimethyl-4,4'-diaminodiphenylmethane or 3,3'-diethyl-4,
By using a polyimide containing 4'-diaminodiphenylmethane as a monomer, curling was suppressed, and it was found that a polyimide / metal foil laminate excellent in adhesiveness, heat resistance and strength was obtained, and the present invention was completed. . That is, the present invention is specified by the following items [1] to [7].

[1] A polyimide / metal foil laminate comprising a polyimide layer containing a polyimide having a repeating unit represented by the chemical formula (I) (Formula 6) and a metal foil layer (chemical formula (I) In the formula, R represents a methyl group or an ethyl group, Z represents an optionally substituted tetravalent aromatic group, or
It is at least one group selected from the group consisting of the chemical formula (II) (Formula 6). However, in the chemical formula (II),
Y represents a group selected from the group consisting of a direct bond, a methylene group, an isopropylidene group, a hexafluorinated isopropylidene group, a thio group, a sulfinyl group, a sulfonyl group, and an oxide. r is each independently 1 carbon atom
Represents an alkyl group, a halogen group, or a phenyl group. a represents 0 or an integer of 1 to 4. ).

Embedded image

[2] A polyimide containing a polyimide having a repeating unit represented by the chemical formula (III) (Formula 7) and a polyimide containing a metal foil layer.
Metal foil laminate.

Embedded image

[3] The polyimide / metal foil laminate according to [1] or [2], wherein the metal foil is a copper foil.

[4] 3,3′-dimethyl-4,4′-
A polyamic acid solution obtained by reacting diaminodiphenylmethane or 3,3′-diethyl-4,4′-diaminodiphenylmethane with aromatic tetracarboxylic dianhydride is coated on a metal foil, dried and imidized A polyimide layer comprising a polyimide having a repeating unit represented by the chemical formula (I) (Formula 8),
And a method for producing a polyimide / metal foil laminate comprising the metal foil layer (wherein, in the chemical formula (I), R represents a methyl group or an ethyl group, and Z represents an optionally substituted tetravalent aromatic group. Or, at least one group selected from the group consisting of the chemical formula (II) (Formula 8), provided that in the chemical formula (II), Y is a direct bond, a methylene group, an isopropylidene group, or a hexafluorinated group. Represents an isopropylidene group, a thio group, a sulfinyl group, a sulfonyl group, and a group selected from the group consisting of oxides, r is each independently an alkyl group having 1 to 4 carbon atoms, or a halogen group, Represents a phenyl group, a represents 0 or an integer of 1 to 4).

Embedded image

[5] 3,3′-dimethyl-4,4′-
A polyamic acid solution obtained by reacting diaminodiphenylmethane with pyromellitic dianhydride is coated on a metal foil, dried, and imidized, and is characterized by the chemical formula (III) (Formula 9). A method for producing a polyimide / metal foil laminate comprising a polyimide layer comprising a polyimide having units and the metal foil layer.

Embedded image

[6] The method for producing a polyimide / metal foil laminate according to [4] or [5], wherein the metal foil is a copper foil.

A flexible printed circuit board comprising the polyimide / metal foil laminate according to any one of [1] to [3].

The method for producing the polyimide / metal foil laminate of the present invention is not particularly limited, but a method of laminating a film of the polyimide on a metal foil via an adhesive, or a method of preparing a precursor of the polyimide on a metal foil. It can be produced by a method of applying and drying a polyamic acid solution. The method for producing a polyimide / metal foil laminate of the present invention is particularly preferably a method in which a polyamic acid solution is applied to a metal foil and dried.

The polyimide constituting the polyimide / metal foil laminate of the present invention may be 3,3'-dimethyl-4,4'-diaminodiphenylmethane or 3,3'-diethyl-
Obtained by reacting 4,4'-diaminodiphenylmethane with aromatic tetracarboxylic dianhydrides

Such aromatic tetracarboxylic dianhydrides are not limited, for example, pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride , Bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfide dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3 4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride,
2,2-bis (3,4-dicarboxyphenyl) -1,
1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis (3,4-dicarboxyphenoxy)
Benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) biphenyl dianhydride, 2,2-bis [ (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-
Naphthalenetetracarboxylic dianhydride, 2,2 ', 3
3'-biphenyltetracarboxylic dianhydride, 2,2-
Bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl)-
1,1,1,3,3,3-hexafluoropropane dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) sulfide dianhydride, bis (2,3-dicarboxyphenyl) sulfone dianhydride, 1,3-bis (2,3-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (2,3-dicarboxyphenoxy) benzene dianhydride And 1,2,5,6-naphthalenetetracarboxylic dianhydride and the like are used. These aromatic tetracarboxylic dianhydrides can be used alone or in combination of two or more.

In the production of the polyimide constituting the polyimide / metal foil laminate of the present invention, and also in the production of the polyimide precursor, an end-capping agent can be used if necessary. Typical end capping agents are monoamines or dicarboxylic anhydrides.

Examples of the monoamine include aniline,
o-toluidine, m-toluidine, p-toluidine,
2,3-xylidine, 2,4-xylidine, 2,5-xylidine, 2,6-xylidine, 3,4-xylidine,
3,5-xylysine, o-chloroaniline, m-chloroaniline, p-chloroaniline, o-bromoaniline,
m-bromoaniline, p-bromoaniline, o-nitroaniline, m-nitroaniline, p-nitroaniline,
o-anisidine, m-anisidine, p-anisidine, o
-Phenetidine, m-phenetidine, p-phenetidine, o-aminophenol, m-aminophenol, p
-Aminophenol, o-aminobenzaldehyde, m
-Aminobenzaldehyde, p-aminobenzaldehyde, o-aminobenzonitrile, m-aminobenzonitrile, p-aminobenzonitrile, 2-aminobiphenyl, 3-aminobiphenyl, 4-aminobiphenyl,
-Aminophenylphenyl ether, 3-aminophenylphenyl ether, 4-aminophenylphenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenone, 2-aminophenylphenyl sulfide, 3-aminophenylphenyl sulfide, -Aminophenylphenyl sulfide, 2
-Aminophenylphenylsulfone, 3-aminophenylphenylsulfone, 4-aminophenylphenylsulfone, α-naphthylamine, β-naphthylamine, 1-
Amino-2-naphthol, 2-amino-1-naphthol, 4-amino-1-naphthol, 5-amino-1-naphthol, 5-amino-2-naphthol, 7-amino-
2-naphthol, 8-amino-1-naphthol, 8-amino-2-naphthol, 1-aminoanthracene, 2-
Aminoanthracene, 9-aminoanthracene, methylamine, dimethylamine, ethylamine, diethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, butylamine, dibutylamine, isobutylamine, diisobutylamine, pentylamine, dipentylamine, benzylamine , Cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine and the like.

Examples of the dicarboxylic anhydride include phthalic anhydride, 2,3-benzophenone dicarboxylic anhydride, 3,4-benzophenone dicarboxylic anhydride,
3-dicarboxyphenyl ether anhydride, 3,4-dicarboxyphenyl phenyl ether anhydride, 2,3-
Biphenyl dicarboxylic anhydride, 3,4-biphenyl dicarboxylic anhydride, 2,3-dicarboxyphenyl phenyl sulfone anhydride, 3,4-dicarboxyphenyl phenyl sulfone anhydride, 2,3-dicarboxyphenyl phenyl sulfide anhydride 3,4-dicarboxyphenylphenyl sulfide anhydride, 1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarboxylic anhydride, 1,2
-Anthracene dicarboxylic anhydride, 2,3-anthracene dicarboxylic anhydride, 1,9-anthracene dicarboxylic anhydride and the like. These monoamines or dicarboxylic anhydrides may have a part of their structure substituted by a group having no reactivity with amine or dicarboxylic anhydride.

In the present invention, the logarithmic viscosity of the polyamic acid when applied to the metal foil is not particularly limited, but the preferred logarithmic viscosity is preferably from 0.1 to 2.0, more preferably from 0.2 to 2.0. 1.9 is more preferable, and 0.3 to 1.8 is preferable.
Is more preferable, and 0.4 to 1.7 is more preferable.
0.5 to 1.6 is more preferred.

When the logarithmic viscosity of the polyamic acid is too low, the strength and the toughness of the polyimide layer generally decrease, which may cause a problem. If the logarithmic viscosity of the polyamic acid is too high, generally, there may be a problem in the coatability of the polyamic acid solution.

In the production of the polyimide constituting the polyimide / metal foil laminate of the present invention, and also in the production of the polyamic acid, it is preferable to carry out the reaction in an organic solvent. The solvent used in the reaction is
Although not limited, for example,

(A) Phenol solvents such as phenol, o-chlorophenol, m-chlorophenol,
p-chlorophenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-
Xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol,

(B) N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-, which are aprotic amide solvents 2-imidazolidinone, N-methylcaprolactam, hexamethylphosphorotriamide,

(C) 1,2-ether which is an ether solvent
Dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, tetrahydrofuran, bis [2- (2-methoxyethoxy) ethyl] ether, 1,4-dioxane,

(D) pyridine, which is an amine solvent,
Quinoline, isoquinoline, α-picoline, β-picoline, γ-picoline, isophorone, piperidine, 2,4-
Lutidine, 2,6-lutidine, trimethylamine, triethylamine, tripropylamine, tributylamine,

(E) Other solvents such as dimethyl sulfoxide, dimethyl sulfone, diphenyl ether,
Sulfolane, diphenyl sulfone, tetramethyl urea,
And anisole. These solvents may be used alone or in combination of two or more. Among these solvents, N, N-dimethylformamide, N, N
-Dimethylacetamide is particularly preferred.

In the production of the polyamic acid solution used in the present invention, the concentration of the polyamic acid in the polyamic acid solution (here, the concentration is based on the weight; hereinafter, referred to as "polymerization concentration"). There are no restrictions. Preferred polymerization concentrations are from 5 to 40%, more preferably from 10 to 30%.

In the preparation of the polyamic acid solution used in the present invention, the reaction temperature, reaction time and reaction pressure are not particularly limited, and known conditions can be applied. That is, the reaction temperature is preferably in the approximate range of −10 ° C. to 100 ° C., and more preferably the ice-cooling temperature (for example, −2 to 0).
C.) to about 60 ° C., and most preferably practically 50 to 60 ° C. in practical terms. The reaction time varies depending on the type of monomer used, the type of solvent, and the reaction temperature, but is preferably 1 to 48 hours. More preferably, it is about 2 to 3 hours to about ten and several hours, and most preferably 4 to 10 hours in practical terms. Still further, the reaction pressure is sufficient at normal pressure.

The method of applying the polyamic acid solution to the metal foil is not particularly limited, and may be a comma coater, a knife coater,
Known coating devices such as a roll coater, a reverse coater, and a die coater can be used. The metal foil coated with the polyamic acid solution is heated for drying and imidization, and the method is usually performed under reduced pressure or under an inert atmosphere such as nitrogen, helium, argon, etc. It may be at least the boiling point of the solvent and at least the temperature at which the imidization reaction proceeds. Incidentally, when an aprotic amide solvent is used, the temperature may be 200 ° C. or higher. Further, the firing time is not particularly limited, but usually 2 hours or more is sufficient.

In the polyimide / metal foil laminate of the present invention, the thickness of the polyimide layer is not particularly limited, but is usually preferably in the range of 3 to 100 μm, and particularly preferably in the range of 5 to 80 μm. The metal foil used in the present invention may be any metal foil, but is generally a copper foil or a stainless steel foil (SUS foil). The thickness of the metal foil is not limited, but is generally preferably 9 to 150 μm, more preferably 9 to 50 μm.

In the polyimide / metal foil laminate of the present invention, there is no problem even if any treatment is applied to the surface of the metal foil in order to further increase the adhesion between the polyimide and the metal foil. For example, a metal oxide layer or an alloy layer is formed on a metal foil, a surface treatment is performed with a silane coupling agent, or a resin having excellent adhesiveness is present as an anchor coat layer. Processing may be performed.

[0033]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Test methods for various tests in the examples are as follows.

(A) Logarithmic viscosity (ηinh) Logarithmic viscosity (ηinh) is 2.50 g of polyamic acid solution (20% by weight), that is, 0.5 g of polyamic acid.
Was dissolved in 100 ml of the solvent used for the solution,
It was measured at 5 ° C. with an Ubbelohde viscometer according to a standard method.

(B) 5% weight loss temperature (Td5) The 5% weight loss temperature (Td5) is measured in air by DTA-T
G (TG-DTA2000, manufactured by Mac Science) was used at a heating rate of 10 ° C./min.

(C) Glass transition temperature (Tg) and crystal melting temperature (Tm) The glass transition temperature (Tg) and the crystal melting temperature (Tm) are measured by differential scanning calorimetry (DSC, DS manufactured by Mac Science Co., Ltd.).
C3100) at a heating rate of 10 ° C./min.

(D) Linear Expansion Coefficient The linear expansion coefficient is TMA (TMA4 manufactured by Mac Science).
000S) in nitrogen, a load of 5 g, and a temperature rising rate of 10 ° C.
/ Min, and the coefficient of linear expansion was determined in the range of 100 to 200 ° C.

(E) Mechanical properties of the film (tensile strength, tensile elongation and tensile elastic modulus) The mechanical properties of the film (tensile strength, tensile elongation and tensile elastic modulus) were measured using a tensile compression tester manufactured by Imada Seisakusho. It was measured.

Example 1 A flask equipped with a stirrer, a nitrogen introducing tube, and a thermometer was charged with 3,3′-dimethyl-4,
4′-diaminodiphenylmethane 30.0 g (0.13 g)
3mol), and 150.7 g of N, N-dimethylacetamide as a solvent were completely dissolved at 40 ° C. Thereafter, the mixture is once cooled to around room temperature, and 28.6 g (0.131 mol) of pyromellitic dianhydride is charged while paying attention to the rise in temperature. At this time, the temperature in the system is
It rises from around room temperature to 55 ° C. After completely dissolved, the reaction was carried out at 60 ° C. for 6 hours. After completion of the reaction, the obtained polyamic acid solution was subjected to pressure filtration with a 5 μm filter. This polyamic acid solution has ηinh of 0.53 d
At 1 / g, the E-type mechanical viscosity was 17,300 mPa · s.

This polyamic acid solution was coated on a glass plate so as to have a coating thickness of 0.40 mm, and was heated in a nitrogen-substituted inert oven from room temperature to 35 for 45 minutes.
Drying and imidation were performed at 0 ° C. After cooling to room temperature, the polyimide film was peeled off from the glass plate. The obtained polyimide film had a thickness of 55 μm, and no warping was observed as long as it was visually confirmed. When a thermal analysis measurement was performed on this polyimide film,
No Tg was observed and Td5 was 500 ° C. in air. The linear expansion coefficient of this polyimide film is 1
It was 11 ppm / K in the range of 00 to 200 ° C. The mechanical properties of the polyimide film are as follows: tensile strength is 121 MPa, tensile modulus is 5.2 GPa, and elongation is 3.
3%. Table 1 summarizes the measurement results.

[Example 2] N, N-dimethylacetamide in the solvent used in Example 1 was changed to N, N-dimethylformamide, except that the treatment was carried out in the same manner as in Example 1 to obtain a polyamic acid solution. I got This polypolyamic acid had ηinh of 0.52 dl / g and E-type mechanical viscosity of 10,450 mPa · s. This polyamic acid solution is applied on a glass plate so that the coating thickness becomes 0.40 mm, and is dried and imidized in a nitrogen-substituted inert oven at a temperature rising time of 45 minutes from room temperature to 350 ° C. Was. After cooling to room temperature, the polyimide film was peeled off from the glass plate. The obtained polyimide film had a thickness of 74 μm, and no warping was observed as long as it was visually confirmed. Table 1 summarizes the measurement results of other physical property values.

[Comparative Example 1]
30.0 g (0.133 mol) of 3'-dimethyl-4,4'-diaminodiphenylmethane was changed to 26.1 g (0.133 mol) of 4,4'-diaminodiphenylmethane, and otherwise the same as in Example 1 The treatment was performed to obtain a polyamic acid solution. This polyamic acid has an ηinh of 0.52 dl / g and an E-type mechanical viscosity of 11,000 mPa.
-It was s. This polyamic acid solution was coated on a glass plate so that the coating thickness became 0.40 mm, and the temperature was raised from room temperature to 3 in a nitrogen-substituted inert oven for 45 minutes.
Drying and imidation were performed at 50 ° C. After cooling to room temperature, the polyimide film was peeled off from the glass plate. The obtained polyimide film was significantly curled in the direction of the glass substrate bonding surface. The thickness of the film was 54 μm. Table 1 summarizes the measurement results of other physical property values.

Comparative Example 2 30.2 g (0.133 mol) of 4,4′-diaminobenzanilide and N, N-dimethylacetamide 330 as a solvent were placed in a flask equipped with a stirrer, a nitrogen inlet tube, and a thermometer. 0.3 g was completely dissolved at 40 ° C. Thereafter, the mixture was cooled to near room temperature once, and then 28.1 g of pyromellitic dianhydride was obtained.
(0.129 mol) while paying attention to the rise in temperature. After completely dissolved, the reaction was carried out at 60 ° C. for 6 hours. After completion of the reaction, the obtained polyamic acid solution was
The mixture was filtered under pressure with a filter of m. This polyamic acid is
ηinh is 1.64 dl / g and E type mechanical viscosity is 708
It was 00 mPa · s. This polyamic acid solution is applied on a glass plate so that the coating thickness becomes 0.40 mm, and is dried and imidized in a nitrogen-substituted inert oven from room temperature to 350 ° C. in a heating time of 45 minutes for 45 minutes. Was. After cooling to room temperature, the polyimide film was peeled off from the glass plate. The obtained polyimide film was significantly curled in the direction of the glass substrate bonding surface. The thickness of the film is 34
μm. Table 1 summarizes the measurement results of other physical property values.

[Embodiment 3]
30.0 g (0.133 mol) of 3'-dimethyl-4,4'-diaminodiphenylmethane was converted to 33.8 g of 3,3'-diethyl-4,4'-diaminodiphenylmethane.
(0.133 mol), and the others were the same as in Example 1.
Was performed in the same manner as described above to obtain a polyamic acid solution. This polyamic acid had ηinh of 0.48 dl / g and E-type mechanical viscosity of 16,400 mPa · s. This polyamic acid solution is applied on a glass plate so that the coating thickness becomes 0.40 mm, and is dried and imidized in a nitrogen-substituted inert oven from room temperature to 350 ° C. in a heating time of 45 minutes for 45 minutes. Was. After cooling to room temperature, the polyimide film was peeled off from the glass plate. The obtained polyimide film had a thickness of 54 μm, and no warping was observed as long as it was visually confirmed. Table 1 summarizes the measurement results of other physical property values.

Example 4 The polyamide acid varnish obtained in Example 1 was coated on a copper foil having a thickness of 25 μm to a coating thickness of 0.20.
mm, and the temperature was raised from room temperature to 350 ° C. for 1 hour in a nitrogen-substituted inert oven, followed by firing at 350 ° C. for 1 hour. After cooling to room temperature, a laminate of a polyimide film and a copper foil was obtained. This laminate was almost smooth without any warpage.

[0046]

[Table 1]

[0047]

One of the effects of the present invention is that it is possible to provide a polyimide / metal foil laminate in which curling is significantly suppressed. One of the effects of the present invention is that not only the curl is remarkably suppressed and the surface is smooth, but also the adhesiveness, heat resistance, and strength have made it possible to provide a polyimide / metal foil laminate excellent in strength. That is. One of the effects of the present invention is that not only the curl is remarkably suppressed and smooth, but also the adhesiveness, heat resistance, and strength are significantly improved by using a polyimide / metal foil laminate which is remarkably excellent in strength. Another object of the present invention is to provide a highly reliable flexible printed wiring board. One of the effects of the present invention is that not only the curl is significantly suppressed but also smooth,
The use of a polyimide / metal foil laminate with remarkably excellent adhesiveness, heat resistance and strength has made it possible to improve the productivity of flexible printed wiring boards with high quality and high reliability. It is.

Continued on the front page (72) Inventor Yuichi Okawa 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc. (72) Inventor Shoji Tamai 580-32 Nagaura, Sodegaura-shi, Chiba F-term (Reference) 4F100 AB01B AB17B AB33B AK49A AK49K BA02 BA10A BA10B EH462 EJ082 EJ862 GB43 JJ03 JK01 JK06 JL04 4J043 PA02 PA19 PB23 PC016 QB15 QB26 RA35 SA06 SB01 TA22 TB01 UA122 UA131 UA142 UA1 UB1 UA1 UA1 ZB60

Claims (7)

[Claims] 1. A polyimide layer comprising a polyimide having a repeating unit represented by the chemical formula (I) (Formula 1),
And a metal foil layer comprising: a metal foil layer (where R is a methyl group or an ethyl group, Z
Is a tetravalent aromatic group which may be substituted, or at least one selected from the group consisting of the chemical formula (II) (Formula 1)
Is a seed group. However, in the chemical formula (II), Y is
Represents a group selected from the group consisting of a direct bond, a methylene group, an isopropylidene group, a hexafluorinated isopropylidene group, a thio group, a sulfinyl group, a sulfonyl group, and an oxide. r independently represents 1 to 4 carbon atoms
Represents an alkyl group, a halogen group, or a phenyl group.
a represents 0 or an integer of 1 to 4. ). Embedded image 2. A polyimide / metal foil laminate comprising: a polyimide layer containing a polyimide having a repeating unit represented by the chemical formula (III) (Formula 2); and a metal foil layer. Embedded image 3. The metal foil is a copper foil.
2. The polyimide / metal foil laminate described in 1. above. 4. A method according to claim 1, wherein 3,3′-dimethyl-4,4′-diaminodiphenylmethane or 3,3′-diethyl-4,
A polyamic acid solution obtained by reacting 4'-diaminodiphenylmethane with aromatic tetracarboxylic dianhydride is coated on a metal foil, dried and imidized, characterized by the following chemical formula (I): A) a polyimide layer comprising a polyimide having a repeating unit represented by:
A method for producing a polyimide / metal foil laminate comprising the metal foil layer (where R is a methyl group or an ethyl group, Z is an optionally substituted tetravalent aromatic group or And at least one group selected from the group consisting of: Chemical formula (II) (Formula 3), provided that in Chemical formula (II), Y represents a direct bond, a methylene group, an isopropylidene group, or a hexafluorinated group. Represents a group selected from the group consisting of an isopropylidene group, a thio group, a sulfinyl group, a sulfonyl group, and an oxide, wherein r is each independently an alkyl group having 1 to 4 carbon atoms, a halogen group, or a phenyl group; A represents 0 or an integer of 1 to 4). Embedded image 5. A polyamic acid solution obtained by reacting 3,3′-dimethyl-4,4′-diaminodiphenylmethane with pyromellitic dianhydride is coated on a metal, dried and imidized. The chemical formula (II
I) A method for producing a polyimide / metal foil laminate comprising a polyimide layer comprising a polyimide having a repeating unit represented by (Chemical Formula 4) and the metal foil layer. Embedded image 6. The metal foil is a copper foil.
3. The method for producing a polyimide / metal foil laminate described in 1. above. 7. A flexible printed circuit board comprising the polyimide / metal foil laminate according to claim 1.