JP2011051203A - Multilayer polyimide film and printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate using a polyimide film having high heat resistance and dimensional stability as a substrate. <P>SOLUTION: The laminate is a multi-layer polyimide film consisting of a polyimide resin layer, a fluororesin layer and a polyimide resin layer, laminated in the order, and has a linear expansion coefficient of 10-25 ppm/°C. A copper-laminated multi-layer polyimide film consisting of a copper layer laminated on at least one side of the multi-layer polyimide film and a printed wiring board in which a circuit pattern is formed by removing parts of the copper layer are also provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention is a multilayer polyimide film used for electronic devices, flexible printed wiring boards that reduce the size and weight of components, a copper-coated multilayer polyimide film laminated with a copper layer, and a circuit by removing a part of the copper layer. The present invention relates to a printed wiring board formed with a pattern and a multilayer printed wiring board formed by laminating these.

In general, improvement in transmission speed and reduction in noise are demanded in signal transmission in a high-frequency region, and studies on substrate materials, wiring technology, circuit form, etc. are also being advanced for flexible printed wiring boards.
Conventionally, a polyimide resin excellent in heat resistance is used as an electrical insulator layer in a flexible printed wiring board composed of a laminate having a conductor layer and an electrical insulator layer. The following three methods are used as a manufacturing method of the laminated body which consists of a polyimide resin layer and a conductor layer.
(1) A method of bonding a polyimide film and a copper foil through an adhesive layer,
(2) A method of forming a metal layer on a polyimide resin film by a method such as vapor deposition and / or metal plating,
(3) A method of coating a metal foil with a polyimide resin precursor, then forming a polyimide resin from the precursor by heat treatment or the like, and forming a polyimide resin layer on the metal foil (see Patent Document 1).
However, in such a method, the adhesiveness between the polyimide resin layer and the conductor layer is not sufficient, which may cause malfunction of the circuit.
It is disclosed that adhesion between the conductor layer and the electrical insulator layer is improved by forming irregularities of about 3 μm on the surface of the conductor layer on the side in contact with the electrical insulator layer (see Patent Document 2). ). However, in such a method, due to the skin effect in the high frequency region, the signal arrival time is shifted between the uneven surface and the non-roughened surface, so that the uneven surface needs to be made as low profile as possible.
In general, it is known that when a fluorine atom is introduced into a polyimide molecule, the dielectric constant decreases. For example, a polyimide-metal composite film having a metal layer formed on the surface of a fluorinated polyimide film is disclosed (see Patent Document 3). Also disclosed is a multilayer wiring board using a fluorinated polyimide film as at least one selected from the group consisting of a base material, an adhesive layer and a surface protective film (see Patent Document 4). However, in such a method, as the content of fluorine atoms introduced into the polyimide molecule increases, the tensile modulus and tensile fracture strain of the polyimide film decrease, and the mechanical strength decreases. There's a problem.

A substrate made of only a fluororesin having the smallest dielectric constant among plastics is disclosed (see Patent Document 5). However, the tensile strength and elongation, which are mechanical properties of fluororesin, are equivalent to polyolefin at room temperature, and the linear expansion coefficient is 60 ppm / ° C. to 160 ppm / ° C. (see Non-Patent Document 1). When a copper layer having a thickness of 16 ppm / ° C. is laminated, there is a great difference between the coefficients of linear expansion of each other, which may cause peeling during use or warpage.
As a means for suppressing the linear expansion coefficient of the fluororesin, there is an example in which it is laminated with a polyimide resin (see Patent Documents 6 and 7) (see Non-Patent Document 2). However, the linear expansion coefficient of the laminate obtained by this method has not yet solved the warp with the copper foil.

JP 2004-001510 A JP 05-055546 A Japanese Patent No. 2866155 JP 2001-308542 A Japanese Patent Laid-Open No. 07-038215 Japanese Patent Laying-Open No. 2005-310973 JP 2006-059865 A

"Fluorine resin handbook revised 11th edition", Japan Fluoropolymer Industry Association, P8-P15 "Printed Circuit Handbook 2nd Edition", Modern Science, P25-25 to P25-26

The present invention is a feature of a polyimide resin by laminating a polyimide resin, which is suitable for a base material of an electronic component, with little deformation even under high temperature treatment and excellent heat resistance through a fluororesin layer. Linear expansion coefficient (linear expansion coefficient equivalent to copper as multilayer polyimide film), high mechanical properties, low dielectric constant and low water absorption that are the characteristics of fluororesin, multilayer polyimide film, copper-coated multilayer polyimide film, print It aims at providing a wiring board, a multilayer printed wiring board, etc.

As a result of intensive studies, the present inventors have found that when a multilayer polyimide film obtained by laminating a polyimide film through a fluororesin layer is used for a copper-clad laminate and a printed wiring board, FPC, TAB tape, COF tape, etc. The present invention has been completed by finding that a product that does not peel off at high temperature and high humidity and has excellent electrical characteristics can be obtained.
That is, this invention consists of the following structures.
1. (B) Polyimide resin layer / (A) Fluororesin layer / (B) A polyimide resin layer is laminated in this order, and the linear expansion coefficient of the multilayer polyimide film is 10 ppm / ° C. to 25 ppm / ° C. And (A) layer thickness ratio {total (A) layer / multilayer polyimide film} is 60% to 90%, and the (A) layer is a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer. A multilayer which is a thermoplastic fluororesin layer comprising any one of (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), and tetrafluoroethylene / hexafluoropropylene / perfluoroalkyl vinyl ether copolymer (EPE) Polyimide film.
2. (A) The layer is a layer of a functional group-containing thermoplastic fluororesin. Multilayer polyimide film.
3. (B) The layer is a polyimide layer having a polyimide benzoxazole component, and the linear expansion coefficient is −10 ppm / ° C. to 10 ppm / ° C. Or 2. Multilayer polyimide film.
4). (A) The thickness of the layer is 1.0 μm to 100 μm, and (B) the thickness of the layer is 1.0 μm to 38 μm. ~ 3. Any multilayer polyimide film.
5). (A) Storage elastic modulus at room temperature of layer: E ′ (A) and storage elastic modulus at room temperature of layer (B): ratio of E ′ (B) {E ′ (A) / E ′ (B)} Is 2.0% to 20%. ~ 4. 5. Any multilayer polyimide film 1. ~ 5. A copper-clad multilayer polyimide film in which a copper layer is laminated on at least one surface of any multilayer polyimide film.
7). 6). A printed wiring board obtained by removing a part of the copper layer of the copper-coated multilayer polyimide film and forming a circuit pattern.
8). 1. ~ 7. A multilayer printed wiring board formed by laminating any one of the multilayer polyimide films, the copper-coated multilayer polyimide film, and the printed wiring board.

The multilayer polyimide film obtained by laminating the (B) polyimide resin layer / (A) fluororesin layer / (B) polyimide resin layer in this order of the present invention has a low linear expansion coefficient (as a multilayer polyimide film), which is a feature of the polyimide resin. , A linear expansion coefficient equivalent to that of copper), a multilayer film capable of satisfying both high mechanical properties and low dielectric constant and low water absorption, which are the characteristics of fluororesin.
The multilayer polyimide film of the present invention has little deviation from the copper layer linear expansion coefficient of 16 ppm / ° C. and has a low water absorption rate, so that it hardly causes warping or distortion even in an environment of high temperature and high humidity. As a result, the quality of the printed wiring board obtained as a result and the yield during production are improved.
The copper-coated multilayer polyimide film, printed wiring board, and multilayer printed wiring board using the multilayer polyimide film of the present invention are used as electronic components exposed to high temperatures, and warpage and distortion of the base material occur during its production. This makes it possible to produce high-quality electronic components that are difficult to achieve and have excellent electrical characteristics and to improve yields, which is extremely meaningful in the industry.

FIG. 1 is an explanatory view showing a printed wiring board of application example 1. FIG. FIG. 2 is an explanatory view showing a printed wiring board of application example 2. FIG.

The present invention is described in detail below.
The (A) fluororesin layer used in the present invention is formed by applying a fluororesin film obtained by casting a fluororesin melt into a film, or applying the fluororesin melt to a polyimide resin layer (film). In view of handling and productivity, the form of a fluororesin film is preferable.
The fluororesin can be appropriately selected from conventionally known thermoplastic fluororesins used for general molding.
Examples of thermoplastic fluororesins include polymers or copolymers such as unsaturated fluorinated hydrocarbons, unsaturated fluorinated chlorinated hydrocarbons, ether group-containing unsaturated hydrocarbons, or these unsaturated fluorinated hydrocarbons. Examples include ethylene copolymers. Specific examples include polymers or copolymers of monomers selected from tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether), vinylidene fluoride and vinyl fluoride, or these monomers and Examples include ethylene copolymers.
More specific examples of the thermoplastic fluororesin include tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / hexafluoropropylene / Perfluoroalkyl vinyl ether copolymer (EPE), tetrafluoroethylene / ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene / ethylene copolymer ( ECTFE).
Among them, from the viewpoint of heat resistance, flame retardancy, and electrical properties, a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) and a tetrafluoroethylene / hexafluoropropylene copolymer, which are copolymers of total fluorine. (FEP) and tetrafluoroethylene / hexafluoropropylene / perfluoroalkyl vinyl ether copolymer (EPE) are preferred.

The fluororesin is more preferably a functional group-containing thermoplastic fluororesin. When a thermoplastic fluororesin that does not contain a functional group is used, it is necessary to subject the polyimide film to surface treatment such as honing treatment, corona treatment, plasma treatment, ion gun treatment, and etching treatment in order to obtain adhesiveness that can withstand practical use. Therefore, the cost may increase.
The thermoplastic fluororesin containing a functional group includes a carboxylic acid group or a derivative group thereof, a hydroxyl group, a nitrile group, a cyanato group, a carbamoyloxy group, a phosphonooxy group, a halophosphonooxy group, a sulfonic acid group or a derivative group thereof, and a sulfo group. Mention may be made of thermoplastic fluororesins (functional group-containing fluororesins) containing functional groups selected from halide groups. Thus, as the functional group-containing fluororesin, a thermoplastic fluororesin usually used in the general molding is used in which the functional group is contained within a range that does not significantly impair the properties. In order to obtain such a functional group-containing fluororesin, for example, a thermoplastic fluororesin as shown in the above example used for general molding is synthesized and then introduced by adding or substituting these functional groups. Alternatively, it can be obtained by copolymerizing monomers having these functional groups during the synthesis of the thermoplastic fluororesin exemplified above.
Specific examples of the functional group include -COOH, -CH2COOH, -COOCH3, -CONH2, -OH, -CH2OH, -CN, -CH2O (CO) NH2, -CH2OCN, -CH2OP (O) (OH) 2,- Groups such as CH2OP (O) Cl2 and -SO2F can be exemplified. These functional groups are preferably introduced into the fluororesin by copolymerizing a fluorine-containing monomer having a functional group during the production of the fluororesin.

These monomers containing functional groups are preferably copolymerized in the functional group-containing fluororesin in an amount of 0.5 to 10% by weight, more preferably 1 to 5% by weight. Distribution of the functional group-containing monomer in the functional group-containing fluororesin may be uniform or non-uniform. If the content ratio of the functional group-containing monomer in the functional group-containing fluororesin is too small, the effect as a compatibilizer is small, while if the content ratio increases, the functional group-containing fluororesin is similar to the crosslinking reaction due to strong interaction between the functional group-containing fluororesins. Reactions can occur and the viscosity can suddenly increase, making melt molding difficult. Moreover, when the content rate of a functional group containing monomer increases, there exists a tendency for the heat resistance of a functional group containing fluororesin to worsen.
There is no particular limitation on the viscosity or molecular weight of the functional group-containing fluororesin, but it is within the range not exceeding the viscosity or molecular weight of the thermoplastic fluororesin for general molding blended with these functional group-containing fluororesins, preferably the same. Good level.
The fluororesin preferably contains 0.1 to 2% by mass of an antistatic agent that imparts antistatic properties. As the antistatic agent, surfactants such as nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants are preferable.

The fluororesin preferably contains an inorganic filler that lowers the dielectric constant and dielectric loss tangent. Inorganic fillers include silica, clay, talc, calcium carbonate, mica, diatomaceous earth, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, calcium hydroxide, magnesium hydroxide, water Aluminum oxide, basic magnesium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dosonite, hydrotalcite, calcium sulfate, barium sulfate, calcium silicate, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass Examples include beads, silica-based balloons, carbon black, graphite, carbon fibers, carbon balloons, wood powder, and zinc borate.
The inorganic filler may be used alone or in combination of two or more. As for content of an inorganic filler, 1-100 mass% is preferable with respect to a fluororesin. Further, it is preferable that these inorganic fillers are porous because the dielectric constant and dielectric loss tangent are further reduced.

As for the thickness of the said fluororesin layer, 1.0 micrometer-100 micrometers are preferable, More preferably, they are 1.0 micrometer-75 micrometers, More preferably, they are 1.0 micrometer-50 micrometers. Thicknesses greater than 100 μm are not preferred for the purpose of reducing the weight of electronic components. On the other hand, a film thickness of less than 1.0 μm is not preferable because surface modification effects such as improvement of electrical characteristics, reduction of water absorption, and improvement of adhesiveness due to the fluororesin are reduced.
The storage elastic modulus: E ′ (A) of the fluororesin layer is not particularly limited, and it is known that a value of 0.3 GPa to 1.0 GPa is generally used when the fluororesin having the above composition is used.
Moreover, the linear expansion coefficient of the said fluororesin layer is not specifically limited, If it uses the fluororesin of the said composition, it will be generally taken as the value of 60 ppm / degrees C-160 ppm / degrees C.
Furthermore, it is preferable that the film has a small dielectric constant and dielectric loss tangent from the viewpoint of high frequency response. The dielectric constant and dielectric loss tangent of the fluororesin layer are not particularly limited, and it is known that generally low values are obtained when the fluororesin having the composition is used. Specifically, the dielectric constant at 1 MHz is 2.0 to 2.2, and the dielectric loss tangent at 1 MHz is 3.0 × 10 ^{−4 to} 5.0 × 10 ⁻⁴ .
The surface of the fluororesin layer is subjected to a treatment with a coupling agent (aminosilane, epoxysilane, etc.), a sand plast treatment, a rolling treatment, a corona treatment, a plasma treatment, an ion gun treatment, an etching treatment as necessary. Also good.

The (B) polyimide resin layer used in the present invention is composed of, for example, aromatic tetracarboxylic acids (anhydrides, acids, and amide bond derivatives are collectively referred to as classes below) and aromatic diamines (amines and amide bonds). A polyimide film obtained by a method of casting, drying, heat treatment (imidization) to form a film, and the polyamic acid solution. Is a layer formed by applying to a fluororesin layer (film), drying, and heat-treating (imidizing), and the form of polyimide film is preferable from the viewpoint of handling and productivity.
Hereinafter, the polyimide film will be mainly described in detail.
Although the said polyimide is not specifically limited, The combination of the following aromatic diamine and aromatic tetracarboxylic acid (anhydride) is mentioned as a preferable example.
A. Combination with aromatic tetracarboxylic acid having pyromellitic acid residue and aromatic diamine having benzoxazole structure.
B. A combination of an aromatic diamine having a phenylenediamine skeleton and an aromatic tetracarboxylic acid having a biphenyltetracarboxylic acid skeleton.
C. A combination of an aromatic diamine having a diphenyl ether skeleton and an aromatic tetracarboxylic acid having a pyromellitic acid residue.
In particular, A. A polyimide film having an aromatic diamine residue having a benzoxazole structure is preferred.

  The molecular structure of the aromatic diamines having the benzoxazole structure is not particularly limited, and specific examples include the following. These diamines are preferably 70 mol% or more, more preferably 80 mol% or more of the total diamine.

  Among these, from the viewpoint of easy synthesis, each isomer of amino (aminophenyl) benzoxazole is preferable, and 5-amino-2- (p-aminophenyl) benzoxazole is more preferable. Here, “each isomer” refers to each isomer in which two amino groups of amino (aminophenyl) benzoxazole are determined according to the coordination position (eg, the above “formula 1” to “formula 4”). Each compound described in the above. These diamines may be used alone or in combination of two or more.

  Furthermore, as long as it is 30 mol% or less of the total diamine, one or more of the diamines exemplified below may be used in combination. Examples of such diamines include 4,4′-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, and bis [4- (3-aminophenoxy) phenyl]. Sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3′-diamino Diphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-dia Nodiphenyl sulfide, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide, 4,4′-diaminodiphenyl sulfoxide, 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4 , 4′-diaminodiphenylsulfone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4, 4′-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-amino) Phenoxy) phenyl] ethane, 1,1-bis [4- 4-aminophenoxy) phenyl] propane, 1,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4- (4-aminophenoxy) phenyl] butane, , 4-bis [4- (4-aminophenoxy) phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,3-bis [4- (4-aminophenoxy) phenyl ] Butane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-a Minophenoxy) -3-methylphenyl] propane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2- Bis [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexa Fluoropropane, 1,4-bis (3-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4 -Aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-amino) Enoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1, 3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] Benzene, 4,4′-bis [(3-aminophenoxy) benzoyl] benzene, 1,1-bis [4- (3-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) ) Phenyl] propane, 3,4'-diaminodiphenyl sulfide, 2,2-bis [3- (3-aminophenoxy) phenyl -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1 , 2-bis [4- (3-aminophenoxy) phenyl] ethane, bis [4- (3-aminophenoxy) phenyl] sulfoxide, 4,4′-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-Amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} fe Sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethyl Benzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-fluoro) Phenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4 -Amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene, 3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-dipheno Cibenzophenone, 3,4'-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino- 4-phenoxybenzophenone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4′-diamino-4,5′-dibiphenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone, 4,4′-diamino-5-biphenoxybenzophenone, 3,4′-diamino-4 -Biphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone 1,3-bis (3-amino-4-phenoxybenzoyl) benzene, 1,4-bis (3-amino-4-phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-phenoxybenzoyl) Benzene, 1,4-bis (4-amino-5-phenoxybenzoyl) benzene, 1,3-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,4-bis (3-amino-4-bi) Phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-amino-5-biphenoxybenzoyl) benzene, 2,6-bis [4- ( 4-amino-α, α-dimethylbenzyl) phenoxy] benzonitrile and some or all of the hydrogen atoms on the aromatic ring of the aromatic diamine are halogen atoms, An alkyl group having 1 to 3 carbon atoms, an alkoxyl group, a cyano group, or an alkyl group or an alkoxyl group having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of the alkyl group or alkoxyl group are substituted with halogen atoms. Examples thereof include substituted aromatic diamines.

  The molecular structure of the aromatic tetracarboxylic acid anhydrides is not particularly limited, and specific examples include the following. These acid anhydrides are preferably 70 mol% or more, more preferably 80 mol% or more of the total acid anhydride.

These tetracarboxylic dianhydrides may be used alone or in combination of two or more.
Furthermore, as long as it is 30 mol% or less of the total tetracarboxylic dianhydrides, one or more of the non-aromatic tetracarboxylic dianhydrides exemplified below may be used in combination. Examples of such tetracarboxylic acid anhydrides include butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, and cyclobutanetetracarboxylic acid. Acid dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohex-1-ene-2,3 5,6-tetracarboxylic dianhydride, 3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3 -(1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride 1-ethylcyclohexane -(1,2), 3,4-tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane- 1- (2,3), 3- (2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] Heptane-2,3,5,6-tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1 -(2,3), 3- (2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ', 4'-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane -2,3,5,6-tetracarboxylic dianhydride, bisic [2.2.2] Octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride An anhydride etc. are mentioned.

  The solvent used when reacting (polymerizing) the aromatic tetracarboxylic acid and the aromatic diamine to obtain a polyamic acid is particularly suitable as long as it can dissolve both the raw material monomer and the produced polyamic acid. Although not limited, polar organic solvents are preferred, such as N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, dimethyl Examples thereof include sulfoxide, hexamethylphosphoric amide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, and halogenated phenols. These solvents can be used alone or in combination. The amount of the solvent used may be an amount sufficient to dissolve the monomer as a raw material. As a specific amount used, the weight of the monomer in the solution in which the monomer is dissolved is usually 5 to 40% by weight, The amount is preferably 10 to 30% by weight.

  Conventionally known conditions may be applied for the polymerization reaction for obtaining the polyamic acid (hereinafter also simply referred to as “polymerization reaction”). As a specific example, in a temperature range of 0 to 80 ° C., 10 Stirring and / or mixing continuously for minutes to 30 hours. If necessary, the polymerization reaction may be divided or the temperature may be increased or decreased. In this case, the order of adding both monomers is not particularly limited, but it is preferable to add aromatic tetracarboxylic acid anhydrides to the solution of aromatic diamines. The viscosity of the polyamic acid solution obtained by the polymerization reaction is measured with a Brookfield viscometer (25 ° C.), and is preferably 10 to 2000 Pa · s, more preferably 100 to 1000 Pa · s, from the viewpoint of the stability of liquid feeding. It is.

Vacuum degassing during the polymerization reaction is effective in producing a good quality polyamic acid solution. Moreover, you may perform superposition | polymerization by adding a small amount of terminal blockers to aromatic diamine before polymerization reaction. Examples of the end capping agent include compounds having a carbon-carbon double bond such as maleic anhydride. The amount of maleic anhydride used is preferably 0.001 to 1.0 mol per mol of aromatic diamine.
In order to form a polyimide film from the polyamic acid solution obtained by the polymerization reaction, a green film (a self-supporting precursor film is obtained by applying the polyamic acid solution on a support and drying, then, Examples of the method of imidization reaction by subjecting the green film to heat treatment include, but are not limited to, application of the polyamic acid solution to the support, including casting from a slit-attached base and extrusion by an extruder. A conventionally known solution coating means can be appropriately used.

  The conditions for drying the polyamic acid coated on the support to obtain a green sheet are not particularly limited, and examples include a temperature of 70 to 150 ° C. and a drying time of 5 to 180 minutes. A conventionally known drying apparatus that satisfies such conditions can be applied, and examples thereof include hot air, hot nitrogen, far infrared rays, and high frequency induction heating. Next, in order to obtain a target polyimide film from the obtained green sheet, an imidization reaction is performed. As a specific method thereof, a conventionally known imidation reaction can be appropriately used. For example, there may be mentioned a method (so-called thermal ring closure method) in which an imidization reaction proceeds by subjecting it to a heat treatment after performing a stretching treatment as necessary using a polyamic acid solution containing no ring closure catalyst or a dehydrating agent. The heating temperature in this case is exemplified by 100 to 500 ° C. From the viewpoint of film physical properties, more preferably, a two-stage heat treatment in which the treatment is performed at 150 to 250 ° C. for 3 to 20 minutes and then treatment at 350 to 500 ° C. for 3 to 20 minutes. Is mentioned.

Another example of the imidization reaction is a chemical ring closure method in which a polyamic acid solution contains a ring closure catalyst and a dehydrating agent, and the imidization reaction is performed by the action of the ring closing catalyst and the dehydrating agent. In this method, after the polyamic acid solution is applied to the support, the imidization reaction is partially advanced to form a film having self-supporting property, and then imidization can be performed completely by heating. In this case, the condition for partially proceeding with the imidization reaction is preferably a heat treatment for 3 to 20 minutes at 100 to 200 ° C., and the condition for allowing the imidization reaction to be completely performed is preferably 200 to 400 ° C. For 3 to 20 minutes.

As for the thickness of the polyimide film which forms the said polyimide resin layer, 1.0 micrometer-38 micrometers are preferable, More preferably, they are 1.0 micrometer-25 micrometers, More preferably, they are 1.0 micrometer-20 micrometers. A film thickness greater than 38 μm is not preferred for the purpose of reducing the weight of electronic components. Moreover, since the ratio of the polyimide with respect to the whole laminated body becomes high and exerts a bad influence on physical properties, such as a water absorption rate and an electrical property, it is unpreferable. On the other hand, if the film thickness is less than 1.0 μm, film formation is very difficult because the film is easily broken during conveyance and easily wrinkled.
The storage elastic modulus: E ′ (B) of the polyimide film forming the polyimide resin layer is not particularly limited, but is preferably 6.0 GPa or more, more preferably 7.0 GPa or more, and even more preferably 8.0 GPa or more. . If the tensile strength at break is less than 6 GPa, the effect of reinforcing the fluororesin layer by the polyimide film may not be obtained.
The linear expansion coefficient of the polyimide film forming the polyimide resin layer is preferably −10 ppm / ° C. to 10 ppm / ° C., more preferably −7.5 ppm / ° C. to 7.5 ppm / ° C., more preferably − 5 ppm / ° C to 5 ppm / ° C. If the linear expansion coefficient exceeds this range, distortion and wrinkles may occur during high temperature exposure such as soldering.

For the polyimide film forming the polyimide resin layer, treatment with a coupling agent (aminosilane, epoxysilane, etc.), sandplast treatment, rolling treatment, corona treatment, plasma treatment, ion gun treatment, etching treatment, etc. You may use for.

The linear expansion coefficient of the multilayer polyimide film in the present invention is preferably 10 ppm / ° C. to 25 ppm / ° C., more preferably 10 ppm / ° C. to 23 ppm / ° C., further preferably 10 ppm / ° C. to 20 ppm / ° C. When the coefficient of linear expansion exceeds this range, when a copper layer having a coefficient of linear expansion of 16 ppm / ° C is laminated, the difference between the coefficients of linear expansion is large, and there is a risk of peeling during use or warping. There is a fear.
In order to set the linear expansion coefficient of the multilayer polyimide film within the range of 10 ppm / ° C. to 25 ppm / ° C., the thickness ratio of the (A) layer in the multilayer polyimide film {total (A) layer / multilayer polyimide film} is 60%. The storage elastic modulus at room temperature of the (A) layer: E ′ (A) and the storage elastic modulus at room temperature of the (B) layer: E ′ (B) ratio {E ′ (A) / E ′ (B)} is preferably 2.0% to 20%, more preferably a thickness ratio of 65% to 90% and a storage modulus ratio of 2.5% to 15%, More preferably, the thickness ratio is 65% to 85%, and the storage modulus ratio is 3.0% to 10%.
By setting the thickness ratio or the storage elastic modulus ratio within this range, a multilayer polyimide film having a target linear expansion coefficient can be obtained.

The thickness of the copper layer used in the present invention is preferably 1.0 μm to 25 μm, more preferably 1.0 μm to 12.5 μm, still more preferably 1.0 μm to 10 μm.
The copper layer lamination method of the copper-clad multilayer polyimide film used in the present invention is not particularly limited, and the following means are exemplified.
A means for forming a copper layer on a multilayer polyimide film using vacuum coating techniques such as vapor deposition, sputtering, and ion plating.
A means for forming a copper layer on a multilayer polyimide film by a wet plating method such as electroless plating or electroplating.
A copper layer can be laminated on at least one surface of the multilayer polyimide film by combining these means alone or in combination.

  The copper-clad multilayer polyimide film of the present invention is coated with a photoresist on the side of a conductive copper layer or a post-added thick film copper layer formed on the conductive copper layer, if necessary, by an ordinary method, and after exposure, A wiring circuit pattern is formed by the steps of development, etching, and photoresist stripping. Further, if necessary, solder resist coating, plastic and electroless tin plating are performed, a flexible printed wiring board, a multilayer printed wiring board obtained by multilayering them, Further, a printed wiring board having a semiconductor chip directly mounted thereon can be obtained. There are no particular limitations on the method for creating these circuits, making them multi-layered, and mounting a semiconductor chip, and the methods may be appropriately selected from known methods.

An inorganic coating such as a single metal or a metal oxide may be formed on the surface of the copper layer used in the present invention or, if necessary, the surface of the thick film metal layer that is formed later. In addition, the surface of the copper layer or later thick film metal layer formed on the copper layer, if necessary, treatment with a coupling agent (aminosilane, epoxysilane, etc.), sandplast treatment, rolling treatment, corona treatment, plasma You may use for a process, an ion gun process, an etching process, etc.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited by a following example. In addition, the evaluation method of the physical property in the following examples is as follows.

1. Reduced viscosity (ηsp / C)
A solution dissolved in N-methyl-2-pyrrolidone (or N, N-dimethylacetamide) so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. with an Ubbelohde type viscosity tube.
2. Thickness The film to be measured was measured using a micrometer (Minetron 1245D, manufactured by Finelfu).

3. About the film | membrane of storage elastic modulus measurement object, viscoelasticity measurement (DMA) was performed on the following conditions, and the value of storage elastic modulus: E 'in 25 degreeC was calculated | required.
Device name: Rheogel-E4000 manufactured by UBM
Jig: Stretch jig
Sample length: 14mm
Sample width: 5 mm
Frequency: 10Hz
Temperature rise start temperature: 0 ° C
Temperature increase rate: 5 ° C / min
Atmosphere: Nitrogen

4). Linear expansion coefficient (CTE)
For the film to be measured, the stretch rate in the MD direction and the TD direction is measured under the following conditions, and the stretch rate / temperature at intervals of 90 to 100 ° C., 100 to 110 ° C.,. Was performed up to 400 ° C., and the average value of all measured values from 100 ° C. to 350 ° C. was calculated as CTE (average value).
Device name: TMA4000S manufactured by MAC Science
Sample length: 10mm
Sample width: 2mm
Initial load: 34.5 g / mm ²
Temperature rise start temperature: 25 ° C
Temperature rise end temperature: 400 ° C
Temperature increase rate: 5 ° C / min
Atmosphere: Argon

5). The film to be measured was subjected to differential scanning calorimetry (DSC) under the following conditions, and the melting point (Tm) was determined according to JIS K7121.
Device name: DSC3100S manufactured by MAC Science
Bread: Aluminum bread (non-airtight type)
Sample mass: 4mg
Temperature rising start temperature: 30 ° C
Temperature rise end temperature: 400 ° C
Temperature increase rate: 20 ° C / min
Atmosphere: Argon A fluororesin film to be measured for dielectric constant and dielectric loss tangent was cut into a size of 3 mm (thickness) × 200 mm × 120 mm to prepare a test film. Conductive paste was applied to both sides of the test film and wired, and the dielectric constant and dielectric loss tangent at 1 MHz were measured.

7). Peel strength (resin)
The peel strength between the polyimide resin layer / fluororesin layer of the multilayer polyimide film to be measured was determined by performing a 90 ° peel test under the following conditions.
Device name: Autograph AG-IS, manufactured by Shimadzu Corporation
Sample length: 100mm
Sample width: 10mm
Measurement temperature: 25 ° C
Peeling speed: 50mm / min
Atmosphere: Atmosphere

<< Evaluation of Substrate >> For each single-sided copper-coated polyimide film consisting of a warped multilayer polyimide film and a copper layer, according to the appearance inspection, those having no warpage are evaluated as ◯, those having warpage are evaluated as △, and those wrapped in a roll shape are evaluated as ×. did.
<< Evaluation of Substrate >> Each double-sided copper-bonded multilayer polyimide film consisting of a moisture and heat resistant multilayer polyimide film and a copper layer is processed under JEDEC LEVEL1 conditions (85 ° C / 85% RH-168hr + 245 ° C / 3sec × 3 times), and tested. The subsequent peel strength was evaluated. In addition, in the appearance inspection after the test, the case where peeling, blistering, or discoloration was not observed was indicated as “◯”, the case where peeling, blistering, or discoloration was slightly observed was indicated as Δ, and the case where peeling, blistering, or discoloration was observed was indicated as “X”.
<< Evaluation of Substrate >> Each double-sided copper-bonded multilayer polyimide film consisting of a heat-resistant multilayer polyimide film and a copper layer is placed in a stainless mesh cage and subjected to heat treatment at 250 ° C. for 24 hours in the atmosphere to determine the peel strength after the test. evaluated. In addition, in the appearance inspection after the test, the case where peeling, blistering, or discoloration was not observed was indicated as “◯”, the case where peeling, blistering, or discoloration was slightly observed was indicated as Δ, and the case where peeling, blistering, or discoloration was observed was indicated as “X”.

[Production Example 1]
(Preparation of polyimide film A)
The inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 223 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole and 4416 parts by mass of N, N-dimethylacetamide were added. 40.5 parts by mass of Snowtex (DMAC-ST30, manufactured by Nissan Chemical Industries, Ltd.) (containing 8.1 parts by mass of silica), pyromellitic acid, which is prepared by completely dissolving the colloidal silica in dimethylacetamide. When 217 parts by mass of dianhydride was added and stirred for 24 hours at a reaction temperature of 25 ° C., a brown and viscous polyamic acid solution A was obtained. This reduced viscosity was 3.9 dl / g.
This polyamic acid solution A was coated on a non-lubricant surface of polyethylene terephthalate film A-4100 (manufactured by Toyobo Co., Ltd.) using a comma coater, dried at 110 ° C. for 5 minutes, and then not peeled off from the support. The polyamic acid film was wound up. The polyamic acid film is passed through a pin tenter having three heat treatment zones, the first stage 150 ° C. × 2 minutes, the second stage 220 ° C. × 2 minutes, the third stage 475 ° C. × 4 minutes, and 20 minutes after passing through the tenter. Six rolls were passed to give a double-sided free process, and finally slit to 500 mm width to obtain polyimide films A1 to A4.
Table 1 shows the physical property values of the obtained polyimide films A1 to A4.
Next, sputtering and plating were performed.
Polyimide films A1 to A4 were cut to A4 size and fixed by being sandwiched between stainless steel frames having openings. This frame was fixed to a substrate holder in the sputtering apparatus. The substrate holder and the polyimide film are fixed in close contact. For this reason, the temperature of a polyimide film can be set by flowing a refrigerant in a substrate holder. Next, plasma treatment of the polyimide film surface was performed. The plasma treatment conditions were argon gas, frequency 13.56 MHz, output 200 W, gas pressure 1 × 10 ⁻³ Torr, treatment temperature 2 ° C., treatment time 2 minutes. Next, a frequency of 13.56 MHz, an output of 450 W, a gas pressure of 3 × 10 ⁻³ Torr, a nickel-chromium (chromium 10 mass%) alloy target, and a DC magnetron sputtering method in an argon atmosphere, 1 nm / second. A nickel-chromium alloy film (underlayer) having a thickness of 7 nm is formed at a rate of 5 mm, and then a refrigerant whose temperature on the back side of the sputtered surface of the substrate is controlled to 2 ° C. is set inside so that the temperature of the substrate is set to 2 ° C. Washed away. Next, sputtering was performed in contact with the SUS plate of the substrate holder to form a copper thin film having a thickness of 0.25 μm, thereby obtaining single-side underlying metal thin film-formed polyimide films A1 to A4. Here, the thickness of the copper and NiCr layers was confirmed by a fluorescent X-ray method. The obtained single-sided underlying metal thin film forming polyimide films A1 to A4 were fixed to a plastic frame, and a copper layer having a thickness of 9 μm was formed using a copper sulfate plating bath. The electrolytic plating conditions were immersion in an electrolytic plating solution (copper sulfate 80 g / l, sulfuric acid 210 g / l, HCl, a small amount of brightener), and electricity was passed through 1.5 Adm ² . Then, it heat-dried at 120 degreeC for 10 minute (s), and obtained copper-clad laminated board (CCL) A1-A4 which is a polyimide film which formed the copper layer in the single side | surface.

[Production Example 2]
(Preparation of polyimide film B)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, 200 parts by mass of diaminodiphenyl ether and 4170 parts by mass of N-methyl-2-pyrrolidone were added and completely dissolved, and then colloidal silica was added. 40.5 parts by mass of Snowtex (DMAC-ST30, manufactured by Nissan Chemical Industries, Ltd.) dispersed in dimethylacetamide (containing 8.1 parts by mass of silica), 217 parts by mass of pyromellitic dianhydride were added, and 25 ° C. When the mixture was stirred at the reaction temperature of 5 hours, a brown viscous polyamic acid solution B was obtained. This reduced viscosity was 3.6 dl / g.
This polyamic acid solution B was coated on a non-lubricant surface of polyethylene terephthalate film A-4100 (manufactured by Toyobo Co., Ltd.) using a comma coater, dried at 110 ° C. for 5 minutes, and then not peeled off from the support. The polyamic acid film was wound up. The polyamic acid film is passed through a pin tenter having three heat treatment zones, the first stage is 150 ° C. × 2 minutes, the second stage is 220 ° C. × 2 minutes, the third stage is 400 ° C. × 4 minutes, and 20 minutes after passing through the tenter. Six rolls were passed to give a double-side free process, and finally slit to 500 mm width to obtain polyimide film B.
Table 1 shows the physical property values of the obtained polyimide film B.
Next, sputtering and plating were performed in the same manner as in Production Example 1 to obtain a copper-clad laminate (CCL) B.

[Production Example 3]
(Preparation of polyimide film C)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was replaced with nitrogen, 108 parts by mass of phenylenediamine and 4010 parts by mass of N-methyl-2-pyrrolidone were added and completely dissolved, and then colloidal silica was added. Snowtex (DMAC-ST30, manufactured by Nissan Chemical Industries, Ltd.) 40.5 parts by mass (including 8.1 parts by mass of silica) dispersed in dimethylacetamide and 292.5 parts by mass of diphenyltetracarboxylic dianhydride In addition, when the mixture was stirred at a reaction temperature of 25 ° C. for 12 hours, a brown viscous polyamic acid solution C was obtained. This reduced viscosity was 4.3 dl / g.
This polyamic acid solution C was coated on a non-lubricant surface of polyethylene terephthalate film A-4100 (manufactured by Toyobo Co., Ltd.) using a comma coater, dried at 110 ° C. for 5 minutes, and then not peeled off from the support. The polyamic acid film was wound up. The polyamic acid film is passed through a pin tenter having three heat treatment zones, the first stage is 150 ° C. × 2 minutes, the second stage is 220 ° C. × 2 minutes, the third stage is 460 ° C. × 4 minutes, and 20 minutes after passing through the tenter. Six rolls were passed to give a double-side free process, and finally slit to a width of 500 mm to obtain a polyimide film C having a thickness of 25 μm.
Table 1 shows the physical property values of the obtained polyimide film C.
Next, sputtering and plating were performed in the same manner as in Production Example 1 to obtain a copper-clad laminate (CCL) C.

[Production Example 4]
(Create fluororesin film)
Using a commercially available fluororesin, a fluororesin film was prepared by a conventionally known method.
The types and physical properties of the obtained fluororesin film are shown in Tables 2 and 3.

[Example 1]
A functional group-containing fluororesin film D1 (Fluon PFA adhesive grade, manufactured by Asahi Glass Co., Ltd.) and a polyimide film A1 are arranged in this order on one side of a polyimide film A1 cut out to a size of 150 mm × 150 mm, and is 330 or higher than the melting point of the fluororesin film. Heat-press molding was performed at 5 ° C. for 30 minutes at a temperature of 5 ° C. to obtain a multilayer polyimide film of polyimide resin layer / fluorine resin layer / polyimide resin layer. Table 4 shows the evaluation results of the thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film.
On the other hand, the functional group-containing fluororesin film D1 and the polyimide film A1 are arranged in this order on the surface of the polyimide film A1 of the copper-clad laminate (CCL) A1 cut into a size of 150 mm × 150 mm, and the melting point of the fluororesin film is 330 or more. Heat-press molding was performed at 5 ° C. for 30 minutes at a temperature of 5 ° C. to obtain a single-sided copper-bonded multilayer polyimide film of copper layer / polyimide resin layer / fluorine resin layer / polyimide resin layer. Table 4 shows the evaluation results of the warpage of the obtained single-sided copper-clad multilayer polyimide film.
Furthermore, the functional group-containing fluororesin film D1 and the copper-clad laminate (CCL) A1 are arranged in this order on the polyimide film A1 surface of the copper-clad laminate (CCL) A1 cut into a size of 150 mm × 150 mm, and the fluororesin film Heating and pressing were performed for 30 minutes at 330 ° C. and 5 MPa, which is equal to or higher than the melting point, to obtain a double-sided copper-bonded multilayer polyimide film of copper layer / polyimide resin layer / fluorine resin layer / polyimide resin layer / copper layer. Table 4 shows the evaluation results of the moisture and heat resistance test and heat resistance test of the obtained double-sided copper-coated multilayer polyimide film.

[Example 2]
A laminate is prepared in the same manner as in Example 1 except that polyimide film A2 is used instead of polyimide film A1, and copper-clad laminate (CCL) A2 is used instead of copper-clad laminate (CCL) A1. evaluated. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 4.

[Examples 3 and 4]
A laminate was prepared and evaluated in the same manner as in Examples 1 and 2 except that the functional group-containing fluororesin film D2 was used instead of the functional group-containing fluororesin film D1. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 4.

[Examples 5 and 6]
A laminate was prepared and evaluated in the same manner as in Examples 1 and 2 except that the functional group-containing fluororesin film D3 was used instead of the functional group-containing fluororesin film D1. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 5.

Example 7
A laminate is prepared in the same manner as in Example 5 except that polyimide film A3 is used instead of polyimide film A1, and copper-clad laminate (CCL) A3 is used instead of copper-clad laminate (CCL) A1. evaluated. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 5.

Example 8
A laminate was prepared and evaluated in the same manner as in Example 7 except that the functional group-containing fluororesin film D4 was used instead of the functional group-containing fluororesin film D3. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 5.

Example 9
Create a laminate in the same manner as in Example 8 except that polyimide film A4 is used instead of polyimide film A3, and copper-clad laminate (CCL) A4 is used instead of copper-clad laminate (CCL) A3. evaluated. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 5.

[Examples 10 to 13]
The polyimide film A2 cut out to a size of 150 mm × 150 mm was set in a Nikketsu plasma treatment machine and evacuated to a vacuum. Then, oxygen gas was introduced to cause discharge, and plasma treatment was performed. The processing conditions are a degree of vacuum of 3 × 10 Pa, a gas flow rate of 1.5 SLM, and a discharge power of 12 KW. Functional group-free fluororesin film E (Fluon PFA, manufactured by Asahi Glass Co., Ltd.), F (neoflon PFA, manufactured by Daikin Industries, Ltd.), G (neoflon FEP, manufactured by Daikin Industries, Inc.), H (EPE, manufactured by Daikin Industries, Ltd.) was disposed, and heat-pressure molding was performed for 30 minutes at 330 ° C. and 5 MPa, which is higher than the melting point of the fluororesin film, to obtain a multilayer polyimide film. Table 6 shows the evaluation results of the thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film.
On the other hand, the copper-clad laminate (CCL) A2 was set in a Nikketsu plasma processing machine and evacuated to a vacuum, and then oxygen gas was introduced to cause discharge to perform plasma processing. The processing conditions are a degree of vacuum of 3 × 10 Pa, a gas flow rate of 1.5 SLM, and a discharge power of 12 KW. The obtained plasma-treated copper-clad laminate (CCL) A2 was cut into a size of 150 mm × 150 mm, and the functional group-free fluororesin films E to H and the plasma-treated polyimide film A2 were arranged in this order on the surface of the polyimide film A2, Heat-press molding was performed at 330 ° C. and 5 MPa, which is equal to or higher than the melting point of the fluororesin film, for 30 minutes to obtain a single-sided copper-bonded multilayer polyimide film of copper layer / polyimide resin layer / fluororesin layer / polyimide resin layer. Table 6 shows the evaluation results of the warpage of the obtained single-sided copper-clad multilayer polyimide film.
Furthermore, functional group-free fluororesin films E to H and plasma-treated copper-clad laminate (CCL) A2 are placed in this order on the polyimide film A2 surface of the plasma-treated copper-clad laminate (CCL) A2 cut into a size of 150 mm × 150 mm. And heat-pressure molding for 30 minutes at 330 ° C. and 5 MPa, which is above the melting point of the fluororesin film, and a copper layer / polyimide resin layer / fluororesin layer / polyimide resin layer / copper layer double-sided copper-bonded multilayer polyimide film Got. Table 6 shows the evaluation results of the heat and moisture resistance test and heat resistance test of the obtained double-sided copper-clad multilayer polyimide film.

[Comparative Example 1]
A laminate is created in the same manner as in Example 2 except that polyimide film B is used instead of polyimide film A2, and copper-clad laminate (CCL) B is used instead of copper-clad laminate (CCL) A2. evaluated. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test Table 7 shows the evaluation results.
When the linear expansion coefficient of the polyimide film is large, the linear expansion coefficient of the obtained multilayer polyimide film is also large, and the difference from the linear expansion coefficient of copper is large, so that the adhesion and quality after the reliability test are lowered.

[Comparative Examples 2 and 3]
Example 2 except that functional group-containing fluororesin film I (Fluon LM-ETFE AH2000, manufactured by Asahi Glass Co., Ltd.) and J (neoflon EFEP RP5000, manufactured by Daikin Industries, Ltd.) are used instead of functional group-containing fluororesin film D1. A laminate was prepared and evaluated in the same manner. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test Table 7 shows the evaluation results.
Since ETFE is inferior in heat resistance, moist heat resistance, and electrical properties as compared with perfluorinated resins such as PFA, FEP, and EPE, the adhesiveness and quality after the reliability test are lowered.

[Comparative Examples 4 and 5]
A functional group-free fluororesin film K (Fluon ETFE, manufactured by Asahi Glass Co., Ltd.) and L (neoflon ETFE, manufactured by Daikin Industries, Ltd.) are used in place of the functional group-free fluororesin film E. A laminate was prepared by the method and evaluated. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test Table 7 shows the evaluation results.
Since ETFE is inferior in heat resistance, moist heat resistance, and electrical properties as compared with perfluorinated resins such as PFA, FEP, and EPE, the adhesiveness and quality after the reliability test are lowered.

[Comparative Example 6]
A laminate is created in the same manner as in Example 1 except that polyimide film A4 is used instead of polyimide film A1, and copper-clad laminate (CCL) A4 is used instead of copper-clad laminate (CCL) A1. evaluated. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 8.
If the thickness ratio of the fluororesin is too small, the linear expansion coefficient of the resulting multi-layer fluororesin will be small, but the contribution of low moisture absorption, which is a feature of the fluororesin, will be small. Decreased.

[Comparative Examples 7 and 8]
A laminate was prepared and evaluated in the same manner as in Comparative Example 6 except that functional group-containing fluororesin films D2 and D3 were used instead of functional group-containing fluororesin film D1. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 8.
If the thickness ratio of the fluororesin is too small, the linear expansion coefficient of the resulting multi-layer fluororesin will be small, but the contribution of low moisture absorption, which is a feature of the fluororesin, will be small. Decreased.

[Comparative Examples 9 and 10]
A laminate in the same manner as in Example 8 except that polyimide films A1 and A2 are used instead of polyimide film A3, and copper-clad laminates (CCL) A1 and A2 are used instead of copper-clad laminate (CCL) A3. Was created and evaluated. Evaluation results of thickness ratio, storage elastic modulus ratio, and linear expansion coefficient of the obtained multilayer polyimide film, evaluation results of warpage of multilayer polyimide film with single-sided copper adhesion, wet heat resistance test of multilayer polyimide film with double-sided copper adhesion, heat resistance test The evaluation results are shown in Table 8.
When the thickness ratio of the fluororesin is too large, the linear expansion coefficient of the obtained multilayer fluororesin is also increased, and the difference from the linear expansion coefficient of copper is increased, so that the adhesiveness and quality after the reliability test are lowered.

[Application 1]
A functional group-containing fluororesin film D2 is arranged on the surface of the polyimide film A2 of a copper-clad laminate (CCL) A2 cut out to a size of 150 mm × 150 mm, and heated at 330 ° C. and 5 MPa, which is higher than the melting point of the fluororesin film, for 30 minutes. Pressure forming was performed to obtain a three-layer laminate of copper layer / polyimide resin layer / fluorine resin layer.
On the other hand, a multilayer polyimide film with a copper layer / polyimide resin layer / fluorine resin layer / polyimide resin layer / copper layer obtained in Example 4 was used, and a photoresist (FR-200, Shipley on one side of the copper layer was used. After application and drying, the film was exposed to light with a glass photomask, and further developed with a 1.2 mass% KOH aqueous solution. Next, using a cupric chloride etching line containing HCl and hydrogen peroxide, etching is performed at a spray pressure of 40 ° C. and 2 kgf / cm ² to form a test pattern, followed by cleaning, and annealing at 125 ° C. for 1 hour. Processing was performed to obtain a single-sided copper-clad multilayer polyimide film with a single-sided pattern.
The pattern forming surface of the single-sided copper-clad multilayer polyimide film with a single-sided pattern faces the fluororesin surface of the three-layer laminate, and heat-press molding is performed at 330 ° C. and 5 MPa, which is higher than the melting point of the fluororesin film, for 30 minutes, A multilayer printed wiring board as shown in FIG. 1 was obtained. The obtained multilayer printed wiring board is very useful as a high-frequency member because the copper wiring is covered with a fluororesin having a low dielectric constant.

[Application 2]
The copper layer / polyimide resin layer / fluorine resin layer / polyimide resin layer / copper layer double-sided copper-bonded multilayer polyimide film obtained in Example 4 was used, and photoresist (FR-200, manufactured by Shipley Co., Ltd.) was used on both sides of the copper layer. After coating and drying, the film was exposed to light with a glass photomask, and further developed with a 1.2% by mass aqueous KOH solution. Next, using a cupric chloride etching line containing HCl and hydrogen peroxide, etching is performed at a spray pressure of 40 ° C. and 2 kgf / cm ² to form a test pattern, followed by cleaning, and annealing at 125 ° C. for 1 hour. It processed and obtained the multilayer polyimide film with a double-sided pattern.
The fluororesin surfaces of the three-layer laminate obtained in Application Example 1 are faced to both sides of the multilayer polyimide film with a double-sided pattern, and heat-press molding at 330 ° C. and 5 MPa, which is higher than the melting point of the fluororesin film, for 30 minutes. A multilayer printed wiring board as shown in FIG. 2 was obtained. The obtained multilayer printed wiring board is very useful as a high-frequency member because the copper wiring is covered with a fluororesin having a low dielectric constant.

  A multilayer polyimide film in which the polyimide resin layer / fluorine resin layer / polyimide resin layer of the present invention is laminated in this order, the multilayer polyimide film having a linear expansion coefficient of 10 ppm / ° C. to 25 ppm / ° C., at least of the multilayer polyimide film Copper-coated multilayer polyimide film with a copper layer laminated on one side and a printed wiring board with a circuit pattern obtained by removing a part of this copper layer produce almost no warping or distortion even in an environment such as high temperature and high humidity. As a result, the quality of the printed wiring board obtained and the yield at the time of production are improved, and high-quality electronic component manufacturing with excellent electrical characteristics can be realized.

1 Copper 2 Fluorine resin layer 3 Polyimide resin layer

Claims (8)

(B) Polyimide resin layer / (A) Fluorine resin layer / (B) Polyimide resin layer / are laminated in this order, and the linear expansion coefficient of the multilayer polyimide film is 10 ppm / ° C. to 25 ppm / (A) layer thickness ratio {total (A) layer / multilayer polyimide film} is 60% to 90%, and the (A) layer is co-polymerized with tetrafluoroethylene perfluoroalkyl vinyl ether. This is a thermoplastic fluororesin layer made of any one of a polymer (PFA), a tetrafluoroethylene / hexafluoropropylene copolymer (FEP), and a tetrafluoroethylene / hexafluoropropylene / perfluoroalkyl vinyl ether copolymer (EPE). Multilayer polyimide film. The multilayer polyimide film according to claim 1, wherein the layer (A) is a layer of a functional group-containing thermoplastic fluororesin. The multilayer polyimide film according to claim 1 or 2, wherein the layer (B) is a polyimide layer having a polyimide benzoxazole component, and has a linear expansion coefficient of -10 ppm / ° C to 10 ppm / ° C. The multilayer polyimide film according to any one of claims 1 to 3, wherein the (A) layer has a thickness of 1.0 to 100 µm, and the (B) layer has a thickness of 1.0 to 38 µm. (A) Storage elastic modulus at room temperature of layer: E ′ (A) and storage elastic modulus at room temperature of layer (B): ratio of E ′ (B) {E ′ (A) / E ′ (B)} The multilayer polyimide film according to any one of claims 1 to 4, wherein the content is 2.0% to 20%. A copper-coated multilayer polyimide film in which a copper layer is laminated on at least one surface of the multilayer polyimide film according to claim 1. The printed wiring board formed by removing a part of copper layer of the copper adhesion multilayer polyimide film of Claim 6, and forming a circuit pattern. The multilayer printed wiring board formed by laminating | stacking the multilayer polyimide film in any one of Claims 1-7, a copper adhesion multilayer polyimide film, and a printed wiring board.