JP2006116738A - Adhesive laminated film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive laminated film which is equipped with heat-resistance, high frequency corresponding property, and flexibility at a high level, and also, can achieve the reliability and the reduction (thinning) of insulation by using a polyimide having a thickness of a specified value or lower as the insulating layer. <P>SOLUTION: For this adhesive laminated film, an adhesive layer of which the thickness is 5 μm or lower is formed at least on one surface of a high polymer film of which the modulus of tensile elasticity is 6 GPa or higher, the glass transition temperature is 150°C or higher, and the thickness is 1 to 10 μm. Preferably, the polymer film is a polyimide benzooxazole film in the adhesive laminated film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an adhesive laminated film used for forming an insulating layer in a printed wiring board or the like, or an adhesive laminated film used for manufacturing a multilayer printed wiring board having a multilayer structure by laminating thin insulating layers. Related to film.

When an adhesive film is used to form an insulating layer in a printed wiring board or the like, a so-called prepreg in which a glass fiber cloth is impregnated with an uncured epoxy resin or the like has been used. Also, an aramid fiber fabric is used instead of the glass fiber fabric. These prepregs have a thick cloth and cannot meet the demand for lightening in recent years.
In recent years, electronic devices have been improved in functionality, performance, and size, and there is a demand for downsizing and weight reduction of electronic components used therewith. For this reason, multilayer printed wiring boards, semiconductor element packaging methods, and wiring materials or wiring components for mounting them have been required to have higher density, higher functionality, and higher performance. A material excellent in heat resistance, electrical reliability, adhesion, and insulation that can be suitably used as a high-density mounting material such as a semiconductor package, COL and LOC package, MCM, or FPC material such as a multilayer flexible printed wiring board. It has been demanded.
Various proposals have been made in order to achieve reduction in weight (lightness) as a result of forming an insulating layer on a printed wiring board or the like and forming the insulating layer.
It is known that various epoxy resins with relatively high heat resistance are used as the insulation layer, but the insulation from the meaning that the dielectric loss tangent is larger, such as non-uniformity of the insulation layer due to non-uniform flow and resin contamination. Has the problem of lack of reliability.

In order to solve the above problem, an adhesive film in which a resin from a silicone copolymer polyimide resin and an epoxy resin is provided on a temporary support with an adhesive layer thickness of 50 μm has been proposed (see Patent Document 1). Although this method is also excellent in permeability between circuits (conductors), the above-mentioned problem cannot be solved completely, and a certain thickness of the insulating layer cannot be ensured, and characteristic impedance is not obtained. There is a problem in forming an insulating layer such as a high-frequency circuit board that requires strict security.
It has also been proposed to use a thermoplastic polyimide resin (see Patent Documents 2, 3, and 4).
Furthermore, a film is also proposed in which an adhesive layer made of thermoplastic polyimide and thermosetting tree is provided on at least one side of a polyimide film (see Patent Document 5).
JP 2003-089784 A JP 2000-143981 A JP 2000-144092 A JP 2003-306649 A JP 2003-011308 A

In Patent Document 2 to Patent Document 5 and the like, the thickness as the adhesive layer and the thickness of the film are not considered, and the problem to achieve lightening (lightening) is to be solved. Even if listed, the thickness of the polyimide film and the thickness of the adhesive layer are not limited.
When producing an adhesive laminated film, if the base film that forms the adhesive layer on one or both sides of the film is a thin film, handling of the film becomes extremely difficult. As a thin film that can be handled, mechanical properties are important, and in particular, tensile modulus is important. The present invention has a higher level of heat resistance, high frequency compatibility, and flexibility, and uses a polyimide having a thickness of a certain thickness or less as an insulating layer to reduce the reliability of insulation and lightness (lightness). Another object of the present invention is to provide an adhesive laminated film that has also been achieved.

As a result of intensive studies, the present inventors have a higher level of heat resistance, high frequency response and flexibility by laminating an adhesive layer having a specific thickness or less on a polyimide film having a specific property or less. In addition, the present invention provides an adhesive laminated film that achieves insulation reliability and lightness (light thinness) by using polyimide having a thickness of a certain thickness or less as an insulating layer.
That is, the present invention is characterized in that an adhesive layer having a thickness of 5 μm or less is formed on at least one surface of a polymer film having a tensile elastic modulus of 6 GPa or more, a glass transition temperature of 150 ° C. or more, and a thickness of 1 μm to 10 μm. The adhesive laminated film, the polymer film is the above-mentioned adhesive laminated film, which is a polyimide film, and the polymer film is the above-mentioned adhesive laminated film, which is a polybenzoxazole film, and has a total thickness. Is the above-mentioned adhesive laminated film having a thickness of 15 μm or less.
Furthermore, the polymer film is the above-mentioned adhesive laminated film which is a polymer film containing a lubricant having a volume average particle diameter of 1/10 or less of the thickness of the polymer film, and the polymer film is a linear film. The adhesive laminate film, which is a polymer film having a coefficient of expansion (CTE) of 10 ppm / ° C. or less, and the polymer film is a polymer film having a water absorption of 2.5% or less. It is a film.

  The adhesive laminated film of the present invention uses a thin polymer film having a specific mechanical property, preferably a polyimide film, so that it can be efficiently produced with excellent handling properties when an adhesive layer is formed on at least one side. It is possible to achieve penetration filling between circuits with an adhesive layer, and since a specific physical property polymer film, preferably a polyimide film, is used, these polymers are also used during pressure heating molding when forming an insulating layer. Deformation of the film is suppressed and the pressure uniformity to the adhesive layer is improved, so that the adhesive layer can be efficiently penetrated between circuits, and the insulating layer thickness is ensured by the constant thickness of the polymer film. It is possible to guarantee heat-resistant insulation by the use, and because the total thickness is extremely small, the multilayer printed wiring board obtained when used for interlayer insulation such as multilayer printed wiring board is light (light ) Are those capable of achieving reduction, high functionality of electronic devices, high performance, it is effective to light a small reduction.

The polymer film of the present invention is not particularly limited as long as it has the properties of the above-described tensile elastic modulus of 6 GPa or more, the glass transition temperature of 150 ° C. or more, and the thickness of 10 μm or less to 1 μm or more. Examples thereof include a polyamide film, a wholly aromatic polyester film, a polyetherimide film, a polyamideimide film, and a polyimide film. Among these, a polyimide film is preferable, and a polyimide benzoxazole film is most preferable because it can satisfy electrical insulation, ease of production, high tensile elastic modulus, a glass transition temperature of 150 ° C. or higher, and a film having a constant thickness.
The polymer film in the present invention needs to have a thickness of 10 μm or less and 1 μm or more, and when it is less than 1 μm, there are many problems from the viewpoint of manufacturing difficulty, handling difficulty, and insulation. When the thickness exceeds 10 μm, there is little effect on lightening, and when the adhesive laminated film of the present invention is pressure-heat molded as an insulating layer, it becomes impossible to adapt to unevenness of a printed wiring board, for example, formed in a circuit. It will hold fatal faults such as.

The polymer film of the present invention must have a glass transition temperature of 150 ° C. or higher, preferably 210 ° C. or higher, more preferably 270 ° C. or higher, or a clear glass transition temperature even at high temperatures. When it has a glass transition temperature of less than 150 ° C., it exhibits the same behavior as that of a thermoplastic adhesive layer depending on the temperature when the adhesive laminated film of the present invention is pressure-heat molded as an insulating layer. Therefore, it becomes impossible to maintain the predetermined insulating layer thickness.
When the adhesive laminated film of the present invention is pressure-molded as an insulating layer because the glass transition temperature is 150 ° C. or higher, for example, it can adapt to the unevenness of the printed wiring board and has a convex surface (mainly a conductor portion or a circuit portion). ) Can also be an adhesive laminated film that can ensure an insulating layer thickness equivalent to the thickness of the polymer film.
The polymer film of the present invention is required to have a tensile elastic modulus of 6 GPa or more. From the standpoint of handling a thin film in a predetermined range and handling it in a process of laminating an adhesive layer, etc. If it is less, manufacturing and handling will be difficult.
The tensile elastic modulus of the polymer film in the present invention is essential to be 6 GPa or more, preferably 7 GPa or more, more preferably 8 GPa or more. The upper limit of the tensile elastic modulus of the polymer film in the present invention is not particularly limited, but is about 30 GPa from the viewpoint of maintaining the minimum flexibility in handling.

The polyimide film preferably used in the present invention is preferably composed of a polyimide obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid anhydride.
An aromatic diamine and an aromatic tetracarboxylic acid anhydride are subjected to a ring-opening polyaddition reaction in a solvent to obtain a polyamic acid solution. Then, after forming a green film from the polyamic acid solution, dehydration condensation (imide) The polyimide film can be obtained.
In the present invention, among these aromatic diamines, aromatic diamines having a benzoxazole structure are suitable diamines, and have a tensile modulus of 6 GPa or more, a glass transition temperature of 150 ° C. or more, and a thickness of 1 μm or more to 10 μm. It becomes easy to obtain the following films.
Specific examples of aromatic diamines having a benzoxazole structure that are particularly preferably used in the present invention include the following.

Among these, amino (aminophenyl) benzoxazole isomers are preferable from the viewpoint of ease of synthesis. 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. In the present invention, it is preferable to use 70 mol% or more of the aromatic diamine having the benzoxazole structure.

The following diamines can be used without being limited to the diamine. Examples of these diamines include 4,4′-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, 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'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide 4,4′-diaminodiphenyl sulfoxide, 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone, 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-Bi [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) 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, 1,4-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-aminophenoxy) -3-methylphenyl] propane, 2- [4- ( 4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) -3,5-dimethylphen Le] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane,

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-aminophenoxy) 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} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3 -Bis [4- (4-amino-6-fluorophenoxy) -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′-diphenoxybenzophenone, 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-biphenoxybenzoyl) 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) pheno Si] benzonitrile and some or all of the hydrogen atoms on the aromatic ring in the aromatic diamine are halogen atoms, alkyl groups having 1 to 3 carbon atoms or alkoxyl groups, cyano groups, or alkyl groups or alkoxyl group hydrogen atoms. Examples thereof include aromatic diamines substituted with a halogenated alkyl group having 1 to 3 carbon atoms partially or wholly substituted with a halogen atom or an alkoxyl group.

Preferred as the acidic component used in the production of the polyimide film preferably used as the polymer film of the present invention is a tetracarboxylic acid anhydride, and aromatic tetracarboxylic acid anhydrides.
Specific examples of the aromatic tetracarboxylic acid anhydrides include the following.

These tetracarboxylic dianhydrides may be used alone or in combination of two or more.
In the present invention, one or two or more non-aromatic tetracarboxylic dianhydrides exemplified below may be used in combination as appropriate as long as they are less than 30 mol% of the total tetracarboxylic dianhydrides.
Non-aromatic tetracarboxylic dianhydrides include, for example, butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, Cyclobutanetetracarboxylic 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-ethyl Cyclohexane-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic acid Dianhydride, 1-ethylcyclohexa -1- (1,2), 3,4-tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropyl Cyclohexane-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, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and the like. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  The solvent used when polyamic acid is obtained by polymerizing aromatic diamines and aromatic tetracarboxylic acid anhydrides is particularly limited as long as it dissolves both the raw material monomer and the polyamic acid to be produced. Although not preferred, 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 sulfoxide Hexamethylphosphoric amide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, halogenated phenols and the like.

The concentration of the polyamic acid in the polyamic acid solution obtained by the polymerization reaction is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and the viscosity of the solution is measured with a Brookfield viscometer (25 ° C.). From the viewpoint of the stability of liquid feeding, it is preferably 10 to 2000 Pa · s, and more preferably 100 to 1000 Pa · s.
The reduced viscosity (ηsp / C) of the polyamic acid in the present invention is not particularly limited, but is preferably 3.0 or more in order to improve the tensile elastic modulus, tensile breaking strength, and tensile breaking elongation. The above is more preferable, and 5.0 or more is more preferable.

In the polymer film of the present invention, it is preferable to add and contain a lubricant in the film to give fine irregularities to the film surface and improve the adhesiveness of the film. As the lubricant, inorganic or organic fine particles having an average particle diameter of about 0.03 μm to 3 μm can be used. Specific examples include titanium oxide, alumina, silica, calcium carbonate, calcium phosphate, calcium hydrogen phosphate, calcium pyrophosphate, Examples include magnesium oxide, calcium oxide, and clay minerals.
These fine particles are preferably contained in the range of 0.20 to 2.0% by mass with respect to the film. When the content of the fine particles is less than 0.20% by mass, there is not so much improvement in adhesion, which is not preferable. On the other hand, if it exceeds 2.0% by mass, the surface unevenness becomes too large, and even if the adhesiveness is improved, problems such as a decrease in smoothness remain, which is not preferable.

As a method of forming a polyimide film from the polyamic acid solution obtained by the polymerization reaction, a green film is obtained by applying the polyamic acid solution on a support and drying, and then subjecting the green film to a heat treatment. A method of imidization reaction may be mentioned.
The support on which the polyamic acid solution is applied needs only to have smoothness and rigidity sufficient to form the polyamic acid solution into a film, and a drum or belt whose surface is made of metal, plastic, glass, porcelain, etc. And the like. Among them, the surface of the support is preferably a metal, more preferably stainless steel that does not rust and has excellent corrosion resistance. The surface of the support may be plated with metal such as Cr, Ni, or Sn. The surface of the support can be mirror-finished or processed into a satin finish as necessary. In addition, a polymer film such as a polyethylene terephthalate film or a polyethylene naphthalate film can be used as the support.
Application of the polyamic acid solution to the support includes, but is not limited to, casting from a slit base, extrusion through an extruder, squeegee coating, reverse coating, die coating, applicator coating, wire bar coating, etc. Conventionally known solution coating means can be appropriately used.

A polyamic acid solution is formed into a film to obtain a precursor film (green film), which is imidized to obtain a polyimide film. As a specific imidization method, a conventionally known imidation reaction can be appropriately used. For example, using a polyamic acid solution that does not contain a ring-closing catalyst or a dehydrating agent, the imidization reaction proceeds by subjecting it to a heat treatment (so-called thermal ring-closing method), or the polyamic acid solution contains a ring-closing catalyst and a dehydrating agent. In order to obtain a polyimide film in which the difference in surface orientation between the front and back surfaces of the polyimide film is small, a chemical ring closing method can be mentioned in which an imidization reaction is performed by the action of the above ring closing catalyst and dehydrating agent. The thermal ring closure method is preferred.
100-500 degreeC is illustrated as a heating maximum temperature of a thermal ring closure method, Preferably it is 200-480 degreeC. When the maximum heating temperature is lower than this range, it is difficult to close the ring sufficiently, and when it is higher than this range, deterioration proceeds and the film tends to become brittle. A more preferable embodiment includes a two-stage heat treatment in which treatment is performed at 150 to 250 ° C. for 3 to 20 minutes and then treatment is performed at 350 to 500 ° C. for 3 to 20 minutes.
In the chemical ring closure method, after the polyamic acid solution is applied to a support, the imidization reaction is partially advanced to form a self-supporting film, 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.

The linear expansion coefficient of the polymer film in the present invention is preferably 10 ppm / ° C. or less, more preferably 8 ppm / ° C. or less, still more preferably 7 ppm / ° C. or less. When the linear expansion coefficient exceeds this range, the dimensional stability of the laminated substrate is lowered. The lower limit of the linear expansion coefficient is about −20 ppm / ° C. When the linear expansion coefficient is smaller than the lower limit, alignment becomes difficult.
The water absorption rate of the polymer film in the present invention is preferably 2.5% by mass or less, and more preferably 2.0% by mass or less. The water absorption is obtained by immersing the film dried at 150 ° C. for 1 hour or more in pure water at 25 ° C. for 24 hours and increasing the weight before and after that. If the water absorption exceeds this range, bubbles may be generated during lamination processing. Further, the lower limit of the water absorption rate is not particularly limited, and it is theoretically desired to be 0.0% by mass.

  The adhesive layer in the present invention is not limited as long as it has a thickness of 5 μm or less and has no particular difficulty in insulation, but is preferably a thermoplastic polyimide resin or a polyamideimide resin. , Epoxy resins, acrylic resins, and the like, and one or more resin blends of these resins. If necessary, an organic or inorganic filler, a flame retardant, or the like can be added to the adhesive layer.

In the adhesive laminated film of the present invention, an adhesive layer is laminated on a polymer film as a base material. However, since the adhesive layer is extremely thin, it is difficult to laminate and apply to the base film. In this case, an adhesive layer is first formed on a release film such as a film in which a release agent is applied to one side of a polyethylene terephthalate film, and a base polymer film is laminated on the adhesive layer. Furthermore, a means such as forming an adhesive layer on a surface not laminated with the adhesive layer or laminating an adhesive layer surface on which an adhesive layer is formed on a releasable film may be employed. These adhesive laminated films may be appropriately peeled off from the release film at the time of use.

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 of polyamic acid (ηsp / C)
A solution dissolved in N-methyl-2-pyrrolidone so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. using an Ubbelohde type viscosity tube.

2. The thickness of the polymer film The thickness was measured using a micrometer (Millitron 1245D, manufactured by Finelfu).

3. Tensile modulus, tensile rupture strength, and tensile rupture elongation of a polymer film A polymer film to be measured is cut into strips of 100 mm × 10 mm in the flow direction (MD direction) and the width direction (TD direction), respectively. A test piece was obtained. Using a tensile tester (manufactured by Shimadzu Corp., Autograph (R) model name AG-5000A) under the conditions of a tensile speed of 50 mm / min and a distance between chucks of 40 mm, the tensile elastic modulus and tensile rupture in each of the MD and TD directions. Strength and tensile elongation at break were measured.

5. Melting point and glass transition temperature of polymer film Differential scanning calorimetry (DSC) is performed on the polymer film to be measured under the following conditions, and the melting point (melting peak temperature Tpm) and glass transition point (Tmg) conform to JIS K 7121. And asked.
Device name: DSC3100S manufactured by MAC Science
Pan ： Aluminum pan (non-airtight)
Sample weight; 4mg
Temperature rising start temperature: 30 ° C
Temperature rising end temperature: 600 ° C
Temperature increase rate: 20 ° C / min
Atmosphere; Argon Atmosphere; Argon

4). Coefficient of linear expansion (CTE) of polymer film
For the polymer film to be measured, the stretch rate in the MD direction and TD direction is measured under the following conditions, and the stretch rate / temperature at intervals of 30 ° C. to 45 ° C., 45 ° C. to 60 ° C.,. Then, this measurement was performed up to 300 ° C., and the average value of all measured values was calculated as CTE. The MD direction means the vertical direction, and the TD direction means the width direction.
Device name: TMA4000S manufactured by MAC Science
Sample length; 20mm
Sample width: 2 mm
Temperature rise start temperature: 25 ° C
Temperature rising end temperature: 400 ° C
Temperature increase rate: 5 ° C / min
Atmosphere: Argon

5. Water Absorption Rate of Polymer Film The polymer film was cut into about 10 cm × 10 cm for testing. First, the test piece is dried in a dry oven at 150 ° C. for 1 hour. Immediately after that, the mass is measured to obtain an initial value, and then the test piece is placed in 25 ° C. ion-exchanged water for 24 hours. The sample was wiped off and reweighed to obtain the water absorption value. The water absorption was determined from the following formula.
Water absorption rate = 100 × (water absorption value−initial value) / (initial value) [wt%]

Example 1
(Preliminary dispersion of inorganic particles)
2.23 parts by mass of spherical particles of amorphous silica Seahoster KE-P30 (manufactured by Nippon Shokubai Co., Ltd.) and 1000 parts by mass of N-methyl-2-pyrrolidone are placed in a container and homogenizer T-25 basic (manufactured by IKA Labortechnik) The mixture was stirred at 10000 rpm for 1 minute to obtain a preliminary dispersion. The average particle size in the preliminary dispersion was 0.38 μm, the standard deviation was 0.032 μm, the CV value was 8.4%, and the sphericity was 0.98.
(Preparation of polyamic acid solution)
The inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 500 parts by mass of sufficiently dried 5-amino-2- (p-aminophenyl) benzoxazole was added. Next, after 9000 parts by mass of N-methyl-2-pyrrolidone is added and completely dissolved, 1000 parts by mass of a pre-dispersed liquid in which the above-mentioned inorganic particles are dispersed is added, and further 485 parts by mass of pyromellitic acid 2 Anhydrous anhydride was added and stirred at 25 ° C. for 48 hours to obtain a brown viscous polyamic acid solution. The reduced viscosity (ηsp / C) was 5.2.

(Preparation of polyimide film)
The obtained polyamic acid solution was coated on a stainless steel belt (squeegee / belt gap was 100 μm) and dried at 90 ° C. for 60 minutes. The polyamic acid film that became self-supporting after drying was peeled from the stainless steel belt to obtain a green film having a thickness of 15 μm.
The obtained green film was passed through a continuous heat treatment furnace purged with nitrogen, the first stage was heated at 180 ° C. for 3 minutes, and the heating rate was 4 ° C./second, and the second stage was at 460 ° C. for 5 minutes. The imidation reaction was allowed to proceed by applying two stages of heating under the conditions described above. Then, the polyimide film of Example 1 which exhibits brown was obtained by cooling to room temperature in 5 minutes. The resulting polyimide film had a thickness of 10 μm, a tensile modulus in the MD direction of 7.9 GPa, a glass transition temperature of 270 ° C. or higher and was not measurable, a water absorption of 1.9%, and a CTE of 4 ppm / ° C. It was.
(Lamination of adhesive layer)
N, N-dimethylacetamide as an organic polar solvent, 1,3-bis (3-aminophenoxy) benzene and 3,3′-dihydroxy-4,4′-diaminobiphenyl as a diamine compound in a molar ratio of 9: 1 A solution of a polyamic acid polymer was obtained using 3,3 ′, 4,4′-ethylene glycol benzoate tetracarboxylic dianhydride as the ester tetracarboxylic acid.
This polyamic acid polymer solution was heated under reduced pressure to obtain a thermoplastic polyimide. 8 g of this thermoplastic polyimide, 10 g of Epicoat 1032H60 as a thermosetting resin (epoxy resin), 3.0 g of 4,4′-diaminodiphenyl ether as a curing agent are added to 91.0 g of dioxolane as an organic solvent, Stir to dissolve. Thereby, an adhesive solution was obtained.
The obtained solution was cast on one side of a 12.5 μm-thick releasable polyethylene terephthalate film having a release layer formed on one side and dried at 60 ° C. for 2 minutes to form an adhesive layer having a thickness of 2.5 μm. The two formed films thus obtained were laminated with the adhesive layer and both surfaces of the polyimide film obtained above to obtain an adhesive laminated film. There was no problem in handling the polyimide film during this lamination.
The total thickness of the polymer film and the adhesive layer of the obtained adhesive laminated film was 15 μm.

Example 2
(Preparation of polyimide film)
A polyimide film having a thickness of 5 μm was obtained in the same manner as in Example 1. The resulting polyimide film had a tensile modulus in the MD direction of 9.2 GPa, a glass transition temperature of 270 ° C. or higher and was not measurable, a water absorption rate of 1.9%, and a CTE of 1 ppm / ° C.
(Lamination of adhesive layer)
Dimethyl terephthalate; 78 parts by mass, dimethyl isophthalate; 68 parts by mass, adipic acid; 34 parts by mass, 2-methyl-1,3-propanediol; 99 parts by mass, 1,4-butanediol; 99 parts by mass Copolyester resin (a) was obtained. The number average molecular weight of the obtained copolyester resin was 15000, and the acid value was 150 meq / kg.
Polyester (a): 100 parts by mass, 2,2-dimethylolbutanoic acid (DMBA): 9 parts by mass, hexamethylene diisocyanate; From 8 parts by mass, methyl ethyl ketone and toluene were used to adjust the solid content concentration to 30% by mass. A solution of polyester / polyurethane resin (1) was obtained. The obtained polyester / polyurethane resin had an acid value of 520 meq / kg, a number average molecular weight of 16000, a low molecular weight component having a molecular weight of 5000 or less, 5.6% by mass, and a glass transition temperature of 11 ° C.
15 parts by mass of a cresol novolac type epoxy resin YDCN703 manufactured by Toto Kasei Co., Ltd. was added to 100 parts by mass of a 30% by mass solution of the obtained polyester / polyurethane resin, and mixed well to obtain an adhesive (A) solution.
The obtained solution was cast on one side of a 12.5 μm-thick releasable polyethylene terephthalate film having a release layer formed on one side and dried at 80 ° C. for 12 minutes to form a 2.5 μm-thick adhesive layer. Each of the two obtained films thus formed was laminated with an adhesive layer and both sides of the polyimide film obtained above to obtain an adhesive laminated film. There was no problem in handling the polyimide film during this lamination. The total thickness of the polymer film and the adhesive layer of the obtained adhesive laminated film was 10 μm.

Example 3
A polyimide film having a thickness of 7 μm was obtained in the same manner as in Example 1. The obtained polyimide film had a tensile modulus of 8.1 GPa, a glass transition temperature of 270 ° C. or higher and was not measurable, a water absorption rate of 1.8%, and a CTE of 2 ppm / ° C.
Further, an adhesive layer was laminated on both sides of this polyimide film in the same manner as in Example 2. There was no problem in handling the polyimide film during this lamination. The total thickness of the polymer film and the adhesive layer of the obtained adhesive laminated film was 12 μm.

Comparative Example 1
A polyimide film having a thickness of 12.5 μm was obtained in the same manner as in Example 1. The obtained polyimide film had a tensile modulus of 6.8 GPa and a glass transition temperature of 270 ° C. or higher, which was not measurable, the water absorption was 2.0%, and the CTE was 7 ppm / ° C.
Further, an adhesive layer was laminated on both sides of this polyimide film in the same manner as in Example 2. There was no problem in handling the polyimide film during this lamination. The total thickness of the polymer film and the adhesive layer of the obtained adhesive laminated film was 17.5 μm.

Comparative Example 2
(Preparation of polyamic acid solution)
216 parts by mass of 3,3′-diaminodiphenyl ether as diamine, 216 parts by mass of 4,4′-diaminodiphenyl ether, 436 parts by mass of pyromellitic dianhydride as tetracarboxylic acid, and N-methyl-2-pyrrolidone as solvent Using 4340 parts by mass, the previously obtained preliminary dispersion was added to obtain a brown viscous polyamic acid solution. The reduced viscosity (ηsp / C) was 2.5.
(Preparation of polyimide film)
The obtained polyamic acid solution was coated on a stainless steel belt (squeegee / belt gap was 100 μm) and dried at 110 ° C. for 60 minutes. The polyamic acid film that became self-supporting after drying was peeled from the stainless steel belt to obtain a green film having a thickness of 11 μm.
The obtained green film was passed through a continuous heat treatment furnace purged with nitrogen, the first stage was heated at 180 ° C. for 3 minutes, and the heating rate was 4 ° C./second, and the second stage was at 460 ° C. for 5 minutes. The imidation reaction was allowed to proceed by applying two stages of heating under the conditions described above. Then, the polyimide film of the comparative example 2 which exhibits brown was obtained by cooling to room temperature in 5 minutes, However, Generation | occurrence | production of a wrinkle and a twist generate | occur | produced in the imidation process. The resulting polyimide film had a thickness of 7 μm, a tensile modulus in the MD direction of 3.6 GPa, a glass transition temperature of 270 ° C. or higher and could not be measured, a water absorption rate of 2.7%, and a CTE of 35 ppm.
(Lamination of adhesive layer)
The adhesive layer was laminated | stacked on both surfaces similarly to Example 2 at the obtained polyimide film. At the time of lamination, problems such as film twisting and wrinkling occurred in handling the polyimide film. The total thickness of the polymer film and the adhesive layer of the obtained adhesive laminated film was 12 μm.

(Evaluation of adhesive laminated film)
Both surfaces of the 7 μm-thick polyimide film obtained in Example 3 were plasma-treated in a gas of argon / oxygen = 85: 15 (mass parts ratio), and nickel chrome (80:20 parts by mass ratio) was formed on the entire surface of each surface. ) Was sputtered to a thickness of 100 mm, and then copper was similarly sputtered to a thickness of 1000 mm to produce a double-sided conductive film.
A negative resist with a film thickness of 6 μm is formed on one side of the produced double-sided conductive film using a liquid resist, copper is thickened with a thickness of 3 μm by electroplating, the resist is peeled off, and a conductive layer is formed by flash etching and nickel remover. Was removed, and a test circuit pattern of 5 cm × 5 cm, which was assumed to be mounted on an LCD driver including fine lines with a line spacing / line width of 10 μm / 10 μm, was formed. Similarly, a square pattern of 5 mm square was formed in a lattice pattern with a pattern spacing of 0.5 mm on the back surface, and a large number of test circuit boards were produced in the same manner. The area density of the pattern is 50% on both the front and back sides. Prepare three test circuit boards that were prepared, sandwich the adhesive laminated films of each example and comparative example between each board and top and bottom, and laminate them with a hot press. A seven-layer test multilayer substrate was prepared. (See Figs. 1 and 2)
The following evaluations, such as adhesive strength, were performed using the produced test multilayer substrate.

1. Adhesive strength A multilayer board for test was slit to 2 mm width, and was first peeled to a length that could be chucked with a tensile tester using a cutter knife so that the adhesive surface emerged from the end face. A test piece having a peeled surface on the back surface (square pattern) is selected and peeled 90 degrees at a tensile speed of 50 mm / min using a tensile tester (manufactured by Shimadzu Corporation, Autograph (R) model name AG-5000A). The test was performed, and the adhesive strength with the copper foil surface and the adhesive strength with the film surface were read out from the obtained chart.
2. Appearance Observation on a surface plate was visually observed for warp, distortion, blistering, and other appearance abnormalities by magnifying observation with a 10 × stereo microscope.

3. Cross-sectional observation The test multi-layer substrate was cut in a direction in which the cross-section in the width direction of the fine line pattern appeared, embedded in resin, polished on the end face, magnified and observed with a microscope, and the following points were evaluated.
(1) Embedding property between circuits The presence or absence of voids was observed at 100 points between the lines.
(2) Uniformity of insulating layer thickness (copper foil thickness, film thickness)
The thickness of the insulating layer of the part with copper foil and the part without copper foil placed on the side in contact with the square pattern on the back side was measured at 10 points for each, and the average value was obtained. The thickness between the polymer films on the pattern side.
(3) Deformation of polymer film It was evaluated whether there was any deformation of the polymer film as shown in FIG.
The evaluation results are shown in Table 1 below.

ＭＤ：フィルム長手方向、 ＴＤ：フィルム幅方向
ＤＡＭＢＯ：５−アミノ−２−（ｐ−アミノフェニル）ベンゾオキサゾール
３ＤＡＤＥ：３，３’−ジアミノジフェニルエーテル、
４ＤＡＤＥ：４，４’−ジアミノジフェニルエーテル
ＰＭＤＡ：ピロメリット酸二無水物

MD: Film longitudinal direction TD: Film width direction DAMBO: 5-amino-2- (p-aminophenyl) benzoxazole 3DADE: 3,3′-diaminodiphenyl ether,
4DADE: 4,4′-diaminodiphenyl ether PMDA: pyromellitic dianhydride

  In the adhesive laminated film of the present invention, the deformation of the polymer film of the base material is suppressed at the time of pressurizing and heating at the time of forming the insulating layer, and the pressure uniformity to the adhesive layer is improved, and the adhesive layer Penetration between circuits can be achieved efficiently. Multilayer printed wiring obtained when used for interlayer insulation such as multilayer printed wiring boards because the heat resistance insulation can be ensured by guaranteeing the insulation layer thickness with a certain thickness of polymer film and the total thickness is extremely thin It can achieve miniaturization (lightness and thinness) of plates, etc., and is useful for increasing the functionality, performance, and miniaturization of electronic devices.

It is a figure which represents typically the structure of the circuit board for a test before lamination | stacking. It is a figure which represents typically the structure of the circuit board for a test after lamination | stacking.

Claims (7)

  An adhesive laminate comprising an adhesive layer having a thickness of 5 μm or less formed on at least one surface of a polymer film having a tensile modulus of 6 GPa or more, a glass transition temperature of 150 ° C. or more, and a thickness of 1 to 10 μm. the film.   The adhesive laminated film according to claim 1, wherein the polymer film is a polyimide film.   The adhesive laminated film according to claim 1, wherein the polymer film is a polybenzoxazole film.   The adhesive laminated film according to claim 1, wherein the total thickness of the polymer film and the adhesive layer is 15 μm or less.   The adhesive laminated film according to any one of claims 1 to 4, wherein the polymer film is a polymer film containing a lubricant having a volume average particle diameter of 1/10 or less of the thickness of the polymer film.   The adhesive laminated film according to claim 1, wherein the polymer film is a polymer film having a linear expansion coefficient (CTE) of 10 ppm / ° C. or less.   The adhesive laminated film according to claim 1, wherein the polymer film is a polymer film having a water absorption of 2.5% or less.

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