JP2008024763A - Adhesive sheet, metal laminate sheet and printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet with an excellent flat surface property and uniformity and less vaporization of a remained solvent at working and use at a high temperature, a metal laminate sheet in which a metal foil is laminated on the adhesive sheet, and a printed wiring board in which the metal laminate sheet is subjected to circuit working. <P>SOLUTION: The adhesive sheet in which a thermosetting adhesive layer is formed on at least one surface of a base material, i.e., a polyimide film comprises the adhesive sheet in which an amount of remained solvent in the adhesive sheet is 0.01 to 1 ppm, the metal laminate sheet in which the metal foil is laminated on the adhesive sheet, and the printed wiring board in which the metal laminate sheet is subjected to circuit working. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an adhesive sheet used for forming an insulating layer in a printed wiring board or the like used for an electronic device, a flexible printed wiring board or the like for reducing the size and weight of a component, and a metal foil for the adhesive sheet. The present invention relates to a laminated metal laminated sheet and a printed wiring board obtained by processing the metal laminated sheet. More specifically, the present invention relates to an adhesive sheet and a metal laminate sheet for the flexible printed circuit board used for TAB, COF, PGA, BGA, CSP, LOC tape, etc. in semiconductor packaging and the like. More particularly, the present invention relates to a metal laminated sheet after metal lamination and a printed wiring board obtained by processing the metal laminated sheet, and a metal laminated sheet and printed wiring board with less warpage and curl.

When an adhesive sheet or 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 entirely, and a certain thickness of the insulating layer cannot be guaranteed, and the characteristics There is a problem in forming an insulating layer such as a high-frequency circuit board that requires strict impedance guarantee.
It has also been proposed to use a thermoplastic polyimide resin (see Patent Documents 2, 3, and 4).
Furthermore, a film in which an adhesive layer composed of a thermoplastic polyimide and a thermosetting resin is provided on at least one surface of the polyimide film has also been proposed (see Patent Document 5).
Furthermore, the polyimide long film with few curls in 25 degreeC is also proposed by making the ratio of the orientation of a polyimide long film front and back into a predetermined value or less (refer patent document 6).
JP 2003-089784 A JP 2000-143981 A JP 2000-144092 A JP 2003-306649 A JP 2003-011308 A JP 2000-085007 A

The use of a substrate film made of a conventionally known polyimide film or polyimide benzoxazole film is inferior in heat resistance compared to the use of a substrate made of ceramic, and warping and distortion occur when electronic parts are produced due to physical property differences in the film. There was a problem that it was easy. In order to eliminate the warp and distortion of the film, measures have been taken to reduce the apparent warp of the film by heat treatment under stretching. However, even if the apparent warpage of the film, that is, the manifested warpage of the film, can be eliminated, it is necessary to process at a high temperature particularly when applied as an electronic component. The problem that the existing strain becomes obvious and the curling occurs has not been solved. Furthermore, there is a problem of product deterioration due to dielectric breakdown or peeling due to volatilization of the residual solvent during processing at high temperature or during use.
Therefore, even when the film has a small apparent warp, curling occurs when processing or using it, leading to a decrease in production yield, and it is often difficult to obtain high-quality electronic components due to evaporation of the solvent. .

  The present invention is excellent in flatness and homogeneity suitable as a base material for electronic components, and has little warpage and curl even when subjected to high temperature treatment, dielectric breakdown due to volatilization of residual solvent during high temperature processing and use, and An adhesive sheet using a polyimide film with excellent heat resistance without product deterioration due to peeling as a base film, a metal laminated sheet obtained by laminating a metal foil on this adhesive sheet, and a printed wiring board obtained by circuit processing of this metal laminated sheet The purpose is to provide.

As a result of intensive studies, the present inventors have used a polyimide film regulated to a specific residual solvent amount as an adhesive sheet, a metal laminated sheet, and a base film such as an FPC (flexible printed wiring board), TAB tape, COF tape film, etc. As a result, it was found that high-quality and uniform FPC (flexible printed wiring board), TAB tape, and COF tape film were obtained, and the present invention was completed.
That is, this invention consists of the following structures.
1. The base film is a polyimide film obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid, and is an adhesive sheet in which a thermosetting adhesive layer is formed on at least one side of the base film. An adhesive sheet, wherein the residual solvent amount in the adhesive sheet is 0.01 ppm or more and 1 ppm or less.
2. 1. Aromatic tetracarboxylic acids are pyromellitic acid, and aromatic diamines are diamines having a benzoxazole skeleton. Adhesive sheet.
3. The aromatic tetracarboxylic acid is at least one selected from pyromellitic acid and biphenyltetracarboxylic acid, and the aromatic diamine is at least one selected from p-phenylenediamine and diaminodiphenyl ether. Adhesive sheet.
4). 1. ~ 3. A metal laminate sheet, wherein a metal foil is laminated on the thermosetting adhesive layer side of any one of the adhesive sheets.
5. 4). A printed wiring board, wherein a circuit pattern is formed by partially removing a metal foil of the metal laminate sheet.
6). 5. A multilayer printed wiring board, wherein a plurality of printed wiring boards are stacked.
7). 5. Or 6. A printed wiring board comprising a semiconductor chip mounted on any printed wiring board.
8). A polyimide film obtained by reacting an aromatic diamine having an amount of residual solvent of 0.01 ppm or more and 10 ppm or less and an aromatic tetracarboxylic acid is used as a substrate film, and at least one surface of the substrate film is thermosetting. The manufacturing method of the adhesive sheet characterized by forming an adhesive layer and manufacturing the adhesive sheet whose residual solvent amount is 0.01 ppm or more and 1 ppm or less.

The adhesive sheet, the metal laminate sheet, and the printed wiring board using the polyimide film in the present invention as a base film, for example, in a printed wiring board, form a metal foil layer on one or both sides of the polyimide film, and this metal foil layer The wiring pattern having a line width of 5 to 30 μm, a line spacing of 5 to 30 μm, and a thickness of about 3 to 40 μm is formed.
Heat treatment at the time of laminating this metal foil layer affects the base film, and the physical properties of the polyimide film, especially the residual solvent amount of the film, and as a result, the residual solvent amount of the adhesive sheet are constant during various treatments and use at high temperatures. If it is within the range, the polyimide film and adhesive sheet will not cause product degradation due to dielectric breakdown or peeling due to volatilization of the residual solvent, and the resulting quality of the printed wiring board, etc. This improves the yield, improves the yield, and maintains flatness even after high-temperature processing such as annealing and soldering that these printed wiring boards undergo, and does not cause product deterioration due to dielectric breakdown or peeling. The yield of these products is improved.
In this way, the polyimide film as a heat resistant film is often exposed to heat, and the residual solvent amount of the film against the heat and the residual solvent amount of the adhesive sheet are extremely important when used as a base material for industrial products. Quality.
The specific adhesive sheet, the metal laminate sheet and the printed wiring board using the specific polyimide film of the present invention are used as electronic parts exposed to high temperature, and the substrate is hardly warped or distorted at the time of manufacture, and remains. It does not cause product degradation due to dielectric breakdown or peeling due to solvent volatilization, and can produce high-quality electronic components and improve yield, which is extremely significant in industry.

The polyimide film as the base film in the adhesive sheet in the present invention is a polyimide film obtained by reacting aromatic diamines and aromatic tetracarboxylic acids, and the residual solvent amount in the polyimide film is 0.01 ppm or more and 10 ppm. It is not particularly limited as long as it is a polyimide film and the adhesive sheet has a residual solvent amount of 0.01 ppm to 1 ppm, but preferably the following aromatic diamines and aromatic tetracarboxylic acids Combinations with acids (anhydrides) are preferred examples.
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 diaminodiphenyl ether skeleton and an aromatic tetracarboxylic acid having a pyromellitic acid skeleton.
C. A combination of an aromatic diamine having a phenylenediamine skeleton and an aromatic tetracarboxylic acid having a pyromellitic acid skeleton.
D. A combination of one or more of the above ABCs.
Among them, (1) a combination of an aromatic diamine having a benzoxazole structure and pyromellitic acid, (2) a combination of paraphenylenediamine and pyromellitic acid, (3) a combination of diaminodiphenyl ether and pyromellitic acid, (4) Combination of paraphenylenediamine, diaminodiphenyl ether and pyromellitic acid, (5) Combination of paraphenylenediamine and biphenyltetracarboxylic acid, (6) Combination of paraphenylenediamine, diaminodiphenyl ether, biphenyltetracarboxylic acid and pyromellitic acid Is preferred.
Preferred examples of diaminodiphenyl ether include 4,4′-diaminodiphenyl ether.
Examples of aromatic diamines having a benzoxazole structure that can be preferably used in the present invention include the following compounds.

これらのジアミンは、単独で用いてもよいし、二種以上を併用してもよい。

These diamines may be used alone or in combination of two or more.

The present invention is not limited to the above-mentioned matters, and the following aromatic diamines may be used. Preferably, the diamines exemplified below are one or two kinds as long as they are less than 30 mol% of the total aromatic diamines. As mentioned above, you may use together.
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, m-aminobenzylamine, p-aminobenzylamine,

3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide, 4,4′-diaminodiphenyl Sulfoxide, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 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) pheny ] 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 entirely substituted with halogen atoms, or alkoxyl groups.

  The aromatic tetracarboxylic acids used in the present invention are, for example, aromatic tetracarboxylic anhydrides. Specific examples of the aromatic tetracarboxylic acid anhydrides include the following. Of these, pyromellitic acid of Chemical formula 5 and biphenyltetracarboxylic acid of Chemical formula 6 can be preferably used, and at least one of these is preferably used by 70 mol% or more of the total aromatic tetracarboxylic acids.

  In the present invention, tetracarboxylic acid or tetracarboxylic dianhydride other than chemical formula 5 or chemical formula 6 may be used as long as it is less than 30 mol% of the total tetracarboxylic dianhydride. These non-aromatic tetracarboxylic dianhydrides may be used singly or in combination of two or more. 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, 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 reacting (polycondensing) the aromatic diamines with aromatic tetracarboxylic acids (anhydrides) dissolves both the raw material monomer and the resulting polyamic acid. Although it will not specifically limit if it carries out, A polar organic solvent is preferable, for example, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, Examples thereof include N-dimethylacetamide, dimethyl 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 mass of the monomer in the solution in which the monomer is dissolved is usually 5 to 40% by mass, The amount is preferably 10 to 30% by mass.

The polymerization reaction conditions for obtaining the polyamic acid may be conventionally known conditions. As a specific example, stirring and / or continuous in an organic solvent at a temperature range of 0 to 80 ° C. for 10 minutes to 30 hours. Mixing may be mentioned. 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 mass 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 dl / g or more, and more preferably 4.0 dl / g or more.
Vacuum defoaming during the polymerization reaction is effective for producing a high-quality polyamic acid organic solvent solution. Moreover, you may perform superposition | polymerization by adding a small amount of terminal blockers to aromatic diamines before a 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.

  As an imidization method by high-temperature treatment, 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 particular, a chemical ring closing method in which an imidization reaction is performed by the action of the above ring closing catalyst and a dehydrating agent can be given.

In the chemical ring closure method, imidation can be completely performed by heating after forming a precursor complex having self-supporting property by partially proceeding imidization reaction of the polyamic acid solution.
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 timing for adding the ring-closing catalyst to the polyamic acid solution is not particularly limited, and may be added in advance before the polymerization reaction for obtaining the polyamic acid. Specific examples of the ring-closing catalyst include aliphatic tertiary amines such as trimethylamine and triethylamine, and heterocyclic tertiary amines such as isoquinoline, pyridine, and betapicoline. Among them, heterocyclic tertiary amines are mentioned. At least one amine selected from is preferred. Although the usage-amount of a ring-closing catalyst with respect to 1 mol of polyamic acids does not have limitation in particular, Preferably it is 0.5-8 mol.
The timing of adding the dehydrating agent to the polyamic acid solution is not particularly limited, and may be added in advance before the polymerization reaction for obtaining the polyamic acid. Specific examples of the dehydrating agent include aliphatic carboxylic acid anhydrides such as acetic anhydride, propionic anhydride, butyric anhydride, and aromatic carboxylic acid anhydrides such as benzoic anhydride. Among them, acetic anhydride, benzoic anhydride, etc. Acids or mixtures thereof are preferred. Moreover, the usage-amount of the dehydrating agent with respect to 1 mol of polyamic acids is not particularly limited, but is preferably 0.1 to 4 mol. When a dehydrating agent is used, a gelation retarder such as acetylacetone may be used in combination.

The polyamic acid solution is cast on a support and dried to obtain a green film. When the green film is dried to the extent that self-supporting properties are obtained, the residual solvent amount of the polyimide film obtained by the subsequent imidization is controlled within a predetermined range by controlling the residual solvent amount with respect to the total mass after drying. An unimpaired polyimide film can be obtained. Specifically, it is important that the amount of residual solvent with respect to the total mass after drying is preferably 25 to 50% by mass. When the residual solvent amount is lower than 25% by mass, drying on one side of the green film proceeds excessively, and it becomes difficult to obtain a green film with a small difference in the degree of drying between the front and back surfaces. Green film tends to be brittle. Moreover, when it exceeds 50 mass%, self-supporting property becomes inadequate and conveyance of a film becomes difficult in many cases.
In order to achieve such conditions, a drying apparatus such as hot air, hot nitrogen, far infrared rays, and high frequency induction heating can be used, but the following temperature control is required as the drying conditions.
When performing hot air drying, when drying the green film to the extent that self-supporting properties are obtained, in order to make the range of the dryness of the green film front and back surfaces and the difference thereof within a predetermined range, the constant rate drying condition is lengthened, It is preferable to operate so that the solvent volatilizes uniformly from the entire coating film. Constant rate drying is a drying region in which the coating film surface is a free liquid surface and the volatilization of the solvent is governed by mass transfer in the outside world. Under the drying conditions where the coating surface is dried and solidified and the solvent diffusion within the coating is rate-limiting, the physical property difference between the front and back surfaces is likely to occur. The preferable dry state varies depending on the type and thickness of the support, but the temperature setting, the air flow setting, and the atmospheric temperature above the coating film (green film) on the support (green film side) are usually higher. The coating film is dried under the condition that the ambient temperature on the opposite side (opposite side of the coating film side) is 1 to 55 ° C. higher. In the description of the atmospheric temperature, the direction is defined with the direction from the coating film toward the support being the downward direction and the opposite being the upward direction. Such a description in the vertical direction is made for concisely expressing the position of the region to be noted, and is not for specifying the absolute direction of the coating film in actual production.

The “atmosphere temperature on the coating film side” is a temperature in a region (usually a space) from directly above the coating film to 30 mm on the coating film side, and a temperature at a position 5 to 30 mm away from the coating film in the upward direction. By measuring with a thermocouple or the like, the ambient temperature on the coating film surface side can be determined.
The “atmospheric temperature on the opposite side” is the temperature in the region (often including the support and the lower part of the support) from directly below the coating (support part) to the lower 30 mm of the coating. By measuring the temperature at a position 5 to 30 mm downward from the membrane with a thermocouple or the like, the atmosphere temperature on the opposite side can be obtained.
If the atmospheric temperature on the opposite surface side is 1 to 55 ° C. higher than the atmospheric temperature on the coating film side during drying, a high-quality film can be obtained even if the drying temperature is increased and the drying speed of the coating film is increased. Can do. If the atmospheric temperature on the opposite surface side is lower than the atmospheric temperature on the coating surface side, or if the difference between the atmospheric temperature on the coating surface side and the atmospheric temperature on the opposite side is less than 1 ° C., the vicinity of the coating surface is first There is a concern that the film may be dried into a film to form a “lid”, and thereafter, the evaporation of the solvent to be evaporated from the vicinity of the support is hindered, and the internal structure of the film is distorted. It is undesirable for the apparatus and the economy to be disadvantageous in that the atmospheric temperature on the opposite side is higher than the atmospheric temperature on the coating film side and the temperature difference is greater than 55 ° C. Preferably, at the time of drying, the ambient temperature on the opposite side is higher by 10 to 50 ° C., more preferably 15 to 45 ° C. than the ambient temperature on the coating film side.
The setting and management of such drying conditions require more strict setting and management in the case of a thin polyimide film of about 1 μm to 15 μm in the residual solvent amount and physical properties of the resulting polyimide.
The setting of the atmospheric temperature as described above may be performed over the entire process of drying the coating film, or may be performed in a part of the process of drying the coating film. When the coating film is dried by a continuous dryer such as a tunnel furnace, the above-mentioned atmospheric temperature may be set in the drying effective length, preferably 10 to 100%, more preferably 15 to 100%. .
The drying time is 10 to 90 minutes in total, desirably 15 to 45 minutes.

The green film that has undergone the drying step is then subjected to an imidization step, but may be either inline or off-line.
When the off-line is adopted, the green film is wound up once. At this time, curling can be reduced by winding the green film on the tubular body so that the green film is on the inner side (the support is on the outer side).
In any case, it is preferable to carry or wind the film so that the radius of curvature does not become 30 mm or less.
The residual solvent amount of the present invention is predetermined by imidizing a green film obtained by such a method in which the degree of dryness (residual solvent amount) of the front and back surfaces and the difference thereof are controlled within a predetermined range under predetermined conditions. A polyimide long film in the range is obtained.
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 or a polyimide long film as a preferred base film of the present invention, a chemical ring closure method in which an imidization reaction is performed by the action of the ring closure catalyst and the dehydrating agent can be mentioned. Thermal ring closure is preferred.

In the present invention, the residual solvent amount of the polyimide film used as the base film is preferably 0.01 ppm or more and 10 ppm or less, more preferably 0.01 ppm or more and 1 ppm or less, and further preferably 0.01 ppm or more and 0.5 ppm. The following is preferable, but the smaller the amount, the better. However, considering the ease of production, cost, etc., it is sufficient that the defect does not substantially occur. The lower limit is specifically 0.01 ppm. .
The “solvent residual amount” was measured by gas chromatograph measurement, and the residual solvent amount in the polyimide film or the adhesive sheet was quantified and measured by the following method.
First, a polyimide film or an adhesive sheet as an object to be measured was collected to a size of about 10 mg, and its mass was accurately measured. After weighing, the sample was filled in a gas chromatograph glass insert, and the glass insert was set in the inlet of a gas chromatograph equipped with a packed column. While maintaining the inlet temperature at 350 ° C., it was purged with nitrogen carrier gas for 30 minutes, and the vaporized solvent component was trapped in the packed column at room temperature. The trapped product was directly subjected to gas chromatographic analysis with an FID detector, and the residual solvent amount of the measurement film was quantified by a direct calibration curve method. The standard solution used for preparing the calibration curve was water or methanol, spiked into the injection port, and the same measurement as the film was performed. The measurement conditions of the gas chromatograph are shown below.
[Measurement condition]
Equipment: Shimadzu GC14A
Separation column: Inner diameter 3 mm × 1.6 m Glass packing material: TENAX-TA
Carrier gas: N2, 40 ml / min.
Inlet temperature: 350 ° C
Oven temperature: room temperature trap 30 minutes → 80 to 250 ° C. (15 ° C./min.)

The method for obtaining a polyimide film in which the amount of residual solvent with respect to the polyimide film is within a predetermined range is not particularly limited, but the conditions for drying and high-temperature imidization of the green film precursor of the polyimide film should be selected and carried out. As a drying condition for obtaining a green film, for example, when N, N-dimethylacetamide is used as a solvent, the drying temperature is preferably 70 to 130 ° C, more preferably 80 to 125 ° C. More preferably, it is 85-120 degreeC. When this drying temperature is higher than 130 ° C., the molecular weight is lowered, and the green film tends to be brittle. In addition, imidization partially proceeds during the production of the green film, and it becomes difficult to obtain desired physical properties during the imidization process. On the other hand, when the temperature is lower than 70 ° C., the drying time becomes long, the molecular weight tends to decrease, and the handling property tends to be poor due to insufficient drying. Further, the drying time is preferably 5 to 90 minutes, more preferably 15 to 80 minutes, although it depends on the drying temperature. When the drying time is longer than 90 minutes, the molecular weight is lowered and the film tends to be fragile. When the drying time is shorter than 5 minutes, the handling property tends to be poor due to insufficient drying.
A conventionally known drying apparatus can be applied, and examples thereof include hot air, hot nitrogen, far infrared rays, and high frequency induction heating.

A polyimide film having a residual solvent amount of 0.01 ppm or more and 10 ppm or less can be obtained by imidizing the obtained green film under predetermined conditions.
As a specific method of imidization, a conventionally known imidation reaction and imidization treatment can be used as appropriate. Preferably, the maximum treatment temperature is 450 ° C. or more and less than 510 ° C., and 3 minutes or more and 30 minutes. It is preferable to perform the high temperature imidization treatment in the following time.
The imidization treatment is performed by holding both ends of the film with a pin tenter or a clip. At that time, in order to maintain the uniformity of the film, it is desirable to make the tension in the width direction and the longitudinal direction of the film as uniform as possible. Specifically, just before the film is subjected to a pin tenter, the both ends of the film can be pressed with a brush, and the pins can be pierced uniformly into the film. The brush is preferably a fibrous material having rigidity and heat resistance, and a high-strength, high-modulus monofilament can be adopted. By satisfying these imidization conditions (temperature, time, and tension), the occurrence of orientation strain inside the film (front and back and plane direction) is suppressed, the residual solvent amount is within a predetermined range, and mechanical properties, that is, tensile elasticity. It can be set as the polyimide film which fully maintained the rate and the tensile breaking strength.
The thickness of the polyimide film is not particularly limited, but is preferably 1 to 25 μm, more preferably 3 from the viewpoint of productivity and reduction of the residual solvent amount in consideration of use for a light and short printed circuit board base substrate. ~ 15 μm.
This thickness can be easily controlled by the amount of the polyamic acid solution applied to the support and the concentration of the polyamic acid solution.
The polyimide film of the present invention is usually an unstretched film, but may be stretched uniaxially or biaxially. Here, the unstretched film refers to a film obtained without intentionally applying a mechanical external force in the surface expansion direction of the film by tenter stretching, roll stretching, inflation stretching, or the like.

In the adhesive sheet, metal laminate sheet and printed wiring board of the present invention, it is preferable to basically use a polyimide film having a residual solvent amount of polyimide of 0.01 ppm or more and 10 ppm or less as a base material. It is an adhesive sheet in which a thermosetting adhesive layer is formed and laminated on at least one surface of a base film, and the residual solvent amount is 0.01 ppm or more and 1 ppm or less. It is a metal laminated sheet with metal foil laminated on the curable adhesive layer side, and in the printed wiring board, it is a printed wiring board in which unnecessary portions of the metal foil of the metal laminated sheet are removed by etching to form a circuit pattern. In addition, it is a multilayer printed wiring board in which a plurality of printed wiring boards are laminated. Semiconductor chip but is implemented directly on the wiring board.
Furthermore, the adhesive sheet of the present invention can be used for forming an insulating layer between printed wiring boards.

The thermosetting adhesive used in the present invention is not particularly limited as long as it is thermosetting and has excellent heat resistance and adhesiveness, but the tensile elastic modulus of the adhesive is that of the base material. It is preferably smaller than the tensile elastic modulus. The tensile modulus of the adhesive / the tensile modulus of the substrate (ratio of the tensile modulus) is preferably 0.01 to 0.5, more preferably 0.3 or less, and particularly preferably 0.1 or less. If the tensile modulus of the thermosetting adhesive is higher than that of the base film, the stress strain of the base film and the metal foil with different linear expansion coefficients cannot be relaxed and absorbed by the adhesive layer. Since connection reliability with the metal foil layer is not expressed, it is not preferable.
As the thermosetting adhesive used in the present invention, epoxy-based, urethane-based, acrylic-based, silicone-based, polyester-based, imide-based, polyamide-imide-based, etc. can be used, and more specifically, for example, mainly a polyamide resin. Examples thereof include those containing a flexible resin such as phenol and a hard material such as phenol as main components and containing an epoxy resin and imidazoles. More specifically, dimer acid-based polyamideimide resin, room temperature solid phenol, room temperature liquid epoxy and the like can be exemplified, having moderate softness, hardness, adhesiveness, etc. The semi-cured state can be easily controlled. Further, as the polyamideimide resin, those having a weight average molecular weight of 5,000 to 100,000 are suitable. Furthermore, since the cohesive force of the amideimide resin also changes depending on the carboxylic acid and amine of the polyamideimide resin raw material, it is preferable to select the molecular weight, softening point, etc. of the phenol or epoxy resin as appropriate. Moreover, a polyamide resin, a polyester resin, an acrylonitrile butadiene resin, a polyimide resin, a butyral resin, or the like can be used instead of the polyamideimide resin. Furthermore, these silicone-modified materials and the like are more preferable because they exhibit flexibility.

In addition to phenolic resins and epoxy resins, maleimide resins, resole resins, triazine resins and the like can also be used. Nitrile butadiene rubber can also be blended and copolymerized.
The thermosetting adhesive of the present invention is controlled in a cured state to a semi-cured state, as a method for controlling the cured state, for example, heating with hot air when applying and drying the adhesive on the substrate, Heating with far / near infrared rays, electron beam irradiation, etc. In the control by heating, it is preferable to heat at 100 to 200 ° C. for 1 to 60 minutes, more preferably at 130 to 160 ° C. for 5 to 10 minutes. The cured state can also be controlled by heat treatment for several hours to several hundred hours at a relatively low temperature of, for example, about 40 to 90 ° C. while the FPC or TAB tape is wound into a roll. The conditions for controlling the cured state are preferably determined in consideration of the composition of the adhesive, the curing mechanism, and the curing rate. In this way, it is possible to obtain a semi-cured adhesive by controlling the cured state. The thermosetting adhesive of the present invention is used once in a semi-cured state.
Here, the semi-cured state is a solid phase state that can be softened or melted by heating and finally cured. The thermosetting adhesive of the present invention basically includes a component that imparts flexibility and a component that imparts heat resistance so that a semi-cured state can be maintained.

Note that plasma treatment, corona treatment, and alkali treatment of the polyimide film surface before applying the thermosetting adhesive is a preferable method for increasing the adhesive force, and such plasma is an inert gas plasma. Nitrogen gas, Ne, Ar, Kr, or Xe is used as the active gas. There is no particular limitation on the method for generating plasma, and an inert gas may be introduced into the plasma generator to generate plasma.
The time required for the plasma treatment is not particularly limited, and is usually 1 second to 30 minutes, preferably 10 seconds to 10 minutes. There are no particular restrictions on the frequency and output of the plasma during the plasma processing, the gas pressure for generating the plasma, and the processing temperature as long as they can be handled by the plasma processing apparatus. The frequency is usually 13.56 MHz, the output is usually 50 W to 1000 W, the gas pressure is usually 0.01 Pa to 10 Pa, and the temperature is usually 20 ° C. to 250 ° C., preferably 20 ° C. to 180 ° C. If the output is too high, the substrate film surface may crack. Moreover, when gas pressure is too high, there exists a possibility that the smoothness of the base film surface may fall.

Next, a thermosetting adhesive layer is formed on the surface-treated polyimide film surface, but the method is not limited, and a thermosetting adhesive is applied to the polyimide film surface and dried to form a thermosetting adhesive. A method for forming the adhesive layer, or a thermosetting adhesive layer on the polyimide film surface by forming a thermosetting adhesive layer in advance on another release sheet or film and pasting or transferring it to the polyimide film surface. An example is a method of forming a layer.
The thickness of the thermosetting adhesive layer is preferably 0.5 or less (1.0 or less in the case of both surfaces) with respect to the thickness of the base polyimide film to be used, more preferably 0. The thickness is 3 or less (in the case of both surfaces, 0.6 or less).
In the adhesive sheet in which these thermosetting adhesive layers are formed on at least one surface of the base polyimide film, the residual solvent amount measured by the method for measuring the residual solvent amount is 0.01 ppm or more and 1 ppm or less. It is essential that the amount of residual solvent contained in the thermosetting adhesive layer and the base polyimide film is 0.01 ppm or more and 1 ppm or less.
The polyimide film (adhesive sheet) with the adhesive layer thus obtained can be used as a die bonding tape or a lead-on-chip film.
In the lamination of the metal foil, the metal foil is laminated on the thermosetting adhesive layer formed on the polyimide film surface with or without the plasma treatment and laminated using pressure, heat, or the like.
The metal as the metal foil of the present invention is silver, copper, gold, platinum, rhodium, nickel, aluminum, iron, chromium, zinc, tin, brass, bronze, bronze, monel, tin lead solder, tin copper solder, Tin-silver solder or the like alone or an alloy thereof is used, but using copper is a preferred embodiment in terms of balance between performance and economy. When the metal foil layer is used for a circuit (conductive), the thickness of the metal layer is preferably 1 to 175 μm, more preferably 3 to 50 μm. When using the polyimide film which bonded the metal foil layer as a heat sink, the thickness of a metal layer becomes like this. Preferably it is 50-3000 micrometers.
A metal foil with a carrier can be used as the metal foil. The metal foil with a carrier is composed of a thin metal foil and a support, and the support with the support facilitates handling of the ultrathin metal foil, and the carrier portion is peeled off after lamination. As an actual example, a release copper electrical component is provided on a polyester film, etc., and a metal foil portion is formed by electroplating, or a thick metal foil such as a copper foil is used as a carrier, and a release layer is provided for further electrolysis. The thing etc. which provided the thin metal foil part by plating etc. can be illustrated. When such a metal foil with a carrier is used, particularly when the carrier is peeled after lamination, there may be a defect that the ultrathin metal foil portion is attached to the carrier side and peeled off from the laminate. In other words, by controlling the amount of residual solvent on the laminated substrate side within a specific range, it is possible to reduce the peeling failure of the ultrathin metal foil at the time of carrier peeling.

Although the surface roughness of the polyimide film surface laminated through the thermosetting adhesive layer of the metal foil layer is not particularly limited, the centerline average roughness in JIS B 0601 (definition and display of surface roughness) It is preferable that the values represented by (hereinafter referred to as Ra) and ten-point average roughness (hereinafter referred to as Rz) are 0.1 μm or less for Ra and 1.0 μm or less for Rz.
In this invention, it is a preferable aspect that the metal laminated sheet which is a composite_body | complex of the polyimide film and metal foil obtained by the said method is further heat-processed at 200-350 degreeC. This heat treatment is preferably 220 to 330 ° C, more preferably 240 to 310 ° C. The heat treatment reduces the strain of the base film and the strain generated in the manufacturing process of the metalized polyimide film, and can more effectively express the effects of the present invention. And reliability can be improved. If it is less than 200 ° C., the effect of alleviating the strain becomes small. Conversely, if it exceeds 350 ° C., the polyimide film of the base material deteriorates, which is not preferable.

The thus obtained metal laminated sheet of the present invention is coated with a photoresist on the side of a conductive metal foil layer or a later thick film metal layer formed on the conductive metal foil layer, if necessary. After drying, a wiring circuit pattern is formed by the steps of exposure, development, etching, and photoresist stripping. Further, if necessary, solder resist coating, curing and electroless tin plating are performed to form a flexible printed wiring board and multilayering them. A multilayer printed wiring board or a printed wiring board on which a semiconductor chip is directly mounted can be obtained. There are no particular limitations on the method for producing these circuits, making them multi-layered, and mounting a semiconductor chip, and the methods may be appropriately selected from conventionally known methods.
In the present invention, when manufacturing a so-called TAB tape having a flying lead, a device hole is secured by pre-punching an adhesive sheet coated with an adhesive in advance, and then laminated with a copper foil, A conductor pattern including a flying lead can be formed according to a conventional method.
On the surface of the metal (foil) layer used in the present invention or, if necessary, the thick film metal layer attached later, an inorganic coating such as a single metal or a metal oxide may be formed. Good. In addition, the surface of the metal foil layer or the post-attached thick film metal layer formed on the metal foil layer, if necessary, is treated with a coupling agent (aminosilane, epoxysilane, etc.), sand plast treatment, rolling treatment, corona treatment, You may use for a plasma process, an etching process, etc.

Examples of the present invention will be described below, but the present invention is not limited thereto. In addition, the evaluation method of the physical property in the following examples is as follows except for the above.
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. Film thickness of polyimide film The thickness of the film was measured using a micrometer (Finereuf, Millitron 1254D).

<Preparation of polyamic acid (1)>
The inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 300 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole (p-DAMBO) was charged. Next, 4400 parts by mass of DMAC was added and completely dissolved, and then 300 parts by mass of pyromellitic dianhydride was added and stirred at a reaction temperature of 25 ° C. for 17 hours, whereby a brown and viscous polyamic acid solution (1) was obtained. Obtained. Ηsp / C of this product was 4.1 dl / g.

<Production of Film 1 to Film 6)
The obtained polyamic acid solution (1) was coated on a surface not containing a lubricant of a polyester film (Cosmo Shine A4100 (manufactured by Toyobo Co., Ltd.)) having a thickness of 188 microns and a width of 800 mm so as to have a width of 740 mm (squeegee / The gap between the belts was varied depending on the resulting film thickness) and dried through a continuous drying oven with four drying zones. Each zone has three rows of slit-shaped air outlets above and below the film. The hot air temperature between the air outlets can be controlled within a range of plus or minus 1.5 ° C and the air volume difference can be controlled within a range of plus or minus 3%. Has been. The width direction is controlled to be within ± 1 ° C. until a width corresponding to 1.2 times the effective film width.
The setting of the drying oven is as follows.
Leveling zone temperature 25 ° C, no air volume 1st zone upper temperature 105 ° C, lower temperature 105 ° C
Air volume 20-25 cubic m / min for both top and bottom Zone 2 Upper temperature 100 ° C, Lower temperature 100 ° C
Air volume 30 to 35 cubic m / min in both upper and lower zones Third zone Upper temperature 95 ° C, Lower temperature 100 ° C
Air volume 20-25 cubic m / min on both top and bottom Zone 4 Upper temperature 90 ° C, Lower temperature 100 ° C
Upper air volume 15-18 cubic m / min, lower air volume 20-25 cubic m / min The length of each zone is the same.
The air volume is the total of the air volumes from the outlets of each zone, and the production of the polyamic acid film (GF) of Films 1 to 6 was changed within the above range.
In addition, it is confirmed that the temperature is within ± 1.5 ° C. by monitoring at intervals of 10 cm by a thermocouple supported at a position of 10 mm on the film at the portion directly below the blowout port at the center of each zone.
The polyamic acid film (GF) that became self-supporting after drying was peeled from the polyester film to obtain each GF. The values of the residual solvent ratio of each GF were 35%, 37%, 38%, and 36%, respectively. 37% and 38%.
Each of the obtained GFs was provided with a brush made of an aromatic polyamide monofilament strand so as to be in contact with both ends of the film, and continuously substituted with nitrogen in a state where both ends of the film were evenly stabbed into the pins of the pin tenter. The first stage is heated at 180 ° C. for 5 minutes, and the heating rate is 4 ° C./second, and the second stage is heated at 500 ° C. for 5 minutes for 2 minutes under the condition of imide The reaction was allowed to proceed. Then, the film 1-the film 6 which are each IF (polyimide film) which exhibits brown were obtained by cooling to room temperature in 5 minutes.
The thickness and solvent residual ratio of each IF obtained were 5.0 μm and 3.6 ppm for film 1, 7.5 μm and 4.1 ppm for film 2, 12.5 μm and 1.6 ppm for film 3, and 4 film. The film was 25 μm and 0.9 ppm, the film 5 was 33 μm and 0.6 ppm, and the film 6 was 50 μm and 0.3 ppm.

<Production of Film 1b to Film 6b)
In the same manner as in Films 1 to 6, the obtained polyamic acid solution (1) was applied to a surface of a polyester film (Cosmo Shine A4100 (manufactured by Toyobo Co., Ltd.)) having a thickness of 188 microns and a width of 800 mm that does not contain a lubricant. It was coated to 740 mm (the squeegee / belt gap was varied depending on the resulting film thickness) and dried through a continuous drying oven with four drying zones. The setting of the drying oven is as follows.
Leveling zone temperature 25 ° C, no air volume 1st zone upper temperature 105 ° C, lower temperature 105 ° C
Air volume 20-25 cubic m / min for both top and bottom Zone 2 Upper temperature 100 ° C, Lower temperature 100 ° C
Air volume 30 to 35 cubic m / min on both top and bottom Zone 3 Upper temperature 95 ° C, Lower temperature 95 ° C
Air volume 20-25 cubic m / min for both top and bottom Zone 4 Upper side temperature 90 ° C, Lower side temperature 90 ° C
Air volume 20-25 cubic m / min in both top and bottom The length of each zone is the same.
Also, the air volume is the total of the air volumes from the outlets of each zone, and the production of the polyamic acid film (GF) of the films 7 to 9 is changed within the above range.
In addition, it is confirmed that the temperature is within ± 1.5 ° C. by monitoring at intervals of 10 cm by a thermocouple supported at a position of 10 mm on the film at the portion directly below the blowout port at the center of each zone.
The polyamic acid film (GF) that became self-supporting after drying was peeled from the polyester film to obtain each GF. The values of the residual solvent ratio of each GF were 48%, 47%, 49%, and 48%, respectively. 47% and 48%.
Each of the obtained GFs was provided with a brush made of an aromatic polyamide monofilament strand so as to be in contact with both ends of the film, and continuously substituted with nitrogen in a state where both ends of the film were evenly stabbed into the pins of the pin tenter. The first stage is heated at 180 ° C. for 5 minutes, and the heating rate is 4 ° C./second, and the second stage is heated at 500 ° C. for 5 minutes for 2 minutes under the condition of imide The reaction was allowed to proceed. Then, imidation was advanced by cooling to room temperature in 5 minutes. Then, the film 1b-the film 6b which are each IF (polyimide film) which exhibits brown were obtained by cooling to room temperature in 5 minutes.
The thickness and solvent residual ratio of each IF obtained were 5.0 μm and 69.9 ppm for film 1b, 7.5 μm and 59.7 ppm for film 2b, 12.5 μm and 47.7 ppm for film 3b, and 4b for film 4b. They were 25 μm and 39.8 ppm, 33 μm and 23.2 ppm for film 5b, and 50 μm and 13.1 ppm for film 6b.
Contrary to expectations, when a polyimide film is produced under conditions similar to the conventional method without any new device, the thin film has a higher residual solvent ratio than the thicker film, and the appearance is inferior. There were many things.

<Preparation of polyamic acid (2)>
A container equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then ODA was added. Next, after adding DMAC and completely dissolving it, PMDA is added, and ODA and PMDA as monomers are polymerized in DMAC at a molar ratio of 1/1 so that the monomer charge concentration becomes 15% by mass. After stirring at 25 ° C. for 5 hours, a brown viscous polyamic acid solution (2) was obtained. ηsp / C was 2.1 dl / g.

<Preparation of Film 7 to Film 10)
The obtained polyamic acid solution (2) was coated on a surface not containing a lubricant of a polyester film (Cosmo Shine A4100 (manufactured by Toyobo Co., Ltd.)) having a thickness of 188 microns and a width of 800 mm so as to have a width of 740 mm (squeegee / The gap between the belts was varied depending on the resulting film thickness) and dried through a continuous drying oven with four drying zones. Each zone has three rows of slit-shaped air outlets above and below the film. The hot air temperature between the air outlets can be controlled within a range of plus or minus 1.5 ° C and the air volume difference can be controlled within a range of plus or minus 3%. Has been. The width direction is controlled to be within ± 1 ° C. until a width corresponding to 1.2 times the effective film width.
The setting of the drying oven is as follows.
Leveling zone temperature 25 ° C, no air volume 1st zone upper temperature 105 ° C, lower temperature 105 ° C
Air volume 20-25 cubic m / min for both top and bottom Zone 2 Upper temperature 100 ° C, Lower temperature 100 ° C
Air volume 30 to 35 cubic m / min in both upper and lower zones Third zone Upper temperature 95 ° C, Lower temperature 100 ° C
Air volume 20-25 cubic m / min on both top and bottom Zone 4 Upper temperature 90 ° C, Lower temperature 100 ° C
Upper air volume 15-18 cubic m / min, lower air volume 20-25 cubic m / min The length of each zone is the same.
The air volume is the total of the air volumes from the outlets of each zone, and the production of the polyamic acid film (GF) of Films 1 to 6 was changed within the above range.
In addition, it is confirmed that the temperature is within ± 1.5 ° C. by monitoring at intervals of 10 cm by a thermocouple supported at a position of 10 mm on the film at the portion directly below the blowout port at the center of each zone.
The polyamic acid film (GF) that became self-supporting after drying was peeled from the polyester film to obtain each GF. The values of the residual solvent ratio of each GF were 35%, 37%, 38%, and 36%, respectively. Met.
Each of the obtained GFs was provided with a brush made of an aromatic polyamide monofilament strand so as to be in contact with both ends of the film, and continuously substituted with nitrogen in a state where both ends of the film were evenly stabbed into the pins of the pin tenter. The first stage is heated at 180 ° C. for 5 minutes, and the heating rate is 4 ° C./second, and the second stage is heated at 500 ° C. for 5 minutes for 2 minutes under the condition of imide The reaction was allowed to proceed. Then, the film 7-the film 10 which are each IF (polyimide film) which exhibits brown were obtained by cooling to room temperature in 5 minutes.
The thickness and solvent residual ratio of each IF obtained were 5.0 μm and 9.6 ppm for film 7, 7.5 μm and 9.1 ppm for film 8, 12.5 μm and 8.7 ppm for film 9, and 10 for film 10. 25 μm and 5.7 ppm.

<Production of Film 7b to Film 10b)
Using the polyamic acid solution (2), films 7b to 10b were produced in the same manner as in the production conditions of films 1b to 6b.
The thickness and solvent residual ratio of each IF obtained were 5.0 μm and 89.1 ppm for film 7b, 7.5 μm and 68.1 ppm for film 8b, 12.5 μm and 55.3 ppm for film 9b, and 10b for film 10b. They were 25 μm and 25.9 ppm.

<Preparation of polyamic acid (3)>
PMDA and BPDA are used as aromatic tetracarboxylic dianhydride components, and four types of monomers, ODA and P-PDA, are used as diamine components, and PMDA / BPDA / ODA / P-PDA is 1 / 0.5 / 1/0. A polyamic acid solution (3) was prepared by polymerizing in DMF at a molar ratio of 0.5 so that the monomer charge concentration was 16% by mass.

<Production of Film 11 to Film 12)
Each GF was obtained in the same manner as Film 7 to Film 10 except that the polyamic acid solution (3) was coated on the stainless steel belt.
The thickness and solvent residual ratio of each IF obtained were 10 μm and 8.6 ppm for film 11, and 25 μm and 5.1 ppm for film 12, respectively.

<Production of Film 11b to Film 12b)
Using the polyamic acid solution (3), films 11b to 12b were produced in the same manner as in the production conditions of films 1b to 6b.
The thickness solvent residual ratio of each IF obtained was 10 μm and 77.7 ppm for the film 11b, and 25 μm and 28.1 ppm for the film 12b.

<Preparation of polyamic acid (4)>
ODA was dissolved in DMAC by supplying 60 mol% based on the total diamine, and then P-PDA (40 mol%) and PMDA were sequentially supplied and stirred at room temperature for about 1 hour. Finally, a solution having a polyamic acid concentration of 20% by mass comprising a tetracarboxylic dianhydride component and a diamine component having a stoichiometry of about 100 mol% was prepared. This polyamic acid solution was ice-cooled, acetic anhydride and β-picoline were added and stirred to obtain a polyamic acid solution (4).

<Preparation of Film 13 to Film 15>
Each GF was obtained in the same manner as in Film 7 to Film 10 except that the polyamic acid solution (4) was coated on a stainless steel belt.
The thickness and solvent residual ratio of each IF obtained were 10 μm and 6.8 ppm for film 13, 25 μm and 3.3 ppm for film 14, and 50 μm and 2.0 ppm for film 15.

<Production of Film 13b to Film 15b)
Using the polyamic acid solution (3), films 13b to 15b were produced in the same manner as in the production conditions of films 1b to 6b.
The thickness and solvent residual ratio of each IF obtained were 10 μm and 73.5 ppm for film 13b, 25 μm and 35.4 ppm for film 14b, and 50 μm and 12.1 ppm for film 15b.

<Preparation of polyamic acid (5)>
A container equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then P-PDA was added. Next, after DMAC is added and completely dissolved, BPDA is added, and P-PDA and BPDA as monomers are polymerized in DMAC at a molar ratio of 1/1, and the monomer charge concentration becomes 15% by mass. Thus, when stirred at 25 ° C. for 5 hours, a brown viscous polyamic acid solution (5) was obtained.

<Production of Film 16 to Film 18>
Each GF was obtained in the same manner as Film 7 to Film 10 except that the polyamic acid solution (5) was coated on the stainless steel belt.
The thickness and solvent residual ratio of each IF obtained were 7.5 μm and 4.9 ppm for film 16, 12.5 μm and 2.7 ppm for film 17, and 25 μm and 1.1 ppm for film 18.

<Production of Film 16b to Film 18b)
Using the polyamic acid solution (5), films 16b to 18b were produced in the same manner as in the production conditions of films 1b to 6b.
The thickness and solvent residual ratio of each IF obtained were 7.5 μm and 53.5 ppm for the film 16b, 12.5 μm and 31.4 ppm for the film 17b, and 25 μm and 13.0 ppm for the film 18b.

<Preparation of polyamic acid (6)>
A container equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then P-PDA was added. Next, DMAC is added and completely dissolved, then PMDA is added, and P-PDA and PMDA as monomers are polymerized in DMAC at a molar ratio of 1/1, and the monomer charge concentration becomes 15% by mass. Thus, when stirred at 25 ° C. for 5 hours, a brown viscous polyamic acid solution (6) was obtained.

<Production of Film 19 to Film 20>
Each GF was obtained in the same manner as Film 7 to Film 10 except that the polyamic acid solution (5) was coated on the stainless steel belt.
The thickness and solvent residual ratio of each IF obtained were 12.5 μm and 8.3 ppm for film 19 and 25 μm and 7.0 ppm for film 20.

<Production of Film 19b to Film 20b)
Using the polyamic acid solution (5), films 16b to 18b were produced in the same manner as in the production conditions of films 1b to 6b.
The thickness and solvent residual ratio of each IF obtained were 12.5 μm and 77.6 ppm for film 19b, and 25 μm and 23.0 ppm for film 20b.

(Examples 1-40, Comparative Examples 1-40)
<Manufacture of adhesive sheet>
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.
80 parts by mass of this thermoplastic polyimide, 100 parts by mass of Epicoat 1032H60 as a thermosetting resin (epoxy resin), 30 parts by mass of 4,4′-diaminodiphenyl ether as a curing agent, and 900 parts by mass of dioxolane as an organic solvent And dissolved by stirring. Thereby, an adhesive solution was obtained.
The obtained adhesive 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 bond 2.5 μm in thickness. An adhesive layer-formed polyethylene terephthalate film having an agent layer was obtained.

The adhesive layer of the obtained adhesive layer-formed polyethylene terephthalate film and one side of the polyimide film obtained above were laminated and laminated to obtain each single-sided adhesive sheet from each polyimide film. (When using as an adhesive sheet, of course, this polyethylene terephthalate film is detached and used.)
Tables 1 and 2 show the solvent residual ratios of the obtained single-sided adhesive sheets.

Using two adhesive layer-formed polyethylene terephthalate films, the adhesive layer and both sides of the polyimide film obtained above were laminated and laminated to obtain double-sided adhesive sheets from the polyimide films. (When using as an adhesive sheet, of course, this polyethylene terephthalate film is detached and used.)
Tables 3 and 4 show the solvent residual ratios of the obtained adhesive sheets.

<Manufacture of metal laminate sheet>
The roll surface temperature was heated to 240 ° C. by heating using a thermocompression bonding machine of a roll internal heating and external heating combined method. Through the double-sided adhesive sheet (thermocompression-bonding multilayer polyimide film) obtained between the rolls, supply copper foil with carrier from both sides, from copper foil with carrier / multi-layer polyimide film with heat-fusion / copper foil with carrier Each laminate sheet was manufactured, and further, the carrier was peeled from both sides to obtain each double-sided metal laminated sheet from each polyimide film having a copper foil with a thickness of 3 μm on both sides.

<Manufacture of printed wiring boards>
A liquid crystal resist is used to form a negative resist having a film thickness of 6 μm on one side of each double-sided metal laminate sheet prepared above, the copper layer is removed by etching, and the LCD includes fine lines having a line spacing / line width of 20 μm / 15 μm. A test circuit pattern of 4.8 cm × 4.8 cm assumed to be mounted on a driver was formed. Similarly, a square pattern of 4 mm square was formed in a lattice shape with a pattern spacing of 0.5 mm on the back surface, and a large number of test circuit boards from each polyimide film 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, and use each film and each adhesive sheet of the same production example between each test circuit board and each test circuit board. Each single-sided adhesive sheet of the same production example as each of the films used was arranged on the top and bottom so as to be made of the same polyimide film, and laminated by thermocompression bonding to prepare each test multilayer substrate.
In each multilayer board for test using the polyimide film of each polyimide film 1 to film 20 (one using the adhesive sheet of Example 1 and Example 21, the same applies hereinafter), all the patterns are not peeled off. However, in each test multilayer substrate from the polyimide films of film 1b to film 20b, peeling of the pattern was often observed.
In addition, for cross-sectional observation, each test multilayer substrate is cut in the direction in which the cross-section in the width direction of the fine line pattern comes out, embedded with resin, end-face polished, and then magnified with a microscope, and there is no deformation of the adhesive sheet In each of the multilayer substrates for testing from the polyimide films of the polyimide films 1 to 20 (using the adhesive sheets of Example 1 and Example 21, hereinafter the same), all are adhesive sheets. Although there was no deformation of the circuit and no abnormal part of the circuit, each test multilayer board from the polyimide film of films 1b to 20b (using the adhesive sheet of Comparative Example 1 and Comparative Example 21) In the following description, deformation of the adhesive sheet was observed, and a part peeled from the circuit film was observed.

<Examples 41 to 48, Comparative Examples 41 to 42>
Using each film obtained in each production example, each polyimide film was first slit to a width of 508 mm and subjected to corona treatment, and then RV50 manufactured by Toyobo Co., Ltd. was used as a thermosetting adhesive on the surface of each polyimide film. The double-sided coating was applied to a coating thickness of 10 μm and dried in a dry oven at 80 ° C. for 15 minutes to obtain each double-sided adhesive sheet from each polyimide film.
Table 5 shows the residual solvent ratio of the obtained double-sided adhesive sheet.

Next, the adhesion treatment surface of the electrolytic copper foil (12 μm) and the adhesive application surface of the double-sided adhesive sheet are combined, laminated with a silicon rubber roller laminator at a roll temperature of 120 ° C. and a feed rate of 60 cm / min, and wound. Then, it processed at 150 degreeC for 5 hours in the vacuum dryer, the adhesive agent was hardened, and each double-sided metal lamination sheet from each polyimide film was obtained.
In each double-sided metal laminated sheet of Examples 41 to 48, cut in the direction in which the cross-section of each double-sided metal laminated sheet comes out for cross-sectional observation, embedded in resin, polished end-face, and then magnified and observed with a microscope. The sheet was evaluated for deformation and peeling, but no peeling of the metal layer was observed. In Comparative Examples 41 and 42, peeling of the metal layer was often observed.

As described above, the adhesive sheet, the metal laminate sheet and the printed wiring board using the polyimide film having specific physical properties of the present invention as a base material are excellent in flatness and product yield, for example, Even when processed into a printed wiring board, it is not warped or distorted and has excellent flatness maintenance, and also has excellent abnormalities in the adhesion of the metal foil layer due to flatness maintenance. .
In addition, since uniform lamination processing is performed even when multilayered, it is suitable for display drivers, high-speed arithmetic devices, graphic controllers, high-capacity memory elements, etc. that require warping, small deformation, particularly high-density fine wiring. It is useful as a substrate to be used. In particular, they are useful as printed circuit boards such as display drivers, high-speed arithmetic devices, graphic controllers, and high-capacity memory devices that are often exposed to high temperatures.

Claims (8)

  The base film is a polyimide film obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid, and is an adhesive sheet in which a thermosetting adhesive layer is formed on at least one side of the base film. An adhesive sheet, wherein the residual solvent amount in the adhesive sheet is 0.01 ppm or more and 1 ppm or less.   The adhesive sheet according to claim 1, wherein the aromatic tetracarboxylic acid is pyromellitic acid and the aromatic diamine is a diamine having a benzoxazole skeleton.   The adhesive sheet according to claim 1, wherein the aromatic tetracarboxylic acid is at least one selected from pyromellitic acid and biphenyltetracarboxylic acid, and the aromatic diamine is at least one selected from p-phenylenediamine and diaminodiphenyl ether.   A metal laminate sheet, wherein a metal foil is laminated on the thermosetting adhesive layer side of the adhesive sheet according to claim 1.   A printed wiring board, wherein a circuit pattern is formed by partially removing the metal foil of the metal laminate sheet according to claim 4.   A multilayer printed wiring board, wherein a plurality of printed wiring boards according to claim 5 are stacked.   A printed wiring board comprising a semiconductor chip mounted on the printed wiring board according to claim 5.   A polyimide film obtained by reacting an aromatic diamine having an amount of residual solvent of 0.01 ppm or more and 10 ppm or less and an aromatic tetracarboxylic acid is used as a substrate film, and at least one surface of the substrate film is thermosetting. The manufacturing method of the adhesive sheet characterized by forming an adhesive layer and manufacturing the adhesive sheet whose residual solvent amount is 0.01 ppm or more and 1 ppm or less.