JP2009299009A - Polyamic acid varnish composition, polyimide resin, and metal-polyimide complex - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamic acid varnish composition having excellent adhesion to a metallic foil without an intervening adhesive layer and having a linear thermal expansion coefficient equal to that of the metallic foil; a polyimide resin; and a metal-polyimide complex. <P>SOLUTION: The present polyamic acid varnish composition includes a polyamic acid solution and a diamine having a structure represented by formula (1) therein. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a highly adhesive metal-polyimide composite for a flexible printed circuit board, a polyimide resin, and a polyamic acid varnish composition therefor.

  In recent years, with the miniaturization and portability of electronic devices, the use of flexible printed boards capable of high-density mounting of components and elements as circuit board materials is increasing. From the viewpoint of reliability such as miniaturization of wiring corresponding to further higher density and folding resistance, matching of linear thermal expansion coefficient of metal and insulating resin, improvement of adhesion, and polyimide layer forming insulating resin layer Therefore, it is necessary to reduce the film thickness and lower the elastic modulus.

  As a method for producing a metal polyimide composite material for a flexible substrate, a casting method in which a polyamic acid varnish is directly applied to a metal foil to form a film is known. However, matching of the linear thermal expansion coefficient with metal and high adhesion are known. It is difficult to apply at the same time, and in order to ensure adhesion, an adhesive layer of thermoplastic polyimide, a soluble polyimide having a low glass transition temperature, or a polyamic acid solution having a low glass transition temperature after imidation is required. In order to realize the above, a manufacturing method by multi-layer coating is adopted (see Patent Document 1). Therefore, an increase in manufacturing cost, an increase in substrate cost due to a thick film, a decrease in folding resistance, and a decrease in reliability such as a wiring failure due to deformation of the adhesive layer during high-temperature bonding during mounting have been brought about. Although studies have been made to improve adhesion by using an additive such as an imidazole compound in the varnish without separately providing an adhesive layer (see Patent Document 2), at this time, the imidazole compound is plasticized in the film. Since it works as an agent, there are problems that the glass transition temperature, the linear thermal expansion coefficient, etc. are decreased, and the hygroscopic expansion coefficient is increased with the introduction of polar groups.

  In addition, a polyimide resin layer (hereinafter also referred to as “polyimide film”) having a low linear thermal expansion coefficient, in which diamine having an amide group is used as a monomer, and the resulting polyamic acid has improved adhesion without using an adhesive layer in a thin metal state. )) (See Patent Document 3), the water absorption performance was lowered by introducing a polar group such as an amide group into the polyimide skeleton.

Similarly, a diamine having an amide group is used as a monomer to form an oxazole ring when imidizing polyamic acid, and a polyimide film having a low thermal expansion coefficient has been obtained (see Patent Document 4). The increase in elastic modulus accompanying the formation of an oxazole ring during imidation causes a reduction in flexibility required for a flexible printed circuit board. In addition, a diamine having an amide group that forms an oxazole ring in the polyimide skeleton is used as a copolymerization component and introduced into the polyimide skeleton, resulting in an increase in production cost.
Japanese Patent No. 2746555 JP-A-4-85363 Japanese Patent Laid-Open No. 03-61352 Japanese Patent No. 3019704

  The present invention has been made in view of the above points, and has a polyamic acid varnish composition that has excellent adhesion to a metal foil without using an adhesive layer, and has a linear thermal expansion coefficient equivalent to the linear thermal expansion coefficient of the metal foil. It is an object to provide a product, a polyimide resin, and a metal-polyimide composite.

The polyamic acid varnish composition of the present invention contains a polyamic acid solution and a diamine having a structure of the formula (1) therein.

In the polyamic acid varnish composition of the present invention, the diamine is preferably a diamine represented by any one or more of formulas (2), (3), (4), and (5).
(Wherein X1 is a tetravalent aromatic group represented by formula (2) or formula (3), X2 is a divalent aromatic group represented by formula (4), Y1 to Y3 are ether, —S—, C1 to C4 saturated, unsaturated alkylene group, sulfonyl group, or phenyl group, and Z1 and Z2 each represent a divalent aromatic group or aliphatic group, each independently. R1 to R9 are C1 to C4 alkyl groups, alkoxy groups, halogenated alkyl groups, halogen groups, nitro groups, cyano groups, hydroxyl groups, and —SO _2. H, -OPh, -SCH ₃ , or -SPh, and n = 0, 1, 2)

Moreover, in the polyamic-acid varnish composition of this invention, it is preferable that the said diamine is diamine shown by any one or more types of Formula (6), Formula (7), and Formula (8).
(Wherein X3 is a tetravalent aromatic group represented by formula (6). X4 is a divalent aromatic group represented by formula (7).)

  Moreover, in the polyamic-acid varnish composition of this invention, it is preferable to contain 100 mass parts of polyamic acids and 0.01-20 mass parts of said diamines.

  The polyimide resin of the present invention is obtained by imidizing the polyamic acid varnish composition.

  The metal-polyimide composite of the present invention comprises a polyimide resin obtained by imidizing the polyamic acid varnish composition, and a metal foil.

  In the metal-polyimide composite of the present invention, the ten-point average roughness Rz of the metal foil is preferably 0.7 μm or less.

  The method for producing a polyamic acid varnish composition of the present invention is a method for producing a polyamic acid varnish composition containing polyamic acid and a diamine containing the structure of the general formula (1) therein, Is a polymer of an aromatic tetracarboxylic dianhydride and an aromatic diamine, characterized in that after the polyamic acid is polymerized, the diamine is added to the polyamic acid.

  According to the present invention, the polyamic acid varnish composition, the polyimide resin, and the metal-polyimide having excellent adhesion to the metal foil without using an adhesive layer and having a linear thermal expansion coefficient equivalent to the linear thermal expansion coefficient of the metal foil A complex can be provided.

Hereinafter, the present invention will be specifically described.
The diamine having the structure of the formula (1) added after the addition polymerization of the polyamic acid (hereinafter also referred to as “external addition”) is any of the formulas (2), (3), (4) and (5). It is preferable that it is diamine shown by 1 or more types. In the formula, X1 is a tetravalent aromatic group represented by formula (2) or formula (3), X2 is a divalent aromatic group represented by formula (4), Y3 is ether, —S—, a C1-C4 saturated, unsaturated alkylene group, a sulfonyl group, or a phenyl group. Z1 and Z2 each represent a divalent aromatic group or aliphatic group, and are independent and may be the same or different. R1 to R9 are C1 to C4 alkyl groups, alkoxy groups, halogens An alkyl group, a halogen group, a nitro group, a cyano group, a hydroxyl group, —SO ₂ H, —OPh, —SCH ₃ , or —SPh, and n = 0, 1, or 2.

Moreover, it is more preferable that it is diamine shown by any 1 or more types of Formula (6), Formula (7), and Formula (8) from a heat resistant point. In the formula, X3 is a tetravalent aromatic group represented by the formula (6). X4 is a divalent aromatic group represented by the formula (7).

  There is no restriction | limiting in particular in the manufacturing method of the diamine which has a structure of Formula (1) used for this invention, Various well-known manufacturing methods can be used. For example, according to the method described in Japanese Patent No. 3019704, after reacting nitroaminophenol and p-nitrobenzoyl chloride in a tetrahydrofuran solvent at 0 ° C. in a nitrogen atmosphere, the precipitated reaction product is filtered. After washing with water or methanol, drying and recrystallizing to obtain hydroxy-dinitrobenzanilide as a precursor, hydrogen is introduced and reduced in a Pd catalyst to contain the structure of general formula (1) inside Diamines can be obtained. Here, containing the structure of the general formula (1) inside means that the molecular skeleton of the diamine has the structure of the general formula (1).

  The polyamic acid varnish composition of the present invention is obtained by externally adding a diamine to a polyamic acid solution obtained by addition polymerization of an aromatic tetracarboxylic dianhydride and a diamine in a solvent, and mixing and dissolving. can get. The term “external addition” as used herein means that diamine is added to the polyamic acid solution after completion of the polymerization without addition during polyamic acid addition polymerization. During the addition polymerization of polyamic acid, the viscosity in the solution increases as the molecular weight increases. Completion of polymerization can be confirmed when the increase in viscosity in the solution is no longer observed.

  The blending amount of the diamine in the polyamic acid varnish composition is preferably 0.01 parts by mass to 20 parts by mass, more preferably 100 parts by mass of the polyamic acid which is a solid component, from the viewpoint of adhesive strength and heat resistance. 0.1 parts by mass to 10 parts by mass.

  The polyamic acid according to the present invention is obtained by addition polymerization of an aromatic tetracarboxylic dianhydride and a diamine.

  A conventionally well-known thing can be used as aromatic tetracarboxylic dianhydride in the polyamic-acid solution based on this invention. For example, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, p-phenylenebis (trimellitic acid monoester acid anhydride), p-methylphenylenebis (trimellitic acid monoester acid anhydride), p- Biphenylenebis (trimellitic acid monoester anhydride) (hereinafter referred to as TABP), 2,3,3 ′, 4′-biphenyltetracarboxylic acid, pyromellitic acid, benzophenonetetracarboxylic acid, oxydiphthalic acid, diphenylsulfonetetra Examples thereof include carboxylic acid and acid dianhydrides such as 2,3,6,7-naphthalenetetracarboxylic acid. From the viewpoints of linear thermal expansion coefficient, glass transition temperature, etc., 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, p-phenylenebis (trimellitic acid monoester anhydride), p-methylphenylene Bis (trimellitic acid monoester acid anhydride), p-biphenylenebis (trimellitic acid monoester acid anhydride), 2,3,6,7-naphthalenetetracarboxylic dianhydride is preferably used. Moreover, each aromatic tetracarboxylic dianhydride may be used alone or in combination. Moreover, you may use acid dianhydrides, such as non-aromatic tetracarboxylic acid, cyclobutane tetracarboxylic acid, and cyclohexane tetracarboxylic acid, in the range which does not impair the effect of this invention.

  As the diamine in the polyamic acid solution according to the present invention, conventionally known diamines can be used, but it is preferable to use a diamine that does not contain the structure of the general formula (1) from the viewpoint of elastic modulus. . For example, paraphenylenediamine, metaphenylenediamine, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminobenzanilide, 2,2-dimethyl-4,4-diaminobiphenyl, 1, 3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis (4-aminophenoxyphenyl) propane, 4-aminophenyl-4′-aminobenzoate , APAB), 2-methyl-4-aminophenyl-4′-aminobenzoate, 4-aminophenyl-3′-aminobenzoate, 2-methyl-4-aminophenyl-3′-aminobenzoate, bis (4 -Aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate (Hereinafter referred to as BPIP), 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) sulfone, Bis (4- (3-aminophenoxy) phenyl) sulfone is exemplified. From the viewpoint of linear thermal expansion coefficient and glass transition temperature, paraphenylenediamine, metaphenylenediamine, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4-aminophenyl-4′-aminobenzoate, 4- Aminophenyl-3′-aminobenzoate, 2-methyl-4-aminophenyl-3′-aminobenzoate, bis (4-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, 4,4′-bis ( 4-aminophenoxy) biphenyl is preferably used.

  The polyamic acid in this invention is obtained by making the said tetracarboxylic dianhydride component and a diamine acid component react. The regularity of the repeating unit constituting the polyamic acid may include a block structure or a random structure. The polyimide resin of the present invention is a polyimide resin having a linear thermal expansion coefficient at 50 ° C. to 200 ° C. of 8 ppm / ° C. to 25 ppm / ° C. Moreover, it is more preferable that it is 15 ppm / degrees C-22 ppm / degrees C from the point of matching of coefficient of linear thermal expansion with copper.

  The polyimide resin of the present invention can be obtained by imidizing the polyamic acid varnish composition of the present invention by a conventional known technique. Usually, the molecular weight and terminal structure of the polyimide resin to be produced can be adjusted by adjusting the charging ratio of the tetracarboxylic dianhydride and the diamine compound used in the production. The preferred molar ratio of total tetracarboxylic dianhydride to total diamine is 0.90 to 1.10.

  The terminal structure of the resulting polyimide becomes an amine or acid anhydride structure depending on the molar charge ratio of all tetracarboxylic dianhydrides and all diamines at the time of production. When the terminal structure is an amine, it may be end-capped with a carboxylic acid anhydride. Examples of these include phthalic anhydride, 4-phenylphthalic anhydride, 4-phenoxyphthalic anhydride, 4-phenylcarbonylphthalic anhydride, 4-phenylsulfonylphthalic anhydride, and the like. This is not a limitation. You may use these carboxylic anhydrides individually or in mixture of 2 or more types.

  In addition, when the terminal structure is an acid anhydride, the terminal structure may be capped with a monoamine. Specific examples include aniline, toluidine, aminophenol, aminobiphenyl, aminobenzophenone, naphthylamine and the like. You may use these monoamines individually or in mixture of 2 or more types.

  As a solvent in the polyamic acid varnish composition of the present invention, any solvent can be used as long as it is mixed with the above polyamic acid. Examples thereof include γ-butyrolactone, γ-valerolactone, N-methyl-2-pyrrolidone, N, N- Examples include dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, 1,3-dioxane, 1,4-dioxane, cyclopentanone, cyclohexanone, diethylene glycol dimethyl ether, and tetramethylurea. Preferred solvents for use in the present invention are γ-butyrolactone, N, N-dimethylacetamide and N-methyl-2-pyrrolidone. These can be used alone or in admixture of two or more.

  In addition, as long as physical properties are not impaired, additives such as dehydrating agents, fillers such as silica, surface modifiers such as silane coupling agents and titanate coupling agents, and pyridine, imidazole, and triazole that promote curing of polyimide An imidizing agent, etc. may be added.

  There is no restriction | limiting in particular in the usage-amount of these solvents, According to the viscosity etc. of a polyamic-acid varnish composition, it can utilize.

  The polyamic acid varnish composition of the present invention can be obtained by externally adding a diamine to a polyamic acid obtained by addition polymerization of an aromatic tetracarboxylic dianhydride and a diamine, and mixing and dissolving them.

  There is no restriction | limiting in particular in solid content concentration in a solvent. The solid content concentration is a percentage of the sum of the masses of the total aromatic tetracarboxylic dianhydride component and the total diamine component with respect to the total mass of the polyamic acid (or polyimide) solution. A preferable solid content concentration is 5% by mass to 35% by mass, and more preferably 10% by mass to 25% by mass.

  About addition polymerization conditions, it can carry out according to the addition polymerization conditions of the polyamic acid currently performed conventionally. Specifically, first, diamines are dissolved in a solvent at 0 ° C. to 80 ° C. under an inert atmosphere such as nitrogen, helium, and argon, and then tetracarboxylic dianhydride at 40 ° C. to 100 ° C. The product is subjected to addition polymerization for 4 to 8 hours while quickly adding the product. Thereby, a polyamic acid varnish composition is obtained. About the viscosity of the polyamic acid varnish obtained, it is preferable to adjust the solid content concentration so as to be 1 poise to 2500 poise.

  Moreover, from the viewpoint of polyimide film toughness and varnish handling, the intrinsic viscosity of the polyamic acid is preferably in the range of 0.1 dL / g to 25.0 dL / g, preferably 0.3 dL / g to 20 dL / g. The range of 0.5 dL / g to 15.0 dL / g is more preferable.

  The metal-polyimide composite of the present invention is one in which a polyimide resin layer (polyimide film) is provided on a metal. A composite with a polyimide resin layer obtained by imidizing the polyamic acid varnish composition of the present invention on a metal, or a polyimide resin layer obtained by high-temperature drying of the polyamic acid varnish composition of the present invention on a metal And a complex. Although the thickness of a polyimide resin layer is not specifically limited, Preferably it is 50 micrometers or less, More preferably, they are 1 micrometer-25 micrometers.

  Although various metal foils can be used as the metal, aluminum foil, copper foil, stainless steel foil and the like are suitably used for the flexible printed circuit board. These metal foils may be subjected to surface treatment such as mat treatment, plating treatment, chromate treatment, aluminum alcoholate treatment, aluminum chelate treatment, silane coupling agent treatment, and the like.

  Although the thickness of metal foil is not specifically limited, Preferably it is 35 micrometers or less, More preferably, it is 18 micrometers or less. Further, the ten-point average roughness (hereinafter referred to as Rz) on the surface of the metal foil is preferably 2.2 μm or less, more preferably 1.0 μm or less, and more preferably 0.7 μm or less from the viewpoint of fine wiring properties during etching. Further preferred.

  The metal-polyimide composite obtained from the polyamic acid varnish composition of the present invention can be produced as follows. First, the polyamic acid varnish composition of the present invention is coated on a metal foil using a blade coater, lip coater, gravure coater, etc., and then dried to form a polyamic acid varnish composition layer as a polyimide precursor resin layer. Form. The coating thickness is affected by the solid content concentration of the polyamic acid varnish composition. A polyimide resin insulating layer can be formed by thermally imidizing the polyamic acid varnish composition layer at 200 ° C. to 400 ° C. in an inert atmosphere such as nitrogen, helium, and argon.

  The metal-polyimide composite thus obtained has good adhesion between a metal, particularly copper and a polyimide resin layer.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following Examples, the properties of the polyamic acid varnish composition and the physical properties of the polyimide resin and copper-polyimide composite after imidization were measured as follows.

(1) Intrinsic viscosity (η)
A 0.5 mass% polyamic acid varnish composition was measured at 30 ° C. using an Ostwald viscometer.

(2) Glass transition temperature (Tg) and coefficient of linear thermal expansion (CTE)
The obtained copper-polyimide composite was cut into a length of 50 mm, a width of 3 mm, and a thickness of 25 μm, and immersed in a ferric chloride aqueous solution (manufactured by Tsurumi Soda Co., Ltd.), and the copper foil layer was etched and washed with water. After drying the obtained polyimide film at 105 ° C. with a hot air dryer, using a thermal analyzer (TMA-50, manufactured by Shimadzu Corporation), tensile mode, 5 g load, sample length 15 mm, temperature rise Measurement was performed at a rate of 10 ° C./min in an N ₂ atmosphere, Tg was determined from the intersection of tangents, and the linear thermal expansion coefficient from 50 ° C. to 200 ° C. was calculated.

(3) Adhesive strength In the same manner as described above, a copper-polyimide composite was cut into a length of 150 mm, a width of 10 mm, and a thickness of 25 μm. It was immersed in an aqueous solution (manufactured by Tsurumi Soda Co., Ltd.), and the copper foil layer was etched and washed with water. Thereafter, the vinyl tape was removed, and the obtained flexible substrate was dried with a hot air dryer at 105 ° C., and then a copper foil having a width of 3 mm was peeled from the polyimide layer, and the stress was measured. The peeling angle was 90 ° and the peeling speed was 50 mm / min.

(4) Solder heat resistance A 3 cm long x 6 cm wide copper-polyimide composite is cut out, and 2.5 cm x 2.5 cm in the center is masked with a vinyl tape to make a ferric chloride aqueous solution (manufactured by Tsurumi Soda Co., Ltd.). The copper foil layer was etched and washed with water. Thereafter, the vinyl tape was removed, and the obtained copper-polyimide composite was dried at 105 ° C. with a hot air dryer, and then the sample was placed in a solder bath set at 300 ° C., and the copper foil glossy side was soldered. Evaluation was performed based on changes in appearance when allowed to stand for 1 minute so as to contact the bath.

(5) Boiling solder heat resistance In the same manner as described above, a copper-polyimide composite having a length of 3 cm and a width of 6 cm was cut out, and a central portion of 2.5 cm × 2.5 cm was masked with a vinyl tape, and a ferric chloride aqueous solution ( It was immersed in Tsurumi Soda Co., Ltd.), and the copper foil layer was etched and washed. Thereafter, the vinyl tape is removed, and the obtained sample is immersed in boiling water for 2 hours, then immersed in water at room temperature, taken out, wiped off water adhering to the surface, and immediately left at 280 ° C. for 1 minute. Evaluation was performed based on changes in appearance.

(6) Hygroscopic expansion coefficient: CHE
Using an ULVAC-RIKO thermomechanical analyzer (TM-9400) and a humidity atmosphere controller (HC-1), a film having a width of 3 mm, a length of 20 mm (15 mm between chucks), and a thickness of 20 μm to 25 μm was prepared. The hygroscopic expansion coefficient of the polyimide film was determined as an average value in 30% RH to 70% RH from the elongation of the test piece when the humidity was changed from 30% RH to 70% RH at 5 ° C. and a load of 5 g.

(7) Elastic modulus, elongation at break Using a RTG-1210 type tensile tester manufactured by Orientec Co., Ltd., a polyimide film of 3 mm × 50 mm was stretched at a test length of 50 mm and a test speed of 50 mm / min. It calculated from the inclination of the stress between tensile elongation 0.4%-1.0%. (When a 50 mm sample breaks when it is stretched to 100 mm, it is described as “tensile elongation at break of 100%”.)

Synthesis Example 1 Synthesis of Diamine 1
In a 2 L separable flask, 1200 ml of N, N-dimethylformamide, 200 mmol of 3,3′-dihydroxy-4,4′-diaminobiphenyl (manufactured by Wakayama Seika Kogyo Co., Ltd.) and 400 mmol of triethylamine are dissolved, and the reaction is performed under a nitrogen atmosphere. Cooled to 0 ° C. Thereafter, a solution obtained by dissolving 400 mmol of p-nitrobenzoyl chloride in 100 ml of N, N-dimethylformamide was added dropwise over 2 hours so as to be 10 ° C. or lower, followed by stirring for 6 hours. Next, the precipitate is filtered, washed with N, N-dimethylformamide, further washed with water, and dried to obtain yellowish white crystals of 3,3′-dihydroxy-4,4′-dinitrobiphenylanilide. It was. Hydrogen is introduced while stirring 300 ml of 3,3′-dihydroxy-4,4′-dinitrobiphenylanilide obtained in a 1000 ml autoclave with 5 g of 5% Pd / C and 600 ml of N, N-dimethylformamide. Stirring was continued until no more was observed. After cooling, the catalyst was removed by filtration, concentrated under reduced pressure and poured into water, the precipitate was filtered, washed with water, dried under reduced pressure, and diamine (3,3′-dihydroxy-4 represented by the following formula (9) , 4′-diaminobiphenylanilide) was obtained (hereinafter referred to as “BBOz”).

Synthesis Example 2 Synthesis of Diamine 2
The same as Synthesis Example 1 except that 5-nitro-2-aminophenol was used instead of 3,3′-dihydroxy-4,4′-diaminobiphenyl, and the molar ratio charged with p-nitrobenzoyl chloride was equivalent. The amide group structure-containing diamine (hereinafter referred to as BOz) represented by the following formula (10) is prepared by synthesizing a precursor in N, N-dimethylformamide, and performing a reduction reaction and separation / purification in an autoclave. Obtained).

[Example 1]
<Evaluation of polyamic acid varnish composition, imidization and polyimide film characteristics>
4-Aminophenyl-4′-aminobenzoate (hereinafter referred to as APAB) 47.5 mmol, 4,4′-diaminodiphenyl ether containing an ester group in the monomer skeleton in a well-closed sealed reaction vessel with a stirrer (Wakayama Seika) Kogyo Co., Ltd.) (hereinafter referred to as ODA) 2.5 mmol, N-methyl-2-pyrrolidone 191 mL (dehydrated) (Wako Pure Chemical Industries, Ltd.) (hereinafter referred to as NMP) 50 mmol of p-methylphenylenebis (trimellitic acid monoester acid anhydride) (hereinafter referred to as MTAHQ) containing an ester group was gradually added thereto. After 30 minutes, the solution viscosity increased rapidly. Furthermore, it stirred at 80 degreeC for 4 hours, and obtained the polyamic-acid solution (varnish) which has a transparent, uniform and viscous ester group. In this polyamic acid solution, the diamine (BBOz) obtained in Synthesis Example 1 was externally added so as to be 6 parts by mass with respect to the resin solid content and dissolved to obtain a polyamic acid varnish composition. The obtained polyamic acid varnish composition did not precipitate or gel at all even when allowed to stand at room temperature and −20 ° C. for one month, and showed high solution storage stability. The intrinsic viscosity of the polyamic acid varnish composition measured with an Ostwald viscometer in NMP at a concentration of 0.5% by mass at 30 ° C. was 0.72 dL / g.

  This polyamic acid varnish composition is allowed to stand on a metal coating table with a 12 μm-thick copper foil (F2-WS, Furukawa Circuit Foil Co., Ltd.) mat surface side as the surface. The surface temperature of the coating table is set to 90 ° C., and the Rz = 2.1 μm polyamic acid varnish composition is applied to the copper foil mat surface with a doctor blade. Then, after leaving still at a coating stand for 30 minutes, and also leaving still at 100 degreeC and 30 minutes in a dryer, the polyamic-acid film (45 micrometers in thickness) without tackiness was obtained. After that, the polyamic acid film is attached to the metal plate made of SUS, and in a hot air drier in a nitrogen atmosphere at a heating rate of 5 ° C./min, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 400 ° C. for 1 hour. Imidization was performed. A polyimide film with a 25 μm-thick copper foil without curling was obtained.

  This polyimide film with copper foil was etched with a ferric chloride solution to obtain a light brown polyimide film with a thickness of 25 μm. This polyimide film did not break even in the 180 ° bending test and showed flexibility. Moreover, it did not show any solubility in organic solvents. This polyimide film showed a linear thermal expansion coefficient (average value between 50 ° C. and 200 ° C.) of 19 ppm / ° C. as low as that of the copper foil by TMA measurement. Further, when the hygroscopic expansion coefficient was measured, it was 5.5 ppm /% RH (an average value between 30% RH and 70% RH) and an extremely low hygroscopic expansion coefficient. Further, when the 90 ° copper foil adhesive strength was measured, it showed a high adhesive strength of 1.0 kg / cm.

  Similarly, this polyamic acid varnish composition was spin-coated on a 6-inch silicon wafer with a spin coater (MS-250 Mikasa Co., Ltd.), left standing at 100 ° C. for 30 minutes in a dryer, and then tacky. A polyamic acid film (thickness: 17 μm) with no film was obtained. Thereafter, the silicon wafer was imidized in a hot air drier in a nitrogen atmosphere at a rate of temperature increase of 5 ° C./minute, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 400 ° C. for 1 hour. Thereafter, it was peeled from the silicon wafer with hydrofluoric acid to obtain a polyimide film having a thickness of 10 μm. The obtained polyimide film was subjected to a tensile test to obtain an elastic modulus of 7.8 GPa and an elongation at break of 55%.

[Example 2]
As diamine, as shown in Table 1 instead of BBOz, the BOz obtained in Synthesis Example 2 is externally added so as to be 6 parts by mass with respect to the resin solid content, and the same operation as in Example 1 is repeated. As a result, a polyamic acid varnish, a polyimide resin, and a copper-polyimide composite were obtained. Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Example 3]
In a 1000 ml glass separable three-necked flask equipped with a stainless steel vertical stirrer, 220 mmol of paraphenylenediamine (manufactured by Seiko Chemical) (hereinafter abbreviated as PPD) and 55 mmol of ODA in a nitrogen gas atmosphere It melt | dissolved in NMP694ml at 50 to 80 degreeC so that it might become a density | concentration of 15 mass%, and hold | maintained at 80 degreeC. Thereafter, 278 mmol of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (Mitsubishi Chemical Co., Ltd.) (hereinafter abbreviated as BPDA) was gradually added to the flask and kept at 80 to 100 ° C. for 4 hours. Stir. In this polyamic acid solution, the diamine (BBOz) obtained in Synthesis Example 1 was externally added and dissolved so as to be 6 parts by mass with respect to the resin solid content to obtain a polyamic acid varnish composition. The obtained polyamic acid varnish composition did not precipitate or gel at all even when allowed to stand at room temperature and −20 ° C. for one month, and showed high solution storage stability. The intrinsic viscosity of the polyamic acid varnish composition measured with an Ostwald viscometer at 30 ° C. and a concentration of 0.5% by mass in NMP was 1.7 dL / g.

  This polyamic acid varnish composition is allowed to stand on a metal coating table with a 12 μm-thick copper foil (F2-WS foil, Rz = 2.1 μm, Furukawa Circuit Foil Co., Ltd.) with the mat surface side as the surface. Thereafter, the same operation as in Example 1 was repeated to obtain a polyimide resin and a copper-polyimide composite.

  Similarly, this polyamic acid varnish composition was spin-coated on a 6-inch silicon wafer with a spin coater (MS-250 Mikasa Co., Ltd.), and allowed to stand at 100 ° C. for 30 minutes in a dryer. A polyamic acid film (thickness 17 μm) having no tackiness was obtained. Thereafter, the silicon wafer was imidized in a hot air drier in a nitrogen atmosphere at a rate of temperature increase of 5 ° C./minute, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 400 ° C. for 1 hour. Thereafter, it was peeled from the silicon wafer with hydrofluoric acid to obtain a polyimide film having a thickness of 10 μm.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Example 4]
As diamine, as shown in Table 1 instead of BBOz, BOz obtained in Synthesis Example 2 is externally added so as to be 6 parts by mass with respect to the resin solid content, and the same operation as Example 3 is repeated. Thus, a polyamic acid varnish composition, a polyimide resin and a copper-polyimide composite were obtained.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Example 5]
The same operation as Example 3 except that NA-DFF foil (Mitsui Metals Co., Ltd., Rz = 0.6 μm) was used instead of F2-WS foil (Furukawa Circuit Foil Co., Ltd.) as a 12 μm thick copper foil. Was repeated to obtain a polyamic acid varnish composition, a polyimide resin and a copper-polyimide composite.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Example 6]
In a well-dried sealed reaction vessel with a stirrer, diamine represented by formula (11) (hereinafter referred to as BPIP) 6.42 mmol, diamine represented by formula (12) (hereinafter referred to as APAB) 6.42 mmol Was dissolved in 61 ml of NMP at 50 ° C. to 80 ° C. and kept at 80 ° C. so that the solid content concentration was 15% by mass under a nitrogen gas atmosphere. Thereafter, 13.38 mmol of acid dianhydride (hereinafter referred to as TABP) represented by the formula (13) was gradually added to the flask, followed by stirring for 4 hours while maintaining at 80 ° C. In this polyamic acid solution, BBOz was externally added and dissolved so as to be 3 parts by mass with respect to the resin solid content to obtain a polyamic acid varnish composition. The obtained polyamic acid varnish composition did not precipitate or gel at all even when allowed to stand at room temperature and −20 ° C. for one month, and showed high solution storage stability. The intrinsic viscosity of the polyamic acid varnish composition measured with an Ostwald viscometer at 30 ° C. and a concentration of 0.5 mass% in NMP was 1.2 dL / g.

  This polyamic acid varnish composition is allowed to stand on a metal coating table with a 12 μm-thick copper foil (F2-WS foil manufactured by Furukawa Circuit Foil Co., Ltd., Rz = 2.1 μm) with the mat surface side as the surface. Thereafter, the same operation as in Example 1 was repeated to obtain a polyimide resin and a copper-polyimide composite.

  Similarly, this polyamic acid varnish composition was spin-coated on a 6-inch silicon wafer with a spin coater (MS-250 Mikasa Co., Ltd.), and allowed to stand at 100 ° C. for 30 minutes in a dryer. A polyamic acid film (thickness 17 μm) having no tackiness was obtained. Thereafter, the silicon wafer was imidized in a hot air drier in a nitrogen atmosphere at a rate of temperature increase of 5 ° C./minute, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 400 ° C. for 1 hour. Thereafter, it was peeled from the silicon wafer with hydrofluoric acid to obtain a polyimide film having a thickness of 10 μm.

Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Example 7]
The same operation as in Example 6 except that NA-DFF foil (Mitsui Metals Co., Ltd., Rz = 0.6 μm) was used instead of F2-WS foil (Furukawa Circuit Foil Co., Ltd.) as a 12 μm thick copper foil. Was repeated to obtain a polyamic acid varnish composition, a polyimide resin and a copper-polyimide composite. Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Comparative Example 1]
After dissolving in 47.5 mmol of APAB containing ester groups in the monomer skeleton, 2.5 mmol of ODA and 191 mL of NMP (dehydrated) in a well-dried sealed reaction vessel with a stirrer, MTAHQ containing ester groups in the monomer skeleton was added to this solution. Gradually 50 mmol of powder was added. After 30 minutes, the solution viscosity increased rapidly. Furthermore, it stirred at 80 degreeC for 4 hours, and obtained the polyamic-acid solution which has a transparent, uniform and viscous ester group. The obtained polyamic acid solution did not precipitate or gel at all even when it was allowed to stand at room temperature and −20 ° C. for one month, and showed high solution storage stability. The intrinsic viscosity of the polyamic acid solution measured with an Ostwald viscometer at 30 ° C. and a concentration of 0.5 mass% in NMP was 0.72 dL / g.

  In the same manner as in Example 1, this polyamic acid solution was applied to a metal coating table with a copper foil having a thickness of 12 μm (F2-WS manufactured by Furukawa Circuit Foil, Rz = 2.1 μm) on the mat surface side. Leave on. The surface temperature of the coating table is set to 90 ° C., and the polyamic acid solution is applied to the copper foil mat surface with a doctor blade. Then, after leaving still at a coating stand for 30 minutes, and also leaving still at 100 degreeC for 30 minutes in a dryer, the polyamic-acid film (45 micrometers in thickness) without tackiness was obtained. After that, the polyamic acid film is attached to the metal plate made of SUS, and in a hot air drier in a nitrogen atmosphere at a heating rate of 5 ° C./min, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, 400 ° C. for 1 hour. Imidization was performed. A polyimide film with a copper foil having a thickness of 25 μm and no curling was obtained.

  This film with copper foil was etched with a ferric chloride solution to obtain a light brown polyimide film having a thickness of 25 μm. This polyimide film did not break even in the 180 ° bending test and showed flexibility. Moreover, it did not show any solubility in organic solvents.

  Similarly, this polyamic acid varnish composition was spin-coated on a 6-inch silicon wafer with a spin coater (MS-250 Mikasa Co., Ltd.), and allowed to stand at 100 ° C. for 30 minutes in a dryer. A polyamic acid film (thickness 17 μm) having no tackiness was obtained. Thereafter, the silicon wafer was imidized in a hot air drier in a nitrogen atmosphere at a rate of temperature increase of 5 ° C./minute, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 400 ° C. for 1 hour. Thereafter, it was peeled from the silicon wafer with hydrofluoric acid to obtain a polyimide film having a thickness of 10 μm.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Comparative Example 2]
Polyamic acid varnish composition in which 2-ethyl-4-methyl-imidazole (product name 2E4MZ, manufactured by Shikoku Kasei Co., Ltd.) was added to the polyamic acid solution obtained in Comparative Example 1 so as to be 6 parts by mass with respect to the resin solid content. I got a thing. By repeating the same operation as in Comparative Example 1, a polyimide resin and a copper-polyimide composite were obtained.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Comparative Example 3]
To a 1000-ml glass separable three-necked flask equipped with a stainless steel vertical stirrer, PPD 220 mmol and ODA 55 mmol are added to NMP 694 ml at 50 ° C. to 80 ° C. so that the solid content concentration is 15% by mass in a nitrogen gas atmosphere. It melt | dissolved at 0 degreeC and hold | maintained at 80 degreeC. Thereafter, 278 mmol of BPDA was gradually added to the flask and stirred for 4 hours while maintaining at 80 to 100 ° C. to obtain a polyamic acid varnish composition. The obtained polyamic acid varnish composition did not precipitate or gel at all even when allowed to stand at room temperature and −20 ° C. for one month, and showed high solution storage stability. The intrinsic viscosity of the polyamic acid varnish composition measured with an Ostwald viscometer at 30 ° C. and a concentration of 0.5% by mass in NMP was 1.7 dL / g.

  This polyamic acid varnish composition is allowed to stand on a metal coating table with a 12 μm-thick copper foil (F2-WS foil manufactured by Furukawa Circuit Foil, Rz = 2.1 μm) with the mat surface side as the surface. Thereafter, the same operation as in Example 1 was repeated to obtain a polyimide resin and a copper-polyimide composite.

  Similarly, this polyamic acid varnish composition was spin-coated on a 6-inch silicon wafer with a spin coater (manufactured by MS-250 Mikasa Co., Ltd.), allowed to stand at 100 ° C. for 30 minutes in a dryer, and then tacked. A polyamic acid film (thickness: 17 μm) was obtained. Thereafter, the silicon wafer was imidized in a hot air drier in a nitrogen atmosphere at a rate of temperature increase of 5 ° C./minute, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 400 ° C. for 1 hour. Thereafter, the film was peeled from the silicon wafer with hydrofluoric acid to obtain a film having a thickness of 10 μm.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Comparative Example 4]
The polyamic acid varnish composition obtained by adding 2-ethyl-4-methyl-imidazole to the polyamic acid varnish composition obtained in Comparative Example 3 so as to be 6 parts by mass with respect to the resin solid content was obtained. By repeating the same operation as in Comparative Example 3, a polyimide resin and a copper-polyimide composite were obtained.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Comparative Example 5]
In a 1000 ml glass separable three-necked flask equipped with a stainless steel vertical stirrer, 220 mmol of paraphenylenediamine (manufactured by Seiko Chemical Co., Ltd.) (hereinafter abbreviated as PPD) and 55 mmol of ODA in a nitrogen gas atmosphere, NMP 694 ml Was dissolved at 50 ° C. to 80 ° C. and kept at 80 ° C. Thereafter, 278 mmol of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (Mitsubishi Chemical Co., Ltd.) (hereinafter abbreviated as BPDA) and the diamine (BBOz) obtained in Synthesis Example 1 were used as the total monomer solid content. The mixture was gradually added to the flask so as to be 6 parts by mass, and stirred for 4 hours while maintaining the temperature at 80 to 100 ° C. to obtain a polyamic acid solution. Thereafter, the same operation as in Comparative Example 4 was repeated to obtain a polyimide resin and a copper-polyimide composite.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Comparative Example 6]
The same operation as Comparative Example 3 except that NA-DFF foil (Mitsui Metals Co., Ltd., Rz = 0.6 μm) was used instead of F2-WS foil (Furukawa Circuit Foil Co., Ltd.) as a 12 μm thick copper foil. Was repeated to obtain a polyamic acid varnish composition, a polyimide resin and a copper-polyimide composite.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Comparative Example 7]
In a well-dried sealed reaction vessel with a stirrer, BPIP 6.42 mmol and APAB 6.42 mmol were dissolved in NMP 61 ml at 50-80 ° C. and kept at 80 ° C. so that the solid content concentration was 15% by mass in a nitrogen gas atmosphere. did. Thereafter, 13.38 mmol of TABP was gradually added to the flask and stirred for 4 hours while maintaining at 80 ° C. The obtained polyamic acid varnish did not precipitate or gel at all even when it was allowed to stand at room temperature and −20 ° C. for one month, and showed high solution storage stability. The intrinsic viscosity of the polyamic acid varnish measured with an Ostwald viscometer at 30 ° C. and a concentration of 0.5% by mass in NMP was 1.2 dL / g.

  This polyamic acid varnish composition is allowed to stand on a metal coating table with a 12 μm-thick copper foil (F2-WS foil manufactured by Furukawa Circuit Foil Co., Ltd., Rz = 2.1 μm) with the mat surface side as the surface. Thereafter, the same operation as in Example 1 was repeated to obtain a polyimide resin and a copper-polyimide composite.

  Similarly, this polyamic acid varnish composition part was spin-coated on a 6-inch silicon wafer with a spin coater (manufactured by MS-250 Mikasa Co., Ltd.), and allowed to stand at 100 ° C. for 30 minutes in a dryer. A polyamic acid film (thickness 17 μm) having no tackiness was obtained. Thereafter, the silicon wafer was imidized in a hot air drier in a nitrogen atmosphere at a rate of temperature increase of 5 ° C./minute, 150 ° C. for 30 minutes, 200 ° C. for 1 hour, and 400 ° C. for 1 hour. Thereafter, it was peeled from the silicon wafer with hydrofluoric acid to obtain a polyimide film having a thickness of 10 μm.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

[Comparative Example 8]
The same operation as Comparative Example 7 except that NA-DFF foil (Mitsui Metals Co., Ltd., Rz = 0.6 μm) was used instead of F2-WS foil (Furukawa Circuit Foil Co., Ltd.) as a 12 μm thick copper foil. Was repeated to obtain a polyamic acid varnish composition, a polyimide resin and a copper-polyimide composite.

  Glass transition temperature (Tg) and linear thermal expansion coefficient (CTE), hygroscopic expansion coefficient (CHE), elastic modulus, elongation at break, adhesive strength of copper-polyimide composite, solder heat resistance and moisture absorption solder heat resistance of the obtained polyimide resin The sex results are shown in Table 1.

  The diamine-containing polyamic acid varnish composition, polyimide resin, and metal-polyimide composite according to the present invention are suitable for wiring substrates such as flexible printed boards and IC package boards that require high-density wiring and high reliability. is there.

Claims (8)

A polyamic acid varnish composition comprising a polyamic acid solution and a diamine having a structure of formula (1) therein.

2. The polyamic acid varnish composition according to claim 1, wherein the diamine is a diamine represented by any one or more of formulas (2), (3), (4), and (5). object.
(In the formula, X1 is a tetravalent aromatic group represented by Formula (2) or Formula (3), X2 is a divalent aromatic group represented by Formula (4), and Y1 ~ Y3 is ether, -S-, C1-C4 saturated, unsaturated alkylene group, sulfonyl group or phenyl group, Z1 and Z2 each represent a divalent aromatic group or aliphatic group, There may be different even in the same. also, R1 to R9 are, C1 -C4 alkyl group, alkoxy group, halogenated alkyl group, a halogen group, a nitro group, a cyano group, a hydroxyl group, _-SO 2 H , -OPh, -SCH ₃ , or -SPh, and n = 0, 1, or 2.)

The polyamic acid varnish composition according to claim 1 or 2, wherein the diamine is a diamine represented by any one or more of formulas (6), (7), and (8). .
(Wherein X3 is a tetravalent aromatic group represented by formula (6). X4 is a divalent aromatic group represented by formula (7).)

  The polyamic acid varnish composition according to any one of claims 1 to 3, comprising 100 parts by mass of a polyamic acid and 0.01 to 20 parts by mass of the diamine.   A polyimide resin obtained by imidizing the polyamic acid varnish composition according to any one of claims 1 to 4.   A metal-polyimide composite comprising: a polyimide resin obtained by imidizing the polyamic acid varnish composition according to claim 1; and a metal foil.   The metal-polyimide composite according to claim 6, wherein the metal foil has a ten-point average roughness Rz of 0.7 μm or less. A method for producing a polyamic acid varnish composition comprising polyamic acid and a diamine containing the structure of formula (1) therein, wherein the polyamic acid comprises an aromatic tetracarboxylic dianhydride and an aromatic diamine. A method for producing a polyamic acid varnish composition comprising: polymerizing the polyamic acid and adding the diamine to the polyamic acid.