JP2008274220A - Resin composition and flexible printed wiring board using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive cover lay film having excellent mechanical properties. <P>SOLUTION: The present invention relates to a resin composition containing a resin (A) and a plasticizer (B), characterized in that, when only the plasticizer (B) is heated, the heat-generation at starting temperture is T1(°C) and, when a composition (composition (a)) which is a mixture of the resin (A) and the plasticizer (B) is heated, the heat generation starting temparature is T2(°C) and a glass transition temperature of the resin composition is T3(°C), no heat generation is observed when the above composition (composition (a)) is heated, or the composition satisfies formula (1): T1+15°C<T2 (provided that T2(°C) is at most 250°C) and T3 satisfies formula (2): T3≤100°C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a film suitable for a coverlay of a flexible printed wiring board and a flexible printed wiring board using the film.

  A flexible printed wiring board (hereinafter abbreviated as FPC) having flexibility is mainly manufactured using a copper-clad laminate (hereinafter abbreviated as FCCL). A predetermined circuit pattern made of copper is formed on the surface (conductor surface) of the FCCL, and the circuit pattern is exposed. Since this copper circuit pattern may be altered as it is, the cover lay film (insulating protective film) is laminated on the surface to prevent the alteration. The coverlay film also has a function of improving the bending characteristics of the FPC. As this coverlay film, a film made of polyimide is suitably used from the viewpoint of flexibility and flame retardancy required for it.

  When a film is laminated on the surface of a substrate having a circuit pattern (hereinafter referred to as a circuit board), a method such as thermocompression bonding is used.

  However, in order to laminate a polyimide film by thermocompression bonding to form a coverlay film, since the glass transition point of the polyimide film is high, a high temperature of 300 to 400 ° C. is necessary, which is not practical.

Therefore, there is a technique that enables thermocompression bonding by adding a monomer component such as acrylic or a thermosetting resin component to the polyimide film. In these techniques, a photopolymerization initiator is contained in a film, and a monomer component and a thermosetting resin component are polymerized when patterning is performed using the coverlay film (for example, Patent Document 1 and Patent Document 2). ). When a monomer component or a thermosetting resin component is polymerized, there is a concern that the obtained film is inferior in mechanical properties.
JP 2002-3516 A International Publication No. 00/61658 Pamphlet

  This invention is made | formed in view of this point, and provides the film which has the outstanding mechanical physical property which was difficult with the film which polymerizes and hardens the conventional additive component.

In the resin composition of the present invention, the resin composition containing the resin (A) and the plasticizer (B) has a heat generation start temperature of T1 (° C.) when only the plasticizer (B) is heated. ), And T2 (° C.) is the heat generation start temperature of the heat generated when the composition (composition (a)) in which the resin (A) and the plasticizer (B) are mixed is heated. When the glass transition point of the product is T3 (° C.), the composition (composition (a)) does not generate heat when heated or satisfies the following formula (1), and T3 is The resin composition characterized by satisfying the following formula (2).
T1 + 15 ° C. <T2 Formula (1)
(However, T2 (° C) is 250 ° C or less)
T3 ≦ 100 ° C. Formula (2)

In the resin composition of this invention, it is a resin composition obtained by heat-processing the said resin composition, Comprising: It is preferable that temperature T4 (degreeC) of the said heat processing satisfy | fills following formula (3).
120 ° C. ≦ T4 <T2 Formula (3)

  In the resin composition of this invention, it is preferable that the said resin (A) is a polyimide. In this case, it is preferable that the polyimide has a silicone skeleton. In this case, the polyimide preferably has a hydroxyl group and / or a carboxyl group.

  In the resin composition of the present invention, the plasticizer (B) preferably has a molecular weight of 1000 or less.

  In the resin composition of the present invention, the plasticizer (B) is preferably a compound containing a nitrogen atom and / or a phosphorus atom. In this case, the plasticizer (B) containing the nitrogen atom and / or phosphorus atom has at least one selected from the group consisting of a carbon-carbon double bond, an alkyl oxide chain, and an ester bond. preferable.

  In the resin composition of this invention, it is preferable that the said plasticizer (B) is 50 weight part or less with respect to 100 weight part of said resin (A).

  In the resin composition of this invention, it is preferable to contain a photoreactive compound (C). In this case, the photoreactive compound (C) is preferably a quinonediazide compound.

  The film of this invention is comprised with the said resin composition, It is characterized by the above-mentioned.

  The laminated film of the present invention comprises the above film and a carrier film provided on the film.

  The laminated film of the present invention preferably includes a cover film.

  The flexible printed wiring board of the present invention comprises: a base material having wiring; and a cover lay formed on the base material so as to cover the wiring and configured by the film or the laminated film. And

  In the resin composition of the present invention, the plasticizer component hardly causes a reaction such as polymerization or crosslinking, and does not deteriorate the mechanical properties of the film, so that a film having good mechanical properties can be achieved.

  The resin composition of the present invention contains a resin (A) and a plasticizer (B). The resin composition of the present invention can be obtained by drying from a state in which at least the resin (A) and the plasticizer (B) are dissolved or dispersed in an appropriate solvent. Although there is no restriction | limiting in particular in drying temperature, 100 degrees C or less is preferable. Under the present circumstances, it is preferable that the resin composition of this invention is a film form from a viewpoint of workability. Such a film may have tack or no tack on the surface.

In the resin composition of the present invention, the heat treatment temperature is set to T1 (° C.) as the heat generation start temperature of the heat generated when only the plasticizer (B) is heated, and the resin (A) and the plasticizer ( When the exothermic start temperature of the exotherm seen when heating the composition (composition (a)) mixed with B) is T2 (° C.), the resin (A) and the plasticizer (B) It is preferable that the composition in which is mixed does not generate heat when it is heated or satisfies the formula (1).
T1 + 15 ° C. <T2 Formula (1)
(However, T2 (° C) is 250 ° C or less)

  When the composition in which the resin (A) and the plasticizer (B) are mixed is heated, it is unlikely that the plasticizer (B) is undergoing a reaction such as polymerization or crosslinking. Suggests that. Thus, no heat is generated when the composition is heated, or if there is slight heat generation, the mechanical properties of the film composed of the heat-treated resin composition are good, preferable.

  When heat generation is observed when a composition obtained by mixing the resin (A) and the plasticizer (B) is heated, a composition (composition) obtained by mixing the resin (A) and the plasticizer (B) The heat generation start temperature T2 (° C.) seen when heating (a)) is higher than the heat generation start temperature T2 (° C.) when only the plasticizer (B) is heated. A shift is preferred. The shift of T2 (° C.) to a high temperature suggests that the progress of reactions such as polymerization and crosslinking is reduced. It is presumed that this is because the plasticizer (B) molecular motion is suppressed in the resin (A), or because of the diluting effect due to dispersion in the resin (A).

  When the temperature difference between T1 (° C.) and T2 (° C.) is small, a reaction such as polymerization or crosslinking is likely to proceed. Therefore, in consideration of the mechanical properties of the film formed of the obtained resin composition after the heat treatment, the temperature of T2 (° C.) is preferably 15 ° C. or more higher than T1 (° C.).

  The resin (A) and the plasticizer (B) are used as the total weight of the resin (A) and the plasticizer (B) in the resin composition from the viewpoint of film forming properties when processed into a film. It is preferable to contain 50% by weight or more in the composition. More preferably, it is 70 weight% or more.

  Moreover, it is preferable that the addition amount of a plasticizer (B) is 50 weight part or less with respect to 100 weight part of resin (A). Within this range, the plasticizer hardly causes a reaction such as polymerization or crosslinking, and the mechanical properties when the resin composition is made into a film are good.

  As a preferable combination of the resin (A) and the plasticizer (B), the resin (A) is preferably a polyimide from the viewpoint of mechanical properties of the film, and the plasticizer (B) is a compound containing a nitrogen atom and / or a phosphorus atom. preferable. Since these plasticizers contain a nitrogen atom and / or a phosphorus atom in the compound structure, polar groups such as an amide group, an imide group, a urea group, an isocyanuric acid ring, and a phosphoric acid ester are contained in the resin (A It is presumed that it contributes to the improvement of the compatibility with the resin (A) and exhibits a dilution effect by being dispersed in the resin (A).

T3 (° C.) is a glass transition point of the resin composition before the heat treatment. Specifically, the glass transition point of the resin composition is a glass transition point when the resin composition of the present invention is formed on a film. From the viewpoint of thermocompression bonding, T3 (° C.) is 100 ° C. or less. It is preferable that there is (Formula (2)).
T3 ≦ 100 ° C. Formula (2)

  T3 (° C.) can be lowered by adding a plasticizer (B) to the resin (A). At this time, the plasticizer (B) contains a nitrogen atom and / or a phosphorus atom. Among these compounds, a plasticizer containing a compound having a carbon-carbon double bond and / or an alkyl oxide chain and / or an ester bond in the compound is preferable. Since these plasticizers have a large glass transition point when the resin composition is used as a film and have a high plasticizing effect, it is possible to effectively lower T3 (° C.).

  Also, by introducing a silicone skeleton into the polyimide of the resin (A) component, the flexibility of the resin (A) component increases, so that T3 (° C.) can be lowered.

The resin composition of the present invention can be subjected to heat treatment. When the heat treatment is performed, the mechanical properties can be improved by the orientation of the resin component being changed by heat. As shown in Formula (3), from the viewpoint of imparting chemical resistance and flame retardancy, the temperature T4 (° C.) of the heat treatment is preferably 120 ° C. or higher. Moreover, it is preferable that temperature T4 (degreeC) which heat-processes is lower than T2 (degreeC). In the heat treatment at a temperature lower than T2, there is a low possibility that a reaction such as polymerization or cross-linking of the plasticizer (B) has progressed, so the mechanical properties of the film composed of the obtained resin composition are good. is there. For this reason, the temperature T4 (° C.) at which the heat treatment is performed preferably satisfies the following formula (3).
120 ° C. ≦ T4 <T2 Formula (3)

  T4 (° C.) may exceed T2 (° C.). In this case, if the combination of the composition (composition (a)) satisfies the above formula (1), the plasticizer (B) Therefore, the mechanical properties of the film obtained from the resin composition of the present invention are good. T4 (° C.) is preferably 120 ° C. or more and less than 250 ° C. in consideration of processability. More preferably, it is 140 degreeC or more and 200 degrees C or less.

  Therefore, it is preferable that the reaction such as polymerization or crosslinking of the plasticizer (B) is not likely to proceed within a range of 250 ° C. or lower, and T2 is preferably observed within a range of 250 ° C. or lower. .

  The resin (A) is not particularly limited as long as the resin composition can be formed into a film, but polyimide is preferable from the viewpoint of mechanical properties of a film formed of the resin composition. Moreover, what has a silicone frame | skeleton from the viewpoint of the softness | flexibility of the film which consists of a resin composition among a polyimide is preferable.

  The polyimide is composed of a polycondensate of a diamine component and a tetracarboxylic acid component, and the silicone skeleton can be obtained by using a diamine having a silicone skeleton as a raw material.

（但し、化学式（１）中、複数あるＲ^１は、それぞれ同じでも異なっていても良く、アルキル基、シクロアルキル基、フェニル基、１個から３個のアルキル基又はアルコキシル基で置換されたフェニル基、を表し、ｋ及びｍはそれぞれ独立して１〜３の整数を表し、ｎは３〜３０の整数を表す。）

（但し、化学式（２）及びか化学式（３）中、ｎは化学式（１）と同じである。化学式（２）中のｐは１〜４の整数を表す。）
これらのシリコーン骨格を有するジアミンは、１種類のみでも使用できるが、２種類以上を組み合わせて使用しても良い。 As the diamine having a silicone skeleton, those having a structure represented by the following chemical formulas (1) to (3) are preferable.

(However, in the chemical formula (1), a plurality of R ^{1 s} may be the same or different, and phenyl substituted with an alkyl group, a cycloalkyl group, a phenyl group, 1 to 3 alkyl groups or an alkoxyl group. And k and m each independently represent an integer of 1 to 3, and n represents an integer of 3 to 30.)

(However, in chemical formula (2) and chemical formula (3), n is the same as chemical formula (1). P in chemical formula (2) represents an integer of 1 to 4.)
These diamines having a silicone skeleton can be used alone or in combination of two or more.

As the diamine having the silicone skeleton, for example, commercially available products sold by Shin-Etsu Chemical Co., Ltd., Toray Dow Corning, and Chisso can be used as they are. Specifically, KF-8010 manufactured by Shin-Etsu Chemical Co., Ltd. (amino group equivalent of about 450, in chemical formula (1), R ¹ is a methyl group, k and m are 3), X-22-161A (amino group equivalent of about 840, In formula (1), R ¹ is a methyl group, k and m are 3), and the like.

  From the viewpoint of the solubility of polyimide in an organic solvent and the curl of forming a protective film on a flexible wiring substrate, the content of the diamine having a silicone skeleton is 1 mol% or more with respect to the total number of moles of the diamine component. On the other hand, the content of the diamine having a silicone skeleton is preferably 80 mol% or less from the viewpoint of heat resistance and mechanical properties of a film composed of a resin composition composed of an organic solvent-soluble polyimide. That is, the diamine having a silicone skeleton is preferably in the range of 1 to 80 mol%, more preferably in the range of 5 to 70 mol%, still more preferably in the range of 10 to 60 mol%, based on the total number of moles of the diamine component. Contained.

  The polyimide that can be used in the present invention may have a hydroxyl group and / or a carboxyl group in order to develop alkali developability when used as a photosensitive resin composition. A polyimide having a hydroxyl group and / or a carboxyl group can be obtained by using a diamine having a hydroxyl group and / or a carboxyl group as a raw material.

  The diamine having a hydroxyl group and / or a carboxyl group is not particularly limited as long as it has a hydroxyl group and / or a carboxyl group. Preferred examples include diaminophenols such as 2,4-diaminophenol; 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, 4 , 4′-diamino-2,2′-dihydroxybiphenyl, hydroxybiphenyl compounds such as 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxybiphenyl; 3,3′-diamino-4, 4'-dihydroxydiphenylmethane, 4,4'-diamino-3,3'-dihydroxydiphenylmethane, 4,4'-diamino-2,2'-dihydroxydiphenylmethane, 2,2-bis (3-amino-4-hydroxyphenyl) ) Propane, 2,2-bis (4-amino-3-hydroxyphenyl) propane, 2,2-bis (3- Hydroxydiphenylalkanes such as hydroxydiphenylmethane such as mino-4-hydroxyphenyl) hexafluoropropane, 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenylmethane; 3,3′-diamino-4 , 4′-dihydroxydiphenyl ether, 4,4′-diamino-3,3′-dihydroxydiphenyl ether, 4,4′-diamino-2,2′-dihydroxydiphenyl ether, 4,4′-diamino-2,2 ′, 5 Hydroxydiphenyl ether compounds such as 3,5′-tetrahydroxydiphenyl ether; 3,3′-diamino-4,4′-dihydroxydiphenylsulfone, 4,4′-diamino-3,3′-dihydroxydiphenylsulfone, 4,4′- Diamino-2,2'-dihydroxy Diphenyl sulfone compounds such as phenyl sulfone and 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenyl sulfone; 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] Bis [(hydroxyphenyl) phenyl] alkane compounds such as propane; Bis (hydroxyphenoxy) biphenyl compounds such as 4,4′-bis (4-amino-3-hydroxyphenoxy) biphenyl; 2,2-bis Bis [(hydroxyphenoxy) phenyl] sulfone compounds such as [4- (4-amino-3-hydroxyphenoxy) phenyl] sulfone; diaminobenzoic acids such as 3,5-diaminobenzoic acid; 3,3′-diamino-4 , 4′-dicarboxybiphenyl, 4,4′-diamino-3,3′-dicarboxybiphe Carboxybiphenyl compounds such as nil, 4,4′-diamino-2,2′-dicarboxybiphenyl, 4,4′-diamino-2,2 ′, 5,5′-tetracarboxybiphenyl; 3,3′- Diamino-4,4′-dicarboxydiphenylmethane, 4,4′-diamino-3,3′-dicarboxydiphenylmethane, 4,4′-diamino-2,2′-dicarboxydiphenylmethane, 2,2-bis [3 -Amino-4-carboxyphenyl] propane, 2,2-bis [4-amino-3-carboxyphenyl] propane, 2,2-bis [3-amino-4-carboxyphenyl] hexafluoropropane, 4,4 ′ A carboxydiphenylamine such as carboxydiphenylmethane such as diamino-2,2 ′, 5,5′-tetracarboxydiphenylmethane Cans; 3,3′-diamino-4,4′-dicarboxydiphenyl ether, 4,4′-diamino-3,3′-dicarboxydiphenyl ether, 4,4′-diamino-2,2′-dicarboxydiphenyl ether Carboxydiphenyl ether compounds such as 4,4′-diamino-2,2 ′, 5,5′-tetracarboxydiphenyl ether; 3,3′-diamino-4,4′-dicarboxydiphenyl sulfone, 4,4′-diamino -3,3'-dicarboxydiphenyl sulfone, 4,4'-diamino-2,2'-dicarboxydiphenyl sulfone, 4,4'-diamino-2,2 ', 5,5'-tetracarboxydiphenyl sulfone, etc. Diphenylsulfone compound; 2,2-bis [4- (4-amino-3-carboxyphenoxy) pheny Bis [(carboxyphenoxy) phenyl] alkane compounds such as propane; bis (carboxyphenoxy) biphenyl compounds such as 4,4′-bis (4-amino-3-carboxyphenoxy) biphenyl; 2,2-bis Mention may be made of bis [(carboxyphenoxy) phenyl] sulfone compounds such as [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone. These may be used alone or in combination of two or more.

  More preferred diamines having a hydroxyl group and / or a carboxyl group are 3,5-diaminobenzoic acid, 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 2,2-bis (3-amino-4-hydroxy). Phenyl) propane, 1-hydroxy-2,4-diaminobenzene, 3,3′-dihydroxybenzidine, 3,3′-dihydroxy-4,4′-diaminodiphenyl ether, 1,4-bis- (3-hydroxy-4) -Aminophenoxy) benzene, 2,2-bis (4-amino-3-hydroxyphenyl) propane, bis (3-amino-4-hydroxyphenyl) propane, 2,2-bis (3-amino-4-hydroxyphenyl) ) Hexafluoropropane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (3-amino-) -Hydroxyphenyl) sulfide and 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 1,3-diamino-4-carboxybenzene, 1,3-diamino-5-carboxybenzene, 1,4 -At least one selected from the group consisting of diamino-2-carboxybenzene. Further preferred diamines are 3,5-diaminobenzoic acid, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 1,3-diamino-5-carboxybenzene.

  When these diamines are used, the adhesion to the circuit board and the embedding property are further improved, and the developability and the mechanical properties after the heat treatment are further improved. The content of the diamine having a hydroxyl group and / or a carboxyl group with respect to the total diamine is preferably in the range of 1 to 50 mol%, more preferably in the range of 5 to 50 mol%, further preferably relative to the total number of moles of the diamine component. Is in the range of 10-50 mol%. The content of the diamine having a hydroxyl group and / or a carboxyl group with respect to the total organic diamine is preferably 1 mol% or more from the viewpoint of solubility of the unexposed area, and 50 mol% or less from the viewpoint of resistance to alkali of the unexposed area. Is preferred.

  As the diamine used as a raw material for polyimide, for example, the following may be used in addition to a diamine having a silicone skeleton and a diamine having a hydroxyl group and / or a carboxyl group.

  For example, p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4 ′ -Diaminodiphenyl sulfone, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 6 -Amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 4,4'-diaminobenzanilide, 3,5-diamino-3'-trifluoromethylbenzanilide, 3,5- Diamino-4′-trifluoromethylbenzanilide, 3,4′-diaminodiphenyl ether, 2,7-di Minofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4' -Diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-diamino-2, 2′-bis (trifluoromethyl) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1 , 4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) -biphenyl, 1,3-bis (4-aminophenoxy) benzene, 1, -Bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) fluorene, 4,4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-(m-phenyleneisopropylidene) bisaniline 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-bis [4- (4-amino-2-trifluoromethyl) phenoxy] An aromatic diamine such as octafluorobiphenyl; an aromatic diamine having two amino groups bonded to an aromatic ring such as diaminotetraphenylthiophene and a hetero atom other than the nitrogen atom of the amino group; 1,1-metaxylyl Range amine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octene Tamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylenediethylenediamine, Aliphatic diamines such as 4,4′-methylenebis (cyclohexylamine) and alicyclic diamines may be mentioned. These can be used alone or in combination. Particularly preferred are 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-, from the viewpoint of the glass transition point of the polyimide film. Aminophenoxy) benzene.

  Moreover, the tetracarboxylic acid component used as a raw material for polyimide is not particularly limited as long as it is a tetracarboxylic acid component. Preferably, for example, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbonane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2 , 2,2] -Octo-7-ene-2,3,5,6-tetracarboxylic dianhydride or the like; pyromellitic dianhydride, 3 3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic Acid dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3 4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxypheno) B) Diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (phthal Acid) phenylphosphine oxide dianhydride, p-phenylenebis (trimellitic acid monoester acid anhydride), ethylene glycol bis (trimellitic acid monoester acid anhydride), m-phenylenebis (trimellitic acid monoester acid anhydride) Product), bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylmethanoic acid dianhydride, etc. 1,3,3a, 4,5,9b-hexahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan- 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan- 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan- 1,3-dione and the like. These tetracarboxylic dianhydrides can be used alone or in combination of two or more.

More preferably, 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, p-phenylenebis (trimellitic acid monoester Acid anhydride), ethylene glycol bis (trimellitic acid monoester anhydride) and bicyclo [2,2,2] -oct-7-enetetracarboxylic dianhydride. In particular, p-phenylenebis (trimellitic acid monoester acid anhydride) or ethylene glycol bis (trimellitic acid monoester acid anhydride) is preferable from the viewpoint of improving developability when a photosensitive film is obtained.
These tetracarboxylic dianhydride components can be used alone or in combination.

  Polyimide can be obtained, for example, by mixing the diamine and tetracarboxylic dianhydride in a suitable solvent to synthesize polyamic acid, which is a polyimide precursor, and then imidating by heating the reaction solution. it can.

  Examples of the solvent used for the synthesis include polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, tetramethylurea, hexanemethylphosphoric triamide, and γ-butyrolactone. It is done.

In addition to these solvents, ketones, esters, ethers, and hydrocarbons can be mentioned. Ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like. Esters include methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, dimethyl carbonate, diethyl malonate, and the like. Examples of ethers include diethyl ether, isopropyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and tetrahydrofuran. Hydrocarbons include hexane, heptane, octane, benzene, toluene, xylene and the like.
These can be used alone or in combination of two or more.

  Imidization may be performed only by heating, or may be performed by adding a catalyst. As heating temperature, 150-200 degreeC is preferable and 160-180 degreeC is more preferable. As the catalyst, for example, acid anhydrides, lactones, and bases can be used. Examples of the acid anhydride include acetic anhydride. The lactone is preferably γ-valerolactone, and the base is preferably pyridine and / or methylmorpholine.

  The water produced by the imidation reaction can be removed from the reaction system together with a solvent azeotropic with water, such as toluene and xylene. The catalyst used for imidization is preferably removed after synthesis.

  Removal of the catalyst used in the imidation reaction can be removed by azeotroping with water generated during imidization, for example, by adding a solvent azeotropic with water such as toluene or xylene to the synthesis solvent. it can.

  The obtained reaction liquid can be used as it is as a polyimide varnish for blending the resin composition of the present invention.

  The plasticizer (B) that can be used in the present invention is a glass of a resin composition mainly composed of the resin (A) and the plasticizer (B) by adding the plasticizer (B) to the resin (A). It has a function in which the transition point is lower than the glass transition point of the resin composition of the resin (A). The plasticizer (B) that can be used in the present invention has a molecular weight of 1000 or less from the viewpoint of the plasticizing effect of the resin composition before heat treatment and the mechanical properties of the resin composition after heat treatment. It is preferable.

  As such a plasticizer, for example, a diol or a triol having an alkyl oxide chain is preferable from the viewpoint of the plasticizing effect of the resin composition. Examples of such diols include polyethylene glycols such as ethylene glycol, diethylene glycol, and triethylene glycol; polypropylene glycols such as propylene glycol, dipropylene glycol, and tripropylene glycol; alkyls such as butanediol, pentanediol, and hexanediol. Examples include diols. Examples of such triols include polyethylene triol and polypropylene triol.

  Moreover, the compound containing a nitrogen atom and / or a phosphorus atom can be used as a plasticizer (B). Such a compound is preferable from the viewpoint of flame retardancy. From the viewpoint of the plasticizing effect, the plasticizer (B) preferably has a carbon-carbon double bond and / or an alkyl oxide chain and / or an ester bond.

  Examples of the compound containing a nitrogen atom include CIC acid, bis CIC acid, N-butylbenzenesulfonamide and the like.

  Examples of the compound containing a nitrogen atom and having a carbon-carbon double bond include isocyanuric acid EO-modified triacrylate, isocyanuric acid EO-modified diacrylate, ε-caprolactone-modified tris (acryloxyethyl) isocyanurate, triallyl isocyanurate, , 3,5-triacryloylhexahydro-s-triazine, triallyl 1,3,5-benzenecarboxylate, triallylamine, N-acryloyloxyethylhexahydrophthalimide, urethane acrylate having a polyalkyl oxide chain, and the like.

  Examples of the compound containing a nitrogen atom and having an alkyl oxide chain include urethane acrylate having a polyalkyl oxide chain described above.

  Examples of the compound containing a nitrogen atom and having an ester bond include isocyanuric acid EO-modified triacrylate, isocyanuric acid EO-modified diacrylate, ε-caprolactone-modified tris (acryloxyethyl) isocyanurate, triallyl isocyanurate, 1, 3, 5 -Triacryloyl hexahydro-s-triazine, triallyl 1,3,5-benzenecarboxylate, triallylamine, N-acryloyloxyethyl hexahydrophthalimide and the like.

  As compounds containing a phosphorus atom, 10- (2,5-dihydroxyphenyl) -10-H-9-oxa-10-phosphananthrene-10-oxide, 9,10-dihydro-9-oxa-10-phos Examples include phaphenanthrene-10-oxide.

  Examples of the compound containing a phosphorus atom and having a carbon-carbon double bond include triallyl phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxyethyl acid phosphate, acid phosphooxypolyoxyethylene glycol methacrylate, and acid phospho. Examples thereof include oxypolyoxypropylene glycol methacrylate.

  Examples of the compound containing a phosphorus atom and having an alkyl oxide chain include 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxyethyl acid phosphate, acid phosphooxypolyoxyethylene glycol methacrylate, and acid phosphooxypolyoxy. Examples thereof include compounds such as propylene glycol methacrylate and compounds such as tris (butoxyethyl) phosphate.

  Examples of the compound containing a phosphorus atom and having an ester bond include phosphate ester compounds and aromatic condensed phosphate esters. Examples of the phosphate ester compound include trimethyl phosphate, triethyl phosphate, triphenyl phosphate, trigresyl phosphate, trisylenyl phosphate, cresyl diphenyl phosphate, cresyl di-2,6, -xylenyl phosphate, bis (2 -Ethylhexyl) phosphate, 2-ethylhexyl-2-ethylhexyl phosphonate, tributyl phosphate, tris (2-ethylhexyl) phosphate, tris (butoxyethyl) phosphate, 2-ethylhexyl diphenyl phosphate, and the like. Examples of the aromatic condensed phosphate ester include resorcinol bis (diphenyl phosphate), bisphenol A bis (diphenyl phosphate), resorcinol bis (dicresyl phosphate), resorcinol bis (dixylenyl phosphate), and the like.

  Among these plasticizers, tris (butoxyethyl) phosphate and ε-caprolactone-modified tris (acryloxyethyl) isocyanurate are particularly preferable because of their high plasticizing effect. These plasticizers (B) may be used alone or in combination of two or more. Moreover, the plasticizer (B) may contain a solvent, a polymerization inhibitor, a stabilizer, and the like.

  The resin composition of the present invention contains a photoreactive compound (C) and can be used as a photosensitive film. As the photoreactive compound (C), a quinonediazide compound is preferably used from the viewpoint of alkali developability.

（式中Ｑは、水素原子、式（５）、のいずれかから選ばれるものである。但し、各化合物中のＱのうち少なくとも１つは化学式（５）から選ばれるものである。）

Examples of the quinonediazide compound include an orthoquinonediazide compound, and examples thereof include an orthobenzoquinonediazide compound, an orthonaphthoquinonediazide compound, and an orthoquinolinequinonediazide compound, and among them, an orthonaphthoquinonediazide compound is preferable. Specifically, for example, a compound represented by the chemical formula (4) is preferable.

(In the formula, Q is selected from any one of a hydrogen atom and formula (5), provided that at least one of Q in each compound is selected from chemical formula (5).)

  As shown in formula (5), orthonaphthoquinonediazide includes 1,2-naphthoquinonediazide-4-sulfonic acid ester (right of formula (5)) and 4-position 1, There is 2-naphthoquinonediazide-5-sulfonic acid ester (formula (5) left), any of which may be used, but 1,2-naphthoquinonediazide-5-sulfonic acid ester is preferred from the viewpoint of mechanical properties.

  The resin composition of the present invention forms a film and can be processed into a laminated film including a carrier film. The laminated film may include a cover film.

  As a carrier film, arbitrary carrier films, such as a polyethylene terephthalate film and a metal film, can be used, for example.

  As the cover film, for example, any antifouling film such as a low-density polyethylene film or a protective film can be used.

  Moreover, the coverlay film of a flexible printed circuit board can be produced using this laminated film. In that case, the step of performing the heat treatment is preferably performed after the coverlay film is formed on the flexible printed board. When a photosensitive film is used as the cover film, after laminating the coverlay film on the flexible printed circuit board, a desired pattern is obtained through at least a step of exposing the coverlay film and a step of developing with an alkali developer. After forming on a flexible printed circuit board, it can heat-process as needed.

  When laminating a coverlay film on a flexible printed circuit board, it can be laminated on a substrate having wiring by any method such as a thermal laminating method, a hot pressing method, a thermal vacuum laminating method, or a thermal vacuum pressing method.

  Although there is no restriction | limiting in particular in the film thickness of the coverlay formed by these methods, From points, such as a circuit characteristic, it is preferable that they are 4 micrometers-50 micrometers, It is more preferable that they are 6 micrometers-40 micrometers, It is 10 micrometers-30 micrometers. It is particularly preferred.

  The light source used for the exposure is not particularly limited, and examples thereof include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a xenon lamp, a fluorescent lamp, a tungsten lamp, an argon laser, and a helium cadmium laser.

  The aqueous alkali solution used for development is not particularly limited, and examples thereof include an aqueous sodium carbonate solution, an aqueous potassium hydroxide solution, an aqueous sodium hydroxide solution, and an aqueous tetramethylammonium hydroxide solution. Although there is no restriction | limiting in particular as a developing method, For example, immersion development, paddle development, and spray development are mentioned.

  Heating may be performed in either an air atmosphere or a nitrogen atmosphere. Moreover, there is no restriction | limiting in particular as a heating method, However, It can carry out using oven, a baking furnace, a hotplate, etc.

  Although it is essential to perform the heating temperature at a temperature that satisfies the above-described conditions, 140 to 200 ° C. is preferable from the viewpoint of not damaging the FPC.

  In this way, a base material having wiring, and a coverlay formed on the base material so as to cover the wiring and made of a substance obtained by exposing, developing, and heating the film of the present embodiment, , A flexible printed wiring board can be produced.

Next, a method for measuring T1 (° C.), T2 (° C.), and T3 (° C.) will be described.
Regarding the exothermic start temperature T1 (° C.) of the exotherm seen when only the plasticizer (B) is heated, a commercially available monomer component containing a polymerization inhibitor, a stabilizer, a solvent, etc. is used as the plasticizer (B). When using, the measured value when it measures with a thermal analysis instrument as it is can be used, without removing those polymerization inhibitors, stabilizers, solvents, and the like.

  Regarding the heat generation start temperature T2 (° C.) of the heat generated when the composition (composition (a)) obtained by mixing the resin (A) and the plasticizer (B) is heated, the resin (A) and the plasticizer ( B) can be mixed in a suitable solvent and dried, and the measured value obtained by measuring a film composed of the composition (composition (a)) obtained by drying with a thermal analyzer can be used. . The compounding ratio of the resin (A) and the plasticizer (B) in the composition (a) is the resin (A) in the resin composition containing the resin (A) and the plasticizer (B) of the present invention. It is necessary to match the blending ratio with the plasticizer (B).

  At that time, the film produced only with the resin (A) was also measured under the same conditions, and the heat generated by the composition (composition (a)) in which the resin (A) and the plasticizer (B) were mixed was generated. It is desirable to confirm that the heat is derived from the plasticizer (B).

  The resin composition containing the resin (A) and the plasticizer (B) of the present invention may contain a photoreactive compound (C) and the like in addition to the resin (A) and the plasticizer (B). The glass transition point T3 (° C.) of the resin composition before the heat treatment of the resin composition is such that the resin (A) and the plasticizer (B) are further mixed with a photoreactive compound (C) or the like as an appropriate solvent. The measured value at the time of measuring the film obtained by drying after mixing in a thermal-analysis apparatus can be used.

  For the measurement of T1 (° C.) and T2 (° C.), for example, differential thermal analysis (hereinafter referred to as DTA) or differential scanning calorimetry (hereinafter referred to as DSC) can be used. The measurement is performed in an air atmosphere, and the heating rate during measurement is preferably 10 ° C./min from the viewpoint of measurement accuracy. As the heat generation start point, the value of the intersection of the tangent line extrapolating the slope of the baseline and the tangent line extrapolated from the point where the slope of the middle of the heat generation peak is substantially constant is used.

  T3 (° C.) can be measured by using a tensile measurement of a thermomechanical analyzer (hereinafter referred to as TMA). The gradient of the change curve of the linear expansion coefficient with respect to the temperature obtained by the TMA tensile measurement changes remarkably at a certain temperature region. The heating rate during measurement is preferably 10 ° C./min from the viewpoint of measurement accuracy. The glass transition point is the value of the intersection of the tangent line extrapolating the slope in the low temperature region of the change curve and the tangent line extrapolating the slope in the high temperature region.

  The resin composition according to the present invention may further contain a photosensitizer. There is no restriction | limiting in particular as a photosensitizer, A well-known photosensitizer can be used. For example, aromatic azides such as azidoanthraquinone and azidobenzalacetophenone; coumarin compounds such as coumarin, ketocoumarin, 3,3′-carbonylbis (diethylaminocoumarin) and 3-ketocoumarin; Aromatic ketones such as benzophenone and p, p′-tetramethyldiaminobenzophenone; N-phenyldiethanolamine, N-phenylglycine, p-nitroaniline, 2,4-dinitroaniline, 2-chloro-4-nitroaniline 2, Aromatic amines such as 6-dinitro-4-nitroaniline and Michlerketone; thioxanthone compounds such as thioxanthone, diethylthioxanthone and isopropylthioxanthone; anthracene, naphthalene, diphenyl, p Aromatic hydrocarbons such as nitro diphenyl; anthraquinone, naphthoquinone, quinones such as benzoquinone, and the like. In addition, for example, coumarin compounds having a heterocyclic ring described in JP-A-3-239703 and JP-A-5-289335; 3-ketocoumarin compounds described in JP-A-63-221110; JP-A-4-221958 Xanthene dyes described in JP-A-4-219756; pyromethene dyes described in JP-A-6-19240; JP-A-47-2528; JP-A-54-155292; (P-dialkylaminobenzylidene) ketones and styryl dyes described in JP-A-56-166154 and JP-A-59-56403; sensitizing dyes having a julolidyl group described in JP-A-6-295061; The diaminobenzene compound described in 11-326624 gazette can be mentioned. Of these, compounds having absorption in the vicinity of 300 to 450 nm are preferable, and specifically, coumarin compounds, thioxanthone compounds, and aromatic ketones are preferable.

  A known additive can be added to the resin composition of the present invention as needed within a quantitative and qualitative range that does not depart from the effects of the present invention. Specifically, adhesion improvers, surfactants, antioxidants, UV inhibitors, light stabilizers, plasticizers, waxes, fillers, pigments, dyes, foaming agents, antifoaming agents, dehydrating agents, charging Examples thereof include an inhibitor, an antibacterial agent, an antifungal agent, a leveling agent, and a dispersant.

Next, examples performed for clarifying the effects of the present invention will be described.
[Polyimide Synthesis Example 1]
A 1-liter separable three-necked flask equipped with a stirrer was equipped with a ball condenser equipped with a moisture meter. Under a nitrogen stream, 268.52 g of γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.), 31.02 g (100 mmol) of 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride (manufactured by Manac Corporation) ), 1,3-bis (3-aminopropyl) polysiloxane 68.55 g (75 mmol) (molecular weight 916 / manufactured by Shin-Etsu Chemical Co., Ltd .: KF-8010), 3,5-diaminobenzoic acid 7.61 g (50 Mmol) (manufactured by Aldrich) was added and stirred at room temperature for 2 hours.

  The above flask was charged with 1.5 g (15 mmol) of γ-valerolactone, 2.4 g (30 mmol) of pyridine, and 50 g of toluene, heated to 180 ° C., and 2 at 180 rpm while removing the azeotrope of toluene-water. Stir for hours. After allowing to cool to room temperature, 20.62 g (50 mmol) of ethylene glycol bis (trimellitic acid monoester anhydride) (manufactured by Shin Nippon Rika Co., Ltd .: Ricacid TMEG-100), 1,3-bis (4-aminophenoxy) 7.31 g (25 mmol) of benzene (manufactured by Wakayama Seika Co., Ltd.) and 166.21 g of γ-butyrolactone were charged and stirred at room temperature for 2 hours. Thereafter, the temperature was raised to 180 ° C., the mixture was stirred at 180 rpm for 2 hours while removing the toluene-water azeotrope, and then allowed to cool. The polymer concentration of the obtained polyimide solution was 25% by weight. This polyimide solution was used for production of the composition (a) and the resin composition as they were.

[Measurement of T1 (° C)]
The heat generation start temperature T1 (° C.) of the plasticizer is determined by measuring DTA by increasing the temperature from 40 ° C. to 250 ° C. at 10 ° C./min using TG / DTA6200 (manufactured by SII Nano Technology). did.

As the plasticizer (B), the following plasticizer B1, plasticizer B2, and plasticizer B3 were used.
Plasticizer B1: ε-caprolactone modified tris (acryloxyethyl) isocyanurate (manufactured by Toagosei Co., Ltd .: Aronix M-327 Toluene less than 1%, containing polymerization inhibitor)
Plasticizer B2: Tris (butoxy ethyl) phosphate (manufactured by Daihachi Chemical Industry Co., Ltd .: TBXP)
Plasticizer B3: Cresol novolac type epoxy acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK Oligo EA7420 / PGMAC average molecular weight about 3200 / solid content 70%, propylene glycol monomethyl ether acetate 30%, containing polymerization inhibitor)
Each exothermic starting point T1 (° C.) was as follows.
Plasticizer B1: T1 (° C.) = 188 ° C.
Plasticizer B2: T1 (° C.) = 248 ° C.
Plasticizer B3: T1 (° C.) = 216 ° C.

（表１中、樹脂（Ａ）の配合量はポリイミド溶液中に含まれるポリイミド成分の値である。） [Formulation Example 1]
For the resin (A), the polymer synthesized in Polyimide Synthesis Example 1 was used. Moreover, B1, B2, B3 mentioned above was used for the plasticizer (B). Formulation examples are shown in Table 1 below.

(In Table 1, the compounding amount of the resin (A) is the value of the polyimide component contained in the polyimide solution.)

[Composition (a) Film production]
The resin composition varnish produced with the formulation shown in Table 1 above was coated on a 25 μm thick PET film (T100-H25 / Mitsubishi Chemical Polyester Film Co., Ltd.) with a blade coater and then dried in an oven at 95 ° C./30 minutes. After obtaining a dry film, the PET film was peeled off and the film was isolated.

[Measurement of T2 (° C)]
T2 (° C.) was determined by measuring DTA under the same conditions as the measurement of T1 (° C.). The sample used was a film obtained by the production of the composition (a) film. From the measurement results, it was determined whether or not there was any heat generation or whether it corresponds to Equation (1). The results are shown in Table 3 below.

（表２中、樹脂（Ａ）の配合量はポリイミド溶液中に含まれるポリイミド成分の値である。） [Formulation Example 2]
For the resin (A), the polymer synthesized in Polyimide Synthesis Example 1 was used. As the plasticizer (B), B1, B2, and B3 described above were used. Moreover, the following photoreactive compound C1 and photoreactive compound C2 were used for the photoreactive compound (C). Formulation examples are shown in Table 2 below.
Photoreactive compound C1: α, α, α′-tris (4-hydroxyphenyl) -1-ethyl-4isopropyl-benzene (1 mol) and 4-diazo-4,5-dihydro-5-oxonaphthalene-1 -Ester with sulfonic acid (2.8 mol) Photoreactive compound C2: α, α, α'-tris (4-hydroxyphenyl) -1-ethyl-4isopropyl-benzene (1 mol) and 4-diazo- Esters with 4,5-dihydro-4-oxonaphthalene-1-sulfonic acid (2.3 mol)

(In Table 2, the compounding amount of the resin (A) is the value of the polyimide component contained in the polyimide solution.)

[Resin composition film production 1]
The resin composition prepared with the composition shown in Table 2 above was coated on a 25 μm thick PET film (T100-H25 / Mitsubishi Chemical Polyester Film Co., Ltd.) with a blade coater, then dried in an oven at 95 ° C./30 minutes and dried. After obtaining the film, the PET film was peeled off, and the film made of the resin composition was isolated.

[Measurement of T3 (° C)]
T3 was determined by increasing the temperature at 40 ° C. to 250 ° C. at 10 ° C./min using TMA / SS6100 (manufactured by SII Nanotechnology Co., Ltd.) and measuring TMA. As the sample, the film obtained in Resin Composition Film Production 1 was used, and the size was 4 mm wide × 10 mm long × about 20 μm thick. From the measurement results, it was determined whether or not T3 falls below 100 ° C. The results are also shown in Table 3 below.

[Resin composition film production 2]
The resin composition prepared with the formulation shown in Table 2 above was coated on a glossy surface of a 12 μm thick copper foil with a blade coater, dried in an oven at 95 ° C./30 minutes to obtain a film, and then the film on the copper foil Was heated in air in an oven at 120 ° C. for 1 hour, and then heat-treated at each heat treatment temperature for 1 hour. After the heat treatment, the copper foil was etched with an iron chloride solution, and the film was isolated.

[Mechanical properties measurement]
The film obtained in Resin Composition Film Preparation 2 was conditioned for 24 hours under constant temperature and humidity conditions of 23 ° C./45% humidity, and then measured for mechanical properties. Mechanical properties were evaluated by conducting a tensile test using a Tensilon universal testing machine RTG-1210 (manufactured by A & D Co., Ltd.). A load cell of 500N was used, the pulling speed was 100 mm / min, and the sample piece was 5 mm wide × 50 mm long × about 20 μm thick. The evaluation results are also shown in Table 3 below, where ◯ indicates that the measured elongation of the film is 20% or more and x indicates that the elongation is less than 20%.

（表３中、「発熱なし又はＴ１＋１５℃＜Ｔ２」の欄の○は、発熱なし又はＴ１＋１５℃＜Ｔ２を満たすことを意味し、×は、発熱なし又はＴ１＋１５℃＜Ｔ２に該当しないことを意味する。「Ｔ３≦１００℃」の欄の○は、ガラス転移点Ｔ３が１００℃以下であることを意味し、×は、ガラス転移点が１００℃より高いことを意味する。「１２０℃≦Ｔ４＜Ｔ２」の欄の○は、加熱処理温度Ｔ４が発熱開始点Ｔ２より低い温度であることを意味し、×は加熱処理温度Ｔ４が発熱開始点Ｔ２より高い温度であることを意味する。ただし組成物（ａ）の発熱がない場合は加熱処理温度が１２０℃以上であれば○とした。「機械物性」の欄の○は、測定したフィルムの伸度が２０％以上であることを意味し、×は２０％未満であることを意味する。） [Evaluation example]

(In Table 3, ○ in the column of “No heat generation or T1 + 15 ° C. <T2” means no heat generation or satisfies T1 + 15 ° C. <T2, and x means no heat generation or does not fall under T1 + 15 ° C. <T2. “O” in the column of “T3 ≦ 100 ° C.” means that the glass transition point T3 is 100 ° C. or less, and “X” means that the glass transition point is higher than 100 ° C. “120 ° C. ≦ T4”. In the column <T2>, “◯” means that the heat treatment temperature T4 is lower than the heat generation start point T2, and “x” means that the heat treatment temperature T4 is higher than the heat generation start point T2. In the case where the composition (a) does not generate heat, the heat treatment temperature was 120 ° C. or more, and “◯” in the column of “mechanical properties” means that the measured film elongation was 20% or more. X means less than 20%.

[FPC coverlay production]
A resin composition prepared by blending 1-2, blending 2-2, blending 3-2, blending 5-2, and blending 6-2 was used as a 25 μm thick PET film (T100-H25 / Mitsubishi Chemical Polyester Film Co., Ltd.). Manufactured) and then dried in an oven at 95 ° C. for 30 minutes to obtain a dry film. Using the obtained dry film, AL-700 (manufactured by Asahi Kasei Co., Ltd.), an FPC board having a test pattern with a copper pattern height of 12 μm L / S = 100 μm / 100 μm, with a substrate residual heat of 60 ° C. and a laminating temperature of 140 ° C. Lamination was performed under conditions of 0.34 MPa and 0.5 m / min, and after laminating on the FPC substrate, the PET film was peeled off to obtain a coverlay on the FPC substrate.

The obtained coverlay was subjected to contact exposure with an ultrahigh pressure mercury lamp (HMW-201KB / Oak Co., Ltd.) using a positive mask. The exposure amount was 1,300 mJ / cm ² . The development was performed by spray development with a 3% aqueous sodium hydroxide solution at a development temperature of 40 ° C. and a spray pressure of 0.2 MPa. Spray water washing was performed with distilled water at 40 ° C. and a spray pressure of 0.2 MPa, and the resulting pattern was observed with an optical microscope. It was possible to form a 100 μm circular hole pattern in any coverlay.

[Polyimide synthesis example 2]
A 1-liter separable three-necked flask equipped with a stirrer was equipped with a ball condenser equipped with a moisture meter. Under a nitrogen stream, 341-64 g of γ-butyrolactone (manufactured by Wako Pure Chemical Industries, Ltd.), 31.02 g (100 mmol) of oxydiphthalic dianhydride (manufactured by Manac Corporation), 1,3-bis (3-aminopropyl) ) 68.55 g (75 mmol) of polysiloxane (molecular weight 914 / manufactured by Shin-Etsu Chemical Co., Ltd.), 14.31 g (50 mmol) of 3,3′-dicarboxy-4,4′-diaminodiphenylmethane (Wakayama Seika Co., Ltd.) Prepared) and stirred at room temperature for 2 hours.

  The above flask was charged with 1.5 g (15 mmol) of γ-valerolactone, 2.4 g (30 mmol) of pyridine, and 50 g of toluene, heated to 180 ° C., and 2 at 180 rpm while removing the azeotrope of toluene-water. Stir for hours. After allowing to cool to room temperature, 20.62 g (50 mmol) of 1,2- (ethylene) bis (trimellitate anhydride) (manufactured by Nippon Nippon Chemical Co., Ltd.), 7.31 g of 1,3-bis (3-aminophenoxy) benzene ( 25 mmol) (manufactured by Wakayama Seika Co., Ltd.) and 67.59 g of γ-butyrolactone were charged and stirred at room temperature for 2 hours. Thereafter, the temperature was raised to 180 ° C., the mixture was stirred at 180 rpm for 2 hours while removing the toluene-water azeotrope, and then allowed to cool. The polymer concentration of the obtained polyimide solution was about 25% by weight. This polyimide solution was used for production of the composition (a) and the resin composition as they were.

  In Example 9, the resin (A) of Formulation 2-1 and Formulation 2-2 was replaced with the resin described in [Polyimide Synthesis Example 2], and the heat treatment temperature T4 was set to 180 ° C. Evaluation was performed in the same manner. As a result, “no heat generation or T1 + 15 ° C. <T2” was “good”, “T3 ≦ 100 ° C.” was “good”, “120 ° C. ≦ T4 <T2” was “good”, and “mechanical properties” were “good”.

  In Example 10, evaluation was performed in the same manner as in Example 4 except that the resin (A) in Formulation 5-1 and Formulation 5-2 was replaced with the resin described in [Polyimide Synthesis Example 2]. As a result, “no heat generation or T1 + 15 ° C. <T2” was “good”, “T3 ≦ 100 ° C.” was “good”, “120 ° C. ≦ T4 <T2” was “good”, and “mechanical properties” were “good”.

  As is clear from the evaluation examples, it was found that the film of the present embodiment has good mechanical properties and is suitable for an FPC coverlay.

  The present invention is not limited to the embodiment described above, and can be implemented with various modifications. It is not limited to this about the numerical value and component in the said embodiment, It is possible to change suitably and to implement. In addition, various modifications can be made without departing from the scope of the present invention.

  The resin composition of the present invention can be applied to a photosensitive film using photolithography capable of alkali development, and can be suitably used as an FPC coverlay.

Claims (15)

In the resin composition containing the resin (A) and the plasticizer (B), the heat generation start temperature of the heat generated when only the plasticizer (B) is heated is T1 (° C.), and the resin (A) And T2 (° C.) as the exothermic starting temperature of the exotherm seen when the composition (composition (a)) mixed with the plasticizer (B) is heated, and the glass transition point of the resin composition is T3 ( )), The composition (composition (a)) does not generate heat when heated or satisfies the following formula (1), and T3 satisfies the following formula (2) A resin composition characterized by the above.
T1 + 15 ° C. <T2 Formula (1)
(However, T2 (° C) is 250 ° C or less)
T3 ≦ 100 ° C. Formula (2) It is a resin composition obtained by heat-processing the resin composition of Claim 1, Comprising: Temperature T4 (degreeC) of the said heat processing satisfy | fills following formula (3), The resin composition characterized by the above-mentioned.
120 ° C. ≦ T4 <T2 Formula (3)   The resin composition according to claim 1 or 2, wherein the resin (A) is polyimide.   The resin composition according to claim 3, wherein the polyimide has a silicone skeleton.   The resin composition according to claim 3 or 4, wherein the polyimide has a hydroxyl group and / or a carboxyl group.   The resin composition according to any one of claims 1 to 5, wherein the plasticizer (B) has a molecular weight of 1000 or less.   The resin composition according to any one of claims 1 to 6, wherein the plasticizer (B) is a compound containing a nitrogen atom and / or a phosphorus atom.   The plasticizer (B) containing the nitrogen atom and / or phosphorus atom has at least one selected from the group consisting of a carbon-carbon double bond, an alkyl oxide chain, and an ester bond. Item 8. The resin composition according to Item 7.   The resin composition according to any one of claims 1 to 8, wherein the plasticizer (B) is 50 parts by weight or less with respect to 100 parts by weight of the resin (A).   The resin composition according to claim 1, comprising a photoreactive compound (C).   The resin composition according to claim 10, wherein the photoreactive compound (C) is a quinonediazide compound.   A film comprising the resin composition according to any one of claims 1 to 11.   A laminated film comprising: the film according to claim 12; and a carrier film provided on the film.   The laminated film according to claim 13, further comprising a cover film.   A substrate having wiring and a cover lay formed on the substrate so as to cover the wiring and configured by the film or laminated film according to any one of claims 12 to 14. A flexible printed wiring board characterized by