KR20200027969A - Laminated structure, dry film and flexible printed wiring board - Google Patents

Abstract

A flexible printed wiring board having, as a protective film, a laminated structure, a dry film, and a cured product thereof, which have so far exhibited high flexibility and particularly excellent crack resistance against excessive seam folding. It is a laminated structure which has the resin layer (A) and the resin layer (B) laminated | stacked on a flexible printed wiring board through the resin layer (A). The resin layer (B) consists of a photosensitive thermosetting resin composition comprising an alkali-soluble resin, a photopolymerization initiator, a heat-reactive compound and a block copolymer, and the resin layer (A) comprises an alkali-soluble resin and a heat-reactive compound. It consists of an alkali developing resin composition.

Description

Laminated structure, dry film and flexible printed wiring board

The present invention relates to a laminate structure, a dry film, and a flexible printed wiring board (hereinafter also simply referred to as a "wiring board") useful as an insulating film for a flexible printed wiring board.

In recent years, with the spread of smartphones and tablet terminals, the miniaturization of electronic devices has reduced the size of circuit boards. For this reason, the use of flexible printed wiring boards that can be bent and stored is expanded, and the flexible printed wiring boards are also required to have higher reliability than ever.

On the other hand, currently, as an insulating film for securing insulation reliability of a flexible printed wiring board, a polyimide-based coverlay having excellent mechanical properties such as heat resistance and flexibility is used as a bent portion (bending portion) (for example, a patent) Literatures 1 and 2), and a mixing process using a photosensitive resin composition that is excellent in electrical insulation, solder heat resistance, and the like, and that can be finely processed, is widely adopted for the mounting portion (non-bending portion).

That is, a polyimide-based coverlay is not suitable for fine wiring because processing by mold punching is required. Therefore, it was necessary to partially use an alkali developing type photosensitive resin composition (solder resist) capable of processing by photolithography in a chip mounting portion requiring fine wiring.

Japanese Patent Publication No. 62-263692 Japanese Patent Publication No. 63-110224

As described above, in the manufacturing process of the conventional flexible printed wiring board, the mixing process of the process of butting the coverlay and the process of forming the solder resist is compelled, and there is a problem in that cost and workability are poor.

On the other hand, until now, it has been considered to apply an insulating film as a solder resist or an insulating film as a coverlay as a solder resist and a coverlay of a flexible printed wiring board. However, in response to the demand for small space of the circuit board, the solder resist and a coverlay A material capable of satisfactorily satisfying both required performances has not yet been put to practical use.

Specifically, when a flexible printed wiring board is accommodated in a device in response to the demand for a small space of the circuit board, the flexible printed wiring board on which the components are mounted is bent in a state of seam folding to be accommodated. For this reason, a load is applied to the flexible printed wiring board and its insulating film in a seam-folded state, but in this regard, it has not been developed a material that can still sufficiently satisfy the required performance of both the solder resist and the coverlay. Was. Here, shim folding means bending the upper surface side of the flexible printed wiring board by 180 °. For this reason, flexible printed wiring boards have been required to have an insulating film suitable for a solder resist and a coverlay having a high bending property, and particularly excellent crack resistance even if excessively seam folding is performed.

Therefore, the main object of the present invention is to provide a laminated structure that satisfies the required performance of both the solder resist and the coverlay, and has excellent flexural properties, particularly excellent seam resistance even when excessively seam folding. In addition, another object of the present invention is a protective film, for example, an insulating film of a flexible printed wiring board, particularly a laminated structure, a dry film, and a cured product suitable for the batch forming process of a bent part (bent part) and a mounting part (non-bent part), for example It is to provide a flexible printed wiring board having as a coverlay or solder resist.

The present inventors have studied earnestly to solve the above problems, and have come to complete the present invention.

That is, the laminated structure of the present invention is a laminated structure having a resin layer (A) and a resin layer (B) laminated on a flexible printed wiring board through the resin layer (A),

The resin layer (B) is composed of a photosensitive thermosetting resin composition comprising an alkali-soluble resin, a photopolymerization initiator, a heat-reactive compound and a block copolymer, and the resin layer (A) is an alkali-soluble resin and a heat-reactive compound. It is characterized by comprising an alkali developing type resin composition.

In the laminated structure of the present invention, it is preferable that the block copolymer has a structure represented by the following formula (I), and the mass average molecular weight (Mw) of the block copolymer is suitably 20,000 to 400,000.

X-Y-X (I)

(In formula (I), X is a polymer unit with a glass transition point Tg of 0 ° C or higher, and may be the same or different, and Y is a polymer unit with a glass transition point Tg of less than 0 ° C.)

Moreover, in the laminated structure of this invention, it is preferable to contain a photobase generator as a photoinitiator of the said resin layer (B). Further, in the laminated structure of the present invention, it is preferable that the resin layer (A) is made of an alkali-developing resin composition that does not contain a photopolymerization initiator.

The laminated structure of the present invention can be used for at least one of a bent portion and a non-flexed portion of a flexible printed wiring board, and can also be used for at least one of a coverlay, a solder resist, and an interlayer insulating material of the flexible printed wiring board.

In addition, the dry film of the present invention is characterized in that at least one side of the laminated structure of the present invention is supported or protected by a film.

Further, the flexible printed wiring board of the present invention is characterized by having an insulating film using the laminated structure of the present invention.

Here, the flexible printed wiring board of the present invention may have an insulating film formed by forming a layer of the laminate structure of the present invention on the flexible printed wiring board, patterning it by light irradiation, and collectively forming a pattern with a developer. Further, without using the laminated structure according to the present invention, the resin layer (A) and the resin layer (B) are sequentially formed on a flexible printed wiring board, and then patterned by light irradiation, and the pattern is collectively formed with a developer. It may have an insulating film formed. In addition, in the present invention, "pattern" means a patterned cured product, that is, an insulating film.

According to the present invention, it is possible to provide a laminate structure that satisfies the required performances of both the solder resist and the coverlay, and has higher flexural properties than above, particularly excellent crack resistance even when excessive seam folding is performed. In addition, an insulating film of a flexible printed wiring board, in particular, a laminate structure, a dry film, and a cured product suitable for the batch forming process of a bent portion (bending portion) and a mounting portion (non-bending portion) having a protective film, such as a coverlay or a solder resist It became possible to realize a flexible printed wiring board.

1 is a process diagram schematically showing an example of a method for manufacturing a flexible printed wiring board of the present invention.
2 is a process diagram schematically showing another example of the method for manufacturing a flexible printed wiring board of the present invention.
3 is a schematic explanatory diagram showing an MIT test in an example.
4 is a schematic explanatory diagram showing a seam folding test in Examples.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

(Laminated structure)

The laminated structure of the present invention has a resin layer (A) and a resin layer (B) laminated on a flexible printed wiring board through the resin layer (A). Here, in the laminated structure of the present invention, the resin layer (A) and the resin layer (B) function substantially as adhesive layers and protective layers, respectively. The layered structure of the present invention, while the resin layer (B) is made of a photosensitive thermosetting resin composition comprising an alkali-soluble resin, a photopolymerization initiator, a heat-reactive compound and a block copolymer (also referred to as "block copolymer" (BCP)), can be The base layer (A) is characterized by comprising an alkali developing resin composition containing an alkali-soluble resin and a heat-reactive compound.

In the present invention, by containing a block copolymer in the resin layer (B) on the upper layer side of the laminated structure formed by laminating two layers of resin layers, the above-mentioned high bending property, particularly excellent crack resistance against excessive seam folding, and It became possible to realize excellent heat resistance with a good balance.

In other words, such a laminated structure of the present invention has a resin layer (A) and a resin layer (B) on a flexible printed wiring board in which a copper circuit is formed on a flexible substrate, and the resin layer (B) on the upper layer side is irradiated with light. It consists of a photosensitive thermosetting resin composition which can be patterned by, and even if the resin layer (A) of the lower layer side does not contain a photopolymerization initiator, it is possible to form a pattern by the resin layer (B) and the resin layer (A) collectively by development. It becomes.

The reason is that, when the resin layer (A) on the printed wiring board side does not contain a photopolymerization initiator, in general, this resin layer (A) cannot be patterned as a single layer, but in the laminated structure of the present invention, during exposure This is because active species such as radicals generated from the photopolymerization initiator contained in the resin layer (B) of the upper layer diffuse into the resin layer (A) immediately below, so that both layers can be patterned simultaneously.

[Resin layer (A)]

(Alkali development type resin composition)

The alkali developing type resin composition constituting the resin layer (A) may be a composition containing an alkali-soluble resin developable with an alkali solution and a heat-reactive compound, containing at least one functional group among phenolic hydroxyl groups and carboxyl groups. Preferably, a resin composition containing a compound having a phenolic hydroxyl group, a compound having a carboxyl group, a compound having a phenolic hydroxyl group and a carboxyl group is used, and a known conventional one is used.

For example, a resin composition containing a carboxyl group-containing resin or a carboxyl group-containing photosensitive resin, a compound having an ethylenically unsaturated bond, and a heat-reactive compound, which has been conventionally used as a solder resist composition.

Here, as a compound having a carboxyl group-containing resin or a carboxyl group-containing photosensitive resin, and an ethylenically unsaturated bond, a known conventional compound is used,

Moreover, as a heat-reactive compound, the well-known conventional compound which has the functional group capable of hardening reaction by heat, such as a cyclic (thio) ether group, the same as the heat-reactive compound used in the resin layer (B) is used.

Although such resin layer (A) may or may not contain a photoinitiator, the same photopolymerization initiator used in the resin layer (B) is used as the photopolymerization initiator used when the photopolymerization initiator is included.

Further, in the present invention, it is necessary to contain the block copolymer in the resin layer (B), but the resin layer (A) also does not affect the effects of the present invention, that is, the required performance of both the solder resist and the coverlay. You may contain a block copolymer to an extent. As a block copolymer in this case, the same thing as the block copolymer used in the resin layer (B) can be used. The blending amount of the block copolymer in the resin layer (A) is preferably 15 parts by mass or less, more preferably 3 parts by mass or less, and particularly preferably, the resin layer ( The block copolymer is not contained in A), but only in the resin layer (B). When the blending amount of the block copolymer is 15 parts by mass or less, the developability, flexibility, crack resistance and heat resistance are not affected.

[Resin layer (B)]

(Photosensitive thermosetting resin composition)

The photosensitive thermosetting resin composition constituting the resin layer (B) includes an alkali-soluble resin, a photopolymerization initiator, a heat-reactive compound, and a block copolymer.

(Alkali soluble resin)

As the alkali-soluble resin, the same conventionally used one as the resin layer (A) can be used, but a carboxyl group-containing resin having at least one of an imide structure and an amide structure, which is more excellent in properties such as bending resistance and heat resistance, is suitably used. Can be used.

Examples of the carboxyl group-containing resin having at least one of the imide structure and the amide structure include (1) a carboxyl group-containing resin having an imide structure and an amide structure, and (2) a carboxyl group-containing resin having an imide structure and not having an amide structure. And (3) carboxyl group-containing resins having an amide structure and no imide structure, and these resins can be used alone or as a mixture of two or more. In the present invention, it is preferable to use a carboxyl group-containing resin having an imide structure and an amide structure among carboxyl group-containing resins having at least one of an imide structure and an amide structure.

Moreover, the carboxyl group-containing resin having at least either of an imide structure and an amide structure may further have a phenolic hydroxyl group.

(1) A carboxyl group-containing resin having an imide structure and an amide structure

The carboxyl group-containing resin having an imide structure and an amide structure is preferably a polyamideimide resin, for example, diamine containing at least carboxyl group-containing diamine and at least three carboxyl groups, and an acid in which two of them are anhydrous It can be obtained by reacting an acid anhydride containing anhydride (a1) to obtain an imide, and then reacting the obtained imide with a reaction raw material containing a diisocyanate compound. As described later, it is preferable that the reaction raw material further contains an acid anhydride (a2) having at least three carboxyl groups and two of them anhydrous in addition to the imide and diisocyanate compounds.

Here, as the diamine used in the synthesis of the polyamideimide resin, at least a carboxyl group-containing diamine is included, but it is preferable to use a diamine having an ether bond in combination.

Examples of the carboxyl group-containing diamine include diaminobenzoic acids such as 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, and 3,4-diaminobenzoic acid, 3,5-bis (3-aminophenoxy) Aminophenoxybenzoic acids such as benzoic acid and 3,5-bis (4-aminophenoxy) benzoic acid, 3,3'-methylenebis (6-aminobenzoic acid), 3,3'-diamino-4,4'- Carboxybiphenyl compounds such as dicarboxybiphenyl, 3,3'-diamino-4,4'-dicarboxydiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, etc. And carboxydiphenyl ether compounds such as carboxydiphenyl alkanes and 3,3'-diamino-4,4'-dicarboxydiphenyl ether. These may be used alone or in combination as appropriate.

Further, examples of the diamine having an ether bond include polyoxyethylenediamine, polyoxypropylenediamine, and polyoxyalkylenediamines containing oxyalkylene groups having different carbon chain numbers.

The molecular weight of the diamine having an ether bond is preferably 200 to 3,000, and more preferably 400 to 2,000.

Examples of polyoxyalkylene diamines include polyoxyethylene diamines such as Jeffamine ED-600, ED-900, ED-2003, EDR-148, HK-511 manufactured by Huntsman, USA, and Jeffamine D-230, D-. And polyoxymethylene ethylene groups such as polyoxypropylene diamines such as 400, D-2000, and D-4000, and Jeffamine XTJ-542, XTJ533, and XTJ536. In addition, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane may be used as the diamine having an ether bond.

As such a diamine, other diamines may be used in combination. As other diamines which can be used in combination, general-purpose aliphatic diamines, aromatic diamines, or the like can be used alone or in appropriate combinations. Specifically, as other diamines, for example, p-phenylenediamine (PPD), 1,3-diaminobenzene, 2,4-toluenediamine, one diamine of benzene nucleus, 4,4'-diaminodiphenyl ether , Diaminodiphenyl ethers such as 3,3'-diaminodiphenyl ether and 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4 , 4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,3-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) Benzene, 1,3-bis [2- (4-aminophenyl) isopropyl] benzene, 1,4-bis [2- (3-aminophenyl) isopropyl] benzene, 3,3'-bis (3-amino Phenoxy) biphenyl, 3,3'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy ) Biphenyl, bis [3- (3-aminophenoxy) phenyl] ether, bis [3- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether, 3 , 3'-diamino-4,4'-dihydroxydiphenylsulfide Aromatic diamines, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-dia And aliphatic diamines such as minoheptane and 1,8-diaminooctane.

The acid anhydride (a1) used for the synthesis of the polyamideimide resin includes an acid anhydride having at least three carboxyl groups and two of them being anhydrous. Examples of such an acid anhydride include those having at least one of an aromatic ring and an aliphatic ring, and having an aromatic ring as trimellitic anhydride (trimellitic anhydride) (benzene-1,2,4-tricarboxylic acid 1) Hydrogenated trimellitic anhydride (cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride) as having an aliphatic ring such as, 2-anhydride, TMA), 4,4'-oxydiphthalic anhydride , H-TMA) and the like. These acid anhydrides may be used individually by 1 type, or may be used in combination of 2 or more type.

Moreover, you may use together carboxylic dianhydride. Examples of the carboxylic dianhydride include tetracarboxylic anhydride such as pyromellitic dianhydride and 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride.

As the diisocyanate compound used for the synthesis of the polyamideimide resin, diisocyanates such as aromatic diisocyanates and isomers and multimers thereof, aliphatic diisocyanates, alicyclic diisocyanates and isomers thereof, and other general-purpose diisocyanates Can be used, but is not limited to these. Moreover, you may use these diisocyanate compounds individually or in combination.

As described above, the polyamideimide resin can be obtained by reacting a reaction raw material containing an imide product and a diisocyanate compound, but in addition, even if it contains the same acid anhydride (a2) used when obtaining an imide product. do. As this acid anhydride (a2), the same thing as the above-mentioned acid anhydride (a1) may be used, or a different one may be used. The content of the acid anhydride (a2) in the reaction raw material in this case is not particularly limited.

As for the polyamideimide resin as described above, in particular, the use of diamine having a carboxyl group-containing diamine and an ether bond and H-TMA, an alicyclic trimellitic acid, improves alkali solubility and improves developability. desirable. Moreover, for the same reason, it is also preferable to use an aliphatic diisocyanate compound in the reaction in the second step. Thereby, it is possible to effectively increase the alkali solubility without significantly lowering the properties by effectively introducing the fatty chain or alicyclic structure into the structure.

Moreover, as the carboxyl group-containing resin having an imide structure and an amide structure, a polyamideimide resin having a structure represented by the following general formula (1) and a structure represented by the following general formula (2) can be used.

Here, X ₁ is a residue of an aliphatic diamine (a) derived from dimer acid having 24 to 48 carbon atoms. X ₂ is a residue of an aromatic diamine (b) having a carboxyl group. Y is each independently a cyclohexane ring or an aromatic ring.

Specifically, examples of the polyamideimide resin having such a structure include those represented by the following general formula (3).

In the general formula (3), X is independently a diamine residue, Y is each independently an aromatic ring or a cyclohexane ring, and Z is a residue of a diisocyanate compound. n is a natural number.

(2) A carboxyl group-containing resin having an imide structure and no amide structure

The carboxyl group-containing resin having an imide structure and no amide structure is not particularly limited as long as it is a resin having a carboxyl group and an imide ring. For synthesis of a carboxyl group-containing resin having an imide structure and no amide structure, a known conventional method of introducing an imide ring into a carboxyl group-containing resin can be used. For example, a resin obtained by reacting a carboxylic acid anhydride component with an amine component and / or an isocyanate component is mentioned. The imidization may be carried out by thermal imidization or chemical imidization, or may be used in combination.

Here, examples of the carboxylic acid anhydride component include tetracarboxylic anhydride, tricarboxylic anhydride, and the like, but are not limited to these acid anhydrides, and are compounds having an acid anhydride group and a carboxyl group reacting with an amino group or an isocyanate group. , And derivatives thereof. Moreover, you may use these carboxylic acid anhydride components individually or in combination.

Examples of the tetracarboxylic acid anhydride include pyromellitic dianhydride, 3-fluoropyromellitic dianhydride, 3,6-difluoropyromellitic dianhydride, and 3,6-bis (trifluoromethyl). Pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 4,4'-ox Cydiphthalic dianhydride, 2,2'-difluoro-3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 5,5'-difluoro-3,3', 4,4 '-Biphenyltetracarboxylic dianhydride, 6,6'-difluoro-3,3', 4,4'-Biphenyltetracarboxylic dianhydride, 2,2 ', 5,5', 6 , 6'-hexafluoro-3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2'-bis (trifluoromethyl) -3,3', 4,4'- Biphenyltetracarboxylic dianhydride, 5,5'-bis (trifluoromethyl) -3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 6,6'-bis (trifluoro Romethyl) -3,3 ', 4,4'-biphenylte Lacarboxylic dianhydride, 2,2 ', 5,5'-tetrakis (trifluoromethyl) -3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 6,6'-tetrakis (trifluoromethyl) -3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 5,5', 6,6'-tetrakis (trifluoromethyl) ) -3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 2,2', 5,5 ', 6,6'-hexakis (trifluoromethyl) -3,3', 4,4'-biphenyltetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3 ", 4,4" -terphenyltetracarboxylic dianhydride, 3 , 3 '", 4,4'"-quaterphenyltetracarboxylic dianhydride, 3,3 "", 4,4 ""-quinquephenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic acid Dianhydride, 1,1-ethynidene-4,4'-diphthalic acid dianhydride, 2,2-propylidene-4,4'-diphthalic acid dianhydride, 1,2-ethylene-4,4'-di Phthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic acid Dihydrate, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoro Propane dianhydride, difluoromethylene-4,4'-diphthalic dianhydride, 1,1,2,2-tetrafluoro-1,2-ethylene-4,4'-diphthalic dianhydride, 1,1 , 2,2,3,3-hexafluoro-1,3-trimethylene-4,4'-diphthalic dianhydride, 1,1,2,2,3,3,4,4-octafluoro- 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,1,2,2,3,3,4,4,5,5-decafluoro-1,5-pentamethylene-4, 4'-diphthalic dianhydride, thio-4,4'-diphthalic dianhydride, sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis (3,4-dicarboxyphenyl) -1, 1,3,3-tetramethylsiloxane dianhydride, 1,3-bis (3,4-dicarboxyphenyl) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenyl) benzene dianhydride, 1, 3-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,3-bis [2- (3,4-di Carboxyphenyl) -2-propyl] benzene dianhydride, 1,4-bis [2- (3,4-dicarboxyphenyl) -2-propyl] benzene dianhydride, bis [3- (3,4-dicarboxyphenoxy) phenyl ] Methane dianhydride, bis [4- (3,4-dicarboxyphenoxy) phenyl] methane dianhydride, 2,2-bis [3- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2 , 2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis [3- (3,4-dicarboxyphenoxy) phenyl] -1,1,1, 3,3,3-hexafluoropropane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, bis (3,4-dicarboxyphenoxy) dimethylsilane Dianhydride, 1,3-bis (3,4-dicarboxyphenoxy) -1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1 , 2,7,8-phenanthrene tetracarbox Acid dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1 , 2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3 ', 4,4'-bicyclohexyltetracarboxylic dianhydride Water, carbonyl-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride , 1,2-ethylene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethynidene-4,4'-bis (cyclohexane-1,2 -Dicarboxylic acid) dianhydride, 2,2-propylidene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1,1,3,3,3- Hexafluoro-2,2-propylidene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis (cyclohexane-1,2-dica Leic acid) dianhydride, thio-4,4'-bis Clohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 3,3'-difluorooxy- 4,4'-diphthalic dianhydride, 5,5'-difluorooxy-4,4'-diphthalic dianhydride, 6,6'-difluorooxy-4,4'-diphthalic dianhydride, 3,3 ', 5,5', 6,6'-hexafluorooxy-4,4'-diphthalic dianhydride, 3,3'-bis (trifluoromethyl) oxy-4,4'-di Phthalic dianhydride, 5,5'-bis (trifluoromethyl) oxy-4,4'-diphthalic dianhydride, 6,6'-bis (trifluoromethyl) oxy-4,4'-diphthalic dianhydride Water, 3,3 ', 5,5'-tetrakis (trifluoromethyl) oxy-4,4'-diphthalic dianhydride, 3,3', 6,6'-tetrakis (trifluoromethyl) Oxy-4,4'-diphthalic dianhydride, 5,5 ', 6,6'-tetrakis (trifluoromethyl) oxy-4,4'-diphthalic dianhydride, 3,3', 5,5 ', 6,6'-hexakis (trifluoromethyl) oxy-4,4'-diphthalic dianhydride, 3,3'-difluorosulfonyl-4,4' -Diphthalic acid dianhydride, 5,5'-difluorosulfonyl-4,4'-diphthalic acid dianhydride, 6,6'-difluorosulfonyl-4,4'-diphthalic acid dianhydride, 3, 3 ', 5,5', 6,6'-hexafluorosulfonyl-4,4'-diphthalic dianhydride, 3,3'-bis (trifluoromethyl) sulfonyl-4,4'-di Phthalic dianhydride, 5,5'-bis (trifluoromethyl) sulfonyl-4,4'-diphthalic dianhydride, 6,6'-bis (trifluoromethyl) sulfonyl-4,4'-di Phthalic dianhydride, 3,3 ', 5,5'-tetrakis (trifluoromethyl) sulfonyl-4,4'-diphthalic dianhydride, 3,3', 6,6'-tetrakis (trifluor Romethyl) sulfonyl-4,4'-diphthalic acid dianhydride, 5,5 ', 6,6'-tetrakis (trifluoromethyl) sulfonyl-4,4'-diphthalic acid dianhydride, 3,3 ', 5,5', 6,6'-hexakis (trifluoromethyl) sulfonyl-4,4'-diphthalic dianhydride, 3,3'-difluoro-2,2-perfluoropropyl Liden-4,4'-diphthalic dianhydride, 5,5'-difluoro-2,2-perfluoropropylidene-4,4'-diphthalic acid Dianhydride, 6,6'-difluoro-2,2-perfluoropropylidene-4,4'-diphthalic dianhydride, 3,3 ', 5,5', 6,6'-hexafluoro -2,2-perfluoropropylidene-4,4'-diphthalic dianhydride, 3,3'-bis (trifluoromethyl) -2,2-perfluoropropylidene-4,4'-di Phthalic dianhydride, 5,5'-bis (trifluoromethyl) -2,2-perfluoropropylidene-4,4'-diphthalic dianhydride, 6,6'-difluoro-2,2- Perfluoropropylidene-4,4'-diphthalic dianhydride, 3,3 ', 5,5'-tetrakis (trifluoromethyl) -2,2-perfluoropropylidene-4,4'- Diphthalic dianhydride, 3,3 ', 6,6'-tetrakis (trifluoromethyl) -2,2-perfluoropropylidene-4,4'-diphthalic dianhydride, 5,5', 6 , 6'-tetrakis (trifluoromethyl) -2,2-perfluoropropylidene-4,4'-diphthalic dianhydride, 3,3 ', 5,5', 6,6'-hexakis (Trifluoromethyl) -2,2-perfluoropropylidene-4,4'-diphthalic dianhydride, 9-phenyl-9- (triple Luoromethyl) xanthene-2,3,6,7-tetracarboxylic dianhydride, 9,9-bis (trifluoromethyl) xanthene-2,3,6,7-tetracarboxylic dianhydride , Bicyclo [2,2,2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 9,9-bis [4- (3,4-dicarboxy) phenyl] flu Oren dianhydride, 9,9-bis [4- (2,3-dicarboxy) phenyl] fluorene dianhydride, ethylene glycol bistrimellitate dianhydride, 1,2- (ethylene) bis (trimellitate anhydride) , 1,3- (trimethylene) bis (trimellitate anhydride), 1,4- (tetramethylene) bis (trimellitate anhydride), 1,5- (pentamethylene) bis (trimellitate anhydride), 1 , 6- (hexamethylene) bis (trimellitate anhydride), 1,7- (heptamethylene) bis (trimellitate anhydride), 1,8- (octamethylene) bis (trimellitate anhydride), 1,9 -(Nonmethylene) bis (trimellitate anhydride), 1,10- (decamethylene) bis (trimellitate anhydride), 1,1 2- (dodecamethylene) bis (trimellitate anhydride), 1,16- (hexadecamethylene) bis (trimellitate anhydride), 1,18- (octadecamethylene) bis (trimellitate anhydride), etc. Can be lifted. Examples of the tricarboxylic anhydride include trimellitic anhydride, nuclear hydrogenated trimellitic anhydride, and the like.

As the amine component, diamines such as aliphatic diamines and aromatic diamines, polyamines such as aliphatic polyetheramines, diamines having carboxylic acids, diamines having phenolic hydroxyl groups, and the like can be used, but are not limited to these amines. Moreover, you may use these amine components individually or in combination.

As the diamine, for example, diamine of one benzene nucleus such as p-phenylenediamine (PPD), 1,3-diaminobenzene, 2,4-toluenediamine, 2,5-toluenediamine, and 2,6-toluenediamine , Diaminodiphenyl ethers such as 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, and 3,4'-diaminodiphenyl ether, 4,4'-diaminodi Phenylmethane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl)- 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetramethyl-4,4'-diaminodiphenyl Methane, bis (4-aminophenyl) sulfide, 4,4'-diaminobenzanilide, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine (o-tolidine), 2,2'-dimethyl Benzidine (m-tolidine), 3,3'-dimethoxybenzidine, 2,2'-dimethoxybenzidine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4, 4'-diaminodiphenyl ether, 3,3'-diami Nodiphenyl sulfide, 3,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone , 4,4'-diaminodiphenylsulfone, 3,3'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzophenone, 3,3'-diamino-4,4 '-Dimethoxybenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis (3-aminophenyl ) Propane, 2,2-bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4, 2 diamines, 1,3-bis (3-aminophenyl) benzene, such as 4'-diaminodiphenyl sulfoxide, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 1 , 3-bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1,4-bis (4-aminophene) ) Benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) -4-trifluoromethylbenzene, 3,3'-diamino-4- (4-phenyl) phenoxybenzophenone, 3,3'-diamino-4,4'-di (4-phenylphenoxy) benzophenone, 1,3-bis (3-aminophenylsulfide) benzene, 1,3-bis (4-aminophenylsulfide) benzene, 1,4-bis (4-aminophenyl) Sulfide) benzene, 1,3-bis (3-aminophenylsulfone) benzene, 1,3-bis (4-aminophenylsulfone) benzene, 1,4-bis (4-aminophenylsulfone) benzene, 1,3 -Bis [2- (4-aminophenyl) isopropyl] benzene, 1,4-bis [2- (3-aminophenyl) isopropyl] benzene, 1,4-bis [2- (4-aminophenyl) iso Propyl] 3 diamines such as benzene, 3,3'-bis (3-aminophenoxy) biphenyl, 3,3'-bis (4-aminophenoxy) biphenyl, 4,4'-bis ( 3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, bis [3- (3-aminophenoxy) phenyl] eth , Bis [3- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, bis [3- (3-aminophenoxy) phenyl] ketone, bis [3- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy Si) phenyl] ketone, bis [3- (3-aminophenoxy) phenyl] sulfide, bis [3- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl ] Sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [3- (3-aminophenoxy) phenyl] sulfone, bis [3- (4-aminophenoxy) phenyl] sulfone, Bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] methane, bis [3- ( 4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 2,2-bis [3- (3 -Aminophenoxy) phenyl] propane, 2,2-bis [3- (4-aminophenoxy) phenyl] prop Plate, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3- (3 -Aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [3- (4-aminophenoxy) phenyl] -1,1,1,3 , 3,3-hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] aromatic diamines, such as four diamines of four benzene nuclei, such as 1,1,1,3,3,3-hexafluoropropane, 1,2-diaminoethane, 1 , 3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9 And aliphatic diamines such as diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and 1,2-diaminocyclohexane, and aliphatic. Examples of the polyetheramine include ethylene glycol and / or propylene glycol polyhydric amines. .

Examples of the amine having a carboxyl group include diaminobenzoic acids such as 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid and 3,4-diaminobenzoic acid, 3,5-bis (3-aminophenoxy) benzoic acid, Aminophenoxybenzoic acids such as 3,5-bis (4-aminophenoxy) benzoic acid, 3,3'-diamino-4,4'-dicarboxybiphenyl, 4,4'-diamino-3,3 Carboxy, such as '-dicarboxybiphenyl, 4,4'-diamino-2,2'-dicarboxybiphenyl, 4,4'-diamino-2,2', 5,5'-tetracarboxybiphenyl Biphenyl compounds, 3,3'-diamino-4,4'-dicarboxydiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 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 Carboxydiphenyl alkanes, such as carboxydiphenylmethane, such as '-diamino-2,2', 5,5'-tetracarboxydiphenylmethane, 3,3'-diamino-4,4'-dicarbox Diphenyl ether, 4,4'-diamino-3,3'-dicarboxydiphenyl ether, 4,4'-diamino-2,2'-dicarboxydiphenyl ether, 4,4'-diamino- Carboxydiphenyl ether compounds such as 2,2 ', 5,5'-tetracarboxydiphenyl ether, 3,3'-diamino-4,4'-dicarboxydiphenylsulfone, 4,4'-diamino- 3,3'-dicarboxydiphenylsulfone, 4,4'-diamino-2,2'-dicarboxydiphenylsulfone, 4,4'-diamino-2,2 ', 5,5'-tetracarboxy Diphenylsulfone compounds such as diphenylsulfone, bis [(carboxyphenyl) phenyl] alkane compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] propane, 2,2- And bis [(carboxyphenoxy) phenyl] sulfone compounds such as bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone.

As the isocyanate component, diisocyanates such as aromatic diisocyanates and isomers and multimers thereof, aliphatic diisocyanates, alicyclic diisocyanates and isomers thereof, and other general-purpose diisocyanates can be used, but are not limited to these isocyanates. . Moreover, you may use these isocyanate components individually or in combination.

Examples of the diisocyanate include aromatics such as 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, biphenyl diisocyanate, diphenyl sulfone diisocyanate, and diphenyl ether diisocyanate. Aliphatic diisocyanates such as diisocyanate and isomers, multimers, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, or alicyclic diisocyanates and isomers obtained by hydrogenating the aromatic diisocyanate, or And other general-purpose diisocyanates.

(3) A carboxyl group-containing resin having an amide structure and no imide structure

The carboxyl group-containing resin having an amide structure and no imide structure is not particularly limited as long as it is a resin having a carboxyl group and an amide bond.

The carboxyl group-containing resin suitably used as the alkali-soluble resin of the present invention as described above, preferably has an acid value of 20 to 200 mgKOH / g, more preferably 60 to 150 mgKOH / g, in order to cope with the photolithography process. Do. When the acid value is 20 mgKOH / g or more, the solubility in alkali increases, developability becomes good, and further, since the degree of crosslinking with the thermosetting component after light irradiation increases, sufficient development contrast can be obtained. On the other hand, if this acid value is 200 mgKOH / g or less, accurate pattern drawing is facilitated, and in particular, so-called heat blurring in the PEB (POST EXPOSURE BAKE) process after light irradiation described later can be suppressed, and the process margin becomes large.

In addition, the molecular weight of such a carboxyl group-containing resin, in view of developability and cured coating film properties, is preferably a mass average molecular weight Mw of 100,000 or less, more preferably 1,000 to 100,000, and even more preferably 2,000 to 50,000. When this molecular weight is 100,000 or less, alkali solubility of the unexposed portion increases, and developability is improved. On the other hand, if the molecular weight is 1,000 or more, after exposure and PEB, sufficient developing resistance and cured property can be obtained in the exposed portion.

(Photopolymerization initiator)

As the photopolymerization initiator used in the resin layer (B), a conventionally known one can be used, and in particular, when used in a PEB process after light irradiation described later, a photopolymerization initiator that also has a function as a photobase generator is suitable. Moreover, in this PEB process, you may use together a photoinitiator and a photobase generator.

A photopolymerization initiator that also has a function as a photobase generator is one that can function as a catalyst for the polymerization reaction of a thermally reactive compound described later by changing the molecular structure or cleaving the molecule by light irradiation such as ultraviolet light or visible light. It is a compound that produces the above basic substance. As a basic substance, secondary amine and tertiary amine are mentioned, for example.

As a photopolymerization initiator which also has a function as such a photobase generator, for example, α-aminoacetophenone compound, oxime ester compound, acyloxyimino group, N-formylated aromatic amino group, N-acylated aromatic amino group, nitrobenzylcar And compounds having substituents such as barmate groups and alkoxybenzyl carbamate groups. Especially, an oxime ester compound and an alpha-amino acetophenone compound are preferable, and an oxime ester compound is more preferable. As the α-aminoacetophenone compound, it is particularly preferable to have two or more nitrogen atoms.

The α-aminoacetophenone compound has a benzoin ether bond in the molecule, and when irradiated with light, cleavage occurs in the molecule, and a basic substance (amine) exerting a curing catalytic action is produced.

Any oxime ester compound may be used as long as it is a compound that generates a basic substance by light irradiation.

These photopolymerization initiators may be used alone or in combination of two or more. The blending amount of the photopolymerization initiator in the resin composition is preferably 0.1 to 40 parts by mass, more preferably 0.3 to 15 parts by mass with respect to 100 parts by mass of the alkali-soluble resin. In the case of 0.1 part by mass or more, the contrast of the developing resistance of the light irradiated / unradiated portion can be satisfactorily obtained. Further, in the case of 40 parts by mass or less, the properties of the cured product are improved.

(Thermoreactive compound)

As the heat-reactive compound, a known conventional compound having a functional group capable of curing reaction by heat such as a cyclic (thio) ether group, for example, an epoxy compound or the like is used.

Examples of the epoxy compound include bisphenol A type epoxy resin, brominated epoxy resin, novolac type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, and alicyclic Formula epoxy resins, trihydroxyphenylmethane type epoxy resins, bixylenol type or nonphenol type epoxy resins, or mixtures thereof; Bisphenol S-type epoxy resin, bisphenol A novolak-type epoxy resin, tetraphenylolethane-type epoxy resin, heterocyclic epoxy resin, diglycidyl phthalate resin, tetraglycidyl xylenoethane resin, naphthalene group-containing epoxy resin, dish And an epoxy resin having a clopentadiene skeleton, a glycidyl methacrylate copolymer-based epoxy resin, a copolymer epoxy resin of cyclohexyl maleimide and glycidyl methacrylate, and a CTBN-modified epoxy resin.

As the compounding quantity of the said heat-reactive compound, it is preferable that the equivalent ratio with alkali-soluble resin (alkali-soluble group, such as a carboxyl group: heat-reactive group, such as an epoxy group) is 1: 0.1-1: 10. By setting it as the range of such a compounding ratio, image development becomes favorable and it becomes what can form a fine pattern easily. The equivalent ratio is more preferably 1: 0.2 to 1: 5.

(Block copolymer)

The block copolymer is the most characteristic in the resin layer (B) constituting the laminated structure of the present invention, in order to realize a high balance of unprecedented high flexibility, particularly excellent crack resistance against excessive seam folding, and excellent heat resistance. Ingredients.

As the block copolymer, a polymer having a molecular structure in which two or more types of polymer units having different properties are connected by covalent bonds to form a long chain is generally used. In the present invention, as the block copolymer, a known conventional one can be used, an X-Y type or X-Y-X type block copolymer is preferred, and an X-Y-X type block copolymer is more preferred. X in the X-Y-X type block copolymer may be the same or different, respectively.

Moreover, it is preferable that X is a polymer unit in which a glass transition point Tg is 0 degreeC or more among X-Y type or X-Y-X type block copolymer. More preferably, X is a polymer unit having a glass transition point Tg of 50 ° C or higher. Moreover, it is preferable that Y is a polymer unit whose glass transition point Tg is less than 0 degreeC, More preferably, it is a polymer unit whose glass transition point Tg is -20 degreeC or less. The glass transition point Tg is measured by differential scanning calorimetry (DSC).

It is more preferable that the block copolymer is a solid at 20 to 30 ° C. In this case, it may just be a solid within this range, and may be solid even at a temperature outside this range. By being solid in the above-mentioned temperature range, it becomes excellent in tackiness when dry-filmed or when it is applied to a substrate and temporarily dried.

Moreover, among the X-Y-X type block copolymers, it is preferable that X has high compatibility with a heat-reactive compound, and it is preferable that Y has low compatibility with a heat-reactive compound. In this way, it is considered that the blocks at both ends are compatible with the matrix and the central block is a block copolymer that is incompatible with the matrix, so that it is easy to exhibit a specific structure in the matrix.

As the polymer unit X, polymethyl methacrylate (PMMA), polystyrene (PS), and the like are preferable, and as the polymer unit Y, polyn-butyl (meth) acrylate (PBA), polybutadiene (PB), and the like are preferable. . In addition, when a hydrophilic unit having excellent compatibility with an alkali-soluble resin represented by a styrene unit, a hydroxyl group-containing unit, a carboxyl group-containing unit, an epoxy group-containing unit, or an N-substituted acrylamide unit is introduced into a part of the polymer unit X, compatibility is achieved. It becomes possible to further improve. It is particularly preferable to introduce an epoxy group-containing unit to a part of the polymer unit X. Among the above, it is preferable that the polymer unit X is polystyrene, polyglycidyl methacrylate, or N-substituted polyacrylamide, polymethyl (meth) acrylate, or a carboxylic acid modified product or a hydrophilic product modified product thereof. Moreover, it is preferable that Y is polyn-butyl (meth) acrylate or polybutadiene. X and Y may be respectively composed of one type of polymer unit, or may be composed of polymer units of two or more components.

As a manufacturing method of a block copolymer, the method of Unexamined-Japanese-Patent No. 2005-515281 and Unexamined-Japanese-Patent No. 2007-516326 is mentioned, for example.

As a commercial item of a X-Y-X type block copolymer, the acrylic triblock copolymer manufactured using living polymerization by Arkma Corporation is mentioned. As a specific example thereof, an XYX type block copolymer represented by polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate (for example, M51, M52, M53, M22, etc.), further modified with carboxylic acid XYX type block copolymers (for example, SM4032XM10, etc.) and hydrophilic modification-treated XYX type block copolymers (for example, M52N, M22N, M65N, etc.) are mentioned.

In addition, the mass average molecular weight (Mw) of the block copolymer is usually 20,000 to 400,000, and preferably in the range of 30,000 to 300,000. It is preferable that the molecular weight distribution (Mw / Mn) is 3 or less.

When the mass average molecular weight is 20,000 or more, while having mechanical properties such as flexibility and elasticity of the composition, the tackiness is not excessively high, and the effect of improving the flexibility and crack resistance is improved, and the tackiness is also improved. On the other hand, if the mass average molecular weight is 400,000 or less, the viscosity of the composition is not excessively high, and printability and developability are unlikely to decrease.

As the block copolymer, one type may be used alone, or two or more types may be used in combination. The blending amount of the block copolymer is preferably 1 to 60 parts by mass, more preferably 2 to 50 parts by mass, and particularly preferably 3 to 40 parts by mass with respect to 100 parts by mass of the alkali-soluble resin. When the blending amount of the block copolymer is 1 part by mass or more, the bendability and heat resistance are improved, and when it is 60 parts by mass or less, the balance between bendability and heat resistance is improved.

The following components can be mix | blended with the resin composition used for resin layer (A) and resin layer (B) as mentioned above as needed.

(Polymer resin)

For the purpose of improving the flexibility and the dryness of touch of the resulting cured product, a known resin can be blended, except for the above-mentioned block copolymer. Examples of such polymer resins include cellulose-based, polyester-based, phenoxy-resin-based polymers, polyvinyl acetal-based, polyvinyl butyral-based, polyamide-based, polyamide-imide-based binder polymers, and elastomers. One type of this polymer resin may be used alone, or two or more types may be used in combination.

(Weapon filler)

The inorganic filler can be blended to suppress curing shrinkage of the cured product and to improve properties such as adhesion and hardness. Examples of such inorganic fillers include barium sulfate, amorphous silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, boron nitride, and Neuburg diatomaceous earth. You can.

(coloring agent)

As the colorant, known conventional colorants such as red, blue, green, yellow, white, and black can be blended, and any of pigments, dyes, and pigments may be used.

(Organic solvent)

The organic solvent can be blended for the preparation of the resin composition or for the adjustment of viscosity for application to the substrate or carrier film. Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum-based solvents. These organic solvents may be used alone or as a mixture of two or more.

(Other ingredients)

If necessary, components such as mercapto compounds, adhesion promoters, antioxidants, and ultraviolet absorbers can be blended. These can use well-known conventional ones. In addition, known conventional thickeners such as fine silica, hydrotalcite, organic bentonite, montmorillonite, antifoaming agents such as silicone-based, fluorine-based, and polymeric-based and / or leveling agents, silane coupling agents, rust inhibitors, etc. You can.

Since the laminated structure of the present invention is excellent in flexibility, it can be used in at least one of a bent portion and a non-flexed portion of a flexible printed wiring board, and also at least one of a coverlay, a solder resist, and an interlayer insulating material of the flexible printed wiring board. Can be used as

It is preferable to use the laminated structure of this invention which concerns on the structure as mentioned above as a dry film whose at least one side is supported or protected by the film.

(Dry film)

The dry film of this invention can be manufactured as follows, for example. That is, first, on the carrier film (supporting film), the composition constituting the resin layer (B) and the composition constituting the resin layer (A) are each diluted with an organic solvent, adjusted to an appropriate viscosity, and comma according to a conventional method. Apply sequentially by a known method such as a coater. Thereafter, a dry film composed of a resin layer (B) and a resin layer (A) can be formed on the carrier film by drying at a temperature of usually 50 to 130 ° C for 1 to 30 minutes. On this dry film, a cover film (protective film) that can be peeled can be additionally laminated for the purpose of preventing dust from adhering to the surface of the film. As the carrier film and the cover film, a conventionally known plastic film can be appropriately used, and when the cover film is peeled off, the cover film is preferably one that is smaller than the adhesion between the resin layer and the carrier film. The thickness of the carrier film and the cover film is not particularly limited, but is generally appropriately selected in the range of 10 to 150 μm.

(Flexible printed wiring board)

The flexible printed wiring board of the present invention has an insulating film formed by forming a layer of the laminated structure of the present invention on a flexible printed wiring board, patterning it by light irradiation, and collectively forming a pattern with a developer.

(Method of manufacturing a wiring board)

The flexible printed wiring board using the laminated structure of the present invention can be produced in accordance with the procedure shown in the process diagram of FIG. 1. That is, the step of forming a layer of the laminated structure of the present invention on a flexible wiring substrate on which a conductor circuit is formed (lamination process), a step of irradiating the layer of the laminated structure with active energy rays in a pattern (exposure process), and It is a manufacturing method including the process (developing process) of collectively forming the layer of a patterned laminated structure by alkali-developing the layer of this laminated structure. Further, if necessary, after alkali development, further photocuring or thermal curing (postcuring step) is performed, and the layer of the laminated structure is completely cured, so that a highly reliable flexible printed wiring board can be obtained.

Moreover, the manufacturing of the flexible printed wiring board using the laminated structure of this invention can also be performed according to the procedure shown in the process drawing of FIG. That is, a step of forming a layer of the laminated structure of the present invention on a flexible wiring substrate having a conductor circuit (lamination process), a step of irradiating active energy rays in a pattern of the layer of the laminated structure in a pattern (exposure process), It is a manufacturing method including the process of heating the layer of a laminated structure (heating (PEB) process) and the process of alkali-developing the layer of a laminated structure to form a layer of a patterned laminated structure (development process). Further, if necessary, after alkali development, further photocuring or thermal curing (postcuring step) is performed, and the layer of the laminated structure is completely cured, so that a highly reliable flexible printed wiring board can be obtained. In particular, in the case of using the carboxyl group-containing resin having at least one of an imide structure and an amide structure in the resin layer (B), it is preferable to use the procedure shown in the process chart of FIG. 2.

Hereinafter, each process shown in FIG. 1 or FIG. 2 will be described in detail.

[Lamination process]

In this step, the resin layer 3 (resin layer (A)) and the resin layer made of an alkali developing type resin composition containing an alkali-soluble resin and the like on the flexible printed wiring base material 1 on which the conductor circuit 2 is formed. (3) A laminated structure composed of a resin layer 4 (resin layer (B)) made of a photosensitive thermosetting resin composition containing an alkali soluble resin or the like is formed. Here, each resin layer constituting the laminated structure forms resin layers 3 and 4 by, for example, sequentially applying and drying the resin composition constituting the resin layers 3 and 4 on the wiring substrate 1. Alternatively, the resin composition constituting the resin layers 3 and 4 may be formed in a dry film form having a two-layer structure by a method of laminating the wiring substrate 1.

The coating method of the resin composition to the wiring substrate may be any known method such as a blade coater, a lip coater, a comma coater, or a film coater. In addition, the drying method uses a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection oven, or the like equipped with a heat source of a heating method by steam, a method of countercurrently contacting hot air in a dryer, and spraying from a nozzle to a support A known method such as a method to be used may be sufficient.

As a method of laminating a resin composition to a wiring base material, it is preferable to bond under pressure and heating using a vacuum laminator or the like. By using such a vacuum laminator, even if there are irregularities on the surface of the wiring substrate, since the dry film is in close contact with the wiring substrate, there is no mixing of air bubbles, and the hole filling property of the concave portion of the surface of the wiring substrate is also improved. The pressurization condition is preferably about 0.1 to 2.0 MPa, and the heating condition is preferably 40 to 120 ° C.

[Exposure process]

In this step, the photopolymerization initiator contained in the resin layer 4 is activated in a negative pattern by irradiation of active energy rays to cure the exposed portion. In the case of a composition using the PEB process described later, a photopolymerization initiator or photobase generator having a function as a photobase generator is activated in a negative pattern to generate a base.

As an exposure machine used in this step, a direct drawing device, an exposure machine equipped with a metal halide lamp, or the like can be used. The patterned exposure mask is a negative mask.

As the active energy ray used for exposure, it is preferable to use laser light or scattered light having a maximum wavelength in the range of 350 to 450 nm. By setting the maximum wavelength in this range, the photopolymerization initiator can be effectively activated. In addition, although the exposure amount differs depending on the film thickness or the like, it can usually be set to 100 to 1500 mJ / cm ² .

[PEB process]

In this step, the exposed portion is cured by heating the resin layer after exposure. In this step, the resin layer (B) is formed by the base generated in the exposure step of the resin layer (B) comprising a photopolymerization initiator having a function as a photobase generator or a composition using a photopolymerization initiator and a photobase generator in combination. ) To the core. The heating temperature is, for example, 80 to 140 ° C. The heating time is, for example, 10 to 100 minutes. Since curing of the resin composition in the present invention is, for example, a ring-opening reaction of an epoxy resin by thermal reaction, it is possible to suppress deformation or curing shrinkage as compared with a case where curing proceeds in a photoradical reaction.

[Development process]

In this step, the unexposed portion is removed by alkali development to form a negative patterned insulating film, particularly a coverlay and solder resist. As a developing method, it can be based on well-known methods, such as dipping. Further, as the developing solution, an imidazole such as sodium carbonate, potassium carbonate, potassium hydroxide, amines, 2-methylimidazole, an alkaline aqueous solution such as tetramethylammonium hydroxide aqueous solution (TMAH), or a mixture thereof can be used.

[Post curing process]

In this step, after the developing step, the insulating film is completely thermally cured to obtain a highly reliable coating film. The heating temperature is, for example, 120 ° C to 180 ° C. The heating time is, for example, 5 minutes to 120 minutes. In other words, before or after post-curing, the insulating film may be further irradiated with light.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited by these Examples and Comparative Examples.

<Synthesis example 1: Synthesis example of polyimide resin solution>

3,3'-diamino-4,4'-dihydroxydiphenylsulfone 22.4g, 2,2'-bis [in a separable three-necked flask equipped with a stirrer, nitrogen introduction tube, fractionation ring, and cooling ring [ 4- (4-aminophenoxy) phenyl] propane 8.2g, NMP 30g, γ-butyrolactone 30g, 4,4'-oxydiphthalic anhydride 27.9g, trimellitic anhydride 3.8g , Stirred at room temperature under nitrogen atmosphere at 100 rpm for 4 hours. Subsequently, 20 g of toluene was added, and the mixture was stirred for 4 hours while distilling and removing toluene and water at a silicone bath temperature of 180 ° C. and 150 rpm to obtain a polyimide resin solution (PI-1) having a phenolic hydroxyl group and a carboxyl group.

The acid value of the obtained resin (solid content) was 18 mgKOH, Mw was 10,000, and the hydroxyl group equivalent was 390.

(Examples 1 to 6 and Comparative Examples 1 to 4)

According to the component composition shown in Table 1 and Table 2, the materials described in Examples 1 to 6 and Comparative Examples 1 to 4 were respectively blended and premixed in a stirrer, then kneaded in three roll mills to form each resin layer. A resin composition for the following was prepared. The values in the table are parts by mass of solids, unless otherwise specified.

<Formation of resin layer (A)>

A flexible printed wiring substrate on which a circuit with a copper thickness of 18 µm was formed was prepared, and pretreatment was performed using McCarse CZ-8100. Thereafter, the resin compositions constituting each resin layer (A) obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were applied to the flexible printed wiring base material subjected to pretreatment so that the film thickness after drying was 25 µm, respectively. Thereafter, the resin layer (A) was formed by drying at 90 ° C / 30 minutes in a hot air circulation type drying furnace.

<Formation of resin layer (B)>

On the resin layer (A) formed above, the resin compositions constituting each of the resin layers (B) obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were respectively coated so that the film thickness after drying became 10 µm. Then, it dried at 90 degreeC / 30 minutes in the hot-air circulation type drying furnace, and formed the resin layer (B).

Thus, an uncured laminate structure composed of the resin layers (A) and resin layers (B) described in Examples 1 to 6 and Comparative Examples 1 to 4 was formed on the flexible printed wiring substrate.

<Flexibility>

(Production of test piece)

For the uncured laminated structure on each flexible printed wiring substrate on which the laminated structure was formed as described above, first, 500 mJ / cm through a negative mask using an exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp. ^The entire surface was exposed with ² . Thereafter, the PEB process was performed at 90 ° C for 30 minutes, followed by development (30 ° C, 0.2 MPa, 1% by mass Na ₂ CO ₃ aqueous solution) for 60 seconds, followed by thermal curing at 150 ° C x 60 minutes to cure the laminated structure. A flexible printed wiring board having been formed was produced.

Then, the flexible printed wiring board was cut to about 15 mm x about 110 mm to prepare a test piece.

(MIT test)

For each of the obtained test pieces, an MIT fracture fatigue testing machine D type (manufactured by Toyo Seki Seisakusho) was used, an MIT test was performed in conformity with JIS P8115, and the flexibility was evaluated. Specifically, as shown in FIG. 3, the test piece 10 is mounted on the device, and the load piece F (0.5 kgf) is loaded, and the test piece 10 is vertically installed on the clamp 11 to bend. Bending was performed at an angle α of 135 degrees and a speed of 175 cpm, and the number of reciprocating bending times (times) until fracture was measured. Further, the test environment was 25 ° C.

The evaluation criteria are as follows.

(Circle): It bend | folded 200 times or more, and the crack did not arise in the cured coating film of the bending point.

(Circle): It bent 170-199 times, and the crack did not arise similarly.

(Triangle | delta): It bend | folded 150-169 times, and the crack did not arise similarly.

×: Cracks occurred when the number of bendings was 149 or less.

(Sim folding test)

Moreover, the bending property in the case where the seam folding test was performed under the excessive conditions shown below was evaluated for each obtained test piece. Specifically, as shown in FIG. 4, the test piece 10 is bent between 180 plates so that the conductor circuit and the formation surface X of the cured coating film are bent at 180 ° to the outside. After inserting the load G (standard weight of 1 kg) for 10 seconds and folding the shim, using an optical microscope, the operation of checking whether cracks have not occurred in the cured coating portion 20 of the bending site is performed as one cycle, and the crack is generated. The number of previous occurrences was recorded. The test environment was 25 ° C.

The evaluation criteria are as follows.

(Circle): It bend | folded 10 times or more, and the crack did not generate | occur | produce in the cured coating film of the bending part.

(Circle): It bend | folded 6-9 times, and the crack did not generate | occur | produce similarly.

(Triangle | delta): It bend | folded 3 to 5 times, and a crack did not generate | occur | produce similarly.

×: Cracks occurred when the number of bendings was 2 or less.

Table 1 and Table 2 show the evaluation results.

<Heat resistance>

About the uncured laminated structure on each flexible printed wiring base material in which the laminated structure was formed as described above, first, using a metal halide lamp-mounted exposure apparatus (HMW-680-GW20), a diameter of about 2 mm to about copper was used. The exposure was performed at 500 mJ / cm ² through a negative mask having an opening of 5 mm. Thereafter, the PEB process was performed at 90 ° C for 30 minutes, followed by development (30 ° C, 0.2 MPa, 1% by mass Na ₂ CO ₃ aqueous solution) for 60 seconds, followed by thermal curing at 150 ° C x 60 minutes to cure the laminated structure. A flexible printed wiring board (test substrate) was formed.

A rosin-based flux was applied to the test substrate, and immersed in a solder bath set at 260 ° C and 280 ° C for 10 seconds in advance to evaluate the occurrence of excitation, expansion, and peeling of the cured coating film.

The evaluation criteria are as follows.

◎: There was no occurrence of excitation, expansion, or peeling at any dipping of 260 ° C and 280 ° C.

(Circle): There is no excitation, expansion, and peeling at 260 ° C immersion, but excitation, expansion, and peeling occurs at 280 ° C immersion.

X: Lifting and peeling occurred at any dipping of 260 ° C and 280 ° C.

Table 1 and Table 2 show the evaluation results.

<Resolution>

For the uncured layered structure on each flexible printed wiring substrate on which the layered structure was formed as described above, an exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp was first used, and 500 mJ / cm through a negative mask. ² was pattern-exposed to form an opening having a diameter of 200 µm. Then, after performing PEB process at 90 ° C for 30 minutes, developing (30 ° C, 0.2MPa, 1% by mass Na ₂ CO ₃ aqueous solution) was performed for 60 seconds to draw a pattern, and heat-cured at 150 ° C x 60 minutes to open. A flexible printed wiring board having a cured laminated structure having a structure was produced. The opening formed in the laminated structure of the obtained flexible printed wiring board was observed using an optical microscope adjusted to 100 times, and the resolution was evaluated.

The evaluation criteria are as follows.

○: An opening is completely formed.

×: No opening was formed.

The evaluation results are shown in Table 1 and Table 2 together.

* 1) Alkali soluble resin 1: ZAR-1035: acid-modified bisphenol A-type epoxy acrylate, acid value 98 mgKOH / g (manufactured by Nippon Kayaku Co., Ltd.)

* 2) Polyimide resin: PI-1: Synthesis Example 1

* 3) Photocurable monomer: BPE-500: ethoxylated bisphenol A dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

* 4) Epoxy resin: E828: bisphenol A type epoxy resin, epoxy equivalent 190, mass average molecular weight 380 (Mitsubishi Chemical Co., Ltd.)

* 5) Photopolymerization initiator: IRGACURE OXE02: Oxime-based photopolymerization initiator (manufactured by BASF)

* 6) Block copolymer 1: M52N: X-Y-X type block copolymer mass average molecular weight (Mw) about 100,000, manufactured by Arkma, NANOSTRENGTH (registered trademark)

* 7) Block copolymer 2: M65N: X-Y-X type block copolymer mass average molecular weight (Mw) about 100,000 to 300,000, manufactured by Arkma, NANOSTRENGTH (registered trademark)

* 8) Alkali soluble resin 2: P7-532: Polyurethane acrylate, acid value 47 mgKOH / g (manufactured by Kyoeisha Chemical Co., Ltd.)

As is evident from the evaluation results shown in the above table, in the laminated structure of each example, by containing a block copolymer in the resin layer (B) on the upper layer side, excellent performance was obtained in any of the flexibility, heat resistance, and resolution. You can see that you are losing. On the other hand, in Comparative Example 1 and Comparative Example 2, which are single-layer structures, the flexural properties, in particular, excellent crack resistance against excessive seam folding are insufficient, and in Comparative Example 3, which does not contain a block copolymer even in a laminated structure, good results for heat resistance Was obtained, but the flexibility, particularly good crack resistance against excessive seam folding, was insufficient. Further, in Comparative Example 4 in which the block copolymer was contained only in the resin layer (A) on the lower layer side of the laminated structure, good results were obtained with respect to heat resistance, but excellent crack resistance and resolution against bending resistance, particularly excessive seam folding, were insufficient. Got done

From the above, in the laminated structure in which two layers of resin layers are laminated, by containing the block copolymer in the resin layer (B) on the upper layer side, the flexibility, particularly excessive, is maintained while maintaining the original properties of the photosensitive resin composition such as resolution. It became possible to improve the excellent crack resistance and heat resistance against shim folding with a good balance.

1 Flexible printed wiring equipment
2 conductor circuit
3 Resin layer
4 Resin layer
5 mask
10 test pieces
11 Clamp
12 reputation
20 cured coating part
X conductor circuit and formation surface of cured coating film

Claims (9)

A laminated structure having a resin layer (A) and a resin layer (B) laminated on a flexible printed wiring board through the resin layer (A),
The resin layer (B) is composed of a photosensitive thermosetting resin composition comprising an alkali-soluble resin, a photopolymerization initiator, a heat-reactive compound and a block copolymer, and the resin layer (A) is an alkali-soluble resin and a heat-reactive compound. A laminate structure comprising an alkali-developing resin composition. The layered structure according to claim 1, wherein the block copolymer has a structure represented by the following formula (I).
XYX (I)
(In Formula (I), X is a polymer unit having a glass transition point Tg of 0 ° C or higher, and may be the same or different, and Y is a polymer unit having a glass transition point Tg of less than 0 ° C.) The layered structure according to claim 1, wherein the block copolymer has a mass average molecular weight (Mw) of 20,000 to 400,000. The layered structure according to claim 1, comprising a photobase generator as a photopolymerization initiator of the resin layer (B). The laminated structure according to claim 1, wherein the resin layer (A) is made of an alkali developing type resin composition that does not contain a photopolymerization initiator. The laminated structure according to claim 1, which is used for at least one of a bent portion and a non-bended portion of a flexible printed wiring board. The laminate structure according to claim 1, which is used for at least one of a coverlay, a solder resist, and an interlayer insulating material of a flexible printed wiring board. A dry film, characterized in that at least one side of the layered structure according to claim 1 is supported or protected by a film. A flexible printed wiring board comprising the insulating film using the layered structure according to claim 1.

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