JP6387444B1 - Laminated structure, dry film and flexible printed wiring board - Google Patents

Abstract

The present invention provides a laminated structure, a dry film, and a flexible printed wiring board having a cured film as a protective film, which has higher flexibility than ever, particularly excellent crack resistance against excessive folding. A laminated structure having a resin layer (A) and a resin layer (B) laminated on a flexible printed wiring board via the resin layer (A). The resin layer (B) is composed of a photosensitive thermosetting resin composition containing an alkali-soluble resin, a photopolymerization initiator, a thermoreactive compound and a block copolymer, and the resin layer (A) is alkali-soluble. It consists of an alkali developable resin composition containing a reactive resin and a thermally reactive compound. [Selection figure] None

Description

  The present invention relates to a laminated structure useful as an insulating film of a flexible printed wiring board, a dry film, and a flexible printed wiring board (hereinafter also simply referred to as “wiring board”).

  In recent years, as electronic devices have become smaller and thinner due to the spread of smartphones and tablet terminals, it has become necessary to reduce the space of circuit boards. Therefore, the use of the flexible printed wiring board which can be folded and accommodated is expanded, and the flexible printed wiring board is required to have higher reliability than ever.

  On the other hand, as an insulating film to ensure the insulation reliability of flexible printed wiring boards, a cover based on polyimide with excellent mechanical properties such as heat resistance and flexibility is used for the bent part (bent part). Using a lay (see, for example, Patent Documents 1 and 2), the mounting part (non-bent part) has a mixed mounting process using a photosensitive resin composition that is excellent in electrical insulation and solder heat resistance and can be finely processed. Widely adopted.

  That is, a cover lay based on polyimide is not suitable for fine wiring because it requires processing by die punching. Therefore, it is necessary to partially use an alkali developing type photosensitive resin composition (solder resist) that can be processed by photolithography in a chip mounting portion that requires fine wiring.

Japanese Patent Application Laid-Open No. Sho 62-263692 Japanese Unexamined Patent Publication No. 63-110224

  As described above, the conventional flexible printed wiring board manufacturing process has to employ a mixed mounting process of bonding the coverlay and forming the solder resist, which is inferior in cost and workability. It was.

  On the other hand, it has been studied to apply an insulating film as a solder resist or an insulating film as a coverlay as a solder resist and coverlay for flexible printed wiring boards. However, a material that can sufficiently satisfy the required performance of both the solder resist and the coverlay has not yet been put to practical use.

  Specifically, when a flexible printed wiring board is stored in a device in response to a demand for a small circuit board space, the flexible printed wiring board on which components are mounted is folded and stored. The For this reason, a load is applied to the flexible printed wiring board and its insulating film in a folded state, but in this respect, materials that can sufficiently satisfy the required performance of both the solder resist and the coverlay are still being developed. The fact was not. Here, the hull fold means that the upper surface side of the flexible printed wiring board is bent by 180 °. Therefore, a flexible printed wiring board is required to have an insulating film suitable for a solder resist and a cover lay having higher flexibility than ever, particularly excellent crack resistance even when excessively folded.

  Accordingly, 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 higher flexibility than ever, particularly excellent crack resistance even if excessively folded. There is. Another object of the present invention is to provide an insulating film for a flexible printed wiring board, particularly a laminated structure suitable for a batch forming process of a bent portion (bent portion) and a mounting portion (non-bent portion), a dry film, and The object is to provide a flexible printed wiring board having the cured product as a protective film, for example, a coverlay or a solder resist.

As a result of intensive studies to solve the above problems, the present inventors have completed 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 the flexible printed wiring board via the resin layer (A),
The resin layer (B) is composed of a photosensitive thermosetting resin composition containing an alkali-soluble resin, a photopolymerization initiator, a thermoreactive compound and a block copolymer, and the resin layer (A) It consists of an alkali-developable resin composition containing an alkali-soluble resin and a heat-reactive compound.

In the laminated structure of the present invention, the block copolymer preferably has a structure represented by the following formula (I), and the block copolymer has a mass average molecular weight (Mw) of preferably 20 , 400,000 to 400,000.
XYX (I)
(In the formula (I), X is a polymer unit having a glass transition point Tg of 0 ° C. or more, and may be the same or different, and Y is a polymer unit having a glass transition point Tg of less than 0 ° C. )

  Furthermore, in the laminated structure of this invention, it is preferable that a photobase generator is included as a photoinitiator of the said resin layer (B). Furthermore, 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-bent portion of a flexible printed wiring board, and among the cover lay, solder resist, and interlayer insulating material of the flexible printed wiring board It can be used for at least one of the applications.

  The dry film of the present invention is characterized in that at least one surface of the laminated structure of the present invention is supported or protected by a film.

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

  According to the present invention, there is provided a laminated structure that satisfies the required performance of both a solder resist and a cover lay, has higher flexibility than ever, and has excellent crack resistance even when excessively folded. Can do. In addition, an insulating film of a flexible printed wiring board, particularly a laminated structure suitable for a batch forming process of a bent part (bent part) and a mounting part (non-bent part), a dry film, and a cured film thereof as a protective film, For example, it has become possible to realize a flexible printed wiring board having a coverlay or a solder resist.

It is process drawing which shows typically an example of the manufacturing method of the flexible printed wiring board of this invention. It is process drawing which shows typically the other example of the manufacturing method of the flexible printed wiring board of this invention. It is a schematic explanatory drawing which shows the MIT test in an Example. It is a schematic explanatory drawing which shows the helical fold test in an Example.

Hereinafter, embodiments of the present invention will be described in detail.
(Laminated structure)
The laminated structure of this invention has a resin layer (A) and the resin layer (B) laminated | stacked on a flexible printed wiring board via the resin layer (A). Here, in the laminated structure of the present invention, the resin layer (A) and the resin layer (B) substantially function as an adhesive layer and a protective layer, respectively. In the laminated structure of the present invention, the resin layer (B) includes a photosensitive thermosetting resin containing an alkali-soluble resin, a photopolymerization initiator, a heat-reactive compound, and a block copolymer (also referred to as a block copolymer, “BCP”). The resin layer (A) is characterized in that it is made of an alkali-developing resin composition containing an alkali-soluble resin and a heat-reactive compound.

  In the present invention, by including a block copolymer in the upper resin layer (B) of the laminated structure formed by laminating two resin layers, the flexibility is higher than ever, especially excessively. It has become possible to achieve a good balance of excellent crack resistance against heat fold and excellent heat resistance.

  In addition, such a laminated structure of the present invention has a resin layer (A) and a resin layer (B) in this order on a flexible printed wiring board in which a copper circuit is formed on a flexible substrate, and an upper layer side resin. The layer (B) is composed of a photosensitive thermosetting resin composition that can be patterned by light irradiation, and the resin layer (B) even when the lower resin layer (A) does not contain a photopolymerization initiator. And the resin layer (A) can form a pattern collectively by development.

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

[Resin layer (A)]
(Alkali developable resin composition)
The alkali-developable resin composition constituting the resin layer (A) includes an alkali-soluble resin that contains at least one functional group of phenolic hydroxyl group and carboxyl group and can be developed with an alkali solution, and thermal reactivity. What is necessary is just a composition containing a compound. Preferred examples include a resin composition containing a compound having a phenolic hydroxyl group, a compound having a carboxyl group, and a compound having a phenolic hydroxyl group and a carboxyl group, and known ones are 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 thermally reactive compound, which has been conventionally used as a solder resist composition.

Here, as the carboxyl group-containing resin or the carboxyl group-containing photosensitive resin, and the compound having an ethylenically unsaturated bond, known and commonly used compounds are used,
In addition, as the heat-reactive compound, a known and commonly used compound having a functional group capable of curing reaction by heat, such as a cyclic (thio) ether group, similar to the heat-reactive compound used in the resin layer (B) is used.

  Such a resin layer (A) may or may not contain a photopolymerization initiator, but as a photopolymerization initiator used when it contains a photopolymerization initiator, the resin layer (B) The same thing as the photoinitiator used in can be mentioned.

  In the present invention, the resin layer (B) needs to contain a block copolymer, but the resin layer (A) also has the effect of the present invention, that is, the required performance of both the solder resist and the coverlay. You may contain a block copolymer to such an extent that it does not exert influence. As the block copolymer in this case, the same 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 a resin with respect to 100 parts by mass of the alkali-soluble resin. The layer (A) does not contain a block copolymer, but is contained only in the resin layer (B). If 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, a known and conventional resin similar to the resin layer (A) can be used. However, at least one of an imide structure and an amide structure, which is superior in characteristics such as flex resistance and heat resistance, is used. The carboxyl group-containing resin which has can be used suitably.
The carboxyl group-containing resin having at least one of the imide structure and the amide structure includes (1) a carboxyl group-containing resin having an imide structure and an amide structure, and (2) an amide structure and no amide structure. Examples thereof include a carboxyl group-containing resin and (3) a carboxyl group-containing resin 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, among the carboxyl group-containing resins having at least one of an imide structure and an amide structure, it is preferable to use a carboxyl group-containing resin having an imide structure and an amide structure.
The carboxyl group-containing resin having at least one of an imide structure and an amide structure may further have a phenolic hydroxyl group.

(1) 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, a diamine containing at least a carboxyl group-containing diamine and at least 3 After reacting with an acid anhydride (a1) containing acid anhydrides having two carboxyl groups and two of them being anhydrous, an imidized product is obtained, and then the obtained imidized product and diisocyanate compound are used. It can be obtained by reacting the reaction raw materials. In addition to the imidized product and diisocyanate compound, the reaction raw material further contains an acid anhydride (a2) having at least three carboxyl groups and two of which are anhydrous, as will be described later. It is preferable to make it.

Here, the diamine used for the synthesis of the polyamideimide resin includes at least a carboxyl group-containing diamine, but a diamine having an ether bond is preferably used in combination.
Examples of the carboxyl group-containing diamine include 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, diaminobenzoic acids such as 3,4-diaminobenzoic acid, and 3,5-bis (3-aminophenoxy) benzoic acid. Acid, aminophenoxybenzoic acids such as 3,5-bis (4-aminophenoxy) benzoic acid, 3,3′-methylenebis (6-aminobenzoic acid), 3,3′-diamino-4,4′-dicarboxyl Carboxybiphenyl compounds such as biphenyl, carboxydiphenylalkanes such as 3,3′-diamino-4,4′-dicarboxydiphenylmethane, 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 3,3 ′ Carboxydiphenyl ether compounds such as -diamino-4,4'-dicarboxydiphenyl ether, etc. Alone or in combination as appropriate can be used.

Examples of the diamine having an ether bond include polyoxyethylene diamine, polyoxypropylene diamine, and other polyoxyalkylene diamines containing oxyalkylene groups having different numbers of carbon chains.
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 polyoxyalkylenediamines include polyoxyethylene diamines such as Jeffamine ED-600, ED-900, ED-2003, EDR-148, and HK-511 manufactured by Huntsman, Inc., and Jeffamine D-230 and D-400. And polyoxypropylene diamines such as D-2000 and D-4000, and those having polytetramethylene ethylene groups such as Jeffamine XTJ-542, XTJ533, and XTJ536. Further, 2,2′-bis [4- (4-aminophenoxy) phenyl] propane may be used as a diamine having an ether bond.

  As such a diamine, other diamines may be used in combination. As other diamines that can be used in combination, general-purpose aliphatic diamines and aromatic diamines can be used alone or in appropriate combination. Specifically, as other diamines, for example, p-phenylenediamine (PPD), 1,3-diaminobenzene, 2,4-toluenediamine, one benzene nucleus diamine, 4,4′-diaminodiphenyl ether, 3 , 3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, and other diaminodiphenyl ethers, 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′-bi (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] ether, bis [3- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether, 3,3′-diamino-4 , 4'-dihydroxydiphenyl sulfone, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1, Examples thereof include aliphatic diamines such as 7-diaminoheptane 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, two of which are anhydrous. Examples of the acid anhydride include those having at least one of an aromatic ring and an aliphatic ring, and trimellitic anhydride (trimellitic anhydride) (benzene-) having an aromatic ring. Hydrogenated trimellitic anhydride (cyclohexane-1,2,4) having an aliphatic ring such as 1,2,4-tricarboxylic acid 1,2-anhydride, TMA), 4,4′-oxydiphthalic anhydride 4-tricarboxylic acid-1,2-anhydride, H-TMA) and the like can be preferably mentioned. These acid anhydrides may be used individually by 1 type, and may be used in combination of 2 or more type.
Furthermore, you may use together carboxylic dianhydride. Examples of the carboxylic dianhydride include tetracarboxylic anhydrides such as pyromellitic dianhydride and 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride.

  Diisocyanate compounds used in the synthesis of the polyamideimide resin include aromatic diisocyanates and isomers and multimers thereof, aliphatic diisocyanates, alicyclic diisocyanates and isomers thereof, and other general-purpose diisocyanates. However, it is not limited to these. These diisocyanate compounds may be used alone or in combination.

  As described above, the polyamide-imide resin can be obtained by reacting a reaction raw material containing an imidized product and a diisocyanate compound. Further, the same acid anhydride (a2) as that used for obtaining the imidized product can be obtained. May be included. As this acid anhydride (a2), the same thing as the acid anhydride (a1) mentioned above may be used, and a different thing may be used. In this case, the content of the acid anhydride (a2) in the reaction raw material is not particularly limited.

  In particular, the polyamideimide resin as described above uses a carboxyl group-containing diamine, a diamine having an ether bond, and H-TMA, which is an alicyclic trimellitic acid, to improve alkali solubility and developability. Is more preferable in terms of improvement. For the same reason, it is also preferable to use an aliphatic diisocyanate compound for the polyamideimide resin in the second stage reaction. Thereby, it becomes possible to enhance alkali solubility without significantly reducing the characteristics by effectively incorporating the fatty chain or alicyclic structure into the structure.

In addition, 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.

Wherein, _{X 1} is a residue of an aliphatic diamine derived from a dimer acid with a carbon number of 24-48 (a). X ₂ is a residue of the 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 independently an aromatic ring or a cyclohexane ring, and Z is a residue of a diisocyanate compound. n is a natural number.

(2) 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 the resin has a carboxyl group and an imide ring. . For synthesizing a carboxyl group-containing resin having an imide structure and no amide structure, a publicly known and commonly used technique for introducing an imide ring into the carboxyl group-containing resin can be used. Examples thereof include a resin obtained by reacting a carboxylic anhydride component with an amine component and / or an isocyanate component. The imidization may be performed by thermal imidization or chemical imidization, and these can be used in combination.

  Here, examples of the carboxylic acid anhydride component include tetracarboxylic acid anhydrides and tricarboxylic acid anhydrides, but are not limited to these acid anhydrides, and acid anhydrides that react with amino groups or isocyanate groups. Any compound having a physical group and a carboxyl group can be used, including derivatives thereof. These carboxylic anhydride components may be used alone or in combination.

  Examples of the tetracarboxylic acid anhydride include pyromellitic dianhydride, 3-fluoropyromellitic dianhydride, 3,6-difluoropyromellitic dianhydride, 3,6-bis (trifluoromethyl) pyro Merit acid dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic acid Anhydride, 2,2′-difluoro-3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 5,5′-difluoro-3,3 ′, 4,4′-biphenyltetracarboxylic acid Anhydride, 6,6′-difluoro-3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 5,5 ′, 6,6′-hexafluoro-3,3 ′ , 4,4'-biphenyltet Carboxylic dianhydride, 2,2′-bis (trifluoromethyl) -3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 5,5′-bis (trifluoromethyl) -3, 3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 6,6′-bis (trifluoromethyl) -3,3 ′, 4,4′-biphenyltetracarboxylic 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" "-kinkphenyltetracarboxylic acid Dianhydride, methylene-4,4′-diphthalic dianhydride, 1,1-ethynylidene-4,4′-diphthalic dianhydride, 2,2-propylidene-4,4′-diphthalic dianhydride 1,2-ethylene-4,4′-diphthalic dianhydride, 1,3-trimethylene-4,4′-diphthalic dianhydride, 1,4-tetramethylene-4,4′-diphthalic acid Anhydride, 1,5-pentamethylene-4,4'-diph Talic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, difluoromethylene-4,4′-diphthal Acid 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-dicarboxyphene) ) -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-Dicarboxyphenyl) -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-naphthalene Tetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic Acid dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid Anhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3 ′ , 4,4′-bicyclohexyltetracarboxylic dianhydride, 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-ethynylidene-4,4′-bis (cyclohexane) San-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-dicarboxylic acid) dianhydride Thio-4,4′-bis (cyclohexane-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 acid Anhydride, 3, 3 ', 5, 5', 6 6′-hexafluorooxy-4,4′-diphthalic dianhydride, 3,3′-bis (trifluoromethyl) oxy-4,4′-diphthalic dianhydride, 5,5′-bis (tri Fluoromethyl) oxy-4,4′-diphthalic dianhydride, 6,6′-bis (trifluoromethyl) oxy-4,4′-diphthalic dianhydride, 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'-diflu Orosulfonyl-4,4′-diphthalic dianhydride, 5,5′-difluorosulfonyl-4,4′-diphthalic dianhydride, 6,6′-difluorosulfonyl-4,4′-diphthalic dianhydride 3,3 ′, 5,5 ′, 6,6′-hexafluorosulfonyl-4,4′-diphthalic dianhydride, 3,3′-bis (trifluoromethyl) sulfonyl-4,4′- Diphthalic dianhydride, 5,5′-bis (trifluoromethyl) sulfonyl-4,4′-diphthalic dianhydride, 6,6′-bis (trifluoromethyl) sulfonyl-4,4′-diphthalic acid Dianhydride, 3,3 ′, 5,5′-tetrakis (trifluoromethyl) sulfonyl-4,4′-diphthalic dianhydride, 3,3 ′, 6,6′-tetrakis (trifluoromethyl) sulfonyl -4,4'-diphthalate Dianhydride, 5,5 ′, 6,6′-tetrakis (trifluoromethyl) sulfonyl-4,4′-diphthalic dianhydride, 3,3 ′, 5,5 ′, 6,6′-hexakis ( Trifluoromethyl) sulfonyl-4,4′-diphthalic dianhydride, 3,3′-difluoro-2,2-perfluoropropylidene-4,4′-diphthalic dianhydride, 5,5′-difluoro -2,2-perfluoropropylidene-4,4'-diphthalic 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'-diphthalate Acid dianhydride, 5,5′-bis (trifluoromethyl) -2,2-perfluoropropylidene-4,4′-diphthalic dianhydride, 6,6′-difluoro-2,2-perfluoro Propylidene-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'-diph Talic dianhydride, 9-phenyl-9- (trifluoromethyl) 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] fluorene dianhydride, 9,9-bis [4- (2,3-dicarboxy) phenyl] fluorene dianhydride, ethylene glycol bistrimellitic dianhydride, 1,2- ( Ethylene) bis (trimellitic anhydride), 1,3- (trimethylene) bis (trimellitic anhydride), 1,4- (tetramethylene) bis (trimellitic anhydride), 1,5- (pentamethylene) bis (trimetic anhydride) Retate anhydride), 1,6- (hexamethylene) bis (trimellitic anhydride), 1,7- (heptamethylene) bis (trimellitate anhydride), 1,8- (octamethylene) bis (trimellitic anhydride), 1,9- (nonamethylene) bis (trimellitic anhydride), 1,10- (decamethylene) bis (trimellitic anhydride), 1,12- (dodecamethylene) bis (trimellitic anhydride), 1,16- (hexadeca) Methylene) bis (trimellitate anhydride), 1,18- (octadecamethylene) bis (trimellitate anhydride), and the like. Examples of the tricarboxylic acid anhydride include trimellitic acid anhydride and nuclear hydrogenated trimellitic acid anhydride.

  Examples of the amine component include diamines such as aliphatic diamines and aromatic diamines, polyvalent amines such as aliphatic polyether amines, diamines having carboxylic acids, and diamines having phenolic hydroxyl groups. It is not limited to. These amine components may be used alone or in combination.

  Examples of the diamine include one diamine nucleus diamine such as p-phenylenediamine (PPD), 1,3-diaminobenzene, 2,4-toluenediamine, 2,5-toluenediamine, and 2,6-toluenediamine. , 4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, diaminodiphenyl ethers such as 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 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′-diaminodiphenylme , Bis (4-aminophenyl) sulfide, 4,4′-diaminobenzanilide, 3,3′-dichlorobenzidine, 3,3′-dimethylbenzidine (o-tolidine), 2,2′-dimethylbenzidine (m -Toridine), 3,3'-dimethoxybenzidine, 2,2'-dimethoxybenzidine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diamino Diphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3, 3'-diaminobenzophenone, 3,3'-diamino- , 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, 4,4 ′ -Two diamine diamines such as diaminodiphenyl sulfoxide, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane 1,3-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1,4-bis (4-aminophenyl) ) 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-aminophenyl sulfide) benzene, 1,3-bis (4-aminophenyl sulfide) benzene, 1,4-bis (4-aminophenyl) Rufido) 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) isopropyl] benzene, etc. Benzene nucleus of three diamines, 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] ether, bis [3- ( -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) phenyl] ketone, bis [3- (3-amino Phenoxy) 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] propane, 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-he Safluoropropane, 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] -1,1,1,3,3,3-hexa Aromatic diamines such as four diamines of benzene nucleus such as fluoropropane, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1 It includes aliphatic diamines of 2-diaminocyclohexane, etc., the aliphatic polyether amines, polyvalent amines ethylene glycol and / or propylene glycol and the like.

  Examples of the amine having a carboxyl group include 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, diaminobenzoic acids such as 3,4-diaminobenzoic acid, and 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′-di Carboxybiphenyl compounds such as carboxybiphenyl, 4,4′-diamino-2,2′-dicarboxybiphenyl, 4,4′-diamino-2,2 ′, 5,5′-tetracarboxybiphenyl, 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′-diamino- Carboxydiphenylalkanes such as carboxydiphenylmethane such as 2,2 ′, 5,5′-tetracarboxydiphenylmethane, 3,3′-diamino-4,4′-dicarboxydiphenyl ether, 4,4′-diamino-3,3 Carboxydiphenyl ether compounds such as '-dicarboxydiphenyl ether, 4,4'-diamino-2,2'-dicarboxydiphenyl ether, 4,4'-diamino-2,2', 5,5'-tetracarboxydiphenyl ether, 3, 3'-diamino-4,4'-dicarboxydiphenylsulfur 4,4′-diamino-3,3′-dicarboxydiphenyl sulfone, 4,4′-diamino-2,2′-dicarboxydiphenyl sulfone, 4,4′-diamino-2,2 ′, 5 Diphenyl sulfone compounds such as 5′-tetracarboxydiphenyl sulfone, bis [(carboxyphenyl) phenyl] alkane compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] propane, 2, Examples thereof include bis [(carboxyphenoxy) phenyl] sulfone compounds such as 2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone.

  Diisocyanates such as aromatic diisocyanates and their isomers and multimers, aliphatic diisocyanates, alicyclic diisocyanates and their isomers, and other general-purpose diisocyanates can be used as the isocyanate component. It is not limited. These isocyanate components may be used alone or in combination.

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

(3) Carboxyl group-containing resin having an amide structure and not having an imide structure The carboxyl group-containing resin having an amide structure and not having an imide structure is particularly limited as long as it is a resin having a carboxyl group and an amide bond. Not.

  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, and 60 to 150 mgKOH in order to cope with the photolithography process. / G is more preferable. If the acid value is 20 mgKOH / g or more, the solubility in alkali increases, the developability becomes good, and further, the degree of crosslinking with the thermosetting component after light irradiation increases, so that sufficient development contrast is obtained. Can be obtained. On the other hand, when the acid value is 200 mgKOH / g or less, accurate pattern drawing is facilitated. In particular, so-called heat fogging in the PEB (POST EXPOSURE BAKE) step after light irradiation described later can be suppressed, and the process margin is large. Become.

  In addition, the molecular weight of such a carboxyl group-containing resin is preferably 100,000 or less, more preferably 1,000 to 100,000, considering the developability and cured coating properties, 2,000 to 50,000 is more preferable. When the molecular weight is 100,000 or less, the alkali solubility in the unexposed area is increased and the developability is improved. On the other hand, when the molecular weight is 1,000 or more, sufficient development resistance and cured properties can be obtained in the exposed area after exposure and PEB.

(Photopolymerization initiator)
As the photopolymerization initiator used in the resin layer (B), known and commonly used photopolymerization initiators can be used. In particular, when used in the PEB process after light irradiation described later, the light also has a function as a photobase generator. A polymerization initiator is preferred. In this PEB step, a photopolymerization initiator and a photobase generator may be used in combination.

A photopolymerization initiator that also functions as a photobase generator is a polymer that undergoes a polymerization reaction of a thermoreactive compound, which will be described later, when the molecular structure is changed by light irradiation such as ultraviolet light or visible light, or when the molecule is cleaved. It is a compound that produces one or more basic substances that can function as a catalyst. Examples of basic substances include secondary amines and tertiary amines.
Examples of the photopolymerization initiator that also functions as a photobase generator include α-aminoacetophenone compounds, oxime ester compounds, acyloxyimino groups, N-formylated aromatic amino groups, and N-acylated aromatics. And compounds having a substituent such as a group amino group, a nitrobenzyl carbamate group, and an alkoxybenzyl carbamate group. Among these, an oxime ester compound and an α-aminoacetophenone compound are preferable, and an oxime ester compound is more preferable. As the α-aminoacetophenone compound, those having two or more nitrogen atoms are particularly preferable.

  The α-aminoacetophenone compound is not particularly limited as long as it has a benzoin ether bond in the molecule and is cleaved within the molecule when irradiated with light to produce a basic substance (amine) that exhibits a curing catalytic action.

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

  Such a photoinitiator may be used individually by 1 type, and may be used in combination of 2 or more type. 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 parts by mass or more, the development resistance contrast of the light irradiated part / non-irradiated part can be favorably obtained. Moreover, in 40 mass parts or less, hardened | cured material characteristic improves.

(Thermo-reactive compound)
As the thermoreactive compound, a known and commonly used compound having a functional group capable of curing reaction by heat such as a cyclic (thio) ether group, for example, an epoxy compound 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 type. Epoxy resin, trihydroxyphenylmethane type epoxy resin, bixylenol type or biphenol type epoxy resin 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 xylenoyl ethane resin, naphthalene group-containing epoxy resin, epoxy resin having dicyclopentadiene skeleton, glycidyl meta Acrylate copolymer epoxy resins, copolymerized epoxy resins of cyclohexylmaleimide and glycidyl methacrylate, and the like CTBN modified epoxy resin.

  As a compounding quantity of the said thermoreactive compound, equivalent ratio (alkali-soluble groups, such as a carboxyl group: thermal-reactive groups, such as an epoxy group) with alkali-soluble resin is 1: 0.1 to 1:10. It is preferable. By setting the mixing ratio in such a range, the development is good and a fine pattern can be easily formed. The equivalent ratio is more preferably 1: 0.2 to 1: 5.

(Block copolymer)
The block copolymer is a resin layer that constitutes the laminated structure of the present invention in order to realize a good balance of higher flexibility than ever, particularly excellent crack resistance against excessive folds, and excellent heat resistance. It is the most characteristic component in (B).
The block copolymer generally means a copolymer having a molecular structure in which two or more kinds of polymer units having different properties are connected by a covalent bond to form a long chain. In the present invention, as the block copolymer, a known and usual one can be used, and an XY type or XYX type block copolymer is preferable, and an XYX type block copolymer is used. Is more preferable. X in the XY-X type block copolymer may be the same or different from each other.

  In the XY type or XYX type block copolymer, X is preferably a polymer unit having a glass transition point Tg of 0 ° C. or higher. More preferably, X is a polymer unit having a glass transition point Tg of 50 ° C. or higher. Y is preferably a polymer unit having a glass transition point Tg of less than 0 ° C., more preferably a polymer unit having a glass transition point Tg of −20 ° C. or less. The glass transition point Tg is measured by differential scanning calorimetry (DSC).

  The block copolymer is preferably solid at 20 to 30 ° C. In this case, it is sufficient if it is solid within this range, and it may be solid even at a temperature outside this range. By being solid in the above temperature range, it is excellent in tackiness when formed into a dry film or applied to a substrate and temporarily dried.

  Among the XY-X type block copolymers, those in which X is highly compatible with the heat-reactive compound are preferable, and those in which Y is low in compatibility with the heat-reactive compound are preferable. Thus, it is considered that a specific structure in the matrix can be easily shown by using a block copolymer in which the blocks at both ends are compatible with the matrix and the central block is incompatible with the matrix.

  The polymer unit X is preferably polymethyl methacrylate (PMMA), polystyrene (PS) or the like, and the polymer unit Y is preferably poly n-butyl (meth) acrylate (PBA) or polybutadiene (PB). In addition, a hydrophilic unit excellent in compatibility with an alkali-soluble resin typified by a styrene unit, a hydroxyl group-containing unit, a carboxyl group-containing unit, an epoxy group-containing unit, an N-substituted acrylamide unit, etc. is provided as part of the polymer unit X. When introduced, the compatibility can be further improved. It is particularly preferable to introduce an epoxy group-containing unit into a part of the polymer unit X. Among the above, the polymer unit X is preferably polystyrene, polyglycidyl methacrylate, N-substituted polyacrylamide, polymethyl (meth) acrylate, a carboxylic acid-modified product or a hydrophilic group-modified product thereof. Y is preferably poly n-butyl (meth) acrylate or polybutadiene. X and Y may each be composed of one type of polymer unit, or may be composed of polymer units of two or more components.

  Examples of the method for producing the block copolymer include the methods described in JP-T 2005-515281 and JP-T 2007-516326.

  As a commercial item of an XYX type block copolymer, the acryl-type triblock copolymer manufactured using the living polymerization made from Arkema is mentioned. Specific examples thereof include XYX type block copolymers represented by polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate (for example, M51, M52, M53, M22, etc.), and further carboxylic acid modification. XYX type block copolymers (for example, SM4032XM10 etc.) and XYX type block copolymers (for example, M52N, M22N, M65N etc.) subjected to hydrophilic group modification treatment.

  Moreover, the mass average molecular weight (Mw) of a block copolymer is 20,000-400,000 normally, and what is in the range of 30,000-300,000 is preferable. The molecular weight distribution (Mw / Mn) is preferably 3 or less.

  When the weight average molecular weight is 20,000 or more, the composition has the mechanical properties such as flexibility and elasticity, and the tackiness is not increased too much, and the effect of improving the flexibility and crack resistance is improved. The property is also good. On the other hand, when the mass average molecular weight is 400,000 or less, the viscosity of the composition does not become too high, and the printability and developability are unlikely to deteriorate.

  A block copolymer may be used individually by 1 type, and may be used in combination of 2 or more type. 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, flexibility and heat resistance are improved, and when it is 60 parts by mass or less, a balance between flexibility and heat resistance is improved.

  In the resin composition used in the resin layer (A) and the resin layer (B) as described above, the following components can be blended as necessary.

(Polymer resin)
For the purpose of improving the flexibility and dryness of the touch of the resulting cured product, the polymer resin can be blended with known ones except for the block copolymer described above. 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. This polymer resin may be used individually by 1 type, and may use 2 or more types together.

(Inorganic filler)
An inorganic filler can be mix | blended in order to suppress the cure shrinkage of hardened | cured material and to improve characteristics, such as adhesiveness 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, Neuburg Sicilius Earth etc. are mentioned.

(Coloring agent)
As the colorant, known and commonly used 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)
An organic solvent can be mix | blended for the preparation of a resin composition, and the viscosity adjustment for apply | coating to a base material or a carrier film. Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. Such an organic solvent may be used individually by 1 type, and may be used as a 2 or more types of mixture.

(Other ingredients)
If necessary, components such as a mercapto compound, an adhesion promoter, an antioxidant, and an ultraviolet absorber can be further blended. As these, known and commonly used ones can be used. In addition, known and commonly used thickeners such as finely divided silica, hydrotalcite, organic bentonite, montmorillonite, defoamers and / or leveling agents such as silicones, fluorines and polymers, silane coupling agents, rust inhibitors Known and conventional additives such as can be blended.

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

  The laminated structure of the present invention according to the configuration as described above is preferably used as a dry film in which at least one surface is supported or protected by a film.

(Dry film)
The dry film of the present invention can be produced, for example, as follows. That is, first, on the carrier film (support film), the composition constituting the resin layer (B) and the composition constituting the resin layer (A) are each diluted with an organic solvent and adjusted to an appropriate viscosity. According to a conventional method, coating is performed sequentially by a known method such as a comma coater. Then, normally, the dry film which consists of a resin layer (B) and a resin layer (A) can be formed on a carrier film by drying at the temperature of 50-130 degreeC for 1 to 30 minutes. A peelable cover film (protective film) can be further laminated on the dry film for the purpose of preventing dust from adhering to the surface of the film. As the carrier film and the cover film, conventionally known plastic films can be used as appropriate. When the cover film is peeled off, the adhesive force between the resin layer and the carrier film may be smaller. preferable. Although there is no restriction | limiting in particular about the thickness of a carrier film and a cover film, Generally, it selects suitably in the range of 10-150 micrometers.

(Flexible printed circuit board)
The flexible printed wiring board of the present invention comprises an insulating film formed by forming a layer of the laminated structure of the present invention on a flexible printed wiring substrate, patterning by light irradiation, and forming the pattern in a batch with a developer. It is what you have.

(Method for manufacturing a wiring board)
The manufacture of a flexible printed wiring board using the laminated structure of the present invention can be performed according to the procedure shown in the process diagram of FIG. That is, a step of forming the layer of the laminated structure of the present invention on the flexible wiring substrate on which the conductor circuit is formed (lamination step), a step of irradiating the layer of the laminated structure with active energy rays in a pattern (exposure step) ) And a step (development step) in which the layer of the laminated structure is alkali-developed to form a layer of the patterned laminated structure at once (development step). In addition, if necessary, after alkali development, further photocuring or thermosetting (post-cure process) can be performed to completely cure the layer of the laminated structure to obtain a highly reliable flexible printed wiring board. .

  Moreover, the manufacture of the flexible printed wiring board using the laminated structure of the present invention can also be performed according to the procedure shown in the process diagram of FIG. That is, a step of forming the layer of the laminated structure of the present invention on the flexible wiring substrate on which the conductor circuit is formed (lamination step), a step of irradiating the layer of the laminated structure with active energy rays in a pattern (exposure step) ), A step of heating the layer of the laminated structure (heating (PEB) step), and a step of alkali-developing the layer of the laminated structure to form a layer of the patterned laminated structure (developing step) It is a manufacturing method containing. In addition, if necessary, after alkali development, further photocuring or thermosetting (post-cure process) can be performed to completely cure the layer of the laminated structure to obtain a highly reliable flexible printed wiring board. . In particular, when a carboxyl group-containing resin having at least one of an imide structure and an amide structure is used in the resin layer (B), it is preferable to use the procedure shown in the process diagram of FIG.

Hereafter, each process shown in FIG. 1 or FIG. 2 is demonstrated in detail.
[Lamination process]
In this step, a resin layer 3 (resin layer (A)) made of an alkali-developable resin composition containing an alkali-soluble resin and the like is formed on the flexible printed wiring substrate 1 on which the conductor circuit 2 is formed, And a resin layer 4 (resin layer (B)) made of a photosensitive thermosetting resin composition containing an alkali-soluble resin or the like. Here, each resin layer constituting the laminated structure forms, for example, the resin layers 3 and 4 by sequentially applying and drying the resin composition constituting the resin layers 3 and 4 on the wiring substrate 1. Alternatively, the resin composition that forms the resin layers 3 and 4 may be formed by laminating the resin composition in the form of a two-layer dry film on the wiring substrate 1.

  The application method of the resin composition to the wiring substrate may be a known method such as a blade coater, a lip coater, a comma coater, or a film coater. Also, the drying method is a method using a hot-air circulation type drying furnace, IR furnace, hot plate, convection oven, etc., equipped with a heat source of the heating method by steam, and the hot air in the dryer is counter-contacted and supported by the nozzle A known method such as a method of spraying on the body may be used.

  As a method of laminating the resin composition on the wiring substrate, it is preferable to use a vacuum laminator or the like to bond under pressure and heating. By using such a vacuum laminator, even if there are irregularities on the surface of the wiring substrate, the dry film adheres to the wiring substrate, so there is no mixing of bubbles, and filling of the recesses on the surface of the wiring substrate is possible. Will also improve. The pressurizing 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 into a negative pattern by irradiation with active energy rays, and the exposed portion is cured. In the case of a composition using a 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 apparatus, 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 within this range, the photopolymerization initiator can be activated efficiently. Moreover, although the exposure amount changes with film thickness etc., it can usually be set to 100-1500 mJ / cm < ² >.

[PEB process]
In this step, after exposure, the exposed portion is cured by heating the resin layer. In this step, a base generated in the exposure step of the resin layer (B) made of a composition using a photopolymerization initiator having a function as a photobase generator or a combination of a photopolymerization initiator and a photobase generator is used. By this, the resin layer (B) can be cured to a deep part. The heating temperature is, for example, 80 to 140 ° C. The heating time is, for example, 10 to 100 minutes. Since the curing of the resin composition in the present invention is, for example, a ring-opening reaction of an epoxy resin by a thermal reaction, distortion and curing shrinkage can be suppressed as compared with a case where curing proceeds by 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 cover lay and a solder resist. The developing method can be a known method such as dipping. As the developer, sodium carbonate, potassium carbonate, potassium hydroxide, amines, imidazoles such as 2-methylimidazole, alkaline aqueous solutions such as tetramethylammonium hydroxide aqueous solution (TMAH), or a mixed solution thereof. Can be used.

[Post cure process]
In this step, after the development step, the insulating film is completely thermoset 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. Note that the insulating film may be further irradiated with light before or after the post cure.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited by these Examples and a comparative example.

<Synthesis Example 1: Synthesis Example of Polyimide Resin Solution>
To a separable three-necked flask equipped with a stirrer, a nitrogen introduction tube, a fractionation ring, and a cooling ring, 22.4 g of 3,3′-diamino-4,4′-dihydroxydiphenylsulfone, 2,2′-bis [4 -(4-aminophenoxy) phenyl] propane 8.2 g, NMP 30 g, γ-butyrolactone 30 g, 4,4′-oxydiphthalic anhydride 27.9 g, trimellitic anhydride 3.8 g, The mixture was stirred at room temperature and 100 rpm for 4 hours under a nitrogen atmosphere. Next, 20 g of toluene was added, and the mixture was stirred for 4 hours while distilling off toluene and water at a silicon 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 equivalent was 390.

(Examples 1-6 and Comparative Examples 1-4)
In accordance with the component composition described in Table 1 and Table 2, the materials described in Examples 1 to 6 and Comparative Examples 1 to 4 were blended, premixed with a stirrer, kneaded with a three-roll mill, and each resin layer The resin composition for forming was prepared. Unless otherwise specified, the values in the table are parts by mass of the solid content.

<Formation of resin layer (A)>
A flexible printed wiring board on which a circuit with a copper thickness of 18 μm was formed was prepared, and pretreated using MEC CZ-8100. Then, the film thickness after drying each resin composition which comprises each resin layer (A) obtained in Examples 1-6 and Comparative Examples 1-4 on the flexible printed wiring board which performed the pre-processing is 25 micrometers. It applied so that it might become. Then, it dried at 90 degreeC / 30 minutes with the hot-air circulation type drying furnace, and formed the resin layer (A).

<Formation of resin layer (B)>
On the resin layer (A) formed above, the resin composition constituting each resin layer (B) obtained in Examples 1 to 6 and Comparative Examples 1 to 4 has a thickness of 10 μm after drying. It applied so that it might become. Then, it dried at 90 degreeC / 30 minutes with the hot-air circulation type drying furnace, and formed the resin layer (B).

  Thus, the unhardened laminated structure which consists of the resin layer (A) and resin layer (B) which were described in Examples 1-6 and Comparative Examples 1-4 on the flexible printed wiring base material was formed.

<Flexibility>
(Preparation of test piece)
For the uncured laminated structure on each flexible printed wiring board on which the laminated structure is formed as described above, first, using a metal halide lamp mounted exposure apparatus (HMW-680-GW20), through a negative mask. The entire surface was exposed at 500 mJ / cm ² . Then, after performing a PEB process at 90 ° C. for 30 minutes, development (30 ° C., 0.2 MPa, 1 mass% Na ₂ CO ₃ aqueous solution) is performed for 60 seconds, and cured by heat curing at 150 ° C. × 60 minutes. A flexible printed wiring board on which the laminated structure was formed was produced.
And this flexible printed wiring board was cut | disconnected to about 15 mm x about 110 mm, and the test piece was produced.

(MIT test)
Each test piece obtained was subjected to an MIT test in accordance with JIS P8115 using a MIT folding fatigue tester D type (manufactured by Toyo Seiki Seisakusho), and the flexibility was evaluated. Specifically, as shown in FIG. 3, with the test piece 10 mounted on the apparatus and a load F (0.5 kgf) applied, the test piece 10 is vertically attached to the clamp 11, and the bending angle α is Folding was performed at 135 degrees and a speed of 175 cpm, and the number of reciprocating bending (times) until breaking was measured. The test environment was 25 ° C.
The evaluation criteria are as follows.
(Double-circle): It bent 200 times or more, and the crack did not enter into the cured coating film of the bending part.
O: 170-199 was bent and cracks were not generated.
(Triangle | delta): It bent 150-169, and the crack did not enter similarly.
X: Cracks occurred when the number of bendings was 149 or less.

(Shell fold test)
Furthermore, the bendability was evaluated when each of the obtained test pieces was subjected to a shell fold test under the excessive conditions shown below. Specifically, as shown in FIG. 4, the test piece 10 is sandwiched between two flat plates 12 in a state where the test piece 10 is bent at 180 ° so that the surface X of the conductor circuit and the cured coating film is on the outside. After applying G (1 kg standard weight) for 10 seconds and folding it, the operation of checking whether the cured coating film part 20 at the bent part is cracked using an optical microscope is regarded as one cycle. The number of times before it occurred was recorded. The test environment was 25 ° C.
The evaluation criteria are as follows.
(Double-circle): It bent | folded 10 times or more and the crack did not arise in the cured coating film of the bending part.
O: 6-9 were bent and cracks were not generated.
(Triangle | delta): It bent 3-5, and the crack did not arise similarly.
X: Cracks occurred when the number of bendings was 2 or less.
These evaluation results are shown in Table 1 and Table 2 together.

<Heat resistance>
For the uncured laminated structure on each flexible printed wiring substrate on which the laminated structure is formed as described above, first, using a metal halide lamp mounted exposure apparatus (HMW-680-GW20), the diameter is formed on copper. It exposed at 500 mJ / cm < ² > through the negative mask in which the opening of about 2 mm to 5 mm is formed. Then, after performing a PEB process at 90 ° C. for 30 minutes, development (30 ° C., 0.2 MPa, 1 mass% Na ₂ CO ₃ aqueous solution) is performed for 60 seconds, and cured by heat curing at 150 ° C. × 60 minutes. A flexible printed wiring board (test board) on which the laminated structure was formed was produced.

A rosin-based flux was applied to the test substrate and immersed in a solder bath set at 260 ° C. and 280 ° C. in advance for 10 seconds to evaluate the occurrence of floating, swelling and peeling of the cured coating film.
The evaluation criteria are as follows.
A: No floating, swelling, or peeling occurred in any immersion at 260 ° C. and 280 ° C.
◯: No floatation, blistering, or peeling occurred at 260 ° C. immersion, but floating, swelling, or peeling occurred at 280 ° C. immersion.
X: Floating and peeling occurred in both immersion at 260 ° C. and 280 ° C.
The evaluation results are shown in Table 1 and Table 2 together.

<Resolution>
First, using an exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp, an uncured laminated structure on each flexible printed wiring board on which the laminated structure is formed as described above is 500 mJ through a negative mask. The pattern exposure was performed so as to form an opening having a diameter of 200 μm at / cm ² . Then, after performing a PEB process at 90 ° C. for 30 minutes, development (30 ° C., 0.2 MPa, 1 mass% Na ₂ CO ₃ aqueous solution) is performed in 60 seconds to draw a pattern, and heat curing is performed at 150 ° C. × 60 minutes. As a result, a flexible printed wiring board on which a cured laminated structure having openings was formed was produced. The opening formed in the laminated structure of the obtained flexible printed wiring board was observed with an optical microscope adjusted to 100 times, and the resolution was evaluated.
The evaluation criteria are as follows.
◯: The opening is completely formed.
×: No opening was formed.
The evaluation results are shown in Table 1 and Table 2 together.

＊１）アルカリ溶解性樹脂１： ＺＡＲ−１０３５：酸変性ビスフェノールＡ型エポキシアクリレート，酸価９８ｍｇＫＯＨ／ｇ（日本化薬（株）製）
＊２）ポリイミド樹脂： ＰＩ−１：合成例１
＊３）光硬化性モノマー： ＢＰＥ−５００：エトキシ化ビスフェノールＡジメタクリレート（新中村化学（株）製）
＊４）エポキシ樹脂： Ｅ８２８：ビスフェノールＡ型エポキシ樹脂，エポキシ当量１９０，質量平均分子量３８０（三菱化学（株）製）
＊５）光重合開始剤： ＩＲＧＡＣＵＲＥ ＯＸＥ０２：オキシム系光重合開始剤（ＢＡＳＦ社製）
＊６）ブロック共重合体１： Ｍ５２Ｎ：Ｘ−Ｙ−Ｘ型ブロック共重合体 質量平均分子量（Ｍｗ）約１００，０００、アルケマ社製、ＮＡＮＯＳＴＲＥＮＧＴＨ（登録商標）
＊７）ブロック共重合体２： Ｍ６５Ｎ：Ｘ−Ｙ−Ｘ型ブロック共重合体 質量平均分子量（Ｍｗ）約１００，０００〜３００，０００、アルケマ社製，ＮＡＮＯＳＴＲＥＮＧＴＨ（登録商標）
＊８）アルカリ溶解性樹脂２： Ｐ７−５３２：ポリウレタンアクリレート，酸価４７ｍｇＫＯＨ／ｇ（共栄社化学（株）製）

* 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 (manufactured by Mitsubishi Chemical Corporation)
* 5) Photopolymerization initiator: IRGACURE OXE02: Oxime-based photopolymerization initiator (BASF)
* 6) Block copolymer 1: M52N: XYX type block copolymer Mass average molecular weight (Mw) of about 100,000, manufactured by Arkema, NANOSTRENGTH (registered trademark)
* 7) Block copolymer 2: M65N: XYX type block copolymer Mass average molecular weight (Mw) of about 100,000 to 300,000, manufactured by Arkema, 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 clear from the evaluation results shown in the above table, in the laminated structure of each example, the flexibility, heat resistance and solution of the upper layer resin layer (B) are contained by including a block copolymer. It can be seen that excellent performance is obtained for any of the image properties. On the other hand, in Comparative Example 1 and Comparative Example 2 having a single layer structure, the flexibility, particularly the excellent crack resistance against excessive fold folding, is insufficient, and the block copolymer can be used even in a laminated structure. In Comparative Example 3 which does not contain, good results were obtained with respect to heat resistance, but flexibility, particularly excellent crack resistance against excessive hull folding, is insufficient. Moreover, 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. Excellent crack resistance and resolving power against folds.
As described above, by including the block copolymer in the upper resin layer (B) in the laminated structure in which the two resin layers are laminated, the photosensitive resin composition originally such as resolution can be obtained. While maintaining the above characteristics, it is possible to improve the flexibility, in particular, the excellent crack resistance and heat resistance against excessive seam folding in a well-balanced manner.

DESCRIPTION OF SYMBOLS 1 Flexible printed wiring board 2 Conductor circuit 3 Resin layer 4 Resin layer 5 Mask 10 Test piece 11 Clamp 12 Flat plate 20 Cured coating film part X Formation surface of conductor circuit and cured coating film

Claims (9)

A laminated structure having a resin layer (A) and a resin layer (B) laminated on the flexible printed wiring board via the resin layer (A),
The resin layer (B) is composed of a photosensitive thermosetting resin composition containing an alkali-soluble resin, a photopolymerization initiator, a thermoreactive compound and a block copolymer, and the resin layer (A) Ri Do from alkali development type resin composition comprising an alkali-soluble resin and a heat-reactive compound,
The block copolymer is an XY type or an XYX type, wherein X is a polymer unit having a glass transition point Tg of 0 ° C. or higher, and Y has a glass transition point Tg of less than 0 ° C. A laminated structure characterized by being a polymer unit . The laminated structure according to claim 1 , wherein the block copolymer is of the XYX type .   The laminated structure according to claim 1 or 2, wherein the block copolymer has a mass average molecular weight (Mw) of 20,000 to 400,000.   The laminated structure according to any one of claims 1 to 3, comprising a photobase generator as a photopolymerization initiator of the resin layer (B).   The laminated structure according to any one of claims 1 to 4, wherein the resin layer (A) is made of an alkali developing resin composition that does not contain a photopolymerization initiator.   The laminated structure according to any one of claims 1 to 5, which is used for at least one of a bent portion and a non-bent portion of the flexible printed wiring board.   The laminated structure according to any one of claims 1 to 6, which is used for at least one of a cover lay of a flexible printed wiring board, a solder resist, and an interlayer insulating material.   A dry film, wherein at least one surface of the laminated structure according to any one of claims 1 to 7 is supported or protected by a film.   A flexible printed wiring board comprising an insulating film using the laminated structure according to claim 1.

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