Photosensitive resin composition, dry film using same, printed wiring board, and method for producing printed wiring board

1. A dry film having a carrier film and a photosensitive layer formed from a photosensitive resin composition comprising (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerization initiator, (C) a thiol group-containing compound, and (E) photopolymerizable compound, wherein the component (A) contains at least one acid-modified vinyl group-containing epoxy resin (A1)which is obtained from a bisphenol-novolak epoxy resin (a1) having a structural unit represented by the following general formula (IV) or (V), and an acid-modified vinyl group-containing epoxy resin (A2) which is obtained from an epoxy resin (a2) differing from the epoxy resin (a1):

wherein R 13 represents a hydrogen atom or a methyl group, Y 4 and Y 5 each independently represent a hydrogen atom or a glycidyl group, and plural R 13 's may be the same or different, with the proviso that at least one of the Y 4 and Y 5 is a glycidyl group;

wherein R 14 represents a hydrogen atom or a methyl group, Y 6 and Y 7 each independently represent a hydrogen atom or a glycidyl group, and plural R 14 's may be the same or different, with the proviso that at least one of the Y 6 and Y 7 is a gylcidyl group, and wherein the thiol group-containing compound (C) is at least one selected from mercaptobenzoxazole, mercaptobenzothiazole and mercaptobenzimidazole.

2. The dry film according to claim 1 , wherein the epoxy resin (a2) is at least one selected from a novolak epoxy resin having a structural unit represented by the following general formula (I), an epoxy resin represented by the following general formula (II′), and an epoxy resin represented by the following general formula (III′)

wherein R 11 represents a hydrogen atom or a methyl group and Y 1 represents a hydrogen atom or a glycidyl group;

wherein R 12 represents a hydrogen atom or a methyl group, Y 2 represents a hydrogen atom or a glycidyl group, plural R 12 's may be the same or different, and n 2 indicates a number from 1 to 100;

wherein Y 3 represents a hydrogen atom or a glycidyl group and plural Y 3 's may be the same or different, with the proviso that at least one of Y 3 is a glycidyl group, and n 3 indicates a number from 1 to 100.

3. The dry film according to claim 2 , wherein the acid-modified vinyl group containing epoxy resin (A1) is one obtained from a bisphenol-novolak epoxy resin containing a structural unit represented by a general formula (IV), and the acid-modified vinyl group-containing epoxy resin (A2) is one obtained from an epoxy resin represented by the general formula (II′).

4. The dry film according to claim 1 , wherein the photopolymerization initiator (B) is an acylphosphine oxide photopolymerization initiator.

5. The dry film according to claim 1 , wherein the photopolymerizable compound (E) is a compound having a (meth)acryloyl group.

6. The dry film according to claim 1 , wherein the acid-modified vinyl group-containing epoxy resins (A1) and (A2) are resins obtained by reacting the epoxy resins (a1) and (a2), respectively, with a vinyl group-containing monocarboxylic acid (b) to obtain, respectively, resins (A1′) and (A2′), and reacting resins (A1′) and (A2′), respectively, with a saturated or unsaturated group-containing polybasic acid anhydride (c).

7. The dry film according to claim 1 , further comprising an inorganic filler (F).

8. The dry film according to claim 1 , further comprising a pigment (D).

9. A printed wiring board comprising a permanent mark resist formed of the dry film having a carrier film and a photosensitive layer according to claim 1 .

10. A method for producing a printed wiring board, comprising, in this order, a step of providing, on a substrate, a photosensitive layer formed from the dry film having a carrier film and a photosensitive layer according to claim 1 , a step of patterning the photosensitive layer, and a step of curing the photosensitive layer to form a permanent mask resist.

11. A dry film having a carrier film and a photosensitive layer formed from a photosensitive resin composition comprising (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerization initiator, (C) a thiol group-containing compound, and (E) a photopolymerizable compound, wherein the component (A) contains at least one acid-modified vinyl group-containing expoxy resin (A1) which is obtained from a bisphenol-novolak epoxy resin (a1) having a structural unit represented by the following general formula (IV) or (V), and an acid-modified vinyl group-containing epoxy resin (A2) which is obtained from an epoxy resin (a 2 ) differing from the epoxy resin (a1):

wherein R 13 represents a hydrogen atom or a methyl group, Y 4 and Y 5 each independently represent a hydrogen atom or a glycidyl group, and plural R 13 's may be the same or different, with the proviso that at least one of Y 4 and Y 5 is a glycidyl group;

wherein R 14 represents a hydrogen atom or a methyl group, Y 6 and Y 7 each independently represent a hydrogen atom or a glycidyl group, and plural R 14 's may be the same or different, with the proviso that at least one of Y 6 and Y 7 is a glycidyl group, and wherein the content of the thiol group-containing compound (C) is, based on the total solid content in the photosensitive resin composition, from 0.01 to 5% by mass.

12. The dry film according to claim 11 , wherein the thiol group-containing compound (C) is at least one selected from mercaptobenzoxazole, mercaptobenzothiazole and mercaptobenzimidazole.

13. The dry film according to claim 11 , wherein the epoxy resin (a2) is at least one selected from a novolak epoxy resin having a structural unit represented by the following general formula (I), an epoxy resin represented by the following general formula (II′), and an epoxy resin represented by the following general formula (III′)

wherein R 11 represents a hydrogen atom or a methyl group and Y 1 represents a hydrogen atom or a glycidyl group;

wherein R 12 represents a hydrogen atom or a methyl group, Y 2 represents a hydrogen atom or a glycidyl group, plural R 12 's may be the same or different, and n 2 indicates a number from 1 to 100;

wherein Y 3 represents a hydrogen atom or a glycidyl group and plural Y 3 's may be the same or different, with the proviso that at least one of Y 3 is a glycidyl group, and n 3 indicates a number from 1 to 100.

14. The dry film according to claim 13 , wherein the acid-modified vinyl group-containing epoxy resin (A1) is one obtained from a bisphenol-novolak epoxy resin containing a structural unit represented by the general formula (IV), and the acid-modified vinyl group-containing epoxy resin (A2) is one obtained from an epoxy resin represented by the general formula (II′).

15. The dry film according to claim 11 , wherein the photopolymerization initiator (B) is an acylphosphine oxide photopolymerization initiator.

16. The dry film according to claim 11 , wherein the photopolymerizable compound (E) is a compound having a (meth)acryloyl group.

17. The dry film according to claim 11 , wherein the acid-modified vinyl group-containing epoxy resins (A1) and (A2) are resins obtained by reacting the epoxy resins (a1) and (a2), respectively, with a vinyl group-containing monocarboxylic acid (b) to obtain, respectively, resins (A1′) and (A2′), and reacting resins (A1′) and (A2′), respectively, with a saturated or unsaturated group-containing polybasic acid anhydride (c).

18. The dry film according to claim 11 , further comprising an inorganic filler (F).

19. The dry film according to claim 11 , further comprising a pigment (D).

20. A printed wiring board comprising a permanent mask resist formed of the dry film having a carrier film and a photosensitive layer according to claim 11 .

21. A method for producing a printed wiring board, comprising, in this order, a step of providing, on a substrate, a photosensitive layer formed from the dry film having a carrier film and a photosensitive layer according to claim 11 , a step of patterning the photosensitive layer, and a step of curing the photosensitive layer to form a permanent mask resist.