PHOTOSENSITIVE DRY FILM RESIST, PRINTED WIRING BOARD MAKING USE OF THE SAME, AND PROCESS FOR PRODUCING PRINTED WIRING BOARD
The present invention is to provide (i) a photosensitive dry film resist which allows water system development and which is excellent in resolution, flame retardancy, adhesiveness, moisture resistance, electric reliability, and preservation stability, (ii) a method for producing the photosensitive dry film resist, and (iii) usage thereof. The foregoing object can be achieved by using a multi-layer photosensitive dry film resist comprising at least: a first photosensitive layer which essentially includes a binder polymer (A1), a (meth)acrylic compound (B1), a photoreaction initiator (C1), and a flame retardant (D1), and a second photosensitive layer which essentially includes a binder polymer (A2), a (meth)acrylic compound (B2), a photoreaction initiator (C2) and which substantially does not include a flame retardant (D2), wherein: when a weight ratio of the flame retardant (D1) to an entire weight of the first photosensitive layer is defined as a first photosensitive layer flame retardant content and a weight ratio of the flame retardant (D2) to an entire weight of the second photosensitive layer is defined as a second photosensitive layer flame retardant content, the second photosensitive layer flame retardant content is 0 wt % or more and 10 wt % or less, and in case where the first photosensitive layer flame retardant content is 100, the second photosensitive layer flame retardant content is 0 wt % or more and 50 wt % or less.
1 . A multi-layer photosensitive dry film resist, comprising at least:
a first photosensitive layer which essentially includes
a binder polymer (A1),
a (meth)acrylic compound (B1),
a photoreaction initiator (C1), and
a flame retardant (D1); and
a second photosensitive layer which essentially includes
a binder polymer (A2), and
a (meth)acrylic compound (B2),
and which substantially does not include a flame retardant (D2), wherein:
when a weight ratio of the flame retardant (D1) to an entire weight of the first photosensitive layer is defined as a first photosensitive layer flame retardant content and a weight ratio of the flame retardant (D2) to an entire weight of the second photosensitive layer is defined as a second photosensitive layer flame retardant content, the second photosensitive layer flame retardant content is 0 wt % or more and 10 wt % or less, and in case where the first photosensitive layer flame retardant content is 100, the second photosensitive layer flame retardant content is 0 or more and 50 or less.
2 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein the second photosensitive layer further includes a photoreaction initiator (C2) as an essential component.
3 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein the second photosensitive layer is an outermost layer of a multi-layer structure.
4 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein a phosphorus compound is used as the flame retardant (D1) and/or the flame retardant (D2).
5 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein vinyl polymer containing carboxyl group is used as the binder polymer (A1) and/or the binder polymer (A2).
6 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein polyamide acid is used as the binder polymer (A1) and/or the binder polymer (A2).
7 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein polyamide acid partially made of polysiloxane diamine represented by formula (1) is used as the binder polymer (A1) and/or the binder polymer (A2),
where each R 1 independently represents a hydrocarbon whose carbon number is 1 to 5, and each R 2 independently represents an organic group selected from an alkyl group whose carbon number is 1 to 5 and a phenyl group, and n represents an integer from 1 to 20.
8 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein polyamide acid having a constitutional unit represented by formula (2) and a constitutional unit represented by formula (3) is used as the binder polymer (A1) and/or the binder polymer (A2),
where R 1 represents a tetravalent organic group, each R 2 independently represents an alkylene group whose carbon number is 2 to 5, and each R 3 independently represents a methyl group or a phenyl group, and a content of the phenyl group in R 3 is 15% or more and 40% or less, and m is an integer of 4 or more and 20 or less,
where R 4 represents a tetravalent organic group, and R 5 represents a bivalent organic group obtained by excluding two amino groups from aromatic diamine.
9 . The multi-layer photosensitive dry film resist as set forth in claim 8 , wherein the polyamide acid further has a structure represented by formula (4)
where R 6 represents a tetravalent organic group and R 7 has a constitutional unit represented by formula a, b, c, d, e, f, or g,
where m of the formula a represents an integer ranging from 1 to 20, n of the formula a represents an integer ranging from 0 to 10, R 8 of the formula f represents a hydrogen atom, a methyl group, an ethyl group, or a butyl group.
10 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein polyamide acid having a constitutional unit represented by formula (4) and a constitutional unit represented by formula (3) is used as the binder polymer (A1) and/or the binder polymer (A2),
where R 6 represents a tetravalent organic group and R 7 has a constitutional unit represented by formula a, b, c, d, e, f, or g,
where m of the formula a represents an integer ranging from 1 to 20, n of the formula a represents an integer ranging from 0 to 10, R 8 of the formula f represents a hydrogen atom, a methyl group, an ethyl group, or a butyl group,
where R 4 represents a tetravalent organic group, and R 5 represents a bivalent organic group obtained by excluding two amino groups from aromatic diamine.
11 . The multi-layer photosensitive dry film resist as set forth in claim 8 , wherein the constitutional unit represented by the formula (3) includes a constitutional unit in which at least one of aromatic rings bound to the two amino groups of the aromatic diamine in R 5 of the formula (3) has two bonds at a meta position with respect to a main chain.
12 . The multi-layer photosensitive dry film resist as set forth in claim 8 , wherein the aromatic diamine is m-phenylene diamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenylether, 3,3′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, 3,3′-diamino benzanilide, 2,2-bis (3-aminophenyl)hexafluoropropane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 4,4′-bis(3-aminophenoxy)-biphenyl, 1,3-bis(3-aminophenoxy)benzene, bis[4-(3-aminophenoxy)phenyl]sulfone, or 2,2-bis(3-aminophenyl)propane.
13 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein soluble polyimide containing carboxyl group and/or hydroxyl group is used as the binder polymer (A1) and/or the binder polymer (A2).
14 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein soluble polyimide containing carboxyl group and/or hydroxyl group which soluble polyimide is partially made of polysiloxane diamine represented by formula (1) is used as the binder polymer (A1) and/or the binder polymer (A2),
where each R 1 independently represents a hydrocarbon whose carbon number is 1 to 5, and each R 2 independently represents an organic group selected from an alkyl group whose carbon number is 1 to 5 and a phenyl group, and n represents an integer from 1 to 20.
15 . The multi-layer photosensitive dry film resist as set forth in claim 1 , wherein: when a thickness of the first photosensitive layer is regarded as 100, a thickness of the second photosensitive layer is 500 or less.
16 . A printed wiring board, comprising as an insulating protection layer the multi-layer photosensitive dry film resist as set forth in claim 1 .
17 . The printed wiring board as set forth in claim 16 , wherein the photosensitive dry film resist is such that the second photosensitive layer serves as an outermost layer which is in contact with a circuit face and the first photosensitive layer serves as the other outermost layer.
18 . A method for producing a printed wiring board, comprising the step of curing the photosensitive dry film resist as set forth in claim 1 at 180° C. or lower so as to form an insulating protection layer.
19 . The multi-layer photosensitive dry film resist as set forth in claim 10 , wherein the constitutional unit represented by the formula (3) includes a constitutional unit in which at least one of aromatic rings bound to the two amino groups of the aromatic diamine in R 5 of the formula (3) has two bonds at a meta position with respect to a main chain.
20 . The multi-layer photosensitive dry film resist as set forth in claim 10 , wherein the aromatic diamine is m-phenylene diamine, 3,3′-diaminodiphenylmethane, 3,3′-diaminodiphenylether, 3,3′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, 3,3′-diamino benzanilide, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 4,4′-bis(3-aminophenoxy)-biphenyl, 1,3-bis(3-aminophenoxy)benzene, bis[4-(3-aminophenoxy)phenyl]sulfone, or 2,2-bis(3-aminophenyl)propane.