Liquid solder resist composition and printed wiring board
A liquid solder resist composition contains a carboxyl group-containing resin (A), a thermosetting component (B), a photopolymerizable component (C), and a photopolymerization initiator (D). The thermosetting component (B) contains a powdery epoxy compound (B11) represented by following formula (1).
1. A liquid solder resist composition comprising:
a carboxyl group-containing resin (A);
a thermosetting component (B);
a photopolymerizable component (C); and
a photopolymerization initiator (D),
the thermosetting component (B) containing an epoxy compound (B1),
the epoxy compound (B1) containing a powdery epoxy compound (B11) represented by following formula (1) and an epoxy compound (B12) other than the epoxy compound (B11),
R 1 , R 2 , R 3 , and R 4 in the formula (1) being independently a methyl group, a hydrogen atom, or a t-butyl group,
the epoxy compound (B11) having a melting point within a range of 138 to 145° C.,
an amount of the epoxy compound (B11) with respect to a total amount of the carboxyl group-containing resin (A), the thermosetting component (B), and the photopolymerizable component (C) being within a range of 4.0 to 8.0 weight %, and
an equivalent weight of epoxy groups in the epoxy compound (B1) with respect to 1 equivalent of carboxyl groups in the carboxyl group-containing resin (A) being within a range of 1.0 to 4.0 equivalent.
2. The liquid solder resist composition according to claim 1 , wherein
the epoxy compound (B12) contains a compound having a inching point or softening point higher than or equal to 60° C.
3. The liquid solder resist composition according to claim 1 , wherein
the epoxy compound (B12) contains an aromatic ring-free compound.
4. The liquid solder resist composition according to claim 1 further comprising titanium dioxide (E).
5. A printed wiring board, comprising a solder resist layer including a cured product of the liquid solder resist composition according to claim 1 .