PURPOSE: To provide a solder resist ink compsn. having excellent heat radiatability by incorporating a binder and an inorg. packing material having the thermal conductivity of a specific value or above into the solder resist ink compsn.
CONSTITUTION: A solder resist film 3 is formed on a glass epoxy substrate 1 by partly exposing copper foil 2. This solder resist ink compsn. consists of at least the binder and the inorg. packing material having ≥50W/mK thermal conductivity at 25°C. The film consisting of the solder resist ink compsn. which allows the escape of heat is obtd. by incorporating such inorg. packing material into the compsn. Further, the inorg. packing material has preferably ≥105Ω.cm volmetric resistance value at 25°C. The grain size of the inorg. packing material is preferably ≤50μm and the material thereof consists preferably of ≥1 kinds selected form aluminum nitride (AlN), silicon carbide (SCn) and beryllium oxide (BeO).
HARUKI MUNEYUKI
YAMAMOTO KUNIHARU
