| 摘要 |
PROBLEM TO BE SOLVED: To provide a process of manufacturing a circuit board capable of printing characters and such without using character and symbol printing and such by a screen printing.SOLUTION: The process of manufacturing a circuit board in which, by changing ultraviolet light irradiation amount to a combined coat of a coloring ink layer and a solder resist ink layer (also called as a permanent resist) containing an epoxy resin and an acrylic resin to generate a difference of ratio in crosslinking density and a degree of polymerization of the solder resist ink on the circuit board, differences in refractive index and transparency are generated to make color of the coloring ink visible. |
