Hitachi Chemical Company, Ltd.

Hitoshi Aisawa

Tamotsu Ueyama

Hiroharu Kamiyama

Masaji Homma

Tatsuhisa Shibata

Yukihiko Wada

Takayoshi Komatsu

A novel circuit board in which circuit portions including pad portions, through-hole portions and conductors are formed, at least at the pad portions and the through-hole portions of the circuit, in the vacant portions defined by a cured photopolymeric resin composition and the vacant portions are plated with electroless copper. When only the pad portions and through-hole portions are plated with electroless copper, the conductors are all covered with the resin composition, thereby enabling fears of mechanical and chemical damages to be eliminated. When all the circuit portions are plated with electroless copper, the amount of copper required can be considerably reduced. Such circuit board is prepared by applying onto a laminate with or without copper clad thereon a specific photopolymerizable resin composition, irradiating the resin composition-applied laminate with ultraviolet rays through a pattern mask, treating the thus irradiated laminate with a solvent to remove the unexposed portions of resin composition and applying an electroless copper plating to the unexposed portions. A durable and reliable printed circuit board having a high pecision and high density circuit pattern can be provided very simply, easily at low cost.

Growing community of inventors

Shimodate, Japan

Hitoshi Aisawa