| 摘要 |
PURPOSE: To provide a printed circuit board with uniform thickness, by laminating a filmy additive adhesive after an undercoating material printed on a patterned inner-layer circuit is semi-cured and hardening the board in a heat treatment step. CONSTITUTION: A both-sided copper clad board made of glass epoxy is patterned to form an inner-layer circuit board 1 with an inner-layer circuit 2. After a copper foil has a black surface in a conventional surface treatment step and dried, both sides of the copper foil is coated with an undercoating material in a screen printing machine and semi-cured in a heat treatment step. Active adhesive with a carrier film 5 is laminated using a hard roller 6 and hardened in a heat treatment step. Then, the board is molded integrally while the shape is kept by the adhesive 4 with a constant film thickness. As a result, accuracy in thickness is improved, regardless of the rate of residual inner-layer copper foil. |
