| 摘要 |
PURPOSE:To enable a printed wiring board to be protected against warpage, distortion, and the like and enhanced in electromagnetic shielding property and heat dissipating property by a method wherein a solid pattern of metal evaporation layer is formed on the printed wiring board as the outermost layer. CONSTITUTION:An inner board 4 of copper plated laminate board is subjected to etching for the formation of a second and a third circuit pattern, 6 and 7. Prepreg and copper foil are laminated on the surface of the inner board 4 and hardened by hot pressing to form an outer board 2, and a first circuit pattern 5 is formed by etching. Thereafter, an outer board 3 and a filled resin 11 are formed. The laminated copper foil is etched to provide a fourth land 8b to the surface of the outer board 3, a through-hole 12 is bored, and a plated through-hole 13 is formed. A fourth solid pattern 15 of copper evaporation layer is formed on the surface of the outer board 3 where the copper foil has been removed through vacuum evaporation. Electromagnetic noises are blocked by the solid pattern 15 to prevent electromagnetic troubles from occurring. |
