| 摘要 |
PURPOSE:To enhance two insulating layers in adhesion between them and in bonding workability by a method wherein the insulating layer is of two or more-layered structure composed of different insulating resins, and one of the insulating layers is formed of photosensitive insulating resin. CONSTITUTION:An SLC multilayer printed wiring board 1A is provided, wherein a circuit is formed on the copper foil of a copper-clad laminate to serve as a first conductor circuit 31. An insulating layer 4a formed of insulating resin excellent in resistance to cracking and migration is provided onto the surface of the copper-clad laminate on which the first conductor circuit 31 is formed. It is preferable that the insulating layer 4a is formed of alkali-soluble non- photosensitive resin. Then, a photosensitive insulating layer 4b is formed on the surface of the insulating film 4a. The insulating layer 4b is formed of alkali- soluble photosensitive insulating resin excellent in adhesion to a second conductor circuit 81 formed by copper plating. As mentioned above, an insulating layer is composed of two or more layers, so that a multilayer printed wiring board of this constitution is enhanced in electrical reliability. |
