摘要 |
PROBLEM TO BE SOLVED: To provide a multilayer circuit substrate, in which a conductor material filled in a via hole is connected surely to a metal wiring layer through an adhesive film, even when fluororesin substrates are to be multilayered, using an adhesive film. SOLUTION: A protrusion 4a of a conductor material 4 filled in a via hole 8 of a fluororesin substrate (core member) 1 is formed at an top edge of the conductor material 4 with a height h from the surface of the core member 1, which is larger than the thickness of the adhesive film 3. In the adhesive film 3, a through-hole 9 is formed at each position that corresponds to each via hole 8, and the protrusion 4a of the conductor material 4 is inserted into the through-hole 9. Each core member 1 is stacked and heat-pressed, to form the multilayer circuit substrate. |