| 摘要 |
PURPOSE:To obviate the formation of many vias by forming a step, where the surface of a rigid substrate is exposed, at one part at least of the peripheral margin of a rigid board, and forming a conductor strip for a large current from the step to the specified place of a film-shaped multilayer interconnection part. CONSTITUTION:A fine multilayer interconnection structure is composed of a rigid substrate 20 excellent in heat radiation property and a film-shaped multilayer interconnection part 22 capable of wiring in high density. A step 24 is formed around the film-shaped multilayer interconnection part 22, and a fine wiring pattern is made on the top. The wiring pattern 26 is its one part, and also a conductor strip 30 for a large current is made on the film-shaped multilayer interconnection part 22. The conductor strip 30 extends from the step part 24 to the vicinity of LSI 28. This obviates the necessity to form many vias in the film-shaped multilayer interconnection 22, for the electric connection between the ceramic substrate 20 and an electric part 28 large in current consumption. |
