| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the resistance of a via conductor formed by packing conduc tor paste containing metallic powder and an organic resin in a via hole. SOLUTION: A through hole 3 is formed through a laminate composed of an insulating sheet 2 containing an organic resin and a metallic sheet 1 composed of metal foil of at least one kind of metal selected from among Cu, Ag, Au, and Al or formed by applying paste containing conductive powder of the metal by heat-melting the metal in a portion of the metallic sheet 1 by irradiating the portion with laser light and, at the same time, thermally decomposing the spot of the insulating sheet 2 facing the irradiated portion of the metallic sheet 1 by the heat. Then the via hole conductor 5 composed of a metallic body 4 is formed by solidifying the molten metal by cooling.</p> |
