MULTILAYER WIRING BOARD AND METHOD OF MANUFACTURING SAME

PROBLEM TO BE SOLVED: To solve the problem that a resistance value of a via portion increases if the aperture of a via consisting of conductive paste is decreased, relating to a heat-resistant substrate that uses a conventional film.SOLUTION: A multilayer wiring board 11 at least includes a heat-resistant film 14 whose thickness is 30 μm or less, a wiring 12 fixed on both surfaces of the heat-resistant film 14 through an adhesive layer 13, a hole 23 formed on the heat-resistant film 14, and a conductive paste 21 which is packed in the hole 23 for interlayer connection with the wiring 12. Here, the diameters of the holes 23 differ each other by 10-100% on both surfaces of the heat-resistant film 14. The average thickness of the adhesion layer 13 is 3-25 μm. A ring-like bent part 16 is provided around the hole. Thus, increase in resistance value of the via portion is reduced.