| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable mounting LSI chips on both main surfaces of a wiring board and laminating a plurality of wiring boards on which LSI chips are mounted. SOLUTION: A wiring board is constituted by forming a wiring film 7, on one side of an insulating resin film 5, having an aperture 6 for electric continuity between upper and lower surfaces, and forming on the other side, two kinds of metal protrusions 12, 13 of different height, which are connected with the wiring film 7 through the aperture 6. In this wiring board 14, a solder film 2 is formed selectively on the surface of base metal 1, a metal film 3 is formed on the whole surface, the insulating film 5 having the aperture 6 and the wiring film 7 are formed in the order, and a second solder film 11 is formed on the rear of the base metal 1. By using the solder film 11 as a mask, the base metal 1 is etched, and by using the solder film 2, 11 as masks, the metal film 3 is etched, and the higher metal protrusion 12 and the lower metal protrusion 13 are formed.</p> |
