| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a multilayered wiring substrate which has superior surface flatness suitable for flip-chip mounting of a semiconductor element and the method by which it can easily be manufactured. SOLUTION: This is a multilayered wiring board C formed by forming an insulating layer 3 containing thermosetting resin, a 2nd wiring circuit layer 4 formed on the top surface of the insulating layer 3, and a wiring layer B having a via hole conductor 9 electrically connecting the 1st wiring layer 2 and the 2nd wiring layer 4, on the top surface of a core substrate A formed by adhering and forming the 1st wiring circuit layer 2 on the top surface of an insulating substrate 1. The 2nd wiring circuit layer 4 is formed of metal foil in an inverse trapezoid shape and embedded in the top surface of the insulating layer 3 in level with the top surface of the insulating layer 3, and a metal plating layer 8 is formed on the internal wall of a via hole 7 formed by irradiation with laser light so that the via hole conductor 9 penetrates the insulating layer 3 and reaches the 1st wiring circuit layer 4.</p> |
