A multilayer wiring board manufacturing method and a multilayer wiring board obtained thereby

A piercing step of forming a via hole by laser processing in the prepreg, and filling a conductive paste containing a resin component and a metal powder on the holes, is copper foil or patterned above and below the filled conductive paste and the method for manufacturing a multilayer substrate including a step of pressing by disposing copper foil portion of the substrate, the alloy type paste metal powder with each other at least a portion of the metal powder as the conductive paste adjacent the molten alloying the use, as a prepreg, the storage modulus at the inflection point to change the storage modulus a, from decrease to increase at the inflection point of the storage elastic modulus is changed from increase to decrease at a temperature profile of raising the temperature from 60 ° C. to 200 ° C. used as 10 or more before preheating the ratio a / B and B, the ratio a / B was preheated prepreg before piercing process By less than 10, obtaining superior multilayer wiring board to the conductive and long-term stability.