Patent ID: 7045198

Claim:
A method for manufacturing a circuit board comprising: forming a first layer that is an insulating layer including a resin; forming a second layer that is a porous layer including pores that connect an upper and a lower surface of the second layer; forming a laminate of at least one first layer and at least one second layer; forming via holes through the laminate in a thickness direction and filling the via holes with a conductive paste; and heating and pressing the laminate so that the resin included in the first layer flows and is absorbed into the second layer and the conductive paste is compressed into an electrical conductor, wherein the method further comprises: depositing at least one selected from a metal foil and a wiring pattern on at least one surface of the laminate after forming the laminate and before heating and pressing the laminate, and the flow of resin included in the first layer into the second layer is controlled by at least one selected from an open area ratio and an average pore diameter of the pores at the upper and the lower surface of the second layer.