Method for manufacturing circuit board

A method for manufacturing a circuit board, comprising:

• a process of manufacturing a first metal layer being formed into a pattern shape by disposing, on a surface of a first metal foil that is opposite to a surface on which a first insulating base material is to be laminated, a third metal layer containing a metal that is different from the first metal foil and a fourth metal layer in succession and etching the first metal foil from a direction in which the first insulating base material is laminated;
• a process of removing a portion of the third metal layer by etching from the direction in which the first insulating base material is laminated;
• a process of manufacturing a cured first insulating base material in which the first metal layer being formed into a pattern shape is disposed at a first surface, a second metal layer being formed into a pattern shape is disposed at a second surface, and a first through hole that is formed between the first metal layer and the second metal layer is filled with a first conductive paste that connects the first metal layer and the second metal layer;
• a process of removing the entire fourth metal layer by etching;
• a process of removing the entire third metal layer by etching;
• a process of manufacturing a unit component including the first insulating base material and a semi-cured second insulating base material that is disposed on a side of the first insulating base material corresponding to the second surface and in which a second through hole communicating with the second metal layer is filled with a second conductive paste connected to the second metal layer;
• and
• a process of laminating a plurality of unit components by joining to one another the first insulating base material of one of the plurality of the unit components and the second insulating base material of another unit component of the plurality of the unit components.