Patent ID: 8710374

Claim:
A method for manufacturing a multilayer printed wiring board, comprising: providing a core substrate having an insulation substrate and a conductive circuit provided on the insulation substrate; forming a first inner insulation layer on a first surface of the core substrate; forming a second inner insulation layer on a second surface of the core substrate opposite to the first surface; roughening surfaces of the first inner insulation layer and the second inner insulation layer; forming a first outer insulation layer on the first inner insulation layer such that a first build-up structure comprising the first outer insulation layer and the first inner insulation layer provided between the first outer insulation layer and the core substrate is formed; forming a second outer insulation layer on the second inner insulation layer such that a second build-up structure comprising the second outer insulation layer and the second inner insulation layer provided between the second outer insulation layer and the core substrate is formed; and forming a solder-resist layer on at least one of the first outer insulation layer and the second outer insulation layer, wherein the insulation substrate, the first outer insulation layer and the second outer insulation layer comprise a reinforcing material, the first inner insulation layer and the second inner insulation layer are free from a reinforcing material, and the first build-up structure and the second build-up structure are formed such that the first and second build-up structures have a same number of insulation layers.