Patent ID: 8212365

Claim:
A printed wiring board configured to be connected to an organic substrate in a state where a semiconductor chip is mounted on one surface of said printed wiring board and the other surface of said printed wiring board is connected to said organic substrate, the printed wiring board comprising: a plurality of first layers formed of a material having the same coefficient of thermal expansion as said semiconductor chip; and a plurality of second layers formed of a material having the same coefficient of thermal expansion as said organic substrate, wherein said first layers have different thicknesses from each other and said second layers have different thicknesses from each other; said first layers and said second layers form a lamination by being laminated alternately one layer on another layer; the thicknesses of said first layers decrease from a side where said semiconductor chip is mounted toward a side where said organic substrate is connected; and the thicknesses of said second layers decrease from the side where said organic substrate is connected toward the side where said semiconductor chip is mounted.