| 摘要 |
A method of forming a semiconductor device having a multi-layered wiring structure that includes a conductor layer to be electrically connected to a packaging substrate, with the multi-layered wiring structure being provided on a circuit formation surface of a semiconductor chip. Ball-like terminals are formed, disposed in a grid array on the surface of the multi-layered wiring structure on the packaging substrate side. The multi-layered wiring structure is formed to include a buffer layer for relieving a thermal stress provided between the semiconductor chip and the packaging substrate, due to the packaging procedure. In the semiconductor device formed, the wiring distance is shorter than that of a conventional semiconductor device, so that an inductance component becomes smaller, to thereby increase signal speed. The distance between a ground layer and a power supply layer is shortened, to reduce noise produced upon operation, and also a thermal stress upon packaging is relieved by the buffer layer of the multi-layered wiring structure, resulting in improved connection reliability, and the number of terminals per unit can be increased, because of elimination of wire bonding. The buffer layer can be made of an elastomer, and can have a modulus of elasticity of 10 kg/mm2 or less. |
