Nec Corporation

Sumitomo Light Metal Industries, Ltd.

Harumi Mizunashi

Yoshio Sato

Fujio Shimizu

Sueo Morishige

Yuji Matubara

Shigetoshi Takasu

A packaged semiconductor device comprises a packaging substrate having a core substrate having core wiring layers formed on opposite surfaces thereof, respectively, and a plurality of core via holes in the core substrate for mutually electrically connecting the core wiring layers formed on the opposite surfaces of the core substrate. Upper and lower buildup layers, each having a wiring layer, are formed on an upper surface and a lower surface of the core substrate, respectively. A semiconductor device chip is mounted on mounting pads formed on the upper buildup layer, and externally connecting electrodes are formed on the lower buildup layer. The position of the core via holes in the core substrate is standardized, regardless of the size of semiconductor device chip to be mounted. When a semiconductor device chip having a different chip size, the mounting pads formed on the upper buildup layer are located to coincide connection terminals of the semiconductor device chip of the different kind to be mounted.

Semiconductor device and process for fabricating the same

A multilayer printed circuit board has a substrate, an inner interconnection layer formed on each surface of the substrate, and an outer interconnection layer overlying each inner interconnection layer. The inner interconnection layer is formed of a copper sheet and two latticed metal films made of a metal having a low thermal expansion coefficient and bonded to boty surfaces of the copper sheet under application of pressure. The area ratio of exposed portions of the copper sheet to the whole surface of the interconnection layer is between 25 and 75%. Thermal expansion coefficient of the resultant circuit board is lowered to be close to the thermal expansion coefficient of a LSI, thereby obtaining reliability of a electronic product due to a low thermal stress. The metallic film is made of Kovar or Invar.

Multilayer printed circuit board having latticed films on an

Heat-radiating fin for a heat sink

Growing community of inventors

Tokyo, Japan

Harumi Mizunashi