| 摘要 |
PURPOSE:To enhance an isolation characteristic by a method wherein two or more constant-potential wiring parts are formed in the state of a coaxial cable around the signal wiring parts in the coaxial direction with reference to signal wiring parts and the signal wiring parts are shielded from each other to a degree identical to the coaxial cable. CONSTITUTION:A semiconductor chip 1 composed of GaAs or the like is mounted on the bottom of a cavity 101 in a substrate 100 via a metal film 2. The chip 1 is connected to electrodes 4 of the substrate 100 via bonding wires 3. An internal constant-potential wiring part 6 is formed between a signal wiring part 5 and a signal wiring part 5. External constant-potential wiring parts 7 are formed on side faces at the outside of the substrate 100. The signal wiring parts are shielded by the wiring parts 7, the wiring part 6 and the metal film 2. A cap 8 shields the bonding wires 3 and the chip 1 from an external electric field. By this setup, an isolation characteristic can be enhanced. |
