| 摘要 |
PROBLEM TO BE SOLVED: To decrease the number of trial manufacture for substrates and to shorten the development cost and period by connecting a GND connection points to a casing on a circuit board and the GND on the circuit board, only via packaging of chip parts. SOLUTION: When chip part 1 is mounted to pads 2, a GND conductor patterns 4 on the circuit board are connected via screw hole land connection conductor patterns 3 to screw hole lands 5 which are formed as through-holes. The metal screws used for these screw holes are connected to a frame, and the GND conductor patterns 4 are GND connected. If a frame GND(FG) connection by mounting of such chip parts 1 is made at all the connection points on the circuit board, the easy changing of the FG connection state by the choice on whether to change to mount or not to package the chip parts 1 is made possible. Thus, the evaluation design for optimization of lowering the level of electromagnetic unwanted radiation noise (EMI) can be made easily. A 0Ωresistor is preferably used as the chip parts 1.
|
