| 摘要 |
PURPOSE:To enhance the freedom of a mounting layout, by providing dummy leads, whose outer ends are provided in the vicinity of the periphery of a package and which do not play the role of the electric leads and are selected from every several pieces of leads in the package. CONSTITUTION:The dummy leads 6 are positioned at the centers of the sides and four corners of the package 1. The dummy leads do not play the electric role, and are cut at the vicinity of the surface of the package 1. They are not protruded from the part under the lower surface of the package 1 like the other leads 2. They do not contact with wiring layers 4 of a printed board 7. Even through the package 1 is mounted on the printed board 7 and many wiring layers 4 are provided, wiring layers 4 can pass through the parts corresponding to many dummy leads 6 under the periphery of the package 1. Therefore the mounting layout becomes easy. |
