| 摘要 |
PURPOSE:To improve the electrical characteristics of a multilayered printed circuit board by making the plane land clearance of a grounding layer and a power supply layer get necessary and, minimum dimension, in a multi-layered printed circuit board using various kind of voltage. CONSTITUTION:A potential difference calculation means 31 calculating the potential difference between the plane and the through-hole of the grounding layer or power supply layer to be generated based on signal pattern design data in which the the component arrangement and signal layer pattern design of the multi-layered printed circuit board are completed, a land shape data storage means 32 preliminarily defining and storing land shape data for each of plural potential difference regions, a selection means 33 selecting the land shape corresponding to the potential difference obtained by the potential difference calculation means 31 from the land shape data of the land shape data storage means 32, and an arrangement means 34 arranging the land shape selected by the selection means 33 at a through-hole position in the grounding layer and/or power supply layer, are provided. |
