| 摘要 |
PROBLEM TO BE SOLVED: To ideally match the connection surfaces of the upper layer to the lower layer of a multilayer printed circuit board by a method wherein a through hole, having non-circulate cross section, not the normally used circular cross section, is used. SOLUTION: A non-circular through hole 3, not the circular through hole used in the past, is perforated, lands 2a and 2b, having a flange part which covers a conductive material, are formed and printed pattern 1a and 1b are connected to the lands. Accordingly, the connection point to the lands 2a of the upper layer printed pattern 1a can be moved to the position of the printed pattern 1c, and the connection point to the land 2b of the lower layer printed pattern 1b can be moved to the position of a printed pattern 1b. As a result, the connection of the upper and the lower layers of the multilayter printed circuit board has high degree of freedom and versatility, the conduction between the front and the back sides of the multilayer printed circuit board can be secured, and heat dissipating property can be improved. |
