| 摘要 |
PURPOSE:To increase the resistance to thermal stresses of a multilayered printed circuit board by increasing the plating thickness at land sections of outer-layer conductor circuits and the connecting section of an inner-layer conductor circuit with the plated section of a through hole. CONSTITUTION:This multilayered printed circuit board 1 is provided with conductive substratum layers 13 at land sections 3a of outside-layer conductor circuits 3 and the connecting section of the plated section 5 of a through hole with an inside-layer conductor circuit 6 so as to make the plating thickness at such sections thicker. Therefore, even when an insulating board 2 swells or contracts by heat, the plated sections are not broken, and thus, the resistance of the board 1 to thermal stress can be improved, since the mechanical strength of the board 1 is increased. |
