Printed wiring board and manufacturing method therefor

A printed wiring board having a circuit substrate having a conductor circuit and a through hole, and a joining ball joined to said through hole;

• a joining pin having a leg portion inserted into said through hole, said joining pin having an enlarged end section comprising said joining ball, the leg portion having a smaller diameter than the diameter of the through hole, the leg portion having a smaller diameter than the diameter of the joining ball, the joining pin having an intermediate section extending between and connecting the joining ball to the leg portion, said intermediate section inserted into said through hole, the intermediate section having a smaller diameter than the leg portion, and the intermediate section having a smaller diameter than the joining ball;
• the printed wiring board being characterized in that said joining ball is manufactured by using a material unmelted at a heating temperature in joining the joining ball to an opposite party pad, and is constructed by a joining head portion having a diameter greater than the diameter of an opening portion of said through hole and forming a joining portion for joining and connection to said opposite party pad, and a bottom portion facing the opening portion of said through hole, and the bottom portion is arranged in proximity to the opening portion of said through hole and is joined to the through hole by a conductive material filling the interior of the through hole.