Lead pin for printed circuit board and printed circuit board using the same

A printed circuit board, comprising:

• a base substrate having a connection pad exposed through an opening of a solder resist layer;
• a lead pin including a connection pin and a pin head part formed at one end portion of the connection pin and including a protrusion, the diameter thereof being formed to be increasingly small based on a surface contacting the connection pin and the outer peripheral surface thereof being provided with a plurality of depression-shaped bands, the plurality of the bands having a stairstep pattern;
• and
• a solder bonding the pin head part of the lead pin on a connection pad of the base substrate,
• wherein:
• the pin head part further includes a head having a plate shape that is formed at one end portion of the connection pin and is disposed between the connection pin and the protrusion,
• the protrusion is disposed on a surface contacting the head and the outer peripheral surface thereof is provided with a plurality of grooves having a band shape,
• the protrusion is provided with a semi-sphere formed on a surface contacting the head and a plurality of grooves having a circular band shape formed at the outer peripheral surface of the semi-sphere in a vertical direction to the connection pin, and
• the diameter of the circular band is small stepwise based on a surface contacting the connection pin.