Patent ID: 7068520

Claim:
A circuit board made of resin with pins, comprising: flat pins each including: a rod portion having a diameter of not greater than 0.35 mm, and a concentric tabular large diameter portion having a larger diameter than that of the rod portion formed on one end of the rod portion, the flat pins each being soldered to a pin bonding portion provided on a main surface of the board at the large diameter portion, wherein the ratio (W/S) of the diameter of the large diameter portion to the rod portion is from not smaller than 2.16 to not greater than 2.67, if the diameter of the rod portion and the large diameter portion of the flat pin are S and W, respectively, wherein the formed thickness of a solder layer is adjusted to be not greater than 0.30 mm along the vertical direction from the first main surface of the pin bonding portion toward the flat pin.