Patent 7995353 was granted and assigned to Hon Hai Precision Industry Co Ltd on August, 2011 by the United States Patent and Trademark Office.
A circuit board includes four positioning pads placed on a surface of the circuit board, four positioning holes corresponding to the positioning pads, respectively, and a solder mask placed on the surface around the periphery of the positioning pads. An arc-shaped recess is defined at a side of each positioning pad near the corresponding positioning hole and the space between the edges of the positioning pad and the positioning hole ranges from 0.2 mm to 0.5 mm.