Abstract: A method of preventing EMI for a fastening hole in a circuit board includes the steps of providing a circuit board which includes a plurality of fastening holes extending through opposite first and second surfaces thereof and a plurality of solder pads disposed on the second surface, each fastening hole being surrounded by the solder pads; disposing an electronic component on the first surface; positioning the circuit board on a fixture such that the solder pads are not covered by the fixture; and wave soldering the circuit board so that the electronic component is fixed to the circuit board and the solder pads are attached with solder materials.

Abstract: An elastic electrical contact includes a base, a connecting member extending from an end of the base, and a resisting member extending from an end of the connecting member configured for resisting against an electronic element. The base includes a bottom surface being soldered to a circuit board and a top surface, and defines a through hole and a portion of tin between the bottom surface and the circuit board. When soldering to the circuit board, tin can extend through the through hole.