A beryllium copper alloy is provided, having a thickness \u201ct\u201d in a range from 0. The method of manufacturing comprises feeding one or multiple pieces of elastic nonwoven fabric, layering and folding, welding and sealing, die-cutting, punching, winding on a core, and finishing with determined quantity to make a roll. A control circuit is also used to integrate and output a set of video and audio signals through an AV cable to a large display. Accordingly, a slope uniformly extending over the whole width of the solder resist layer is formed at the edge portion of the solder resist layer to improve electrical connectivity.