Abstract: A method for manufacturing circuit board includes steps of forming upper and lower copper foil layers on upper and lower surface of a PI substrate, respectively, etching the upper and lower copper foil layers to form first and second electrical circuits, attaching first and second PI coverlays to the upper and lower copper foil layers, respectively, etching the PI substrate through a PI etching process to form at least one opening exposing the lower copper foil layer, and performing a surface treatment to form a solder layer electrically connected to the electrical circuit of the lower copper foil layer for soldering electrical elements in a subsequent process. Therefore, the circuit board with double side circuit and single side assembly is obtained. The present invention do not employ the process of exposure ink, thereby simplifying the whole manufacturing procedure and greatly improving preciseness of the circuit board.

Abstract: A frame of a photovoltaic panel includes at least one L-shaped corner joint at least one first frame body and at least one second frame body. The L-shaped corner joint includes a support, a first joint arm and a second joint arm respectively disposed on different surfaces of the support, wherein the first joint arm and the second joint arm respectively have at least one first riveting hole and at least one second riveting hole. The first frame body has a first engaging groove therebetween. The first joint arm is inserted in the first engaging groove. Part of the first inner frame plate is caved in the first riveting hole. The second frame body has a second engaging groove. The second joint arm is inserted in the second engaging groove. Part of the second inner frame plate is caved in the second riveting hole.