Abstract: According to the present invention, a circuit board for mounting electronic components wherein a metal layer united with a substrate layer has a predetermined portion exposed is manufactured by:(1) arranging a mask between the substrate layer and a part of the metal layer to become the exposed part, and thereafter unitizing the substrate layer with the metal layer;(2) projecting a laser beam onto that part of the substrate layer on the metal layer which surrounds the mask, in a direction from a side of the substrate layer to a side of the metal layer, thereby to cut away the part of the substrate layer surrounding the mask; and(3) stripping off that part of the substrate layer which remains on the mask, together with the mask.

Abstract: According to the present invention, a circuit board for mounting electronic components including a metal layer united with a substrate layer with a predetermined portion of the metal layer exposed is manufactured by disposing a mask between a substrate layer and a metal layer where the metal layer is to be exposed and uniting the substrate layer and the metal layer with the mask therebetween, projecting a laser beam onto the substrate layer at the periphery of the mask to cut away the substrate layer adjacent to the mask, and stripping off that part of the substrate layer which remains on the mask and the mask.

Abstract: A method of manufacturing a substrate for mounting electronic components according to this invention comprises the steps of forming a mask on a portion to be electrically connected to an exterior of a lead frame, of forming resin layers on both side surfaces of the lead frame by prepregs or the like, of removing the resin layer on the mask, and of removing the mask, and in the substrate for mounting electronic components manufactured according to this method, the substrate is integrally formed with the lead frame, and the electrical connection of the substrate to the lead frame is performed by through hole plating without using fine metal wiring.