US Patent 7301104 Double-sided flexible printed circuits

A double-sided flexible printed circuit comprises: an electrically insulating base; a first copper layer having a first conductive pattern; a second copper layer having a second conductive pattern, the second conductive pattern disposed offset from the first conductive pattern; and electrically insulating coverlays. A first area opposing a first contact point of first contacts that press upon the first conductive patterns, is reinforced by copper foil extending from the second conductive patterns, and a second area opposing a second contact point of second contacts that press upon the second conductive patterns, is reinforced by copper foil extending from the first conductive patterns.