AIR GAP FPC is FPC which is constructed by 2 layers or over off CCL (Cu & Base). And these CCL materials are laminated with Thermo Setting Adhesive (TSA) like Muti - layer FPC. But TSA doesn't exist at same areas. It means CCLs are laminated each other partly. And this areas (non lamination area) is called as AIR - GAP area. Because each CCLs arestayed individually. This structure can make high flexibility and density.