Abstract: A surface-treated copper foil according to exemplary embodiments includes a copper foil layer and a protrusion layer formed on one surface of the copper foil layer. Pores are formed inside the protrusion layer or around a boundary between the copper foil layer and the protrusion layer. Abnormal growth of the protrusions may be prevented through the pores and thus a bonding force with the insulation layer may be improved.

Abstract: Disclosed is a hybrid type air-compressor, which has a main body including a cylinder having upper and lower portions, a motor assembly including an eccentric shaft passing through a side surface of the main body to eccentrically rotate in the cylinder, a first communication part covering an upper portion of the cylinder of the main body and introducing air to discharge the air to the upper portion of the cylinder, a second communication part covering a lower portion of the cylinder of the main body and introducing air to discharge the air to the lower portion of the cylinder; and an air compressing means connected to the eccentric shaft of the motor assembly and vertically moving in the cylinder to alternately compress air introduced into the upper and lower portions of the cylinder.

Abstract: Disclosed is a hybrid type air-compressor, which has a main body including a cylinder having upper and lower portions, a motor assembly including an eccentric shaft passing through a side surface of the main body to eccentrically rotate in the cylinder, a first communication part covering an upper portion of the cylinder of the main body and introducing air to discharge the air to the upper portion of the cylinder, a second communication part covering a lower portion of the cylinder of the main body and introducing air to discharge the air to the lower portion of the cylinder; and an air compressing means connected to the eccentric shaft of the motor assembly and vertically moving in the cylinder to alternately compress air introduced into the upper and lower portions of the cylinder.