The method of bonding an interposer and an integrated circuit chip includes preparing an interposer including an insulator and conductive lines each having one end exposed to a first surface of the insulator and another end exposed to a second surface opposite to the first surface; placing a bonding mask on the interposer; forming through-holes on the bonding mask before or after the placing of the bonding mask on the interposer; filling the plurality with a conductive material; and bonding an integrated circuit chip to the bonding mask.