<p>The pressure of bonding wire to a pad is controlled by two steps and ultra-sonic and bonding time is controlled appropriately so that crack and cratering are decreased. The method comprises the steps of: (a) forming a metal ball at the end of bonding wire; (b) pressing the metal ball to a bonding pad with a first pressure during a certain time; (c) pressing the metal ball to a bonding pad with a second pressure during a certain time; (d) rubbing the metal ball to a bonding pad; and (e) lifting a capillary and cutting a wire to a certain length.</p>
