Apparatus and method for manufacturing semiconductor device

An apparatus for manufacturing a semiconductor device, wherein a bonding wire of copper or copper alloy is looped between an electrode pad of a semiconductor element and an outer lead of a lead frame, comprising:

• a convey path for conveying the lead frame along a convey direction, said convey path being provided with a wire bonding portion and a postbonding portion which are separated from each other along the convey direction, said convey path comprising a cover, a portion of said cover corresponding to said wire bonding portion including a window for supplying the bonding wire to said convey path therethrough;
• ball forming means for heating the bonding wire at said wire bonding portion and forming balls at both ends of the bonding wire, said ball forming means including a double-structure burner having an inner tube and an outer tube outside said inner tube, wherein a first gas mixture of an H.sub.2 gas and an O.sub.2 gas in a mixing ratio of 2:1 H.sub.2 to O.sub.2 is blown from said inner tube to form an oxyhydrogen torch, and a second gas mixture of an O.sub.2 gas and an N.sub.2 gas is blown from a space between said outer tube and said inner tube to form an air curtain around the oxyhydrogen torch;
• bonding wire feeding means for feeding the bonding wire to said wire bonding portion and compressing the ball of the bonding wire on the electrode pad;
• compressing means for compressing the ball of the bonding wire on the outer lead at said postbonding portion;
• and
• gas supply means for supplying a reducing gas to said wire bonding portion and said postbonding portion and surrounding the bonding wire and the balls by a reducing atmosphere to prevent the balls from being oxidized.

An apparatus for manufacturing a semiconductor device, wherein a bonding wire formed of copper or a copper alloy is bonded onto an electrode pad of a semiconductor element, comprising:

• a convey path for conveying the semiconductor along a convey direction, said convey path being provided with a wire bonding portion;
• ball forming means for heating the bonding wire at said wire bonding portion and forming a ball at one end of the bonding wire, said ball forming means including a double-structure burner having an inner tube and an outer tube outside said inner tube, wherein a first gas mixture of an H.sub.2 gas and an O.sub.2 gas in a mixing ratio of 2:1 H.sub.2 to O.sub.2 is blown from said inner tube to form an oxyhydrogen torch, and a second gas mixture of an O.sub.2 gas and an N.sub.2 gas is blown from a space between said outer tube and said inner tube to form an air curtain around the oxyhydrogen torch;
• bonding wire feeding means for feeding the bonding wire to said wire bonding portion and compressing the ball of the bonding wire on the electrode pad;
• and
• gas supply means for supplying a reducing or inert gas to said wire bonding portion and surrounding the bonding wire and the ball by the reducing gas to prevent the ball from being oxidized.

A bonding method comprising the steps of:

• preparing a bonding wire made of copper or a copper alloy;
• conveying a lead frame in a convey direction along a convey path, the convey path being provided with a wire bonding portion and postbonding portion which are separated from each other along the convey direction;
• heating one end of the bonding wire to form a ball at the end of the bonding wire by using a double-structure burner having an inner tube and outer tube outside the inner tube, said heating step including a blowing a first gas mixture of an H.sub.2 gas and an O.sub.2 gas in a mixing ratio of 2:1 O.sub.2 to N.sub.2 from the inner tube to form an oxyhydrogen torch and blowing a second gas mixture of O.sub.2 gas and N.sub.2 gas from a space between the outer tube and the inner tube to form an air curtain around the oxyhydrogen torch;
• feeding the bonding wire so that the ball of the bonding wire contacts the electrode pad;
• compressing the ball of the bonding wire onto the electrode pad;
• and
• supplying a reducing or inert gas to the ball of the bonding wire at the wire bonding and post bonding portions to surround the bonding wire by the reducing gas, thereby preventing the ball from being oxidized.