Method of manufacturing semiconductor device and wire bonding apparatus

A method of manufacturing a semiconductor device having a wire loop to be connected to a first bonding point and a second bonding point with a wire-bonding apparatus having a load sensor for detecting pressing load applied at a tip end of a capillary, the method comprising:

• a first bonding step of bonding a wire to a first bonding point by means of a capillary;
• a second bonding step of, after the first bonding step, bonding the wire to a second bonding point by means of the capillary in such a manner that the capillary is raised while feeding the wire out of the tip end of the capillary and subsequently looped to the second bonding point along a predetermined trajectory, and then the wire is bonded to the second bonding point, thereby forming a wire loop connecting to the first bonding point and the second bonding point;
• a first folding step of, after the second bonding step, folding the wire on the wire loop by means of the capillary in such a manner that the capillary is raised while feeding the wire out of the tip end thereof and subsequently moved to the first bonding point by a first predetermined distance, and then the wire fed out of the tip end of the capillary is brought into contact with the upper face of the wire loop, and the capillary is lowered to the wire loop until the pressing load detected with the load sensor becomes equal to a predetermined value, thereby forming the wire fed out of the tip end of the capillary into a first folded portion having a shape that follows the upper face of the wire loop;
• a second folding step of, after the first folding step, folding the wire on the first folded portion by means of the capillary in such a manner that the capillary is raised while further feeding the wire out of the tip end thereof and subsequently moved in a direction opposite to the first bonding point by a second predetermined distance, and then the capillary is lowered, thereby forming the wire further fed out of the tip end of the capillary into a second folded portion having a shape that follows the upper face on the first folded portion;
• and
• a third bonding step of, after the second folding step, bonding the wire by means of the capillary in such a manner that the capillary is lowered to bond the wire to immediately adjacent to a bonded portion where the wire has bonded to the second bonding point, thereby bonding the wire thereto while causing the capillary to crush at least a portion of the first and second folded portions located at the second bonding point side with a face portion of the capillary located at the first bonding point side in such a manner as to be overlapped to the wire loop located at the second bonding point side.