Method and apparatus for performing wire bonding by using solder wire
AssigneeRohm Co., Ltd.
InventorsHiroyuki Takahashi, Shinichi Fujino, Kazuhiro Sakamoto, Tomoyasu Hirano
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Abstract
A method for bonding a solder wire is provided wherein a lower ball end of a material solder wire is first bonded to a first bonding portion of a workpiece. Then, the material solder wire is thermally cut to provide a solder wire segment held bonded to the first bonding portion and having an upper ball end. Finally, the upper ball end is bonded to a second bonding portion of the workpiece. All of the wire bonding process steps are performed in an oxygen-free atmosphere to prevent oxidation of the solder wire.
Claims17
A wire bonding method for electrically connecting between a first and a second bonding portions of a workpiece by a solder wire, the method comprising the steps of:
- forming an upward stream of an oxygen-free gas from below a vertically movable capillary tool, the capillary tool being capable of continuously supplying a material solder wire which has a lower ball end projecting from the capillary tool;
- lowering and then raising the capillary tool for bonding the lower ball end of the material solder wire to the first bonding portion of the workpiece in the oxygen-free gas stream;
- bringing a thermal melting means to a first limit position located closest to the material solder wire for thermally cutting the material solder wire in the oxygen-free gas stream to provide a solder wire segment held bonded to the first bonding portion of the workpiece and having an upper ball end, the thermal melting means being movable also to a second limit position located farthest from the material solder wire;
- forming a new lower ball end of the material solder wire in the oxygen-free gas stream while the thermal melting means is positioned between the first and second limit positions;
- and
- bonding the upper ball end of the solder wire segment to the second bonding portion of the workpiece.
A wire bonding apparatus for electrically connecting between a first and a second bonding portions of a workpiece by a solder wire, the apparatus comprising:
- a tunnel through which the workpiece is transferred;
- a supply means for supplying an oxygen-free gas to the tunnel;
- a discharge means for discharging the oxygen-free gas in an upward stream from the tunnel;
- a vertically movable capillary tool arranged above the discharge means for holding and supplying a material solder wire, the capillary tool serving also as a first bonding tool for bonding a lower ball end of the material solder wire to the first bonding portion of the workpiece;
- a thermal melting means movable to a first limit position closest to the material solder wire for thermally cutting the material solder wire under the capillary tool to provide a solder wire segment held bonded to the first bonding portion of the workpiece and having an upper ball end, the melting means being further capable of forming a new lower ball end of the material solder wire before moving to a second limit position farthest from the material solder wire;
- and
- a second bonding tool for bonding the upper ball end of the solder wire segment to the second bonding portion of the workpiece.
Dependencies are inferred from the claim text.