Welding apparatus having coaxial welding electrodes

• US 5,360,958 A
• Filed: 05/17/1993
• Issued: 11/01/1994
• Est. Priority Date: 05/17/1993
• Status: Expired due to Term

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delco Electronics Corporation (General Motors Company)
• Inventors: Osborne, Hollis D., Bogue, Terry L.
• Primary Examiner(s): Shaw, Clifford C.
• Application Number:
  US08/061,469
• Time in Patent Office: 533 Days
• Field of Search: 219/56, 219/56.1, 219/56.21, 219/56.22, 219/86.51, 219/86.9, 219/110
• US Class Current: 219/86.51
• CPC Class Codes: B23K 11/3009 Pressure electrodes
• CPC Class Codes: B23K 2101/40 Semiconductor devices

Abstract

A resistance welding apparatus for welding a wire to a metallic pad of an integrated circuit. The welding apparatus has coaxial welding electrodes with the outer electrode being in the form of a tube. The inner electrode is a cylindrical rod and is located in the outer electrode. The end of the outer electrode has two opposed open-ended V-shaped slots. The slots receive and position the wire. With the wire located in the slots, the end of the outer electrode is engaged with the pad and the inner electrode pushes the wire against the pad. Welding current can now be applied to the electrodes. Each electrode is associated with a load cell that senses electrode force. Welding current is applied to the electrodes only after the electrode force of each electrode attains certain predetermined values.

Claims

1. A resistance welding apparatus for welding a wire to a metallic conductor pad comprising, an outer tubular metallic welding electrode and an inner cylindrical metallic welding electrode recessed within said outer metallic welding electrode, and an electrical insulator disposed between said electrodes for electrically insulating said electrodes from each other, said outer electrode having a pair of opposed V-shaped slots for capturing said wire and positioning said wire in alignment with said pad and said inner electrode in preparation for welding said wire to said pad, said outer electrode having a pair of spaced surfaces for engaging said conductor pad and said inner electrode adapted to move axially within said outer electrode to maintain said wire in tight engagement with said pad when said wire is welded to said pad.

2. A resistance welding apparatus for welding a wire to a metallic conductor pad including an outer tubular metallic welding electrode, an inner cylindrical metallic welding electrode recessed within said outer metallic welding electrode, and an electrical insulator disposed between said electrodes for electrically insulating said electrodes from each other, the improvement wherein:

a pair of opposed V-shaped slots are formed in said outer electrode for capturing said wire and positioning said wire in alignment with said pad and said inner electrode in preparation for welding said wire to said pad.

3. A resistance welding apparatus for welding a wire to a metallic pad comprising, a first metallic welding electrode for engaging and forcing said wire into engagement with a surface of said pad, a second metallic welding electrode coaxial with and disposed about said first welding electrode for directly engaging said surface of said pad and having a pair of opposed slots for receiving and positioning said wire for engagement with said first electrode, a first electrode force sensor associated with said first electrode for sensing the force of said first electrode, a second electrode force sensor associated with said second electrode for sensing the force of said second electrode, a source of welding current, means electrically connecting said source of welding current to said electrodes including at least one switching means, and means for causing said switching means to apply welding current to said electrodes when the force of said first electrode has a first predetermined value and when the force of said second electrode has a second predetermined value.