Electrode changers and methods of operation for electrical bonding apparatus

A method of operating an electrical bonding machine having a frame, a retaining element, at least one electrode defining a plurality of contact regions on said retaining element and electrical transmission elements on said frame and said retaining element comprising the steps of:

• (a) maintaining said retaining element in fixed position relative to said frame so as to maintain one of said contact regions in operative disposition;
• (b) repetitively engaging the contact region in operative disposition with successive workpieces;
• (c) biasing said electrical transmission elements against one another so as to maintain the same in electrical contact with one another and transmitting electrical current through said electrical transmission elements to the contact region in a operative position so as to thereby perform a bonding operation on each workpiece;
• (d) intermittently moving said retaining element relative to said fixed element so as to bring a new one of said contact regions into operative disposition, whereby said electrical transmission elements will move relative to one another during such intermittent movement, and repeating the aforesaid steps with the new contact region in operative position;
• and
• (e) temporarily relieving said bias concomitantly with each said intermittent movement.

A method of operating an electrical bonding machine comprising the steps of:

• (a) providing a plurality of electrode holders each having an electrode releasably mounted thereon;
• (b) positioning said electrode holders in sequence in an operative disposition on said machine;
• and
• (c) engaging the electrode of each holder with successive workpieces while that holder is in operative disposition and performing a bonding operation on each such workpiece using the electrode mounted on such holder, said step of positioning said holders in sequence including the step of detaching each electrode holder from the machine after use in said bonding operations and replacing each such detached electrode holder with another one of said electrode holders, the method further comprising the steps of adjusting the position of the electrode mounted in each electrode holder relative to such holder while such holder is detached from the machine, reusing each said holder after said adjustment in said replacing step as a replacement for a previously used holder, and using each such replacement holder and the electrode mounted therein in further bonding operations without additional adjustment of the electrode relative to the holder or of the holder relative to the machine.

An electrode changer for an electrical bonding machine comprising:

• (a) a plurality of separate electrode holders, each said electrode holder including means for engaging an electrode and means for adjusting the position of the engaged electrode relative to the holder;
• (b) a retainer element;
• (c) means for mounting said retainer element on the machine;
• (d) means for releasably securing at least one said holder to the retainer element so that one said holder is in an operative disposition on the machine;
• and
• (e) holder change means for replacing the electrode holder in operative disposition with another one of said electrode holders.

An electrical bonding machine comprising:

• (a) an electrically conductive retainer element having a bore extending in forward and rearward directions, an opening at the forward end of the bore and a forwardly facing abutment surface;
• (b) an electrically conductive electrode holder having an elongated shank defining opposite first and second axial directions, an abutment surface facing in said first axial direction and means for engaging an electrode so that said electrode projects from said electrode holder in said second axial direction and so that the position of said electrode in said axial directions with respect to said electrode holder is adjustable;
• (c) means for releasably engaging said holder with said retainer element so that said shank is received in said bore, the electrode retained on said holder projects forwardly and said abutment surface of said holder faces rearwardly and confronts said abutment surface of said retainer element;
• (d) means for biasing said retainer element in said forward direction so as to force the electrode engaged in the electrode holder into engagement with the workpiece whereby said bias will also force said abutment surfaces into engagement with one another;
• and
• (e) means for transmitting electrical current to said retainer element so that such current is transmitted through said engaged abutment surfaces to the electrode holder and from the electrode holder to the electrode engaged therewith.