Wire bonding apparatus

A processor controlled linear drive mechanism for converting rotary motion to predetermined linear motion comprising:

• a support frame,
• a drive motor mounted on said support frame,
• rotary position indicating means connected to said drive motor,
• eccentric drive means connected to said drive motor,
• a driven follower member connected to said eccentric drive means,
• said driven follower member being guided for movement in a linear motion path,
• processor control means having a memory for storing digital data indicative of different increments of rotational movement of said drive motor,
• said different increments of rotational movement being indicative of predetermined linear movements of said driven follower member,
• said rotary position indicating means providing an output position signal coupled to said processor, and
• arithmetic means in said processor for comparing said output position signal with one of said digital data indications of a predetermined increment of rotational movement of said drive motor and for producing a forcing function signal coupled to said drive motor indicative of the difference between a desired predetermined linear position and the actual linear position of said driven follower member, whereby said drive motor forcing function signal is varied to position said drive motor at variable rates of change.

A digital data processor controlled linear drive apparatus for converting rotary motion to a predetermined linear motion, the combination comprising:

• a support frame;
• a drive motor mounted on said support frame,
• rotary position indicating means connected to said drive motor,
• eccentric drive means connected to said drive motor,
• a driven follower member connected to said eccentric drive means,
• said driven follower being guided for movement in a linear motion path,
• processor control means of the type having a memory for storing digital data and means for performing arithmetic computation on said digital data,
• program means stored in said memory means for generating a digital address indicative of a desired linear position of said driven follower member,
• conversion means stored in said memory means for converting a desired digital address position to digital data indicative of a desired rotary position of said drive motor,
• said arithmetic means of said processor control means being adapted to substract the difference between said desired rotary position of said drive motor and the digital position of said drive motor indicated by said rotary position indicating means, and
• means for converting the arithmetic difference between said drive motor position and said desired position into an analog current signal coupled to said drive motor for driving said driven follower to said linear desired position.

A processor controlled drive apparatus for a semiconductor wire bonder comprising:

• a support frame,
• a Z drive motor mounted on said support frame,
• bonding tool holder means mounted on said support frame for movement in a vertical direction by said Z drive motor,
• a bonding tool mounted on said bonding tool holder means,
• sensing means on said bonding tool holder means actuated by said bonding tool when said bonding tool engages a touchdown Z position during a bonding operation,
• processor control means for recording said touchdown Z position of said bonding tool when it engages said workpiece,
• program means in said processor control means for generating an inflection point representative of a Z position higher than said touchdown Z position, and
• said program means further comprising means for driving said Z drive motor to displace said bonding tool in a Z direction at substantially constant velocity between said inflection point and said touchdown Z position and at varying velocities when approaching said inflection point.

A processor controlled Z direction drive apparatus for a semiconductor wire bonder comprising:

• a support frame,
• a Z drive motor mounted on said support frame,
• bonding tool holder means mounted on said support frame for movement in the Z direction by said Z drive motor,
• a bonding tool mounted on said bonding tool holder,
• processor control means comprising program means stored in memory means for directing said bonding tool to a first plurality of established predetermined vertical positions during a bonding operation,
• said program means comprising means for computing a plurality of variable predetermined vertical positions intermediate two sequential positions of said established predetermined vertical positions and means for temporarily storing said variable predetermined vertical positions in said memory means, and
• said program means comprising means for sequentially directing said bonding tool from one to the other of said two sequential established predetermined vertical positions by continuously directing said Z drive motor to move said bonding tool to individual ones of said plurality of variable predetermined vertical positions.