ELECTROMAGNETIC FORCE SYSTEM FOR INTEGRATED CIRCUIT FABRICATION

• US 3,727,822 A
• Filed: 11/10/1971
• Issued: 04/17/1973
• Est. Priority Date: 10/05/1970
• Status: Expired due to Term

• Current Assignee: Charles Wayne Umbaugh
• Original Assignee: Charles Wayne Umbaugh
• Inventors: Umbaugh, Charles Wayne
• Primary Examiner(s): Overholser, J. Spencer
• Assistant Examiner(s): Lazarus, Richard Bernard
• Application Number:
  US05/197,406
• Time in Patent Office: 524 Days
• Field of Search: 29/488,497.5,498 228/1,8,9 219/109,110
• US Class Current: 228/1.1
• CPC Class Codes: B23K 20/10 making use of vibrations, e.g. ultrasonic welding
• CPC Class Codes: B23K 31/125 Weld quality monitoring
• CPC Class Codes: H01L 21/67138 Apparatus for wiring semiconductor or solid state device

Abstract

A feedback controlled spacial-force mechanism is used with a variety of tools for integrated circuit fabrication. The mechanism utilizes a force producing element having a force which may be held constant over a practical range of displacement. An optical-mechanical tool is also provided having an optical surface for contacting and bonding an integrated circuit work piece for effecting interconnection of circuit elements.

Claims

1. An electromagnetic force system with feedback control for fabricating integrated circuits, comprising:

a movable, force-producing iron core having a generally cupshaped form with a closed end and a generally cylindrical sidewall, said core including a central member extending from the closed end;

a fixed, generally toroidal shaped coil for generating a magnetic field in response to an electric current, said coil disposed within said core and encircling said central member;

means for maintaining said coil and said core at a selected temPerature;

a displacement transducer coaxial with the central member of said core and attached to the closed end of said core, said displacement transducer generating an output signal representative of the displacement of the core;

a force transducer attached to and coaxial with the central member of said core, said force transducer generating an output signal representative of the force produced by said core;

a tool coaxial with and attached to said force transducer;

means for supplying both thermal and vibratory energy to said tool; and

means for varying the electric current supplied to said coil in response to the output signals from said displacement and force transducers, to control the force applied to said tool.

2. An electromagnetic force system with feedback control for fabricating integrated circuits, comprising:

a movable, force-producing iron core having a generally cup-shaped form with a closed end and a generally cylindrical sidewall, said core including a central member extending from the closed end;

a fixed, generally toroidal shaped coil for generating a magnetic field in response to an electric current, said coil disposed within said core and encircling said central member;

means for maintaining said coil and said core at a selected temperature;

a displacement transducer coaxial with the central member of said core and attached to the closed end of said core, said displacement transducer generating an output signal representative of the displacement of the core;

a force transducer attached to and coaxial with the central member of said core, said force transducer generating an output signal representative of the force produced by said core;

a thermocompression bonding tool coaxial with and attached to said force transducer; and

means for varying the electric current supplied to said coil in response to the output signals from said displacement and force transducers, to control the force applied to said tool.

3. An electromagnetic force system as defined in claim 2 wherein said thermocompression bonding tool comprises:

a source of infrared radiation for heating;

a lens for focusing the radiation from said source; and

a surface on said lens for contacting the integrated circuit, said surface having the focused radiation emanating therefrom.