Abstract: This invention relates to a wire bonding apparatus for bonding wire to a substrate wherein the components used to guide, bond and cut the wire have a reduced cross-sectional dimension near the substrate to enable close proximity, deep access, fine pitch bonding. This is accomplished in part by forming a wire guide integrally through a substantial portion of the bonding tool, thereby completely eliminating one component found in conventional wire bonding apparatus. This is further accomplished by tapering the size of the bonding tool toward the substrate such that the bonding tool in a lower portion has a smaller cross-sectional area. A cutter extends adjacent the lower portion of the bonding tool and into the area that would otherwise be occupied by the lower portion of the bonding tool if not for the taper. Thus, both the cutter and the lower portion of the bonding tool occupy a minimal amount of space adjacent the substrate.

Abstract: An alignment method for ultrasonic wire bonders of the type using capillary ball type and wedge type bonding tools utilizes a bonding tool construction having an elongated shank angle obliguely At any desired azimuthal angle from the lower working face of a tool tip. This angular offset allows a workpiece to be positioned laterally to place a desired wire bond site on an integrated circuit or other such workpiece in precise alignment with a target image in the field of view of a television camera or other optical imaging device viewing the location of a desired bond site along the line of action of the tool tip. Because of the angular offset construction of the bonding tool, the line of site of the imaging device is coincident with the line of action of the tool tip eliminating parallax errors and permitting viewing of the bond site continuously during motion of the tool tip along its line of action.

Abstract: A de-spooler apparatus for paying out fine wire from a spool of wire, for use in wire bonding machines, maintains a relatively constant slack length of wire within the apparatus, thereby allowing wire to be drawn from the machine as needed with a minimum amount of tension exerted on the wire. The apparatus includes a spool drive motor for paying out wire from a spool, a hairpin-shaped bail for containing a slack length of wire, and a nozzle for directing a stream of pressurized gas downwards into the open end of the bail, causing wire within the bail to form a curved slack length. The apparatus also includes a proximity-type feed sensor for detecting when the slack length straightens and shortens a pre-determined amount, bringing the slack length into the detection range of the feed sensor, which outputs an electrical signal that causes the drive motor to rotate in a forward sense, paying off wire from the supply spool and increasing the slack length.

Abstract: An improved tool for ultrasonic wire bonding, and a novel method by which the tool may be semi-automatically threaded with bonding wire are disclosed. The overall exterior shape of the tool is that of an elongated rectangular cross-section bar having at the lower end thereof a tapered, smaller cross-section tip. The tip includes a flattened front toe section for applying ultrasonic energy to wire and a bonding pad, and an upawardly angled oblique lower face rearward of the toe section. A wire guide hole through the tip that has a longitudinal axis that slopes upward at a steeper angle than the oblique lower face has an exit opening in the lower oblique face, just rearward of the front toe section. The guide hole has an enlarged opening in the rear face of the tip. An elongated straight shallow groove formed in a side wall of the tip extends obliquely downwards from the rear face to front face of the tip.

Abstract: A method and apparatus for attaching semiconductor dice to substrates includes a novel die-grasping apparatus and technique which employs a tweezer-like clamping device which has one fixed leg. The second leg of the clamping device is movable laterally towards the fixed leg by means of a linear actuator coupled to the movable leg through a spring. Lateral spacing between the linear actuator and the movable leg is adjustable, allowing the spring to be prestressed to a precisely adjustable value, thereby resulting in a precisely pre-adjustable side-gripping force on the lateral sides of a semiconductor chip or die, ensuring that the fragile die will not be broken by the grasping action. The preferred embodiment employs a micro-manipulator to precisely position a die in place on a molten solder pre-form on a substrate, and a vacuum probe for first placing the pre-form on the substrate.

Abstract: An apparatus and method for conducting pull testing of the wires and wire bonds of an electronic apparatus in which a bond wire is engaged by a hook, and the force with which that wire is urged to move away from the hook is measured as the force required to maintain the hook stationary.

Abstract: Semiautomatic threading of bonding wire into the guide hole of a wire bonding tool is accomplished by holding the end of the wire in a reference position while its standing part is disposed in the wire feed mechanism of the machine and by activating the feed mechanism after the tool and work positioning mechanism of the machine have placed the bonding tool in line with the wire proximate to the wire end. A preferred apparatus for holding the end of the wire in place is a structure which forms a ledge and has a notch in the edge of that ledge.

Abstract: A sonic, lead wire bonding tool has both bonding elements and wire cutting elements formed on its working face and a bail which limits lateral movement of the bonding wire and aids in forming the lead wire as it is payed out between between bonds. The bonding tool applies sonic energy to complete the wire bonds and to sever the wire with the aid of wire pulling force after completion of bonding.