Hughes Aircraft Company

Other

Palomar Technologies, Inc.

William H Hill

Joseph E Donner

William M Fries

John B Gabaldon

Dale W Cawelti

Thomas L Ratledge

Daniel D Evans, Jr

Brent A Thorn

Todd G Wieseler

A bond head is provided for a wire bonding machine having a linear axis frame, a rotary axis frame, a bond tool and a wire clamp. The linear axis frame is vertically linearly displacable along a linear axis, while the rotary axis frame is rotationally displacable along a rotary axis. A pivotal connector is provided which pivotally connects the rotary axis frame to the linear axis frame, enabling the rotary axis frame to rotate independent of linear displacement of the linear axis frame. The bond tool is connected to the rotary axis frame and is vertically linearly displacable in response to vertical linear displacement of the linear axis frame and rotationally displacable in response to rotational displacement of the rotary axis frame. The wire clamp is connected to the linear axis frame and is vertically linearly displacable in response to vertical linear displacement of the linear axis frame, while the wire clamp is maintained rotationally stationary during rotational displacement of the rotary axis frame. The bond head also includes a linear motion assembly and a rotary motion assembly. The linear motion assembly has a linear driver, a linear position detector and a linear driver controller. The rotary motion assembly correspondingly has a rotary driver, a rotary position detector and a rotary driver controller.

Bond head having dual axes of motion

A wire conveyance system is provided for a wire bonding machine having, in series, a first wire handler, a wire slacking device and a second wire handler. The wire slacking device includes a wire support chamber having a substantially enclosed bottom, opposing first and second vertical sidewalls, a substantially open top, a back opening and a front opening. The wire slacking device further includes a pressurized fluid source and first and second fluid orifices for receiving a pressurized fluid from the pressurized fluid source. The fluid orifices extend through the first or second sidewall of the wire support chamber with the second fluid orifice being positioned downstream of the first fluid orifice. First and second fluid paths are provided in fluid communication with the pressurized fluid source via the first and second fluid orifices. The first and second fluid paths extend upward between the first and second sidewalls of the wire support chamber and out the open top. A wire support path extends laterally through the wire support chamber above the first and second fluid orifices. The wire support path is substantially contactless with respect to the wire slacking device.

Wire conveyance system having a contactless wire slacking device

Improved ultrasonic wire bonders, and improvements to ultrasonic wire bonding transducers that are used with such ultrasonic wire bonders. The improvements to the ultrasonic wire bonding transducer includes driver-node mounting of the transducer and a clamping arrangement for a bonding tool in the transducer. The driver-node mounting of the transducer is achieved by mounting it in the ultrasonic bonder such that a 3/4--wavelength distance is created between a mounting bracket of the transducer and a distal end of the transducer at which the bonding tool is disposed. As a result, vibrational problems caused by the transducer not being located at the node are eliminated. The driver-node mounting aspect of the present invention provides a shorter overall transducer and concentrates the mass at the driver end for less tool impact, and reduces manufacturing variables related to achieving a one-half wavelength distance between the driver node and the transducer node. The mounting arrangement is achieved by using a set screw, and more particularly a soft point set screw, opposite a drilled-out back wall of the transducer. The set screw directly secures the bonding tool or engages a clamping shoe that radially secures the bonding tool to the end of the transducer. As a consequence, rigid clamping of the bonding tool is achieved. Therefore, the clamping force exerted on the bonding tool is in line with the direction of ultrasonic motion imparted to the bonding tool. The present clamping arrangement improves the transfer of ultrasonic energy that excites the bonding tool into transverse (flexural) vibration.

Ultrasonic wire bonder and transducer improvements

A parallel-gap welder applies a precisely controlled force to the weld head (40) by means of a solenoid (60) having a plunger (72) aligned with the axis of the welding electrodes (50,52). To precisely control the amount of force applied by the solenoid a load cell (80) is interposed between the weld head (40) and the solenoid plunger (72) to provide a feedback force signal (158) indicative of the force applied by the solenoid. The feedback force signal is used to control current through the solenoid coil (68) and thereby servo the applied force to a force command input. The solenoid plunger (72) and load cell (80) are axially aligned with the axis of the electrodes (50,52) and solenoid force is applied through a universal joint (76,78) connection to assure an in-line driving force on the electrodes.

Pressure welding with closed loop force control

Two parallel elongated closely spaced electrodes for welding electronic circuit components are mounted for limited rotation about an axis extending generally longitudinally of the electrodes to allow the electrode pair to be oriented with respect to a workpiece without angularly moving the workpiece. The electrodes are mounted in a pair of mutually aligned and mutually insulated bobbins against which are firmly pressed a pair of contacts for conducting weld current between the electrodes. The bobbins and the electrodes mounted therein are free to rotate relative to the fixed contacts, but the latter are firmly pressed against the bobbins to provide increased contact pressure and decreased electrical resistance between the contacts and bobbins and to provide a relatively large surface area for such contact.

Dual tip rotating welding electrode

Wire bonds are closely spaced about the edge of a semiconductor chip device (150) in an orthogonal array. Even though the wires may have a fan out pattern to their second bond locations, close spacing of the first bond pads is achieved by use of rectangular pads (154) having their long dimensions all perpendicular to the chip edge, making all of the first bonds along lines perpendicular to the chip edge and then bending the wire to extend to the second bond.

Orthogonal bonding method and equipment

A force limiting weld head (11) which includes a supporting structure (13), a pressure barrel (15) and an output member (17) mounted for movement on the supporting structure, a fixed electrode (19) mounted on the supporting structure, a movable electrode (21) driven by the output member, a coupling (23) for drivingly coupling the pressure barrel and the output member. The coupling includes a variable-volume chamber (89) and a piston (77) responsive to overtravel for varying the volume of the chamber.

Force limiting weld head

A method and apparatus for spray-coating the marginal area of a surface includes an air nozzle movable with the spray head for directing an air curtain against the surface spaced from the edge to limit coating spray from the head to a determined marginal area and vacuum means disposed adjacent the edge of the surface and movable with the air nozzle means for withdrawing airborne coating particles from the spray area at the side opposite the air curtain.

Method of and apparatus for spraying

A movable open center mounting for the tool of an ultrasonic wire bonding machine employs ball-bearing rollers (22, 24, 30, 32) to permit limited motion of the wire bonding tip (13a) substantially constrained to a vertical line with a minimum of tip skid. The mounting structure which is all positioned on one side of the tool tip includes a frame (10) of inverted U-shape having a pair of mutually spaced ball-bearing rollers (22, 24, 30, 32) on the end of each frame leg and a transducer support (12) positioned between the frame legs and having fixed roller contacting rods (90, 92, 96, 98) extending fore-and-aft between and partly under each of the respective rollers. A pair of springs (80, 82) urges the transducer support upwardly to press the fixed rods against the roller surfaces, allowing the transducer support to effectively rock about a center of motion (120) that is well below the bonder frame and transducer support, with the rocking motion being so constrained that the bonder tip moves substantially in a straight vertical line for small displacements.

Wire bonder with open center of motion

A bonding tool and clamp assembly is disclosed and includes an upper wire guide (23,51) and a bonding tool (17,75) having a short guide hole (45) adjacent the heel of the bonding tool foot (41). The bonding tool tip (17a) includes a clamping surface (47) adjacent the guide hole (45); and a clamp (21b,49b) is selectively forced toward the clamping surface (47) to clamp the bonding wire (39,77). The clamp (21b,49b) is biased toward the clamping surface by a spring (37,73), and is released from the clamping surface by an electromagnet (29,57).

Bonding tool and clamp assembly and wire handling method

A flexural pivot structure useful in a wire bonding machine bonding head (10) is disclosed and includes first and second leaf spring assemblies (39,41) which provide a pivot axis (PA) displaced from the pivoting structure. Each leaf spring assembly includes leaf spring arms (39a,39b,41a,41b) extending outwardly from a central mounting position (39c,41c) so that each assembly forms a truncated vee. The center portions of the leaf springs are secured to a transducer bridge (25) in which a transducer (59) is mounted. The ends of the leaf springs are secured in a bracket (11) with respect to which the transducer (59) pivots about an axis located at the intersection of converging lines along the leaf springs (39a,39b,41a,41b) of each leaf spring assembly (39,41).

Growing community of inventors

Pala, CA, United States of America

William H Hill