Abstract: A multi-resonance frequency ultrasonic transducer has a plurality of useful resonance frequencies for wire bonding operation and comprises an integral unibody with a rectangular aperture in the center of its mass. A multi-frequency stack of transducer drivers is mounted in the rectangular aperture with compression wedges. The length L of the stack of transducer drivers is equal to or less than one-quarter of one wavelength of the lower useful resonance frequency and the design envelopes for the useful frequencies embrace two or more useful fixed frequencies separated from spurious unusable frequencies by a minimum of two kilohertz.

Abstract: There is provided an ultrasonic generator of the type having a power amplifier. The output of the power amplifier is connected across and through an ultrasonic transducer which holds a bonding tool to be engaged on a bonding target. A current sufficient to induce a resonant frequency is applied across the ultrasonic transducer in air and before touch down on the bonding target while continuously monitoring the current and voltage across the transducer. A touch down detector circuit is coupled to the current and voltage being monitored and initiates a touch down signal which is employed to control these Z-axis drive motor of an automatic wire bonder within several microseconds of the actual touch down time.

Abstract: A novel method for locating eye point features on patterns or objects whose size varies between the reference object and the find object includes generating a set of reference vectors that define the location of the reference eye point. The set of vectors is modified and separated equidistant from each other. A centroid of the object area is calculated. When a fixed object is to be located, an area of certainty is established which contains a plurality of candidate eye points one of which is the proper find eye point of the object to be located. Sets of find vectors are generated for each candidate eye point which are compared with the set vectors for the reference eye point. Centroids of the find objects having the best comparison are calculated and compared with the centroid of the reference object. The candidate eye point having a best vector correlation match and the best centroid comparison is selected as the eye point of the find object.

Abstract: A low mounting impedance ultrasonic transducer for mounting on a bonding machine comprises a prior art type transducer having a modified mounting flange which includes one or more elongated apertures in the mounting flange or the transducer body to isolate transverse radial stress in the transducer body from entering into the mounting flanges and coupling to the bonding machine.

Abstract: A novel pull strength tester is incorporated into an automatic wire bonder for performing pull strength tests during production bonding operation. The pull strength tester is provided with a control for automatically applying increments of pull force on a fine wire after making a bond. The control senses the elongation of the fine wire as a result of the force applied and is capable of terminating the pull test at a predetermined threshold value or continuing to increase the force until a break occurs. After each increase in force, a continuity circuit determines if the wire has broken at the bond or the bond has lifted off the bonding target. The system employs the information to determine if a proper bond was made and/or if a short tail was made which could affect the subsequent attempt to form a proper ball for a subsequent first bond.

Abstract: In a motor system controlled by a central processing unit, an observer-compensator is provided which modifies the command signal being applied to the actual motor system to be controlled. The observer-compensator comprises in the observer portion, a simulated ideal motor system without disturbance forces. The velocity output of the simulated ideal motor system is compared to the velocity output of the actual system to produce a velocity error signal (Verr). A feedback compensator in the simulated ideal motor system is adjusted to compensate for the velocity error signal without disturbance forces.After disturbance forces are introduced into the actual motor system, a comparison of the output of the actual motor system with the output of the simulated ideal motor system produces a position error signal (P.sub.D --P.sub.A) which is applied to the compensator portion of the observer-compensator. The compensator portion comprises a disturbance reconstruction device which is coupled to the position error signal.

Abstract: A multi-resonance frequency ultrasonic transducer as a plurality of useful resonance frequencies for wire bonding operation and comprises an integral unibody with a rectangular aperture in the center of its mass. A multi-frequency stack of transducer drivers is mounted in the rectangular aperture with compression wedges. The length L of the stack of transducer drivers is equal to or less than one-quarter of one wavelength of the lower useful resonance frequency and the design envelopes for the useful frequencies embrace two or more useful fixed frequencies separated from spurious unusable frequencies by a minimum of two kilohertz.

Abstract: A novel high-speed capillary/wedge bonding tool is provided for use on an automatic fine wire bonder which has either a rotating bonding head or a workstation which rotates relative to the bonding head. The novel working tip of the novel bonding tool is provided with two closely spaced parallel sides having substantially zero degree cone angle when viewed from the side. The bonding tool is further provided with a substantially rectangular shaped wedge foot which extends between a segment of the chamfer diameter and a segment of the tip diameter when viewed from the front. In the preferred embodiment, the novel chamfer recess in the novel capillary/wedge bonding tool is elongated so that balls bonded at first bond are more narrow in width than in length and occupy approximately the same area as prior art high speed gold ball bonds. The novel rectangular wedge shape foot produces second mashed wedge wire bonds which are as robust as, and/or stronger than prior art mashed wedge wire bonds.

Abstract: An aligning and positioning system for a bonder including a bond sensor for sensing the X, Y and .theta. coordinates of a substrate at the bonding location and a die sensor for sensing the X, Y and .theta. coordinates of the die on a die transport. A controller correlates the sensed coordinates from the sensors and adjusts the X, Y and .theta. of the die and the substrate relative to each other to place the die at a preselected bond site on the substrate. The Z coordinate of the surface of the substrate, as well as its planarity, may be sensed by a Z optical sensor. The X and Y coordinates of the substrate are adjusted and the .theta. coordinate of the die on the die transport is adjusted.A pattern recognition system is used with the die and bond sensors to determine the coordinates as well as quality control of the substrate prior to bonding, the quality of paste pattern on the die or the substrate prior to bonding and the quality of the bond and the coordinates of the die after bonding.

Abstract: A novel bonding tool is designed for use in conventional ultrasonic transducers. The bonding tool body is mounted in the ultrasonic transducer at an angle or in an offset holder so that the working face of the bonding tool is offset and out from under the end of the ultrasonic transducer. The axis of a wedge bonding tool body is mounted at an inclined angle of up to forty-five degrees and the tapered wedge of the bonding tool is inclined in the opposite direction so that the working face of the offset tapered wedge is in a horizontal working plane.

Abstract: A diamond impregnated saw blade of the type used in dicing saws is adapted for mounting on a high cooling flange or standard flange hubs and useful for cutting very hard objects. The saw blade is made in the form of an annular ring comprising a homogenous mixture of diamonds held in situ by a binder material and is characterized by alternately spaced raised teeth and recessed cooling grooves through which a stream of cooling fluid is directed into the kerf of an object being cut as well as on all cutting surfaces of the cutting saw blade.

Abstract: A novel ultrasonic transducer comprises a machined solid metal unibody having a rectangular aperture in the center between a tool mounting end and a balanced end. The end portions are connected by two axial side members which connect to two transverse sides of the rectangular aperture. A stack of piezo electric crystals are mounted in said rectangular aperture between the transverse sides and spaced apart from the axial sides of the aperture. A bonding tool is mounted in a cylindrical aperture in the mounting end of the transducer and tightly mechanically coupled to the mounting end so that the stack of piezo electric crystals are acoustically coupled through the unibody to the bonding tool in a cylindrical aperture by a tightly coupled mounting surfaces.

Abstract: An improved fine pitch bonding tool for use in automatic gold ball bonders for bonding fine gold wires onto closely spaced pads on semiconductors comprises a cylindrical body portion which fits into an ultrasonic transducer and is provided with a bottle-neck working tip on the other end of the body portion for bonding fine gold wires. The working tip is provided with a wire hole diameter less than 1.4 times the diameter of the fine wire to be bonded and is further provided with a chamfer diameter on the working tip which is less than 2.5 mils across. The total tip diameter on the working tip is less than 6 mils and the working face which comprises an annular ring between the chamfer diameter and the tip diameter is provided with a face angle of approximately 22 degrees plus or minus 3 degrees. Even though the bonding tool has a smaller area working face, it has been found to produce second bonds whose pull strength is equal to prior art capillary bonding tools having larger tip diameters and working faces.

Abstract: A multi-level fine wire tensioning apparatus is provided for use in high speed automatic wire bonders. The tensioning apparatus which surrounds the fine wire is mounted close to the bonding capillary and is adapted to apply one of a plurality of tension forces on the wire depending on the phase of the bonding cycle. The tensioning apparatus comprises a housing containing an aspirating tube which applies tension to the fine wire that is threaded through the tube. A controller is coupled to a high speed selector which connects one of a plurality of different level vacuum or pressure sources to the tensioning apparatus which in turn applies different tension forces to the fine wire in the capillary.

Abstract: Apparatus and a method for controlling the power output of an ultrasonic generator to a transducer includes a variable impedance network circuit which is interposed between the generator and the transducer. Sensing circuits and a microprocessor are coupled to the input of the transducer so that the total impedance Z.sub.T, the transducer impedance in free air Z.sub.FA and the load impedance Z.sub.L may be calculated and the network impedance Z.sub.NW may be set for a bonding operation to maintain the power level P.sub.L or the impedance Z.sub.L at a desired predetermined level.

Abstract: Apparatus for monitoring the length of a fine wire tail made after the second bond of a fine wire interconnection includes a continuity circuit and a wire bond monitoring system (WBMS) in an automatic wire bonder. The Z axis position of the bonding tool is sensed to determined the height of the bonding tool on second bond and at the time the fine wire breaks from second bond. The monitoring circuit determines if the wire clamps are initiated and when and if the electronic flame-off control is fired. Logic circuit in the WBMS determine if wire tail after second bond is of a proper length to make a ball on the wire tail and if not, what remedial measures must be made to avoid damage to the semiconductor device being bonded.

Abstract: Apparatus and a method for orienting individual bonding sites of a lead frame having a plurality of bonding sites includes a universal work station in a work holder. The work holder comprises a gripper mechanism which is mounted on a transverse rail or bar for grasping a lead frame at an edge portion thereof while exposed in a supply magazine. The jaws of the gripper mechanism are pivoted in a horizontal direction which permits the exposed edge of the lead frame to be aligned parallel to a reference plane in a theta orientation direction. While oriented in the theta orientation direction, the lead frame is moved precisely to the window of the work station of the work holder where it is clamped by the top plate and lower plate of the work station before being subsequently bonded.

Abstract: A low mass self-aligning wire clamp jaw assembly is provided which may be employed as a replaceable wire clamp jaw assembly or as a complete integrated wire clamp assembly with an actuator. The novel self-aligning wire clamp jaw assembly comprises a wire clamp jaw mounting arm which is adapted to be connected to a bonding head support. The wire clamp jaw mounting arm serves as a fixed lever to which is attached a first fixed flat surface clamping jaw and also serves as a mount to which a second and pivotal jaw is positioned juxtaposed the first jaw. A force mounting spring is also mounted on the mounting arm for applying a unidirectional force to one end of the second pivotal jaw to bias the pivotal jaw in a normally open or normally closed position.

Abstract: Apparatus and a method for orienting individual bonding sites of a lead frame having a plurality of bonding sites includes a universal work station in a work holder. The work holder comprises a gripper mechanism which is mounted on a transverse rail or bar for grasping a lead frame at an edge portion thereof while exposed in a supply magazine. The jaws of the gripper mechanism are pivoted in a horizontal direction which permits the exposed edge of the lead frame to be aligned parallel to a reference plane in a theta orientation direction. While oriented in the theta orientation direction, the lead frame is moved precisely to the window of the work station of the work holder where it is clamped by the top plate and lower plate of the work station before being subsequently bonded.

Abstract: A method of pre-forming a length of fine wire while simultaneously making a fire wire interconnection between a first and a second bonding point on a semiconductor device includes the steps of teaching the location of the edges of the die and teaching a plane in space which is located away from the edges of said die. After teaching the height of the clearance above the die and the XYZ location of the first and second bonding points the automatic wire bonder in directed to generate a desired geometric link profile between bonding points which defines the length of links L1, L2 and L3. Using the geometric profile and empirically determined constants the automatic wire bonder calculates a tool trajectory for pre-forming the fine wire while simultaneously making a fine wire interconnection with an automatic wire bonder.