JPH028461B2 - - Google Patents

Description

Claim 1: A bonder apparatus of the type capable of connecting a conductor to a conductor element on a workpiece, comprising a frame apparatus forming a work station for supporting the workpiece, and a conductor feeding apparatus, the combination of which comprises: a support arm for defining a support arm; a bonding tool supported by the support arm and adapted to cooperate with the conductor to form a contact end on the conductor for connection to the conductor element; and the bonding tool; and an associated lead wire is spaced from a workpiece when supported on the work station; and a first position in which the bonding tool is actuated to bring the contact end of the lead wire into contact with the workpiece. a bonding head apparatus comprising: an apparatus for supporting said support arm for movement between two positions; and a bonding head apparatus operatively associated with said support arm for movement of said support arm to a contact position and thereafter contacting said contact end of said conductor. an actuator for tilting the support arm so as to gradually increase the contact pressure with the workpiece in a predetermined manner;

2. The bonder apparatus of claim 1, wherein the actuating device is electrically energizable, operatively connected to the support arm, and between the contact end of the conductor and the workpiece. a control circuit arrangement adapted to provide a predetermined ramp energization signal to the electrically energizable actuator to gradually increase the contact pressure of the bonder in a predetermined manner.

3. The bonder apparatus according to claim 2, wherein the control circuit device generates a predetermined contact bonding force between the contact end of the conductive wire and the workpiece, and maintains the bonding force for a predetermined period of time. A bonder device that works like this.

4. A bonding apparatus according to claim 2, wherein the weight of the support arm is eliminated as a component of the contact pressure provided by the bonding tool when energizing the electrically energizable actuator. A bonder apparatus including a counterbalancing spring device operatively associated with said support arm.

5. The bonder apparatus according to claim 1, including a pair of clamp arms supported by the support arm, and a gripping position where the clamp arms grip the conducting wire therebetween, and a gripping position where the conducting wire and the bonding a bonder device adapted for relative pivoting between a release position and a release position allowing relative movement between the bonder and the head;

6. The bonder apparatus of claim 5, wherein the bonder is operatively associated with at least one of the clamp arms and selective between the grip position and the release position with respect to the other of the clamp arms. A bonder apparatus including a gripping actuator adapted for movement.

7. The bonder apparatus according to claim 6, wherein the gripping actuation device includes a gripping solenoid device operatively connected to the at least one of the clamp arms, and a gripping solenoid device operatively connected to the at least one of the clamp arms. a control circuit device operable to energize in a predetermined manner;
Bonder equipment, including:

8. The bonder apparatus of claim 7, wherein the control circuit arrangement is operative to selectively move the clamp arm between the clamping position and the release position, thereby the bonder device, wherein the wire is withdrawn from the supply device during movement from the first position to the second position.

9. The bonder apparatus of claim 1, wherein the actuating device is pivotally mounted to the frame device and connected to the support arm, so that from the first position, the bonding tool A bonder apparatus including a control lever for moving said support arm to an intermediate position in a predetermined relationship to the piece.

10. The bonder apparatus of claim 9, wherein the control lever is actuated to move the support arm from the first position to the intermediate position in response to movement of the lever in a predetermined direction. and a spring device that biases the support arm toward the first position.

11. The bonder apparatus according to claim 1, wherein the conductor supply device includes a conductor supply reel having a central axis, and the supply reel is arranged such that the central axis of the supply reel is inclined from a horizontal direction with respect to the frame device. and a guide tube coaxial with the central axis of the supply reel for receiving the conductor and guiding the conductor down an inclined track toward the bonding tool. . The bonder apparatus, wherein the inertia of the conductor within the guide tube facilitates withdrawal of the conductor from the supply reel.

12. The bonder apparatus according to claim 11, wherein the guide tube is interposed between the guide tube and the bonding tool, and is configured to hold the conducting wire at a predetermined axial tension as the conducting wire approaches the bonding tool. A bonder apparatus including a drag control device operatively associated with said conductor.

13. The bonder apparatus of claim 1, wherein the work station has a generally planar surface for supporting a workpiece, the bonder forms a line of sight generally perpendicular to the support surface, and The bonding tool further includes an optical viewing device that allows the operator to view the workpiece positioned on the support surface, and the bonding tool is positioned relative to the line of sight so as not to significantly obstruct visual observation through the viewing device during the bonding operation. The bonder device is tilted.

14. The bonder apparatus according to claim 1, wherein the conductor supply device includes a conductor supply reel;
a reel actuator supporting the supply reel and operative to unwind a conductor from the supply reel in response to a predetermined signal; and a reel actuator operatively associated with the reel actuator to direct the conductor from the supply reel to the bonding tool. a conductor tension detection device for detecting the axial tension of the conductor as it is fed;
and the tension sensing device provides a predetermined signal to the reel actuator when the tension in the conductor reaches a predetermined magnitude, thereby causing the tension in the conductor to operate until the tension in the conductor decreases below the predetermined magnitude. A bonder device that operates to pay out conductor wire from a reel.

15. The bonding apparatus of claim 14, wherein the actuating device includes an electric drive motor, and the tension sensing device is in continuous contact with the conductive wire and detects the tension of the conductive wire as it advances to the bonding tool. a tension arm that operates to operate as described above;
and a switch device operatively associated with the tension arm to energize the electric drive motor to pay out the conductor from the supply reel when the tension of the conductor reaches the predetermined magnitude.
bonder equipment.

16. The bonder apparatus of claim 3, wherein said control circuit arrangement includes means operative to generate an audible signal when said predetermined contact bonding force is reached.

17. The bonder apparatus of claim 16, wherein the audible signal generating device is operative to generate an audible signal at the end of the predetermined time period.

18 A bonding head apparatus having a conductor supply apparatus and a bonding tool that receives a generally continuous length of conductor from the conductor supply apparatus and enables selective bonding of the conductor to the workpiece. In a bonder apparatus of the type connectable to a conductor element, the conductor supply apparatus supports a conductor supply reel, the supply reel in a predetermined relationship with respect to the bonding head apparatus, and in response to a predetermined signal, conductor wire is removed from the supply reel. a reel actuator operative to pay out the conductor; and a conductor tension sensing device operatively associated with the reel actuator and detecting axial tension of the conductor as the conductor progresses from the supply reel to the bonding tool. and the tension detection device provides the predetermined signal to the reel actuator when the tension of the conductor reaches a predetermined magnitude, and the tension detection device provides the predetermined signal to the reel actuator when the tension of the conductor reaches a predetermined magnitude, and the tension detection device provides the predetermined signal to the reel actuator when the tension of the conductor reaches a predetermined magnitude. A bonder device characterized in that it operates to feed out a conductive wire from.

19. The bonder apparatus of claim 18, wherein the actuation device includes an electric drive motor;
The tension detection device is in circuit connection with the electric drive motor and a tension arm operative to continuously contact the conductor to detect tension as the conductor advances to the bonding tool. a switch device operatively associated with the tension arm to energize the drive motor to unwind the conductor from the supply reel when the tension reaches the predetermined magnitude.

20 A bonding head used for bonding a conductive wire to a conductive element on a workpiece, comprising: a base; a support arm; a device for supporting the support arm on the base; and a bonding tool mounted on the support arm. the bonding tool is adapted to guide a continuous length of conductive wire through the bonding tool so that the conductive wire advances longitudinally along a trajectory generally oriented in a predetermined direction with respect to the bonding tool; a pair of wire clamping arms carried in generally parallel relationship by said support arm, each arm having a clamping device disposed proximate said bonding tool; relative movement therebetween to releasably grip a conductor by said clamping device as it passes through a predetermined trajectory, generally parallel to the longitudinal axis of said support arm while passing through a predetermined trajectory; the clamp arm is movable relative to the support arm in a plane such that the clamp arm passes a trajectory that generally corresponds to the predetermined trajectory traversed by the conductor when guided by the bonding tool; a device cooperating with the clamp arm and the support arm to cause the conductor to travel linearly along its predetermined trajectory when gripped by the clamp device; a first actuator operative to selectively move the clamp arm along the predetermined trajectory.

21. A bonding head according to claim 20, wherein the device cooperates with and allows relative movement between the clamp arm and the support arm, connecting the clamp arm to the support arm and A bonding head comprising an apparatus for causing said clamp arm to move in a generally circular arc as it passes through a predetermined trajectory.

22. A bonding head according to claim 20, wherein the bonding head is operative to cooperate with at least one of the clamp arms and to cause relative movement therebetween so as to selectively grip a conductor with the clamp arm. A bonding head including a second actuator.

23. The bonding head according to claim 21, further comprising a device that presses the clamp arm in a predetermined direction along the predetermined arcuate trajectory, and when the first actuating device is biased, the bonding head a first wire feeder actuator for moving the clamp arm a first incremental distance along the predetermined arcuate trajectory in a direction opposite to a predetermined direction; and when biased in the opposite direction. a second wire feeder actuator for moving the clamp arm a second incremental distance along the predetermined arcuate trajectory.

24. A bonding head according to claim 23, wherein said first conductor feeder actuator is connected to said clamp arm via a pneumatic connection.

25. The bonding head of claim 23, wherein said first and second conductor feeder actuators include parallel electrically actuated solenoids, whereby energizing said solenoids in sequence causes said The clamp arm is sequentially moved stepwise in the direction opposite to the predetermined direction in which it is pressed by the clamp arm's clamping device, and the force applied by one of the solenoids moves along an arcuate trajectory through which the clamp arm passes. a bonding head connected to said clamp arm for action in a direction generally coincident with said clamp arm;

26. The bonding head of claim 20, wherein the device for supporting the support arm on the base is adapted to pivot about a first pivot generally transverse to the support arm. a pivot plate pivotally connected to a base plate such that the support arm pivots relative to the pivot plate about a second pivot axis parallel to but spaced apart from the first pivot axis; A bonder apparatus comprising: a device pivotally mounted to the pivot plate; and a device for biasing the support arm into a predetermined position relative to the pivot plate.

27. The bonding head of claim 25, wherein the pivot plate is operatively connected to the base plate and the pivot plate is operatively connected to the base plate about the first pivot axis for manually controlled movement of the bonding tool. a bonding head including an actuator that allows the support arm to pivot under manual control.

28. The bonding head of claim 24, wherein said biasing device is selectively adjustable to reorient said support arm relative to said pivot plate.

29. The bonding head of claim 20, wherein the base has a microscopic device disposed at the generally horizontal reference plane above the plane of the reference plane and forming a generally vertical line of sight. the support arm is supported on the base so as to be positioned in a generally horizontal plane when the base is positioned on the reference surface, and the bonding tool is configured to perform a bonding operation. a bonding head which is adapted to lie below the microscope apparatus in the vicinity of the vertical line of sight, but is inclined relative to the vertical so as not to significantly obstruct the line of sight;

30. The bonding head of claim 20, wherein the clamp arm defines a longitudinal axis lying in a generally horizontal plane containing the longitudinal axis of the support arm to provide a low profile bonding head. bonding head.

31. The bonding head of claim 26, wherein the bonding head is interposed between the pivot plate and the support arm and is adapted to gradually apply a bonding force in a predetermined manner during a bonding operation in response to a supplied gradient electrical signal. a bonding head including an electrically actuated actuator for moving said support arm and associated bonding tool in a direction capable of increasing said support arm and associated bonding tool;

32. A bonding head according to claim 21, wherein the device for connecting the clamp arm to the support arm is configured to connect one of a pair of mutually opposing surfaces of the support arm and at least one of the clamp arms. A bonding head comprising an individually formed elongate slot device and a ball device held in generally fixed relationship to the other of said mutually opposed surfaces and slidable within said elongate slot.

33. The bonding head of claim 26, wherein the bonding tool has a generally flat bonding surface that lies in a generally horizontal plane when the support arm is in the predetermined position relative to the pivot plate; The support arm is sufficiently relative to the first pivot such that a relatively small amount of pivoting of the pivot plate about the first pivot does not significantly shift the bonding surface from the horizontal plane. long bonding head.

34. The bonding head of claim 20, wherein said base has a generally planar base surface on which the bonding head can be positioned on a support surface.

35. A bonding head according to claim 32, including means for allowing said base to be releasably attached to a support surface.

36. A bonding head according to claim 33, wherein said releasable attachment device comprises either a vacuum device or a magnetic device.
bonding head.

37. The bonding head of claim 20, wherein the first actuating device is axially associated with the support arm and the clamp arm for selectively incrementally moving the clamp arm. A bonding head that includes a plurality of actuators interconnected in register.

38. The bonding head of claim 37, wherein said axially aligned actuator comprises a pair of solenoids.

39 In the device according to claim 2,
The control circuit arrangement includes an arrangement that begins generating a predetermined ramp bias signal when the bonding tool and conductor contact end contact a workpiece.

40. The apparatus of claim 39, wherein the control circuit arrangement includes a device operative to stop application of the applied contact force when the bonding tool is lifted from the workpiece. Device.

41. The apparatus of claim 39, wherein the bonding head arrangement supports a bonding tool via an ultrasonic transducer, and the control circuit arrangement is configured to modify when the bonding tool contacts the workpiece. circuit arrangement adapted to provide a generally continuous predetermined energy signal to the transducer and begin providing the predetermined ramp energization signal in response to the modification of the energy signal by the transducer; bonder equipment.

42. The apparatus of claim 41, wherein the predetermined energy signal provided to the transducer is a low amplitude signal.

BACKGROUND OF THE INVENTION The present invention relates generally to bonding apparatus;
In particular, it relates to a novel bonding device of the type capable of connecting conductive wires to conductive elements on a workpiece, such as, for example, microelectronic chips.

For example, in the design and fabrication of integrated circuit packages employed in microprocessor devices, it is often desirable to analyze or test the circuitry of a semiconductor chip during the research and development stage. Testing and analysis often require conducting conductive connections between two or more conductive elements on a semiconductor chip, or connecting conductive elements on a semiconductor chip to external circuitry. The ability to conductively connect conductive elements within a single semiconductor chip or what is called a microelectronic chip would eliminate the need to create an entirely new chip, and would be desirable for the development of new or alternative microcircuits. be. Also,
By interconnecting conductive elements within a single chip, suspected defects can be bypassed, thereby localizing the problem area and leading to failure analysis of the chip.

The connection of circuits or conductor elements on semiconductor chips to each other or to external conductors, such as carrier plates or lead frames, can be done in a conventional manner by wire bonding. Wire bonding is essentially a welding operation in which a weld is formed between a conductive bonding wire, or ribbon, and a metallic conductive element, or pad, on a microelectronic chip or wafer. A weld is formed when two metal surfaces come into close molecular contact and are subjected to short-range atomic attraction forces.This process generally requires some degree of adhesion for both the conductor and the conductive elements on the chip to bond well. Requires plastic deformation.

Known wire bonder equipment typically performs bonding using one of three basic techniques. That is, the first technique uses a flame or spark to melt the ends of the conductor, which due to surface tension will form a ball, and then said ball falls onto the conductive element or pad on the chip. , thermal compression ball bonding, in which heat and pressure are applied by a capillary tool through which a wire is passed to attach it to the element or pad. The second technique is thermosonic ball bonding, which is generally similar to thermocompression ball bonding, except that the ultrasonic energy is delivered through the bonding tool and less heat is delivered to the chip. A third technique is ultrasonic wedge bonding, in which a wedge-shaped bonding tool applies a combination of pressure and ultrasonic energy to bond between the conductive wire and the conductive elements on the chip.

Known wire bonders have significant disadvantages or limitations in that their application to the design and development of microelectronic chips is severely limited and their use is limited to chips with high circuit densities that require very thin conductive wires in bonding operations. There is. For example, known bonders cannot be easily used to interconnect circuits within a single wafer or chip. Additionally, known bonders are difficult to use in high power microscopes having generally vertical lines of sight, which are highly desirable for high density chips, for example to reduce parallax.

SUMMARY OF THE INVENTION In accordance with the present invention, a bonder is provided for use in connecting conductive wires to conductive elements on a workpiece, such as a microelectronic chip or wafer. The bonder has a base frame forming a work station adapted to support a workpiece for observation via a microscopic viewing device. The bonding head includes a support arm on which is mounted a bonding tool adapted to receive a series of lengths of conductor from a conductor supply reel under controlled tension, and the bonding head incrementally transfers the conductor to the bonding tool. It has a selectively movable wire clamp arm suitable for feeding. The support arm can be manually moved to a first probe station, after which the support arm undergoes a predetermined ramp movement to gradually and predetermined increase the contact force between the contact end of the conductor and the workpiece. be made to do. In one embodiment, the clamp arm is adapted to cooperate with an actuator to move the clamp finger along the path traversed by the conductor as the conductor is guided through the bonding tool. Therefore, when the lead wire is gripped by the clamp finger, the lead wire is moved forward linearly.

It is therefore an overall object of the present invention to provide a novel bonder apparatus of the type capable of sustaining conductive wires to conductive elements on a workpiece, such as a microelectronic chip.

A more particular object of the present invention is to provide a new bonder apparatus that is particularly useful for interconnecting two conductive points within a single microelectronic chip or wafer.

A feature of the bonding apparatus according to the invention is that bonding is carried out with extremely low impact forces by applying a predetermined ramp contact force between the workpieces, which prevents chips from cracking as experienced with conventional apparatus. It is an object of the present invention to provide a device that eliminates the problems of dripping, metallization damage, or tool bounce.

Another feature of the bonding device according to the invention is that it has a support arm carrying a clamp arm having a clamp finger for selectively gripping the conductor in the vicinity of the bonding tool, the clamp arm carrying a clamp arm that selectively grips the conductor in the vicinity of the bonding tool; movable in a generally arcuate trajectory relative to an associated support arm and cooperating with said clamping arm for generally linear movement of the conductor along a normally predetermined trajectory guided by the bonding tool; It is an object of the present invention to provide a bonding head having an actuating device for sequentially and incrementally moving a clamp arm in a predetermined manner during a bonding operation.

A further feature of the bonder apparatus according to the invention is that it provides a bonding head that is relatively short and small in size so that it can be easily installed as a modular unit in analytical probe apparatus and the like.

Another feature of the bonding apparatus according to the invention is the provision of a motorized wire feeder, which is associated with a wire tensioning device and which controls the feed and therefore the tension of the wire fed to the bonding tool.

Another feature of the bonder apparatus according to the invention is that it provides a novel method of mounting the bonding head on the support arm so as not to interfere with viewing the workpiece through the vertical line of sight of the associated microscopic viewing apparatus.

Further features of the bonder device according to the invention are:
It is an object of the present invention to provide a control circuit that provides an audible signal at the beginning of a conductor and provides a second audible signal indicating the end of a predetermined bonding time.

Other objects, advantages and features of the invention, as well as its mechanism and method of operation, will become apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings in which like reference numerals refer to like elements throughout the several drawings.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a bonder device constructed according to an embodiment of the present invention; FIG. 2 is a perspective view of the bonder device shown in FIG. 1;
A side view with the observation microscope, work holder, and conductor supply device removed and partially cut away for clarity; FIG. 3 is a plan view of a portion of the bonder device shown in FIG. 2; FIG. 4 is a plan view of the present invention FIG. 5 is a partial perspective view showing a part of the bonder head used in the device shown in FIG.
A plan view of the conductor feeder shown in Fig. 4; Fig. 6 is partially cut away for clarity.
FIG. 7 is a top view of the bonding head shown in FIG. 8 with the cover removed; FIG. 8 is a side view of a bonding head constructed in accordance with an alternative embodiment of the invention; FIG. 8 is a plan view of the bonding head shown in FIG. FIG. 9 is an exploded view of the bonding head shown in FIG. 8; FIG. 10 is a perspective view of an alternative conductor supply device according to the invention; FIG. Figure 12 is a logic diagram of the control circuit used in the bonder equipment shown in Figures 1 to 3; Figure 13 is the same as shown in Figures 6 to 9. Logic diagram for the control circuit used in the bonding head; FIG. 14 is a circuit diagram of a circuit for applying a gradient bonding force by means of a bonder device according to the invention; FIG. FIG. 16 is a partial plan view, partially broken away for clarity, of a clamp arm according to an alternative embodiment of the invention; FIG. 17 is a circuit diagram of a contact detection circuit used in the bonding head shown in FIG. FIG. 3 is a partial side view of the clamp arm device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, and in particular to FIG. 1, a bonder constructed in accordance with one embodiment of the present invention is designated generally at 10. The bonder 10 attaches conductive wires or wires to conductive elements on a workpiece, such as a microelectronic chip or wafer, by the generally known principles of either thermosonic bonding or thermocompression bonding, depending on the type of bonding tool used. It has particular use in connecting conductor ribbons. Bonder 10 is particularly useful for bonding very small diameter conductors, e.g. 5 to 12 microns, and for bonding single microelectronic chips or wafers, alternatively referred to as semiconductor chips, used e.g. in microprocessor circuits. To facilitate conductive connection of two or more conductive elements within the range of a chip. Bonder 10 can bond conductors made of virtually any ductile material, such as, for example, gold, copper, aluminum, and platinum.

Very generally, the bonder 10 has an overall diameter of 12
It includes a base frame arrangement, generally indicated at 14, forming a workstation adapted to support a workpiece. In the illustrated embodiment, the workstation 14 includes a support plate 16 for selectively supporting a workpiece, such as a microelectronic chip or wafer, to which one or more conductive wires are to be connected by bonding; A workpiece holder 18 of known construction is supported having a generally horizontal workpiece support upper surface 18a adapted to be heated. Frame arrangement 12 is indicated generally at 22 and supports a workpiece viewing device in the form of a microscope device. The viewing device allows the operator to view the workpiece being bonded through optical eyepieces 22a and 22b.
The microscope device 22 is of conventional construction and does not itself form part of the present invention and therefore does not need to be described in detail here. If desired, a workpiece illumination device may be installed to direct the light beam onto the workpiece.

A bonding head assembly, indicated generally at 26, positions the bonding tool 28 up against the workpiece support surface 18a and a microscope assembly 2.
The second observation lens is supported downwardly by a base frame device. The bonding head device 26 has a total of 3
Receives and guides a continuous length of conductor from a conductor supply device designated by 0. The supply device is connected to the bonding tool 2 so as not to interfere with other members of the bonder.
It is supported generally above and to the rear of 8 by a frame arrangement 12 . A cabinet or casing 32 is attached to frame assembly 121 to suitably enclose the control circuitry and other various components of bonder 10. Cabinet 32
has a front panel 34 on which various control knobs, switches, indicators and function indicator lights are mounted and displayed as will become apparent below. A first operating handle 36 facilitates manual control of the vertical height movement of the bonding tool 28 relative to a workpiece positioned on the workpiece support surface 18a and lowers the bonding tool to a search position before beginning bonding. and then used to control the loop height when making electrical connections to the workpiece. A second operating handle or lever 38 extends forwardly from the cabinet 32;
Workstation support plate 16 and work holder 18 are facilitated by operator control and movement in a generally horizontal plane.

Returning to the detailed description of bonder 10 and referring to FIGS. 2, 3 and 4 in conjunction with FIG. 1, bonding head assembly 26 includes a support arm 44 having a major central axis extending along its longitudinal direction. It is an axis and supports the bonding tool 28 at its leading edge. The support arm 44 is pivotally connected to a pivot plate 46 near its rear end and pivots relative to the pivot plate 46 about a pivot 48 transverse to the longitudinal axis of the support arm 44 . Pivoting plate 4
6 includes an upright support plate 50 for pivoting about a transverse axis 52 parallel to said axis 48.
is pivoted near its rear end. axis 52,4
8 are the first and second for the support arm 44, respectively.
forming a lateral axis.

In the illustrated embodiment, support arm 44 supports bonding tool 26 via an ultrasonic transducer 56, which itself is of well-known design.
The bonding tool is mounted to the support arm so as to extend forwardly in a generally axially aligned relationship with the longitudinal axis of the support arm to position the bonding tool in a predetermined relationship to the line of sight, indicated at 58, of the microscopy device 52. ing. In the embodiment shown in FIGS. 1-3, bonding tool 28 comprises a tubular capillary tool of conventional construction and is mounted within a suitable lateral opening at the other end of transducer 56;
It is held firmly inside. If desired, capillary bonding tool 28 may be replaced by a wedge-type bonding tool that receives and guides a relatively flat underbonding surface and a continuous length of conductor. It has an opening so that the connecting end lies below the bonding surface and is bonded to a conductive element on the workpiece.

The support arm 44 has a first position in which the bonding tool 28 and associated conductive wire are spaced a predetermined distance from the workpiece when supported by the workpiece support apparatus 18 and a predetermined relationship between the bonding tool and the workpiece. is pivotable about a lateral pivot 52 between an intermediate, ie, a first search position, in which there is no full bonding contact. The movement of the support arm to the first search position is carried out by the operating handle 3.
6, the handle being fixed to a pivot block 60 which in turn pivots on a lateral pivot shaft 62 suitably supported on the base frame arrangement 12. Supported for free movement.

A connecting rod 64 is pivotally connected at both ends to a pivot block 60 and a control plate 66 about pivots 68,70. A control plate 66, alternatively referred to as an actuation plate, is attached to a lateral pivot 72.
is pivotally connected to the pivot plate 46 via a pair of compression springs 74a, 74b such that the control plate is generally coplanar with the pivot plate 46. The springs 74a, 74b are connected to a control plate 66 and associated spring retaining arms 76a, 76b secured to the upper and lower surfaces of the pivot plate 46, respectively.
As shown in FIGS. 2 and 3, the pivot plate 46 is located above and below the pivot plate 46, as shown in FIGS.

Compression springs 74a and 74b are attached to pivot plate 46.
During the initial downward movement of the control plate 66 into the pivot plate 46 until the head of the adjustable stop screw 78 supported on the support member 80 engages the stop member 82 secured to the upright support member 84 of the frame 12. It is chosen to maintain a coplanar relationship overall. Stop screw 78 is adjustable relative to support member 80 to allow selective adjustment of the probing position of bonding tool 28 relative to the workpiece supported on workpiece support member 18 . Operating handle 36 and associated connecting rod 64 and control plate 66 are in operative association with support arm 44 to direct the support arm from its first raised position relative to the workpiece such that the bonding tool is closely spaced. The intermediate that comes to a given relationship, i.e. the first
A first actuating device is provided that allows manually controlled movement to a search position.

As explained in more detail below, the support arm 4
4 moves downwardly to the search position where the stop screw 78 engages the stop member 82, the operating handle 36
By further moving the compression spring 74b
, which causes control plate 66 to move downwardly relative to pivot plate 46 about pivot axis 72 . This further movement of the operating handle and control plate causes the bonding tool to be tilted downward, so that the lower ball end of the conductor located below the bonding tool and the selected point on the workpiece to which the conductor is to be bonded are aligned. Gradually increase the contact force between the two as specified.

For tilting the bonding tool, a second actuating device in the form of an electrically energizable actuating solenoid 86, referred to as a contact force solenoid, is mounted on the pivot plate 46 and is connected to the actuating core member, namely the plunger 86a. extends generally at right angles upwardly through appropriate openings in the pivot plate. The upper end of the core member or plunger 86a is secured to the support arm 44, for example via a screw 88, so that when the solenoid 86 is released, the support arm 44 is held in a generally parallel relationship with the pivot plate 46. Ru. When the solenoid 86 is energized, the support arm 44
is pivoted about a lateral pivot 48 towards the pivot plate 46, thus moving the bonding tool in a direction beneath the workpiece. According to one feature of the invention, after manually pushing the operating handle 36 to move the bonding tool to its first search position, a ramp signal is provided to the solenoid 86 to contact the conductor to obtain the desired bonding pressure. A predetermined tilting movement of the support arm and associated bonding tool from a first search position, i.e. an intermediate position, to a second position is carried out so as to gradually increase the contact force between the end and the core member in a predetermined manner.

Both ends of the coil compression spring 90 are attached to the pivot plate 46
and is received in a suitable spring pocket in support member 80 and pivots when operating handle 36 is moved from its lowered position to its upper position and returns control plate 66 to a generally coplanar position with respect to pivot plate 46. Pivot plate 46 upward. The ends of coil compression spring 92 (FIG. 3) are suitably received in pockets in pivot plate 46 and support arm 44 to bias the support arm upwardly against pivot plate 46. A cap screw 93 is received through a suitable opening in support arm 44 and pivot plate 46
is threadedly engaged to establish the upper adjustable position of the support arm relative to the pivot plate 46.

To begin providing a tilt energization signal to the solenoid 86, a switch device in the form of a microswitch 94 is inserted into the support arm 80 such that its switch contact actuation arm 94a is located below the control plate 66.
and is actuated by an adjustment screw 95 carried by the control plate when the operator moves the operating handle 36 downward after the pivot plate 46 has reached the lower limit set by the search position stop screw 78.

During a bonding operation, as the support arm 44 and associated bonding tool 28 move between their first up position and their fully lowered position, the bonding wire, a portion of which is indicated at 96 in FIG. is selectively clamped between a pair of clamp arms 100a and 100b supported by support arm 44 to prepare a new exposed end or "tip" of the bonding wire after each bond-loop-bond cycle. Incrementally advance the conductor. One of the clamp arms, e.g. Allow pivoting between them. As shown in Figures 2 and 3,
The clamp arm 100 is pivoted transversely to the support arm 44 by a pair of identically sized balls 102.
It is set between a and 100b. The clamping arms 100a,b each have a gripping finger, ie, a clamping finger 104a, 104b, which in the embodiment shown in FIGS. 1-4 has a tensioner suitably connected therebetween. It is biased to the normally open position by a spring 106. The conductor gripping control solenoid 108 is supported by the clamp arm 100b, and its core member is connected to the clamp arm 100a via a spring 109, so that when the solenoid 108 is energized, the clamp fingers, that is, the jaws 104a, b are activated. Close. The stop screw 110 is connected to the clamp arm 100
Preferably, the clamp fingers 104a,b are received in a suitable tapered hole to selectively limit the maximum opening between the clamp fingers 104a,b.

A bonding wire guide tube 114 is supported by a support arm 116 that is secured to the clamp arm 100b so that the lower end of the guide tube 114 is located generally axially above the capillary bonding tool 28. The guide tube 114 receives the wire to be bonded from the wire supply device 30 and guides the wire to the bonding tool. Clamp fingers 104a,b
is located between the guide tube and the bonding tool. In the illustrated thermosonic type bonder 10, an electrode arm 120 that emits an electronic flame is supported by a pivot block 122, and the pivot block 122 generates a spark and heats the advancing tip of the conductive wire 96 to be bonded. The conductor can be selectively pivoted to a position to form a ball in the conductor in preparation for bonding. Electronic flame generating electrode 120 and its operation are well known in the art and therefore need not be described in detail here.

Referring now to FIGS. 4 and 5, bonding lead supply apparatus 30 includes an annular spool or reel mount 130 secured to support plate 132 by screws 134. Referring now to FIGS. Support plate 1
32 has an angled mounting edge 132a secured to an upright support member 84. Support member 84 also provides a mounting arrangement for microscope apparatus 22. An annular plate 138 is located between the spool mount 130 and the support plate 132, and a transparent protective cover 1
It has a circular outer surface that acts as a guide for 40. Spool mount 130 is adapted to receive a conductor supply spool 144 on which a continuous conductor 96 is wound. A circular guide plate 146 having a smoothly curved outer circumferential surface 146a is attached to the spool mount 130 to hold the conductor supply spool 144 thereon and provide a smooth surface over which the conductor is drawn during payout to the bonding tool 28. I will provide a. Guide plate 146 has an annular externally threaded boss that releasably threadedly connects with an internally threaded hole 130a formed in the axial direction of spool mount 130.
A tubular conductor guide tube 150 is connected to the guide plate 1.
46, boss 148 and plates 138, 132
is received and supported within a centrally located annular alignment hole to receive a lead wire 196 withdrawn from the supply spool 144 . Information tube 15
0 is preferably made of glass and has an outwardly flared inlet end 150a to provide low frictional resistance to movement of the conductor.

The support plate 132 has an elongated support arm 15.
4 are suitably fixed and extend from the guide tube 150 in spaced relation parallel to the axis of the tube. Support arm 154 supports tubular wire guide device 156 in axial relationship with guide tube 150 . The guide device 156 is connected to the guide tube 15
It is preferably the same size as 0 and made of glass.
Guide tube 156 receives conductor 96 therethrough and has a drag fiber 158 inserted therein, which fiber is adjustable to selectively vary the drag force applied to the conductor. According to one feature of the invention, the conductor supply device 30 includes:
Support member 84 is configured such that the central axis of supply spool or reel 44 and the associated guide track formed by guide tubes 150 and 156 are inclined downwardly from the horizontal so that the conductor travels an inclined track toward the bonding tool. is attached to. In this way, the supply spool and guide tube 1
The inertia of the conductor between the conductor 56 and the conductor 56 makes it easier to unwind the conductor from the supply reel. By adjusting the drag fiber 158, a predetermined axial tension can be maintained in the wire as it approaches the bonding tool 28. Support arm 15 acts on the conductor to maintain the desired tension as the conductor enters guide tube 114.
4 is preferably equipped with a conductor tension arm 160.

Regarding the operation of the bonder 10 explained so far, the first section showing the logic for the control circuit adopted in the bonder 10 will be explained.
This can best be understood by referring to the logic diagram in Figure 2. As mentioned above, if it is desired to bond conductor 96 to a workpiece located below it,
The operator pushes the operating handle 36 to move the bonding tool to the search position. In the illustrated embodiment, the search position is adjusted to position the bonding tool at a predetermined distance above the workpiece. If desired, the operator may then precisely position the workpiece relative to the bonding tool. Thereafter, the operator further pushes the operating handle 36 to adhere to the bonding ball. This movement causes control plate 66 to pivot downward relative to pivot plate 46, causing switch 94 to pivot approximately at the point at which the bonding ball touches down on the workpiece.
Activate. Switch 94 is shown schematically as a sequence logic switch 94 in the logic diagram of FIG.

Switch 94 acts as a contact detection switch
When activated, it generates a pulsed signal that varies from high to low as contact is made.
This signal, called the "go" signal, is the input buffer and the logic pulse circuit 1 of FIG.
Sent to 70. The input buffer and pulse circuit buffers, pulses the input signal, and provides the output signal to a logic shifter, such as a 4000 series CMOS, which provides four output pulse signals Q1, Q2, Q3, and Q4. Thus, the first pulse output signal Q1 is generated at the time the wire bonding bulb contacts the workpiece and provides a signal to the first bonding timer and setup circuit 174. First bonding timer 174
is an ultrasonic (U/S) and contact force selection circuit 176
The circuit 176 simultaneously provides signals to the ultrasound generating circuit 178 and the contact force generating circuit 180. The ultrasonic generation circuit 178 is the converter 56
As is well known, when the transducer is energized and the transducer is activated,
Scrub the bonding bulb of the conductor at the interface with the workpiece.

Force generator 180 provides a ramp output signal to contact force solenoid 86 to provide a predetermined incremental increase, or ramp increase, in the contact force between the wire bonding ball and the underlying workpiece surface. An example of a contact force generation circuit that provides a ramp output signal to solenoid 86 is illustrated in the circuit diagram of FIG. 14, in which values for various components are shown. The voltage gradient supply to the solenoid 86 is provided by a differential amplifier with a capacitance load and is adjustable via a control switch 182 mounted on the front panel 34 of the bonder cabinet 32 as shown in FIG. Includes a device for selectably adjusting the maximum voltage level through a potentiometer.

The lead clamp fingers 104a,b are normally biased into their open position and remain open during initial bonding. At the end of the predetermined bonding time set by the first bonding timer and setup circuit 174, the bonding contact force solenoid 86 is released and the bonding tool is moved to the search position, ie, the return height, by the action of the compression return spring 92. It can be returned. The operator then lifts the control arm 36 to raise the bonding tool to the desired loop height and move the workstation toward the second bonding location. The upward movement of the control arm releases contact force switch 94 and sets pulse signal Q2 from logic shifter circuit 172. Pulse Q2 is loop inhibit and usable circuit 19
2, which circuit sends a signal to the wire clamp and flame generation selection circuit 194 to hold the clamp jaw in a relatively open position. The operator then lowers the operating handle 36, positions the bonding tool again at the search level, and performs final positioning of the workpiece so that the desired bonding location is under the bonding tool. When the final adjustment is made, the operator depresses the operating handle 36 further to activate the contact force switch 94 again. This provides a signal to the input buffer and pulse circuit 170, which activates the logic shifter 172 to
provides a pulse signal Q3 to the bonding timer and enable circuit 198 which in turn sends a signal to the ultrasonic and contact pressure selection circuit 176 and back to the ultrasonic generator circuit 178 and the contact force generation circuit 182. and perform the second bonding in the same way as the first bonding. The duration of the second bonding is controlled by an adjustable control knob 200 mounted on the control panel 34 in the same manner as the duration of the first bonding. During the second bonding, the wire clamp fingers 104a,b remain open.

Upon completion of the second bonding, the second timer and enable circuit 198 activates the contact force solenoid 86.
to again allow upward movement of support arm 44 relative to pivot plate 46 and compression spring 9
2 returns the bonding tool to its spaced position upward from the workpiece. This movement actuates the clamp control switch 204, which enables the wire grip and flame selection circuit 194 to energize the clamp solenoid 108, closing the clamp finger at a predetermined distance above the second bond. When the operator lifts control arm 36 following the second bonding, switch 92 is actuated again so that logic shifter circuit 174 provides pulse signal Q4 to home inhibit and enable circuit 202. The home inhibit and enable circuit 202 now sends a signal to the wire clamp and flame selection circuit 194 which energizes the clamp solenoid 108, thereby causing the control arm 36 to rise and connect to the second bonding connection. Cut the conductor at the top to create a new conductor tip that will connect to the workpiece during the next bonding cycle. Further, by raising the control arm 36, the flame generation control switch 203 attached to the support member 80 is activated, and the switch 94 is activated.
Similarly, an adjustable screw carried on control plate 66 actuates switch contact 203a.
When the flame generation switch is activated, the flame generation control circuit 206 is adjusted via the home usable circuit 202 and the flame generation selection circuit 194, the flame generation mechanism is energized, the flame generation electrode 120 is activated, and a new tip of the conductor is generated. form a sphere.

Bonding time control actuation knob 212 to facilitate selectively controlling the first and second bonding durations and the energy level delivered to ultrasonic transducer 56 during each bonding.
A, 212b and ultrasonic energy level control knobs 214a, 214b are mounted on the control panel 34 for operator access. control knob 212
a, b and 214a, b enable each control circuit to be controlled by a potentiometer, as is well known. Main output switch 216, electronic flame generation output control switch 218, workstation temperature control knob 220, LED workstation temperature setting indicator 222, workstation temperature test switch 224, ultrasonic output meter 22
6 and the ultrasonic generator test switch 228 can be tested by the operator and the LED signals 230a, 230b.
are respectively attached to the control panel 34 for ease of control to direct the energization during the first and second bonding rounds.

In accordance with one aspect of the invention, an apparatus is provided which provides an audible signal at the beginning of a bonding cycle when a bonding head is contacted and which provides an audible signal indicating the end of a bonding cycle. The audible signal device may be a conventional piezoelectric audio device or may be energized and released in response to changes in the amplitude of an ultrasonic transducer arm during contact of the bonding head and during release of the head from the workpiece. It may comprise any suitable sound generating device operatively coupled to the ultrasonic transducer 56 to produce a sound.

6 through 9 illustrate a bonding head, designated generally at 240, constructed in accordance with another embodiment of the present invention. As will become clearer below, the bonding head 240 may, for example,
It is particularly suited for relatively small diameter conductors, such as 12 microns, so it can be used to make interconnections within a single microelectronic chip or wafer. The components of bonding head 240 and their geometry provide a size that allows for easy installation as a modular unit in analytical probe equipment such as those used in the design, development and testing of semiconductor chips with high circuit densities. A small and relatively compact bonding head can be provided.

Very commonly the bonding head 240
includes a base, indicated generally at 242, to which is pivotally mounted a pivot plate, indicated generally at 244, which pivotably supports a support arm, indicated generally at 246. do. The support arm 246 is a wedge-shaped bonding tool 248
and supports a pair of clamp arms 250a and 250b. The support arm 246 defines a longitudinal axis along a majority of its length and is pivoted to the pivot plate 244 for pivoting about an axis transverse to the longitudinal axis of the support arm. . The pivot plate 244 pivots on the base 2 about a pivot transverse to the longitudinal axis of the support arm.
42 so that the support arm can pivot independently with respect to the pivot plate 244 and pivot with the pivot plate about an axis defined between the pivot plate and the base plate. Make it.

The base plate 242 includes a lower plate 242a, middle plates 242b and 242c that cooperate to allow linear movement of the support arm 246 in both the "X" and "Y" axes when the base is mounted on a horizontal support surface. Consists of a synthetic plate with. Lower base plate 242a
has a lower plane which is preferably releasably attached to a support surface having a reference plane, such as a type of probe device that allows detection and analysis of microelectronic chips or wafers. For this purpose,
The base plate 242a has a recess 25 on its lower surface.
6 so that when the base plate is attached to a flat surface a generally sealed chamber is formed. A vacuum passageway (not shown) is provided in communication with the recess 256 and has fittings to permit connection to a vacuum source such that the base can be releasably attached to the support surface. Alternatively, one or more magnets (not shown) may be mounted within the lower base surface 254 for releasable magnetic attachment to a ferromagnetic support surface. 9th
As shown, the intermediate plate 242b has a dovetail connection to the lower base plate 242a;
Upper base plate 242c has a dovetail connection to the middle base plate. For example, by selectively rotating the screw shafts via corresponding control knobs 270, the base plates 242a,b
and internally threaded bosses 2 to facilitate manual adjustment of the movement between pairs 242b,c.
An adjustment device in the form of a threaded shaft 264 having threaded connection with 66 is attached to the upper and lower plates 242a, 242c via brackets 268. A spring 272 biases each base plate into the return position.

A pivot plate 244 is pivotally connected to upper base plate 242c via a pair of axially aligned pivot pins, one designated at 274 in FIG. Pivot pin 274 is secured to pivot plate 244, for example by the illustrated retaining member 276, so that the conical end 274a of the pivot pin extends into and is supported in a conical recess formed in bushing 278. The bush 278 is supported within an upright support member 280 formed in the base plate 242c. Pivoting plate 24
4 is biased by a coil compression spring 284 to an upwardly pivoted position relative to the base plate 242c. The lower end of the coil spring 284 is received in a circular recess 286 formed in the base plate 242c, and the upper end is received in an annular spring retaining member 288 secured within a circular opening in the pivot plate. Compression spring 28 against pivot plate 244
A threaded cap 288a is attached to the annular holding member 2 so as to adjust the upward elastic force applied by the annular holding member 2.
88.

Pivoting plate 2 relative to base plate 242
44 is limited and controlled by a control device in the form of a cam 290 that allows shaft 290a to rotate within a hole 292 formed in support bracket 294. Cylindrical follower 296 and cam 2 supported on pivot plate 244 by support screws 298
The bracket 294 is attached to the upper surface of the base plate 242c so that the brackets 90 are in a vertical relationship and engage with each other. Connection member 302 allows control handle 300 to be connected on the opposite side of cam 290.
is fixed to the end of the shaft 298 and the cam 290
is rotated to allow manual control of vertical movement of pivot plate 244 and support arm 246 relative to resilient spring 240. This action causes the bonding tool 2 to move against the workpiece located below.
The vertical movement of 48 can be manually controlled.

A support arm 246 is pivotally attached to pivot plate 244 similar to the pivot plate on base 242c. In particular, the support arm 246 is connected to a pair of axially aligned pivot pins 27 secured to the pivot plate 244 via a support member 276'.
4' to the pivot plate 244 such that the conical end of the pivot pin 274' is formed in the transverse arm portion 310 of the support arm 246, one of which 3 in Figure 9
It is in pivotal relationship with a corresponding bushing 278' received in the appropriate hole indicated at 08.

A plate member 312 is attached to the transverse arm portion 310 of the support arm 246 so as to extend along and form a portion of the longitudinal axis of the support arm. Plate member 312 is spaced above pivot plate 244 by pivoting support arm 246 to pivot plate 244 about lateral pivot axis 274'. A threaded shaft 316 is secured to the pivot plate 244 in a normal upright relationship and freely extends through a suitable opening 318 formed in the plate member 312. A compression spring 320 is mounted on the shaft 316 between the pivot plate 244 and the plate member 312, and a similar coil compression spring 322 is mounted between the plate member 312 and an adjustable nut 324 mounted on the upper end of the shaft 316. It is attached above the shaft 16 in between. A nut 326 is screwed onto the shaft 316 above the plate member 312 and, under the action of the compression spring 320, the plate member 3
Preferably, it is adjustable to limit upward pivoting of 12. Compression springs 320 and 322 have the same spring rate to balance their effect on support arm 246 by adjusting nut 324 so that bonding tool 248 is not affected during the bonding operation.
The weight of the support arm as a component of the contact force supplied by the contact force may be eliminated.

Clamp arms 250a, 250b are clamps, that is, gripping fingers 33a, 33b, respectively.
The fingers are preferably made of stainless steel and have large diameter arm portions 392a and 332b, respectively, which are connected to each clamp arm 250.
Appropriate holes 334a, 3 formed in holes 334a, 250b
34b. The arm 33
2a,b are bonding heads 24 attached to support arms 246 via ultrasonic transducers 338.
8, the clamp or gripping finger 330a
It is long enough to locate. The ultrasonic transducer 338 is attached to the support arm 24 such that the ultrasonic coil 338a is disposed within the recess 246a of the support arm and its longitudinal axis coincides with the axis of the support arm.
6 through circular aperture 340 .

The wedge-shaped bonding tool 248 has a cylindrical guide hole (not shown) formed therein for receiving and guiding the conductor 96 to be bonded, so that the tip or contact end of the conductor is formed at the base of the bonding tool. flat bonding surface 24
It is arranged in a vertical relationship with 8a. A bonding tool 248 is mounted inside the bore of the transducer shaft. According to one feature of the bonding head 240, the bonding tool 248 has an angle in the vertical plane, considered as the angle between the longitudinal axis of the tool and a vertical plane transverse to the shaft of the transducer. angularly inclined relative to a plane transverse to the transducer shaft at an angle of approximately 25 degrees. By tilting the bonding tool as described above, it forms a vertical aiming trajectory generally perpendicular to the surface of the workpiece on which the conductor is to be bonded. Particularly applicable is the inclination of the bonding tool so that its lower end is generally above a predetermined bonding location on the workpiece without disturbing the vertical viewing line of sight.

a spool of conductor that, in operation, is routed to bonding head 248 through a suitable passageway in the shaft of the transducer such that the conductor moves longitudinally through a generally arcuate trajectory from the supply spool;
Alternatively, the bonding head 240 may be mounted on a generally horizontal support surface of the apparatus adapted to support the ribbon.
is normally located. Bonding head 24
According to another feature of 0, the clamp arm 250
a, b are support arms 2 for movement relative to the support arm in a plane generally parallel to the longitudinal axis of the support arm during transverse movement in a predetermined trajectory;
46 to cause the clamp fingers 330a,b to move laterally in a trajectory that generally corresponds to the predetermined arcuate trajectory along which the conductor 96 moves laterally as the clamp fingers 330a,b are guided relative to the bonding tool 248. Specifically, the clamp arms 250a, 25 of the illustrated embodiment
0b connects the support arm 246 via a device that causes the clamp arm to perform a generally arcuate movement in a plane generally parallel to the longitudinal axis of the support arm when transversely moving along said predetermined trajectory. It is connected to the. Clamp arms 250a,b are interconnected so that movement of one clamp arm in a direction generally parallel to the longitudinal axis of support arm 246 causes a corresponding movement of support arm 246. exercise accordingly. The interconnection device includes a pair of identical ball bearings 344, which are formed in a pair of mutually opposed hemispherical or conical shaped portions 348a and 348b of clamp arms 250a,b, respectively. Recesses 346a, 346
b. The ball bearing 344 is of sufficient size to maintain arm portions 348a,b in a slightly spaced relationship while forming a pivot transverse to the longitudinal axis of the support arm 246. The clamp arm has a pair of coil tension springs 35.
0, the springs are coplanar with the ball bearings 344, and their ends are respectively connected to opposing clamp arms by pin connections.

The clamp arm 250a has three balls 352a,
interconnected to the support arm 246 by devices in the form of screws 354 and clamping arm 250 in a predetermined guide trajectory as the arm 250a moves in a plane generally parallel to the longitudinal axis of the support arm. to guide you. A screw 354 is received through a slot 356 in pivot arm 250a and threadably connects with a hole 358 in support arm 246;
The head of the screw 354 thus holds the clamp arm 250a against the balls 350a, b, c while allowing the clamp arm to move in its own plane. Balls 350a, b, c are clamp arm 2
It is received within a suitable elongated slot formed in support arm 246 opposite 50a. As such, the elongated slot forms an arcuate guide track in the pivot arm 246, the longitudinal axis of which allows the conductor 96 to be bonded to move laterally as it approaches and is guided through the bonding tool 248. The center of curvature generally coincides with the center of curvature of the trajectory of the trajectory.

The ends of coil tension spring 366 are connected to support arm 246 and clamp arm 250a, respectively, through pins 368a and 368b, so that clamp arms 250a and b
is biased into a forward position relative to the pivot arm, while remaining in a generally parallel relationship relative to the support arm 246 during its movement. Clamp arm 250b is similarly preferably loosely supported on support arm 246 by a screw 354' received through a slot 356' thereof, with screw 354' having a threaded connection with the support arm; The clamp arm 250b can be pivoted both longitudinally and outwardly. In addition to the clamp arm being adapted to move in a plane generally parallel to the longitudinal axis of the support arm 246, the clamp arm 250b is also pivotable relative to the clamp arm 250 so that the clamp or The gripping fingers 330a,b are movable between a relatively closed position for gripping the wire to be bonded and an open position for releasing the wire.

A pair of parallel, electrically energized actuators, in the form of solenoids 372, 374, which together form actuators for an incremental conductor feeder, actuate the clamp arms 250a,b and direct the conductors to the bonding head. 248, the grip finger 3 makes a stepwise incremental movement that generally corresponds to the transverse trajectory of the conductor to be bonded.
Add to 30a and b. The solenoid 372,3
74 is a support bracket 37 such that the longitudinal axes of the solenoids 372, 374 are located in a plane containing the arc of motion of the clamp arms 250a, b.
6 and mounted in parallel relationship. solenoid 372
has a solenoid core 372a whose outer end is pivotally connected to one end of connecting rod 378 and whose other end is received within an opening 380 in clamp arm 250a, which connects conductor feed solenoid 272 and clamp arm 250.
Provide a pneumatic connection between a. The other conductor feed solenoid 374 is connected to the clamp arm 250a via a connecting rod 382, and the clamp arm 2
50a and a core member 374a that does not move freely. Conductor feed solenoids 372 and 374 are connected in a control circuit for bonding head 240 and
66 forces the clamp arms 250a,b to an outward position relative to the support arm 246.
Activation of the conductor feed solenoid 372 causes the clamp arm to move rearwardly by a first predetermined incremental distance, and then energization of the conductor feed solenoid 372 causes the clamp arm to move rearwardly by a predetermined first incremental distance.
moving the clamp arm rearwardly by a second predetermined incremental distance that is generally less than the distance due to the second bias. The second incremental movement of clamp arms 250a,b relative to support arm 246 is effected by the aforementioned conductor feed solenoid 372 and clamp arm 25.
This is made possible by a pneumatic connection between 0 and 0.

Relative pivoting between clamp arms 250a,b for gripping and releasing movements of clamp fingers 330a,b relative to bonding conductor 96 is provided by actuation in the form of a clamp solenoid 384 supported by bracket 376. provided by the device. When energized, the clamping solenoid acts against the end 386 of the clamping arm 250b, forcing the clamping arm 250a,b and thus the associated clamping finger 330a,
The clamp arm is moved against the resilient force of the coil spring 388 which forces the clamp arm into a normally closed gripping relationship.

A bonding force control actuator in the form of a solenoid 390 is mounted to support bracket 376 and has a movable core member 390a acting upwardly against the lower surface of plate member 312. By providing a tilt output signal to solenoid 390 , support arm 246 pivots 27 relative to pivot plate 244 .
4' to ramp or gradually increase the bonding force applied by the bonding tool after it contacts the workpiece below.

The wire feed control solenoids 372, 374, the wire gripping solenoid 384, and the bonding solenoid 390 are connected in an electrical control circuit that operates the bonding head 240 according to the logic diagram shown in FIG. The various circuit elements described above are generally conventional and incorporated into a circuit board located in a separate portable modular cabinet having a control panel similar to the front control panel 34 used in bonder 10. be able to. Alternatively, the control circuitry may be integrated into a test or analysis device that may employ bonding head 240.

In operation, referring to the logic diagram for the bonding head 240 shown in FIG. 13, the bonding head is positioned so that the bonding tool 248 is in a predetermined height relationship on an adjustable workpiece support member, or pedestal. After this, the operator actuates the control handle 300 and moves the support arm 2 so that the bonding surface 248a engages the tip, or contact end, of the conductor to be bonded against the workpiece in a so-called touch-down condition.
46 and associated bonding tool are lowered about pivot 274. Bonding head 240-1
According to one feature, when the control circuit is first connected to the power supply, a low level amplitude signal, e.g.
8a. The control circuit is 40 in Figure 13.
0 and includes a contact detection circuit that detects changes in the amplitude of the transducer upon contact and elevation of the bonding tool. The contact detection circuit is shown in FIG.

Upon contact, a signal pulse is provided to input buffer and pulse circuit 402, which provides an output signal to logic shifter circuit 172'. Logic shifter circuit 1
72' is substantially the same as the four-phase shift logic shifter 172 described above. Similarly, other circuit elements shown schematically in the logic circuit of FIG. 13 and designated by prime numbers are generally the same as corresponding elements in the logic circuit described above with respect to bonder 10. Logic shifter circuit 172', as is well known, when provided with a series of input pulses from input buffer and pulse circuit 402, outputs four output signals Q1, Q2, Q3, and Q4 in a shifting but continuous order. It is designed to provide the following. The first pulse output signal Q1 is provided to a circuit 174' that controls the time of the first bond on contact, which circuit sends a signal to a circuit 176' that selects the ultrasound and bonding force, which circuit 176' Sound wave generator circuit 17
8' and a signal of a predetermined amplitude to the bonding force generator circuit 180'. Ultrasonic generator circuit 178' energizes ultrasonic transducer 338 while bonding force generator circuit 18
0' is timed to the bonding force generating solenoid 390 so as to gradually and predetermined increase the contact force between the bonding tool and the underlying workpiece to which the bonding connection is to be made; Provides a sloped output signal. Bonding force generator circuit 180' may be generally identical to bonding force generator circuit 180 shown in FIG.

At the end of the predetermined initial bonding time set by bonding timer 174', the contact detection circuit detects a change in transducer amplitude due to lifting of the bonding tool and sends a pulse signal to logic shifter circuit 172'. was made to send
The circuit 172' provides the detected pulse signal Q2 to the loop inhibit and enable circuit 192'. Loop inhibit and enable circuit 192 sends a signal to wire feed and grip circuit 404 which energizes wire grip solenoid 384 to open grip or clamp fingers 330a,b. to release the conductor 96. This allows the operator to move the workpiece to a second position to perform a second bonding. The conductive wire to be bonded is looped between the first and second bonding connections. Also, at this time, the conductor feeding and gripping circuit 40
4 sends a signal to the conductor feed solenoid 372,
The solenoid 372 is connected to the clamp arm 250a,
b and associated grip fingers 330a,b are moved a first incremental distance relative to the conductor to be bonded along the aforementioned predetermined trajectory formed by the elongated grooves 360a,b.

After positioning the workpiece to make the second bonding connection, the operator
00 is reactivated to move the bonding tool to the contact position, thereby triggering pulse Q3 from the logic shifter circuit. Pulse Q3 is the second bonding timer and usable circuit 19
8', which provides signals to the ultrasonic and contact force selection circuit 176' and to the wire feed and grip circuit 404. The signal to the ultrasonic and contact force selection circuit 176' is transmitted to the ultrasonic transducer 3.
A second signal of a predetermined amplitude is sent to the bonding force solenoid 390, and a predetermined timed and sloped output signal is supplied to the bonding force solenoid 390 in the same way as when the first bonding force was supplied in a timed manner. start. A signal provided to the wire feeding and gripping circuit 404 energizes the wire gripping solenoid 384 to apply a second bonding contact force during looping to the second bonding position. between clamps, that is, gripping fingers 330a,
b in a relatively open position.

At the end of the second bonding, as set by the second bonding timer and enabling circuit 198', the operator controls the control handle 300.
By activating again and lifting the bonding tool, the contact detection circuit 400 detects the amplitude change of the transducer again and transfers the pulse signal to the logic shifter 17.
2'. The logic shifter circuit generates a pulse Q4 that is provided to the home inhibit and enable circuit 202', which signals the wire feed and grab circuit 404;
The signal to the gripping solenoid 384 is terminated to allow the clamp or gripping fingers 330a,b to grip the conductor again. At the same time, conductor feed,
and the gripping circuit 404 provides a relatively short pulse signal to the wire feed solenoid 374 sufficient to disconnect the wire from the second bonding portion.
A predetermined second incremental or stepwise movement of the clamp arms 250a,b is performed. solenoid 37
The energizing signal to 2,374 energizes the solenoid 372 to obtain the desired lead tip length and to shorten the closed clamp finger sufficiently to disconnect the lead from the second bonding portion. It is electrically timed to automatically terminate after the exercise is performed. After releasing solenoids 372, 374, return spring 366 releases clamp arm 250.
a and b to their front positions, and the tip of the newly created conductor wire is placed on the bonding surface 248b.
Send it to the position below.

According to another feature of the invention, as indicated at 406 in the logic diagram, an audible signal circuit, generally of well-known construction, is provided which provides an audible signal at the beginning and end of each bonding cycle. As much as possible
It is connected to the contact detection circuit 400 and the first and second bonding circuits 174' and 198'.

For example, by connecting the bonding head 24 to a control circuit capable of moving the workpiece support station and support arm 246 according to a predetermined programmed motion.
It is recognized that 0 and its associated control circuitry can easily be adapted for automatic operation.

10 and 11, the supply reel or spool is directed generally at 410 to apply a predetermined axial tension as the corresponding conductor is fed in successive lengths to the associated bonding tool. 2 shows an alternative embodiment of a wire supply device adapted to feed the wire to be bonded from the wire;
The conductor supply device 410 includes an electric drive motor 41
2, the motor is mounted to the mounting plate 414 such that its longitudinal axis is disposed generally perpendicular to the mounting plate 414. The motor 412 is equipped with a suitable speed reducer 416 having an output shaft 416a on which is mounted a hub 418 that supports a reel or spool.
is connected to. The support hub 418 is equipped with a spool or reel of conductive wire 420 to be bonded, and reliably rotates the spool or reel in response to the energization of the drive motor 412. Drive motor 412 is preferably adapted for incremental rotational movement, such as a suitable step motor, in response to a series of signals applied thereto. A transparent protective cover 422 is attached to support plate 414 to generally enclose spool 420.

A support arm 424 is attached to the support plate 414 and supports a guide tube 426 for the wire to be bonded. The guide tube 426 is made of glass, and its axis is connected to the annular conductor spool 4.
The support arm 4 is oriented generally in the tangential direction with respect to 20.
Preferably, it extends parallel to 24.

The switch actuating member 428a is, for example, a screw 43.
Microswitch 42 is positioned above a tension sensing device in the form of a wire member 430 suitably secured at one end to support arm 424 by 2.
8 is attached to the support arm 424 so that the opposite end of the tension sensing wire 430 extends forwardly from the outlet end of the guide tube 426.
The conductive wire to be bonded is engaged as it is withdrawn from the guide tube 426. Mounting plate 412 is adapted to be mounted to the bonder, such as the previously described upright support member 84 of bonder 10, with support arm 424 extending in a downwardly inclined direction toward the associated bonding tool.

A microswitch 428 is connected in the control circuit to the electric motor 412 and cooperates with the tension detection wire 430 to set the tension of the conductor to be bonded, if fed from the spool 420 and passed over the looped lower end of the tension detection wire. of tension is applied, microswitch 428 is energized to rotate spool 420 incrementally and pay out the wire until the tension is reduced to a predetermined desired maximum tension;
8 is activated again and stops the energizing signal to the drive motor 412.

16 and 17 show an alternative embodiment of a clamp arm, designated 440 and 442, which is attached to a support arm, such as support arm 44 of bonder 10, and which connects the leads to the associated bonding tool. Particularly adapted to the use of wedge-type bonding operations, which facilitate the incremental supply of the wire and also allow an incremental stepwise movement of the corresponding clamp finger in order to facilitate the cutting of the conductor after the second bonding. . To this end, the clamp arm 440 has an inclined coplanar surface 440a at its forward end to facilitate attachment of a pair of conductor clamp fingers 444, 446, which are pivoted to each other about a pivot point 448. and are biased toward each other toward a relative closed position by an adjustable coil spring 450. Clamp arm 440 has a leg 440b that supports a gripping solenoid 452 that is actuated via control arm 454 to open clamp fingers 444,446.

The clamp arm 442 has mounting screws 456a,
b to an associated support arm, for example as indicated at 45' in FIG. The screw 462 is received through a suitable opening in the clamp arm 440 to allow relative longitudinal movement between the clamp arms. Clamp arm 442 is solenoid 4
Solenoid 4 connected to core member 466a of 66
A pair of conductor feeding solenoids 464 and 466 are supported in axial alignment with the core member 464a of No. 64. The opposite end 466b of the solenoid core member 466a is connected to the second leg portion 440c of the clamp arm 440. Clamp arm 4
Coil tension spring 468 between 40 and 442
is connected and presses the clamp arm to the forward position against the fixed clamp arm 442.

In wedge-type bonding, when operating a bonder that employs clamp arms 440 and 442, the clamp arms 44 are activated by energizing the solenoid 464 after the first bonding.
Therefore, the movement of the solenoid core member 464a acting on the leg 440c via the core member 466a of the solenoid coil 466 causes the clamp fingers 444, 446 to move incrementally in a predetermined manner; ,446
to a relatively open position. At the end of the second bonding, solenoid 464 is released and solenoid 466 is energized, causing core member 466a to advance a predetermined second incremental distance and clamp arm 4
40 second increments, step movements and associated clamps. The latter movement is of short duration and closes the clamp fingers 444, 446 to disconnect the conductor from the second bonding connection in preparation for the next bonding cycle.

While the preferred embodiment of the invention has been illustrated and described, changes may be made without departing from the scope of the invention.
It is understood that modifications are possible. Various features of the invention are defined in the following claims.