Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
  • B23K20/002—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating specially adapted for particular articles or work
  • B23K20/004—Wire welding
  • B23K20/005—Capillary welding
  • B23K20/007—Ball bonding
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/071—Connecting or disconnecting
  • H10W72/075—Connecting or disconnecting of bond wires
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
  • B23K20/002—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating specially adapted for particular articles or work
  • B23K20/004—Wire welding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
  • B23K20/26—Auxiliary equipment
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/071—Connecting or disconnecting
  • H10W72/0711—Apparatus therefor
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/50—Bond wires
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2101/00—Articles made by soldering, welding or cutting
  • B23K2101/36—Electric or electronic devices
  • B23K2101/40—Semiconductor devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2101/00—Articles made by soldering, welding or cutting
  • B23K2101/36—Electric or electronic devices
  • B23K2101/42—Printed circuits
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/01—Manufacture or treatment
  • H10W72/015—Manufacture or treatment of bond wires
  • H10W72/01551—Changing the shapes of bond wires
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/071—Connecting or disconnecting
  • H10W72/0711—Apparatus therefor
  • H10W72/07141—Means for applying energy, e.g. ovens or lasers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/071—Connecting or disconnecting
  • H10W72/0711—Apparatus therefor
  • H10W72/07183—Means for monitoring
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/071—Connecting or disconnecting
  • H10W72/075—Connecting or disconnecting of bond wires
  • H10W72/07511—Treating the bonding area before connecting, e.g. by applying flux or cleaning
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/071—Connecting or disconnecting
  • H10W72/075—Connecting or disconnecting of bond wires
  • H10W72/07531—Techniques
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W90/00—Package configurations
  • H10W90/701—Package configurations characterised by the relative positions of pads or connectors relative to package parts
  • H10W90/751—Package configurations characterised by the relative positions of pads or connectors relative to package parts of bond wires
  • H10W90/756—Package configurations characterised by the relative positions of pads or connectors relative to package parts of bond wires between a chip and a stacked lead frame, conducting package substrate or heat sink

Definitions

• the invention relates to wire bonding operations, and in particular, to techniques for monitoring the accuracy of a bonding force on a wire bonding machine.
• wire bonding continues to be the primary method of providing electrical interconnection between two locations within a package (e.g., between a die pad of a semiconductor die and a lead of a leadframe). More specifically, using a wire bonder (also known as a wire bonding machine) wire loops are formed between respective locations to be electrically interconnected.
• the primary methods of forming wire loops are ball bonding and wedge bonding.
• various types of bonding energy may be used, including, for example, ultrasonic energy, thermosonic energy, thermocompressive energy, amongst others.
• Wire bonding machines e.g., stud bumping machines are also used to form conductive bumps from portions of wire.
• Such wire bonding machines typically include a bond head assembly (i.e., a bond head) that carries a wire bonding tool (e.g., a capillary tool) that contacts a workpiece during the wire bonding operation.
• a bonding force is applied to the wire bonding tool.
• the bonding force applied during wire bonding is accurate.
• the applied force is different from an intended (e.g., programmed) bonding force.
• the bonding force may vary over time based on conditions such as environmental factors, hours of machine operations, amongst others.
• a method of operating a wire bonding machine includes: (a) operating a wire bonding machine during at least one of (i) an automatic wire bonding operation and (ii) a dry cycle wire bonding operation, wherein a bonding force is applied during the operation of the wire bonding machine; and (b) monitoring an accuracy of the bonding force of the wire bonding machine during the at least one of (i) the automatic wire bonding operation and (ii) the dry cycle wire bonding operation.
• a method of operating a wire bonding machine includes the steps of: incrementally adjusting a bonding force applied to a bond head assembly while detecting a z-height position of a portion of the bond head assembly; and determining a desired bonding force at which an incremental adjustment does not result in a change of the z-height position of the bond head assembly.
• a method of operating a wire bonding machine includes the steps of: incrementally adjusting a bonding force applied to a bond head assembly while detecting a z-height position of a portion of the bond head assembly; and determining a desired bonding force at which an incremental adjustment from results in a peak z- height position of the bond head assembly.
• a method of operating a wire bonding machine includes the steps of: incrementally decreasing a bonding force applied to a bond head assembly while detecting a z-height position of a portion of the bond head assembly, until the z- height position changes from an initial height by a predetermined height adjustment; and detecting a bonding force value upon the z-height position changing from the initial height by the predetermined height adjustment.
• a method of operating a wire bonding machine includes the steps of: incrementally increasing a bonding force applied to a bond head assembly while detecting a z-height position of a portion of the bond head assembly, until the z- height position changes from an initial height by a predetermined height adjustment; and detecting a bonding force value upon the z-height position changing from the initial height by the predetermined height adjustment.
• the methods of the invention may also be embodied as an apparatus (e.g., as part of the intelligence of a wire bonding machine), or as computer program instructions on a computer readable carrier (e.g., a computer readable carrier including a wire bonding program used in connection with a wire bonding machine).
• a computer readable carrier e.g., a computer readable carrier including a wire bonding program used in connection with a wire bonding machine.
• FIGS. 1A-1C are a series of block diagram side views of a wire bonding machine illustrating a method of operating a wire bonding machine in accordance with an exemplary embodiment of the invention
• FIGS. 2A-2C are another series of block diagram side views of a wire bonding machine illustrating a method of operating a wire bonding machine in accordance with an exemplary embodiment of the invention
• FIGS. 3A-3F are yet another series of block diagram side views of a wire bonding machine illustrating a method of operating a wire bonding machine in accordance with an exemplary embodiment of the invention
• FIG. 4 is a timing diagram illustrating a z-height position of a portion of a bond head assembly, and the bonding force applied by the bond head assembly, versus time, in accordance with an exemplary embodiment of the invention.
• FIGS. 5-8 are flow diagrams illustrating methods of operating wire bonding machines in accordance with various exemplary embodiments of the invention.
• methods of operating wire bonding machines are provided, for example, methods of automatically verifying bonding force (sometimes referred to as bond force), and methods of monitoring bonding force in real time, on a wire bonding machine.
• the methods may include an automatic mode bonding force verification process and/or a closed loop bonding force adjustment process (e.g., including offset adjustments of the bonding force).
• aspects of the invention relate to the monitoring and/or the automatic correction/adjustment of bonding force applied on a wire bonding machine, with the goal of achieving a desirable wire bonding performance.
• the bonding force (and/or the accuracy of the bonding force) is monitored in an automatic wire bonding mode (and/or a dry cycle bonding mode), where a response may be provided if the accuracy of the monitored bonding force is not within an acceptable range (e.g., the monitored bonding force has shifted due to any reason).
• the response may be (i) to provide an alarm, warning or error message to a machine operator; (ii) to cease operation of the wire bonding machine; (iii) to automatically adjust the bonding force of the wire bonding machine (e.g., closed loop force offset adjustment); etc.
• the bonding force of the wire bonding machine e.g., closed loop force offset adjustment
• methods are provided for verifying the machine bonding force in automatic mode. Such methods may include applying multiple levels of bonding force, and monitoring the response of the bond head position. For example, the starting force (e.g., a preverified force F pv , which may or may not be a zero gram force) may be gradually decreased in small increments until it moves up a set height (e.g., h a ), and then the force may be increased until it moves back down to the starting point (e.g., hinit).
• This force verification can be performed at dry cycle and automatic mode.
• the two force values (and/or additional force values such as Fb within the scope of the invention) (e.g., the force value corresponding to the set height h a , and the force value corresponding to the return to the starting point hinit) are recorded. If the force values do not meet the expectation (e.g., are not within an acceptable tolerance of the expected force values), a response may be provided (e.g., the response may be: to provide an alarm, warning or error message to a machine operator; to cease operation of the wire bonding machine; to automatically adjust the bonding force of the wire bonding machine to an acceptable level).
• the invention provides significant advantages over past practice.
• Existing methods of bonding force calibration involve operators performing calibrations offline (not in automatic mode). Such calibrations tend to be time consuming, and require the removal of certain hardware parts (e.g., a flow head for reducing gas), and the installation of calibration weights.
• Aspects of the invention provide force verification in automatic mode with a minimal (or no) time penalty, and may also be used to provide closed loop bonding force adjustments.
• aspects of the invention relate to monitoring an accuracy of the bonding force of a wire bonding machine during at least one of (i) an automatic wire bonding operation and (ii) a dry cycle wire bonding operation. Exemplary techniques for monitoring such accuracy of the bonding force are disclosed herein. However, other techniques for accomplishing such monitoring (during at least one of an automatic wire bonding operation, and a dry cycle wire bonding operation) are contemplated within the scope of the invention.
• zero gram force is an example of an applied bonding force at which an incremental force adjustment (e.g., an increase or decrese in the bonding force) does not result in a change of the z-height position of the bond head assembly.
• the term “zero gram force” may also be used to refer to an applied bonding force that results in a peak height (either a high peak height or a low peak height) of a portion of a bond head assembly (e.g., force Fb resulting in height hb, and force Fa resulting in height ha, both described in connection with FIG. 4).
• zero gram force values may be determined from a single value (e.g., see Fb from FIG. 4, Fa from FIG. 4, etc.).
• a determined “zero gram force” or a determined “desired” force within the scope of the invention may utilize multiple measured values (e.g., see Fb from FIG. 4, Fa from FIG. 4, etc.) to determine a single force value.
• a single force value may be determined by averaging (or otherwise mathematically manipulating) the multiple measured values from a single cycle (as in FIG. 4) or multiple cycles.
• aspects of the invention relate to detecting a bonding force applied at different height positions of a bond head assembly of a wire bonding machine. For example, a force value may be detected upon the z-height position changing from one height to another height (e.g., changing from an initial height by the predetermined height adjustment). In other aspects of the invention, height positions of a bond head assembly of a wire bonding machine are detected at different values of applied bonding force. Using such bonding force and/or height position information, the accuracy of the bonding force may be monitored. [0025] While the invention is largely described in connection with a force control mode of a wire bonding machine, it is not limited thereto. For example, a position control mode may be utilized.
• a characteristic of a z-axis driving force (which corresponds to a bonding force) may be determined while substantially maintaining a predetermined z-axis position to monitor the accuracy of the bonding force.
• a characteristic may be, for example, an electrical characteristic of a z-axis motor, an electrical current of a z-axis motor providing the driving force, etc.
• FIGS. 1A-1C illustrate wire bonding machine 100.
• Wire bonding machine 100 includes support structure 102 (e.g ., a heat block, an anvil, etc.) for supporting a workpiece 104 (e.g., a semiconductor element such as a leadframe holding one or more semiconductor die) during a wire bonding operation.
• workpiece 104 e.g., a semiconductor element such as a leadframe holding one or more semiconductor die
• wire bonding machine 100 also includes wire bonding tool 108 (e.g., a capillary wire bonding tool, a wedge bonding tool, etc.) for bonding wire portions to workpiece 104.
• wire bonding tool 108 e.g., a capillary wire bonding tool, a wedge bonding tool, etc.
• wire bonding tool 108 (carried by bond head assembly 110) is moveable along a plurality of axes of wire bonding machine 100 to perform wire bonding operations.
• wire bonding tool 108 may be moved along the x-axis and y-axis through movement of bond head assembly 110.
• a linkage 110a is provided as part of the bond head assembly 110. Linkage 110a is configured for movement along the z-axis of the wire bonding machine 100 with the bond head assembly 110, and is driven along the z-axis by z-axis motor 116 (which is controlled by computer 114 of wire bonding machine 100).
• a z-axis position detector 112 (e.g., a z-axis encoder) is provided that detects the z-axis position of linkage 110a (and hence a relative z-axis position of wire bonding tool 108), and provides data corresponding to this z-axis position (e.g., real time) to computer 114 of wire bonding machine 100.
• computer 114 has information related to the z-axis position of wire bonding tool 108 through its motions.
• z-axis motor 116 may be used to apply bonding force in connection with wire bonding operations.
• free air ball 106 is seated at a working tip 108a (the contact portion) of wire bonding tool 108.
• free air ball 106 is not required within the scope of the invention (e.g., the inventive methods may be performed with no wire portion at working tip 108a).
• the initial height shown in FIG. 1A is hinit (e.g., see left side of timing diagram in FIG. 4, described below in connection with FIG. 3A) . While hinit is shown with respect to the working tip 108a of wire bonding tool 108 (adjacent free air ball 106), this is a relative height, and could be illustrated with respect to any part of bond head assembly 110 that moves along the z- axis.
• a bonding force applied to the bond head assembly 110 is incrementally decreased while detecting a z-height position of a portion of the bond head assembly 110 (using z-axis position detector 112), until the z-height position changes from hinit by a predetermined height adjustment (in FIG. IB, until it reaches height h a ) (e.g., see h a in the timing diagram in FIG. 4, described below in connection with FIG. 3B).
• the bonding force value is detected upon the z-height position changing from hinit by the predetermined height adjustment shown in FIG. IB.
• the bonding force applied to the bond head assembly 110 is incrementally increased while detecting the z-height position of the portion of the bond head assembly 110 (using z-axis position detector 112), until the z-height position returns to hinit as shown in FIG. 1C (e.g., see hinit as caused by F c in the timing diagram in FIG. 4, described below in connection with FIG. 3D).
• the bonding force value is detected upon the z-height position changing back to hinit as shown in FIG. 1C.
• the accuracy of the bonding force (e.g., including the accuracy of the zero gram force) may be monitored (e.g., the accuracy of the applied bonding force as compared to the intended (e.g., programmed) bonding force).
• the accuracy of the bonding force e.g., including the accuracy of the zero gram force
• the accuracy of the applied bonding force may be monitored (e.g., the accuracy of the applied bonding force as compared to the intended (e.g., programmed) bonding force).
• variations, and additional process steps may be included in this exemplary process.
• FIGS. 1A-1C illustrate another technique for monitoring the accuracy of the bonding force (and/or method of operating a wire bonding machine).
• FIGS. 2A-2C illustrate another non-limiting example. Referring specifically to FIG. 2A, the initial height shown is hinit. While hinit is shown with respect to the working tip 108a of wire bonding tool 108 (adjacent free air ball 106), this is a relative height, and could be illustrated with respect to any part of bond head assembly 110 that moves along the z-axis.
• a bonding force applied to bond head assembly 110 is incrementally increased while detecting a z-height position of a portion of bond head assembly 110 (using z-axis position detector 112), until the z-height position changes from hinit by a predetermined height adjustment (in FIG. 2B, until it reaches height h a ).
• the bonding force value is detected upon the z-height position changing from hinit by the predetermined height adjustment shown in FIG. 2B.
• the bonding force applied to bond head assembly 110 is incrementally decreased while detecting the z-height position of the portion of bond head assembly 110 (using z-axis position detector 112), until the z-height position returns to hinit as shown in FIG. 2C.
• the bonding force value is detected upon the z-height position changing back to hinit as shown in FIG. 2C.
• the accuracy of the bonding force e.g., including the accuracy of the zero gram force
• the accuracy of the bonding force may be monitored (e.g., the accuracy of the applied bonding force as compared to the intended (e.g., programmed) bonding force).
• FIGS. 3A-3F illustrate another non-limiting example for monitoring the accuracy of the bonding force (and/or method of operating a wire bonding machine).
• FIG. 4 is a timing diagram illustrating a z-height position of a portion of the bond head assembly, and the bonding force applied by the bond head assembly, versus time. The timing diagram of FIG. 4 aligns with the process steps shown in FIGS. 3A-3F as described below.
• wire bonding machine 100 is illustrated with free air ball 106 at a position hinit.
• the force applied at this point can be described as the pre-verified zero gram force (see “F pv " of FIG. 4).
• wire bonding tool 108 is moved upward (i.e., +Z direction) to position h a as the applied force to wire bonding tool 108 is decreased (this is illustrated in FIG. 4 as the applied force changes from Fpv and F a ) (See FIG. 4, where a force F a is applied, at which time the applied force begins to increase).
• FIG. 4 See FIG. 4, where a force F a is applied, at which time the applied force begins to increase.
• wire bonding tool 108 continues to move upward to a position hb even though the force is increasing (this is illustrated in FIG. 4 between points h a and hb), for example, due to the momentum of bond head assembly 110.
• a zero gram force e.g., force Fb
• Fb force
• a zero gram force may be determined/monitored at this point (i.e., at height hb, where the height is at a local maxima).
• a zero gram force may be determined in connection with an applied bonding force that results in the peak height hb (i.e., force Fb resulting in height hb, as described in connection with FIG. 4).
• wire bonding tool 108 is moved back to the initial position hinit when the applied force is at its peak, F c (this is illustrated in FIG. 4 between points Fb and Fc).
• wire bonding tool 108 is moved to position hd as the applied force is being decreased (this is illustrated in FIG. 4 between points F c and Fd).
• Another zero gram force e.g., Fd
• Fd Another zero gram force
• hd Another zero gram force
• a zero gram force may be determined in connection with an applied bonding force that results in the peak height hd (i.e., force Fd resulting in height hd, as described in connection with FIG. 4).
• wire bonding tool 108 moves back to position hmit as the applied force continues to decrease (this is illustrated in FIG. 4 between points Fd and Fe).
• the timing diagram illustrated in FIG. 4 is a short duration (e.g ., a single cycle), however, it is understood that this process shown in FIG. 4 (or any part thereof claimed in this application) may be repeated for a plurality of cycles until the desired result occurs (e.g., a desired bonding force is determined, a stable bonding force value is determined, an accurate zero gram force value is determined, the accuracy of the bonding force has been determined, etc.).
• the desired result e.g., a desired bonding force is determined, a stable bonding force value is determined, an accurate zero gram force value is determined, the accuracy of the bonding force has been determined, etc.
• FIGS. 5-8 are flow diagrams illustrating methods of operating wire bonding machines (and related methods) in accordance with various exemplary embodiments of the invention. As is understood by those skilled in the art, certain steps included in the flow diagrams may be omitted; certain additional steps may be added; and the order of the steps may be altered from the order illustrated.
• a method of operating a wire bonding machine is illustrated.
• a wire bonding machine is operated during at least one of (i) an automatic wire bonding operation and (ii) a dry cycle wire bonding operation, wherein a bonding force is applied during the operation of the wire bonding machine.
• an accuracy of the bonding force of the wire bonding machine is monitored during the at least one of (i) the automatic wire bonding operation and (ii) the dry cycle wire bonding operation. For example, in Step 502, the accuracy of an applied bonding force as compared to the intended (e.g., programmed) bonding force may be monitored.
• Step 502 may occur during a force control mode (or a position control mode) of operation of the wire bonding machine.
• a force applied to a bond head assembly of the wire bonding machine may be incrementally adjusted (e.g., incrementally increasing a force, incrementally decreasing a force, both incrementally increasing and decreasing a force, etc.) while detecting a z- height position of a portion of the bond head assembly.
• an accurate zero gram force may be determined during Step 502.
• a desired force may be determined at which an incremental adjustment from Step 500 does not result in a change of the z-height position of the bond head assembly.
• a desired force may be determined at an applied force where an incremental adjustment from Step 500 results in a peak z-height position of the bond head assembly (e.g., force Fb resulting in height hb, force Fd resulting in height hd, both as described in connection with FIG. 4).
• the wire bonding tool may be being positioned above, and not in contact with, a workpiece on the wire bonding machine.
• the wire bonding tool may be in contact with a workpiece on the wire bonding machine.
• a response is provided if the accuracy of the bonding force monitored during Step 502 is not within an acceptable range.
• the response may include at least one of: (a) providing an alarm to a machine operator, (b) providing a warning to the machine operator, (c) providing an error message to the machine operator, (d) ceasing operation of the wire bonding machine, and (e) automatically adjusting the bonding force of the wire bonding machine.
• a bonding force applied to a bond head assembly is incrementally adjusted (e.g., incrementally increasing the bonding force, incrementally decreasing the bonding force, both incrementally increasing and decreasing the bonding force, etc.) while detecting a z-height position of a portion of the bond head assembly.
• a desired bonding force is determined at which an incremental adjustment from Step 600 does not result in a change of the z-height position of the bond head assembly.
• the desired bonding force may be a zero gram force.
• Step 602 An alternative to Step 602 would be to determine the desired force at an applied force where an incremental adjustment from Step 600 results in a peak z-height position of the bond head assembly (e.g., force Fb resulting in height hb, force Fd resulting in height hd, both as described in connection with FIG. 4).
• a peak z-height position of the bond head assembly e.g., force Fb resulting in height hb, force Fd resulting in height hd, both as described in connection with FIG. 4).
• Steps 600 and 602 may be repeated for a plurality of cycles until the desired bonding force is determined at a stable value by a wire bonding machine at Step 602. Further, Steps 600 and 602 may occur during a force control mode (or a position control mode) of operation of a wire bonding machine. [0043] Referring now to FIG. 7, yet another method of operating a wire bonding machine is illustrated.
• a bonding force applied to a bond head assembly is incrementally decreased while detecting a z-height position of a portion of the bond head assembly, until the z-height position changes from an initial height (e.g., hmit) by a predetermined height adjustment (e.g., see height adjustment to height h a in FIG. IB and FIG. 3B).
• a bonding force value e.g., see F a in FIG. 4, referring to h a from FIG. IB or FIG. 3B
• Step 704 after Step 702, the bonding force applied to the bond head assembly is incrementally increased while detecting the z-height position of a portion of the bond head assembly, until the z-height position returns to the initial height (e.g., see return to hmit in FIG. 1C and FIG. 3D, corresponding to bonding force F c from FIG. 4).
• the z-height position may continue to change until it reaches a peak height position (e.g., see height hb from FIG. 3C, corresponding to bonding force value Fb).
• a peak height position e.g., see height hb from FIG. 3C, corresponding to bonding force value Fb.
• Steps 700 and 702 may occur during a force control mode (or a position control mode) of operation of a wire bonding machine.
• a bonding force applied to a bond head assembly is incrementally increased while detecting a z-height position of a portion of the bond head assembly, until the z-height position changes from an initial height (e.g., hinit) by a predetermined height adjustment (e.g., see height adjustment to height h a in FIG. 2B).
• a bonding force value e.g., the bonding force corresponding to height h a in FIG. 2B
• the predetermined height adjustment e.g., the bonding force corresponding to height h a in FIG. 2B
• Step 804 after Step 802, the bonding force applied to the bond head assembly is incrementally decreased while detecting the z-height position of the portion of the bond head assembly, until the z- height position returns to the initial height (e.g., see return to hinit in FIG. 2C).
• a bonding force value may be detected upon the z- height position returning to the initial height.
• Step 800 the z-height position may continue to change until it reaches a peak height position. At this peak height position, the bonding force value may be detected.
• Steps 800 and 802 may occur during a force control mode (or a position control mode) of operation of a wire bonding machine.

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• 2021
  • 2021-11-03 JP JP2023527217A patent/JP7794821B2/ja active Active
  • 2021-11-03 TW TW110141006A patent/TWI895537B/zh active
  • 2021-11-03 CN CN202180074875.4A patent/CN116420221A/zh active Pending
  • 2021-11-03 US US17/517,827 patent/US11597031B2/en active Active
  • 2021-11-03 KR KR1020237018943A patent/KR20230098652A/ko active Pending
  • 2021-11-03 WO PCT/US2021/057820 patent/WO2022098697A1/en not_active Ceased
• 2023
  • 2023-02-01 US US18/104,423 patent/US11865633B2/en active Active

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