Method and system for automatically calibrating consistency of transducers of wire welding machine

Abstract

The invention discloses a method and a system for automatically calibrating the consistency of transducers of a wire bonder, and relates to the technical field of semiconductor packaging equipment manufacturing and precision control. Constructing an ideal transfer function between the driving electric signal and the dynamic displacement of the bonding head; in the calibration mode, a target wire welding machine drives digital quantity signals of an ultrasonic transducer to be in an actual working state, corresponding actual extremely small displacement responses of a bonding head under different input signals are synchronously collected, and an actual transfer function is obtained through fitting; comparing the ideal transfer function with the actual transfer function, solving a compensation function, and calculating a compensation factor parameter covering the whole working interval; dispersing the compensation factor parameters to obtain a compensation parameter table of the target wire welding machine, wherein the compensation parameter table is used for performing closed-loop correction on actual output; the system is deeply integrated in the wire welding machine, and through cooperative work of all the modules, accurate measurement and calibration of the output characteristics of the ultrasonic transducer and approximation of ideal data are achieved, and consistency of batch production of machines is achieved.

Description

Technical Field

[0001] This application belongs to the field of semiconductor packaging equipment manufacturing and precision control technology, specifically relating to an automatic calibration method and system for the consistency of transducers in wire bonding machines. Background Technology

[0002] Wire bonding machines, as high-precision, high-speed semiconductor packaging equipment, integrate cutting-edge technologies from multiple fields. Their stable production and consistent wire bonding results are crucial to the packaging process. In actual production environments, it is generally desirable to only require one set of process parameters for the same packaging material, which can be directly reused across different machines to ensure consistent and stable output results. However, wire bonding machines consist of numerous functional modules. Due to manufacturing tolerances, assembly deviations, and the inherent dispersion of performance among modules, differences in overall performance arise between different machines. These deviations accumulate at each level, not only increasing the difficulty of controlling performance consistency across machines but also significantly increasing the complexity of process debugging.

[0003] As the core energy conversion component of a wire bonding machine, the ultrasonic transducer is responsible for converting electrical energy into mechanical vibration energy, providing crucial energy input for the welding process. Its performance consistency directly determines the uniformity and reliability of the weld quality. Currently, parameter tuning for a single ultrasonic transducer relies heavily on trial and error based on engineers' experience, a time-consuming and technically demanding process. A more significant problem is that due to individual hardware differences, parameters optimized for one machine cannot be directly applied to another, requiring repeated and complex tuning for each new machine or after maintenance. This has become a major technical bottleneck restricting the efficiency of multi-machine collaborative production, improving process consistency, and reducing operating costs.

[0004] Therefore, there is an urgent need for a systematic and automated method that can quickly and accurately calibrate the output characteristics of ultrasonic transducers in different wire bonding machines, so that they can produce consistent mechanical outputs under the same process parameter input, thereby achieving "one-time debugging, universal applicability to multiple machines" for process parameters. Summary of the Invention

[0005] In order to solve the technical problems of difficulty in transferring process parameters, long debugging cycle and poor consistency among multiple machines caused by the performance dispersion of ultrasonic transducers in the prior art, this application provides an automatic calibration method and system for the consistency of transducers in wire bonding machines.

[0006] The technical solution is as follows: On the one hand, an automatic calibration method for transducer consistency in a wire bonding machine is provided, comprising: Construct an ideal transfer function between the driving electrical signal and the dynamic displacement of the head; In calibration mode, the target wire bonding machine drives the ultrasonic transducer digital signal to the actual working state and simultaneously collects the actual and minute displacement response of the bonding head under different input signals, and fits the actual transfer function. By comparing the ideal transfer function with the actual transfer function, the compensation function is obtained, and the compensation factor parameters corresponding to the full working range are calculated. The compensation factor parameters are discretized to generate and store a compensation parameter table for the target wire bonding machine; In production mode, the compensation parameter table is queried based on the input drive electrical signal, and the drive electrical signal is corrected in real time and then output so that the bonding head displacement response of the target wire bonding machine approximates the ideal transfer function.

[0007] Preferably, in the calibration mode, the target wire bonding machine drives the ultrasonic transducer to simulate the actual working state as follows: the bonding head is controlled to maintain a constant contact force with the simulated wire bonding to keep stable, and this is carried out under this stable state.

[0008] Preferably, the ideal transfer function is preset based on the physical laws of ultrasonic wave propagation and process practice data.

[0009] Preferably, the actual transfer function is obtained by fitting the collected discrete data using an off-curve fitting algorithm, and the actual transfer function is expressed as a first-order linear or higher-order polynomial.

[0010] Preferably, the compensation factor includes gain correction and bias compensation. The compensation factor is identified using the least squares method. The compensation factor is stored in a compensation parameter table as a piecewise constant.

[0011] Preferably, the method further includes: generating and storing an independent compensation parameter table for each type of bonding wire.

[0012] On the other hand, an automatic calibration system for transducer consistency in wire bonding machines is provided to implement the aforementioned automatic calibration method for transducer consistency in wire bonding machines, comprising: The host computer control unit is used to execute the calibration process control, and to perform data fitting, compensation calculation, and management and storage of compensation parameter tables based on the collected displacement data. The motion control card is connected to the host computer control unit and is used to generate motion control signals to control the movement of the head according to the instructions from the host computer control unit. A bonding module, connected to a motion control card, includes a bonding head and a drive mechanism, the drive mechanism being used to drive the bonding head to perform simulated wire bonding movements according to the motion control signal; An ultrasonic generator is used to convert instructions from a host computer control unit into high-frequency drive electrical signals with corresponding amplitude and power. An ultrasonic transducer, connected to an ultrasonic generator and a head module, is used to convert the high-frequency driving electrical signal into a mechanical vibration signal of the same frequency and transmit it to the head. A displacement sensor is installed at the connector module to collect the displacement changes at the end of the connector in real time during the calibration process and to feed the displacement data back to the host computer control unit. The host computer control unit, motion control card, ultrasonic generator, head module, ultrasonic transducer and displacement sensor work together to form a closed-loop system for performing calibration data acquisition and real-time compensation control.

[0013] Preferably, the displacement sensor is a grating ruler.

[0014] The technical solution includes at least the following technical effects: Based on the physical laws of ultrasonic wave propagation and transduction in elastic media, the mechanical properties of materials, and long-term technological practice, the correspondence between the driving electrical signal and the dynamic displacement of the transducer is summarized and discretized, and an ideal transfer function between the ultrasonic driving signal and the dynamic displacement of the transducer is constructed. In calibration mode, the digital signal of the transducer is driven to the actual working state by the host computer control unit, and the actual transducer's extremely small displacement response under different input signals is simultaneously and with high precision acquired, and the actual transfer curve of the transducer system of this specific machine is fitted. By comparing and analyzing the ideal curve and the actual curve, a specific algorithm is used to analyze the nonlinear mapping relationship between the two, and a dynamic compensation factor covering the entire working range, including gain correction and bias compensation, is calculated. Using the calculated compensation factor, closed-loop correction is performed on the actual output, so that different devices can approximate the same target displacement response under the same input excitation, thereby normalizing the transfer characteristics of the transducer output between machines.

[0015] The traditional trial-and-error debugging process, relying on manual experience and performed on a per-device basis, is transformed into a systematic and replicable calibration process. Software algorithms automatically identify and compensate for characteristics, significantly reducing the technical barriers and time costs of on-site debugging and improving the cross-device portability of parameter sets. Its superiority lies in combining theoretical models with measured data to suppress nonlinear errors introduced by individual hardware differences at the system level, ensuring consistency in solder joint morphology and bonding strength across multiple devices under the same parameters in high-precision packaging processes.

[0016] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] Figure 1 A schematic diagram of an automatic calibration system for transducer consistency in a wire bonding machine, provided as a preferred embodiment of this application; Figure 2 A flowchart of an automatic calibration system for transducer consistency in a wire bonding machine, provided as a preferred embodiment of this application; Figure 3 A flowchart of an automatic calibration method for transducer consistency in a wire bonding machine, provided as a preferred embodiment of this application; Figure 4 An output diagram of the actual ball thickness measured on different machines before calibration is provided in a preferred embodiment of this application for an automatic calibration system for transducer consistency of a wire bonding machine; Figure 5 This application provides a preferred embodiment of an automatic calibration system for transducer consistency of a wire bonding machine, showing the output diagram of the actual ball thickness measured on different machines after calibration. Figure 6 A preferred embodiment of this application provides a thrust output diagram of different machines before calibration for an automatic calibration system for transducer consistency of a wire bonding machine; Figure 7 This application provides a preferred embodiment of an automatic calibration system for transducer consistency of a wire bonding machine, showing the thrust output diagram of different machines after calibration. Figure 8 The graph shows the performance difference of the same machine calibrator before and after using the system and method of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] Digital-to-Analog Converter (DAC): A digital-to-analog converter that handles digital control signals.

[0022] As attached Figure 1As shown, a preferred embodiment of the present invention provides an automatic calibration system for transducer consistency in a wire bonding machine, comprising a host computer control unit, a motion control card, a displacement sensor, a bonding module, an ultrasonic generator, and an ultrasonic transducer, constructed around a closed-loop calibration process of "instruction generation, action execution, and data feedback". This system is deeply integrated into the wire bonding machine, and through the collaborative work of its modules, it achieves precise measurement and calibration of the ultrasonic transducer's output characteristics and approximation of ideal data.

[0023] The host computer control unit is used to execute the calibration process control, and to perform data fitting, compensation calculation, and management and storage of compensation parameter tables based on the collected displacement data.

[0024] The motion control card, connected to the host computer control unit, generates motion control signals to control the movement of the bonding head based on instructions from the host computer control unit. The motion control card is a dedicated motion control card based on a high-performance multi-core digital signal processor. It receives calibration program instructions from the host computer control unit and converts them into high-precision control signals that can be recognized by the actuator. Its function is to precisely control the motor of the bonding head module to complete simulated wire bonding actions such as pressing and contacting at a predetermined speed, acceleration, and trajectory. This ensures that the application of ultrasonic excitation and the timing of displacement measurement correspond precisely, providing timing assurance for obtaining the actual mapping curve.

[0025] The bonding head module, connected to the motion control card, includes a bonding head and a drive mechanism (motor). The drive mechanism is used to drive the bonding head to perform simulated wire bonding actions such as pressing and contacting based on the mechanical vibration signal.

[0026] The bonding module is a highly integrated mechanical actuator and force-bearing carrier. It typically consists of a high-precision linear motor, a guide rail, and a bonding head. During calibration, its core functions are twofold: first, as an actuator, it precisely completes mechanical actions such as contact leveling under the drive of the motion control card; second, as an energy transfer and force-bearing interface, its front end contacts the workpiece surface, transmitting the longitudinal vibration generated by the ultrasonic transducer to the contact point, and in the process, generating a measurable micro-displacement itself.

[0027] An ultrasonic generator, connected to the host computer control unit, is used to convert motion control signals sent by the host computer control unit into high-frequency drive electrical signals of corresponding amplitude and power. The ultrasonic generator is a high-precision, programmable power signal source whose function is to generate high-frequency electrical signals of corresponding amplitude and power based on received digital control signals (DAC).

[0028] An ultrasonic transducer, connected to an ultrasonic generator and a connector module, is used to convert the high-frequency driving electrical signal into a mechanical vibration signal of the same frequency. The ultrasonic transducer is an electromechanical energy conversion device, typically composed of a piezoelectric ceramic stack and an amplitude transformer. Its core function is to efficiently and linearly convert the high-frequency electrical signal from the generator into mechanical vibration of the same frequency, and then amplify it through the amplitude transformer before outputting it to the connector. In this calibration system, these are the objects to be characterized and calibrated, and the consistency of their output mechanical properties is the ultimate goal.

[0029] A displacement sensor, which is electrically connected to the head module, is used to collect the displacement data of the head in real time during the calibration process and feed it back to the host computer control unit.

[0030] Preferably, a high-resolution displacement sensor is used. A high-resolution displacement sensor is a precision measuring device such as a grating ruler, which is used to detect micron-level displacement changes at the end of the ultrasonic transducer in real time, continuously, and with high precision during operation. The displacement data collected is the only direct physical quantity characterizing the actual mechanical output of the ultrasonic transducer, and is the basis for all subsequent calculations and compensations.

[0031] The host computer control unit, motion control card, ultrasonic generator, head module, ultrasonic transducer and displacement sensor work together to form a closed-loop system for performing calibration data acquisition and real-time compensation control.

[0032] As attached Figure 2 As shown, the workflow of this system is as follows: First, enter calibration mode and collect different input signals from the ultrasonic transducer. The corresponding output below The actual curve is obtained by fitting discrete data pairs. ,according to and Solving the relationship for the compensation function After discretization, a compensation parameter table is obtained. In actual production, the system looks up the compensation parameter table based on the input signal to obtain the calibrated output.

[0033] The motion control card drives the motor of the bonding head module according to the position command. The motor drives the bonding head to move, so that the bonding head and the workpiece maintain a constant simulated contact state.

[0034] Input signal This is the input variable for this step, which is the drive signal. The host computer control unit controls the ultrasonic generator, inputting a series of different digital control quantities into the ultrasonic transducer. .

[0035] The transducer operates and generates vibration. Figure 2 The transducer in the middle is an ultrasonic transducer.

[0036] The displacement of the bearing head is the output variable. A high-resolution displacement sensor measures the displacement in real time for each bearing head. Actual displacement of the head .

[0037] Loop to check data pairs Is data collection complete?: Determine if all data has been collected within the entire working area, using a preset step size. Value incentives and Value collection. If not, continue collecting; if yes, proceed to the next step.

[0038] Fitting : Utilizing all collected discrete data points A continuous curve, i.e., the actual transfer function of the machine, is obtained through an algorithm (such as polynomial fitting). . Characterized by "input signal" → Actual displacement of the head The mapping relationship between "".

[0039] Solve the compensation function This is the core algorithmic step of the calibration. The actual curve obtained in the previous step... With the system's pre-stored ideal transfer function Compare them.

[0040] The goal is to solve a compensation function. So that when the input signal passes through After compensation, then through the actual system When the output approximates the ideal output, it satisfies: .

[0041] In an alternative embodiment, for the first-order linear case, this step identifies the gain bias using the least squares method. and bias deviation and construct .

[0042] Discretization / Piecewise Processing: Compensation Function It is a continuous mathematical function. To facilitate rapid processing by embedded systems, it needs to be discretized and piecewise linearized. That is, according to... The range of values ​​is divided into several segments, and within each segment, a pair of constants (gain compensation factor and bias compensation factor) are used. , To approximate the representation Its function in this section.

[0043] Generate a compensation parameter table: This involves processing all compensation factors in segments. , ) according to The interval order is compiled into a lookup table and stored in the control system of the wire bonding machine. This is the "identity card" parameter table of the equipment for a specific wire.

[0044] Real-time compensation process in production mode ( Figure 2 Right side): End calibration, enter production mode.

[0045] Receiving Commands and Signals: The system receives position commands and ultrasonic energy input signals from the process recipe. .

[0046] Query and application compensation: The system calculates based on the current input signal. The value is used to query the previously stored compensation parameter table to find the compensation factor corresponding to its interval. , ).

[0047] Calculate the compensated driving signal: use the found factors to adjust the original input. Perform real-time calculations to generate compensated drive signals. Real-time calculation: ; Drive and Output: The compensated signal is sent to the ultrasonic generator to drive the transducer and head, ultimately obtaining a displacement output that has undergone automatic consistency calibration, thus ensuring that different machines operate under the same input. The output results are consistent.

[0048] The specific workflow is as follows: Before performing automatic consistency calibration, real input-output characteristic data of the ultrasonic transducer system of a specific machine are first collected under controlled conditions. The motion control card issues high-precision position commands according to the preset motion trajectory, controlling the bonding head to simulate the wire bonding contact state with a constant contact force. In this stable state, the host computer controls the ultrasonic generator to continuously increase the DAC input value in preset steps within a specified working range. Simultaneously, the actual displacement of the bearing head, measured by a high-resolution displacement sensor, is recorded under each input value condition. To obtain a set of discrete data pairs By statistically analyzing these discrete data, a continuous relationship curve is obtained: ; in, For digital control quantities, This represents the actual displacement of the connector. The slope of the curve (gain bias), This is the bias amount (bias deviation). and These are compensation factors.

[0049] The actual relationship curve is strongly correlated with the physical properties of the welding wire used (such as material, diameter, hardness, etc.). Different wires, due to differences in their elastic modulus, damping characteristics, and coefficient of friction with the working surface, will cause changes in the dynamic response of the entire vibration transmission system. Therefore, the fitted characteristic curve may exhibit a simple linear relationship, or it may present a more complex second-order or even higher-order nonlinear mapping relationship, such as: ; ; ; in, Represents a second-order curve relationship. This represents the relationship of a third-order curve.

[0050] Obtain the actual relationship curve of the machine. Then (taking a first-order curve as an example), according to the ideal relationship curve Based on the correspondence, construct a compensation function. The compensated system satisfies: ; That is, after the actual DAC output value of the machine is calculated by superimposing compensation factors, a curve close to the ideal relationship can be obtained. The displacement output.

[0051] On a global scale, the ideal relationship curve Relationship curve with reality There is an input-related gain bias. and bias deviation Using parameter identification methods such as the least squares method, the following can be estimated: and Value: ; ; ; ; in, , For discrete data pairs The average value.

[0052] Then construct the compensation function for: ; Because the data recorded by the machine is discrete, in practical applications, continuous curves are segmented according to the discrete data recorded by the machine, and within each segment... and Approximate as the constant of the corresponding segment and This allows us to construct the transducer consistency compensation factor parameter table for the machine and store it in the system.

[0053] During actual compensation, this system downloads the calculated compensation parameter table to the wire bonding machine's underlying controller. When the ultrasonic transducer receives the input DAC, it queries the compensation parameter table based on the input value range, calculates the compensation for the input value, and obtains a new output value that approximates the ideal relationship curve. When different machines receive the same process parameters, they will compensate for the deviations caused by their respective hardware based on their own recorded compensation parameters, bringing the final output to the same level as the ideal relationship curve. This achieves seamless transfer of process parameters across machines and uniform wire bonding results.

[0054] Furthermore, this system will independently execute the above calibration process and store a dedicated compensation parameter table according to different wire materials. When the operator selects or changes the wire type in the process formula, the host computer will automatically index and load the corresponding compensation parameter set to the underlying controller. The compensation strategy can be switched without manual intervention, ensuring the consistency and reliability of the process output after the line change.

[0055] As attached Figure 3 As shown, in one embodiment, in order to implement the above-described automatic calibration system for transducer consistency in a wire bonding machine, an automatic calibration method for transducer consistency in a wire bonding machine is provided, comprising the following steps: Step S1: Based on the physical laws of ultrasonic wave propagation and energy transduction in elastic media, material mechanical properties, and long-term process practice, the correspondence between the driving electrical signal and the dynamic displacement of the head is summarized and discretized, and an ideal transfer curve between the driving electrical signal and the dynamic displacement of the head is constructed; the ideal transfer function is preset based on the physical laws of ultrasonic wave propagation and process practice data.

[0056] Step S2: In calibration mode, the target wire bonder drives the ultrasonic transducer digital signal to the actual working state through the host computer control unit, and simultaneously collects the actual extremely small (1~10um) displacement response of the bonding head under different input signals, and fits the actual transfer function (curve) of the ultrasonic transducer of the target wire bonder; the target wire bonder drives the ultrasonic transducer to simulate the actual working state in calibration mode as follows: the bonding head is controlled to maintain a constant contact force with the simulated wire bonder to keep stable, and this is carried out under this stable state.

[0057] The actual transfer function is obtained by fitting the collected scattered data using an off-curve fitting algorithm. The actual transfer function is expressed as a first-order linear or higher-order polynomial.

[0058] Step S3: Compare the ideal transfer function (curve) with the actual transfer function (curve), solve for the compensation function (using a specific algorithm to analyze the nonlinear mapping relationship between the two), and calculate the compensation factor parameters covering the entire working range; in one embodiment, the calculated compensation factor is a dynamic compensation factor covering the entire working range, including gain correction and bias compensation; the compensation factor is identified by the least squares method; the compensation factor is stored in the compensation parameter table in the form of piecewise constants. For different types of bonding wires, an independent compensation parameter table is generated and stored for each type of wire.

[0059] Step S4: Discretize the compensation factor parameters to generate and store a compensation parameter table for the target wire bonding machine; Step S5: In production mode, the compensation parameter table is consulted based on the input drive electrical signal, and the drive electrical signal is corrected in real time before being output, so that the bonding head displacement response of the target wire bonding machine approximates the ideal transfer function. The compensation parameter table is used to perform closed-loop correction on the actual output, so that different devices can approximate the same target displacement response under the same input excitation, thereby normalizing the transfer characteristics of the transducer output between machines.

[0060] The significance of this method lies in transforming the traditional trial-and-error debugging process, which relies on manual experience and is performed on a per-device basis, into a systematic and replicable calibration process. By automatically identifying and compensating for characteristics through software algorithms, it significantly reduces the technical threshold and time cost of on-site debugging and improves the cross-device portability of parameter sets. Its superiority lies in its combination of theoretical models and measured data, which suppresses nonlinear errors introduced by individual hardware differences at the system level, ensuring the consistency of solder joint morphology and bonding strength produced by multiple devices under the same parameters in high-precision packaging processes.

[0061] The verification results of implementing the system and method of this invention in specific scenarios are as follows: Appendix Figure 4 The image shown is an output graph of the actual ball thickness measured on different machines before calibration, according to a preferred embodiment of this application's automatic calibration system for transducer consistency in wire bonding machines. The horizontal axis represents different machines, and the vertical axis represents the actual measured ball thickness. (See attached image.) Figure 5 The image shown is an output graph of the actual ball thickness measured on different machines after calibration, according to a preferred embodiment of the automatic calibration system for transducer consistency of a wire bonding machine provided in this application. The horizontal axis represents different machines, and the vertical axis represents the actual measured ball thickness. (See attached image.) Figure 6The figure shown is a thrust output diagram of different machines before calibration for an automatic calibration system for transducer consistency of a wire bonding machine according to a preferred embodiment of this application. The horizontal axis represents different machines, and the vertical axis represents the actual measured thrust. (See attached figure.) Figure 7 The diagram shown is a thrust output graph of different machines after calibration according to a preferred embodiment of the automatic calibration system for transducer consistency of a wire bonding machine. The horizontal axis represents different machines, and the vertical axis represents the actual measured thrust. It can be seen that the output difference between different machines is reduced after calibration. It should be noted that during data collection before calibration, due to hardware issues, machine #5017 did not collect data. Therefore, the data displayed before calibration was from 5 machines, while the data displayed after calibration is from 6 machines, but this does not affect the overall data.

[0062] Appendix Figure 8 The figure shows the performance difference of the system and method of this application before and after using the same machine calibrator. Figure 8 As can be seen, after calibration on the same machine, the output is closer to the standard output.

[0063] Implementing this invention not only enhances the precise control of the core variables of wire bonding process, ultrasonic energy and mechanical displacement, and improves the control capability of key results such as solder ball size, shape and interface bonding quality, but also enhances the overall consistency of ultrasonic transducer modules and the stability and synergy of multi-machine production systems, providing an important equipment foundation for the development of advanced semiconductor packaging towards higher precision and better repeatability.

[0064] Through the aforementioned closed-loop calibration and real-time compensation mechanism, the system of this invention fundamentally enhances the precise control of ultrasonic transducer output consistency. This improved control capability directly translates into better repeatability and controllability of key welding results. From a broader production system perspective, this solution significantly enhances the post-shipment consistency and long-term stability of ultrasonic transducer modules, eliminates the bottleneck of equipment differences during parallel production of multiple machines, and lays a crucial equipment foundation for building a highly collaborative and stable advanced packaging production line. This strongly supports the development of semiconductor packaging technology towards higher precision, higher yield, and stronger repeatability.

[0065] Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0066] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0067] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0068] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0069] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

Claims

1. An automatic calibration method for transducer consistency in a wire bonding machine, characterized in that, include: Construct an ideal transfer function between the driving electrical signal and the dynamic displacement of the head; In calibration mode, the target wire bonding machine drives the ultrasonic transducer digital signal to the actual working state and simultaneously collects the actual and minute displacement response of the bonding head under different input signals, and fits the actual transfer function. By comparing the ideal transfer function with the actual transfer function, the compensation function is obtained, and the compensation factor parameters corresponding to the full working range are calculated. The compensation factor parameters are discretized to generate and store a compensation parameter table for the target wire bonding machine; In production mode, the compensation parameter table is queried based on the input drive electrical signal, and the drive electrical signal is corrected in real time and then output so that the bonding head displacement response of the target wire bonding machine approximates the ideal transfer function.

2. The automatic calibration method for transducer consistency in a wire bonding machine according to claim 1, characterized in that, In calibration mode, the target wire bonding machine drives the ultrasonic transducer to simulate the actual working state: the control head maintains a constant contact force with the simulated wire bonding to keep stable, and this is carried out under this stable state.

3. The automatic calibration method for transducer consistency in a wire bonding machine according to claim 1, characterized in that, The ideal transfer function is pre-set based on the physical laws of ultrasonic wave propagation and process practice data.

4. The automatic calibration method for transducer consistency in a wire bonding machine according to claim 1, characterized in that, The actual transfer function is obtained by fitting the collected scattered data using an off-curve fitting algorithm. The actual transfer function is expressed as a first-order linear or higher-order polynomial.

5. The automatic calibration method for transducer consistency in a wire bonding machine according to claim 1, characterized in that, The compensation factors include gain correction and bias compensation.

6. The automatic calibration method for transducer consistency in a wire bonding machine according to claim 5, characterized in that, The compensation factor is identified using the least squares method.

7. The automatic calibration method for transducer consistency in a wire bonding machine according to claim 1, characterized in that, The compensation factor is stored in the compensation parameter table in the form of piecewise constants.

8. The automatic calibration method for transducer consistency in a wire bonding machine according to claim 1, characterized in that, The method further includes generating and storing an independent compensation parameter table for each type of bonding wire.

9. An automatic calibration system for transducer consistency in a wire bonding machine, used to implement the automatic calibration method for transducer consistency in a wire bonding machine as described in any one of claims 1 to 8, characterized in that, include: The host computer control unit is used to execute the calibration process control, and to perform data fitting, compensation calculation, and management and storage of compensation parameter tables based on the collected displacement data. The motion control card is connected to the host computer control unit and is used to generate motion control signals to control the movement of the head according to the instructions from the host computer control unit. A bonding module, connected to a motion control card, includes a bonding head and a drive mechanism, the drive mechanism being used to drive the bonding head to perform simulated wire bonding movements according to the motion control signal; An ultrasonic generator is used to convert instructions from a host computer control unit into high-frequency drive electrical signals with corresponding amplitude and power. An ultrasonic transducer, connected to an ultrasonic generator and a head module, is used to convert the high-frequency driving electrical signal into a mechanical vibration signal of the same frequency and transmit it to the head. A displacement sensor is installed at the connector module to collect the displacement changes at the end of the connector in real time during the calibration process and to feed the displacement data back to the host computer control unit. The host computer control unit, motion control card, ultrasonic generator, head module, ultrasonic transducer and displacement sensor work together to form a closed-loop system for performing calibration data acquisition and real-time compensation control.

10. The automatic calibration system for transducer consistency of a wire bonding machine according to claim 9, characterized in that, The displacement sensor is a grating ruler.

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