CN-121995852-A - Automatic calibration method and system for consistency of transducer of wire bonding machine

CN121995852ACN 121995852 ACN121995852 ACN 121995852ACN-121995852-A

Abstract

The application discloses an automatic calibration method and system for transducer consistency of a wire bonding machine, which relate to the technical field of semiconductor packaging equipment manufacture and precise control, and are characterized in that an ideal transfer function between a driving electric signal and dynamic displacement of a bonding head is constructed, a target wire bonding machine drives an ultrasonic transducer digital quantity signal to an actual working state in a calibration mode, corresponding bonding head actual extremely tiny displacement responses under different input signals are synchronously collected, the fitted actual transfer function is compared with the ideal transfer function and the actual transfer function, a compensation function is solved, compensation factor parameters covering a full working interval are calculated, a compensation parameter table of the target wire bonding machine is obtained after the compensation factor parameters are discretized, the compensation parameter table is used for carrying out closed-loop correction on actual output, the system is deeply integrated in the wire bonding machine, and the precise measurement calibration of ultrasonic transducer output characteristics and the approximation of ideal data are realized through the cooperative work of all modules, so that the consistency of mass production of a batch machine is realized.

Inventors

HE YUNBO
Ji Haizhong
YAN YIJUN
LI HAOLIN
ZHOU LIN

Assignees

广东阿达半导体设备股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260408

Claims (10)

1. A method for automatically calibrating the consistency of a transducer of a wire bonding machine, comprising: An ideal transfer function between the driving electric signal and the dynamic displacement of the bonding head is constructed; in a calibration mode, the target wire welding machine drives an ultrasonic transducer digital quantity signal to an actual working state, and synchronously acquires corresponding actual extremely small displacement responses of the bonding head under different input signals, and a fitted actual transfer function is obtained; Comparing the ideal transfer function with the actual transfer function, solving to obtain a compensation function, and calculating compensation factor parameters corresponding to the coverage full-working interval; The compensation factor parameters are generated and stored in a compensation parameter table for the target wire bonding machine after being scattered; And in the production mode, inquiring the compensation parameter table according to the input driving electric signal, and outputting the driving electric signal after real-time correction so as to enable the response of the head displacement of the target wire bonding machine to approach the ideal transfer function.
2. The method of claim 1, wherein in the calibration mode, the target wire bonding machine is configured to simulate an actual operating state of the ultrasonic transducer by controlling the bonding head to maintain a stable contact with the simulated wire at a constant contact force.
3. The method of claim 1, wherein the ideal transfer function is predetermined based on physical laws of propagation of ultrasonic waves and process practice data.
4. The method of claim 1, wherein the actual transfer function is obtained by fitting the collected scattered data by a discrete curve fitting algorithm, and the actual transfer function is in the form of a first-order linear or higher-order polynomial.
5. The wire bonding machine transducer uniformity auto-calibration method according to claim 1, wherein the compensation factors include gain correction and bias compensation.
6. The wire bonding machine transducer uniformity automatic calibration method according to claim 5, wherein said compensation factor is identified by a least squares method.
7. The method of claim 1 wherein the compensation factor is stored in a table of compensation parameters in the form of a piecewise constant.
8. The wire bonding machine transducer uniformity automatic calibration method according to claim 1, further comprising generating and storing a separate table of said compensation parameters for each wire for different types of wire bonding.
9. A wire bonding machine transducer uniformity automatic calibration system for implementing a wire bonding machine transducer uniformity automatic calibration method as recited in any one of claims 1 to 8, comprising: The upper computer control unit is used for executing calibration flow control, and carrying out data fitting, compensation calculation and management and storage of a compensation parameter table based on the acquired displacement data; the motion control card is connected with the upper computer control unit and used for generating a motion control signal for controlling the movement of the bonding head according to an instruction from the upper computer control unit; The bonding head module is connected with the motion control card and comprises a bonding head and a driving mechanism, wherein the driving mechanism is used for driving the bonding head to execute simulated welding wire motion according to the motion control signal; The ultrasonic generator is used for converting the instruction of the upper computer control unit into a high-frequency driving electric signal with corresponding amplitude and power; the ultrasonic transducer is connected with the ultrasonic generator and the head bonding module, and is used for converting the high-frequency driving electric signal into a mechanical vibration signal with the same frequency and transmitting the mechanical vibration signal to the head bonding module; the displacement sensor is arranged at the head bonding module and used for collecting the displacement change of the tail end of the head bonding in real time in the calibration process and feeding back the displacement data to the upper computer control unit; The upper computer control unit, the motion control card, the ultrasonic generator, the head bonding module, the ultrasonic transducer and the displacement sensor work cooperatively to form a closed loop system for executing calibration data acquisition and real-time compensation control.
10. The wire bonding machine transducer uniformity automatic calibration system according to claim 9, wherein the displacement sensor is a grating ruler.

Description

Automatic calibration method and system for consistency of transducer of wire bonding machine Technical Field The application belongs to the technical field of semiconductor packaging equipment manufacturing and precise control, and particularly relates to an automatic calibration method and system for transducer consistency of a wire bonding machine. Background The wire bonding machine is used as high-precision and high-speed semiconductor packaging equipment, integrates the multi-field front edge technology, and the consistency of stable production and wire bonding effect is critical to the packaging technology. In an actual production environment, it is generally desirable to debug only one set of process parameters for the same packaging material, and to be able to directly multiplex between different devices, so as to ensure consistency and stability of output results. Wire bonding machines, however, are composed of numerous functional modules, and the overall performance varies from one device to another due to manufacturing tolerances, assembly variances, and inherent dispersion of the performance of the modules. These deviations are accumulated step by step, which not only increases the consistency control difficulty of the performance among the devices, but also obviously increases the complexity of process debugging. The ultrasonic transducer is used as a core energy conversion component of the wire bonding machine and is responsible for converting electric energy into mechanical vibration energy so as to provide key energy input for the welding process. The uniformity of the quality of the welding wire is directly determined by the uniformity and the reliability of the performance. At present, parameter debugging of an ultrasonic transducer for a single device mainly depends on experience of engineers to test errors, and the process is time-consuming and has a high technical threshold. The more prominent problem is that parameters optimized on one device cannot be directly applied to another device due to individual differences in hardware level, and complicated debugging is required to be carried out again after each new device or device is maintained. The method has become a main technical bottleneck for restricting the cooperative production efficiency of multiple machines, improving the process consistency and reducing the operation cost. Therefore, a systematic and automatic method is needed to quickly and accurately calibrate the output characteristics of ultrasonic transducers of different wire bonding machines, so that the ultrasonic transducers generate consistent mechanical output under the same process parameter input, and the one-time debugging and multi-machine universal process parameters are realized. Disclosure of Invention The application aims to solve the technical problems of difficult process parameter transplanting, long debugging period and poor multi-machine consistency caused by the dispersion of ultrasonic transducer performance in the prior art, and provides an automatic calibration method and system for transducer consistency of a wire bonding machine. The technical proposal is as follows: In one aspect, a method for automatically calibrating consistency of a transducer of a wire bonding machine is provided, comprising: An ideal transfer function between the driving electric signal and the dynamic displacement of the bonding head is constructed; in a calibration mode, the target wire welding machine drives an ultrasonic transducer digital quantity signal to an actual working state, and synchronously acquires corresponding actual extremely small displacement responses of the bonding head under different input signals, and a fitted actual transfer function is obtained; Comparing the ideal transfer function with the actual transfer function, solving to obtain a compensation function, and calculating compensation factor parameters corresponding to the coverage full-working interval; The compensation factor parameters are generated and stored in a compensation parameter table for the target wire bonding machine after being scattered; And in the production mode, inquiring the compensation parameter table according to the input driving electric signal, and outputting the driving electric signal after real-time correction so as to enable the response of the head displacement of the target wire bonding machine to approach the ideal transfer function. Preferably, in the calibration mode, the target wire bonding machine drives the ultrasonic transducer to simulate the actual working state, namely, the bonding head is controlled to be in stable contact with the simulated bonding wire under constant contact force, and the ultrasonic transducer is operated in the stable state. Preferably, the ideal transfer function is preset based on the propagation physical rule of ultrasonic waves and process practice data. Preferably, the actual transfer function is obtained by fitting the collec