Piezoelectric ceramic drive controller

Abstract

The present invention discloses a piezoelectric ceramic drive controller, which belongs to the technical field of crystal bonding equipment. The piezoelectric ceramic drive controller is used to drive the crystal pricking mechanism of the crystal bonding equipment. The piezoelectric ceramics include X-axis piezoelectric ceramics and Y-axis piezoelectric ceramics. The piezoelectric ceramic drive controller includes an industrial computer and a control circuit. A DDS circuit is provided inside the control circuit. The DDS circuit converts digital signals into analog signals, which are divided into two paths, X and Y, and are output to the X-axis piezoelectric ceramics and the Y-axis piezoelectric ceramics respectively. Unlike traditional piezoelectric ceramic drivers, the present invention shapes the piezoelectric ceramic drive voltage through a feedforward controller, changes the dynamic characteristics of the piezoelectric ceramics, and realizes the suppression of mechanical structure vibration; the present invention expands discrete voltage values ​​into high-order differentiable continuous curves through the Bessel model, and realizes a smooth transition of the force on the piezoelectric ceramics. The present invention can suppress the vibration of the crystal pricking mechanism of the crystal bonding equipment and realize high-speed and high-precision operation of the crystal pricking mechanism.

Description

Technical Field

[0001] The present invention relates to the technical field of die bonding equipment, and in particular to a piezoelectric ceramic drive controller for driving a die bonding device's die pricking mechanism to perform high-speed and high-precision displacement. Background Art

[0002] my country has long been subject to foreign restrictions in the field of semiconductor manufacturing, and advanced integrated circuit processing and manufacturing technologies still have theoretical and technical problems that need to be solved urgently. Among them, the packaging process is one of the important links in the production and manufacturing of semiconductor products. Its main purpose is to provide the necessary mechanical support and electrical signal interconnection lines for the chip. Die bonding is the core process of the packaging process. Its purpose is to fix the chip to the specified position and provide the necessary conditions for subsequent welding and other work.

[0003] The die bonding process is primarily performed by a die bonder / equipment. Wafer transfer can be accomplished using a suction nozzle or a stinger mechanism. Compared to die bonders based on a suction nozzle design, stinger-based die bonders offer the advantages of lower cost, shorter mechanical motion paths, and higher efficiency. In the stinger-based die bonding fields of semiconductors, optoelectronic displays, and other applications, piezoelectric ceramic-based die bonders operate by controlling the deformation of the piezoelectric ceramic using a power supply. This deformation is amplified by levers, hinges, and other mechanisms to control the stinger mechanism's movement. The stinger mechanism of a die bonder can be considered a flexible robotic arm. The mechanical structure experiences high-frequency vibrations during large-scale operation, significantly impacting the die bonder's positioning accuracy. The stinger mechanism vibrates around its initial position, directly impacting the positioning accuracy of the next cycle. Excessive vibration amplitude can damage the die. Furthermore, high-frequency vibrations can cause the die to fall, increasing the defective rate.

[0004] The operating conditions of piezoelectric ceramics are closely related to the voltage at both ends of the piezoelectric ceramics. Optimizing the performance of the piezoelectric ceramic driving power supply plays an important role in improving the positioning accuracy of the crystal bonding equipment. In the existing technology, the driving power supply of piezoelectric ceramics mostly adopts a linear power supply structure. From the perspective of hardware structure, the optimization of the power supply is mostly integrated and modularized, with the purpose of reducing the size of the power supply; from the perspective of control algorithm, the optimization of the power supply mostly considers the creep and hysteresis characteristics of the piezoelectric ceramics, with the purpose of rapid positioning. The above optimization work cannot effectively suppress the vibration of the crystal mechanism. In addition, since the displacement of the piezoelectric ceramic is approximately linearly related to the voltage at both ends of the piezoelectric ceramic, and the secondary derivative of the voltage curve is approximately linearly related to the force at both ends of the piezoelectric ceramic, the existing technology mostly considers the continuous and smooth change of the voltage waveform, and cannot guarantee the smooth transition of the force at both ends of the piezoelectric ceramic, which may bring impact to the piezoelectric ceramic and shorten its service life. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a piezoelectric ceramic drive controller that can suppress the vibration of the crystal-bonding device's crystal-pinching mechanism and realize high-speed and high-precision operation of the crystal-pinching mechanism.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A piezoelectric ceramic drive controller is used to drive a die-pinning mechanism of a die-bonding device. The piezoelectric ceramics include X-axis piezoelectric ceramics and Y-axis piezoelectric ceramics. The piezoelectric ceramic drive controller includes an industrial computer and a control circuit, wherein:

[0008] The output end of the industrial computer is connected to the input end of the control circuit to realize the transmission of the control signal;

[0009] The control circuit processes the received control signal to generate a digital control signal; a DDS circuit is provided inside the control circuit, and the DDS circuit converts the digital signal into an analog signal, which is divided into two paths, X and Y, and outputted to the X-axis piezoelectric ceramic and the Y-axis piezoelectric ceramic respectively;

[0010] For the X-axis piezoelectric ceramics and Y-axis piezoelectric ceramics, the industrial computer obtains an ideal voltage curve for controlling the piezoelectric ceramics of each axis based on the correspondence between the deformation of the piezoelectric ceramics of each axis and the applied voltage, and transmits the limited voltage reference points on the ideal voltage curve to the control circuit. The control circuit fits the discrete voltage reference points into a high-order differentiable voltage curve through a Bessel model, which is used as the control voltage curve of the piezoelectric ceramics of each axis. The control circuit is also provided with an X-axis feedforward controller and a Y-axis feedforward controller to shape the control voltage curve of the piezoelectric ceramics of each axis. The X-axis feedforward controller and the Y-axis feedforward controller are both composed of several sine functions. The amplitude and phase of these sine functions can be adjusted according to the actual operating conditions of the piezoelectric ceramics of each axis, and then added to the control voltage curve of the piezoelectric ceramics of each axis to form a control voltage curve for driving the piezoelectric ceramics of each axis.

[0011] Furthermore, a communication circuit is provided between the industrial computer and the control circuit.

[0012] Furthermore, an isolation protection circuit is provided at the output end of the control circuit.

[0013] Furthermore, the DDS circuit includes a D / A conversion chip.

[0014] Furthermore, the isolation protection circuit includes an optocoupler isolation chip.

[0015] Furthermore, an X-axis voltage closed-loop control circuit, an X-axis power amplifier circuit and an X-axis voltage signal acquisition and conditioning circuit are provided between the isolation protection circuit and the X-axis piezoelectric ceramic. After the X-axis voltage waveform passes through the X-axis power amplifier circuit, it drives the X-axis piezoelectric ceramic to deform, thereby controlling the thorn crystal mechanism to operate in the X-axis direction; the X-axis voltage signal acquisition and conditioning circuit collects the voltage across the X-axis piezoelectric ceramic, compares it with the X-axis voltage waveform output by the control circuit, and forms a voltage closed-loop control of the X-axis piezoelectric ceramic.

[0016] Furthermore, the X-axis voltage closed-loop control circuit includes an operational amplifier;

[0017] The X-axis power amplifier circuit includes two MOSFET tubes, which form a push-pull circuit, and the output of the circuit is connected to the X-axis piezoelectric ceramic;

[0018] The X-axis voltage signal acquisition and conditioning circuit includes a voltage divider resistor and an operational amplifier.

[0019] Furthermore, a Y-axis voltage closed-loop control circuit, a Y-axis power amplifier circuit and a Y-axis voltage signal acquisition and conditioning circuit are provided between the isolation protection circuit and the Y-axis piezoelectric ceramic. After the Y-axis voltage waveform passes through the Y-axis power amplifier circuit, it drives the Y-axis piezoelectric ceramic to deform, thereby controlling the crystal mechanism to operate in the Y-axis direction; the Y-axis voltage signal acquisition and conditioning circuit collects the voltage across the Y-axis piezoelectric ceramic, compares it with the Y-axis voltage waveform output by the control circuit, and forms a voltage closed-loop control of the Y-axis piezoelectric ceramic.

[0020] Furthermore, the Y-axis voltage closed-loop control circuit includes an operational amplifier;

[0021] The Y-axis power amplifier circuit includes two MOSFET tubes, which form a push-pull circuit, and the output of the circuit is connected to the Y-axis piezoelectric ceramic;

[0022] The Y-axis voltage signal acquisition and conditioning circuit includes a voltage divider resistor and an operational amplifier.

[0023] Furthermore, the process of the control circuit fitting discrete voltage reference points into a high-order differentiable voltage curve through a Bessel model includes:

[0024] Set the starting point A and end point C of the curve;

[0025] Reasonably select control point B;

[0026] Find points D and E on line segments AB and BC respectively, connect DE, and find point F on line segment DE so that the lengths of the segments satisfy AD / AB=BE / BC=DF / DE.

[0027] Move point D from A to B, and the trajectory of point F is what we want.

[0028] The present invention has the following beneficial effects:

[0029] The piezoelectric ceramic drive controller of this invention suppresses vibration in the die-bonding equipment's pricking mechanism, enabling high-speed, high-precision operation. Unlike traditional piezoelectric ceramic drivers, this invention uses a feedforward controller to shape the piezoelectric ceramic drive voltage, altering the piezoelectric ceramic's dynamic characteristics and suppressing mechanical structure vibration. Using a Bessel model, this invention expands discrete voltage values ​​into a high-order, continuous, and differentiable curve, achieving a smooth transition in the force applied to the piezoelectric ceramic. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of circuit connection of the piezoelectric ceramic drive controller of the present invention;

[0031] Figure 2 for Figure 1 The control system operation block diagram of the piezoelectric ceramic drive controller shown;

[0032] Figure 3 for Figure 1 Schematic diagram of the Bezier curve generation process in the piezoelectric ceramic drive controller shown;

[0033] Figure 4 for Figure 1 Schematic diagram of the steps for generating a Bezier curve in the piezoelectric ceramic drive controller shown;

[0034] Figure 5 This is a diagram showing the operation of a die-bonding device under conventional driving mode in the prior art;

[0035] Figure 6 This is a diagram showing the operation of the crystal bonding equipment under the action of the present invention. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0037] This invention optimizes the performance of the piezoelectric ceramic drive power supply and improves the motion characteristics of the piezoelectric ceramic to suppress vibration of the crystal-bonding mechanism, thereby enhancing the operating accuracy of the die-bonding equipment. It can also output a high-order, conductive, and smooth voltage curve, reducing the impact on both ends of the piezoelectric ceramic.

[0038] The present invention provides a piezoelectric ceramic drive controller for driving a crystal pricking mechanism of a crystal bonding device, such as Figure 1-2As shown, the piezoelectric ceramics include an X-axis piezoelectric ceramic 108 and a Y-axis piezoelectric ceramic 111. The piezoelectric ceramic drive controller includes an industrial computer 101 and a control circuit 103, wherein:

[0039] The output terminal of the industrial computer 101 is connected to the input terminal of the control circuit 103 to realize the transmission of control instructions / signals;

[0040] The control circuit 103 processes the received control signal to generate a digital control signal. A DDS (Direct Digital Synthesizer) circuit 105 is internally provided in the control circuit 103. The DDS circuit 105 converts the digital signal into an analog signal and outputs it to the X-axis piezoelectric ceramic 108 and the Y-axis piezoelectric ceramic 111, respectively.

[0041] For the X-axis piezoelectric ceramics 108 and the Y-axis piezoelectric ceramics 111, the industrial computer 101 obtains an ideal voltage curve for controlling the piezoelectric ceramics of each axis based on the corresponding relationship between the deformation of the piezoelectric ceramics of each axis and the applied voltage, and transmits the limited voltage reference points on the ideal voltage curve to the control circuit 103. The control circuit 103 fits the discrete voltage reference points into a high-order differentiable voltage curve through a Bessel model, which is used as the control voltage curve of the piezoelectric ceramics of each axis. The control circuit 103 is also provided with an X-axis feedforward controller and a Y-axis feedforward controller to shape the control voltage curve of the piezoelectric ceramics of each axis. The X-axis feedforward controller and the Y-axis feedforward controller are both composed of a plurality of sinusoidal functions. The amplitude and phase of these sinusoidal functions can be adjusted according to the actual operating conditions of the piezoelectric ceramics of each axis, and then added to the control voltage curve of the piezoelectric ceramics of each axis to form a control voltage curve for driving the piezoelectric ceramics of each axis.

[0042] Specifically, if Figure 2 As shown, based on the correspondence between the deformation of the X-axis piezoelectric ceramic 108 and the applied voltage, the industrial computer 101 obtains an ideal voltage curve for controlling the X-axis piezoelectric ceramic 108. The industrial computer 101 transmits a limited number of voltage reference points 201 on the ideal voltage curve to the control circuit 103. The control circuit 103 uses a Bessel model 202 to fit these discrete points into a high-order differentiable (at least second-order differentiable) voltage curve 203, ensuring a smooth transition of the force applied to the piezoelectric ceramic. Furthermore, the present invention establishes an X-axis feedforward controller based on the actual operating characteristics of the X-axis piezoelectric ceramic 108 to shape the control voltage curve 203 of the X-axis piezoelectric ceramic 108. The X-axis feedforward controller is composed of several sinusoidal functions. The amplitudes 204 and phases 205 of these sinusoidal functions can be adjusted according to the actual operating conditions of the X-axis piezoelectric ceramic 108. These functions are then added to the control voltage curve 203 of the X-axis piezoelectric ceramic 108 to form a voltage curve 206 for driving the X-axis piezoelectric ceramic 108.

[0043] Based on the correspondence between the deformation of the Y-axis piezoelectric ceramic 111 and the applied voltage, the industrial computer 101 obtains an ideal voltage curve for controlling the Y-axis piezoelectric ceramic 111. The industrial computer 101 transmits a limited number of voltage reference points 207 on the ideal voltage curve to the control circuit 103. The control circuit 103 uses a Bessel model 208 to fit these discrete points into a high-order differentiable (at least second-order differentiable) voltage curve 209, ensuring a smooth transition of force applied to the piezoelectric ceramic. Furthermore, the present invention establishes a Y-axis feedforward controller based on the actual operating characteristics of the Y-axis piezoelectric ceramic 111 to shape the control voltage curve 209 of the Y-axis piezoelectric ceramic 111. The Y-axis feedforward controller is composed of several sinusoidal functions. The amplitudes 210 and phases 211 of these sinusoidal functions can be adjusted according to the actual operating conditions of the Y-axis piezoelectric ceramic 111. These functions are then added to the control voltage curve 209 of the Y-axis piezoelectric ceramic 111 to form a control voltage curve 212 for driving the Y-axis piezoelectric ceramic 111.

[0044] The piezoelectric ceramic drive controller of this invention suppresses vibration in the die-bonding equipment's pricking mechanism, enabling high-speed, high-precision operation. Unlike traditional piezoelectric ceramic drivers, this invention uses a feedforward controller to shape the piezoelectric ceramic drive voltage, altering the piezoelectric ceramic's dynamic characteristics and suppressing mechanical structure vibration. Using a Bessel model, this invention expands discrete voltage values ​​into a high-order, continuous, and differentiable curve, achieving a smooth transition in the force applied to the piezoelectric ceramic.

[0045] Specifically, the advantages of the present invention are:

[0046] (1) The drive controller of the present invention is provided with a feedforward controller to shape the voltage curve, thereby improving the dynamic characteristics of the mechanism driven by the piezoelectric ceramics, thereby changing the motion characteristics of the mechanical structure, effectively suppressing the vibration of the mechanical structure, and improving the positioning accuracy. At an operating frequency of 100 Hz, the positioning accuracy of the thorn crystal mechanism is within ±5 μm;

[0047] (2) Based on the Bessel model, the present invention expands the limited, discrete voltage value into a high-order, divisible voltage curve, ensuring a continuous and smooth transition of the force on the piezoelectric ceramic, reducing the impact on the piezoelectric ceramic, and greatly improving the service life of the piezoelectric ceramic;

[0048] (3) The feedforward controller in the present invention is composed of a plurality of superimposed sine functions. The voltage curve is shaped by changing the amplitude and phase of the sine function. The feedforward controller fully considers the operating characteristics of the piezoelectric ceramic and the vibration characteristics of the mechanical structure, and the calculation process is simple.

[0049] In the present invention, the industrial computer 101 may include a display screen and control buttons. A communication circuit 102 may be provided between the industrial computer 101 and the control circuit 103. The industrial computer 101 and the communication circuit 102 may be connected via a cable line. The communication circuit 102 and the control circuit 103 may be connected using a 485 serial bus interface. External control instructions are transmitted to the control circuit 103 through the serial interface.

[0050] The control circuit 103 preferably uses ST's STM32F407 as its core, and its main function is to receive control instructions from the industrial computer 101, generate digital control signals, and generate analog signals through the DDS circuit 105.

[0051] The DDS circuit 105 preferably uses a high-precision 14-bit D / A conversion chip as its core, receives the 14-bit parallel digital signal output by the control circuit 103, converts it into an analog quantity, and generates two drive signals, one of which controls the X-axis piezoelectric ceramic 108 and the other controls the Y-axis piezoelectric ceramic 111.

[0052] The output end of the control circuit 103 can be provided with an isolation protection circuit 104. The isolation protection circuit 104 preferably uses an optocoupler isolation chip as its core to achieve electrical isolation between the control circuit 103 and the power part circuits 105-113, thereby improving the safety performance of the system and the anti-interference ability of the control circuit 103.

[0053] In order to improve the driving capability and control accuracy of the X-axis piezoelectric ceramic 108, preferably, an X-axis voltage control circuit 106, an X-axis power amplifier circuit 107 and an X-axis voltage signal acquisition and conditioning circuit 112 are provided between the isolation protection circuit 104 and the X-axis piezoelectric ceramic 108. After the X-axis voltage waveform passes through the X-axis power amplifier circuit 107, it drives the X-axis piezoelectric ceramic 108 to deform, thereby controlling the thorn crystal mechanism to operate in the X-axis direction; the X-axis voltage signal acquisition and conditioning circuit 112 collects the voltage across the X-axis piezoelectric ceramic 108, compares it with the X-axis voltage waveform output by the control circuit 103, and forms a voltage closed-loop control of the X-axis piezoelectric ceramic 108.

[0054] In a specific implementation, the X-axis voltage control circuit 106 may be based on an operational amplifier, which controls the driving voltage required by the X-axis piezoelectric ceramic 108.

[0055] The X-axis power amplifier circuit 107 uses a MOSFET tube as its core. Two MOSFET tubes form a push-pull circuit, and its output is connected to the X-axis piezoelectric ceramic 108;

[0056] The X-axis voltage signal acquisition and conditioning circuit 112 is composed of a voltage-dividing resistor and an operational amplifier. The precision resistor divides the voltage across the X-axis piezoelectric ceramic 108, and the voltage signal is introduced into the operational amplifier. By reasonably setting the proportional amplification resistor of the operational amplifier, the voltage signal is controlled within the range of 0-3.3V. The feedback voltage signal is compared with the control signal output by the DDS circuit 105 and input into the X-axis voltage control circuit 106.

[0057] In this way, the X-axis voltage control circuit 106 is designed by using components such as operational amplifiers, thereby reducing the computational pressure of the controller.

[0058] In order to improve the driving ability and control accuracy of the Y-axis piezoelectric ceramic 111, preferably, a Y-axis voltage control circuit 109, a Y-axis power amplifier circuit 110 and a Y-axis voltage signal acquisition and conditioning circuit 113 are provided between the isolation protection circuit 104 and the Y-axis piezoelectric ceramic 111. After the Y-axis voltage waveform passes through the Y-axis power amplifier circuit 110, it drives the Y-axis piezoelectric ceramic 111 to deform, thereby controlling the crystal mechanism to operate in the Y-axis direction; the Y-axis voltage signal acquisition and conditioning circuit 113 collects the voltage across the Y-axis piezoelectric ceramic 111, and compares it with the Y-axis voltage waveform output by the control circuit 103, thereby forming a voltage closed-loop control of the Y-axis piezoelectric ceramic 111.

[0059] In a specific implementation, the Y-axis voltage control circuit 109 may be based on an operational amplifier, which controls the driving voltage required by the Y-axis piezoelectric ceramic 111.

[0060] The Y-axis power amplifier circuit 110 uses a MOSFET tube as its core. Two MOSFET tubes form a push-pull circuit, and its output is connected to the Y-axis piezoelectric ceramic 111;

[0061] The Y-axis voltage signal acquisition and conditioning circuit 113 is composed of a voltage-dividing resistor and an operational amplifier. The precision resistor divides the voltage across the Y-axis piezoelectric ceramic 111, and the voltage signal is introduced into the operational amplifier. By reasonably setting the proportional amplification resistor of the operational amplifier, the voltage signal is controlled within the range of 0-3.3V. The feedback voltage signal is compared with the control signal output by the DDS circuit 105 and input into the Y-axis voltage control circuit 109.

[0062] In this way, the Y-axis voltage control circuit 109 is designed by using components such as operational amplifiers, thereby reducing the calculation pressure of the controller.

[0063] The control system operation block diagram of the piezoelectric ceramic drive controller of the present invention is as follows: Figure 2 As shown:

[0064] Based on the correspondence between the voltage across the piezoelectric ceramic and the deformation, the industrial computer 101 generates an ideal voltage control curve for controlling the X-axis piezoelectric ceramic 108. The industrial computer 101 transmits a limited voltage reference point 201 to the control circuit 103. The control circuit 103 expands the discrete voltage reference point 201 into a high-order, differentiable, continuous curve 203 using a Bessel model 202. Directly using the voltage curve 203 to control the deformation of the X-axis piezoelectric ceramic 108, and thus the movement of the thorn crystal mechanism in the X-axis direction, can cause vibration of the mechanical structure. To suppress vibration of the mechanical structure, the present invention incorporates an X-axis feedforward controller within the controller to shape the curve 203. The X-axis feedforward controller comprises a series of sinusoidal signals. The amplitude 204 and phase 205 of the sinusoidal signals are adjusted according to the vibration of the mechanical structure. The output signal of the X-axis feedforward controller is superimposed on the curve 203 to generate a signal 206 for controlling the deformation of the X-axis piezoelectric ceramic. Using the control curve 206, vibration of the mechanical structure is effectively suppressed.

[0065] Based on the correspondence between the voltage across the piezoelectric ceramic and the deformation, the industrial computer 101 generates an ideal voltage control curve for controlling the Y-axis piezoelectric ceramic 111. The industrial computer 101 transmits a limited voltage reference point 207 to the control circuit 103. The control circuit 103 expands the discrete voltage reference point 207 into a high-order, differentiable continuous curve 209 via a Bessel model 208. Directly using the voltage curve 209 to control the deformation of the Y-axis piezoelectric ceramic 111, and thereby controlling the motion of the thorn crystal mechanism in the Y-axis direction, may cause vibration of the mechanical structure. To suppress vibration of the mechanical structure, the present invention provides a Y-axis feedforward controller within the controller to shape the curve 209. The Y-axis feedforward controller comprises a series of sinusoidal signals. The amplitude 210 and phase 211 of the sinusoidal signals are adjusted according to the vibration of the mechanical structure. The output signal of the Y-axis feedforward controller is superimposed on the curve 209 to generate a signal 212 for controlling the deformation of the Y-axis piezoelectric ceramic. Using the control curve 212, vibration of the mechanical structure is effectively suppressed.

[0066] In the embodiment of the present invention, Figure 3-4 As shown, the process of the control circuit fitting discrete voltage reference points into a high-order differentiable voltage curve through a Bessel model preferably includes:

[0067] Step 1: Set the starting point A and end point C of the curve;

[0068] Step 2: Reasonably select control point B;

[0069] Step 3: Find points D and E on line segments AB and BC respectively, connect DE, and find point F on line segment DE so that the lengths of the segments satisfy AD / AB=BE / BC=DF / DE.

[0070] Step 4: Move point D from A to B, and the trajectory of point F is what we want.

[0071] In this way, the required control voltage curve can be obtained conveniently, quickly and accurately.

[0072] After testing, it was found that when the piezoelectric ceramics driven by conventional power supply in the existing technology are used to control the operation of mechanical equipment, high-frequency, small-amplitude vibrations will be superimposed when the mechanical equipment swings over a large range, such as Figure 5 As shown. When the piezoelectric ceramic driven by the present invention controls the operation of mechanical equipment, the vibration of the mechanical equipment is effectively suppressed when the mechanical equipment swings over a large range, as shown Figure 6 shown.

[0073] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A piezoelectric ceramic drive controller for driving a die-bonding device's die-piercing mechanism, wherein the piezoelectric ceramics include X-axis piezoelectric ceramics and Y-axis piezoelectric ceramics, characterized in that: The piezoelectric ceramic drive controller includes an industrial computer and a control circuit, wherein: The output end of the industrial computer is connected to the input end of the control circuit to realize the transmission of the control signal; The control circuit processes the received control signal to generate a digital control signal; a DDS circuit is provided inside the control circuit, which converts the digital signal into an analog signal and divides it into two control signals, X and Y. The two control signals are output to the X-axis piezoelectric ceramic and the Y-axis piezoelectric ceramic respectively after closed-loop control; For the X-axis piezoelectric ceramics and Y-axis piezoelectric ceramics, the industrial computer obtains an ideal control voltage curve signal for controlling the piezoelectric ceramics of each axis based on the correspondence between the deformation of the piezoelectric ceramics of each axis and the applied voltage, and transmits the limited voltage reference points on the ideal control voltage curve signal to the control circuit. The control circuit fits the discrete voltage reference points into a high-order, differentiable ideal control voltage curve signal through a Bessel model; the control circuit is also provided with an X-axis feedforward controller and a Y-axis feedforward controller. The X-axis feedforward controller and the Y-axis feedforward controller are each composed of a plurality of sinusoidal signal modules. The sinusoidal signal amplitudes and phases of these sinusoidal signal modules can be adjusted according to the actual operating conditions of the piezoelectric ceramics of each axis. The adjusted signals are then added to the high-order, differentiable ideal control voltage curve signals of the piezoelectric ceramics of each axis to form the controller output control voltage signals for driving the piezoelectric ceramics of each axis.

2. The piezoelectric ceramic drive controller according to claim 1, characterized in that: A communication circuit is provided between the industrial computer and the control circuit.

3. The piezoelectric ceramic drive controller according to claim 1, characterized in that: An isolation protection circuit is provided at the output end of the control circuit.

4. The piezoelectric ceramic drive controller according to claim 1, characterized in that: The DDS circuit includes a D / A conversion chip.

5. The piezoelectric ceramic drive controller according to claim 3, characterized in that: The isolation protection circuit includes an optocoupler isolation chip.

6. The piezoelectric ceramic drive controller according to claim 3, characterized in that: An X-axis voltage closed-loop control circuit is provided between the isolation protection circuit and the X-axis piezoelectric ceramic. The X-axis voltage closed-loop control circuit includes an X-axis voltage control circuit, an X-axis power amplifier circuit, and an X-axis voltage signal acquisition and conditioning circuit. The voltage signal output by the X-axis voltage control circuit drives the X-axis piezoelectric ceramic to deform after passing through the X-axis power amplifier circuit, thereby controlling the thorn crystal mechanism to operate in the X-axis direction; the X-axis voltage signal acquisition and conditioning circuit collects the voltage across the X-axis piezoelectric ceramic, compares it with the X-axis control voltage signal output by the control circuit, and then inputs it into the X-axis voltage control circuit to form a voltage closed-loop control of the X-axis piezoelectric ceramic.

7. The piezoelectric ceramic drive controller according to claim 6, characterized in that: The X-axis voltage control circuit includes an operational amplifier; The X-axis power amplifier circuit includes two MOSFET tubes, which form a push-pull circuit, and the output of the circuit is connected to the X-axis piezoelectric ceramic; The X-axis voltage signal acquisition and conditioning circuit includes a voltage divider resistor and an operational amplifier.

8. The piezoelectric ceramic drive controller according to claim 3, characterized in that: A Y-axis voltage closed-loop control circuit is provided between the isolation protection circuit and the Y-axis piezoelectric ceramic. The Y-axis voltage closed-loop control circuit includes a Y-axis voltage control circuit, a Y-axis power amplifier circuit and a Y-axis voltage signal acquisition and conditioning circuit. The voltage signal output by the Y-axis voltage control circuit drives the Y-axis piezoelectric ceramic to deform after passing through the Y-axis power amplifier circuit, thereby controlling the thorn crystal mechanism to operate in the Y-axis direction; the Y-axis voltage signal acquisition and conditioning circuit collects the voltage across the Y-axis piezoelectric ceramic, compares it with the Y-axis control voltage signal output by the control circuit, and then inputs it into the Y-axis voltage control circuit to form a voltage closed-loop control of the Y-axis piezoelectric ceramic.

9. The piezoelectric ceramic drive controller according to claim 8, characterized in that: The Y-axis voltage control circuit includes an operational amplifier; The Y-axis power amplifier circuit includes two MOSFET tubes, which form a push-pull circuit, and the output of the circuit is connected to the Y-axis piezoelectric ceramic; The Y-axis voltage signal acquisition and conditioning circuit includes a voltage divider resistor and an operational amplifier.

10. The piezoelectric ceramic drive controller according to any one of claims 1 to 9, characterized in that: The process of fitting the discrete voltage reference points into a high-order and differentiable ideal control voltage curve signal by the control circuit through the Bessel model includes: Set the starting point A and end point C of the curve; Reasonably select control point B; Find points D and E on line segments AB and BC respectively, connect DE, and find point F on line segment DE so that the lengths of the segments satisfy AD / AB=BE / BC=DF / DE; Move point D from A to B, and the trajectory of point F is what we want.

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