Drive and current detection circuit for voice coil motor of die bonder

By introducing a negative feedback system with components such as an MCU and an isolation optocoupler circuit into the voice coil motor, the problems of poor output stability and difficulty in quantifying current of the voice coil motor are solved, and stable driving and accurate current detection are achieved.

CN224124058UActive Publication Date: 2026-04-14安徽中科创芯科技有限公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2025-04-22
Publication Date
2026-04-14

AI Technical Summary

Technical Problem

Voice coil motors have poor output stability and it is difficult to effectively quantify and detect the current.

Method used

It employs an MCU, an isolation optocoupler circuit, a DAC module, a precision operational amplifier circuit, a power drive circuit, a current acquisition circuit, and a current detection circuit. Through a negative feedback system, it stably drives a voice coil motor, detects the current, and converts it into an output voltage to achieve quantization.

Benefits of technology

It improves the output stability of the voice coil motor and enables effective quantitative detection of current.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model relates to a voice coil motor of a die bonder, in particular to a drive and current detection circuit for the voice coil motor of the die bonder, which comprises an isolation optocoupler circuit and a circuit for isolating and protecting a control signal sent by an MCU (Microprogrammed Control Unit) from the voice coil motor. The DAC module is used for programming input voltage, digitally controlling the voltage of the voice coil motor so as to control the current of the voice coil motor, and inputting the output voltage to the precise operational amplifier circuit; the precise operational amplifier circuit is used for conditioning the output voltage of the DAC module by taking a reference source as a reference voltage and inputting the output voltage to the power driving circuit; the power driving circuit is used for providing voltage suitable for driving for the voice coil motor according to the output voltage of the precise operational amplifier circuit and the current of the voice coil motor; according to the technical scheme provided by the utility model, the defects that the output stability of the voice coil motor is poor and the current of the voice coil motor is difficult to effectively and quantitatively detect in the prior art can be effectively overcome.
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Description

Technical Field

[0001] This utility model relates to voice coil motors in die bonders, specifically to a drive and current detection circuit for voice coil motors in die bonders. Background Technology

[0002] The die bonder is one of the key pieces of equipment in semiconductor packaging processes, requiring high-speed and precision control. A voice coil motor is a direct-drive motor characterized by fast response, no hysteresis, high efficiency, and linear control. The working principle of a voice coil motor, where the stator is a permanent magnet and the rotor is a coil, is as follows: the energized coil experiences an Ampere force within the magnetic field of the permanent magnet, and the magnitude of this force is directly proportional to the current flowing through the coil.

[0003] The impedance of a voice coil motor is easily affected by temperature, which causes the current of the voice coil motor to change accordingly. This results in poor output stability of the voice coil motor and makes it difficult to effectively quantify and detect the current of the voice coil motor. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a driving and current detection circuit for the voice coil motor of a die bonder, which can effectively overcome the defects of poor output stability of the voice coil motor and difficulty in effectively quantifying and detecting the current of the voice coil motor.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A drive and current detection circuit for a voice coil motor in a die bonder includes an MCU, an isolation optocoupler circuit, a DAC module, a precision operational amplifier circuit, a power drive circuit, a current acquisition circuit, a current detection circuit, and a power-on timing management and freewheeling protection circuit.

[0009] The MCU sends control signals to the DAC module through an isolation optocoupler circuit to change the output of the DAC module;

[0010] An isolation optocoupler circuit isolates the control signals sent by the MCU from the voice coil motor, thus protecting the circuit.

[0011] The DAC module features a programmable input voltage, digitally controlling the voltage of the voice coil motor, which in turn controls the current of the voice coil motor, and then inputs the output voltage to a precision operational amplifier circuit.

[0012] The precision operational amplifier circuit uses a reference source as a reference voltage to condition the output voltage of the DAC module and inputs the output voltage to the power drive circuit.

[0013] The power drive circuit provides a suitable driving voltage to the voice coil motor based on the output voltage of the precision operational amplifier circuit and the current of the voice coil motor.

[0014] The current acquisition circuit acquires the current of the voice coil motor and inputs the current of the voice coil motor to the power drive circuit.

[0015] The current detection circuit collects the current of the voice coil motor and converts the current of the voice coil motor into a corresponding output voltage. The current of the voice coil motor is determined by detecting the output voltage.

[0016] The power-on timing management and freewheeling protection circuit ensures that the voice coil motor is disconnected before the output voltage of the precision operational amplifier circuit reaches the power drive circuit, thus avoiding thermal damage to the voice coil motor caused by the high voltage drive at the moment of power-on. At the same time, a freewheeling diode is set between the power drive circuit and the voice coil motor to avoid damage to the circuit due to the non-sudden change in current of the inductive load at the moment of power-off.

[0017] Preferably, the power drive circuit includes an operational amplifier U9, the non-inverting input terminal of the operational amplifier U9 is grounded through a resistor R42, the inverting input terminal of the operational amplifier U9 is connected to the output terminal of a precision operational amplifier circuit through a resistor R41, and the inverting input terminal of the operational amplifier U9 is connected to the output terminal of a current acquisition circuit.

[0018] The output terminal of the operational amplifier U9 is connected to the inverting input terminal of the operational amplifier U9 through resistor R60 and capacitor C30. The output terminal of the operational amplifier U9 is connected to one end of the voice coil motor through fuse F1. One end of the voice coil motor is connected to the positive power supply and the negative power supply through diode D19 and diode D20, respectively.

[0019] Preferably, the current acquisition circuit includes resistors R52 and R53. One end of resistor R52 is connected to the other end of the voice coil motor and one end of resistor R53. The other end of resistor R52 is connected to the inverting input terminal of operational amplifier U9, and the other end of resistor R53 is grounded.

[0020] Preferably, resistors R52 and R53 form a current feedback loop. When the current of the voice coil motor changes, the current of the voice coil motor is pulled back to the set value through negative feedback. The current I1 of the voice coil motor is calculated according to the virtual short and virtual open circuits of the operational amplifier and Kirchhoff's laws.

[0021]

[0022] Where Ui is the output voltage of the precision operational amplifier circuit.

[0023] Preferably, the current detection circuit includes an operational amplifier U1, the non-inverting input terminal of the operational amplifier U1 is connected to the power supply VCC through a resistor R3, the non-inverting input terminal of the operational amplifier U1 is connected to the inverting input terminal of the operational amplifier U1 through resistors R3 and R1, and the current I1 of the voice coil motor is connected between the inverting input terminal of the operational amplifier U1 and ground.

[0024] The output terminal of the operational amplifier U1 is connected to the gate of the field-effect transistor Q1, the drain of the field-effect transistor Q1 is connected to the non-inverting input terminal of the operational amplifier U1, and the source of the field-effect transistor Q1 is grounded through the resistor R4, forming negative feedback. The output voltage Uout of the current detection circuit is output through the resistor R4.

[0025] Preferably, the voltage drop across resistor R1 is equal to the voltage drop across resistor R3:

[0026] I1×R1=I R3 ×R3;

[0027] Among them, I R3 The current in resistor R3;

[0028] Meanwhile, for the output voltage Uout of the current detection circuit:

[0029] Uout=I R4 ×R4=I R3 ×R4;

[0030] Among them, I R4 The current in resistor R4;

[0031] Based on the two formulas above, the current I1 of the voice coil motor can be calculated:

[0032]

[0033] Therefore, the current I1 of the voice coil motor can be determined by detecting the output voltage Uout of the current detection circuit.

[0034] (III) Beneficial Effects

[0035] Compared with the prior art, the driving and current detection circuit for the voice coil motor of the die bonder provided by this utility model adopts a current parallel negative feedback system, which can stably drive the voice coil motor and avoid the negative impact on the output stability of the voice coil motor caused by the temperature affecting the motor impedance. This effectively improves the output stability of the voice coil motor. At the same time, it converts the current of the voice coil motor into the corresponding output voltage. By detecting the output voltage of the current detection circuit, the current of the voice coil motor can be determined, thereby enabling quantitative detection of the current of the voice coil motor. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the system of this utility model;

[0038] Figure 2 This is a schematic diagram of the process by which the abnormal battery identification unit of this utility model uses a trained abnormal battery identification model to monitor abnormal batteries in real time.

[0039] Figure 3 This is a schematic diagram of the process by which the battery degradation prediction unit in this invention uses a trained battery degradation prediction model to perform real-time degradation prediction of abnormal batteries. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0041] A drive and current detection circuit for the voice coil motor of a die bonder, such as... Figure 1 As shown, it includes an MCU, an isolation optocoupler circuit, a DAC module, a precision operational amplifier circuit, a power drive circuit, a current acquisition circuit, a current detection circuit, and a power-on timing management and freewheeling protection circuit.

[0042] The MCU sends control signals to the DAC module through an isolation optocoupler circuit to change the output of the DAC module;

[0043] An isolation optocoupler circuit isolates the control signals sent by the MCU from the voice coil motor, thus protecting the circuit.

[0044] The DAC module features a programmable input voltage, digitally controlling the voltage of the voice coil motor, which in turn controls the current of the voice coil motor, and then inputs the output voltage to a precision operational amplifier circuit.

[0045] The precision operational amplifier circuit uses a reference source as a reference voltage to condition the output voltage of the DAC module and inputs the output voltage to the power drive circuit.

[0046] The power drive circuit provides a suitable driving voltage to the voice coil motor based on the output voltage of the precision operational amplifier circuit and the current of the voice coil motor.

[0047] The current acquisition circuit acquires the current of the voice coil motor and inputs the current of the voice coil motor to the power drive circuit.

[0048] The current detection circuit collects the current of the voice coil motor and converts the current of the voice coil motor into a corresponding output voltage. The current of the voice coil motor is determined by detecting the output voltage.

[0049] The power-on timing management and freewheeling protection circuit ensures that the voice coil motor is disconnected before the output voltage of the precision operational amplifier circuit reaches the power drive circuit, thus avoiding thermal damage to the voice coil motor caused by the high voltage drive at the moment of power-on. At the same time, a freewheeling diode is set between the power drive circuit and the voice coil motor to avoid damage to the circuit due to the non-sudden change in current of the inductive load at the moment of power-off.

[0050] like Figure 2 As shown, the power drive circuit includes an operational amplifier U9. The non-inverting input of the operational amplifier U9 is grounded through a resistor R42 (used to match and eliminate the input offset of the operational amplifier). The inverting input of the operational amplifier U9 is connected to the output of the precision operational amplifier circuit through a resistor R41 (a high-precision low-temperature drift resistor). The inverting input of the operational amplifier U9 is connected to the output of the current acquisition circuit.

[0051] The output terminal of operational amplifier U9 is connected to the inverting input terminal of operational amplifier U9 through resistor R60 and capacitor C30. The output terminal of operational amplifier U9 is connected to one end of voice coil motor through fuse F1 (used to protect the power drive circuit). One end of voice coil motor is connected to the positive power supply and negative power supply respectively through diode D19 and diode D20 (both Schottky diodes, used to protect the power drive circuit from abnormal sinking current of external load).

[0052] like Figure 2 As shown, the current acquisition circuit includes resistors R52 and R53. One end of resistor R52 is connected to the other end of the voice coil motor, and one end of resistor R53 is connected to the other end of the operational amplifier U9. The other end of resistor R52 is connected to the inverting input terminal of the operational amplifier U9, and the other end of resistor R53 is grounded.

[0053] In the current acquisition circuit, resistors R52 and R53 form a current feedback loop. When the current of the voice coil motor changes, the current of the voice coil motor is pulled back to the set value through negative feedback. The current I1 of the voice coil motor is calculated based on the virtual short and virtual open circuits of the operational amplifier and Kirchhoff's laws.

[0054]

[0055] Where Ui is the output voltage of the precision operational amplifier circuit.

[0056] like Figure 3 As shown, the current detection circuit includes an operational amplifier U1 (an op-amp with small input offset should be selected). The non-inverting input terminal of the operational amplifier U1 is connected to the power supply VCC through a resistor R3. The non-inverting input terminal of the operational amplifier U1 is connected to the inverting input terminal of the operational amplifier U1 through resistors R3 and R1 (which are the sampling resistors connected in series to the load circuit and should be very small). The current I1 of the voice coil motor is connected between the inverting input terminal of the operational amplifier U1 and ground.

[0057] The output terminal of operational amplifier U1 is connected to the gate of field-effect transistor Q1, the drain of field-effect transistor Q1 is connected to the non-inverting input terminal of operational amplifier U1, and the source of field-effect transistor Q1 is grounded through resistor R4, forming negative feedback. The output voltage Uout of the current detection circuit is output through resistor R4.

[0058] In the current detection circuit, the voltage drop across resistor R1 is equal to the voltage drop across resistor R3:

[0059] I1×R1=I R3 ×R3;

[0060] Among them, I R3 The current in resistor R3;

[0061] Meanwhile, for the output voltage Uout of the current detection circuit:

[0062] Uout=I R4 ×R4=I R3 ×R4;

[0063] Among them, I R4 The current through resistor R4;

[0064] Based on the two formulas above, the current I1 of the voice coil motor can be calculated:

[0065]

[0066] Therefore, the current I1 of the voice coil motor can be determined by detecting the output voltage Uout of the current detection circuit.

[0067] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A driving and current detection circuit for a voice coil motor in a die bonder, characterized in that: Includes MCU, isolation optocoupler circuit, DAC module, precision operational amplifier circuit, power drive circuit, current acquisition circuit, current detection circuit, and power-on timing management and freewheeling protection circuit; The MCU sends control signals to the DAC module through an isolation optocoupler circuit to change the output of the DAC module; An isolation optocoupler circuit isolates the control signals sent by the MCU from the voice coil motor, thus protecting the circuit. The DAC module features a programmable input voltage, digitally controlling the voltage of the voice coil motor, which in turn controls the current of the voice coil motor, and then inputs the output voltage to a precision operational amplifier circuit. The precision operational amplifier circuit uses a reference source as a reference voltage to condition the output voltage of the DAC module and inputs the output voltage to the power drive circuit. The power drive circuit provides a suitable driving voltage to the voice coil motor based on the output voltage of the precision operational amplifier circuit and the current of the voice coil motor. The current acquisition circuit acquires the current of the voice coil motor and inputs the current of the voice coil motor to the power drive circuit. The current detection circuit collects the current of the voice coil motor and converts the current of the voice coil motor into a corresponding output voltage. The current of the voice coil motor is determined by detecting the output voltage. The power-on timing management and freewheeling protection circuit ensures that the voice coil motor is disconnected before the output voltage of the precision operational amplifier circuit reaches the power drive circuit, thus avoiding thermal damage to the voice coil motor caused by the high voltage drive at the moment of power-on. At the same time, a freewheeling diode is set between the power drive circuit and the voice coil motor to avoid damage to the circuit due to the non-sudden change in current of the inductive load at the moment of power-off.

2. The drive and current detection circuit for the voice coil motor of a die bonder according to claim 1, characterized in that: The power drive circuit includes an operational amplifier U9. The non-inverting input of the operational amplifier U9 is grounded through a resistor R42, the inverting input of the operational amplifier U9 is connected to the output of a precision operational amplifier circuit through a resistor R41, and the inverting input of the operational amplifier U9 is connected to the output of a current acquisition circuit. The output terminal of the operational amplifier U9 is connected to the inverting input terminal of the operational amplifier U9 through resistor R60 and capacitor C30. The output terminal of the operational amplifier U9 is connected to one end of the voice coil motor through fuse F1. One end of the voice coil motor is connected to the positive power supply and the negative power supply through diode D19 and diode D20, respectively.

3. The drive and current detection circuit for the voice coil motor of a die bonder according to claim 2, characterized in that: The current acquisition circuit includes resistors R52 and R53. One end of resistor R52 is connected to the other end of the voice coil motor and one end of resistor R53. The other end of resistor R52 is connected to the inverting input terminal of operational amplifier U9, and the other end of resistor R53 is grounded.

4. The drive and current detection circuit for the voice coil motor of a die bonder according to claim 3, characterized in that: Resistors R52 and R53 form a current feedback loop. When the current of the voice coil motor changes, the current is pulled back to the set value through negative feedback. The current I1 of the voice coil motor is calculated based on the virtual short and virtual open circuits of the operational amplifier and Kirchhoff's laws. Where Ui is the output voltage of the precision operational amplifier circuit.

5. The drive and current detection circuit for the voice coil motor of a die bonder according to claim 1, characterized in that: The current detection circuit includes an operational amplifier U1. The non-inverting input terminal of the operational amplifier U1 is connected to the power supply VCC through a resistor R3. The non-inverting input terminal of the operational amplifier U1 is connected to the inverting input terminal of the operational amplifier U1 through resistors R3 and R1. The current I1 of the voice coil motor is connected between the inverting input terminal of the operational amplifier U1 and ground. The output terminal of the operational amplifier U1 is connected to the gate of the field-effect transistor Q1, the drain of the field-effect transistor Q1 is connected to the non-inverting input terminal of the operational amplifier U1, and the source of the field-effect transistor Q1 is grounded through the resistor R4, forming negative feedback. The output voltage Uout of the current detection circuit is output through the resistor R4.

6. The drive and current detection circuit for the voice coil motor of a die bonder according to claim 5, characterized in that: The voltage drop across resistor R1 is equal to the voltage drop across resistor R3: I1×R1=I R3 ×R3; Among them, I R3 The current in resistor R3; Meanwhile, for the output voltage Uout of the current detection circuit: Uout=I R4 ×R4=I R3 ×R4; Among them, I R4 The current through resistor R4; Based on the two formulas above, the current I1 of the voice coil motor can be calculated: ； Therefore, the current I1 of the voice coil motor can be determined by detecting the output voltage Uout of the current detection circuit.