A digital thermocompression welding device compatible with multiple types of sensors

Abstract

This invention discloses a digital thermocompression welding device compatible with multiple types of sensors, including a main circuit, a main control circuit, a PWM drive circuit, a multi-channel temperature acquisition circuit, a detection circuit, and a human-machine interface touch screen. The main control circuit is connected to the PWM drive circuit, the multi-channel temperature acquisition circuit, the detection circuit, and the human-machine interface touch screen. The PWM drive circuit is connected to the main circuit. The user completes parameter settings on the touch screen, and the main control circuit performs power control on the main circuit to achieve high-precision real-time closed-loop temperature control. Simultaneously, the touch screen supports real-time temperature data plotting, historical data browsing, multi-sensor switching, and over-temperature, over-voltage, and over-current monitoring functions. The MCU of the main control circuit is equipped with a real-time operating system, which completes the scheduling and management of welding control, human-machine interaction, data storage, and equipment communication. This invention, through a real-time operating system combined with a touch screen, plots the welding temperature curve in real time during the welding process, facilitating production management.

Description

Technical Field

[0001] This invention relates to the field of automated production of pulse reflow soldering (thermo-press soldering), and in particular to a digital thermo-press soldering device compatible with multiple types of sensors. Background Technology

[0002] Pulse reflow soldering (thermal pressure soldering), as one of the main processes for connecting electronic components, has gradually achieved automated production. The types of components soldered are diverse, with varying shapes and sizes of workpieces and diverse welding process parameters, placing higher demands on the intelligence and digitalization of welding machines. This is mainly reflected in aspects such as temperature control precision, ease of parameter setting and adjustment, data storage, communication interface compatibility, and equipment stability.

[0003] Traditional thermocompression welding equipment operation and data management methods are insufficient to meet the demands of modern digital industrial production. Parameter setting and adjustment mainly rely on knobs and buttons, and parameter display is primarily via digital tubes or small LCD screens, resulting in low ease of operation and visualization. Furthermore, traditional thermocompression welding equipment only supports a single sensor / thermocouple, failing to meet diverse production needs. Data display in traditional thermocompression welding equipment has poor real-time performance, and monitoring of the welding process is limited, with temperature curves only displayed after welding is complete. In addition, data management methods are relatively limited, preventing users from accessing production data through multiple means. An existing automated thermocompression welding device and method (CN115106640B) achieves dual closed-loop control of temperature and pressure, but welding process parameters require pre-programming, and thermocouple support is limited. It cannot achieve online parameter adjustment in the production environment, nor can it flexibly replace thermocouple types.

[0004] To address the aforementioned issues, there is an urgent need in this field for a digital thermocompression welding solution that supports multiple types of sensors and offers a user-friendly human-machine interface. Summary of the Invention

[0005] The purpose of this invention is to provide a digital thermobaric welding device that is compatible with multiple types of sensors, achieving compatibility with multiple sensor interfaces, digital human-machine interaction, and data visualization of the welding process.

[0006] The present invention is achieved by at least one of the following technical solutions.

[0007] A digital thermocompression welding device compatible with multiple types of sensors includes a main circuit, a main control circuit, a PWM drive circuit, a multi-channel temperature acquisition circuit, a detection circuit, and a human-machine interface touch screen. The main control circuit is connected to the PWM drive circuit, the multi-channel temperature acquisition circuit, the detection circuit, and the human-machine interface touch screen. The PWM drive circuit is connected to the main circuit. Users complete parameter settings on the touch screen and control the power of the main circuit through the main control circuit to achieve high-precision real-time closed-loop temperature control. At the same time, the touch screen supports real-time temperature data plotting, historical data browsing, multi-sensor switching, and over-temperature, over-voltage, and over-current monitoring functions.

[0008] Furthermore, the main circuit includes a primary full-bridge rectifier diode, an IGBT full-bridge inverter circuit, a high-frequency transformer, and a secondary full-wave rectifier; The output terminal of the primary full-bridge rectifier diode is connected to the inverter full-bridge through a filter capacitor. After inversion, the inverter full-bridge generates a high-frequency AC voltage, which is then transmitted to the secondary side through a high-frequency transformer. Finally, it is rectified by a full-wave rectifier to generate DC power for welding.

[0009] Furthermore, the main control circuit includes a main control MCU, a power-down storage chip, a dual RS485 interface circuit, a PWM drive circuit interface, an ADC temperature acquisition interface, and a multi-channel optocoupler IO interface, wherein the main control MCU generates a PWM drive signal to drive the PWM drive circuit to complete the inverter bridge.

[0010] Furthermore, the PWM drive circuit includes a multi-winding transformer, a flyback circuit, an LDO regulator, a two-stage transistor amplifier circuit, and a full-bridge inverter MOSFET amplifier circuit. The AC mains power is connected to the multi-winding transformer after passing through the full-bridge rectifier. The multi-winding transformer is connected to the flyback circuit, which generates a stable DC output voltage. The DC output voltage is input to the LDO regulator, which converts the DC output voltage into two DC output voltages for powering the multi-channel temperature acquisition circuit. It is also converted into a voltage for powering the main control MCU and the dual RS485 interface circuit. The PWM signal of the main control MCU is connected to the transistor dual-stage amplifier circuit. The transistor dual-stage amplifier circuit is connected to the input terminal of the full-bridge inverter MOSFET. The output of the full-bridge inverter MOSFET is connected to the isolation transformer to generate the final IGBT drive signal. The IGBT drive signal is input to the IGBT full-bridge inverter circuit of the main circuit.

[0011] Furthermore, the multi-channel temperature acquisition circuit is a three-channel differential adjustable amplifier circuit, each of which is a two-stage operational amplifier circuit with voltage compensation function, and can be individually adapted to up to three types of thermocouples according to usage requirements.

[0012] Furthermore, the dual-stage operational amplifier circuit includes a front-end differential acquisition circuit and a rear-end amplification circuit.

[0013] Furthermore, the detection circuit and multi-channel temperature acquisition circuit are used for automatic identification and matching of sensor types. The main control MCU determines the type of thermocouple connected based on the detection circuit and displays it on the touch screen.

[0014] Furthermore, the detection circuit includes two IO channels. The two differential signal lines of the thermocouple are connected to the two IO channels respectively. The thermocouple signal is amplified by a three-way differential adjustable amplifier circuit and then connected to the ADC temperature acquisition interface of the main control MCU.

[0015] Furthermore, the main control circuit is equipped with an STM32F407 real-time operating system to manage multiple threads, including a startup thread, an error handling thread, a main thread, a touch screen read / write thread, a host computer communication thread, a monitoring thread, a USB read / write thread, and an idle thread.

[0016] Furthermore, the touchscreen is a capacitive touchscreen, which includes a parameter setting page, a waveform display page, an alarm page, a temperature curve plotting page, a historical data browsing page, and other setting pages, and displays touch interaction through digital visualization.

[0017] Compared with existing technologies, the beneficial effects of the present invention are as follows: 1. It provides both digital and visual platforms. The parameter setting panel on the touch screen reduces the difficulty for users to use / operate the equipment, making human-computer interaction more user-friendly and in line with current digital usage habits.

[0018] 2. Compatible with multiple types of thermocouples / sensors, allowing switching between different thermocouples according to actual welding and temperature control requirements. For applications requiring high temperature control accuracy and response speed, the E-type thermocouple welding head can be replaced. The welding machine automatically identifies and matches the sensor type and displays the device status and connection type in real time.

[0019] 3. By combining a real-time operating system with a touch screen, welding temperature curves are plotted in real time during the welding process, facilitating production management and monitoring. The touch screen interface uses a self-designed UI, supporting online browsing of historical data and production logs. It also supports offline browsing of production data by connecting storage media such as USB flash drives, which facilitates the control of production quality. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of a digital thermobaric welding device compatible with multiple types of sensors, as shown in the embodiment.

[0021] Figure 2This is a schematic diagram of the main control circuit structure for an example.

[0022] Figure 3 This is a schematic diagram of the PWM drive circuit structure for an example.

[0023] Figure 4 This is a schematic diagram of the multi-channel temperature acquisition and detection circuit structure for an example.

[0024] Figure 5 This is a schematic diagram showing the connection between the multi-channel temperature acquisition and detection circuit and the main control circuit in an embodiment.

[0025] Figure 6 This is a diagram of the real-time operating system software architecture for an example.

[0026] Figure 7 This is a schematic diagram of the waveform display interface of the touch screen in an embodiment.

[0027] Figure 8 This is a schematic diagram of the interface for drawing the temperature curve of the touch screen in an example.

[0028] Figure 9 This is a schematic diagram of the alarm interface of the touch screen in an embodiment.

[0029] Figure 10 This is a schematic diagram of the parameter setting interface of the touch screen in an embodiment. Detailed Implementation

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] like Figure 1 As shown, this embodiment of a digital thermobaric welding device compatible with multiple types of sensors includes a main circuit, a main control circuit, a multi-channel temperature acquisition circuit, a detection circuit, a PWM drive circuit, and a human-machine interface touchscreen. The main control circuit is connected to the multi-channel temperature acquisition circuit, the detection circuit, the PWM drive circuit, and the human-machine interface touchscreen, respectively. It receives voltage signals fed back from the temperature acquisition circuit, combines a low-pass filtering algorithm with a feedforward compensated PID algorithm, and outputs a PWM signal to the PWM drive circuit to regulate the power of the main circuit, completing closed-loop temperature control. Simultaneously, the main control circuit carries a real-time operating system to drive and manage the various modules.

[0032] The main control circuit supports communication interfaces such as RS485 / SPI, and can be connected to peripheral devices such as a host computer, touch screen, and power-down memory chip (EEPROM). The MCU of the main control circuit captures temperature signals through a multi-channel temperature acquisition circuit and outputs PWM signals in real time to control the inverter full-bridge to achieve closed-loop temperature control. The touch screen connected to the main control circuit can be used to complete parameter setting, real-time monitoring of welding data, alarm management, and also supports online browsing of historical data.

[0033] The main circuit includes a primary full-bridge rectifier diode, an IGBT full-bridge inverter circuit, a high-frequency transformer, and a secondary full-wave rectifier.

[0034] In one embodiment, the primary full-bridge rectifier diode is an integrated bridge rectifier (GBPC5010+); the IGBT full-bridge inverter circuit includes four high-power IGBTs (S1~S4) of model 2MBI100VA-120-50; the high-frequency transformer has a center tap, a turns ratio of 40, and the two coils on the secondary side have the same number of turns, with iron core material; the secondary full-wave rectifier includes two Schottky diodes (VD1, VD2) of model MBR40010WCT. A 220V AC mains power is input to the primary full-bridge rectifier diode. The output of the rectifier diode has large filter capacitors C1 and C2 to filter out ripple voltage. This voltage is then applied to the inverter full-bridge, inverted to generate a high-frequency AC voltage, which is then transmitted to the secondary side via the high-frequency transformer and finally rectified by the full-wave rectifier to generate DC power for welding.

[0035] The main control circuit includes a main control MCU, an EEPROM (Electronic Epidemic Memory), a dual RS485 interface circuit, a PWM drive circuit interface, an ADC temperature acquisition interface, a multi-channel optocoupler I / O interface, and a USB interface. The main control MCU is connected to the multi-channel temperature acquisition circuit through the ADC temperature acquisition interface. Simultaneously, the PWM drive signal generated by the main control MCU is input to the PWM drive circuit through the PWM drive circuit interface to drive the inverter bridge.

[0036] like Figure 2As shown, the main control MCU is an STM32F407 series microcontroller from STMicroelectronics. Regarding power supply, the PWM drive circuit is equipped with multiple outputs of +3.3V / ±15V / +5V / +24V, sequentially powering the main control MCU, the multi-channel temperature acquisition circuit, the dual RS485 interface circuit, and the multi-channel optocoupler I / O interface circuit. The main control MCU captures temperature signals from the multi-channel temperature acquisition circuit via the ADC (analog-to-digital converter) temperature acquisition interface. The main control circuit is also connected to the PWM drive circuit to transmit PWM signals. The main control circuit features a dual RS485 interface circuit, based on the ADM2483 chip, which converts the main control MCU's serial port TTL level to RS485 level. Through this dual RS485 interface circuit, the main control MCU uses the MODBUS-RTU protocol and a custom communication protocol to complete data reading and writing with the host computer and UI control of the human-machine interface touchscreen, enabling data transfer and parameter updates. The main control circuit is also equipped with a power-down memory chip for storing multiple preset settings parameters, which can be dynamically modified during normal equipment operation. Furthermore, the main control circuit features an integrated optocoupler (TLP521) to implement multiple optocoupler I / O channels, supporting read / write control of various external signals. Its input I / O is used to monitor alarm information from the main circuit during the welding process and start signals from the production line equipment. Simultaneously, its output I / O is used to control external relays and serves as a reserved expansion interface for secondary development of the equipment. Further, the main control circuit is equipped with a USB interface to acquire historical production data for offline browsing. For example, a USB flash drive can be connected to retrieve historical production data for offline viewing, facilitating production management and quality control.

[0037] like Figure 3 As shown, the PWM drive circuit includes a multi-winding transformer, a flyback circuit, and an LDO regulator, supporting multiple DC outputs of +24V, ±15V, +5V, and +3.3V. +24V is used to drive the cooling fan, ±15V powers the multi-channel temperature acquisition circuit, +5V powers the dual RS485 interface circuit, and +3.3V powers the main control MCU. In one embodiment, the PWM drive circuit further includes a two-stage transistor amplifier circuit and a full-bridge inverter MOSFET amplifier circuit. The connection relationships of each component are as follows: (1) Auxiliary power supply section: The 220V AC mains power is connected to the multi-winding transformer after passing through the full-bridge rectifier (model KBL610). The multi-winding transformer is connected to the flyback circuit, which generates a stable +24V DC output voltage. The +24V DC output voltage is input to the LDO regulator, which converts the 24V voltage into ±15V DC output for the subsequent multi-channel temperature acquisition circuit. It is also converted into +3.3V for the main control MCU power supply, and +5V voltage is used for the dual RS485 interface circuit.

[0038] (2) PWM signal driving section: The PWM signal of the main control MCU is connected to the transistor dual-stage amplifier circuit. The transistor dual-stage amplifier circuit is connected to the full-bridge inverter MOSFET. Finally, the output of the full-bridge inverter MOSFET is connected to the isolation transformer to generate the final IGBT drive signal. The IGBT drive signal is input to the four IGBTs of the full-bridge inverter circuit and is mainly used to drive the four IGBTs of the inverter full-bridge.

[0039] like Figure 5 As shown, the multi-channel temperature acquisition circuit includes three differential adjustable amplifier circuits, each with a dual-stage operational amplifier circuit with voltage compensation. The dual-stage operational amplifier circuit includes a front-end INA154 (chip) differential acquisition circuit and a rear-end NE5532 (chip) amplifier circuit. It can individually adapt to up to three types of thermocouples / sensors according to usage requirements. It also includes an access detection circuit for automatic identification and matching of the accessed sensor type. The amplification gain of different thermocouples can be adapted according to the calibration table. It also supports access detection. The main control MCU determines the type of accessed thermocouple based on the detection circuit and displays it on the touch screen. The connection relationship of the above parts is as follows: First, the two differential signal lines of the thermocouple are connected to the two IO channels of the detection circuit. The detection circuit is connected to the three differential adjustable amplifier circuits to amplify the signal before connecting it to the ADC temperature acquisition interface of the main control MCU. This invention allows for switching between different thermocouples based on actual welding and temperature control requirements. For example, in situations where high precision in temperature control and response speed are required, an E-type thermocouple welding head can be used. The welding machine automatically identifies and matches the sensor type and displays the device status and connection type in real time.

[0040] like Figure 4 As shown, the detection circuit includes two I / O channels, each connected to a GPIO pin of the main control MCU. The detection circuit is connected to a three-channel differential adjustable amplifier circuit, which in turn is connected to the main control MCU. After a thermocouple is connected, the detection circuit first determines the connection type, completing thermocouple type identification. Then, the thermocouple signal is transmitted to the three-channel differential adjustable amplifier circuit to complete temperature signal acquisition.

[0041] The main control circuit is equipped with an STM32F407 real-time operating system to manage multiple threads, such as... Figure 6As shown in the diagram, the system can be divided into several threads: startup thread, error handling thread (protection thread), main thread (welding real-time control thread), touchscreen read / write thread (touchscreen control thread), host computer communication thread, monitoring thread, USB read / write thread, and idle thread. The startup process handles the initial configurations during system startup, creates the remaining threads, and then destroys the startup thread, allowing the remaining threads to begin normal operation. The threads are arranged from highest to lowest priority, with the error handling thread having the highest priority. This thread is responsible for timely response to various alarm events, stopping power output, and sending signals to the touchscreen thread. When an alarm is triggered, the thread stops output and controls the touchscreen to jump to the alarm page. The main thread is primarily responsible for real-time temperature control during the welding process and high-precision closed-loop control of real-time temperature data acquisition. The touchscreen read / write thread handles UI read / write / refresh control, parameter refresh, and real-time temperature curve drawing. The host computer communication thread handles data transmission and reading / writing with the host computer. The monitoring thread, USB read / write thread, and idle thread are responsible for monitoring device status, offline storage of USB data, and software resource recycling, respectively.

[0042] The human-computer interaction touchscreen is a capacitive touchscreen, and its parameter settings and related interfaces are as follows: Figures 7-10 As shown: The touchscreen UI is custom-designed and includes parameter setting pages, waveform display pages, alarm pages, temperature curve plotting pages, historical data browsing pages, and other settings pages. Through digital visualization and touch interaction, users can easily set parameters, monitor equipment operation, and observe welding process data.

[0043] The main control circuit connects to the touchscreen and host computer via dual RS485 interfaces, controlling the refresh of the touchscreen UI components and the reading and updating of parameters. It also supports real-time plotting of temperature curves during the welding process. The touchscreen has historical data storage capabilities, supporting online viewing of historical production data and alarm logs.

[0044] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A digital thermocompression welding device compatible with multiple types of sensors, characterized in that: The system includes a main circuit, a main control circuit, a PWM drive circuit, a multi-channel temperature acquisition circuit, a detection circuit, and a human-machine interface touchscreen. The main control circuit is connected to the PWM drive circuit, the multi-channel temperature acquisition circuit, the detection circuit, and the human-machine interface touchscreen. The PWM drive circuit is connected to the main circuit. Users can set parameters on the touchscreen and control the power of the main circuit through the main control circuit to achieve high-precision real-time closed-loop temperature control. The touchscreen also supports real-time temperature data plotting, historical data browsing, multi-sensor switching, and over-temperature, over-voltage, and over-current monitoring functions.

2. The digital thermocompression welding equipment compatible with multiple types of sensors according to claim 1, characterized in that: The main circuit includes a primary full-bridge rectifier diode, an IGBT full-bridge inverter circuit, a high-frequency transformer, and a secondary full-wave rectifier. The output terminal of the primary full-bridge rectifier diode is connected to the inverter full-bridge through a filter capacitor. After inversion, the inverter full-bridge generates a high-frequency AC voltage, which is then transmitted to the secondary side through a high-frequency transformer. Finally, it is rectified by a full-wave rectifier to generate DC power for welding.

3. The digital thermocompression welding equipment compatible with multiple types of sensors according to claim 1, characterized in that: The main control circuit includes a main control MCU, a power-down storage chip, a dual RS485 interface circuit, a PWM drive circuit interface, an ADC temperature acquisition interface, and a multi-channel optocoupler IO interface. The main control MCU generates a PWM drive signal to drive the PWM drive circuit to complete the inverter bridge.

4. The digital thermocompression welding equipment compatible with multiple types of sensors according to claim 3, characterized in that: The PWM drive circuit includes a multi-winding transformer, a flyback circuit, an LDO regulator, a two-stage transistor amplifier circuit, and a full-bridge inverter MOSFET amplifier circuit. The AC mains power is connected to the multi-winding transformer after passing through the full-bridge rectifier. The multi-winding transformer is connected to the flyback circuit, which generates a stable DC output voltage. The DC output voltage is input to the LDO regulator, which converts the DC output voltage into two DC output voltages for powering the multi-channel temperature acquisition circuit. It is also converted into a voltage for powering the main control MCU and the dual RS485 interface circuit. The PWM signal of the main control MCU is connected to the transistor dual-stage amplifier circuit. The transistor dual-stage amplifier circuit is connected to the input terminal of the full-bridge inverter MOSFET. The output of the full-bridge inverter MOSFET is connected to the isolation transformer to generate the final IGBT drive signal. The IGBT drive signal is input to the IGBT full-bridge inverter circuit of the main circuit.

5. The digital thermocompression welding equipment compatible with multiple types of sensors according to claim 1, characterized in that: The multi-channel temperature acquisition circuit consists of three differential adjustable amplifier circuits, each of which is a two-stage operational amplifier circuit with voltage compensation function, and can be individually adapted to up to three types of thermocouples according to usage requirements.

6. The digital thermocompression welding equipment compatible with multiple types of sensors according to claim 5, characterized in that: The two-stage operational amplifier circuit includes a front-end differential acquisition circuit and a rear-end amplification circuit.

7. The digital thermocompression welding equipment compatible with multiple types of sensors according to claim 5, characterized in that: The detection circuit and multi-channel temperature acquisition circuit are used for automatic identification and matching of sensor types. The main control MCU determines the type of thermocouple connected based on the detection circuit and displays it on the touch screen.

8. The digital thermocompression welding equipment compatible with multiple types of sensors according to claim 7, characterized in that: The detection circuit includes two IO channels. The two differential signal lines of the thermocouple are connected to the two IO channels respectively. The thermocouple signal is amplified by a three-way differential adjustable amplifier circuit and then connected to the ADC temperature acquisition interface of the main control MCU.

9. The digital thermocompression welding equipment compatible with multiple types of sensors according to claim 1, characterized in that: The main control circuit is equipped with an STM32F407 real-time operating system to manage multiple threads, including a startup thread, an error handling thread, a main thread, a touch screen read / write thread, a host computer communication thread, a monitoring thread, a USB read / write thread, and an idle thread.

10. A digital thermocompression welding device compatible with multiple types of sensors according to claim 1, characterized in that: The touchscreen is a capacitive touchscreen, which includes a parameter setting page, a waveform display page, an alarm page, a temperature curve plotting page, a historical data browsing page, and other settings pages, and uses digital visualization to display touch interaction.

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