【摘要】 热压焊是一种应用于电子元器件的焊接方法，热压焊头温度的稳定性是焊接质量的决定性因素。热压焊接时间短，热电偶测温热惯性及随机噪声对热压焊过程温度控制有较大影响。文中研制了一种以STM32F407微处理器为核心的热压焊电源，设计了电源的主电路与控制系统；通过对热电偶的延迟响应和时间常数误差的分析，设计了一种基于扩展卡尔曼滤波器（EKF）的热压焊控制方法，实现了脉宽调制以及输出温度的稳定控制；分析了热压焊头的加热和热辐射效应，建立了热压焊头的温度模型，并以上述的主电路和控制方案为基础，建立了热压焊系统仿真模型，验证控制方法的有效性。搭建热压焊系统试验平台，按照仿真模型设定的工艺参数进行试验，将仿真温度波形与试验测量波形进行对比分析。结果表明：仿真与试验温度波形趋势呈现相同变化规律，相较于仅PID控制，基于EKF的控制方法具有更短的调节时间，减少了有效噪声对热压焊系统的影响，提高了温度控制的稳定性；该热压焊系统仿真模型为热压焊电源设计提供了一种参考模型；最后进行了FPC与PCB板、同轴线与LED电路板热压焊试验，实现了元器件的可靠连接。更多还原

【Abstract】 Hot bar soldering is a method used to connect electronic components. The stability of soldering horn temperature is the decisive factor of soldering quality. Due to the short time of hot bar soldering, the thermal inertia and random noise of thermocouple measurement have a great influence on the temperature control of the process.This paper developed a hot bar soldering power supply with STM32F407 microprocessor as the core, and designed the main circuit and control system of the power supply. By analyzing the delay response and time constant error of the thermocouple, this paper designed a new control method of hot bar soldering based on an Extended Kalman Filter(EKF) state observer, which realizes pulse width modulation and stable control of soldering temperature. It also analyzed the heating and thermal radiation effects of the heater tip, established a temperature model of the heater tip, and developed a simulation model of the hot bar soldering system based on the above main circuit and control scheme to verify the effectiveness of the control methods. A testing platform for the hot bar soldering system was built, and experiments were conducted according to the process parameters set by the simulation model. The simulated temperature waveform was compared and analyzed with the measured waveform. The results show that the trend of the simulated and tested temperature waveforms follows the same pattern. Compared to only using PID control, the control method based on EKF achieves a shorter adjustment time, reduces the impact of effective noise on the hot bar soldering system, and improves temperature control stability. The simulation model of the hot bar soldering system provides a reference model for the design of the hot bar soldering power supply. Finally, the hot bar soldering tests of FPC and PCB board, coaxial cable and LED circuit board were carried out to achieve the reliable connection of the components.更多还原