Temperature control method of hot bar bonder based on dynamic compensation for thermocouple

A temperature control method for hot bar bonder was proposed to avoid temperature overshoot, improve stability of temperature control and achieve smooth temperature curves. Time constant of thermocouple was identified based on dynamic response characteristics of thermocouple and its identification value can be adjusted during the welding process. The output signal of thermocouple was compensated in real time using dynamic compensation technology for thermocouple, so that the actual temperature of the heater tip can be estimated and the compensation value was used in feedback control. Tests on the temperature control system showed that, compared with conventional PID algorithm, the temperature curve obtained with the proposed method was smooth with fast heating up speed and temperature overshoot was suppressed effectively with satisfied temperature control.