扫频调幅式真空镀膜电源设计与实现

Novel Type of Power Supply for Mid-Frequency Induction Heater in Industrial Thin Film Deposition Reactor

准确控制真空镀膜电源的输出功率,确保镀膜厚度一致是镀膜工艺的关键。本文针对现有中频感应加热电源采用移相控制存在的诸多问题,如调整开关频率会引起负载阻抗和相位的强烈变化,造成功率控制不准确、功率因数低、装置繁琐、单体设备无法级联等缺陷。提出了采用扫频调幅控制策略实现,并完成了实际产品的研制。结果表明,采用扫频调幅控制策略实现的真空镀膜电源具有效率高、功率精准控制、加热均匀等优点。

We reported the solution of the control problems of conventional power supply for mid-frequency induction heating in industrial thin film deposition reactor： including the low control accuracy, great current distortion, small power factor, large fluctuations of load resistance and phase, complicated control unit, incapability of cascading individual power supply, and importantly, non-uniform thickness. The solution was the modification of the conventional phase-shift frequency control with the frequency-sweeping amplitude-modulation control. The prototyped power supply with the modified control scheme has been field tested for over 3 years. The results show that the newly-developed power supply outperforms the conventional one because of higher control procession, lower distortion, more uniform heating and film thickness, greater productivity, and importantly, capability of cascading multiple power supplies as required. We suggest the new power supply be of some technological interest in coating industries.