PEM老炼过程中的温度闭环控制系统

Closed-loop temperature control system for a PEM during burn-in

当前,老炼仍被广泛应用于塑封微电路(PEM)的可靠性保证。为了解决老炼过程中存在的热失控及温度不一致的问题,该文设计了一套温度闭环控制系统。在由老炼箱自身装置提供箱内基础温度的基础上,设计的温度闭环控制系统以每个封装夹具内的微环境为控制对象,采用模糊自适应算法,最优配置比例积分(PI)控制器的控制参数,最终驱动执行器,对被老炼器件及时加热或散热。通过试验证实,老炼过程中加入温度闭环控制系统后,被测器件的温度在更短的时间内(20min)达到稳态,稳态精度控制在1℃以内,且被测器件温度的差异由2℃降低到基本一致。而后,当系统采用模糊自适应控制算法后,系统的动态响应时间更短,抗干扰能力更强。因此,该系统达到了防止器件热失控及保证不同器件间温度一致的目的。

The plastic encapsulated microcircuits（PEM）burn-in method helps guarantee the reliability of PEM.Thermal runaway and uneven temperatures between different devices during burn-in are controlled by a closed-loop temperature control system.The control system adjusts the temperature of each burn-in socket relative to the oven temperature using a fuzzy adaptive algorithm to configure the control parameters of the PI controller that drives the heating or cooling actuators.The device temperature more quickly achieves steady state（20min）with steady state errors of less than1℃ and the temperature differences between the tested devices are reduced by 2℃so that the temperature are almost the same with the closed-loop temperature control system. The fuzzy adaptive algorithm makes the system dynamic response much faster with stronger anti-interference ability. Thus,this system prevents thermal runaway and makes the temperatures equal between the different tested devices.