废旧电路板元器件分离位移模型研究

在焊料加热熔化的前提下，电子元器件拆解取决于在拆解外力作用下元器件相对电路板基板产生的位移即元器件分离位移。首先建立水平拆解和垂直拆解两种方式下不同元器件的分离位移模型；然后重点针对3种典型类型元器件引脚下的焊料在垂直拆解时的断裂高度进行分析，基于牛顿静压力方程和拉普拉斯方程建立了焊料断裂高度的数学模型，并通过实验验证了模型的正确性。废旧电路板上元器件分离位移模型对于确定拆解工艺参数具有重要价值。

Study on Separating Displacement Models for Component from Waste Printed Circuit Board

Under conditions of melt solder, whether components might be disassembled was decided by the separating distance between components and the substrate (named as separating displacement) caused by removal force. Firstly, the models of separating displacement for surface mount devices (SMD) and through-hole devices (THD) were established under the conditions of vertical disassembly and horizontal disassembly. Secondly, based on the Laplace equation and the Newton’s equation for hydrostatic pressure, tensile breaking height of solder was analyzed and modeled in vertical disassembly for 3 typical kinds of components and the programmed algorithm was elaborated in detail. Finally, to verify the models for tensile breaking height of the melted solder, based on SMD with mounting base experiments were performed and the results show that the models for tensile breaking height are effective for melting solder. Models of separating displacements for components will be helpful to quantify the distance between components and the substrate, which is helpful for preparing the dismantling process of waste PCBs.