印刷线路板振动拆解模型及其拆解过程分析

The Disassembly Model and Its Analysis of PCB by Vibration

废弃印刷线路板(Printed circuit boards,PCB)上的元器件具有较高的重用价值,而元器件的重用是基于合理的线路板拆解工艺的。目前相关研究多关注拆解力的分析和计算,然而由于拆解时元器件与线路板间存在熔融状态的焊料,即便提供足够大的拆解力也难以保证元器件被拆解。在基于已建立的拆解力模型,提出综合考虑拆解力和元器件分离位移的拆解能作为拆解准则,并基于这一准则研究了垂直振动激励下元器件的拆解分离过程,分析了废弃线路板在对边简支对边自由的边界条件下强迫振动的模态,基于薄板振动理论建立PCB的运动微分方程,获得PCB的加速度及位移响应;分析了垂直振动拆解中贴片元器件和插装元器件的不同分离过程,并且采用拆解能模型对不同拆解激振频率、位于线路板不同位置、具有不同最小拆解加速度的元器件进行拆解分析;提出以拆解能图来比较元器件实际获得的拆解能与所需的最小拆解能,为拆解工艺参数的确定提供依据。最后在试验中验证拆解能模型的正确性。

Components on waste printed circuit boards （PCB） are worthy reusing. Moreover components reusing is depended on appropriate PCB disassembly. At present researchers focus on the analysis and calculation of removal force. However, as there are melted solder between components and PCB when disassembling, even enough removal force cannot guarantee that components can be disassembled. Based on the removal force model put forward by our research group, the disassembly energy which takes both removal force and components separating displacement into account is treated as the disassembly criterion. According to it, the disassembly process under vibration is researched, the PCB modal on the condition of opposite side simply supported and the other opposite free is analyzed, based on the vibration plate theory PCB movement differential equation is built and PCB displacement and acceleration response is got. Separating process of through-hole devices and surface-mount devices under vertical disassembly is studied, and component disassembly is analyzed in situations of different excitation frequency, different location in PCB, components having different minimum disassembly acceleration. Disassembly figure method is proposed to compare the energy components get in disassembly process and the minimum energy components need, which will give a guild to disassembly parameters. At last, experiments are performed to prove the disassembly model.