Disassembling approaches and quality assurance of electronic components mounted on PCBs

Disassembly is essential when components on retired PCBs are treated separately to increase the total income of reutilization. By comparing structural characteristics, value distribution and disassembling difficulty of various components, our research set two goals for PCB disassembly: one is to resume functional value of some SMT components with high density of function and the other is to retrieve material value of the rest components. Correspondingly, disassembling approaches can be classified into two categories: quality ensured disassembly for the first goal and destructive disassembly for the second goal. Simultaneous approaches are expected to cut down on cost and time consumption of quality ensured disassembly. However, simultaneous disassembly tends to cause more failures on components than stepwise disassembly. To provide reference for adapting approaches and equipments to simultaneous disassembly, several modes of mechanical failure of disassembled components and their causes are presented based on testing and analysis. We also present a design on adapting the air heating approach to simultaneous disassembly and discuss benefits of applying disassembly in material retrieval of PCBs.