For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarc...For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time, a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach was implemented to minimize the time of nozzle changing. And then, to minimize picking time, an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally, in order to shorten pick-and-place time, a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM. The experimental results were used to analyse the assembly line performance.展开更多
随着通讯技术的发展,阵列天线的应用导致环行器的需求量迅猛增加。为适应微波组件集成化的批量生产工艺要求,急需解决环行器表面贴装技术难题。环行器实现表贴结构形式,通常有三种工艺途径,即低温共烧(LTCF)、MENS和多层印制电路板(PCB...随着通讯技术的发展,阵列天线的应用导致环行器的需求量迅猛增加。为适应微波组件集成化的批量生产工艺要求,急需解决环行器表面贴装技术难题。环行器实现表贴结构形式,通常有三种工艺途径,即低温共烧(LTCF)、MENS和多层印制电路板(PCB)叠片工艺。阐述了8 mm多层PCB结构表贴式环行器的设计。采用带状线环行器的设计方案,电路制作在印制电路板上,利用多层PCB工艺进行制作。为了形成一体化,电路两面用金属化过孔连接。信号通过金属化过孔引到底面与端口线连接,形成表贴结构。通过仿真优化,在27~30 GHz的频率范围内,器件的损耗小于0.83 d B,隔离度大于15.5 d B,输入端口电压驻波比小于1.63。展开更多
文摘For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time, a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach was implemented to minimize the time of nozzle changing. And then, to minimize picking time, an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally, in order to shorten pick-and-place time, a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM. The experimental results were used to analyse the assembly line performance.
文摘随着通讯技术的发展,阵列天线的应用导致环行器的需求量迅猛增加。为适应微波组件集成化的批量生产工艺要求,急需解决环行器表面贴装技术难题。环行器实现表贴结构形式,通常有三种工艺途径,即低温共烧(LTCF)、MENS和多层印制电路板(PCB)叠片工艺。阐述了8 mm多层PCB结构表贴式环行器的设计。采用带状线环行器的设计方案,电路制作在印制电路板上,利用多层PCB工艺进行制作。为了形成一体化,电路两面用金属化过孔连接。信号通过金属化过孔引到底面与端口线连接,形成表贴结构。通过仿真优化,在27~30 GHz的频率范围内,器件的损耗小于0.83 d B,隔离度大于15.5 d B,输入端口电压驻波比小于1.63。
