To reveal the drop failure modes of the wafer level chip scale packages （WLCSPs） with Sn-3.0Ag-0.5Cu solder joints, board level drop tests were performed according to the JEDEC standard. Six failure modes were iden...To reveal the drop failure modes of the wafer level chip scale packages （WLCSPs） with Sn-3.0Ag-0.5Cu solder joints, board level drop tests were performed according to the JEDEC standard. Six failure modes were identified, i.e., short FR-4 cracks and complete FR-4 cracks at the printing circuit board （PCB） side, split between redistribution layer （RDL） and Cu under bump metallization （UBM）, RDL fracture, bulk cracks and partial bulk and intermetallic compound （IMC） cracks at the chip side. For the outmost solder joints, complete FR-4 cracks tended to occur, due to large deformation of PCB and low strength of FR-4 dielectric layer. The formation of complete FR-4 cracks largely absorbed the impact energy, resulting in the absence of other failure modes. For the inner solder joints, the absorption of impact energy by the short FR-4 cracks was limited, resulting in other failure modes at the chip side.展开更多
A new self-adaptive phosphor coating technology has been successfully developed, which adopted a slurry method combined with a self-exposure process. A phosphor suspension in the water-soluble photoresist was applied ...A new self-adaptive phosphor coating technology has been successfully developed, which adopted a slurry method combined with a self-exposure process. A phosphor suspension in the water-soluble photoresist was applied and exposed to LED blue light itself and developed to form a conformal phosphor coating with self- adaptability to the angular distribution of intensity of blue light and better-performing spatial color uniformity. The self-adaptive phosphor coating technology had been successfully adopted in the wafer surface to realize a wafer- level scale phosphor conformal coating. The first-stage experiments show satisfying results and give an adequate demonstration of the flexibility of self-adaptive coating technology on application of WLSCP.展开更多
5G时代的到来将通信系统的工作频段推入毫米波波段,这给毫米波器件的封装带来了挑战.5G系统需要将射频、模拟、数字功能和无源器件以及其他系统组件集成在一个封装模块中,这个要求恰恰体现了异质异构集成的特征.在所有的异质异构集成解...5G时代的到来将通信系统的工作频段推入毫米波波段,这给毫米波器件的封装带来了挑战.5G系统需要将射频、模拟、数字功能和无源器件以及其他系统组件集成在一个封装模块中,这个要求恰恰体现了异质异构集成的特征.在所有的异质异构集成解决方案中,2.5D/3D系统级封装(System in Package,SiP)因其高度集成化被视为解决5G系统封装的重要突破口.文章以SiP为切入口,着重介绍了未来5G封装发展重点的2.5D/3D SiP技术以及目前备受瞩目的Chiplet技术.基于5G毫米波器件的系统级封装解决方案,探讨了适用于毫米波器件封装的基板材料以及SiP所需的先进封装技术.最后,针对5G天线模块的封装,介绍了片上天线和封装天线两种解决方案.展开更多
基金Projects(51475072,51171036)supported by the National Natural Science Foundation of China
文摘To reveal the drop failure modes of the wafer level chip scale packages （WLCSPs） with Sn-3.0Ag-0.5Cu solder joints, board level drop tests were performed according to the JEDEC standard. Six failure modes were identified, i.e., short FR-4 cracks and complete FR-4 cracks at the printing circuit board （PCB） side, split between redistribution layer （RDL） and Cu under bump metallization （UBM）, RDL fracture, bulk cracks and partial bulk and intermetallic compound （IMC） cracks at the chip side. For the outmost solder joints, complete FR-4 cracks tended to occur, due to large deformation of PCB and low strength of FR-4 dielectric layer. The formation of complete FR-4 cracks largely absorbed the impact energy, resulting in the absence of other failure modes. For the inner solder joints, the absorption of impact energy by the short FR-4 cracks was limited, resulting in other failure modes at the chip side.
基金supported by the Guangdong Province Scientific Research Program(Nos.2011B090400083,2011A081301019)
文摘A new self-adaptive phosphor coating technology has been successfully developed, which adopted a slurry method combined with a self-exposure process. A phosphor suspension in the water-soluble photoresist was applied and exposed to LED blue light itself and developed to form a conformal phosphor coating with self- adaptability to the angular distribution of intensity of blue light and better-performing spatial color uniformity. The self-adaptive phosphor coating technology had been successfully adopted in the wafer surface to realize a wafer- level scale phosphor conformal coating. The first-stage experiments show satisfying results and give an adequate demonstration of the flexibility of self-adaptive coating technology on application of WLSCP.
文摘5G时代的到来将通信系统的工作频段推入毫米波波段,这给毫米波器件的封装带来了挑战.5G系统需要将射频、模拟、数字功能和无源器件以及其他系统组件集成在一个封装模块中,这个要求恰恰体现了异质异构集成的特征.在所有的异质异构集成解决方案中,2.5D/3D系统级封装(System in Package,SiP)因其高度集成化被视为解决5G系统封装的重要突破口.文章以SiP为切入口,着重介绍了未来5G封装发展重点的2.5D/3D SiP技术以及目前备受瞩目的Chiplet技术.基于5G毫米波器件的系统级封装解决方案,探讨了适用于毫米波器件封装的基板材料以及SiP所需的先进封装技术.最后,针对5G天线模块的封装,介绍了片上天线和封装天线两种解决方案.
