Based on surface mount products virtual assembly technology,the solder joint reliability of plastic ball grid array (PBGA) was studied. Four process parameters,including the upper pad diameter,the stencil thickness,th...Based on surface mount products virtual assembly technology,the solder joint reliability of plastic ball grid array (PBGA) was studied. Four process parameters,including the upper pad diameter,the stencil thickness,the chip weight on a single solder joint and the lower pad diameter were chose as four control factors. By using an L25(56) orthogonal array the PBGA solder joints which have 25 different process parameters’ levels combinations were designed. The numerical models of all the 25 PBGA solder joints were developed and the finite element analysis models were setup. The stress and strain distribution within the PBGA solder joints under thermal cycles were studied by finite element analysis,and the thermal fatigue life of PBGA solder joint was calculated using Coffin-Manson equation. Based on the calculated thermal fatigue life results,the range analysis was performed. The results of study show that that the impact sequence of the four factors from high to low on the fatigue life of PBGA solder joints are the stencil thickness,the upper pad diameter,the lower pad diameter and the chip weight on a single solder joint; the best level combination ofprocess parameters that results in the longest fatigue life is the lower pad diameter of 0.6 mm,the stencil thickness of 0.175 mm,the chip weight on asingle solder joint of 28×10 -5 N and the upper pad diameter of 0.5 mm.展开更多
Nanoindentation test is performed on study the plastic and creep properties of the Sn-Ag-Cu （SAC） lead-free ball grid array （ BGA ） solder joints. The dynamic hardness of two kinds of solder joints decreases with ...Nanoindentation test is performed on study the plastic and creep properties of the Sn-Ag-Cu （SAC） lead-free ball grid array （ BGA ） solder joints. The dynamic hardness of two kinds of solder joints decreases with indentation depth increase. SACO705 BiNi/ Cu exhibits a higher ultimate dynamic hardness and a smaller indentation depth than SAC305/ Cu. Then the strain hardening phenomenon of SAC305/ Cu is more obvious compared to that of SACO705 BiNi/ Cu. The indentation creep of SACO705BiNi/ Cu solder joint is lower than that of SAC305/ Cu solder joint before and after thermal shock. The creep rate sensitive index of SACBiNi/Cu solder joint is lower than that of solder joint. SACO705BiNi/Cu solder joint is superior to SAC305/Cu solder joint in the anti-creep property. The plasticity of SACOTOSBiNi/Cu and SAC305/Cu solder joints are similar. Compared with SAC305 solder, the SACO705 BiNi solder pe^forms higher hardness and solder creep resistance and still maintains a good plasticity.展开更多
基金Funded by Science Foundation of Guangxi Zhuang Autonomous Region (No.02336060) .
文摘Based on surface mount products virtual assembly technology,the solder joint reliability of plastic ball grid array (PBGA) was studied. Four process parameters,including the upper pad diameter,the stencil thickness,the chip weight on a single solder joint and the lower pad diameter were chose as four control factors. By using an L25(56) orthogonal array the PBGA solder joints which have 25 different process parameters’ levels combinations were designed. The numerical models of all the 25 PBGA solder joints were developed and the finite element analysis models were setup. The stress and strain distribution within the PBGA solder joints under thermal cycles were studied by finite element analysis,and the thermal fatigue life of PBGA solder joint was calculated using Coffin-Manson equation. Based on the calculated thermal fatigue life results,the range analysis was performed. The results of study show that that the impact sequence of the four factors from high to low on the fatigue life of PBGA solder joints are the stencil thickness,the upper pad diameter,the lower pad diameter and the chip weight on a single solder joint; the best level combination ofprocess parameters that results in the longest fatigue life is the lower pad diameter of 0.6 mm,the stencil thickness of 0.175 mm,the chip weight on asingle solder joint of 28×10 -5 N and the upper pad diameter of 0.5 mm.
基金This work was supported by National Natural Science Foundation of China （ Grant No. 51174069 and 51075107） and Research Special Funds for Technology Creative Talents of Harbin （Grant No. 2013RFQXJ166）.
文摘Nanoindentation test is performed on study the plastic and creep properties of the Sn-Ag-Cu （SAC） lead-free ball grid array （ BGA ） solder joints. The dynamic hardness of two kinds of solder joints decreases with indentation depth increase. SACO705 BiNi/ Cu exhibits a higher ultimate dynamic hardness and a smaller indentation depth than SAC305/ Cu. Then the strain hardening phenomenon of SAC305/ Cu is more obvious compared to that of SACO705 BiNi/ Cu. The indentation creep of SACO705BiNi/ Cu solder joint is lower than that of SAC305/ Cu solder joint before and after thermal shock. The creep rate sensitive index of SACBiNi/Cu solder joint is lower than that of solder joint. SACO705BiNi/Cu solder joint is superior to SAC305/Cu solder joint in the anti-creep property. The plasticity of SACOTOSBiNi/Cu and SAC305/Cu solder joints are similar. Compared with SAC305 solder, the SACO705 BiNi solder pe^forms higher hardness and solder creep resistance and still maintains a good plasticity.
