The effects of adding small amounts of cerium(Ce) to Sn-3.3 Ag-0.2 Cu-4.7 Bi solder on microstructure,wettability characteristic,interfacial morphology and the growth of interfacial intermetallic compound(IMC) during ...The effects of adding small amounts of cerium(Ce) to Sn-3.3 Ag-0.2 Cu-4.7 Bi solder on microstructure,wettability characteristic,interfacial morphology and the growth of interfacial intermetallic compound(IMC) during thermal cycling were investigated by optical microscopy(OM),scanning electron microscopy(SEM) and solderability tester.It is found that the p-Sn phase,Ag_(3)Sn phase and Cu6 Sn5 phase in the solder are refined and the wetting force increases.Ce is an active element;it more easily accumulates at the solder/flux interface in the molten state,which decreases the interfacial surface energy and reduces the driving force for IMC formation on Cu substrate;therefore,the thickness of IMC at the solder/Cu interface decreases when appropriate Ce was added into the solder.Moreover,the Ce-containing solders have lower growth rate of interfacial IMC than solders without Ce during the thermal cycling between-55 and 125℃.When the Ce content is 0.03 wt% in the Sn-3.3 Ag-0.2 Cu-4.7 Bi solder,the solder has the best wettability and the minimum growth rate of interfacial IMC layer.展开更多
The effects of bump shape on the aging resistance and mechanical properties of Sn3.0 Ag0.5 Cu(SAC)solder bump joints were investigated by high-temperature aging test and shear test.Three different SAC solder bump join...The effects of bump shape on the aging resistance and mechanical properties of Sn3.0 Ag0.5 Cu(SAC)solder bump joints were investigated by high-temperature aging test and shear test.Three different SAC solder bump joints with barrel type,cylinder type,and hourglass type,respectively,were provided by controlling solder process.The results indicate that as the bump volume decreases from barrel bump to hourglass bump in the reflow,the thickness growth rate of intermetallic compounds(IMCs)between different solder joints and Cu substrates in the isothermal aging of 150℃decreases.And the change of shear strength of hourglass interconnection solder joint with the increase in temperature is the minimum in the three interconnection solder joints.Thus,as the solder dosage decreases properly,hourglass interconnection solder joint is obtained,which is avail to enhance the solder joint reliability at the high-temperature aging and the ability to adapt to the change of environment temperature suddenly.展开更多
基金financially supported by the National Science and Technology Major Project of China(No.2011ZX02607)。
文摘The effects of adding small amounts of cerium(Ce) to Sn-3.3 Ag-0.2 Cu-4.7 Bi solder on microstructure,wettability characteristic,interfacial morphology and the growth of interfacial intermetallic compound(IMC) during thermal cycling were investigated by optical microscopy(OM),scanning electron microscopy(SEM) and solderability tester.It is found that the p-Sn phase,Ag_(3)Sn phase and Cu6 Sn5 phase in the solder are refined and the wetting force increases.Ce is an active element;it more easily accumulates at the solder/flux interface in the molten state,which decreases the interfacial surface energy and reduces the driving force for IMC formation on Cu substrate;therefore,the thickness of IMC at the solder/Cu interface decreases when appropriate Ce was added into the solder.Moreover,the Ce-containing solders have lower growth rate of interfacial IMC than solders without Ce during the thermal cycling between-55 and 125℃.When the Ce content is 0.03 wt% in the Sn-3.3 Ag-0.2 Cu-4.7 Bi solder,the solder has the best wettability and the minimum growth rate of interfacial IMC layer.
基金financially supported by the National Science and Technology Major Project of China(No.2011ZX02607)。
文摘The effects of bump shape on the aging resistance and mechanical properties of Sn3.0 Ag0.5 Cu(SAC)solder bump joints were investigated by high-temperature aging test and shear test.Three different SAC solder bump joints with barrel type,cylinder type,and hourglass type,respectively,were provided by controlling solder process.The results indicate that as the bump volume decreases from barrel bump to hourglass bump in the reflow,the thickness growth rate of intermetallic compounds(IMCs)between different solder joints and Cu substrates in the isothermal aging of 150℃decreases.And the change of shear strength of hourglass interconnection solder joint with the increase in temperature is the minimum in the three interconnection solder joints.Thus,as the solder dosage decreases properly,hourglass interconnection solder joint is obtained,which is avail to enhance the solder joint reliability at the high-temperature aging and the ability to adapt to the change of environment temperature suddenly.
