| 摘要: | 本研究主要討論Sn-3.0Ag-0.5Cu銲料分別與四種無電鍍鈷系統之界面反應，並探究其表面形貌之改變與相變化。此無電鍍鈷系統包含無電鍍鈷(Electroless Cobalt，EC)、無電鍍鈷/浸金(Electroless Cobalt/Immersion Gold，ECIG)、無電鍍鈷/無電鍍鈀(Electroless Cobalt/Electroless Palladium，ECEP)及無電鍍鈷/無電鍍鈀/浸金(Electroless Cobalt/Electroless Palladium/Immersion Gold，ECEPIG)等，其中無電鍍鈷層內含有磷及微量的鎢元素，即Co(W,P)。
實驗結果顯示，系統添加鈀層之後，不僅改變介金屬化合物之表面形貌，更引致(Co,Cu,Pd)Sn3發生大規模剝離。在Co(W,P)消耗完之後的迴銲過程，高的界面能及厚的介金屬化合物，造成(Co,Cu,Pd)Sn3內部產生壓應力。因此，藉由彎曲釋放內部壓應力，可能為引致(Co,Cu,Pd)Sn3發生大規模剝離之驅動力。
This study investigates the interfacial reactions and microstructures of SAC305 solders on four different Co-based surface finishes, electroless Co(W,P) (EC), electroless Co(W,P)/immersion Au (ECIG), electroless Co(W,P)/electroless Pd (ECEP), and electroless Co(W,P)/electroless Pd/immersion Au (ECEPIG). The evolution of microstructure at different reflow conditions revealed that Pd layer not only changed the morphology of the intermetallic compound but also generated higher interfacial energy between solders and Co-based substrates. High interfacial energy and thick reaction phase could induce compressive stress within the (Co,Cu,Pd)Sn3 layer during the reflow process after exhausting Co(W,P). The reduction of the stress could be the possible driving force for massive spalling of the (Co,Cu,Pd)Sn3 intermetallic compound. |
