本論文主要以無電鍍方式鍍製擴散阻障層於n型鉍碲材(Bi2Te2.55Se0.45)料上，探討無電鍍鎳磷層與n型鉍碲材料、無鉛銲料的界面反應，分析生成的介金屬化合物，討論錫、鎳、碲原子於界面處的擴散情形。以SEM觀察多次迴銲於270 oC持溫30秒的界面形貌，與長時間熱處理下介金屬化合物的生長狀況。利用EPMA定量分析鑑定生成相的組成，線掃描觀察無電鍍鎳磷層阻擋各原子擴散的情形。以慢速推力機檢測多孔性碲化錫對於機械性質的關係，量化銲接點的機械強度，並評估無電鍍鎳磷層對於熱電裝置是否有影響，最後比較與p型熱電(Bi0.25Sb0.75)2Te3於推力強度上的差異。 實驗結果顯示，沒有鍍製擴障層的試片在長時間退火下生成的碲化錫會隨退火時間增長而加厚，而在鍍製鎳磷層的試片中並無發現碲化錫的生長，除此之外迴銲後的反應界面有相當大的差異。線掃描的結果顯示錫與碲原子皆被無電鍍鎳磷層擋住，因而無碲化錫相的生成，且經15天退火的試片依然有相同結果。而推力測試的部分，有鍍製鎳磷層的機械強度表現皆較佳，且破壞界面由碲化錫界面轉移至銲料中，表示無電鍍鎳磷層可藉由抑止碲化錫的生長，進而增強熱電裝置的機械性質。與p型熱電推力結果比較，發現與n型有相同的結果，無電鍍鎳磷層對於p型熱電也有助益。因此，以無電鍍鎳磷層對於鉍碲材料來說除了能做為有效的擴散阻障層的同時，亦提升了系統的機械性質。 ;In electronic packaging, plating a diffusion barrier is commonly way to prevent the formation of undesirable intermetallic compounds (IMCs), and Nickel have known as an effective diffusion barrier to block the diffusion of Sn atoms. In this study, electroless Ni-P act as a diffusion barrier in lead-free solders/Bi2Te2.55Se0.45 system to obstruct the formation of SnTe. After multiple-reflowing and aging, the different IMCs form at the interface would be observed by scanning electron microscope (SEM). The composition of IMCs and the diffusion profile of Sn atoms would be revealed in quantitative analysis and line scanning conducted by electron probe x-ray microanalyzer (EPMA), respectively. Shear test is applied to investigate the mechanical property attributed to porous SnTe IMCs and the effect of electroless Ni-P plating. The results elucidate no SnTe layer is observed after electroless Ni-P depositing. Based on line scanning analysis, Sn atoms is obstructed by Ni-P layer and result in the prohibition of forming SnTe IMCs. In shear test, shear strength is significant improving for Ni-P depositing samples. Moreover, the ball grid array (BGA) fractured from the interface between solder and Bi2Te2.55Se0.45 into solder. It is implied that electroless Ni-P enhance the mechanical properties of Bi2Te2.55Se0.45 due to the lack of SnTe IMCs. Thus, electroless Ni-P plating is an effective diffusion barrier for lead-free solders/Bi2Te2.55Se0.45 systems and improve the mechanical properties of systems.
