本實驗選用Sn-xNi (x=0.2, 0.5, 1 wt.%)和SAC105四種不同無鉛銲錫合金應用於光伏模組上。實驗分為兩部份，首先為銲錫合金顯微組織觀察、熔點量測和拉伸性質分析；第二部份為銲錫合金應用於光伏模組，以剝離力測試和回銲界面微觀組織觀察，進而評估銲錫合金於光伏模組的適用性。並以高電流加速實驗測試，藉以模擬實際應用界面IMC變化對光伏模組體電組之影響。
由微觀組織觀察和拉伸測試發現，Sn-1Ni銲錫合金具有較密且針棒狀第二相，使得其YS、UTS和TE均比SAC105銲錫合金高。並藉由熔點量測評估應用於光伏模組的回銲溫度，再以剝離力測試評估光伏模組接合強度。以相同條件回銲後，因Sn-1Ni/Ag界面之Ag濃度梯度比SAC105f/Ag界面大，導致其剩餘銀膠層較薄 (7.4μm<8.6μm)。回銲後Sn-1Ni/Cu界面形成厚 (2.2μm)且高電阻的(Cu,Ni)6Sn5，故Sn-1Ni光伏模組體電組大於SAC105f (0.030Ω>0.028Ω)。經高電流通電72小時後， Sn-1Ni/Cu界面的(Cu,Ni)6Sn5可有效減緩Cu3Sn的生成及IMC的成長 (2.3μm)，但所有純銀層皆以消耗完畢；SAC105f/Cu界面形成Cu6Sn5 (2.0μm)和Cu3Sn (2.1μm)的IMC，雖然於回銲時可有效抑制銀膠層的消耗，但長時間通電後所有純銀層皆轉變成Ag3Sn。然而Sn-1Ni光伏模組雖然可以抑制IMC成長，但在浸鍍及回銲製程即形成高電阻IMC界面，故其體電組仍較高。因此選擇低Ni含量銲錫合金 (Sn-0.2Ni)在長時間通電後，可抑制Cu3Sn相的生成且形成較薄的IMC界面 (由熱浸鍍Solder/Cu界面解析中，可發現Sn-0.2Ni具有較薄 (1.7μm)的IMC層)。故Sn-0.2Ni為最低體電組的光伏模組，其具有低成本和市場應用潛力。

The lead-free solders of Sn-1Ag-0.5Cu (SAC105) and Sn-xNi (x = 0.2, 0.5, 1 wt.%) were used in photovoltaic (PV) ribbons in this study that included two parts. First, the properties of solders contained microstructure, melting point and mechanical properties. Second part, the applicability of solders in PV module assessed their applicability by peeling test and interface microstructure. In order to accelerate experiment with high current density, which simulated the actual application how the interface transition of IMC affected the volume resistance of PV modules.
After the electric test with high current density for 72 hours, all of silver layer transformed into Ag3Sn in positive zone. The formation of (Cu,Ni)6Sn5 at Sn-1Ni/Cu interface was prevented the formation of Cu3Sn and retarded the growth of IMC during the electric test. Although the PV ribbon of Sn-1Ni could inhibit the growth of IMC, but the thickness of IMC formed was larger during dipping and reflowing process, so the PV module of Sn-1Ni was still high volume resistance after electric test for 72 hours. Therefore, the addition of low Ni content PV ribbons could inhibit the generation of Cu3Sn phase and the thinness of IMC formed at Solder/Cu interface, so the photovoltaic module of Sn-0.2Ni had the lowest volume resistance than other PV modules. In terms of cost and application considerations for the PV ribbons of Sn-0.2Ni had potential.

Keywords: Sn-Ni, Sn-Ag-Cu, Photovoltaic module, IMC

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