The Manufacturing Process and Reliability Investigations of Si/Ta/TaCu/Cu/Ni-P/Sn-Pb Solder Bump

• Main Authors: Chen-Chi Hou, 侯振祺
• Other Authors: Kwang-Lung Lin
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/36041587676822730818

碩士 === 國立成功大學 === 材料科學及工程學系 === 89 === This research mainly investigated the solder bump structure of Si/Ta/TaCu/Cu/Ni-P/Sn-Pb, and integrated the best process parameter. First, we used the photolithography and alignment process to define the circle shape of which the diameter is 80 μm as a sputtering pad, then deposited the amorphous Electroless Ni-P alloy as a diffusion barrier layer which prevent the interdiffusion of Copper and Tin to form the intermetallic compoud. And the solder bump was eutectic Sn-Pb alloy which formed by plating and reflow process. This research also investigated the stability of the electroless Ni-P deposited solution and Sn-Pb plating solution. Finally, high temperature aging and temperature-humidity testing were applied to investigate the reliability of the producted solder bump. The intermetallic compound (IMC) Ni3Sn4 formed at the interface between Ni-P layer and Sn-Pb alloy after reflow. The compounds are of needle and irregular shape extended to Sn-Pb alloy but it forms a continuous layer near the Ni-P deposite. At high temperature aging, the continuous layer grows with the test time, while the needle structure becomes dull. The intermetallic compoud was not the fracture site after shear test and it exhibits a better strength than Sn-Pb alloy. The shear strength of solder bump only slightly degrades after high temperature aging test. The shear strength was between 18 and 20 gram per bump. After the temperature(85℃)-humidity(85% RH) test, the shear strength was also between 18 and 20 gram. Therefore, the shear strength slightly degrades after the both reliability test. This research also studied the efficacy of Ni-P layer as diffusion barrier. It was found that Ni-P layer is effective as a barrier layer between Cu and Sn during high temperature aging and temperature-humidity test. It was also found that a layer of 5.5 μm Ni-P is adequate for preventing the interdiffusion between Cu and Sn even under solid/liquid interaction of multi-reflow test. 中文摘要…………………………………………………………. Ⅰ 英文摘要………………………………………………………… Ⅲ 總目錄…………………………………………………………… Ⅴ 表目錄…………………………………………………………… Ⅶ 圖目錄…………………………………………………………… Ⅷ 第一章 簡介……………………………………………………… 1 1-1 電子構裝技術之發展…………………………………… 1 1-2 覆晶接合技術之簡介……………………………………… 3 1-3 無電鍍鎳技術及其應用………………………………….. 11 1-3-1 無電鍍鎳之簡介……………………………………… 11 1-3-2 無電鍍鎳之鍍層性質及其反應機構………………… 12 1-3-3 無電鍍鎳的應用……………………………………… 15 1-4 可靠度試驗……………………………………………….. 17 1-4-1 可靠度的重要性……………………………………… 17 1-4-2 可靠度試驗的種類…………………………………… 20 1-4-3 可靠度試驗的失效評估方法………………………… 24 1-5 研究目的………………………………………………….. 26 第二章 實驗方法與步驟………………………………………… 27 2-1 實驗構想與設計………………………………………….. 27 2-2 銲錫隆點之製作…………………………………………… 28 2-2-1 矽晶片前處理………………………………………… 28 2-2-2 微影製程……………………………………………… 31 2-2-3 濺鍍製程……………………………………………… 32 2-2-4 對位製程……………………………………………… 36 2-2-5 無電鍍鎳磷層………………………………………… 38 2-2-6 電鍍鉛錫合金………………………………………… 38 2-2-7 蝕刻銅膜……………………………………………… 44 2-2-8 重流製程……………………………………………… 44 2-3 結合強度之測試………………………………………….. 44 2-4 剪力強度之測試…………………………………………… 47 2-5 可靠度測試………………………………………………… 49 第三章 結果與討論……………………………………………… 50 3-1 Si/Ta/TaCu/Cu鍍層的性質………………………………… 50 3-2 對位製程之結果…………………………………………… 56 3-3 無電鍍鎳磷鍍層之性質…………………………………… 56 3-3-1 無電鍍鎳磷鍍液的穩定性…………………………… 56 3-3-2 無電鍍鎳磷鍍層的剪力強度………………………… 59 3-3-3 無電鍍鎳磷鍍層的結合強度………………………… 59 3-4 電鍍鉛錫合金……………………………………………… 62 3-4-1 最佳的電鍍條件……………………………………… 62 3-4-2 鉛錫鍍液的穩定性…………………………………… 66 3-5 重流製程之結果………………………………………… 66 3-6 可靠度試驗……………………………………………… 69 3-6-1 高溫時效試驗………………………………………… 74 3-6-2 恆溫恆溼試驗………………………………………… 88 3-7 多次重流對於無電鍍鎳磷層擴散障礙的影響…………… 97 第四章 結論……………………………………………………… 102 參考文獻…………………………………………………………. 103 誌謝………………………………………………………………. 110 自述………………………………………………………………. 111