微量Al及Co元素添加對Sn-0.7Cu-0.05Ni無鉛銲錫合金之界面反應影響

Abstract

本研究主要為探討Sn-Cu-Ni-Al以及Sn-Cu-Ni-Co銲錫合金之顯微組織、機械性質以及接合後之性質。先以熱浸銲(hot dip soldering)方式製備Cu基材對銲試棒，並且將試棒分別進行75℃、100℃及150℃高溫儲存實驗25~500小時後，分別進行顯微組織觀察，界面反應層分析，探討界面反應以及銲點拉伸強度試驗。 經過實驗結果分析，可以得知Sn-0.7Cu-Ni合金銲點之接合界面顯微組織係由Sn基地+Cu6Sn5介金屬化合物所組成。添加Al成份對合金整體影響並不大，顯微組織亦為Sn基地+Cu6Sn5介金屬化合物。三種合金材料的拉伸強度在銲接後並沒有很大的差異，但是在經過時效處理之後，添加Co元素的合金拉伸強度衰退率最低，顯示Co元素的添加有助於改善Sn-0.7Cu-Ni合金銲點於高溫長時間之可靠度。

The effects of Al and Co additions on the interfacial reactions with Cu substrates of Sn-0.7Cu-Ni Lead-free solders were investigated. This study was focused on the intermetallic compound (IMC) growth, interfacial reaction and the joint strength as a function of thermal aging and solder composition. Thermal aging was conducted at 75℃, 100℃ and 150℃ for up to 500 h to accelerate the interfacial reactions between solders and Cu substrates. After high temperature storage test, the growth of interfacial Cu3Sn IMCs was inhibited by the adding of Co into the Sn-0.7Cu solder. The addition of Co elements can improve the joint strength of the solder joints. The microstructure of three kinds of solder were identified as Cu6Sn5 by SEM and EDS. Additionally, the solder with addition of Co element has better mechanical properties than the other two materials.