( 1. 哈爾濱工業(yè)大學(xué)現(xiàn)代焊接生產(chǎn)技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室, 哈爾濱 150001;
2. 香港先進(jìn)自動(dòng)器材有限公司（ASM），香港)
摘 要: 研究了熔融的SnPb釬料由固定高度滴落到Au/Ni/Cu焊盤上的溫度變化過(guò)程和界面反應(yīng)情況。結(jié)果表明： 對(duì)釬料熔滴到達(dá)焊盤瞬時(shí)的接觸溫度， 熔滴初始溫度是其主要影響因素， 而高度變化對(duì)其影響不大。 釬料與焊盤界面產(chǎn)生的金屬間化合物形態(tài)受釬料熔滴初始溫度影響很大。隨著滴落釬料初始溫度的提高， 界面層由Au層基本不反應(yīng)，變?yōu)樾纬闪诉B續(xù)層狀A(yù)uSn2及針狀A(yù)uSn4。 當(dāng)初始溫度升高到450℃時(shí)， AuSn2完全轉(zhuǎn)化為AuSn4， 棒狀A(yù)uSn4生長(zhǎng)極為明顯, 在離界面不遠(yuǎn)的釬料里發(fā)現(xiàn)細(xì)小的AuSn4。 由計(jì)算推出界面反應(yīng)的時(shí)間約為6~7ms, 在如此短的時(shí)間內(nèi)， 發(fā)生Au的溶解和Au-Sn化合物的形成， 其原因在于Au在熔融釬料中溶解速度隨溫度變化的特殊性。
關(guān)鍵字: 釬料熔滴； 凸點(diǎn)； 接觸溫度； 金屬間化合物； 溶解速率
TIAN Yan-hong1, P. Liu2
（ 1. State Key Laboratory of Advanced Welding Production Technology,Harbin Institute of Technology, Harbin 150001, China;
2. ASM Assembly Automation Ltd, Hong Kong, China）
Abstract: Temperature variation of solder droplet, interfacial reaction between molten SnPb droplet and Au/Ni/Cu pad were investigated. The 63Sn37Pb solder ball was heated to the specific temperature above melting point and then dropped to the pad from a certain height. The results show that the instantaneous temperature of solder droplet when it reached the pad is mainly determined by the initial temperature. The morphology of intermetallic compounds is strongly influenced by initial temperature of solder droplet. With the increasing initial temperature, a continuous AuSn2 and needle-like AuSn4 formed at the interface. When the temperature reached 450℃, all AuSn2 converted into AuSn4. Rod-like AuSn4 grew strongly, some tiny AuSn4 distributed inside the solder near the interface. The interfacial reaction time is about 6~7ms, during which Au is quickly dissolved into molten solder forming Au-Sn intermetallic compounds. This process attributed to the discontinuity in the dependence of the dissolution rate of gold on temperature in molten eutectic SnPb solder.
Key words: solder droplet; bump; instantaneous temperature; intermetallic compounds; dissolution rate
