發(fā)布時(shí)間：2018-01-03 06:24

  本文關(guān)鍵詞：Sn基軟釬料合金的晶須快速生長(zhǎng)行為和抑制方法研究　出處：《哈爾濱工業(yè)大學(xué)》2017年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： Sn晶須 Sn基釬料合金 超聲輔助釬焊 快速生長(zhǎng)行為 抑制方法

【摘要】：Sn基軟釬料的晶須生長(zhǎng)問(wèn)題對(duì)電子封裝互連可靠性的威脅由來(lái)已久。隨著封裝密度不斷提高、互連點(diǎn)間距不斷減小,數(shù)微米的Sn晶須就可能引發(fā)互連點(diǎn)的短路,因此探索可以有效減緩或抑制Sn晶須生長(zhǎng)的方法成為了學(xué)術(shù)界的重要研究?jī)?nèi)容之一。然而Sn晶須生長(zhǎng)的長(zhǎng)期性和偶然性的特點(diǎn)對(duì)其研究工作造成很大困擾,所以加速晶須的形核和長(zhǎng)大成為研究其形成機(jī)制和抑制機(jī)理的首要條件。目前,加速Sn晶須生長(zhǎng)的方法主要有施加壓力、電遷移誘導(dǎo)、等溫時(shí)效和熱循環(huán)等。不過(guò)上述方法均存在孕育期長(zhǎng)、晶須密度低等缺點(diǎn);此外,試樣制備工藝同樣會(huì)對(duì)Sn晶須的生長(zhǎng)行為產(chǎn)生影響,進(jìn)而干擾實(shí)驗(yàn)結(jié)果�；谏鲜鲈�,本研究創(chuàng)造性地開(kāi)發(fā)了一種行之有效的Sn晶須加速生長(zhǎng)方法,深入分析了釬料晶粒尺寸和彈性模量對(duì)Sn晶須生長(zhǎng)的影響,并且提出了兩種Sn晶須生長(zhǎng)的抑制方法。該研究對(duì)明晰Sn基釬料晶須生長(zhǎng)行為以及降低釬料晶須生長(zhǎng)風(fēng)險(xiǎn)有重要的指導(dǎo)意義。本研究通過(guò)自主開(kāi)發(fā)的超聲輔助釬焊設(shè)備制造了Mg/Sn/Mg焊接接頭,發(fā)現(xiàn)了該接頭經(jīng)過(guò)短時(shí)間室溫等溫時(shí)效之后焊縫表面有高密度的Sn晶須形成,確定了Sn晶須生長(zhǎng)所需的驅(qū)動(dòng)力主要來(lái)源于固溶在焊縫釬料基體內(nèi)的間隙Mg原子原子轉(zhuǎn)化為Mg2Sn過(guò)程中所引起的體積膨脹,提出了超聲輔助釬焊制備Mg/Sn/Mg焊接接頭的工藝可作為一種Sn晶須的快速生長(zhǎng)方法并用于Sn晶須相關(guān)領(lǐng)域的研究。其次,本研究通過(guò)機(jī)械壓合和超聲振動(dòng)相結(jié)合的方式制備了Sn-Si C復(fù)合釬料,利用超聲輔助釬焊工藝與納米Si C顆粒的異質(zhì)形核作用制備了具有不同Sn晶粒尺寸的Mg/Sn-x Si C/Mg焊接接頭,分析了提高Sn晶界數(shù)量對(duì)Sn晶須形核與生長(zhǎng)的促進(jìn)作用;通過(guò)對(duì)比Mg/Sn-x Pb/Mg接頭焊縫表面Sn晶須生長(zhǎng)特征分析了釬料基體的彈性模量和組織結(jié)構(gòu)對(duì)Sn晶須生長(zhǎng)的影響規(guī)律。再次,本研究觀察了Sn-9Zn釬料中Zn原子在Sn晶界的偏聚行為,發(fā)現(xiàn)了Zn原子的晶界偏聚形成的位阻效應(yīng)將嚴(yán)重阻礙Sn原子的晶界擴(kuò)散,同時(shí)片層狀富Zn相結(jié)構(gòu)將破壞Sn原子的長(zhǎng)程擴(kuò)散,最終確認(rèn)了Zn原子對(duì)Sn晶須生長(zhǎng)的抑制作用。最后,本研究利用冷壓焊工藝制備了具有良好接合界面的Sn/Cu/Sn釬料預(yù)制片,通過(guò)短時(shí)間加熱獲得了Cu焊盤/IMC/Cu/IMC/Cu焊盤結(jié)構(gòu)的焊點(diǎn),該合金化焊點(diǎn)不但可以完全避免Sn晶須生長(zhǎng)風(fēng)險(xiǎn),而且還具有耐高溫能力,可用于大功率高溫半導(dǎo)體器件的互連封裝。
[Abstract]:The problem of whisker growth of Sn-base solder has long been a threat to the interconnection reliability of electronic packaging. A few microns of Sn whiskers may cause short circuit of interconnect points. Therefore, exploring methods that can effectively slow down or inhibit the growth of Sn whiskers has become one of the important research contents in academic circles. However, the long-term and accidental characteristics of Sn whiskers growth have caused great problems to its research work. Therefore, accelerating the nucleation and growth of whiskers has become the most important condition to study the mechanism of formation and inhibition. At present, the main methods to accelerate the growth of Sn whiskers are to apply pressure and induce electromigration. The isothermal aging and thermal cycling, however, have the disadvantages of long incubation period and low whisker density. In addition, the sample preparation process will also affect the growth behavior of Sn whisker, and then interfere with the experimental results. In this study, an effective method of Sn whisker growth was developed creatively, and the effects of grain size and elastic modulus of solder on the growth of Sn whisker were analyzed. Two methods of inhibiting the growth of Sn whiskers are proposed. This study is of great significance in clarifying the growth behavior of Sn based brazing whiskers and reducing the growth risk of Sn whiskers. Mg/Sn/Mg welding joint is manufactured by brazing equipment. High density Sn whiskers were found on the weld surface after a short time isothermal aging at room temperature. It is determined that the main driving force for Sn whisker growth is the volume expansion caused by the transformation of the interstitial mg atoms in the solder base into Mg2Sn. It is suggested that ultrasonic assisted brazing can be used as a rapid growth method of Sn whiskers and can be used in the research of Sn whiskers. In this study, Sn-Si C composite solder was prepared by mechanical compression and ultrasonic vibration. Mg/Sn-x sic / mg welded joints with different Sn grain sizes were prepared by ultrasonic assisted brazing process and heterogeneous nucleation of nano sic particles. The effect of increasing the amount of Sn grain boundary on the nucleation and growth of Sn whisker was analyzed. By comparing the growth characteristics of Sn whiskers on the weld surface of Mg/Sn-x Pb/Mg joints, the effects of elastic modulus and microstructure of solder matrix on the growth of Sn whiskers were analyzed. In this study, the segregation behavior of Zn atoms at Sn grain boundaries in Sn-9Zn solders was observed. It was found that the steric resistance of Zn atoms formed by grain boundary segregation would seriously hinder the grain boundary diffusion of Sn atoms. At the same time, the Zn-rich phase structure of lamellar layer will destroy the long-range diffusion of Sn atom, and finally confirm the inhibitory effect of Zn atom on the growth of Sn whisker. In this study, Sn/Cu/Sn solder prefabricated with good interface was prepared by cold pressing welding process. The solder joints of Cu / IMC / Cu / IMC / Cu / Cu pad structure were obtained by short time heating. The alloyed solder joints not only completely avoid the risk of Sn whisker growth, but also have high temperature resistance. It can be used in interconnection packaging of high-power high-temperature semiconductor devices.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG425.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 王彥橋;劉曉陽(yáng);朱敏;;疊層式3D封裝技術(shù)發(fā)展現(xiàn)狀[J];電子元件與材料;2013年10期

2 龐學(xué)永;劉志權(quán);王紹青;尚建庫(kù);;元素?fù)诫s對(duì)Bi電遷移影響的第一原理計(jì)算[J];中國(guó)有色金屬學(xué)報(bào);2011年04期

3 王春青,梁旭文,王金銘,錢乙余;SMT焊點(diǎn)形態(tài)對(duì)熱應(yīng)力分布影響的有限元分析[J];電子工藝技術(shù);1996年06期

，

本文編號(hào)：1372759