發(fā)布時間：2018-04-17 12:53

  本文選題：功率電子 + 芯片鍵合　； 參考：《哈爾濱工業(yè)大學》2017年碩士論文

【摘要】：隨著電子科學技術(shù)的發(fā)展與普及,微電子器件朝著小型化、輕便化、良好的機電性能以及低成本的方向發(fā)展,且愈發(fā)惡化的器件工作環(huán)境,像高溫、大電流和潮濕的氣氛,使得芯片封裝面臨諸多挑戰(zhàn)。與此同時,第三代寬禁帶半導體Si C和Ga N的出現(xiàn),在高溫功率電子領(lǐng)域?qū)⑷〈壳癝i芯片。因此,加強新的封裝材料和方法的研究,對于Si C芯片在汽車電子、航空航天、軍事、發(fā)光二極管等高溫功率電子中優(yōu)良性能的發(fā)揮起著至關(guān)重要的作用。本文基于瞬態(tài)液相法的原理,將釬料膏中Sn合金顆粒優(yōu)化為Sn/Ni混合顆粒,并施加超聲作用,既實現(xiàn)了接頭的快速成型,同時生成的化合物接頭具有良好的高溫穩(wěn)定性。通過試驗,系統(tǒng)地研究了釬料中Ni的含量、Ni顆粒尺寸以及超聲功率對接頭組織和性能的影響。研究發(fā)現(xiàn),Ni顆粒的尺寸直接影響到釬料的潤濕性和接頭的組織形貌,而且接頭內(nèi)生成的Ni3Sn4的含量隨著釬料中Ni的增加而增加。當焊接溫度為250℃、超聲功率為500W、焊接時間為10s時,采用Sn-24%Ni釬料作為中間層能夠獲得剪切強度為43.4MPa,電阻率為24.09μΩ·cm的高性能全化合物接頭。經(jīng)過300℃空氣中高溫老化72h后,接頭組織無相變發(fā)生,剪切強度有所下降,但仍高達33.4MPa。當增加釬料中Ni的顆粒尺寸為20μm、含量為40%時,在250℃回流90min后,獲得了Ni與Ni3Sn4組成的低楊氏模量的混合組織接頭。深入探討了界面化合物生長規(guī)律和超聲作用機制,確定Ni-Sn體系中首先生成的化合物為Ni3Sn4,在不施加超聲情況下,Ni3Sn4的生長主要依靠Ni原子的擴散,生長規(guī)律呈類拋物線形式。通過計算得知,Ni3Sn4在250℃時的生長常數(shù)較小,僅為4.643×10-11cm2/s。超聲的加入能夠很好的解決單獨依靠原子擴散而造成化合物生長速率較低的問題,它的“空化”和“聲流”作用能夠?qū)i周圍形成的Ni3Sn4層破碎,增大Ni與Sn的直接接觸面積,極大加快冶金反應(yīng)的進行速率,從而實現(xiàn)化合物接頭的快速成型。
[Abstract]:With the development and popularization of electronic science and technology, microelectronic devices are developing towards miniaturization, portability, good electromechanical performance and low cost, and worsening working environment, such as high temperature, high current and humid atmosphere,Chip packaging faces many challenges.At the same time, the appearance of the third generation wide band gap semiconductors, sic and gan, will replace the current Si chips in the field of high-temperature power electronics.Therefore, strengthening the research of new packaging materials and methods plays an important role in the performance of sic chips in automotive electronics, aerospace, military, light-emitting diodes and other high-temperature power electronics.Based on the principle of transient liquid phase method, the Sn alloy particles in solder paste were optimized to be Sn/Ni mixed particles, and ultrasonic action was applied to realize the rapid prototyping of the joint, and the compound joint had good high temperature stability.The effects of Ni content in the filler metal and the ultrasonic power on the microstructure and properties of the joint were studied systematically.It was found that the size of Ni particles directly affected the wettability of solder and the microstructure of the joint, and the content of Ni3Sn4 in the joint increased with the increase of Ni in the filler metal.When the welding temperature is 250 鈩，

本文編號：1763690