Cu/Sn-58Bi-xCe/Cu钎焊接头基体组织和力学性能的研究

研究了Ce对Cu/Sn-58Bi/Cu钎焊接头显微组织和力学性能的影响规律。结果表明:Ce颗粒的添加可有效细化钎料基体组织,当Ce添加量为0.5wt%时,组织最为细小弥散,具有较小的Sn-Bi两相片层间距;铺展系数随Ce含量的增加而表现出先上升后下降的趋势,Sn-58Bi-0.5Ce钎料表现出较好的铺展性能;Cu/Sn-58Bi-0.5Ce/Cu钎焊接头在获得最佳抗拉强度的同时,仍表现出较好韧性;Ce的最佳添加量为0.5wt%。     

纳米Ag颗粒对Sn-58Bi无铅钎料组织及焊点可靠性的影响

研究了纳米Ag颗粒对Sn-58Bi钎料焊点微观组织、界面金属间化合物、铺展性能以及力学性能的影响。结果表明:添加Ag颗粒可以细化焊点组织,复合钎料的组织随Ag颗粒含量的增加呈先细化后粗化的趋势;Ag颗粒的添加使界面金属间化合物的厚度增大,复合钎料的界面金属间化合物的厚度随Ag颗粒含量的增加而增加;Ag颗粒的添加可以改善钎料的铺展性能,复合钎料的铺展性能随Ag颗粒含量的增加呈先增大后减小的趋势;适量Ag颗粒的添加可以改善焊点的拉伸性能,随着Ag颗粒含量的增加复合钎料焊点的拉伸性能呈先上升后下降的趋势;Ag的最佳添加量0.5%(质量分数)。     

Cu/Sn-58Bi-0.5Ce/Cu钎焊接头的热时效行为

对比研究了不同时效温度下Sn-58Bi和Sn-58Bi-0.5Ce钎焊接头的组织、界面IMC形态、厚度及接头拉伸性能和断口形貌。结果表明:Ce颗粒的添加细化了Sn-58Bi钎料的组织,抑制了Sn-58Bi钎料接头时效过程中组织的粗化、IMC形貌变化及厚度的增大。随时效温度的升高,Cu/Sn-58Bi-0.5Ce/Cu钎焊接头IMC形貌从扇贝状逐渐趋于平整,厚度逐渐增大,抗拉强度逐渐降低,拉伸断口由韧性断裂转变为脆性断裂。     

镍包覆碳纳米管增强Sn-58Bi复合钎料焊点的组织和力学性能研究

研究了镍包覆碳纳米管(Ni-CNTs)对Sn-58Bi钎料焊点微观组织和可靠性的影响。结果表明:Ni-CNTs的添加提高了Sn-58Bi钎料润湿性能,复合钎料焊点界面IMC(intermetallic compound)呈现扇贝状,细化了Sn-58Bi钎料的微观组织,提高了复合钎料接头的拉伸和剪切性能。随着Ni-CNTs含量的增加,铺展面积呈现先上升后下降的趋势,IMC厚度呈现下降的趋势;复合钎料接头的抗拉强度和抗剪强度均呈现先上升后下降的趋势。当Ni-CNTs含量为0.03wt%时,复合钎料铺展面积最大,为58.3 mm2;复合钎料接头的抗拉强度和抗剪强度最大,分别为99.2、14.1 MPa。     

微量Zn颗粒对Sn-0.7Cu-xZn钎料焊点组织及力学性能的影响

研究了微量Zn颗粒对Sn-0.7Cu钎料焊点微观组织、钎料铺展性能及Cu/Sn-0.7Cu-x Zn/Cu接头力学性能的影响。结果表明:适量Zn颗粒的添加可以细化钎料组织,减小界面IMC的厚度,提高钎料的铺展性能和硬度;过量Zn的添加则会粗化钎料组织,增大界面IMC的厚度,降低钎料的铺展性能和硬度值;接头抗拉强度随Zn的添加呈先增大后减小的趋势。当Zn含量小于0.20wt%拉伸断口类型为韧断,超过0.20wt%,拉伸断口类型为脆断。Zn的最佳添加量为0.20 wt%。     

纳米Ag颗粒对Sn-0.7Cu-xAg钎料组织及性能的影响

研究了纳米Ag颗粒对Sn-0.7Cu-x Ag钎料组织和性能的影响。结果表明:在Sn-0.7Cu钎料中加入适量的纳米Ag颗粒可以改善钎料的润湿性。当Ag含量为2%时,润湿性最好,铺展系数可以达到74.66%。添加微量的Ag增加了钎料的形核率,细化了钎料的微观组织。但是Ag含量过多时IMC层厚度大。当Ag含量为4%时,钎料的显微硬度最大,其焊点抗拉强度最大,焊点抗拉强度为55.69 MPa。当Ag含量为8%时,钎料的IMC层厚度最大,达到3.88μm,其焊点的抗拉强度最小。     

石墨烯纳米片增强的Sn-58Bi/Cu焊点可靠性（英文）

将不同含量(0%,0.025%,0.05%,0.075%,0.1%,0.2%,质量分数)的石墨烯纳米片(GNSs)添加到Sn-58Bi低温钎料中,研究了GNSs对钎料熔化温度、润湿性能、剪切强度、显微组织和界面反应的影响。结果表明:添加GNSs可以改善Sn-58Bi钎料焊点的润湿性能和抗剪切强度,但对其熔化温度的影响较小。随着GNSs的添加,钎料得到了相对细化的显微组织,界面金属间化合物(IMC)的厚度明显降低,并逐渐趋于平整。另外,随着GNSs的加入,Sn-58Bi钎料的剪切断裂模式从脆性断裂转变为脆性和韧性混合的断裂模式,这与其抗剪切强度的变化是一致的。因此,添加微量的GNSs是增强Sn-58Bi/Cu焊点可靠性的有效途径。     

Y2O3/Sn-58Bi复合钎料制备及其性能分析

文中通过粉末冶金法制备了Y₂O₃/Sn-58Bi复合钎料.结果表明,添加少量Y₂O₃,对复合钎料熔点影响较小;随着Y₂O₃质量分数提高,复合钎料的密度和显微维氏硬度先升高后降低;复合钎料的润湿角表现出相反的趋势,随着Y₂O₃质量分数提高,复合钎料的润湿角先降低后升高.通过测试Sn-58Bi钎料和0.1%（质量分数）Y₂O₃/Sn-58Bi复合钎料拉伸试样的力学性能发现,添加质量分数为0.1%的Y₂O₃对复合钎料强度稍有提高,但能明显提高复合钎料的延展性,从而解决传统Sn-58Bi钎料较脆的难题.通过观察钎料拉伸断口发现,添加Y₂O₃能够细化复合钎料微观组织,使裂纹沿着断裂方向扩展时受到阻碍,抑制了钎料脆性断裂的趋势.     

Al_2O_3颗粒对Sn58Bi钎料组织及力学性能的影响

研究了不同Al2O3颗粒添加量对Sn58Bi钎料显微组织、润湿性及力学性能的影响。结果表明,添加Al2O3颗粒的复合钎料组织细小均匀,且添加量为0.5wt%时,细化效果最明显。复合钎料的润湿性随Al2O3颗粒含量的增加呈现先上升后下降的趋势,当Al2O3的添加量为0.5wt%时,复合钎料的铺展系数最大,相比于Sn58Bi钎料,增加幅度为11.69%,润湿性得到明显改善;微型焊点拉伸试验结果表明,添加适量的Al2O3颗粒可以明显提高微焊点的抗拉强度及伸长率,呈现出优异力学性能。     

Cu/Sn-0.7Cu-0.05x/Cu焊点界面组织形貌及力学性能的研究

研究了Cu/Sn-0.7Cu-0.05Ni/Cu和Cu/Sn-0.7Cu-0.05Fe/Cu焊点的界面组织形貌、钎料铺展性能及焊点力学性能。结果表明:在Sn-0.7Cu钎料中添加Fe和Ni颗粒均可以抑制金属间化合物层生长,使得界面致密平整,同时减小了液态钎料在铜基板上的表面张力,提高了铺展性能,而且使钎料的抗拉强度和塑性性能得到了一定程度的提高。与Fe颗粒相比,Ni颗粒的添加能更好地改善钎焊焊点的性能。     

Combined effects of Bi and Sb elements on microstructure,thermal and mechanical properties of Sn-0.7Ag-0.5Cu solder alloys

This research investigated the combined effects of addition of Bi and Sb elements on the microstructure, thermal properties, ultimate tensile strength, ductility, and hardness of Sn-0.7Ag-0.5Cu (SAC0705) solder alloys. The results indicated that the addition of Bi and Sb significantly reduced the undercooling of solders, refined the β-Sn phase and extended the eutectic areas of the solders. Moreover, the formation of SbSn and Bi phases in the solder matrix affected the mechanical properties of the solder. With the addition of 3 wt.% Bi and 3 wt.% Sb, the ultimate tensile strength and hardness of the SAC0705 base alloy increased from 31.26 MPa and 15.07 HV to 63.15 MPa and 23.68 HV, respectively. Ductility decreased due to grain boundary strengthening, solid solution strengthening, and precipitation strengthening effects, and the change in the fracture mechanism of the solder alloys.     

Influence of bismuth on microstructure,thermal properties,mechanical performance,and interfacial behavior of SAC305-xBi/Cu solder joints

This research sought to improve the properties of SAC305 solder joints by the addition of 1 and 2 wt.% Bi. The effects of bismuth doping on the microstructure, thermal properties, and mechanical performance of the SAC305-xBi/Cu solder joints were investigated. Bi-doping modified the microstructure of the solder joints by refining the primary β-Sn and eutectic phases. Bi-doping below 2 wt.% dissolved in the β-Sn matrix and formed a solid solution, whereas Bi additions equal to or greater than 2 wt.% formed Bi precipitates in the β-Sn matrix. Solid solution strengthening and precipitation strengthening mechanisms in the β-Sn matrix increased the ultimate tensile strength and microhardness of the alloy from 35.7 MPa and 12.6 HV to 55.3 MPa and 20.8 HV, respectively, but elongation decreased from 24.6% to 16.1%. The fracture surface of a solder joint containing 2 wt.% Bi was typical of a brittle failure rather than a ductile failure. The interfacial layer of all solder joints comprised two parallel IMC layers: a layer of Cu₆Sn₅ and a layer of Cu₃Sn. The interfacial layer was thinner and the shear strength was greater in SAC305-xBi/Cu joints than in SAC305/Cu solder joints. Therefore, small addition of Bi refined microstructure, reduced melting temperature and improved the mechanical performance of SAC305/Cu solder joints.     

石墨烯纳米片增强的Sn-58Bi/Cu焊点可靠性

将不同含量（0%,0.025%,0.05%,0.075%,0.1%,0.2%,质量分数）的石墨烯纳米片（GNSs）添加到Sn-58Bi低温钎料中,研究了GNSs对钎料熔化温度、润湿性能、剪切强度、显微组织和界面反应的影响。结果表明：添加GNSs可以改善Sn-58Bi钎料焊点的润湿性能和抗剪切强度,但对其熔化温度的影响较小。随着GNSs的添加,钎料得到了相对细化的显微组织,界面金属间化合物（IMC）的厚度明显降低,并逐渐趋于平整。另外,随着GNSs的加入,Sn-58Bi钎料的剪切断裂模式从脆性断裂转变为脆性和韧性混合的断裂模式,这与其抗剪切强度的变化是一致的。因此,添加微量的GNSs是增强Sn-58Bi/Cu焊点可靠性的有效途径。     

铋和磷元素对Sn-Zn-RE电子微连接钎料组织与性能的影响

制备了含不同Bi,P元素的（Sn-9Zn0.05Ce）xBi和（Sn-9Zn0.05Ce）xP钎料合金,观察并分析了钎料的显微组织形貌,测试了钎料的抗拉强度、断后伸长率以及维氏硬度.结果表明,添加Bi元素能显著提高Sn-9Zn0.05Ce钎料合金的抗拉强度和硬度,但同时会明显降低其断后伸长率,而添加微量P元素对钎料的抗...     

硼酸铝晶须对Sn-58Bi/Cu界面金属间化合物 层演变及剪切行为的影响

研究了硼酸铝晶须对Sn-58Bi/Cu界面金属间化合物(IMC)层组织演变的影响.结合钎焊接头显微组织、剪切性能以及断口形貌,分析了Sn-58Bi-1.2%Al₁₈B₄O₃₃钎焊接头的断裂机理.结果表明,硼酸铝晶须的加入可以细化钎料组织,抑制大块富铋相的出现;钎料/基板界面IMC层厚度和晶粒粒径均随着重熔次数的增加而增大,但硼酸铝晶须的加入能够阻碍界面IMC层的增厚和晶粒粗化,提高钎焊接头的性能;不同重熔次数下Sn-58Bi-1.2% Al₁₈B₄O₃₃/Cu钎焊焊点比Sn-58Bi/Cu钎料焊点能承受更高的剪切载荷,且经过多次重熔后接头强度保持稳定.     

Sn-0.7Cu-xNb复合钎料微观组织和力学性能

文中主要研究了纳米Nb颗粒对Sn-0.7Cu基复合钎料显微组织和力学性能的影响。结果表明,添加纳米Nb颗粒细化了Sn-0.7Cu复合钎料微观组织,提高了Sn-0.7Cu复合钎料的抗拉强度。当Nb含量为0.12%时抗拉强度达最大值25.36 MPa,但此时钎料的断后伸长率有所降低。Sn-0.7Cu-x Nb复合钎料的断裂模式均为塑性断裂,随Nb含量的增加,Sn-0.7Cu基复合钎料断口表面的韧窝尺寸逐渐变小,表明微量的纳米Nb可以抑制合金内Cu 6 Sn 5金属间化合物的长大。     

Microstructural evolution and tensile properties of Sn-5Sb solder alloy containing small amount of Ag and Cu

The near peritectic Sn-5Sb Pb-free solder alloy has received considerable attention for high temperature electronic applications, especially on step soldering technology, flip-chip connection. In the present study, a separate addition of the same amount of Ag and Cu are added with the near-peritectic Sn-5Sb solder alloy to investigate the effect of a third element addition on the microstructural, thermal and mechanical properties of the newly developed ternary solder alloys. The results indicate that the melting point of Sn-5Sb solder is enhanced by Ag and Cu additions. Besides, the Ag and Cu content refine the microstructure and form new intermetallic compounds (IMCs) with the near-peritectic Sn-5Sb solder alloy. The tensile tests revealed that all alloys exhibit higher mechanical strength with increasing strain rate and/or decreasing testing temperature, suggesting that the tensile behavior of the three alloys is strain rate and temperature dependence. The yield and ultimate tensile strength are higher for Sn-5Sb-0.7Cu alloy compared with Sn-5Sb and Sn-5Sb-0.7Ag alloys. Good mechanical performance of Sn-5Sb-0.7Cu solder is often correlated to a fine β-Sn grain size and more dispersed Cu-Sn IMC particles, which makes the solder exhibit high strength and yield stress.     

稀土Er对Sn-3.0Ag-0.5Cu无铅焊料合金组织与性能的影响

研究稀土Er含量对Sn-3．0Ag-0．5Cu无铅焊料合金显微组织以及性能的影响。结果表明：当Er含量为0．05％～0．50％（质量分数）时，对该无铅焊料合金的导电性和腐蚀性影响不大，但使熔化区间温度降低：当Er含量为0．05％时，焊点剪切强度最高；当Er含量为0．10％时，焊料铺展面积最大，焊料润湿性有所改善，同时焊料的拉伸强度达到最高；当Er含量为0．25％时，伸长率最大。随着Er含量的增加，该焊料合金的组织由树枝晶向等轴晶转变，且组织逐渐细化。Er的较佳添加量为0．05％～0．25％。     

热循环对Sn58Bi(纳米Ti)/Cu焊点界面与性能影响

为了改善Sn-58Bi低温钎料的性能,通过在Sn-58Bi低温钎料中添加质量分数为0.1%的纳米Ti颗粒制备了Sn-58Bi-0.1Ti纳米增强复合钎料。在本文中,研究了纳米Ti颗粒的添加对-55～125 _^oC热循环过程中Sn-58Bi/Cu焊点的界面金属间化合物(IMC)生长行为的影响。研究结果表明：回流焊后,在Sn-58Bi/Cu焊点和Sn-58Bi-0.1Ti/Cu焊点的界面处都形成一层扇贝状的Cu₆Sn₅ IMC层。在热循环300次后,在Cu₆Sn₅/Cu界面处形成了一层Cu₃Sn IMC。Sn-58Bi/Cu焊点和Sn-58Bi-0.1Ti/Cu焊点的IMC层厚度均和热循环时间的平方根呈线性关系。但是,Sn-58Bi-0.1Ti/Cu焊点的IMC层厚度明显低于Sn-58B/Cu焊点,这表明纳米Ti颗粒的添加能有效抑制热循环过程中界面IMC的过度生长。另外计算了这两种焊点的IMC层扩散系数,结果发现Sn-58Bi-0.1Ti/Cu焊点的IMC层扩散系数(整体IMC、Cu₆Sn₅和Cu₃Sn IMC)明显比Sn-58Bi/Cu焊点小,这在一定程度上解释了Ti纳米颗粒对界面IMC层的抑制作用。