共查询到18条相似文献,搜索用时 156 毫秒
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波峰焊及再流焊无铅焊点组织演变规律的研究 总被引:6,自引:1,他引:5
以电子封装线上的波峰焊无铅焊点Sn-0.7Cu/Cu、回流焊无铅焊点Sn-3Ag-0.5Cu/Cu为对象,研究了150 ℃时效过程中无铅焊点处金属间化合物(IMC)、焊料合金组织的演化规律及界面处金属间化合物生长的动力学.试验结果表明:两种无铅焊点处IMC层的厚度随着时效时间的延长而增加,IMC层的生长基本上符合抛物线规律,因此IMC层的长大受元素扩散控制;且两种无铅焊点处IMC层的生长速率常数相近,但Sn-0.7Cu焊料中Sn的晶粒尺寸较Sn-3Ag-0.5Cu中的大;长期时效后,在试样的IMC层内发现有孔洞产生. 相似文献
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为了研究电迁移过程中焊点与焊盘界面金属问化合物(IMC)的变化,在28℃下,对无铅Sn3.0Ag0.5Cu焊点进行了6.5A直流电下的电迁移实验.结果发现,通电144h后,阳极侧IMC层变厚,平均达到10.12 μm;阴极侧IMC层大部分区域变薄至0.86μm,局部出现Cu焊盘的溶解消失,但在界面边缘处出现Cu3Sn5... 相似文献
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利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究了Sn3.8Ag0.7Cu(Sn37Pb)/Cu焊点在时效过程中的界面金属间化合物(IMC)形貌和成份。结果表明:150℃高温时效50、100、200、500h后,Sn3.8Ag0.7Cu(Sn37Pb)/Cu焊点界面IMC尺寸和厚度增加明显,IMC颗粒间的沟槽越来越小。50h时效后界面出现双层IMC结构,靠近焊料的上层为Cu6Sn5,邻近基板的下层为Cu3Sn。之后利用透射电镜观察了Sn37Pb/Ni和Sn3.8Ag0.7Cu/Ni样品焊点界面,结果显示,焊点界面清晰,IMC晶粒明显。 相似文献
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SnSb4.5CuNi/Cu焊点在175℃进行等温时效,分析了不同时效时间的SnSb4.5CuNi/Cu焊点中金属间化合物(IMC)组织形貌演变,通过纳米压痕法测量SnSb4.5CuNi/Cu焊点界面IMC的硬度和弹性模量,对焊接接头进行拉伸强度和低周疲劳测试。结果表明,时效48 h的焊缝中Cu6Sn5呈曲率半径均匀的半圆扇贝状特征,IMC的弹性模量与铜基板很接近,在恒幅对称应变条件下焊点的抗低周疲劳的性能最佳,焊点的抗拉强度高;当时效时间大于48 h,焊接接口的抗疲劳性能和抗拉伸强度逐渐变差。 相似文献
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研究了Sb和稀土化合物的添加对Sn3.0Ag0.5Cu无铅焊料焊接界面金属间化合物层生长的影响。研究结果表明,固态反应阶段界面化合物层的生长快慢排序如下:v(SAC0.4Sb0.1LaB6/Cu)v(SAC0.4Sb/Cu)v(SAC0.1LaB6/Cu)v(SAC/Cu)。计算各种界面IMC生长的激活能Q结果表明,Sn3.0Ag0.5Cu/Cu界面IMC生长的激活能最高,为92.789 kJ,其他焊料合金Sn3.0Ag0.5Cu0.4Sb0.1LaB6/Cu,Sn3.0Ag0.5Cu0.1LaB6/Cu和Sn3.0Ag0.5Cu0.4Sb/Cu界面IMC生长的激活能分别为85.14,84.91和75.57 kJ。在老化温度范围内(≤190℃),Sn3.0Ag0.5Cu0.4Sb0.1LaB6/Cu的扩散系数(D)最小,因而其界面化合物的生长速率最慢。 相似文献
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微量Ni对Sn-3.0Ag-0.5Cu钎料及焊点界面的影响 总被引:2,自引:2,他引:0
研究了Ni的含量对无铅钎料Sn-3.0Ag-0.5Cu润湿性、熔点、重熔及老化条件下界面化合物(IMC)的影响。结果表明:微量Ni的加入使SnAgCu润湿力增加6%;使合金熔点略升高约3℃;重熔时在界面形成了(Cu,Ni)6Sn5IMC层,且IMC厚度远高于SnAgCu/Cu的Cu6Sn5IMC厚度。在150℃老化过程中,SnAgCuNi/Cu重熔焊点IMC随着时间的增加,其增幅小于SnAgCu/Cu的增幅,此时Ni对IMC的增长有一定抑制作用。 相似文献
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含铅焊料应用在电子产品上已超过50年的时间。然而出于环境方面的考虑,在未来的几年含铅焊料的使用将被禁止。作为替代,必须发明不含铅的焊料。对无铅焊料总的要求类似于含铅焊料。它们要求类似的诸如焊接温度及时间工艺参数窗口和相当于含铅焊料或更好的特性。科学家们已研究了许多不同类型的无铅焊料,从中我们选取Sn3、5Ag0.7Cu作为本次研究的对象,因为它可能目前是在欧洲应用最广泛的一种无铅合金。通过下面几项工作中我们研究了Sn3.5Ag0.7Cu的疲劳特性。制成板(PCBA)温度循环(热冲击)试验:用Sn3.5Ag0.7Cu无铅焊料在不同的焊接气氛下将各种不同类型的器件焊在有不同可焊性表面覆层的印制板上,做成试验制成板(PCBA)。将125℃到-15℃的温度循环(热冲击)施与试验制成板并研究板上焊点在经受不同次数的温度循环后其微观组织结构及变化。模型焊点的机械应力循环试验:室温条件下利用特别设计的环一插针模型焊点,Sn3.5Ag0.7Cu无铅焊点被施加机械应力循环并和传统的Sn-Pb焊点进行比较。包含不同铅含量的焊点也被研究以确认铅杂质对无铅焊点特性的影响。比起传统的Sn-Pb焊料,Sn3.5Ag0.7Cu有更好的疲劳特性。然而研究同时发现一个2%-5%的铅杂质含量对无铅焊点的寿命是有害的。 相似文献
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Microstructure characterization of SnAgCu solder bearing Ce for electronic packaging 总被引:1,自引:0,他引:1
Liang Zhang Song-bai Xue Li-li GaoWei Dai Feng JiYan Chen Sheng-lin Yu 《Microelectronic Engineering》2011,88(9):2848-2851
The creep-rupture lives of Sn3.8Ag0.7Cu and Sn3.8Ag0.7Cu0.03Ce lead-free solder joints for electronic packaging were investigated, respectively. And the relationship between creep behavior and intermetallic compound (IMC: Ag3Sn, Cu6Sn5, CeSn3) particles in SnAgCu/SnAgCuCe solder joints has been obtained. Meanwhile, rare earth Ce concentration gradient and retardation effect of Ce on the IMC layer have been observed at the solder/Cu interface. Moreover, aging reaction of Sn and Cu, and the effect mechanism of rare earth Ce on two IMCs (Cu6Sn5 and Cu3Sn) are reported. 相似文献
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The morphological and compositional evolutions of intermetallic compounds (IMCs) formed at three Pb-free solder/electroless
Ni-P interface were investigated with respect to the solder compositions and reflow times. The three Pb-free solder alloys
were Sn3.5Ag, Sn3.5Ag0.75Cu, and Sn3Ag6Bi2In (in wt.%). After reflow reaction, three distinctive layers, Ni3Sn4 (or Ni-Cu-Sn for Sn3.5Ag0.75Cu solder), NiSnP, and Ni3P, were formed on the electroless Ni-P layer in all the solder alloys. For the Sn3.5Ag0.75Cu solder, with increasing reflow
time, the interfacial intermetallics switched from (Cu,Ni)6Sn5 to (Cu,Ni)6Sn5+(Ni,Cu)3Sn4, and then to (Ni,Cu)3Sn4 IMCs. The degree of IMC spalling for the Sn3.5Ag0.75Cu solder joint was more than that of other solders. In the cases of
the Sn3.5Ag and Sn3Ag6Bi2In solder joints, the growth rate of the Ni3P layer was similar because these two type solder joints had a similar interfacial reaction. On the other hand, for the Sn3.5Ag0.75Cu
solder, the thickness of the Ni3P and Ni-Sn-P layers depended on the degree of IMC spalling. Also, the shear strength showed various characteristics depending
on the solder alloys and reflow times. The fractures mainly occurred at the interfaces of Ni3Sn4/Ni-Sn-P and solder/Ni3Sn4. 相似文献
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在焊点与铜基之间形成的Cu-Sn合金成分对表面安装器件的疲劳寿命起着关键性的作用。本文着重研究了93.5Sn3.5Ag(简写为Sn-Ag)焊料与Cu基界面间形成的合金层,通过电子扫描显微镜(SEM),X衍射(XDA)及能谱X射线(EDX)等分析发现,在Sn-Ag与Cu基界面上存在Cu6Sn5及Cu3Sn两种合金成分,且随着热处理时间增加,Cu6Sn5合金层增厚,并在该处容易出现裂纹而导致焊点强度减弱,从而使焊点产生疲劳失效。 相似文献
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Zhuo-Ming Guan Guo-Xun Liu Tao Liu 《Advanced Packaging, IEEE Transactions on》2000,23(4):737-742
The characteristics of thickening kinetics of the intermetallic compounds (IMC) (Cu/sub 6/Sn/sub 5/+Cu/sub 3/Sn) during aging at 120/spl deg/C and 90/spl deg/C in solid state were studied by quantitative metallographic analysis for three solder alloy systems: 40Sn-Bi/Cu, 40Sn-Bi-2Ag/Cu and Sn-37Pb/Cu. The diffusion couples were prepared by hot immersion in the molten solder bath. The results showed that the rate of the IMC thickening increases in the order Sn-37Pb/Cu<40Sn-Bi/2-Ag/Cu<40Sn-Bi/Cu. The IMC thickening rate in the Sn-Bi eutectic system is one order of magnitude faster than that in Sn-Pb eutectic system. The time exponents are different from each other. The relationship between the increase of IMC and aging time follows a parabolic function in the Sn-Pb system, and a linear relation in the Sn-Bi system. Addition of Ag in Sn-Bi inhibits the IMC thickening process. 相似文献
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In general, formation and growth of intermetallic compounds (IMCs) play a major role in the reliability of the solder joint
in electronics packaging and assembly. The formation of Cu-Sn or Ni-Sn IMCs have been observed at the interface of Sn-rich
solders reacted with Cu or Ni substrates. In this study, a nanoindentation technique was employed to investigate nanohardness
and reduced elastic moduli of Cu6Sn5, Cu3Sn, and Ni3Sn4 IMCs in the solder joints. The Sn-3.5Ag and Sn-37Pb solder pastes were placed on a Cu/Ti/Si substrate and Ni foil then annealed
at 240°C to fabricate solder joints. In Sn-3.5Ag joints, the magnitude of the hardness of the IMCs was in the order Ni3Sn4>Cu6Sn5>Cu3Sn, and the elastic moduli of Cu6Sn5, Cu3Sn, and Ni3Sn4 were 125 GPa, 136 GPa, and 142 GPa, respectively. In addition, the elastic modulus of the Cu6Sn5 IMC in the Sn-37Pb joint was similar to that for the bulk Cu6Sn5 specimen but less than that in the Sn-3.5Ag joint. This might be attributed to the strengthening effect of the dissolved
Ag atoms in the Cu6Sn5 IMC to enhance the elastic modulus in the Sn-3.5Ag/Cu joint. 相似文献
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通过对Sn0.3Ag0.7Cu/Cu和Sn3.0Ag0.5Cu/Cu焊点进行剪切测试结果表明:两种钎料焊点的剪切强度与加载速率有着明显的相关性,即焊点的剪切强度都随着加载速率的增加而增加。当加载速率为0.01 mm/s时,断裂模式为韧脆混合断裂,随着加载速率的增加,两种钎料焊点断口的韧窝数量不断增加,呈现韧性断裂特征,断口以韧窝为主。另外在相同加载速率下,Sn3.0Ag0.5Cu/Cu焊点断口的韧窝数量和分布情况都优于Sn0.3Ag0.7Cu/Cu焊点,即其韧性断裂的趋势更加明显,剪切强度更大。 相似文献