In对低银SnAgCu性能及焊点可靠性的影响
发布时间：2018-07-24 20:35
【摘要】：随着电子行业无铅化进程的推进,Sn-Ag-Cu系无铅钎料以其良好的润湿性、力学性能和可靠性成为Sn-Pb钎料最具潜力的替代合金。与此同时,Sn-Ag-Cu系无铅钎料熔点较高,等温时效时钎料中Cu6Sn5粗化等问题亟待解决。另外,金属Ag价格高,也是制约Sn-Ag-Cu钎料普及的主要原因之一。因此,对于低银Sn-Ag-Cu钎料及其微合金化对其组织和性能的研究具有重要意义。本文首先对不同Ag含量的Sn-Ag-Cu合金(Sn-3.0Ag-0.5Cu、Sn-1.0Ag-0.5Cu、Sn-0.3Ag-0.7Cu和Sn-0.7Cu)的力学性能性能与显微组织进行系统的比较,讨论采用低银Sn-1.0Ag-0.5Cu钎料替代高银钎料的可行性。其次,在低银Sn-1.0Ag-0.5Cu无铅钎料的基础上添加少量金属元素In(1.0%-4.0%),研究其对钎料合金显微组织、熔化温度、润湿性能、界面金属间化合物(IMC)的生长以及焊点可靠性的影响,重点讨论了焊点在等温时效过程中抗拉强度和抗剪强度的变化。研究结果表明,随着Sn-Ag-Cu钎料中Ag含量的增加,Sn-Ag-Cu合金的润湿性能得到提升,基体中网状共晶相增加,Sn-AgCu/Cu界面IMC的尺寸逐渐减小,但Sn-1.0Ag-0.5Cu钎料与高银Sn-3.0Ag-0.5Cu钎料的现象相差不大。等温时效的过程中,BGA焊点的剪切强度先下降后趋于稳定,150℃时效960h后,Sn-1.0Ag-0.5Cu和Sn-3.0Ag-0.5Cu的剪切强度相差3MPa左右。以上结果可以说明,在高温服役足够长的时间后,Sn-1.0Ag-0.5Cu合金完全可以取代高银SnAg-Cu合金的使用。添加In元素后,Sn-1.0Ag-0.5Cu-x In合金的熔点随着In含量的增加而逐渐降低。当In的添加量为4.0%时,其合金的铺展面积最大,但钎料的抗氧化性能逐渐下降。In的添加,细化了Sn-1.0Ag-0.5Cu钎料合金的组织。当In的添加量超过2.0%时,Sn-1.0Ag-0.5Cu-x In合金在高温时效后基体中出现大量的块状IMC。回流后的BGA焊点中Sn-1.0Ag-0.5Cu-x In/Cu界面IMC的形貌与厚度变化不大,In参与了界面金属间化合物的形成,IMC成分为Cu6(Sn,In)5。在等温时效的过程中,IMC的厚度逐渐增加,In的添加抑制了界面IMC的生长,阻碍了Cu6(Sn,In)5向Cu3(Sn,In)转变。其中,当In的添加量为2.0%时,对界面IMC生长的抑制作用最为明显。力学性能方面,随着In含量的增加,Sn-1.0Ag-0.5Cu-xIn合金的抗拉强度和剪切强度逐渐升高。时效过程中,合金的力学性能逐渐下降并最终趋于稳定。时效960h后,Sn-1.0Ag-0.5Cu-2.0In的抗拉强度和剪切强度最高。结合成本原因,综合考虑得出In的添加量不宜超过2.0%。
[Abstract]:With the development of lead-free process in electronic industry, Sn-Ag-Cu system lead-free solders have become the most promising substitute alloys for Sn-Pb solders because of their good wettability, mechanical properties and reliability. At the same time, the melting point of Sn-Ag-Cu lead-free solder is high, and the Cu6Sn5 coarsening in the solder during isothermal aging is urgent to be solved. In addition, the high price of metal Ag is also one of the main factors restricting the popularity of Sn-Ag-Cu solders. Therefore, it is of great significance to study the microstructure and properties of low silver Sn-Ag-Cu solders and their microalloying. In this paper, the mechanical properties and microstructure of Sn-Ag-Cu alloys with different Ag content (Sn-3.0 Ag-0.5CuN Sn-1.0 Ag-0.5CuSn-0.3Ag-0.7Cu and Sn-0.7Cu) were systematically compared. The feasibility of using low-silver Sn-1.0Ag-0.5Cu filler metal to replace high-silver filler metal was discussed. Secondly, on the basis of low silver Sn-1.0Ag-0.5Cu lead-free solder, a small amount of metal element in (1.0-4.0%) was added to study the effect of the filler metal on microstructure, melting temperature, wettability, growth of intermetallic compound (IMC) and reliability of solder joint. The variation of tensile strength and shear strength of solder joints during isothermal aging was discussed. The results show that with the increase of Ag content in Sn-Ag-Cu solder, the wettability of Sn-Ag-Cu alloy is improved, and the size of IMC at the interface of Sn-AgCu / Cu decreases with the increase of netlike eutectic phase in the matrix, but the phenomenon of Sn-1.0Ag-0.5Cu solder is not different from that of high silver Sn-3.0Ag-0.5Cu solder. During isothermal aging, the shear strength of Sn-1.0Ag-0.5Cu and Sn-3.0Ag-0.5Cu decreases first and then tends to stabilize at 150 鈩，
本文编号：2142580
[Abstract]:With the development of lead-free process in electronic industry, Sn-Ag-Cu system lead-free solders have become the most promising substitute alloys for Sn-Pb solders because of their good wettability, mechanical properties and reliability. At the same time, the melting point of Sn-Ag-Cu lead-free solder is high, and the Cu6Sn5 coarsening in the solder during isothermal aging is urgent to be solved. In addition, the high price of metal Ag is also one of the main factors restricting the popularity of Sn-Ag-Cu solders. Therefore, it is of great significance to study the microstructure and properties of low silver Sn-Ag-Cu solders and their microalloying. In this paper, the mechanical properties and microstructure of Sn-Ag-Cu alloys with different Ag content (Sn-3.0 Ag-0.5CuN Sn-1.0 Ag-0.5CuSn-0.3Ag-0.7Cu and Sn-0.7Cu) were systematically compared. The feasibility of using low-silver Sn-1.0Ag-0.5Cu filler metal to replace high-silver filler metal was discussed. Secondly, on the basis of low silver Sn-1.0Ag-0.5Cu lead-free solder, a small amount of metal element in (1.0-4.0%) was added to study the effect of the filler metal on microstructure, melting temperature, wettability, growth of intermetallic compound (IMC) and reliability of solder joint. The variation of tensile strength and shear strength of solder joints during isothermal aging was discussed. The results show that with the increase of Ag content in Sn-Ag-Cu solder, the wettability of Sn-Ag-Cu alloy is improved, and the size of IMC at the interface of Sn-AgCu / Cu decreases with the increase of netlike eutectic phase in the matrix, but the phenomenon of Sn-1.0Ag-0.5Cu solder is not different from that of high silver Sn-3.0Ag-0.5Cu solder. During isothermal aging, the shear strength of Sn-1.0Ag-0.5Cu and Sn-3.0Ag-0.5Cu decreases first and then tends to stabilize at 150 鈩，
本文编号：2142580
本文链接：https://www.wllwen.com/kejilunwen/jiagonggongyi/2142580.html
