Wall-slip effects in SnAgCu solder pastes used in electronics assembly applications
Wall-slip effects in SnAgCu solder pastes used in electronics assembly applications
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DOI：
10.1016/j.matdes.2009.05.028
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发表时间：
2009-12
影响因子：
8.4
通讯作者：
S. Mallik;Nduka Nnamdi (Ndy) Ekere;R. Durairaj;A. Marks;A. Seman
中科院分区：
文献类型：
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作者：
S. Mallik;Nduka Nnamdi (Ndy) Ekere;R. Durairaj;A. Marks;A. Seman
焊膏是电子制造业表面贴装元件组装中最重要的战略键合材料。随着电子产品的电子化趋势的持续，人们越来越需要更好地了解焊膏配方的流动和变形，即流变行为。壁面滑移在表征焊膏材料的流动行为中起着重要的作用。由于焊料颗粒和测量几何形状的壁之间的各种吸引力和排斥力，出现了壁滑移的问题。这些相互作用可能导致在壁附近存在薄的溶剂层，这引起滑移。在流变测量中，通常可以通过使用粗糙表面测量几何形状来避免滑移效应。本文提出了一种新的技术来研究无铅焊膏流变测量中的壁滑移效应。三种不同的焊膏样品（从测量不同的表面粗糙度的几何形状）的粘度和振荡数据进行了分析和比较。在粘度测量中，滑移效应在低剪切速率下占主导地位，并且发现使用锯齿状表面在最小化滑移效应方面非常有效。振荡测量也受到粗糙化测量几何体表面的影响。
Solder paste is the most important strategic bonding material used in the assembly of surface mount components in electronics manufacturing. As the trend towards miniaturisation of electronic products continues, there is an increasing demand for better understanding of the flow and deformation that is, the rheological behaviour of solder paste formulations. Wall slip plays an important role in characterising the flow behaviour of solder paste materials. The problem of wall slip arises due to the various attractive and repulsive forces acting between the solder particles and the walls of the measuring geometry. These interactions could lead to the presence of a thin solvent layer adjacent to the wall, which gives rise to slippage. In rheological measurements, slip effects can generally be avoided by using roughened surfaces for measuring geometries. In this paper, a novel technique is developed to study the effect of wall slip in the rheological measurements of lead-free solder paste. The viscosity and oscillatory data obtained for three different solder paste samples (from measuring geometries of different surface roughness) have been analysed and compared. In viscosity measurements, slip effects were dominant at low shear rates and the use of serrated surfaces was found to be quite effective in minimizing slip effects. Oscillatory measurements were also affected by roughening the surfaces of measuring geometries.