Fluxless non-eutectic joints fabricated using gold-tin multilayer composite
Fluxless non-eutectic joints fabricated using gold-tin multilayer composite
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DOI：
10.1109/tcapt.2003.815109
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发表时间：
2003-08
影响因子：
--
通讯作者：
Chin C. Lee;R. Chuang
中科院分区：
文献类型：
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作者：
Chin C. Lee;R. Chuang
采用两种不同的非共晶金-锡（Au-Sn）多层复合材料实现了高质量焊点的无焊剂键合工艺。与80 wt. %的Au和20 wt. % Sn，我们采用了一种极具成本效益的策略，特意设计和构建我们的焊点，以富锡为主，而不是广泛依赖黄金作为主要成分。在研究两个设计实施;一个与80在组成。% Sn（70.54wt. % Sn）和20 at. % Au（29.46重量%）% Au）和95 at. % Sn（91.82wt. % Sn）和5at. %的Au（8.18wt. % Au）。选择用于构造80 Sn-20 Au和95 Sn-5Au接头的键合工艺温度分别为285/spl deg/C和225/spl deg/C。一旦生产，这两种类型的关节进行了检查，使用X射线微焦点成像和扫描声学显微镜（SAM）的组合，以确认粘接质量和所获得的结果是几乎无空隙。为了研究样品的微观结构和组成，在接头横截面上进行了配备有能量色散X射线（EDX）检测器的扫描电子显微镜（SEM），并且分别从80 Sn-20 Au和95 Sn-5Au接头中均匀地识别出3.9和2.1 μ/m的焊料厚度。此外，EDX数据一致表明，AuSn/sub 2/和AuSn/sub 4/金属间化合物的混合物从80 Sn-20 Au样品接头中被发现，而AuSn/sub 2/和AuSn/sub 4/嵌入/spl β/-Sn基质中从95 Sn-5 Au样品中被发现。此外，对样品进行的剪切测试明确表明，每个接头的剪切强度实际上大于模具本身。最后，80 Sn-20 Au和95 Sn-5 Au焊料试样的重熔温度范围分别为275至281/spl deg/C和214至220/spl deg/C，也被实验确定。
Fluxless bonding processes using two different noneutectic gold-tin (Au-Sn) multilayer composites to fabricate high quality solder joints have been successfully achieved. In contrast to the well-known eutectic solders of 80 wt. % Au and 20 wt. % Sn commonly selected by the packaging industry, we have adopted a substantially cost-effective strategy by purposely designing and constructing our solder joints to be predominantly tin-rich instead, rather than relying extensively on gold as a major ingredient. In research two designs were implemented; one with compositions of 80 at. % Sn (70.54 wt. % Sn) and 20 at. % Au (29.46 wt. % Au), and another with 95 at. % Sn (91.82 wt. % Sn) and 5 at. % Au (8.18 wt. % Au). The bonding process temperatures chosen for constructing 80Sn-20Au and 95Sn-5Au joints are 285/spl deg/C and 225/spl deg/C, respectively. Once produced, both types of joints were examined using the combination of X-ray microfocus imaging and scanning acoustic microscopy (SAM) to confirm the bonding quality and the results obtained are nearly void-free. To study the microstructure and composition of the samples the scanning electron microscopy (SEM) equipped with energy dispersive X-ray (EDX) detector were conducted on the joint cross sections and the solder thickness of 3.9 and 2.1/spl mu/m were uniformly identified throughout from 80Sn-20Au and 95Sn-5Au joints, respectively. Furthermore, the EDX data obtained have consistently shown that a mixture of AuSn, AuSn/sub 2/, and AuSn/sub 4/ intermetallics were spotted from the 80Sn-20Au sample joints, while AuSn/sub 2/ and AuSn/sub 4/ embedded in /spl beta/-Sn matrix were discovered from 95Sn-5Au specimens. In addition, the shear tests conducted on the samples unequivocally suggest the shear strength of each joint measured is actually greater than the die itself. Finally, the re-melting temperatures of 80Sn-20Au and 95Sn-5Au solder specimens ranging from 275 to 281/spl deg/C and 214 to 220/spl deg/C, respectively, were also experimentally determined.