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论文类型：期刊论文

发表时间：2015-08-27

发表刊物：SCIENTIFIC REPORTS

收录刊物：SCIE、PubMed、Scopus

卷号：5

页面范围：13491

ISSN号：2045-2322

摘要：The growth behavior of intermetallic compounds (IMCs) at the liquid-solid interfaces in Cu/Sn/Cu interconnects during reflow at 250 degrees C and 280 degrees C on a hot plate was investigated. Being different from the symmetrical growth during isothermal aging, the interfacial IMCs showed clearly asymmetrical growth during reflow, i.e., the growth of Cu6Sn5 IMC at the cold end was significantly enhanced while that of Cu3Sn IMC was hindered especially at the hot end. It was found that the temperature gradient had caused the mass migration of Cu atoms from the hot end toward the cold end, resulting in sufficient Cu atomic flux for interfacial reaction at the cold end while inadequate Cu atomic flux at the hot end. The growth mechanism was considered as reaction/thermomigration-controlled at the cold end and grain boundary diffusion/thermomigration-controlled at the hot end. A growth model was established to explain the growth kinetics of the Cu6Sn5 IMC at both cold and hot ends. The molar heat of transport of Cu atoms in molten Sn was calculated as + 11.12 kJ/mol at 250 degrees C and + 14.65 kJ/mol at 280 degrees C. The corresponding driving force of thermomigration in molten Sn was estimated as 4.82 x 10(-19) N and 6.80 x 10(-19) N.