【摘要】 研究了215℃时效过程中Sn3.8Ag0.7Cu无铅钎料焊点内部及与Cu基板界面处显微组织的演化规律。结果表明:试样在时效过程中的放置方式对显微组织的变化会产生重要影响。当钎料焊点处于Cu基板的上方时,215℃时效后显微组织的变化与以往170℃时效后显微组织的变化相似,即界面处金属间化合物层的厚度会随着时效时间的延长而逐渐增加。然而,当钎料焊点处于Cu基板的下方时,215℃时效后钎料焊点内部及界面处的显微组织发生了显著的变化,伴随着Cu基板的溶解在钎料焊点表面形成了大量的体积较大的金属间化合物Cu6Sn5。更多还原

【Abstract】 The evolution of microstructure and the intermetallic compounds for lead-free Sn3.8Ag0.7Cu solder during 220℃ aging was investigated.The results indicate that the placement way of the sample in the furnace plays an important role in the microstructure evolution during 220℃ aging.When the sample is placed in the furnace with the solder cap on the top of the Cu substrate,the similar microstructure evolution is observed after 220℃ aging compared with 170℃ aging,that is the thickness of the intermetallic compound layer(IML) increases with the increase of aging time.However,when the sample is placed in the furnace upside down,great changes in microstructure evolution appear both inside the solder cap and at the inerface between the solder and Cu substrate,a great number of large-sized Cu6Sn5IMCs form at the bottom of the solder cap which is accompanied by the dissolution of Cu substrate.更多还原