摘要通过在 Sn–3.5Ag–0.7Cu 钎料中添加 In、Ge 和 Ce 等微量元素,探讨其对钎料熔点、抗氧化性、界面化合物厚度以及接头性能的影响。结果表明,微量 In 的加入能够有效降低钎料熔点(5~7℃),但不利于钎料抗氧化性;微量 Ge 与 Ce 加入到 SnAgCuIn 之后可以有效改善钎料的抗氧化性。In、Ge 和 Ce 微量元素的添加可以减少钎料在 Cu 基体界面上产生化合物的概率,且对接头强度影响不大。Sn–3.5Ag–0.7Cu–1In–0.05Ge–0.03Ce 钎料综合性能最好,固液相线分别降低 5.9℃ 和 3.9℃,并且抗氧化性较好,焊后界面化合物厚度相比 SnAgCu 钎料减少 36.6%,时效 20 天后化合物厚度减少 23.0%。
Abstract:By adding the trace elements such as In, Ge and Ce to the Sn–3.5Ag–0.7Cu solder, the effects on the melting point, oxidation resistance, interfacial compound thickness and joint properties of the solder were investigated. The results show that the addition of trace In can effectively reduce the melting point of the solder (5–7℃), but it is not conducive to the oxidation resistance of the solder. The addition of trace Ge and Ce to SnAgCuIn can effectively improve the oxidation resistance of the solder. The addition of trace elements of In, Ge and Ce reduces the probability of the solder producing compounds at the Cu matrix interface and has little effect on the joint strength. The Sn–3.5Ag–0.7Cu–1In– 0.05Ge–0.03Ce solder has the best overall performance, with a solidus line reduction of 5.9℃ and a liquidus reduction of 3.9℃, meanwhile has good oxidation resistance. The interfacial compound thickness was reduced by 36.6% compared to the SnAgCu solder, and the compound thickness was reduced by 23.0% after 20 days of aging.