Abstract The wettability and formation of intermetallic compounds (IMCs) formed between a Co–Cr–Mo-based alloy and Sn-solder metal were investigated using the reflow soldering method. Soldering was conducted in an electric furnace in separate experiments at temperatures of 533, 553, 573, 623, and 673 K for 600 s. The morphology of the intermetallic layer formed at the Co–Cr–Mo-based/Sn-solder interface was characterized by scanning electron microscopy (SEM). The chemical composition and phase of the formed intermetallic layer were analyzed by electron probe microscopic analysis (EPMA) and X-ray diffraction analysis. Wettability analysis indicated that the soldering temperature influenced the wettability. With increasing soldering temperatures, the spreading factor increased, whereas the contact angle decreased. The intermetallic layers were found in triples in the intermediate zone between the solidified Sn-solder and the Co–Cr–Mo-based substrate. The thickness of the intermetallic layers increased in proportion with increasing soldering temperature. The EPMA analysis indicated only two IMCs formed at the interface of the joint at all of the investigated soldering temperatures, although three interfacial layers were observed by SEM analysis. The Sn-richer phase, Co(Cr,Mo)Sn2, formed adjacent to the Sn-solder matrix, whereas the Co(Cr,Mo)Sn was found near the Co–Cr–Mo-based substrate. The nanoindentation measurement revealed that the formed Co(Cr,Mo)Sn2 and Co(Cr,Mo)Sn IMCs possessed lower hardness values compared to the Sn–Cu intermetallic systems.

中文翻译：

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Co-Cr-Mo合金和Sn-Solder之间的润湿性和金属间相形成的研究，用作倒装芯片封装凸点下金属化的潜力

摘要 使用回流焊接方法研究了 Co-Cr-Mo 基合金和 Sn 焊料金属之间形成的金属间化合物 (IMC) 的润湿性和形成。焊接是在电炉中在 533、553、573、623 和 673 K 的温度下进行 600 秒的单独实验。通过扫描电子显微镜（SEM）表征在 Co-Cr-Mo 基/Sn-焊料界面形成的金属间化合物层的形态。通过电子探针显微分析(EPMA)和X射线衍射分析分析形成的金属间化合物层的化学成分和相。润湿性分析表明，焊接温度影响润湿性。随着焊接温度的升高，扩展因子增加，而接触角减小。在凝固的 Sn 焊料和 Co-Cr-Mo 基基材之间的中间区域中发现了三重金属间层。金属间化合物层的厚度随着焊接温度的升高而增加。EPMA 分析表明，在所有研究的焊接温度下，在接头的界面处仅形成了两个 IMC，尽管通过 SEM 分析观察到三个界面层。Sn 富集相 Co(Cr,Mo)Sn2 形成在 Sn 焊料基质附近，而 Co(Cr,Mo)Sn 则在 Co-Cr-Mo 基基体附近发现。纳米压痕测量表明，与 Sn-Cu 金属间化合物体系相比，形成的 Co(Cr,Mo)Sn2 和 Co(Cr,Mo)Sn IMC 具有较低的硬度值。金属间化合物层的厚度随着焊接温度的升高而增加。EPMA 分析表明，在所有研究的焊接温度下，在接头的界面处仅形成了两个 IMC，尽管通过 SEM 分析观察到三个界面层。Sn 富集相 Co(Cr,Mo)Sn2 形成在 Sn 焊料基质附近，而 Co(Cr,Mo)Sn 则在 Co-Cr-Mo 基基体附近发现。纳米压痕测量表明，与 Sn-Cu 金属间化合物体系相比，形成的 Co(Cr,Mo)Sn2 和 Co(Cr,Mo)Sn IMC 具有较低的硬度值。金属间化合物层的厚度随着焊接温度的升高而增加。EPMA 分析表明，在所有研究的焊接温度下，在接头的界面处仅形成了两个 IMC，尽管通过 SEM 分析观察到三个界面层。Sn 富集相 Co(Cr,Mo)Sn2 形成在 Sn 焊料基质附近，而 Co(Cr,Mo)Sn 则在 Co-Cr-Mo 基基体附近发现。纳米压痕测量表明，与 Sn-Cu 金属间化合物体系相比，形成的 Co(Cr,Mo)Sn2 和 Co(Cr,Mo)Sn IMC 具有较低的硬度值。尽管通过SEM分析观察到三个界面层。Sn 富集相 Co(Cr,Mo)Sn2 形成在 Sn 焊料基质附近，而 Co(Cr,Mo)Sn 则在 Co-Cr-Mo 基基体附近发现。纳米压痕测量表明，与 Sn-Cu 金属间化合物体系相比，形成的 Co(Cr,Mo)Sn2 和 Co(Cr,Mo)Sn IMC 具有较低的硬度值。尽管通过SEM分析观察到三个界面层。Sn 富集相 Co(Cr,Mo)Sn2 形成在 Sn 焊料基质附近，而 Co(Cr,Mo)Sn 则在 Co-Cr-Mo 基基体附近发现。纳米压痕测量表明，与 Sn-Cu 金属间化合物体系相比，形成的 Co(Cr,Mo)Sn2 和 Co(Cr,Mo)Sn IMC 具有较低的硬度值。