【摘要】 应用荧光分析法、X光电子能谱法（XPS）及正电子湮没寿命谱法（PALS）等研究了从含硫酸铈添加剂的酸性光亮锡镀液获得的锡镀层结构缺陷与可焊性的关系。结果表明,电镀时Ce与Sn不发生共沉积,Ce³⁺的主要作用是阻化Sn²⁺的水解和氧化使镀液稳定,因而使锡镀层纯度提高、结构致密、表层氧含量减少,有利于提高镀层的可焊性。当Ce³⁺浓度控制在3.5g/L左右时,可使镀层结构缺陷较少,可焊性较佳,说明结构缺陷是影响锡镀层可焊性的直接原因。更多还原

【Abstract】 The relationship between the structure defect and weldability of Sn coating, electrodeposited from the acidic bright bath containing Ce3+ ion as the additive, has been investigated by means of flu-orometry, X-ray photoelectron spectroscopy (XPS) and positron annihilation lifetime spectroscopy (PALS), It was shown that the co-deposition of Ce and Sn did not occur during the electrodeposition process. The.effect of Ce3+ in the bath was to inhibit the hydrolysis and oxidation of Sn2+ resulting in the stabilization of the electrolyte as shown in Table 2 and Fig. 1, which in turn decreased the oxygen content in the Sn coating surface(Fig. 2). This is one of the reasons for that Ce3+ ion in bath is favorable to improving the weldability of the coating. But the experimental results of PALS showed that only those Sn coating obtained from the bath containing ~- 3. 5 g/L of Ce3+ possessed a lower structrue defect as indicating by the positron average lifetime τ, which was responsible for the higher weldability as shown in Fig. 3.更多还原