【摘要】 以甲基磺酸锡为镀锡液的主盐,采用Stoney镀层应力测试方法,以及锡晶须生长趋势评价标准(JEDEC标准JESD22Al21.01),研究了双向脉冲电沉积参数对纯锡镀层拉应力大小及其晶须生长特性影响的规律。利用扫描电子显微镜(SEM)表征了锡镀层晶须生长前后的微观形貌,优选出了锡镀层应力低、锡晶须生长趋势小的双向脉冲电沉积参数(平均电流密度为10 A/dm~2,占空比为0.7,逆向脉冲系数为0.5,频率为10 Hz)。结果表明,通过调控双向脉冲参数,可控制纯锡镀层内应力的大小,进而制备出可抑制锡晶须生长的纯锡镀层。更多还原

【Abstract】 The effects of bidirectional-pulse parameters on the tensile stress of the tin coatings and the growth characteristics of tin whisker were investigated,based on the bath containing tin methyl sulfonate as the main salt.The coating stress was evaluated using the Stoney method,and the tin whisker growth tendency was examined according to the JEDEC Standard(JESD22 A121.01).The microstructure of tin coatings before and after the appearance of tin whisker were characterized using scanning electron microscope(SEM).On this basis,the optimal bidirectional-pulse tin electrodeposition parameters(average current density of 10 A/dm~2,duty cycle of 0.7,reverse pulse coefficient of 0.5,frequency of 10 Hz) were revealed for the preparation of tin coatings with less stress and less tendency of tin whisker growth.The results show that tin coating capable of suppressing tin whisker growth can be prepared by controlling the internal stress of tin coating via adjusting the bidirectional-pulse parameters.更多还原