冷却介质对BGA焊球质量的影响

摘要

Uniform droplet spraying technique was employed to fabricate the BGA balls. Silicone oil and peanut oil were employed as cooling mediums. When temperatures of cooling mediums were 150, 200 and 250 ℃5, influences on the sphericity and the surface quality of Sn-3.0Ag-0.5Cu solder balls were studied, and the microstructure of the solder balls was investigated. The results demonstrate that with silicone oil and peanut oil as cooling mediums, the optimal sphericities of solder balls can be obtained when the temperature of cooling medium is 200 ℃, those are 92.2％ and 98.2％, respectively.In addition, the increased temperature of the cooling medium can improve the surface quality of solder balls. The suitable the super cooling of the cooling medium, the more the hypoeutectic phases can be filled into β-Sn dendrites. Accordingly,the improvements on surface quality of solder balls can be achieved.%采用均匀液滴喷射法制备BGA焊球,以硅油和花生油作为冷却介质,研究了冷却介质在150,200和250℃时对Sn-3.0Ag-0.5Cu焊球球形度和表面质量的影响,对焊球的显微组织进行了分析.结果表明,硅油和花生油作为冷却介质,温度为200℃时得到的焊球球形度最好,球形度分别为92.2%和98.2%.另外,提高冷却介质温度可以提高焊球的表面质量;发现合适的过冷度可以产生较多的亚共晶组织填充在β-Sn之间,得到表面质量较好的焊球.