汽相再流焊立碑缺陷的产生原因

Causes of Tombstoning in Vapor Phase Reflow Soldering

汽相再流焊具有加热效率高,温度均匀性好,加热不受元器件物理结构和几何形状限制等优点,但是汽相再流焊更容易引发立碑缺陷是每个用户必须面对的问题。结合汽相再流焊的工艺特点,建立了片式元件焊接时的受力模型,分析了汽相再流焊导致立碑的自身原因。通过减小汽相升温速率和调高印制板在蒸气层中的位置,有效降低了立碑缺陷的发生概率。

Vapor phase reflow soldering is more and more used in the production of high reliable electronic products for aerospace,military and industrial area because of the advantages of high heat efficiency,good temperature uniformity,no restriction for structure and shape of components,etc.But tombstoning in vapor phase reflow soldering is the problem faced to each user.The characteristics of vapor phase reflow soldering process are described.Force model of chip in reflow soldering is established,the causes of tombstoning in vapor phase reflow soldering are analyzed,and the countermeasures are proposed.