基于围坝胶BGA的三防涂层保护方法研究  

Study on protection method of BGA triple-proof coating based on dam encapsulant

作　　者：杜映洪 文永森 刘勇 刘绍辉 DU Yinghong;WEN Yongsen;LIU Yong;LIU Shaohui(China Key System&Integrated Circuit Co.,Ltd.,Wuxi 214072,Jiangsu China)

机构地区：[1]中科芯集成电路有限公司,江苏无锡214072

出　　处：《粘接》2023年第12期29-33,共5页Adhesion

摘　　要：三防漆是1种保护性化学材料,可作为薄层涂敷在印刷电路板(PCB)组件上,其作用是防止外部环境因素与电气组件之间的相互影响。由于三防涂层具有与电子元件不同的材料热力学性能,可能会在电路板上引起额外的机械应力。介绍了一种围坝胶和三防漆相结合的BGA封装器件三防保护方法。基于有限元方法,评估了围坝胶对BGA焊点热疲劳可靠性的影响,并进行了材料参数影响分析。结果显示,围坝胶通过轴向变形和剪切变形2种机制影响焊点损伤。高热膨胀系数(CTE)、低模量的围坝胶对BGA焊点热疲劳寿命没有不利的影响,低CTE、高模量的围坝胶有助于提高BGA焊点抗热疲劳的能力;而采用高CET、高模量的围坝胶会导致BGA焊点热疲劳可靠性劣化。Triple-proof coating is a protective chemical material that can be applied as a thin layer on printed circuit board(PCB)assemblies,and its role is to prevent the interaction between external environmental factors and electrical components.Due to the fact that triple-proof coatings have different thermo-mechanical properties as compared to electronic components,they may induce additional mechanical stresses on the circuit board.A method of triple protection for BGA package devices by combining a dam encapsulant and a triple-proof coating was presented.Based on the finite element analysis,effect of dam encapsulant on thermal fatigue reliability of BGA solder joints was evaluated,and the influence of the material parameters was analyzed.The results showed that the dam encapsulant affected the welded joint damage through two mechanisms:axial deformation and shear deformation.High coefficient of thermal expansion(CTE)and low modulus of dam encapsulanthad no adverse effect on thermal fatigue life of BGA solder joints.The low CTEhigh modulus materials helped to enhance the thermal fatigue resistance of BGA solder joints,while high CET high modulus materials led to the deterioration effect on thermal fatigue reliability of BGA solder joints.

关 键 词：BGA三防 围坝胶 热疲劳可靠性 

分 类 号：TQ437.6[化学工程]