导热绝缘胶BGA底部微空间填充工艺研究

Research on microspace filling process of thermal insulation adhesive at bottom of BGA

通过对导热绝缘胶本征性能、组成配方、印制板组件实际空间位置关系和主要球栅阵列(BGA)器件封装结构的特点进行分析,设计制作工艺试验件,进行了导热绝缘胶填充模型理论研究,探究了黏度、预热温度、填充方式和真空度等因素对填充效果的影响。经过导热绝缘胶填充系列工艺试验研究和填充围堰工装的设计优化,获取了影响填充的较佳工艺参数、填充方式及工艺流程。制作的验证样件经过断层扫描(CT)设备检测,填充空洞率小于10%。采用玻璃基BGA工艺器件实现了可视化填充工艺验证,工艺方法简便,合理可行。

By analyzing the intrinsic properties of thermal insulation adhesive,composition formula,the actual spatial position relationship of printed circuit board assembly and the characteristics of main ball grid array(BGA)device packing structure,the process test pieces were designed and manufactured,the theoretical research on the filling model of thermal insulation adhesive was carried out,and the effects of viscosity,preheating temperature,filling mode and vacuum degree on the filling effect were explored.After a series of process test and research on thermal insulation adhesive filling and the design optimization of filling cofferdam tooling,the optimized process parameters,filling mode and process flow affecting the filling were obtained.The prepared verification sample was tested by computed tomography(CT)scan,and the filling void rate was less than 10%.The visualization filling process verification was realized by adopting the glass-based BGA process device,and the process method was simple,reasonable and feasible.