基于数值仿真的气动喷射阀回流间隙的优化

Optimization of the backflow gap of pneumatic jetting valve based on numerical simulation

气动喷射阀是微电子封装中不可或缺的封装设备,但现有气动喷射阀在喷射高黏胶液时仍不能完全满足工业界对胶滴一致性的需求,原因在于其喷射高黏胶液时常出现因喷射速度太小而导致的挂胶漏喷现象.要减小上述现象的发生概率,就必须提高现有气动喷射阀的高黏流体喷射能力.回流间隙作为气动喷射阀的关键尺寸,直接影响着喷射阀的喷射能力.为了通过优化回流间隙来提高喷射能力,首先建立气动喷射阀的胶液喷射数值仿真模型并通过实验验证其可靠性,同时基于不同回流间隙的仿真数据建立了相应的高斯拟合模型.然后利用拟合模型以胶滴滴落速度为优化目标对回流间隙进行优化,通过优化前后的喷射对比验证了优化结果的可靠性,最后获得气动喷射阀的最优回流间隙.

Pneumatic jetting valve plays an indispensable role in the microelectronic packaging.However,the current pneumatic jetting valves can＇t meet the industrial requirement of droplet consistency completely for the frequent occurrence of jetting omission when it is used to jet highviscosity adhesives.Jetting capacity must be enhanced to reduce the probability of the problem occurrence.As a key dimension of pneumatic jetting valve,the size of backflow gap influences its jetting capacity directly.In order to improve jetting capacity by optimizing backflow channes,a numerical model of the jetting process was established firstly and its validity was verified by corresponding experiment.Meanwhile,a Gaussian fitting model was built based on simulation data with different backflow channels.After that,the model was utilized to optimize the size of backflow gap by choosing droplet speed as optimization objective.The reliability of optimization results was verified by comparison of the jetting performance before and after optimization.Finally,the optimal size of backflow gap of pneumatic jetting valve was obtained.