LED透镜注射成型工艺稳健性优化分析

Steady Experimental Design of Injection Molding Process for LED Lens

采用稳健设计方法,以LED透镜折射率变化为实验目标,模具温度(A)、熔体温度(B)、保压压力(C)、保压时间(D)、冷却时间(E)为影响因素,设计了L16(45)正交实验矩阵,并对LED透镜的注射成型过程采用Moldflow软件进行模拟分析,获得最优工艺参数的组合为A2B4C4D3E4。结果表明,保压压力对LED透镜折射率的影响最大,保压时间次之,模具温度、熔体温度、冷却时间对折射率的影响不大,保压压力越大,信噪比越大,折射率变化越小;优化后采用较高的保压压力和较长的冷却时间,可以改善透镜内部残余应力,减小体积收缩率,折射率变化和翘曲变形量减少,透镜各个方向上光的相移明显降低,从而提高了LED透镜的光学性能和成型质量。

Using steady experimental design method,refractive index variation of LED lens as experiment objective,and mold temperature（A）,melting temperature（B）,holding pressure（C）,holding time（D） and cooling time（E） as influence factor,L16（45） orthogonal experiment matrix is designed. Injection molding process for LED lens was simulated through Moldflow software,and optimum processing parameter A2B4C4D3E4 is obtained. The results show that the influence on refractive index of LED lens is holding pressure first,holding time second,and mold temperature,melting temperature and cooling time unobviously. The greater holding pressure is,the greater signal-to-noise ratio is,and the smaller refractive index changes is. The optimization result indicate that higher holding pressure and longer cooling time can improve interior residual stress and reduce volume shrinkage,which make refractive index variation,warpage deformation and optical phase shift in all direction reduce. Therefore,optical performance and processing quality of LED lens are improved.