基于有限元方法的探针台屏蔽箱屏蔽效能分析

Shielding Effectiveness Analysis of Shielding Enclosure for Prober System Based on FEM

探针台因其检测对象易受电磁噪声干扰,因此如何有效抑制探针台外部电磁干扰非常重要。以探针台的屏蔽箱体作为研究对象,利用基于有限元方法的电磁仿真软件ANSYS HFSS,建立了平面波辐射条件下的探针台屏蔽箱模型,分析了缝隙宽度、箱体材料、孔缝形状对屏蔽效能的影响。仿真结果表明:孔缝宽度对屏蔽箱体的屏蔽效能有很大影响,电场极化方向与孔缝长边垂直时,屏蔽箱体的屏蔽效能大幅下降,典型金属材料对屏蔽效能有影响,但相差不是很大,屏蔽箱屏蔽效能与垂直于电场极化方向的孔洞线性尺寸成反比。仿真结果有利于探针台屏蔽箱的结构设计,提高箱体的电磁屏蔽效能。

The prober system＇ s test object is susceptible to EMI, so how to suppress the external EMI effectively is very important. The paper models the prober＇ s shielding enclosure under plane wave with electromagnetic simulation software ANSYS HFSS based on FEM. Some parameters in aperture＇ s size, materials of enclosure and aperture＇ s type were concerned in the analysis on their effect on SE. The works show that, the aperture＇ s size makes big effect on SE, SE is reduced largely when the long side is perpendicular to the direction of the electric field polarization ; typical metal materials make little difference impact on SE; and SE grows in inverse proportion to the aperture＇ s size perpendicular to the direction of the electric field polarization. The conclusion is helpful for the reasonable layout of the prober＇ s shielding enclosure, thus it can improve the ability of enclosure to suppress the EMI.