3-Dimensional Characteristic of Electric Field and Potential Induced by Internal Charging Effects in Typical PCB

To assess satellite internal charging effects more accurately, a 3-D computation method is developed to study the internal charging problems with realistic geometry and grounding configuration. The method includes two steps: 3-D electron transport simulation and internal electric field computation. The transport simulation is carried out by a self-developed software based on GEANT4. And 3-D internal electric field is calculated through solving a set of electrostatic equations by COMSOL Multiphysics. In this work, the 3-D characteristics of electric field and potential in a typical PCB irradiated by an electron beam through an aluminum shield are demonstrated. This PCB is partially grounded by a rectangular circuit and the electron beam uses the GEO space-like spectrum with flux in the worst case. According to these conditions, the 3-D field and potential distributions in charging stationary state can be computed. Finally, the following conclusions are drawn: distributions of dose and charge deposition rate have remarkable edge effects. Severe distortion of electric field can arise around edges of partial grounding, especially at corners. The degree of field distortion decreases significantly with the increase of the distance from the grounding surface.