Impact of BGA Package Failure on Crosstalk in Microwave Circuits Using GSG Structure

Ball grid arrays provide a small size and high-density package, which may lead to crosstalk in complex working environments. Of specific interest in this current work, the impact of failed ground solder balls on crosstalk in microwave circuits using ground-signal-ground structure was evaluated by simulations and measurements. In the 3-D electromagnetic model, two single-ended signal transmission channels were developed to analyze the effects of failed solder balls and the distance between two soldering areas on the signal transmission performance and crosstalk. Based on the frequency distribution of resonance points and structural characteristics of the soldering area with failed ground solder balls, an inductive coupling model was proposed to quantify the impact of above-mentioned factors on signal crosstalk. The results obtained from 3-D electromagnetic and equivalent circuit models are in good agreements. Experimental tests were then conducted to verify the simulation results.