A high-frequency performance and degradation study of adhesive conductive EMI shielding tapes during High-Temperature Storage

Inhalt:
The variation of the contact impedance of adhesive conductive EMI shielding tapes under high temperature storage (HTS) of 110 °C. is investigated. The adhesive tapes under test are implemented as signal return paths in microstrip lines. Changes in the ground plane impedance by adhesive deterioration are analyzed by S-parameter measurements from 1MHz to 3GHz. A circuit model for contact impedance degradation is proposed and applied in simulation of board level shielding. Contact resistance and contact capacitance are found to increase significantly after 2400h, causing a declined magnetic field shielding effectiveness by 30 dB below 500 MHz.