The described embodiments relate generally to a capacitor assembly for mounting on a printed circuit board (PCB) and more specifically to designs for mechanically isolating the capacitor assembly from the PCB to reduce an acoustic noise produced when the capacitor imparts a piezoelectric force on the PCB. Termination elements in the capacitor assembly, including a porous conductive layer in the capacitor assembly may reduce an amount of vibrational energy transferred from the capacitor to the PCB. Termination elements including a soft contact layer may also reduce the amount of vibrational energy transferred to the PCB. Further, capacitor assemblies having thickened dielectric material may reduce the amount of vibrational energy transferred to the PCB.