Water-repellent monolithic ceramic capacitor suppresses ion migration

05-08-2015 | Murata | Design Applications

Electronic devices are becoming ever more compact and densely packed with components, with this comes an increase in the possibility of malfunctions influencing circuit operation due to ion migration. In response, Murata has developed a water-repellent monolithic ceramic capacitor by applying an innovative surface treatment.

Ion migration may occur when voltage is applied to a capacitor where moisture is present between the electrodes. This may result in the anode metal becoming ionized and changing to a cathode. Then, when gaining electrons as a cathode, the metal may undergo the electrochemical phenomenon of deposition and growth that can eventually result in a short-circuit. This is particularly prone to occur when the capacitor is moistened by condensation.

To address this issue Murata developed the water-repellent monolithic ceramic capacitor which is treated with a film so that moisture forms into scattered, rather than larger, droplets. These droplets are suppressed to a size that is not big enough to span the gap between the external electrodes and this prevents ion migration.

The capacitor has applications particularly in navigation systems, body control electronic control units (ECUs), air conditioner ECUs, meter ECUs and engine ECUs, etc. Sample shipments have already begun and the capacitor is scheduled to enter mass production within the year, says the company.

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