Several factors can contribute to the failure of ceramic capacitors, including excessive voltage stress, temperature extremes, mechanical stress, aging, and manufacturing defects.
The migration of silver ions and the consequent accelerated aging of titanium-containing ceramic dielectrics are the main reasons for the failure of ceramic capacitors. Some manufacturers have used nickel electrodes instead of silver electrodes in the production of ceramic capacitors, and electroless nickel plating is used on the ceramic substrate.
In addition to these failures, capacitors may fail due to capacitance drift, instability with temperature, high dissipation factor or low insulation resistance. Failures can be the result of electrical, mechanical, or environmental overstress, "wear-out" due to dielectric degradation during operation, or manufacturing defects.
Why do multilayer ceramic capacitors crack?
Cracking remains the major reason of failures in multilayer ceramic capacitors (MLCCs) used in space electronics. Due to a tight quality control of space-grade components, the probability that as manufactured capacitors have cracks is relatively low, and cracking is often occurs during assembly, handling and the following testing of the systems.
What makes a ceramic capacitor worthless?
The failure of ceramic capacitors during dielectric breakdown, which renders the device worthless, is another pertinent component of these devices . For power devices, Cer-aLinkTM, a new ceramic capacitor technology from EPCOS, may be the ideal option.
Why do paper and plastic film capacitors fail?
Paper and plastic film capacitors are subject to two classic failure modes: opens or shorts. Included in these categories are intermittent opens, shorts or high resistance shorts. In addition to these failures, capacitors may fail due to capacitance drift, instability with temperature, high dissipation factor or low insulation resistance.
What causes a hermetically sealed capacitor to fail?
Fatigue in the leads or mounting brackets can also cause a catastrophic failure. The altitude at which hermetically sealed capacitors are to be operated will control the voltage rating of the capacitor. As the barometric pressure decreases so does the terminal "arc-over" susceptibility increase.