The most common failure mode among surface-mount MLCCs is internal cracking of the ceramic layers caused by flexing of the PCB under thermal and mechanical loads (also referred to as flex cracks). Surface-mount MLCCs that are placed close to push connectors are particularly vulnerable. Flex cracks can also be induced during manufacturing processes such as depanelization or final assembly. They tend to originate on the inside edge of the mounted termination band and propagate upward through the ceramic layers. If the crack extends through opposing internal electrodes, any ionic penetration or humidity will allow current to pass and will most likely lead to a short-circuit failure.

The attached wire lead material extends the electrical termination connection of the ceramic chip capacitor while mechanically isolating the capacitor body from the circuit board. Isolation addresses the primary failure mode of Surface Mount MLCCs. The wire leads of both Axial and Radial devices inhibits the transfer of board stress to the rigid ceramic body, therefore mitigating flex cracks which can result in low IR or short circuit failures. Mechanical isolation technology is the most effective when addressing the primary failure mode of ceramic capacitors. As outlined in this illustration, the ceramic body of a surface mount device is not protected and is susceptible to damage when the PCB is placed under a thermal or mechanical load.