We read several application notes about MLC capacitors and learned that because of their brittle nature, multilayer ceramic capacitors are more susceptible to excesses of mechanical stress than other components used in surface mounting. In our case, when we tighten the mounting screws, the PCB bends slightly. Excessive bending of the board can create mechanical cracks within the ceramic capacitor. Over time, moisture penetrates the crack and can cause a reduction in insulation resistance that is accelerated by humidity and temperature, and this generates a conductive path. As a result, it gets shorted and because of high current flow through the capacitor, the capacitor gets burned. Although these mechanical cracks may not lead to capacitor failure during the final assembly test, failures may occur once the product is in the field, when they are expensive and time consuming to correct.