Today's manufacturing techniques have considerably improved DC-DC reliability. The use of surface-mount placement for all components, computerised optical inspection of solder joints, automated test and laser marking have eliminated most manual tasks in the production process. In making its CC-E series of DC-DC converters, TDK Lambda even uses double-armed robots to form the converter leads, attach metal EMI shielding covers and package the final product into trays. Increased product reliability has led many DC-DC converter manufacturers to offer five-year warranties. Internally, ceramic capacitors have replaced electrolytics that age as their electrolyte dries out. Consequently, mean time between failure (MTBF) calculations are correspondingly higher. Based on the Telcordia reliability prediction procedure, TDK-Lambda's CCG15 series of 15W converters have calculated MTBFs of millions of hours. Naturally, this number varies with temperature and output load, as component reliability decreases as temperature rises; see Figure 1.
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