Efficiency improvement of a DC/DC converter using LTCC substrate

We propose a substrate with high thermal conductivity, manufactured by the low‐temperature co‐fired ceramic (LTCC) multilayer circuit process technology, as a new DC/DC converter platform for power electronics applications. We compare the reliability and power conversion efficiency of a converter using the LTCC substrate with the one using a conventional printed circuit board (PCB) substrate, to demonstrate the superior characteristics of the LTCC substrates. The power conversion efficiencies of the LTCC‐ and PCB‐based synchronous buck converters are 95.5% and 94.5%, respectively, while those of nonsynchronous buck converters are 92.5% and 91.3%, respectively, at an output power of 100 W. To verify the reliability of the LTCC‐based converter, two types of tests were conducted. Storage temperature tests were conducted at −20 °C and 85 °C for 100 h each. The variation in efficiency after the tests was less than 0.3%. A working temperature test was conducted for 60 min, and the temperature of the converter was saturated at 58.2 °C without a decrease in efficiency. These results demonstrate the applicability of LTCC as a substrate for power conversion systems.