In the present study, we introduce a heater dummy chip equipped with temperature sensor, with extremely high capability of high heat-density using SiC wafer. As often used in high voltage/temperature SiC devices exhibit their advantage of high thermal stability and heat conductivity. Our testing heater chip (thermal test engineering group, TEG) consist of insulated SiC and Pt thin-film heater and temperature sensor realizes extreme heat density of 250 W/mm2 with reliability above 300°C of high temperature. The TEG chip was the n-doped 4H SiC chip, which is used generally for SiC devices, coated with an alumina insulation film and molded the Pt heater and sensor by lithography technique. Using the TEG chip, we demonstrate simple but accurate heat resistant measurements of several types of metal bonded ceramic substrates. The combination of SiC TEG chip and heat resistance measurement system is also applied to power cycle testing, avoiding numerous problems arising from using actual working device chips. Therefore, this study systematically was carried out the thermal measurement technology of SiC with repetitive power cycle by TEG chip as new concept heat system. Through this progress, the technologies developed in the study may have further applications in evaluation and testing of various packaging materials targeted for high temperature/wattage power modules.