A Modularized Thermal Test Chip Design and Verification

With the development of system on chip, the power distribution in the chip becomes more complicated. Clock frequency increasing and high speed signal rate multiplication make certain local power to be much more higher compared to the average power in the chip. The evaluation and testing of thermal solution becomes more challenge due to complex power distribution in chip. To simply the evaluation the thermal performance of chip, a thermal test chip(TTC) is developed, in which the power distribution is controllable and large numbers of temperature sensors is available, to reproduce the real chip power distribution and temperature map. In this paper, the design of modularized thermal test chip is illustrated firstly, in which there is a heater and a resistance temperature detective sensor using BEOL serpentine metal resistance. The module size is about 1mm square. Heater and sensor are designed with Kelvin-connection for accurately measurement. Secondly, the thermal test chip is verified by resistance measurement and the statistics results indicate resistance of heater is within ±10%. RTD sensor has high linearity after calibration. And an uniform power test is conducted, which the temperate difference between test and simulation is within ±1°C. Thirdly, the method using TTC to reproduce a real chip power map is introduced. From the simulation results we can find the modularized TTC can obtain an almost the same temperature map compared to real chip, by adjusting the power distribution of heater.