Development and fabrication of a thin film thermo test chip and its integration into a test system for thermal interface characterization

This paper deals with the development und fabrication of a thermal test chip (TTC) to be used for thermal characterisation and qualification of materials and packages. The TTC is designed as a modular chip with the smallest full functional chip cell of 3.2mm × 3.2mm and consists of a heater structure and a temperature sensor. The chips can be applied in any required matrix. Heater and temperature sensors are realised by a 70 nm single Titanium layer as adhesion and barrier layer. The Titanium is structured a on 670μm silicon wafer by the cost efficient thin film technology. 3×3 matrix chips have been sawn, assembled on a FR4 substrate by flip chip technology and integrated into a test stand for characterisation of thermal interface materials (TIMA Tester). The calibration curves of the temperature sensors show 4-time higher sensitivity then Si diodes. The homogeneity of the surface temperature was checked by the Lock-In infra-red thermography and compared with a commercial thermo test chip.