Temperature Sensors in Nickel Thin Film Technology

The measurement of temperature is for many applications the most important measurement for safety and reliability of systems. Ni-thin film Resistance Temperature Detectors (Ni-RTD's) are manufactured by PVD-deposition on silicon substrate. In the next step the resistance meander is micromechanically structured before the thin film structure is covered by a passivation layer for environmental protection. Using a digital tuning by laser shaping a precise basis resistance value is achieved. Finally these chips are diced and mounted on the lead frame of a SOT23 package. This technology allows producing very small size, low cost, high precision and long term stable temperature sensors. The resistance drift caused by different qualification tests is found to be always below 0.1%.