H540 S high-temperature micro heater sensor

It is a passive Pt1000 resistance temperature sensor, not an active micro heater. Its resistance is 1,000 Ω at 0 °C and changes with temperature at a coefficient of 3,850 ppm/K, allowing the connected measurement circuit to determine temperature. The recommended excitation current is only 0.1 to 0.3 mA and is intended for resistance measurement rather than deliberate heat generation. Any self-heating is treated as an error source, with a coefficient below 0.4 K/mW in the unassembled condition. Select this component when local temperature feedback is required; a separate heating element is necessary if the design must generate heat.

The underside is designed for silver sintering, while the top contacts are intended for ultrasonic thick-wire bonding. Its AgPd back-side metallisation works with the silver-sinter attachment process, and the AgPt top surface supports 300 µm Al H11 bonding wire. Reference test results give a back-side shear strength above 10 N/mm² minimum and above 20 N/mm² mean, with a top-side pull value above 210 cN. These figures should be treated as process-validation references rather than automatic acceptance limits for every assembly. The production line therefore needs suitable die-attach, sintering and wire-bonding capability rather than relying solely on conventional PCB reflow equipment.

Class F 0.6 (2B) applies during continuous operation from -50 °C to +200 °C. Within this range, the Pt1000 element follows a 3,850 ppm/K characteristic based on DIN EN IEC 60751. Operation above +200 °C is indicated, but no defined upper temperature or tolerance class is given beyond that point. Total system accuracy will also depend on excitation-current stability, analogue front-end error, conversion accuracy and the thermal path between the monitored surface and the sensor. Designs operating above +200 °C should therefore use application-specific characterisation rather than assuming that the stated tolerance class continues unchanged.

The recommended measuring-current range is 0.1 to 0.3 mA, with the final value selected around noise, resolution and self-heating requirements. At 0 °C, a 0.1 mA current through 1,000 Ω dissipates 0.01 mW, while 0.3 mA dissipates 0.09 mW. Applying the unassembled self-heating coefficient of less than 0.4 K/mW gives estimated temperature rises below 0.004 K and 0.036 K respectively under those reference conditions. Resistance increases with temperature, and the completed assembly will have a different thermal environment, so the worst-case calculation must use the actual operating resistance and mounting structure. Pulsed excitation can be considered where reduced average dissipation is more important than continuous measurement.

Yes, the electrically isolated underside is intended to support placement on or close to heat-generating components. Insulation resistance is greater than 1,000 MΩ at 20 °C, and the theoretical dielectric strength is 7.5 kV based on the substrate properties and sensor geometry. However, the completed assembly may achieve a lower dielectric strength because sintering, encapsulation, potting materials and the potting meniscus can alter the electrical field and insulation path. The sensor rating does not replace the creepage, clearance or insulation-coordination requirements of the complete power module. Production assemblies should therefore undergo insulation and high-voltage validation in their final mechanical configuration.

The maximum stated R₀ drift is 0.23% after each of three independently performed tests. These tests comprise 1,000 hours at +200 °C with at least 0.1 mA, 1,000 hours at +85 °C and 85% relative humidity, and 1,000 cycles between -40 °C and +150 °C. For a 1,000 Ω element, 0.23% corresponds to 2.3 Ω, which is approximately 0.6 °C near 0 °C when related to a 3.85 Ω/K sensitivity. This result should not be interpreted as the guaranteed drift after every possible combined mission profile. Engineers should include sensor drift, electronics drift, mounting effects and any required recalibration interval in the complete error budget.

The electrical and sensing specifications are the same for both order numbers, so selection is primarily determined by packaging and assembly flow. Part number 5164075 is supplied on a wafer frame, which can suit batch die-handling and sinter-attach processes. Part number 5195006 is supplied on a blister reel for feed-based automated handling, with approximately 4,200 face-up pieces per reel and smaller quantities potentially available in individual cases. Both packaging formats have a stated minimum storage life of nine months when unopened and an MSL 1 unlimited classification. The final choice should therefore reflect placement equipment, production volume, material handling and procurement requirements rather than electrical performance.