I. Product Overview
The ERHV0402 series current sensing resistors are high-performance high-voltage thick film chip resistors that strictly comply with EIA standard sizing specifications. With their compact 0402 package (corresponding to 1/16W power rating), they demonstrate excellent adaptability in various electronic devices with strict space requirements. The product adopts a high-quality structural design consisting of an alumina ceramic substrate and a ruthenium oxide (RuO₂)/silver (Ag) resistive layer, with a dual protective coating of glass and epoxy resin on the surface. This not only ensures outstanding electrical performance but also provides excellent stability and reliability. It can be widely used in high-voltage electronic systems requiring precise current sensing, laying a solid foundation for the safe and stable operation of equipment.
II. Core Performance Parameters
- Power and Voltage Characteristics: At an operating temperature of 70°C, the rated power is 1/16W (0.063W), the maximum continuous working voltage can reach 100VDC, and the maximum overload voltage is 200VDC (twice the maximum working voltage). It should be noted that the maximum allowable continuous working voltage of the resistor shall be the smaller value between the specified value in the specification sheet and the calculated value of power rating (Watts) × resistance (Ohms), ensuring the product operates within a safe voltage range.
- Resistance Specifications: The resistance range covers 39KΩ~100MΩ, offering two standard resistance value series: E-24 and E-96, to meet the precise matching needs of different scenarios. The tolerance grades are ±1% (code F) and ±5% (code J). The temperature coefficient varies according to the resistance range: ±100ppm/℃ for 39KΩ~1MΩ, ±200ppm/℃ for 1.02MΩ~10MΩ (E-96 series) and 1.1MΩ~20MΩ (E-24 series), and ±400ppm/℃ for 22MΩ~100MΩ (E-24 series), ensuring resistance stability over a wide temperature range.
- Operating Temperature Range: The applicable temperature range is -55℃~+155℃, which can adapt to the working requirements in extreme environments and exhibit strong environmental tolerance.
III. Product Structure and Process
The ERHV0402 series resistors adopt a sophisticated multi-layer structural design, with the core components as follows: The substrate is made of alumina material with high insulation and thermal conductivity, providing a stable supporting foundation for the resistive layer; the resistive layer uses high-performance ruthenium oxide (RuO₂) material to ensure precise resistance value and excellent temperature stability; the electrode system includes a bottom silver electrode, a top silver-palladium electrode, and an edge nickel-chromium electrode, combined with a nickel barrier layer and a tin terminal plating, effectively improving the conductivity, oxidation resistance, and solderability of the electrodes; the surface is sequentially covered with an inner glass protection layer and an outer epoxy resin protection layer, fully resisting the erosion of the resistive layer by the external environment and extending the product service life.
In terms of manufacturing process, the product strictly follows high industry standards. Through a series of refined processes such as thick film printing, precision photolithography, and high-temperature sintering, precise control of the resistance value and tight bonding of each structural layer are ensured, ultimately achieving consistency and reliability of product performance.
IV. Environmental and Mechanical Characteristics
- Environmental Adaptability: It has excellent resistance to temperature changes and damp heat. After rapid temperature change cycle tests between -55℃ and 155℃, the resistance change is controlled within ±(0.5%+0.05Ω) (1% tolerance) and ±(1.0%+0.05Ω) (5% tolerance); after working for 1000 hours in a loaded damp heat environment of 40℃ and 90~95% relative humidity, the resistance change does not exceed ±(2%+0.10Ω) (1% tolerance) and ±(3%+0.10Ω) (5% tolerance), adapting to complex and harsh working environments.
- Mechanical Reliability: It exhibits excellent bending strength. After bending at a bending radius of 3mm for 5 seconds, the resistance change meets the strict standards of ±(1%+0.05Ω) (1% tolerance) and ±(1.0%+0.05Ω) (5% tolerance), ensuring that it is not prone to performance failure due to mechanical stress during PCB assembly and subsequent use.
- Soldering Performance: The terminals have good solderability. When soldered at 245℃±5℃ for 3 seconds, the solder coverage is not less than 95%; after withstanding a soldering thermal shock of 260℃±5℃ for 10 seconds, the resistance change is only ±(0.5%+0.05Ω) (1% tolerance) and ±(1.0%+0.05Ω) (5% tolerance), meeting the requirements of conventional soldering processes and enabling convenient and efficient assembly.
V. Conclusion
With its compact package size, excellent high-voltage performance, precise resistance control, and strong environmental adaptability, the ERHV0402 series current sensing resistors have broad application prospects in high-voltage electronic equipment, precision instruments, industrial control, and other fields. Its scientific structural design and strict manufacturing process ensure the stable and reliable operation of the product under complex working conditions, enabling it to provide customers with high-precision and high-stability current sensing solutions. Whether for miniaturized equipment with strict space constraints or high-voltage systems with high performance requirements, the ERHV0402 series resistors are a trustworthy choice for core components.
