Bare Alloy Resistor

Core Structure & Materials

• Resistive element: Manganin, Constantan, Nichrome, Karma alloy.

   

  Electrodes are mostly high-conductivity pure copper, connected by electron beam welding / laser welding.

   

  Common packages: 3920, 5930, 2725, available in flat sheet and zig‑zag structures.
   
• Resistance range: Typically 0.1 mΩ – 5 mΩ;

   

  Tolerance up to ±0.01%;

   

  TCR as low as ±10–25 ppm/℃;

   

  Parasitic inductance < 3 nH, non‑inductive design.
   
• Power rating: Starts from 5 W, some models 10–15 W;

   

  Operating temperature: -55℃ to 170℃, compliant with AEC‑Q200.
   

Key Advantages & Precautions

1. Excellent heat dissipation: Large exposed surface area enables fast heat release and higher power density.
2. Ultra‑stable resistance: Low temperature coefficient, low thermal EMF, high surge current capability; suitable for harsh working conditions.
3. Soldering restrictions: Generally only compatible with reflow soldering; avoid high-temperature damage from wave soldering. Anti‑oxidation and mechanical protection required. Not suitable for unprotected dusty or humid environments.

Typical Applications

Selection & Purchasing Tips

• Select package and power rating based on maximum current, power dissipation, and PCB space. Prioritize low TCR, low inductance, and Kelvin 4‑terminal design.
• Soldering process must match reflow soldering. Apply coating or housing for protection if necessary.