KOA Speer...

A Leader in
Anti-Sulfuration
Chip Resistors


Silver-based inner electrodes in flat chip resistors can lose conductivity when the silver reacts with sulfur in a high-sulfur environment. The electrodes can lose all conductivity and disconnect the circuit as sulfuration continues. KOA Speer has developed a complete line of anti-sulfur chip resistors and arrays to protect against sulfuration of the resistor electrodes.

Features:

  • Excellent anti-sulfuration characteristics due to use of high sulfuration-proof inner top electrode material
  • Excellent heat resistance and environmental resistance by applying metal glaze thick film to resistive film
  • AEC-Q200 Qualified
  • Passes ASTM-B809 anti-sulfuration testing

Anti-Sulfur Performance Comparison

Why Choose Anti-Sulfur?

Sulfuration is a phenomenon that occurs in resistors with silver-based inner electrodes. When a resistor is used in a high-sulfur atmosphere, the sulfur molecules can migrate between the protective film and the outer electrode to the inner electrode, where they react to form silver sulfide. Silver sulfide is an insulator, and the resistance of the device increases toward an open circuit. KOA's product line includes resistors with sulfuration-resistant inner electrodes.

Chip Resistor Disconnected by Sulfuration

Needle crystals of
silver sulfide (Ag2S)

KOA Speer's Family of
Anti-Sulfur Chip
Resistors


General Purpose

RK73B-RT

- ±2%, ±5% General Purpose Flat Chip Resistor


RK73H-RT

- ±0.5%, ±1% High Precision Flat Chip Resistor


RK73Z-RT

- Zero ohm with max. resistance of 50mΩ



High Precision

RS73-RT NEW

- High reliability with ΔR of ±0.2%, ±0.4% in reliability test


RK73G-RT

- ±0.5%, ±1% Ultra Precision Flat Chip Resistor



Wide Terminal

WK73R-RT

- Power rating: 0.75W (0508, 0612), 1W (0508, 0612, 1020, 1218), 1.5W (1225), 2W (1225)


WK73S-RT

- Power rating: 0.75W (0508, 0612), 1W (0508, 0612, 1020, 1218), 1.5W (1225), 2W (1225)


WK73R-RT (Higher Power) NEW

- Higher power rating: 1.5W (0612), 2W (1020), 3W (1225)


WK73S-RT (Higher Power) NEW

- Higher power rating: 1.5W (0612), 2W (1020), 3W (1225)



High Voltage

HV73V-RT

- High Voltage Flat Chip Resistor for Automotive


HV73-RT

- High Voltage Flat Chip Resistor



Anti-Surge

SG73-RT

- Superior to RK73 series in surge withstanding voltage and pulse withstanding voltage


SG73P-RT
NEW

- Able to select resistance from +0.5%


SG73S-RT
NEW

- Surge Precision, Low Resistance (0.1Ω)



Current Sense

SR73-RT

- Low Resistance (0.1Ω)



Network

CN-RT,
CN_K-RT

- Concave, Square Corner Isolated Chip Array Network


Structural Chart of Flat Chip Resistor (Standard)