Anti Sulfuration Flat Chip Resistors

Sulfuration is a phenomenon that occurs in the resistor that applies silver for *inner electrode. Typical product where sulfuration is concerned is thick film chip resistor. When a resistor is used under atmosphere including sulfur, sulfur inserts between protective film and outer electrode, which leads to reaction with silver of inner electrode. This reaction is called sulfuration. Silver sulfide produced through this reaction has no conductivity therefore resistor gets disconnected.

Mechanism of Sulfuration

Sulfur is included as sulfur gas near hot springs or volcanos but also produced through firing of raw oil. Some rubber products apply sulfur to increase the strengths. When you use the above chip resistors under such atmosphere or near the product, the resistor should be prepared e.g. resin-molded. 
KOA's product lineup includes anti-sulfur type resistors that apply non sulfur type inner electrodes and slow-sulfur type flat chip resistors that sulfur is unlikely to insert.

※ "Inner electrode" is the electrode that is not disclosed to outside of resistor, and is applied in order to connect resistive element and outer electrode(which is for soldering on the pattern) electrically.

Anti-Sulfur Type Resistors

Thick Film Chip Resistors　RK73B-RT（general-purpose）/RK73H-RT（precision type）/RK73Z-RT（jumper）, RK73G-RT(Ultra precision)

Anti-Surge/Anti-Pulse Resistors　SG73-RT, SG73S-RT(Anti-surge)/SG73P-RT(Anti-pulse)

Wide Terminal Chip Resistors　WK73-RT

Low Resistance Resistors   SR73-RT

High Voltage Resistors　HV73-RT

High Voltage Resistors(Automotive type)   HV73V-RT

Chip Network Resistors　CN-RT(concave type) / CN-KRT(convex type)

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