RNCP0603FTD33K2

The RNCP0603FTD33K2 is a 33.2kΩ high-power anti-sulfur thin film chip resistor from Stackpole Electronics’ RNCP series. This resistor series is specifically engineered to address the growing need for reliable resistor performance in high-sulfur environments where standard silver-terminated resistors suffer from sulfidation-induced failure.

With a 0.125W power rating in an 0603 package, the RNCP series delivers 25% more power handling capability than standard 0603 thick film resistors (typically 0.1W), achieved through optimized thin film construction and thermal design. The 33.2kΩ resistance value is an E96 standard value with ±1% tolerance and ±100ppm/°C temperature coefficient, making it suitable for a broad range of precision general-purpose applications.

The defining feature of the RNCP series is its anti-sulfur termination design. Standard chip resistors typically use silver in the outer electrode layer, which can react with sulfur compounds present in certain environments — such as industrial facilities, automotive under-hood compartments, mining operations, and pulp and paper mills — forming silver sulfide. This sulfidation process can cause the resistance to drift upward over time, eventually leading to complete open-circuit failure. Stackpole’s RNCP series eliminates silver from the termination structure entirely, using a proprietary inner termination design that is completely impervious to sulfur contamination.

Additionally, the RNCP series contains no lead-based glass in its construction, making it fully RoHS compliant without any exemptions — an important distinction from some thick film resistors that rely on lead-containing glass formulations and require RoHS exemptions.

AEC-Q200 qualified for automotive applications, the RNCP0603FTD33K2 operates across the full -55°C to +155°C temperature range with linear power derating above 70°C. The 150V working voltage and 300V overload voltage provide robust voltage handling for a 0603 package size. Supplied on 7-inch paper tape reels (code FT = 7″ reel, D packaging) with 5,000 pieces per reel, the RNCP0603FTD33K2 is fully REACH compliant, lead-free, and halogen-free.

Stackpole Electronics is a leading global manufacturer of resistive products, and the RNCP series represents their expertise in developing application-specific resistor solutions that solve real-world reliability challenges in harsh environments.

A high-power anti-sulfur thin film resistor operates by combining precision thin film resistive technology with a specially engineered termination system that provides immunity to sulfur-induced degradation while maintaining high power handling capability.

In the RNCP0603FTD33K2, the fabrication begins with a high-purity alumina ceramic substrate. A metallic resistive film — typically based on a nichrome or similar thin film alloy — is deposited onto the substrate using sputtering technology. The sputtering process creates a dense, uniform film with precise thickness control. Unlike standard thick film resistors where the resistive element is screen-printed and fired, thin film sputtering produces a much more homogeneous resistive layer with better stability and lower noise.

The resistive film is patterned and then laser trimmed to achieve the ±1% tolerance specification. Laser trimming works by precisely ablating (vaporizing) portions of the resistive film with a focused laser beam, effectively lengthening the current path and increasing the resistance until it reaches the target value within the specified tolerance range.

The power rating of 0.125W for this 0603 device — higher than the typical 0.1W for standard 0603 thick film resistors — is achieved through several design optimizations including optimized film composition for better thermal stability, improved thermal coupling between the resistive film and the ceramic substrate, and overall better heat dissipation characteristics inherent to the thin film structure. The power rating is specified at 70°C ambient temperature and derates linearly to zero at the 155°C maximum operating temperature.

The anti-sulfur termination is the key innovation of the RNCP series. In conventional chip resistors, the outer electrode layer often contains silver (Ag), which reacts with sulfur compounds (H2S, elemental sulfur) in the environment to form silver sulfide (Ag2S). This silver sulfide can migrate along the resistor surface, eventually causing the resistance to increase dramatically and potentially leading to open-circuit failure. The RNCP series solves this problem by completely eliminating silver from the termination structure. The electrode system uses a multi-layer metal structure with a base adhesion layer, a nickel barrier layer, and a tin outer plating — none of which are susceptible to sulfur-induced corrosion.

Additionally, the RNCP series uses no lead-containing glass in its construction, another common component of thick film resistor formulations. This makes the RNCP0603FTD33K2 fully RoHS compliant without requiring any of the exemptions that apply to many thick film resistors that contain lead glass.

When current flows through the resistor, the Joule heating effect (P = I²R) generates heat at the resistor element. The high thermal conductivity of the alumina substrate efficiently conducts this heat to the end terminations and then to the PCB pads. The 150V working voltage rating is the maximum continuous DC or RMS voltage that can be applied, while the 300V overload voltage is the maximum voltage that can be applied for short-duration overload conditions without causing permanent damage.

The AEC-Q200 qualification ensures that the resistor has passed a comprehensive suite of automotive-grade reliability tests including temperature cycling, humidity bias, high-temperature storage, and sulfur resistance testing — confirming its suitability for the demanding conditions found in automotive and industrial applications.

Note: The RNCP0603FTD33K2 is a non-polarized passive component. Either terminal can be connected to either side of the circuit. The anti-sulfur termination eliminates silver from the electrode structure, providing immunity to sulfur contamination in harsh environments.

• Automotive electronics — engine compartments, transmission controllers
• Industrial control systems in high-sulfur environments
• Heavy equipment, mining machinery, and construction vehicles
• Pulp and paper industry electronics
• Power supply circuits and DC-DC converters
• Voltage division and current sensing applications
• UPS systems and backup power equipment
• Audio equipment and high-speed communication systems
• HVAC systems and industrial thermostats
• Energy metering and monitoring equipment