Stackpole Moisture Sensitive Applications Solutions - RNCS & HDM Series
Moisture Sensitive Applications
This pitch pack will discuss Stackpole™ RNCS Passivated Nichrome thin film chips and HDM series axial leaded, moisture withstanding carbon film resistors. In the past, applications which required resistors to operate in high humidity or uncontrolled environments were forced to use less common and more expensive technologies. The RNCS and HDM series provide a relatively inexpensive SMD and thru-hole solution to these high moisture environments.
RNCS - Passivated Nichrome Thin Film Chip Resistors
For surface mount resistor requirements in high humidity, engineers were forced to design in either thick film solutions, which were limited in the amount of precision they could offer, or tantalum nitride solutions, which were much more expensive than their equivalent nichrome based counterparts. However, nichrome elements in applications with excessive moisture and under low power loading were susceptible to corrosion. The RNCS series utilizes an intermediate layer of silicon oxide or silicon nitride to form a moisture impervious barrier which acts like the tantalum nitride element without the high manufacturing cost. In addition, the passivation on the RNCS is designed to more reliably cover the resistive element and reduce the occurrences of pinholes which might allow moisture to penetrate the outer protective layer. The result is a part that shows outstanding stability even under the harshest conditions. The RNCS series will shift less than 0.15% over 3000 hours of standard biased humidity testing at 40C, 95% relative humidity, cycled power 1.5 hours on 0.5 hour off.
The RNCS is available in sizes from 0402 to 2512, in tolerances as low as 0.1%. Resistance values range from 10 ohms to 1M with most of the resistance values available in TCRs down to 15 ppm. For certain sizes, a higher power version of the RNCS may be available as the RNCH. Contact Stackpole for details.
HDM - Moisture Withstanding Carbon Film Resistors
Axial leaded resistors have had a similar dilemma. Applications with moisture withstanding requirements were often forced to use metal glaze technology or some other more exotic and expensive technology. Stackpole has developed a relatively inexpensive carbon film resistor series, the HDM that is impervious to high moisture environments. The HDM series utilizes special materials, processes, and process controls to provide a carbon film resistive element with proven corrosion resistance capabilities. Under accelerated humidity testing at 120°C, 2 atmospheres pressure, and 100% relative humidity, the HDM series maintains its resistive value within its specified tolerance, while other carbon film resistors fail. The HDM series performs twice as well as standard carbon film technology under the industry standard humidity test, Mil STD 202, method 106.
The HDM is available in standard ¼ watt and ½ watt sizes in tolerances down to 1%. Resistance value ranges from 1 ohm to 2.2 Meg ohms.
Applications for the RNCS and HDM include a variety of testing and monitoring devices, network power supplies, industrial controls and automation, motor controls, laser controls, medical applications, audio applications, automotive infotainment, avionics, security and safety equipment, HVAC and heating controls, and robotics.
For more information about Stackpole products, contact us at:
Stackpole Electronics, Inc.
2700 Wycliff Road Suite 410,
Raleigh NC 27607
Stackpole Electronics Inc. is a leading global manufacturer of resistors supplying to the worlds largest OEMs, contract manufacturers and distributors. Headquartered in Raleigh, N.C., the privately held company began manufacturing in 1928 as part of Stackpole Carbon Company in St. Mary's, Pennsylvania. Now affiliated with Akahane Electronics, Stackpole has manufacturing facilities in Japan, Taiwan, China and Mexico; warehousing facilities in El Paso, Hong Kong and Japan; and sales offices in Tokyo, Hong Kong and Taiwan.