Precision Foil Resistors offer flexible termination systems.

Press Release Summary:

Designed to minimize transfer of PCB stresses caused by differential thermal coefficients of expansion, Flex Series of Bulk Metal® Foil COTS Resistors provide load-life stability of ±0.005% (50 ppm) after 2,000 hr at 70°C and low TCR of ±0.05 ppm/°C nominal (0 to +60°C) and ±0.2 ppm/°C nominal (-55 to +125°C). Surface mount devices offer power ratings to 600 mW at +70°C and resistance range from 1 Ω to 80 kΩ with tight resistance tolerance to ±0.01%.

Original Press Release:

VPG COTS Precision Foil Resistors with Flexible Termination Systems Now Available from Digi-Key

MALVERN, Pa. — Vishay Precision Group, Inc. (NYSE: VPG) today announced that its Vishay Foil Resistors product line (VFR) has introduced the new Flex Series of Bulk Metal® Foil commercial off-the-shelf (COTS) resistors featuring flexible terminations. The devices are designed to minimize transfer of PCB stresses caused by differential thermal coefficients of expansion (TCE), providing load-life stability of ±0.005% (50 ppm) after 2,000 hours at 70°C and low TCR of ±0.05 ppm/°C nominal (0°C to + 60°C) and ±0.2 ppm/°C nominal (-55°C to +125°C). The Flex Series product line is also now available from Digi-Key Corporation, an authorized distributor of VFR products (

"The Flex Series is the future of COTS resistors, providing superior flex performance compared to standard termination systems to isolate the resistor body from harmful PCB stresses due to a difference in the TCE," said Yuval Hernik, senior director of application engineering for VFR. "It is the perfect solution for applications where the PCB will be exposed to high levels of board flexure during assembly or mounting, or where resistors are going to be subjected to heavy shock or vibration."

When mounted on a board that is bent or flexed during the manufacturing process or in the field, resistors can develop cracks that affect their electrical performance and reliability. The VFR Flex Series is a surface-mount precision resistor that incorporates a unique flexible termination system which isolates the resistors from board stresses to help prevent them from reaching the resistance element. Integrated with the latest generation of Bulk Metal Foil technology — Z-Foil — this system is designed to establish pliability while maintaining terminal strength, solderability, stability, and electrical performance.

Flex Series resistors offer low harmonic distortion, power ratings to 600 mW at +70°C, and a PCR (ΔR due to self-heating) of 5 ppm at rated power. The devices feature a resistance range from 1Â Ω to 80 kΩ, with tight resistance tolerance to ±0.01%. Any conceivable ohmic value within this range, to six digits, is available with no additional cost or lead time effect. Featuring a non-inductive (<0.08 ìH), non-capacitive design, the resistors offer a thermal stabilization time of < 1 s (within 10 ppm of steady state value), voltage coefficient of <0.1 ppm/V, and current noise of 0.010 ìVRMS/V of applied voltage (<-40 dB). Flex Series devices are designed to withstand ESD spikes to at least 25 kV and are available with lead (Pb)-free and tin/lead alloy terminations.

"The Flex Series resistors are now available from Digi-Key in custom order quantities," continued Hernik. "Through collaboration with VFR, Digi-Key is helping to set a new standard by shipping the exact number of resistors needed of the precise resistance value and tolerances required, such as 120Â Ω and 350Â Ω for strain-gage applications or 250Â Ω for 4 mA to 20 mA current loops. This provides an invaluable source for small-quantity prototype runs and quick changes prior to full production."

Samples and production quantities of the Flex Series are available now, with lead times of five working days for prototype samples and six weeks for standard orders.

Further information about Vishay Foil Resistors products is available at Follow Vishay Foil Resistors at

About Vishay Precision Group, Inc. (VPG)

VPG is an internationally recognized designer, manufacturer and marketer of: components based on its resistive foil technology; sensors; and sensor-based systems specializing in the growing markets of stress, force, weight, pressure, and current measurements. VPG is a market leader of Foil Technology Products, providing ongoing technology innovations in precision foil resistors and foil strain gages, which are the foundation of the company's Force Sensors Products and its Weighing and Control Systems. The product portfolio consists of a variety of well-established brand names recognized for precision and quality in the marketplace. To learn more, visit VPG at

About VPG Foil Resistors

VPG Foil Resistors produces the most precise and stable resistors available. Distinguished by the premier brands Vishay Foil Resistors, Powertron, and Alpha Electronics, the VPG Foil Resistors portfolio includes discrete resistors and resistor networks in surface mount and through-hole (fixed-lead) configurations; customized chip resistor networks; precision trimming potentiometers; and discrete chips for use in hybrid circuits. These devices are used in applications requiring a high degree of precision and stability, such as in medical testing equipment, semiconductor equipment, precision measuring instruments, aerospace, and military applications. To learn more, visit

Bulk Metal is a registered trademark of Vishay Precision Group, Inc. (VPG).

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