VPG – Bulk Metal Foil resistors perform in the most demanding applications (RCK and S series)

Vishay Precision Group’s (VPG) VFR brand’s RCK and S series high-precision Bulk Metal Foil resistors and HTHA series ultra-high-precision Bulk Metal Z1-Foil hybrid chip resistors satisfy the most demanding application needs.

The RCK and S series resistors represent the latest in a long series of advancements that began with a breakthrough packaging concept developed by foil technology inventor Dr. Felix Zandman. In 1962, Dr. Zandman - world-renowned for his work in stress analysis – took his ideas for uniquely isolated strain gages and applied them to the electronics industry. The result was the most precise and stable resistor ever developed. The first high-precision foil resistor introduced to the market was the S102, the archetype of the current S102C and RCK devices. The S102 was also the first resistor with a flat rectangular case. This unusual configuration was at first questioned by the market. However, once Dr. Zandman demonstrated the board efficiency achieved by stacking multiple square resistors side-by-side, the square configuration was readily accepted and has since become the standard in many applications.

RCK and S series resistors feature an advanced design and manufacturing process that results in improved power dissipation, load life stability of 0.005%, fast thermal stabilization of <1s (nominal value achieved within 10ppm of steady state value), low thermal EMF of 0.05μV/C, resistance tolerance to ±0.005% (50ppm), and increased performance in high-moisture, high-temperature, and high-pulse applications. The resistors are built to handle unconventional environmental conditions with minimal drift, making them suitable for any analog circuit where stability is the main concern.

HTHA resistors are part of the fourth generation of Foil technology that was developed by the VFR R&D team guided by Dr. Zandman before he passed away in June 2010. The HTHA series was launched to celebrate VFR’s 50-year anniversary. The devices were designed for demanding high-temperature applications to +240C, including geothermal measuring equipment, turbine engine control, and environmental test chambers in military, industrial, automotive, and down-hole drilling systems. For these applications, the resistors feature exceptional load-life stability to ±0.05% at +220C for 2,000 hours at working power, and long-term stability to ±0.05% at +240C for 2,000 hours (no power). The devices can be connected using aluminium wire bonding or surface-mounted by electrical conductive epoxy or reflow soldering. The resistors are available in a gold-wire bonding version – the HTHG.