FRSM

FRSM Series of Precision Chip Resistors Vishay Foil Resistors Z-1 Foil Ultra High Precision Wrap-around Chip Resistor for Improved Load Life Stability of 0.0025% (25 ppm) with TCR of ± 0.05 ppm/°C and withstands ESD of 25 KV min FEATURES • Temperature coefficient of resistance (TCR): 0.05 ppm/°C typical (0 °C to + 60 °C) 0.2 ppm/°C typical (- 55 °C to + 125 °C, + 25 °C ref.) • Resistance tolerance: to ± 0.01 % • Power coefficient “ΔR due to self heating”: 5 ppm at rated power • Power rating: to 750 mW at + 70 °C • Load life stability: ± 0.0025 % at 70 °C, 2000 h at rated power. ± 0.005 % at 70 °C, 10,000 h at rated power. • Resistance Range: 5 Ω to 125 kΩ (for higher and lower values, please contact us) • Vishay Foil resistors are not restricted to standard values; we can supply specific “as required” values at no extra cost or delivery (e.g. 1K2345 vs. 1K) • Thermal stabilization time < 1 s (nominal value achieved within 10 ppm of steady state value) • Electrostatic discharge (ESD) at least to 25kV • Short time overload: 0.005 % • Rise time: 1 ns effectively no ringing • Current noise: 0.010 µVRMS/V of applied voltage (< - 40 dB) • • • • • • Voltage coefficient: 0.1 ppm/V Non inductive: 0.08 µH Non hot spot design Terminal finishes available: lead (Pb)-free, tin/lead alloy(1) Matched sets are available on request Prototype quantities available in just 5 working days or sooner. For more information, please contact foil@vishaypg.com • For higher temperature application up to +240 °C and for better performances, please contact us Top View INTRODUCTION The FRSM is based on the new generation Z1- technology of the Bulk Metal® Precision Foil resistor elements by Vishay Precision Group (VPG), which makes these resistors virtually insensitive to destabilizing factors. Their element, based on the new Z-1 Foil is a solid alloy that displays the desirable bulk properties of its parent material; thus, it is inherently stable (remarkably improved load life stability of 25 ppm), noise-free and withstands ESD to 25KV or more. The alloy is matched to the substrate and forms a single entity with balanced temperature characteristics for an unusually low and predictable TCR over a wide range from -55 C° to more than 175C°. Resistance patterns are photo-etched to permit trimming of resistance values to very tight tolerances. Our application engineering department is available to advise and make recommendations. For non-standard technical requirements and special applications, please contact us using the e-mail address in the footer below. FIGURE 1 - POWER DERATING CURVE - 55 °C + 70 °C Rated Power (%) 100 75 50 25 0 - 75 TABLE 1 - TOLERANCE AND TCR VS. RESISTANCE VALUE (1) (- 55 °C to + 125 °C, + 25 °C Ref.) RESISTANCE VALUE (Ω) 250 to 125K 100 to < 250 50 to < 100 25 to < 50 10 to < 25 5 to < 10 TOLERANCE (%) ± 0.01 ± 0.02 ± 0.05 ± 0.1 ± 0.25 ± 0.5 TYPICAL TCR AND MAX. SPREAD (ppm/°C) ± 0.2 ± 1.8 ± 0.2 ± 1.8 ± 0.2 ± 2.8 ± 0.2 ± 3.8 ± 0.2 ± 3.8 ± 0.2 ± 7.8 - 50 - 25 0 + 25 + 50 + 75 + 100 + 125 + 150 + 175 Ambient Temperature (°C) Lead (Pb)-free terminals Tin/lead alloy terminals (1) Pb containing terminations are not RoHS compliant, exemptions may apply. Document Number: 63209 Revision: 7-Apr-11 For any questions, contact: foil@vishaypg.com www.vishayfoilresistors.com 1 FRSM Series of Precision Chip Resistors Vishay Foil Resistors ABOUT THE FRSM Several factors need to be considered when choosing a resistor for applications that require long term stability, including TCR (ambient temperature), Power TCR (self heating), load-life stability for more than 10K hours (instead of the typical 1000 or 2000 hours load-life),  end-of-life tolerance (which is more important than the initial tolerance), thermal EMF (low values, D.C), thermal stabilization and ESD. Some precision resistor technologies such as Precision Thin Film offer designers tight initial tolerances as low as 0.02 % but have poor load life stability, high end-of-life tolerance, long thermal stabilization, high drifts during operational life and ESD sensitivity. Other resistor technologies, such as Wirewounds, provide low absolute TCR and excellent current noise of -40 dB but have high inductance and poor rise time (or thermal lag) for more than a few seconds.  There are essentially only three resistance technologies widely used for precision resistors in military and space applications:  Thin Film, Wirewound and Bulk Metal® Foil.   Each has its own balance of characteristics and costs that justify its selection in these applications.  Thin Films are most cost-efficient within their normal range of characteristics but have the highest TCR, highest noise and have the least stability of the three technologies.  Wirewounds have low noise, low TCR and a high level of stability at moderate cost but also have high impedance and slow signal response.  Wirewounds can also have a higher power density, but some stability is lost through temperature cycling and load-life when made in smaller configurations. Bulk Metal® Foil resistors have the lowest noise, lowest TCR, highest stability and highest speed of any technology but may have a higher cost, depending upon model. With Bulk Metal® Foil resistors, savvy designers often save overall by concentrating the circuit stability in the foil resistors where exceptional stability allows for use of less-costly active devices---an option not available with other resistor technologies because foil requires a smaller total error budget through all cumulative resistor life exposures.  Also, foil often eliminates extra circuitry added merely for the purpose of correcting the limitations of other resistor components. FRSM’s Bulk Metal® Foil resistors, based on new generation technology and improved production methods starting from February 2011, offer designers the complete set of top performance characteristics to simplify circuitry and lower overall system costs by reducing the number of required parts while assuring a better end product. The new series of FRSM feature a long-term load-life stability within 0.0025 % after 2000 hours and 0.005% after 10000 hours under full rated power at + 70 °C, first time in the history of all resistor technologies. In addition to their low absolute TCR of almost zero TCR , the devices offer Power TCR (“ΔR due to self heating”) to ±5 ppm at rated power; tight tolerance from 0.01% and thermal EMF of 0.05 µV/°C. Current design practice has been to over specify resistors to allow for expected tolerance degradation during service and there is a trend to move to commercial off the shelf (COTS) parts instead of MIL spec Qualified (QPL) parts.  Vishay Precision Group offers a new approach with lower prices to bring Foil resistors within the reach of designers whose end-of-life tolerance target is 0.05 % (total end of life cumulative deviation from nominal) or less with COTS resistors having all the inherent features for long term reliability. While other resistor technologies can take several seconds or even minutes to achieve a steady state thermal stabilization (thermal lag), Vishay Foil resistors feature an almost instantaneous thermal stabilization time and a nearly immeasurable 1 ns rise time effectively with no ringing. The stress levels of each application are different so the designer must make an estimation of what they might be and assign a stress factor to each one.  The stress may normally be low but for these purposes, we must assure that the installed precision resistor is capable of reliability withstanding all potential stresses.  For example, if the resistor is installed in a piece of equipment that is expected to go out into an oil field in the back of a pickup truck, shock and vibration and heat from the sun are obvious factors.  The specific causes of resistor drift are listed in Table 4 and the allowances shown are for full scale exposure. The designer may choose to use a percentage of full scale stress factor if the equipment will never see the full scale conditions.  For example, a laboratory instrument that is expected to be permanently installed in an air-conditioned laboratory does not need an end-of-life allowance for excessive heat. There are other reasons for tolerancing the resistors tighter than the initial calculation:  Measurement equipment accuracy is traditionally ten times better than the expected accuracy of the devices under test. So, these tighter tolerance applications require a Foil resistor.  Also, the drift of the resistor without any stress factor considerations results in a shift over time that must be considered. FRSMs have the least amount of time shift.  The manufacturer’s recommended recalibration cycle is a factor in the saleability of the product and the longer the cycle, the more acceptable the product.  Foil resistors contribute significantly to the longer calibration cycle.   FIGURE 2 - TRIMMING TO VALUES* (Conceptual Illustration) Interloop Capacitance Reduction in Series Current Path Before Trimming Current Path After Trimming Trimming Process Removes this Material from Shorting Strip Area Changing Current Path and Increasing Resistance Mutual Inductance Reduction due to Change in Current Direction Note: Foil shown in black, etched spaces in white * To acquire a precision resistance value, the Bulk Metal® Foil chip is trimmed by selectively removing built-in “shorting bars.” To increase the resistance in known increments, marked areas are cut, producing progressively smaller increases in resistance. This method eliminates “hot spot” and improves the long term stability of the resistor. www.vishayfoilresistors.com 2 For any questions, contact: foil@vishaypg.com Document Number: 63209 Revision: 7-Apr-11 FRSM Series of Precision Chip Resistors Vishay Foil Resistors FIGURE 3 - TYPICAL RESISTANCE/ TEMPERATURE CURVE(2) +250 +200 +150 +100 0 R (ppm) -50 -100 -150 -200 -250 -55 - 0.16 ppm/ºC -25 0 +25 +50 0.05 ppm/ºC - 0.1 ppm/ºC 0.1 ppm/ºC 0.14 ppm/ºC 0.2 ppm/ºC +65 +75 +100 +125 +250 +200 +150 +100 +50 0 -50 -100 -150 -200 -250 TABLE 3 - SPECIFICATIONS(1) CHIP SIZE 0402(3) 0603 0805 1206 1506 2010 2512 RATED POWER (mW) at + 70 °C 50 100 200 300 300 500 750 MAX. WORKING VOLTAGE (≤ P × R ) 5V 22 V 40 V 87 V 95 V 187 V 220 V RESISTANCE RANGE (Ω) 100 to 500 100 to 4K* 5 to 8K 5 to 25K 5 to 30K 5 to 70K 5 to 125K MAXIMUM WEIGHT (mg) 2 4 6 11 12 27 40 ΔR * For 0603 values between 4K and 5K, please contact us TABLE 2 - DIMENSIONS in Inches (Millimeters) Top View L T D CHIP SIZE 0603 0805 1206 1506 2010 2512 (1) W L ± 0.005 (0.13) 0.063 (1.60) 0.080 (2.03) 0.126 (3.20) 0.150 (3.81) 0.198 (5.03) 0.249 (6.32) W ± 0.005 (0.13) 0.032 (0.81) 0.050 (1.27) 0.062 (1.57) 0.062 (1.57) 0.097 (2.46) 0.127 (3.23) THICKNESS MAXIMUM 0.025 (0.64) 0.025 (0.64) 0.025 (0.64) 0.025 (0.64) 0.025 (0.64) 0.025 (0.64) D ± 0.005 (0.13) 0.011 (0.28) 0.015 (0.38) 0.020 (0.51) 0.020 (0.51) 0.025 (0.64) 0.032 (0.81) Notes For tighter performances and non-standard values up to 150K, please contact VPG application engineering using the e-mail addresses in the footer below. (2) The TCR values for < 100 Ω are influenced by the termination composition and result in deviation from this curve. TABLE 4 - PERFORMANCES TEST OR CONDITIONS Thermal Shock, 100 x (- 65 °C to + 150 °C) (see Figure 6) Low Temperature Operation, - 65 °C, 45 min at Pnom Short Time Overload, 6.25 x Rated Power, 5 s High Temperature Exposure, + 150 °C, 100 h Resistance to Soldering Heat, +245°C for 5 sec,+235°C for 30 sec Moisture Resistance Load Life Stability + 70 °C for 2000 h at Rated Power (see Figure 8) Load Life Stability + 70 °C for 10,000 h at Rated Power Note (3) As shown + 0.01 Ω to allow for measurement errors at low values. ΔR LIMITS OF PRECISION THIN FILM ± 0.1 % ± 0.1 % ± 0.1 % ± 0.1 % ± 0.1 % ± 0.1 % ± 0.1 % ± 0.5 % TYPICAL MAXIMUM ΔR LIMITS OF FRSM ΔR LIMITS OF FRSM SERIES SERIES(3) ± 0.005% (50 ppm) ± 0.0025% (25 ppm) ± 0.005% (50 ppm) ± 0.0025% (25 ppm) ± 0.005 % (50 ppm) ± 0.003% (30 ppm) 0.0025% (25 ppm) 0.005% (50 ppm) ± 0.01% (100 ppm) ± 0.005% (50 ppm) ± 0.01% (100 ppm) ± 0.005% (50 ppm) ± 0.01% (100 ppm) ± 0.01% (100 ppm) ± 0.005% (50ppm) ± 0.015% (150ppm) Document Number: 63209 Revision: 7-Apr-11 For any questions, contact: foil@vishaypg.com www.vishayfoilresistors.com 3 FRSM Series of Precision Chip Resistors Vishay Foil Resistors FIGURE 4 - RECOMMENDED MOUNTING Notes (1) IR and vapor phase reflow are recommended. (2) Avoid the use of cleaning agents which could attack epoxy resins, which form part of the resistor construction (3) Vacuum pick up is recommended for handling (4) Soldering iron may damage the resistor PULSE TEST TEST DESCRIPTION All parts baked at +125°C for 1 hr and allowed to cool at room temperature for 1 hr, prior to testing. By using an electrolytic 0.01µF capacitor charged to 1000 VDC, a single pulse was performed on 20 units of 1206, for each value: 100Ω, 1KΩ and 10KΩ of Surface Mount Vishay Foil resistor and Thin Film resistor. The unit was allowed time to cool down, after which the resistance measurement was taken and displayed in ppm deviation from the initial reading. TEST RESULTS FIGURE 6 - THERMAL SHOCK TEST Test per MIL PRF 55342 4.8.3 Mil STD 202, Method 107 Test Conditions: 100 X (-65°C to +150°C), n=10 100 80 60 ∆R (ppm) 40 20 FIGURE 5 - PULSE TEST DESCRIPTION 0 0805 1K 0805 8K 1206 1K 1206 25K 2512 1K -20 2512 75K ELECTROSTATIC DISCHARGE (ESD) ESD can be categorized into three types of damages "#  *+ !) Parametric Failure - occurs when the ESD event alters one or more device parameters (resistance in the case of resistors), causing it to shift from its required tolerance. This failure does not directly pertain to functionality; thus a parametric failure may be present while the device is still functional. Catastrophic Damage - occurs when the ESD event causes the device to immediately stop functioning. This may occur after one or a number of ESD events with diverse causes, such as human body discharge or the mere presence of an electrostatic field. Latent Damage - occurs when the ESD event causes moderate damage to the device, which is not noticeable, as the device appears to be functioning correctly. However, the load life of the device has been dramatically reduced, and further degradation caused by operating stresses may cause the device to fail during service. Latent damage is the source for greatest concern, since it is very difficult to detect by re-measurement or by visual inspection, since damage may have occurred under the external coating. TABLE 5 - PULSE TEST RESULTS AVERAGE DEVIATION (%) VALUE VOLTAGE T= RC VISHAY FOIL RESISTOR 35 >0.008 100R 1K 10K 1000VDC 1µsec 10 µsec 100 µsec www.vishayfoilresistors.com 4 For any questions, contact: foil@vishaypg.com Document Number: 63209 Revision: 7-Apr-11 FRSM Series of Precision Chip Resistors Vishay Foil Resistors TEST DESCRIPTION By using a electrolytic 500 pF capacitor charged up to 4500 V, pulses were performed on 10 units of 1206, 10KΩ of three different Surface Mount Chip Resistors technologies, with an initial voltage spike of 2500 V (Figure 7). The unit was allowed time to cool down, after which the resistance measurement was taken and displayed in ppm deviation from the initial reading. Readings were then taken in 500 V increments up to 4500 V. TEST RESULTS POWER COEFFICIENT OF RESISTANCE (PCR) In precision resistors with low TCR, the self heating (Joule effect) causes the resistor not to perform strictly to its TCR specifications. This inaccuracy will result in an error at the end in the resistance value under applied power. Vishay Foil Resistors introduced a new concept of Power Coefficient of Resistance (PCR) along with a new Z-Foil technology which leads to reduction of the sensitivity of precision resistor to ambient temperature variations and changes of applied power. Figure 9 represents PCR behavior of three different resistor technologies under applied power. FIGURE 7 - ESD TEST DESCRIPTION 2500 V to 4500 V 1 MΩ 500 pF FIGURE 9 - BEHAVIOR OF THREE DIFFERENT RESISTOR TECHNOLOGIES UNDER APPLIED POWER (POWER COEFFICIENT TEST) 0.1 0.2 Thick Film Surface Mount Chip 0.3 0.4 Thin Film Surface Mount Chip 0.5 Rx + 100 ppm DMM Δ R (ppm) ------R 0 ppm Z-Foil Surface Mount Chip TABLE 6 - ESD TEST RESULTS VOLTS 2500 3000 3500 4000 4500 ∆R (%) THICK FILM -2.7 -4.2 -6.2 -7.4 -8.6 THIN FILM 97 366 >5000 >5000 OPEN FOIL