LRF3W

Low Value 3W Chip Resistors LRF3W Series Welwyn Components • • • 3 Watts @ 70°C Resistance range from 0.003 to 0.1Ω Tolerances to ±1% Electrical Data Characteristic Power dissipation @70°C Resistance Range Dielectric withstand Ambient temp range Resistance tolerance TCR Pad & trace area for maximum power rating* Value 3 Watts 0.003 to 0.100Ω 200V -55 to +150°C ≤R005 5%, >R005 2, 5%, ≥R01 1, 2, 5% ±100ppm/°C 300mm2 Power Derating Curve 100 % Of Power Rating 80 60 40 20 0 25° 70° Temperature in °C 150° Physical Data Top Bottom (Board Side) 0.81 ± 0.13mm Recommended Solder Pad Layout 0.51 ± 0.13mm Plating wrap-around 6.35 ± 0.13mm 2.29 ± 0.13mm 7.6mm 2mm 1mm 0.94 mm max thickness 3.18 ± 0.13mm Weight 0.065g typ. General Note Welwyn Components reserves the right to make changes in product specification without notice or liability. All information is subject to Welwyn’s own data and is considered accurate at time of going to print. A subsidiary of TT electronics plc Issue D · 07.06 © Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 84 Low Value 3W Chip Resistors LRF3W Series Construction Patented non-noble copper based thick film material, overglaze and organic protection are screen printed on a 96% alumina substrate. The components are laser trimmed to achieve the required resistance tolerance. Welwyn Components Chips can withstand immersion in solder at 250°C for 90 seconds and are suitable for reflow or wave soldering mounting applications. Marking The body protection and marking are resistant to all normal industrial cleaning solvents suitable for printed circuits. Chips are packed and mounted with marking side up. The LRF3W Chips are mounted with the actual resistor element mounted face down on its termination pads. Terminations The wrap-around terminations have an electroplated nickel barrier and matte tin finish, this ensures excellent ‘leach’ resistance properties and solderability. Performance Data Typical Load at rated power: 1000 hours at 70°C MIL-PRF-55342 Overload: 6.25 x rated power for 2 seconds MIL-PRF-55342 High temperature exposure: MIL-PRF-55342 Low temperature operation: MIL-PRF-55342 Low temperature storage: -65°C, 100 hours Moisture: MIL-PRF-55342 Temperature cycling: MIL-STD-883 Method 1010 Test condition B Thermal shock: MIL-STD-202 Method 107 condition B -65°C +125°C Resistance to solder heat: MIL-STD-202 Method 210 Shelf life test: 12 months at room temperature Leach resistance: molten solder 250°C ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% ∆R% 1 0.5 0.5 0.5 0.5 0.5 0.25 0.25 0.25 0.1 90 Seconds min. Packaging LRF3W Resistors are supplied taped and reeled as per IEC 286-3. The standard quantity per reel is 1800 parts. T2 D0 P2 P0 T Marking (Both sides) 33 ± 1.0 13 ± 0.5mm E F 13 ± 0.5 178 ± 2 80 ± 2 B0 2.5 ± 0.5 0.8 ± 0.15 T1 K0 A0 P1 D1 Tape dimensions in mm LRF3W W ±0.3 12 P1 ±0.1 8 P0 ±0.1 4 P2 ±0.05 2 D0 ±0.1 1.5 D1 ±0.2 1.5 E ±0.1 1.75 F ±0.05 5.5 A0 ±0.1 3.61 B0 ±0.1 6.96 K0 ±0.1 1.17 T ±0.05 0.28 T1 nom 0.06 G T2 ±0.15 1.45 © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com Issue D · 07.06 W 85 Low Value 3W Chip Resistors LRF3W Series Welwyn Components Ordering Procedure Specify type reference, value and tolerance as shown in this example of LRF3W 5mΩ 2%: Type Resistance value (IEC62 code) Tolerance (IEC62 code) F G J 1% 2% 5% LRF3W R005 G © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com Issue D · 07.06 86