SC3

High Power Chip Resistors SC3 Series Welwyn Components • • • 3 Watts in a 1 Watt size package* Resistance range from 1 to 200 Tolerances to ±1% * Rated Power @ 70˚C Electrical Data Characteristic Power dissipation @70˚ C Resistance Range LEV Ambient temp range Resistance tolerance TCR Termination Pad & trace area for maximum power rating Value 3 Watts 1.0 to 200 50V -55 to +150˚C 1, 2, 5% ±100ppm/˚C Leach-resistant solder-plated copper wrap-around 300mm2 Power Derating Curve 100 % Of Power Rating 80 60 40 20 0 25˚ 70˚ Temperature in ˚C 150˚ Physical Data Top 0.51 ± 0.13mm Bottom (Board Side) 0.61 ± 0.13mm Recommended Solder Pad Layout Plating wrap-around 6.35 ± 0.13mm 2.29 ± 0.13mm 7.6mm 2mm 1mm 0.762 ± 0.127mm thickness 3.18 ± 0.13mm 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 B 03.02 Issue A · 01.07 © 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 High Power Chip Resistors SC3 Series Construction Resistive 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 SC3 Chips are mounted with the actual resistor element mounted face down on its termination pads. Terminations The wrap-around terminations have anhelectroplatedoplated wrap-around copper terminations ave an electr nickel barrierbarrier and tin-lead solder ensures this ensures nickel and matte tin finish. This coating, excellent ‘leach’ resistance properties and solderability. 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. Temperature Rise vs Pad Area 1000 Temperature Rise (˚C) Pulse Power Rating 100 100 Power (watts) 100mm2 1 watt 10 10 1 300mm2 Termination Pad Area (each end) 2 watt 3 watt 1000mm2 0.1 1.0 Time (sec) 10.0 © 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 A 03.02 Issue B ·· 01.07 85 High Power Chip Resistors SC3 Series Welwyn Components Packaging LRF3W Resistors re supplied taped a reeled as as er 286-3. The standard rd quantity er r is is 1800 parts. SC3 Resistors areasupplied taped and nd reeled perpIECIEC 286-3. The standaquantity perpreeleel1800 parts. T2 D0 P2 P0 T Marking (Both sides) 33 ± 1.0 13 ± 0.5mm E 13 ± 0.5 F 178 ± 2 80 ± 2 B0 2.5 ± 0.5 0.8 ± 0.15 T1 K0 A0 P1 D1 Tape dimensions in mm LRF3W SC3 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 Ordering Procedure Specify type reference etc. as shown in this example of SC3 at 33 Type Resistance value (IEC62 code) Tolerance (IEC62 code) F G J 1% 2% 5% 1% SC3 - 33R F © 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 86 Issue B ·· 01.07 Issue A 03.02 W T2 ±0.15 1.45