General Purpose Surface Mounted Resistors WCR SERIES ● Excellent reliability ● Wide range of sizes and ohmic values ● Wrap around terminations ● Inner electrode protection Electrical Data 0402 0603 0805 1206 2010 2512 Power rating at 70°C watts 0.063 0.063 0.10 0.125 0.25 0.5 1.0 Resistance range ohms 4R7 to 2M2 1R to 22M 1R to 22M 1R to 22M 1R to 22M 1R to 10M 1R to 10M Limiting element voltage volts 50 50 150 200 200 200 TCR ppm/°C see table below Resistance tolerance % see table below Standard values E24 / E96 preferred. Other values to special order Ambient temperature range °C -55 to 125 Tolerance/Resistance/TCR WCR 0402 Tolerance ± 0.5% ± 1% ± 2% ± 5% ± 10% Ohmic Range (Ohms) WCR 0603 TCR ppm /°C Ohmic Range (Ohms) WCR 0805 TCR ppm /°C* Ohmic Range (Ohms) WCR 1206@1/8W WCR 1206@1/4W TCR ppm /°C* Ohmic Range (Ohms) TCR ppm /°C* MIN MAX Ohmic Range (Ohms) WCR 2010 TCR ppm /°C* Ohmic Range (Ohms) MIN MAX TCR ppm /°C* MIN MAX WCR 2512 Ohmic Range (Ohms) TCR ppm /°C* MIN MAX MIN MAX MIN MAX MIN MAX 100R 100K ±50 100R 100K ±50 100R 100K ±100 100R 100K ±100 10R 1MO ±100 1R 10M ±100 1R 10M ±100 1R 10M ±100 10R 1M ±100 1R 10M ±300 1R 10M ±300 10R 1M ±200 1R 10M ±200 1R 10M ±200 1R 10M ±200 10R 1M ±200 10R 1M 10R 1M 4R7 2M2 ±300 1R 10M ±200 1R 10M ±200 1R 10M ±200 10R 1M ±200 1R 10M ±300 ±200 ±200 1R 10M ±300 11M 22M ±300 11M 22M ±300 11M 22M ±300 Zero jumper chips also available *Note: TCR for low values 1R to 4R3 -100 to +600 ppm/°C. TCR for high values 3M3 to 22M ± 300ppm/°C. Physical Data Dimensions (mm) Style L W T C A 0402 1.0 ± 0.05 0.5 ± 0.03 0.35 ± 0.05 0.20 ± 0.1 0.25 ± 0.1 0603 1.6 ± 0.15 0.8 ± 0.15 0.5 + 0.15 -0.05 0.25 ± 0.2 0.25 ± 0.2 0805 2.0 + 0.2 1.25 + 0.2 -0.1 0.5 + 0.15 -0.10 0.4 ± 0.2 0.4 ± 0.2 1206 3.2 + 0.1 -0.15 1.6 + 0.1 -0.15 0.55 + 0.15 -0.05 0.5 + 0.2 -0.25 0.5 + 0.2 -0.25 2010 5.0 ± 0.15 2.5 ± 0.15 0.56 ± 0.15 0.60 ± 0.25 0.60 ± 0.25 2512 6.3 ± 0.15 3.2 ± 0.15 0.56 ± 0.15 0.60 ± 0.25 0.60 ± 0.25 C T A L A W Wrap-around terminations (3 faces) *N.B. The minimum distance between the underside terminations of the WCR 1206 is 0.2mm. 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. © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, England Tel: 01670 822181 Fax: 01670 829465 Web: http://www.Welwyn-TT.co.uk Issue A 07/99 15 General Purpose Surface Mounted Resistors WCR SERIES CONSTRUCTION The chips have a high alumina substrate (96% minimum) with a ruthenium oxide resistance element and silver palladium, nickel and solder plated terminations. A glazed protection coat is applied to the resistive element (See Fig. 1) Solder Plating Nickel Barrier Dipped Conductor Epoxy Melamine Glass Dielectric Resistance Element Silver Palladium TERMINATIONS Solderability The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2. Strength The terminations meet requirements of IEC 68.2.21. MARKING All resistors are individually marked with 3 digits. The first two digits are the significant figures and the third defines the number of added zeros. Jumpers are marked 000. Type 0402 have no marking. E96 1% components that can not be marked with 4 digits will be marked with a standard 3 digit code. Details can be supplied upon request. 96% min Alumina Substrate Figure 1 SOLVENT RESISTANCE The protective epoxy lacquer and marking are resistant to all normal industrial cleaning fluids suitable for printed circuits. Performance Data MAXIMUM CHANGE Load: 1000 hrs at 70°c ∆R% Shelf life: 12 months at room temp. ∆R% 0402 0603 0805 1206 2010 2512 4R7 - 100K:1 >100K:2 1R - 100K:1 >100K:2 1R - 100K:1 >100K:2 1R - 100K:1 >100K:2 1R - 100K:1 >100K:2 3% + 0.1R 0.2 0.2 0.2 0.2 0.2 0.2 2.5 400 2.5 200 5.0 200 3 3 3 3 3 3 Derate linearly to zero from 70°C ∆R% Short term overload (6.25 x rated power) Max voltage ∆R% volts 2 100 2.5 100 2.5 200 Climatic ∆R% 3 3 3 Climatic category ∆R% Long term damp heat ∆R% Temperature rapid change ∆R% 1 1 1 1 1 1 Resistance to solder heat ∆R% 2.5 2.5 2.5 2.5 2.5 2.2 Vibration and bump ∆R% 1 1 1 1 1 1 500 500 500 zero at 125°C 55/125/56 3 3 3 Noise see table 3 Insulation resistance ohms Voltage proof volts > 1G 100 500 Pulse Handling PACKAGING All chips are tape mounted and supplied on standard 8mm tape reel, as IEC publication 286-3. 180mm (7 inch) reel carries 5,000 pieces. (Except 0402 carries 10,000 pieces) 250mm (10 inch) reel carrying 10,000 pieces can be supplied by agreement. Chips are taped element side up as standard. If chips are to be taped face down please specify. Type 2010 – 4,000 pcs Type 2512 – 4,000 pcs 500 Data available on request CHIP RESISTOR LAB STOCK FOR DESIGNERS WCR chip resistors are available in a special package containing 50 each of the E24 values. Please contact the sales desk for full details of this excellent solution for designers and your prototype build requirements. BULK CASSETTE PACK AVAILABLE © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, England Tel: 01670 822181 Fax: 01670 829465 Web: http://www.Welwyn-TT.co.uk 16 Issue A 07/99