PCR_C.qxd 28/4/03 9:59 am Page 1 Precision Thick Film Surface Mounted Resistors Welwyn Components PCR Series * Tolerance down to 0.1% * Excellent load stability * Termination available for wire bonding or soldering * * Resistance range 10 ohms to 1M ohms Any resistance value available within specified range Electrical Data Power rating at 70C watts Resistance range ohms Limiting element voltage PCR0805 PCR1005 PCR1206 0.1 0.125 0.25 10R to 1M volts 100 150 TCR -55C to +155C ppm/C 100 TCR +20C to +70C ppm/C 50 Resistance tolerance Notes % 200 0.1, 0.25, 0.5, 1 Values E24 & E96 preferred Thermal impedance C/watt 360 290 Any value to order For 10 devices mounted 200 on a 50 x 25 mm p.c.b. area Ambient temperature range* C -55 to 155 *See Application Notes Physical Data Dimensions of standard styles (mm) & Weight (g) Wrap around Style L W planar T T A B* C Wt 0.3 0.15 0.9min 0.3 0.1 0.009 0.4 0.15 0.015 0.4 0.15 0.020 0805 2.0 0.3 1.25 0.2 0.6 1005 2.5 0.3 1.25 0.2 0.7 1206 3.2 0.4 1.6 0.2 0.7 Not available 0.4 0.2 1.7min C A B L A C W T Wrap-around terminations (3 faces) Alternative styles for surface mounting resistors L W Planar terminations *This dimension determines the number of conductors which may pass under the surface mounted device. Construction Terminations Thick film resistor material, overglaze and organic protection are screen printed on a 96% alumina substrate. Planar (or single-sided) termination is gold and suitable for wire-bonding; wrap around is suitable for soldering. Adjustment Solderability The components are adjusted to final value using a specially developed technique, which assures optimum load stability performance. Wrap-around terminations have an electroplated nickel barrier and tin/lead solder coating, this ensures excellent `leach' resistance properties and solderability. They will withstand immersion in solder at 260C for 30 seconds. 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. (c) 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 A subsidiary of TT electronics plc Issue C * 04.03 33 PCR_C.qxd 28/4/03 9:59 am Page 2 Precision Thick Film Surface Mounted Resistors Welwyn Components PCR Series Performance Data Load at rated power: 1000 hours at 70C Load at rated power: 8000 hours at 70C R% R% Maximum Typical 10 - 25k: 0.10 10 - 25k: 0.05 >25k - 1M: 0.4 >25k - 1M: 0.2 10 - 25k: 0.20 10 - 25k: 0.10 >25k - 1M: 0.80 >25k - 1M: 0.4 Load at 50% rated power: 1000 hours at 70C R% 10 - 1M: 0.10 10 - 1M: 0.03 Load at 50% rated power: 8000 hours at 70C R% 10 - 1M: 0.20 10 - 1M: 0.06 Shelf life: 12 months at room temperature R% 0.05 0.01 Derating from rated power at 70C Zero at 155C Overload R% Dry heat: 1000 hours at 155C R% Long term damp heat R% 0.1 0.04 Temperature rapid change R% 0.03 0.01 Resistance to solder heat R% 0.10 0.02 Voltage proof volts 0.04 0.1 0.04 500 Value Ranges Size/Tol.% 1 0.5 0.25 0.1 PCR0805 10 to 1M 10 to 1M 100 to 1M 100 to 1M PCR1005 10 to 1M 10 to 1M 100 to 1M 100 to 1M PCR1206 10 to 1M 10 to 1M 100 to 1M 100 to 1M Application Notes Operating Temperature Range Packaging The chips can operate at a maximum temperature of 155C (see Performance Data). For soldered chips, the joint temperature should not exceed 110C. This condition is met when the stated power levels at 70C are used. Resistor chips are supplied taped and reeled on standard 8mm tape to IEC 286-3. Quantity per reel 3000 max. Planar Terminations Mounting Resistor chips are supplied in waffle packs. This chip resistor is ideally suited for handling by automatic methods due to its rectangular shape and the small dimensional tolerances. Electrical connection to a ceramic substrate or to a printed circuit board can be made by wire bonding (eg suffix `G' in PCR0805G) or by reflow soldering of wrap-around terminations (eg suffix `F' in PCR0805F). The `F' terminations provide good leach properties and ensure reliable contact. Due to the robust construction the resistor chip can be immersed in the solder bath for 30 seconds at 260C. This enables the resistor to be mounted on one side of a printed circuit and other wire-leaded components on the other side. (c) 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 34 Issue C * 04.03