PCR_D.qxd 8/9/04 3:54 PM 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 PCR0805 Power rating at 70°C watts Resistance range ohms Limiting element voltage PCR1005 PCR1206 0.125 0.25 0.1 10R to 1M volts 100 150 TCR -55°C to +155°C ppm/°C 100 TCR +20°C to +70°C 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 200 For 10 devices mounted 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 T 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 A 0.3 ± 0.15 0.9min Not available 0.4 ± 0.2 planar B* 1.7min C T Wt 0.3 ± 0.1 0.009 0.4 ± 0.15 0.015 0.4 0.15 0.020 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 solder coating, this ensures excellent ‘leach’ resistance properties and solderability. They will withstand immersion in solder at 260°C 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. A subsidiary of TT electronics plc © Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com Issue D · 08.04 33 PCR_D.qxd 8/9/04 3:54 PM Page 2 Precision Thick Film Surface Mounted Resistors Welwyn Components PCR Series Performance Data Maximum Load at rated power: 1000 hours at 70°C ∆R% 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 Load at rated power: 8000 hours at 70°C ∆R% >25k - 1M: 0.80 >25k - 1M: 0.4 Load at 50% rated power: 1000 hours at 70°C ∆R% 10 - 1M: 0.10 10 - 1M: 0.03 Load at 50% rated power: 8000 hours at 70°C ∆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 70°C Zero at 155°C Overload ∆R% Dry heat: 1000 hours at 155°C ∆R% 0.1 0.04 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 0.04 500 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 155°C (see Performance Data). For soldered chips, the joint temperature should not exceed 110°C. This condition is met when the stated power levels at 70°C 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 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 260°C. This enables the resistor to be mounted on one side of a printed circuit and other wire-leaded components on the other side. Resistor chips are supplied in waffle packs. Ordering Procedure Specify type reference, value and tolerance as shown in this example of PCR1206 1M0 0.1%: Type 1206 B Resistance value (IEC62 code) Tolerance (IEC62 code) B 0.1% C 0.25% D 0.5% © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com 34 1M0 Issue D · 08.04