Precision Thick Film
Surface Mounted Resistors
PCR Series
Welwyn Components
Performance Data
Maximum
Load at rated power: 1000 hours at 70°C
Load at rated power: 8000 hours at 70°C
Load at 50% rated power: 1000 hours at 70°C
Load at 50% rated power: 8000 hours at 70°C
Shelf life: 12 months at room temperature
Derating from rated power at 70°C
Overload
Dry heat: 1000 hours at 155°C
Long term damp heat
Temperature rapid change
Resistance to solder heat
Voltage proof
∆R%
∆R%
∆R%
∆R%
∆R%
volts
0.1
0.1
0.03
0.10
500
∆R%
∆R%
∆R%
∆R%
∆R%
10 - 25k: 0.10
>25k - 1M: 0.4
10 - 25k: 0.20
>25k - 1M: 0.80
10 - 1M: 0.10
10 - 1M: 0.20
0.05
Zero at 155°C
0.04
0.04
0.04
0.01
0.02
Typical
10 - 25k: 0.05
>25k - 1M: 0.2
10 - 25k: 0.10
>25k - 1M: 0.4
10 - 1M: 0.03
10 - 1M: 0.06
0.01
Value Ranges
Size/Tol.%
PCR0805
PCR1005
PCR1206
1
10 to 1M
10 to 1M
10 to 1M
0.5
10 to 1M
10 to 1M
10 to 1M
0.25
100 to 1M
100 to 1M
100 to 1M
0.1
100 to 1M
100 to 1M
100 to 1M
Application Notes
Operating Temperature Range
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.
Packaging
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
Resistance value
(IEC62 code)
Tolerance
(IEC62 code)
B
C
D
0.1%
0.25%
0.5%
1206
1M0
B
© 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 D · 08.04
WELWYN [ WELWYN COMPONENTS LIMITED ]
