Precision Thick Film
Surface Mounted Resistors
PCR Series
Welwyn Components
•
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
Resistance range
Limiting element voltage
TCR -55°C to +155°C
TCR +20°C to +70°C
Resistance tolerance
Values
Thermal impedance
Ambient temperature range*
°C/watt
°C
360
watts
ohms
volts
ppm/°C
ppm/°C
%
100
0.1
PCR1005
0.125
10R to 1M
150
100
50
0.1, 0.25, 0.5, 1
E24 & E96 preferred
290
-55 to 155
200
Any value to order
For 10 devices mounted
on a 50 x 25 mm p.c.b. area
200
PCR1206
0.25
Notes
*See Application Notes
Physical Data
Dimensions of standard styles (mm) & Weight (g)
Wrap around
Style
0805
1005
1206
L
W
T
0.6
0.7
0.7
A
0.3 ± 0.15
0.4 ± 0.2
B*
0.9min
1.7min
2.0 ± 0.3 1.25 ± 0.2
2.5 ± 0.3 1.25 ± 0.2
3.2 ± 0.4 1.6 ± 0.2
planar
C
0.3 ± 0.1
0.4 ± 0.15
0.4 0.15
Wt
0.009
0.015
0.020
A
B
L
A
W
T
C
C
T
Wrap-around terminations
(3 faces)
Not available
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
Thick film resistor material, overglaze and organic protection
are screen printed on a 96% alumina substrate.
Terminations
Planar (or single-sided) termination is gold and suitable for
wire-bonding; wrap around is suitable for soldering.
Adjustment
The components are adjusted to final value using a specially
developed technique, which assures optimum load stability
performance.
Solderability
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 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
Issue C · 04.03
© 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
33
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.
© 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
Power technology
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