General Purpose Surface
Mounted Resistors
WCR Series
sExcellent reliability
sWide range of sizes and ohmic values
sWrap around terminations
sInner electrode protection
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, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com Iss 07.03
A subsidiary of
TT electronics plc
Welwyn Components
* Notes – TCR for low values 1R to 10R: -400 to +600ppm/ºC, 11R to 100R: ±200ppm/ºC
TCR for high values 3M3 to 10M: ±300ppm/º
1
20025 50
Power rating @ 70C watts
Resistance range ohms
Limiting element votage volts
TCR* ppm/C
Resistance Tolerance %
Zero-ohm Jumper Chip Rating amps
0.05
0201
10R to 1M0
0.5
0.25
1210
1R0 to 10M
0.063
0402
<50
1.5 2
0.1
0603
0.125
0805
150
0.25
1206
0.5
2010
1.0
2512
E24 or E96
-55 to 125
Standard values
Ambient temperature range C
Zero-ohm Jumper Chip Resistance milliohms
1
250 100 200
Electrical Data
W
0.3 ± 0.03
0.5 ± 0.03
0.8 ± 0.15
1.25+ 0.2 -0.1
1.6 + 0.1 -0.15
2.6 ± 0.15
2.5 ± 0.15
3.2 ± 0.15
L
0.6 ± 0.03
1.0 ± 0.05
1.6 ± 0.15
2.0 ± 0.2
3.2 +0.1 -0.25
3.2 + 0.1 -0.2
5.0 ± 0.15
6.3 ± 0.15
T
0.23 ± 0.03
0.35 ± 0.05
0.5 ± 0.15
0.5 + 0.15 -0.10
0.55 +0.15 -0.1
0.55 +0.15 -0.1
0.56 ± 0.15
0.56 ± 0.15
C
0.12 ± 0.05
0.2 ± 0.1
0.25 ± 0.2
0.4 ± 0.2
0.5 + 0.2-0.25
0.5 ± 0.25
0.60 ± 0.25
0.60 ± 0.25
A
0.15 ± 0.05
0.25 ± 0.1
0.25 ± 0.2
0.4 ± 0.2
0.5+ 0.2 -0.25
0.5 ± 0.2
0.60 ± 0.25
0.60 ± 0.25
T
W
A
A
L
Wrap-around terminations
(3 faces)
C
Style
0201
0402
0603
0805
1206
1210
2010
2512
Dimensions (mm)
Physical Data
Construction
The chips have a high alumina substrate (96% minimum) with
a ruthenium oxide resistance element and silver palladium,
nickel and tin plated terminations. A glazed protection coat
is applied to the resistive element (See Fig.1)
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.
Figure 1
Tin Plating
Nickel Barrier
Dipped Conductor
Silver
Palladium
96% min Alumina Substrate
Epoxy Melamine
Glass Dielectric
Resistance Element
Protection
General Purpose Surface
Mounted Resistors
WCR Series
© 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 Issue D · 07.03
Welwyn Components
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. Types 0201
and 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.
Solvent Resistance
The protective epoxy lacquer and marking are resistant to all
normal industrial cleaning fluids suitable for printed circuits.
Table 1
Packaging
All chips are tape mounted and supplied on standard 8mm
tape reel, as IEC publication 286-3.
180mm (7 inch) reel is standard carries 5,000 pieces.
(Except 0402 carries 10,000 pieces)
Chip Resistor Labstock For Designers
WCR chip resistors are available in a special package of the most
popular sizes containing 50 each of the E24 values.
Please contact the sales desk for full details of this excellent
esioNecnatsiseR
Bdsmhoeulav
01-R001
>100R, 0K01
>10K, 51+K001
>100K, 02+0M1
03+0M1>
Packaging
All chips are tape mounted and supplied on standard 8mm
tape reel, as IEC publication 286-3.
180mm (7 inch) reel is standard
250mm (10 inch) reel carrying double the standard quantity
can be supplied by agreement.
Chip Resistor Labstock For Designers
WCR chip resistors are available in a special package of the most
popular sizes 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.
02.09
Performance Data
Load: 1000 hrs at 70°C 10R-100K : 1
>100K : 2
Shelf life: 12 months at room temp. 0.2
0201 0402 0603 0805
Maximum Change
1206 1210 2010 2512
2 2 2.5 2.5 2.5 2.5 2.5 5
33333333
1111
1
1111
2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
11111111
50 100 100
500
200 400 400 400 400
100 500 500 500 500 500
0.2 0.2
zero @ 125 °C
55/125/56
see table 1
> 1G
0.20.2 0.2 0.2 0.2
R%
R%
R%
R%
R%
R%
Derate linearly to zero from 70°C
Short term overload (6.25 x rated power)
Max voltage
Climatic
Climatic Catagory
Long term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
Noise
ohms
volts
Insulation resistance
Voltage proof
volts
R%
R%
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
1R-100K : 1
>100K : 2
3% + 0.1R
Note: For zero ohm jumper chips use the dummy value & tolerance code R005J
