General Purpose Surface
Mounted Resistors
WCR Series
Welwyn Components
•
Excellent reliability
•
Wide range of sizes and ohmic values
•
Wrap around terminations
•
Inner electrode protection
Electrical Data
Power rating at 70°C
Resistance range
Limiting element voltage
TCR
Resistance tolerance
Standard values
Ambient temperature range
Zero Ohm Jumper Chip Rating
Zero Ohm Jumper Chip Resistance
watts
ohms
volts
ppm/°C
%
°C
A
mOhms
0402
0.063
4R7 to 2M2
50
0603
0.1
1R to 22M
50
0805
1206
2010
0.125
0.25
0.5
1R to 22M
1R to 22M
1R to 10M
150
200
200
see table below
see table below
E24 / E96 preferred. Other values to special order
-55 to 155
1
1.5
2
2
<50
<50
<50
2512
1.0
1R to 10M
200
1
<50
<50
Tolerance/Resistance/TCR
Tolerance
WCR 0402
Ohmic
TCR
Range
ppm
(Ohms)
/°C
MIN MAX
100R 100K ±50
10R 1MO ±100
10R
4R7
1M ±200
2M2 ±300
WCR 0603
Ohmic
TCR
Range
ppm
(Ohms)
/°C*
MIN
100R
1R
1R
1R
11M
MAX
100K ±50
10M ±100
10M ±200
10M ±200
22M ±300
WCR 0805
Ohmic
TCR
Range
ppm
(Ohms)
/°C*
MIN MAX
100R 100K ±100
1R
10M ±100
1R
1R
11M
10M ±200
10M ±200
22M ±300
*Note:
WCR 1206@
1
/
4
W
Ohmic
TCR
Range
ppm
(Ohms)
/°C*
MIN
10R
10R
10R
MAX
1M
1M
1M
±100
±200
±200
WCR 2010
Ohmic TCR
Range ppm
(Ohms) /°C*
MIN MAX
1R0 9R1
-100 to +600
10R 1M0
1M0 10M
±100
±300
WCR 2512
Ohmic
TCR
Range
ppm
(Ohms)
/°C*
MIN
1R
10R
1R
MAX
10M
1M
10M
±300
±200
±300
± 0.5%
± 1%
± 2%
± 5%
± 10%
TCR for low values 1R to 4R3 -100 to +600 ppm/°C.
TCR for high values 3M3 to 22M ± 300ppm/°C.
Physical Data
Dimensions (mm)
Style
0402
0603
0805
1206
2010
2512
L
1.0 ± 0.05
1.6 ± 0.15
2.0 + 0.2
5.0 ± 0.15
6.3 ± 0.15
W
0.5 ± 0.03
0.8 ± 0.15
T
0.35 ± 0.05
0.5 + 0.15 -0.05
C
0.20 ± 0.1
0.25 ± 0.2
0.4 ± 0.2
0.60 ± 0.25
0.60 ± 0.25
A
0.25 ± 0.1
0.25 ± 0.2
0.4 ± 0.2
0.60 ± 0.25
0.60 ± 0.25
A
L
A
W
T
C
1.25 + 0.2 -0.1 0.5 + 0.15 -0.10
2.5 ± 0.15
3.2 ± 0.15
0.56 ± 0.15
0.56 ± 0.15
3.2 + 0.1 -0.15 1.6 + 0.1 -0.15 0.55 + 0.15 -0.05 0.5 + 0.2 -0.25 0.5 + 0.2 -0.25
Wrap-around terminations
(3 faces)
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 D · 07.03
© 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
15
General Purpose Surface
Mounted Resistors
WCR Series
Construction
The chips have a high alumina substrate (96% minimum) with
a ruthenium oxide resistance element and silver palladium,
nickel and solder plated terminations. A glazed protection
coat is applied to the resistive element (See Fig. 1)
Figure 1
Welwyn Components
Solder Plating
Nickel Barrier
Dipped Conductor
Silver
Palladium
Epoxy Melamine
Glass Dielectric
Resistance Element
Terminations
Solderability
Strength
The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2.
The terminations meet requirements of
IEC 68.2.21.
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. Type 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.
96% min Alumina Substrate
Table 1
Resistance
value ohms
≤100R
>100R,
≤10K
>10K,
≤100K
>100K,
≤1M0
>1M0
Noise
dB
-10
0
+15
+20
+30
Solvent Resistance
The protective epoxy lacquer and marking are resistant to all
normal industrial cleaning fluids suitable for printed circuits.
Performance Data
Maximum Change
0402
Load: 1000 hrs at 70°c
Shelf life: 12 months at room temp.
Derate linearly to zero from 70°C
Max voltage
Climatic
Climatic category
Long term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
Noise
Insulation resistance
Voltage proof
ohms
volts
100
500
500
∆R%
∆R%
∆R%
2
100
3
3
1
2.5
1
2.5
100
3
3
1
2.5
1
volts
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
3
1
2.5
1
see table 1
> 1G
500
500
500
4R7 - 100K:1
>100K:2
0.2
0603
1R - 100K:1
>100K:2
0.2
0805
1R - 100K:1
>100K:2
0.2
2.5
200
3
55/125/56
3
1
2.5
1
3
1
2.5
1
3
1
2.2
1
1206
1R - 100K:1
>100K:2
0.2
2.5
400
3
2010
1R - 100K:1
>100K:2
0.2
2.5
200
3
2512
3% + 0.1R
0.2
5.0
200
3
zero at 125°C
Short term overload (6.25 x rated power)
∆R%
Packaging
All chips are tape mounted and supplied on standard 8mm
tape reel, as IEC publication 286-3.
180mm (7 inch) reel carries 5,000 pieces. (Except 0402 carries
10,000 pieces)
250mm (10 inch) reel carrying 10,000 pieces can be supplied
by agreement.
Chips are taped element side up as standard.
If chips are to be taped face down please specify.
Type 2010 – 4,000 pcs
Type 2512 – 4,000 pcs
Bulk cassette pack available
Chip Resistor Labstock For Designers
WCR chip resistors are available in a special package
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.
© 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
16
Issue D · 07.03
