DATA SHEET
Product Name Wide Terminal Thick Film Chip Resistors
Part Name WR Series
Uniroyal Electronics Global Co., Ltd.
88#, Longteng Road, Economic & Technical Development Zone, Kunshan, Jiangsu, China
Tel
Email
Manufacture Plant
+86 512 5763 1411 / 22 /33
marketing@uni-royal.cn
Uniroyal Electronics Industry Co., Ltd.
Aeon Technology Corporation
Royal Electronic Factory (Thailand) Co., Ltd.
Royal Technology (Thailand) Co., Ltd.
Wide Terminal Thick Film Chip Resistors
1. Scope
1.1 This datasheet is the characteristics of Wide Terminal Thick Film Chip Resistors manufactured by UNI-ROYAL.
1.2 Suitable for both wave & re-flow soldering
1.3 Application：AV adapters，LCD back-light，camera strobe etc
2. Part No. System
Part No. includes 14 codes shown as below:
2.1 1
st
~4
th
codes: Part name. E.g.: WR08, WR12, WR20, WR18, WR25
2.2 5
th
~6
th
codes: Power rating.
E.g.: W=Normal Size
“1~G” = “1~16”
Wattage
Normal Size
1/32
WH
3/4
07
1/2
W2
1/3
W3
1/4
W4
1/8
W8
1/10
WA
1/16
WG
1/20
WM
1
1W
If power rating is equal or lower than 1 watt, 5
th
code would be “W” and 6
th
code would be a number or letter.
E.g.: WA=1/10W
W4=1/4W
th
2.3 7 code: Tolerance. E.g.: D=±0.5%
F=±1%
G=±2%
J=±5%
K= ±10%
th
th
2.4 8 ~11 codes: Resistance Value.
2.4.1 If value belongs to standard value of E-24 series, the 8
th
code is zero, 9
th
~10
th
codes are the significant figures of resistance value, and the
11
th
code is the power of ten.
2.4.2 If value belongs to standard value of E-96 series, the 8
th
~10
th
codes are the significant figures of resistance value, and the 11
th
code is
the power of ten.
2.4.311
th
codes listed as following:
0=10
0
1=10
1
2=10
2
3=10
3
4=10
4
5=10
5
6=10
6
J=10
-1
K=10
-2
L=10
-3
M=10
-4
2.5 12
th
~14
th
codes.
2.5.1 12
th
code: Packaging Type. E.g.: C=Bulk
T=Tape/Reel
th
2.5.2 13 code: Standard Packing Quantity.
4=4,000pcs
5=5,000pcs
C=10,000pcs
D=20,000pcs
E=15,000pcs
Chip Product: BD=B/B-20000pcs
TC=T/R-10000pcs
th
2.5.3 14 code: Special features.
E = Environmental Protection, Lead Free, or Standard type.
3. Ordering Procedure
(Example: WR18 1W ±5% 10KΩ T/R-4000)
W
R 1
8
1
W
J
0
1
0
3
T
4
E
Product Type:
Product Type:
Fill-in 4 digits with
the chip resistor
type as follows:
WR08、WR12、
WR20、WR18、
WR25
Wattage:
Normal size:
W3=1/3W
W2=1/2W
1W=1W
WK=2/3W
2W=2W
3W=3W
Resistance Value:
5%(E-24 series):
The 1
st
digit will be “0”; the 2
nd
& 3
rd
digits are for the
significant figures of the
resistance and the 4
th
digit
indicate the numbers of zeros
following.
1% (E-96 series):
The 1
st
to 3
rd
digits are for the
significant figures of the
resistance and 4th digit denotes
number of zeros following.
J=10
-1
; K=10
-2
; L=10
-3
Packing quantity:
4=4000PCS
5=5000PCS
C=10,000pcs
D=20,000pcs
E=15,000pcs
Special Feature
E= Lead-Free
Tolerance:
F=±1%
J=±5%
Packing Type:
T=Tape/Reel
B=Bulk in poly bag
C=Bulk in cassette
Apr.24,2019 V.4
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Wide Terminal Thick Film Chip Resistors
4. Marking
4.1±5% tolerance products (E-24 series):
3 codes.
1
st
~2
nd
codes are the significant figures of resistance value,
and the rest code is the power of ten.
.
4.2
±5%Tolerance:
Below 10Ω show as
following, read alphabet ”R” as decimal point.
2R2→ 2.2Ω
4.3
±1%
tolerance products (E-96 series):
4 codes.
1
st
~3
rd
codes are the significant figures of resistance value,
and the rest code is the power of ten.
Letter "R" in mark means decimal point.
4.4
±5%,±1%
Tolerance ,Product below 1Ω,show
as following, the first digit is“R”which as decimal point.
R500
→
0.5Ω
333
→
33KΩ
2701
→
2.7KΩ
5. Dimension
Type
WR08(0508)
WR12(0612)
WR20(1020)
WR18(1218)
WR25(1225)
Dimension(mm)
L
1.20±0.10
1.60±0.15
2.50±0.15
3.10±0.10
3.10±0.15
W
2.0±0.10
3.20±0.15
5.00±0.15
4.60±0.15
6.25±0.15
H
0.55±0.10
0.55±0.10
0.55±0.10
0.55±0.10
0.55±0.10
A
0.20±0.10
0.30±0.20
0.40±0.20
0.45±0.20
0.45±0.20
B
0.30±0.20
0.45±0.20
0.60±0.20
0.40±0.20
0.65±0.20
6. Resistance Range
Resistance Range
Type
Power Rating at 70℃
±1%
1/3W
WR08
2/3W
1/2W
WR12
1W
10Ω~1M
WR20
WR18
WR25
3W
1W
1W
2W
10mΩ~1Ω
10mΩ~1MΩ
1Ω＜R≤1M
10mΩ≤R≤1Ω
10m~10Ω
10Ω＜R≤1M
10mΩ≤R≤10Ω
1Ω~1M
10Ω~1M
±5%
Apr.24,2019 V.4
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Wide Terminal Thick Film Chip Resistors
7. Ratings
Max.
Overload
Current
of Jumper
8A
10A
12A
10A
15A
Type
Max
Working
Voltage
150V
200V
200V
200V
200V
Max
Overload
Voltage
300V
400V
400V
400V
400V
Dielectric
Withstanding
Voltage
500V
500V
500V
500V
500V
Resistance
Value of
Jumper
＜50mΩ
＜50mΩ
＜50mΩ
＜50mΩ
＜50mΩ
Rated
Current
of Jumper
4A
5A
6A
6A
6A
Operating
Temperature
-55℃~155℃
-55℃~155℃
-55℃~155℃
-55℃~155℃
-55℃~155℃
WR08
WR12
WR20
WR18
WR25
8.
Soldering pad size recommended
Dimension(mm)
B
C
1.0±0.1
2.0±0.1
1.0±0.1
3.2±0.1
1.2±0.1
5.0±0.1
1.2±0.1
4.6±0.1
1.3±0.1
6.4±0.1
Type
WR08
WR12
WR20
WR18
WR25
A
0.5±0.1
0.6±0.1
1.1±0.1
2.2±0.1
1.4±0.1
D
2.7±0.1
2.9±0.1
3.5±0.1
4.6±0.1
4.0±0.1
9. Derating Curve
Power rating will change based on continuous load at ambient temperature from -55 to 155℃.
It is constant between -55 to 70℃, and derate to zero when temperature rise from 70 to 155℃.
Voltage rating:
Resistors shall have a rated direct-current (DC) continuous working voltage or an approximate sine-wave
root-mean-square (RMS) alternating-current (AC) continuous working voltage at commercial-line
frequency and waveform corresponding to the power rating, as determined from the following formula:
RCWV =
√
× R
Remark: RCWV: Rating Continuous Working Voltage (Volt.) P: power rating (Watt)
R: nominal resistance (Ω)
In no case, the rated DC or RMS AC continuous working voltage must be greater than the applicable maximum value.
The overload voltage is 2.5 times RCWV or Max. Overload voltage whichever is lower.
10 . Structure
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Wide Terminal Thick Film Chip Resistors
11. Performance Specification
Test Methods
(GB/T5729&JIS-C-5201&IEC60115-1)
Characteristic
WR08：
Limits
10mΩ≦R<30mΩ:0~+400 PPM/℃
30mΩ≦R＜10Ω:0~+150 PPM/℃
10Ω：±400 PPM/℃
10Ω<R≦100Ω:±200 PPM/℃
>100Ω:±100 PPM/℃
WR12：
10mΩ≦R<100mΩ:0~+200 PPM/℃
100mΩ≦R≦10Ω:0~+150 PPM/℃
10Ω<R≦100Ω±200 PPM/℃
>100Ω:±100 PPM/℃
WR20：
10mΩ≤R＜30mΩ :0~+200 PPM/℃
Temperature
Coefficient
30mΩ≤R≤1Ω :0~+100 PPM/℃
1Ω＜R≦10Ω:±400 PPM/℃
10Ω<R≦100Ω:±200 PPM/℃
>100Ω:±100 PPM/℃
WR18：
10mΩ≤R＜30mΩ:0~+200 PPM/℃
30mΩ≤R≤1Ω:0~+100 PPM/℃
1Ω＜R≦10Ω:±400 PPM/℃
10Ω<R≦100Ω±200 PPM/℃
>100Ω:±100 PPM/℃
WR25：
10mΩ≤R＜30mΩ:0~+150 PPM/℃
30mΩ≤R≤1Ω:0~+100 PPM/℃
1Ω＜R≦10Ω:±400 PPM/℃
10Ω<R≦100Ω±200 PPM/℃
>100Ω:±100 PPM/℃
±1%
Short-time overload
±5%
±(1.0%+0.005Ω)
±(2.0%+0.005Ω)
4.13 Permanent resistance change after the application of 2.5
times RCWV for 5 seconds.
4.18 Dip the resistor into a solder bath having a temperature of
260℃±5℃ and hold it for 10±1 seconds.
4.7 Resistors shall be clamped in the trough of a 90℃metallic v-
block and shall be tested at ac potential respectively specified in
the given list of each product type for 60-70 seconds.
Wave solder:
Coverage must be over 95%.
Test temperature of solder: 245℃±3℃ dipping time in solder: 2-
3 seconds.
Reflow:
Solderability
Go up tin rate bigger than half of end pole
4.8 Natural resistance changes per temp. Degree centigrade
R
2
-R
1
× 10
6
(PPM/℃)
R
1
(t
2
-t
1
)
R
1
: Resistance Value at room temperature
（t
1
）;
R
2
: Resistance at test temperature
(Upper limit temperature or Lower limit temperature
)
t
1:
+25°C or specified room temperature
t
2:
Upper limit temperature or Lower limit temperature test
temperature
Soldering
heat
Dielectric
withstanding
voltage
±(1.0%+0.005Ω)
No evidence of flashover mechanical damage,
arcing or insulation breaks down.
Apr.24,2019 V.4
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