Walsin Technology Corporation
Page 1 of 8 WR12X / WR08X / WR06X Version 19 Nov.-2006
WR12X / WR08X / WR06X
±1%, ±5%
General purpose chip resistors
Size 1206 / 0805 / 0603
Customer :
Approval No :
Issue Date :
Customer Approval :
Walsin Technology Corporation
Page 2 of 8 WR12X / WR08X / WR06X Version 19 Nov.-2006
FEATURE
1. High reliability and stability
2. Reduced size of final equipment
3. Lower assembly costs
4. Higher component and equipment reliability
5. Lead free products upon customer requested
APPLICATION
• Consumer electrical equipment
• Automotive application
• EDP, Computer application
• Telecom application
DESCRIPTION
The resistors are constructed in a high grade ceramic body (aluminum oxide). Internal metal electrodes are
added at each end and connected by a resistive paste that is applied to the top surface of the substrate. The
composition of the paste is adjusted to give the approximate resistance required and the value is trimmed to
within tolerance by laser cutting of this resistive layer.
The resistive layer is covered with a protective coat. Finally, the two external end terminations are added. For
ease of soldering the outer layer of these end terminations is a Lead-tin or Tin (lead free) alloy.
Fig 1. Consctruction of a Chip-R
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Page 3 of 8 WR12X / WR08X / WR06X Version 19 Nov.-2006
QUICK REFERENCE DATA
Item General Specification
Series No. WR12 WR08 WR06
Size code 1206(3216) 0805(2012) 0603(1608)
Resistance Range 1Ω~10MΩ(±5% tolerance),10Ω~1MΩ(±1% tolerance), Jumper
Resistance Tolerance ±1%
E96/E24
±5%
E24
±1%
E96/E24
±5%
E24
±1%
E96/E24
±5%
E24
TCR (ppm/°C)
R≥1MΩ
1MΩ＞R＞10Ω
R≤10Ω
≤ ± 100
-300~+500
≤ ± 200
≤ ± 200
-300~+500
≤ ± 100
-300~+500
≤ ± 200
≤ ± 200
-300~+500
≤ ± 100
-300~+500
≤ ± 200
≤ ± 200
-300~+500
Max. dissipation @
Tamb=70°C 1/4 W 1/8 W 1/10 W
Max. Operation
Voltage (DC or RMS) 200V 150V 50V
Max. Overload
Voltage (DC or RMS) 400V 300V 100V
Climatic category (IEC
60068) 55/155/56
Note :
1. This is the maximum voltage that may be continuously supplied to the resistor element, see “IEC publication
60115-8”
2. Max. Operation Voltage : So called RCWV (Rated Continuous Working Voltage) is determined by
ValueResistancePower RatedRCWV ×= or Max. RCWV listed above, whichever is lower.
3. The resistance range 1~10Ω and 1M ~10MΩ with 1% tolerance please refer to WR12W / WR08W / WR06W
series.
4. The resistance of Jumper is defined <0.05Ω.
DIMENSIONS
WR12X WR08X WR06X
L 3.10 ± 0.10 2.00 ± 0.10 1.60 ± 0.10
W 1.60 ± 0.10 1.25 ± 0.10 0.80 ± 0.10
T 0.60 ± 0.15 0.50 ± 0.15 0.45 ± 0.15
Tb 0.45 ± 0.20 0.40 ± 0.20 0.30 ± 0.15
Tt 0.50 ± 0.20 0.40 ± 0.20 0.30 ± 0.10
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Page 4 of 8 WR12X / WR08X / WR06X Version 19 Nov.-2006
MARKING
Size \ Nr. Of digit of code\tolerance ±5% ±1%
1206 (3216) 3-digits marking 4-digits marking
0805 (2012) 3-digits marking 4-digits marking
0603 (1608) 3-digits marking 3-digits marking
3-digits marking（±5% : 1206 & 0805 & 0603 ）
Each resistor is marked with a three digits code on the protective coating to designate the nominal resistance value. For
values up to 91Ω the R is used as a decimal point. For values of 100Ω or greater the first 3 digits apply to the resistance
value and fourth indicate the number of zeros to follow.(EX. Jumper(0Ω) can be 0 or 000)
3-digits marking（±1% : 0603）
Nominal resistance Description
1.E-24 series As 0603 WR06X ±5%.
2.E-96 series The 1st two digit codes are referring to the CODE on the table, the 3rd code is the index of resistance
value :
Y=10-2，X=10-1，A=100，B=101，C=102，D=103，E=104，F=105
EX : 17.8Ω=25X，178Ω=25A，1K78 =25B
17K8=25C， 178K=25D， 1M78=25E
3. Remark There is no marking for the items are not under E-24 and E-96 series
CODE R_value CODE R_value CODE R_Value CODE R_value CODE R_value CODE R_value CODE R_value CODE R_value
01 100 13 133 25 178 37 237 49 316 61 422 73 562 85 750
02 102 14 137 26 182 38 243 50 324 62 432 74 576 86 768
03 105 15 140 27 187 39 249 51 332 63 442 75 590 87 787
04 107 16 143 28 191 40 255 52 340 64 453 76 604 88 806
05 110 17 147 29 196 41 261 53 348 65 464 77 619 89 825
06 113 18 150 30 200 42 267 54 357 66 475 78 634 90 845
07 115 19 154 31 205 43 274 55 365 67 487 79 649 91 866
08 118 20 158 32 210 44 280 56 374 68 499 80 665 92 887
09 121 21 162 33 215 45 287 57 383 69 511 81 681 93 909
10 124 22 165 34 221 46 294 58 392 70 523 82 698 94 931
11 127 23 169 35 226 47 301 59 402 71 536 83 715 95 953
12 130 24 174 36 232 48 309 60 412 72 549 84 732 96 976
4-digits marking（±1% : 1206/0805）
Each resistor is marked with a four digits code on the protective coating to designate the nominal resistance value. For
values of <97.6Ω the R is used as a decimal point. For values of 100Ω or greater the first 3 digits are significant, the fourth
indicates the number of zeros to follow.
Example
RESISTANCE 10Ω 12Ω 100Ω 6800Ω 0Ω
3-digits marking（1206 & 0805 & 0603 ±5% ） 100 120 101 682 0 or 000
4-digits marking 10R0 12R0 1000 6801 ----
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Page 5 of 8 WR12X / WR08X / WR06X Version 19 Nov.-2006
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E24 series for resistors with a tolerance of ±5%,
and E96 series for resistors with a tolerance of ±1%. The values of the E24/E96 series are in accordance
with “IEC publication 60063”
Derating
The power that the resistor can dissipate depends on the operating temperature; see Fig.2
Figure 2. Maximum dissipation in percentage of rated power
As a function of the ambient temperature
MOUNTING
Due to their rectangular shapes and small tolerances, Su rface Mountable Resistors are suitable for handling by
automatic placement systems.
Chip placement can be on ceramic substrates and printed-circuit boards (PCBs).
Electrical connection to the circuit is by individual soldering condition.
The end terminations guarantee a reliable contact.
SOLDERING CONDITION
The robust construction of chip resistors allows
them to be completely immersed in a solder bath
of 260°C for one minute. Therefore, it is possible
to mount Surface Mount Resistors on one side of
a PCB and other discrete components on the
reverse (mixed PCBs).
Surface Mount Resistors are tested for
solderability at 235°C during 2 seconds. The test
condition for no leaching is 260°C for 60
seconds. Typical examples of soldering
processes that provide reliable joints without any
damage are given in Fig 3.
Fig 3. Infrared soldering p ro file for Chip Resistors
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Page 6 of 8 WR12X / WR08X / WR06X Version 19 Nov.-2006
CATALOGUE NUMBERS
The resistors have a catalogue number starting with .
WR12 X 472_ J T _
Size code
WR12 : 1206
WR08 : 0805
WR06 : 0603
Type code
X : Normal
Resistance code
E24 : 2 significant digits followed
by no. of zeros and a blank
4.7Ω =4R7_
10Ω =100_
220Ω =221_
Jumper =000_
(“_” means a blank)
E96 : 3 significant digits followed
by no. of zeros
102Ω =1020
37.4KΩ =3742
Tolerance
F : ±1%
J : ±5%
P : Jumper
Packaging code
T : 7” Reeled taping
Q : 10” Reeled taping
G : 13” Reeled taping
B : Bulk
Termination code
_ = SnPb base
(“_” means a
blank)
L = Sn base
(lead free)
1. Reeled tape packaging : 8mm width paper taping 5000pcs per 7” reel, 10kpcs per 10” reel, 20kpcs per 13” reel.
2. Bulk packaging : 5000pcs per polybag
TEST AND REQUIREMENTS(JIS C 5201-1 : 1998)
Essentially all tests are carried out according to the schedule of IEC publication 115-8, category
LCT/UCT/56(rated temperature range : Lower Category Temperature, Upper Category Temperature; damp
heat, long term, 56 days). The testing also meets the requirements specified by EIA, EIAJ and JIS.
The tests are carried out in accordance with IEC publication 68, "Recommended basic climatic and mechanical
robustness testing procedure for electronic components" and under standard atmospheric conditions according
to IEC 60068-1, subclause 5.3. Unless otherwise specified, the following value supplied :
Temperature: 15°C to 35°C.
Relative humidity: 45% to 75%.
Air pressure: 86kPa to 106 kPa (860 mbar to 1060 mbar).
All soldering tests are performed with midly activated flux.
TEST CONDITION FOR JUMPER (0 Ω)
Item WR12X WR08X WR06X
Power Rating At 70°C 1/4W 1/8W 1/10W
Resistance MAX.50mΩ
Rated Current 2A 1.5A 1A
Peak Current 5A 3.5A 3A
Operating Temperature -55~155°C
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Page 7 of 8 WR12X / WR08X / WR06X Version 19 Nov.-2006
REQUIREMENT
TEST PROCEDURE / TEST METHOD Resistor 0Ω
DC resistance
Clause 4.5
DC resistance values measured at the test voltages specified below :
<10Ω@0.1V, <100Ω@0.3V, <1KΩ@1.0V,
<10KΩ@3V, <100KΩ@10V, <1MΩ@25V, <10MΩ@30V
Within the specified tolerance <50mΩ
Temperature
Coefficient of
Resistance(T.C.R)
Clause 4.8
Natural resistance change per change in degree centigrade.
()
6
121
12 10×
−
−
ttR RR (ppm/°C) t1 : 20°C+5°C-1°C
R1 : Resistance at reference temperature
R2 : Resistance at test temperature
Refer to
“QUICK REFERENCE
DATA” N/a
Short time overload
(S.T.O.L)
Clause 4.13
Permanent resistance change after a 5second application of a voltage
2.5 times RCWV or the maximum overload voltage specified in the
above list, whichever is less.
∆R/R max. ±(2%+0.10Ω) <50mΩ
Resistance to
soldering heat(R.S.H)
Clause 4.18
Un-mounted chips completely immersed for 10±1second in a solder
bath at 270℃±5ºC ΔR/R max. ±(1%+0.05Ω)
no visible damage <50mΩ
Solderability
Clause 4.17
Un-mounted chips completely immersed for 2±0.5second in a solder
bath at 235℃±5℃ 95% coverage min., good tinning and no
visible damage
Leach Test
Clause 4.18
Un-mounted chips completely immersed for 60±1second in a solder
bath at 260℃±5℃ Ditto
Temperature cycling
Clause 4.19
30 minutes at -55°C±3°C, 2~3 minutes at 20°C+5°C-1°C, 30 minutes at
+155°C±3°C, 2~3 minutes at 20°C+5°C-1°C, total 5 continuous cycles ∆R/R max. ±(1%+0.05Ω) < 50mΩ
Damp Heat
(Load life in humidity)
Clause 4.24
1000+48/-0 hours; 1.5hours ON, 0.5hours OFF at RCWV in a humidity
chamber controlled 40±2°C, 90~95% RH
10Ω≤R<1MΩ :
∆R/R max. ±(3%+0.10Ω)
R<10Ω, R≥1MΩ :
∆R/R max. ±(5%+0.10Ω)
< 50mΩ
Load Life (Endurance)
Clause 4.25
1000+48/-0 hours; loaded with Pn or Vmax; 1.5 hours ON, 0.5 hours OFF Ditto.
Bending strength
Clause 4.33
Resistors mounted on a 90mm glass epoxy resin PCB(FR4), bending
once 3mm for 10sec.
No visual damaged,
∆R/R max. ±(1%+0.05Ω) < 50mΩ
Adhesion
Clause 4.32
Pressurizing force: 5N, Test time: 10±1sec. No remarkable damage or removal of the
terminations
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Page 8 of 8 WR12X / WR08X / WR06X Version 19 Nov.-2006
PACKAGING
Paper Tape specifications (unit :mm)
Series No. A B W F E
WR12X 3.60±0.20 2.00±0.20 8.00±0.30 3.50±0.20 1.75±0.10
WR08X 2.40±0.20 1.65±0.20 8.00±0.30 3.50±0.20 1.75±0.10
WR06X 1.90±0.20 1.10±0.20 8.00±0.30 3.50±0.20 1.75±0.10
Series No. P1 P0 ΦD T
WR12X / WR08X 4.00±0.10 4.00±0.10 1.0 0.0
50.1 +
−
Φ Max. 1.0
WR06X 4.00±0.10 4.00±0.10 1.0 0.0
50.1 +
−
Φ 0.65±0.05
7” Reel dimensions
Symbol A B C D
(unit : mm) Φ178.0±2.0 Φ60.0±1.0 13.0±0.2 9.0±0.5
