Approval sheet
Page 1 of 10 ASC_WFxxQ_V16 Nov. 2016
WF25Q,WF20Q,WF10Q,WF12Q,WF08Q,
WF06Q,WF04Q,WF02Q
1%, 0.5%, 0.25%, 0.1%,
0.05%, 0.01%
TC50
High Precision Power Thin Film chip
resistors
(RoHS compliant 、Halogen Free)
Size 2512, 2010, 1210, 1206, 0805, 0603,
0402, 0201
*Contents in this sheet are subject to change without prior notice.
Approval sheet
Page 2 of 10 ASC_WFxxQ_V16 Nov. 2016
FEATURE
1. SMD metal film resistor
2. High reliability and stability of 0.5% and below per customer request
3. High performance of TCR: 50 ppm/C and below per customer request
4. Low current noise
5. RoHS compliant and lead free
APPLICATION
Medical equipment
Measuring instrument
Communication device
Computer
Printer
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 layer that is applied to the top surface of the substrate. The
composition of the resistive layer is adjusted to give the approximate resistance required and the value is
trimmed to nominated value within tolerance which controlled by laser trimming of this resistive layer.
The resistive layer is covered with a protective coat. Finally, the two external end terminations are added. For
environmental soldering issue, the outer layer of these end terminations is a Lead-free solder .
Fig 1. Construction of Chip-R WFxxQ
Approval sheet
Page 3 of 10 ASC_WFxxQ_V16 Nov. 2016
QUICK REFERENCE DATA
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.
DIMENSIONS:(unit:mm)
Type
WF25Q
WF20Q
WF10Q
WF08Q
WF06Q
WF04Q
WF02Q
L
6.35 0.10
5.00 0.10
3.10 0.10
2.00 0.10
1.55 0.10
1.00 0.10
0.6 0.03
W
3.20 0.15
2.50 0.15
2.60 0.15
1.25 0.10
0.80 0.10
0.50 0.05
0.3 0.03
A
0.60 0.20
0.60 0.20
0.50 0.20
0.25 0.20
0.25 0.15
0.15 0.10
0.10 0.05
B
0.90 0.25
0.60 0.25
0.50 0.20
0.40 0.20
0.30 0.15
0.25 0.10
0.15 0.05
t
0.55 0.10
0.55 0.10
0.55 0.10
0.50 0.15
0.45 0.15
0.30 0.05
0.23 0.03
Item
General Specification
Series No.
WF25Q
WF20Q
WF10Q
WF12Q
WF08Q
WF06Q
WF04Q
WF02Q
Size Code
2512
(6432)
2010
(5025)
1210
(3225)
1206
(3216)
0805
(2012)
0603
(1608)
0402
(1005)
0201
(0603)
Resistance Tolerance
1.0%, 0.5%, 0.25%, 0.1%, 0.05%, 0.01%
Resistance Range
10 ~
1.5M
10 ~
1.5M
10 ~
1M
4.7 ~
1M
4.7 ~
1M
4.7 ~
680K
10 ~
100K
27 ~
22K
TCR
50 ppm/C
Max. Dissipation at
Tamb=70C
1W
3/4W
2/5W
1/4W
1/8W
1/10W
1/10W
1/20W
Max. Operation Voltage
200V
200V
200V
200V
150V
75V
50V
15V
Max. Overload Voltage
400V
400V
400V
400V
300V
150V
100V
30V
Operation Temperature
- 55~ +155’C
Protective coat
Resistive layer
End termination
Ceramic Substrate
t
B
A
T
W
L
1001
Approval sheet
Page 4 of 10 ASC_WFxxQ_V16 Nov. 2016
MARKING
3-digits marking for 0603 size
WFxxQ has same marking rule as WRxx ±1%.
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 for 2512, 2010, 1210, 1206, 0805 size
For E24+E96, each resistor is marked with a four digits code on the protective coating to designate the
nominal resistance value. For values below 976 the R is used as a digit. For values of 100 or greater, the
first 3 digits are significant, the fourth digit indicates the number of multiple to follow.
Example
RESISTANCE
100
6800
47000
4-digits marking
1000
6801
4702
No marking code for 0402 and 0201 size
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E192 & E24 series for resistors with a tolerance of
1.0%, 0.5%, 0.25%, 0.1%. The values of the E24/E192 series are in accordance with “IEC publication
60063”.
Approval sheet
Page 5 of 10 ASC_WFxxQ_V16 Nov. 2016
Derating
The power that the resistor can dissipate depends on the operating temperature; see Fig.2
MOUNTING
Due to their rectangular shapes and small tolerances, Surface 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.
Approval sheet
Page 6 of 10 ASC_WFxxQ_V16 Nov. 2016
SOLDERING CONDITION
The robust construction of chip resistors allows them to be completely immersed in a solder bath of 260C for 10
seconds. 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 235C during 2 seconds within lead-free solder bath. The
test condition for no leaching is 260C for 30 seconds. Typical examples of soldering profile and condition that
provide reliable joints without any damage are given in Fig 3. and Table 1.
Fig. 3 Infrared soldering profile for Chip Resistors
Table 1. Infrared soldering condition for Chip Resistors
Temperature Condition
Exposure Time
Average ramp-up rate (217C to 260C)
Less than 3C/second
Between 150 and 200C
Between 60-120 seconds
> 217C
Between 60-150 seconds
Peak Temperature
260ºC +0/-5C
Time within 245C
Min. 30 seconds
Ramp-down rate (Peak to 217C)
Less than 6C/second
Time from 25C to Peak
No greater than 480 seconds
Approval sheet
Page 7 of 10 ASC_WFxxQ_V16 Nov. 2016
CATALOGUE NUMBERS
The resistors have a catalogue number starting with .
WF06
Q
xxxx
B
T
L
Size code
WF25: 2512
WF20: 2010
WF10: 1210
WF12: 1206
WF08: 0805
WF06: 0603
WF04: 0402
WF02: 0201
Type code
Q: TCR = 50 ppm
& High power
Resistance code
R is first code followed by
3 significant digits.
100 =1000
37.4K =3742
Tolerance
T : 0.01%
A : 0.05%
B : 0.10%
C : 0.25%
D : 0.50%
F : 1.00%
Packaging code
T : Reeled
A : 7” Reel 15k pcs
Termination code
L = lead free
1. Reeled tape packaging: 8mm width paper taping.
5,000pcs/reel for WF10Q, WF12Q, WF08Q, WF06Q;
10,000pcs/reel for WF04Q;
15,000pcs/real for WF02Q.
2. Reeled tape packaging: 12mm width paper taping
4,000pcs/reel for WF25Q, WF20Q.
Approval sheet
Page 8 of 10 ASC_WFxxQ_V16 Nov. 2016
TEST AND REQUIREMENTS(JIS C 5201-1 : 1998)
TEST
PROCEDURE
REQUIREMENT
Resistor
DC resistance
Clause 4.5
DC resistance values measured
Within the specified tolerance
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)
R1 : Resistance at reference temperature
R2 : Resistance at test temperature
t1 : 20°C+5°C-1°C
t2 : 125°C+5°C-1°C
Refer to
“ QUICK REFERENCE DATA “
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. ±(0.5%+0.05)
Resistance to
soldering
heat(R.S.H)
IEC 60068-2-
58:2004
Un-mounted chips completely immersed for
10±1second in a SAC solder bath at 260℃±5ºC
no visible damage
R/R max. ±(0.25%+0.05)
Solderability
IEC 60068-2-
58:2004
Un-mounted chips completely immersed for 2±0.5
second in a SAC solder bath at 235℃±5℃
good tinning (>95% covered)
no visible damage
Temperature
cycling
Clause 4.19
30 minutes at -55C3C, 2~3 minutes at
20°C+5°C-1°C, 30 minutes at +155C3C, 2~3
minutes at 20°C+5°C-1°C, total 5 continuous
cycles
no visible damage
R/R max. ±(0.5%+0.05)
Load life
(endurance)
Clause 4.25
70±2ºC, 1000 hours, loaded with RCWV or
Vmax,1.5 hours on and 0.5 hours off
R/R max. (0.5%+0.05)
Load life in
Humidity
Clause 4.24
1000 hours, at rated continuous working voltage in
humidity chamber controller at 40C2C and
90~95% relative humidity, 1.5hours on and 0.5 hours
off
R/R max. (0.5%+0.05)
Bending strength
Clause 4.33
Resistors mounted on a 90mm glass epoxy resin
PCB(FR4); bending : 3 mm, once for 10 seconds.
R/R max. ±(0.1%+0.05)
Adhesion
Clause 4.32
Pressurizing force: 5N, Test time: 10±1sec.
No remarkable damage or removal of the
terminations.
Approval sheet
Page 9 of 10 ASC_WFxxQ_V16 Nov. 2016
PACKAGING
Paper Tape specifications (unit :mm)
Series No.
Tape
z
B
W
F
E
WF25
Plastic
6.90±0.20
3.60±0.20
12.00±0.30
5.50±0.10
1.75±0.10
WF20
Plastic
5.50±0.20
2.80±0.20
12.00±0.30
5.50±0.10
1.75±0.10
WF10
Paper
3.60±0.20
3.00±0.20
8.00±0.30
3.50±0.20
1.75±0.10
WF12
Paper
3.60±0.20
2.00±0.20
8.00±0.30
3.50±0.20
1.75±0.10
WF08
Paper
2.40±0.20
1.65±0.20
8.00±0.30
3.50±0.20
1.75±0.10
WF06
Paper
1.90±0.20
1.10±0.20
8.00±0.30
3.50±0.20
1.75±0.10
WF04
Paper
1.20±0.10
0.70±0.10
8.00±0.30
3.50±0.05
1.75±0.10
Series No.
P1
P0
D
T
WF25
4.00±0.10
4.00±0.10
1.0 0.0
50.1
Max 1.2
WF20
4.00±0.10
4.00±0.10
1.0 0.0
50.1
Max 1.2
WF10
4.00±0.10
4.00±0.10
1.0 0.0
50.1
Max. 1.0
WF12
4.00±0.10
4.00±0.10
1.0 0.0
50.1
Max. 1.0
WF08
4.00±0.10
4.00±0.10
1.0 0.0
50.1
Max. 1.0
WF06
4.00±0.10
4.00±0.10
1.0 0.0
50.1
0.65±0.05
WF04
2.00±0.10
4.00±0.10
1.0 0.0
50.1
0.40±0.05
Approval sheet
Page 10 of 10 ASC_WFxxQ_V16 Nov. 2016
Reel dimensions
A
B
C
D
WF25Q , WF20Q
Symbol
A
B
C
D
(unit : mm)
178.0±2.0
60.0±1.0
13.0±0.2
14.0±0.5
WF12Q , WF10Q , WF08Q , WF06Q , WF04Q
Symbol
A
B
C
D
(unit : mm)
178.0±2.0
60.0±1.0
13.0±0.2
9.0±0.5
Taping quantity
- Chip resistors 4,000 pcs per reel ( WF25Q, WF20Q )
- Chip resistors 5,000 pcs per reel ( WF10Q, WF12Q, WF08Q, WF06Q )
- Chip resistors 10,000 pcs per reel ( WF04Q )
- Chip resistors 15.000 pcs per reel ( WF02Q )