POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH PRECISION THIN FILM CHIP RESISTOR
Ver: 1
Page: 1 of 8
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H
HS
S
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WF12U, WF08U, WF06U, WF04U
±0.5%, ±0.1%
TC25
High Precision Thin Film chip resistors
Size 1206, 0805, 0603, 0402
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH PRECISION THIN FILM CHIP RESISTOR
Ver: 1
Page: 2 of 8
FEATURE
1. SMD metal film resistor
2. High reliability and stability of 0.1% and below per customer request
3. High performance of TCR: 25 ppm/K and below per customer request
4. Low current noise
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. Consctruction of Chip-R WFxxU
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH PRECISION THIN FILM CHIP RESISTOR
Ver: 1
Page: 3 of 8
QUICK REFERENCE DATA
Item General Specification
Series No. WF12U WF08U WF06U WF04U
Size code 1206 ( 3216 )
0805 ( 2012 ) 0603 ( 1608 ) 0402 ( 1005 )
Resistance Tolerance ±0.5%, ±0.1%
Resistance Range 4.7Ω ~ 1MΩ
( E24 +E96 ) 4.7Ω ~ 1MΩ
( E24 +E96 ) 10Ω ~ 330KΩ
( E24 +E96 ) 10Ω ~ 100KΩ
( E24 +E96 )
TCR (ppm/°C) +25 ~ -25 ppm/°C
Max. dissipation at Tamb=70°C 1/8W 1/10W 1/16W 1/16W
Max. Operation Voltage (DC or RMS) 150V 100V 50V 25V
Climatic category (IEC 60068) 55/125/56
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.
Dimensions:
Type WF12U WF08U WF06U WF04U
L 3.10 ± 0.10 2.00 ± 0.10 1.60 ± 0.10 1.00 ± 0.05
W 1.60 ± 0.10 1.25 ± 0.10 0.80 ± 0.10 0.50 ± 0.05
A 0.60 ± 0.15 0.50 ± 0.15 0.45 ± 0.15 0.35 ± 0.05
B 0.45 ± 0.20 0.40 ± 0.20 0.30 ± 0.20 0.25 ± 0.10
t 0.50 ± 0.20 0.40 ± 0.20 0.30 ± 0.20 0.20 ± 0.10
Protective coat
Resistive layer
End termination
Ceramic Substrate
t
B
A
T
W
L
1001
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH PRECISION THIN FILM CHIP RESISTOR
Ver: 1
Page: 4 of 8
Marking
Each resistor is marked with a three digits code on the protective coating to designate the
nominal resistance value. WF04U has no marking!
Example: E24 serious 1% 39R0 => 390 820R =>821
E96 serious 1% 17R8 =>25X， 178R => 25A
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E96 & E24 series for resistors with a tolerance of
±0.5%, ±0.1%. 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, 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.
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH PRECISION THIN FILM CHIP RESISTOR
Ver: 1
Page: 5 of 8
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 245°C during 3 seconds within lead-free solder bath. 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.
Catalogue numbers
The resistors have a catalogue number starting with .
WF06 U xxxx B T _
Size code
WF12 : 1206
WF08 : 0805
WF06 : 0603
WF04 : 0402
Type code
U :TCR 25ppm
Resistance code
E96 +E24:
4 significant digits.
E24: 39R0=>39R0
820R =>8200
E96: 17R8 =>17R8
178R =>1780
Tolerance
B : ±0.1%
D : ±0.5%
Packaging code
T : 7” Reeled taping
B : Bulk
Termination code
_ = SnPb base (“_”
means a blank)
L = Sn base (lead
free)
1. Reeled tape packaging: 8mm width paper taping.
5,000pcs/reel for WF12U, WF08U, WF06U;
10,000pcs/reel for WF04U.
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH PRECISION THIN FILM CHIP RESISTOR
Ver: 1
Page: 6 of 8
TEST AND REQUIREMENTS
TEST PROCEDURE REQUIREMENT
Resistor
DC resistance DC resistance values measured at the test
voltages specified below : Within the specified tolerance ±0.5% & ±0.1%
Resistance <100Ω <1KΩ <10KΩ
Test voltage
0.3V 1.0V 3.0V
Resistance <100KΩ
<1MΩ <10MΩ
Test voltage
10V 25V 50V
Temperature
Coefficient of
Resistance
( TCR )
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 : 25°C
Test temperature –55°C ~ +125°C
TCR: ≦±25 ppm/°C
Short time
overload
( STOL )
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. ±(0.1%+0.05Ω)
Resistance to
soldering heat Unmounted chips 10±1 seconds, 260±5ºC no visible damage
∆ R/R max. ±(0.1%+0.05Ω)
Solderability Unmounted chips completely immersed for
3±1sec. in a lead-free solder bath at 245±5ºC
good tinning (>95% covered)
no visible damage
Temperature
cycling 1. 30 minutes at -55°C±3°C,
2. 2~3 minutes at room temperature,
3. 30 minutes at +155°±3°C,
4. 2~3 minutes at room temperature,
Total 5 continuous cycles
no visible damage
∆R/R max. ±(0.1%+0.05Ω)
Load life
(endurance) 70±2ºC, 1000 hours, loaded with RCWV or
Vmax,1.5 hours on and 0.5 hours off ∆R/R max. ±(0.5%+0.05Ω)
Load life in
Humidity 1000 hours, at rated continuous working voltage
in humidity chamber controller at 40°C±2°C and
90~95% relative humidity, 1.5hours on and 0.5
hours off
∆R/R max. ±(0.5%+0.05Ω)
Bending and
Termination
strength
Resistors mounted on a 90mm glass epoxy
resin PCB(FR4); bending : 3 mm, once for 10
seconds
Pulling test : 500grams
∆R/R max. ±(0.1%+0.05Ω)
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH PRECISION THIN FILM CHIP RESISTOR
Ver: 1
Page: 7 of 8
PACKAGING
Paper Tape specifications (unit :mm)
FP0
D
Series No. A B W D E
WF12 3.60±0.20 2.00±0.20 8.00±0.30 3.50±0.20 1.75±0.10
WF08 2.40±0.20 1.65±0.20 8.00±0.30 3.50±0.20 1.75±0.10
WF06 1.90±0.20 1.10±0.20 8.00±0.30 3.50±0.20 1.75±0.10
WF04 1.20±0.10 0.7±0.10 8.00±0.20 3.50±0.05 1.75±0.10
Series No. F P0 ΦD T
WF12 4.00±0.10 4.00±0.10 1.0 0.0
50.1 +
−
Φ Max. 1.0
WF08 4.00±0.10 4.00±0.10 1.0 0.0
50.1 +
−
Φ Max. 1.0
WF06 4.00±0.10 4.00±0.10 1.0 0.0
50.1 +
−
Φ 0.65±0.05
WF04 2.00±0.10 4.00±0.10 1.0 0.0
50.1 +
−
Φ 0.40±0.05
Reel dimensions
AB
C
D
Symbol A B C D
(unit : mm) Φ178.0±2.0 Φ60.0±1.0 13.0±0.2 9.0±0.5
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH PRECISION THIN FILM CHIP RESISTOR
Ver: 1
Page: 8 of 8
Taping quantity
- Chip resistors 5,000 pcs per reel ( WF12U, WF08U, WF06U )
- Chip resistors 10,000 pcs per reel ( WF04U )
