Walsin Technology Corporation
WF12H, WF08H, WF06H, WF04H
±0.5%
High precision chip resistors
Size 1206, 0805, 0603, 0402
Customer
:
Approval No :
Issue Date
:
Customer Approval :
Page 1 of 8
WFxxHD ±0.5%
Version 09
Nov.-2006
Walsin Technology Corporation
FEATURE
1. Small size and light weight
2. High reliability and stability
3. Reduced size of final equipment
4. High precision
5. Higher component and equipment reliability
APPLICATION
•
•
•
•
•
Power supply
PDA
Digital meter
Computer
Palmtop computers
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
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
ease of soldering the outer layer of these end terminations is a Lead-tin or Tin (lead free) alloy.
Fig 1. Consctruction of Chip-R
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WFxxHD ±0.5%
Version 09
Nov.-2006
Walsin Technology Corporation
QUICK REFERENCE DATA
Item
Series No.
Size code
Resistance Range
TCR (ppm/°C) 10Ω≤ R
≤
1MΩ
Max. dissipation at T
amb
=70°C
Max. Operation Voltage (DC or RMS)
Max. overload voltage (DC or RMS)
Climatic category (IEC 60068)
Note :
1.
2.
This is the maximum voltage that may be continuously supplied to the resistor element, see “IEC publication
60115-8”
Max. Operation Voltage : So called RCWV (Rated Continuous Working Voltage) is determined by
1/4 W
200V
400V
WF12H
1206 (3216)
General Specification
WF08H
0805 (2125)
≤ ±
100 ppm/°C
1/8 W
150V
300V
55/155/56
1/10 W
50V
100V
WF06H
0603 (1608)
WF04H
0402 (1005)
≤ ±
200 ppm/°C
1/16W
50V
100V
10Ω ~ 1MΩ ( E96+E24 series) Tolerance
±0.5%
RCWV
=
Rated Power
×
Resistance Value
or Max. RCWV listed above, whichever is lower.
3.
Non E96 series resistance upon requested.
DIMENSIONS
Part No
L
W
Tt
Tb
t
WF12H
3.10
±
0.1
1.60
±
0.1
0.50
±
0.2
0.45
±
0.2
0.65
±
0.15
WF08H
2.0
±
0.10
1.25
±
0.10
0.40
±
0.20
0.40
±
0.20
0.5
±
0.15
WF06H
1.60
±
0.10
0.80
±
0.10
0.30
±
0.10
0.30
±
0.20
0.45
±
0.15
WF04H
1.00±0.05
0.50±0.05
0.20±0.10
0.25±0.10
0.35±0.05
MARKING
WFxxH ±0.5% has same marking rule as WRxx ±1%.
4-digits marking for 1206, 0805 size
Each resistor is marked with a four digits code on the protective coating to designate the nominal resistance
value. For values below 97Ω6 the R is used as a digit. For values of 100Ω or greater, the first 3 digits are
significant, the fourth digit indicates the number of multiple to follow.
Example
RESISTANCE
4-digits marking
10Ω
10R0
12Ω
12R0
100Ω
1000
6800Ω
6801
47000Ω
4702
3-digits marking for 0603 size
No marking code for 0402 size
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WFxxHD ±0.5%
Version 09
Nov.-2006
Walsin Technology Corporation
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E96 & E24 series for resistors with a tolerance of
±0.5%.
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.
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.
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Walsin Technology Corporation
Fig 3. Infrared soldering profile for Chip Resistors
CATALOGUE NUMBERS
The resistors have a catalogue number starting with :
WF06
Size code
WF12
WF08
WF06
WF04
: 1206
: 0805
: 0603
: 0402
Type code
H : High precision,
<1%, TCR>50ppm
H
3742
Resistance code
E96 +E24:
3 significant digits followed
by no. of zeros
102Ω
37.4KΩ
220Ω
=1020
=3742
=2200
B
Tolerance
B :
±0.1%
D :
±0.5%
T
Packaging code
T
: 7” Reeled taping
_
Termination code
_ = SnPb base (“_”
means a blank)
L
=
Sn base (lead
free)
Reeled tape packaging
0402.
: 8mm width paper taping 5000pcs per 7” reel for 1206/0805/0603, 10000pcs per 7” reel for
TEST AND REQUIREMENTS(JIS C 5201-1 : 1998)
TEST
DC resistance
Clause 4.5
PROCEDURE
DC resistance values measured at the test voltages specified below :
<10Ω@0.1V,
<100Ω@0.3V, <1KΩ@1.0V, <10KΩ@3V,
<10MΩ@30V
Refer to
“QUICK REFERENCE DATA”
(ppm/°C)
; t1 :
20°C+5°C-1°C
REQUIREMENT
Within the specified tolerance
<100KΩ@10V, <1MΩ@25V,
Temperature
Coefficient of
Resistance(T.C.R)
Clause 4.8
Natural resistance change per change in degree centigrade.
R
2
−
R
1
×
10
6
R
1
(
t
2
−
t
1
)
R1 : Resistance at reference temperature
R2 : Resistance at test temperature
Short time overload
(S.T.O.L)
Clause 4.13
Resistance to
soldering
heat(R.S.H)
Clause 4.18
Solderability
Clause 4.17
Leach Test
Clause 4.18
Un-mounted chips completely immersed for 2±0.5second in a solder bath at good tinning (>95% covered)
235℃±5℃
no visible damage
Un-mounted chips completely immersed for 60±1second in a solder bath at 260 Ditto
℃±5℃
Permanent resistance change after a 5second application of a voltage 2.5
∆R/R
max.
±(2%+0.10Ω)
times RCWV or the maximum overload voltage specified in the above list,
whichever is less.
Un-mounted chips completely immersed for 10±1second in a solder bath at 270 no visible damage
℃±5ºC
∆
R/R max.
±(1%+0.05Ω)
Temperature cycling 30 minutes at -55°C±3°C, 2~3 minutes at 20°C+5°C-1°C, 30 minutes at no visible damage
+155°C±3°C, 2~3 minutes at 20°C+5°C-1°C, total 5 continuous cycles
∆R/R
max.
±(1%+0.05Ω)
Clause 4.19
Load life
(endurance)
Clause 4.25
70±2ºC, 1000 hours, loaded with RCWV or Vmax,1.5 hours on and 0.5 hours
∆R/R
max.
±(3%+0.1Ω)
off
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Version 09
Nov.-2006
