Walsin Technology Corporation
WF12H, WF08H, WF06H, WF04H
±0.1%
High precision chip resistors
Size 1206, 0805, 0603, 0402
Customer
:
Approval No :
Issue Date
:
Customer Approval :
Page 1 of 7
WFxxHB
±0.1%
Version 10
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
6. Lead free termination upon customer requested
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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WFxxHB
±0.1%
Version 10
NOV.-2006
Walsin Technology Corporation
QUICK REFERENCE DATA
Item
Series No.
Size code
Resistance Range
TCR (ppm/°C)
1MΩ
≥
R
≥
10Ω
1/4 W
200V
400V
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
WF12H
1206 ( 3216 )
General Specification
WF08H
0805 ( 2012 )
≤ ±
100
1/8 W
150V
300V
55/155/56
WF06H
0603 ( 1608 )
WF04H
0402 ( 1005 )
≤ ±
200
1/16 W
50V
100V
10Ω ~ 1MΩ ( E96+E24 series) Tolerance
±0.1%
1/10 W
50V
100V
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
±
0.10
1.60
±
0.10
0.50
±
0.20
0.45
±
0.20
0.65
±
0.15
WF08H
2.00
±
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
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WFxxHB
±0.1%
Version 10
NOV.-2006
Walsin Technology Corporation
MARKING
WF12H, WF08H, WF06H ±0.1% has same marking rule as WRxxX ±1%.
WF04H, ±0.1% has no marking.
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 of 976Ω the R is used as a decimal point. For values of 1KΩ or greater the first 3 digits are significant, the
fourth indicates the number of zeros to follow.
Example
RESISTANCE
4-digits marking
10Ω
10R0
12Ω
12R0
100Ω
100R
6800Ω
6801
47000Ω
4702
Typically no marking for 0603 size. Please contact with WTC if required marking.
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E96 & E24 series for resistors with a tolerance of
±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.
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WFxxHB
±0.1%
Version 10
NOV.-2006
Walsin Technology Corporation
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 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
B
: 7” Reeled taping
: Bulk
_
Termination code
_ = SnPb base (“_”
means a blank)
L
=
Sn base (lead
free)
Taping quantity
Reeled tape packaging
Bulk packaging
: 8mm width paper taping 5,000pcs per reel for WF12H, WF08H, WF06H.
8mm width paper taping 10,000pcs per reel for WF04H.
: 5000pcs per polybag
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WFxxHB
±0.1%
Version 10
NOV.-2006
