POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
Ver: 1
Page: 1 of 7
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WF12G, WF08G, WF06G, WF04G
±5%
High ohmic chip resistors
Size 1206, 0805, 0603, 0402
Customer :
Approval No :
Issue Date :
Customer Approval :
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
Ver: 1
Page: 2 of 7
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
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
Ver: 1
Page: 3 of 7
QUICK REFERENCE DATA
Item General Specification
Series No. WF12G WF08G WF06G WF04G
Size code 1206 ( 3216 ) 0805 ( 2125 ) 0603 ( 1608 ) 0402 ( 1005 )
Resistance Range and tolerance
±5% tolerance
10MΩ < R ≤ 30MΩ ( E24 series)
TCR (ppm/°C) ≤ ± 300 ppm/°C
Max. dissipation at Tamb=70°C 1/4 W 1/8 W 1/10 W 1/16W
Max. Operation Voltage (DC or RMS)
200V 150V 50V 50V
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:
series WF12G WF08G WF06G WF04G
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
Tt 0.50 ±
0.20
0.40 ±
0.20
0.30 ± 0.10
0.20 ± 0.10
Tb 0.45 ±
0.20
0.40 ±
0.20
0.30 ± 0.20
0.25 ± 0.10
T 0.60 ±
0.15
0.50 ±
0.15
0.45 ± 0.15
0.35 ± 0.05
Marking
3-digits marking
Each resistor is marked with a three digits code on the protective coating to designate the nominal resistance
value. For values up to 910Ω the R is used as a decimal point. For values of 1KΩ or greater the first 3 digits
apply to the resistance value and fourth indicate the number of zeros to follow.
Example
306 = 30 MΩ
186 = 18 MΩ
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
Ver: 1
Page: 4 of 7
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E96 & E24 series for resistors with a tolerance of
±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 230°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
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
Ver: 1
Page: 5 of 7
CATALOGUE NUMBERS
The resistors have a catalogue number starting with :
WF06 G 226_ J T _
Size code
WF12 : 1206
WF08 : 0805
WF06 : 0603
WF04 : 0402
Type code
G : High ohmic >10MΩ
Resistance code
E24:
2 significant digits followed by
no. of zeros and a blank
11MΩ =116_
22MΩ =226_
30MΩ =306_
(“_” means a blank)
Tolerance
J : ±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 5000pcs per 7” reel for 1206, 0805, 0603 ( 10,000pcs for 0402 )
2. Bulk packaging : 5000pcs per polybag
TEST AND REQUIREMENTS
TEST PROCEDURE REQUIREMENT
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~+125°C
≤±300ppm/°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. ±(3%+0.10Ω)
Resistance to
soldering heat Unmounted chips 10±1 seconds, 260±5ºC no visible damage
∆ R/R max. ±(2%+0.10Ω)
Solderability Termination SnPb base : Unmounted chips completely
immersed for 2±0.5 sec. in a solder bath at 230±5ºC
Termination Sn base (lead free) : Unmounted chip completely
immersed in a lead free solder bath, 245°C±5°C, 3±1 sec
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 +125°±3°C,
4. 2~3 minutes at room temperature,
Total 5 continuous cycles
no visible damage
∆R/R max. ±(3%+0.10Ω)
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
Ver: 1
Page: 6 of 7
TEST PROCEDURE REQUIREMENT
Load life
(endurance) 70±2ºC, 1000 hours, loaded with RCWV or Vmax,1.5 hours on
and 0.5 hours off ∆R/R max. ±(3%+0.1Ω)
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. ±(5%+0.1Ω)
Bending and
Termination
strength
Resistors mounted on a 90mm glass epoxy resin PCB(FR4);
bending : 5 mm, once for 10 seconds
Pulling test : 500grams
∆R/R max. ±(1%+0.10Ω)
POE International Corp
M01-00-E-07
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
Ver: 1
Page: 7 of 7
PACKAGING
Paper Tape specifications (unit :mm)
Series No. A B W F E
WF12G 3.60±0.20 2.00±0.20 8.00±0.30 3.50±0.2 1.75±0.10
WF08G 2.40±0.20 1.65±0.20 8.00±0.30 3.50±0.2 1.75±0.10
WF06G 1.90±0.20 1.10±0.20 8.00±0.30 3.50±0.2 1.75±0.10
Series No. P1 P0 ΦD T
WF12G 4.00±0.10 4.00±0.10
1.0 0.0
50.1 +
−
Φ
0.65±0.1
WF08G 4.00±0.10 4.00±0.10 0.65±0.1
WF06G 4.00±0.10 4.00±0.10 0.65±0.1
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
Taping quantity
- Chip resistors 5,000 pcs/reel for 1206, 0805, 0603 ( 10,000 pcs/reel for 0402 )
