POE International Corp
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
M01-00-E-07
Ver: 1
Page:
1 of 7
ROHS compliance
WF12G, WF08G, WF06G, WF04G
±5%
High ohmic chip resistors
Size 1206, 0805, 0603, 0402
Customer
:
Approval No :
Issue Date
:
Customer Approval :
POE International Corp
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
M01-00-E-07
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
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
M01-00-E-07
Ver: 1
Page:
3 of 7
QUICK REFERENCE DATA
Item
Series No.
Size code
Resistance Range and tolerance
±5%
tolerance
TCR (ppm/°C)
Max. dissipation at T
amb
=70°C
Max. Operation 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
10MΩ < R
≤
30MΩ ( E24 series)
≤ ±
300 ppm/°C
1/8 W
150V
55/125/56
1/10 W
50V
1/16W
50V
WF12G
1206 ( 3216 )
General Specification
WF08G
0805 ( 2125 )
WF06G
0603 ( 1608 )
WF04G
0402 ( 1005 )
RCWV
=
Rated Power
×
Resistance Value
or Max. RCWV listed above, whichever is lower.
Dimensions:
series
L
W
Tt
Tb
T
WF12G
3.10
±
0.10
1.60
±
0.10
0.50
±
0.20
0.45
±
0.20
0.60
±
0.15
WF08G
2.00
±
0.10
1.25
±
0.10
0.40
±
0.20
0.40
±
0.20
0.50
±
0.15
WF06G
1.60
±
0.10
0.80
±
0.10
0.30
±
0.10
0.30
±
0.20
0.45
±
0.15
WF04G
1.00
±
0.05
0.50
±
0.05
0.20
±
0.10
0.25
±
0.10
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
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
M01-00-E-07
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
SPECIFICATION OF HIGH OHMIC CHIP RESISTOR
M01-00-E-07
Ver: 1
Page:
5 of 7
CATALOGUE NUMBERS
The resistors have a catalogue number starting with :
WF06
Size code
WF12
WF08
WF06
WF04
: 1206
: 0805
: 0603
: 0402
Type code
G : High ohmic >10MΩ
G
226_
Resistance code
E24:
2 significant digits followed by
no. of zeros and a blank
11MΩ
22MΩ
30MΩ
=116_
=226_
=306_
J
Tolerance
J :
±5%
T
Packaging code
T
B
: 7” Reeled taping
: Bulk
_
Termination code
_ = SnPb base (“_”
means a blank)
L
=
Sn base (lead
free)
(“_” means a blank)
1.
2.
Reeled tape packaging
Bulk packaging
: 8mm width paper taping 5000pcs per 7” reel for 1206, 0805, 0603 ( 10,000pcs for 0402 )
: 5000pcs per polybag
TEST AND REQUIREMENTS
TEST
Temperature
Coefficient of
Resistance
(TCR )
PROCEDURE
Natural resistance change per change in degree centigrade.
REQUIREMENT
Test temperature
–55~+125°C
≤±300ppm/°C
R
2
−
R
1
×
10
6
R
1
(
t
2
−
t
1
)
(ppm/°C)
R
1
: Resistance at reference temperature
R
2
: Resistance at test temperature
t
1
: 25°C
Short time
overload (STOL )
Resistance to
soldering heat
Solderability
Permanent resistance change after a 5second application of a
∆R/R
max.
±(3%+0.10Ω)
voltage 2.5 times RCWV or the maximum overload voltage
specified in the above list, whichever is less.
Unmounted chips 10±1 seconds, 260±5ºC
no visible damage
∆
R/R max.
±(2%+0.10Ω)
Termination SnPb base : Unmounted chips completely good tinning (>95% covered)
immersed for 2±0.5 sec. in a solder bath at 230±5ºC
no visible damage
Termination Sn base (lead free) : Unmounted chip completely
immersed in a lead free solder bath, 245°C±5°C, 3±1 sec
1.
2.
3.
4.
30 minutes at -55°C±3°C,
2~3 minutes at room temperature,
30 minutes at +125°±3°C,
2~3 minutes at room temperature,
no visible damage
∆R/R
max.
±(3%+0.10Ω)
Temperature
cycling
Total 5 continuous cycles
