WW04P
±
1%,
±
5%
Low ohm power chip resistors
Size 0402(1005)
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WW04P_V01
Mar.2011
FEATURE
1. High power rating and compact size
2. High reliability and stability
3. Reduced size of final equipment
4. Lead free product is upon customer requested.
5. Current sensing resistor
APPLICATION
•
•
•
•
PDA
Cable Modem
Battery charger
DC-DC power converter
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 Tin (lead free) alloy.
Fig 1. Consctruction of Chip-R
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WW04P_V01
Mar.2011
QUICK REFERENCE DATA
Item
Series No.
Size code
Resistance Tolerance
Resistance Range
TCR (ppm/°C)
0.47 ~ 0.976 ohm
0.1 ~ 0.43 ohm
Max. dissipation at T
amb
=70°C
Max. Operation current (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
0 ~ +200 ppm/°C
0 ~ +300 ppm/°C
1/8 W
1.11 amper
55/125/56
General Specification
WW04P
0402 ( 1005 )
±1%, ±5%
0.1Ω ~ 0.91Ω
RCWV
=
Rated Power
×
Resistance Value
or Max. RCWV listed above, whichever is lower.
3.
Lead free product is upon customer requested.
MECHANICAL DATA
Unit : mm
L
W
T
Tt
Tb
WW04P
1.00
±
0.05
0.50
±
0.05
0.35
±
0.05
0.20
±
0.10
0.25 +0.05/- 0.10
W T
L
Tt
T
Protec tive coat
End term ination
Tb
Resistive layer
Ceram ic Substrate
MARKING
WW04P series has no marking on the product overcoat for both 5% & 1%.
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WW04P_V01
Mar.2011
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E96 & E24 series for resistors with a tolerance of
±5%
&
±1%.
The values of the E24/E96 series are in accordance with “IEC publication 60063”.
Derating curve
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 10 seconds. 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 30
seconds. Typical examples of soldering
processes that provide reliable joints without any
damage are given in Fig 3.
Fig 3. Infrared soldering profile
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WW04P_V01
Mar.2011
CATALOGUE NUMBERS
The resistors have a catalogue number starting with .
WW04
Size code
WW04 : 0402
P
Type code
P : 1/8 W
R100
Resistance code
E96 + E24:
R is first digit followed by 3
significant digits.
0.100Ω = R100
0.510Ω = R510
J
Tolerance
J :
±5%
F :
±1%
T
Packaging code
T : 7” Reel taping
L
Termination code
L
=
Sn base (lead
free)
Reeled tape packaging
: 8mm width paper taping 1000pcs per reel.
TEST AND REQUIREMENTS
TEST
Temperature
Coefficient of
Resistance
( TCR )
PROCEDURE
Natural resistance change per change in degree centigrade.
REQUIREMENT
Test temperature –55 ~ +125°C
Refer to quick reference
(ppm/°C)
R
2
−
R
1
×
10
6
R
1
(
t
2
−
t
1
)
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 2second application of a
∆R/R
max.
±1%
voltage 2.5 times RCWV or the maximum overload voltage
specified in the above list, whichever is less.
Unmounted chips 5±1 seconds, 260±5ºC
no visible damage
∆
R/R max.
±1%
Unmounted chip completely immersed in a lead free solder good tinning (>95% covered)
bath, 235°C±5°C, 2±1 sec
no visible damage
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.
±1%
Temperature
cycling
Total 5 continuous cycles
Load life
(endurance)
Damp heat
steady state
Bending and
Adhesion
70±2ºC, 1000 hours, loaded with RCWV or Vmax,1.5 hours on
∆R/R
max.
±5%
and 0.5 hours off
40°C±2°C and 90~95% relative humidity,
without current applied, 1000hours
Resistors mounted on a 90mm glass epoxy resin PCB(FR4);
∆R/R
max.
±1%
bending : 3 mm, once for 10 seconds
Pressurizing force 5N, test time 10±1sec
∆R/R
max.
±5%
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WW04P_V01
Mar.2011
Test/Measurement
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