Approval sheet
Page 1 of 8 ASC_WWxxX_V12 Nov.- 2011
WW12X, WW08X, WW06X, WW04X
±
±±
±1%, ±
±±
±5%
Thick Film Low ohm chip resistors
Size 1206, 0805, 0603, 0402
*Contents in this sheet are subject to change without prior notice.
Approval sheet
Page 2 of 8 ASC_WWxxX_V12 Nov.- 2011
FEATURE
1. High power rating and compact size
2. High reliability and stability
3. Reduced size of final equipment
4. RoHS compliant and Lead free products
APPLICATION
• Power supply
• PDA
• Digital meter
• Computer
• Automotives
• 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 Tin (lead free) alloy.
Fig 1. Construction of Chip-R
Approval sheet
Page 3 of 8 ASC_WWxxX_V12 Nov.- 2011
QUICK REFERENCE DATA
Item General Specification
Series No. WW12X WW08X WW06X WW04X
Size code 1206 ( 3216 ) 0805 ( 2012 )
0603 ( 1608 ) 0402(1005)
Resistance Tolerance ±5%, ±1%
Resistance Range 0.010Ω ~
0.976Ω 0.020Ω ~
0.976Ω 0.10Ω ~ 0.976Ω
N/a
N/a
≤ 500 ppm/°C ≤ 600 ppm/°C
TCR (ppm/°C) 0.01Ω ≤ Rn < 0.05Ω
0.05Ω ≤ Rn < 0.10Ω
0.10Ω ≤ Rn < 0.50Ω
0.50Ω ≤ Rn < 1Ω
≤ 2100 ppm/°C
≤ 1000 ppm/°C
≤ 500 ppm/°C
≤ 400 ppm/°C
≤ 1500 ppm/°C
≤ 1000 ppm/°C
≤ 500 ppm/°C
≤ 300 ppm/°C
≤ 300 ppm/°C ≤ 600 ppm/°C
Max. dissipation at T
amb
=70°C 1/4 W 1/8 W 1/10 W 1/16 W
Max. Operation Voltage (DC or RMS) 200V 100V 50V
Max. Overload voltage (DC or RMS) 400V 200V 100V
Climatic category (IEC 60068) 55/155/56
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.
MECHANICAL DATA
Symbol
WW12X WW08X WW06X WW04X
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
T 0.60 ± 0.15
0.50 ± 0.15
0.45 ± 0.15
0.35 ± 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
Approval sheet
Page 4 of 8 ASC_WWxxX_V12 Nov.- 2011
MARKING
4-digits marking for 1206, 0805 size
Each resistor is marked with a four-digit code on the protective coating to designate the nominal resistance
value.
3-digits marking for 0603 size
Each resistor is marked with a
three
-digit code on the protective coating to designate the nominal resistance
value.
WW04X series has no marking on the product overcoat for both 5% & 1%.
Marking code list.
Approval sheet
Page 5 of 8 ASC_WWxxX_V12 Nov.- 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
Approval sheet
Page 6 of 8 ASC_WWxxX_V12 Nov.- 2011
CATALOGUE NUMBERS
The resistors have a catalogue number starting with .
WW12 X R020 F T L
Size code
WW12 : 1206
WW08 : 0805
WW06 : 0603
WW04 : 0402
Type code
X : Normal
Resistance code
E96 +E24:
R is first digit followed by 3
significant digits.
0.020Ω = R020
0.510Ω = R510
0.025Ω = R025
0.400Ω = no marking
Tolerance
J : ±5%
G : ±2%
F : ±1%
Packaging code
T : 7” Reel taping
Termination code
L = Sn base (lead
free)
Tape packaging WW12,WW08,WW06 : 8mm width paper taping 5,000pcs per reel.
WW04:
8mm width paper taping 10,000pcs per reel.
Approval sheet
Page 7 of 8 ASC_WWxxX_V12 Nov.- 2011
TEST AND REQUIREMENTS(JIS C 5201-1 : 1998)
TEST PROCEDURE REQUIREMENT
Temperature Coefficient of
Resistance(T.C.R)
Clause 4.8
Natural resistance change per change in degree centigrade.
( )
6
121
12 10×
−
−
ttR RR
(ppm/°C) t
1
: 20°C+5°C-1°C
R
1
: Resistance at reference temperature
R
2
: Resistance at test temperature
Refer to
“QUICK REFERENCE DATA”
Short time overload (S.T.O.L)
Clause 4.13 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. ±(2%+0.005Ω)
WW04X max ±(2%+0.010Ω)
Resistance to soldering
heat(R.S.H)
Clause 4.18
Un-mounted chips completely immersed for 10±1 second in a
SAC solder bath at 260℃±5ºC no visible damage
∆ R/R max. ±(1%+0.005Ω)
WW04X max ±(1%+0.010Ω)
Solderability
Clause 4.17
Un-mounted chips completely immersed for 2±0.5 second in a
SAC solder bath at 235℃±5℃ good tinning (>95% covered)
no visible damage
Temperature cycling
Clause 4.19 30 minutes at -55°C±3°C, 2~3 minutes at 20°C+5°C-1°C, 30
minutes at +155°C±3°C, 2~3 minutes at 20°C+5°C-1°C, total 5
continuous cycles
no visible damage
∆R/R max. ±(1%+0.005Ω)
WW04X max ±(1%+0.010Ω)
Load life (endurance)
Clause 4.25 1000 +48/-0 hours, loaded with RCWV or Vmax in chamber
controller 70±2ºC, 1.5 hours on and 0.5 hours off ∆R/R max. ±(3%+0.005Ω)
WW04X max ±(5%+0.010Ω)
Load life in Humidity
Clause 4.24 1000 +48/-0 hours, loaded with RCWV or Vmax 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. ±(3%+0.005Ω)
WW04X max ±(5%+0.010Ω)
Bending strength
Clause 4.33 Resistors mounted on a 90mm glass epoxy resin PCB(FR4);
bending : 2 mm, once for 10 seconds ∆R/R max. ±(1%+0.005Ω)
WW04X max ±(1%+0.010Ω)
Adhesion
Clause 4.32 Pressurizing force: 5N, Test time: 10±1sec. No remarkable damage or
removal of the terminations
Insulation Resistance
Clause 4.6 Apply the maximum overload voltage (DC) for 1minute R≧10GΩ
Dielectric Withstand Voltage
Clause 4.7 Apply the maximum overload voltage (AC) for 1 minute No breakdown or flashover
Approval sheet
Page 8 of 8 ASC_WWxxX_V12 Nov.- 2011
PACKAGING
Paper Tape specifications (unit :mm)
Series No. A B W F E
WW12X 3.60±0.20 2.00±0.20
WW08X 2.40±0.20 1.65±0.20
WW06X 1.90±0.20 1.10±0.20
WW04X 1.20±0.10 0.70±0.10
8.00±0.30 3.50±0.20 1.75±0.10
Series No. P1 P0 ΦD T
WW12X / WW08X
Max. 1.0
WW06X 4.00±0.10 4.00±0.10 0.65±0.05
WW04X 2.00±0.10 4.00±0.10
1.0 0.0
50.1
+
−
Φ
0.40±0.05
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
