Approval sheet
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E96 & E24 series for resistors with a tolerance of
0.5%, 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
SOLDERING CONDITION
The robust construction of chip resistors allows them
to be completely immersed in a solder bath of 260C
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
235C during 2 seconds. The test condition for no
leaching is 260C 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 for Chip Resistors
CATALOGUE NUMBERS
The resistors have a catalogue number starting with :
WF06
H
3742
Resistance code
E96+E24:
D
T
L
Size code
Type code
Tolerance
D : 0.5%
B : 0.1%
Packaging code
Termination code
WF12 : 1206
WF08 : 0805
WF06 : 0603
WF04 : 0402
H : High precision,
<1%
T
: 7” Reeled taping
L
= Sn base (lead
free)
3 significant digits followed
by no. of zeros
102
37.4K
220
=1020
=3742
=2200
Reeled tape packaging : 8mm width paper taping 5000pcs per 7” reel for 1206/0805/0603, 10000pcs per 7” reel for
0402.
Page 4 of 6
ASC_WFxxH_V03
May – 2023