Syfer Technology Ltd. SFJE Issue 2 (P108893) Release Date 04/03/14 Page 3 of 4
Surface Mount and Panel Mount Solder-in filters
Solder pad layouts are included with the detailed information
for each part.
Recommended soldering profile
Soldering of filters
The soldering process should be controlled such that the filter
does not experience any thermal shocks which may induce
thermal cracks in the ceramic dielectric.
The pre-heat temperature rise of the filter should be kept to
around 2°C per second. In practice successful temperature
rises tend to be in the region of 1.5°C to 4°C per second
dependent upon substrate and components.
The introduction of a soak after pre-heat can be useful as it
allows temperature uniformity to be established across the
substrate thus preventing substrate warping. The magnitude
or direction of any warping may change on cooling imposing
damaging stresses upon the filter.
E01, E03, E07 SBSP ranges are compatible with all standard
solder types including lead-free, maximum temperature
260°C. For SBSG, SBSM and SFSS ranges, solder time should
be minimised, and the temperature controlled to a maximum
of 220°C. For SFSR, SFST and SFSU ranges the maximum
temperature is 250°C.
Cooling to ambient temperature should be allowed to occur
naturally. Natural cooling allows a gradual relaxation of
thermal mismatch stresses in the solder joints. Draughts
should be avoided. Forced air cooling can induce thermal
breakage, and cleaning with cold fluids immediately after a
soldering process may result in cracked filters.
Note: The use of FlexiCap™ terminations is strongly
recommended to reduce the risk of mechanical cracking.
Soldering to axial wire leads
Soldering temperature
The tip temperature of the iron should not exceed 300°C.
Dwell time
Dwell time should be 3-5 seconds maximum to minimise the
risk of cracking the capacitor due to thermal shock.
Heat sink
Where possible, a heat sink should be used between the solder
joint and the body, especially if longer dwell times are
required.
Bending or cropping of wire leads
Bending or cropping of the filter terminations should not be
carried out within 4mm (0.157”) of the epoxy encapsulation,
the wire should be supported when cropping.
Soldering irons should not be used for mounting surface
mount filters as they can result in thermal shock
damage to the chip capacitor.
A more comprehensive application note covering
installation of all Syfer products is available on the Syfer
website.
