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© EPCOS AG 2016
Cautions and Warnings
General
VEPCOS thermistors are designed for specic
applications and should not be used for purposes not
identied in our specications, application notes and
data books unless otherwise agreed with EPCOS during
the design-in-phase.
VEnsure suitability of thermistor through reliability testing
during the design-in phase. The thermistors should
be evaluated taking into consideration worst-case
conditions.
Storage
VStore thermistors only in original packaging. Do not
open the package prior to processing.
VStorage conditions in original packaging: storage
temperature −25 °C ... +45 °C, relative humidity ≤ 75%
annual mean, maximum 95%, dew precipitation is
inadmissible.
VAvoid contamination of thermistors surface during
storage, handling and processing.
VAvoid storage of thermistor in harmful environment with
effect on function on long-term operation (examples
given under operation precautions).
VUse thermistor within the following period after delivery:
– Through-hole devices (housed and leaded PTCs):
24 months
– Motor protection sensors, glass-encapsulated sensors
and probe assemblies: 24 months
– Telecom pair and quattro protectors (TPP, TQP):
24 months
– Leadless PTC thermistors for pressure contacting:
12 months
– Leadless PTC thermistors for soldering: 6 months
– SMDs in EIA sizes 3225 and 4032, and for PTCs with
metal tags: 24 months
– SMDs in EIA sizes 1210 and smaller: 12 months
Handling
VPTCs must not be dropped. Chip-offs must not be
caused during handling of PTCs.
VThe ceramic and metallization of the components
must not be touched with bare hands. Gloves are
recommended.
VAvoid contamination of thermistor surface during
handling.
Soldering (where applicable)
VUse rosin-type ux or non-activated ux.
VInsufcient preheating may cause ceramic cracks.
VRapid cooling by dipping in solvent is not
recommended.
VComplete removal of ux is recommended.
VStandard PTC heaters are not suitable for soldering.
Mounting
VElectrode must not be scratched before/during/after the
mounting process.
VContacts and housing used for assembly with thermistor
have to be clean before mounting. Especially grease or
oil must be removed.
VWhen PTC thermistors are encapsulated with sealing
material, the precautions given in chapter “Mounting
instructions”, “Sealing and potting” must be observed.
VWhen the thermistor is mounted, there must not be any
foreign body between the electrode of the thermistor
and the clamping contact.
VThe minimum force and pressure of the clamping
contacts pressing against the PTC must be 10 N and
50 kPa, respectively. In case the assembly is exposed
to mechanical shock and/ or vibration this force should
be higher in order to avoid movement of the PTC during
operation.
VDuring operation, the thermistor’s surface temperature
can be very high. Ensure that adjacent components are
placed at a sufcient distance from the thermistor to
allow for proper cooling at the thermistors.
VEnsure that adjacent materials are designed for
operation at temperatures comparable to the surface
temperature of thermistor. Be sure that surrounding
parts and materials can withstand this temperature.
VAvoid contamination of thermistor surface during
processing.
Operation
VUse thermistors only within the specied temperature
operating range.
VUse thermistors only within the specied voltage and
current ranges.
VEnvironmental conditions must not harm the thermistors.
Use thermistors only in normal atmospheric conditions.
Avoid use in deoxidizing gases (chlorine gas, hydrogen
sulde gas, ammonia gas, sulfuric acid gas etc),
corrosive agents, humid or salty conditions. Contact
with any liquids and solvents should be prevented.
VBe sure to provide an appropriate fail-safe function
to prevent secondary product damage caused by
abnormal function (e.g. use VDR for limitation of
overvoltage condition).
This listing does not claim to be complete, but merely
reects the experience of EPCOS AG.
Display of ordering codes for EPCOS products
The ordering code for one and the same EPCOS product
can be represented differently in data sheets, data books,
other publications, on the EPCOS website, or in order-
related documents such as shipping notes, order conr-
mations and product labels. The varying representations
of the ordering codes are due to different processes
employed and do not affect the specications of the
respective products. Detailed information can be found
on the Internet under www.epcos.com/orderingcodes