B57237S259M Datasheet, PDF (17/20 Pages) EPCOS – NTC thermistors for inrush current limiting

Inrush current limiters
ICLs
B57237S0***M0**
S237
Cautions and warnings
General
See "Important notes" on the last page.
Storage
Store thermistors only in original packaging. Do not open the package before storage.
Storage conditions in original packaging: storage temperature 25 °C ... +45 °C, relative
humidity ≤75% annual mean, maximum 95%, dew precipitation is inadmissible.
Avoid contamination of thermistors surface during storage, handling and processing.
Avoid storage of thermistor in harmful environments like corrosive gases (SO_x, Cl etc).
Solder thermistors after shipment from EPCOS within the time specified:
 Leaded components: 24 months
Handling
NTC inrush current limiters must not be dropped. Chip-offs must not be caused during handling
of NTC inrush current limiters.
Components must not be touched with bare hands. Gloves are recommended.
Avoid contamination of thermistor surface during handling.
In case of exposure of the NTC inrush current limiters to water, electrolytes or other aggressive
media, these media can penetrate the coating and reach the surface of the ceramic. Low-ohmic
or high-ohmic behavior may occur due to the formation of an electrolyte with metals
(silver/lead/tin from metallization or solder). Low-ohmic behavior is caused by electrochemical
migration, high-ohmic behavior by dissolving of the electrode. In either case, the functionality of
the NTC inrush current limiters can not be assured.
Washing processes may damage the product due to the possible static or cyclic mechanical
loads (e.g. ultrasonic cleaning). They may cause cracks to develop on the product and its parts,
which might lead to reduced reliability or lifetime.
Bending / twisting leads
A lead (wire) may be bent at a minimum distance of twice the wire’s diameter plus 4 mm from
the component head or housing. When bending ensure the wire is mechanically relieved at the
component head or housing. The bending radius should be at least 0.75 mm.
Twisting (torsion) by 180° of a lead bent by 90° is permissible at 6 mm from the bottom of the
thermistor body.
Soldering
Use resin-type flux or non-activated flux.
Insufficient preheating may cause ceramic cracks.
Rapid cooling by dipping in solvent is not recommended.
Complete removal of flux is recommended.
Please read Cautions and warnings and
Important notes at the end of this document.
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