Precaution

1、Soldering
When soldering, care must be taken that the thermistor is not damaged by excessive heat. The following maximum temperature, maximum time spans and minimum distances must be observed:
　　　　　　　　　　　　　　　　　 Dip soldering　　　Iron soldering
Bath temperature　　　　　　　　　　max. 260 ℃　　　　 max. 360℃
Soldering time　　　　　　　　　　　 max. 10s　　　　　 max. 5 s
Distance from thermistor　　　　　　  min. 6mm 　　　　    min. 6mm
Under more severe soldering conditions the resistance may change.

2、Sealing and Potting
When thermistors are sealed or potted, there must be no mechanical stress through differing thermal expansion in the curing process and during later operation. In the curing process the upper category temperature of the thermistor must not be exceeded. It is also necessary to ensure that the potting compounds are chemically neutral. Sealing and potting compounds may degenerate the titanate ceramic of PTC thermistors and lead to the formation of low-ohmic conduction bridges. In conjunction with a change in dissipation conditions due to the potting compound, local overheating may finally damage the thermistor.

3、Cleaning
　　You may use gentle cleaner such as freon, trichloroethane, Tetrachloroethylene to clean ceramic and solder joint. You can also use ultrasonic cleaning. Some solvents may damage thermistor. Please test before cleaning or inquire Ampron.

4、Storage conditions and terms.
If stored properly, there is no limitation on storage terms. In order to maintain solderability, thermistor should be stored in non-corrasive environment. Care should be taken for air humidity, temperature and container material. Better store thermistor in original packing. Contact with metal cladding of PTC thermistor uncoated may lead to degeneration of solderability. Exposition in over damp or over high temperature may lead to thermsitor performance change, such as the solerability. Thermistor can be long time kept in normal storage condition.