5 Sealing and potting
Sealing or potting processes can affect the reliability of the component.
When thermistors are sealed, potted or overmolded, there must be no mechanical stress caused
by thermal expansion during the production process (curing / overmolding process) and during
later operation. The upper category temperature of the thermistor must not be exceeded. Ensure
that the materials used (sealing / potting compound and plastic material) are chemically neutral.
As thermistors are temperature sensitive components it should be considered that molding can af-
fect the thermal surrounding and may influence e.g. the response time.
Extensive testing is encouraged in order to determine whether overmolding or potting influences
the functionality and/ or reliability of the component.
6 Cleaning
Cleaning processes can affect the reliability of the component.
If cleaning is necessary, mild cleaning agents are recommended. Cleaning agents based on wa-
ter are not allowed. Washing processes may damage the product due to the possible static or
cyclic mechanical loads (e.g. ultrasonic cleaning). They may cause cracks which might lead to re-
duced reliability and/ or lifetime.
7 Storage
In order to maintain their solderability, thermistors must be stored in a non-corrosive atmosphere.
Humidity, temperature and container materials are critical factors.
Do not store SMDs where they are exposed to heat or direct sunlight. Otherwise, the packing ma-
terial may be deformed or SMDs may stick together, causing problems during mounting. After
opening the factory seals, such as polyvinyl-sealed packages, use the SMDs as soon as possible.
The components should be left in the original packing. Touching the metallization of unsoldered
thermistors may change their soldering properties.
Storage temperature: 25 °C up to 45 °C
Relative humidity (without condensation): ≤75% annual mean
<95%, maximum 30 days per annum
Solder the thermistors listed in this data book after shipment from EPCOS within the time speci-
fied:
SMDs with AgPd termination: 6 months
SMDs with nickel barrier termination: 12 months
Leadless components: 12 months
Leaded components: 24 months
Temperature measurement B57863S
Miniature sensors with bendable wires S863
Page 13 of 21Please read Cautions and warnings and
Important notes at the end of this document.
