2

Conductive adhesion

An alternative to soldering is the gluing of thermistors with conductive adhesives. The benefit of

this method is that it involves no thermal stress. The adhesives used must be chemically inert.

3

Clamp contacting

Pressure contacting by means of clamps is particularly suitable for applications involving frequent

switching and high turn-on powers.

4

Robustness of terminations (leaded types)

The leads meet the requirements of IEC 60068-2-21. They may not be bent closer than 4 mm

from the solder joint on the thermistor body or from the point at which they leave the feed-

throughs. During bending, any mechanical stress at the outlet of the leads must be removed. The

bending radius should be at least 0.75 mm.

Tensile strength:

Test Ua1:

Leads

∅ ≤0.25 mm =

1.0 N

0.25 <

∅ ≤0.35 mm =

2.5 N

0.35 <

∅ ≤0.50 mm =

5.0 N

0.50 <

∅ ≤0.80 mm = 10.0 N

0.80 <

∅ ≤1.25 mm = 20.0 N

Bending strength: Test Ub:

Two 90

°-bends in opposite directions at a weight of 0.25 kg.

Torsional strength: Test Uc: severity 2

The lead is bent by 90

° at a distance of 6 to 6.5 mm from the thermistor body.

The bending radius of the leads should be approx. 0.75 mm. Two torsions of

180

° each (severity 2).

When subjecting leads to mechanical stress, the following should be observed:

Tensile stress on leads

During mounting and operation tensile forces on the leads are to be avoided.

Bending of leads

Bending of the leads directly on the thermistor body is not permissible.

A lead may be bent at a minimum distance of twice the wire's diameter +2 mm from the solder

joint on the thermistor body. During bending the wire must be mechanically relieved at its outlet.

The bending radius should be at least 0.75 mm.

Twisting of leads

The twisting (torsion) by 180

° of a lead bent by 90° is permissible at 6 mm from the bottom of the

thermistor body.

Temperature measurement

B57875S

Leaded NTC thermistors, lead spacing 5 mm

S875

Page 20 of 27

Please read Cautions and warnings and

Important notes at the end of this document.