Mounting instructions

1

Soldering

1.1

Leaded NTC thermistors

Leaded thermistors comply with the solderability requirements specified by CECC.

When soldering, care must be taken that the NTC thermistors are not damaged by excessive

heat. The following maximum temperatures, maximum time spans and minimum distances have

to be observed:

Dip soldering

Iron soldering

Bath temperature

max. 260

°C

max. 360

°C

Soldering time

max. 4 s

max. 2 s

Distance from thermistor

min. 6 mm

min. 6 mm

Under more severe soldering conditions the resistance may change.

1.2

Leadless NTC thermistors

In case of NTC thermistors without leads, soldering is restricted to devices which are provided

with a solderable metallization. The temperature shock caused by the application of hot solder

may produce fine cracks in the ceramic, resulting in changes in resistance.

To prevent leaching of the metallization, solder with silver additives or with a low tin content

should be used. In addition, soldering methods should be employed which permit short soldering

times.

2

Clamp contacting

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

switching and high turn-on powers.

3

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

Temperature measurement and compensation

B57964S

Leaded NTC thermistors, lead spacing 2.5 mm

S964

Page 10 of 17

Please read Cautions and warnings and

Important notes at the end of this document.