Mounting instructions

1

Soldering

1.1

SMD NTC thermistors

SMD NTC thermistors can be provided with a nickel barrier termination or on special request with

silver-palladium termination. The usage of mild, non-activated fluxes for soldering is recommend-

ed as well as a proper cleaning of the PCB.

The nickel barrier layer of the silver/nickel/tin termination (see figure 1) prevents leaching of the

silver base metalization layer. This allows great flexibility in the selection of soldering parameters.

The tin prevents the nickel layer from oxidizing and thus ensures better wetting by the solder. The

nickel barrier termination is suitable for all commonly-used soldering methods.

Note: SMD NTCs with AgPd termination are not approved for lead-free soldering.

Figure 1

SMD NTC thermistors, structure of nickel barrier termination

1.1.1

Solderability (test to IEC 60068-2-58)

Preconditioning: Immersion into flux F-SW 32.

Evaluation criterion: Wetting of soldering areas

≥95%.

Solder

Bath temperature (

°C)

Dwell time (s)

SnPb 60/40

215

±3

3

±0.3

SnAg (3.0 ... 4.0), Cu (0.5 ... 0.9)

245

±3

3

±0.3

1.1.2

Resistance to soldering heat (test to IEC 60068-2-58)

Preconditioning: Immersion into flux F-SW 32.

Evaluation criterion: Leaching of side edges

≤1/3.

Solder

Bath temperature (

°C)

Dwell time (s)

SnPb 60/40

260

±5

10

±1

SnAg (3.0 ... 4.0), Cu (0.5 ... 0.9)

260

±5

10

±1

Temperature measurement and compensation

B573**V2

SMD NTC thermistors, case size 0603 (1608)

Standard series

Page 11 of 21

Please read Cautions and warnings and

Important notes at the end of this document.