1.3

General notes on soldering

Permissible heat exposure loads on film capacitors are primarily characterized by the upper cate-

can lead to changes in the plastic dielectric and thus change irreversibly a capacitor's electrical

characteristics. For short exposures (as in practical soldering processes) the heat load (and thus

the possible effects on a capacitor) will also depend on other factors like:

Pre-heating temperature and time

Forced cooling immediately after soldering

Terminal characteristics:

diameter, length, thermal resistance, special configurations (e.g. crimping)

Height of capacitor above solder bath

Shadowing by neighboring components

Additional heating due to heat dissipation by neighboring components

Use of solder-resist coatings

The overheating associated with some of these factors can usually be reduced by suitable coun-

termeasures. For example, if a pre-heating step cannot be avoided, an additional or reinforced

cooling process may possibly have to be included.

EPCOS recommends the following conditions:

Pre-heating with a maximum temperature of 110

°C

Temperature inside the capacitor should not exceed the following limits:

MKP/MFP 110

°C

MKT 160

°C

When SMD components are used together with leaded ones, the leaded film capacitors should

not pass into the SMD adhesive curing oven. The leaded components should be assembled af-

ter the SMD curing step.

Leaded film capacitors are not suitable for reflow soldering.

Uncoated capacitors

For uncoated MKT capacitors with lead spacings

≤10 mm (B32560/B32561) the following mea-

sures are recommended:

pre-heating to not more than 110

°C in the preheater phase

rapid cooling after soldering

Application note for X1 / X2 EMI capacitors

B32921C/D ... B32928C/D

X2 / 305 V AC

Page 14 of 22

Please read Cautions and warnings and

Important notes at the end of this document.