Topic

Safety information

Reference chapter

"Mounting guidelines"

Soldering

Do not exceed the specified time or temperature

limits during soldering.

1 "Soldering"

Cleaning

Use only suitable solvents for cleaning capacitors. 2 "Cleaning"

Embedding of

capacitors in

finished assemblies

When embedding finished circuit assemblies in

plastic resins, chemical and thermal influences

must be taken into account.

Caution: Consult us first, if you also wish to

embed other uncoated component types!

3 "Embedding of

capacitors in finished

assemblies"

Design of EMI Capacitors

EPCOS EMI capacitors use polypropylene (PP) film metalized with a thin layer of Zinc (Zn).

The following key points have made this design suitable to IEC/UL testing, holding a minimum

size.

Overvoltage AC capability with very high temperature Endurance test of IEC60384-14

× V

maximum temperature, during 1000 hours, with a capacitance drift less than 10%.

Higher breakdown voltage withstanding if compared to other film metallizations, like Aluminum.

voltage tests performed at 4.3

× V

R

1 minute, impulse testing at 2500 V for C= 1 µF and active

flammability tests.

Damp heat steady state: 40

°C/ 93% RH / 56 days. (without voltage or current load)

Effect of humidity on capacitance stability

Long contact of a film capacitor with humidity can produce irreversible effects. Direct contact with

liquid water or excess exposure to high ambient humidity or dew will eventually remove the film

metallization and thus destroy the capacitor. Plastic boxed capacitors must be properly tested in

the final application at the worst expected conditions of temperature and humidity in order to

check if any parameter drift may provoke a circuit malfunction.

In case of penetration of humidity through the film, the layer of Zinc can be degraded, specially

under AC operation (change of polarity), accelerated by the temperature, provoking an increment

of the serial resistance of the electrode and eventually a reduction of the capacitance value.

For DC operation, the parameter drift is much less.

Plastic boxes and resins can not protect 100% against humidity. Metal enclosures, resin potting or

coatings or similar measures by customers in their applications will offer additional protection

against humidity penetration.

B32921C/D ... B32928C/D

X2 / 305 V AC

Page 17 of 22

Please read Cautions and warnings and

Important notes at the end of this document.