Electrolytic Capacitors - Product safety - Philips Semiconductors / NXP Semiconductors

1996 Dec 03 1

Philips Components

Electrolytic Capacitors Product safety

WARNING

GUIDELINES

Correct application and strict adherence to the important information listed below, will ensure optimum performance of

the capacitors over their entire specified useful life.

Please note, that ignoring these rules may reduce the equipment life time or even destroy the capacitor, together with

parts of the equipment or property involved. The consequences may be a short or open circuit of the component,

leakage of electrolyte or heat generation. Opening of the case or vent (danger of injury) may be regarded as

hazardous and cause liquids, vapours or dust to be released. Similar precautions should be taken when testing

electrolytic capacitors.

Please consult your local Philips Components sales organization, if one or more of these limits cannot be adhered to.

PARAMETER IMPORTANT INFORMATION − PRODUCT SAFETY MORE DETAILS

POLARITY,

REVERSE

VOLTAGE

Electrolytic capacitors for DC applications require polarization.

Check the polarity of each capacitor: both in circuit design and in mounting

(polarity is clearly indicated on the capacitor). For short periods a limited

reverse voltage is allowed (see detail speciﬁcation); for conditions and

maximum parameter changes, see

“This Handbook, Section Tests and

Requirements”

. Exceeding reverse voltage may result in early failures.

detail speciﬁcation

TESTS AND

REQUIREMENTS

VOLTAGE Do not apply a voltage exceeding the capacitor's voltage rating.

Check the maximum voltage across the capacitor which can occur over the

whole equipment life. In normal operation the rated voltage of the capacitor

shall not be exceeded; if so, early failures may occur. However, for short

periods the voltage may be raised up to surge voltage value (see detail

speciﬁcation); for conditions and maximum parameter changes, see

“This

Handbook, Section Tests and Requirements”

detail speciﬁcation

TESTS AND

REQUIREMENTS

RIPPLE LOAD Do not allow excessive ripple current to pass.

The rated ripple current given for certain conditions (temperature, frequency

and useful life) shall not be exceeded. If so, early failure may result.

Keep ripple voltage within ratings.

The sum of DC-bias and maximum amplitude of ripple voltage shall be within

rated voltage and 0 V. Electrolytic capacitors are not normally designed for

AC application.

detail speciﬁcation

TEMPERATURE

RANGE Use capacitors within speciﬁed temperature range.

Applicable temperature range is given in the relevant detail speciﬁcation.

A general principle is that lower ambient temperature means longer life;

therefore, wherever possible, electrolytic capacitors should be placed at the

coolest positions on the board (please ensure that electrolytic capacitors are

placed away from ‘heating’ components such as power resistors, switching

diodes/transistors or transformers). Exceeding the permitted temperature

range may cause early failures.

detail speciﬁcation

1996 Dec 03 2

Philips Components

Electrolytic Capacitors Product safety

CHARGE-

DISCHARGE Observe charge-discharge limitations.

Frequent charge-discharge load via low resistance may cause capacitance

drop or destroy the capacitor. Under well deﬁned conditions (see

“This

Handbook, Section Tests and Requirements”)

frequent charge-discharge

operation is allowed. The resulting current through the capacitor may not

exceed the ripple current limit.

TESTS AND

REQUIREMENTS

SERIES/

PARALLEL

CONNECTIONS

When connecting in series/parallel, apply corresponding design rules.

Connecting electrolytic capacitors in series/parallel is possible, provided that

balancing resistors are applied to each capacitor, in order to stabilize the

voltage over each individual capacitor. Rules for correct design are given in

the introduction.

INTRODUCTION

PC BOARD

DESIGN Conducting tracks or lands should not be located under upright mounted

electrolytic capacitors; short circuits under the capacitor with danger of ﬁre

could be the result.

INSULATION The capacitor case is not insulated from the cathode terminal.

Axial capacitors have a direct contact between case and cathode terminal;

radial and power capacitors exhibit an indeterminate resistance between the

cathode terminal and the metal case. Metal parts other than terminals should

never make contact to conducting tracks or metal parts of other components.

Dummy pins are connected to the cathode.

STORAGE AND

TRANSPORT Excessive storage time or conditions may have adverse effects on

capacitors.

Capacitors should be stored at room temperature, low humidity and out of

direct sunlight. Storage at elevated temperature and/or high relative humidity

may have a negative inﬂuence to taping accuracy, solderability, leakage

current and life expectancy.

Packages with electrolytic capacitors should be handled with care, or bent

leads and/or incorrect taping dimensions could be the result.

INTRODUCTION

TESTS AND

REQUIREMENTS

HIGH AIR

PRESSURE Do not expose capacitors to overpressure.

Maximum operating pressure is 150 kPa. Higher pressure may cause a short

circuit.

LOW AIR

PRESSURE The capacitors may be used at an altitude of ≤12000 m.

Minimum air pressure: 8.5 kPa for short periods (in accordance with

“IEC 384-4, subclause 4.11.4”)

TESTS AND

REQUIREMENTS

MOUNTING Avoid excessive stress to the lead wires or terminals.

Excessive stress can be caused by component processing machines if lead

wires are not sufﬁciently ﬁxed during bending, cutting, cropping or inserting

operations. Other possible reasons are incorrect hole distance on

printed-circuit or bending of the component after soldering. Care should be

taken when the manual bending of terminals or mounted capacitors is

required. For maximum allowed mechanical load and time of application, see

“This Handbook, Section Tests and Requirements”

Mechanically damaged capacitors may not be used.

Safety vent should have enough space to function correctly.

TESTS AND

REQUIREMENTS

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1996 Dec 03 3

Philips Components

Electrolytic Capacitors Product safety

SOLDERING Keep soldering temperature and time under control.

For maximum soldering conditions, see Chapter

“Tests and Requirements”

Additional temperature load e.g. for curing the glue of Surface Mounting

Devices (SMDs) are allowed to a certain limit, which depends on series and

exact details, please apply to your sales engineer for your speciﬁc conditions.

Molten solder or the soldering iron should not make contact with the

capacitor's insulation. Reﬂow soldering is only suitable for SMD components.

TESTS AND

REQUIREMENTS

BOARD

CLEANING No guarantees can be given with regard to solvents based on

halogenated hydrocarbons or ozone depleting chemicals (ODCs).

Warning: such solvents are hazardous to the environment.

Component cleaning using solvents such as demineralized or distilled water,

isopropanol, methanol, etanol and propanol would not normally have any

detrimental effects and therefore do not require any special precautions.

Aqueous cleaning methods may be used in conjunction with saponiﬁcation

using a neutral detergent like calgonite at 20 g/l. It is recommended that

immediate drying of the component in hot air is carried out at approximately

85 °C (or 70 °C for products with an upper category temperature of 70 °C) for

at least 5 minutes. For further information regarding the application of solvent

temperatures exceeding the temperature mentioned in

“IEC 68-2-45”

, consult

your local Philips Components sales organization.

ADHESIVES,

COATING

MATERIALS

Some adhesives and coating materials affect capacitors adversely.

For varnishing, coating, lacquering, embedding or gluing at the capacitor's

sealing, ensure that the materials used are halogene-free in all their

constituent parts (base material, thinners, binders, reacting agents,

propellants, additives). For reasons see ‘BOARD CLEANING’ above.

When applying such materials, ensure that the rubber area is not completely

sealed off.

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1996 Dec 03 4

Philips Components

Electrolytic Capacitors Product safety

DISPOSAL Electrolytic capacitors are subject to special waste regulations.

Aluminium electrolytic capacitors are free from PCB- or PBDE-containing

substances. Dioxines or furanes are not constituent parts of electrolytic

capacitors. However, because of other polluting ingredients, larger quantities

(in weight) of electrolytic capacitors are subject to special waste regulations in

accordance with the relevant national laws; please consult your local Philips

Components sales organization.

In general, electrolytic capacitors have to be disposed under controlled

circumstances in a high temperature incinerator at minimum 900 °C.

PERSONNEL

SAFETY WARNING NOTE.

Non-solid electrolytic capacitors may contain chemicals which can be

regarded as hazardous if handled incorrectly. Caution is necessary if the outer

case is fractured; vapours or dust particles should not be inhaled (good

ventilation is essential); skin, eye or clothing contact with liquids should be

avoided. In case of such contact, ﬂush thoroughly with running water as soon

as possible, then wash skin or clothing with soap and water or a mild

detergent. Any possible discoloration of the wetted skin will disappear after a

few days.

In the event of ﬁre, the organic parts of electrolytic capacitors may release

such constituents as carbon monoxide, nitric oxides or dust particles; take

caution when breathing-in.

PARAMETER IMPORTANT INFORMATION − PRODUCT SAFETY MORE DETAILS