Polymer Guide

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Vishay

Revision: 13-Apr-2021

10

Document Number: 40076

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

GUIDE TO APPLICATION

1.

AC Ripple Current: the maximum allowable ripple

current shall be determined from the formula:

where,

P =

power dissipation in W at +45 °C as given in

the tables in the product datasheets.

the specified frequency.

2.

AC Ripple Voltage: the maximum allowable ripple

voltage shall be determined from the formula:

or, from the formula:

where,

P =

power dissipation in W at +45 °C as given in

the tables in the product datasheets.

the specified frequency.

Z =

The capacitor impedance at the specified

frequency.

2.1

The tantalum capacitors must be used in such a

condition that the sum of the working voltage and

ripple voltage peak values does not exceed the rated

voltage as shown in figure below.

3.

Temperature

Derating:

power

dissipation

is

affected by the heat sinking capability of the

mounting surface. If

these capacitors

are to

be operated at temperatures above +45 °C, the

permissible ripple current (or voltage) shall be

calculated using the derating coefficient as shown in

the table below:

4.

Reverse Voltage: the capacitors are not intended for

use with reverse voltage applied. However, they are

capable of withstanding momentary reverse voltage

peaks, which must not exceed the following values:

At 25 °C: 10 % of the rated voltage or 1 V, whichever

is smaller.

At 85 °C: 5 % of the rated voltage or 0.5 V, whichever

is smaller.

At 105 °C: 3 % of the rated voltage or 0.3 V,

whichever is smaller.

5.

Mounting Precautions:

5.1

Soldering:

capacitors

can

be

attached

by

conventional soldering techniques; vapor phase,

convection reflow, infrared reflow, wave soldering,

and hot plate methods. The soldering profile charts

show recommended time / temperature conditions

for soldering. Preheating is recommended. The

recommended maximum ramp rate is 2 °C per s.

Attachment

with

a

soldering

iron

is

not

recommended due to the difficulty of controlling

temperature and time at temperature. The soldering

iron must never come in contact with the capacitor.

5.2

Limit Pressure on Capacitor Installation with

Mounter: pressure must not exceed 4.9 N with a tool

end diameter of 1.5 mm when applied to the

capacitors using an absorber, centering tweezers, or

similar (maximum permitted pressurization time: 5 s).

An excessively low absorber setting position would

result in not only the application of undue force to the

capacitors but capacitor and other component

scattering, circuit board wiring breakage, and / or

cracking as well, particularly when the capacitors are

mounted together with other chips having a height of

1 mm or less.

5.3

Flux Selection

5.3.1

Select a flux that contains a minimum of chlorine and

amine.

5.3.2

After flux use, the chlorine and amine in the flux

remain must be removed.

5.4

Cleaning After Mounting: the following solvents are

usable when cleaning the capacitors after mounting.

Never use a highly active solvent.

• Halogen organic solvent (HCFC225, etc.)

• Alcoholic solvent (IPA, ethanol, etc.)

• Petroleum solvent, alkali saponifying agent, water,

etc.

Circuit board cleaning must be conducted at a

temperature of not higher than 50 °C and for an

immersion time of not longer than 30 minutes. When

an ultrasonic cleaning method is used, cleaning must

be conducted at a frequency of 48 kHz or lower, at

not higher than 40 °C, and for a time of 5 minutes or

shorter.

Notes

• Care must be exercised in cleaning process so that the

mounted capacitor will not come into contact with any

cleaned object or the like or will not get rubbed by a stiff

brush or similar. If such precautions are not taken

particularly when the ultrasonic cleaning method is

employed, terminal breakage may occur

• When performing ultrasonic cleaning under conditions

other than stated above, conduct adequate advance

checkout

MAXIMUM RIPPLE CURRENT TEMPERATURE

DERATING FACTOR

≤ 45 °C

1.0

55 °C

0.8

85 °C

0.6

105 °C

0.4

125 °C

0.25

I

RM S

P

R

ESR

------------

=

V

RM S

Z

P

R

ESR

------------

=

V

RMS

I

RM S

x

Z

=

Rated voltage

Ripple voltage

Operating

voltage

Working voltage

Time (s)