Micro Guide
www.vishay.com
Vishay Sprague
Revision: 09-Mar-17
9
Document Number: 40115
For technical questions, contact: tantalum@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
GUIDE TO APPLICATION
1. AC Ripple Current: the maximum allowable ripple
current shall be determined from the formula:
where,
P = power dissipation in watts at +25 °C (see
paragraph number 5 and the table Power
Dissipation as given in the tables in the
product datasheets)
R
ESR
= the capacitor equivalent series resistance at
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 watts at +25 °C (see
paragraph number 5 and the table Power
Dissipation as given in the tables in the
product datasheets)
R
ESR
= the capacitor equivalent series resistance at
the specified frequency
Z = the capacitor impedance at the specified
frequency
2.1 The sum of the peak AC voltage plus the applied DC
voltage shall not exceed the DC voltage rating of the
capacitor.
2.2 The sum of the negative peak AC voltage plus the
applied DC voltage shall not allow a voltage reversal
exceeding 10 % of the DC working voltage at
+25 °C.
3. Reverse Voltage: these capacitors are capable of
withstanding peak voltages in the reverse direction
equal to 10 % of the DC rating at +25 °C, 5 % of the
DC rating at +25 °C, 5 % of the DC rating at +85 °C,
and 1 % of the DC rating at +125 °C.
4. Temperature Derating: if these capacitors are to be
operated at temperatures above +25 °C, the
permissible RMS ripple current shall be calculated
using the derating factors as shown:
5. Power Dissipation: power dissipation will be
affected by the heat sinking capability of the
mounting surface. Non-sinusoidal ripple current may
produce heating effects which differ from those
shown. It is important that the equivalent I
RMS
value
be established when calculating permissible
operating levels. (Power Dissipation calculated using
+25 °C temperature rise.)
6. Printed Circuit Board Materials: molded capacitors
are compatible with commonly used printed circuit
board materials (alumina substrates, FR4, FR5, G10,
PTFE-fluorocarbon and porcelanized steel).
7. Attachment:
7.1 Solder Paste: the recommended thickness of the
solder paste after application is 0.007" ± 0.001"
[0.178 mm ± 0.025 mm]. Care should be exercised in
selecting the solder paste. The metal purity should
be as high as practical. The flux (in the paste) must
be active enough to remove the oxides formed on the
metallization prior to the exposure to soldering heat.
In practice this can be aided by extending the solder
preheat time at temperatures below the liquidous
state of the solder.
7.2 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.
7.2.1 Backward and Forward Compatibility: capacitors
with SnPb or 100 % tin termination finishes can be
soldered using SnPb or lead (Pb)-free soldering
processes.
8. Cleaning (Flux Removal) After Soldering: molded
capacitors are compatible with all commonly used
solvents such as TES, TMS, Prelete, Chlorethane,
Terpene and aqueous cleaning media. However,
CFC / ODS products are not used in the production
of these devices and are not recommended.
Solvents containing methylene chloride or other
epoxy solvents should be avoided since these will
attack the epoxy encapsulation material.
8.1 When using ultrasonic cleaning, the board may
resonate if the output power is too high. This
vibration can cause cracking or a decrease in the
adherence of the termination. DO NOT EXCEED 9W/l
at 40 kHz for 2 min.
9. Recommended Mounting Pad Geometries: proper
mounting pad geometries are essential for
successful solder connections. These dimensions
are highly process sensitive and should be designed
to minimize component rework due to unacceptable
solder joints. The dimensional configurations shown
are the recommended pad geometries for both wave
and reflow soldering techniques. These dimensions
are intended to be a starting point for circuit board
designers and may be fine tuned if necessary based
upon the peculiarities of the soldering process and /
or circuit board design.
TEMPERATURE DERATING FACTOR
+25 °C 1.0
+85 °C 0.9
+125 °C 0.4
I
RMS
P
R
ESR
------------=
V
RMS
Z
P
R
ESR
------------=
