PRECAUTIONS
CAPACITORS
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Technical considerationsStages Precautions
Precautions on the use of Multilayer Ceramic Capacitors
1.Circuit Design Verification of operating environment, electrical rating and per-
formance
1. A malfunction in medical equipment, spacecraft, nuclear re-
actors, etc. may cause serious harm to human life or have
severe social ramifications. As such, any capacitors to be
used in such equipment may require higher safety and/or reli-
ability considerations and should be clearly differentiated from
components used in general purpose applications.
Operating Voltage (Verification of Rated voltage)
1. The operating voltage for capacitors must always be lower
than their rated values.
If an AC voltage is loaded on a DC voltage, the sum of the two
peak voltages should be lower than the rated value of the ca-
pacitor chosen. For a circuit where both an AC and a pulse
voltage may be present, the sum of their peak voltages should
also be lower than the capacitor's rated voltage.
2. Even if the applied voltage is lower than the rated value, the
reliability of capacitors might be reduced if either a high fre-
quency AC voltage or a pulse voltage having rapid rise time is
present in the circuit.
1.The following diagrams and tables show some examples of recommended patterns to
prevent excessive solder amourts.flarger fillets which extend above the component end
terminationsg
Examples of improper pattern designs are also shown.
(1) Recommended land dimensions for a typical chip capacitor land patterns for PCBs
2.PCB Design Pattern configurations
(Design of Land-patterns)
1. When capacitors are mounted on a PCB, the amount of sol-
der used (size of fillet) can directly affect capacitor performance.
Therefore, the following items must be carefully considered in
the design of solder land patterns:
(1) The amount of solder applied can affect the ability of chips
to withstand mechanical stresses which may lead to break-
ing or cracking. Therefore, when designing land-patterns
it is necessary to consider the appropriate size and con-
figuration of the solder pads which in turn determines the
amount of solder necessary to form the fillets.
(2) When more than one part is jointly soldered onto the same
land or pad, the pad must be designed so that each
component's soldering point is separated by solder-re-
sist.
Recommended land dimensions for wave-soldering (unit: mm)
Recommended land dimensions for reflow-soldering (unit: mm)
Type 107 212 316 325
1.6 2.0 3.2 3.2
0.8 51.25 1.6 2.5
A0.8V1.0 1.0V1.4 1.8V2.5 1.8V2.5
B0.5V0.8 0.8V1.5 0.8V1.7 0.8V1.7
C0.6V0.8 0.9V1.2 1.2V1.6 1.8V2.5
L
W
Size
Excess solder can affect the ability of chips to withstand mechanical stresses. Therefore,
please take proper precautions when designing land-patterns.
Size L
W
Size
L
W
Type
212(2 circuits) 110(2 circuits) 096(2 circuits)
2.0 1.37 0.9
1.25 1.0 0.6
a0.5V0.6 0.35V0.45 0.25V0.35
b0.5V0.6 0.55V0.65 0.15V0.25
c0.5V0.6 0.3V0.4 0.15V0.25
d 1.0 0.64 0.45
Type 042 063 105 107 212 316 325 432
0.4 0.6 1.0 1.6 2.0 3.2 3.2 4.5
0.2 0.3 0.5 0.8 51.25 1.6 2.5 3.2
A
0.15V0.25 0.20V0.30 0.45V0.55
0.6V0.8 0.8V1.2 1.8V2.5 1.8V2.5 2.5V3.5
B
0.10V0.20 0.20V0.30 0.40V0.50
0.6V0.8 0.8V1.2 1.0V1.5 1.0V1.5 1.5V1.8
C
0.15V0.30 0.25V0.40 0.45V0.55
0.6V0.8 0.9V1.6 1.2V2.0 1.8V3.2 2.3V3.5
Size
L
W
Type
212(4 circuits)
2.0
1.25
a0.5V0.6
b0.5V0.6
c0.2V0.3
d0.5