Datasheet

1-7 Cleaning Agings
3. Influence of Input Ripple Current Against Working life
Passing of some ripple current when the electrolytic capacitor a s a wave
Circuit Board Cleaning
filteror smoothing function , the internal temperature of electrolytic
1. Foreword
capacitor will be bring some more influence to working life as well .
When a halide substance seeps into the aluminum electrolytic capacitor
Hence , a maximum ripple current will be listed caused by such ripple
The halide dissolves and frees halogen ions.
current and directly specifically by each manufacturer; it has been
RX + H
2
O ROH + H
+
+ X
-
Eq.3
considered as a overlapping by DC voltage & AC voltage when
Also the following reaction can occur
incorporate electrolytic capacitors with a power that ripple current
Al + 3X
-
AlX
3
+ 3e
-
Eq.4
Eq.5
Eq.6
included . The losing electronic power caused by the alternate resistance
& direct leakage current inside the electrolytic capacitors will be come
AlX
3
+ 3H
2
O Al(OH)
3
+ 3H
+
+ 3X
-
to heat . Kindly refer to following for relation between in rated ripple
current and temperate raising:
When this reaction is repeated. The leakage current increases and the safety
W = ( I
Ripple )
2
R ESR
ESR
+
+
V I Leakage
Leakage
vent will be activated and may lead to open vent. Because of this halogen
where W: Internal power loss
type cleaning agents or adhesive material and coating material is not
I Ripple : Ripple current
recommended for usage. The following explains the recommended condition
R ESR : Equivalent Series Resistance
for cleaning. When a halogen type cleaning agent will be used due to cleaning
V : Applied voltage
capabilities.
I Leakage : Leakage current
Normally the losing voltage power of DC leakage current that caused by
2. Recommended Cleaning Condition
the DC voltage which to be inflicted in the electrolytic capacitor will be
Applicable
Any type.any ratings
lower than a losing voltage power caused by ripple current, therefore:
Cleaning Agents
Pine Alpha ST-100S
W
( I RIPPLE )
2
R
R
ESR
ESR
Clean Through 750H,750L,710M
The formula for reaching of temperature balance on the internal
Sanelek B-12
temperature raising as well as the hot dissipation as below:
Aquq Cleaner 210 SEP
W
( I
RIPPLE
)
2
R
ESR
=
Techno Care FRw 14 17
: Heat radiation constant
Isopropyl Alcohol
= Surface area of container (cm
2
)
Cleaning Conditions
Total cleaning time shall be no greater than 5 minutes
= /4 D (D + 4L)
by immersion , ultrasonic or other method .
D: case diameter (cm)
After cleaning , capacitors should be dried using hot air for minimum of 10
L: case length (cm)
minutes along with the PC board .
T : Temperature raising created by internal heating ( ).
Hot air temperature should be below the maximum operating temperature of
Through the formula above can see the temperature raising caused
the capacitor .
by the ripple current and:
Insufficient dries after water runse may cause appearance problems , such as
T =
T =
( I
RIPPLE
)
2
R
ESR
=
( I
RIPPLE
)
2
Tan
sleeve shrinking , bottom-plate bulging .
It is recommended to monitor conductivity , pH , and concentration of the
agent . Please do not keep a product after cleaning in condition that cleaning
Due to : R
ESR
=
Tan
agents exists as steam, or in non ventilated containers .
C
Tan
: DF at 120HZ
3. CFC substitute
w : 2
f (f = 120HZ)
The anti-solvent capacitor listed in the catalogue can be cleaned using
C : The static capacity (F) at 120HZ
AK-255AES. If used within the following condition.
In general , the allowed ripple current value would be specifica lly listed
Please monitor contamination of solution by measuring conductivity, pH ,
by the manufacturer - A revised coefficient of allowed ripple current
specific gravity , water content and such .
& working frequency to the electrolytic capacitor .
Furthermore , do not store capacitors in a cleaning agent atmosphere or
Table-2 Snap-in terminal type capacitors (for input smoothing circuit)
sealed container after cleaning .
Also avoid using using ozone depleting substances for cleaning agents in
difference to our global environments.
Applicable
Anti-solvent capacitors
Cleaning Agents
AK-255AES
Cleaning Conditions
Within 5 minutes, total cleaning time by immersion
Table-3 Lead type capacitors (for output smoothing circuit)
, vapor spray , or ultrasonic and such . For SMD and ultra-miniature type 2
minutes maximum of total cleaning time .
4. Fixing Material and Coating Material
DO not use any affixing or coating materials, which contain halide
substance.
Remove flux and any contamination, which remains in the gap
between the end seal and PC board.
Table-4 The coefficient between allowed ripple current & working
Remove flux and any contamination, which remains in the gap
temperature to the electrolytic capacitors.
between the end seal and PC board.
Please dry the cleaning agent on the PC board before using affixing
or coating material.
Please do not apply any material all around the end seal when using
affixing or coating material.
There are variations of cleaning agents, fixing and coating material, so please
contact those manufacture or our sales office to make sure that the material
would not cause any problems.
C
C