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4-2.Flow Soldering
1. When sudden heat is applied to the components, the
mechanical strength of the components will decrease
because a sudden temperature change causes
deformation inside the components. In order to prevent
mechanical damage in the components, preheating should
be required for both of the components and the PCB board.
Preheating conditions are shown in table 2. It is required to
keep temperature differential between the solder and
the components surface (ΔT) as small as possible.
2. Excessively long soldering time or high soldering
temperature can result in leaching of the outer electrodes,
causing poor adhesion or a reduction in capacitance value
due to loss of contact between electrodes and end termination.
3. When components are immersed in solvent after mounting,
be sure to maintain the temperature difference (ΔT)
between the component and solvent within the range
shown in the table 2.
4. Do not apply flow soldering to chips not listed in Table 2.
Table 2
Part Number
GC□18/21/31
Recommended Conditions
Preheating Peak Temperature
Soldering Peak Temperature
Atmosphere
Pb-Sn Solder: Sn-37Pb
5. Optimum Solder Amount for Flow Soldering
5-1. The top of the solder fillet should be lower than the
thickness of components. If the solder amount is
excessive, the risk of cracking is higher during
board bending or any other stressful condition.
JEMCGC-2702N
Temperature Differential
ΔT≦150℃
Pb-Sn Solder
Lead Free Solder
90～110℃
100～120℃
240～250℃
250～260℃
N
Air
2
Lead Free Solder: Sn-3.0Ag-0.5Cu
[Standard Conditions for Flow Soldering]
Temperature(℃)
Soldering Peak
Temperature
Preheating Peak
[Allowable Soldering Temperature and Time]
280
270
260
250
240
230
220
0
In case of repeated soldering, the accumulated
soldering time must be within the range shown above.
Adhesive
18
!
Soldering
Gradual
Cooling
△Ｔ
Preheating
Time
5 seconds max.
30-90 seconds
30
60
90
120
Soldering Time(sec.)
Up to Chip Thickness
in section
Caution
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