!
Caution
4-1.Reflow Soldering
1. When sudden heat is applied to the components, the
mechanical strength of the components will decrease
because a sudden temperature change causes
[Standard Conditions for Reflow Soldering]
deformation inside the components. In order to prevent
mechanical damage to the components, preheating is
required for both the components and the PCB.
Preheating conditions are shown in table 1. It is required to
keep the temperature differential between the solder and
the components surface (ΔT) as small as possible.
Temperature(℃)
Soldering
Peak Temperature
Gradual
Cooling
220℃
ΔT
190℃
170℃
150℃
Preheating
2. When components are immersed in solvent after mounting,
be sure to maintain the temperature difference (ΔT)
between the component and the solvent within the range
shown in the table 1.
Time
60-120 seconds 30-60 seconds
[Allowable Reflow Soldering Temperature and Time]
Table 1
280
270
260
Temperature
Differential
Series
GR□
GR□
ChipꢀDimension(L/W)ꢀCode
18/21/31
ΔT≦190℃
250
240
230
220
32/42/43/52/55
ΔT≦130℃
0
30
60
90
120
Soldering Time(s)
ꢀꢀꢀꢀꢀꢀꢀꢀIn the case of repeated soldering, the accumulated
ꢀꢀꢀꢀꢀꢀꢀꢀsoldering time must be within the range shown above.
Recommended Conditions
Peak Temperature
Lead Free Solder
240 to 260℃
Air or N2
Atmosphere
Lead Free Solder : Sn-3.0Ag-0.5Cu
3. When a capacitor is mounted at a temperature lower than the peak reflow temperature recommended by the
solder manufacturer, the following quality problems can occur. Consider factors such as the placement of
peripheral components and the reflow temperature setting to prevent the capacitor’s reflow temperature from
dropping below the peak temperature specified. Be sure to evaluate the mounting situation beforehand and
verify that none of the following problems occur.
･Drop in solder wettability
･Solder voids
･Possible occurrence of whiskering
･Drop in bonding strength
･Drop in self-alignment properties
･Possible occurrence of tombstones and/or shifting on the land patterns of the circuit board
4. Optimum Solder Amount for Reflow Soldering
4-1. Overly thick application of solder paste results in a excessive solder fillet height.
This makes the chip more susceptible to mechanical and thermal stress on the board and may cause the chips to crack.
4-2. Too little solder paste results in a lack of adhesive strength on the termination, which may result in chips breaking loose
from the PCB.
4-3. Please confirm that solder has been applied smoothly to the termination.
Inverting the PCB
Make sure not to impose any abnormal mechanical shocks to the PCB.
JEMCGC-05049F
15
MURATA [ muRata ]
