Multilayer Ceramic Capacitors
Soldering Flux and Solder
(1) Solder Flux:
a. The content of halogen in the soldering shall be 0.2 wt% or less.
b. Rosin-based and non-activated soldering flux is recommended.
(2) Water soluble type Soldering Flux:
In case of water soluble type soldering flux being applied, the flux residue on the surface of PC boards may have influences on the
reliability of the components and cause deterioration and failures of them.
An eutectic solder (Sn63:Pb37) is recommended.
Since a multilayer ceramic chip capacitor comes into direct contact with melted solder during soldering. It is exposed to potentially
damaging mechanical stress caused by the sudden temperature change. The capacitor may also be subject to silver migration, and
to contamination by the flux. Because of these factors, soldering technique is critical. Adhere to the following guidelines.
In hand soldering of the Capacitors, large temperature gradient between preheated the capacitors and the tip of soldering iron may
cause electrical failures and mechanical damages such as cracking of breaking of the devices. The soldering shall be carefully
controlled and carried out so that the temperature gradient is kept minimum with following recommended
conditions for hand soldering.
Recommended Soldering Conditions:
φ1mm Thread eutectic solder (Sn63:Pb37) with soldering flux *in the core.
*Rosin-based, and mom-activated flux is recommended.
The capacitors shall be preheated so that “Temperature Gradient” between the devices and the tip of soldering iron is 150°C or
(3) Soldering iron:
Rated Power of 20W Max with 3mm soldering tip in diameter.
Temperature of soldering iron tip: 300°C maximum.
(The required amount of solder shall be melted in advance on the soldering tip.)
After soldering, the Capacitors shall cooled gradually at room ambient temperature.
In flow soldering process, abnormal and thermal and mechanical stresses, caused by “Temperature Gradient” between the mounted
Capacitors, resulting in failures and damages of the capacitors. So it is essential that the soldering process shall controlled to the
following recommended conditions and precautions. (See Figure 6)
Figure 6 Recommended Soldering Temperature Time Profile (Flow soldering)