What are the preheating and soldering temperature conditions for automatic soldering on PCBs?

Through-hole mounting type

[1-1 Preheating process]
Preheating: 110°C max. / Duration: Within 40 seconds

1. Caution
   
   • Be sure to preheat to improve the solderability.
   • Preheat under the above conditions.
   • Do not use a relay that has been left in high temperature for a long time due to equipment failure which may cause a change in initial characteristics.
2. Availability of preheating
   
   • Closed type: Not applicable
   • Flux-resistant type: Applicable
   • Plastic-sealed type: Applicable

[1-2 Soldering]
Solder temperature: ca. 260°C / Soldering time: Within about 5 seconds

1. Caution
   
   • The flow solder type is recommended for uniformity of quality.
   • Adjust the fluid level so that the solder does not overflow on the PCB.
2. Availability of automatic soldering
   
   • Closed type: Not applicable
   • Flux-resistant type: Applicable
   • Plastic-sealed type: Applicable

Surface-mount type
Examples of recommended soldering conditions for the IRS (infrared reflow soldering) are shown in the following temperature profile (PCB surface).

• Recommended soldering conditions may differ for each relay. Please check individual specifications before use (refer to the Precautions for each model).
• Do not soak the product in cold liquid such as cleaning solution immediately after soldering. Doing so may damage the seal.
• Do not soak the relay in the solder bath. Doing so may cause malfunction due to resin deformation.

[Solder for mounting: Lead-free solder]

[Solder for mounting: Lead solder]

For more information, see Safty Precautions for All Relays: 6-10 Automatic Mounting of Relays for PCBs.

1. After automatic soldering, immediately blow air to cool the relay and other components so that they do not deteriorate due to the heat of soldering.
2. You may clean the plastic-sealed type but do not soak it in cold liquid such as cleaning solution immediately after soldering.
   Doing so may damage the seal.

*Precautions: Cooling is required for flux-resistant and plastic-sealed relays.

We have prepared a technical support page dedicated to high-capacity relays that explains in detail "I don't know" when using high-current, high-voltage PCB power relays, such as back EMF voltage (Zener diode and varistor) of the coil, holding voltage application circuit, recommended conditions for high-current substrate flow solder, the influence of magnetic fields, and precautions when connecting in series and parallel. Please also use this as well.
Click here for the high-capacity power relay technical support page.