First, coated flux
PCB board non-plastic sealed relays vulnerable to flux contamination, it is recommended to use solder-type or plastic-enclosed relays to prevent the flux gas from the lead-out end and the base and the shell of the gap intrusion, such as solder resist relay preheat drying (100 ℃ 1 Minute), the flux can be further prevented from intruding.
Second, the welding process
When using flux or automatic soldering, care should be taken not to damage relay performance. Solder relay or molded relay may be suitable for dip soldering or wave soldering processes, but the maximum soldering temperature and time should be controlled according to the relay selected.
1, wave soldering: Recommended soldering temperature is: 240 ℃ ~ 260 ℃, time is about 5 seconds, the best welding temperature is 250 ℃. For other soldering temperatures and soldering times (such as shorter soldering times for higher soldering temperatures), contact our technical service support or confirm the soldering quality.
2, manual welding: recommended welding temperature is 300 ℃ -350 ℃, welding time controlled within 2 seconds.
3, Cooling: As the relay heating caused by the solder process can be mitigated by cooling at the end of the process, do not suddenly change the temperature, especially to avoid the cold impact on the thermal relay.
Whenever possible, use no-clean flux for soldering and avoid the overall cleaning of the relay. Prevent cleaning agent from entering the relay causing failure. Prohibit the use of ultrasonic cleaning, in order to avoid ultrasonic welding cold welding contacts, enameled wire breakage and other structural damage. After cleaning and drying, ventilation should be carried out immediately, so that the relay down to room temperature.
Sometimes in order to ensure the circuit board is resistant to moisture and high insulation, it is necessary to apply full-agent protection on the circuit board. A softer glue that does not contain silicon should be used. The glue application process should avoid negative pressure of the relay and inhale the preservative.