Relay Welding Process and Cleaning Process

In this article, MEISHUO will introduce the RELAY welding process and cleaning process.

Coating Flux

PCB type non plastic relay is easy to be polluted by flux. It is suggested to use anti flux or plastic relay to prevent flux gas from invading the gap between the lead end of the base and the shell. If the anti flux relay is preheated and dried (100℃ for 1 minute), it can further prevent flux from invading.

Welding Process

When using flux coating or automatic welding, care should be taken not to damage the relay performance. Flux resistant relay or plastic encapsulated relay can be used for immersion welding or wave soldering process, but the maximum welding temperature and time should be controlled according to the selected relay.

a. Wave Soldering: the recommended soldering temperature is 240℃～ 260℃, the time is about 5 seconds, and the best soldering temperature is 250℃. For other welding temperatures and welding times (for example, higher solder temperatures will shorten the tin dipping time), please contact our technical service support or confirm the welding quality.

b. Manual Welding: the recommended welding temperature is 300℃ - 350℃, and the welding time is controlled within 2 seconds.

c. Cooling: the heating of the relay caused by the soldering process can be alleviated by cooling in the process, so do not change the temperature suddenly, especially to avoid cold shock to the thermal relay.

Cleaning Process

Clean free flux shall be used for welding as far as possible, and integral cleaning of the relay shall be avoided. Prevent the detergent from entering the relay and causing failure. It is forbidden to use ultrasonic cleaning to avoid contact with cold welding, enameled wire breakage, and other structural damage caused by ultrasonic energy. After cleaning and drying, ventilation should be carried out immediately to reduce the relay to room temperature.

Apply Preservative

Sometimes, in order to ensure the moisture resistance and high insulation of the circuit board, it is necessary to coat the circuit board with preservatives. The soft adhesive without silicon should be selected. The coating process should avoid the negative pressure generated by the relay and the inhalation of preservatives.