The initial stage of the wave soldering process in SMT processing is the most important part of the entire wave soldering quality control link, as long as this part of the preparation work is carefully done, we only need to control the temperature control, transmission speed and inclination in the rest of the production process to ensure the quality of SMT processing wave welding. The following and into the small series to explain the stand-alone wave soldering process:

one  Component leads are formed and a printed board is pasted with solder resistance tape

two  Insert components

three  printed board into the welding machine fixture

four  Apply flux

five Preheat

six  Wave soldering

seven Cool down

eight Remove the printed board

nine Remove the solder mask tape

ten Inspection

eleven ocL welding

twelve. Cleaning

thirteen Inspection

Place in the shipping box

Give you a brief overview of the initial stage of wave soldering in SMT processing need to do preparation and attention to the details:

One. Dry

During the manufacturing process, there may be residual solvents and moisture hidden in the PCB, if there is a bubble phenomenon on the PCB during the welding process, it is best to pre-dry the PCB before the line.

The thin PCB below 1.5mm can choose a lower temperature and a shorter time, and the multi-layer PCB can continue to dry at 105 degrees Celsius for two to four hours.

PCB pre-drying can effectively eliminate the residual stress formed in the process of PCB board making, and also reduce the warping and deformation of PCB during wave soldering.

Two Preheat

The preheating temperature is not fixed, but is adjusted with the change of time, power supply voltage, ambient temperature, season and ventilation.

Three Solder

We need the molten solder to have good fluidity and wettability, and in this case the welding temperature should be higher than the melting point of the solder itself.

Four Transfer

SMT welding time and transfer speed are closely related. We can determine the best transfer speed we need in wave soldering according to the specific production efficiency, the heat capacity of PCB substrate and components, preheating temperature and other factors.

Five Tilt  Angle 

Transmission Angle is now the most widely used in the SMT processing industry is 4° ~ 6°. This range can effectively reduce the occurrence of tin deficiency, less tin, tin and other adverse phenomena.