Optimizing Conveyor Angle in Wave Soldering for SMT Assembly

Conveyor Angle in Wave Soldering for SMT Assembly

In Smt assembly, a printed circuit board (PCB) with surface mount components is placed onto an automated machine. The machine will then reflow solder the components to permanently fix them on the PCB pads. The reflow soldering process is carried out inside a wave-shaped oven with different temperature zones. The oven is used to melt and reflow the solder paste that has been applied on the corresponding pads on the PCB. This is a high-temperature and short-time process that ensures that the melted solder will flow around the component leads and provide a good connection between the PCB and the components.

The reflow soldering process can be improved by optimizing the conveyor angle of the wave soldering machine. Ideally, the conveyor angle should be set at around 3-7 degrees, which will help to remove excess solder from the PCB and make it easier for the PCB to leave the wave soldering zone. In addition, the conveyor angle will also reduce the occurrence of solder balls on the PCB.

If the conveyor angle is too low, it will not be possible for the molten solder to flow from the PCB to the nozzle wall, and this will lead to an incomplete solder fillet. This problem can also be caused by other factors, including a poor hole-to-lead ratio, steep conveyor angles, excessive wave temperature and contamination on the edge of the copper pads. If the problem is not resolved, the smt assembly will be deemed unusable and will have to be replaced.

Optimizing Conveyor Angle in Wave Soldering for SMT Assembly

Another important factor to consider when optimizing the conveyor angle is the length of the component leads. The lead length should be long enough to provide a pathway for the solder to connect between adjacent pins, but not so long that it causes webbing between the components. This will reduce the occurrence of bridging shorts and increase the reliability of the solder joint.

The wave-shaped molten solder surface is known as the “wave pallet.” This surface has a number of characteristics that can impact the quality of the finished product, including solder ball formation and spatter generation. In order to minimize these issues, the wave pallet should be designed with a wide crest and a flat center. The resulting design will ensure that the molten solder will flow smoothly over the entire surface of the PCB.

In addition, it is essential to optimize the conveyor angle when using a liquid reflow system. Ideally, the PCB should exit the wave peak at or near the zero speed area. This will prevent the reflow solder from being drawn back into the wave by a force created by a tilted pinching method and will reduce the formation of tip-free joints. It is also advisable to use a protective oil injection system, as this will improve the mechanical state of the solder wave at the exit point and prevent oxidation. Moreover, the pump impeller should be equipped with a special protective coating.