- Complexity
Wave soldering is much more complex. At first, the board is placed on the conveyor belt, and it goes to the solder wave. It isn’t easy to achieve the solder wave and adjust its conditions. The wave might not offer the results if not handled carefully. The worker or handler must be an expert.
On the other hand, reflow soldering is much easier. The process is quite simple.
- Environmental Conditions
Environmental conditions are necessary to maintain because the solder is in molten condition to form a wave. Any fluctuation will affect the wave, which will directly impact the quality of solder joints.
In reflow soldering, it is difficult to maintain all the conditions. The wave of the solder needs to be under perfect environmental conditions to work as expected.
First, the board is preheated to increase its temperature. This preheating needs to be done carefully under controlled conditions. Otherwise, it can destroy the board. Then, the molten solder needs to be at the required temperature to behave like a fluid. Due to temperature shifts, there can be defects and imperfections in the soldering. Thus, the environmental conditions need to stay stable.
In reflow soldering, the conditions can be controlled easily. The reflow oven only needs to melt the solder in the paste. It is much easier because the conditions can be easily maintained.
- Constraints
Other than temperature, there are more constraints. In reflow soldering, the duration of the board under the wave has an impact on the soldering quality. It needs to be done very precisely, and the time cannot exceed the limits. If the board stays longer, then there will be excess solder, and if the board stays lesser than usual, the pads and joints won’t be perfect, or some components might not have enough solder. Thus, it is essential to control the duration of the board under the wave.
Moreover, the pad shape, size, orientation, and many other things play an important role in wave soldering.
In reflow soldering, you need to control the time, but it is easier.
- Speed
Wave soldering is much quicker than reflow soldering. Therefore, it is preferred for large volume PCB productions. It is because the flux is sprayed, and the PCBs just go over the solder wave. But in reflow soldering, solder paste is applied using a stencil, and then the PCB spends time inside the reflow oven.
- Cost
Wave soldering is a cheaper option compared to reflow soldering. For large volume orders, wave soldering is the most suitable option.
Reflow soldering is expensive as you need a special stencil production, and the reflow oven is more expensive than a wave soldering machine.
- Usage
Wave soldering is perfect for through-hole components, and reflow soldering is perfect for SMDs.