How does selective wave soldering work?


2022-06-01 10:19

Selective wave soldering is soldering on the back of the circuit board (that is, what we usually call the solder joint surface or the component foot surface), and selective soldering will not have any effect on all components on the surface of the circuit board. When performing selective soldering, the circuit board must be fixed in a frame first, and all subsequent operations are automatically carried out according to the pre-programmed program of the process control system for this circuit board.


Select welding type

For each solder joint, the machine operator controls the flux, preheat time, and solder position to reduce adverse effects on other solder joints on the circuit board. Select soldering is not like the wave soldering process, which targets the entire circuit board. , without the ability to identify solder joints. All process steps for selective soldering are done independently, one solder at a time, until all soldering is done on the entire board:


  1. 1. Apply flux to all areas to be selectively soldered;
  2. 2. Preheat all areas to be selectively soldered to activate the flux;
  3. 3. Weld each spot according to the welding plan, one spot at a time. In addition to welding only one spot at a time, selection welds can also be designed to perform "move down" and "drag" movements. These are designed for closely spaced joints that can be soldered to multiple joints with the same soldering operation in a single downstroke, or to solder a row of joints in a very long connector, e.g. by Drag so that the solder tips touch them one after the other.

The above process is aimed at standard selective soldering equipment, as shown in the figure above, type 2, while type 1 is desktop small selective wave soldering, which only has flux coating and soldering, and no preheating part. Modular selective soldering may include multiple Each welding process is shown in Figures 3 to 5. Regardless of the choice of welding, their process may be different, but the process is the same.