Knowing the spatter of solder splashes, we first understand what tin solder is, which is the major defect in the surface mount (SMT) process, occurring mainly around the chip resistive element (CHIP), for many reasons, The article has (analysis of the reasons for the PCB tin beads have been analyzed), today we are talking about the wave solder splashes, if the solder when the solder ball splashed on the PCB, the impact is very serious. So how should we prevent it from splashing tin beads, the following discussion:

1, improve the preheating temperature;

2, replace the flux;

3, slow down the board speed (if the preheating temperature, do not slow down);

4, the PCB has moisture or contaminated and other reasons in the wave soldering beads in the PCB solder paste is formed at the time of departure from the liquid solder.

5, when the wave soldering PCB circuit board and the tin wave separation, PCB circuit board will be pulled out of the tin column, tin column broken back to the tin cylinder, the splashed solder will fall on the PCB board to form tin beads. Therefore, in the design of tin wave generator and tin cylinder, care should be taken to reduce the height of tin landing. A small landing height helps reduce tin dross and splashing tin,
Solution:

(1) as much as possible to reduce the solder temperature;

(2) The use of more flux can reduce tin beads but lead to more flux residue;

(3) As much as possible to improve the preheating temperature, but to follow the flux preheating parameters, or the activation of the flux is too short;

(4) faster conveyor belt speed can also reduce the tin-lead gas lead to frying tin;

6, wave soldering speed, angle, peak height, etc. did not adjust well, the PCB surface is too smooth and other factors lead to splashing tin (like rain down to the surface after the splash of water the same reason, this is why the components of the foot Local tin beads more than one of the reasons); In this case it is recommended to stop the N2 protection for a period of time before the basic ok if it is to improve the tin, because the surface of N2 protection solder easy to form oxide film to increase the surface tension.

7, the working environment wet circuit board after the preheating zone, the moisture immediately caused by the plate surface humidity is too large, resulting in tin spatter and tin beads; circuit board welding parts of the pin is too dense, and through-hole or through-hole design Irrational, resulting in poor soldering between the wave soldering surface and the tin liquid, resulting in splashing and tin beads.