Common causes of virtual welding

It should be noted that there are no strict boundaries between virtual welding and false welding. The main phenomenon is that the alloy layer between the welding pot and the welded metal surface is not really formed.

Virtual welding is a common defect in welding work, and  is the most difficult to find out the welding quality problems.

The main reasons for virtual welding are as follows.

1)The solder used is of poor quality.

2) the reducibility of the flux used is poor or the dosage is not enough.

3)The surface of the welded pin is not clean and the weldability is poor.

4) the temperature of the soldering iron head is too high or too low, too high temperature will make the solder melt too fast and too much and it will not be easy to touch tin, too low temperature will cause the solder to be not fully melted and take on the form of bean curd.

5) oxide layer is on the surface of electric soldering iron.

The welding time of components is not well mastered.

During the welding process, the soldering iron is removed before the solder is solidified, thus causing the pin of the welded component to move.

Copper foil pad on printed circuit board surface oil stain or oxidation layer not clean, or coated with flux, the solderability of the pad become worse.

To prevent virtual welding should be done: soldered metal in advance tin, printed circuit board on the pad or coated with flux, grasp the welding temperature and time, to avoid welding metal parts in the process of movement. If it is suspected to be a virtual welding, you can add flux to reweld if necessary.

This article is from ALLICDATA ELECTRONICS　LIMITED.