What are the reasons for tin explosion during welding? How to prevent?

Date：2023-01-09 15:41:27 Views：1803

Tin blasting is a poor welding phenomenon in the PCBA processing process, specifically refers to the phenomenon that the solder paste at the solder joints produces explosive bombs during the welding process. Tin blasting will lead to incomplete PCBA solder joints, such as air holes, etc. At the same time, tin blasting is also the main reason for the occurrence of solder beads. So what is the reason for the occurrence of tin blasting? Let's take a closer look.

The phenomenon of tin explosion refers to that when the high-temperature soldering iron head touches the solder wire during the welding operation, it will make a sound of explosion, and at the same time, some small tin bead solid metal with bright color will pop up. This is the phenomenon of tin blasting.

In fact, the main reason for tin frying is generally due to moisture, or the PCB board is affected with moisture or solder is affected with moisture. If the PCB board is exposed to the air for a long time, it will cause the PCB board to absorb too much moisture, which will lead to moisture. If the preheating time is insufficient, the moisture is not completely volatilized. At this time, tin frying will occur when it contacts with liquid solder under high temperature, If the solder is wet, it will also lead to tin explosion during PCBA welding. In the actual production process, we can eliminate the possibility of PCB being wet by baking and preheating the pcb board or electronic components for enough time before welding to completely volatilize the moisture, and vacuum packaging the PCB.

In addition, improper use of the flux is also the main reason for tin explosion, such as too much flux, the flux is damp or the composition proportion of the flux is abnormal. To avoid this phenomenon, we should follow the dosage specification when using the flux, mainly check the solution composition of the flux, and also store the flux in a sealed manner. It is prohibited to contact the flux with the air for a long time, To avoid the phenomenon of tin explosion caused by moisture of flux.

Preventive measures:

1. Strengthen storage measures to prevent moisture. Control temperature and humidity, dry storage or working environment.

2. During the production process of solder wire, patrol inspection and control shall be strengthened to prevent the solder wire with cracks from entering the wire drawing link. If any, the parts with cracks shall be cut off for disposal.

3. Strengthen the sampling inspection of semi-finished products and finished products.

4. In case of wet or rainy weather, please dry the plates to be welded before welding to remove the moisture from the air on the surface of the plate pad.

The above is about tin blasting during the welding of wound core detection small knitting, and I hope it will be helpful to you. Our company has a team of professional engineers and industry elites, and has built three standardized laboratories with an area of more than 1800 square meters, which can undertake a variety of test projects such as electronic component test verification, IC authenticity identification, product design material selection, failure analysis, functional testing, factory incoming material inspection and tape weaving.