How to deal with itLead-free solder pasteTo remove post-weld residues and make the weld points brighter? Generally, when dealing with this situation, I need to pay attention to several points of knowledge. Otherwise, when using lead-free solder paste, it is easy to have the problem of the solder joints not being bright enough, which does not meet the customer's requirements for brightness. Lead-free solder paste placed in the air is prone to volatilization and oxidation, reducing the performance of the solder paste. At this time, the brightness of the solder joints of the solder paste will not be so good!

Everyone knows that lead-free solder paste is used after the electric soldering is completed, perhaps Some residue will appearPCBOn the board, in this case, how can it be removed? The prerequisite is that we need to know why the clearance must be done well. After lead-free solder paste is soldered, there will be more or less residues left, and these residues can be classified into several types: granular contaminants can easily cause problems such as electrical short circuits; Dirt on the positive and negative electrodes can cause dielectric breakdown, electrical leakage and rotting of electronic device circuits, etc. Non-polar dirt and grime can damage the surface, mainly composed of white powder and adhered dust layers, and cause poor electrical contact.

In addition, although it was realized that the cleaning was necessary, incorrect cleaning methods were adopted. There are several aspects to this: When there is no ultrasound at all, it willpcbThe board is simply soaked and then taken out to dry in the sun. Dip the brush in the cleaning agent. RightpcbThe board is not cleaned very frequently. The components of lead-free solder paste residues are complex. The problems caused by insufficient removal are far more serious than those caused by no removal at all. Therefore, once removed, it must be thoroughly washed. In that case, how should it be cleaned?

1It should be removed as soon as possible after electric welding(Within one hour); 

2Increase the heating temperature of the cleaning agent;

3Improve the clearing time; 

4Replace the cleaning agent frequently with new ones.

After the cleaning is completed, it would be best for everyone to check again to see if everything has been truly cleaned up. The simple way is to use estimation and check under a microscope.

Shenzhen CityJJYCarry out mutually beneficial cooperation with electronic raw material producers, and also produce solder wires, solder rods, solder pastes and flux pastes for other enterprises. With a rich variety of successful cases in the research and development of chemical raw materials, our overall strength has created a sales market that is of high quality and honest and trustworthy.