Lead-free solder pasteWhat is the granular state after welding and why is it not smooth? The transformation of market demands drives the reform and development of the field, and scientific research and product development technology drive the new upgrading of the industrial chain in the future. When many people apply the heavy metal-free solder paste surface mount technology, they find that the circuit boards after soldering have granular conditions, are not very smooth, and appear granular. What's going on here?Today, JJY Enterprise will share with you:

    The key factors causing unevenness after lead-free solder paste soldering are as follows:

1If the solder paste is heated for a long time, some of its components will evaporate. Moreover, the solder paste will oxidize throughout the process here. Using such solder paste will cause problems There is a granular condition after welding. This kind of situation can generally be handled by reducing the heating time period. Lowering the heating time usually does not exceed2Minutes.     

2If the electronic components are not clean or there are residues on the surface of the circuit board, the solder paste cannot come into direct contact with the circuit board and protrudes. After electric soldering, it will also cause unevenness. For such situations, gradually inspect the electronic components and circuit boards to ensure that the surfaces are clear and clean before starting to use them.     

3Even if the solder paste is made, the effect of the electric soldering is not good and it will be granular. Therefore, the wettability of the solder paste must be ensured.    

4The problem of flux paste.    

5Lead-free solder paste should have excellent lubricity;Under normal circumstances, the duration for which solder remains above the high-performance liquid phase line in a reflow soldering oven is30~90In seconds, the feet of the welded steel pipe are reached by the wave soldering machinepcbThe duration of contact between the substrate surface of the circuit board and the solder wave soldering is4After applying the heavy metal-free solder for about a second, it is necessary to ensure that the solder can exhibit excellent wetting performance within the above-mentioned time period to guarantee high-quality welding results;     

6The electrical conductivity and thermal conductivity of the solder paste after electric soldering both need to be in line with63/37The tin-aluminum alloy solder is close to each other;

7,Lead-free solder paste The compressive strength, ductility, plasticity and stress relaxation resistance of spot welding all need to be not much different from those of tin-aluminum alloy.

If you want to know about solder paste, lead-free solder paste, solder paste and other soldering issues, partners are welcome to consult Shenzhen JJY Industrial Technology Co., LTD. Let's learn and grow together! The solder wire, solder paste and solder rods of JJY brand are always waiting for partners to come and take them together .