Whether solder paste
can replace solder, I believe some people will have this question. When it comes to solder paste and solder work, the final result is to weld components firmly, but whether they can be replaced, the specific analysis is as follows :
First of all, solder paste is a paste-like solid that is uniformly mixed with solder alloy powder and flux carrier system in a certain proportion; the viscosity of solder paste has rheological properties, that is, the viscosity decreases under the action of shearing force to facilitate printing, while printing The viscosity then recovers, thus serving to hold the electronic components in place before reflow soldering. During the reflow soldering process, the solder alloy powder melts, and with the aid of the flux to remove the oxide film, the outer lead segments of the electronic components and the metal surface of the printed circuit board pads are decorated and reacted, and finally the mechanical connection between the two is formed. electrical connection.
Solder paste consists of alloy powder and flux. Flux is composed of activator, binder, wetting agent, solvent, thixotropic agent and other additives. Solder paste is a paste. Compared with solder wire, its external shape is completely different. To achieve solder paste soldering, it needs to solidify the solder paste. It only needs to put solder paste on the circuit board and then solidify. bonding purpose. Compared with solder, the safety factor is higher, and the strength of welding is also high. Are the two alternatives?
1. First of all, solder paste curing requires equipment. The most basic equipment is heating platform, oven, etc. The reflow soldering equipment is more suitable for solder paste curing operation conditions. The solder paste soldering process is more stable in reflow soldering operation; The work can be done by hand or by machine. Generally, the components that need to be repaired after reflow soldering need to be repaired with solder, which is better, convenient and fast. Manual soldering needs to buy a soldering iron. If the quantity is large, you can buy an automatic soldering machine. This is The equipment requirements for both during the operation.
2. Secondly, the size of the components for soldering and manual soldering of the solder paste, and the difficulty of the soldering process will have certain limitations, and they cannot be 100%, and now with the more sophisticated electronic components , more compact, pure soldering can no longer meet the requirements for these small and light components, so under the new trend of the times, the emergence of new technology SMT solves this problem, solder paste is indeed a must in SMT patch One of the few raw materials, we can see the importance of solder paste, and the relative solder has become a substitute tool.
3. In terms of environmental protection requirements for tin paste and solder, tin paste will be more in line with the environmental protection requirements of modern industries, and solder will take a second place in this regard, because solder will be dry in the production process to the welding process. Sound, smell, oil pollution and other factors that have adverse effects on the environment, which is why more and more factories are now changing the original solder production line to a patch line, whether from environmental protection or manual operation, it is in line with the current situation. In the long run, it saves labor costs, greatly improves the operation efficiency, and reduces the defect rate.
Someone will ask again here, then it is said that solder paste can completely replace solder. In fact, this is a process. To say that it is completely replaced is not. Although solder wire is not as good as solder paste in terms of labor cost and production efficiency, but For post-soldering, the repair work after reflow soldering is still more convenient, so in some specific cases, soldering is more practical. The two are complementary and mutually beneficial.