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The conditions of PCB soldering
Jul 13, 2018

To ensure the normal execution of PCB soldering work, it is best to understand what conditions are needed and ready, and prepare for soldering to be completed smoothly. Let us tell you the necessary conditions for a few solders to complete the soldering process.


First, the surface of the weldment should be cleaned in order to achieve a good bond between the weld and the weldment, and the weldment surface must be kept clean. Even for weldments with good weldability, if there is oxide layer, dust and oil on the surface of the weldment. Be sure to clean before soldering, otherwise it will affect the formation of the alloy layer around the weldment, so the quality of the solder cannot be guaranteed.


Second, the weldment should be weldable. The quality of soldering depends primarily on the ability of the solder to wet the surface of the weldment, ie the wettability of the two metallic materials. If the weldability of the weldment is poor, it is impossible to weld a qualified weld. Solderability refers to the formation of a good bond between the weldment and the solder under the proper temperature and flux.


Not all materials can be connected by soldering. Only some metals have good solderability. Generally, copper and its alloys, gold, silver, zinc, nickel, etc. have good solderability, while aluminum, stainless steel, cast iron The solderability is very poor. Special fluxes and methods are generally required for soldering.


Next, the soldering time should be set appropriately. Solder time is the time required to make physical and chemical changes during soldering. It includes the soldering time to solder temperature, the melting time of the solder, the role of the flux and the time to form the metal alloy. The soldering time of the circuit board should be appropriate. If it is too long, it will damage the soldering parts and devices. If it is too short, it will not meet the requirements.


Then, the solder temperature setting should be reasonable. Thermal energy is an indispensable condition for soldering. In soldering, the role of thermal energy is to spread the solder to the component and raise the temperature of the solder joint to a suitable solder temperature to form a metal alloy with the solder.


Finally, the choice of flux should be appropriate. There are many types of fluxes, and the effects are different. When using them, different fluxes should be selected according to different soldering processes and materials of the weldments. Excessive amounts of flux will increase the side effects of flux remnants. The amount of flux is too small and the fluxing effect is poor. Flux fluxes are commonly used in solder electronics. The rosin flux has no corrosion, removes oxidation, and enhances the flowability of the solder, which helps to wet the soldering surface and make the soldering spot bright and beautiful.


PCB soldering technology is an important part of electronic technology, and PCBs are essential in the manufacture of electronic products. Regardless of how fast the technological level develops in the future, PCB soldering is an eternal technical topic


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