Welding is the process of joining metal parts with vari […]
Welding is the process of joining metal parts with various fusible alloys (solder). The melting point of the solder is lower than that of the material to be soldered, so that the part will be welded by intermolecular contact on its surface without being melted.
Welding can be divided into soft welding and hard welding, soft soldering temperature is lower than 450 ° C, and hard soldering is higher than 450 ° C. Hard soldering is usually used for metals such as silver, gold, steel, copper, etc. The solder joints are much stronger than soft soldering, and the shear strength is 20 to 30 times that of soft soldering. The above two types of thermal joints generally use the term soldering because in both cases the molten solder is written into the elongated gaps of the clean and near solid metal surfaces of the two devices to be installed.
Welding ensures the continuity of the metal. On the one hand, the two metals are connected to each other by bolting or physical attachment, which is expressed as a strong metal whole, but the connection is discontinuous, and sometimes the surface of the metal has an oxide insulating film, even Right or wrong physical contact. Another drawback compared to soldering is that the contact surface continues to oxidize and the resistance is added. In addition, chatter and other mechanical shocks can also loosen the joint. Welding eliminates these problems, the welding parts do not move relative to each other, the contact surfaces do not oxidize, and continuous conductive methods are adhered to. Welding is a process of fusion between two metals. In the molten state, the solder will dissolve some of the metal in contact with it, while the surface of the metal to be welded often has a thin layer of oxide film that cannot be dissolved by the solder. The flux is used to remove it. This layer of oxide film. The welding process usually includes:
1) melting of the flux, thereby removing the oxide film on the surface of the metal to be soldered;
2) melting the solder to float the impure material and the light flux suspended between them to the surface;
3) Somely dissolve some metal that is connected to the solder;
4) Cool and complete the melting of the metal and solder.
Often in order to locate the problems of circuit function, it is necessary to take the components off the printed circuit board and make the necessary measurements. This repair process usually includes:
1) the disassembly of extra components;
2) Inspection of components;
3) communication of defective components;
4) Verify the function of the circuit.
In the operation of extracting and exchanging electronic components, it is required to carry out the welding process.
The reliable and successful operation of space, defense, medical electronics, traffic control systems, communication systems, and supervisory and control system equipment relies on excellent welding. Under strict and hostile environmental conditions,
For example, temperature changes, wetting, vibration, etc., even a bad solder joint can cause some or all of the system to get out of control. There are countless solder joints in the equipment, and these solder joints should be even more reliable than the equipment itself. Discussions in this area have now led to the addition of knowledge of materials and their properties, and many advances have been made in the possible welding processes. Welding technology is a companion technology. With the development of the electronics industry, more and more useful packaging technologies and smaller components will continue to occur. Welding technology will continue to expand to meet the needs of the electronics industry and environmental issues. That's why welding is becoming more and more professional about technology professors in the electronics industry today.