Introducció a la diferència en potència mida de elèctrics soldadors ferros
En el procés de reparació elèctrica, un soldadura elèctrica ferro és una eina essencial, però molts manteniment personal que no acaba d'entrar en contactar amb soldar fers fer no saber què estàndards a utilitzar a seleccionar la potència del soldadura ferro durant el procés de soldadura sovint, un soldadura sobre el sobre el_món. La conseqüència més directa és que el efecte de soldadura és no ideal de de no prestar atenció a el potència mida de la soldadura ferro.
The electric soldering iron used has excessive power, which can easily burn out components (usually when the junction temperature of the transistor exceeds 200 degree ) and cause printed wires to detach from the substrate; The power of the soldering iron used is too low, the solder cannot be fully melted, the flux cannot evaporate, the solder joints are not smooth and firm, and it is easy to produce virtual soldering. Generally, it is used for soldering integrated circuits, printed circuit boards, CMOS circuits, decorative transistors, IC recorders, televisions, and conducting ordinary circuit experiments. It is generally recommended to use 20W. For repairing vacuum tube machines such as gallbladder machines and old instruments, 35W is recommended. For external heating type machines, 45W is recommended. For soldering the wiring of large transformers and grounding main lines on metal substrates, internal heating type 50W and external heating type 75W are used. If welding metal materials, an external heating soldering iron with a power of over 100W should be selected. If conditions permit, amateur radio enthusiasts can equip themselves with a 2OW internal heating type, a 35W internal or external heating type, and a 150W external heating type soldering iron, which can basically meet various welding needs.
The solder we use is generally divided into two types: lead solder and lead-free solder, but the most commonly used is lead solder, which has a composition of 63% tin, 37% lead, and a melting point of 183 degree . Lead free solder has a composition of 99% tin and a flux of about 1%, with a melting point of 227 degree . The advantages of lead soldering are low melting point, easy soldering, and low price, but it is not environmentally friendly. Lead is harmful to the human body, so after soldering is completed, it is necessary to wash hands carefully. During the soldering process, it is best to wear a mask or in a bright place to ensure a certain distance between the head and the workpiece. With the increasing awareness of environmental protection among people, lead-free soldering is now used for machine welding in factories. Due to the high melting point of lead-free solder, it is not difficult to understand why it is sometimes difficult to melt solder when repairing imported electrical appliances.
Electric soldering iron is an electric heating device that can generate a high temperature of about 250 degree when powered on. The electric soldering iron is actually a process of heat conduction during the welding process. When it contacts the welding surface, the heat on the soldering iron tip is transferred to the solder. The solder absorbs the heat and melts and flows, and under the action of surface tension, a bright and round solder joint is formed. In the process of welding heat conduction, since metals are good conductors of heat, the heat transfer is fast. In the process of solder melting, due to the heat loss of the soldering iron tip, its temperature has more or less dropped. If the area of the welding point is large, it needs to absorb more heat to make the solder on it reach the melting point. If the soldering iron tip is small in size and stores less heat, the temperature drops faster. Since the heat generated by the soldering iron core is small in power, it is too late to replenish the lost heat. At this time, the most intuitive phenomenon is that the solder does not melt or melts incompletely. In this case, we have to use a high-power soldering iron for welding. On the contrary, if the welded part is small, we do not need to use a high-power soldering iron; if a high-power soldering iron is used, we must pay attention to the soldering time, otherwise excessive heat can easily cause the current to flow through the circuit, damage the circuit board, and cause the printed copper foil to fall off. There is no specific quantitative requirement for the specific power of the soldering iron. The long-term work experience of maintenance personnel is the best way to choose a soldering iron that suits them.
