How to use electric soldering iron - Solutions - Huaqiang Electronic Network
Soldering iron soldering, it looks simple and easy. When beginners really do hands-on welding, there are often many problems involved. It is not so easy to weld high-quality solder joints. Let's talk about the basics of soldering. It is difficult to solder the components on the board. I believe everyone has this experience. I have a few small experiences as follows: Car Screen Protector,Car Center Console Screen Protector,Car Touchscreen Screen Protector Shenzhen Jianjiantong Technology Co., Ltd. , https://www.jjttpucuttingplotter.com
1. The flux is available for metal (conductive material) welding. There are many kinds of fluxes. Commonly used are zinc chloride. Solder paste (commonly known as solder oil). Although zinc chloride is very strong in decontamination and degreasing, it is very corrosive. It must not be used for soldering of electronic components. Solder paste is most convenient to use, but after use, some residual liquid is often in the vicinity of the solder joint, which is not only easy to be contaminated with dust, but also has some corrosive effect on components due to acidity. In addition to some special circumstances, it is not suitable for soldering electronic components. The most suitable flux for soldering electronic circuit components is rosin or rosin alcohol solvent. Because rosin is a neutral substance, it has no corrosive effect on components. It should be noted that rosin and Solder should be added to the solder joints. Do not use hot soldering iron to remove rosin. A commercially available rosin solder wire (solder wire is hollow, hollow is filled with rosin), the effect is good.
2. The component pins are cleaned. The metal pins of the electronic components often have a layer of oxide. The oxide has poor conductivity and the adsorption force on the tin molecules is not strong. Therefore, the metal surface of the solder joint should be rubbed with an eraser before soldering. Polishing and polishing. Some people often use a small knife to scrape the oxide layer on the pin. This is unreasonable. Because the pins of the electronic components are surface-treated, the purpose is to make the component leads easy to solder. The basic material that exposes the surface of the component leads to the exposed pins is less likely to be soldered firmly. Only the pins of the cleaned electronic components will not be "flashed" after soldering.
3. The use of electric iron soldering iron is the main tool for welding. The general electronic components for soldering are commonly used in 20w internal heating soldering iron (for beginners). The newly bought electric soldering iron should be "on the tin" before use. The method is to use sandpaper. Or the trowel is polished in advance, and the power is connected. When the temperature of the soldering iron is higher than the melting point of the solder, use it to remove the solder wire with rosin. The surface of the soldering iron will be covered with a bright tin, and the soldering iron will be attached. Can be used. There is no soldering iron on the tin, it will not eat tin when welding, it is difficult to weld.
If the soldering iron is used for a long time or the soldering iron is too high, the soldering iron will oxidize, causing the soldering iron to "burn" and not soldering, and it is difficult to solder the components to the printed board.
The soldering iron tip should be kept clean. The uncleaned local area will not be tinned, and it will be oxidized quickly. After a long time, the soldering iron tip is often corroded. This makes the soldering work more difficult. The soldering iron tip is in a state to be soldered for a long time. If the temperature rise is too high, it will cause the soldering iron to "burn". Therefore, it must be fully prepared during soldering. Try to shorten the time of the soldering iron (powering). Once it is not soldered, remove the soldering iron power.
4. When welding components, the low melting point rosin tin wire should be used. When the temperature of the soldering iron is appropriate, the contact time between the soldered component and the soldering iron should be appropriate. The short time will also cause the solder joint. The time is too long. Will burn the components. The general component soldering time is about 2-3 seconds. The solder at the solder joint is not cold until it is solidified. Do not shake the soldering head of the component. Otherwise, it will also be used for soldering. Do not move the iron head and pressure welding, this will not help the welding work, but also affect the quality of the solder joints. It should be noted that the soldering of special devices should be carried out according to the component requirements. If some CMOS devices require the soldering iron to be uncharged, or the soldering iron Metal casing plus grounding wire.
Welding technology is a basic skill that electronic enthusiasts must master. It is also an important link to ensure reliable circuit operation. Beginners must add more welding to continuously improve welding skills in practice.
As we all know, welding is an important part of radio production and maintenance. The first problem encountered in beginner electronic technology is also the welding problem. Soldering electronic components to the printed board is subject to soldering requirements. In addition to mastering the soldering method, proper use of solder and solder, it is also related to the proper use of soldering iron. Here I mainly talk about how to use the electric soldering iron.
1. Reasonable choice of the power of the soldering iron We all know that with small power soldering iron, it is impossible to solder large electronic components (here, it refers to large solder joints). If it is forcibly soldered, the result is poor contact. If a high-power soldering iron is used to solder general electronic components on a printed board, copper foil lines or electronic components (such as triodes, switching diodes) are often burnt, resulting in undue loss. Therefore, when soldering, the power of the soldering iron should be compatible with the object to be soldered. In general, when soldering conventional components (such as transistors, diodes, RC components, integrated circuits, small and medium power tubes) on a printed circuit board, it is preferable to use a 20--30 watt internal heat type soldering iron. Beginners should use 20w because of the slow welding speed; if there are many components for one welding and the speed is fast, 30w should be used; but the device with a very large lead or a large grounding point on the printing plate should be welded. For power type connectors, 45w, 75w or 100w soldering iron should be used according to the heat consumption during soldering to ensure the robustness between components and related carriers such as printed boards or wires after soldering.
2. Adapt to the use of electric iron in amateur conditions, often can not be equipped with a variety of soldering iron, then you must use the electric iron. There are two situations that are often encountered:
(1) Increase the temperature of the tip. When the temperature in winter is very low, the soldering iron head dissipates quickly and the temperature rises slowly. At this time, it is more difficult to weld larger solder joints. In this case, a long cylindrical heat preservation cover can be placed on the iron frame by using a heat-insulating material (such as asbestos cloth) in the iron sheet, and then the electric iron head is inserted into the heat preservation cover, which not only accelerates the temperature rise rate of the iron tip. And can keep it at a higher temperature. After the above-mentioned heat preservation cover is installed, the effect of the 20w electric soldering iron can be improved to nearly 30w; the 30w can be increased to nearly 40w (short time).
(2) Lower the temperature of the tip. Electronic enthusiasts, if the power of the soldering iron on the hand is large (more than 30w) and there is no low-power soldering iron, if the ordinary electronic components are soldered, the soldering iron temperature is too high. At this time, a cooling method can be adopted, and a rectifier diode (IN40007) or a series of large wattage bulbs can be connected in series between the high-power electric soldering iron and the power source, or a 3--4 microfarad capacitor can be connected in series, so that the electric power can be directly reduced. The supply voltage of the soldering iron, so as to reduce the working temperature of the soldering iron. Of course, this cooling method must be determined by experiments according to the power of the soldering iron used, the grid voltage and the ambient temperature. For example, a 75w electric soldering iron and a 3--4 microfarad capacitor (withstand voltage 400v) can be connected in series to reduce power to about 20 to 40w.
(3) The soldering iron tip is an important factor in soldering. Commercially available long-life soldering iron tips of various shapes are required for soldering various components. Commonly used with hollow core to eat tin head, flat eat tin head, can solder most of the existing components. Regardless of which soldering iron tip is in the state to be soldered, it is advisable to remove the soldering iron power supply to prevent the temperature of the soldering iron tip from being too high, and the head is severely oxidized, and the soldering point is too small, so that the soldering quality is degraded. Of course, welding is a practical technique, and multiple welds can improve the level.
1. Use the tweezers to clamp the root of the component pin. When the solder joint is melted, quickly pull the pin away from the solder joint. Here, the tweezers have both clamping and heat dissipation, and the pin can be pulled out when the pin is pulled out. .
2. Thin copper wire adhesion method: The copper wire is peeled and coated with flux, which is slowly pulled from the molten solder joint, and the tin liquid on the component leads adheres to the copper wire. This method is suitable for small solder joints. Such as the pins of integrated circuits.
3. Blow the air to the newly melted solder joints and blow the tin to blow away the tin liquid. Pay attention to the direction of the blow and do not blow the other nodes of the circuit. This method is suitable for thick solder joints.
Note that when taking components, heat dissipation should be done. When solder joints are aged, flux should be added to promote dissolution. It is best to combine the above methods.