What is the reason why the electric soldering iron does not heat up after being idle for a period of time?
1. Not hot at all
If it is not hot at all, use the electric resistance of the multimeter to measure the resistance of the power cord plug, it must be ∞. Disassemble the electric soldering iron, remove or peel off the insulating sleeve at the connection between the power cord and the soldering iron core, measure the resistance of these two points, if there is resistance, it means that the core of the electric soldering iron is good, and it is the problem of the power cord— ——It was pulled off or there was a bad contact in the plug. If the resistance value is still ∞, it means that the soldering iron core is broken. The following are two common soldering iron cores: external heating type and internal heating type.
Reasons for the damage of the chromium iron core: ●Because of falling and knocking. Since the heating wire of the chromium-iron core is wound on the quartz or in the ceramic tube, these insulating media are inherently brittle, and become more brittle once heated, and cannot withstand knocking or falling, otherwise, they will break and cause damage. ●The quality of the soldering iron itself is poor, and the heating wire is blown. Now on the market, electric soldering irons worth 3 to 5 yuan a piece have basically the same appearance as those worth tens of yuan a piece. They can be faked, but the quality is very poor and they are not durable. People often say "you get what you pay for," and it's true.
2. It can be hot, but the heat is not enough to melt tin
The characteristic of this phenomenon is that the soldering iron has black hair and cannot melt the solder. It seems that the heat is not enough, but in fact the tip of the soldering iron is "burned to death".
If this happens, dip the soldering iron that is still heating with rosin repeatedly and rub it on the tin block until the tip of the soldering iron is tinned, that is, the color changes from black to bright. For the long-life electric soldering iron with a pointed tip, it is strictly forbidden to use a file to file, because the alloy head will be filed off.
The tip and core of the soldering iron are consumable materials, and damage is a normal phenomenon, but mastering the correct use of the soldering iron can prolong its service life.
5-step method for correct soldering with electric soldering iron
Step 1: Prepare the welding material
For welding, we must first prepare the welding materials, such as electric soldering iron, solder wire, materials to be soldered, components and flux, etc. Besides the first time, we also need to hold the electric soldering iron and solder wire, usually with the right hand The electric soldering iron takes the solder wire in the left hand, installs the components on the PCB, and puts them on the table to wait for soldering. Note that the temperature of the soldering iron is very high after heating for a period of time. Do not touch it with your hands, otherwise it may cause burns.
Step Two: Heating the Soldering Elements
After heating the electric soldering iron, it is best to put the electric soldering iron in the flux for a while. It would be even better if some flux can be added to the soldering place, which is convenient for us to solder. The necessity of putting the soldering iron into the flux does not take a long time, about two seconds or so.
Step 3: Add Solder Wire
After the soldering iron is heated to a certain temperature, we start to solder. First, put the solder wire on the pin of the soldered component, then let the soldering iron close to the solder wire, put the soldering iron tip on the solder wire for a while, and then solder After melting, the solder liquid can surround the component pins. When soldering integrated chips, be careful not to add too much solder.
Step Four: Remove the Solder Wire
After the solder melts and drips onto the components to be soldered, more than half of our work is completed. The next step is to wait for the solder wire to solidify, so we don't need to put the solder wire on the soldering place. We should remove the solder in time Soldering, so that the tin liquid solidifies.
Step Five: Remove the Soldering Iron
After the solder wire is removed, in order to make the welding more beautiful, we can use an electric soldering iron to re-melt the tin liquid at the original welding position, so as to avoid the phenomenon that the solder wire cannot be fully melted and lead to virtual welding. Put it on the place to be soldered, if the temperature of the soldering iron is too high if it stays here for a long time, it may cause the pad to fall off, which will cause the PCB board to be scrapped.
