Soldering iron enthusiasts often choose 35 - watt internal - heating soldering irons. When using a soldering iron for the very first time, it's crucial to tin the tip. It not only makes future soldering tasks easier but also ensures better performance.
Tinning is a simple process. Before powering on, please simply clean the tip with sandpaper or a small knife. Once you've powered on and the tip reaches the right temperature, melt some solder on it. This will coat the end face with a layer of tin, and then your soldering iron tip is ready to use.
How to Use a Soldering Iron
1. Gather Your Tools: You'll need a soldering iron, solder wire, and rosin, which are easily available at tools stores.
2. Prepare the New Soldering Iron: If it's a brand - new iron, scrape the tip lightly with a knife to remove any oxidation. Then, plug it in. Be careful as the temperature rises quickly, it can get extremely hot.
3. Prime the Iron: Once the iron is hot, touch the tip to some rosin, followed by applying a bit of solder. This helps create a good working surface on the tip.
4. Prepare the tip: Apply rosin and then solder to the wires you are going to solder. This pre - treatment makes the soldering process smoother.
5. Make the Connection: Carefully solder the pre - treated wires to the component. we need to solder quickly or the higher temperature will damage the components.
6. When Not in Use: To prevent the iron from dry - burning, apply a small amount of solder to the tip when it is not in used .
7. Choose Your Flux Wisely: Rosin is a great choice for flux. Solder paste, on the other hand, has some corrosive properties, so it's best to avoid it if possible.
Remember, every soldering iron has three connection terminals. Two are for the heating element, connecting to the 220V AC power supply, and the third is for ground. It's a good practice to use a multimeter to check for any broken or short - circuited wires in the heating element before use. For a 20 - 30 watt soldering iron, the resistance of the heating element usually ranges from 1500 - 2500 ohms.
Precautions Before, During, and After Soldering
Before Soldering
Trim the excess part of the component's lead and then tin it. If the lead is oxidized and won't take the tin easily, clean it with fine sandpaper or a knife. Then, use the soldering iron tip to pick up some rosin - cored solder and tin the lead. If you're still having trouble, place the lead on a rosin block and touch it with the iron tip while rotating the lead. This should ensure an even coat of tin.
Be careful not to over - tin. The tinning process for each lead should only take 2 - 3 seconds to avoid damaging the component. When tinning diodes or transistors, use metal tweezers to hold the lead near the tube. This helps dissipate heat. Also, don't cut the leads too short, as it can affect heat dissipation and make soldering difficult.
During Soldering
Position the tinned lead at the soldering point, like in a printed circuit board's solder pad hole or a connector's solder tab. Hold the soldering iron tip, with a proper amount of solder on it, at the joint for about 3 seconds. After removing the iron, you should see a smooth solder joint.
To get a better result, tin the soldering area in advance. Keep the lead steady during soldering; any movement can lead to a weak or false solder joint. The iron should be held for just the right amount of time. Too long, and you risk damaging the component; too short, and the solder may not bond properly.
After Soldering
Take a close look at the solder joint. It should be a nice, smooth hemisphere, not too high or too flat. There should be no visible pores or dents. A poor - looking joint could mean a weak or false connection, especially when multiple leads are soldered together.
Step - by - Step Soldering Process
1. Get Ready: Hold the solder wire in your left hand and the soldering iron in your right. Make sure the iron tip is clean and has a thin layer of solder on it.
2. Heat the Parts: Touch the iron tip to the connection of the two parts you're soldering. Heat them evenly for about 1 - 2 seconds. If you're soldering on a printed circuit board, ensure the iron tip touches both the lead and the solder pad.
3. Add Solder: Once the parts are hot enough, bring the solder wire in from the side opposite the iron. Don't touch the wire directly to the iron tip.
4. Remove the Solder: As soon as the solder has melted enough to cover the joint, pull the solder wire away at a 45 - degree angle to the upper left.
5. Withdraw the Iron: After the solder has spread evenly, remove the soldering iron at a 45 - degree angle to the upper right. The entire process from adding the solder to removing the iron should take about 1 - 2 seconds.
General Tips for a Successful Solder
1. Keep the Tip Clean: The iron tip can quickly oxidize and get covered in impurities. Regularly wipe it with a wet sponge. When not in use for a while, add some solder to the tip to prevent oxidation.
2. Even Heating: Heat the parts evenly by increasing the contact area, not by applying pressure. This ensures a proper bond.
3. Timing is the Key: Withdraw the iron at the right time. The angle of withdrawal affects the shape of the solder joint.
4. Don't Disturb the Joint: Until the solder has fully solidified, keep the parts still. Any movement can create a weak joint.
5. Use the Right Amount of Solder: The solder wire already contains flux. Use just enough solder to create a good joint.
6. Flux Management: Don't over - use rosin flux. Too much means extra cleaning later and longer heating times. Too little can lead to a "夹渣" (slag inclusion) problem.
7. Avoid Transferring Solder with the Tip: Some people try to use the iron tip to transfer solder. But this can oxidize the solder, as the tip is very hot, which can break down the flux in the solder wire.
