Soldering iron - how to choose solder wire?
In the production process of the electronics factory, solder wire is one of the essential materials, so when selecting solder wire, you must be careful and careful in order to buy a truly good product. First of all, when we are selecting solder wire, it is best to go directly to the manufacturer for purchase. The second is to pay attention to its packaging when selecting solder wire. Although exquisite packaging does not explain any problems, any solder wire produced by a standardized manufacturer will be marked on the product packaging. Any quality problems can also be found in the manufacturer for replacement. Then, when purchasing, you should make a reasonable selection according to your actual situation. Many brothers like to purchase in electronic cities or hardware tool stores. The reason is that these local products are relatively cheap, but you get what you pay for. During the process, the appearance of blackened solder joints, lack of plumpness, etc. on the solder wire is all due to the low quality of the solder wire.
Solder wire is mainly composed of tin alloy and additives. The composition of the alloy is divided into tin-lead and lead-free additives, which are evenly poured into the center of the tin alloy. The types of solder wire are different, and the additives used are also different. Some additives are used to improve the auxiliary heat conduction of the solder wire during the welding process, remove oxidation, reduce the tension on the surface of the material to be welded, and remove the oil on the surface of the material to be welded. , thus increasing the welding area. The characteristic of solder wire is tin alloy wire with a certain length and diameter, which can be used in conjunction with electric soldering iron in the welding of electronic components.
There are two main types of solder wire, one is lead solder wire and the other is lead-free solder wire. There are many standards in these two types. Solder wires with different standards have different melting points. If you want solder wires to perform welding operations effectively, you must know the melting point of solder wires to ensure a good solder wire. welding effect.
The basic condition for welding with solder wire is to melt the solder wire, and the temperature required to change the solid state of the solder wire into a liquid state is the melting point of the solder wire. The melting point of solder wire is a physical property of a substance. The solution of solder wire will also change with the change of tin content. When the temperature required for the melting of solder wire does not reach its melting point, the solder wire is transformed from a solid state When it is in a liquid state, the wettability and solderability will lose their effect, resulting in failure to meet the welding requirements.
Let's talk about the specific method of selecting
one look
Visual inspection, good tin wire should be smooth, shiny, no oxidation, blackening phenomenon! (High-quality solder wire has a layer of film protection to avoid oxidation)
The quality of solder wire is generally better if the color is bright, while the dark solder wire has a higher lead content and is relatively less likely to melt.
The color of good solder wire is shiny (with lead), or silver white (without lead) instead of white.
Two, touch
Good solder wire is white and shiny, and it is not easy to smear it on your hands when you wipe it with your hands, while the tin wire with high lead content is black, and it is easy to get black hands when you wipe it with your hands!
The ductility of tin is very good, and the higher the purity of the tin wire, the less likely it is to break. Of course, tin wire with a high tin content is very soft and does not belong to hard metal products.
3. Wettability
Wetting performance performance to judge. The lead-free solder wire should be judged according to whether it meets the ROHS standard, flux residue, halogen-free, and tinning speed. Smoke, spatter, residue, and brightness are also criteria for judging the quality of solder wire.
4. Packaging
Pay attention to the packaging appearance of solder wire. Although the packaging appearance cannot represent the quality, all solder wire produced by regular manufacturers will have corresponding detailed identification. If there is a quality problem, it can be checked better. The basic information of the solder wire such as the tin content or degree, lead content, flux amount, melting point, and packaging weight of the solder wire should be indicated in the product label.
5. Brand
Choosing a solder manufacturer is the best way to ensure quality. Many friends are greedy for convenience, and often go to the nearest electronic city or hardware tool store to buy solder wire. As a dealer, these stores must make money. It is conceivable that the profit lies in the price difference, so we try to choose the manufacturer to buy directly when purchasing.
