How solders differ in melting point
The main material uses in soldering is a special alloy called solder. One of lead solder temperature most important characteristics is the melting point.
There are many different alloys uses as solders when making solder joints in metal products. They have differences in chemical composition and physical and mechanical properties.
- Composition of soldering alloys
- Choice of solder material
- Warm up
Classification of division of lead solder temperature
In accordance with the state standard, there is the following classification division of solders according to their melting point:
Low temperature, they also call soft. The melting temperature of these soldering alloys does not exceed 450℃. In turn, this category is divided into two subcategories. Soldering alloys melting at temperatures up to 145 ℃ call extra low melting alloys, melting in the range from 145 to 450 ℃ are called low melting alloys;
High temperature or solid. These include solders with a melting point exceeding 450℃. This class of alloys includes three subcategories. Medium-melting are those that melt at temperatures up to 1100 ℃, having a melting point from 1100 to 1850 ℃ call high-melting.
Filler materials uses in lead solder temperature, which occupy even higher temperature positions, are refractory.
Composition of lead solder alloys
The physical and mechanical properties of consumable filler materials, in particular, their melting point, determine by the content of the components that make up their composition.
Typically, such alloys consist of several chemical elements, but the name of the compositions is determined by the element that is the main one and surpasses all others in content. For example, solders based on tin are called tin solders.
There is a large family of solders containing significant proportions of lead and tin. Such soldering alloys call tin-lead.
For them, the letter designation POS is adopted, followed by a number showing the percentage of tin in the composition of this lead solder temperature.
The components that make up the solder affect the physical properties of the alloy, forming something new that is not inherent in each of the components separately.
The resulting properties of the solder
In this case, the greatest influence on the resulting properties of the solder (such as its melting point) is exerted by the element that has the highest specific gravity in the alloy. So, soldering alloys based on such a low-melting metal as tin are classified as low-temperature or soft. This emphasizes the relationship between the melting temperature of the metal and its mechanical hardness.
That is, metals that melt at a lower temperature are softer. It is for this reason that when lead solder temperature a metal product, they try to use an additive based on the same metal as the metal of the product.
At the same time, the lower melting point of the solder provides by additional components included in its composition.
True, it should note that it is never possible to equalize these characteristics when soldering. That is, during mechanical tests for destruction, a fracture will always occur at the junction.
The strength of the joint
In some specific types of lead solder temperature, the strength of the joint plays a minor role. For example, when soldering jewelry, the aesthetic part of the work is the main one. Therefore, products made of gold, silver and platinum solder only with solders based on the metals of the same name, and of the same sample.
The main soldering tools
Depending on the melting temperature of the filler material uses, various heating methods use for soldering. In the case of soft materials containing tin, zinc, lead, an ordinary soldering iron can serve as the main soldering tool.
An example is the assembly and repair of electronic circuits containing components that are critical to overheating. In this situation, lead-tin materials with a low melting point and low-power electric soldering irons usually use.
The mechanical strength of the lead solder temperature
The mechanical strength of the joints plays a secondary role here; the main thing is to ensure reliable electrical contact.
When it comes to soldering with high-temperature materials, the soldering iron is powerless. In these cases, heating carry out by means of gas burners and special installations using high frequency currents. This applies to industrial soldering in shop floor conditions and the use of hard solders.
Lead solder temperature in Desoldering
When desoldering components from circuit boards, there are often difficulties with elements that have many pins. This is clear. If you use a conventional lead solder temperature iron for such work, then removing a small component from the circuit is not difficult.
It is enough to warm up the leads and pull out the part while the solder is soft. If there are many conclusions, then it is not possible to warm up everything at the same time. In this case, a desoldering braid or other special devices are uses.
Role of Dismantling methods
In some cases, it allows to use a soldering dryer for dismantling, which, by heating a large area, melts the solder on all contacts.
But using a hair dryer can inconvenient with close installation. It is possible to heat up the lead solder temperature on the legs of adjacent components. The ideal would be a disassembly that leaves the pads clean and tinned. Sometimes mechanical and chemical methods are uses.
For accurate removal of solder from the board, it is better to use a soldering iron. In this case, several options are possible:
- remove the solder directly on the tip of the soldering iron;
- use a desoldering pump to remove excess solder;
- remove with braid.
Role of a chemical method in lead solder
The solder can mechanically remove with a file, needle file. This method is fast, but rough. When using a chemical method, the lead solder temperature dissolve by aggressive materials, for example, by any acid solutions.
Sometimes compressed air is uses to clean the board, which blows off excess material. But this method rarely uses, as it is rude and even quite traumatic.
How to use the braid?
To use the braid when removing solder, you will need a soldering iron and a bottle of liquid flux.
If there is no liquid flux, they take any other, but it will be uncomfortable to work. You can prepare a liquid flux yourself if you dissolve pieces of pine rosin in alcohol or pieces of zinc in hydrochloric acid in advance.
A copper braid is best for lead solder temperature. The piece of braid must be covered with flux.