Читать книгу All sciences. №4, 2023. International Scientific Journal - Ibratjon Xatamovich Aliyev - Страница 11

UDC 004.94

Sayitov Shavkatjon Sameddinovich

Lecturer of the Department of "Electronics and Instrumentation" of the Faculty of Computer Design Systems of the Fergana Polytechnic Institute

Ferghana Polytechnic Institute, Ferghana, Uzbekistan

Annotation. Speaking of the necessary devices for the soldering process, it is definitely possible to note as such a device the soldering device itself, better known as a soldering iron and along with this is most often a hand tool used during tinning and soldering to heat parts, flux, melt solder and make it into the contact point of soldered parts. The working part of the soldering iron can be noted the tip, which is heated either by flame, a vivid example of this is heating from a blowtorch, or by electric current.

Keywords: soldering iron, soldering, mathematical apparatus, mathematical modeling, pressing force.

Аннотация. Говоря же о необходимых устройствах для осуществления процесса пайки, однозначно можно отметить в качестве такого устройства непосредственно само паяльное устройство, более известное как паяльник и наряду с этим чаще всего являющееся ручным инструментом, применяющийся при лужении и пайке для нагрева деталей, флюса, расплавления припоя и внесении его в место контакта спаиваемых деталей. Рабочей частью паяльника можно отметить жало, которое нагревается либо пламенем, яркий тому пример нагрев от паяльной лампы, либо при помощи электрического тока.

Ключевые слова: паяльник, пайка, математический аппарат, математическое моделирование, сила нажатия.

The main large types of such a device include two large classes of soldering irons with periodic or constant heating. The first class includes hammer and end soldering irons, which are a massive working tip mounted on a long metal handle, the length of which ensures safe operation of the tool. To perform this type of work, these soldering irons are equipped with special shaped tips or shaped stings. Such soldering irons are heated mainly from external heat sources, in the person of which fire from gas or gasoline burners can mainly act. This type of soldering iron is the oldest and has been known since ancient times.

The next type of soldering iron – arc, was quite popular in the XIX century, which follows from its name. And also another consequence of the name of this type is the use of a method for heating it to create an electric arc, periodically excited between a carbon electrode placed between the soldering iron itself and the tip. For example, an arc soldering iron can have a tip mass of 1 kg and heat up to 500 degrees Celsius, at a voltage of 24 Volts for 3 minutes, with a power consumption of about 1.5—2 kW.

Soldering irons with constant heating are more modern. These also include electric soldering irons with a built-in electric heating element that operates from the mains, that is, directly, or through a step-down transformer, or from batteries.

The gas type of soldering irons also works constantly, thanks to the built-in gas burner, where the combustible gas is supplied from the built-in canister, with pre-liquefied gas. However, although much less often, gas can be supplied via a hose from an external source. To another type of soldering irons, it is possible to include soldering irons on liquid fuel, which still have the honor to be called liquid fuel. They are similar to gas, but heating is already carried out by the flame of burning liquid fuel, which is also known.

Another type of soldering irons with constant heating can be attributed to thermal air types of soldering irons, in such types, parts are heated, and the solder melts by blowing them with a jet of hot air, which resembles an industrial hair dryer, but unlike it, a thin high-temperature air jet is used in this case. And also, along with this type, it is possible to bring very logically, correctly, the type cited is infrared.

In it, as can also be seen from the name, heating is carried out by an infrared radiation source. A variety of such soldering irons are infrared laser soldering irons. And if these were only the main varieties, then it is worth paying attention to the types of various soldering irons, which include soldering stations, rod and most often common soldering irons, pulse soldering irons and finally induction soldering irons.

Now, if you familiarize yourself with each of these types, it can be noted that the rapidly developing technology of miniaturization of electronic components, improvement in sensitivity to high temperature, as well as the use of lead-free solders with a higher melting point has led to the appearance of soldering stations with additional functions such as:

· The ability to select an arbitrary temperature, thermostating, or more precisely, the ability to hold a certain temperature of the tip, rapid heating, which occurs in less than 15 seconds;

· The possibility of using stingers of various shapes, allowing replacement literally on the fly;

· The presence of a standby mode with low temperature and auto-off with the use of a ball tilt sensor, also known as an accelerometer.

In such types of stations, one can also observe the fact that a film heater on a ceramic substrate placed in a sealed housing made of heat-conducting ceramics can be used as a heating element.

The main positive aspects of this type of heaters are a relatively long service life and reliable electrical insulation of the tip from the heating circuit. Along with this, it can also be noted the act of having such soldering systems with hot air, in which infrared radiation is mainly possible, they are more favorable for dismantling parts, due to which they are also equipped with special parts for solder suction or devices for automatic or semi-automatic solder and flux feeding. Speaking of a rod soldering iron, it can be pointed out that the design of the most common soldering iron in everyday life is very simple and is a metal casing equipped with a plastic or wooden handle, in which a tubular heating element, aka a heater, is placed.

Inside such a heater, a displaced copper rod is placed at one end, this is the sting sharpened on the protruding end. In general, taking the form of a cone or a dihedral angle. The end of the sting is a tinned working end.

The heater itself is a wire made of nichrome or another alloy with a high resistivity and resistance to oxidation at high temperature wound on a ceramic pipe or a metal pipe wrapped with sheet mica. In modern soldering irons of this type, a film heater mounted on a ceramic tubular base or a ceramic volumetric heater is most often used. The heater itself is connected to a live wire passing through the handle and connected to the mains or a step-down transformer.

A pulsed soldering iron is one of the varieties of a household soldering iron, sometimes presented in the form of a soldering gun, at the end of which there are 2 electrical contacts and almost always a source of illumination of the soldering zone. The contacts are connected to the secondary winding of the transformer located in the body of the soldering iron itself and surprisingly, the winding has only 1 or 2 turns of copper wire. A piece of thick copper wire with a thickness of about 1-2 mm and a length of 3-5 cm is attached to the terminals of these contacts, which is both a heating element and a soldering iron sting. When the tool is turned on, the secondary winding current, reaching several tens of amperes, quickly heats up the copper wire to the operating temperature in a few seconds.

In pulsed soldering irons, instead of a massive transformer operating at an industrial frequency of 50-60 Hz, a pulsed electronic converter is used, with a frequency of tens of kHz, which reduces their weight and dimensions, and therefore makes their use much more convenient, which is achieved in the end.

And finally, the last type of soldering iron – induction by its nature is based on the idea of heating by inducing electric currents with a high-frequency electromagnetic field created by an inductor coil. Inside the sting itself, in fact, there is a ferromagnetic core that heats up due to hysteresis losses and, to a lesser extent, due to eddy currents, most often referred to as Foucault currents. In such soldering irons, only the tip itself is heated, which allows you to make the soldering iron extremely light and miniature. Speaking of their thermal stabilization, it is worth saying that this is feasible either in the traditional way, for example, by thermocouples or thermistors, or by choosing the material of the ferromagnetic core at a Curie temperature equal to the required tip temperature.

And in order to understand how well the soldering process went, it is worth considering it in more detail, realizing that initially, as soon as the terminal is lowered, a layer of solder – tin is fed under it in a simplified model (a more complicated one will be considered later). Under the same layer there is a silver layer of a metal heater, and already under it a layer of rear-view glass.

Empirically, it was found that the energy of the gap between the silver layer and the glass is 100 N. It may follow from this that the sum of the rupture forces between the solder and the terminal, as well as between the solder and the silver layer, is less than this value, since if it were greater than or equal to this value, the terminal itself would have sufficient force to carry the entire system with it when it breaks. But it is also clear that for rupture, that is, for deformation by the elastic force (3.2.1), where stiffness is determined through the Young’s modulus (3.2.2), its energy is equal to the energy of destruction of the crystal lattice, that is, the product of the specific heat of melting and the amount of matter (3.2.3), is equal to the potential energy of deformation (3.2.4).

To determine the rupture force, which is already a priori the sum of the rupture forces between silver and solder, as well as between the terminal and solder, it is sufficient to use (3.2.5), where the distance is determined from the constancy of the area and the value of the volume change, which is calculated depending on the temperature (3.2.6), and from here the rupture force (3.2.7).

Now that the force of the rupture has been calculated, we can stop a little at the moment of pressing. From such a calculation, it became possible to determine that with a specific heat of 7.19 kJ/mol, with an amount of substance of the order of 0.0434 mol and 0.005149 grams and a density of the order of 7190 kg/m3, the area is 7.04424 *10-7 m2, with a side of 0.8393 mm, from which the temperature coefficient of 0.0042 K-1 is taken into account, with a resultant force of 99.99886267 N, that meets all the specified conditions.

Speaking of the pressing force, it can be noted that due to the attraction energy of the liquid flow of the alloy, it can be comparatively determined on the scale of the difference between the boundaries between the resulting force and the boundary force, from which a value of 0.001137328 N is obtained.

Used literature

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