What is used for soldering

What are soldering stations: which one is better to choose for your home, soldering features

When the capabilities of a conventional soldering iron become insufficient, it makes sense to think about using a special soldering station (SS). Carrying out high-quality installation of some elements on a printed circuit board without special equipment can be either very difficult or completely impossible.

Modern printed circuit boards are assembled on automated lines using special substations. It is logical that such devices must be used for repairs.

Moreover, when heated with a conventional soldering iron (even with a thin tip), there is a high risk of overheating the element itself or the textolite base on which it is mounted.

What is a soldering station

A soldering station is specialized equipment used for soldering high-temperature and voltage-sensitive radio components (microcircuits, transistors, capacitors).

The main parts of such equipment are:

• Control module - a block that includes a step-down transformer, a soldering iron temperature control chip;
• Soldering iron is a working part of this equipment connected to the control module by a flexible shielded cable;
• Stand - located on the side of the control module and serves to safely place a heated soldering iron during breaks between soldering jobs.

More complex models also contain a hair dryer, thermal tweezers, and an infrared emitter for heating a certain area of ​​the printed circuit board. Some stations have a small air compressor built inside that pumps air into the hairdryer with a heating element.

Heating element type

The soldering irons used use two types of heating elements: ceramic and nichrome.

Comparative characteristics:

1. A nichrome element has less power than a ceramic element, which has compact dimensions;
2. The nichrome element has a short service life compared to ceramic ones (the difference can reach several years);
3. Ceramics are less resistant to mechanical damage; even microscopic cracks prevent further use of the heater;
4. The cost of a soldering iron with a ceramic element is higher.

Important! Ceramic elements can crack due to temperature imbalances that occur when using a poorly installed tip.

Types of soldering stations

All modern stations differ in such characteristics as the soldering method, the type of soldering iron heating control (the temperature of a hair dryer or infrared emitter), and purpose.

Contact and non-contact

Operating principle of RCD

Depending on the method of soldering radio components, all soldering stations are divided into:

• Contact - in such equipment, radio components are soldered using a soldering iron with a sharp tip. According to the method of heating the tip, such stations are induction (the tip is heated by eddy currents generated when high voltage is applied to the coil located around it), pulse (the soldering iron is not heated constantly, but only at the moment the tip comes into contact with the working surface);
• Non-contact - soldering in such stations occurs due to the flow of hot air or thermal radiation. Non-contact devices are divided, in turn, into two types: hot-air (soldering occurs due to a high-temperature hair dryer supplying heated air to the working surface) and infrared (soldering occurs thanks to soldering irons with infrared emitters).

For your information. This classification is conditional - in many modern stations the equipment consists of contact and non-contact devices for soldering.

Analog and digital

Analog and digital soldering stations

According to the method of regulating the heating of the working body, soldering stations are divided into 2 types:

• Analog - in such stations, the heating of the tip is controlled by one sensor, which is connected to a relay that closes and opens the circuit of the heating element of the soldering iron;
• Digital - the heating of the soldering iron tip in such stations is regulated using switches and buttons located in the controller (microcircuit) located in the control module.

Analog soldering stations, due to their design features, are more reliable and repairable. However, this is where their advantages end - digital soldering equipment, in comparison with them, has more precise heating settings, which allows it to be used when soldering very temperature-sensitive radioelements.

Assembly and dismantling

Depending on their purpose, soldering stations are divided into:

• Assembly equipment - equipment structurally designed for soldering radio components onto printed circuit boards;
• Dismantling - soldering stations, which are used for quick and high-quality removal of solder and dismantling of burnt-out radio components.

In most cases, dismantling stations are used only in large radio engineering productions - ordinary radio amateurs remove remnants of old solder and dismantle failed radio components using conventional assembly soldering irons.

Repair

Soldering equipment of this type is used to carry out a large range of work. It includes not only various types of soldering irons, but also a special desoldering pump for removing solder particles and smoke, a clamp for fixing the part (board), and a lamp for illuminating the working surface. Such a station, thanks to its expanded configuration, combines the functions of the above-described installation and dismantling types of this equipment.

From the history of soldering and metallurgy

Soldering is widely used in industry and everyday life. Thus, in the mechanical engineering field it is used in the production of turbine blades, disks, pipeline systems and many other products. Soldering is used in the production of electronic equipment for various purposes.

Soldering electronic equipment

The advantages of this technological process include the following:

1. Low temperature heating of connected parts. this allows you to preserve the structure and mechanical parameters of the materials.
2. This method allows you to ensure the mechanical cleanliness of the seam and this allows you to avoid additional mechanical processing.
3. Modern soldering methods make it possible to connect parts made of steel alloys, non-ferrous metals, etc.

Soldering is one of the oldest methods of metal processing. Its use helped solve many problems in the manufacture of dishes, weapons, jewelry, etc.

Several thousand years ago, soldering was already widely used by artisans. Thus, during excavations on the territory of Babylon, gold items were discovered, in which individual parts were soldered.

And on the site of ancient Rome, lead pipes were found that were part of the water supply system and assembled using tin-lead solder.

Moreover, some researchers are convinced that the legendary Monomakh hat, kept in the Kremlin, is assembled from several thousand elements made of gold and connected by soldering.

Arc welding

Before the advent of electric arc welding, soldering was used along with welding performed in a forge to create permanent connections between metal parts. In principle, we can say that the advent of electric welding significantly stopped the development of soldering and its transformation into a technical process for joining metal parts.

Brazing Technology

But the emergence and rapid development of aviation construction, astronautics, and microelectronics has led to the emergence of a high and stable demand for the use of this method of assembling parts. In particular, soldering is used to create complex components in mechanical engineering and the construction of various devices. In some cases, soldering turned out to be the only way to connect parts.

Features of choice

The main characteristics taken into account when choosing a soldering station are its power, equipment, and the type of flux used for soldering.

Power

Blocking generator: operating principle

The choice of a soldering station based on this characteristic depends on its purpose:

• For soldering small radio components that are sensitive to overheating, equipment with a power of 40-60 W is used;
• To work with printed circuit board elements that are not so sensitive to high temperatures, stations with a power of 70-90 W are used;
• More powerful equipment (power over 100W) is used for professional daily soldering in medium and large production of household and computer equipment.

Note! The most convenient and productive stations for amateur radio are those with a power of 60 to 90 W.

Equipment

The most convenient configuration of a soldering station includes the following components:

• Soldering iron with replaceable tips of various shapes;
• Hot air hair dryer, tripod for vertical mounting;
• Tubular Solder Reel;
• Special lamp.

Although such equipment will not be cheap, it will allow you to perform all types of amateur radio soldering work.

Flux selection

The best flux is soldering acid

Flux is a substance that prevents the formation of an oxide layer on the surface on which solder is applied, as well as on the soldering iron tip. The quality and speed of soldering work depend on the correct choice of flux.

The following are used as fluxes for soldering stations:

• Rosin (hardened pine or spruce resin);
• Alcohol solution of rosin;
• Orthophosphoric soldering acid.

For your information. Among these types of rosin, the most convenient and effective to apply is orthophosphoric soldering acid.

Short review

Let's start with a station with a Quick 203H digital control unit (its photo is shown in the figure below).

Appearance of the QUICK 203Н station

The original model of this station costs between $220-$240, a Chinese analogue can be found at half the price (when choosing, pay attention to the package, it can be supplied without a soldering iron). Works great with SMD radio components and lead-containing solder.

review and operation in real conditions of the QUICK 203H station

Negative points: massive elements and lead-free solder require a long time to warm up.

Characteristics:

• The power declared by the manufacturer is 90W.
• Operating temperature from 200C° to 420C°.
• A voltage of 36V with a frequency of 400kHz is supplied to the induction coil.
• Stabilization of the established thermal regime is carried out with an error of 2C°.
• Heating to an operating temperature of 350C° takes no more than 25 seconds.

The digital control unit allows you to set 10 temperature profiles, set a power-on password lock, perform calibration, and set a delay time for turning on the sleep mode and turning off the device.

Those who purchased a Chinese analogue of the device are advised to immediately worry about purchasing the original tip, since what is included in the kit is more decorative than working.

Source: https://instanko.ru/elektroinstrument/dlya-chego-nuzhna-payalnaya-stanciya.html

What you need for soldering | Useful articles - Kabel.RF

To the frequently asked query in search engines: “Why do you need soldering?” This article will help answer. In short, soldering is used to reliably connect wires together, connect power to an LED strip, or secure a part to a printed circuit board of an electronic device.

Learn to solder

Before you start learning how to solder skillfully, you need to know what consumables and devices are required for this.

What you need when soldering

The main device used for soldering is a soldering iron. For household use, devices with a power of 25-75 W are sufficient. In modern soldering irons, instead of a nichrome heater and a copper tip, a ceramic heating element and a nickel-plated metal tip are used.

The advantages of soldering irons of this type are less time required to warm up to operating temperature and cool down, as well as the ability to smoothly regulate the temperature using a special power supply. In some models, the regulator may be built into the device body.

However, when you have to work with refractory solder or need to tin large parts, you need to use soldering irons with more power.

Before soldering wires or assembling printed circuit boards of electronic components, you need to decide on the type of soldering iron tip. Devices with a flat tip are used to work with large radio components or for tinning and connecting medium-section wires.

Soldering irons with a conical tip are necessary for soldering medium-sized parts, and those with a needle-shaped tip are needed for working with microcircuits or assembling LED lighting.

What is flux used for?

In addition to the soldering iron itself, we need flux and solder for soldering. Flux is necessary to clean the surface of wires or terminals of radio components from a film of oxides, grease and other contaminants, as well as to prevent further oxidation of the soldering area. The flux is selected depending on which metals are to be soldered.

What is rosin needed for? This flux is used to connect copper wires for soldering radio components with copper terminals (including tinned ones). Rosin can be in solid, gel or liquid form. Soldering acid is used to clean heavily oxidized copper contacts before soldering or to remove oxides from steel surfaces, including stainless steel. A special flux is used to connect aluminum wires by soldering.

For direct soldering of wires or parts, solders are used, the melting point of which must be lower than the melting temperature of the metals being connected.

Solders are produced on the basis of tin, lead, nickel or other metals in the form of rods or wires of various diameters.

How to learn to solder

Modern soldering irons with a nickel-plated tip do not require preparation before starting work. During their operation, it is enough to periodically clean the tip from residual solder and flux using a damp sponge.

But the copper tip of a soldering iron with a nichrome heater requires special preparation. Before starting work you need:

1. clean the tip from oxides using a needle file or file;
2. heat the device;
3. immerse the tip in flux (rosin);
4. rub the solder over the surface of the tip.

The same procedure must be carried out from time to time to clean the tip from the remains of burnt flux and solder.

In the following articles we will tell you how to use a soldering iron and how to solder wires correctly .

Source: https://cable.ru/articles/id-2017.php

The essence and application of metal soldering

The process of joining workpieces, as a result of which their material does not melt, is called soldering. That is, the material does not change its technical characteristics and qualities.

Soldering of metals occurs by wetting the surfaces of the workpieces with liquid solder, which fills the gap between two metal products. Solder is a metal or an alloy of several metals, usually tin and lead.

Connection by soldering, without melting, makes it possible to separate parts in the future (unsolder or re-solder) without disturbing their properties. The quality of soldering depends on the types of metals being connected, the solder and flux, heating and type of connection.

Advantages and disadvantages

The advantages of the soldering process include:

• the ability to combine steel with non-ferrous metals;
• high technological effectiveness of the process;
• the ability to carry out soldering operations in hard-to-reach and inconvenient places;
• the ability to connect complex units and parts;
• the process can be carried out not exactly along the contour of the connection, but along the entire plane;
• Heating during soldering provides heat treatment of metal workpieces.

As for the disadvantages of soldering, the main one is the low peel and shear strength of the solder joint due to the softness of the solder metal. It is difficult to carry out operations that involve high-temperature technology.

Where is it used?

After welding, soldering ranks second in application in the metal joining category. And in some areas of production it occupies a dominant position.

For example, in the production of computers, cell phones and other IT equipment. After all, the smallest details of this technology require compact contact with each other.

In addition, soldering is used to connect copper tubes in the production of refrigerators, heat exchangers, and when connecting carbide parts to each other, for example, cutting plates to cutters.

When carrying out body work, parts are connected to thin metal sheets. Tinning is also part of the soldering process, and this operation is used to protect various structures from metal corrosion.

In general, we can say that if in some situations it is impossible to connect two metal workpieces together by welding, bolting, studs, rivets, glue or other methods, then metal soldering comes to the rescue.

Varieties

The classification of metal soldering is quite complex, because in each category a large number of different parameters have to be taken into account. The type of solder, the heating method, whether there is pressure in the gap or not, how the solder seam crystallizes matters.

But most often the separation is carried out according to the temperature of the molten solder. This is a low temperature process (up to 450℃) and high temperature (over 450℃).

Low-temperature soldering is most often used in electronics, because the technology itself is quite simple and economical. At the same time, it becomes possible to solder small parts, which is important for this industry. In addition, this method can be used to connect dissimilar metals and materials.

As for high-temperature technology, it is indicated by the high strength characteristics of the joint; such a connection can withstand even shock loads and high pressure.

In small-scale production, high temperatures are provided by gas burners or induction currents of medium or high frequency.

There is another division in the classification of the soldering process, which is based on the type of solder. The most common way is to use ready-made solder.

By the way, these are not necessarily rods made of alloys; they can be a special paste. The solder simply melts and flows into the gap between the parts. This is where the capillary phenomenon comes into play. Surface tension forces force the molten metal to penetrate into all the pores and cracks of the parts.

The second position in this division is the reaction-flux operation, for which zinc-containing flux is used. Essentially, a chemical reaction occurs between the heated edges of the metal workpiece and the flux material, the end result of which is solder.

Heating Methods

Soldering materials can be heated in different ways. If we talk about home use of the metal soldering process, the most common option is a soldering iron or torch.

The first tool is used if it is necessary to carry out a low-temperature process, the second - if a high-temperature one. The variety of modern soldering irons is great. Among them there are devices with automatic temperature control and other useful functions.

The production uses mainly other technologies: oven soldering, using induction heaters, immersion in special baths with metal or salts.

Electrical resistance heating is used, when the solder and the workpieces being connected are heated due to the flow of electric current through them, and others.

Solders

In the implementation of soldering of elements, solders are important. They are made from pure metals or their alloys. When choosing, pay attention to their two main characteristics: wettability and melting point. The first property is the adhesion of solder to workpieces, where the strength of the connection between them becomes higher than between the molecules of the solder material itself.

As for temperature, there is one requirement - the melting temperature of the solder metal must be lower than the same indicator for the workpieces. Therefore, solder material is divided into two categories: low-melting and high-melting .

The first are materials based on tin and lead in pure form or with the addition of various components. The second are materials based on silver or copper. These are copper-zinc solders that can be used to solder copper, bronze and steel workpieces.

Silver grades are considered the best; they have high strength characteristics, so they are used for joining parts that operate under vibration or shock.

In addition to the main types, other varieties are also used in industry. For example, nickel is used for parts operating at high temperatures.

Gold – for joining gold jewelry or soldering tubes operating under vacuum. Magnesium - for joining magnesium blanks or parts made from alloys of this metal.

The solder itself can be made in the form of rods, paste, powder, tablets, thin foil, granules of various sizes.

Fluxes

The main requirement for the quality of the connection is physical contact of the solder with the metal of the two parts. Therefore , it is very important that an oxide film does not form on the edges of the workpieces .

This is precisely why fluxes are used in the soldering process. Their main task is to remove the old film and prevent the formation of a new one.

The classification of fluxes is based on a number of differences in composition and properties. They are:

• active and neutral;
• with low heating temperature and high;
• solid, paste-like, liquid, in the form of gels;
• water-based and anhydrous.

Of all the varieties that are used today for soldering metals, the most common are boric acid and its sodium salt (borax), zinc chloride, rosin and phosphoric acid.

Soldering Features

Since different projects are implemented in industry, different metals may be involved in the soldering process. Therefore, soldering technologies may differ, and in some cases its use is extremely difficult.

Steel

It should be noted right away that steel blanks can only be soldered with tin-based solders. Zinc-containing materials are not suitable for this operation due to low wetting. Here is a technological map of the stages being carried out.

The edges of metal workpieces are cleaned of dirt. Then they are treated with sandpaper or an iron brush, thereby removing the oxide film.

The degreasing process is carried out using any solvent. The blanks are joined with a gap of 2-3 mm. Heating is carried out with a blowtorch or other heating tool.

Flux is added to the heating zone, and then solder. Please note that the latter should no longer be heated from the flame of the fire, but from the heated edges of the workpieces. After the process is completed, the remaining flux and solder are removed from the joint area.

Cast iron

Only gray or ductile cast iron can be connected by soldering; white cast iron cannot be soldered. The rules for soldering cast iron are based on solving two problems. The first is the poor wettability of the metal due to its high graphite content.

The problem is easily solved. Before soldering, it is necessary to treat the joint surfaces with boric acid. The second problem is that during the heating process, changes in the metal’s structure occur, so it is recommended to solder cast iron at a temperature no higher than 50 ℃.

Titanium

Soldering titanium is one of the most difficult. On the surface of this metal there is an alpha layer, which is saturated with atmospheric gases. It will have to be removed either by etching or sandblasting. And even after this, an oxide film will remain on the surface.

To ensure a high-quality connection, soldering is carried out either in a vacuum, or with argon, or with special fluxes. The latter option does not guarantee high quality of the final result. In this case, it is necessary to strictly observe the temperature regime, which varies for a given metal in the range of 800-900 ℃.

As for solders, either silver or aluminum are used here. Tin and lead solders are rarely used because they do not bond well with titanium itself. Although if you apply a tin or lead layer to the surface of a titanium workpiece, you can guarantee good soldering quality.

Nichrome

Soldering nichrome is the simplest process, because the alloy itself (which is a symbiosis of chromium and nickel) is heat-resistant and ductile.

Its melting point, depending on the additives, varies between 1100-1400 ℃. That is, even refractory solder material can be used for soldering.

Soldering of nichrome parts is carried out at low temperatures. Joining the alloy to steel requires high-temperature soldering. Many craftsmen make their own solders at home by mixing Vaseline (100 g), glycerin (5 g) and powdered zinc chloride (7 g).

The scope of soldering makes it possible to connect parts made of different non-ferrous metals. Of course, the choice of soldering methods must be approached from the standpoint of compliance with the connection technology and the correct choice of consumables.

But, as practice shows, the process is based on the type of workpieces themselves, that is, how high their melting temperature is.

Based on this, the type of soldering operation itself is selected. After all, the melting temperature of the solder should be lower than that of the metal of the parts being connected. And this law must not be violated under any circumstances. They violated it - they received a poor-quality connection or, in general, did not receive any soldering.

Source: https://svaring.com/soldering/tehnologii/pajka-metallov

Tin for soldering: melting point, solder composition

Everyone knows from school that tin with the chemical symbol “Sn” is used for soldering microcircuits and other radio components. The main requirement for this alloy is a low melting point.

This is because the solder must melt during the process, not the part being joined.

Pure tin with a melting temperature of 232 °C is quite suitable for these purposes, but in practice, pure tin is not actually used for soldering due to its high cost; alloys with lead and other metals are more often used.

Characteristics

Tin is indispensable in the production of electronic devices. Due to its properties, it is used for welding components in radio engineering. The alloy, called Eutectica, consists of lead (Pb), silver (Ag), copper (Cu) and nickel (Ni). Thanks to these additives, tin melts at different temperatures depending on the percentage of each of them.

Tin for soldering

Tin is soft and malleable, but very resistant to corrosion and does not form rust, has very good electrical conductivity and a relatively low melting point. All these characteristics make it indispensable for creating electronic devices.

The soldering process takes place in soft welding, which consists of combining two base elements by introducing a third element with a lower melting point into the base.

For example, soldering a copper circuit board pad to a capacitor leg uses molten tin, which melts at a much lower temperature than the base elements.

During the heating process, liquid tin, due to its capillary properties, is attracted to the base components, and then cools in soft soldering mode.

Eutectica alloy

Types of solders and fluxes

In our country, the POS brand of solder has become widespread - an alloy of tin Pb and lead Sn. Depending on the type, cadmium, nickel, copper, and other metals may be added to it. PIC is mainly produced in the form of rods, wires, balls and paste. Its chemical composition is strictly regulated by GOST 21930-76. In Russia, the following types of solder are widely used: POS18, POS30, POS50, POS90, which are soft alloys with a melting temperature of up to 300 degrees.

POS brands

POS-18

Solder is regulated by state standards; in addition to Pb (0.8%) and Sn (17-19%), it contains impurities of many metals. Regulatory authorities strictly ensure that the manufacturer limits the presence of toxic arsenic in the composition, which reduces the fluidity of the liquid alloy and increases fragility under conditions of alternating loads.

Composition of POS-18 impurities in percent:

• Cu - 0.1;
• Bi0 - 0.05;
• S—0.02;
• Fe - 0.02;
• Al, Ni, Zn - 0.002 each.

Technical data:

1. Density—10.3g/cm2.
2. The resistivity indicator is 0.200 µOhm•cm.
3. The Brinnel hardness index is 11 HB.
4. Thermal conductivity—0.37 kcal/cm*C*deg.
5. T at which the solder will melt solidus/liquidus—183/285 C.

Solder Advantages:

• Wide area of ​​alloy in liquid state;
• reduced content of impurities that cause brittleness;
• corrosion resistance of the soldering area, which is important for parts located in humid environments.

Disadvantages of POS-18:

• Special solder, not mass produced.
• The presence of harmful additives in the composition - Pb.

POS-18

POS-18 belongs to the universal alloys and is a substitute for antimony-free alloys; it is used:

• For the production of radio equipment;
• soldering low power printed circuit boards;
• car body repair in the form of tinning;
• connections of units made of copper-zinc alloys;
• repair of equipment in heating systems: boilers, radiators and other heating elements.

The price of POS-18 solder as of September 1, 2019 is from 710 rubles/kg.

POS-30

Solder is standardized by GOST 21930.76 / 21931.76 and belongs to soft alloys with a melting temperature of 256.0 C. Its properties are similar to grades with POS-40 and 50 and consists of Pb and Sn in a percentage ratio of 30:70, as well as other elements no more than 1 %. It differs from pure tin in its dark color and increased hardness of the alloy.

Solder POS-30

Composition of impurities in percentage:

• Sb - 0.1;
• Cu - 0.05;
• Bi0 - 0.2;
• S, As, Fe - 0.02 each;
• Al, Zn - 0.002 each.

Technical data:

1. Density - 9.72 g/cm2.
2. The resistivity indicator is 0.185 µOhm•cm.
3. The Brinell hardness index is 12 HB.
4. Thermal conductivity - 0.37 kcal/cm*C*deg.
5. Solidus/liquidus melting temperature - 183/256 C.

Solder Advantages:

• High fluidity;
• low melting temperature;
• low resistance allows you to work with small parts;
• high impact strength equal to pure tin;
• high scope of application, with the possibility of replacing expensive materials, for example, for soldering zinc or brass plates;
• Possibility of use for repairing household appliances.

The disadvantage of POS-30 is the presence of harmful additives in the composition - Pb.

The price of POS-30 as of September 1, 2019 is from 766 rubles/kg.

POS-50

It is produced in accordance with the requirements of GOST 21931.76, it is distinguished by a practically equal ratio of lead and tin.

Solder POS -50

Composition of POS-50 impurities in percent:

• Sb - 0.8;
• Cu - 0.1;
• Bi - 0.05;
• As - 0.05;
• S, Fe - 0.02 each;
• Ni, Al, Zn - 0.002 each.

Technical data:

1. Density - 8.87 g/cm2.
2. The resistivity indicator is 0.158 µOhm•cm.
3. The Brinell hardness index is 14 HB.
4. Thermal conductivity - 0.48 kcal/cm*C*deg.
5. Solidus/liquidus melting temperature - 183/209 C.

Solder Advantages:

• Good fluidity;
• good thermal and electrical conductivity;
• Possibility of use in wet environments;
• good ductility of the seam allows it to be used for products with increased requirements for tightness, for example, in measuring instruments and low-power PC circuits.

Disadvantages of POS-50:

• Ineffective when soldering thick products due to unstable heating; the presence of harmful additives in the composition - Pb;
• accelerated crystallization of the melt does not make it possible to use the alloy in manual soldering technology.

The price of POS-50 solder as of September 1, 2019 is from RUB 1,102.00/kg.

POS-90

The solder is characterized by low thermal conductivity and high hardness, which is explained by the high content of tin 90, the material is silver in color, which gives the resulting joints an aesthetic appeal.

Solder POS - 90

Composition of POS-90 impurities in percent:

• Sb - 0.1;
• Cu - 0.05;
• Bi - 0.2;
• As - 0.01;
• S, Fe - 0.02 each;
• Ni, Al, Zn - 0.002 each.

Technical data:

1. Density - 7.6 g/cm2.
2. The resistivity indicator is 0.120 µOhm•cm.
3. The Brinell hardness index is 15.4 HB.
4. Thermal conductivity - 0.13 kcal/cm*C*deg.
5. Solidus/liquidus melting temperature - 183/220 C.

Advantages of POS-90:

• Wide range of applications from household, medical to industrial sectors;
• good fluidity;
• high level of wettability in the liquid state;
• low melting temperature;
• good electrical conductivity;
• good tightness, the ability to use in water and gas environments; good plasticity of the seam allows it to be used for products with high
• sealing requirements, for example in measuring instruments and low-power PC circuits.

The disadvantages of POS-90 are the presence of harmful additives in the composition (lead).

The price of POS-90 solder as of September 1, 2019 is from RUB 1,778.00/kg.

What is the melting point

Tin, which is used in electronics, is usually a eutectic type, meaning that it is an alloy with a lower melting point for each of its constituent elements. So, if there is a 60% tin alloy (melting temperature - 232 C) and 40% lead (melting temperature - 327 C), then the total melting temperature of the alloy will be approximately 183 C.

Melting tin

The most common solder used in EU countries for electronic work is 63/37 SnPb. It is a eutectic alloy with a melting point of 183 C. The 60Sn alloy has a working range of 183-238. There is a lower temperature alloy Sn43Pb43Bi14, which has a melting point of 144-163.

Solder composition

The lead contained in the alloy is gradually being phased out in accordance with new EU directives (RoHS and WEEE) and is being replaced by solders consisting of tin-antimony alloys. Already today in the EU many stores do not sell it. Things are different here for now; it will probably be many years before lead solder in our country is replaced forever.

Important! Lead-free alloy has a higher melting point than lead alloy and uses more aggressive fluxes. This means that the soldering iron must be made for lead-free soldering to ensure the correct temperature of around 230 C. Lead-free solder is generally about 20-50% more expensive than lead solder.

How to choose the right one

The choice of solder depends on the type of work and purpose of the finished product, as well as on the conditions under which the product will be used.
Criteria to consider before choosing solder for soldering:

1. Soldering iron type.
2. Wire size. Diameters vary from centimeters or millimeters, the size of the wire depends on the work being performed.
3. The flux cleans the soldering area, making it easier for the solder to flow and therefore a perfect solder joint. Flux changes surface tension as it increases adhesive properties in the solder joint.
4. Before purchasing, you need to know at what temperature tin melts for soldering.
   Compound. The debate about whether to use lead or lead-free solder on PCBs is still ongoing. Despite debates caused by environmental and health concerns, many electrical technicians use lead.

Note! The expiration date and industry guidelines require its use within three years from the date of manufacture. The expiration date is indicated on the product and can be found in the store upon purchase. If you use expired solder paste, oxidation may occur on the solder surface, rendering the connection ineffective.

Usage

Experts give useful tips that are very helpful for novice radio amateurs to solder correctly:

1. Choose solder with a minimum lead content.
2. It is necessary to ensure the cleanliness of the soldering iron tip; it should not have dirty deposits.
3. For cleaning, use a file or sandpaper. After cleaning, the tip is tinned with rosin.
4. It is not recommended to hold the device at the solder point for a long time, since the parts being connected can suffer high temperature damage. To reduce the harmful effect of T on the part, it is held with tweezers, which will act as a heat sink.
5. The product is cleaned before soldering, and the contact contacts are additionally tinned to ensure excellent adhesion.

Soldering technology

Additional Information. When soldering, safety precautions must be taken. Always wear safety glasses to protect your eyes from flying drops of hot liquid solder. The tip of the soldering iron is very hot by design, exceeding 370 C. Do not allow the tip to come into contact with skin, clothing or other objects. When working, you need to use a special holder for a soldering iron.

To summarize, we can say that soldering tin is still widely used in the domestic electronics industry and everyday life. The product is widely represented on the Russian and foreign markets, in the form of lead and lead-free solders. In order to protect the environment and the requirements of international organizations, consumption of the first type will be steadily reduced.

Source: https://rusenergetics.ru/ustroistvo/olovo-dlya-payki

Soldering iron. Types and work. Application and how to choose. Peculiarities

A soldering iron is a fairly simple, convenient and effective device. It is used to connect parts made of plastic and metal. It is often used when soldering wires, installing pipes, tinning or burning. It is indispensable when connecting small parts.

The product is widely used not only in everyday life, but also in many industrial sectors. These are industries that work with electronic and electrical circuits, plastic pipes and a number of other products. For each type of activity, devices with certain characteristics are used.

They are selected taking into account the type of soldering, the solder used and the materials being joined.

Kinds

Soldering irons can be classified according to the heating method.

Nichrome

These devices are made using nichrome wire. It is to this that voltage is applied to subsequently release the required amount of heat. The current can be supplied alternating or direct. In the simplest types of nichrome products, a wire spiral is wound around a dielectric body. It contains a tip. The nichrome spiral is often coated with insulating material to reduce heat loss.

The advantages of such a device include low price, unpretentiousness and resistance to mechanical stress. However, this device has disadvantages: long heating time, the possibility of burning out the coil, which significantly reduces the service life of the product. However, such models are used for small jobs.

Ceramic

These devices are made using ceramic rods. When current is supplied to the contacts of the rod, it heats up.

The advantages of such a device include a long service life, no risk of burnout in case of intensive use, and fairly rapid heating. However, such models require the use of only original tips, and the rods themselves, made of ceramics, do not tolerate impacts.

Induction

The induction coil is a tip heater. The advantages of such a device include automatic maintenance of the required soldering temperature, the absence of temperature sensors, and complex control microcircuits. At the same time, such devices can only maintain a given temperature, as a result of which completely different tips will be needed for different cases.

Pulse

These devices are made using a high-frequency transformer, as well as a frequency converter.

The advantages of such devices include very fast heating and ease of use. However, there are also disadvantages: such devices are not suitable for long-term work.

Structurally similar devices can be:

• Rodzhnev . They are traditional types of devices. Products are made in the form of a rod. The handle has a working part with a sting. Such products are good for working with small parts.
• Pistol . Such products are widely used when working with electrical wires.

• Soldering stations . These are the most complex products, which consist of a working element and a control unit. According to their characteristics they can be;

— infrared – works through infrared heating;

- thermal air - heating is carried out by heating air masses;

— digital — heating is performed by reducing the transformer voltage. These devices are ideal for precision work, for example when repairing electrical circuit boards.

These devices are also divided into the following groups:

• With continuous heating.
• With periodic heating.
• Abrasive.
• Ultrasonic.

Soldering iron device

The copper rod is heated by a heater made of a nichrome spiral. It could also be special ceramics that conduct current. When using a nichrome heater in a product, the power is determined by the cross-section of the wire. The rod is an important part of the product, because it is this end that comes into contact with the melted material. Therefore, it is often called a sting.

The rod is installed in a metal tube. A winding made of insulating material is used to insulate the heating element. Mica or fiberglass can be used as it. A nichrome thread is wrapped around the top. A channel is drilled in the device holder through which the electrical cord is passed. It is through it that the current is supplied to power the product. The holder is made of heat-resistant plastic or wooden material.

Operating principle

Soldering irons have a fairly simple operating principle. When the device is connected to the electrical network, the current is directed to a spiral made of nichrome. Due to the significant resistance of the nichrome element, a large amount of heat is generated. It is transferred to a copper rod. The rod is usually heated to a temperature in the range of 300-350 degrees Celsius. The tip of the device (copper rod) melts the solder and also heats the parts being soldered.

Other types of devices have a similar operating principle:

• In pulse soldering irons, the converter initially increases the voltage frequency (18-40 kHz). Afterwards, the high-frequency transformer lowers the voltage to the working voltage for the soldering iron. The tip is connected to the secondary transformer winding, which allows the highest currents to pass through it and provide instant heating. The specified heating is carried out only at the moment of pressing the start button, the rest of the time cooling occurs;
• Induction devices are made using an inductor coil. The product is equipped with a tip and coated with ferromagnets. It is with its help that a magnetic field is formed, which ensures heating of the core. When the required temperature is reached, heating stops. If the temperature drops, heating begins again. This is caused by the ferromagnetic properties of this device.

The soldering iron is widely used:

• Low power devices (up to 40 W) are used for soldering electronic components using tin-lead based solders.
• Soldering devices are an indispensable device for electromechanics and electricians.
• Electric soldering irons of higher power (from 100 W) are used for soldering and tinning of large parts.
• To work with small parts in industries related to the production and repair of microcircuits, stations and pulse devices are most often used.
• Soldering devices are also used in various industries, workshops and everyday life when carrying out soldering operations. Most often they are used to connect electrical wires, pipelines, and so on.

How to choose

• The soldering iron must be selected taking into account what parts need to be soldered. In most cases, these products are used for extending wires, soldering antenna connectors or simple circuits, and so on. For these works, a product with a power of 25-40 W is suitable. Such devices are distinguished by their low price. However, they have limited use. For professional tasks, you should choose specialized soldering irons with high power and the function of regulating the soldering temperature.
• To perform work with massive parts, for example, soldering radiators, you should choose devices with a power in the range of 100-200 W. To wire resistors, it is recommended to use ceramic devices with a power of 3-10 W with a nickel tip.
• When selecting, you also need to pay attention to the shape and material of the tip. The dimensions of the device will also be of considerable importance. A device with a straight heat-resistant tip is considered the simplest and most versatile. It is recommended to choose a tip made of copper material, because it is easier to clean.
• It is better to select a device for home with a spiral heater. Options with a ceramic heater are more capricious. In addition, they cost an order of magnitude more.
• For frequent work with microcircuits, devices with a power of up to 20 W should be used. Thin stings should come with them. It is recommended to take a closer look at products with temperature control functions.

How not to use a soldering iron

• If you lent it to someone and this person does not pay it back, then a soldering iron, of course, can help. However, it is better to do without it. Otherwise, problems with the law may arise.
• Do not dip the device in water. This is fraught not only with electric shock, but also with failure of the product. The tip may crack or the winding may burn out. As a result, you will need to go to the store for a new purchase.
• Do not ignore the switched on soldering iron. There is a high risk of fire.

Related topics:

Source: https://tehpribory.ru/glavnaia/instrumenty/paialnik.html

Solder for soldering

The process of repairing electronics and performing work in radio engineering occurs with the help of a soldering iron. High-quality work serves as the basis for durable connection of parts.

The work is done with a soldering iron; reliable connections are made not only with a high-quality tool, but also with flux and solder. The main solder is an alloy of light-alloy metals, which melts when a certain temperature is reached.

Tin in its pure form is considered the most suitable option, but the material is very expensive.

Solder for soldering

What types of solders are there?

There are a large number of materials for soldering, the main division is into soft and hard. Radio equipment is installed using low-melting material; its melting point ranges from 300 to 450 °C. In terms of strength, soft types of solders are not inferior to others when soldering; they are used in the assembly of almost all electronic products.

The soldering process is based on an alloy of tin and lead with a certain standard and quantity.

Some refractory solders have steel alloys, which makes it possible to implement certain parameters when connecting. Impurities are used to achieve certain characteristics, anti-corrosion properties, and strength levels. Solder for soldering is used in most cases of the POS brand, which means tin-lead solders. The number indicates the percentage of tin in the composition.

Tin-lead solder

If a situation occurs where solders and fluxes used in soldering are of unknown origin, they can be distinguished by the following physiological properties:

• The melting point of lead-tin solders varies from 183 to 265 °C.
• A bright metallic sheen indicates a high tin content, presumably grade POS-61 and higher.
• A high lead content is indicated by a dull gray tint and matte surface.
• A large amount of lead increases the ductility of the wire; a product with a diameter of 6 mm can be easily bent by hand, but a higher quality product cannot be bent.

Different types of solder are produced by manufacturers depending on certain factors. Most modern soldering materials use a flux tolerance of 1 to 3%, which significantly improves working conditions.

There is no need to bring the tip of the soldering tool to the flux each time if it is contained in the solder core. A type of lead-tin product is POSSu brand solder.

The designation involves the addition of antimony, is used in various industries, and is suitable for use with tin parts.

Solder Sn63Pb37

The most common type of solder used for soldering and tinning copper and bronze parts through which current flows is tertiary solder. The melting point of this variety is 190 °C, resulting in a sealed seam. The foreign analogue is Sn63Pb37, where the content of tin to lead corresponds to the name.

Low temperature solders

Low-melting solders have a transition temperature to the liquid state of up to 450 °C. They are used in radio engineering connections, when soldering wires, and other works. The main components of such soldering products are alloys of tin, lead, cadmium or bismuth. In the process of degreasing and tinning technical boards, Wood or Rose alloys are used. Such substances become liquid already at around 70 °C.

Low temperature solder

Metals have different melting points, it is important to familiarize yourself with the composition of the solder before purchasing.

1. Tin is a low-melting metal that is dissolved by sulfuric or hydrochloric acid. The metal melts at 232 °C; exposure to standard room temperatures does not affect it, but at -50 °C the composite crystal lattice is destroyed.
2. Lead is popular due to its fusibility and easy processing. Only the surface exposed to ambient air is oxidized.
3. Cadmium is used for anti-corrosion purposes when soldering tin and lead products. The material itself is toxic, melting at 321 °C.
4. Bismuth is added to the composition due to its solubility in sulfuric acid and nitrogen media.

The most convenient form of release for soldering radio components is wire with a diameter of 2-2.5 cm. The composition of modern products is rosin, which acts as a flux.

Soft solders are used in conjunction with an electric soldering iron and flux. The tin included in the composition is an environmentally friendly product and can be used to connect elements of the food industry. The most common soldering product is the tertiary, which got its name due to the composition containing a third of lead . Soft solders are divided into varieties according to their purpose and melting temperature.

Solder POSV-33

Low-melting solders are used for soldering heat-sensitive parts such as fuses and transistors. The composition includes lead, tin, bismuth and cadmium, the latter material is toxic and is not used in all areas of activity. Melting of Wood's products begins at the lowest temperature - 69 °C.

Domestic brands of products are labeled POS; with the addition of some substances, the name changes. For example, POSV - 33 has equal parts of lead, tin and copper, and is applied to brass and copper parts that require a sealed seam.

Main technical characteristics of soft solders for soldering
with an electric soldering iron

The technical characteristics of materials used for soldering are divided into several parameters:

• conductivity or electrical resistivity is 0.1 ohm per meter. Tin-lead type solder conducts electric current an order of magnitude worse than aluminum or copper;
• Tensile strength is measured kg/mm; low-temperature solders do not include this parameter, because not designed for load. The parameter depends on the amount of tin; the more there is, the higher the number. For example, POS-61 brand solder has a strength of 4.3 kg per mm, and POS-90 solder has a strength of 4.9 kg/mm.
• The melting point depends on the purpose and components.

An auxiliary substance that promotes the spreading of soldering materials over the surface of the parts being soldered is flux. High-quality connections are created by solders and fluxes ; without one of the components, soldering is impossible. A common type of flux is rosin, made from hard coniferous trees. Softening occurs at 50 °C, and when the temperature reaches 250 °C, the process begins to boil the composition.

Flux for soldering aluminum

Due to the hydrolysis provided for in the manufacture of rosin, the material is not resistant to atmospheric influences. After soldering, it is necessary to remove flux residues, because... the compound may undergo an oxidation process. By absorbing moisture from the atmosphere, rosin can disrupt the operation of radio components.

Popular fluxes for soldering with an electric soldering iron

Soldering of metal joints occurs using various substances. Fluxes are divided into three main categories, differing in their area of ​​application and method of preparation. The process of preparing elements for work may vary; after soldering, it is necessary to remove residues in the manner described in the instructions.

1. Inactive rosin fluxes are used for soldering copper and other types of soft metals. There is a light rosin that is ready for use and does not include additional substances. Alcohol-rosin solution is made from components with a concentration of 1 to 5. It is used for soldering in hard-to-reach places, it is produced in powder form, and must be mixed with alcohol before use. Glycerin - rosin materials are used when a hermetic connection is necessary.
2. Active fluxes suitable for soldering precious and non-ferrous metals include zinc chloride, alcohol or petroleum jelly. The last parameter differs in its composition, when used in a liquid or paste state. It is more convenient to work with flux as a paste; it is possible to apply it directly to the product in the required amount.
3. Acid-active flux is divided into zinc chloride and phosphoric acid. It is performed in the form of liquid solutions or paste, using rosin, zinc chloride, alcohol or petroleum jelly.

Orthophosphoric acid

Orthophosphoric acid consists of water, ethyl alcohol and the acid itself with a density of 1.7. It is used for soldering stainless materials, copper, and silver. Alcohol-based fluxes must be stored in airtight containers. A convenient container for storage is a nail polish jar, the brush does not react to the active medium, and the lid allows you to tightly close the container, avoiding evaporation of the components.

Tinol soldering pastes for soldering

Among the substances offered, there are solder pastes that are produced with a mixed type of flux. It is used when installing open-frame elements in hard-to-reach places. Application occurs with a special spatula, then heating with an electric tool. The result is a reliable, high-quality connection, which is actively used by novice craftsmen in the absence of appropriate experience.

Tinol pasta

It is possible to prepare an alloy for soldering with your own hands; for this you will need the solder required by the element. Using a medium-grain file, tin for soldering in the form of wire is crushed to the state of metal chips. A flux selected from the above in a liquid state is added to the composition, after which the elements are mixed. The composition must be prepared in a small container, the shelf life is limited to 6 months, after which the metal oxidizes in an acidic environment.

Use of tin-lead group alloys

The soldering process is the joining of several metallized parts together. In this case, the exposure temperature does not exceed the critical threshold at which destruction of parts or circuit boards occurs. The main objectives of using soldering products are to ensure the most even temperature viscosity, at which uniform spreading occurs over the surface.

Tin is used for soldering quite often; the material serves as a component of the largest number of solders. In its pure form, the metal is very expensive and is used for soldering important products and elements. Divided into categories with and without lead.

Lead solders

Various soldering materials are used using lead. The material is fusible, soft and easy to process. Easily dissolves in an alkaline environment and acidic impurities.

Lead solder

Products labeled PIC are considered the most popular in use. The percentage of elements allows you to work with different environments and materials. They differ in temperature and other parameters that are important for a reliable connection. Zinc, bismuth or antimony are added to lead compounds to provide protection against oxidation and other destructive factors.

How to choose solder

The main task for the master is to create a high-quality, reliable fastening that will last for a long time. Solder selection is based on the following parameters:

• Materials that are processed. It is necessary to accurately familiarize yourself with the characteristics of the materials being soldered. There is a temperature threshold for melting fragile elements, transistors, capacitors, etc. Radio amateurs use fusible substances.
• The composition of the solder is selected according to the parameters of thickness and purpose of the product. When soldering wires and other large elements, it is possible to use refractory elements.
• Some cases require choosing the optimal conductivity. The resistance of tin is lower than that of lead; more expensive brands of solder are used on high-frequency boards.

In any situation, it is necessary to be scrupulous about the compliance of soldering parameters and the product. High-quality products are used for soldering, the price is not high, and the choice on the market is huge.

Source: https://stankiexpert.ru/spravochnik/svarka/pripoj-dlya-pajki.html

Hand soldering and tinning technology

This instruction establishes the technology for manual soldering and tinning of electrical and radio products (ERI). The instructions were developed on the basis and development of OST 4G 0.033.200 “Solders and fluxes for soldering”, OST 4GO 054. 267 “Soldering of electrical connections. Typical technological operations."

The instructions apply to workshop workers performing technological operations of manual installation and soldering of electronic components on printed circuit boards.

Safety precautions

Solders, fluxes, and washing liquids used for manual soldering and tinning are generally toxic and irritating substances.

To prevent their exposure, it is necessary to keep the workplace clean and work under local exhaust ventilation at the workplace.

Personal protective equipment is:

robe, knitted gloves with polymer coating of the “Multex” type, protective respirator masks.

Harmful components in tubular and wire solders, fluxes, flushing liquids

Modified rosin (contained in X39, JM-20, Crystal 502 solders)	May cause irritation upon contact with skin and inhalation of soldering fumes.
Lead in solders	At soldering temperatures above 500ºC, lead vapor reaches a high concentration, which can cause nausea, weakness, and convulsions.
Flushing liquid VIGON EFM Flux MF 210 (X33-12i), WF-9942.	May cause irritation upon contact with skin.

I. Technical data:

Soldering is the basis for assembling a printed circuit assembly. Soldering combines two or more metal surfaces into one metallurgical joint.

The soldering process is the application of molten solder to flux-treated surfaces; the flux is applied to wet the soldered surfaces with solder; wetting is required to obtain a metallurgical joint during soldering.

Wettability is defined as the formation of a uniform, smooth, unbroken, non-adhesive film of solder on the base metal.

 Solderability is a property of a metal surface that allows it to be wetted with solder.

The process of soldering a printed circuit assembly involves simultaneously applying heat and solder.

For manual soldering and tinning the following are used:

• flux: pine rosin grade “A” GOST 19113-84, requiring cleaning after soldering;
• alcohol-rosin flux FKSp OST 4G 0.033.200, requiring cleaning;
• flux MF 210 (X33-12i), which does not require cleaning, from Multicore Solders (England);
• flux WF-9942, which does not require cleaning, INDIUM Corporation (USA);
• solder wires of various diameters, brand POS-61;
• tubular solders of various diameters, brand POS-61, with flux that requires cleaning;   
• multi-channel tubular solders of various diameters, brands 60EN X39, 60EN Crystal 502 from Multicore Solders (England), CW-801 from INDIUM Corporation (USA), JM-20 from KOKI (Japan), containing flux that does not require cleaning;   
• alcohol-gasoline washing liquid (a mixture of ethyl alcohol and nefras);
• flushing liquid VIGON EFM from ZESTRON (Germany).

FLUXES

Fluxes are necessary to ensure high quality solder joints.

The purpose of fluxes is to dissolve oxides and sulfides that prevent solder from wetting metal surfaces, protect soldered surfaces from re-oxidation, reduce the surface tension of molten solder at the metal-solder-flux interface, and improve the spreadability of solder. 

When manual soldering, flux must be applied only to the areas to be soldered.

The need to remove flux residues after soldering is indicated in the technological processes.

• Fluxes MF 210 (X33-12i), WF-9942, no-clean, low solids, do not contain halogens (corrosive components), leave virtually no residue after soldering. Transparent flux residues after soldering are compatible with moisture-proof coatings on boards. Fluxes MF 210, WF-9942 have a high ability to penetrate through metallized holes.
• Flux FKSp OST 4G 0.033.200 leaves residues on the board that require washing with an alcohol-gasoline mixture.
• Flux “pine rosin grade “A” in a solid state is used to clean the tips of the fingertips from carbon deposits.     

SOLDER

Solder is a metal alloy used to create mechanical connections between electronic components and printed circuit board pads.

The diameter of the wire or tubular solder should be half the diameter of the soldering iron tip.

Domestic solders brand POS 61 – alloy of tin (61%) and lead (39%),

example notation: 

• PRv KR1 POS 61 GOST 21930-76 – solder wire, round, 1 mm in diameter, tin-lead;
• POS 61T1A GOST 21930-76 – tin-lead solder, tubular, 1 mm in diameter, single-channel, filler – pine rosin grade “A” flux.

Imported tubular solders:

• SN62 X39 – alloy of tin (62%), lead (36%), silver (2%), multi-channel tubular solder f. Multicore Solders (England), contains 1% solid flux X39, which does not require cleaning. The presence of silver in solder increases the mechanical strength of solder joints and prevents the migration of silver from the contact surfaces of electronic components into the solder during the soldering process.
• 60EN X39 – alloy of tin (60%) and lead (40%), multi-channel tubular solder f. Multicore Solders, contains 1% solid flux X39, which does not require cleaning. Analog – JM-20 solder from KOKI (Japan),
• СW-801 - alloy of tin (63%) and lead (37%), multi-channel tubular solder f. Indium (USA), contains 2% CW-801 flux, which does not require cleaning.
• 60EN Crystal 502 - an alloy of tin (60%) and lead (40%), multi-channel tubular solder, contains 3% Crystal solid flux, which does not require cleaning. Used for soldering metals with a high melting point, such as nickel.

Multichannel solders (up to 5 flux channels in a solder rod, see Fig. 1) have an advantage over single-channel ones:      

the increased number of flux channels ensures uniform distribution of flux without gaps along the length of the rod, which prevents the possibility of dry soldering - without flux, as is the case with single-channel solders.

After soldering, the flux in imported solder leaves transparent residues around the soldering area that do not interfere with inspection and are electrically insulating (non-conducting currents).

Rice. 1. Cross-section of a multi-channel solder rod

WASHING LIQUIDS

Flushing liquids are designed to clean solder joints and printed circuit boards from contamination in order to ensure the operational durability of products.

There are three main sources of pollutants:

Printed circuit boards (typical contaminants include:

• fat from processing;
• food residues;
• tobacco;
• epoxy resin;
• fiberglass;
• internal copper contamination).

PCB mounted components (typical contaminants include:

• fat from processing,
• leftover food products,
• tobacco,
• defects in component materials,
• internal contamination of component leads).

Soldering technology used (typical contaminants include:

• flux,
• flux residues
• solder balls,
• internal contamination of the solder,
• fat from processing,
• leftover food products,
• tobacco.

1. The washing liquid “alcohol-gasoline mixture” is used to remove residues of alcohol-rosin flux, mechanical contaminants, dust, grease prints, but does not remove salts released from board coatings, components, or fingerprints. After washing with an alcohol-gasoline mixture, whitish stains remain on the board.

2. VIGON EFM washing liquid (based on alcohol compounds) is used to remove flux residues from the printed circuit assembly during manual cleaning and repair. Effectively removes grease and salt contaminants, solder balls, chemical residues from the etching process in the manufacture of printed circuit boards, flux activators, which, under intense operating conditions of products, can lead to corrosion processes on the board.

3. The washing liquid is applied to the area to be cleaned with a KFK file brush and dried in air. If there is a large amount of flux residue on the board after soldering, you can wash the board by placing a cotton napkin on it and applying washing liquid to the napkin with a brush.  

The need to clean the printed circuit assembly after soldering with flushing liquids is indicated in the technological processes.

PREPARATION FOR WORK

when working with personal soldering irons of the BM type and copper tips of our own factory production (including Solomon soldering irons equipped with copper tips of our own factory production):  

The tip of the pin (tip) can be of different shapes and sizes for the best contact and heat transfer to the soldered surfaces.

The copper tip of the soldering iron must be cleaned of carbon deposits and oxide with rosin: dip the heated tip into solid pine rosin flux and clean it on a calico napkin. If necessary, sharpen the copper tip for an individual soldering iron with a file.

Attention: When sharpening the soldering iron, sharp edges must be dulled.

Before tinning or soldering, the tip must be tinned. For this purpose, use wire or tubular solder: wrap several turns of solder (as shown in Figure 2) around the tip of the tip and heat it until the solder melts.

                                Rice. 2. Maintenance of the soldering iron tip

when working with original soldering irons of PACE, HAKKO, Solomon, Lukey soldering stations using original imported tips:

It is strictly forbidden to strip the original soldering iron tips.

Source: https://gostost.ru/paika-pechatnie-platy/