Soldering SMD components with a regular soldering iron. Soldering SMD components at home. Checking the quality of work

SMD components are small electronic components that are mounted on a surface. printed circuit board. "SMD" (in transcription "SMD") is an abbreviation of the phrase from in English“Surface Mounted Device”, which translates as “surface-mounted device”.

Another meaning of the word “surface” is that soldering is not carried out traditional way, when component leads are inserted into a hole on a printed circuit board and soldered to conductive tracks on the reverse side. SMD components are mounted on front side, where all the tracks are located. This type of landing is called surface mounting.

SMD components, thanks to the use latest technologies, have small size and mass. Any small element, functionally containing dozens or even hundreds of resistors, capacitors and transistors, will be several times smaller than an ordinary semiconductor diode.

Thanks to this, electronic devices made from surface-mount components are very compact and lightweight.

The small size of SMD components does not create conditions for the occurrence of induced currents in the elements themselves. They are too small for this enclosure and do not affect performance characteristics. As a result, devices assembled on such parts work better without creating interference or reacting to interference from other devices.

SMD components can be placed very close to each other on the board. Modern parts are so small that most space began to be occupied by conductive paths, rather than radio components. This prompted manufacturers to make circuit boards multilayer. They are like a sandwich of several boards, only the contacts from all the tracks are brought to the surface of the topmost one. These contacts are called mounting pads. Such multilayer boards very compact. They are used in the manufacture mobile phones, smartphones, tablet computers. The details on them are so small that they can often be seen only under a microscope.

Soldering technology

As mentioned above, SMD components are soldered directly onto the surface of the mounting pads. Very often, the leads of the parts are not even visible after installation. Therefore, using a traditional soldering iron is not possible.

Soldering of SMD components is carried out in one of several ways:

heating the entire board in an oven;
using an infrared soldering iron;
using a hot air soldering iron or hair dryer.

When devices using SMD components are manufactured using industrial methods, special automatic robots are used. In this case, the mounting spots are already pre-applied with solder in an amount sufficient for installation. In other cases, during preparation, solder paste for SMD components is applied over a stencil. The robot manipulator places the parts in place and securely fixes them. After this, the boards with installed SMD components are sent to the oven.

The temperature in the furnace is gradually increased to a certain value at which the solder melts. For the material from which boards and radio components are made, this temperature is not dangerous. After all the solder has melted, the temperature is reduced. The reduction is carried out smoothly according to a specific program determined by the thermal profile. It is with this cooling, and not with sudden cooling, that the soldering will be the most durable.

Preparing the board at home

To successfully solder SMD components in a home workshop, you will need an infrared soldering iron or hot air station. Before soldering, you must prepare the board. To do this, you need to clean it and tin the spots. If the board is new and has never been used anywhere, you can clean it with a regular eraser. After this, it is necessary to degrease the surface by applying flux. If it is old, and there are dirt and remnants of the previous solder on it, you can prepare it using fine-grained sandpaper, also degreasing it after cleaning with flux.

Soldering SMD components with a regular soldering iron is not very convenient due to the small size of the contact pads. But if not soldering station, then you can also use a soldering iron with a thin tip, working with it carefully, picking up solder onto the heated tip and quickly touching the contact.

Applying paste

To properly solder microcircuits, it is better to use solder paste rather than solder. To do this, the element must be placed on the board and fixed. Tools used include tweezers, plastic clamps, and small clamps. When the leads of the SMD component are exactly on the mounting spots, solder paste is applied to them. To do this, you can use a toothpick, a thin brush or a medical syringe.

You can apply the composition without worrying that it also covers the surface of the board around the mounting spots. During heating, surface tension forces will collect it into drops and localize it in places of future contacts of the SMD component with the tracks.

Warming up

After application, it is necessary to warm up the installation area. infrared soldering iron or hairdryer (temperature approximately 250 °C). The soldering compound should melt and spread over the contacts of the mounted component and the patch. The power of the hair dryer must be adjusted so that it does not blow drops of solder paste off the board. If the characteristics of the device used for soldering allow, the temperature should be reduced gradually. It is not allowed to accelerate cooling by blowing air onto the contacts of SMD components.

The same technology is used to solder LEDs in case of replacing burnt-out elements in a lamp or, for example, in instrument lighting. The only difference is that during soldering the board must be heated from the side opposite to the one on which the components are installed.

Types of solder pastes

Solder paste is the best remedy for automated soldering of SMD components. It is a viscous, low-flowing flux substance that contains tiny particles of solder in suspension.

To be able to use it successfully, the paste must meet certain requirements:

should not oxidize and separate into components;
must have a certain viscosity, that is, be liquid enough to melt when heated, and at the same time thick enough not to spread over the entire board;
should not leave dirt and slag at the soldering site;
The paste should be washed well with ordinary solvents.

Based on the method of use, the compositions are divided into cleaning and non-cleaning. As the name suggests, any traces of cleaning paste must be removed from the soldering area after completion, otherwise the components included in its composition may have an aggressive effect on the traces and leads of the parts. No-clean compounds can remain after soldering, as they are completely neutral to the materials of boards and SMD components.

In turn, cleaning agents can be water-soluble and halogen-containing. Water-soluble cleaning compounds can be washed off boards with deionized water.

Sometimes cleaning pastes contain halogens. They are added to the composition to improve performance properties. Halogen-containing pastes can be used for high-speed printing or, conversely, where a very long setting time is required. The introduction of halogens also improves soldering properties. Halogen-containing pastes are washed off with solvents.

Making your own soldering paste

There are many brands and types of solder pastes on sale that meet all the conditions and requirements necessary for high-quality installation.

At home, you can make such a composition, having a rod on hand brazing solder, soldering oil and flux.

The solder must be ground into a very fine fraction. This can be done with a file or emery. The resulting dust from the tin-lead rod must be collected in small capacity and mechanically mix with solder fat. If solder fat is not on hand, you can use any liquid flux, and use regular Vaseline as a binder and thickener.

The consistency of the paste can be determined by eye, roughly calculating the proportions. Ready composition can be kept in a small plastic container with a tight-fitting lid. It’s even better to load it into a regular medical syringe with a thick needle.

If you squeeze out the paste in measured doses onto the future soldering site, using such paste will be very convenient, and the result will be durable and reliable.

Sometimes it happens that you urgently need to solder an SMD element, but you don’t have it at hand special tools. Just a regular soldering iron, solder and rosin. In this case, solder miniature SMD element difficult, but possible if you know certain features of such soldering.

It is impossible to make the sting not tremble

Not a single person is capable of making an instrument (any one - not only soldering iron) did not tremble in my hands. Once upon a time I read about masters who paint miniature paintings or murals. The technology they use in their work was described there. Its essence is that it is necessary to coordinate the movements of the hand with the beats of the heart. This actually happens from heartbeats inevitable trembling of hands.

There is no need to fight trembling - it is useless. You need to learn to adapt to it.

Bird's beak technique

When a bird builds a nest, by inserting another branch, it makes short and multiple movements beak. Even if it is necessary to correct a twig that has already been inserted into the nest, the bird performs each action by making several small and precise movements. In truth, these movements are not always accurate, but in total they still give the desired result.

The main mistake of many beginners is what they try to do when soldering long and continuous movement. It's useless. The secret is that you need to make short movements (ideally they are coordinated with the heartbeats, but you don’t need to specially concentrate on this - over time it should work out by itself).

Soldering an SMD element in three stages

The main difficulty in soldering SMD elements with a conventional soldering iron is that hold the part with tweezers.

Those. At the very beginning of soldering, the main attention should be concentrated on the strength of the hand holding the tweezers. It is also important here to choose correct angle review to clearly see how smoothly the part fits into place.

It wouldn't hurt to know one thing little secret.
At the very beginning, the detail is only slightly " grab"No need to try to solder it on the first side right away! Good soldering requires transferring attention to the soldering process itself - concentration on the tweezers is lost...

Thus, first we only grab the part from one end.
Having grabbed the part, we get rid of the tweezers, and solder the second side of the part. And only then do we return to the final soldering of the first side.

Do not forget that the areas for the element on the board must be smooth. If there was solder there, you need to carefully remove the excess before soldering, otherwise the part will remain “skewed” after soldering.

So, when the part is stuck, it is no longer possible to move it (unless you overheat or apply noticeably great effort). This allows you to take a break from holding it and concentrate on soldering from the other end, then return to the first one.
Thus, soldering occurs in three stages:

"Sticking" of the part
Soldering the end opposite to the “stuck” one
Return to soldering the “stuck” end

All the tools used are simple and crude, including a homemade brush made from fishing line (with which I wash the soldering area alcohol). Rosin - ordinary, "pebble". Soldering iron - 25 watt.
BY THE WAY! Most best soldering iron for “delicate” parts, the one on which the rosin “smoke”, but does not have time to boil completely on the tip for about 7 seconds. If the rosin boils away within 2-3 seconds, then the soldering iron tip is too high temperature and may damage the SMD element.

The soldering was not done perfectly, but I wanted the most ordinary one to be captured. acceptable soldering, even with some minor blemishes (touching the adjacent pad, dripping of excess rosin), which was facilitated by the camera, due to which it was necessary to hold the tools almost outstretched arms. Nevertheless, this soldering is normal and the essence of the technique was demonstrated here.
I recommend expanding the video to full screen and setting the quality to "Full HD" in the video settings.

Installation and soldering SMD elements at home - nowadays assembly is becoming increasingly popular electronic devices specifically on SMD components intended for installation on the surface of the board. This installation technology is due to the most dense arrangement of parts, and in terms of economics it is a technologically cheap production. On the Internet you can find many articles devoted to methods of mounting such electronic components, but each radio amateur has his own ways of working with SMD parts, and in my article I want to share my skills in carrying out surface mounting of electronic parts with both beginning radio amateurs and those godfathers have never had the opportunity to work with SMD.

Attention! All pictures are clickable.

Required tools and materials

A little about the tools and materials that will be required during the work process. You must have good tweezers, a needle (you can use a syringe), to apply flux you will need a syringe with a thick needle, wire cutters, low-melting solder, and since the parts themselves are miniature and difficult to work with with the naked eye, you will also need a magnifying glass. And ideally, it wouldn’t be a bad idea to have a device such as a head loupe, for example this brand: MG81001-3LED - this is a magnifying glass with a set of three-dimensional lenses and a built-in LED backlight. And another mandatory material must be a liquid flux, for example F-3 or one prepared independently from pure rosin powder and alcohol, but it is still recommended to use fluxes industrial production, there is a huge selection of them on sale.

IN living conditions It is preferable to solder SMD parts with hot air; there are special soldering stations for this, and instead of a regular soldering iron, electric hair dryer. Such equipment is now on sale in large quantities, and if made in China, then the prices are low. Here in the photo is shown such a Chinese device, the name is difficult to pronounce, but this station has been working for about three years and so far without failure.

Naturally, you will not need a large soldering iron with a thin tip, where would you be without it? The advantage here is given to the set of “Microwave” soldering tips, manufactured using technology by the German company Ersa with 80 years of experience. The set contains tips of various shapes and purposes; the more common design is a tip with an internal recess, in which a dosed amount of solder accumulates and is convenient when working with parts of a dense layout, and also reduces the likelihood of sticking between closely spaced pins of microcircuits. Be sure to purchase a set of replacement soldering tips, which will make soldering much easier for you. If you have not yet acquired such tips, you can solder with an ordinary thin conical tip.

Installation on factory conveyors SMD parts produced by the method of application to the board special paste, then, with the help of robots, the components are placed in their installation positions, thereby sticking to the solder paste and sent along a conveyor to a thermal oven. In the oven, the boards are heated to a given temperature. During the heating process, the flux from the solder paste evaporates, and the solder melts and forms a reliable contact connection between the part and the printed circuit board.

Based on factory technologies, you can try to reproduce these works in a home workshop. I think it won’t be difficult to purchase solder paste now, since it is available in a wide range in electronics stores and radio markets. To apply the paste to the board in measured quantities, you need to use a thin syringe needle. I think the most suitable option the syringe itself will be used, into which the paste is drawn, and then squeezed onto the contact pads of the board. The photo shows how not to do it, that is, it is squeezed out too much a large number of pastes, especially on the left side of the board.

Nevertheless, we continue to work on installing components. We place the parts on the platforms with the applied paste, on this moment These are capacitors and resistors. At this stage of the layout, there is no way to do without tweezers, and the tweezers should preferably have curved ends; for example, this is more convenient for me to use.

For one-time installation of parts, you can, of course, do without tweezers, say, take a toothpick and lubricate its tip with some kind of sticky substance, maybe the same flux, then it is quite possible to install the component on the site. Here it’s just someone how to adapt.

After completing the assembly of the parts and installing them in their intended places, the heating process with hot air begins. Low-melting solder begins to melt at a temperature of +178°C, and the value of the hot air temperature must be set by the regulator on the soldering station within +250°C, then placing the tip of the hair dryer at a distance of approximately 100 mm, begin to carefully heat the board while gradually bringing the nozzle of the hair dryer closer to the board. You need to be more careful with hot pressure air flow, in cases of strong pressure, there is a high probability of blowing away all the parts from the board. Just as in industrial production, in a heating furnace the flux evaporates when heated, and the solder changes its color as it melts, and gradually turns from dark to light and shiny. The picture below shows exactly the moment of its melting.

After the solder has finished melting, the nozzle of the hair dryer must be slowly moved away from the surface of the printed circuit board, thereby allowing it to cool. The photo shows what happened in the end. Research has shown that large drops of solder at the ends of the parts indicate that there is excess paste in these places, and where there is little solder, it means there was not enough paste.

It may happen that there is no solder paste in your region or it is too expensive for you, that is, there is an option for soldering without using paste. This method will be shown in the photo, and the microcircuit will serve as an example. First, you need to cover all the sites where the components will be installed with a thick layer of solder, that is, apply tinning.

The photographs should show that the contact pads are covered with solder so that they form a kind of bump. Here is one of important conditions is to uniformly apply solder to all areas, that is, the tubercles should be the same in height. After you have tinning, drop a little flux from a syringe onto the installation sites of the elements and wait a bit until it thickens. In this state, SMD parts will stick to the flux more easily. With special care, using tweezers, install the microcircuit in the designated place. Aligning the pins of the microcircuit with the pads on the board is a matter of principle.

Near the microcircuit I placed a number of passive elements, ceramic and polar capacitors. To avoid parts falling out from the board under the influence of a hot stream of air from a hair dryer, we begin to heat the board as already written above, with some distance between the hair dryer nozzle and the surface of the parts. The main thing is not to rush to warm up, do not carefully move the air stream and small parts everyone will fly away.

Here's a look at what happened as a result of these actions. The picture shows that the containers are soldered, as they should be, but several legs of the microcircuit, marked in red, are not soldered. This defect can be caused by several reasons, such as not enough solder on the pads or not enough flux was applied. This can be corrected with an ordinary soldering iron with a thin conical tip. You need to again add a little flux to the pad and solder it with added solder. To prevent such defects, you should always use a magnifying glass.

For those radio amateurs who do not have a soldering station, you can get by, as mentioned above, a simple soldering iron. Below, the pictures show examples of soldering resistors and two microcircuits using a soldering iron. The first example would be a resistor. We install a resistor on previously prepared contact pads, that is, with solder and flux already applied to them. To prevent it from shifting during soldering, it must be pressed with an awl or needle.

Next, a brief touch of the soldering iron tip to the part output on the pad is enough and the component will be immediately soldered. Try not to apply too much solder with the soldering iron tip, otherwise the excess may cause solder to leak into adjacent pins or tracks.

Here is the result of soldering the resistor

The quality certainly leaves much to be desired, but it is reliable. The decrease in soldering quality occurs due to the inconvenience of simultaneously soldering, pressing the resistor and taking a photo, that is, the problem is the absence of a “third hand”.

Rest electronic components soldered in a similar way. As for me, first I solder the base of a powerful transistor to the contact pad, but I don’t skimp on solder. Parts of the solder must flow under the semiconductor body, which will create additional reliable electrical and thermal contact.

So that there is no doubt about the reliability of soldering, when you start soldering the part, move the transistor body with the needle, it should slide a little, this proves that the solder under the body has completely melted, and the excess will be squeezed out, thereby improving thermal contact. The picture shows an already sealed stabilizer chip.

After soldering one leg, you need to once again check the accuracy of the installation of the microcircuit and the coincidence of its legs with the pads, and then solder the remaining pins along the edges.

Now the chip is securely fastened on four sides. Using caution, we solder the remaining legs, while being careful not to make solder bridges between the pins of the microcircuit.

At this stage of the work, a “microwave” soldering iron tip will be very helpful; it was mentioned at the beginning of the article. Using this tip, you can easily solder chip assemblies with big amount enough conclusions the easy way, just move the tip of the soldering iron along the legs of the microcircuit. There are very few jumpers between pins, and soldering a chip with more than fifty pins on one side takes about a minute. This is such an amazing sting. Well, if you don’t have one, then do the job with a simple conical tip, but very carefully.

If such an unpleasant moment occurs as soldering several pins of a microcircuit together, and removing these jumpers with just one soldering iron is always problematic.

Then you can remove them using a piece of braid taken from the shielded wire. The braid must be placed in a container with flux so that it is saturated, and then applied to problem area with a flow of solder and a soldering iron, heat the solder through this braid.

All excess solder will be absorbed into the braid, and the pad and gap between the pins of the chip will remain clean and free from unnecessary sticking.

At the end of the article, we can only hope that this post was at least a little useful to you. And the quality of the photographs did not irritate you, since the photographs were taken simultaneously with soldering. Good luck to everyone in your electronic affairs!

High-quality soldering of the surface of microcircuit boards is ensured by special components, where solder paste for SMD plays a significant role. According to the generally accepted classification, the industry uses several subtypes of materials used for effective connection, in particular:

Washing group.
No-wash group.
Soluble based on aqueous liquid.
Halogen-containing.
Halogen-free.

What is SMD and basic principles

The use of flux for soldering SMD components has its own characteristics, which make it possible to improve the connection of the surface of microcircuits and boards. General recommendation When using flux for soldering, SMD is effective for chip resistors, as well as SOIC, LQFP, QFN and others. The application of the thinnest layer of material allows for production soldering without compromising quality. By the way, verbatim from English meaning SMD soldering paste, translated as “using components for surface soldering” (Surface Mounted Devices). As can be seen from the working name of the paste, it allows for sufficient assembly density of the connection compared to conventional technologies.

Most craftsmen mistakenly believe that using SMD components is impractical at home. Most craftsmen believe that only TN technology can be needed at home, although the main problem is choosing the correct diameter of the soldering iron tip. Inexperienced craftsmen really do not know the intricacies of using SMD soldering with solder paste, since the result of the work is “splattering” of tin on the SMD contacts of the printed circuit board. To avoid typical mistakes, some parameters should be taken into account: capillary effect, which must have a fine structure, as well as surface tension and proper wetting of the surface being treated. Ignoring the tasks at hand will not be able to fully answer the difficult question of which flux is best for soldering SMDs at home or on an industrial scale.

High-quality contact with the legs of the microcircuit of the board with SMD components occurs for one simple reason, the effect begins to be exerted by the general tension force, which forms separate independent drops of tin formation on the surface of the board.”

As can be seen from general description, the actions of the master are minimized and the flux for soldering SMD components only heats the legs of the used parts of the micro-parts. Remember, when working with very small components and parts, seizing (unexpected connection) of technological elements to the tip of a working hot soldering iron may occur, which negatively affects further work microcircuits.

Features of technology in factory conditions

For industrial production, the paste for soldering SMD components is adapted to a group system where electronic system applying flux to the surface of the microcircuit. Fine application technology using silk-screen printing is used on the surface of contact working areas. Thus, in its technology and consistency, the material somewhat reminds us of the familiar toothpaste. The substance includes solder powder, as well as flux components. The entire substance is mixed and applied to the surface of the microcircuit using a conveyor method.

An automated system carefully turns over the boards that need to be soldered, then the microcircuits are moved to a temperature cabinet, where the mass spreads, followed by solder. In the oven, under the influence of the required temperature, a conditional flow occurs around the technological contact legs of the SMD components, and as a result, a fairly strong connection is obtained. After temperature cabinet the chip is moved again to natural environment where cooling occurs.

Is it possible to solder with SMD paste yourself?

Theoretically, yes, but in practice, quite a lot of experience is needed to carry out this technological operation. For work we will need the following tools and preparations:

Special soldering iron with a thin tip for SMD components.
Tool side cutters.
Industrial tweezers.
An awl or a special thin needle.
Solder material.
A magnifying glass or a magnifying glass (you will need to constantly monitor the thin legs of the SMD components).
Flux with neutral no-clean properties (additional preparation).
A syringe with which we will apply flux.
If there is no no-clean preparation, we use alcohol infusion and rosin.
Soldering gun of medium load and power.

Flux should always be in liquid state, thus, you completely disinfect the surface of the microcircuit. In addition, the drug removes the formation of oxides on the surface of the board during operation. Remember that an alcohol solution together with rosin cannot ensure the quality of soldering, and their use is only permissible if a suitable soldering compound is not available.

Soldering iron selection

To work, you need to select a special soldering iron that has an adjustable heating range. To work with the microcircuit, a soldering iron is suitable, which has an operating heating temperature of no more than +250...+300 C. If you do not have such a soldering iron at hand, you can use a device with a power of 20 to 30 W and no more than 12-36 Volts.

A soldering iron with a voltage of 220 Volts will not be able to ensure the quality of soldering, where it is very difficult to regulate the required heating temperature of the flux.

We do not recommend using a soldering iron with a cone-type tip; this will lead to damage to the surface being processed. The most optimal tip is the “microwave” type. A soldering iron with a voltage of 220 Volts not only heats up quickly, but also leads to volatilization of components during the soldering process. For efficient work soldering iron, we recommend using the thinnest wire to ensure interaction between the tip, flux and solder.

We place the SMD components on a special contact working platform.
We apply the liquid preparation to the legs of the involved components very carefully.
Under the influence of operating temperature, flux and solder spread over the contact pad.
We give the necessary time so that the contacts and the preparation on the surface of the board can cool.

But, for a microcircuit, the soldering procedure is slightly different from the above:

We produce SMD installation-contacts to precisely identified contact points.
We moisten the joints with flux.
For high-quality solder, make reliable contact on one side, then solder the other leg.
We solder the other working components very carefully, and do not forget to remove formations with the soldering iron tip.

In some cases, it is possible to use a special soldering gun for soldering, but for this it is necessary to create appropriate working conditions. Remember that the hair dryer can only be heated to a temperature of +250 C, no more (in rare cases, up to +300 C).

Video: how to make flux for soldering SMD with your own hands

All the best! This rating contains the best soldering fluxes and is compiled from personal preferences and reviews from electronics repairers. Many readers will now think: “Well, finally! Master Soldering has started to write at least something about soldering!” and they will be right - for almost 4 years not a single decent article has been written on the blog about the soldering process, although the name of the blog seems to oblige. I admit, I repent, I will correct the situation.

I plan to publish reviews of soldering processes, soldering tools, soldering videos and new technologies in the world of soldering. And today I will give my rating of the 10 best fluxes for soldering. This rating was compiled based on personal preferences and all sorts of reviews from familiar electronics repair technicians of various levels and does not pretend to be exclusive. Let's go - soldering fluxes.

Rating of the most popular soldering fluxes

What should we know about flux?

The flux is designed to improve the quality of the process of soldering two metal surfaces and when heated, cleans surfaces from oxide and greasy films. A good flux should have low temperature melting and small specific gravity. Before the solder melts, it must have time to dissolve the oxides and not penetrate deep into solder joint during the soldering process. The flux should spread well and wet the surface of the solder and metal at the soldering site.

In fifth place is the most popular gumboil of all time, the muse of musicians, gift of nature, Her Majesty rosin. Rosin can be gum (from the resin of coniferous trees, has almost no fatty acids), extraction (extraction of pine sawdust with gasoline, contains more fatty acids than gum) and tall (residues after sulfatocellulose soap production).

In fourth place is the beloved alcohol-rosin flux SKF or FKSp (alcohol-rosin soldering flux). It consists of 60-80% alcohol and 20-40% rosin. This mixture can be prepared at home with your own hands. For example, many people simply crumble rosin into alcohol in a ratio of about 1 to 3. It is convenient to use in a syringe with a needle. But when stored in a loosely closed syringe, the needle begins to dry out and stops flowing.

Advantages:

An affordable and popular inactive flux, easy to apply, does not smoke much.

Flaws:

When heated, the alcohol begins to evaporate violently and hiss.

What to solder: copper wires, gold-plated and silver-plated contacts of microcircuits and radioelements, brass, zinc.

What to wash off with: alcohol, solvents, gasoline, alcohol-gasoline mixture.

So we have come to the Top 3 best fluxes for soldering. In the prize places I have placed professional fluxes, which in ordinary life may not be useful. But in crafts they are very necessary.

Fluxes Amtech RMA-223 and Kingbo RMA-218

The third bronze place goes to Amtech RMA-223 - it is gel flux– a mixture of crushed rosin and solvent.

I also suspect there may be activators and fragrance in the composition. – most main feature fakes– on the sticker there is an inscription in small print “Coliformia” instead of “California”, however, strangely enough, the Chinese counterfeit flux is very good in use, and many services rely only on it. Although the masters from mysku do not recommend using this flux, but it is better to take an analogue.

Advantages:

it’s convenient to apply the gel, good solderability, no need to wash it, the fake is cheap (about 200 rubles), but it solders quite well and smells of perfume.

Expensive (a 10 g tube can cost 1,500 rubles), smelly, there are fakes. The price is a limiting factor, for example, a 30 g tube can cost from 2,000 rubles.

What to solder: mainly responsible lead-free and lead soldering.

What to wash off with: Most do not need to be washed off, alcohol, solvent, there is a branded solvent T2005M.

With this, I consider the Top 10 best fluxes for soldering complete. Of course, there are a lot of other fluxes, including good Chinese and top German and Japanese ones. But I haven’t used them, so I can’t adequately talk about them.

If you, dear readers, use any other flux and consider it the best in the world, then be sure to write to me about it in the comments. Perhaps it will appear in the rankings after testing.

Master Soldering tried his best for you.