And so you decided to plunge headlong into electronics, stocked up on a soldering iron, bought solder and... What next? If worst comes to worst, everyone knows how to solder, but not many people know the subtleties of the technology and come with experience. Well, I’ll speed up this disastrous process and tell you a couple of tricks.
So, you’ve probably already read about it, so we’ll dance from it. In addition to a soldering iron, you will need solder and flux. Read more about them.
Solder.
This is a special alloy that melts at a temperature of about 200 degrees. The most common is 60/40 Alloy, also known as POS-61. An alloy containing 60% tin and 40% lead. Its melting point is 183-230 degrees. Typically sold as wire wound on spools.
For small installations, it is better to take one with a smaller wire diameter - it is easier to dose. I have two coils, one with 0.3 mm solder wire, the second 0.6 mm. Well, I also have one and a half millimeter, but I hardly use it. Only if I massively solder massive parts that require a lot of solder.
It’s better to buy imported solder; unfortunately, the Russian product pretty much sucks. There may be high-quality ones, but usually I came across low-grade slag. A coil of solder, as in the picture, should cost from 150-200 rubles, more expensive is possible, cheaper is not advisable. It’s better to spend money once, but then have beautiful and high-quality soldering and not worry about it. A reel usually lasts for a year and a half or two, which is at least.
It’s also useful to buy yourself some Rose alloy. This is also a kind of solder, but its melting point is completely ridiculous - somewhere around 90-100 degrees. This alloy is sometimes useful for dismantling, but this will be discussed in a separate article later.
Fluxes
During the soldering process, the heat causes the parts to oxidize and the solder stops wetting them. To prevent this from happening, fluxes are used - substances that dissolve the oxide film and promote soldering. By the way, if anyone doesn’t know, the process of coating one metal with another is called tinning. Am I saying banal things? Well, this is an educational program! :)
Rosin
The simplest and most popular flux. This is ordinary purified pine resin. When soldering, first take a little solder onto the tip, then poke it into the rosin to get resin onto the tip, and then quickly solder before the resin evaporates. The method is not very convenient, so they often do it differently. Take ordinary ethyl (medicinal) alcohol and dissolve crushed rosin in it until it dissolves. Afterwards, this solution is applied with a brush to the parts to be soldered and soldered. The activity of rosin is not high, so sometimes nothing works out - the details are not tinned, but rosin has one huge advantage, which sometimes overcomes all its shortcomings. Rosin is absolutely passive. That is, it does not need to be removed from the soldering site, since it does not oxidize or reduce metals, while being an excellent dielectric. This is why I try to make the most critical solderings with alcohol-rosin flux.
One of my favorite fluxes. It is a red liquid that contains rosin and a number of additives. Solder it in the same way as regular alcohol-rosin flux - spread it on the parts with a brush and solder. But there is one trick. In the original version, it is a liquid infection, smeared thin layer and dries out instantly, in general it is not very convenient to use. I figured out how to overcome this.
I made myself a palette of fluxes - I glued a bunch of bottle caps onto a small batch, poured different fluxes into them and glued this thing onto a coil of solder. It turned out very convenient and compact. So, after pouring it into the cap, I let it sit for a couple of days. During this time, it will dry out and thicken to the state of liquid honey. Now it’s convenient to spread it with a sharp toothpick exactly where you need it. And if it thickens too much, then either I’ll drop a little alcohol in there, or I’ll add a little more fresh flux and stir it. The manufacturer claims that there is no need to rinse off. In principle, this seems to be the case, he is not active. But the additives in it confuse me, so I always wash it off. It is washed off with a wide brush dipped in alcohol. Or just use a brush under running tap water. There is nothing wrong with washing the finished board with water, the main thing is to dry it well afterwards.
Rosin-gel
Great stuff. It appeared in radio stores not long ago and has already earned my love and respect. It is a thick brown paste based on rosin, sold in syringes. It spreads perfectly directly where it is needed and does not leave residue on the soldering iron, like LTI-120. Easily washed off with water or alcohol, in general, rulez!
Killer active flux, which is easily washed off with water, does not leave dirty sticky marks or oxides. But it needs to be washed off. Rinse thoroughly. Otherwise, in a couple of years it can corrode the board tracks or its remains will become conductive and terrible leaks will occur along the surface of the board between the tracks, which will have an extremely negative impact on the operation of the circuit. I'm also not sure about the safety of its vapors. You can use it once or twice, but I don’t like using it all the time. But overall, this is an awesome flux, and it’s a pleasure to solder with it.
Glycerin-Salicylic flux.
He is FSGL. Honestly, I have no idea where this crap even comes from. I’ve had a jar of this flux since childhood (which is actually why I almost never soldered with rosin) - my dad stole it from a defense plant. I have never seen it on sale for free. It burns as vigorously as Glycerin-hydrazine, but does not contain any impurities that are questionable from a toxic point of view. It contains 90% glycerin, 5% salicylic acid, 5% water. Should I buy some salicylic acid at the pharmacy and apply it myself? This is such a crazy recipe. One drawback - you need to wash it off, it is active. But it washes off easily with water.
F-34A
Hell of an acid mixture. When soldered, it produces a terrible, caustic exhaust that poisoned half of our laboratory. You can solder this crap only in a gas mask and with a powerful hood, but this crap solders everything, something that other fluxes could never even dream of. This slurry prevents ingress - rust, oxides, steel, coatings, even aluminum can be soldered. So if you have to solder to a rusty nail, then drop this crap, hold your breath and LOOP!
Imported no-clean fluxes.
To be honest, I haven't used them. They say they are cool, but IMHO it’s not rational to solder them just like that - they are too expensive, and they don’t sell them in our city, but it’s a shame for me to order them. Rather they are for professional use, like repairing cell phones or soldering BGA cases (this is when the legs are in the form of an array of balls under the microcircuit body). If you are interested, look for information on cell phone repair forums, they know everything about this matter.
Hemp-based Dutch flux
I have no idea who makes it or where they sell it, but I know for sure that it exists! I was especially convinced of this after poking around in the product diagrams of the company where I previously worked. The developers are clearly sold on them. Since I have never seen such stoned circuit solutions.
Soldering iron in hand and go!!!
I told you about fluxes, now, actually, about the soldering process.
This is not a tricky thing. To begin with, it is advisable to tin the parts. You moisten them with flux, pick up a little bit of solder with the soldering iron tip and spread it over the surface. There is no need to rush; the parts should be covered with an even, thin, shiny layer. There is no need to tin the leads of microcircuits and radio components - they are already tinned at the factory.
The solder should be liquid, like water. If it is lumpy, with pronounced graininess and matte, then there are two reasons - wrong temperature soldering iron, or solder shoddy shit. If the soldering iron is too cold, the solder will be on the verge of being hard and liquid state, will be viscous and will not wet. If the soldering iron is overheated, the solder will instantly become covered with a gray film of oxide and will also tin tin disgustingly. Ideal temperature soldering iron when soldering with POS-40 solder ( 60/40 Alloy), in my opinion, this is about 240-300 degrees. U ST-96 It is enough to set the regulator 2/3 in the direction of increase.
If you solder a printed circuit board, then the tracks also need to be tinned. But this must be done carefully. Textolite that is sold in the vastness of the Motherland often also turns out to be rare shit and when heated, the foil falls off instantly. Therefore, you cannot heat the board for a long time - the tracks will fall off. Usually I just thoroughly lubricate all the tracks with flux and quickly run a flat soldering iron tip with a drop of solder over each one. As a result, I have perfectly tinned tracks with an almost mirror-like surface.
Eat folk way for fast tinning of large boards:
Take a braid to remove solder, this is a copper sponge, sold in rolls of 30 rubles per meter. If you don’t find it, you can pick out the braided shielding from a thick television coaxial cable - the same crap, just more fuss. The board is properly lubricated with flux, the braid is properly impregnated with solder and is also poured with flux. Then this crap is messed around with a soldering iron on the surface of the board. To prevent the braid fibers from sticking to the tracks, it is better to take a larger and more massive soldering iron.
This is how I completely improved the method.
I took an old powerful 60W soldering iron, wrapped the tip in this braid, impregnated it with Rose alloy and now puddle the board in one motion. Why Rose? And it’s easier for them to tinker; when the soldering iron touches the board it cools down sharply, because... gives off heat. If the braid is moistened with ordinary solder, then it is immediately welded with separate fibers to the board, and the Rose alloy is lightweight and does not stick.
Soldering transistors, diodes and microcircuits.
Here I would like to draw special attention. The fact is that semiconductors from too high temperature are destroyed, so there is a risk of burning the microcircuit due to overheating. To prevent this from happening, it is advisable to set up a soldering iron at 230 degrees or so. This is a completely tolerable temperature that the microcircuit can withstand for quite a long time. You can solder and take your time. For conventional, non-adjustable soldering irons, the tip temperature is about 350-400 degrees, so you need to solder quickly, in one touch. No longer than a second on each leg and take at least a 10-15 second break before starting to solder the other leg. You can also hold the leg with metal tweezers - it will serve as a heat sink.
Soldering wires
It is better to tin the ends separately before soldering, and if the wire is soldered to a printed circuit board, then it is very advisable to drill a hole in the board, lead it on the other side and only then solder. In this case, the risk of tearing off the droshky when tugging on the wire is reduced to zero.
Soldering with solder wire.
This is how microcircuits are usually soldered. They grab it diagonally by the outer legs, lubricate everything with flux, and then, holding a soldering iron with one hand and a thin wire of solder with the other, quickly solder all the legs.
Soldering wires in varnish insulation
Every winding wire, like those that are wound around a transformer, is covered with a thin layer of varnish. To solder to it, this layer of varnish needs to be peeled off. How to do it? If the wire is thick, you can burn it a little with the fire of a lighter, the varnish will burn, and the carbon deposits can be cleaned off with rough cardboard. If the wire is thin, then either carefully scrape it with a scalpel, holding the scalpel strictly perpendicular to the wire, or take an aspirin tablet and firmly press and rub the hot tip of the soldering iron along the wire on the aspirin. When heated, the aspirin will release a substance that will eat the varnish insulation and clean the wire. It will really stink :)
Third hand
I recommend getting a grip like this. A damn convenient thing, it allows you to hold some Cthulhu while soldering, the ends do not dangle from side to side. By the way, beware of spring-loaded conductors! When soldering, it can jump off and throw a drop of solder in your face, I can’t remember how many times this has flown into my face, but it could have even hit my eye! So follow safety precautions!
Sponge
The soldering iron tip gradually becomes dirty and becomes covered with soot. This is normal, usually the flux is to blame, the same LTI-120 burns, God forbid. You can use a special sponge to clean the soldering iron. This yellow stuff comes with soldering iron stands. It must be moistened with water and squeezed out, leaving it damp. By the way, the sponge dries constantly, so that it doesn’t get wet every time; you can soak it in regular medical glycerin. Then it won't dry out at all! Damn convenient! If you don’t have a sponge, then take a cotton cloth, put it in an iron tray and also soak it in water or glycerin. Our installers kept the usual waffle towel and they wiped the soldering iron on it.
By the way, about safety precautions.
- First, arrange everything so that it is convenient.
- Keep an eye on power cords. The soldering iron is very loves to burn out his own wire. He's just manic. And this is fraught with the risk of repairing the wire at best, and at worst short circuit and fire.
- Do not leave the soldering iron turned on, even for a short time. Rule " Left - turned off"must be carried out strictly.
- Rule two - the soldering iron must be either in your hand or on its reliable stand. And no other way! Under no circumstances should you put it on the table or on the first thing that comes along on the table. The cord will drag him away in a moment.
- Don't forget about hood and ventilation. If you solder, then at least open the window, ventilate the room, or better yet, put a fan (at least 80mm from the computer) or an extractor hood on the table.
It's better to see once than to read a hundred times:
No problem! At your service are a bunch of videos from You Tube for the request “solder”. You'll see how the professionals do it. Watch and learn!
Many people can solder wires and radio components, but not everyone can solder metal. In this article I will outline the principle of metal soldering as briefly as possible and with examples.
Introduction
Let's start with a general understanding of soldering. Soldering is a physical and chemical process of obtaining a connection as a result of the interaction of solder and the metal being soldered. It is similar to fusion welding, but there are still differences between them. When welding at the seam, the parts being welded melt, but when soldering, the material being soldered does not melt. Also, unlike welding, soldering is carried out at temperatures below the melting point of the metal being soldered. The formation of a seam during soldering occurs by filling the gap between the parts being connected with solder, i.e. the process occurs due to wetting and capillary effect.
The question arises, why use soldering if welding holds parts together better. This has its advantages:
- Soldering is more accessible than welding.
- When soldering, the connections become detachable.
- Small parts cannot be welded.
Soldering is a fairly strong connection if you follow the technology.
Equipment
To solder metal, the following basic equipment is required:
♦ Soldering iron . The power depends on the size of the parts being soldered. For soldering small parts (tin, wire, bolts), a 60-watt soldering iron will do; for larger ones, 100 watts or more. I use 2 soldering irons - 65 and 100 W, which is quite enough for home use.
I will not dwell in detail on how to tin a soldering iron; there are separate articles about this on the Internet. I'll just say the main thing:
- When you turn on the soldering iron for the first time, you need to let it burn - put it on the street and wait until it stops stinking and smoking.
— The tin should evenly cover the tip. When heated, the tip will burn out, it will need to be sharpened and re-tinned.
♦ Soldering acid and solder . A wooden stick is used to apply the acid.
♦ Accessories . These include a file and emery, which are necessary for cleaning the soldering iron and parts.
The soldering iron also needs a stand. The simplest thing that can be used as a stand is any metal object, from which the soldering iron will not roll off.
Various tools, such as vices and pliers, are used to hold the parts to be soldered. The parts can also be secured with nails on the board.
Soldering Basics
Let's now figure out which metals are easy to solder:
- Silver
- Brass
- Nickel
- Iron
- Stainless steel
The remaining metals are soldered using special fluxes and other technology. This topic will not be addressed in this article.
We've sorted out the metals, now let's start studying the soldering process:
- We clean the place where the seam will be located. For this I use .
- We degrease the joint using acetone, gasoline, etc.
- Apply to the seam with a wooden stick soldering acid. We do this as smoothly as possible, because... In the future, solder will spread exactly over this area.
- Remove oxides (if any) from a pre-tinned soldering iron and touch the solder stick with it. The solder should lie on the tip in an even drop. If this does not happen, then the soldering iron is poorly tinned.
- We touch the place of adhesion with the sting. You cannot expect that soldering will occur at the first touch of the soldering iron. To do this, it is necessary to heat the surfaces to be soldered to the melting temperature of the solder. The heat from the soldering iron is not immediately transferred to the place to be soldered. Tin, wires and other thin parts warm up quite quickly, but not instantly. It takes a relatively long time to heat up thick materials.
- To solder thin parts, you need to move the soldering iron quite slowly, moving it further when the solder spreads and floods the seam. When soldering thick objects, you have to hold the soldering iron in one place for a relatively long time and wait until the surfaces to be soldered warm up and the solder spreads along the seam.
- After holding the soldering iron for a certain distance, move it a little back, then forward again and back again, until the solder flows out in an even and clean path. As the solder is used up, it is collected from the stick. You should not collect a lot of solder, especially if the surfaces to be soldered are evenly and tightly connected; Excess solder will cause sagging.
- After soldering is completed, it is necessary to wash off the remaining acid with water. If the acid is difficult to wash off, use soap. Unwashed acid will lead to oxidation of the metal.
It is best to learn soldering on tinplate. It does not need to be cleaned, but it must be degreased. In the presence of fat, the acid does not wet the surface of the tin. Below are examples of soldering wires and sheet metal. You can repeat all this for training.
Soldering tin/sheet metal
“Butt-to-end” connection
Quality: Low strength
"Lapped" connection
Quality: Durable
Connection "Into the castle"
Quality: Very durable
Soldering wire
“Butt-to-end” connection
Quality: Low strength
"Lapped" connection
Quality: Durable
“Amplified” connection
Quality: Very durable
For reinforcement, copper wire is used on the left connection, wound turn to turn; on the right, the rod and thread are wrapped in a strip of tin:
Let's say you need to solder aluminum. Not everyone knows that rosin only uses copper and its alloys. Other soldering needs to be done using special fluxes, acids, and solders. Even steel lends itself to this science, if you approach it wisely. Let's look at how to solder correctly with a soldering iron.
Process characteristics
Inside the soldering iron there is a heating element of a certain power, placed in an insulating jacket made of ceramic or other heat-resistant material. This is necessary so that all the heat goes inside where the tip is located. The main difference between soldering irons is power and shape. Depending on this, the master decides what exactly needs to be used.
They often work as a tool in electronics. In the case under consideration, it is important not to exceed the power dissipation of relatively fragile resistors, microcircuits, and capacitors. If this happens, the work is redone. With the difference that you will have to buy the damaged element in the store. Therefore, it is important to learn how to solder correctly.
It is difficult to say how much power will be required in a particular case. Radio amateurs focus on size.
Soldering iron power
First, the power of the soldering iron is assessed. It is clear that getting a 100 W unit into the motherboard is simply dangerous. It makes more sense to purchase a 20 or 50 W soldering iron. Please note that not all soldering irons are powered by 220 V. There are many examples of non-compliance with the rule. The manufacturer is guided by simple logic: a low-power soldering iron requires a twisted spiral, which introduces large losses at a frequency of 50 Hz. It makes more sense to switch to direct current. In such a case, inductance no longer plays a big role. If you turn on a low-power soldering iron for direct current(far right in the photo) to the network alternating current 220 V, the product will burn. But the Chinese produce small soldering irons (second from left). The one shown in the photo shows a power of 40 W and is powered from a standard outlet. Finally, by default, 100 W soldering irons were produced in the USSR (far left). How to determine power and supply voltage? This is the main difficulty: often the soldering iron does not carry distinguishable symbols. If you take Chinese, there is a red and white sticker on it (see photo) with information, and for a device with a wooden handle, the power is indicated on the plug. Protective cover A 100-watt soldering iron is marked accordingly. GOST is indicated there; information can be gleaned from the documentation. A powerful 100 W soldering iron allows you to work with rough and large parts, indispensable for hard solders.
Section of the sting
The size of the tip (metal rod for soldering) often plays a role. For example, a 100-watt soldering iron has a solid thick copper stick. If you need to solder something thinner, the tip is changed. For the soldering iron in question, it is simply pulled out, and where to buy a spare one is the second question. For example, stings are sold in special stores for radio amateurs and can cost a decent amount. A Chinese 40 W soldering iron with an excellent tip cost 40 rubles (FixPrice), and a tip of this kind can cost 300 rubles separately. The fastening system is different. For example, with a DC soldering iron it is unscrewed, but with a Chinese soldering iron it is held on with screws (like a device with a wooden handle). The material may vary. Bulky tips of 100-watt soldering irons are usually copper, while modest and miniature ones are made from an alloy of non-ferrous and ferrous metals. But both options allow you to work with all solders that can be melted.
Before work, the soldering iron tip is cleaned of waste materials and oxide film with a file or needle file. It is clear that this is not the only way. For example, for such purposes it is allowed to use dissimilar fluxes. It's time for readers to learn how a part is prepared for soldering.
How the surfaces of the part and the tips are prepared for the soldering process using fluxes
The surface of any metal (with rare exceptions) is covered with an oxide film. As a result, the solder simply does not adhere. A group of substances whose purpose is to remove the oxide film from the surface are called fluxes. They come in solid and liquid forms, and are also sold mixed with solder in the form of pastes. The first category includes rosin and a number of other substances. Liquid fluxes are often acids or salt solutions. The basis is alcohol and other liquids.
It is important to understand that it is used for different cases special composition. The only difference is the price, which you should try to save on. When exposed to high temperatures and rosin, the oxide layer is removed from the surface of the copper wire and the varnish insulation, if any, is dissolved (this is typical for transformer windings). At the same time, the flux improves the wettability of the surface. Due to this, the solder spreads easily, and then sticks and hardens. An elastic, resilient and durable contact is formed. Therefore, soldering is used not only by radio amateurs, but also by representatives of other professions. Including car repairs.
For various types surfaces, a specific flux is sold. For example, steel is etched with hydrochloric acid; zinc chloride is often used. It should be understood that after the soldering process the surface is cleaned, otherwise its destruction will continue. They get rid of flux residues with brushes, emery, and often wash the area affected by acids with a weak solution (5%) of soda, and then with hot and cold water.
Pay attention to wettability: to solder aluminum, it is not enough to clean upper layer file. This gives almost no result, since the solder does not spread over the surface. Wetability is poor. After treatment with acid, the balance of power changes radically. As for steel, special acids have been created for it (see photo). They also solder cast iron, cutting the edges for solder. First, the surface is treated with flux, then tinned. Then gradually the entire volume is filled flush with the surrounding surface.
The solution is often confused ammonia with ammonia. The first is ammonium hydroxide (10% solution), and the second is chloride. Solder the wires to both pure form impossible, but they are used for the manufacture of various fluxes. For example, diluting ammonia with water produces hydrochloric acid. Here, amateurs are already inventing their own recipes, many of which can be read in the public domain. It is also recommended to solder aluminum with a soldering iron using an aspirin tablet.
What is solder, types of solders
Solder is a mixture of metals. Main task: obtaining maximum strength and electrical conductivity at minimum costs. More often you have to work with tin-lead solders, but zinc solders are also used for soldering aluminum. The melting point of the latter is higher, and this is one of the criteria by which it is customary to differentiate:
- Particularly fusible - melting point below 145 degrees Celsius.
- Low-melting - the melting point is above 145 degrees Celsius, but below 450.
- Medium melting - melting point above 450 degrees Celsius, but below 1100.
- High-melting - melting point above 1100 degrees Celsius, but below 1850.
- Refractory solders have a melting point above 1850 degrees Celsius.
You have to use a torch already in the upper part of the third group: the melting point is too high for a soldering iron to handle. Let us add that the electrical conductivity of tin is higher than that of lead, for this reason compositions with a high metal content are more expensive for soldiers. But this is not the only reason. When tinning pots, it is important to maintain conditions that are harmless to humans. It is clear that lead is out of the question in the case under consideration.
The percentage of more expensive metals usually appears in the brand name. For example, in PIC (tin-lead solder) this is possible 10, 60 or 90%. The composition often includes antimony. Its percentage usually appears after a dash, for example, POSS 40-0.5. Antimony is added, like many other impurities, to improve the quality of the solder. In particular, it reduces the oxidation of the melt, which leads to high-quality appearance, and there is no need to protect the joint with varnish. Antimony increases the heat resistance of the compound to temperatures above 100 degrees Celsius.
In Europe, a ban on lead-containing solders is currently being introduced. They are replaced with silver ones, although the melting point increases. And the cost increases, of course. But you shouldn’t think that a high price means indispensable quality. Tin is expensive, but Scott's expedition to South Pole died due to the tin plague in 1912. Already at a temperature of four degrees Celsius, negative changes are possible, but with a decrease the process worsens. Imagine what happens to pure tin in the cold.
No one can explain the plague process in detail. It is believed that the tin must be infected, and then the solder seams will crumble. Scott's expedition took barrels of fuel, soldered with the purest metal. Studies have been conducted and it has been found that adding a small percentage of lead blocks the development of plague. Even POS 90 is not afraid of frost, but it is expensive, and in technology POS 40 and lower are often used, despite its relatively low electrical conductivity.
In addition to those listed, copper solders are used in places. Their melting point is relatively high, requiring the use of a burner. In such a case, flux is usually poured onto the surface (liquid is used less often) for cleaning. Then it all depends on the nature of the task. For example, to solder a cable tip, the first one is clamped in a vice with the bulb facing up, and solder crumbs are poured inside. All this is heated by a burner. Then the cable is inserted inside, and the outer insulation is melted. It is recommended to cool the place forcibly, for example by blowing.
Soldering process
Before starting work, prepare a soldering iron. First, the sting is cleaned. Dense carbon deposits are removed by chipping with a sharp tool. The photo shows a soldering iron, part of the tip has been cleaned with a file. It can be seen that from long-term use the surface has become uneven and bumpy. This interferes with the soldering process.
Light carbon deposits are removed after heating. For this, the same acids and rosin are used. The task is to expose the sting. Often, under the influence of fluxes, a thick crust falls off and is difficult to grind off.
The insulation of electrical wires is stripped to the required distance. Then the core is treated with rosin melt or acid. This is done with a soldering iron and in many cases will require good hood. For example, formic acid vapor is often used in industry, but this substance poses a great danger to humans. Before using a chemical to solder copper electrical wires, carefully search the Internet to see what is said about the safety of such actions. The nature of the influence of formic acid becomes creepy.
If you solder electrical wires correctly, then already in the process of removing the oxide film you can see how solder creeps along the surface. We can see this especially clearly on the reverse side. printed circuit boards. The tracks should be covered with a thin layer of solder. Those who think it will take a long time to worry needlessly worry. Literally, you need to bypass the installation with smoking rosin in one fell swoop, and then pick up solder, and it will spread on its own over the surface. A typical power supply takes just minutes. Etch the board in copper sulfate longer.
We believe that readers have already realized that soldering aluminum with tin is possible only after removing the oxide film.
One of the most reliable methods of connecting wires and parts is soldering. How to solder correctly with a soldering iron, how to prepare a soldering iron for work, how to get reliable connection- more on all this later.
In everyday life, “ordinary” electric soldering irons are used. There are those that operate from 220 V, there are from 380 V, there are from 12 V. The latter are characterized by low power. They are used mainly in enterprises in areas with increased danger. They can also be used for domestic purposes, but they heat up slowly, and the power is not enough...
You need to choose the one that fits comfortably in your hand
Power selection
The power of the soldering iron is selected depending on the nature of the work:
In a household, it is enough to have two soldering irons - one low-power one - 40-60 W, and one “medium” one - about 100 W. With their help, it will be possible to cover about 85-95% of needs. But it is still better to entrust the soldering of thick-walled parts to a professional - this requires specific experience.
Preparing for work
When the soldering iron is plugged in for the first time, it often starts to smoke. It's burning out lubricants that were used in the production process. When the smoke stops coming out, turn off the soldering iron and wait until it cools down. Next you need to sharpen the tip.
Sharpening the tip
Next, you need to prepare the tip for work. It is a cylindrical rod made of copper alloy. It is fixed using a clamping screw, which is located at the very end of the heat chamber. In more expensive models the tip may be slightly sharpened, but basically there is no sharpening.
We will change the very tip of the sting. You can use a hammer (flatten the copper as you need), a file or emery (just grind off the unnecessary). The shape of the tip is chosen depending on the intended type of work. It can be:
- Flatten it into a spatula (like a screwdriver) or make it flat on one side (angled sharpening). This type of sharpening is needed if massive parts will be soldered. This sharpening increases the contact surface and improves heat transfer.
- You can grind the edge of the tip into a sharp cone (pyramid) if you plan to work with small details (thin wires, electrical parts). This makes it easier to control the degree of heating.
- The same cone, but not so sharp, is suitable for working with conductors of larger diameter.
Sharpening with a “spatula” is considered more universal. If it is formed with a hammer, the copper will be compacted and the tip will need to be adjusted less often. The width of the “shovel” can be made larger or smaller by trimming it on the sides with a file or emery. With this type of sharpening you can work with thin and medium-sized parts to be soldered (rotate the tip to the desired position).
Soldering iron tinning
If the soldering iron tip does not have a protective coating, it must be tinned - covered with a thin layer of tin. This will protect it from corrosion and rapid wear. This is done the first time you turn on the instrument, when the smoke has ceased to be emitted.
The first method of tinning a soldering iron tip:
- bring to operating temperature;
- touch the rosin;
- melt the solder and rub it along the entire tip (you can use a wooden sliver).
Second way. Moisten a rag with a solution of zinc chloride and rub the heated tip on the rag. Melt the solder and rub it with a piece of table rock salt over the entire surface of the tip. In any case, the copper should be covered with a thin layer of tin.
Soldering technology
Almost everyone now uses electric soldering irons. Those whose work involves soldering prefer to have a soldering station, “hobbyists” prefer to make do with ordinary soldering irons without regulators. Having several soldering irons of different power is enough for different types of work.
To figure out how to solder correctly with a soldering iron, you need to have a good understanding of the process in general, then delve into the nuances. So let's start with brief description sequences of actions.
Soldering involves a sequence of repeated actions. We will talk about soldering wires or radio parts. These are the ones you encounter more often on the farm. The actions are:
This completes the soldering. It is necessary to cool the solder and check the quality of the connection. If everything is done correctly, the soldering area will have a bright shine. If the solder appears dull and porous, this is a sign of insufficient temperature during soldering. The soldering itself is called “cold” and does not provide the required electrical contact. It is easily destroyed - just pull the wires in different sides or even pick something up. The soldering area may also be charred - this is a sign of the opposite error - too high a temperature. In the case of wires, this is often accompanied by melting of the insulation. However, electrical parameters are normal. But, if the conductors are soldered when installing the wiring, it is better to redo it.
Preparation for soldering
First, let's talk about how to properly solder wires with a soldering iron. First you need to remove the insulation. The length of the exposed area can be different - if you are going to solder wiring - power wires, expose 10-15 cm. If you need to solder low-current conductors (the same headphones, for example), the length of the exposed area is small - 7-10 mm.
After removing the insulation, the wires must be inspected. If there is varnish or oxide film on them, it must be removed. Freshly stripped wires usually do not have an oxide film, and sometimes varnish is present (copper is not red in color, but brownish). Oxide film and varnish can be removed in several ways:
- Mechanically. Use fine grit sandpaper. It is used to process the exposed part of the wire. This can be done with single-core wires of fairly large diameter. Process sandpaper thin wiring is inconvenient. Stranded ones can generally be cut off.
- Chemical method. Oxides are highly soluble in alcohol and solvents. Lakovoe protective covering can be removed with acetylsalicylic acid (regular pharmacy aspirin). The wire is placed on the tablet and heated with a soldering iron. Acid will corrode the varnish.
In the case of varnished (enameled) wires, you can do without stripping - you need to use a special flux, which is called “Flux for soldering enamel wires”. It itself destroys the protective coating during soldering. Just so that it does not subsequently begin to destroy the conductors, it must be removed after soldering is completed (with a damp cloth or sponge).
If you need to solder a wire to some metal surface(for example, a ground wire to a loop), the preparation process does not change much. The area to which the wire will be soldered must be cleaned to bare metal. First, all contaminants (including paint, rust, etc.) are mechanically removed, after which the surface is degreased using alcohol or a solvent. Next you can solder.
Fluxing or tinning
When soldering, the main thing is to ensure good contact soldered parts. To do this, before starting soldering, the parts to be joined must be tinned or treated with flux. These two processes are interchangeable. Their main purpose is to improve the quality of the connection and facilitate the process itself.
Tinning
To process the wires you will need a well-heated soldering iron, a piece of rosin, a small amount of solder.
We take the stripped wire, lay it on rosin, and heat it with a soldering iron. While warming up, we turn the conductor. When the wire is completely covered in molten rosin, put a little solder on the soldering iron tip (just touch it with the tip). Then we remove the wire from the rosin and run the tip of the tip along the exposed conductor.
Tinning wires is a mandatory step when soldering
In this case, the solder covers the metal with a thin film. If it is copper, it turns from yellow to silver. The wire also needs to be turned a little, and the tip must be moved up/down. If the conductor is well prepared, it becomes completely silver, without gaps or yellow paths.
Flux treatment
Here everything is both simpler and more complicated. Easier in the sense that you only need the composition and a brush. Dip the brush into the flux and apply a thin layer of the compound to the soldering area. All. This is simplicity.
Difficulty in choosing flux. There are many varieties of this composition and you need to select your own for each type of work. Since we are now talking about how to properly solder wires or electronic components (boards) with a soldering iron, we will give several examples of good fluxes for this type of work:
For soldering electronic components (printed circuit boards), do not use active (acid) fluxes. Better - water or alcohol based. Acidic ones have good electrical conductivity, which can disrupt the operation of the device. They are also very chemically active and can cause destruction of insulation and corrosion of metals. Due to their activity, they prepare metals very well for soldering, so they are used if it is necessary to solder a wire to metal (the pad itself is processed). The most common representative is “Soldering Acid”.
Preheating and temperature selection
If you want to know how to solder correctly with a soldering iron, you need to learn how to determine whether the soldering area is hot enough. If you use a regular soldering iron, you can navigate by the behavior of rosin or flux. At a sufficient level of heating, they actively boil, release steam, but do not burn. If you lift the tip, drops of boiling rosin remain on the tip of the tip.
Using soldering station based on the following rules:
That is, at the station we set it 60-120°C higher than the melting temperature of the solder. As you can see, the temperature gap is large. How to choose? Depends on the thermal conductivity of the metals being soldered. The better it removes heat, the higher the temperature should be.
Soldering
When the soldering area is hot enough, you can add solder. It is introduced in two ways - molten, in the form of a drop on the soldering iron tip, or in solid form (solder wire) directly into the soldering zone. The first method is used if the soldering area is small, the second - for large areas.
If you need to add a small amount of solder, touch it with the soldering iron tip. There is enough solder if the tip turns white and not yellow. If a drop hangs, this is too much, it must be removed. You can tap the edge of the stand a couple of times. Then they immediately return to the soldering zone, running the tip along the soldering area.
In the second case, we insert the solder wire directly into the soldering zone. When heated, it begins to melt, spreading and filling the voids between the wires, taking the place of evaporating flux or rosin. In this case, you need to remove the solder in time - its excess also does not have a very good effect on the quality of soldering. In the case of soldering wires this is not so critical, but when soldering electronic elements on boards is very important.
In order for the soldering to be of high quality, everything must be done carefully: strip the wires, warm up the soldering area. But overheating is also undesirable, as is too much solder. This is where you need measure and experience, and you can gain it by repeating all the steps a certain number of times.
Device for more convenient soldering - third hand
How to learn to solder with a soldering iron
To begin, take several pieces of single-core wire of small diameter (you can use installation wires, those used in communications, etc.) - they are easier to work with. Cut them into small pieces and practice on them. Try to solder the two wires together first. By the way, after tinning or fluxing, it is better to twist them together. This will increase the contact area and make it easier to hold the wires in place.
When soldering is reliable several times, you can increase the number of wires. They will also need to be twisted, but you will have to use pliers (two wires can be twisted by hand).
Normal soldering means:
After you have mastered soldering several wires (three...five), you can try stranded wires. The difficulty lies in stripping and tinning. You can only clear it chemical method, and tin, having previously twisted the wires. Then you can try to twist the tinned conductors, but this is quite difficult. You will have to hold them with tweezers.
When this is mastered, you can train on wires of a larger cross-section - 1.5 mm or 2.5 mm. These are the wires that are used when laying wiring in an apartment or house. Here you can train on them. Everyone too, but working with them is more difficult.
After soldering is completed
If the wires were treated with acid fluxes, after the solder has cooled, its remains must be washed off. For this they use damp cloth or a sponge. They are soaked in the solution detergent or soap, then remove moisture and dry.
You know how to solder correctly with a soldering iron, now you need to acquire practical skills.
Everyone knows what a soldering iron is and what it is needed for, but not everyone knows how to use it. And this tool is very useful not only in the television workshop, but also in the home. With its help, you can qualitatively restore a broken cable, repair power tools, household appliances and much more. However, you need to be able to operate a soldering iron, and you also need to be able to choose the right consumables.
If we are not talking about soldering microcircuits and high-voltage equipment, then the process itself does not present any difficulty. Most household tasks can be performed independently, without turning to a specialist.
Soldering iron device
An electric soldering iron must have a heater. The heater can be nichrome or ceramic. Ceramic heaters are good in their own way, but they are quite demanding in terms of operating conditions. Therefore for household Electric soldering irons with a spiral heater (EPSN) are best suited. These are quite unpretentious and, importantly, inexpensive devices.
The working part of the soldering iron is the tip. The heater brings it to a high temperature, allowing it to melt the tin solder used for soldering. The body of the soldering iron usually has a screw that secures the tip and with which you can adjust its protrusion. The soldering iron handle has an extension or a separate apron, which prevents your hand from even accidentally slipping onto the heated part.
IN last years compact gas soldering irons appeared, which immediately competed with electric soldering irons. They are refilled with purified butane, exactly the same as that used to refill lighters. Soldering with a gas soldering iron occurs due to exposure to the open flame of a miniature nozzle. The flame temperature can be adjusted within 750-1200°C. On one refill, the soldering iron can work for 60-90 minutes, depending on the setting. This tool can completely replace a 150 W electric soldering iron. For household needs it is more than enough, unless, of course, we are talking about soldering pipes or pans.
Soldering iron selection
First of all, you need to determine for what purpose the soldering iron is purchased. For the home, they usually take a device that can be used to solder cables, wires, repair equipment plugs, etc. A 25 W device is suitable for these purposes. More powerful devices are used when soldering massive parts, and this is an industrial application. At the same time, you should not buy too low-power soldering irons of 5-15 W. They are designed for soldering microcircuits and thin equipment, for example for repairing mobile phones.
When purchasing a soldering iron for your home, pay attention to its incoming voltage. It is necessary that this is a device operating from 220 V, and not from 12 or 24.... It is advisable that the soldering iron have a European plug. Modern houses are increasingly equipped with grounding, which in this case will eliminate electrical injury in the event of a breakdown on the housing.
If the tip in the soldering iron is removed, it means that it can be replaced if necessary. It’s very easy to find out - soldering irons with a replaceable tip have a fixation bolt (bolts) on the body. The bolt allows you to adjust the length of the extension, which in turn affects the temperature of the open part.
The tips are copper and nickel plated. The latter do not burn, so they require virtually no maintenance. However, they are somewhat more expensive. Red copper tips need to be cleaned of solder from time to time and filed with a file. There are no difficulties in these operations - you take a file and with its help the tip is given the required shape. It is advisable to do this with the tip removed and clamped in a vice.
As for the shape of soldering irons, in addition to the classic “hand-held” shape, you can find so-called “guns” on sale. The only difference between them is the shape of the handle. There are also pistol-type soldering irons with a transformer that heat up quickly, but they already belong to professional-class devices. Many experts believe that classic shape A soldering iron is more convenient to use.
Soldering consumables
Solder. Connecting parts by soldering involves the use of solder - an alloy of tin and lead. The soldering process can be compared to hot gluing. The glue in this case is solder.
The proportions of tin and lead in solders may vary. Manufacturers apply markings where the number indicates the percentage of tin, for example POS-61 - tin-lead solder, in which the tin content is 61%. Solder made from such an alloy will melt at a temperature of 180°C. This is much lower than the melting point of copper or aluminum, which are most often soldered.
Changes in the ratio of lead and tin are also reflected in the melting temperature of the solder. For example, if the tin in the solder is 40%, then the melting point of such an alloy will be 240°C, and if the tin is 90%, then the alloy begins to melt only at 310°C.
The marking of imported solders differs from domestic ones. To understand what kind of alloy is in front of you, you need to look at the accompanying documents or look for a decoding of the markings on the Internet. However, for household soldering, the solder alloy is not particularly important. The most refractory solder melts at 300°C, which is also lower than the t(pl.) of copper or aluminum. But it is easiest to work with low-melting solders, so preference should be given to balanced solders, where tin and lead are approximately equal.
It is most convenient to use solder in the form of a wire with a diameter of 1-3 mm. There are solders on sale in the form of a tube filled with flux. This kind of solder is not for everyone; Many experts prefer simple wire solder, which leaves the opportunity to more accurately dose solder and flux.
Flux necessary for protection metal parts from thermal oxidation. The copper tip of a soldering iron quickly oxidizes, resulting in the formation of a non-metallic film on it, to which solder does not adhere well. Flux removes oxide film and promotes uniform distribution of solder. Processing parts and contacts with flux is called tinning.
There are two types of fluxes - acidic and non-acidic. Acid fluxes are most often used when soldering iron alloys (cast iron, steel). After working with acid flux, it is necessary to remove its residues so that the acid does not corrode the metal. You need to work with acid fluxes very carefully, because... acid easily corrodes skin.
The most common non-acid flux is rosin - purified pine sulfur. For most household tasks, rosin is sufficient. High-quality rosin is transparent and amber in color; it does not stain the tip so quickly and does not smoke much. You may also want to keep phosphoric acid on hand for cases where oxidation is significant.
Soldering technology
When we need to solder one part to another, solder a contact or ends of wires, our task is to secure the solder with solder.
- Good contact and soldering strength depend on the quality of the work. The parts to be soldered must be well cleaned, degreased and heated.
- If soldering electric wire or any other electrical parts, you must ensure that they are not live.
- It is best to perform soldering under kitchen hood so that the rosin smoke is immediately removed from the room.
- It is very important not to overheat the parts being soldered. They themselves are unlikely to melt from a soldering iron, but plastic (for example, wire insulation) may suffer from high temperature. Therefore, the time of exposure to high temperature on parts should be minimal. It is advisable to perform soldering in one go.
- The parts connected by soldering must be tinned - treated with flux and solder. Tinned wires stop bending, so they are twisted without tinning and only then soldered.
- When splicing cables or wires, the ends are stripped of insulation, the wire itself is mechanically stripped and treated with flux using a soldering iron. To effectively insulate soldered wires it is necessary to first put cambrics made of heat-shrinkable polymer on them. After this, the ends of the wire are twisted together and fixed with solder, which should eventually cover the entire contact part.
- The joint is covered with a heat-shrinkable casing, which, after heating, envelops the joint and reliably isolates it from contact with other wires.
- It is convenient to feed solder wire to the soldering site, rather than picking up tin with a tip. But since a person has only two hands, solder can be applied only if the parts are securely fixed. Do not try to solder overhead - you will only waste your time and nerves. It is better to first secure the parts to be soldered with a clamp, and only then solder them.
That's actually all the technology is. As you can see, it is simple. The main thing is to observe several simple rules and understand what is being done for what and in what order.
