Buy a bath for etching printed circuit boards. Microbubble bath for etching printed circuit boards. PCB holder

Introduction. I don’t think I’ll be revealing a big secret if I say that the speed and quality of etching printed circuit boards several main factors influence. For example: if the etching process occurs in a ferric chloride solution at room temperature, then it usually lasts from 40 minutes. up to 2.5 hours (depending on the saturation of the solution). If the solution is heated, then the etching process itself can be reduced in time by one and a half times. And in general, ideally, the solution itself should be stirred periodically, in which case the process occurs even faster. These factors directly affect the etching rate. If we talk about the quality of the boards, then this applies primarily to those radio amateurs who transfer the design to the textolite using the “ laser printer and iron.” Despite the fact that the toner adheres to the foil quite firmly, if the etching process is delayed in time, then ferric chloride still gets under the toner. In this case, the tracks turn out to be “porous,” which in turn deteriorates the quality of the board itself and the device as a whole.

Technically, the process of mixing the solution can be carried out in several ways (it all depends on the ingenuity and “sharpening” of the hands), but the most optimal, in my opinion, is the “microbubble bath” method. This is how factory boards are made. The essence of the method is quite simple, but very effective. At the bottom of the ferric chloride tank there is a plastic tube in which holes are punched at regular intervals. The tube is plugged at one end and compressed air is supplied at the other. As a result, air bubbles rising from the bottom of the tank naturally mix the ferric chloride solution, thereby speeding up the etching process. However, there is no provision for heating the solution, but since the etching process occurs quite quickly (5 - 10 minutes), this option, in principle, does not make sense, the solution is simply preheated and poured into the tank already warm. So, with this introduction you can complete and proceed directly to the implementation of your plans.

Storage tank. Naturally, any convenient container can be used as a reservoir for this design, but I came across cuvettes for developing photographs. They look like this:

A tube. You can also use any convenient tube, but it seemed to me the most optimal to use a tube from a regular medical dropper; you can buy it at a pharmacy for only 15 rubles. It is glued using regular Moment Crystal glue. Holes are made with a sewing needle, in increments of approximately 1 cm:

Naturally, on one side the tube is plugged in advance, on the other side a tip from the same dropper is attached for more convenient connection to the air source (more on that a little later):

At this stage, it is still necessary to check the operation of the device itself by simply pouring water into the container. The fact is that everything depends on the pressure of the compressor, and the diameter and pitch of the holes directly dance from it, so you may have to experiment:

Net. Perhaps this point will seem superfluous to some. The fact is that it will talk about a mesh stretched at a distance of about 1.5 centimeters from the bottom of the tank (a gap between the tube and the board blanks is still necessary). It is not at all necessary to make a grid; to ensure the required gap, you can simply insert 4-6 matches into the holes of the boards (preferably into those that are intended for fastening the board in the device) so that they form racks. You can make a grid, again, in several ways. My method is as follows: strips approximately 1.5 centimeters wide and slightly shorter than each side of the tank are cut out of plastic approximately 1 mm thick. The result is two long and two short stripes:

On each strip, cuts are made to half the thickness of the plastic, in increments of one centimeter:

Moreover, they are glued in such a way that the cuts are facing the side of the tank wall, and a thin fishing line passes through this cut:

Then between short ones:

The result should be a net similar to the one stretched on a tennis racket:

Lid. Actually, we could have ended there, but when testing this unit with water, one not entirely pleasant feature became clear. The fact is that a working unit sprays very small drops in different directions. Perhaps for some this will not be a problem, but personally I had a desire to make a lid. According to the dimensions of the cuvette, a blank was cut out of plastic, in which holes were drilled sufficient for ventilation, but not sufficient to pollute the surrounding space:

The cuts on the lid are made because there is a tube coming out on one side and a drain on the other (by the way, it has become much more convenient to drain the solution with the lid closed, and there is less chance of spilling it). The lid is ready, all that remains is to make fasteners for it on the tank. It is not made in a completely standard way: clips are glued onto the cuvette, intended for attaching a coaxial cable:

There are six of them in total...

...two on each side as guides for the lid...

... and two more as a stopper when the lid is completely closed:

Compressor. Now we can talk about the air source. The most common is a plastic bottle with a valve into which air is pumped using a pump. An option with a car camera is also possible. In my case, a regular microcompressor for an aquarium AEN-3 is used as an air source, which has been slightly modified for greater performance:

Actually, the modification boiled down to the most optimal location of the magnet in the field of the coil (whoever has ever disassembled such devices will understand what we are talking about). With these simple manipulations, it was possible to increase the compressor performance by approximately two times, which turned out to be quite enough.

Making printed circuit boards with your own hands using the laser-iron method and using photoresist seems to be becoming a thing of the past. Today, more and more methods are appearing that amaze with their sophistication and genius. For example, with the advent and widespread use of 3D printers, it became possible to use these functional devices in the production of printed circuit boards.

An enthusiast named Arvid has come up with a way to use a 3D printer as a CNC machine. program controlled(CNC) to create PCB tracks. This method very simple and does not require any additional equipment other than the 3D printer itself!

A piece of PCB of the required size is first thoroughly cleaned and then painted over with a regular marker, after which it is placed on the printing platform of a 3D printer, which has an engraver installed instead of a nozzle. This engraver removes paint from areas where the copper on the board needs to be etched. After receiving the drawing, the board is placed in a ferric chloride solution for some time until the finished state is obtained. The G-code for the 3D printer was generated in special program FlatCAM, designed for creating printed circuit boards using CNC machines.

This mechanical etching method is the fastest, cleanest, most productive and economical. effective method creating printed circuit boards for prototyping. The FlatCAM program itself, which greatly facilitates the process, has interesting and useful features. Using it, for example, you can create not only single-sided, but also double-sided boards thanks to the built-in special algorithmic tool. The program's TCL console provides flexibility for users who want to automate work and implement their own functions. FlatCAM's convenient viewer allows you to visualize Gerbers, Drill and G-Code files. This way you will always know how your 3D printer will work to create the required printed circuit board. The program can be useful even when the user has several geometric objects, but wants to get one G-code. In this case, FlatCAM will allow you to combine these geometric objects and generate one job for your improvised CNC machine.

Below is a video of the process of making a printed circuit board using a 3D printer.

I don’t think I’ll be revealing a big secret if I say that the speed and quality of printed circuit board etching are influenced by several main factors. For example: if the etching process occurs in a ferric chloride solution at room temperature, then it usually lasts from 40 minutes. up to 2.5 hours (depending on the saturation of the solution). If the solution is heated, then the etching process itself can be reduced in time by one and a half times. And in general, ideally, the solution itself should be stirred periodically, in which case the process occurs even faster. These factors directly affect the etching rate. If we talk about the quality of the boards, then this applies primarily to those radio amateurs who transfer the design to the textolite using the “laser printer and iron” method. Despite the fact that the toner adheres to the foil quite firmly, if the etching process is delayed in time, then ferric chloride still gets under the toner. In this case, the tracks turn out to be “porous,” which in turn deteriorates the quality of the board itself and the device as a whole.

Technically, the process of mixing the solution can be carried out in several ways (it all depends on the ingenuity and “sharpening” of the hands), but the most optimal, in my opinion, is the “microbubble bath” method. This is how factory boards are made. The essence of the method is quite simple, but very effective. At the bottom of the ferric chloride tank there is a plastic tube in which holes are punched at regular intervals. The tube is plugged at one end and compressed air is supplied at the other. As a result, air bubbles rising from the bottom of the tank naturally mix the ferric chloride solution, thereby speeding up the etching process. However, there is no provision for heating the solution, but since the etching process occurs quite quickly (5 - 10 minutes), this option, in principle, does not make sense, the solution is simply preheated and poured into the tank already warm. So, with this introduction you can complete and proceed directly to the implementation of your plans.

Storage tank. Naturally, any convenient container can be used as a reservoir for this design, but I came across cuvettes for developing photographs. They look like this:

A tube. You can also use any convenient tube, but it seemed to me the most optimal to use a tube from a regular medical dropper; you can buy it at a pharmacy for only 15 rubles. It is glued using regular Moment Crystal glue. Holes are made with a sewing needle, in increments of approximately 1 cm:

Naturally, on one side the tube is plugged in advance, on the other side a tip from the same dropper is attached for more convenient connection to the air source (more on that a little later):

At this stage, it is still necessary to check the operation of the device itself by simply pouring water into the container. The fact is that everything depends on the pressure of the compressor, and the diameter and pitch of the holes directly dance from it, so you may have to experiment:

Net. Perhaps this point will seem superfluous to some. The fact is that it will talk about a mesh stretched at a distance of about 1.5 centimeters from the bottom of the tank (a gap between the tube and the board blanks is still necessary). It is not at all necessary to make a grid; to ensure the required gap, you can simply insert 4-6 matches into the holes of the boards (preferably into those that are intended for fastening the board in the device) so that they form racks. You can make a grid, again, in several ways. My method is as follows: strips approximately 1.5 centimeters wide and slightly shorter than each side of the tank are cut out of plastic approximately 1 mm thick. The result is two long and two short stripes:

On each strip, cuts are made to half the thickness of the plastic, in increments of one centimeter:

Moreover, they are glued in such a way that the cuts are facing the side of the tank wall, and a thin fishing line passes through this cut:

Then between short ones:

The result should be a net similar to the one stretched on a tennis racket:

Lid. Actually, we could have ended there, but when testing this unit with water, one not entirely pleasant feature became clear. The fact is that a working unit sprays very small drops in different directions. Perhaps for some this will not be a problem, but personally I had a desire to make a lid. According to the dimensions of the cuvette, a blank was cut out of plastic, in which holes were drilled sufficient for ventilation, but not sufficient to pollute the surrounding space:

The cuts on the lid are made because there is a tube coming out on one side and a drain on the other (by the way, it has become much more convenient to drain the solution with the lid closed, and there is less chance of spilling it). The lid is ready, all that remains is to make fasteners for it on the tank. It is not made in a completely standard way: clips are glued onto the cuvette, intended for attaching a coaxial cable:

There are six of them in total...

...two on each side as guides for the lid...

... and two more as a stopper when the lid is completely closed:

Compressor. Now we can talk about the air source. The most common is a plastic bottle with a valve into which air is pumped using a pump. An option with a car camera is also possible. In my case, a regular microcompressor for an aquarium AEN-3 is used as an air source, which has been slightly modified for greater performance:

Actually, the modification boiled down to the most optimal location of the magnet in the field of the coil (whoever has ever disassembled such devices will understand what we are talking about). With these simple manipulations, it was possible to increase the compressor performance by approximately two times, which turned out to be quite enough.

This is how, as a result of all the work, a simple unit appeared...

...which, nevertheless, increased the quality and speed of manufactured devices several times.

P.S. Perhaps, to some, much in this design will seem unnecessary, because instead of a mesh you can use matches, instead of a lid - a piece of plywood or an old magazine (just not on radio electronics, this is a matter of principle), and instead of a compressor, your own lungs are quite suitable, that’s all The above will definitely not add comfort during work. However, this is just my purely personal opinion, and if all of the above is useful to someone, then I can say with complete confidence that I fulfilled my goal one hundred percent.

Sincerely, Electronic Affairs Master

A bubble bath for etching printed circuit boards is a fairly common and very convenient device that many radio amateurs know about and use. However, the bubble bath has some disadvantages, the solution of which gave rise to a fundamentally new design of the bath for etching printed circuit boards.

Bubble Bath Mixer:

An educated radio amateur knows that for uniform and high-quality (as well as fast) etching of a printed circuit board, the etching solution must be heated and stirred constantly. Heating the etching solution (ferric chloride, for example) speeds up the reaction, and stirring removes the top layer of oxides (this also contributes to the etching speed) and allows you to obtain a high-quality printed circuit board.

A bubble bath (this is not a bubble bath or a jacuzzi) for etching printed circuit boards can be made quite simply with your own hands; in the classic version, a compressor and other aquarium accessories are used to ensure heating and mixing of the etching solution (ferric chloride, for example). But with the classical organization, despite the convenience and economy, the bubble bath has quite significant disadvantages. For example, over time, the sprayer becomes clogged and the bubbles spread haphazardly, so the solution is mixed unevenly. Thus, after much thought on how to refine it, I came up with a rather original, innovative idea to mix the solution using a mixer. The result exceeded all expectations.

I went the classic route, took pieces of organic glass, pre-marked and cut out all the details of the bubble bath.

Then I took dichloroethane and dissolved the shavings left over from cutting plexiglass in it, thus obtaining a good and reliable glue for plexiglass.

After short, but very painstaking operations, I got the body of a bubble bath with pre-provided inputs for the mixer and heater; I simply glued two necks from an ordinary PET bottle.

Two inlet holes in the top of the bath are needed to install the mixer and heater, you guessed it right, they are also quite easy to make yourself. You can use a heater for an aquarium, but you can read how to make a heater for ferric chloride.

But on the design of the mixer, several important emphasis should be placed. To begin with, you must understand that metal cannot be used, ferric chloride will simply eat it up and won’t say thank you. Therefore, I used an ampoule from a pen as a shaft, and a piston from a medical syringe as the mixer itself. I installed the shaft on a miniature M25E-4L cider motor. I recommend using engines of this type, since it consumes little, spins quickly and is designed for long work. And motors of this type are very compact, the M25E-4L will even fit into a PET bottle cap, so I used two caps as a housing for the motor.

My version of the PCB etching bath is a pleasure to use. The solution is primitive, cheap and easy to reproduce and use. Just screw in the plug with the mixer and the heater, and turn on the device. Due to the fact that there are no bubbles, and therefore no splashes, you will protect your pants from getting stained with ferric chloride, and the solution is mixed quite quickly and efficiently. Plus, my version is quite durable and very repairable.

When the mixer is turned on, mixing of the solution begins due to the vortex flow it creates. Stirring not only removes oxides from the surface of the printed circuit board, but also heats the liquid evenly.

PCB Holder:

In the etching bath, special attention should be paid to the holder for printed circuit boards, because for convenience it will also come in handy. I invented it for this purpose simple design plexiglass clothespins, and secured it in the lid.

An ordinary clothespin as a holder for printed circuit boards was not suitable for me, since it had a steel spring, and this does not work against the aggressive environment of the etching solution. Thus, I built a clothespin by combining two thin strips of plexiglass.

Such a clothespin is not afraid of either ferric chloride or other weak etching solutions, since its metal parts are isolated from the external environment, and it itself is made of plexiglass.

This version of the holder holds the boards quite tightly, they are installed and removed quite quickly and easily.

In short, my version of a bubble bath for etching boards, using a mixer instead of an aquarium compressor, has only one advantage: it’s fast, simple, reliable, convenient, high-quality, and economical.

I make printed circuit boards quite often, so I know a lot of subtleties and nuances, and if you are just going to assemble a bath for etching printed circuit boards, then take my word for it, using a mixer instead of a bubbler is much more practical, and such a holder justifies all the efforts spent on its manufacture.

A couple of years ago I made this bath for etching printed circuit boards. The idea had been in my head for a long time, but everything rested on the vessel, and on the Internet, on the site hardlock.org.ua, I saw the implementation of such a bathtub and the most important thing was that the vessel was glued together with aquarium glass sealant. And there was an excellent thermostat diagram on the website, so you didn’t have to waste time coming up with your own diagram. I ordered a vessel from a person who makes custom aquariums, it cost 200 rubles. I bought the cheapest compressor at an aquarium store for 150 rubles + a tube and all sorts of suction cups for about 100 rubles. The most expensive of all purchases was a heater, I don’t remember exactly, but something like 400-500 rubles. Parts for the thermostat cost about 150 rubles. To make it more stable, I made a stand out of chipboard onto which I attached the vessel and thermostat (see photo). I put everything together, tested it, and was completely delighted. The first board was etched in 3 minutes!!! With a fresh solution of ferric chloride the process is very fast, but with a two-year-old solution it takes about 20 minutes :-). Moreover, in this solution I etched about 30-40 boards of different sizes. And he would have worked some more, but there was already 15mm thick sediment at the bottom. which began to clog the air outlet tube. I decided to replace the solution and take a photo at the same time.

Thermostat, housing from baby nipples :)

There is no air atomizer in the photo because I made a homemade one from a plastic tube in which I drilled a dozen holes with a diameter of 1 mm, but due to deposits it became clogged and I threw it away, I will make a new one. Something like this...Can you tell me how to make a lid that is comfortable?