The quality of any homemade electronic device very much depends on how well it was made (yes, it’s a useful phrase, it’s already clear! Well, yes... But I have to start somewhere?). The printed circuit board plays a big role in this (if you don’t have one that can be done with extensive installation). The more complex the device, the more complex the printed circuit board design, and the better quality it must be made. About one of the ways DIY PCB making the speech will go.
There are several ways making printed circuit boards at home. When I was just starting to master the manufacture of printed circuit boards (this was back when I was studying to become an electronics engineer at school), I painted the paths with nail polish (the printed circuit boards turned out to be very brutal), then I switched to a waterproof marker (the boards already looked much better). But only when I switched to laser ironing technology(LOOT) (and this happened relatively recently) I finally started making printed circuit boards that are pleasing to the eye. My hobby is to design and manufacture various electronic gadgets. Is it really interesting to solder something on a scary printed circuit board? But, after some time, I was no longer satisfied with this technology. Despite the advantages of LUT as a technology for manufacturing printed circuit boards, and there are quite a lot of them::
Using laser-iron technology, it was even possible to apply inscriptions, which is what I did in some cases.
But LUT gave an accuracy of no more than 0.3 mm. This is the practical ceiling. I tried to make the tracks thinner, and it worked, although at the same time the percentage of defects increased significantly. In general, I have already drawn out the preface to the article, so let’s move on to the solder mask itself.
FSR8000— two-component composition sensitive to ultraviolet radiation. Has three states.
1. "Raw State". After the two components have been mixed. In this form, it can be washed off with either acetone or a solution of soda ash.
2) "Hardened State".
2a) Not exposed to ultraviolet light. Dissolves with acetone and soda ash solution.
2b) After exposure to ultraviolet light, the mask becomes resistant to soda ash solution, but can still be washed off with acetone.
3) "Baked state". It is obtained after heating to 160 degrees, followed by exposure for several tens of minutes. It is not soluble in acetone and has great mechanical resistance.
In simple terms: a mask is a protective layer that can often be seen on factory-made printed circuit boards. Very often green. This article will discuss the non-standard use of this mask as a photoresist.
To do this, you need to use the first two states, i.e. Using illumination and subsequent development, obtain a pattern of conductors on the PCB. And after etching, wash off this pattern with acetone.
Then the mask can be used for its intended purpose, covering the area of the entire board with a mask, except for the contact pads intended for sealing parts. Then transfer the mask to the third state. And now about the same thing, but in detail and with photographs.
Photomask (phototypesetting film). It can be done in a printing house that has equipment for phototypesetting films. Often this service is not advertised by printing houses, as it is purely internal. But, as a rule, they agree to print your handkerchief designs onto phototypesetting film without any problems. The file format and dimensions of the drawings must be clarified with the specific printing house.
To obtain a board pattern, the template must be inverted (white tracks on a black background). For a protective mask – straight (black circles on a white background). 
The photographs show the photomask itself for the printed circuit board. One side seems embossed, the other should be glossy and smooth. It is important not to confuse the sides - the photo layer is on the side where the relief is. 
A wooden frame (made of balsa, glued with low-viscosity superglue!) with a stretched baby bow. In general, it is best to use special grids. I subsequently abandoned the bow and switched to organza (found where they sew all sorts of curtains and curtains for windows. For example, they gave me scraps of this organza for free) 
We cut out the blank from PCB. We give some margin on the sides. You can not give a reserve, but cut out a printed circuit board blank of the required size at once, but then you need to make sure that the mask does not accumulate on the edge (i.e., try to distribute it evenly) 
Clean the surface with sandpaper. You don’t need to try hard, just remove the dirt - the mask sticks to the PCB very well. 
The photo shows cleaned textolite. Wash off metal shavings with water. 
Iron with thermometer. It is not necessary to always control the process like this. Now I know the position of the regulator for 60-80 degrees, and by setting it to this position, I am confident that I am getting the desired temperature. Be careful, the iron temperature should not exceed 100! If you exceed this temperature, your mask will lose the ability to develop in soda ash. 
We collect the mask components into small syringes. 
Everything you need to make a PCB
- mask components in syringes
- frame
- photo template
- toothpicks
- a piece of polystyrene foam. 
Squeeze the required amount of reagents onto the textolite.
For such a scarf, this is 3 ml of mask (green component) and 1 part of hardener (white component). Those. the proportion should be 3 to 1. 
Stir with a toothpick. We try to stir well, since a lot depends on the quality of stirring. 
Mixed homogeneous mask 
Press down with mesh on top. Here, perhaps, it’s worth saying that in some cases (especially when the mask is already expired) it is better to mix large portions, for several scarves at once. Then place a frame with a mesh on the scarf, and apply the required amount of the mixed mask on top of the mesh. Then the mesh will prevent dense (thickened) lumps of the mask from getting onto the PCB, thereby ruining the whole picture. 
We distribute the mask over the textolite. The point is that the mask remains only in the grid cells. Then, when removing the mesh, we will get a uniformly distributed mask. Therefore, we try to remove excess mask from the surface of the mesh with a piece of foam plastic as in the photo (or a credit card). Without fanaticism! Don't tear the mesh 
Result 
Carefully remove the mesh 
The mask quickly spreads over the entire surface, forming a uniform layer 
We place the future printed circuit board on the iron 
Cover the scarf with something to protect it from dust. And wait a few minutes (or tens of minutes). 
Meanwhile, we throw the mesh with traces of the mask into soda ash. 
It is important to catch the moment when the mask is almost completely dry. You can try checking the mask with your finger on the edge of the scarf (where you left the tolerance. Did you leave the tolerance?! Yes, by the way, if you didn’t leave it, it doesn’t matter - you can touch the mask where there definitely won’t be a pattern. And for printed conductors - your fingerprints are hardly a hindrance). If, when you pass your finger, no traces are left on the surface, and the mask slightly sticks to your fingers, this is what we need.
Scarf with a mask with a cut out pattern. 
We apply the template with a photo layer to the mask and carefully smooth it to the scarf. DO NOT CONFUSE THE SIDE! If the surface is a little sticky, the template sticks to the scarf without any problems. If the surface is already almost dry, it doesn’t matter. Try either moistening the surface with water so that the template sticks, or press the template onto the scarf with something (you can tape it with tape. But be careful!) In general, the template should fit snugly to the scarf. 
We put it in the light. The exposure time is determined experimentally. I can tell you the modes of my illumination: 70 (or even 80) minutes at a distance of 7 cm, under a 22-watt energy saver. A UV lamp will give a much shorter exposure time, but at the same time the time tolerances will correspondingly decrease). 
We prepare the solution for development (in advance, we just threw the frame into it 
Water at room temperature. Cleaned, soft. Dosage – experimental, in the photograph is the dosage for soft St. Petersburg water (As you may have guessed, the photographs were taken by Termite). For hard water, there should be more soda. The solution should be slightly soapy to the touch. If there is too much soda, development will be fast, but the slightly underexposed mask will “peel off” during development. And if there is too little soda, development will be very slow. Moreover, heating the solution will only interfere with development.
After the time required for exposure has passed, remove the film and throw the scarf into the solution 
Scarf in solution. 
If everything is correct, then within a minute you should see a light pattern of conductors. 
When the scarf has completely developed, wash it to remove any remaining soda ash and place it on the iron to dry. 
What happened. Clear PCB drawing 
One of the unpleasant features of the mask is the underdeveloped areas. On a dry scarf, they are very clearly visible as whitish spots. They shouldn't exist! They will prevent the etching solution from reaching the copper. Then we throw the scarf back into the solution and lightly clean those areas with a cotton swab. Again, wash off, dry, control. And if everything is in order, then... 
We poison the scarf. 
During the etching process, we check that there are no air bubbles. Often they are located between the tracks. 
We poison, we poison... 
This is what happened. 
Wash off the mask with acetone. You can check the scarf, ring for breaks and short circuits. After all, we will now apply a protective mask, and then it will be very difficult to correct breaks, and especially short circuits. 
In principle, you can solder, but we have a mask! We need a protective mask! Therefore, we repeat the whole process. Application of components 
Mixing and distribution 
Drying 
This time it takes longer to dry. So that the mask stops sticking altogether. After all, now you need to very accurately combine the template with ready-made tracks, and when the template sticks to the mask, it will be very difficult to do.
Apply the mask template. The accuracy of the registration can be checked against light (if the scarf is one-sided) 
Again into exposure (yes, yes, again for 70-80 minutes, if you don’t have UV. But you can make several printed circuit boards at the same time!) Then into development in the same soda ash solution. In principle, it lasts for a long time. True, you will still have to change it, because in the green solution you cannot see the scarf itself, and how it is made more and more beautiful 
For example, I like to watch how shiny copper pads gradually appear on a green surface 
Result. A very beautiful handmade printed circuit board. 
And the result is clear. We missed the tracks a little 
Next we dry the scarf. At the same temperature (60...80). This is necessary so that the water does not boil and the mask does not swell.
After this, we raise the temperature to 160 degrees and dry the scarf for about another hour. 
And here is the result. Already trimmed, drilled, tinned and soldered. Isn't it - very similar to a printed circuit board manufactured at some factory? 
So, pros using this method on your own PCB manufacturing:
And now the cons.
Keep in mind that the description of the FSR8000 contains a lot of unpleasant things about the toxic properties of the mask vapors. At a minimum, work with the window open. And best of all - under the hood. Now regarding my advice “touch it with your finger to see if it’s dry” - it’s still better not to do this. If you get the mask on your hands, wash it off quickly.
Acetone. Also harmful. It dissolves fat, which means it can do something unpleasant with subcutaneous fat. It is better to avoid prolonged contact.
Ferric chloride. It is better not to inhale its fumes. In general, my whole process takes place on the balcony, with the window open. I go onto the balcony only when my presence is necessary. And after finishing, I ventilate it well.
Make DIY printed circuit board almost factory quality at home- perhaps, and not even very difficult! I would also like to master the high-quality production of vias...
Many thanks to Termite for the photos provided, the description of the technology itself (he was the first to try it), and for the donated mask
To apply a solder mask to a printed circuit board, you need a so-called frame with a well-stretched stencil mesh. The process of stretching the mesh frightens many people and they prefer to buy a ready-made frame. In fact, there is nothing complicated here; it would be a desire and a little free time.
In this article I will tell you how to properly stretch a stencil mesh onto a frame.
We cook from a square iron pipe 20*20 mm. frame of the required size, sand all the corners and sides with sandpaper so that the mesh does not break when tensioned. We paint it on three sides (leave the side where the mesh will be glued unpainted). In this case, the frame has a working field of 210*300 mm, that is, A4 format.
Take a piece of chipboard 26 mm thick. We place the frame on it and, with a 5 mm allowance on the outside, outline it and cut it with a jigsaw.
Then we drill 6 mm through holes around the perimeter. On the other side, we drill these holes to a depth of 5..6 mm. drill 10 mm.
We drive M6 nuts into the drilled holes and screw in M6 bolts on the other side.
We place the frame on the side of the chipboard with nuts, degrease it and use staples evenly, starting from the middle of each side, to fasten the stencil mesh.
In this case it was used screen mesh VS-Monoprint PES 77/48 PW.
We place the chipboard with the frame on its edge, then first tighten the bolts with our hands until they stop evenly along the entire perimeter. We take the key to 10 and tighten the mesh half a turn. We twist the bolts in a checkerboard pattern, that is, evenly. As a result, the frame rises and the mesh is tensioned accordingly. There is no need to overuse the tension here; the mesh should be fairly evenly tensioned and not sag. A weak tension is also not desirable. If you overtighten the mesh, the fastening on the brackets may not hold up and the mesh may break.
We breed a special adhesive for screen mesh KIWOBOND 1100, for this frame size 10 ml is enough. glue. Apply glue to the mesh with a brush, saturate it, it will securely glue it to the frame. You need to immediately apply the glue generously (if you apply little, it dries quickly), and of course, apply it so that the diluted glue is enough to cover the entire frame.
After two hours the glue will harden, remove the tape and cut the mesh around the perimeter of the frame with a paint knife.
Read articles on the original site, do not support thieves.
The result was a frame of the required size with a high-quality stencil mesh stretched over it for applying a solder mask to the printed circuit board. In the same way, the mesh was stretched onto a smaller frame, with a working field of 110 * 170 mm, for small boards.
PCB test, excellent result.
The photo schematically shows the process of applying a solder mask. The distance between the mesh and the board, the inclination of the squeegee and the mesh during application.
The quality of any homemade electronic device very much depends on how well it is made
was manufactured (yes, it’s a useful phrase, it’s already clear! Well, yes... But I need to for some reason
begin?).
The printed circuit board plays a big role in this (unless you have a very simple design that
it is possible
make volumetric installation). The more complex the device, the more complex the printed circuit board design, and the more
better quality
it must be manufactured. About one of the ways DIY PCB making speech
and it will go.
All materials used in this article can be purchased in our store
There are several ways making a printed circuit board at home. At the very beginning (this was back when I was studying to become an electronics engineer at school), I painted paths with nail polish (the result was very brutal printed circuit boards), then I tried a waterproof marker (even better). But only when I mastered laser ironing technology(LUT) (and this happened relatively recently) I was finally able to get the quality of the boards that was pleasing to the eye. After all, I make electronic crafts purely for the sake of the process itself. Well, this is my hobby. What's the point in soldering something on a scary printed circuit board? But after a couple of years, this technology stopped suiting me. Although LUT has many advantages:
Using laser-iron technology, it was even possible to apply inscriptions, which is what I did in some cases.
But LUT gave an accuracy of no more than 0.3 mm. This is the practical ceiling. I tried to make the tracks thinner, and it worked, although at the same time the percentage of defects increased significantly. In general, I have already drawn out the preface to the article, so let’s move on to the solder mask itself.
FSR8000- two-component composition sensitive to ultraviolet radiation. Has three states.
1. "Raw State". After the two components have been mixed. In this form, it can be washed off with either acetone or a solution of soda ash.
2) "Hardened State".
2a) Not exposed to ultraviolet light. Dissolves with acetone and soda ash solution.
2b) After exposure to ultraviolet light, the mask becomes resistant to soda ash solution, but can still be washed off with acetone.
3) "Baked state". It is obtained after heating to 160 degrees, followed by exposure for several tens of minutes. It is not soluble in acetone and has great mechanical resistance.
In simple terms: a mask is a protective layer that can often be seen on factory-made printed circuit boards. Very often green. This article will discuss the non-standard use of this mask as a photoresist.
To do this, you need to use the first two states, i.e. Using illumination and subsequent development, obtain a pattern of conductors on the PCB. And after etching, wash off this pattern with acetone.
Then the mask can be used for its intended purpose, covering the area of the entire board with a mask, except for the contact pads intended for sealing parts. Then transfer the mask to the third state. And now about the same thing, but in detail and with photographs.
Photomask(). It can be done in a printing house that has equipment for phototypesetting films. Often this service is not advertised by printing houses, as it is purely internal. But, as a rule, they agree to print your handkerchief designs onto phototypesetting film without any problems. The file format and dimensions of the drawings must be clarified with the specific printing house.
To obtain a board pattern, the template must be inverted (white tracks on a black background). For a protective mask – straight (black circles on a white background) .
Photoresist Ordyl Alpha 340
The photographs show the photomask itself. One side seems embossed, the other should be glossy and smooth.
It is important not to confuse the sides - the photo layer is on the side where the relief is. 
A wooden frame (made of balsa, glued with low-viscosity superglue!) with a stretched baby bow. 
We cut out the blank from PCB. We give some margin on the sides.
Clean the surface with sandpaper. You don't need to try hard, just remove the dirt. The mask has very good adhesion. 
The photo shows cleaned textolite. Metal shavings must be washed off with water.
Iron with a thermometer. It is not necessary to always control the process like this. Now I know the position of the regulator
for 60-80 degrees, and by setting it to this position, I am sure that I am getting the desired temperature.
Be careful, the iron temperature should not exceed 100! 
We collect the mask components into small syringes. 
Everything you need to get the job done
- mask components in syringes
- frame
- photo template
- toothpicks
- Squeegee rubber 
Squeeze the required amount of reagents onto the textolite.
For such a scarf, this is 3 ml of mask (green component) and 1 part of hardener (white component). Those. the proportion should be 3 to 1
.
Stir with a toothpick. We try to stir well, since a lot depends on the quality of stirring. 
Mixed homogeneous mask 
Press down with mesh on top. Here, perhaps, it is worth saying that in some cases (especially when
when the mask is already expired) it is better to mix large portions, for several at once
handkerchief. Then place a frame with a mesh on the scarf, and apply the required amount of mixed mixture on top of the mesh.
masks. Then the mesh will not allow dense (thickened) lumps of the mask to get onto the PCB, thereby spoiling
the whole picture. 
We distribute the mask over the textolite. The point is that the mask remains only in the grid cells. Then when removing
mesh - we will get a uniformly distributed mask. Therefore, use a piece of squeegee rubber (or a credit card)
We try to remove excess mask from the surface of the mesh. Without fanaticism! Don't tear the mesh 
Result 
Carefully remove the mesh 
The mask quickly spreads over the entire surface, forming a uniform layer 
Place the scarf on the iron 
Cover the scarf with something to protect it from dust. And wait a few minutes (or tens of minutes).
Meanwhile, we throw the mesh with traces of the mask into soda ash. 
It is important to catch the moment when the mask is almost completely dry. You can try checking the mask with your finger on the edge of the scarf.
(where you left the clearance. You left the clearance, right?!). If, when you pass your finger on the surface, there is no
traces, and the mask slightly sticks to the fingers - this is what we need. Scarf with a mask with a cut out pattern. 
We apply the template with a photo layer to the mask and carefully smooth it to the scarf. DO NOT CONFUSE THE SIDE! If the surface
a little sticky - the template sticks to the scarf without any problems. If the surface is already almost dry, it doesn’t matter.
Try either moistening the surface with water so that the template sticks, or using something to press the template onto the scarf.
(You can wrap it with tape. But be careful!) In general, the template should fit snugly to the scarf.
We put it in the light. The exposure time is determined experimentally. I can tell you my lighting modes:
70 (or even 80) minutes at a distance of 7 cm, under a 22-watt energy saver. A UV lamp will give much less
exposure time, but at the same time the time tolerances will correspondingly decrease). 
Preparing the solution for development 
Water at room temperature. Cleaned, soft. Dosage – experimental, in the photo the dosage for
soft St. Petersburg water (As you may have guessed, the photographs were taken by Termite). For hard water - soda should be
more. The solution should be slightly soapy to the touch. If there is too much soda, development will be fast,
but at the same time, the slightly underexposed mask will “peel off” during development. And if there is too little soda, the development will be
very slow. Moreover, heating the solution will only interfere with development. After the time required has passed
for exposure - remove the film and throw the scarf into the solution 
Scarf in solution. 
If everything is correct, then within a minute you should see a light pattern of conductors.
When the scarf has completely developed, wash it to remove any remaining soda ash and place it on the iron to dry. 
What happened. 
One of the unpleasant features of the mask is the underdeveloped areas.
On a dry scarf, they are very clearly visible as whitish spots. They shouldn't exist! They won't give the solution for
etching to get to the copper. Then we throw the scarf back into the solution and lightly clean those areas with a cotton swab.
Again, wash off, dry, control. And if everything is in order, then... We poison the scarf. 
During the etching process, we check that there are no air bubbles. Often they are located between the tracks. 
We poison, we poison... 
This is what happened 
Wash off the mask with acetone. You can check the scarf, ring for breaks and short circuits. After all, we will now
apply a protective mask, and then it will be very difficult to correct breaks, and especially short circuits.
Apply the mask template. The accuracy of the registration can be checked against light (if the scarf is one-sided) 
Again into the light (yes, yes, again for 70-80 minutes, if you don’t have UV. But you can make several scarves at the same time!)
Then go into development in the same soda ash solution. In principle, it lasts for a long time. It's true to change everything
it will have to be the same, because in the green solution you cannot see the scarf itself, and how it is made more and more beautiful 
For example, I like to watch how shiny copper pads gradually appear on a green surface 
So, pros using this method on your own PCB manufacturing:
And now the cons.
Keep in mind - in the description of the FSR8000 a lot of unpleasant things are written about the toxic properties of the mask vapors. At a minimum, work with the window open. And best of all - under the hood. Now regarding my advice “touch it with your finger to see if it’s dry” - it’s still better not to do this. If you get the mask on your hands, wash it off quickly.
Acetone. Also harmful. It dissolves fat, which means it can do something unpleasant with subcutaneous fat. It is better to avoid prolonged contact.
Ferric chloride. It is better not to inhale its fumes. In general, my whole process takes place on the balcony, with the window open. I go onto the balcony only when my presence is necessary. And after finishing, I ventilate it well.
Make DIY printed circuit board almost factory quality at home- perhaps, and not even very difficult! I would also like to master the high-quality production of vias...
15.10.2015
Solder mask (Solder Resist or Solder Mask) is a mandatory heat-resistant protective coating for the conductive pattern of printed circuit boards. Purpose: protection of individual areas of the PP from the adverse effects of flux and solder, as well as the influence of a humid environment and mechanical stress.
The solder mask is applied to either one () or both sides of the PCB. It is necessary to insulate the contact areas (for the output of the microcircuit, etc.) from conductive elements - conductors or transition-type holes. The result is a reduction in labor intensity/soldering time.
If it is necessary to isolate adjacent contact areas, the cutout method is used (creating an area not covered with a solder mask layer). In this case, the size of the cutouts should be 100-150 microns larger than the total size of the contact area. The distance from one edge of the solder mask to the other edge of the contact area should be within 50-75 microns. The minimum width of the jumper - the area between 2 adjacent contact areas - is 75 microns.
The color - red, white, green, blue, black, yellow or super white - is chosen by the customer. In the LED industry, super white/white solder mask color is used, in other fields green is the most popular color. It should be taken into account that the final color saturation of PP is created not by the base material, but by the mask coating.
The process of creating a protective layer
The mask is applied through a stencil in the form of a mesh (the size of one cell is 150 microns). Wet layer thickness: 30-35 microns. Then, the product is dried. Temperature in the drying chamber: no more than 75˚. The dried blanks are sent to the stage of photolithography - combining photo masks of masks with products - and high-power UV exposure. The final stage is the development of the blanks in solution (substance temperature 32-34˚).
This article is devoted to the manufacture of a homemade printed circuit board with green paint.
General issues of making printed circuit boards at home are fairly well covered on the Internet. I will not describe what others have already written a hundred times. Instead, I'll briefly describe my little tricks and processes, especially about vias and masking.
Homemade board 8 mil tracks, 6 mil distance, adapters and mask.
Equipment
Laser printer (Kyocera FS-1100 printer, for toner transfer), laminator, microcompressor.
Materials
Everything is as usual (textolite, ferric chloride, acetone, etc.) except for stained glass paint (Pebeo Vitrea 160).
Process
Sverlovka: Since I use CNC for drilling, the process occurs before the toner transfer, in this case it is easier to position the pattern. 
Transferring toner to the board:
Many people use an iron, but still, the best results were achieved using a laminator. We roll it through the laminator 10-15 times. Paper - here too, everyone can experiment, I use 130 g/m photo paper. Using photo paper, it seems to me, increases the life of the printer itself. Printing mode, select the maximum toner consumption) Unfortunately, the trend is that modern printers are more and more economical (or fortunately, depending on which side you look at) and the thickness of the toner after transfer tends to decrease. This is what happened after the laminator:
Etching:
The etching process takes place in a ferric chloride solution and is no different from classical methods - warmer water, more iron, stir more often)
Vias:
Vias are an integral part of the process of making a homemade double-sided board. You can consider several options for homemade transitions:
1. Use of special bushings. Difficult to find or make. The need for a sufficiently large diameter in VIA.
2. Installation of jumpers using wire. It has one drawback - when the adapter is located under the housing of the SMD chip. This requires some experience. (experience is necessary everywhere, but making jumpers of the required length and then soldering them with a minimum amount of solder is sometimes not easy)
3. Pressing. This method allows you to create a high-quality transition connection between layers. For this purpose, a special press machine was created. Details about the press can be read in.
It would seem that the next step is to earn the payment and go ahead! But no, it's boring and ugly. We are not looking for simple ways. Making a board with greenery
Mask
The mask protects the board from corrosion, creates more favorable conditions during installation, and gives the board a “branded” look. This is the first time anyone has read about a homemade mask. It is based on publicly available stained glass paint. Pebeo Vitrea 160. Water-based paint has one peculiarity - it requires firing (drying) in an oven at a temperature of 160 C for 40 minutes. In fact, I have not tried to fry the board above 130 degrees. A temperature of 130 is quite enough for normal paint polymerization.
First, we print a layer on the same laser printer to protect the pads involved in the installation. Simply put, we cover the necessary areas from the mask. Place it on the board and put it back into the laminator:
Then we apply paint using our mini sprayer. I add 1 part water to 4 parts paint before applying. After application, wait 24 hours for the paint to dry. There is no need to rush - we will always have time to burn the board). After that, we kick my wife out of the kitchen and occupy the stove for 40 minutes. In fact, it is better to get some kind of mini-oven or use a toaster for these purposes. But in any case, you need to carefully monitor the temperature. After 40 minutes, remove the pie from the oven:
The protective layer, consisting of toner, is removed using a solvent or acetone using a slight mechanical force of the hands. The paint falls off from the protected areas due to poor adhesion to the toner. Now you can tin the pads and solder some SDR transceiver or other trinket. In general, the whole method is quite labor-intensive and is necessary, I believe, for very important trinkets. Well, or for real aesthetes who are not used to paying 1000 rubles for a branded double-sided board in China (if anyone is interested, write, I’ll give you the address of the site where you can actually order normal boards for 1000 rubles)
