Paper for making printed circuit boards using LUT technology or how to make a printed circuit board at home. Making quality PCBs using thermal transfer paper using the loot method Choosing paper for loot

Quite a few years ago, I first learned about the manufacture of boards using Laser Iron Technology. For me it was like reinventing the wheel.
Read the continuation of the story under the cut.

Prior to this, the boards were painted with varnish using a reedfeder. To print circuit boards using LUT technology, I even bought a laser printer (about 12 years ago it was very expensive). In the process, I tried a bunch of different types of paper. And more than one square meter of boards made using this technology was made, on the third I stopped counting. At the moment, I settled on paper from the Popular Mechanics magazine, before that I used paper from the Kitchen and Bathrooms magazine, but it disappeared from sale.
But more recently, while reading reviews on Muska, I accidentally saw paper for printing boards in one of the reviews, climbed on Ali and immediately ordered myself a trial 10 pieces of leaves, deciding that if I liked it, I would order 50, since the price difference is between 10 and 50 only about two times.
By the way, be careful, I posted a link to the lot, but now at this place there is a lot of 50 pieces for 10-plus bucks, while the name of the link remains the same, 10 sheets.

I recently received my order. What I was most afraid of happened, the paper came crumpled.
As everyone understands, it is dangerous to put crumpled paper into the printer, the cost of repairs may be more than the cost of the paper itself. I opened a dispute for a 50% refund, since after trimming I can use about that much.

The paper was just in a large envelope, without a bag or file, and a piece of some kind of cardboard was inserted, and this piece of cardboard was smaller in size than the paper. Actually, the main damage was in places where the cardboard was missing.

In the photo, the magazine that I used before and the paper I received chose the leaf more carefully.

To prevent the printer from chewing on my new leaf, I had to cut off some of it, on the other hand I did not cut it off, since it is not critical there, the main thing in that area is simply not to print anything.

Well, since such paper is well, a very specific product, then without testing, there is simply no way.

In general, everyone who is interested is welcome under the spoiler.

Printed circuit board, how it's done.

First I trace printed circuit board, I use Sprint Layout 6, before that I used version 3 for a very long time, and I still can't get used to the differences in control.

When making a board, I always leave a protective zone with a width of 5mm around the perimeter, so the workpiece is taken 10mm more in length and width than the required board, it is so convenient for me.

The workpiece is cleaned with fine sandpaper, it is not the mirror surface that is important, but rather a lot of micro-scratches, then the toner holds better.

We print our future board on paper (I usually print 2 pieces at once, just in case), on the smooth side, by the way, the whole process was done with one take, i.e. I did not correct or alter anything specifically for the review, this was the meaning of the test.
Do not forget that you need to print in a mirror image in relation to the required printed circuit board pattern.

Then I put the blank on a specially trained book :), or rather, this is not a book, but an annual filing of Radio magazines, in a cardboard binding. I do this so that the workpiece does not slip in the process, and does not spoil what is under it from heating.

After that I lay the printout with a drawing to the copper, then cover it on top with a sheet of ordinary printer paper, so it slips less at the initial stage, the most difficult moment is to prevent the printed sheet from slipping to the side, I first put the iron with its wide part on the book and paper, and then smoothly I lower it onto the workpiece.

Then, with smooth movements, with a slight pressure, we stroke our future board, I make several passes from different sides of the board, so that the edges are better ironed, you cannot press hard, otherwise the toner may float, if you do not press at all, then most likely the toner will not stick to the workpiece. I iron this workpiece for about a minute.
By the way, I use Static Control toner, in my opinion this is the best toner for LUT ...

The gluing process is complete, the paper adhered smoothly and beautifully.

Now we throw our board into a bowl of water for 5-10 minutes, you can leave the water on, this will help the paper become softer faster.

After 5-10 minutes, under a slight pressure of water (better than room temperature), roll up the paper with your finger, the tracks should remain in place, you do not need to do this too carefully, since if the toner is erased with your finger, then such a board must be redone, normally glued toner with your finger is not erased , only scratches.

The photo shows the result of transferring the drawing to fiberglass. Toner is black in color, before that when I used paper from a magazine, the toner had a grayish tint, as there were particles of paper on it. Everything is beautiful here, the holes are clean, there are no sticks between the tracks.
I specially selected for the test a printed circuit board with both large flooded polygons and small tracks.

Before etching, I make such a "table", in the corners of the board, in places free from the drawing, I drill 4 holes into which I insert matches (or toothpicks), the board is positioned with the drawing down.

The boards are usually etched with a solution of ferric chloride in water.
(III)
After immersing the board in the solution, it must be lifted almost immediately and air bubbles removed, otherwise there will be no etched places.

After a while (depending on the solution), the board is etched.

I wash off the toner that has already fulfilled its function with acetone (well, or any suitable solvent).

Well, here I will show what print quality I ended up with.
The place for the processor is closer to the center of the board, the width of the contact pads is 0.45mm, the width of the tracks is 0.45-0.5mm. It can be seen that the shape of the pad is even perfectly preserved.

And this is a path along the edge of the board, there are two such places. Usually I correct such places with a permanent waterproof marker, for the test I did not do this on purpose.

After washing off the toner, I drill the necessary holes, then I clean the board with zero sandpaper.

After all these operations, I only cut off the excess, if this is done before stripping, then you can damage the tracks close to the edge of the board with sandpaper. I go through the edges of the board a little with a file to remove the sharp remnants of fiberglass after the scissors.

Now I cover the board with flux (I use alcohol F3), and plunge the tracks.
I know some people don't, but I like the board with spilled tracks better. In general, a matter of taste, well, copper does not oxidize, and microcracks are filled with solder.

The last stage, I wash off the remnants of the flux with acetone.

That's it, the board is ready.

Yes, I know about photography, I know about masking and silk-screening, etc. etc.
These are all good and very useful things, but I think that the option I described is sufficient for most applications. It is very quick and easy to make a board in this way, and you need to have a minimum of chemicals and tools.
The board I made will probably take part in one of my future reviews, some readers will most likely even find out what kind of device it will be.

In general, my resume.
Pros.
I liked it, I think I will order 50 or 100 sheets.
Toner sticks well to the substrate.

Minuses.
The seller packed very badly, for which he was a big minus.
The price, especially the price when buying a lot of 10 leaves, but for a sample is quite enough, although looking for magazines, and then leaves in magazines without pictures (for printing, it is better to use either white pages or only with text) is already tired of the order.

In general, experts, do not judge strictly, I tried to describe it as I could, I will be very glad to advice and additions, and I hope that my review helped someone.
And yes, I know that it is cheaper on BiK :)))