LUT-technology: manufacture of printed circuit boards

What is LUT (laser-iron technology)? Our article will tell about it.

Printed circuit boards

The design of radio electronic devices is closely related to the creation of printed circuit boards. If there is no desire to spend a lot of time on their making, then the method described in the article is ideal for you. If you have the proper skill, it will make it possible to essentially facilitate creativity. The LUT technology can be divided into such stages of manufacturing the printed circuit board:

1. Create a picture.
2. We do the workpiece.
3. We transfer the drawing to it.
4. We are baiting the workpiece.
5. Clear.
6. We make a drill.
7. Tin plating.

As you can see for yourself, in practice LUT-technology at home can be realized without significant problems and costs. Perhaps, you do not even have to acquire anything new, because everything you need for work can easily be found in the back room. LUT-technology of manufacturing printed circuit boards is well suited in cases where there is a single production by an amateur electronics. Speaking about the merits, first of all they remember about cheapness, reliability and ease of work. Of course, this is not all the advantages, nor the above, with more than enough to the advantage of LUT-technology made their choice, many domestic craftsmen.

Create a picture

There is a wide choice of means: from a pencil to special programs. When creating a printed circuit board it is necessary to try to achieve such goals:

1. Minimize the number of jumpers.
2. The tracks relative to each other should be strictly perpendicular and parallel.
3. Compact installation.

When creating drawings, take into account the dimensions of the elements, the location of the terminals of the parts and their dimensions. It is also necessary to take care that the high-current conductors have wider paths. Creating a picture can be compared to playing tetris: you can mark out the elements as you like, until you get an ideal that will help to realize the LUT technology. An inkjet printer (or laser) will help you make it physical, feel with your own hands.

Making workpiece

So, we have a drawing, and we can talk about the size of the board. Now you need to cut out the picture, overlay it on the textolite and point it with the ruler. Is not it so complicated LUT-technology? Foil, that's what we need! Cut along the lines a blank of foil-shaped textolite. Smooth the edges around the perimeter with a file and clean the surface. To do this, you can use a small pencil or wire grater (from those that clean the dishes), together with a detergent.

We transfer the drawing: general information

Let's say that we printed an image on a laser printer. And we now need to transfer it to the workpiece from paper. Put what has turned out, a picture on foil. Evenly iron the iron, but at the same time apply an exceptionally light effort. Paper exfoliate, trim and etch. If you are printing a picture, it is desirable to set the minimum brightness so that a very dark image is obtained. It is also desirable to set a high toner density in the advanced settings. This is necessary to avoid negative effects with lumens, which, alas, has LUT-technology. The minimum size of the gaps is only welcomed, preferably, they are not more than 0.2 millimeters.

Transfer the drawing: paper

This is a delicate thing, so it's necessary to approach it with responsibility. Which samples are better perceived by LUT technology? The paper must be dense, you can take the coated paper. Do not touch fat fingers. It is not necessary to buy coated paper - you can take an advertising booklet. The main thing is that it is white on one side. Just in case, it's better to stock up two copies of the printed circuit boards. Cut and overlay on the workpiece so that the pattern was on the side of the foil. We take a regular iron, we do not use steam. It is better to set the average temperature. We hold the part of the drawing so that it does not move out of the workpiece. Begin smoothly smooth the image, but do not allow it to shift. Also do not overdo it with force: if you press very hard, the toner will smear, and with it the tracks. This can also happen if the iron is too hot. If the edges of the workpiece have been poorly processed, then you can not smooth the toner well into it. When everything is ready, the workpiece must cool down. Then put it in a bowl with warm water. Add a tablespoon of acetic acid. The paper will soften and begin to bubble. For about ten minutes, it will lag behind the toner. Rinse the resulting image with a jet of water. First, there may be individual defects, but when working with the second instance of the experiment should be enough to avoid them. In general, LUT-technology of manufacturing printed circuit boards may seem quite complicated, but it is only at first. By the way, it was recommended to have two papers above in the article, and this is no accident. At the first call many beginners make small mistakes, which turn into smeared toner and other blunders. In order to make the circuit board of higher quality, and was recommended to prepare a spare.

What if there is no laser printer?

You can use a permanent marker. Also for these purposes, and suitable for nail polish, applied by a thin brush. In general, you can act with at least one pencil and eraser. Used in these cases LUT-technology with the use of glue for better results. When you wash off its remains with water, make sure that it really does not remain. Also, when you drill holes, make sure that the conclusions in them will feel good.

Etching the workpiece

To do this, use ferric chloride. When buying a substance, make sure that it is in the form of a powder. Such chlorine iron is most suitable for our purposes. Although the use of a mixture of table salt and copper sulfate is not excluded. But here it is necessary to observe certain proportions. So, one liter of boiled water should take two hundred grams of vitriol and add the salt until it ceases to dissolve. The resulting solution must be filtered. If it is heated to a temperature of 50 degrees Celsius, then copper takes 15-20 minutes to bleed. But back to the chlorine gland. It is necessary to fill the tank for etching with water and add a teaspoon with a slide of ferric chloride. Be careful, because the chemical reaction that will occur will generate heat very much, and the resulting solution may even spatter slightly. Well, everything is mixed. Bring your finger to the solution and make sure it is not too hot. Then put the workpiece in it, preferably with the foil down - so that it lies on the surface. First she will swim and poison. Over time, she drowns. Then turn the PCB with foil up and put it in the solution. Periodically, the container with it must be shaken to dissolve the dissolved copper from the surface. If bubbles appear, remove the board, rinse it and continue etching. Depending on the temperature of the solution and its concentration, this process can take up to 1 hour.

Clean the workpiece from the toner

Now we face the problem of cleanliness. There are special solutions for this, but they do not find good reviews, and many people prefer a mechanical method of removing the toner. For this, it is recommended to use dishwashers for washing dishes, which can provide a decent result.

Drilling

It is worth noting that, to a large extent, this is a matter of purely individual preferences. But as recommendations it is possible to advise the use of DPR micromotors and replaceable collet chucks. The drill can be selected at 0.8 millimeters - in most cases this is more than enough.

Tinning

When you drill a printed circuit board, you need to wash it with soap. Then sweep the cleaning wire, rinse and dry. Then it must be covered with rosin solution for alcohol. You can also hide the board with active soldering fat on Vaseline. How wild it would not sound, but a useful thing. Fat put a thin layer, well rubbing it on the surface. Soldering iron should be placed so that the holes are not sealed. If this still happens, then we pick up a wooden toothpick, warm up the "dirty" place and clean it.

Recommendations for work with printed circuit boards

As a solder, you can advise PIC-61. It is designed to work with circuits in cases where overheating is unacceptable. And if this happens, then the tracks of the PCB can be peeled off. In the end, we can say that the technique considered looks complicated. But this is a deceptive proposition. Believe me, you will have more time to create a good drawing than a printed circuit board. You can also give advice on the time of etching: the fact is that if you leave the PCB in solution for several hours, even the areas protected by toner will not be preserved. Therefore, it is highly desirable to adhere to the time limits specified in the article.

Capabilities

It should be noted that LUT-technology allows you to get a good result in terms of accuracy. So, some masters with her help have learned to etch letters and numbers, the size of which is 0.3 millimeters! Amazing work quality! Of course, to achieve it, you will need training and experience, however, as in any field of activity.

Conclusion

It should be noted that LUT-technology of manufacturing double-sided printed circuit boards does not differ much from the processes described in the article. Of course, you will have to make it a little complicated, and spend more time - but the end result will be worth it. LUT technology allows you to quickly and efficiently create printed circuit boards for all kinds of circuits. If at first something does not work out, it should always be remembered that experience will allow you to understand this. Therefore, you need to take into account your mistakes, learn from them and try again.