LUT or laser-iron technology allows you to speed up the manufacturing process of printed circuit boards. It starts with creating a board in a computer program. Then it is printed on a laser printer (only!) And preferably on a freshly charged one. The print level is "bold", which is achieved by disabling all toner-saving functions. At the same time, it is taken into account that in the future, the board is mirrored from the image that is printed on the printer.
For printing use glossy paper. The best will be taken from magazines - any page is suitable. You should not pay attention to the text and drawings - they are printed with ink having an alcohol base, which does not interfere with the printed circuit boards.
The resulting image is transferred to foil textolite, which is previously degreased with alcohol. For transfer using an iron or laminator. The latter is better, as it allows you to adjust the temperature. It is optimal for the process - 140 ... 155 ° C.
The paper with the printed circuit board is placed on an already pre-heated copper foil textolite with a printed pattern for the foil. The warm-up time, which is sufficient to transfer the toner to the foil, is 1.5 minutes.
Paper removal is done carefully. Textolite is immersed in a bath in which boiling water is poured and detergents are added. After 5 minutes, the paper will lag behind, and its remnants are erased with a fingertip. In the latter they do not show fanaticism.
Next, carry out the etching process. Ferric chloride is used, which is dissolved in water until the granules of the substance begin to precipitate. The solution takes on a dark brown color; it is used for etching, heating to 50 ° C - this temperature must be maintained all the time. The board in the solution is put up the tracks (allows you to control the process), constantly stir, which speeds up the process at times. Its duration is about 5 minutes.
In the process, at first narrow sections are etched, later wide. Time lag can affect quality. Therefore, when designing boards, you need not to make gaps with a width greater than 1 mm - it is better to widen the tracks. The recommendation will allow less bleeding of copper, which will increase the life of the solution.
At the end of the etching process, wash off any remaining toner. This is done with a cotton swab, which is wetted in acetone, solvent 646.
After etching, the board is allowed to dry. The quality of the resulting product is judged by looking at it in the light. Then they are engaged in drilling holes and arranging tracks.