Have you ever had a PCB factory?
1. Engraving method:
This method is the most direct Use carbon paper to copy the pattern on the surface of PCB copper foil CCL Use a special engraving tool polished with a steel saw blade to directly carve the copper foil pattern on the CCL and cut as much as possible, Then tear off the unwanted copper foil outside the figure, and drill holes with a flashlight The key to this method is: the depiction is enough; Excess copper foil should be removed from the edge of the circuit board. When the operation is finished, it can be gradually disassembled into pieces You can use small pointed nose pliers to complete this step Some experimental versions of small circuits are suitable for this method
2. Manual description:
It uses a pen to draw printed graphics directly on the CCL, and then carries out chemical etching and other steps This method seems very simple, but it is not easy to operate! The current electronic components are very small. The pin spacing is small (on the order of millimeters). The trace of copper foil is also very small, and the drawn lines are difficult to modify Drawing such a board depends entirely on your writing skills Experience has shown that the choice of "paint" and brush is crucial I used red nail polish to trace the circuit board in the medical syringe myself The effect is good, but the needle tip should be properly treated Someone also introduced the use of paint chips dissolved in absolute alcohol, and then painted with a duck's beak pen The specific method is as follows :
One piece of lacquer (lac, which can be bought in chemical raw material stores) is dissolved in 3 parts of anhydrous alcohol and properly mixed. After dissolution, add a few drops of medical purple liquid medicine (gentian violet) to make it appear a certain color. After mixing evenly, it can be used as protective paint for circuit boards.
Circuit board
First polish the copper clad laminate with fine sandpaper, and then draw with the duckbill in the drawing tool (or the ink duckbill used to draw figures on the compass). The pen has a nut to adjust the thickness of the stroke. Adjustable, you can draw a very thin straight line with a ruler and a 3 angle ruler. The straight line drawn is smooth and even, without edge serrations, giving you a smooth feeling; At the same time, it can also write lines drawn by Chinese characters, English, Pinyin or symbols in the free position of the circuit board. If there is seepage around and the concentration is too small, a little paint can be added; If you can't draw a brush, it's too thick. You need to drop a few drops of absolute alcohol. If you make a mistake, just use a small wooden stick (match stick) to make a small cotton swab, dip it in a little absolute alcohol, you can easily clean it, and then paint again. After drawing the circuit board diagram, the circuit board may be corroded in 3 ferric chloride solution. It is also convenient to remove the paint after the circuit board is corroded. Wipe off the protective paint with anhydrous alcohol dipped in a cotton ball, dry it for a while, and then apply pine perfume.
Since the alcohol evaporates quickly, the prepared protective paint should be sealed and stored in a small bottle (such as an ink bottle). Don't forget to cover the bottle after use. If the concentration becomes thicker when next used, just add an appropriate amount of absolute alcohol.
3. Texture method:
1. Pre cut marking method
The electronics store has a "standard pre cut symbol and tape". Common specifications of pre cutting symbols include D373 (0D-2.79, ID-0.79), D266 (0D-2.00, ID-0.80), D237 (OD-3.50, ID-1.50), etc. It is better to purchase paper based materials (black) and try not to use plastic based materials (red). Common specifications of tape are 0.3, 0.9, 1.8, 2.3, 3.7, etc. All tissues are mm. According to the circuit design layout, select the corresponding symbol and tape, and paste them on the copper foil surface of the copper clad laminate. Knock the sticker with a soft hammer, such as smooth rubber and plastic, to make it completely adhere to the copper foil. Focus on turning and overlapping of lines. In cold weather, it is best to use a heater to heat the surface to enhance adhesion. After pasting, etching can be carried out.
2. Self adhesive paper mapping method (recommended)
Use Protel or PADS and other design software to draw a printed board diagram, use a dot matrix printer to output to the sticker, paste the sticker on the cleaned copper clad plate, and use a paper cutter to cut along the line outline, and tear off the parts to be corroded. Before putting into use, put it into 3 ferric chloride solution for corrosion, cleaning and drying. This method is similar to the engraving method, but it saves a lot of energy than the engraving method, and can ensure the beautiful and accurate printing of wires!
According to experience, everyone knows that the corrosion of ferric chloride solution is very slow. The author uses dilute nitric acid instead. After this experiment, the corrosion rate is amazing. It will take about five minutes to finish. Its quality is the same as that of 3 chloromethane. I suggest you try it yourself! But this method is more dangerous, remind the producer to pay attention, do not let any part of the body contact with corrosive liquid, otherwise the consequences will be unimaginable! Think back Think back
4、 Mimeography method:
Place the wax paper on the steel plate, use a pen to carve the circuit diagram on the wax paper in 1:1 ratio, cut the circuit diagram carved on the wax paper according to the size of the circuit board, and place the cut wax paper on the printed copper plate. Take a small amount of paint and talcum powder to make appropriate thin and thick printing materials, dip the printing materials with a brush, evenly smear them on wax paper, and repeat several times to print the circuit on the printed board. This prototype can be reused and is suitable for small batch production. Tips: Use the photoelectric copying machine to automatically carve 1:1 size wax paper according to the design drawings.
5. Hot melt plastic film plate making method:
This method is collected from web articles, and its feasibility has not been verified for reference.
1. Print the circuit board diagram on the printer with a scale of 1:1 on 80g copy paper. You can also draw by hand, but the bottom paper should be flat.
2. Find a fax machine, take out the fax paper from the fax machine and replace it with hot melt plastic film (it is said that it can be bought, please contact the webmaster who has this product). Put the circuit diagram into the entrance of the fax machine, and use the copy button of the fax machine to copy the circuit diagram on the hot melt plastic film. At this time, the "Print Original" of the PCB is ready.
3. Use double-sided tape to paste the plastic film that has been painted on the CCL smoothly. Pay attention to flatness and wrinkle free, and the adhesive tape cannot cover the melted part, otherwise the production effect of the circuit board will be affected.
4. Use a paint brush to evenly brush the paint on the plastic film. Note: Do not brush back and forth, but only in one direction. Otherwise, the plastic film will wrinkle together and the lines on the copper plate will overlap. After brushing the circuit diagram, carefully remove the plastic film. At this time, the printed circuit board is printed. It will be corroded after drying.
If you want to print multiple sheets, you can make a wooden frame larger than the circuit board, place the screen flat on the wooden frame and fix it. Then use double-sided tape to stick the fixed plastic film under the screen. Put the CCL on the table, close the grid (the printed image and the CCL should be aligned left and right), paint in one direction with a paint brush, and then remove the grid. The printed circuit board has been printed. If there are any defects, they can be modified with paint and bamboo.
Pay attention to the above process When painting, hand strength should be light and heavy If the paint film is too heavy, the PCB line lace will run out. If the line is too light, the line will break The plastic film must face upwards
The above is the explanation given by the editor of pcb circuit board company.
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