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Production method one:
1. Cut the copper-clad board to the size required by the circuit diagram.
2. Put the wax paper on the steel plate, use a pen to engrave the circuit diagram on the wax paper 1:1, and cut the circuit diagram engraved on the wax paper according to the size of the PCB board, and place the cut wax paper on the printed copper board. Take a small amount of paint and talcum powder to make a suitable thin and thick printing material, dip the printing material with a brush, and evenly apply it to wax paper, repeat it several times, and the circuit can be printed on the printed board. This kind of stereotype can be used repeatedly and is suitable for small batch production.
3. Use 1 gram of potassium chlorate and 40 milliliters of 15% hydrochloric acid to prepare a corrosive solution, and apply it to the corroded areas on the PCB for corrosion.
4. Wash the corroded printed board with water repeatedly. Wipe off the paint with banana water, and then wash it several times to make the printed board clean without leaving corrosive liquid. Apply a layer of rosin solution and let it dry before drilling holes.
Production method two:
There are many ways to make printed boards under amateur conditions, but they are either time-consuming, complicated in "workmanship", or uncomfortable in quality. And my method of making printing plates is one of the better comprehensive effects, the method is as follows:
1. Make a printed board map. The pads in the figure are represented by dots, and the connection can be a single line, but the position and size must be accurate.
2. Cut the printed board according to the size of the printed board drawing, and clean the copper foil surface.
3. Use carbon paper to copy the diagram to the printing board. If the circuit is simple and the producer has certain board-making experience, this step can be omitted.
4. According to the actual situation of the component, paste the standard pre-cut symbols (pads) with different inner and outer diameters; then paste the tape lines of different widths depending on the current. Standard pre-cut symbols and tape are available in electronic stores. The common specifications of pre-cut symbols are D373 (0D-2.79, ID-0.79), D266 (0D-2.00, ID-0.80), D237 (OD-3.50, ID-1.50), etc. It is best to buy paper-based materials. (Black), plastic-based (red) materials should not be used as much as possible. The commonly used specifications of tape are 0.3, 0.9, 1.8, 2.3, 3.7, etc. The units are all millimeters.
5. Use a softer hammer, such as smooth rubber, plastic, etc. to hit the sticker to make it fully adhere to the copper foil. Focus on the turning and overlapping of the line. In cold weather, it is best to use a heater to heat the surface to enhance the adhesion effect.
6. Put it into ferric chloride to corrode, but it should be noted that the liquid temperature is not higher than 40 degrees. After corrosion, it should be taken out and rinsed in time, especially if there are thin lines.
7. Punch the eyes, brighten the copper foil with fine sandpaper, apply rosin alcohol solution, and let it dry. The quality of this printed board is very close to that of a regular printed board. The 0.3mm tape can pass between the IC's feet, which can greatly reduce the short jumpers on the front of the board to save trouble and time. I often use this method to make experimental printing plates or a small amount of products in my work.
Production method three:
Dissolve one part of lacquer (namely shellac, available in chemical raw material stores) in three parts of absolute alcohol, and stir appropriately. Show a certain color, after mixing evenly, it can be used as a protective paint to paint the PCB board.
First polish the copper-clad board with fine sandpaper, and then use the duckbill pen (or the ink duckbill pen used to draw graphics on the compass) in the drawing instrument to draw. The duckbill pen has a nut to adjust the thickness of the stroke, and the thickness of the stroke It is adjustable, and can be drawn with a straightedge or a triangle ruler to draw a very thin line, and the drawn line is smooth and uniform, without edge jagged, giving people a smooth and fluent feeling; at the same time, it can also be in the free place of the PCB board. Write Chinese characters, English, pinyin or symbols.
If the drawn line is infiltrated to the surroundings, the concentration is too small and you can add a little paint flake; if you can't draw the pen, it is too thick, and you need to drop a few drops of anhydrous alcohol. It doesn't matter if you make a mistake, just use a small stick (matchstick) to make a small cotton swab, dipped in a little absolute alcohol, you can easily wipe it off, and then redraw it. Once the circuit board diagram is drawn, it can be corroded in the ferric chloride solution. After the circuit board is corroded, it is also very convenient to remove the paint. Dip a cotton ball with absolute alcohol to wipe off the protective paint, dry it for a while, and then apply pine perfume to use.
Because 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 cap after use. If the concentration becomes thicker when you use it next time, just add an appropriate amount Anhydrous alcohol is sufficient.
Production method four:
Stick the sticky note on the copper foil of the copper-clad board, and then draw the circuit on the veneer, then use a cutter to carve through the veneer to form the required circuit, remove the non-circuit part, and finally use ferric chloride to corrode or current The electrolysis method can produce a more ideal PCB circuit board.
The corrosion temperature can be carried out at about 55 degree Celsius, and the corrosion rate is faster. Rinse the corroded circuit board with clean water, remove the sticky notes on the circuit, make a hole, wipe it clean and apply a rosin alcohol solution for use.
Production method five:
1. Reasonably arrange the density of the components and the position of each component according to the shape of the components used in the PCB schematic diagram and the size of the printed board area. The location of the components should be determined according to the principle of large first, then small, first overall and then local, so that adjacent components in the circuit are placed nearby and arranged neatly and evenly.
2. The connecting wires between the components cannot be turned at right angles at the corners and the intersection of the two lines, they must be transitioned by curves, and they must not cross each other and turn too far. When some wires can't do this, you can consider printing wires on the reverse side of the printed board, and then use studs to connect with the front circuit, or use insulated wires when soldering components.
3. It is better for the input part and the output part to be farther apart to avoid mutual interference.
