PCB Tech - There is always one of the five major circuit board manufacturing methods that suits you

There is always one of the five major circuit board manufacturing methods that suits you

PCB manufacturingmethod one:
1. Cut the copper-clad board to the size required by the circuit diagram.
2. Put 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 circuit board, and place the cut wax paper on the printed copper plate. Take a small amount of paint and talcum powder to make a thin and suitable printing material, dip the printing material with a brush, and apply it evenly on the wax paper, repeat it several times, and then the circuit can be printed on the printed board. This kind of engraving can be used repeatedly and is suitable for small batch manufacturing of PCB.

3. Use 1 gram of potassium chlorate and 40 milliliters of hydrochloric acid with a liquid concentration of 15% to produce a corrosive solution, and apply it to the circuit board where it needs to be corroded to perform corrosion.

4. Wash the corroded printed boards repeatedly with water. Wipe off the paint with banana water, and then wash it several times to keep the printed board clean without leaving corrosive liquid. Apply a layer of rosin solution and let it dry before drilling.

PCB manufacturing method two:

There are many ways to manufacture printed boards under amateur conditions, but they are either time-consuming, complicated in "craftsmanship", or dare not to flatter quality. And my method of manufacturing printed boards belongs to the one with better overall effect, and the method is as follows:

1. Make a printed board map. Use dots to express the pads in the figure, and you can cross the wires to a single line, but the position and size must be correct.

2. Cut the printed board according to the size of the printed board, and clean the copper foil surface.

3. Use carbon paper to copy the diagram to the printed board. If the circuit is simple and the manufacturer has certain board-making experience, this step can be omitted.

4. According to the actual situation of the component, the standard pre-cut symbols (pads) with different inner and outer diameters are adhered; and the tape lines of different widths are adhered according to the current volume. For standard pre-cut symbols and tape, electronic stores are available. 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 do their best to be unnecessary. 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, molecular compound plastic, etc., to beat the sticker to make it fully adhere to the copper foil. Focus on beating the corners and overlaps of the lines. When it is cold, it is best to use a warmer to warm 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 the corrosion is complete, it should be drawn and rinsed as soon as possible, 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 to complete the manufacturing. The quality of this printed board is very close to that of a regular printed board. The 0.3 mm tape can be passed between the two legs of the IC, which can greatly reduce the uprightness of the short jumper to save trouble and time. I use this method to make experimental printing plates or small quantities of products in the office.

Manufacturing method three:

Dissolve one part of paint (namely shellac, available at chemical raw material stores) in three parts of absolute ethanol, and mix them properly. After all of them are dissolved, drop a few drops of medical purple medicinal water (gentian violet) to make it Flash a certain color and mix and average it, then it can be used as best-effort paint to paint circuit boards.

First polish the copper-clad board with fine sandpaper, and then use the duck-billed pen in the drawing spectrograph (or the ink duck-billed pen used to draw graphics on the compass) to perform the drawing, and the duck-billed pen has the thickness of the adjustment strokes. The screw cap has adjustable stroke thickness, and can draw very thin straight lines with false seat ruler and set square, and the drawn lines are smooth and even, without marginal jagged, giving people a smooth, smooth and fluent feeling; at the same time, it is also Chinese, English, pronunciation or symbols can be written in the free space of the circuit board.

If the drawn lines are infiltrated around, the liquid concentration is too small and you can add a little paint; if you can't drag the pen, it is too thick, and you need to drop a few drops of absolute ethanol. It doesn't matter if you make a mistake, just use a small stick (take the lamp pole) and make a small cotton swab, dipped in a little absolute ethanol, you can easily wipe it off, and then paint again. Once the circuit board diagram is drawn, it can be corroded in the ferric chloride solution. After the circuit board is corroded, it is very convenient to remove the paint. Dip a cotton ball with absolute ethanol to wipe off the paint. After a little drying, it can be coated with turpentine and used.

Because ethanol evaporates quickly, the best-effort paint that has been manufactured should be kept tightly sealed in a small bottle (such as an ink bottle). Don't forget to cover the bottle after use. If you find that the liquid concentration has thickened during the next use, Just add an appropriate amount of absolute ethanol.

Manufacturing method four:

Immediately stick it on the copper foil of the copper-clad board, and then draw a good circuit on the veneer, then use a knife to carve through the veneer to form the required circuit, remove the non-circuit part and finally use ferric chloride to corrode or The current electrolysis method can produce a more ideal circuit board.

The corrosion temperature can be performed at about 55°C, and the corrosion rate is faster. Rinse the corroded circuit board neatly with clean water, remove the immediate stickers on the circuit, punch the holes, wipe it neatly, and apply the rosin alcohol solution for use.

Manufacturing method five:

1. Reasonably arrange the density of the components and the position of each component according to the component style used in the circuit schematic and the size of the printed board plane or the surface of the object. Confirm the position of the components should be implemented in accordance with the principle of first large and then small, first group and then part, so that adjacent components in the circuit are placed nearby and arranged evenly.

2. The connecting wires between the components cannot be turned at a 90-degree angle at the corner and the intersection of the two lines. They must be transitioned with a curve, and they must not be interlaced or circuited too far. When a little wire really cannot do this, you can think about the problem of printing wires on the reverse side of the printed board, and then use studs to connect with the front circuit, or use additional insulated wires when soldering components.

3. The distance between the input part and the output part is better to avoid mutual interference.

Manufacturing method six:

Radio enthusiasts have been annoyed by the manufacture of circuit boards. Now I will introduce to you a kind of "sub-printing" method of manufacturing printed circuit boards. The method is as follows:

1. Print the circuit board diagram of the rank of the printer on 80 grams of copy paper at a ratio of 1:1. It can be drawn by hand, but the bottom paper should be flat.

2. Find a fax machine, take out the fax paper in the machine, and replace it with a hot melt plastic film. Put the circuit diagram into the entrance of a fax machine, and use the copy button of a fax machine to copy the circuit diagram on the hot-melt plastic film. At this time, the "printed manuscript" of the printed circuit board is ready.

3. Use double-sided adhesive tape to affix the painted plastic film to the copper-clad board evenly. Pay attention to flat, no wrinkles, tape paper can not cover the melting part, otherwise it will affect the manufacturing effect of the circuit board.

4. Use a paint brush to evenly brush the paint on the plastic film. Note: Do not brush back and forth. You can only brush in one direction. Otherwise, the plastic film will wrinkle together and the lines on the copper plate will be exposed and layered. After the circuit diagrams have been brushed all over, carefully remove the plastic film. At this time, a printed circuit board is printed. After it dries, it can be corroded.

If you want to print multiple pieces, you can make a wooden frame a little larger than the circuit board, and lay the screen on the wooden frame flatly and fix it. Then use double-sided tape to stick the fixed plastic film under the screen. Put the copper-clad board on the table, close the screen frame (the printed picture and the copper-clad board should be aligned left and right), use a paint brush to brush the paint in one direction in sequence, and remove the screen frame. The printed circuit board is printed. If there is any defect, it can be corrected with paint and bamboo chips.

Pay attention to the above process. When painting, the hand strength should be light and allowable. If the paint film is too heavy, the lines will run out of lace, and the lines will show up and break when the paint is too light. The plastic film must face up.