1. Cut the copper clad plate into the size required by the circuit diagram. 2. Put the wax paper on the steel plate, use a pen to carve the circuit diagram on the wax paper according to 1:1, and cut the circuit diagram on the wax paper according to the circuit board size, cut the wax paper on the printed copper plate. Take a small amount of paint and talcum powder into thin and suitable printing material, dip in with a brush printing material, evenly coated on wax paper, repeated several times, printed board can be printed on the circuit. This type of stereotype can be used repeatedly and is suitable for small batch production. 3. Prepare the corrosion solution with 1g potassium chlorate and 40 ml hydrochloric acid with the concentration of 15%, and rub it on the circuit board where it needs to be corrode. 4. Repeatedly clean the corroded PCB with water. Remove the paint with banana oil and clean the board a few more times, leaving no etch. Apply a layer of rosin solution to dry the hole.
In the amateur conditions to make a lot of ways, but is not time consuming, or “craft” complex, or quality dare not be praised. And the method that I make printing plate belongs to a kind with better comprehensive effect, the method is as follows: 1. Printing board drawing. The welding pad in the figure is represented by dots. It can be connected by a single line, but the position and size should be accurate. 2. According to the size of the printing board diagram, cut the printing board and clean the copper foil surface. 3. Use carbon paper to copy the map to the printing plate, if the circuit is simple, and the producer has some experience in plate making, this step can be omitted. 4. Paste the standard pre-cut symbols (pads) with different inner and outer diameters according to the specific conditions of the components; Then paste the tape lines of different widths according to the current. Standard pre-cut symbols and tapes are available in electronic stores. Common specifications of pre-cutting 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 base (red) materials as far as possible do not use. There are 0.3, 0.9, 1.8, 2.3, 3.7 and so on. The units are all millimeters. 5. Use a small, soft hammer, such as smooth rubber, plastic, etc., to hit the stickers, making it fully adhere to the copper foil. The emphasis is on the turning and lap joints. When it’s cold, it’s best to heat the surface with a heater to strengthen adhesion. 6. Corrosion in ferric chloride, but it should be noted that the liquid temperature is not higher than 40 degrees. After corrosion should be taken out and washed clean, especially in the case of thin lines. 7. Punch holes, use fine sandpaper to brighten the copper foil, apply rosin alcohol solution, and dry it. The quality of this PCB is very close to that of normal PCB. 0.3 mm tape can be crossed between IC feet, which can greatly reduce the short jumper on the front of the board to save time and time. I often use this method in the work to do experimental plate or a small number of products.
Paint (that is, shellac, sold in chemical raw materials store) in one part, dissolve in three parts of anhydrous alcohol, and stir properly, after all dissolved, drop a few drops of medical violet (gentian violet), make it appear a certain color, stir evenly, can be used as a protective paint to describe the circuit board.
Apply polish copper plate with fine sand paper first, and then use the drawing pen drawing instrument (or ink drawing pen used to draw graphics on compass), paints, adjust the stroke weight of nut drawing pen, the stroke weight is adjustable, and can borrow ruler, set square depicts a very fine line, and as the line is smooth, uniform, margin serrate, give a person the sense with smooth and fluent; At the same time, Chinese characters, English, pinyin or symbols can be written in the spare space of the circuit board.
The lines drawn, if the infiltration to the surrounding, is too small concentration, you can add a bit of paint; If you can’t start, it’s too thick and you need a few drops of anhydrous alcohol. It doesn’t matter if you make a mistake, just use a small stick (matchstick), make a small cotton swab, dip in a bit of anhydrous alcohol, easily erase it, and then repaint it. Once the circuit board diagram is drawn, it can be corroded in ferric chloride solution. After the circuit board is corroded, it is convenient to paint it. Dip in anhydrous alcohol with cotton ball, and wipe off the protective paint. Once dried, rosin water can be applied to it.
Because alcohol volatilizes fast, the protective paint that has prepared should be put in vial (be like ink bottle) sealed save, do not forget to cover bottle cap after using, if be used next time, discover concentration to thicken, should add right amount to do not have water alcohol only can.
The post-it note is pasted on the copper foil coated with copper plate, and then the circuit is drawn on the veneer, and then the veneer layer is cut through with a carving knife to form the required circuit, and the non-circuit part is removed. Finally, the ideal circuit board can be produced by corrosion of ferric chloride or current electrolysis.
Corrosion temperature can be around 55℃, corrosion speed is fast. Clean the corroded circuit board with water, remove the post-it stickers from the circuit, make holes, wipe off and apply rosin alcohol solution for use.
1. Reasonably arrange the density and position of each element according to the shape of the element used in the circuit schematic diagram and the size of the printing board area. The location of components should be determined in accordance with the principle of first large, then small, first whole, then part, so that adjacent components in the circuit are placed nearby and arranged neatly and evenly.
2. The connection wire between the elements at the corner and the intersection of two lines can not turn a right Angle, must use the curve transition, also can not cross and detour too far. When some wires are really unable to do this, you can consider printing wires on the back of the printing board, and then connect with the front circuit with a pin, or when welding components with another insulated wire connection.
3. The input part and the output part should be far away, so as not to interfere with each other.
Radio enthusiasts have had trouble making circuit boards. Now we introduce a “subprinting” method to make printed circuit board. The methods are as follows:
First, on the printer printed circuit board diagram by 1:1 ratio on 80 grams of copy paper. Hand drawing is ok, but the base paper should be flat.
Find a fax machine, take out the fax paper and replace it with hot melt plastic film (sold by our company). Put the circuit diagram into the fax machine inlet and use the copy key of the fax machine to copy the circuit diagram on the hot-melt plastic film. This is when the printed circuit board’s “printed manuscript” is ready.
Three, with double-sided tape will make good figure of the plastic film flat paste on the copper coating. Be sure that it is flat, not wrinkled, and that the adhesive tape does not cover the melted part, otherwise the production effect of the circuit board will be affected.
Four, with paint brush paint evenly brush on plastic film, note: can not reciprocate to brush, can only follow a direction in turn brush, or plastic film together, the lines on the copper will overlap. When the circuit diagram is completely brushed, carefully remove the plastic film. A printed circuit board is printed. When dry, it will corrode.
If you want to print more blocks, you can make a larger than the circuit board of the wooden frame, the screen (the company has the screen to sell) flat on the wooden frame, fixed. Then use double-sided tape will be fixed shadow plastic film paste in the screen below. Place the plate on the table and close the screen frame (align the print with the plate). Brush the paint in one direction and remove the screen frame. The printed circuit board is printed. If defective, paint and bamboo can be used to modify.
The above process must pay attention to, when painting, hand force to weight appropriate, too heavy paint film is too thick, line will run lace, too light line will appear broken. Plastic film must be face up.