In the last article, we have introduce “ What is PCB and Types of PCB?” and I believe we can not said it again. Next, let’s learn something new. Most of the students majoring in electronic engineering need to try to make simple electronic circuit DIY projects and make PCBs. This article will introduce "how to make PCB at home" without any special materials. Let’s briefly review the content of the previous article.
PCB: The full name is printed circuit board, which is the support of electronic components and the carrier of the connection of electronic components. PCB types can be divided into: single-layer PCB, double-layer PCB, multilayer PCB, rigid PCB, high-frequency PCB, flexible PCB, rigid flexible PCB, aluminum backplane and other types.
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 circuit 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 area on the circuit board 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.
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. 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 printed 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 bend and overlap of the line. When it is cold, it is best to use a heater to increase the surface by .
6. It is corroded by adding ferric chloride, 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. Drill the eyes, polish the copper foil with fine sandpaper, apply rosin alcohol solution, and let it dry to complete the production. The quality of this type of printed board is very close to the distance of the printed board. The 0.3mm tape can pass between the IC legs, but I often use this method to make experimental printing plates or small amounts of products in my work.