The material of the copper plate is the immersion gold process, and the welding holes of the copper plate are exposed copper, which is cash yellow in color. When storing, wrap the solder hole in newspaper to prevent oxidation. In case the solder hole oxidizes (the solder pad loses its luster or is difficult to tin), you can use a cotton swab dipped in alcohol or an eraser to wipe it

The use of the universal board is simple and easy to operate. 1. Plan the route first (when there are many components, you can plan the approximate position and route of the components on the paper). 2. Insert the pins of the components from the front to the back of the universal board. Then use a soldering iron to melt the solder, and the melted solder will bond and fix the pins of the component to the copper ring of the universal board.