remove oil

　　The surface of the aluminum base plate is coated with an oil layer during processing and transportation, and it must be cleaned before use. The principle is to use gasoline (usually aviation gasoline) as a solvent to dissolve it, and then use a water-soluble cleaning agent to remove oil stains. Rinse the surface with running water to make the surface clean and free of water droplets.

　　 skim

　　After the above-mentioned treatment, the surface of the aluminum substrate still has unremoved grease. In order to remove it, soak it with strong alkali sodium hydroxide at 50°C for 5 minutes, and then rinse it with water.

　　 alkaline etching

　　As the base material, the surface of the aluminum plate should have the highest roughness. Since the aluminum substrate and the aluminum oxide film layer on its surface are both amphoteric materials, the surface of the aluminum substrate can be roughened by the corrosive effect of an acidic, alkaline or composite alkaline solution system on the aluminum substrate. In addition, other substances and additives need to be added to the roughening solution to achieve the following objectives.

　　 chemical polishing (dip bright)

"Because the aluminum base material contains other impurity metals, it is easy to form inorganic compounds that adhere to the surface of the substrate during the roughening process, so the inorganic compounds formed on the surface should be analyzed. According to the analysis results, prepare a suitable soaking solution, and place the roughened aluminum substrate in the soaking solution to ensure the best time, so that the surface of the aluminum plate is clean and shiny.

Five requirements for PCB imposition

　In order to facilitate the production and manufacture, the PCB circuit board is generally ***designed with Mark points, V-shaped grooves, and processing edges.

　　 One, PCB jigsaw design

　　1. The frame (clamping edge) of the PCB splicing method should adopt a closed-loop control design scheme to ensure that the PCB splicing method is not easily deformed after being fixed on the fixture.

　　2. The total width of PCB splicing method is ≤260Mm (SIEMENS line) or ≤300mm (FUJI line); if the glue is fully automatic, the total width of PCB splicing method is ≤125mm×180mm.

　　3. The appearance design of the PCB jigsaw method is as close as possible to the square shape. It is strongly recommended to use 2×2, 3×3, ... the jigsaw method; but it is not necessary to spell out the positive and negative boards;