主板构造（Mainboard construction）.docVIP

主板构造（Mainboard construction） 1. circuit board PCB printed circuit boards are indispensable to all computer boards. It is actually made of several layers of resin material, and the inside is made of copper foil. The general PCB circuit board is divided into four layers, the top and bottom two layers are signal layers, and the middle two layer is the ground layer and the power supply layer, and the grounding and the power supply layer are placed in the middle, so that the signal line can be easily modified. Some boards with higher requirements can reach 6-8 layers or more. How is the motherboard (circuit board) manufactured? The manufacturing process of PCB consists of glass epoxy resin (Glass) Epoxy) or a PCB substrate made of similar material. The production of the first step is drawn between parts of wiring optical on-line, the method is the use of negative transfer (Subtractive Transfer) the printed circuit board of the designed PCB circuit board is printed on the metal conductor. The technique is to spread a thin sheet of copper foil over the entire surface and remove the excess. And if the production of double-sided panels, then PCB on both sides of the substrate will be covered with copper foil. And want to do multilayer board, can do two pieces of double deck board with special adhesive, press close rise. Next, the drilling and plating of the plugged components can be done on the PCB board. After drilling according to the requirements of the drilling machine, the hole must be plated (plated through hole), Plated-Through-Hole Technology, PTH). After the inside of the hole is made of metal, each layer of the inner line can be connected with each other. The impurities in the hole must be removed before starting the plating. This is because the resin epoxy will produce some chemical changes after heating, and it will cover the inner PCB layer, so clear it off first. Removal and plating operations are performed in the chemical process. Next, it is necessary to over