PCB process flow chart

　　It can be seen from the process flowchart that the multi -layer board process is developed on the basis of double -faced metal chemical technology. In addition to the two -sided process, it also has several unique contents: the inner layers of metalized holes, drilling and removing epoxy drilling, positioning system, layer pressure, and special materials.

　　Our common computer board card is basically a two -sided printed lineboard of epoxy resin glass, one of which is the other side of the installation element and the other side of the component foot welding surface. The component foot divide vertical welding surface we call it as a pad. Why don't other copper -guided line figures not on tin? In addition to the pads and other parts of tin welding, the other parts have a layer of welded welding film. Most of its surface welded films are green, and a few use yellow, black, blue, etc. Therefore, in the PCB industry, welding oil is often called green oil. Its role is to prevent the phenomenon of bridge during wave welding, improve the quality of welding and saving welds. It is also a permanent protective layer of the printed board, which can play a role in moisture -proof, corrosion corrosion, mildew and mechanical abrasions. From the appearance, the smooth and bright green welded film on the surface is the green oil of the Filin -to -board sensor thermalized green oil. Not only is the appearance look good, it is important that the accuracy of its pads is higher, which improves the reliability of the solder joints.

　　As can be seen from the computer board, there are three ways to install components. One of the plug -in installation processes for transmission, insert electronic components into the puppet holes of the printed circuit board. In this way, it is easy to see that the duration of the two -sided line board is as follows: one is the simple component inserted hole; the other is that the component is installed with the double -sided interconnection pores; the third is the simple double -sided guidance Tongtong; Fourth, the installation and positioning hole of the substrate. The other two installation methods are directly installation and chip installation. In fact, the direct installation technology of the chip can be considered as a branch of surface installation technology. It is to directly stick the chip to the printed board, and then use the wire welding method or load method, inverted method, beam lead method and other packaging technologies to interconnect to print to print On the system. Its welding surface is on the component surface.