The definition of PCB impedance board is that a good laminated structure can control the characteristic impedance of the printed circuit board, and its wiring can form an easily controlled and predictable transmission line structure called the impedance board.

During the process from the inner line pattern transfer of substrate to the outer line pattern transfer by pressing several times, the different longitudinal-weft expansion and contraction of the slab will be caused. From the whole PCB production FLOW-CHART, we can find out the reasons and processes that may cause abnormal expansion and shrinkage of board parts and poor dimensional consistency.

For many friends who do not know much about the circuit board industry, they always think that PCB is PCBA in their consciousness, there is no difference between them, in fact, the difference between PCB bare board and PCBA is very big.

Copper plating is the most widely used in order to improve the binding force of the coating and a pre-coating, copper plating is an important protective decorative coating copper/nickel/chromium system components, flexible and low porosity of copper plating, to improve the binding force and corrosion resistance between the coating plays an important role.

Via hole also known as a conduction hole. In order to meet customer requirements, in the process of PCB production, the through hole must be plugged. Through practice, it is found that in the process of plugging, if the traditional aluminum sheet plugging process is changed, the use of white mesh to complete the plate face welding and plugging, the PCB production can be stable and the quality is reliable.

In the automatic insertion line, if the printed board is not smooth, it will cause inaccurate positioning, and the components can not be inserted into the holes of the board and the surface mount pad, and even break the automatic insertion machine. The board on which the components are installed is bent after welding, and the component feet are difficult to cut neatly.

The typical process of PCB processing uses the "graphic plating method". That is, a layer of lead-tin corrosion resistance layer is pre-plated on the copper foil part that needs to be retained on the outer layer of the board, that is, the graphic part of the circuit, and then the rest of the copper foil is corroded by chemical means, which is called etching.

With regard to the "through hole window" and "through hole cap oil" point (PAD and VIA usage distinction), many customers and design engineers often ask what this means when placing a system order, which option should I choose for my file?

Immersion gold and gild is the process often used in PCB circuit boards, many engineers can not correctly distinguish the difference between the two, and even some engineers think that there is no difference between the two, this is a very wrong view, must be corrected in time.

Although the current EDA tools are very powerful, as the PCB size requirements are getting smaller and smaller, the device density is getting higher and higher, the difficulty of PCB design is not small. How to achieve high PCB flux and shorten the design time?

PCB Multilayer circuit board design tools are mainly used for layout creation software. During the time period in which the circuit is designed, this software is used to automate various tasks that are performed manually in advance by the EDE. A wealth of tools are provided with excellent features and options for designing PCB.

The complexity of the circuit board production process and the complexity of process maintenance, especially in chemical wet treatment, makes it difficult to prevent the foaming defects of the board surface. Based on many years of actual production experience and service experience, the causes of the foaming of the copper plating board surface of the circuit board are briefly analyzed, hoping to help the industry peers!

PCB regardless of the internal quality, the surface is similar. It is through the surface that we see the differences, and these differences are critical to the durability and functionality of the PCB throughout its life.

First-class production comes from first-class design, the production of panel technology can not be separated from your design, the engineers please design according to the conventional production process details.

PCB surface treatment process changes are not very large, it seems to be a relatively distant thing, but it should be noted that long-term slow changes will lead to great changes. In the case of increasing calls for environmental protection, the surface treatment process of PCB will definitely change dramatically in the future.

PCB printed circuit board processing how to remove tin? Generally speaking, there are six methods: direct blowing of hot air gun, tin suction disassembly method, medical hollow needle disassembly method, electric soldering iron brush with disassembly method, increase solder melting disassembly method, and multiple copper wire tin suction disassembly method.