Multilayer PCB board is used in electrical products in the multi-layer circuit boards
Multilayer PCB board is used in electrical products in the multi-layer circuit boards, multi-layer board with more single-sided or double-panel wiring board. With a double-sided inner layer, two single-sided for the outer layer or two double-sided for the inner layer, two single-sided for the outer printed circuit board, through the positioning system and insulation bonding materials alternately and conductive graphics According to the design requirements of the interconnection of the printed circuit board has become a four-story, six-layer printed circuit board, also known as multi-layer printed circuit board.
With the continuous development of SMT (Surface Mount Technology) and the continuous introduction of new generation SMD (Surface Mount Devices), such as QFP, QFN, CSP, BGA (especially MBGA), make electronic products more intelligent and miniaturized To promote the Multilayer PCB industrial technology, a major reform and progress. Since 1991, IBM has successfully developed a high-density Multilayer PCB board, the major groups have also developed a variety of high-density interconnect (HDI) microplates. The rapid development of these processing technology, prompted the design of Multilayer PCB board has been gradually to the multi-layer, high-density wiring direction. Multilayer PCB board with its design flexibility, stable and reliable electrical performance and superior economic performance, is now widely used in the production of electronic products.
Multilayer PCB board and single-panel, double-panel The biggest difference is that the internal power supply layer (to maintain the internal layer) and ground plane, power and ground network mainly in the power layer wiring. However, multi-layer board wiring is mainly to the top and bottom of the main, supplemented by the middle of the wiring layer. Therefore, the design of multi-layer board and double-panel design method is basically the same, the key is how to optimize the wiring of the inner layer, so that the circuit board wiring is more reasonable, better electromagnetic compatibility.
Any piece of Multilayer PCB board, there are other components with the assembly of the problem, so the shape and size of printed circuit board must be based on the product structure. However, from the production process point of view, should be as simple as possible, generally the aspect ratio is not too large of the rectangle, in order to facilitate the assembly, improve production efficiency and reduce labor costs.
The number of layers, must be based on circuit performance requirements, board size and line-intensive degree. For Multilayer PCB printed circuit board, the four-layer board, six-layer board is the most widely used, four-layer board, for example, is the two wire layer (component surface and welding surface), a power layer and a formation.
The layers of the Multilayer PCB board should be symmetrical, and preferably even copper layers, ie, four, six, eight layers and so on. Because of asymmetric lamination, the board is prone to warping, especially for surface-mount multilayer boards, and should be noted.