Method for fabricating printed circuit board, printed circuit board and electronic device

Abstract

The application provides a method for fabricating a printed circuit board. The printed circuit board includes a device layer and a plurality of wiring layers, wherein the device layer is provided witha first predetermined number of ball grid array (BGA) chips. The method includes steps of dividing back drill holes required by wiring into a second predetermined number of categories; determining the total number of the wiring layers including the back drill holes according to the second predetermined number of categories; and using the device layer as a first layer, arranging wires layer by layer in an depth-to-shallow order according to the depth of the back drill holes, wherein the back drill holes of the wiring layer where the wires are arranged earlier are close to the BGA chips, and the back drill holes of the wiring layer where the wires are arranged later are away from the BGA chips. The method can avoid the signal loss caused by too many wires spanning the back drill hole layerswhen the high-speed signal in the BGA chips is out of the PCB, can also arrange the wire sequence, reduce the wiring layers, and reduce the difficulty of manufacturing the printed circuit board. Theapplication also provides a printed circuit board and an electronic device.

Description

technical field [0001] The present application relates to the technical field of hardware packaging, in particular to a method for manufacturing a printed circuit board, a printed circuit board and electronic equipment. Background technique [0002] As the functions of the current server become more and more powerful, the transmission rate of the internal signal of the server is increasing day by day, so the requirements for the performance of the high-speed signal transmission of the server are also getting higher and higher. However, since the chips packaged on the server PCB (Printed Circuit Board, printed circuit board) are becoming more and more dense, the signal performance of the BGA (Ball Grid Array, solder ball array package) chip wiring in the PCB has become a factor that affects the server's high-speed signal transmission performance. Key factor. [0003] At present, the fan-out (Fanout) method is generally used when the BGA chip in the server PCB goes out. The ...

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Problems solved by technology

[0003] At present, the fan-out (Fanout) method is generally used when the BGA chip in the server PCB goes out. The signal is distorted

Therefore, in order to reduce signal loss, it is necessary to reduce the impact of via stubs through back-drilling. However, due to the back-drilling process, back-drilled holes are larger in diameter than ordinary vias, causing the back-drilled area to be used for wiring and The area of ​​copper laying is reduced. At the same time, the hole after back drilling needs to avoid the wiring and copper foil farther away, making it difficult to get out of the area where the BGA chip is located, resulting in chaotic wiring layout, and may also cause a large number of wiring to cross the back when going out. High-speed signal loss caused by drilling level

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