Method for machining PCB through hole

Abstract

The invention discloses a method for machining a PCB through hole. The method includes the steps that a PCB core board is provided, a needed inner-layer circuit is corroded on the PCB core board, and the PCB core board is pressed to form a first multi-layer board; a corresponding shielding hole is drilled in the position, where the through hole needs to be drilled, on the first multi-layer board, and the diameter of the shielding hole is larger than the diameter of the through hole; metallization processing is carried out on the shielding hole, and the shielding hole is filled with non-conducting materials; the first multi-layer board is pressed again to form a second multi-layer board, and copper layers are additionally arranged on the top layer and the bottom layer of the second multi-layer board respectively; the through hole is drilled in the center of the shielding hole and penetrates through the copper layers on the top layer and the bottom layer in a drilling mode; metallization processing is carried out on the through hole, and a needed outer-layer circuit is corroded on the second multi-layer board. By means of the embodiment, a seamless shielding layer is formed at the position of the through hole, and reflection and losses caused during signal transmission of the PCB through hole are effectively reduced.

Description

technical field [0001] The invention relates to the technical field of circuit board printing, in particular to a method for processing PCB via holes. Background technique [0002] With the rapid development of communication and telecommunication industries, the operating frequency of PCB products is getting higher and higher. The existence of capacitive and inductive reactance in via holes in PCB products leads to more and more serious signal reflection problems at via holes. In order to improve PCB Product transmission performance, reduce loss, via holes in PCB design often reduce the signal reflection of the via holes by adding shielding holes around the via holes, but with the design of adding shielding holes around the via holes, the It is impossible to shield the signal reflection, and the via hole cannot be drilled at the position where the signal line is drawn out. The current shielding hole design and PCB processing technology cannot solve the signal reflection prob...

AI Technical Summary

Problems solved by technology

The design and processing technology of the existing via hole shielding hole cannot be infinitely approached due to the limitation of PCB drilling accuracy

If the shielding holes are designed to be tangent, the bridging strength will be low, and the remaining signal lines will be easily broken.

At present, there will inevitably be gaps in this type of design, and at the same time, the position of the signal line cannot be drilled for shielding, so that the via hole cannot achieve a good shielding effect, resulting in a large reflection of the via hole during signal transmission, which affects the performance of signal transmission

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