PCB back drilling control method and PCB

Abstract

The invention belongs to the technical field of PCB manufacturing and discloses a PCB back drilling control method and a PCB. The PCB back drilling control method comprises steps: a through hole is opened in the PCB; with the drilling surface of back drilling as an upper surface, the distance L between an upper surface copper layer to a reference layer is measured; the PCB is electroplated; the thickness T of an electroplating layer on the upper surface copper layer is measured; and back drilling with a depth of L+T is carried out from one side of the upper surface copper layer on the throughhole. The PCB is manufactured by using the above PCB back drilling control method. The distance between the upper surface copper layer and the reference layer is measured before electroplating, the thickness of the electroplating layer on the upper surface copper layer is measured after electroplating, the sum of the two is used as a reference index for the depth of the back drilling, high-precision nondestructive detection on the dielectric thickness is realized, the back drilling depth can be accurately controlled in the case of back drilling, and the setting precision of a through hole residual pile can be improved.

Description

technical field [0001] The invention relates to the technical field of PCB preparation, in particular to a PCB backdrilling control method and a PCB. Background technique [0002] PCB (Printed Circuit Board), the Chinese name is printed circuit board, as a support for electronic components, it is an important electronic component. [0003] The via stubs in the PCB have a serious impact on signal transmission. At present, the impact of via stubs is mainly reduced by back drilling. Due to the influence of uneven thickness at different positions, conventional methods cannot achieve via stubs. High precision and stable control of piles requires the design of a conductive reference layer on the inner layer to detect the actual thickness of the medium. This method mainly requires the design of a conductive induction layer on the inner layer (special graphic design, and a back-drilling rig with special functions is required to cooperate with it. ), the graphic design of the inner ...

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Problems solved by technology

[0003] The via stubs in the PCB have a serious impact on signal transmission. At present, the impact of via stubs is mainly reduced by back drilling. Due to the influence of uneven thickness at different positions, conventional methods cannot achieve via stubs. The high-precision and stable control of piles requires the design of a conductive reference layer on the inner layer to detect the actual medium thickness. This method mainly requires the design of a conductive induction layer on the inner layer (special graphic design, and a back-drilling rig with special functions is required to cooperate with it. ), the graphic design of the inner layer has been changed, and a conductive sensing layer is added to the position of the back-drilling hole, and the sensing layer needs to be connected as a whole, and connected to the via hole on the edge of the board, which will affect the signal of the adjacent layer and cannot meet the signal integrity sexual design requirements

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