Drilling method and device of a printed circuit board

Abstract

The invention relates to a drilling method and device of a printed circuit board. The method includes the steps that a drill bit drills holes from the initial position, when the drill bit makes contact with a first conductive layer of the printed circuit board, a drill generates a first electric signal and determines a first conductive position according to the first electric signal, and first Z-coordinate information corresponding to the first conductive position is obtained; after the first conductive layer is drilled out, the drilling continues, when the drill bit makes contact with a second conductive layer, the drill generates a second electric signal and determines a second conductive position according to the second electric signal, and second Z-coordinate information corresponding to the second conductive information is obtained; the drilling continues, and a through hole is obtained after the printed circuit board is drilled through; back drilling is performed in the through hole position according to a preset depth, wherein the preset depth is the sum of the thickness of the dielectric between the second conductive layer and the first conductive layer and the compensation depth. By acquiring the value of difference between the back drilling face and the layers which must be drilled through in the through hole drilling process, the accurate back drilling depth is acquired, and the Stub length of the back drilling is reduced.

Description

technical field [0001] The present invention relates to the technical field of manufacturing printed circuit boards (Printed Circuit Board, PCB), in particular to a drilling method and device for printed circuit boards. Background technique [0002] With the rapid development of wireless and network communication technologies, the operating frequency of communication products is getting higher and higher, and the increase in operating frequency of communication products puts forward higher requirements for loss control in the transmission process. The back-drilling of the printed circuit board is a processing method that effectively reduces the loss of the hole link. The smaller the length of the redundant hole copper (Stub) above the signal layer after the back-drilling, the smaller the loss. [0003] Under the existing technology, the plated through hole (Plated Through Hole, PTH) is generally back-drilled according to the pre-calculated theoretical back-drilling depth; an...

AI Technical Summary

Problems solved by technology

Due to the uneven thickness of the PCB board, there are certain differences in the thickness of the same batch of PCB boards, even the thickness of different positions of the same PCB board is also different

The disadvantage of the existing technology is that the back-drilling depth obtained according to the test results of the conventional back-drilling Coupon position on the edge of the PCB deviates from the actual depth of the back-drilling position on the PCB, and the thicker the PCB, the greater the absolute value of the deviation , the greater the deviation of the back drilling depth

[0004] The functions realized by the PCB are becoming more and more complex, and the degree of integration is getting higher and higher. Correspondingly, the PCB board needs more layers and greater thickness to meet the functional design requirements of the PCB board, and through the above-mentioned PCB board edge and back drilling Coupon The deviation of the back-drilling depth obtained from the position test results is relatively large, which makes the length of the stub large, and the hole link loss has a great influence on high-frequency signal transmission.

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