A kind of back drilling tool and preparation method thereof

Abstract

The invention relates to the technical field of circuit board processing, in particular to a back drilling tool and a preparation method thereof. The back drilling tool provided by the present invention comprises a handle and a blade, and the blade includes a blade body, a boss and a knife tip connected in sequence, and the blade body is connected to the handle; the maximum diameter of the blade tip and the diameter of the blade body are all less than the diameter of the boss; the blade tip The outer surface of the knife body is non-conductive, and the outer surface of the boss is conductive. During processing, the boss forms an electrical path with the inner layer of the workpiece, which plays a role in signal transmission, so that the hole depth can be precisely controlled. Through innovative tool structure design, get rid of the dependence of hole depth accuracy on workpiece thickness and process control, greatly improve processing efficiency and processing accuracy. The back-drilling tool preparation method provided by the present invention is used for processing the above-mentioned back-drilling tool, so that the back-drilling tool can accurately control the hole depth during back-drilling, get rid of the dependence of hole depth accuracy on workpiece thickness and process control, and greatly improve Processing efficiency and processing accuracy.

Description

technical field [0001] The invention relates to the technical field of circuit board processing, in particular to a back drilling tool and a preparation method thereof. Background technique [0002] The plated-through-hole (PTH) in the multilayer printed circuit board (Printed-Circuit-Board, referred to as PCB) plays the role of interconnecting the inner layer power layer and the ground layer. When the system enters the high-speed signal During transmission, the PTH hole will become the bottleneck and obstacle of signal integrity. It is like an excess "tail" (Stubs) in the transmission line, which acts as a notch filter. In the signal transmission line, two such When stubs are used, a section of oscillation will be formed, whether it is filtering or oscillation, it will cause damage to high-speed signal transmission and distort the signal. Back-drilling is to remove the part of copper (Stubs) that is not conducive to signal transmission in the PTH hole that has been electro...

AI Technical Summary

Problems solved by technology

The disadvantage of method 1 is that the back-drilling depth of the holes processed by this back-drilling method is consistent, and the thickness of the board is uneven. Generally, the board is thinner around the board and thicker in the middle, so the copper remaining in the hole after back-drilling Poor length uniformity limits the improvement of back-drilling capability. The thicker the board, the worse the thickness uniformity and the greater the length of residual copper

The disadvantage of method 2 is: the inner layer is used as the signal feedback layer for back drilling, which is excellent in controlling the copper length of the hole, and the plate thickness uniformity will no longer be an influencing factor for back drilling, but it has high requirements for other steps in the production process. The process control is difficult, and the diameter of back drilling is more than 0.3mm larger than that of the first drilling

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