Printed circuit board hole wall roughness prediction method considering wear characteristic of micro-drill

Abstract

The invention discloses a printed circuit board hole wall roughness prediction method considering wear characteristics of a micro-drill. The method comprises the following steps: obtaining a PCB front image and a PCB bottom image of a micro-drill through optical microscopic photographing equipment on a PCB drilling machine, and reading machining parameters of a feed speed and a rotation speed on the drilling machine at the moment; performing machine vision processing on the PCB front image and the PCB bottom image, specifically, performing contour superposition, a key point selection algorithm and measurement on the PCB front image to obtain an actual diameter of the micro-drill; applying a region growing algorithm to the PCB bottom image to obtain a wear image of a micro-drill blade surface, and obtaining the blade surface wear area of the micro-drill and a notch depth of a micro-drill blade surface through recognition of pixel points in multiple wear zones; and finally, taking the actual diameter, the blade face wear area and the notch depth of the micro-drill, and the two machining parameter characteristics of the feed speed and the rotation speed as input characteristics, and inputting the input characteristics into a trained GBDT network to complete prediction of PCB hole wall roughness.

Description

technical field [0001] The invention belongs to the technical field of predicting the machining quality of printed circuit board (PCB) mechanical drilling, and more specifically, relates to a method for predicting the roughness of the hole wall of a printed circuit board considering the characteristics of the wear amount of the micro-drill. . Background technique [0002] After the PCB is mechanically drilled to form the surface of the microhole, it is necessary to plate copper on the surface of the microhole to complete the connection between the lines. Copper plating is a process from copper in ionic state to copper in solid state through electrochemical reaction, which requires electroplating solution to come into contact with the microporous surface. During the electroplating process, the electroplating solution itself must be continuously exchanged to replenish the copper ions converted into solids, so the ability of copper plating to fill pits is limited. If there ar...

AI Technical Summary

Problems solved by technology

One is that some drill bits that have not exceeded the number of drilling times have actually exceeded the wear standard of micro-drilling, which leads to the substandard roughness of the micro-hole wall, and the other is that some drill bits that have exceeded the number of drilling times have not actually produced more Large wear, replacement or discarding of such drill bits will reduce the actual utilization of micro drills

[0006] From the above analysis, it can be seen that in actual production, the judgment of micro-drill wear and hole wall roughness is usually based on the empirical value of the number of drilling times, and there is a lack of strict and accurate quantitative prediction methods.

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