Optical detecting method and device for back drilling depth

Abstract

The invention relates to the field of detecting back drilling depth of a PCB, in particular to an optical detecting method and device for a back drilling depth. The method comprises the steps of: vertically transmitting a plurality of light beam pulses to a back drilling surface of a workbench at the same moment by a detection instrument, and setting the starting emitting time of the light beam pulses as 0s; receiving the reflected light beam pulses of each light beam pulse by the detection instrument, and recording the receiving time of each reflected light beam pulse, wherein the maximum value of the receiving time is Tmax, and the minimum value of the receiving time is Tmin; and calculating the depth H of the back drilling hole according to the maximum value Tmax and the minimum Tmin inthe receiving time of each reflected light beam pulse, the transmission speed V of the light beam pulses and the angle [theta] of a drilling needle of the back drilling hole. The optical detecting method effectively improves the detection efficiency and rapidly detects the global back drilling situation on the premise without damaging of the workbench; and moreover, the usage of secondary materials is reduced and the purpose of energy-saving and cost-reducing is achieved.

Description

technical field [0001] The invention relates to the field of detection of the back-drilling depth of a PCB, in particular to an optical detection method and a detection device of the back-drilling depth. Background technique [0002] The traditional metallographic slicing method is used to detect the depth of back drilling. This method must destroy the work board. If the internal product is used for detection, it will cause waste of products; if the external test hole is used for detection, it may cause The detection result is distorted. At the same time, this method must be ground on special grinding equipment when slicing, resulting in waste of materials such as sandpaper, water, resin powder and quartz powder, and each slice can only detect local back drilling. [0003] Therefore, the traditional back-drilling depth detection using metallographic slices has the problems of time-consuming and labor-intensive and unable to detect globally. SUMMARY OF THE INVENTION [00...

AI Technical Summary

Problems solved by technology

[0002] The traditional metallographic section method is used to detect the depth of back drilling. This method must destroy the working board. If the internal product is used for detection, it will cause waste of products; if the external test hole is used for detection, it may cause The detection result is distorted

At the same time, this method must be ground on a special grinding device when slicing, resulting in waste of materials such as sandpaper, water, resin powder, and quartz powder, and each slice can only detect local back drilling.

[0003] Therefore, the traditional detection of back-drilling depth using metallographic slices is time-consuming and labor-intensive and cannot be detected globally.

Images