Detection method of figure splicing errors of laser direct imaging device

Abstract

The invention provides a detection method of figure splicing errors of a laser direct imaging device. The method includes the following steps that: splicing detection figures are inputted to the laser direct imaging device; a substrate is installed and commissioned; exposure imaging is performed on the substrate; a CCD image processing system captures the coordinates of the center of the circle at the left side; the CCD image processing system captures the coordinates of the center of the circle at the right side; and a splicing error value can be obtained. According to the detection method of the invention, a spatial light modulator directly images a laser beam on the substrate coated with a light sensing dry film; the CCD image processing system of the laser direct imaging device is utilized to capture the coordinates of the centers of the circles at two sides of a figure splicing position; and the error of the coordinates at the two sides in an X direction and a Y direction is calculated, and the error is a splicing error. According to the method, a chemical development step and a microscopic measurement step are omitted, and therefore, detection efficiency and accuracy can be greatly improved.

Description

technical field [0001] The invention relates to the technical field of graphic transfer of printed circuit boards, in particular to a detection method for graphic splicing accuracy of laser direct imaging equipment. Background technique [0002] For the field of printed circuit board processing, especially the manufacture of high-precision HDI boards and packaging substrates, image transfer equipment is undoubtedly the core part. [0003] At present, there are two types of printed circuit board (PCB) image transfer equipment: traditional projection exposure equipment and laser direct imaging equipment (LDI). The graphics of the traditional projection exposure equipment have been printed on the film film, and the film film is irradiated with ultraviolet rays to transfer the figure to the PCB with a photosensitive dry film on the surface. After the dry film is exposed, the unexposed part of the dry film is dissolved by a chemical solution. In the laser direct imaging equipmen...

AI Technical Summary

Problems solved by technology

In the laser direct imaging equipment, the laser beam directly scans and images the exposure pattern on the photosensitive dry film through the spatial light modulator. Many small patterns with the same size of the modulator, when these small patterns are exposed on the surface of the printed circuit board, these small patterns are re-stitched into a complete pattern. In actual work, due to the accuracy error of the motion control system in the X and Y directions , the stitching between the small graphics will produce a fixed stitching error, that is, the stitching between the small graphics will produce deformation, and this deformation will lead to traces of stitching in the final complete graphic, and then in Factory production will cause product quality problems

[0004] The splicing error detection method usually used at present is to measure the error of the pattern splicing with a microscope after the PCB covered with a dry film is exposed and developed. This method has problems such as low efficiency, low detection accuracy, and large manual measurement errors.

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