Method of removing metal film covering surface of polymer substrate by direct laser etching

Abstract

The invention provides a method of removing a metal film covering the surface of a polymer substrate by direct laser etching. The method includes: setting initial process parameters of direct laser etching, which enable the thickness of the metal film removable by single laser scanning to be smaller than maximum allowable damage depth of the polymer substrate; performing laser scanning according to the initial process parameters, and acquiring an infrared temperature field accumulated image of the surface of a workpiece; comparing the current infrared temperature field accumulated image to a historical infrared temperature field accumulated image; if abrupt change occurs, continuing to scan; if abrupt change occurs, setting improved process parameters which enable the thickness of the polymer substrate removable by single laser scanning to be smaller than a half of the maximum allowable damage depth; and performing final precision laser scanning according to the improved process parameters. The method has the advantages of the process is simple, etching precision is high, applicability is high, closed-loop adaptive control of laser etching process is realized, and the process is well repeatable.

Description

technical field [0001] The invention belongs to the field of laser processing, and in particular relates to a method for removing a metal film covered on the surface of a polymer substrate by means of laser direct etching. Background technique [0002] Laser processing refers to the process in which the laser beam acts on the surface of an object to cause changes in the shape or performance of the object. It has the advantages of no contact, no cutting force, small heat-affected area, clean and environmentally friendly. The focused laser beam has a high power density and can instantly melt or vaporize any solid material. The space and time of the laser beam are well controllable, and the requirements for the shape, size and processing environment of the processing object have a large degree of freedom, and a variety of laser processing processes can be realized. At present, laser processing has been used for cutting, engraving, marking, drilling, welding, surface modificati...

AI Technical Summary

Problems solved by technology

This method has two difficulties in engineering practice: one is that it relies entirely on pre-programming and applies several laser scans to the copper clad film to remove the copper layer, but because the pulse energy stability of actual industrial lasers is not perfect , Copper-clad film production process repeatability error caused by the subtle differences in the individual surface state of the workpiece and other factors, the laser pulse energy that just removes the copper layer without exceeding the damage limit of the polymer substrate is actually very difficult to control, so engraving The etching accuracy and process repeatability are very poor, and the reject rate is high; the second is that for each different surface metal material and different covering metal film thickness, a large number of process tests must be done in advance to ensure that the metal layer is just etched The precise number of laser scans required is time-consuming and labor-intensive, and the process applicability is not good

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