CN102357735B - Double-scanning three-dimensional (3D) laser etching method based on controllable profile shape and power distribution of light beams - Google Patents

Abstract

The invention provides a double-scanning three-dimensional (3D) laser etching method based on controllable cross-section shape and power distribution of light beams, and belongs to the technical field of laser etching. In the method, equivalent laser processing spots with controllable power profile distribution is matched with an optical machine scanning galvanometer so as to carry out double-scanning laser processing on the surface of a workpiece, which can realize the laser etching of a complex 3D microstructure. The double-scanning 3D laser etching method provided by the invention has the beneficial effects of promoting the capability of the existing laser etching technology from a two-dimensional (2D) plane laser etching mode to a 3D any-curve uncovered laser etching mode, and solving the problem of no appropriate processing technology of the 3D microstructure within the size range of 1mu m-1mm, thus having scientific and industrially practical potential.

Description

Double-scanning three-dimensional laser etching processing method based on controllable beam profile shape and power distribution

technical field

The invention belongs to the technical field of laser etching processing, and relates to a laser etching processing method of a three-dimensional complex structure based on a new principle, in particular to a double-scanning three-dimensional laser etching processing method based on controllable beam cross-sectional shape and power distribution .

Background technique

Laser etching refers to the technology of using laser to ablate and remove the surface material of the workpiece. Compared with the relatively mature laser cutting and laser welding, it belongs to a new field of laser processing. It is a surface that has gradually developed with the advancement of high-peak ultrashort pulse laser (nanosecond, picosecond, femtosecond) technology in the past ten years. One of the earliest applications of structural micromachining technology is laser marking. In this technique, a focused laser beam is scanned across the surface to etch characters and various patterns. In essence, it is a plane (two-dimensional) processing technology.

MEMS (Micro-electromechanical Systems) technology is considered to be one of the important supporting technologies in the 21st century, similar to the role of microelectronics technology in the 20th century. The manufacture of three-dimensional rather than planar microstructures and microparts is the key to its development. So far, the typical scale in this field is in the 1μm~1mm range, and involves a wide range of materials. This scale is too small for traditional machining, but too large for microelectronics technology (and microelectronics technology can only perform planar (two-dimensional) processing, mainly limited to silicon materials), so it is not applicable. The only technology currently available in this field is the LIGA technology (Lithography Electroforming Micro Molding). But this technique relies on synchrotron radiation produced by a large cyclotron, one of the few giant facilities in the world. Therefore, it cannot become a practical industrial technology.

Laser lithography is a very promising technology that can be used for the above-mentioned processing tasks. It is a flexible processing technology with a high degree of flexibility and is suitable for a wide range of material types. It is especially important that it has the ability to process three-dimensionally in the range of 1 μm to 1 mm in principle, although it is only used for two-dimensional processing at present. dimension processing. The core content of this patent application is to propose a method that develops from two-dimensional plane laser etching to three-dimensional laser etching processing and has the potential to become an industrially practical technology.

Contents of the invention

The purpose of the present invention is to solve the problems existing in the prior art, and to provide a dual-scanning three-dimensional laser etching processing method based on controllable beam profile shape and power distribution. The method of controlled scanning forms a processing spot with controllable shape and power profile, and then uses an appropriate method to make the "processing spot" perform a second scan.

The purpose of the present invention can be achieved through the following schemes:

Using the orthogonal acousto-optic deflector through the acousto-optic diffraction effect, the laser beam is scanned at a small angle and high-frequency in a small range according to the required setting method to form an equivalent laser spot required for processing. As a processing spot, the galvanometer system is used The three-dimensional microstructure can be produced by guiding the processing spot for a second scan.

In practical application, according to the needs of the processing task, set the excitation waveform and intensity of the AOD, and generate the required waveform from the external waveform generator, so as to obtain the required specific power distribution and shape of the spot to meet different requirements. processing requirements. A specific beam profile can form a corresponding etching profile. Therefore, a more complex three-dimensional etching structure can be formed by using a laser galvanometer scanning system to guide a spot with a specific power distribution and shape for secondary scanning.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention uses mutually orthogonal acousto-optic deflectors to scan the laser at a small angle at high frequency to form an equivalent laser spot with controllable cross-sectional shape and power as the processing spot, and then use the vibrating mirror system to guide the processing spot The second scan forms the corresponding three-dimensional microstructure etching section on the workpiece, realizes the direct laser etching processing of the three-dimensional microstructure, and solves the problem that there is no suitable three-dimensional microstructure processing technology in the scale range of 1 μm ~ 1mm, which is scientific and industrial potential.

(2) Improve the current laser etching processing capability from plane (two-dimensional) to direct processing of three-dimensional three-dimensional arbitrary curved surfaces without concealment, and improve the processing accuracy of the existing two-dimensional etching.

(3) It can be automatically controlled by program control, which is highly flexible.

Description of drawings

Fig. 1 is a schematic diagram of the double-scanning laser processing method of an acousto-optic deflector and a mechanical vibrating mirror of the present invention.

Detailed ways

The dual-scan three-dimensional laser etching processing method of the present invention will be further described below through specific examples.

Referring to FIG. 1 , the orthogonal acousto-optic scanning deflector 2 is placed orthogonally at the output port of the laser 1 . Set the target laser spot area as a triangular spot of ^0.2mm2 . Adjust the excitation waveform of the X and Y direction acousto-optic deflectors (the required waveform is generated by an external waveform generator) and the power of the laser beam to 15W, so that the laser beam can be scanned at a small angle with high frequency to obtain an area of 0.2mm ² , a triangular equivalent laser spot with a power of 15W and uniform distribution of power. Then use the equivalent laser spot as the processing spot, use the laser scanning galvanometer system 3 arranged behind the acousto-optic deflector to control the moving track of the processing spot, and first scan and etch the initial position on the workpiece along the horizontal direction with a period of 0.6mm ; Then the laser processing spot returns to the initial position of etching, and then scans and etch along the vertical direction with the same period of 0.6 mm, that is, a pyramid-shaped array is formed.

Claims (1)

1. based on the two scanning three-dimensional laser ablation processing methods that controlled light beam section shape and power distribute, it is characterized in that: utilize two orthogonal each other acousto-optic deflection devices, and first by orthogonal for the orthogonal acousto-optic deflection device delivery outlet being placed in laser instrument; Setting target laser facula area is 0.2mm ²triangle hot spot; Adjustment X, the excitation waveform of Y-direction acousto-optic deflection device and the power of laser beam are 15W, make laser beam carry out low-angle high frequency sweep, and just obtaining area is 0.2mm ², power is 15W and power equally distributed triangle equivalent laser hot spot; Again using equivalent laser hot spot as processing hot spot, utilize the motion track of the laser scanning galvanometer Systematical control processing hot spot after being arranged on acousto-optic deflection device, first on workpiece, initial position is that 0.6mm carries out scanning and etches by the cycle in the horizontal direction; Then Laser Processing hot spot gets back to etching initial position, more vertically carries out scanning etching by same period 0.6mm, namely forms the array of Pyramid.