WO2019019424A1

WO2019019424A1 - Method for reducing cutting conicity and increasing cutting speed using multiple ultrafast laser beams

Info

Publication number: WO2019019424A1
Application number: PCT/CN2017/106244
Authority: WO
Inventors: 陶沙; 张�杰; 赵晓杰; 秦国双
Original assignee: 英诺激光科技股份有限公司; 常州英诺激光科技有限公司
Priority date: 2017-07-25
Filing date: 2017-10-16
Publication date: 2019-01-31
Also published as: CN107199408A

Abstract

A method for reducing cutting conicity and increasing a cutting speed using multiple ultrafast laser beams during laser cutting, comprising the following steps: dividing one laser beam into at least two laser beams; and focusing the at least two divided laser beams onto a surface of a sample through a focusing lens to form multiple arranged focal points. According to the method, the concentrated energy characteristic of a small light spot is utilized to reduce the conicity, and the mutual effect between the focused laser beams and a material further enhances the energy utilization efficiency.

Description

Method for reducing cutting taper and cutting speed by using multi-beam ultrafast laser

Technical field

The invention belongs to the field of laser processing, and particularly relates to a method for reducing cutting taper and lifting cutting speed by using multiple ultra-fast lasers in laser cutting.

Background technique

Since the beam output by the conventional laser exhibits a Gaussian distribution, the slit is also tapered in the material cutting. When the taper is formed, the material removal efficiency is greatly reduced, and the cutting time increases with the thickness index. In order to achieve complete cutting, an extended processing is performed. Time, or increase laser energy. The result is low processing efficiency, high cost and poor quality. Therefore, it is very important for laser cutting to reduce the taper especially for the processing of ultrafast lasers. This is because ultra-fast laser processing has been accepted by the industry as the demand for high-end manufacturing increases and the stability of ultra-fast lasers increases and the price drops. Therefore, improving the efficiency of ultra-fast laser processing has become a problem that must be solved.

At present, the method for solving the taper in the prior art mainly changes the angle of incident light or adopts flat top light. However, the way to change the angle of the incident light is mainly suitable for drilling. Although flat top light can be used for cutting, However, the depth of focus is limited and it is difficult to achieve a cut of material having a thickness greater than 100 microns. Therefore, it is necessary to find an effective and feasible method to reduce the taper and improve the cutting efficiency.

Summary of the invention

To this end, the technical problem to be solved by the present invention is to overcome the problems of the prior art, and to propose an effective and feasible method for implementing a cutting method that reduces the taper and improves the cutting efficiency.

In order to solve the above technical problem, the present invention discloses a method for reducing a cutting taper and a lifting cutting speed by using a multi-beam ultrafast laser. The method steps are as follows:

1) dividing a laser into two laser beams into at least two laser beams;

2) The laser beam divided into at least two beams is focused on the surface of the sample by a focusing lens to form a plurality of arranged focal points.

Preferably, the distance between the focal points is 1-10 times the diameter of the spot formed by the focus.

Preferably, the laser of the method has a pulse width of from 300 femtoseconds to 50 picoseconds.

Preferably, the laser beam is perpendicular to the surface of the sample at 90 degrees.

Preferably, the laser beam is along the X direction, and the cutting direction may be performed along the X positive or negative direction.

Preferably, the laser beam is cut along the X direction, and the cutting direction may be cut along the Y direction or the negative direction.

Preferably, the laser beam is along the X direction, and the cutting direction can be cut in the positive or negative direction at any angle between XY.

Preferably, the step 1) is to divide the laser into laser beams into a diffractive optical device.

More preferably, the step 1) is to divide the laser into laser beams into a microlens array.

The above technical solution of the present invention has the following advantages over the prior art: the invention is unique in that the taper is reduced by the feature of small spot energy concentration, and more importantly, the focused beam interacts with the material interaction further. Enhanced energy efficiency; great market prospects and economic value.

Detailed ways

Example

Example 1

This embodiment discloses a method for reducing cutting taper and lifting cutting speed by using multiple ultra-fast lasers

1. Using diffractive optics DOE (diffractive optic) Element) splitting a laser into several beams (multiple lasers);

2. A plurality of laser beams are focused on the surface of the sample through a focusing lens to form a plurality of arranged focal points. The processing proceeds in the direction in which the focused spots are arranged. The distance between the focal points is very important for the reduction of the taper, which is generally 5 times the spot size;

3. Two-dimensional multi-beam laser focusing can be used for two-dimensional cutting according to processing needs;

4. The pulse width of the ultrafast laser is 40 picoseconds;

5. The spacing of the focus of the multiple lasers is kept at 5 times the size of the spot.

Wherein the laser beam is perpendicular to the surface of the sample at 90 degrees; the laser beam is along the X direction, and the cutting direction may be performed along the X positive or negative direction.

Example 2

1. Using a microlens array to divide a laser into several beams (multiple lasers);

2. A plurality of laser beams are focused on the surface of the sample through a focusing lens to form a plurality of arranged focal points. The processing proceeds in the direction in which the focused spots are arranged. The distance between the focal points is very important for the reduction of the taper, generally 1 times the spot size;

4. The pulse width of the ultrafast laser is 50 picoseconds;

5. The spacing at the focus of the multiple lasers is kept at 1x the spot size.

Wherein the laser beam is perpendicular to the surface of the sample at 90 degrees; the laser beam is along the X direction, and the cutting direction can be cut along the Y direction or the negative direction.

Example 3

2. A plurality of laser beams are focused on the surface of the sample through a focusing lens to form a plurality of arranged focal points. The processing proceeds in the direction in which the focused spots are arranged. The distance between the focal points is very important for the reduction of the taper, generally 10 times the spot size;

4. The pulse width of the ultrafast laser should be between 300 femtoseconds;

5. The spacing at the focus of the multiple lasers is kept at 10 times the size of the spot.

Wherein the laser beam is perpendicular to the surface of the sample at 90 degrees; the laser beam is along the X direction, and the cutting direction can be cut in a positive or negative direction at any angle between XY.

In summary, such a multi-beam focused laser can achieve a reduced taper when processed in the alignment direction. In addition to the energy concentration of a single focused beam, Another key effect is that during the material removal process, the beams interact with each other. For example, at the position where the material is to be removed, after a pulse is excited, the material is still excited by the subsequent pulse. Thereby improving the removal efficiency and improving the energy utilization efficiency.

It is apparent that the above-described embodiments are merely illustrative of the examples, and are not intended to limit the embodiments. Other variations or modifications of the various forms may be made by those skilled in the art in light of the above description. There is no need and no way to exhaust all of the implementations. Obvious changes or variations resulting therefrom are still within the scope of the invention.

Claims

A method for reducing a cutting taper and a cutting speed by using a multi-beam ultrafast laser, characterized in that the method steps are as follows:

1) dividing a laser into two laser beams into at least two laser beams;

2) The laser beam divided into at least two beams is focused on the surface of the sample by a focusing lens to form a plurality of arranged focal points.
The method of claim 1 wherein the distance between the focal points is 1-10 times the diameter of the spot formed by the focus.
The method of claim 2 wherein said laser in said method has a pulse width of between 300 femtoseconds and 50 picoseconds.
The method of claim 3 wherein said laser beam is perpendicular to said sample surface at 90 degrees.
The method of claim 4 wherein said laser beam is along the X direction and the cutting direction is performed along X positive or negative.
The method of claim 4 wherein said laser beam is directed in the X direction and the cutting direction is cut in the Y forward or negative direction.
The method of claim 4 wherein: The laser beam is along the X direction, and the cutting direction can be cut in the positive or negative direction at any angle between XY.
The method according to any one of claims 1 to 7, wherein the step 1) is to divide the laser into laser beams into a diffractive optical device.
The method according to any one of claims 1 to 7, wherein the step 1) is to divide the laser into laser beams into a microlens array.