Efficient excimer laser processing system

Abstract

The invention discloses an efficient excimer laser processing system which comprises an excimer laser generator (1), a light spot of ultraviolet laser is a rectangular light spot (2) with the side length of centimeter magnitude, and an optical focusing assembly (3) capable of focusing the ultraviolet laser is arranged on a light path of the ultraviolet laser. A light spot of the ultraviolet laser focused by the optical focusing assembly (3) is a strip-shaped light spot (4) with the width of micron dimension and the length of centimeter dimension, a reflecting assembly (6) capable of reflecting the ultraviolet laser in the shape of the strip-shaped light spot to a workpiece (5) is further arranged on a light path of the ultraviolet laser, and after the ultraviolet laser is reflected to the workpiece (5), the workpiece (5) is focused by the reflecting assembly (6). And the strip-shaped light spot (4) moves relative to the workpiece (5) so as to process the workpiece (5). The energy density of the machining light spots is improved, the size of the machining light spots is guaranteed, the laser machining effect is improved, and the requirements for the laser output frequency, the galvanometer scanning speed or the workpiece moving speed are lowered.

Description

[Technical field]

[0001] The invention relates to a highly efficient excimer laser processing system. [Background technology]

[0002] With the development of laser processing industry and the diversification of processing materials, excimer ultraviolet laser processing has become an important processing branch. Ultraviolet laser has important application value in scientific research, medical treatment and industrial fields due to its short wavelength, high single photon energy, large spot and high output single pulse energy.

[0003] like Figure 7 As shown, during processing, it is usually necessary to process a thin line 8 on the workpiece for scribing, grooving, cutting, etc. When the laser processing system processes, cuts, scribes, grooves, etc. on the workpiece 5, the laser output spot (generally, the original laser spot is a circular spot with a diameter of the order of millimeters and the energy is a Gaussian distribution) is focused on the surface of the workpiece 5. The processing spot is generally a circular spot with a size of the order of microns after focusing. The specific processing method and principle are as follows Figure 5 , 6 As shown, the circular laser spot 20 output by the laser device 10 (if it is a rectangular spot of an excimer laser, it is necessary to first intercept the circular laser spot 20 on the light path through an aperture), and then be focused by the optical focusing component 3 to obtain a circular processing spot 30 with a diameter of the micron level. The focused laser is reflected onto the workpiece 5, and then through the relative movement of the laser spot 20 and the workpiece 5, the laser spot 20 can be used to process a thin line 8 on the workpiece 5. Specifically, after the laser spot 20 processes a certain point on the workpiece 5, the laser spot 20 moves forward to process another point, and this point-by-point splicing is repeated to finally process a thin line 8 on the workpiece 5. However, the aforementioned processing method has the following defects for excimer laser processing: a circular aperture is placed in the laser light path to cut out a circular spot from the output excimer laser rectangular spot (generally a flat-top quasi-Gaussian distribution) and focus it on the workpiece surface, and intercepting the circular spot in the rectangular spot will cause a large energy loss; in addition, to process fine lines or surfaces on the workpiece surface, the circular laser spots need to be spliced ​​point by point on the workpiece surface. Since the circular spot is small, the area processed each time is small. When processing a line or a surface, the number of splicing times will be very large, and the processing efficiency is relatively low. If the efficiency is to be improved, the laser output frequency must be increased, and at the same time, the workpiece movement or the galvanometer scanning speed of the reflected laser is required to be very fast, resulting in a high workload and reduced reliability of the laser processing system.

[0004] In order to collect as much energy as possible from the rectangular spot output by the excimer laser and reduce energy loss, the current processing method is to first make a mask plate according to the requirements of the workpiece and then process it through mask processing. However, this processing method requires complex optical structure, fixed processing mode, high mask cost, and high laser energy requirements.

[0005] Therefore, the present invention is just produced based on the above shortcomings. [Summary of the invention]

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art based on the excimer laser spot size and energy distribution characteristics, and to provide an efficient excimer laser processing system. The efficient excimer laser processing system outputs a narrow linear strip spot, which not only increases the energy density of the processing spot, but also greatly guarantees the size of the processing spot, greatly improves the efficiency of laser processing, and also reduces the requirements for laser output frequency, galvanometer scanning speed or workpiece moving speed, and improves system stability.

[0007] The present invention is achieved through the following technical solutions:

[0008] An efficient excimer laser processing system comprises an excimer laser generator 1 capable of emitting ultraviolet laser light, the spot of the ultraviolet laser light is a rectangular spot 2 with a side length of the order of centimeters, an optical focusing component 3 capable of focusing the ultraviolet laser light is arranged on the optical path of the ultraviolet laser light, the spot of the ultraviolet laser light after being focused by the optical focusing component 3 is a strip spot 4 with a width of the order of micrometers and a length of the order of centimeters, and a reflecting component 6 capable of reflecting the ultraviolet laser light in the strip spot onto a workpiece 5 is also arranged on the optical path of the ultraviolet laser light, after the ultraviolet laser light is reflected onto the workpiece 5, the strip spot 4 moves relative to the workpiece 5 to process the workpiece 5.

[0009] The reflection component 6 includes a reflection mirror 61 which can reflect the ultraviolet laser in a strip-shaped spot onto the workpiece 5 . When the workpiece 5 moves in a straight line on the workbench 7 , the laser reflected by the reflection mirror 61 performs linear processing on the workpiece 5 .

[0010] The reflection assembly 6 includes a galvanometer 62 . When the workpiece 5 is fixed on the workbench 7 , the galvanometer 62 changes the reflection direction of the ultraviolet laser during the polarization process, so that the strip spot 4 of the ultraviolet laser moves along a straight line on the workpiece 5 to process the workpiece 5 .

[0011] The optical focusing component 3 is a cylindrical lens. The ultraviolet laser output by the excimer laser generator 1 is focused by the cylindrical lens to form the strip-shaped light spot 4 with a width of micrometer order and a length of centimeter order.

[0012] The excimer laser generator 1 is a gas laser, and the working medium is XeF, XeCl, KrF, ArF or F2.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. The efficient excimer laser processing system of the present invention has the characteristics of ultraviolet laser output, high energy, flat-top distribution of the light beam, and large spot area, which can improve the processing efficiency.

[0015] 2. Based on the characteristics of large energy and large spot of excimer laser, the present invention changes the circular processing spot used in traditional laser processing into a strip-shaped spot of excimer laser, which greatly increases the area of ​​the processing spot and thus improves the efficiency of laser processing.

[0016] 3. The present invention makes maximum use of the characteristics of large ultraviolet laser spot and high output single pulse energy of excimer laser in the ultraviolet band, does not change the basic structure of the laser processing system, adopts the technology of directly focusing the rectangular spot of excimer laser in one direction, and improves the processing efficiency by changing the processing spot mode after laser focusing.

Brief Description of the Drawings

[0017] Figure 1 is a schematic diagram of Embodiment 1 of the present invention;

[0018] Figure 2 is a schematic diagram of Embodiment 2 of the present invention;

[0019] Figure 3 It is a schematic diagram of the ultraviolet laser focusing principle of the present invention;

[0020] Figure 4 It is a schematic diagram of processing a thin wire on a workpiece according to the present invention;

[0021] Figure 5 It is a schematic diagram of the laser focusing principle in the prior art;

[0022] Figure 6 It is a schematic diagram of processing a thin wire on a workpiece in the prior art;

[0023] Figure 7 is a schematic diagram of the workpiece;

[0024] Figure 8 It is a plane schematic diagram of laser energy distribution of the present invention;

[0025] Fig. 9 It is a three-dimensional schematic diagram of the laser energy of the present invention;

[0026] Fig.10 It is a schematic diagram of laser energy distribution in the prior art;

[0027] Fig.11It is a three-dimensional schematic diagram of laser energy distribution in the prior art. [Specific implementation method]

[0028] The present invention will be further described below in conjunction with the accompanying drawings:

[0029] Embodiment 1:

[0030] like Figure 1 , Figure 3 , Figure 4 and Figures 7 to 10 As shown, an efficient excimer laser processing system includes an excimer laser generator 1 capable of emitting ultraviolet laser light. The spot of the ultraviolet laser output by the excimer laser generator 1 is a rectangular spot 2 with a side length of the order of centimeters. The energy is a flat-top quasi-Gaussian distribution, which has the characteristics of large spot and high output single pulse energy. An optical focusing component 3 capable of focusing the ultraviolet laser is provided on the optical path of the ultraviolet laser. After the ultraviolet laser with a rectangular spot with a side length of the order of centimeters is focused by the optical focusing component 3, the spot is compressed and reduced in the width direction and converted into a strip spot 4 with a width of the order of micrometers and a length of the order of centimeters. Therefore, a narrow linear processing spot is formed, which not only improves the energy density of the processing laser spot, but also greatly guarantees the size of the processing spot. The ultraviolet laser in the strip spot is reflected by the reflection component 6 on the transmission optical path to the workpiece 5. In this embodiment, the reflection component 6 includes a reflector 61. When the workbench 7 moves with the workpiece 5 in a straight line along the X-axis or Y-axis direction, the laser reflected by the reflector 61 processes the workpiece 5. Through the movement of the workbench 7, a line or a surface can be processed on the workpiece 5. The specific processing method is that after the strip light spot 4 processes an area on the workpiece 5 that is consistent with its shape, the strip light spot 4 moves forward relative to the workpiece 5 to process another area. This splicing is repeated, and the ultraviolet laser can process a thin line 8 on the workpiece 5. Figure 5 and Figure 6 Compared with the traditional processing method shown in the figure, the processing spot in this embodiment is a narrow linear strip spot. When the width is consistent with the diameter of the traditional circular spot, because its length is in the order of centimeters (and the traditional circular processing spot is also in the order of microns in the processing length direction), the strip spot area is large. Therefore, the narrow linear strip spot 4 of the ultraviolet laser is used to process and splice the entire line or the entire surface. Fewer narrow linear processing spots are needed to complete the processing of a line or a surface, while in the traditional processing, a lot of circular processing spots are needed to complete the processing of a line or a surface. This greatly improves the efficiency of laser processing, and can also reduce the requirements for laser output frequency and workpiece movement speed, thereby improving system stability.

[0031] In this embodiment, the optical focusing component 3 is a unidirectional focusing optical system based on a cylindrical lens. The ultraviolet laser output by the excimer laser generator 1 is focused by the optical system to form the strip light spot 4 with a width of micrometer order and a length of centimeter order.

[0032] The excimer laser 1 is a gas laser, and the working medium is XeF, XeCl, KrF, ArF or F2. The wavelengths of the ultraviolet lasers output by different working media are different. For example, the laser wavelength output by the working medium XeF is 357nm, the laser wavelength output by the working medium XeCl is 308nm, the laser wavelength output by the working medium KrF is 248nm, the laser wavelength output by the working medium ArF is 193nm, and the laser wavelength output by the working medium F2 is 157nm. The appropriate working medium can be selected according to the processing requirements.

[0033] Embodiment 2:

[0034] like Figure 2 As shown, the difference between Example 2 and Example 1 is:

[0035] The reflection assembly 6 includes a galvanometer 62. When the workpiece 5 is fixed on the workbench 7, the galvanometer 62 changes the reflection direction of the ultraviolet laser during the polarization process, so that the stripe light spot 4 of the ultraviolet laser moves on the workpiece 5 to process the workpiece 5. In this embodiment, the workpiece 5 remains stationary, and the galvanometer 62 changes the reflection direction of the ultraviolet laser during polarization scanning, so that the stripe light spot 4 of the ultraviolet laser moves relative to the workpiece 5, so as to process a thin line 8 on the workpiece 5. Of course, since the galvanometer 62 can not only deflect and move in a two-dimensional direction, but also deflect at any angle in a three-dimensional space, after the galvanometer 62 changes the reflection direction of the ultraviolet laser, the ultraviolet laser can process a line or surface of any shape on the surface of the workpiece 5.

Claims

1. An efficient excimer laser processing system, characterized by: The invention comprises an excimer laser generator (1) capable of emitting ultraviolet laser light, wherein the spot of the ultraviolet laser light is a rectangular spot (2) with a side length of the order of centimeters, an optical focusing component (3) capable of focusing the ultraviolet laser light is arranged on the optical path of the ultraviolet laser light, the spot of the ultraviolet laser light after being focused by the optical focusing component (3) is a stripe-shaped spot (4) with a width of the order of micrometers and a length of the order of centimeters, and a reflection component (6) capable of reflecting the ultraviolet laser light in the stripe-shaped spot onto a workpiece (5), and after the ultraviolet laser light is reflected onto the workpiece (5), the stripe-shaped spot (4) and the workpiece (5) move relative to each other to process the workpiece (5).

2. The efficient excimer laser processing system according to claim 1, characterized in that: The reflection component (6) comprises a reflection mirror (61) capable of reflecting ultraviolet laser light in the form of a stripe-shaped light spot onto a workpiece (5); when the workpiece (5) moves in a straight line on the workbench (7), the laser light reflected by the reflection mirror (61) performs linear processing on the workpiece (5).

3. The efficient excimer laser processing system according to claim 1, characterized in that: The reflection component (6) includes a galvanometer (62). When the workpiece (5) is fixed on the workbench (7), the galvanometer (62) changes the reflection direction of the ultraviolet laser during the polarization process, so that the strip-shaped spot (4) of the ultraviolet laser moves along a straight line on the workpiece (5) to process the workpiece (5).

4. The efficient excimer laser processing system according to claim 1, characterized in that: The optical focusing component (3) is a cylindrical lens, and the ultraviolet laser output by the excimer laser generator (1) is focused by the cylindrical lens to form the strip-shaped light spot (4) with a width of the micrometer order and a length of the centimeter order.

5. The efficient excimer laser processing system according to claim 1, characterized in that: The excimer laser generator (1) is a gas laser, and the working medium is XeF, XeCl, KrF, ArF or F2.

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