CN115365642A - A UV laser etching flight optical path - Google Patents

Abstract

The invention relates to an ultraviolet laser etching flight optical path, which includes a first laser optical path module, a second laser optical path module, and a laser processing module. An X-axis moving mechanism is installed on the laser etching machine, and a Z-axis moving mechanism is vertically installed on the X-axis moving mechanism. , the laser processing module is fixed on the Z-axis moving mechanism. The first laser optical path module includes a laser, a primary beam expander, a primary reflector, and a near-point reflector. The laser processing module includes two sets of laser emitting units, and each set of laser emitters Each unit includes a secondary reflector, a secondary beam expander, and a galvanometer scanning head. The upper side of each group of laser emitting units is equipped with a far-point reflector. The laser beam passes through the primary beam expander, the primary reflector, and the Near-point reflector, far-point reflector, secondary reflector, secondary beam expander, galvanometer scanning head. The invention enables the multi-optical path system to share a set of Z-axis lifting mechanism, reduces the design difficulty of the mechanical structure, and guarantees the etching effect at the same time.

Description

A UV laser etching flight optical path

technical field

The invention relates to the technical field of laser etching, in particular to an ultraviolet laser etching flight optical path.

Background technique

Laser micro-nano processing is to use the laser beam emitted by the laser generator to focus it into a spot of Φ0.01mm or smaller through the optical system to obtain an energy density of 108W/cm2～1010W/cm2 and a local high temperature of 10000℃, so that the The processing material is rapidly melted, gasified or chemically changed, and the molten material is ejected in the form of a shock wave to realize cutting or engraving.

In the multi-light path ultraviolet laser etching process, due to the relatively large volume of the ultraviolet laser, the laser generator is fixed during the laser processing process, and the laser transmission direction is also fixed. However, in order to meet the needs, some artificial measures must be taken. Change the transmission direction of the laser. Usually changing the laser transmission direction is to refract the laser through the reflector, the laser generator does not move, and the reflector installed in the reflector base moves with the motion system of the machine tool to reflect the laser into the vibrating mirror, and then focus and scan to the surface of the workpiece through the field mirror On the surface, the processing graphics required by customers are formed.

During the large-format etching process, the relative positional relationship between the laser generator and the lens changes, and the laser emitted by the laser transmitter has a divergence angle, resulting in the farther away from the laser, the larger the laser spot, and the change of the laser spot directly It affects the processing quality consistency and efficiency. However, at present, in the design and adjustment of the optical path, the focus is mainly on the concentricity of the near-point and far-point optical paths of the motion system, and there is no optimal design for the laser divergence angle in the long optical path, which reduces the processing quality and product yield.

Especially in a multi-channel processing system, the consistency of the laser spot and optical parameters cannot be guaranteed for the multiple lasers used, which leads to errors in the working height of the galvanometer and the field mirror, so it is difficult to guarantee the consistency of the processing effect. At the same time, in the multi-optical path galvanometer scanning processing system, the overall mass of each system is relatively large, and a separate design of the Z-axis lifting mechanism for the working height will result in complex and bloated equipment structure and poor reliability.

Therefore, a kind of ultraviolet laser etching flight optical path is needed to solve the above technical problems.

Contents of the invention

The invention aims at the technical problems existing in the prior art, and provides an ultraviolet laser etching flight optical path.

The technical solution of the present invention to solve the above technical problems is as follows: an ultraviolet laser etching flight optical path, including a first laser optical path module, a second laser optical path module, and a laser processing module, the first laser optical path module and the second laser optical path module are respectively Located on both sides of the laser processing module, the first laser optical path module and the second laser optical path module are fixed on the laser etching machine, and the X-axis moving mechanism is installed on the laser etching machine, and the X-axis moving mechanism is vertically installed There is a Z-axis moving mechanism, the laser processing module is fixed on the Z-axis moving mechanism, the first laser optical path module and the second laser optical path module are respectively located at both ends of the X-axis moving mechanism, and the first The laser optical path module has the same structure as the second laser optical path module. The first laser optical path module includes a laser, a primary beam expander, a primary reflector, and a near-point reflector. The laser processing module includes two groups of laser emitters Each group of laser emitting units includes a secondary reflector, a secondary beam expander, and a galvanometer scanning head. The upper side of each group of laser emitting units is provided with a far-point reflector, and the far-point reflector is fixed On the X-axis moving mechanism, the height of the far-point reflector is the same as that of the near-point reflector, and the far-point reflector does not move with the Z-axis moving mechanism. Beam mirror, primary mirror, near-point mirror, far-point mirror, secondary mirror, secondary beam expander, galvanometer scanning head.

Preferably, in the above-mentioned ultraviolet laser etching flight optical path, the included angles between the primary reflector, the near-point reflector, the far-point reflector, the secondary reflector and the horizontal line are all 45°.

Preferably, the above-mentioned ultraviolet laser etching flight optical path, wherein the primary beam expander and the secondary beam expander are all adjustable beam expanders.

Preferably, the above-mentioned ultraviolet laser etching flight optical path, wherein when the laser processing module moves to the midpoint of the travel of the X-axis moving mechanism, the first laser optical path module, the second laser optical path module, and the laser processing module are symmetrical as a whole structure.

Preferably, in the above-mentioned ultraviolet laser etching flight optical path, wherein the lower side of the laser processing module is provided with a Y-axis moving mechanism, and the Y-axis moving mechanism is used to place processed products.

The beneficial effects of the invention are: the invention can effectively optimize the divergence angle of the ultraviolet laser, and correct the diameters of the laser spots at the near point and the far point of the flight optical path to keep them consistent. At the same time, the working height of the galvanometer scanning system can be adjusted in a small range, so that the multi-optical system can share a set of Z-axis lifting mechanism, which reduces the difficulty of designing the mechanical structure and ensures the etching effect at the same time.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the present invention.

In the accompanying drawings, the list of parts represented by each label is as follows:

1. Laser, 2. Primary beam expander, 3. Primary reflector, 4. Near point reflector, 5. Far point reflector, 6. Secondary reflector, 7. Secondary beam expander, 8. galvanometer scanning head, 9. processed product, 10. laser processing module, 11. first laser optical path module, 12. second laser optical path module.

Detailed ways

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

As shown in Figure 1, a kind of ultraviolet laser etching flight optical path includes a first laser optical path module 11, a second laser optical path module 12, and a laser processing module 10. The first laser optical path module 11 and the second laser optical path module 12 are respectively located Both sides of the machining module 10 are processed. The internal structures of the first laser optical path module 11 and the second laser optical path module 12 are the same.

The first laser optical path module 11 and the second laser optical path module 12 are fixed on the laser etching machine, the X-axis moving mechanism is installed on the laser etching machine, the Z-axis moving mechanism is vertically installed on the X-axis moving mechanism, and the laser processing module 10 is fixed on the Z-axis On the moving mechanism, therefore, the laser processing module 10 can perform X-direction horizontal movement and Z-direction lifting movement. The first laser optical path module 11 and the second laser optical path module 12 are respectively located at two ends of the X-axis moving mechanism. When the laser processing module 10 moves to the midpoint of the travel of the X-axis moving mechanism, the whole composed of the first laser optical path module 11 , the second laser optical path module 12 and the laser processing module 10 is a symmetrical structure.

The first laser optical path module 11 includes a laser 1 , a primary beam expander 2 , a primary reflective mirror 3 , and a near-point reflective mirror 4 , and the same is true for the second laser optical path module 12 . The laser processing module 10 includes two groups of laser emitting units, each group of laser emitting units includes a secondary reflector 6, a secondary beam expander 7, and a vibrating mirror scanning head 8, and the upper side of each group of laser emitting units is provided with a far point Mirror 5. The far-point reflector 5 is fixed on the X-axis moving mechanism, the height of the far-point reflector 5 is the same as that of the near-point reflector 4, and the far-point reflector 5 does not move with the Z-axis moving mechanism. The laser 1 emits a laser beam, and the laser beam passes through the primary beam expander 2, the primary reflector 3, the near point reflector 4, the far point reflector 5, the secondary reflector 6, and the secondary beam expander 7 in sequence, and finally passes through the The galvanometer scanning head 8 emits. The included angles between the primary reflector 3 , the near point reflector 4 , the far point reflector 5 , the secondary reflector 6 and the horizontal line are all 45°. Both the primary beam expander 2 and the secondary beam expander 7 are adjustable beam expanders.

The lower side of the laser processing module 10 is provided with a Y-axis moving mechanism, and the Y-axis moving mechanism is used for placing the processed product 9 . By moving the laser processing module 10 along the X axis and the processed product 9 along the Y axis, the etching process of the processed product can be realized.

During the working process of the whole system, the distance between the near-point mirror 4 and the far-point mirror 5 of the first laser optical path module 11 and the second laser optical path module 12 on the left and right sides will change along with the horizontal movement of the X-axis moving mechanism. Variety. Since the laser light emitted by the laser has a certain divergence angle, the farther the distance from the laser is, the larger the laser spot will be. As a result, the laser spot of the laser emitting unit on the left is inconsistent in size when the far-point reflector 5 is close to the near-point reflector 4. And the laser spot of the laser emitting unit on the right side is inconsistent in size when the far point reflector 5 is close to the near point reflector 4, and is just opposite to the laser emitting unit on the left side.

At the same time, the inconsistency of the characteristic parameters of the two lasers 1 leads to the inconsistency of the incident laser spot diameters and divergence angles of the left and right far-point reflectors 5 , which in turn affects the inconsistency of the working heights of the two galvanometer scanning heads 8 . Therefore, the processing effect of the processed product 9 is unstable, or even deteriorated, and the processing quality of the laser emitting unit is inconsistent at different positions of the product.

The beam quality M2 of the laser beam is an important parameter in the output characteristics of the laser. It is also an important reference data for designing the optical path and determining the final focus spot. The main indicators to measure the quality of the laser beam include the beam waist diameter and far-field divergence angle of the laser beam. The expression of the beam quality M2 of the laser beam is as follows:

M ² =πD ₀ θ/(4λ)

In the formula, D0 is the beam waist diameter of the laser beam, and θ is the far-field divergence angle of the laser beam. The product of the beam waist diameter and the far-field divergence angle of the laser beam before and after the transformation of the optical mirror group is constant, and its expression is as follows:

D ₀ θ _o ＝ D ₁ θ ₁

Among them, D0 - the diameter of the laser beam waist before entering the lens;

θ0——The far-field divergence angle of the laser beam before entering the lens;

D1——The diameter of the laser beam waist after passing through the lens;

θ1——the far-field divergence angle of the laser beam after passing through the lens;

Therefore, the product of the beam waist diameter of the laser beam and the far-field divergence angle remains unchanged during laser transmission, and the spot diameter is inversely proportional to the divergence angle. The larger the laser spot diameter, the smaller the divergence angle.

Aiming at the defects and deficiencies of the above-mentioned prior art, the present invention adds a primary beam expander 2 between the laser 1 and the primary reflector 3, and expands the diameter of the exit spot of the laser 1, which can effectively reduce the laser beam. The divergence angle makes the laser spot not change due to the change of the optical path during the horizontal movement of the motion system. At the same time, the primary beam expander 2 all adopts a beam expander with adjustable magnification. Through the laser spot detection equipment, the laser spot size is measured at the light exit holes of the two near-point reflectors 4, and the beam expansion multiple adjustment threads of the two primary beam expanders 2 are adjusted respectively, so that the laser beam spot diameters remain consistent. Then, translate the X-axis motion mechanism so that the distance between the near-point mirror 4 and the far-point mirror 5 on the left is the farthest, measure the diameter of the laser spot at the light entrance of the far-point mirror 5, and adjust the primary beam expander 2 The divergence angle of the screw thread is adjusted so that the spot diameter of the laser beam here is the same as the above-mentioned diameter. Finally, the primary reflector 3 and the near-point reflector 4 are adjusted so that the laser beam is parallel to the moving direction of the X-axis. Adopt the same method to adjust the second laser optical path module 12 on the right side, adjust the primary beam expander 2 on the right side so that the X-axis motion system translates to the near point reflector 4 and far point reflector 5 on the right side with the shortest distance The diameter of the laser beam spot at a distance is the same as the above-mentioned diameter, and finally adjust the primary reflector 3 and the near-point reflector 4 on the right to make the laser beam parallel to the X-axis movement direction.

At the same time, due to the differences in the optical quality M2 of the two lasers 1 and the optical characteristics f of the galvanometer scanning head 8, the working heights of the two lasers cannot be completely consistent, which will lead to differences in the processing effects of the left and right laser emitting units.

The focused spot diameter Df of the laser beam finally focused on the working surface can be calculated by the following formula:

Among them: θf—the far-field divergence angle of the laser beam after focusing;

D——the diameter of the last lens before the laser beam is focused (the laser beam fills the last lens before focusing);

f - the focal length of the last lens before the laser beam is focused;

The diameter of the focused spot of the laser beam is related to the beam quality and wavelength of the laser beam, and is also affected by the focal length of the focusing lens and the diameter of the last lens before focusing, that is, the diameter of the laser beam.

Therefore, a secondary beam expander 7 is added between the secondary mirror 6 and the galvanometer scanning head 8 . At the same time, the secondary beam expander 7 adopts an adjustable beam expander to optimize and compensate the difference in the optical quality M2 of the laser and the focal length f of the scanning head 8 of the galvanometer, so that the focused spots of the left and right laser emitting units are consistent.

Measure the laser spot size at the light entrance hole of the galvanometer scanning head 8 by the laser spot detection device, and adjust the beam expansion factor adjustment thread of the secondary beam expander 7 respectively, so that the laser beam spot diameter remains consistent. Then, raise the Z axis to an appropriate working height, so that the left laser emitting unit focuses on the surface of the product 9 to be processed, and detect the line width or focus spot diameter of the marks processed by the left laser laser emitting unit through a microscope. Detect the line width or focus spot diameter of the trace of the processed product 9 processed by the right laser laser system through a microscope, and properly adjust the divergence angle adjustment thread of the secondary beam expander 7, so that the trace line width or focus spot diameter is consistent with the left laser emitting unit .

The invention can effectively optimize the divergence angle of the ultraviolet laser, correct the diameters of the laser spots at the near point and the far point of the flying light path, and keep them consistent. At the same time, the working height of the galvanometer scanning system can be adjusted in a small range, so that the multi-optical system can share a set of Z-axis lifting mechanism, which reduces the difficulty of designing the mechanical structure.

In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", etc. indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for convenience The present invention is described and the simplified description does not indicate or imply that the device or element referred to must have a specific orientation, as well as a specific orientation configuration and operation, and therefore, should not be construed as limiting the present invention. In addition, "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Therefore, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

An embodiment of the present invention has been described in detail above, but the content described is only a preferred embodiment of the present invention, and cannot be considered as limiting the implementation scope of the present invention. All equivalent changes and improvements made according to the application scope of the present invention shall still belong to the scope covered by the patent of the present invention.

Claims (5)

1. A kind of ultraviolet laser etching flying light path, it is characterized in that: comprise the first laser light path module (11), the second laser light path module (12), laser processing module (10), described first laser light path module (11) , the second laser optical path module (12) is located on both sides of the laser processing module (10), the first laser optical path module (11), and the second laser optical path module (12) are fixed on the laser etching machine, the An X-axis moving mechanism is installed on the laser etching machine, a Z-axis moving mechanism is vertically installed on the X-axis moving mechanism, the laser processing module (10) is fixed on the Z-axis moving mechanism, and the first laser optical path module (11), the second laser optical path module (12) is respectively located at both ends of the X-axis moving mechanism, the first laser optical path module (11) has the same structure as the second laser optical path module (12), and the The first laser optical path module (11) includes a laser (1), a primary beam expander (2), a primary reflector (3), and a near-point reflector (4), and the laser processing module (10) includes two groups Laser emitting unit, each group of laser emitting units includes a secondary reflector (6), a secondary beam expander (7), a vibrating mirror scanning head (8), and the upper side of each group of laser emitting units is provided with a remote A point reflector (5), the far point reflector (5) is fixed on the X-axis moving mechanism, the far point reflector (5) is the same height as the near point reflector (4), and the far point The reflector (5) does not move with the Z-axis moving mechanism, the laser (1) emits a laser beam, and the laser beam passes through the primary beam expander (2), the primary reflector (3), and the near-point reflector (4) in sequence , far-point reflector (5), secondary reflector (6), secondary beam expander (7), vibrating mirror scanning head (8). 2. ultraviolet laser etching flying optical path according to claim 1, is characterized in that: described primary reflector (3), near-point reflector (4), far-point reflector (5), secondary reflector ( 6) The included angle with the horizontal line is 45°. 3. The ultraviolet laser etching flight optical path according to claim 1, characterized in that: the primary beam expander (2) and the secondary beam expander (7) are all adjustable beam expanders. 4. The ultraviolet laser etching flight optical path according to claim 1, characterized in that: when the laser processing module (10) moves to the midpoint of the travel of the X-axis moving mechanism, the first laser optical path module (11) , The second laser optical path module (12) and the laser processing module (10) are symmetrical structures as a whole. 5. The ultraviolet laser etching flight optical path according to claim 1, characterized in that: the lower side of the laser processing module (10) is provided with a Y-axis moving mechanism, and the Y-axis moving mechanism is used to place processed products (9 ).

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