CN215747147U - Laser calibration device and laser processing equipment - Google Patents

Abstract

The utility model belongs to the technical field of laser processing, and relates to a laser calibration device and laser processing equipment, which comprise a workbench, a mounting assembly, a first vision mechanism, a second vision mechanism, a backlight assembly and a processor, wherein the mounting assembly comprises a mounting table, and the mounting table is arranged on the workbench in a clearance manner and is used for mounting a target product; the first visual mechanism and the second visual mechanism are both positioned on one side of the mounting table, which is far away from the workbench. According to the laser calibration device and the laser processing equipment, at least 1 backlight assembly is arranged on one side, close to the workbench, of the mounting table, when the first vision mechanism obtains the outline image of the target object from the front side of the target product, the backlight assembly provides a backlight light source for the first vision mechanism on the back side of the target product, so that the image definition of the outline identified by the first vision mechanism is improved, the overall algorithm identification rate is further improved, and the laser processing precision and the yield of the target object are guaranteed.

Description

Laser calibration device and laser processing equipment

Technical Field

The utility model relates to the technical field of laser processing, in particular to a laser calibration device and laser processing equipment.

Background

In the manufacturing process of semiconductor wafers, a plurality of die units are generally cut on a wafer by laser processing, and adjacent die units are usually separated by mutually perpendicular and staggered cutting streets, i.e. cutting paths during laser processing. In order to improve the processing precision of the wafer, the scribe lines are usually aligned before laser cutting, so that the focus of the laser focus can be aligned with the center of the scribe lines. For alignment of scribe lines, in the prior art, two sets of CCD (Charge coupled Device) vision mechanisms are usually adopted, wherein one set of CCD vision mechanism is used for identifying and aligning an outer contour of a wafer, and the other set of CCD vision mechanism is used for accurately aligning scribe lines of the wafer.

However, the conventional wafer can basically meet the processing precision requirement, but for some special wafers, such as wafers with damaged edges or wafers with special designs on the edges, the situations of fuzzy outline identification images, double images, glue interference and the like of the wafers often occur, the algorithm identification rate is influenced, even the false identification is caused, meanwhile, the situations of frequent alarm and the like can be caused, and finally, the laser processing precision and the yield of the wafers are influenced.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model aims to provide a laser calibration device and laser processing equipment, which are used for solving the technical problems that the processing precision is influenced due to the fact that the universality of contour recognition of the existing laser processing device is not enough and the recognition rate is not high.

In order to solve the technical problem, the embodiment of the utility model adopts the following technical scheme: the laser calibration device comprises a workbench, a mounting assembly, a first vision mechanism, a second vision mechanism, a backlight assembly and a processor;

the mounting assembly comprises a mounting table, the mounting table is arranged on the workbench in a clearance mode, and the mounting table is used for mounting a target product;

the first vision mechanism and the second vision mechanism are both positioned on one side, far away from the workbench, of the mounting table, the first vision mechanism is used for identifying and acquiring an image of the outer contour of a target object in a target product, and the second vision mechanism is used for identifying and acquiring an image of a processing path of the target object;

the number of the backlight assemblies is at least 1, each backlight assembly is arranged on one side, close to the workbench, of the mounting table, and the backlight assemblies are used for providing backlight light sources for identifying the outer contour for the first vision mechanism;

the processor is used for receiving the images acquired by the first visual mechanism and the second visual mechanism, determining the offset of the target product according to the corresponding image data, and controlling the workbench to move according to the corresponding offset so as to enable the laser and the target object to be accurately aligned.

In some embodiments, each of the backlight assemblies includes a fixing block and the backlight source, the fixing block is disposed on a side of the mounting table close to the worktable, the backlight source is mounted on the fixing block, and an emergent light beam of the backlight source can be transmitted through the mounting table and has an outer contour of a target object.

In some embodiments, each of the backlight assemblies further includes an adjusting block and at least one clasping block, the adjusting block is disposed on the fixing block at an end away from the light emitting end of the backlight source, each of the clasping blocks is disposed on the fixing block at intervals along the extending direction of the backlight source, and each of the clasping blocks is configured to clamp the backlight source after the adjusting block adjusts the distance between the light emitting surface of the backlight source and the target product.

In some embodiments, the mounting table comprises a base, a first cover plate and a second cover plate capable of transmitting light, the base is arranged on the workbench in a clearance mode, at least one first light transmitting hole is formed in the base, and a mounting groove is further formed in one end, far away from the workbench, of the base; the first cover plate is covered on the mounting groove, at least one second light through hole communicated with the corresponding first light through hole is formed in the first cover plate, and the second cover plate is covered on the second light through hole.

In some embodiments, the center lines of the first light passing hole and the second light passing hole are located on the same line with the center of the emergent light beam of the backlight light source.

In some embodiments, the second cover plate is a plate that can transmit light and has a diffuse reflection function.

In some embodiments, the backlight assembly further includes a diffuse reflection plate, and at least one third light passing hole is formed in a side of the base close to the worktable along a depth direction of the first light passing hole, and each third light passing hole is communicated with and larger than the corresponding first light passing hole; the diffuse reflection plate is arranged in the third light through hole and is positioned on the top of the light emitting surface of the backlight light source.

In some embodiments, the backlight light source is a point light source or an annular light source.

In some embodiments, the backlight light source emits light that is at least one of red, blue, violet, green, or white.

In order to solve the above technical problem, an embodiment of the present invention further provides a laser processing apparatus, which adopts the following technical solutions: the laser processing equipment comprises a laser component, the laser component comprises a light path component, the laser processing equipment further comprises the laser calibration device, and a first visual mechanism and a second visual mechanism of the laser calibration device are located on the same side of the mounting table as the light path component.

Compared with the prior art, the laser calibration device and the laser processing equipment provided by the embodiment of the utility model have the following main beneficial effects:

according to the laser calibration device, at least 1 backlight assembly is arranged on one side (namely the back side of a target product) of the mounting table close to the working table, when the first vision mechanism obtains an outer contour image of the target object from the front side of the target product, the backlight assembly provides a backlight light source for the first vision mechanism on the back side of the target product, so that the image definition of the outer contour recognized by the first vision mechanism is improved, the overall algorithm recognition rate is improved, and the laser processing precision and the yield of the target object are guaranteed.

Drawings

In order to illustrate the solution of the utility model more clearly, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are some embodiments of the utility model, and that other drawings may be derived from these drawings by a person skilled in the art without inventive effort. Wherein:

FIG. 1 is a schematic, diagrammatic view of a laser machining apparatus in accordance with an embodiment of the present invention;

FIG. 2 is a schematic perspective view of a wafer assembly according to one embodiment of the present invention;

fig. 3 is a front view of the wafer assembly of fig. 2. FIG. 4 is a schematic perspective view of a laser alignment device in accordance with an embodiment of the present invention with the first vision mechanism, the second vision mechanism and the table removed;

FIG. 5 is a cut-away view of the laser alignment device of FIG. 1;

fig. 6 is a partially enlarged view of the laser alignment device of fig. 5 at a.

The reference numbers in the drawings are as follows:

1. laser processing equipment; 10. a laser calibration device;

100. a work table;

200. mounting the component; 210. an installation table; 211. a base; 2111. a first light passing hole; 2113. a third light passing hole; 212. a first cover plate; 213. a second cover plate; 220. a support table;

300. a first vision mechanism; 400. a second vision mechanism;

500. a backlight assembly; 510. a fixed block; 520. a backlight light source; 530. an adjusting block; 531. a screw hole; 540. a hugging block; 550. a diffuse reflection plate;

600. a processor; 700. a target product/wafer assembly; 710. an outer contour; 711. collecting a position of the outline; 720. a fixing ring; 730. a transparent adhesive film; 740. a wafer; 800. a laser assembly; 810. an optical path component.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the terminology used in the description presented herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model, e.g., the terms "length," "width," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," "outer," etc., refer to an orientation or position based on that shown in the drawings, are for convenience of description only and are not to be construed as limiting of the present disclosure.

The terms "including" and "having," and any variations thereof, in the description and claims of this invention and the description of the above figures are intended to cover non-exclusive inclusions; the terms "first," "second," and the like in the description and in the claims, or in the drawings, are used for distinguishing between different objects and not necessarily for describing a particular sequential order. The meaning of "plurality" is two or more unless specifically limited otherwise.

In the description and claims of the present invention and in the description of the above figures, when an element is referred to as being "fixed" or "mounted" or "disposed" or "connected" to another element, it may be directly or indirectly located on the other element. For example, when an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element.

Furthermore, reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the utility model. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

An embodiment of the present invention provides a laser calibration apparatus 10, as shown in fig. 1, the laser calibration apparatus 10 includes a worktable 100, a mounting assembly 200, a first vision mechanism 300, a second vision mechanism 400, a backlight assembly 500, and a processor 600. Wherein, the mounting assembly 200 includes a mounting table 210, and the mounting table 210 is disposed on the worktable 100 with a gap. Specifically, in the present embodiment, in order to ensure the gap between the mounting platform 210 and the worktable 100, the mounting assembly 200 further includes a supporting platform 220, wherein a bottom end of the supporting platform 220 is mounted on a top end of the worktable 100, and a top end of the supporting platform 220 is connected to a bottom end of the mounting platform 210. It should be noted that the height of the supporting platform 220 is generally required to be greater than the height of the backlight assembly 500, so as to provide enough space for the backlight assembly 500 and avoid interference on the installation and adjustment of the backlight assembly 500 caused by too small distance between the installation platform 210 and the worktable 100.

In the present embodiment, the mounting table 210 is mainly used for mounting the target product 700, i.e., the target product 700 is carried by the mounting assembly 200. Additionally, the mounting assembly 200 may be a vacuum chuck assembly for ease of mounting the target product 700, but may be other suitable structural assemblies.

As further shown in fig. 1, the first vision mechanism 300 and the second vision mechanism 400 are both located on a side of the mounting table 210 away from the worktable 100 (i.e. a side close to the target product 700), wherein the first vision mechanism 300 is mainly used for identifying and acquiring an image of an outer contour 710 (see fig. 3) of a target object (see the wafer 740 in the wafer assembly 700 in fig. 3) in the target product 700, and the second vision mechanism 400 is mainly used for identifying and acquiring an image of a processing path (see the scribe line of the wafer 740 in fig. 3) of the target object.

It should be noted that the laser alignment apparatus 10 can be applied to pre-align the outer contour 710 of the wafer 740 and precisely align the scribe lines during the manufacturing process of the semiconductor wafer. It is to be understood that the target product 700 described below may be a wafer assembly 700, the target object may be a wafer 740 in the wafer assembly 700, and the target feature may be a scribe line (not shown) on the wafer 740. Of course, the laser calibration device 10 can also be used for alignment calibration of target objects of other products. In the embodiment of the utility model, for convenience of description, the target product 700 is taken as an example of a wafer assembly.

Specifically, in the present embodiment, as shown in fig. 2 and fig. 3, taking the target product 700 as an example of a wafer assembly, the wafer assembly 700 generally includes a fixing ring 720, a transparent adhesive film 730 and a wafer 740, wherein the wafer 740 is disposed (specifically, can be adhered) on the top surface of the transparent adhesive film 730, the transparent adhesive film 730 is disposed (specifically, can be adhered) on the top surface of the fixing ring 720, and the surface areas of the fixing ring 720, the transparent adhesive film 730 and the wafer 740 are generally gradually reduced.

As shown in fig. 1 and 4, at least 1 backlight assembly 500 is provided, and each backlight assembly 500 is provided on one side of the mounting table 210 close to the work table 100, that is, the backlight assembly 500 and the first vision mechanism 300 are respectively located on both sides (e.g., upper and lower sides) of the mounting table 210. In the present embodiment, the backlight assembly 500 is mainly used for providing the first vision mechanism 300 with the backlight light source 520 for identifying the outer contour 710 (see fig. 3) of the target object. It is understood that when the first vision mechanism 300 polishes the target object from the front side of the target object to identify the outer contour 710, the backlight assembly 500 may provide the first vision mechanism 300 with the backlight light source 520 at the back side of the mounting stage 210, so as to improve the image clarity of the outer contour 710 identified by the first vision mechanism 300, and avoid the identified image from blurring, ghosting, interference of glue, and the like.

In this embodiment, the processor 600 is mainly configured to receive the images acquired by the first and second vision mechanisms 300 and 400, determine an offset of the target product 700 according to the corresponding image data, and further control the movement of the worktable 100 according to the corresponding offset so as to precisely align the laser with the target object of the target product 700. It is understood that, after receiving the image of the outer contour 710 (please refer to fig. 3) of the target object acquired by the first vision mechanism 300, the processor 600 may determine an offset of the target product 700 (e.g., the wafer assembly 700) according to the image data of the outer contour 710, and then control the movement of the stage 100 according to the offset. When the second vision mechanism 400 acquires the target feature of the target object (please refer to the scribe line of the wafer 740 in fig. 3), the target feature is located within the field of view of the second vision mechanism 400, that is, the position of the target object is pre-aligned by the first vision mechanism 300. Correspondingly, after receiving the image of the target feature of the target object acquired by the second vision mechanism 400, the processor 600 may determine the offset of the target product 700 according to the image of the target feature, and then control the movement of the worktable 100 according to the offset, so as to ensure that the laser emitted by the optical path component 810 of the laser component 800 is accurately aligned with the target feature of the target object, thereby improving the laser processing precision of the target object.

It should be noted that in the present embodiment, the optical path component 810 of the laser assembly 800 is located on the same side of the target product 700 as the first vision mechanism 300 and the second vision mechanism 400, that is, on the front surface of the target product 700. In addition, the backlight source 520 of the backlight assembly 500 may be a point light source, and may also be other similar light sources, such as a ring light source. In addition, the light emitted from the backlight light source 520 of the backlight assembly 500 may be at least one of red light, blue light, violet light, green light, or white light. In other words, the color of the outgoing light beam of the backlight light source 520 may be white, and may also be other colors, such as red, blue, and other colors, without being limited thereto. In the present embodiment, the backlight source 520 is a white high-brightness point light source.

In summary, compared with the prior art, the laser calibration apparatus 10 has at least the following advantages: in the laser calibration device 10, at least 1 backlight assembly 500 is arranged on one side of the mounting table 210 close to the workbench 100 (i.e., the back side of the target product 700), and when the first vision mechanism 300 takes an image of the outer contour 710 of the target object from the front side of the target product 700, the backlight assembly 500 provides a backlight light source 520 for the first vision mechanism 300 on the back side of the target product 700, so that the image definition of the outer contour 710 recognized by the first vision mechanism 300 is improved, the overall algorithm recognition rate is improved, and the laser processing precision and the yield of the target object are ensured.

In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to fig. 1 to 6.

In some embodiments, as shown in fig. 4 to 6, each of the backlight assemblies 500 includes a fixing block 510 and a backlight source 520, wherein the fixing block 510 is disposed at a side of the mounting table 210 close to the work table 100 (i.e., a bottom surface of the mounting table 210), and the backlight source 520 is mounted on the fixing block 510. In this embodiment, to realize the backlight assembly 500, the backlight source 520 may be provided to the first vision mechanism 300, and an exit light beam of the backlight source 520 may exit through the mounting table 210 and pass through the outer contour 710 of the target object, so that when the first vision mechanism 300 acquires the outer contour 710 of the target object, the outer contour 710 is irradiated by the exit light beam of the backlight source 520, thereby being beneficial to clearly acquiring an image of the outer contour 710.

In some embodiments, as shown in fig. 4 to 6, each backlight assembly 500 further includes an adjusting block 530 and at least one clasping block 540, wherein at an end (specifically, a bottom end of the backlight source 520) facing away from the light emitting end of the backlight source 520, the adjusting block 530 is disposed on the fixing block 510; the clasping blocks 540 are disposed on the fixing block 510 at intervals along the extending direction of the backlight source 520. In the present embodiment, each of the clasping blocks 540 is mainly used for clamping the backlight source 520 after the distance between the light emitting surface of the backlight source 520 and the target product 700 is adjusted by the adjusting block 530. It can be understood that each of the clasping blocks 540 is mainly used for disposing the backlight source 520 on the fixing block 510, and the specific installation position of the backlight source 520 can be adjusted according to the actual requirement through the cooperation of the clasping blocks 540 and the adjusting blocks 530.

It should be noted that, in the present embodiment, in order to conveniently adjust the installation position or the position of the light emitting surface of the backlight source 520, the adjusting block 530 is provided with a screw hole 531 along the extending direction of the backlight source 520, so that when the adjustment is needed, a screw (not shown) is connected to the screw hole 531 through an internal thread, and the screw abuts against the installation end of the backlight source 520, so that the distance between the light emitting surface of the backlight source 520 and the target product 700 can be conveniently adjusted by directly adjusting the screw, and further, the backlight intensity provided by the backlight source 520 can be adjusted, thereby ensuring the definition of the first visual mechanism 300 for identifying the outer contour 710.

In some embodiments, as shown in fig. 4 to 6, the mounting stage 210 includes a base 211, a first cover 212, and a second cover 213 capable of transmitting light, wherein the base 211 is disposed on the working stage 100 with a gap therebetween, and particularly in this embodiment, the base 211 and the working stage 100 are connected by a support stage 220, and an "i" structure may be formed therebetween. To facilitate mounting of the target product 700, such as the wafer assembly 700, in the present embodiment, the base 211 has a suction function, that is, the wafer assembly 700 is suction-mounted on the worktable 100.

As shown in fig. 6, the base 211 is provided with at least one first light hole 2111, and an installation groove is further provided at an end away from the working platform 100, wherein the first cover plate 212 covers the installation groove, the first cover plate 212 is provided with at least one second light hole (not shown), each second light hole is communicated with the corresponding first light hole 2111, and the second cover plate 213 covers the corresponding second light hole. It is understood that the outgoing light beam of the backlight light source 520 of the backlight assembly 500 may be transmitted out of the second cover plate 213 through each of the first light passing holes 2111 via the corresponding second light passing hole to provide backlight to the first vision mechanism 300.

In the present embodiment, to improve the image recognition clarity and uniformity of the first vision mechanism 300, the first light passing holes 2111 and the second light passing holes (not shown) are uniformly disposed at the center of the wafer 740, and correspondingly, the backlight assembly 500 is also uniformly disposed around the center of the wafer 740. It is understood that the edge of the wafer 740 passes through the hole area of each second through hole, that is, as shown in fig. 3, the position of each second through hole is the contour collection position 711 of the wafer 740. Specifically, in the present embodiment, there are 4 contour collecting positions 711, and correspondingly, there are 4 contour collecting positions in the backlight assembly 500.

It should be noted that, in the present embodiment, in order to realize that the light beam emitted from the backlight source 520 only exits from each light-passing hole, the base 211 and the first cover 212 are made of a non-light-transmitting material, and typically, a ceramic material may be used. Specifically, to facilitate mounting the wafer assembly 700 on the mounting stage 210, the base 211 is a vacuum chuck, such as a vacuum ceramic chuck.

In some embodiments, to further improve the definition and uniformity of the outline recognition of the first visual mechanism 300, the center lines of the first and second light passing holes 2111 and 520 are located on the same line as the center of the outgoing light beam of the backlight source 520.

In some embodiments, the second cover plate 213 is a plate that can transmit light and has a diffuse reflection function. It is to be understood that, in the present embodiment, the second cover plate 213 is integrated with a diffuse reflection function, or a diffuse reflection plate 550 described below is integrated with the second cover plate 213. Specifically, the surface of the second cover plate 213 contacting the target product 700, such as the wafer assembly 700, may be frosted to achieve a diffuse reflection effect. Meanwhile, the second cover plate 213 may be made of a transparent glass material or a transparent polymer material.

Alternatively, in other embodiments, as shown in fig. 6, the backlight assembly 500 further includes a diffuse reflection plate 550, wherein, along the depth direction of the first light passing holes 2111, at least one third light passing hole 2113 is opened on a side of the base 211 close to the worktable 100, and each third light passing hole 2113 is communicated with a corresponding first light passing hole 2111 and is larger than the corresponding first light passing hole 2111. It is understood that the third light passing hole 2113 is opened at the bottom end of the corresponding first light passing hole 2111. Preferably, the center line of the third light passing hole 2113 is located on the same line as the center line of the first light passing hole 2111. As shown in fig. 6, the diffuse reflection plate 550 is disposed in the third light passing hole 2113 and located on the top of the light exit surface of the backlight source 520, so as to scatter the light beam emitted from the backlight source 520, thereby improving the uniformity of the emitted light beam and further improving the definition of the outline recognition. In this embodiment, the diffuse reflection plate 550 may be adhered to the base 211 by an adhesive such as glue. Of course, other suitable means may be provided in the third light passing hole 2113 corresponding to the base 211.

Based on the laser calibration device 10, the embodiment of the present invention further provides a laser processing apparatus 1, where the laser processing apparatus 1 includes a laser assembly 800, the laser assembly 800 includes a light path assembly 810, and the laser processing apparatus 1 further includes the laser calibration device 10, where the first and second vision mechanisms 300 and 400 of the laser calibration device 10 and the light path assembly 810 of the laser assembly 800 are located on the same side of the mounting table 210 (specifically, the front side of the target product 700).

In summary, compared with the prior art, the laser processing apparatus 1 has at least the following beneficial effects: by adopting the laser calibration device 10, the laser processing equipment 1 improves the definition of the outer contour 710 image of the target object of the target product 700, and is beneficial to improving the overall algorithm recognition rate, thereby ensuring the laser processing precision of the laser processing equipment 1, the yield of the product and the stability of the equipment operation.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims (10)

1. A laser calibration device is characterized by comprising a workbench, a mounting assembly, a first vision mechanism, a second vision mechanism, a backlight assembly and a processor;

the mounting assembly comprises a mounting table, the mounting table is arranged on the workbench in a clearance mode, and the mounting table is used for mounting a target product;

the first vision mechanism and the second vision mechanism are both positioned on one side, far away from the workbench, of the mounting table, the first vision mechanism is used for identifying and acquiring an image of the outer contour of a target object in a target product, and the second vision mechanism is used for identifying and acquiring an image of a processing path of the target object;

the number of the backlight assemblies is at least 1, each backlight assembly is arranged on one side, close to the workbench, of the mounting table, and the backlight assemblies are used for providing backlight light sources for identifying the outer contour for the first vision mechanism;

the processor is used for receiving the images acquired by the first visual mechanism and the second visual mechanism, determining the offset of the target product according to the corresponding image data, and controlling the workbench to move according to the corresponding offset so as to enable the laser and the target object to be accurately aligned.

2. The laser alignment apparatus of claim 1, wherein each of the backlight assemblies comprises a fixing block and the backlight source, the fixing block is disposed on a side of the mounting platform adjacent to the working platform, the backlight source is mounted on the fixing block, and an emergent light beam of the backlight source can be transmitted through the mounting platform and has an outer contour of a target object.

3. The laser alignment device according to claim 2, wherein each of the backlight assemblies further includes an adjusting block and at least one clasping block, the adjusting block is disposed on the fixing block at an end away from the light emitting end of the backlight source, each of the clasping blocks is disposed on the fixing block at intervals along the extending direction of the backlight source, and each of the clasping blocks is configured to clamp the backlight source after the adjusting block adjusts the distance between the light emitting surface of the backlight source and the target product.

4. The laser calibration device according to any one of claims 1 to 3, wherein the mounting table comprises a base, a first cover plate and a second cover plate capable of transmitting light, the base is arranged on the workbench in a clearance manner, the base is provided with at least one first light transmitting hole, and one end far away from the workbench is further provided with a mounting groove; the first cover plate is covered on the mounting groove, at least one second light through hole communicated with the corresponding first light through hole is formed in the first cover plate, and the second cover plate is covered on the second light through hole.

5. The laser calibration device according to claim 4, wherein the center lines of the first light passing hole and the second light passing hole are located on the same line with the center of the outgoing light beam of the backlight light source.

6. The laser calibration device according to claim 4, wherein the second cover plate is a plate that is transparent and has a diffuse reflection function.

7. The laser alignment device according to claim 4, wherein the backlight assembly further includes a diffuse reflection plate, and at least one third light passing hole is formed on a side of the base close to the worktable along a depth direction of the first light passing hole, and each third light passing hole is communicated with and larger than the corresponding first light passing hole; the diffuse reflection plate is arranged in the third light through hole and is positioned on the top of the light emitting surface of the backlight light source.

8. The laser calibration device of claim 1, wherein the backlight source is a point light source or an annular light source.

9. The laser calibration device of claim 1, wherein the backlight source emits at least one of red, blue, violet, green, or white light.

10. A laser machining apparatus comprising a laser assembly including a light path assembly, characterised in that the laser machining apparatus further comprises a laser alignment device as claimed in any one of claims 1 to 9, the first and second vision mechanisms of the laser alignment device being located on the same side of the mounting table as the light path assembly.

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