Prism-type beam scanning device, system and beam scanning method for laser micro-hole processing

Abstract

The present invention relates to a prism-type beam scanning device, system and beam scanning method for laser micro-hole processing. The beam scanning device includes: a first special-shaped optical wedge, a second special-shaped optical wedge, a first rotating driving member and a second rotating driving member. The beam scanning device uses two special-shaped optical wedges to control the lateral displacement and tilt angle of the laser beam. Changing the angle between the two special-shaped optical wedges can change the tilt angle and lateral displacement of the laser beam at the same time. It can not only be used to process inverted cone holes, but also solves the problem of the center beam first rubbing the edge in deep hole processing of existing transmission type and combination type devices, greatly improving the deep hole processing capability. The beam scanning system and the beam scanning method with the above-mentioned beam scanning device also have the above-mentioned technical effects.

Description

Technical Field

[0001] The present invention relates to the field of laser processing, and in particular to a prism-type beam scanning device, system and beam scanning method for laser micro-hole processing. Background Art

[0002] At present, the main means of micro-hole processing include mechanical drill, electro-hydraulic beam, electric spark, laser, etc. Compared with other processing methods, laser processing has the characteristics of high processing efficiency, wide range of processable materials, no tool wear, non-contact, little impact on material surface, easy to guide, and flexible. Especially with the application of picosecond and femtosecond lasers, the quality of laser processing has been further improved. Not only is the processing accuracy high and the inner wall quality good, but there is no heat effect, no recast layer, no micro cracks, and no material selectivity. Laser processing has become the choice of more and more people.

[0003] There are three main ways to process micro holes with laser: impact drilling, circular scanning drilling and spiral scanning drilling. In comparison, circular scanning drilling and spiral scanning drilling have better quality. To achieve circular scanning motion or spiral scanning motion, one is to control the motion of the workpiece, and the other is to control the motion of the light beam. In comparison, controlling the motion of the light beam is simpler and more flexible. At present, there are many devices for controlling the two-dimensional motion of the light beam, which are mainly divided into three categories: reflection type (such as galvanometer, PZT), transmission type (such as four wedges or parallel plates + double wedges), and reflection + transmission combination type (such as PZT + parallel plates, reflectors + Dove prisms). Although the reflection type device has a high motion scanning speed, it can only realize the processing of positive cone holes, and cannot realize the processing of cylindrical or inverted cone holes. Therefore, it is only suitable for surface marking, etching or shallow hole processing with no taper requirements; the transmission type device can realize the processing of cylindrical or inverted cone holes, but the structure is complex and 3 to 4 drive motors are required; the reflection + transmission type is either costly or requires high installation accuracy, and the synchronization accuracy is not high. Moreover, both the transmission type and the combination type have the same problem. When deep hole processing is performed, the middle position of the processing is more likely to block light than the edge position. Figure 1 As shown, the lateral displacement amount does not change substantially during the processing of the prior art. After processing to a certain depth, the central scanning beam is blocked by the edge of the hole entrance, causing the laser to fail to reach the center of the deep hole and fail to remove the material at the center, ultimately affecting the improvement of the hole depth-to-diameter ratio. Summary of the invention

[0004] The embodiments of the present invention provide a prism-type beam scanning device, system and beam scanning method for laser micro-hole processing, so as to at least solve the technical problem of the center beam first rubbing the edge in deep hole processing of existing transmission type and combination type devices.

[0005] According to one aspect of an embodiment of the present invention, a prism-type beam scanning device for laser micro-hole processing is provided, wherein the beam scanning device is connected to an external control system, and the beam scanning device comprises: a first special-shaped optical wedge, a second special-shaped optical wedge, a first rotating driving member, and a second rotating driving member;

[0006] The first special-shaped optical wedge comprises a first optical wedge portion with an angle of α and a first parallel flat plate portion with an inclination angle of β, and the angle between the projections of the main cross section of the first optical wedge portion and the main cross section of the first parallel flat plate portion is γ;

[0007] The second special-shaped optical wedge comprises a second optical wedge portion with an angle of α and a second parallel flat plate portion with an inclination angle of β, and the angle between the projections of the main cross section of the second optical wedge portion and the main cross section of the second parallel flat plate portion is -γ;

[0008] Wherein, the γ angle is -90°<γ<90°;

[0009] The first rotating driving member and the second rotating driving member are controlled by the control system to drive the first special-shaped optical wedge and the second special-shaped optical wedge to rotate in sequence, so that the external laser beam passes through the first special-shaped optical wedge and the second special-shaped optical wedge in sequence to generate a predetermined lateral displacement and tilt angle.

[0010] Furthermore, the γ angle is 30°≤|γ|≤60°.

[0011] Furthermore, the rotation axis of the first special-shaped optical wedge driven by the first rotation driving member is parallel to the rotation axis of the second special-shaped optical wedge driven by the second rotation driving member.

[0012] Furthermore, the angle α is 0°<α<5°, and the angle β is 20°<β<60°.

[0013] Furthermore, the first rotation driving member and the second rotation driving member both include a driving motor.

[0014] According to another aspect of an embodiment of the present invention, a prism-type beam scanning system for laser micro-hole processing is provided, comprising: a control system, a laser, a beam scanning device, and a focusing mirror; the beam scanning device is any one of the beam scanning devices described above;

[0015] The control system controls the speed difference between the first special-shaped optical wedge and the second special-shaped optical wedge in the optical beam scanning device, so that the laser beam emitted by the laser generates a predetermined lateral displacement and tilt angle as the angle φ between the first special-shaped optical wedge and the second special-shaped optical wedge changes after passing through the optical beam scanning device, and is emitted after being focused by the focusing mirror.

[0016] Furthermore, the beam scanning system also includes a reflector, and the laser beam emitted by the laser is reflected by the reflector and then emitted into the beam scanning device, and the center line of the laser beam reflected by the reflector coincides with the optical axis of the focusing mirror.

[0017] According to another aspect of an embodiment of the present invention, there is also provided a light beam scanning method using the above-mentioned prism-type light beam scanning system, comprising the following steps:

[0018] A. Determine the inclination angle of the outgoing laser beam according to the shape of the pre-processed micro-hole, and calculate the angle Δφ between the first special-shaped optical wedge and the second special-shaped optical wedge according to the inclination angle of the outgoing laser beam;

[0019] B. controlling the first profiled optical wedge to deflect by Δφ based on the initial position;

[0020] C. Control the first special-shaped optical wedge and the second special-shaped optical wedge to rotate synchronously, and the emitted laser beam performs circular scanning motion at a determined tilt angle.

[0021] Furthermore, the method further includes, before step A: calibrating the relative position relationship between the first special-shaped optical wedge and the second special-shaped optical wedge; during calibration, imaging the laser beam emitted after being focused by the focusing lens into a CCD camera; wherein the CCD camera is located at the focal plane of the focusing lens; and performing calibration according to the following method:

[0022] A1. Turn on the laser, power on the beam scanning device, return the first rotating drive member and the second rotating drive member to zero, and record the driving angle J=0 at this time;

[0023] B1. Control the first rotating drive member and the second rotating drive member to rotate synchronously. At this time, the first shaped optical wedge and the second shaped optical wedge will rotate synchronously at a fixed angle, and record the diameter D0 of the image captured by the CCD camera at this time;

[0024] C1. The first rotary drive member and the second rotary drive member control the corresponding first shaped optical wedge and the second shaped optical wedge to increase the angle by 1°, and repeat the B process to obtain the image diameter D1;

[0025] D1. Repeat the C process to obtain image diameters D2, D3, ... in sequence;

[0026] E1. Compare the image diameters D1, D2, D3, ..., and find the angle corresponding to the minimum image diameter, which is the initial position of the beam scanning device;

[0027] F1. Correct the angle corresponding to the minimum image diameter to the first rotary drive member and the second rotary drive member so that the zero return positions of the first rotary drive member and the second rotary drive member correspond to the initial positions of the light beam scanning device.

[0028] According to another aspect of an embodiment of the present invention, there is also provided a light beam scanning method using the above-mentioned prism-type light beam scanning system, comprising the following steps:

[0029] A. Control the speed difference between the first special-shaped optical wedge and the second special-shaped optical wedge. The speed of the first optical wedge part is V1, and the speed of the second optical wedge part is V2. First, control the speed V1 of the first optical wedge part to be greater than the speed V2 of the second optical wedge part, satisfying the following formula:

[0030] V1 / V2-1=φn / N;

[0031] B. After N turns, the speed V1 of the first optical wedge portion is controlled to be smaller than the speed V2 of the second optical wedge portion, and the following formula is satisfied:

[0032] V1 / V2-1=-φn / N;

[0033] C. After N rounds, it starts to enter process A again;

[0034] Through the process A to C, the laser beam can achieve reciprocating spiral scanning motion from inside to outside and then from outside to inside;

[0035] in:

[0036] i. The starting position of the spiral is the initial position of the beam scanning device, which is φ0;

[0037] ii. The end position of the spiral is φn;

[0038] iii. The spiral line has N turns from the inside to the outside, where N is an integer greater than 1, n is an integer and 0≤n≤N.

[0039] Furthermore, the method further includes, before step A: calibrating the relative position relationship between the first special-shaped optical wedge and the second special-shaped optical wedge; during calibration, imaging the laser beam emitted after being focused by the focusing lens into a CCD camera; wherein the CCD camera is located at the focal plane of the focusing lens; and performing calibration according to the following method:

[0040] A1. Turn on the laser, power on the beam scanning device, return the first rotating drive member and the second rotating drive member to zero, and record the driving angle J=0 at this time;

[0041] B1. Control the first rotating drive member and the second rotating drive member to rotate synchronously. At this time, the first shaped optical wedge and the second shaped optical wedge will rotate synchronously at a fixed angle, and record the diameter D0 of the image captured by the CCD camera at this time;

[0042] C1. The first rotary drive member and the second rotary drive member control the corresponding first shaped optical wedge and the second shaped optical wedge to increase the angle by 1°, and repeat the B process to obtain the image diameter D1;

[0043] D1. Repeat the C process to obtain image diameters D2, D3, ... in sequence;

[0044] E1. Compare the image diameters D1, D2, D3, ..., and find the angle corresponding to the minimum image diameter, which is the initial position of the beam scanning device;

[0045] F1. Correct the angle corresponding to the minimum image diameter to the first rotary drive member and the second rotary drive member so that the zero return positions of the first rotary drive member and the second rotary drive member correspond to the initial positions of the light beam scanning device.

[0046] In the embodiment of the present invention, the laser beam is tilted at a certain angle by passing through a small-angle optical wedge, and then a lateral displacement is generated by passing through a parallel plate, so that the tilt and lateral displacement of the laser beam can be controlled. The beam scanning device uses two special-shaped optical wedges to control the lateral displacement and tilt angle of the laser beam. Changing the angle between the two special-shaped optical wedges can simultaneously change the tilt angle and lateral displacement of the laser beam, thereby achieving the purpose of different lateral displacements corresponding to different tilt angles. It can not only be used to process inverted cone holes, but also solves the problem of the center beam first rubbing the edge in deep hole processing of existing transmission type and combination type devices, greatly improving the deep hole processing capability. The beam scanning system and the beam scanning method equipped with the above-mentioned beam scanning device also have the above-mentioned technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0048] Figure 1 It is a schematic diagram of the phenomenon that the central light beam is blocked first during deep hole processing by an existing laser scanning device;

[0049] FIG2(a) is an equivalent schematic diagram of the first special-shaped optical wedge;

[0050] FIG2( b ) is an equivalent schematic diagram of the second special-shaped optical wedge;

[0051] Figure 3 Schematic diagram of the positional relationship between the γ=0° optical wedge part and the parallel plate part;

[0052] Figure 4 It is a schematic diagram of the projection of the displacement and direction of the laser beam after passing through the beam scanning device on the XOY plane;

[0053] Figure 5 It is a schematic diagram of the incident conditions of the central light beam and the edge light beam during deep hole processing of the present invention;

[0054] Figure 6 It is a diagram of the construction of a light beam scanning device in a specific embodiment;

[0055] Figure 7 A diagram showing the construction of a light beam scanning system in a specific embodiment;

[0056] Figure 8 This is the construction diagram of the calibration platform at the initial position.

[0057] The figures are marked as follows: 1. laser; 2. beam expander; 3. reflector; 4. first special-shaped optical wedge; 5. second special-shaped optical wedge; 6. first drive motor; 7. second drive motor; 8. focusing mirror; 9. workpiece; 10. computer; 11. beam center. DETAILED DESCRIPTION

[0058] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0059] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0060] Example 1

[0061] According to an embodiment of the present invention, a prism-type beam scanning device for laser micro-hole processing is provided, the beam scanning device is connected to an external control system, and the beam scanning device includes: a first special-shaped optical wedge, a second special-shaped optical wedge, a first rotating driving member, and a second rotating driving member;

[0062] The first profiled optical wedge includes a first optical wedge portion with an angle of α and a first parallel flat plate portion with an inclination angle of β. For the convenience of description, the two portions are separated to be equivalent to a first optical wedge portion with an angle of α and a first parallel flat plate portion with an inclination angle of β for optical path description. The surface of the first optical wedge portion opposite to the first parallel flat plate portion is the incident surface of the laser, and the laser enters the first profiled optical wedge from the incident surface and is emitted after being deflected and translated by the first profiled optical wedge. The inclination angle β is the angle between the vertical direction and the first parallel flat plate portion, and the small angle α is the angle between the first parallel flat plate portion and the incident surface. The angles a and β are determined according to the pre-processed micro-hole aperture and depth, and the angle α is 0°<α<5°, and the angle β is 20°<β<60°.

[0063] The angle between the projections of the main cross-section of the first optical wedge part and the main cross-section of the first parallel flat plate part is γ. The light beam incident from the incident surface passes through the first optical wedge part and the first parallel flat plate part and is incident on the projection line of the parallel flat plate part after being deflected and distorted. The misalignment of the first optical wedge part and the first parallel flat plate part at an angle of γ can effectively ensure that the light beam is offset by the desired lateral displacement. The second special-shaped optical wedge has the same structure as the first special-shaped optical wedge, including a second optical wedge part with an angle of α and a second parallel flat plate part with an inclination angle of β. For the convenience of description, the two parts are separated and described as equivalent to a second optical wedge part with an angle of α and a second parallel flat plate part with an inclination angle of β for optical path description. The difference from the first special-shaped optical wedge is that the angle between the projections of the main cross-section of the second optical wedge part and the main cross-section of the second parallel flat plate part is -γ.

[0064] To facilitate understanding of the specification, the γ angle is defined as follows: When the main sections of the parallel plate part and the wedge part are parallel and the positions of the two are Figure 3 When shown, γ=0°, wherein the counterclockwise rotation of the parallel plate section around the small-angle wedge section is defined as positive rotation, and the γ angle is -90°<γ<90°; in practical work, it is preferably 30°≤|γ|≤60. In the technical field, the wedges are basically small-angle, i.e., wedge-shaped, with a triangle with a very small angle. The small-angle wedge here is often used in technical literature in this field.

[0065] The first rotating driving member and the second rotating driving member are controlled by the control system to drive the first special-shaped optical wedge and the second special-shaped optical wedge to rotate in sequence, so that the external laser beam passes through the first special-shaped optical wedge and the second special-shaped optical wedge in sequence to generate a predetermined lateral displacement and tilt angle.

[0066] In the embodiment of the present invention, the laser beam is tilted at a certain angle by passing through the small-angle wedge portion of the special-shaped optical wedge, and then a lateral displacement is generated by passing through the parallel flat plate portion of the special-shaped optical wedge. The beam scanning device uses two special-shaped optical wedges to control the lateral displacement and tilt angle of the laser beam. Changing the angle between the two special-shaped optical wedges can simultaneously change the tilt angle and lateral displacement of the laser beam, thereby achieving the purpose of different lateral displacements corresponding to different tilt angles. It can not only be used to process inverted tapered holes, but also solves the problem of the center beam first rubbing the edge in deep hole processing in existing transmission type and combination type devices, thereby greatly improving the deep hole processing capability.

[0067] Example 2

[0068] According to an embodiment of the present invention, a prism beam scanning system for laser micro-hole processing is provided, comprising: a laser, a beam expander, a reflector, a two-dimensional beam scanning device, a focusing mirror, a workpiece, and a computer. The computer controls the laser output beam, which is collimated by the beam expander and then reflected by a reflector with a certain installation angle to the two-dimensional beam scanning device, generating an output beam with a certain refraction angle and lateral displacement, and finally focusing the laser onto the workpiece through the focusing mirror. The center line of the beam reflected by the reflector coincides with the optical axis of the focusing mirror, and the rotation axes of the two special-shaped optical wedges in the two-dimensional beam scanning device are parallel.

[0069] The two-dimensional light beam scanning device is mainly composed of a first special-shaped optical wedge, a second special-shaped optical wedge and two rotating driving parts that drive the rotation thereof, which are motors in this embodiment, and are controlled by a computer. The first special-shaped optical wedge may include a parallel plate portion with an inclination angle β and an optical wedge portion with an angle α, and there is an angle γ between the main sections of the optical wedge portion and the parallel plate portion, as shown in FIG2(a). For the convenience of description, the second special-shaped optical wedge can be separated and equivalent to a parallel plate portion with an inclination angle β and an optical wedge portion with an angle α, and there is an angle -γ between the main sections of the optical wedge portion and the parallel plate portion, as shown in FIG2(b). The light beam passes through the small-angle optical wedge portion of the special-shaped optical wedge to produce a certain angle of inclination, and then passes through the parallel plate portion to produce a lateral displacement, thereby achieving the purpose of an optical lens to achieve both beam deflection and lateral displacement, thereby reducing the control amount and improving the control accuracy.

[0070] To facilitate understanding of the specification, the small-angle wedge portion and the parallel plate portion are defined as follows: When the parallel plate portion and the small-angle wedge portion are parallel in main cross-section and the positions of the two are as follows: Figure 3When it is shown, γ is defined as 0°; when the cross section of the parallel plate rotates counterclockwise around the cross section of the small angle wedge, it is defined as positive rotation. In order to realize the processing of cylindrical or inverted cone holes, the angle between the lateral displacement direction of the light beam generated by the special-shaped wedge and the projection of the deflection direction on the horizontal plane perpendicular to the optical axis must be an obtuse angle. Accordingly, in the production of special-shaped wedges, -90°<γ<90°, and in actual work, 30°≤|γ|≤60 is preferably taken.

[0071] When the light beam passes through two profiled wedges in sequence, and the angle between the profiled wedges is φ, where φ is the angle between the main section of the first wedge part and the small section of the second wedge part. Figure 4 As shown in the figure, the large circle in the coordinate system represents a cross section below the second profiled optical wedge, where the dotted circle represents the spot position when the light beam passes through the two profiled optical wedges alone, the solid circle represents the combined position of the light beam after passing through the two profiled optical wedges successively, the dotted line passing through the Y axis represents the influence of a single profiled optical wedge on the position and direction of the light beam, and the solid line represents the effect after the two are combined. The arrow represents the projection component of the light beam pointing to the cross section.

[0072] Different φ values ​​correspond to different outgoing beam inclination angles and lateral displacements, that is, the small angle φ generated between the two special-shaped wedges of the two-dimensional beam scanning device corresponds to a small lateral displacement, and the large angle φ corresponds to a large lateral displacement. During the spiral laser drilling process, the two special-shaped wedges rotate and there is a change in the angle φ. As the scanning proceeds, when the angle φ between the two wedges is small, the beam scans the center, and when the angle φ between the two wedges is large, the beam offset is large, and the beam scans the edge of the aperture. This avoids the problem of the center scanning beam easily scanning the edge during deep hole processing, such as Figure 5 shown.

[0073] When φ=0, it is the initial position of the processing, at which time the apex angles of the first wedge portion and the second wedge portion of the two special-shaped wedges are opposite, and the main cross-sections of the wedge portions are parallel.

[0074] The deflection angle of the outgoing beam emitted from the two special-shaped wedges is δ, then

[0075]

[0076] The final maximum hole diameter d = 2Ftanδ;

[0077] Where F is the focal length of the focusing lens and n is the refractive index of the profiled wedge.

[0078] The following is combined with Figures 6-7 The present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

[0079] like Figure 7The beam scanning system shown in the figure is composed of a laser 1, a beam expander 2, a reflector 3, a first profiled optical wedge 4, a second profiled optical wedge 5, a first drive motor 6, a second drive motor 7, a focusing mirror 8, a workpiece 9 and a computer 10 as a control system. The center line of the beam center 11 reflected by the reflector 3 coincides with the optical axis of the focusing mirror 8 and is parallel to the rotation axis of the first profiled optical wedge 4 and the second profiled optical wedge 5.

[0080] The first profiled optical wedge 4 and the second profiled optical wedge 5 are respectively controlled by the first driving motor 6 and the second driving motor 7 through the computer 10. The computer 10 controls the laser 1 to emit a light beam, which is collimated by the beam expander 2 and then reflected by the reflector 3 with a certain installation angle to the first profiled optical wedge 4, generating an output light beam with a certain refraction angle and lateral displacement, which is then refracted and moved laterally by the second profiled optical wedge 5, and finally focused on the workpiece 9 by the focusing mirror 8.

[0081] Example 3

[0082] According to an embodiment of the present invention, a beam scanning method using the above beam scanning system is provided. Before using the two-dimensional beam scanning device, the relative position relationship between the two special-shaped optical wedges is first calibrated to determine the relationship between the rotation amount of the driving motor and the initial position, so as to achieve precise control. Figure 8 As shown: First, a laser beam is emitted from the laser. The laser energy cannot be too large to avoid damaging the CCD camera. It is reflected into the beam scanning device through the reflector. The reflector angle is adjusted to make the center line of the beam coincide with the rotation axis of the beam scanning device as much as possible. The beam emitted from the beam scanning device is focused by the focusing mirror and imaged into the CCD camera, where the CCD camera is located at the focal plane of the focusing mirror. Calibrate as follows:

[0083] A1. Turn on the laser, power on the beam scanning device, return the first rotating drive member and the second rotating drive member, i.e., the two drive motors, to zero, and record the drive motor angle J=0 at this time;

[0084] B1. Control the two drive motors to rotate synchronously. At this time, the first special-shaped optical wedge and the second special-shaped optical wedge will rotate synchronously at a fixed angle, and record the diameter D0 of the image captured by the CCD camera at this time;

[0085] C1. The angle between the first and second shaped optical wedges controlled by the two driving motors increases by 1°, and the process B is repeated to obtain the image diameter D1;

[0086] D1. Repeat the C process to obtain image diameters D2, D3, ... in sequence;

[0087] E1. Compare the image diameters D1, D2, D3, ..., and find the angle corresponding to the minimum image diameter, which is the initial position of the beam scanning device;

[0088] F1. Correct the angle corresponding to the minimum image diameter to the first rotary drive member and the second rotary drive member so that the zero return positions of the first rotary drive member and the second rotary drive member correspond to the initial positions of the light beam scanning device.

[0089] The light beam scanning system of the present invention can perform light beam circular scanning motion and spiral line scanning motion, wherein the light beam scanning method of the light beam circular scanning motion comprises the following steps:

[0090] A. Determine the inclination angle of the outgoing laser beam according to the shape of the pre-processed micro-hole, and calculate the angle Δφ between the first special-shaped optical wedge and the second special-shaped optical wedge according to the inclination angle of the outgoing laser beam;

[0091] B. Control the first profiled optical wedge to deflect Δφ based on the initial position;

[0092] C. Control the first special-shaped optical wedge and the second special-shaped optical wedge to rotate synchronously, and the emitted laser beam performs circular scanning motion at a determined tilt angle.

[0093] The beam scanning method of the spiral scanning motion comprises the following steps:

[0094] A. According to the assumption, the speed difference between the first profiled optical wedge and the second profiled optical wedge is calculated. The speed of the first optical wedge is V1, and the speed of the second optical wedge is V2. The speed V1 of the first optical wedge is greater than the speed V2 of the second optical wedge, satisfying the following formula:

[0095] V1 / V2-1=φn / N;

[0096] B. After N turns, the speed V1 of the first optical wedge portion is less than the speed V2 of the second optical wedge portion, and satisfies the following equation:

[0097] V1 / V2-1=-φn / N;

[0098] C. After N rounds, it starts to enter process A again;

[0099] Through the process A to C, the laser beam can achieve reciprocating spiral scanning motion from inside to outside and then from outside to inside;

[0100] The assumptions are:

[0101] i. The starting position of the spiral is the initial position of the beam scanning device, which is φ0;

[0102] ii. The end position of the spiral is φn;

[0103] iii. The spiral line has N turns from the inside to the outside, where N is an integer greater than 1, n is an integer and 0≤n≤N.

[0104] The technical effects of the present invention are as follows:

[0105] The technical solution of the present invention adopts two special-shaped optical wedges to replace the original four optical wedges, thereby reducing the number of optical wedges and driving motors and reducing costs; the use of double special-shaped optical wedges only requires the calibration of one relative position relationship, while the four optical wedges require the calibration of the position relationship between four optical wedges, which is simpler to operate; the mechanical structure is simpler, fewer error sources are introduced, and the accuracy is improved; compared with the reflection type, transmission type, and transmission + reflection type, the deep hole processing capability is greatly improved.

[0106] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0107] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0108] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0109] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0110] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0111] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0112] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A prism beam scanning system for laser micro-hole processing, characterized in that: include: Control system, laser, beam scanning device, focusing mirror; The light beam scanning device is connected to an external control system, and comprises: a first special-shaped light wedge, a second special-shaped light wedge, a first rotating driving member, and a second rotating driving member; The first special-shaped optical wedge comprises a first optical wedge portion with an angle of α and a first parallel flat plate portion with an inclination angle of β, and the angle between the projections of the main cross section of the first optical wedge portion and the main cross section of the first parallel flat plate portion is γ; The second special-shaped optical wedge comprises a second optical wedge portion with an angle of α and a second parallel flat plate portion with an inclination angle of β, and the angle between the projections of the main cross section of the second optical wedge portion and the main cross section of the second parallel flat plate portion is -γ; Wherein, the γ angle is 30°≤|γ|≤60°; The first rotating driving member and the second rotating driving member are controlled by the control system to sequentially drive the first special-shaped optical wedge and the second special-shaped optical wedge to rotate so that the external laser beam passes through the first special-shaped optical wedge and the second special-shaped optical wedge in sequence to generate a predetermined lateral displacement and tilt angle; the angle between the first special-shaped optical wedge and the second special-shaped optical wedge is φ; The angle α is 0°<α<5°, and the angle β is 20°<β<60°; The control system controls the speed difference between the first special-shaped optical wedge and the second special-shaped optical wedge in the optical beam scanning device, so that the laser beam emitted by the laser generates a predetermined lateral displacement and tilt angle as the angle φ between the first special-shaped optical wedge and the second special-shaped optical wedge changes after passing through the optical beam scanning device, and is emitted after being focused by the focusing mirror; φ is the angle between the main cross-section of the first optical wedge part and the main cross-section of the second optical wedge part; when φ=0, it is the initial position of the processing, at which time the top angles of the first optical wedge part and the second optical wedge part of the two special-shaped optical wedges are opposite, and the main cross-sections of the optical wedge parts are parallel.

2. The prism-type beam scanning system according to claim 1, characterized in that: The beam scanning system also includes a reflector. The laser beam emitted by the laser is reflected by the reflector and then emitted into the beam scanning device. The center line of the laser beam reflected by the reflector coincides with the optical axis of the focusing mirror.

3. The prism-type beam scanning system according to claim 1, characterized in that: The rotation axis of the first special-shaped optical wedge driven by the first rotation driving member is parallel to the rotation axis of the second special-shaped optical wedge driven by the second rotation driving member.

4. The prism-type beam scanning system according to claim 1, characterized in that: The first rotation driving member and the second rotation driving member both include a driving motor.

5. A beam scanning method applied to the prism-type beam scanning system according to claim 1 or 2, characterized in that: The following steps are involved: A. Determine the inclination angle of the outgoing laser beam according to the shape of the pre-processed micro-hole, and calculate the angle φ between the first special-shaped optical wedge and the second special-shaped optical wedge according to the inclination angle of the outgoing laser beam; B. controlling the first special-shaped optical wedge to deflect φ based on the initial position; C. Control the first special-shaped optical wedge and the second special-shaped optical wedge to rotate synchronously, and the emitted laser beam performs circular scanning motion according to a determined tilt angle.

6. The light beam scanning method according to claim 5, characterized in that: The method further comprises, before step A, calibrating the relative position relationship between the first special-shaped optical wedge and the second special-shaped optical wedge; during calibration, imaging the laser beam emitted after being focused by the focusing lens into a CCD camera; wherein the CCD camera is located at the focal plane of the focusing lens; and calibrating according to the following method: A1. Turn on the laser, power on the beam scanning device, return the first rotating drive member and the second rotating drive member to zero, and record the driving angle J=0 at this time; B1. Control the first rotating drive member and the second rotating drive member to rotate synchronously. At this time, the first shaped optical wedge and the second shaped optical wedge will rotate synchronously at a fixed angle, and record the diameter D0 of the image captured by the CCD camera at this time; C1. The first rotary drive member and the second rotary drive member control the corresponding first shaped optical wedge and the second shaped optical wedge to increase the angle by 1°, and repeat the B1 process to obtain the image diameter D1; D1. Repeat the C1 process to obtain image diameters D2, D3, ... in sequence; E1. Compare the image diameters D1, D2, D3, ..., and find the angle corresponding to the minimum image diameter, which is the initial position of the beam scanning device; F1. Correct the angle corresponding to the minimum image diameter to the first rotary drive member and the second rotary drive member so that the zero return positions of the first rotary drive member and the second rotary drive member correspond to the initial positions of the light beam scanning device.

7. A beam scanning method applied to the prism-type beam scanning system according to claim 1 or 2, characterized in that: The following steps are involved: A. Control the speed difference between the first special-shaped optical wedge and the second special-shaped optical wedge. The speed of the first optical wedge part is V1, and the speed of the second optical wedge part is V2. First, control the speed V1 of the first optical wedge part to be greater than the speed V2 of the second optical wedge part, satisfying the following formula: V1 / V2-1=φn / N; B. After N turns, the speed V1 of the first optical wedge portion is controlled to be smaller than the speed V2 of the second optical wedge portion, and the following formula is satisfied: V1 / V2-1=-φn / N; C. After N rounds, it starts to enter process A again; Through the A-C process, the laser beam can achieve reciprocating spiral scanning motion from inside to outside and then from outside to inside. in: i. The starting position of the spiral is the initial position of the beam scanning device, which is φ0; ii. The end position of the spiral is φn; iii. The spiral line has N turns from the inside to the outside, where N is an integer greater than 1, n is an integer and 0≤n≤N.

8. The light beam scanning method according to claim 7, characterized in that: The method further comprises, before step A, calibrating the relative position relationship between the first special-shaped optical wedge and the second special-shaped optical wedge; during calibration, imaging the laser beam emitted after being focused by the focusing lens into a CCD camera; wherein the CCD camera is located at the focal plane of the focusing lens; and calibrating according to the following method: A1. Turn on the laser, power on the beam scanning device, return the first rotating drive member and the second rotating drive member to zero, and record the driving angle J=0 at this time; B1. Control the first rotating drive member and the second rotating drive member to rotate synchronously. At this time, the first shaped optical wedge and the second shaped optical wedge will rotate synchronously at a fixed angle, and record the diameter D0 of the image captured by the CCD camera at this time; C1. The first rotary drive member and the second rotary drive member control the corresponding first shaped optical wedge and the second shaped optical wedge to increase the angle by 1°, and repeat the B1 process to obtain the image diameter D1; D1. Repeat the C1 process to obtain image diameters D2, D3, ... in sequence; E1. Compare the image diameters D1, D2, D3, ..., and find the angle corresponding to the minimum image diameter, which is the initial position of the beam scanning device; F1. Correct the angle corresponding to the minimum image diameter to the first rotary drive member and the second rotary drive member so that the zero return positions of the first rotary drive member and the second rotary drive member correspond to the initial positions of the light beam scanning device.

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