CN114633018A

CN114633018A - Optical lens module for optical axis inclination processing

Info

Publication number: CN114633018A
Application number: CN202011490952.8A
Authority: CN
Inventors: 李隆翔
Original assignee: Usun Technology Co Ltd
Current assignee: Usun Technology Co Ltd
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2022-06-17

Abstract

An optical lens module for optical axis oblique machining is suitable for a laser scanner of a laser machining system, a vibrating mirror scanning module is arranged in a scanning head, a transfer port is arranged at the bottom of the scanning head, the optical lens module installed at the transfer port comprises a first lens unit, a second lens unit and a focusing mirror group which are mutually combined by a fixed sleeve structure, when a laser beam generated by a laser light source is deflected and projected onto the optical lens module through the vibrating mirror scanning module, angles of secondary deflection can be generated sequentially through a first conical lens of the first lens unit and a second conical lens of the second lens unit, and then the focusing mirror of the focusing mirror group is focused onto a machining surface of a machined object to be machined to perform optical axis oblique machining along a circular scanning path, so that a vertical non-taper hole edge is formed on the machining surface.

Description

Optical lens module for optical axis inclination processing

Technical Field

The invention provides an optical lens module for optical axis tilting processing, in particular to an optical lens module which can deflect and project a laser beam by a galvanometer scanning module, sequentially generates a secondary deflection angle through a first conical lens and a second lens unit, and then focuses the laser beam to a processed object by a focusing lens to perform optical axis tilting processing along a circular scanning path so as to form a vertical non-taper hole trimming.

Background

Accordingly, the laser processing technology is one of the most advanced processing and manufacturing technologies in the modern times, has the advantages of high speed, high precision and low resource consumption compared with the traditional processing technologies (such as drilling, milling, sawing, etc.), and is widely applied to the fields of sheet metal processing, circuit boards, optoelectronic semiconductor and panel industries, laser marking, etc., and in the processing process of many precise materials, different kinds and properties of materials can be processed by different laser wavelengths and adjusting pulse widths and powers so as to meet the requirements of the process.

In general, a laser processing system of a galvanometer controls a laser beam at a pre-processing position on a workpiece by changing an incident angle of the laser beam by using a reflector, as shown in fig. 4-6, after the laser beam B is reflected by a reflector a1 in a galvanometer scanning module a, the laser beam B can be focused on the workpiece C by a field flattener lens group a2 to process and generate a processing mark C1, wherein the vertical incident processing means that an optical axis B1 of the laser beam B is perpendicular to a horizontal processing surface of the workpiece C during processing, i.e., the laser beam B1 is vertically incident to the processing surface, and a processing mark C1 with line symmetry (such as an optical axis B1 as a reference line of a center) is generated on the processing surface, and the optical axis oblique processing means that an included angle of about 5 ° to 10 ° is formed between the optical axis B1 of the laser beam B and a normal line of the processing surface of the workpiece C (i.e., the reference line perpendicular to the processing surface) during processing, compared with the normal incidence processing, the asymmetric processing trace C1 can be generated on the processing surface, if parameters such as power and incidence angle are adjusted, it is possible to form a vertical non-taper trimming edge C11 without obvious Heat Affected Zone (HAZ) on the incidence pointing edge, so as to ensure the quality of laser processing (such as drilling or cutting).

However, in the conventional laser processing system, the minimum dimension of the laser processing range and the focused light spot is limited by the focusing lens on the galvanometer system by using the galvanometer scanning method, so that the processing range is effectively enlarged, that is, the lens with different focal lengths must be replaced, and the laser beam has a divergence angle problem, so that the processing position with different optical path travel distances is easy to have a problem of dimension deviation of the focused light spot formed by the laser spot on the processed object, and further becomes a defect of processing quality, therefore, the general practice is to use a lens (i.e. a field lens, also called as an F-Theta field lens, a laser scanning focusing lens or a flat field focusing lens) working near the focal plane of an objective lens, so that the laser beam can form the laser spot with uniform size on the processed object without changing the optical lens characteristics, although the problem of laser spot deformation can be improved, the problem that the focusing width and distance of the laser beam can be changed along with the change of the distance between the processed object and the laser processing system is generated, that is, different focusing lenses need to be moved or replaced, which still causes inconvenience in the overall use.

In addition, there is also a laser processing system using a beam rotator, which uses a hollow servo motor to drive a pair of internal wedge prisms to rotate, and each wedge prism deflects a laser beam emitted from a laser output part, and then focuses the laser beam on a workpiece through a condenser lens to scan along a processing predetermined line for processing.

Disclosure of Invention

In view of the above-mentioned shortcomings, the inventor of the present invention has made various patents and has developed an invention for designing an optical lens module for optical axis tilting processing by collecting relevant data, evaluating and considering the data, and continuously trying on and modifying the data according to years of experience accumulated in the industry.

The main object of the present invention is to provide an optical lens module, which is installed between a scanning head and a laser emitting portion of a laser scanner, and only needs to finely adjust the power output by a laser light source, and a galvanometer scanning module deflects the laser beam to the angle of incidence to the optical lens module, so that the laser beam can sequentially pass through a first cone lens of a first lens unit and a second cone lens of a second lens unit to generate a secondary deflection angle, and then is focused by a focusing lens of a focusing lens set onto a processing surface of a processed object to perform an optical axis tilt processing along a circular scanning path, so that a cut edge of a vertical non-taper hole can be formed on the processing surface, and the design of the optical lens can focus the laser beam on the processed object to form a laser spot with a uniform size without changing the characteristics of the optical lens, and does not need to install a flat field focusing lens between the scanning head and the laser emitting portion, the inconvenience in use caused by the need of moving or replacing different flat field focusing lenses can be avoided, so that the efficiency of laser processing and the quality of the cut edge are improved.

The secondary objective of the present invention is to provide a first lens unit of an optical lens module, which is installed at an adapter of a laser scanner at the bottom of a scanning head through an upper fixing sleeve, and the first lens unit, a second lens unit and a focusing lens group can be combined with each other through the structure of the fixing sleeve without rotating, so that a laser beam can be focused on a workpiece after being deflected for a second time, thereby preventing the problems of unstable laser beam drift, laser spot deformation or deviation of a focusing spot formed on the workpiece caused by high-speed rotation of a servo motor.

To achieve the above object, the present invention provides an optical lens module for optical axis tilting processing, which is suitable for a laser processing system, wherein the laser processing system includes a scanning head of a laser scanner, and a galvanometer scanning module is disposed inside the scanning head for reflecting a laser beam generated by a laser light source to execute a circular scanning path rotating around a central axis, and a rotating interface is disposed at the bottom of the scanning head, the optical lens module comprising: the first lens unit is provided with an upper fixing sleeve arranged at the switching port of the scanning head, a first conical lens is fixed in the upper fixing sleeve, and the upper side surface and the lower side surface of the first conical lens are respectively provided with a conical surface and a plane; a second lens unit having a middle fixing sleeve combined with the lower part of the upper fixing sleeve, and a second conical lens fixed in the middle fixing sleeve, wherein the upper and lower side surfaces of the second conical lens are respectively provided with a plane and a conical surface; and a focusing lens group, which is provided with a lower fixed sleeve combined at the lower part of the middle fixed sleeve and is internally fixed with a focusing lens, when the laser beam is deflected and projected onto the optical lens module through the galvanometer scanning module, the laser beam sequentially passes through the conical surface of the first conical lens and the conical surface of the second conical lens to generate a secondary deflection angle, and then is focused onto a processing surface of a processed object by the focusing lens to perform optical axis inclination processing along a circular scanning path, so that a vertical non-taper hole trimming edge is formed on the processing surface.

Drawings

FIG. 1 is a schematic diagram of the preferred embodiment of the present invention.

FIG. 2 is a schematic diagram of a galvanometer scanning module of the present invention cooperating with an optical lens module to process a laser beam in a circular scanning path.

FIG. 3 is a partially enlarged view showing that the focal point of the laser beam of FIG. 2 is focused on the object to be processed to perform the optical axis tilting processing according to the present invention.

FIG. 4 is a schematic diagram of a conventional galvanometer scanning module

FIG. 5 is a schematic view of a conventional laser vertical incidence processing.

FIG. 6 is a schematic view of conventional laser beam optical axis tilting processing.

List of reference numerals: 1: a laser processing system; 10: a laser beam; 11: a laser scanner; 111: a scanning head; 1111: a transfer port; 112: a galvanometer scanning module; 1121: a mirror; 113: a laser emitting section; 1131: a nozzle; 1132: protective glasses; 2: an optical lens module; 21: a first lens unit; 211: an upper fixed sleeve; 212: a first axicon lens; 2121: a conical surface; 2122: a plane; 213: a frame ring; 22: a second lens unit; 221: a middle fixed sleeve; 222: a second tapered lens; 2221: a plane; 2222: a conical surface; 223: a frame ring; 23: a focusing lens group; 231: a lower fixed sleeve; 232: a focusing mirror; 233: a frame ring; 3: a workpiece; 31: processing the dough; 32: a hole; 321: trimming; α: a cone angle; beta: a cone angle; AX: a central shaft; a: a galvanometer scanning module; a1: a mirror; a2: a flat field focusing lens group; b: a laser beam; b1: an optical axis; c: a workpiece; c1: machining a mark; c11: and (6) trimming.

Detailed Description

To achieve the above objects and advantages, the present invention provides a technical solution and a structure thereof, wherein the structure and function of the preferred embodiment of the present invention are described in detail as follows for a complete understanding.

Referring to fig. 1 to 3, which are respectively a schematic diagram of an architecture, a schematic diagram of a galvanometer scanning module and an optical lens module for processing a laser beam along a circular scanning path, and a schematic diagram of a local magnification of fig. 2 for focusing a focal point of the laser beam on a processed object to perform optical axis tilting processing, it can be clearly seen from the drawings that an optical lens module 2 of the present invention is suitable for a laser processing system 1, the laser processing system 1 includes a laser light source, an adjustable zoom lens group, a laser scanner 11 and a control unit, wherein the laser light source is used for generating a laser beam 10, and the adjustable zoom lens group and the laser scanner 11 on a transmission path of the laser beam 10 are driven and controlled by the control unit, so that a focal length or a divergent angle of a pulse light of the laser beam 10 incident from the adjustable zoom lens group is adjusted, and then the pulse light is incident to the laser scanner 11 to generate a deflection after being reflected, to form a circular scanning path with the optical lens module 2.

Furthermore, the laser scanner 11 has a scanning head 111, and a galvanometer scanning module 112 is disposed inside the housing of the scanning head 111, and the galvanometer scanning module 112 comprises at least one mirror 1121 or polygon mirror capable of being driven by a galvanometer motor, for reflecting the laser beam 10 to change the deflection angle, and then projecting the laser beam to the optical lens module 2 to form a circular scanning path, the bottom of the housing of the scanning head 111 is provided with an interface 1111 at a position corresponding to the galvanometer scanning module 112, an optical lens module 2 is arranged on the transmission path of the laser beam 10 of the adapter 1111, and the housing of the scanning head 111 is provided with a nozzle 1131 of the laser emitting portion 113 at a distance below or on the bottom side of the optical lens module 2, for emitting the laser beam 10 to the workpiece 3 to form a focused spot or focus, and a Glass Window (Glass Window) or a protective lens 1132 for protecting the lens is combined inside the nozzle 1131.

In this embodiment, the optical lens module 2 includes a first lens unit 21, a second lens unit 22 and a focusing lens group 23, the first lens unit 21 has an upper fixing sleeve 211 mounted at the adaptor 1111 of the scanning head 111, and a first axicon lens 212 enclosed in a lens frame ring 213 is fixed at the inner side of the lower opening of the upper fixing sleeve 211, the upper and lower side surfaces of the first axicon lens 212 respectively have a conical surface 2121 and a plane 2122, and a cone angle α formed between the conical surface 2121 and a cone point on the axial center is 165 ° to 175 °, preferably 170 °; the second lens unit 22 has a middle fixing sleeve 221 combined with the lower opening of the upper fixing sleeve 211, and a second conical lens 222 enclosed in the frame ring 223 is fixed at the lower opening of the middle fixing sleeve 221, the upper and lower side surfaces of the second conical lens 222 respectively have a plane 2221 and a conical surface 2222, and a cone angle β formed between the conical surface 2222 and a cone point on the axial center is 160 ° to 170 °, preferably 165 °, the focusing lens group 23 has a lower fixing sleeve 231 combined with the lower opening of the middle fixing sleeve 221, and a focusing lens 232 enclosed in the frame ring 233 is fixed at the lower opening of the lower fixing sleeve 231, and the focal length of the focusing lens 232 is 50 mm to 70mm, preferably 60 mm.

In addition, the upper fixing sleeve 211 of the first lens unit 21 is preferably mounted to the adaptor 1111 of the scanning head 111 by a screw joint, but not limited thereto, and may be integrated by a coupling ring on the coupling surface of the upper fixing sleeve 211 and the scanning head 111 by a rotary fastening or a magnet-attracting positioning; similarly, the fixing sleeves (such as the upper fixing sleeve 211, the middle fixing sleeve 221, and the lower fixing sleeve 231) between the first lens unit 21, the second lens unit 22, and the focusing lens group 23 can be integrated by using a screw-threaded manner, a rotary fastening manner, a magnet attracting and positioning manner, or a combination manner of a rotary fastening manner and a magnet attracting and positioning manner.

In the present embodiment, the laser light source of the laser processing system 1 may preferably be an Ultraviolet (UV) laser, but not limited thereto, and carbon dioxide (CO) may be selected according to the material or thickness of the object 3 to be processed, the required processing state, and the like₂) Excimer laser, far infrared laser or laser with specific wavelength range, and can be set according to the variables of laser frequency adjustment, laser output, laser wavelength, etc. to meet the requirements of practical processing procedure, and the processed object 3 can be preferably a flexible circuit board with non-transparent or interference light on the surfaceThe object 3 to be processed may be an unprocessed substrate or a workpiece such as a semiconductor substrate, a display panel, an electronic component, etc. which is subjected to a pre-processing, and the laser processing system 1 may be applied to high precision processing/special taper angle processing such as jewelry processing, aircrafts, automobile fuel injectors, nozzle hole processing, etc.

When the laser processing system 1 transmits the laser beam 10 generated by the laser light source into the scanning head 111 of the laser scanner 11 through the adjustable zoom lens group (such as the beam splitting unit, the zoom lens group, etc.) on the transmission path (i.e. the optical path), the two rotating shafts (such as the X-axis and the Y-axis) of the galvanometer scanning module 112 are perpendicular to each other, and rotate and reflect to generate a deflection angle, so as to perform circular path scanning rotating around the central axis AX, and deflect the laser beam 10 and project to the optical lens module 2 on the first cone lens 212 of the first lens unit 21, and the angle of the laser beam 10 projected on the conical surface 2121 of the first cone lens 212 is about ± 15 ° and cannot be projected on the middle conical point or the central axis AX, and the laser beam 10 generates a deflection through the first cone lens 212 and projects to the second cone lens 222 of the second lens unit 22, similarly, the laser beam 10 cannot be projected on the conical point in the middle of the second cone lens 222, and the laser beam 10 passes through the conical surface 2222 of the second cone lens 222 to generate a deflection angle, and then is projected onto the focusing lens 232 of the focusing lens assembly 23, so that the laser beam 10 rotating around the central axis AX can be focused onto the processing surface 31 of the object 3 by the focusing lens 232 to form a focal point, so that an asymmetric optical notch is generated on the processing surface 31, and the optical axis is tilted along the circular scanning path by the scheme that the outermost circular arc surface of the laser beam 10 is perpendicular to the processing surface 31, so that the processing surface 31 forms a cut edge 321 perpendicular to the non-tapered hole 32, thereby completing the drilling process of the micro hole with high aspect ratio.

Therefore, the optical lens module 2 of the present invention is installed between the scanning head 111 and the laser emitting portion 113 of the laser scanner 11 of the laser processing system 1, only the output power of the laser light source needs to be finely adjusted, and the galvanometer scanning module 12 deflects the laser beam 10 of the laser light source to enter the angle of the optical lens module 2, so that the laser beam 10 passes through the first conical lens 212 of the first lens unit 21 and the second conical lens 222 of the second lens unit 22 in sequence to generate a secondary deflection angle, and is focused by the focusing lens 232 of the focusing lens group 23 onto the processing surface 31 of the object 3 to be processed to perform the optical axis tilting processing along the circular scanning path, so as to form a cut edge 321 perpendicular to the non-tapered hole 32 on the processing surface 31, thereby eliminating the need to install a flat field focusing lens between the scanning head 111 and the laser emitting portion 113, and avoiding the inconvenience in use caused by the need to move or replace different flat field focusing lenses, so as to improve the efficiency of laser processing (such as drilling or cutting) and the quality of the cutting edge.

In addition, the first lens unit 21 of the optical lens module 2 is mounted at the adapter 1111 of the scanning head 111 through the upper fixing sleeve 211, and the first lens unit 21, the second lens unit 22 and the focusing lens group 23 are mutually combined through the fixing sleeve structure (such as the upper fixing sleeve 211, the middle fixing sleeve 221 and the lower fixing sleeve 231) without rotating, so that the laser beam 10 can be focused on the object 3 after being deflected for a second time, thereby preventing the problems of unstable laser beam drift, laser spot deformation or focus spot deviation formed on the object due to the high-speed rotation of the servo motor.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An optical lens module for optical axis tilting processing is applicable to a laser processing system, and is characterized in that the laser processing system comprises a scanning head of a laser scanner, a galvanometer scanning module is arranged inside the scanning head for reflecting a laser beam generated by a laser light source to execute a circular scanning path rotating around a central shaft, a rotating interface is arranged at the bottom of the scanning head, and the optical lens module comprises:

the first lens unit is provided with an upper fixing sleeve arranged at the switching port of the scanning head, a first conical lens is fixed in the upper fixing sleeve, and the upper side surface and the lower side surface of the first conical lens are respectively provided with a conical surface and a plane;

a second lens unit having a middle fixing sleeve combined with the lower part of the upper fixing sleeve, and a second conical lens fixed in the middle fixing sleeve, wherein the upper and lower side surfaces of the second conical lens are respectively provided with a plane and a conical surface; and

when the laser beam is deflected and projected onto the optical lens module through the vibrating mirror scanning module, the laser beam sequentially passes through the conical surface of the first conical lens and the conical surface of the second conical lens to generate a secondary deflection angle, and then is focused onto a processing surface of a processed object by the focusing mirror to perform optical axis inclined processing along a circular scanning path, so that a vertical cut edge without a taper hole is formed on the processing surface.

2. The optical lens module as claimed in claim 1, wherein the scanning head of the laser scanner is a nozzle having a laser emitting portion disposed at a distance below the optical lens module for emitting the laser beam to the workpiece to form a focus, and a protection lens is coupled to the nozzle.

3. The optical lens module as claimed in claim 1, wherein the first axicon of the first lens unit is enclosed in a frame ring and fixed to the lower opening of the upper fixing sleeve through the frame ring, and a taper angle of the conical surface of the first axicon is between 165 ° and 175 °.

4. An optical lens module for use in optical axis tilting processing according to claim 3, characterized in that the taper angle on the conical surface of the first axicon lens is 170 °.

5. An optical lens module as claimed in claim 1, wherein the second conic lens of the second lens unit is enclosed in a frame ring and fixed to the inner side of the lower opening of the middle fixing sleeve by the frame ring, and a taper angle of the conic surface of the second conic lens at the axial center is between 160 ° and 170 °.

6. The optical lens module for use in optical axis tilting processing according to claim 5, wherein a taper angle on the tapered surface of the second tapered lens is 165 °.

7. The optical lens module as claimed in claim 1, wherein the focusing lens of the focusing lens assembly is enclosed in a lens ring and fixed to the lower fixing sleeve at an inner side of the lower opening through the lens ring, and the focal length of the focusing lens is between 50 mm and 70 mm.

8. The optical lens module as claimed in claim 1, wherein the focusing lens of the focusing lens group is configured to focus the laser beam onto the processing surface of the object to be processed to form a focal point, and perform the optical axis tilting processing along a circular scanning path with the outermost circular arc surface of the laser beam being perpendicular to the processing surface.