Laser beam shrinking device for laser drill

Abstract

The utility model discloses a laser beam shrinking device for a laser drill, which comprises a laser oscillator emitting a first laser beam; the moving assembly passes through the light path of the first laser beam at least twice in the one-way stroke moving process; the beam shrinking assembly moves along with the moving assembly, the beam shrinking assembly comprises a beam expander module, the beam expander module is provided with at least two beam expanders, the moving assembly can drive the at least two beam expanders to sequentially pass through the light path of the first laser beam, and the beam expander module can change the beam diameter of the first laser beam into a second laser beam. According to the utility model, the two groups of beam expanders with common beam shrinkage multiples and the diaphragm assembly with the apertures with different diameters are arranged, so that the beam expanders can quickly change the beam diameter of the laser beam under the driving of the high-precision servo electric cylinder, and the laser generator can quickly punch blind holes with different sizes on a PCB (Printed Circuit Board) at low cost; and the punching efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of laser processing, in particular to a laser beam reduction device used for laser drilling. Background Art

[0002] Laser drilling machine is a high-tech equipment that uses laser beam for drilling processing. It adopts the laser principle and heats the material instantly through a high-power density laser beam, so that the material quickly melts, vaporizes or evaporates, thereby achieving the purpose of drilling. Laser drilling machine has the characteristics of high precision, and the focusing performance of the laser beam is excellent. It can achieve micron-level processing accuracy and meet the needs of high-precision drilling. Among them, CO2 laser drilling machine is commonly used to process 75-150μm blind holes of PCB boards. Blind holes of different diameters require the optical path of the laser drilling machine to be equipped with a module to change the diameter of the laser beam.

[0003] The prior art commonly uses a BET module, which changes the distance between three parallel lenses with different focal lengths to reduce the laser beam emitted by the laser generator and obtain light spots of different diameters to meet different aperture processing requirements. The inventors of this application found in the implementation of the prior art that the BET module changes the distance between the lenses through two sets of high-precision motors, which is not only costly, but also has high requirements for the coaxiality of the three lenses in the optical path, and is difficult and time-consuming to debug. The debugging effect will directly affect the quality of the opening. Utility Model Content

[0004] In order to solve the problem of high cost and low efficiency of laser drilling for processing different apertures, the utility model provides a laser beam reduction device for laser drilling. The specific technical solution is as follows:

[0005] A laser beam reduction device for laser drilling comprises: a laser oscillator, which emits a first laser beam; a moving component, which passes through the first laser beam optical path at least twice during a unidirectional travel; a beam reduction component that moves with the moving component, the beam reduction component comprising a beam expander module, the beam expander module is provided with at least two beam expanders, the moving component can drive the at least two beam expanders to pass through the first laser beam optical path in sequence, and the beam expander module can change the beam diameter of the first laser beam into a second laser beam.

[0006] Furthermore, the moving component comprises a slider, and the moving direction of the slider is perpendicular to the optical path of the first laser beam.

[0007] Furthermore, the beam expander module is provided with a first beam expander and a second beam expander, the axes of the first beam expander and the second beam expander are always parallel to the optical path of the first laser beam, the first laser beam is coaxial with the second laser beam, and when the first beam expander and the second beam expander pass through the optical path of the first laser beam, the first beam expander and the second beam expander can be coaxial with the first laser beam.

[0008] Preferably, the ratio of the diameter of the first laser beam to the diameter of the second laser beam processed by the beam expander module is the beam reduction factor, and the specific formula is as follows:

[0009] f qi / f hj =a k

[0010] Among them, f qi is the focal length of the i-th convex lens that first contacts the laser beam, f hj is the focal length of the jth convex lens that contacts the laser beam later, a k is the beam reduction factor of the kth beam expander, the beam expander module is provided with a first beam expander, the first beam expander comprises a first convex lens and a second convex lens, the first convex lens and the second convex lens are placed in parallel and have a focal point overlapped, the focal length of the first convex lens is f q1 =150mm, the focal length of the second convex lens is f h2 =50mm, so a1 of the first beam expander is 3, the beam expander module is provided with a second beam expander, the second beam expander includes a third convex lens and a fourth convex lens, the third convex lens and the fourth convex lens are placed in parallel and have a focus overlap, the focal length of the third convex lens is f q3 =150mm, the focal length of the fourth convex lens is f h4 =75mm, and a2 of the second beam expander is obtained as 2.

[0011] Preferably, the beam diameter of the first laser beam is 8.4±1 mm.

[0012] Preferably, the aperture unit is provided with a plurality of apertures of different diameters.

[0013] It can be seen from the above technical solution that the utility model has the following beneficial effects:

[0014] The utility model introduces that a convex lens combination with the same refractive index and the use of apertures of different diameters can adjust the beam diameter of a first laser beam to a specific diameter, so that a laser drill can open holes of different sizes. The utility model arranges two groups of beam expanders with commonly used beam reduction multiples, and an aperture assembly with apertures of different diameters, so that the beam expander can quickly change the beam diameter of the laser beam under the drive of a high-precision servo electric cylinder, so that a laser generator can quickly and inexpensively punch blind holes of different sizes on a PCB board, thereby improving the drilling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of an embodiment of the utility model;

[0016] Figure 2 This is a cross-sectional view of the mounting plate of the utility model;

[0017] Figure 3 This is a schematic diagram of the structure of the first beam expander in an embodiment of the utility model;

[0018] Figure 4 This is a schematic diagram of the structure of the second beam expander according to an embodiment of the utility model.

[0019] In the figure: 1. Laser generator, 2. Moving assembly, 3. Beam reduction assembly, 4. Aperture assembly;

[0020] 11. First laser beam, 12. Second laser beam, 21. Servo motor, 22. Slide rail, 23. Slider, 31. Beam expander module, 32. Mounting plate, 311. First beam expander, 312. Second beam expander, 3111. First convex lens, 3112. Second convex lens, 3121. Third convex lens, 3122. Fourth convex lens. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] like Figure 1 As shown, the embodiment of the utility model includes a laser generator 1, which emits a first laser beam 11, and the diameter of the first laser beam 11 is 8400μm. A moving component 2 is arranged on the optical path of the first laser beam 11, and the moving component 2 includes a servo electric cylinder 21, and the telescopic end of the servo electric cylinder 21 is connected to a slider 23 by screws, and the slider 23 is slidably connected to a slide rail 22, and the length direction of the slide rail 22 is parallel to the telescopic direction of the servo electric cylinder 21. The servo electric cylinder 21 can also be replaced by a cylinder, but the precision of the cylinder is not as high as that of the servo electric cylinder 21. After actual application, the inventor of the present application found that only the servo electric cylinder 21 meets the requirements of high precision and low cost.

[0024] At the same time, the right side of the slider 23 is connected with a beam reducer assembly 3 by screw connection, and the beam reducer assembly 3 includes a beam expander module 31 and a mounting plate 32. The mounting plate 32 is connected to the right side of the slider 23 by screws, and the beam expander module 31 is also connected to the mounting plate 32 by screws. The beam expander module 31 includes a first beam expander 311 and a second beam expander 312. The axes of the first and second beam expanders are parallel and perpendicular to the movement path of the slider 23, and the distance between the axes is not greater than the stroke of the servo electric cylinder 21, so that the servo electric cylinder 21 can drive the first and second beam expanders to pass through the first laser beam 11 in sequence. The first laser beam 11 is parallel to the axes of the first and second beam expanders, and in the process of the first and second beam expanders passing through the first laser beam 11, there is a position that makes the first laser beam 11 coincide with the axis of the first or second beam expander.

[0025] In addition, the second laser beam 12 that passes through the first or second beam expander continues to pass through the aperture assembly 4. The aperture assembly 4 is formed with multiple apertures of different diameters, which can trim the cross-section of the second laser beam 12 into circles of different diameters to facilitate subsequent laser drilling.

[0026] like Figure 2 As shown, the cross-sectional view of the mounting plate 32 shows that a hole with the same diameter as the first and second beam expanders is formed at the place where the mounting plate 32 contacts the first and second beam expanders, so that the first laser beam 11 can pass through the mounting plate 32 and then pass through the first or second beam expander.

[0027] like Figure 3 As shown, the left side is the direction of entry of the first laser beam 11, and the first convex lens 3111 and the second convex lens 3112 are placed in the first beam expander 311 from left to right. The focal length of the first convex lens 3111 is f q1 =150mm, the diameter of the first laser beam 11 entering the first convex lens 3111 is d q1 =8.4mm, the focal length of the second convex lens 3112 is f h2 =50mm, the diameter of the second laser beam 12 emitted from the second convex lens 3112 is d h2 =2.8mm, and the refractive index of the first convex lens 3111 can be expressed by the angle α between the parallel light of the first laser beam 11 and its refracted light. Similarly, the refractive index of the second convex lens 3112 can be expressed by the angle β between the parallel light of the second laser beam 12 and its refracted light. When α=β, the formula can be obtained according to similar triangles:

[0028] f q1 / f h2 =d q1 / d h2 ,

[0029] The value of the above formula is named the shrinkage multiple a kThe beam reduction factor is the ratio of the beam diameter of the first laser beam 11 to the beam diameter of the second laser beam 12 processed by the beam expander module 31, a k represents the reduction factor of the kth beam expander, so we can get: q1 / f h2 =a1=3, that is, the beam reduction factor of the first beam expander 311 is 3.

[0030] like Figure 4 As shown, the left side is the direction of entry of the first laser beam 11, and the third convex lens 3121 and the fourth convex lens 3122 are placed in the second beam expander 312 from left to right. The focal length of the third convex lens 3121 is f q1 =150mm, the diameter of the first laser beam 11 entering the third convex lens 3121 is d q1 =8.4mm, the focal length of the fourth convex lens 3122 is f h2 =75mm, the diameter of the second laser beam 12 emitted from the fourth convex lens 3122 is d h2 =4.2mm, and the refractive index of the third convex lens 3121 can be expressed by the angle α between the parallel light of the first laser beam 11 and its refracted light. Similarly, the refractive index of the fourth convex lens 3122 can be expressed by the angle γ between the parallel light of the second laser beam 12 and its refracted light. When α=γ, according to Figure 3 The formula is:

[0031] F q3 / f h4 =d q3 / d h4 =a2=2, that is, the beam reduction factor of the second beam expander 312 is 2.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0033] The technology, shape and structure parts not described in detail in the present invention are all known technologies.

Claims

1. A laser beam reduction device for laser drilling, characterized in that: include: A laser oscillator (1), which emits a first laser beam (11); A moving component (2), wherein the moving component (2) passes through the optical path of the first laser beam (11) at least twice during a unidirectional movement process; A beam shrinking assembly (3) moving with the moving assembly (2), the beam shrinking assembly (3) comprising a beam expander module (31), the beam expander module (31) being provided with at least two beam expanders, the moving assembly (2) being capable of driving the at least two beam expanders to sequentially pass through the optical path of the first laser beam (11), the beam expander module (31) being capable of changing the beam diameter of the first laser beam (11) into a second laser beam (12); An aperture assembly (4) is arranged on the optical path of the second laser beam (12).

2. The laser beam reduction device according to claim 1, characterized in that: The moving component (2) comprises a slider (22), and the moving direction of the slider (22) is perpendicular to the optical path of the first laser beam (11).

3. The laser beam reduction device according to claim 1, characterized in that: The beam expander module (31) is provided with a first beam expander (311) and a second beam expander (312), the axes of the first beam expander (311) and the second beam expander (312) are always parallel to the optical path of the first laser beam (11), and the first laser beam (11) and the second laser beam (12) are coaxial.

4. The laser beam reduction device according to claim 3, characterized in that: When the first beam expander (311) and the second beam expander (312) pass through the optical path of the first laser beam (11), the first beam expander (311) and the second beam expander (312) can be coaxial with the first laser beam (11).

5. The laser beam reduction device according to claim 1, characterized in that: The ratio of the beam diameter of the first laser beam (11) to the beam diameter of the second laser beam (12) after being processed by the beam expander module (31) is the beam reduction factor, and the specific formula is as follows: f qi / f hj =a k Among them, f qi is the focal length of the i-th convex lens that first contacts the laser beam (11), hj is the focal length of the jth convex lens that contacts the laser beam (11) later, a k is the beam reduction factor of the kth beam expander.

6. The laser beam reduction device according to claim 5, characterized in that: The beam expander module (31) is provided with a first beam expander (311), the first beam expander (311) comprising a first convex lens (3111) and a second convex lens (3112), the first convex lens (3111) and the second convex lens (3112) are placed in parallel and have a focal point overlapped, the focal length f of the first convex lens (3111) is q1 =150mm, the focal length of the second convex lens (3112) is f h2 =50mm, so a1 of the first beam expander (311) is =3.

7. The laser beam reduction device according to claim 6, characterized in that: The beam expander module (31) is provided with a second beam expander (312), the second beam expander (312) comprising a third convex lens (3121) and a fourth convex lens (3122), the third convex lens (3121) and the fourth convex lens (3122) are placed in parallel and have a focal point overlapped, the focal length f of the third convex lens (3121) is q3 =150mm, the focal length of the fourth convex lens (3122) is f h4 =75mm, so a2 of the second beam expander (312) is =2.

8. The laser beam reduction device according to claim 1, characterized in that: The beam diameter of the first laser beam (11) is 8.4±1 mm.

9. The laser beam reduction device according to claim 1, characterized in that: The aperture assembly (4) is provided with a plurality of apertures with different diameters.

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