A new ultra-fine hole laser drilling system and process

Abstract

The present invention discloses a novel ultrafine hole laser drilling system and process, aiming to provide a system and process for quickly drilling fine holes by laser. The key points of the technical solution are as follows: the system comprises an equipment platform, the equipment platform is provided with pillars around it, an optical platform is provided on the pillars, an X-axis linear sliding device is provided on the equipment platform, a Y-axis linear sliding device is provided on the X-axis linear sliding device, a workbench is connected to the Y-axis linear sliding device, a control console for controlling the X-axis linear sliding device and the Y-axis linear sliding device is also provided on the pillars, two Z-axis linear sliding devices are also provided on the optical platform, an ultrafast laser facing the two Z-axis linear sliding devices is also provided on the optical platform, and the two Z-axis linear sliding devices include a Z-axis linear sliding device A and a Z-axis linear sliding device B.

Description

Technical Field

[0001] The invention relates to the field of laser drilling equipment, and in particular to a novel ultrafine hole laser drilling system and process. Background Art

[0002] With the development of biomedicine, MEMS systems, and interventional medical devices, more and more products require the processing of ultra-fine holes, with hole diameters ranging from tens of microns to several microns, or even smaller. For example, ultra-fine holes can be drilled on the surface of interventional metal devices to allow drugs to be built in without affecting the performance of the device, thereby accelerating the recovery of diseased tissues; ultra-fine holes are evenly distributed on the surface of micro gas sensors to allow gas to enter the sensor when measuring samples, thereby increasing the sensitivity of the sensor.

[0003] Common ultra-fine holes are made using mechanical drilling or laser drilling. Mechanical drilling is contact drilling, and the diameter of the hole depends on the diameter of the drill bit. Because the drill bit is very thin, it is easy to break when subjected to force, and it is difficult to reduce the drill bit diameter indefinitely. The minimum hole diameter is generally above several hundred microns; conventional laser drilling technology is non-contact drilling, and the hole diameter depends on the waist diameter and focal depth of the laser beam after focusing, as well as the material's absorption efficiency of the laser. The minimum hole diameter can be around tens of microns. Laser processing of ultra-fine holes less than a dozen microns is difficult, and there are limitations on the material and hole size, so ultra-fine holes cannot be processed stably.

[0004] When using nanosecond laser drilling, there are many mechanisms of action between the laser beam and the material, such as thermal evaporation, plasma expansion and eruption, and direct material vaporization. When the laser is irradiated, the various mechanisms interact with each other, resulting in irregular inner wall formation and secondary accumulation of materials when removing materials from the hole, which ultimately affects the geometric shape of the hole. However, the pulse width of ultrafast lasers (picosecond lasers and femtosecond lasers) is narrow, and the interaction time between the laser and the material is very short. The main mechanism for removing materials is direct material vaporization, so the formed hole wall is relatively smooth and there is no secondary accumulation of materials. The shape of the hole is better, which is particularly conducive to increasing the hole depth value when the hole diameter is constant.

[0005] When a convex lens is used to focus a Gaussian laser, the diameter is the smallest at the optical waist, and all energy passes through the optical waist. However, the focal depth of the Gaussian beam is shallow, so the ability to remove materials during drilling is strong, but the formed aperture is large, generally around tens of microns, and it is difficult to further reduce the aperture. When a conical lens is used to focus a Gaussian laser beam, a Bessel-Gaussian beam is formed. This beam can maintain a constant diameter as the distance increases. The beam diameter hardly changes over a short distance, but only part of the energy passes through the center position, which accounts for about 20-30% of the total energy. The specific proportion is related to the optical system parameters and the drilling aperture. Therefore, when a Bessel-Gaussian beam is used for drilling, the laser beam energy at the center position is small, the focal depth is deep, and the ability to remove materials during drilling is small, but a larger focal depth can be obtained, which is conducive to obtaining a larger depth-to-diameter ratio.

[0006] The processing of ultra-fine holes requires the optimization of two parameters:

[0007] 1) Aspect ratio: how to achieve a larger hole depth when the hole diameter is small;

[0008] 2)2) Minimum hole diameter: how to process a hole with a smaller diameter as possible while maintaining the hole's geometric shape. The smaller the hole diameter, the fewer processing methods are available and the greater the difficulty. Summary of the invention

[0009] An object of the present invention is to provide a novel ultrafine hole laser drilling system, which has the advantages of high automation, ability to drill ultrafine holes, and high drilling accuracy.

[0010] The above technical objectives of the present invention are achieved through the following technical solutions:

[0011] A novel ultrafine hole laser drilling system includes an equipment platform, characterized in that: the equipment platform is surrounded by pillars, an optical platform is provided on the pillars, an X-axis linear sliding device is provided on the equipment platform, a Y-axis linear sliding device is provided on the X-axis linear sliding device, a workbench is connected to the Y-axis linear sliding device, a control console for controlling the X-axis linear sliding device and the Y-axis linear sliding device is also provided on the pillars, two Z-axis linear sliding devices are also provided on the optical platform, an ultrafast laser facing the two Z-axis linear sliding devices is also provided on the optical platform, and the two Z-axis linear sliding devices include a Z-axis linear sliding device A and a Z-axis linear sliding device B.

[0012] Further configuration: a CCD image recognition device is also provided on one side of the two Z-axis linear sliding devices.

[0013] Further configuration: The ultrafast laser is connected to a photoelectric switch and an aperture, the aperture is connected to a beam expander collimator, the beam expander collimator is provided with a reflector A and a reflector B, the bottom of the Z-axis linear sliding device A is provided with a conical lens facing the workbench corresponding to the reflector A, and the bottom of the Z-axis linear sliding device B is provided with a convex lens facing the workbench corresponding to the reflector B.

[0014] By adopting the above technical solution, the overall structure is a gantry structure. The bottom of the gantry is a working platform fixed on the XY motion module, which is used to fix the workpiece during processing and drive the workpiece to move to the specified position. Above the gantry is an optical platform, on which the laser and two optical systems are fixed. The light emitted by the ultrafast laser passes through the photoelectric switch, aperture, beam expander collimator, and optical path switching reflector into the two optical systems. The optical path is switched by the reflector to ensure that only one optical system is working at any time. The convex lens focusing system and the conical lens focusing system are respectively fixed on two sets of Z axes perpendicular to the workbench. The control system can control the lifting and lowering of the two sets of Z axes according to the process requirements to meet the proofing requirements. CCD lenses are fixed on each of the two sets of Z axes to identify and locate the drilling position.

[0015] Another object of the present invention is to provide a novel ultrafine hole laser drilling process, which has the advantages of using a layered drilling process to achieve an ultrafine hole processing method, so that the overall accuracy is higher and the degree of automation is higher.

[0016] The above technical objectives of the present invention are achieved through the following technical solutions:

[0017] A novel ultrafine hole laser drilling process includes the following steps:

[0018] D1. Fix the parts on the workbench, set the processing parameters in the controller, and start processing;

[0019] D2. The controller controls the CCD image recognition device of the Z-axis linear slide device B that fixes the convex lens to identify the drilling position of the positioning part, and then adjusts the Z-axis linear slide device B to the processing position, controls the reflector to deviate from the optical path, controls the ultrafast laser to output the laser beam, and then turns on the photoelectric switch. The laser beam passes through the aperture, beam expander collimator and reflector, and then passes through the convex lens to drill a hole on the surface of the workpiece;

[0020] D3. After the drilling is completed, the photoelectric switch is turned off, and the controller controls the workbench to move to the bottom of the aconic lens. The CCD image recognition device obtains the punched position, and accurately positions the Z-axis linear slide device A that fixes the aconic lens to the drilling position. The vertical distance of the Z-axis linear slide device A is adjusted, and the photoelectric switch is turned on. The laser beam enters the aconic lens through the aperture, the beam expander collimator and the reflector, and an ultra-fine hole is drilled on the part until the entire hole processing is completed;

[0021] D4. After the drilling is completed, turn off the ultrafast laser and photoelectric switch, the workbench moves to the set position, and the drilling is completed.

[0022] In summary, the present invention has the following beneficial effects: after the Gaussian laser is focused by a convex lens, all the energy passes through the light waist position, and the ability to remove materials is strong. After the Gaussian laser is focused by a conical lens, a Bessel-Gaussian beam is formed. The focal depth of the Bessel-Gaussian beam is deep, but only part of the energy passes through the center position, so the energy to remove materials is weak. An ultrafast laser focused by a convex lens is used for drilling to form a base hole, and then an ultrafast laser focused by a conical lens is used for drilling to form an ultrafine hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the accompanying drawings.

[0024] Figure 1 Ultrafine hole laser drilling principle diagram

[0025] Figure 2 It is a focused Gaussian beam and energy distribution

[0026] Figure 3 It is a focused Bessel-Gaussian beam and energy distribution

[0027] Figure 4 Ultra-fine hole laser drilling system

[0028] Figure 5 It is a light path diagram.

[0029] In the figure, 100, equipment platform; 101, pillar; 102, optical platform; 103, Z-axis linear sliding device B; 104, Z-axis linear sliding device A; 105, control console; 106, CCD image recognition device; 110, X-axis linear sliding device; 111, Y-axis linear sliding device; 112, workbench; 200, ultrafast laser; 201, photoelectric switch; 202, aperture; 203, beam expander collimator; 210, convex lens; 211, focal depth of Gaussian beam; 212, energy of Gaussian beam; 220, conical lens; 221, focal depth of Bessel-Gaussian beam; 222, energy of Bessel-Gaussian beam; 204, reflector A; 205, reflector B. DETAILED DESCRIPTION

[0030] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0031] The technical solution adopted by the present invention is:

[0032] A novel ultrafine hole laser drilling system and process, comprising an equipment platform 100, the equipment platform 100 is provided with pillars 101 around, an optical platform 102 is provided on the pillars 101, an X-axis linear sliding device 110 is provided on the equipment platform 100, a Y-axis linear sliding device 111 is provided on the X-axis linear sliding device 110, a workbench 112 is connected to the Y-axis linear sliding device 111, a control console 105 for controlling the X-axis linear sliding device 110 and the Y-axis linear sliding device 111 is also provided on the pillars 101, two Z-axis linear sliding devices are also provided on the optical platform 102, and the optical An ultrafast laser 200 facing two Z-axis linear sliding devices is also provided on the platform 102. The ultrafast laser 200 and the Z-axis linear sliding devices are electrically connected to the control console 105. At the same time, a CCD image recognition device 106 is also provided on one side of the two Z-axis linear sliding devices. A photoelectric switch 201 and an aperture 202 are connected to the ultrafast laser 200, and a beam expander collimator 203 is connected to the aperture 202. A reflector is provided on the beam expander collimator 203. A convex lens 210 and a conical lens 220 facing the workbench 112 are respectively provided at the bottom of the two Z-axis linear sliding devices corresponding to the reflector.

[0033] The punching process includes the following steps:

[0034] D1. Fix the parts on the workbench 112, set the processing parameters in the controller, and start processing;

[0035] D2, the controller controls the CCD image recognition device 106 of the Z-axis linear sliding device B103 that fixes the convex lens 210 to identify the drilling position of the positioning part, and then adjusts the Z-axis linear sliding device B103 to the processing position, controls the reflector to deviate from the optical path, controls the ultrafast laser 200 to output the laser beam, and then turns on the photoelectric switch 201. The laser beam passes through the aperture 202, the beam expander collimator 203 and the reflector, and then passes through the convex lens 210 to drill a hole on the surface of the workpiece;

[0036] D3. After the drilling is completed, the photoelectric switch 201 is turned off, and the controller controls the workbench 112 to move to the bottom of the axle lens 220, obtains the drilled position through the CCD image recognition device, and accurately positions the Z-axis linear slide device A104 that fixes the axle lens 220 to the drilling position, adjusts the vertical distance of the Z-axis linear slide device A104, turns on the photoelectric switch 201, and the laser beam enters the axle lens 220 through the aperture 202, the beam expander collimator 203 and the reflector, and drills an ultra-fine hole on the part until the entire hole processing is completed;

[0037] D4. After the drilling is completed, the ultrafast laser 200 and the photoelectric switch 201 are turned off, the workbench 112 moves to the set position, and the drilling is completed.

[0038] Its main working principle is as follows: This system and operation process adopts layered drilling process to realize ultra-fine hole processing. After Gaussian laser is focused by convex lens 210, Figure 1 As shown, the focal depth 211 of the Gaussian beam is shallow, but all the energy 212 passes through the optical waist position, and the ability to remove materials is strong. The Gaussian laser is focused by the aconic lens 220 to form a Bessel Gaussian beam, as shown in FIG. Figure 2 As shown, the focal depth 221 of the Bessel-Gaussian beam is deep, but only part of the energy 222 passes through the center position, so the energy for removing the material is weak. The process principle of layered drilling is used to process ultra-fine holes, such as Figure 3 As shown, when drilling a hole in a material, firstly, an ultrafast laser 200 focused by a convex lens 210 is used to drill a hole to form a base hole, and then an ultrafast laser focused by a conical lens 220 is used to drill a hole to form an ultrafine hole.

[0039] Ultrafine hole laser drilling system Figure 4 As shown, the system consists of an equipment platform 100, an ultrafast laser 200, two optical systems: a convex lens 210 focusing system and a conical lens 220 focusing system, a console 105 and a CCD image recognition device 106. The overall structure of the equipment is a gantry type, a support 101 is fixed on the equipment platform 100, an optical platform 102 is fixed on four supports 101, all optical components and Z-axis linear sliding devices A and Z-axis linear sliding devices B are fixed on the optical platform 102, an X-axis linear sliding device 110 and a Y-axis linear sliding device 111 are fixed on the plane of the equipment platform 100, and a workbench 112 is fixed on the Y-axis linear sliding device 111. During the processing, the workpiece is fixed on the workbench 112, and the console 105 controls the X-axis linear sliding device 110 and the Y-axis linear sliding device 111 to drive the workbench 112 to move horizontally. The Z-axis linear slide device A104 for driving the convex lens 210 focusing system to make vertical movement and the Z-axis linear slide device B103 for driving the conical lens 220 system to make vertical movement are fixed on the side of the optical platform 102 respectively. The CCD image recognition device 106 is fixed on the side of the two Z-axis linear slide devices respectively. During the processing, according to the processing position of the drilling workpiece, the control console 105 can control the Z-axis linear slide device B103 and the Z-axis linear slide device A104 to make vertical movement so that the focused laser beam meets the process requirements. The optical path system is fixed on the upper surface of the optical platform 102, as shown in FIG. Figure 5 As shown, the laser beam emitted by the ultrafast laser 200 enters the beam expander collimator 203 through the photoelectric switch 201 and the aperture 202. After the laser beam is expanded and collimated, it passes through the reflector A204 and the reflector B205 and enters the convex lens 210 and the conical lens 220 respectively. When a base hole needs to be drilled during the processing, the reflector 204 is removed. When an ultra-fine hole needs to be drilled during the processing, the reflector 204 is reset.

[0040] During processing, the part is first fixed on the workbench 112, and after the processing parameters are set in the control console 105, the processing begins. First, the control console 105 controls the CCD image recognition device 106 on the Z-axis linear slide device A104 of the focusing system of the fixed convex lens 210 to identify and locate the punching position of the part, and then adjusts the Z-axis linear slide device A104 to the processing position. The control console 105 controls the reflector A204 to deviate from the optical path, controls the ultrafast laser 200 to output the laser beam, and then turns on the photoelectric switch 201. The laser beam passes through the aperture 202, the beam expander collimator 203 and the reflector B205. Then, through the convex lens 210, a hole is drilled on the surface of the workpiece. After the drilling is completed, the photoelectric switch 201 is turned off, and then the console 105 controls the workbench 112 to move to the bottom of the focusing system of the aconic lens 220, obtains the drilled position, and accurately positions the Z-axis linear slide device B103 that fixes the focusing system of the aconic lens 220 to the drilling position, adjusts the vertical distance of the Z-axis linear slide device B103, turns on the photoelectric switch 201, and the laser beam enters the focusing system of the aconic lens 20 through the aperture 202, the beam expander collimator 203 and the reflector A204, and drills an ultrafine hole in the base of the material until the entire hole processing is completed. After the drilling is completed, the ultrafast laser 200 and the photoelectric switch 201 are turned off, the workbench 102 moves to the set position, and the drilling is completed.

[0041] It should be noted here that the ultrafine hole laser drilling system according to the present invention can be automatically controlled by the control console 105, such as controlling the movement of the workbench 112 and controlling the ultrafast laser 200, which is understandable to those skilled in the art.

[0042] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the invention.

Claims

1. A novel ultrafine hole laser drilling system, comprising an equipment platform (100), characterized in that: The equipment platform (100) is provided with pillars (101) around it, an optical platform (102) is provided on the pillars (101), an X-axis linear sliding device (110) is provided on the equipment platform (100), a Y-axis linear sliding device (111) is provided on the X-axis linear sliding device (110), a workbench (112) is connected to the Y-axis linear sliding device (111), a control console (105) for controlling the X-axis linear sliding device (110) and the Y-axis linear sliding device (111) is also provided on the pillars (101), two Z-axis linear sliding devices are also provided on the optical platform (102), an ultrafast laser (200) facing the two Z-axis linear sliding devices is also provided on the optical platform (102), and the two Z-axis linear sliding devices include a Z-axis linear sliding device A (104) and a Z-axis linear sliding device B (103); The ultrafast laser (200) is connected to a photoelectric switch (201) and an aperture (202); the aperture (202) is connected to a beam expander collimator (203); a reflector A (204) and a reflector B (205) are provided on the beam expander collimator (203); a conical lens (220) corresponding to the reflector A (204) and facing the workbench (112) is provided at the bottom of the Z-axis linear sliding device A (104); and a convex lens (210) corresponding to the reflector B (205) and facing the workbench (112) is provided at the bottom of the Z-axis linear sliding device B (103).

2. A laser drilling process using the ultrafine hole laser drilling system according to claim 1, characterized in that: The method comprises the following steps: D1, first fixing the part on the workbench (112), setting the processing parameters in the controller, and then starting the processing; D2, the controller controls the CCD image recognition device (106) of the Z-axis linear sliding device B (103) that fixes the convex lens (210) to identify the drilling position of the positioning part, then adjusts the Z-axis linear sliding device B (103) to the processing position, controls the reflector to deviate from the optical path, controls the ultrafast laser (200) to output the laser beam, and then turns on the photoelectric switch (201), so that the laser beam passes through the aperture (202), the beam expansion collimator (203) and the reflector, and then passes through the convex lens (210) to drill a hole on the surface of the workpiece; D3. After the drilling is completed, the photoelectric switch (201) is turned off, and the controller controls the workbench (112) to move to the bottom of the conical lens (220). The position of the hole that has been drilled is obtained through the CCD image recognition device, and the Z-axis linear sliding device A (104) that fixes the conical lens (220) is accurately positioned to the drilling position. The vertical distance of the Z-axis linear sliding device A (104) is adjusted, and the photoelectric switch (201) is turned on. The laser beam enters the conical lens (220) through the aperture (202), the beam expander collimator (203) and the reflector, and an ultra-fine hole is drilled on the part until the entire hole processing is completed; D4. After the drilling is completed, the ultrafast laser (200) and the photoelectric switch (201) are turned off, and the workbench (112) moves to the set position, and the drilling is completed.

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