Bidirectional laser processing technology

Abstract

The invention belongs to the technical field of laser processing of non-metallic materials, and particularly relates to a bidirectional laser processing technology. Compared with a conventional one-way laser machining mode and a bidirectional laser machining mode, the two-way laser machining mode has unique advantages in the aspect of punching of materials with large thicknesses, has the advantages of being higher in efficiency, smaller in cutting position taper and controllable in laser perpendicularity, and can machine holes with various section shapes in the aspect of laser punching.

Description

Technical Field

[0001] The invention belongs to the technical field of laser processing of non-metallic materials, and in particular relates to a bidirectional laser processing process. Background Art

[0002] Laser cutting and laser drilling are important areas of laser processing. Compared with traditional mechanical processing methods, laser processing has been applied in more and more scenarios due to its non-contact, high-precision, high-collimation effect and high efficiency. For metal materials, conventional high-power fiber lasers can currently process different metal materials and different thicknesses. For non-metallic materials, processing requirements become much more complicated. For example, hard and brittle materials are not resistant to high temperatures, and they are prone to cracking if the laser power is too high; organic materials are prone to carbonization, and excessive thermal effects can easily carbonize or even burn them.

[0003] At present, the commonly used method for the above materials is to use nanosecond or picosecond laser equipment, using short pulse or ultrashort pulse laser, and processing from a single direction. This type of short pulse or ultrashort pulse laser acts on the processing position, and the material to be processed absorbs the laser energy, forming a hot plasma in a very short time, and finally turns into plasma gas, which overflows from the slit position, thereby completing the drilling or cutting process. Due to the small overall processing thermal effect, no molten layer will be formed on the side wall of the slit; however, for materials with a thickness of more than 0.3mm, this processing method faces a problem. As the slit becomes deeper and deeper, more and more plasma gas accumulates in the gap and cannot be discharged smoothly. The plasma gas retained in the slit will block the laser and absorb the laser energy, causing the cutting efficiency to continue to decrease; at the same time, after the plasma gas absorbs the laser energy, it is converted into heat energy, causing the temperature in the slit to rise sharply, and the material as a whole is at risk of carbonization or explosion.

[0004] To solve this problem, the common practice is to expand the slit width by opening more slits, so as to ensure that the plasma gas has a larger outlet and can overflow smoothly. In order to ensure that the slits can be merged smoothly, the spacing between the slits must not exceed the spot diameter, otherwise the slits will be separated and cannot be merged; generally, the maximum depth-to-diameter ratio (ratio of slit depth to slit opening width) for plasma gas to be discharged smoothly is 20:1. For example, when the slit depth reaches 0.3mm, the slit width is at least 20um, otherwise the processing efficiency will drop sharply; secondly, for materials with a thickness of less than 0.3mm, one cutting slit can be used to complete the punching operation; when the thickness reaches 0.4mm, two cutting slits are generally required to complete it; when the thickness reaches... When the thickness reaches 0.5mm, 4 cutting slits are required; when the thickness reaches 0.6mm, 6 cutting slits are required. However, each additional cutting slit requires additional laser processing, resulting in a geometric reduction in processing efficiency. In addition, the laser cutting slit is a V-shaped groove when viewed from the cross-section. The top width of the V-shaped groove is approximately equal to the opening width of the slit, and the bottom width of the V-shaped groove is infinitely close to 0, making it difficult to achieve consistency in the morphology and size of the material. For the laser drilling process, the taper of the processed hole is significantly increased; for the laser cutting process, the slope of the cut piece will also increase significantly. Therefore, the processing efficiency is low, the taper of the punched hole is large, and the cutting slope is high. This is a problem that plagues the laser cutting, punching and other processing technologies of high-thickness non-metallic materials. Conventional unidirectional processing technology cannot solve this problem, and a new processing solution is urgently needed. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a bidirectional laser processing process to solve the problems of low processing efficiency, large hole taper, high cutting slope, etc. in the prior art when laser cutting and drilling non-metallic materials.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A bidirectional laser processing process comprises the following steps:

[0008] Step 1: Adsorb the object to be processed onto the vertical adsorption platform;

[0009] Among them, the adsorption platform has a through groove opened in advance at the location where the hole needs to be drilled to ensure that it does not hinder the direction of the laser.

[0010] Step 2: Two laser beams are processed simultaneously from two opposite directions until the two laser beams converge at the center of the processed object;

[0011] Step 3: After the two laser beams merge, turn off one of the laser beams and use the other laser beam to trim the hole wall.

[0012] Preferably, the optical paths of the two laser beams are controlled by an optical path system, which includes a laser, a beam splitter, a 1 / 2 glass slide, a reflector, an EOM and a galvanometer;

[0013] When using laser to cut or punch the object to be processed, the laser beam is emitted by the laser, and the laser beam is divided into two by the beam splitter, namely P polarized light and S polarized light. The P polarized light passes through the EOM and the galvanometer in sequence and is projected on one side of the object to be processed, and the S polarized light first passes through the 1 / 2 glass slide to be converted into P polarized light, and then passes through the EOM and the galvanometer in sequence and is projected on the other side of the object to be processed.

[0014] Among them, EOM can control the strength and switch of P-polarized light, and the galvanometer can enable the laser to travel along the set route.

[0015] Preferably, during the processing of the two laser beams, a laser control system, a tooling dust collection system and a precision calibration system are also provided.

[0016] Preferably, the working process of the laser control system is as follows:

[0017] The two laser beams are controlled by the optical path system and do not emit light before moving to the processing position of the object to be processed;

[0018] After moving to the processing position of the object to be processed, the two laser beams emit light at the same time and process in opposite directions; before the two laser beams converge at the center of the processing position of the object to be processed, one of the laser beams stops emitting light and waits to move to the next processing position to emit light for early processing;

[0019] Another laser beam continues to process the current area to modify the hole wall effect;

[0020] After the hole wall modification is completed, it moves to the next processing position and performs processing in the same direction as the laser that performed the previous processing, and so on.

[0021] Preferably, the working process of the tooling dust collection system is as follows:

[0022] The part to be processed is adsorbed on a vertical adsorption platform. Two laser beams are set on the left and right sides of the part to be processed, and irradiated from the left and right sides of the part to be processed toward each other. Dust collection equipment is added near the optical path system to collect dust.

[0023] Preferably, the working process of the precision calibration system is as follows:

[0024] Step (1) attaching a thin glass lens to a vertical adsorption platform;

[0025] Step (2) using a first laser beam to process a photolithographic mark (a circular or cross-shaped pattern array) at a designated coordinate position on one side of the glass lens;

[0026] Step (3) using a second laser beam to process a photolithographic mark (circular or cross-shaped pattern array) at a designated coordinate position on the other side of the glass lens;

[0027] Step (4) using the light transmission property of the glass, using a camera to identify the deviation of the two groups of graphic arrays, and obtaining the two groups of optical system accuracy deviation values ​​(Δx11, Δy11), (Δx12, Δy12) at different coordinate positions, and so on;

[0028] Step (5) compensates the deviation value to the galvanometer control system of the laser, thereby achieving a high degree of synchronization in the processing accuracy of the two laser beams.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] Compared with conventional unidirectional laser processing, bidirectional laser processing has its unique advantages in cutting or punching thicker materials;

[0031] Through laser bidirectional processing, the efficiency of cutting or drilling is doubled, and the taper or slope is doubled;

[0032] Highly flexible processing of special-shaped holes can be achieved through the verticality control of the bidirectional laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of bidirectional laser processing in the present invention;

[0034] Figure 2 It is a working schematic diagram of the optical path system in bidirectional laser processing of the present invention;

[0035] Figure 3 It is a working schematic diagram of the laser control system during bidirectional laser processing in the present invention;

[0036] Figure 4 It is a working schematic diagram of the tooling dust collection system during bidirectional laser processing in the present invention;

[0037] Figure 5 It is a schematic diagram of the process of processing cross-shaped photolithography marks on both sides of a glass lens by using a precision calibration system in the present invention;

[0038] Figure 6 It is a schematic diagram of the deviation value of the photolithography mark processed on both sides of the glass lens by using the precision calibration system in the present invention;

[0039] Figure 7 This is a comparison chart of the number of slits required for one-way processing and two-way processing of objects with different thicknesses;

[0040] Figure 8The result diagram of the improvement ratio of the machining efficiency of bidirectional machining compared with that of unidirectional machining;

[0041] Fig. 9 Comparison of taper conditions during one-way machining and two-way machining;

[0042] Fig.10 When bidirectional laser processing is used in the present invention, different laser verticality methods are used to process special-shaped hole patterns with different characteristics. DETAILED DESCRIPTION

[0043] Example 1

[0044] This embodiment discloses a bidirectional laser processing process, comprising the following steps:

[0045] Step 1: Adsorb the object to be processed onto the vertical adsorption platform;

[0046] Among them, the adsorption platform has a through groove opened in advance at the location where the hole needs to be drilled to ensure that it does not hinder the direction of the laser.

[0047] Step 2: Two laser beams are processed simultaneously from two opposite directions until the two laser beams converge at the center of the processed object;

[0048] Step 3: After the two laser beams merge, turn off one of the laser beams and use the other laser beam to trim the hole wall.

[0049] Example 2

[0050] This embodiment discloses an optical path system, through which the optical path of the laser is controlled;

[0051] The optical path system includes a laser, a beam splitter, a 1 / 2 glass slide, a reflector, an EOM and a galvanometer;

[0052] When using laser to cut or punch the object to be processed, the laser beam is emitted by the laser, and the laser beam is divided into two by the beam splitter, namely P polarized light and S polarized light. The P polarized light passes through the EOM and the galvanometer in sequence and is projected on one side of the object to be processed, and the S polarized light first passes through the 1 / 2 glass slide to be converted into P polarized light, and then passes through the EOM and the galvanometer in sequence and is projected on the other side of the object to be processed.

[0053] Among them, EOM can control the strength and switch of P-polarized light, and the galvanometer can enable the laser to travel along the set route.

[0054] Example 3

[0055] Since the two laser beams are irradiated in opposite directions, if the laser irradiates into the opposite optical path system, it is easy to cause damage to the optical lens of the opposite system;

[0056] This embodiment discloses a laser control system, and the working process is as follows:

[0057] The two laser beams are controlled by the optical path system. Before they move to the processing position of the object to be processed, neither of them emits light. After they move to the processing position of the object to be processed, they emit light at the same time and process in opposite directions. Before the two laser beams converge at the center of the processing position of the object to be processed, one of the laser beams stops emitting light and waits to move to the next processing position to emit light for advance processing. The other laser beam continues to process the current area and modify the hole wall effect. After the modification of the hole wall is completed, it moves to the next processing position and performs processing in opposite directions with the laser beam that performs advance processing, and so on.

[0058] This laser control method can not only avoid the situation where two laser beams irradiate each other, but also ensure that the processing efficiency is not affected.

[0059] Example 4

[0060] This embodiment discloses a tool dust collection system, and the working process is as follows:

[0061] The part to be processed is adsorbed on a vertical adsorption platform, two laser beams are set on the left and right sides of the part to be processed, and irradiated from the left and right sides of the part to be processed. Dust collection equipment is added near the optical path system to collect dust;

[0062] The setting of the tooling dust collection system can prevent the dust generated by laser cutting and punching processes from falling on the optical lens and contaminating the optical lens.

[0063] Example 5

[0064] Because the two laser beams need to converge at the center of the part to be processed, the processing accuracy of the two laser beams is relatively high. Once the deviation in accuracy is too large, the two laser beams will be misaligned.

[0065] This embodiment discloses a precision calibration system, and the working process is as follows:

[0066] Step (1) attaching a thin glass lens to a vertical adsorption platform;

[0067] Step (2) using a first laser beam to process a photolithographic mark (a circular or cross-shaped pattern array) at a designated coordinate position on one side of the glass lens;

[0068] Step (3) using a second laser beam to process a photolithographic mark (circular or cross-shaped pattern array) at a designated coordinate position on the other side of the glass lens;

[0069] Step (4) utilizes the light transmission property of the glass and uses a camera to identify the deviation of the two groups of graphic arrays, and obtains the two groups of optical system accuracy deviation values ​​(Δx11, Δy11), (Δx12, Δy12) at different coordinate positions, and so on;

[0070] Step (5) compensating the deviation value to the galvanometer control system of the laser, thereby achieving high synchronization of the processing accuracy of the two laser beams;

[0071] By using this precision calibration system for calibration, the precision deviation of the two laser beams after calibration can be controlled within 5μm.

[0072] Example 6

[0073] This embodiment discloses a comparison of cutting and processing efficiency when using a bidirectional laser processing method and conventional unidirectional processing:

[0074] For an object with a thickness of 0.4mm, unidirectional processing requires two cuts, and both cuts need to penetrate; while the two laser beams of bidirectional laser processing only need to process a thickness of 0.2mm, and only one cut is required, which doubles the efficiency;

[0075] For a 0.6mm thick object to be processed, unidirectional processing requires 6 cuts, and all 6 cuts need to be through; while the two laser beams of bidirectional laser processing only need to process 0.3mm thickness, and only one cut is required, which increases the efficiency by 6 times;

[0076] For objects of different thicknesses, the comparison results of the number of slits required for one-way processing and two-way processing are as follows: Figure 7 As shown;

[0077] Generally, the reduction in the number of slits means the improvement of processing efficiency, and the theoretical efficiency improvement can be obtained from the comparison of the number of slits;

[0078] For a 0.6mm thick object, the one-way processing takes 120 seconds; the two-way laser processing theoretically only takes 20 seconds, increasing the processing efficiency by 6 times.

[0079] For objects of different thicknesses, the improvement ratio of bidirectional processing efficiency compared to unidirectional processing efficiency is as follows: Figure 8 As shown;

[0080] As can be seen from the figure, for objects with a thickness of 0.5mm, 0.6mm, and 0.7mm, the efficiency improvement effect is 5-6 times; for objects with a thickness of more than 1mm, the efficiency improvement can also be guaranteed to be more than 2 times.

[0081] Example 7

[0082] This embodiment discloses a comparison of taper using a bidirectional laser processing method and a conventional unidirectional processing method:

[0083] The laser processes in both directions, and the width of the upper and lower slits can be kept consistent. The difference in the slit sidewalls of this process comes from the slit width on the surface and the slit width in the middle of the part to be processed. The slit width in the middle of the part to be processed is not infinitely close to 0, but is widened once during the merging of the two laser beams. After the merging, it is modified by another laser beam, and the slit is further widened.

[0084] Theoretically, the slit width in the middle of bidirectional machining will be greater than that in the middle of unidirectional machining. According to the taper or slope formula, the taper or slope of bidirectional machining will be reduced to less than 1 / 2 of the taper of unidirectional machining. Fig. 9 As shown;

[0085] When the overall taper is reduced to less than 1 / 2 of the original process and the slit widths on the upper and lower surfaces are basically the same, the overall consistency is greatly improved.

[0086] Example 8

[0087] This embodiment discloses a method of processing special-shaped holes using a bidirectional laser:

[0088] The bidirectional lasers are controlled independently, and their verticality is controllable. For through holes with bending requirements on the hole wall, the bidirectional lasers can be tilted in the same direction; for hollow drum-shaped through holes with small surface aperture and large internal aperture, the bidirectional lasers can be rotated synchronously; for dog-bone-shaped through holes with large surface aperture and small internal aperture, the bidirectional lasers can be rotated synchronously; for through holes with two twists and turns inside, the bidirectional lasers can be tilted in different directions, such as Fig.10 shown.

[0089] 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.

Claims

1. A bidirectional laser processing process, characterized in that: The following steps are involved: Step 1: Adsorb the object to be processed onto the vertical adsorption platform; Among them, the adsorption platform has a through groove opened in advance at the location where the hole needs to be drilled to ensure that it does not hinder the direction of the laser. Step 2: Two laser beams are processed simultaneously from two opposite directions until the two laser beams converge at the center of the processed object; Step 3: After the two laser beams merge, turn off one of the laser beams and use the other laser beam to trim the hole wall.

2. A bidirectional laser processing process according to claim 1, characterized in that: The optical paths of the two laser beams are controlled by an optical path system, which includes a laser, a beam splitter, a 1 / 2 glass slide, a reflector, an EOM and a galvanometer; When using laser to cut or punch the object to be processed, the laser beam is emitted by the laser, and the laser beam is divided into two by the beam splitter, namely P polarized light and S polarized light. The P polarized light passes through the EOM and the galvanometer in sequence and is projected on one side of the object to be processed, and the S polarized light first passes through the 1 / 2 glass slide to be converted into P polarized light, and then passes through the EOM and the galvanometer in sequence and is projected on the other side of the object to be processed. Among them, EOM can control the strength and switch of P-polarized light, and the galvanometer can enable the laser to travel along the set route.

3. A bidirectional laser processing process according to claim 1, characterized in that: During the two-beam laser processing, a laser control system, a tooling dust collection system and a precision calibration system are also set up.

4. A bidirectional laser processing process according to claim 3, characterized in that: The working process of the laser control system is as follows: The two laser beams are controlled by the optical path system and do not emit light before moving to the processing position of the object to be processed; After moving to the processing position of the object to be processed, the two laser beams emit light at the same time and process in opposite directions; before the two laser beams converge at the center of the processing position of the object to be processed, one of the laser beams stops emitting light and waits to move to the next processing position to emit light for early processing; Another laser beam continues to process the current area to modify the hole wall effect; After the hole wall modification is completed, it moves to the next processing position and performs processing in the same direction as the laser that performed the previous processing, and so on.

5. A bidirectional laser processing process according to claim 3, characterized in that: The working process of the tooling dust collection system is as follows: The part to be processed is adsorbed on a vertical adsorption platform. Two laser beams are set on the left and right sides of the part to be processed, and irradiated from the left and right sides of the part to be processed toward each other. Dust collection equipment is added near the optical path system to collect dust.

6. A bidirectional laser processing process according to claim 3, characterized in that: The working process of the precision calibration system is as follows: Step (1) attaching a thin glass lens to a vertical adsorption platform; Step (2) using a first laser beam to process a photolithography mark at a designated coordinate position on one side of the glass lens; Step (3) using a second laser beam to process a photolithographic mark at a designated coordinate position on the other side of the glass lens; Step (4) using the light transmission property of the glass, using a camera to identify the deviation of the two groups of graphic arrays, and obtaining the two groups of optical system accuracy deviation values ​​(Δx11, Δy11), (Δx12, Δy12) at different coordinate positions, and so on; Step (5) compensates the deviation value to the galvanometer control system of the laser, thereby achieving a high degree of synchronization in the processing accuracy of the two laser beams.

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