Laser mask processing method

Abstract

The present invention relates to laser processing and provides a laser mask processing method, comprising the following steps: presetting the line width of the graphic track of the mask plate according to the linear spot energy distribution of the laser, and the line width at the strong energy point of the linear spot is smaller than that at the weak energy point; preparing the mask plate according to the preset graphic track of the mask plate; placing the prepared mask plate on the product to be processed, and the graphic track of the mask plate is aligned with the processing track of the product to be processed; and the linear spot emitted by the laser is used to scan the product to be processed along the mask plate. In the processing method provided by the present invention, through mask technology, welding smaller than the size of the laser spot can be achieved, and high-precision welding as low as 10 microns can be achieved, and line scanning processing of complex graphics can be achieved, with very high processing efficiency; in addition, the line width of the graphic track of the mask plate is adjusted according to the linear spot energy distribution, thereby achieving a reasonable distribution of laser energy and ensuring the processing quality of the product.

Description

Technical Field

[0001] The present invention relates to laser processing, in particular to a laser mask processing method. Background Art

[0002] In laser welding, mask welding is increasingly used due to its high speed and high precision. Mask processing methods are usually achieved by combining a line spot with a mask plate. It has two key technologies: line spot technology and mask technology. However, there is currently a problem with line spot technology: poor energy uniformity.

[0003] The line spot is generally shaped from the laser fiber to a line or other shape through the external optical path. During this shaping process, the laser shape is shaped from a dot to a rectangle or other shape, which causes laser energy loss and uneven energy distribution. During the mask welding process, the uneven energy will cause the strong energy areas to be welded too much, while the weak energy areas will not be welded at all, resulting in poor plastic welding quality and poor appearance. Summary of the Invention

[0004] The object of the present invention is to provide a laser mask processing method that can at least solve some of the defects in the prior art.

[0005] To achieve the above objectives, an embodiment of the present invention provides the following technical solution: a laser mask processing method, comprising the following steps:

[0006] Presetting the line width of the pattern track of the mask plate according to the energy distribution of the line spot of the laser, and the line width at the strong energy of the line spot is smaller than that at the weak energy; preparing the mask plate according to the preset pattern track of the mask plate;

[0007] Placing the prepared mask plate on the product to be processed, with the pattern track of the mask plate aligned with the processing track of the product to be processed;

[0008] The line spot emitted by the laser scans along the mask plate to process the product to be processed.

[0009] Furthermore, the line spot is divided into a weak energy segment and a strong energy segment according to the energy distribution of the line spot; the mask is divided into a weak energy area and a strong energy area, wherein the weak energy area is the effective area of ​​the weak energy segment of the line spot, and the strong energy area is the effective area of ​​the strong energy segment of the line spot, and the line width of the graphic track located in the strong energy area is smaller than the line width of the graphic track located in the weak energy area.

[0010] Furthermore, the line spot of the laser is shaped, and the shaped line spot has a strong energy segment and two weak energy segments, and the strong energy segment is located between the two weak energy segments.

[0011] Furthermore, the energy of the line light spot increases smoothly from the weak energy segment to the strong energy segment, and the line width of the graphic track increases smoothly from the strong energy region to the weak energy region.

[0012] Furthermore, the mask plate is laser-roughened according to a preset pattern track of the mask plate, and the non-roughened area of ​​the mask plate is the pattern track of the mask plate.

[0013] Furthermore, a light-shielding and high-temperature-resistant material is applied to the roughened area of ​​the mask plate, and the light-shielding and high-temperature-resistant material is heated and cured.

[0014] Furthermore, transparent soft glue is applied on the cured surface of the light-shielding and high-temperature resistant material and the pattern track of the mask plate.

[0015] Furthermore, after the mask plate is roughened, the non-roughened area of ​​the mask plate protrudes from the roughened area by 1-2 mm.

[0016] Furthermore, the prepared mask plate is moved in the vertical direction. When the product to be processed moves horizontally to the position directly below the mask plate, the mask plate is moved vertically downward onto the product to be processed, and the graphic track of the mask plate is aligned with the processing track of the product to be processed.

[0017] After the line spot emitted by the laser scans along the mask plate to process the product to be processed, the mask plate moves vertically upward, and the processed product moves out of the processing area of ​​the laser.

[0018] Furthermore, points are taken along the length direction of the line spot, and a beam quality analyzer is used to detect the spot energy at each point of the line spot. Based on the spot energy at each point, an energy distribution diagram of the entire line spot is prepared.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: when preparing the mask plate, the energy distribution of the laser's line spot during processing is first determined, and the line width at each position of the mask plate's graphic trajectory is determined based on the energy distribution of the line spot. Specifically, the line width corresponding to the strong energy of the line spot is narrower, and on the contrary, the line width corresponding to the weak energy of the line spot is wider. During actual processing, the prepared mask plate is placed on the product to be processed, and the laser's line spot is processed through the mask plate to process the product to be processed. The processing process is line scanning, and the processing efficiency is very high. At the same time, through mask technology, welding smaller than the laser spot size can be achieved, and high-precision welding as low as 10 microns can be achieved. In addition, the line width of the mask plate can control the energy of the laser irradiated on the product to be processed. Experiments have found that the mask plate designed by this method has a significant improvement in quality and appearance compared to the products welded by normal mask plates during the specific welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A processing flow chart of a laser mask processing method provided by an embodiment of the present invention;

[0021] Figure 2 A flowchart of mask plate preparation for the laser mask processing method provided in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the mask plate structure of the laser mask processing method provided by an embodiment of the present invention;

[0023] Figure 4 A line spot energy distribution diagram of the laser mask processing method provided by an embodiment of the present invention;

[0024] Figure 5 A line width distribution diagram of a graphic track of a laser mask processing method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] See also Figure 1-Figure 3 The embodiment of the present invention provides a laser mask processing method, which comprises placing a mask plate 1 on a product to be processed, and transmitting laser light through the mask plate 1 to process the product to be processed. The method specifically comprises the following steps:

[0027] The line width of the graphic track 2 of the mask plate 1 is preset according to the linear spot energy distribution of the laser, and the line width at the location of strong linear spot energy is smaller than that at the location of weak linear spot energy. The linear spot here refers to the laser light emitted by the laser for processing the product to be processed, which is transformed into a linear spot after being shaped, and the product to be processed is processed through this linear spot. In addition, the graphic track 2 of the mask plate 1 is determined according to the processing track of the product to be processed, that is, the graphic track 2 of the mask plate 1 is predetermined, and then the line width of the graphic track 2 of the mask plate 1 is adjusted according to the linear spot energy distribution of the laser. For example, when a laser is used to process the product to be processed, if a part of the graphic track 2 is acted upon by the linear spot with strong energy, the line width of this part of the graphic track 2 is narrower. Similarly, if the graphic track 2 is acted upon by the linear spot with weak energy, the line width of this part of the graphic track 2 is wider. In this step, based on the above logic, the line width of each part of the graphic track 2 is determined before preparing the mask plate 1.

[0028] The mask plate 1 is processed based on the above-mentioned preset graphic track 2 of the mask plate 1, and then the finished mask plate 1 can be obtained. Generally speaking, the base material of the mask plate 1 is high-purity quartz glass, which itself has good light transmittance, and the line spot emitted by the laser can pass through the mask plate 1 to perform laser processing on the product to be processed. In this step, the base material of the mask plate 1 is processed according to the graphic track 2 with a line width pre-designed according to the above steps, and the area corresponding to the graphic track 2 of the processed mask plate 1 has good light transmittance, while the light transmittance of the non-graphic track area 3 is poor. When a laser is used to perform mask processing on the product to be processed, the line spot can pass through the mask plate 1 via the graphic track 2 to process the product to be processed, while for the non-graphic track area 3, the line spot cannot pass through the mask plate 1.

[0029] The prepared mask plate 1 is placed on the product to be processed, and the pattern track 2 on the mask plate 1 is aligned with the processing track of the product to be processed. Specifically, the mask plate 1 is controlled to fit the processing surface of the product to be processed, while ensuring that the pattern track 2 on the mask plate 1 and the processing track of the product to be processed are aligned. Of course, to ensure the accuracy of laser processing, the alignment requirements of the two are relatively high to avoid alignment errors.

[0030] After aligning the positions of the mask plate 1 and the product to be processed, the line spot emitted by the laser performs line scanning processing on the mask plate 1, thereby realizing laser processing of the processing track of the product to be processed. In this step, during processing, only relative linear movement occurs between the line spot and the mask plate 1 (the mask plate 1 and the product to be processed as a whole). Preferably, after the position is adjusted appropriately, the positions of the mask plate 1 and the product to be processed are fixed, and the line spot is controlled to move in a linear manner. The line spot acts directly on the mask plate 1 in a line scanning manner, and since only the graphic track 2 of the mask plate 1 can effectively transmit light, only the processing track of the product to be processed is laser processed. Of course, assuming that the size of the mask plate 1 (or the processing surface of the product to be processed) is not very large, the line spot only needs to move in a straight line once to realize the processing of the product to be processed. When the size of the mask plate 1 is relatively large, the length of the line spot is limited, and multiple line scans can be performed to realize the processing of the product to be processed.

[0031] In the above steps, mask plate 1 is first prepared. Then, mask plate 1 is aligned with the product to be processed. The linear spot generated by the laser passes through mask plate 1 to process the product. For laser processing of the same type of product, mask plate 1 only needs to be prepared once and then reused during actual processing. Although the processing trajectory of the product to be processed is very complex, the linear spot of the laser is applied to mask plate 1 in a line scanning manner, which greatly improves processing efficiency.

[0032] In a specific embodiment, for the same product, using a galvanometer for welding requires more than 21 welds to ensure complete welding, and the welding time is 87.9s. However, using the mask processing method provided by the present invention to weld the product, the line scanning speed of the line spot can reach 10mm / s, and the welding time is 16s, which greatly improves the welding efficiency. In addition, when using a galvanometer for welding, since the number of welds reaches more than 21 times, as the number of welds increases, the weld line will gradually become thicker, and the laser will cause the hot melt ribs to melt and overflow, resulting in an increase in the melted bonding area and poor welding quality. However, using the mask processing method provided by the present invention, the line spot only needs to be welded once, and through mask technology, welding smaller than the laser spot size can be achieved, and high-precision welding as low as 10 microns can be achieved.

[0033] In the present invention, although the energy distribution of the line spot is uneven, by matching the graphic track 2 of the mask plate 1 with the energy distribution of the line spot, the energy is strong-the line width of the graphic track 2 is narrow, and the energy is weak-the line width of the graphic track 2 is wide, thereby achieving effective distribution of laser energy on the product to be processed, thereby ensuring the processing quality of the product.

[0034] The above processing method is optimized, and the line spot is divided into a weak energy segment and a strong energy segment according to the energy distribution of the line spot. Correspondingly, the mask plate 1 is divided into a weak energy area and a strong energy area, wherein the weak energy area is the processing area of ​​the weak energy segment of the line spot, and the strong energy area is the processing area of ​​the strong energy segment of the line spot. That is, during the line scanning process of the line spot, the weak energy area of ​​the mask plate 1 is the irradiation area of ​​the weak energy segment of the line spot, and the line width of the graphic track 2 corresponding to this area is wider, while the strong energy area of ​​the mask plate 1 is the irradiation area of ​​the strong energy segment of the line spot, and the line width of the graphic track 2 corresponding to this area is smaller than the line width of the graphic track 2 in the weak energy area.

[0035] Generally, when a laser emits light that is shaped into a line spot, the energy in the center of the line spot is higher, while the energy at the ends is lower. Therefore, the center region of the line spot is defined as the high-energy segment, and the areas on either side of the high-energy segment are defined as low-energy segments. In other words, the line spot has one high-energy segment and two low-energy segments, with the high-energy segment located between the two low-energy segments. For mask 1, along the length of the line spot, the center region is the high-energy region, while both sides are high-energy regions. This indicates that the line width of pattern track 2 is narrower in the center region, while it is wider in the areas on the sides.

[0036] In one embodiment, although the line light spot is divided into a strong energy segment and a weak energy segment, the energy intensity in the strong energy segment is not uniform, and the energy intensity in the weak energy segment is also inconsistent. Specifically, the energy gradually increases from the weak energy segment to the strong energy segment, and the increase is in the form of a smooth curve. Since the strong energy segment is located in the middle of the line light spot, the energy distribution diagram of the line light spot is a convex structure, see Figure 4 Similarly, the line width of the graphic track 2 in the strong energy area is also inconsistent, and the line width in the weak energy area is also inconsistent, and gradually increases from the strong energy area to the weak energy area. The increase is also a smooth curve. Since the strong energy area is located in the middle of the mask plate 1, the line width distribution diagram of the graphic track 2 is a concave structure, see Figure 5 By optimizing the above embodiment, the increase ratio of the line spot energy is the same as the line width change ratio of the graphic track 2. That is, when the energy distribution curve of the line spot is simulated, the line width change curve of the graphic track 2 can be prepared, and then the line width at each position of the graphic track 2 can be obtained more conveniently, and the processing quality after laser processing can be further guaranteed.

[0037] Preferably, the energy distribution diagram of the line spot is obtained by using the point selection method. Specifically, points are selected along the length of the line spot, and the points are evenly spaced. A beam quality analyzer is used to detect the spot energy at each point of the line spot, and the overall energy distribution diagram of the line spot is prepared based on the spot energy at each point.

[0038] In one embodiment, the mask plate 1 is laser roughened according to the preset graphic track 2 of the mask plate 1. The roughened area is the above-mentioned non-graphic track area 3, and the unroughened area of ​​the mask plate 1 is the graphic track 2 of the mask plate 1. In this embodiment, the mask plate 1 is laser roughened to obtain the graphic track 2 of the mask plate 1. The laser for laser roughening here is different from the corresponding laser for the line spot. The laser is the laser required for the preparation of the mask plate 1. The laser for the line spot is used for product processing. Of course, before the roughening process, the dirt on the surface of the substrate needs to be removed. The substrate of the mask plate 1 is high-purity quartz glass. The substrate of the mask plate 1 is laser-processed by an infrared picosecond laser with a laser power of 5-6w. The area corresponding to the graphic track 2 is avoided. The surface of the substrate is roughened multiple times by the laser, thereby removing a certain thickness of the substrate of the mask plate 1 in the area other than the graphic track 2, and the part of the substrate that is not removed (the surface of the protruding roughened area) is the graphic track 2. The thickness of the removed film is 1-2 mm. This method can reduce the laser transmittance of the mask plate 1 where the substrate is removed to 60%. When the laser power corresponding to the line spot is not very high, the roughened mask plate 1 can be used for product processing. In another embodiment, the mask plate 1 can be blackened. That is, the non-graphic track area 3 of the mask plate 1 can be blackened using a laser. The laser transmittance of the blackened area is very low, while the non-blackened area (graphic track 2) has normal transmittance.

[0039] The above embodiment is optimized by applying a light-shielding, high-temperature resistant material to the roughened area of ​​the mask plate 1. The light-shielding, high-temperature resistant material does not need to be applied to the graphic track 2, and the light-shielding, high-temperature resistant material is heated and cured. Specifically, the light-shielding, high-temperature resistant material can be a high-temperature resistant inorganic glue, such as refractory ceramics and inorganic polymers such as silicate, which have low laser absorption and are opaque. It is first evenly applied to the roughened removal area of ​​the mask plate 1, and at this time, the graphic track 2 protrudes 0.1-0.5mm from the surface of the light-shielding, high-temperature resistant material. The light-shielding, high-temperature resistant material is heated to 180-200 degrees and maintained for 2 hours to solidify. At this time, the laser transmittance of this area of ​​the mask plate 1 drops to below 10%, and it can withstand high-power laser irradiation.

[0040] In a preferred embodiment, a transparent soft glue is applied to the surface of the roughened side of the mask plate 1, and the surface of the graphic track 2 is also coated with the transparent soft glue. When a light-shielding and high-temperature resistant material is applied to the surface of the roughened area of ​​the mask plate 1, the transparent soft glue is covered on the surface of the cured light-shielding and high-temperature resistant material. Since the cured light-shielding and high-temperature resistant material has a certain degree of brittleness, the transparent soft glue can have a certain protective effect on it, which can effectively prevent the surface of the mask plate 1 from being scratched. In addition, when in use, the side of the mask plate 1 coated with the transparent soft glue is in contact with the processing surface of the product to be processed. The transparent soft glue can play a buffering role and can overcome the situation where some products are deformed and the pressing is not tight, resulting in poor welding. Specifically, the transparent soft glue is preferably transparent soft silicone. In this embodiment, after the mask plate 1 is coated with the transparent soft glue, the graphic track 2 area protrudes from the roughened area by 0-0.1mm to ensure that the graphic track 2 area fits well with the processing surface of the product to be processed.

[0041] In one embodiment, the prepared mask plate 1 is horizontally installed on the laser processing equipment, with the roughened surface of the mask plate 1 facing downward, and its horizontal direction is limited, so it can only move in the vertical direction. A product conveyor line is arranged below the mask plate 1, and part of the conveyor line is located directly below the mask plate 1.

[0042] When the product to be processed moves along the product conveyor line to the bottom of the mask plate 1, the mask plate 1 is controlled to move vertically downward to the product to be processed, and the graphic track 2 of the mask plate 1 is aligned with the processing track of the product to be processed;

[0043] The line spot emitted by the laser performs line scanning processing on the mask plate 1 along the length direction perpendicular to the line spot. After the product processing is completed, the mask plate 1 moves vertically upward, and the processed product moves out of the processing area of ​​the laser along the product conveyor line. At the same time, the next product to be processed moves to the bottom of the mask plate 1.

[0044] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A laser mask processing method, characterized in that: The following steps are involved: The line width of the pattern track of the mask is preset according to the energy distribution of the line spot of the laser, and the line width at the strong energy portion of the line spot is smaller than that at the weak energy portion; Prepare a mask according to a preset mask pattern track; Placing the prepared mask plate on the product to be processed, with the pattern track of the mask plate aligned with the processing track of the product to be processed; The line spot emitted by the laser scans along the mask plate to process the product to be processed.

2. The laser mask processing method according to claim 1, wherein: The line light spot is divided into a weak energy segment and a strong energy segment according to the energy distribution of the line light spot; the mask plate is divided into a weak energy area and a strong energy area, wherein the weak energy area is the effective area of ​​the weak energy segment of the line light spot, and the strong energy area is the effective area of ​​the strong energy segment of the line light spot, and the line width of the graphic track located in the strong energy area is smaller than the line width of the graphic track located in the weak energy area.

3. The laser mask processing method according to claim 2, wherein: The line spot of the laser is shaped, and the shaped line spot has a strong energy segment and two weak energy segments, and the strong energy segment is located between the two weak energy segments.

4. The laser mask processing method according to claim 2, wherein: The energy of the line light spot increases smoothly from the weak energy segment to the strong energy segment, and the line width of the graphic track increases smoothly from the strong energy region to the weak energy region.

5. The laser mask processing method according to claim 1, wherein: The mask plate is laser-roughened according to a preset pattern track of the mask plate, and the non-roughened area of ​​the mask plate is the pattern track of the mask plate.

6. The laser mask processing method according to claim 5, wherein: A light-shielding and high-temperature-resistant material is applied to the roughened area of ​​the mask plate, and the light-shielding and high-temperature-resistant material is heated and cured.

7. The laser mask processing method according to claim 6, wherein: Transparent soft glue is applied on the cured surface of the light-shielding and high-temperature-resistant material and the pattern track of the mask plate.

8. The laser mask processing method according to claim 5, wherein: After the mask plate is roughened, the non-roughened area of ​​the mask plate protrudes from the roughened area by 1-2 mm.

9. The laser mask processing method according to claim 1, wherein: The prepared mask plate moves in the vertical direction. When the product to be processed moves horizontally to the position directly below the mask plate, the mask plate moves vertically downward onto the product to be processed, and the graphic track of the mask plate is aligned with the processing track of the product to be processed. After the line spot emitted by the laser scans along the mask plate to process the product to be processed, the mask plate moves vertically upward, and the processed product moves out of the processing area of ​​the laser.

10. The laser mask processing method according to claim 1, wherein: Points are taken along the length direction of the line spot, and the spot energy at each point of the line spot is detected by a beam quality analyzer. Based on the spot energy at each point, an energy distribution diagram of the entire line spot is prepared.

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