CN110877160A - A kind of quartz glass laser three-dimensional cutting material removal method and equipment - Google Patents

Abstract

The invention discloses a quartz glass laser three-dimensional cutting and material removing method and equipment, and belongs to the field of quartz glass laser cutting and material removing. The method adopts nanosecond laser to cut quartz glass from the upper surface to the lower surface, the cutting laser frequency is 30 kHz-60 kHz, and the descending height of a processing path in each processing is less than 0.04 mm; the cutting track is a spiral line track, specifically, a laser spot advances along a spiral line on a processing path, the width of the spiral line is 0.4-0.8 mm, the overlapping rate is 55-80%, and the cutting speed is 100-380 mm/s. The invention skillfully changes the laser cutting direction, subverts the traditional cognition of the transparent material cutting direction from bottom to top, realizes the high-efficiency laser cutting of the quartz glass with larger thickness by combining with the process improvement, has the processing thickness of more than 1mm, simultaneously reduces the use of post-treatment processes such as grinding and polishing and the like, and saves the processing cost.

Description

A kind of quartz glass laser three-dimensional cutting material removal method and equipment

technical field

The invention belongs to the field of quartz glass laser cutting material removal, and more particularly relates to a quartz glass laser three-dimensional cutting material removal method and equipment.

Background technique

Quartz glass is widely used in daily life and scientific research, and occupies an important and even dominant position in semiconductors, medical equipment, optical instruments and other fields. The performance of quartz glass is very good, its linear expansion coefficient is one tenth to one twentieth of ordinary glass, it can withstand high temperature of 1200 ° C, and the light transmittance can reach 93%.

However, in the context of the extensive use of quartz glass, it is a relatively inefficient method of mechanical cutting and polishing. In the context of increasingly thin quartz glass, traditional machining is difficult to meet the processing requirements. In recent years, laser processing has become a hot spot, and laser processing has entered the field of glass laser processing due to its advantages of non-contact, no micro-cracks on the edge, and no need for subsequent cleaning and grinding. And laser processing is faster and more efficient.

The principle of laser glass processing is to focus the laser on the surface of the processed glass, heat the surface of the glass, cause a large thermal compression stress on the surface, control the pressure so that it is not enough to break the glass, and then rapidly cool the area, A large temperature gradient and tensile stress are generated there, and then under the action of the tensile stress, the glass begins to break in a predetermined direction to achieve processing.

But for quartz glass, the introduction of laser processing is not as easy as float glass and rolled glass. Quartz glass has a higher melting point and is much more brittle than the glass that has been used in the field. It is easy to produce micro-cracks and edge chipping during processing. Therefore, the common processing method of quartz glass is mechanical processing, and computer digital control precision mechanical processing is usually used for the processing of quartz glass with a higher degree of fineness. However, this processing method is still difficult to solve the generation of micro-cracks during processing, and problems such as edge chipping are prone to occur. Therefore, in the subsequent processing process, processes such as polishing and grinding are also required to meet the production requirements, which relatively reduces the processing efficiency.

There are a small number of laser processing quartz glass processes, usually using femtosecond or picosecond lasers. This is because picosecond and femtosecond lasers have a smaller spot and a smaller heat-affected zone than nanosecond lasers, and are relatively less likely to produce microseconds. Cracks and chipping. However, on the one hand, the cost of picosecond and femtosecond lasers is much higher than that of nanosecond lasers. In industrial production, the cost needs to be reduced as much as possible; In the case of second and femtosecond lasers, the processing thickness can basically only be controlled below 0.3mm, and it is easy to produce edge chipping, and even directly cause the quartz glass to burst.

Therefore, how to improve the thickness and process quality of quartz glass laser processing, while reducing the processing cost, is called an urgent problem to be solved at present.

SUMMARY OF THE INVENTION

In view of the above defects or improvement requirements of the prior art, the present invention provides a method and equipment for 3D cutting of quartz glass by nanosecond laser, the purpose of which is to realize the thickness of quartz glass above 0.5mm through the improvement of processing direction and processing technology. The nanosecond non-destructive laser cutting can solve the technical problems that the quartz glass thickness is greater than 0.5mm in the prior art, which is prone to chipping or even bursting, and the process cost is high.

In order to achieve the above object, according to one aspect of the present invention, a method for three-dimensional laser cutting and removing of quartz glass is provided. Nanosecond laser is used to cut the quartz glass from the upper surface to the lower surface. The cutting laser frequency is 30 kHz to 60 kHz. The drop height of the secondary processing is less than 0.04mm; the cutting trajectory is a spiral trajectory. Specifically, the laser spot advances along the spiral line on the processing path, the spiral line width is 0.4mm ~ 0.8mm, the overlap rate is 55% ~ 80%, and the cutting speed It is 100mm/s～380mm/s.

Further, the descending method of the processing path is spiral descending; or, the processing path is equidistant concentric cutting lines descending layer by layer, and the distance between adjacent concentric cutting lines on the same layer is less than 0.05 mm.

Further, the nanosecond laser is green light.

According to another aspect of the present invention, a method for three-dimensional laser cutting and removing of quartz glass is provided. Nanosecond laser is used to cut quartz glass from the upper surface to the lower surface. The cutting laser frequency is 30 kHz to 60 kHz. Less than 0.04mm; the processing path is a concentric cutting line. Specifically, several equidistant concentric cutting lines are filled in the area to be cut, the distance between adjacent concentric cutting lines is less than 0.05mm, and the cutting speed is 3000mm/s～5000mm/s.

Further, the descending method of each process is descending layer by layer, wherein the equidistant concentric cutting lines of each layer are on the same plane, and the plane descends successively according to the preset descending height, so that the cutting lines between layers do not intersect.

Further, the shape of the concentric cutting lines is the same as the contour of the area to be cut.

Further, the area to be cut is a circle, and the concentric cutting lines are concentric circles.

Further, the nanosecond laser is green light.

According to another aspect of the present invention, a method for laser three-dimensional cutting and removing of quartz glass is provided, which replaces the nanosecond laser in the method for three-dimensional laser cutting of quartz glass as described in any preceding item with femtosecond or picosecond. laser.

According to another aspect of the present invention, there is provided a device for realizing the method for three-dimensional laser cutting of quartz glass as described in any preceding item.

In general, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

1. The invention subtly changes the laser cutting direction, subverts the traditional understanding that the cutting direction of transparent materials needs to be from bottom to top, and combines with process improvement to achieve high-efficiency laser cutting of quartz glass with a larger thickness, and the processing thickness can reach more than 1mm . Compared with processing quartz glass using femtosecond and picosecond, the processing direction and processing technology selected by the present invention can use nanosecond green light processing to obtain quartz glass holes with good edge quality, which greatly reduces the cost. For ultra-high precision processing requirements, It can also be used for femtosecond and picosecond processing. Since the yield is greatly improved, it can also save costs.

2. In order to facilitate dust removal, the traditional laser processing glass equipment adopts the method of processing from the bottom to the top, so that the glass powder does not interfere with the laser path during the process of falling off. The present invention subtly solves the problem of laser processing quartz glass by changing the processing direction. The problems of edge chipping and explosion in the process have realized the high-quality laser processing of quartz glass. After testing, in the case of no dust removal treatment, using the processing direction and process parameters of the present invention, the roughness Rz of the 1mm quartz glass plate processed by nanosecond laser is generally stable below 40μm, and the roughness Ra is stable at 3.1μm～ 3.9μm, the maximum does not exceed 5μm.

3. After the quartz glass is laser-processed by the solution of the present invention, subsequent processes such as polishing and grinding are no longer required, which greatly shortens the production line, reduces the use of manpower, improves the production efficiency, and reduces the production cost.

Description of drawings

1 is a comparison diagram of the processing direction, processing path and the prior art in Embodiment 1 of the present invention, wherein a is a schematic diagram of the cutting direction from top to bottom of the present invention, and b is a schematic diagram of the cutting direction from bottom to top of the prior art, c is the processing path, and this embodiment is the spiral descending path;

Fig. 2 and Fig. 3 are the schematic diagrams of the helical cutting trajectory of two different overlapping ratios;

Figure 4 is a schematic diagram of the machining path fitting of the helical cutting trajectory, where c is the machining path; d is the actual trajectory of the laser spot, which is the helical cutting trajectory; w is the width of the helix, L is the pitch of the helix, and l is the Overlap width; the machining path c is coplanar with the helical cutting path d;

Fig. 5 is the finished product figure of 1mm thick quartz glass obtained by cutting by the method of the present invention;

Fig. 6 is the finished product figure of 1mm thick quartz glass obtained by cutting by traditional method;

(a) to (d) in Fig. 7 are schematic representations of four different concentric cutting paths, in which the solid line is the outline of the area to be processed, and the dashed line is the concentric cutting path; the rectangular solid line in the outermost circle of Fig. 7 is the quartz glass outline.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

The present invention adopts the method of cutting quartz glass from the upper surface to the lower surface. The laser processing path includes two kinds of helical line cutting and concentric path cutting. It refers to filling several equidistant concentric cutting lines within the contour range of the area to be cut, and both of the process parameters of the present invention can be used.

There are also two ways to change the height of each drop: the first is spiral drop, as shown in Figure 1, the way of arrow a + processing path c. Since the spiral drop cutting is a continuous cutting in the whole process, the drop height is actually the processing path c. The second is the layer-by-layer cutting method, that is, the cutting line of each layer is on the same plane, and the plane drops a certain descending height (that is, the descending height for each processing) along the thickness direction of the quartz glass plate. There is no intersection between the cutting tracks of each layer, and the process parameters of the present invention can be used in both ways.

The range of process parameters is as follows: the cutting frequency is 30kHz to 60kHz, the laser pulse width is 1μm to 5μm, and the drop height is less than 0.04mm for each processing. As shown in Figures 2 to 4, the helical line cutting also includes: the helical line width w is 0.4mm-0.8mm, the overlap ratio l/L is 55%-80%, and the cutting speed is 100mm/s-380mm/s. The concentric track cutting also includes: the distance between adjacent concentric tracks is less than 0.05mm, and the cutting speed is 3000mm/s～5000mm/s. The above process parameters are compatible with nanosecond, femtosecond and picosecond processing.

In the present invention, the processing path c is a virtual path in the process of helical line cutting and concentric trajectory cutting, which does not exist in fact. The present invention provides the processing path c just to express the overall movement trend of the laser spot. The cutting speed is Refers to the forward speed of the machining path c rather than the speed of the spot movement. For concentric trajectory cutting, the processing path c just coincides with the cutting trajectory of the laser spot (ie, the concentric cutting line), and the cutting speed is the same as the spot moving speed; for helical cutting, the forward speed of the processing path c is lower than the spot moving speed. As shown in Figure 4, the spiral cutting line d is the actual cutting track of the laser spot, and the processing path c is coplanar with the spiral cutting line d. The virtual path fitted by the points represents the overall movement trend of the laser spot.

The present invention will be described in detail below with reference to accompanying drawings 1 to 7 , with several more specific embodiments.

[Example 1]

In this embodiment, a green laser with a rated power of 40w and a wavelength of 532nm is used as an example, and quartz glass with a thickness of 1mm is used as the processing material. The processing direction is shown by the arrow a in Figure 1, and the processing path is shown in the processing path c in Figure 1. The spiral cutting method is adopted. The cutting speed is 200mm/s, the frequency is 53kHz, the pulse width is 5μs, and the helix width is 0.5mm. , the overlap rate is 70%, and the 1mm thickness quartz glass can be cut by 0.025mm at a time without chipping and micro-cracks. As shown in the four horizontal holes in Figure 5, the edge roughness Ra and Rz as follows:

Table 1

hole location horizontal left 1 horizontal left 2 horizontal left 3 horizontal left 4 Rz/μm 28.5 25.7 31.0 27.1 Ra/μm 3.1 3.6 3.8 3.7

[Example 2]

The difference between this embodiment and Embodiment 1 is that the cutting speed is 100mm/s, the finished product is shown in the first round hole on the upper right side of Figure 5, Rz=24.5μm, Ra=3.4μm.

[Example 3]

The difference between this embodiment and Embodiment 1 is that the cutting speed is 380mm/s, and the finished product is shown in the first round hole on the upper right side of Figure 5, Rz=30.6μm, Ra=4.3μm.

[Example 4]

This embodiment uses exactly the same samples, lasers and process parameters as Embodiment 1, and the difference lies in the different processing paths and descending methods. As shown by the dotted line in (a) of FIG. 7 , the machining path in this embodiment is a concentric circle cutting line, which can be understood as the machining path c in FIG. 4 forms a circle. Since the circle is a closed figure and cannot be spirally descended like the first embodiment, the descending method in this embodiment is to descend layer by layer, that is, after each layer is processed, it is lowered once, and the distance between the cutting lines of concentric circles on the same layer is 0.05mm. Cut down layer by layer through the concentric circular cutting line. Each layer is cut, and a layer of annular grooves will be formed until the last layer is processed. The finished product is shown in the third circular hole from top to bottom on the right side of Figure 5, Rz=33.5μm, Ra=4.2μm.

[Example 5]

The difference between this embodiment and Embodiment 4 is that the processing path is also a concentric circular cutting line, the difference is that the concentric trajectory cutting method is adopted. For direct cutting, the process parameters are as follows: the cutting frequency is 60kHz, the drop height for each processing is 0.035mm, the distance between adjacent concentric tracks is 0.03mm, the cutting speed is 5000mm/s, and the pulse width is 5μs. After processing, Rz=26.7 μm, Ra=3.4 μm.

[Example 6]

As shown in (b) of FIG. 7 , both the present embodiment and the fourth embodiment adopt the processing method of concentric cutting line processing path + helical cutting + layer-by-layer descending, and the difference has two aspects: on the one hand, the shape of the area to be processed is And the shape of the processing path is different, this embodiment is a rectangle; on the other hand, the cutting speed of this embodiment is 300mm/s, the frequency is 57kHz, the pulse width is 3μs, the helix width is 0.7mm, the overlap rate is 60%, Each processing drops 0.03mm. After processing, Rz=32.1 μm, Ra=3.7 μm.

[Example 7]

As shown in (c) of FIG. 7 , both the present embodiment and the fifth embodiment adopt the processing method of concentric cutting line processing path + concentric trajectory cutting + layer-by-layer descending, and the difference has two aspects: on the one hand, the shape of the area to be processed is And the shape of the processing path is different, this embodiment is a concave shape; on the other hand, the cutting frequency of this embodiment is 55kHz, the drop height of each processing is 0.03mm, the distance between adjacent concentric tracks is 0.03mm, and the cutting speed is 4000mm/s, The pulse width is 2 μs. After processing, Rz=27.2 μm, Ra=3.7 μm.

[Example 8]

As shown in (d) of FIG. 7 , the difference between this embodiment and Embodiment 7 is: on the one hand, the shape of the area to be processed and the shape of the processing path are different, and this embodiment is a convex shape; The cutting frequency is 35kHz, the drop height is 0.015mm per processing, the spacing between adjacent concentric tracks is 0.02mm, the cutting speed is 3500mm/s, and the pulse width is 1μs. After processing, Rz=23.5 μm, Ra=3.5 μm.

Examples 1 to 8 were all processed without dust removal treatment. After testing, using the processing direction and process parameters of the present invention, without dust removal treatment, the overall roughness Rz was stable below 30 μm , the roughness Ra is stable at 3.1μm ~ 3.9μm, the maximum does not exceed 5μm. If conventional dust removal measures are added, such as vacuum cleaner dust removal, or picosecond or femtosecond laser processing is used, the processing accuracy can be further greatly improved.

【Comparative ratio】

On the basis of maintaining the same process parameters as in Example 1 to Example 5, only the processing direction was changed from bottom to top, and the finished product obtained by processing round holes on a 1mm quartz glass plate is shown in Figure 6, and there are different degrees of Although there is no obvious chipping and cracking in the small hole in the middle on the far left, there are obvious burrs and saw teeth.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (10)

1. a quartz glass laser three-dimensional cutting material removal method, is characterized in that, adopts nanosecond laser to cut quartz glass from upper surface to lower surface, and the cutting laser frequency is 30kHz～60kHz, and the processing path is less than 0.04mm at each processing drop height; The cutting trajectory is a spiral trajectory. Specifically, the laser spot advances along a spiral line on the processing path. The spiral line width is 0.4mm~0.8mm, the overlap rate is 55%~80%, and the cutting speed is 100mm/s~380mm/s . 2. A kind of quartz glass laser three-dimensional cutting material removal method as claimed in claim 1, it is characterized in that, the descending mode of the processing path is spiral descending; The spacing between adjacent concentric cutting lines is less than 0.05mm. 3 . The method for three-dimensional laser cutting of quartz glass according to claim 1 or 2 , wherein the nanosecond laser is green light. 4 . 4. A quartz glass laser three-dimensional cutting material removal method, characterized in that a nanosecond laser is used to cut the quartz glass from the upper surface to the lower surface, the cutting laser frequency is 30 kHz to 60 kHz, and the processing path is less than 0.04mm in height for each processing; The processing path is a concentric cutting line. Specifically, a number of equidistant concentric cutting lines are filled in the area to be cut, the distance between adjacent concentric cutting lines is less than 0.05mm, and the cutting speed is 3000mm/s～5000mm/s. 5. A kind of quartz glass laser three-dimensional cutting material removal method as claimed in claim 4, it is characterized in that, each time processing descending way is descending layer by layer, wherein, the equidistant concentric cutting line of each layer is on the same plane, the The plane descends successively according to the preset descending height, so that the cutting lines between layers do not intersect. 6 . The method for three-dimensional laser cutting of quartz glass according to claim 4 , wherein the shape of the concentric cutting lines is the same as the contour of the area to be cut. 7 . 7 . The method according to claim 6 , wherein the area to be cut is circular, and the concentric cutting lines are concentric circles. 8 . 8 . The method for three-dimensional laser cutting of quartz glass according to claim 4 , wherein the nanosecond laser is green light. 9 . 9. A method for removing materials by laser three-dimensional cutting of quartz glass, characterized in that the nanosecond laser in the method for three-dimensional laser cutting of quartz glass according to any one of claims 1 to 8 is replaced by a femtosecond or picosecond laser . 10. A device for realizing the method for material removal by laser three-dimensional cutting of quartz glass according to any one of claims 1 to 9.

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