CN115846904A - Bessel beam cutting process for photovoltaic glass and application of Bessel beam cutting process - Google Patents

Abstract

The invention discloses a Bessel beam cutting process of photovoltaic glass and application thereof, wherein the Bessel beam cutting process comprises the following steps: s1, preprocessing photovoltaic glass to obtain preprocessed photovoltaic glass, wherein the photovoltaic glass comprises a glass substrate layer and a film layer, and the film layer comprises a transparent conducting layer, a window layer, an absorption layer, a back contact layer and a back electrode layer; s2, carrying out Bessel beam cutting on the pretreated photovoltaic glass to obtain cut photovoltaic glass; s3, splitting the cut photovoltaic glass. The photovoltaic glass cut by the method has the advantages of small edge breakage, low taper, no pollution, no loss and high yield of cut products.

Description

Bessel beam cutting process for photovoltaic glass and application of Bessel beam cutting process

Technical Field

The invention relates to the technical field of photovoltaic glass processing, in particular to a Bessel beam cutting process of photovoltaic glass and application thereof.

Background

Solar photovoltaic power generation is a green clean energy source and is rapidly developed in recent years. The photovoltaic glass is used as an important raw material necessary for manufacturing the solar photovoltaic cell module, and the production and manufacturing technology and the matched production and processing equipment thereof are continuously innovated and improved. The BIPV market prospect in the current photovoltaic application field is wide, wherein the demand of the film type power generation glass anisotropic assembly is increased day by day, the existing cutting process for the photovoltaic glass adopts a mechanical cutting and edging mode, and the mechanical cutting mode has the following defects:

1. the mechanical cutting of the glass substrate has large broken edge and rough edge, the size of the broken edge is larger than 100 mu m, and the mechanical cutting has great influence on the strength of glass, so that the glass yield is low and the material utilization rate is low.

2. The speed and precision of mechanical cutting for special-shaped cutting are greatly reduced, and some special-shaped cutting cannot be carried out due to too small rotation angle.

3. The dust amount that machinery + edging cutting photovoltaic glass produced is big, very easily causes the pollution of photovoltaic film chip face, and then influences the generating efficiency, and the different sex product concatenation piece is too big, and the subassembly piece is too big after the lamination influences product appearance.

4. The mechanical cutting speed is slow, the yield is low, and the maintenance cost of the generated mechanical consumables is high.

5. After cutting, complex edging treatment is required, water is required for cleaning, and a large amount of water source waste and pollution are generated.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a laser cutting process of photovoltaic glass and application thereof.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a bessel beam cutting process for photovoltaic glass, comprising the following steps:

s1, preprocessing photovoltaic glass to obtain preprocessed photovoltaic glass; the photovoltaic glass comprises a glass substrate layer and a film layer, wherein the film layer comprises a transparent conducting layer, a window layer, an absorption layer, a back contact layer and a back electrode layer;

s2, carrying out Bessel beam cutting on the pretreated photovoltaic glass to obtain cut photovoltaic glass;

s3, splitting the cut photovoltaic glass.

Optionally, the glass substrate layer comprises ultra-white glass; the transparent conductive layer comprises a TCO layer; the back electrode layer includes a metal back electrode layer.

Optionally, the thickness of the glass substrate layer is 2-4 mm. Furthermore, the thickness of the glass substrate layer is 2.5-3.2 mm.

Optionally, based on the thickness of the glass substrate layer, the focal depth of the Bessel beam cutting is 6mm, the width D of a surface included angle on the glass substrate layer is 250 μm, the cutting precision is within +/-20 μm, and the width of a single edge required to be cut is larger than or equal to 270 μm.

Optionally, the Bessel beam cutting uses an infrared picosecond laser, the laser wavelength is 1064nm, the pulse width is less than 15ps, the repetition frequency is 50-200KHz, and the maximum power is 80W.

Optionally, the bessel beam cutting has a spot spacing of 5 μm.

The pretreatment is membrane removal treatment or high-temperature flame-retardant cloth treatment.

The film removing treatment mainly removes a film layer on a glass substrate, the film removing width has important requirements in the film removing process, and the film removing width is more than or equal to 540 mu m based on the thickness of the glass substrate layer and the Bessel beam cutting parameters.

The film removing mode comprises mechanical film removing, laser film removing, sand blasting film removing and the like. Optionally, the mechanical film removing comprises a needle, a scraper, and the like. Optionally, the laser film removal is to output laser to a light receiving surface of the glass substrate layer. Furthermore, the laser wavelength is 1064nm when the film is removed by the laser, the pulse width is less than 30ns, the repetition frequency is 200-1000KHz, the average power is more than 300W, and the film removing speed is higher when the average power is higher.

Optionally, after the film is removed and before the laser cutting, the positioning camera is used for positioning to guide the laser cutting, so that the cutting track is ensured to fall on the clean film removing area completely.

When the pretreatment is film removal treatment, bessel beams are output on the film surface of the photovoltaic glass subjected to film removal in S2 for cutting.

The treatment process of the high-temperature flame-retardant cloth comprises the following steps: laying high-temperature flame-retardant cloth on the Bessel beam cutting jig, pressing by using a pressing block, and placing the photovoltaic glass, wherein one side of a film layer of the photovoltaic glass is in contact with the high-temperature flame-retardant cloth.

Optionally, the thickness of the high-temperature flame-retardant cloth is 0.2-0.5 mm.

Optionally, the high-temperature flame-retardant cloth can resist the temperature of-60 ℃ to +300 ℃.

Optionally, the high temperature flame retardant cloth is a teflon coated fiberglass cloth.

When the pretreatment is high-temperature flame-retardant cloth treatment, bessel beams output by the light receiving surface of the glass substrate layer are cut in S2.

The breaking of the invention comprises separating the cut photovoltaic glass using mechanical or thermal stress.

Optionally, the thermal stress cracking is cracking by using a carbon dioxide cracking laser, wherein the laser wavelength: 10.6 μm, repetition frequency of 0-200Khz, frequency of 2-400 μ s, and maximum power of 70-100W.

Optionally, the splitting head and the cutting head of the present invention are mounted on the same fixture. The splitting track can be guided to move again along the cutting track, so that the splitting track and the cutting track are guaranteed to be completely coincident.

In a second aspect, the invention provides the use of the bessel beam cutting process for the production of photovoltaic glass-like products.

Furthermore, the photovoltaic glass product is a thin film photovoltaic product with a glass substrate as a main component.

The invention has the beneficial effects that:

the photovoltaic glass is cut by Bessel light beams after pretreatment, laser is focused on the material interlayer, and longitudinal and transverse explosion points are formed in a hot melting mode, so that the molecular bond of the material is changed, the material can be cracked only by a splinter process, 0-taper cutting is realized, the control quantity of edge breakage is very good (generally less than 10 mu m), and meanwhile, the photovoltaic glass can be chamfered by laser cutting.

The pretreatment process of the invention is membrane removal treatment, a photovoltaic glass is usually provided with a membrane layer, the membrane layer comprises a transparent conducting layer, a window layer, an absorption layer, a back contact layer and a back electrode layer, and Bessel beam cutting has a cutting included angle and is only suitable for high-permeability glass, so the membrane layer on a glass substrate layer is removed and then cut by adopting the membrane removal treatment, and if the membrane is not removed, the membrane layer can block Bessel cutting from exciting picosecond laser and can not cut the photovoltaic glass. The product obtained after the film removing treatment of the invention has smooth cutting section, the edge breakage is less than 10 μm, the cutting taper is less than 1 degree, the roughness of the cutting surface is less than 1 degree, the edge splicing seam is less than 2mm, the invention is more beneficial to splicing and using of different products, and the spliced product has a bright edge of about 540 μm.

The thickness of the glass substrate layer is 2-4 mm, the focal depth of the Bessel cutting module is 6mm, the width D of a surface included angle on the substrate glass is 250 mu m, the cutting precision is within +/-20 mu m, and the width of a single side needing to be cut needs 270 mu m at least, so that the film removing width needs to be at least not less than 540 mu m, otherwise, laser can be blocked, and the cutting effect is influenced.

The pretreatment process can also be a high-temperature flame-retardant cloth treatment process, the specific electrical insulation of the high-temperature flame-retardant cloth can protect the electrical characteristics of the photovoltaic glass film layer, and simultaneously can protect a back electrode, the back electrode belongs to a metal layer, the wear resistance of the high-temperature flame-retardant cloth is perfectly suitable for the high-temperature flame-retardant cloth, the film surface is protected, and meanwhile, the high-temperature damage caused by laser can be blocked, so that the requirements of different products are met.

The thickness of the high-temperature flame-retardant cloth is 0.2-0.5mm, the photovoltaic glass cut and cracked under the thickness has no broken edge, no flash and no crack, the end surface is in a fine frosted state, the chip is safe, and the effect of the cut product is directly influenced when the thickness exceeds the range.

The Bezier beam cutting utilizes a high-power infrared picosecond laser, under the condition, the glass substrate layer can generate columnar distribution of the Bezier beam, and the laser is focused to form longitudinal and transverse explosion points.

The photovoltaic glass obtained by the cutting process has no broken edge, no flash, no crack, and fine and smooth frosted end surface, is suitable for industrial production of photovoltaic glass products, is very beneficial to splicing of anisotropic assemblies of thin film photovoltaic chips in the later process, and can well protect the film surface of the photovoltaic glass according to different requirements.

Drawings

FIG. 1 is a diagram illustrating the effect of the film removing process of the present invention;

FIG. 2 is a schematic view showing the determination of the film removal width according to the present invention;

FIG. 3 is a schematic diagram of Bessel beam cutting according to the present invention;

FIG. 4 is a graph showing the cutting effect of the Bessel beam cutting power of 80W and the dot pitch of 5 μm in example 1;

FIG. 5 is a schematic view of the mounting of the splitting head and cutting head;

FIG. 6 is a graph showing the cracking effect of example 1;

FIG. 7 is a graph of the effect of the photovoltaic glass obtained after splitting in example 1 under a 100 Xmicroscope;

FIG. 8 is a comparison of the photovoltaic glass of example 1 after breaking (left) and after mechanical cutting (right);

FIG. 9 is a graph showing the cutting effect of example 1 with a Bessel beam cutting power of 60W and a dot pitch of 5 μm;

FIG. 10 is a schematic view of laying the high-temperature flame-retardant cloth of example 4;

FIG. 11 is a graph of the effect of the photovoltaic glass obtained after splitting in example 4 under a 100 Xmicroscope;

FIG. 12 is a microscope image of the film side of the photovoltaic glass after rubbing on the high temperature flame retardant cloth for 5 minutes;

FIG. 13 is a 100 Xmicroscopic effect graph of photovoltaic glass after splitting in comparative example 1 and comparative example 2.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments in order to make those skilled in the art better understand the technical solutions of the present invention.

Example 1

The Bessel beam cutting process for the photovoltaic glass comprises the following steps:

s1, a film removing process:

and positioning the film removing jig, adsorbing by using vacuum negative pressure, fixing the photovoltaic glass on the surface of the jig, and removing the transparent conducting layer, the window layer, the absorption layer, the back contact layer, the back electrode layer and other film layers of the photovoltaic glass to obtain the film-removed photovoltaic glass.

Wherein, the film removing process specifically comprises the following steps: the laser beam is guided by a galvanometer type laser head to scan according to a specified track, and then the laser beam is focused by a field lens to a specified film layer position for reciprocating scanning processing, after the film layer of one region is removed, the laser head moves along the Y direction, the jig moves along the X direction, and then the next region is processed, the laser wavelength is 1064nm, the pulse width is less than 30ns, the repetition frequency is 200-1000KHz, the average power is more than 300W, and the effect is shown in figure 1. The film removal adopts the repeated scanning processing of a high-precision galvanometer, and the film removal is clean and controllable.

Film removing conditions are as follows: since the thickness of the glass substrate layer is 3.2mm, the focal depth of the cutting module using Bessel beam is 6mm, the width D of the included surface angle on the substrate glass is 250 μm, the cutting precision is within +/-20 μm, the width of the needed cutting of a single side is 270 μm at least, and therefore the film removing width is required to be at least not lower than 540 μm, as shown in FIG. 2.

In this embodiment, the width of the removed film is 600 μm (substantially, the same effect is obtained when the width of the removed film is larger than or equal to 540 μm, but not limited thereto).

S2, bessel beam cutting:

(1) Determining a cutting area: after the film is removed, the film removing jig is in butt joint with the cutting jig, the cutting jig is subjected to vacuum negative pressure adsorption after the film is in place, the photovoltaic glass after the film is removed is fixed on the surface of the cutting jig, the film surface faces upwards, then the photovoltaic glass after the film is removed is positioned under a cutting lobe positioning camera, the position where the film removing area starts and ends is captured by the camera, laser cutting is automatically guided by position information, and the cutting track is ensured to completely fall on the area where the film is removed completely. The camera positioning precision is +/-0.005 mm, the laser cutting position precision is +/-0.02 mm, the film removing processing precision is +/-0.15 mm, and the film removing width is more than or equal to 0.54mm, so that the cutting track can be ensured to fall in a film removing clean area completely, and the cutting precision is not influenced.

(2) Cutting: the cutting adopts Bessel beam cutting, and utilizes a high-power infrared picosecond laser, wherein the laser wavelength is 1064nm, the pulse width is less than 15ps, the repetition frequency is 50-200KHz, and the maximum power is 80W. The picosecond laser beam after optical shaping will penetrate the glass directly to form uniform micro-holes penetrating along the thickness direction, the cutting schematic diagram is shown in fig. 3, and the cutting effect diagram with the dot spacing of 5 μm is shown in fig. 4.

S3, a splitting procedure:

the splinters adopt a carbon dioxide laser with long wavelength, and the laser wavelength is as follows: 10.6 mu m, the repetition frequency of 0-200Khz, the frequency of 2-400 mu s and the maximum power of 70-100W. The irradiation on the cutting track can generate certain heat energy nearby the cutting track, so that the glass nearby the cutting line is heated and expanded, and further the glass is cracked along each through micropore, and the processing is finished.

The splitting head and the cutting head are arranged on the same fixing piece, and the splitting track can be guided to run again along the cutting track, so that the splitting track and the cutting track are completely heavy, and the splitting head and the cutting head are shown in fig. 5. The splinter effect is shown in FIG. 6.

The taper of the photovoltaic glass after the cutting and splitting of the embodiment is less than 1 degree, and the roughness of the cutting surface is as follows: ra is less than 1, the edge-breaking and corner-breaking is less than 10 mu m, the splicing seam is less than 2mm, and the effect picture under a microscope is shown in figure 7. Fig. 8 is a comparison graph of the photovoltaic glass (left) after the cutting and splitting of the embodiment and the photovoltaic glass (right) after the mechanical cutting in the prior art, and it can be seen that the photovoltaic glass after the cutting of the invention has small edge breakage, low taper, no flash and no crack.

Example 2

The process is the same as example 1 except that the thickness of the glass substrate layer in the film removing step of S1 is 2.5mm.

Example 3

The process is the same as example 1 except that in the cutting (2) in the S2 bessel beam cutting process, a cutting effect graph in which the maximum laser power is 60w and the dot pitch is 5 μm is shown in fig. 9.

Example 4

The Bessel beam cutting process for the photovoltaic glass comprises the following steps:

s1, a high-temperature flame-retardant cloth treatment process:

directly laying high-temperature flame-retardant cloth with the thickness of 0.2mm on a cutting jig platform, adjusting modules of the cutting jig according to cutting tracks, pressing the high-temperature flame-retardant cloth by utilizing a pressing block for each independently divided module, and reserving the cutting tracks, wherein the cutting jig can be divided into a plurality of rectangular blocks with the size of 300 multiplied by 300mm, and clearance grooves are formed in the rectangular blocks to avoid laser focuses, as shown in figure 10; and placing the photovoltaic glass on high-temperature flame-retardant cloth with the film surface facing downwards, wherein the thickness of the glass substrate layer of the photovoltaic glass is 3.2mm.

The special electrical insulating property of the high-temperature flame-retardant cloth can protect the electrical characteristics of the photovoltaic glass film layer, and meanwhile, the back electrode can also be protected, belongs to the metal layer, and the wear resistance of the high-temperature flame-retardant cloth is perfect, so that the high-temperature flame-retardant cloth is suitable for the high-temperature flame-retardant cloth, and the high-temperature damage caused by laser can be prevented while the film surface is protected.

S2, bessel beam cutting:

the film surface faces downwards, the light receiving surface of the substrate glass layer is directly cut, bessel beam cutting is adopted, a high-power infrared picosecond laser is used, the laser wavelength is 1064nm, the pulse width is less than 15ps, the repetition frequency is 50-200KHz, the maximum power is 80W, and the dot spacing is 5 micrometers. The picosecond laser beam after optical shaping can directly penetrate through the photovoltaic glass to form uniform micro-holes penetrating along the thickness direction.

S3, a splitting procedure:

the splinters adopt a carbon dioxide laser with long wavelength, and the laser wavelength is as follows: 10.6 μm, repetition frequency of 0-200Khz, frequency of 2-400 μ s, and maximum power of 70-100W. The irradiation on the cutting track can generate certain heat energy nearby the cutting track, so that the glass nearby the cutting line is heated and expanded, and further the glass is cracked along each through micropore, and the processing is finished.

The splitting head and the cutting head are arranged on the same fixing piece, and the splitting track can be guided to move again along the cutting track, so that the splitting track and the cutting track are guaranteed to be completely heavy.

Microscopic (100X) effect diagram of the photovoltaic glass after the cutting and splitting of the embodiment is shown in FIG. 11, and the thermal effect is 130-150 μm.

Example 5

The process is the same as example 4 except that the thickness of the high temperature flame retardant cloth is 0.5mm.

The film layer side of the photovoltaic glass is adsorbed on the high-temperature flame-retardant cloth of examples 4 and 5 to be rubbed for 5 minutes, and the effect under a microscope (100 ×) is shown in figure 12 (the laser scribing in the picture belongs to the conventional process scribing).

Example 6

The process is the same as example 4, except that the thickness of the glass substrate layer of the photovoltaic glass is 2.5mm.

Comparative example 1

The process is the same as example 4 except that the thickness of the high temperature flame retardant cloth is 1mm.

Comparative example 2

The process is the same as example 4 except that the thickness of the high temperature flame retardant cloth is 1.5mm.

The cutting and splintering effects of comparative examples 1 and 2 are shown in FIG. 13, the heat influence is more than 200 μm, while the heat influence is 130 to 150 μm when the thickness of the high temperature flame retardant cloth of the present invention is 0.2 to 0.5mm (see FIG. 11); the heat influence of more than 200 mu m can influence the generating efficiency and the safety performance of the photovoltaic chip (the heat influence can cause electrode short circuit), therefore, only under the thickness of the high-temperature flame-retardant cloth limited by the invention, the photovoltaic glass has no broken edge, no flash and no crack, the end surface is in a fine frosted state, the chip is safe, and the effect of the cut product is directly influenced when the thickness of the high-temperature flame-retardant cloth exceeds the limited range of the invention.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and these modifications and adaptations should be considered within the scope of the invention.

Claims (10)

1. The Bessel beam cutting process of the photovoltaic glass is characterized by comprising the following steps of:

s1, preprocessing photovoltaic glass to obtain preprocessed photovoltaic glass, wherein the photovoltaic glass comprises a glass substrate layer and a film layer, and the film layer comprises a transparent conducting layer, a window layer, an absorption layer, a back contact layer and a back electrode layer;

s2, carrying out Bessel beam cutting on the pretreated photovoltaic glass to obtain cut photovoltaic glass;

s3, splitting the cut photovoltaic glass.

2. The cutting process according to claim 1, wherein the glass substrate layer has a thickness of 2 to 4mm.

3. The cutting process according to claim 2, wherein the focal depth of Bessel beam cutting is 6mm, the width D of the included angle of the surface on the substrate glass layer is 250 μm, the cutting precision is within +/-20 μm, and the width of the single side required to be cut is larger than or equal to 270 μm.

4. The cutting process according to claim 3, wherein the pretreatment is a film removal treatment for removing the film layer, wherein the film removal width is more than or equal to 540 μm.

5. The cutting process according to claim 4, wherein the film removing treatment comprises mechanical film removing, laser film removing, sand blasting film removing.

6. The cutting process according to claim 1, wherein the pretreatment is a high temperature flame retardant cloth treatment, specifically: laying high-temperature flame-retardant cloth on the Bessel beam cutting jig, pressing by using a pressing block, and placing the photovoltaic glass, wherein one side of the film layer is in contact with the high-temperature flame-retardant cloth.

7. The cutting process according to claim 6, wherein the thickness of the high temperature flame retardant cloth is 0.2 to 0.5mm.

8. The cutting process according to claim 6, wherein in S2, the Bessel beam output from the light receiving surface of the glass substrate layer of the photovoltaic glass is cut.

9. The cutting process according to any one of claims 1 to 8, wherein the breaking comprises separating the cut photovoltaic glass using mechanical or thermal stress.

10. Use of a cutting process according to any one of claims 1 to 9 in the manufacture of a photovoltaic glass-like product.

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