WO2019061963A1

WO2019061963A1 - Cutting method employing laser

Info

Publication number: WO2019061963A1
Application number: PCT/CN2018/073501
Authority: WO
Inventors: 袁朝煜
Original assignee: 武汉华星光电半导体显示技术有限公司
Priority date: 2017-09-26
Filing date: 2018-01-19
Publication date: 2019-04-04
Also published as: CN107695533A; CN107695533B

Abstract

A cutting method employing a laser (11). Before a laser (11) has been used to perform a cutting operation, a heat absorption layer (20) is laid over a cutting path on a substrate to undergo a cutting operation, such that when the laser (11) cuts the substrate (10) along the cutting path on the substrate (10), the heat absorption layer (20) can partially absorb heat of the laser (11), thereby reducing a temperature gradient between a cut section and a non-cut section surrounding the cut section on the substrate (10) during cutting, reducing generation of heat stress and formation of defects, such as cracks, and providing a product of good quality.

Description

Laser cutting method

Technical field

The present invention relates to the field of display panel manufacturing technology, and in particular, to a laser cutting method.

Background technique

In the production process of the existing display panel, the whole mother board is usually cut to obtain a display panel of a suitable size. Among them, laser cutting is a common method. However, in the process of laser cutting, due to the high energy density of the laser, a large temperature gradient is generated between the cutting position and the non-cutting position around it, which causes thermal stress to be easily generated between the cutting position and the position nearby. Further, cracks are easily generated in the direction in which the temperature gradient is pressed. Especially for irregular cutting regions such as chamfers and perforations, irregular deformation is likely to occur, and concentration of thermal stress is easily generated, so that defects such as cracks are more likely to occur, thereby affecting the quality of the display panel product.

Summary of the invention

The invention provides a laser cutting method, which can avoid defects such as cracks during laser cutting, and obtain a product with better quality.

The laser cutting method provided by the invention comprises the steps of:

Covering the heat absorbing layer on the cutting track of the substrate to be cut;

Laser illuminating the heat absorbing layer and cutting the substrate to be cut along the cutting trajectory;

The heat absorbing layer on the substrate to be cut after the cutting is completed is removed.

The cutting track includes a regular track and an irregular track. The heat absorption layer covered on the regular track is a plurality of layers, and the heat absorption layer covered on the irregular track is at least one layer.

The number of layers of the heat absorption layer of the regular track is less than the number of layers of the heat absorption layer of the irregular track.

The irregular track includes a chamfer cutting track and a perforated cutting track; and the regular track includes a straight cutting track.

Wherein, the heat absorbing layer is covered on the cutting region of the substrate to be cut by any one of coating, sputtering or vapor deposition.

Wherein, the heat absorbing layer is UV photo-debonding.

Wherein, the "laser irradiation to the heat absorption layer and cutting the substrate to be cut along the cutting track" includes: the heat absorption layer is melted under the laser irradiation, and flows into the laser to cut the to-be-processed Cutting the substrate into the cutting gap.

Wherein, the heat absorbing layer on the substrate to be cut after cutting is completed by wiping or wind sweeping.

Wherein, the width of the heat absorbing layer covering the cutting track is larger than the spot diameter of the laser.

The substrate to be cut is an OLED panel or an LCD panel. The laser cutting method provided by the present invention covers a heat absorbing layer on a cutting track of the substrate to be cut before laser cutting, so that when the laser cuts the substrate to be cut along the cutting track, the suction The thermal layer can partially absorb the thermal energy of the laser, thereby reducing the temperature gradient of the cutting position on the substrate to be cut and the non-cutting position around the cutting surface during cutting, reducing the generation of thermal stress, thereby reducing defects such as cracks. , get better quality products.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a schematic flow chart of a laser cutting method according to an embodiment of the present invention;

2 is a schematic structural view of a substrate to be cut before cutting according to an embodiment of the present invention;

3 is a schematic cross-sectional view of a substrate to be cut before cutting according to an embodiment of the present invention;

4 is a schematic cross-sectional view showing a process of cutting a substrate to be cut according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Please participate in FIG. 1 , the present invention provides a laser cutting method, the laser cutting method comprising the steps of:

Step 110: Referring to FIG. 2 and FIG. 3 together, the heat absorption layer 20 is covered on the cutting track of the substrate 10 to be cut.

In the present invention, the substrate 10 to be cut is cut by laser cutting. The cutting includes cutting the substrate 10 to be cut to obtain a substrate of a suitable size, and further including chamfering, perforating, or the like of the substrate 10 to be cut to obtain a good appearance effect or satisfying certain use requirements. Substrate. Moreover, in order to obtain a substrate of a desired size or having a desired chamfer, perforation, etc., the substrate to be cut 10 has a predetermined cutting trajectory, and the laser 11 is cut along the cutting trajectory to obtain a desired A substrate having a size or having a desired chamfer, perforation, or the like. Specifically, the laser 11 can be cut along the cutting trajectory by fixing the trajectory of the laser head of the laser 11 by fixing the substrate 10 to be cut; or, the laser 11 can be fixedly generated. a laser head that cuts the laser light 11 along the cutting trajectory by preset a motion trajectory of the substrate 10 to be cut; or, by preset a motion trajectory of the substrate 10 to be cut and generates the laser 11 The trajectory of the laser head causes the laser 11 to move relative to the substrate 10 to be cut so that the laser 11 cuts along the cutting trajectory.

In the present invention, the substrate 10 to be cut may be an OLED panel, an AMOLED panel or an LCD panel, or an OLED substrate, an AMOLED substrate or an array substrate, a color film substrate, or the like, or other metal substrate, glass substrate, and flexible which need to be cut. Various types of substrates such as substrates. In this embodiment, the substrate to be cut 10 is a flexible OLED panel, and the substrate to be cut is cut by the laser 11 cutting method, so that the substrate after the cutting is completed meets the use requirements.

The heat absorbing layer 20 is a material having a strong heat absorbing ability. The heat absorbing layer 20 is covered on the cutting track of the substrate 10 to be cut, and the heat absorbing layer 20 can partially absorb and cut the material. The thermal energy of the laser light of the substrate 10 to be cut reduces the magnitude of the temperature gradient generated on the substrate 10 to be cut during cutting, and reduces the change of thermal stress, thereby reducing the occurrence of defects such as cracks, and obtaining a product of better quality. Referring to FIG. 4, preferably, the heat absorbing layer 20 can be converted from a solid state to a molten state under the irradiation of the laser light 11, so that the generated cutting gap can be flowed when the laser 11 cuts the substrate 10 to be cut. In the process of cutting the laser 11 from the surface of the substrate 10 to be cut to the inside of the substrate 10 to be cut, the heat absorbing layer 20 can always be located in the cutting of the substrate 10 to be cut. When the laser 11 is cut into the interior of the substrate 10 to be cut, the inside of the panel 10 to be cut can still be reduced, and cracks can be generated, thereby protecting the quality of the surface and the interior of the substrate 10 to be cut. Thereby, a substrate having a better quality is obtained. In this embodiment, the heat absorbing layer 20 is UV photo-debonded, and is coated on the cutting track by coating. The UV photo-decomposing gel has a strong heat-absorbing ability, and the heat-absorbing process loses viscosity and is in a molten state and has a certain fluidity. It can be understood that the heat absorbing layer 20 can also be other materials having strong heat absorbing ability, and the heat absorbing layer 20 covers the cutting trajectory according to the material of the heat absorbing layer 20. Different ways, for example, may also be sputtering or vapor deposition (including PVD, CVD, etc.); or, when the heat absorbing layer 20 is prefabricated into a sheet-like bonding material, the heat absorbing layer 20 may be directly attached. It is combined with the substrate 10 to be cut.

Moreover, the cutting track includes a regular track and an irregular track, and the heat absorption layer 20 includes a first heat absorption layer 21 and the second heat absorption layer 22. The heat absorbing layer 20 covered on the regular track is a first heat absorbing layer 21, and the heat absorbing layer 20 covered on the irregular track is a second heat absorbing layer 22. In this embodiment, the substrate 10 to be cut after the cutting is completed as a mobile phone display panel, and the cutting track of the substrate 10 to be cut includes a straight cutting track of three sides of the substrate 10 to be cut to meet the display panel of the mobile phone. The size requirement also includes the chamfering of the substrate 10 to be cut and the opening of the earpiece area and the camera area, so as to meet the requirements of the use, assembly requirements and appearance effects of the display panel of the mobile phone.

Specifically, the regular trajectory includes a straight cut trajectory or a curved straight cut trajectory with a large curvature. When the cutting track is a regular track, when the substrate 10 to be cut is cut along the cutting track, the deformation of each position of the cutting track is small, so that the stress concentration is small, and therefore, the cutting track is a regular track. When there are fewer defects. Therefore, in the position where the cutting track is a regular track, the thickness of the heat absorbing layer 20 can be made thinner, that is, the thickness of the first heat absorbing layer 21 can be thinner, and the substrate 10 to be cut is ensured. In the case where the defects of the cutting position are small, the thickness of the heat absorbing layer 20 is reduced as much as possible, thereby saving resources and reducing production costs. In this embodiment, the straight cut track belongs to a regular track, and the first heat absorption layer 21 is covered thereon.

The irregular trajectory includes a chamfered cutting trajectory, a perforated cutting trajectory, or various varying shapes of cutting trajectories such as zigzag, wavy, and the like. When the cutting trajectory is an irregular trajectory, the deformation of each position of the cutting trajectory when the substrate 10 to be cut is cut is large, so that the stress is easily concentrated and defects are easily generated. Therefore, at a position where the cutting track is an irregular track, the thickness of the heat absorbing layer 20 needs to be thicker than when the cutting track is a regular track, so as to ensure that the deformation of each position of the cutting track can be reduced. Reduce the occurrence of such defects. In this embodiment, the thickness of the second heat absorbing layer 22 is greater than the thickness of the first heat absorbing layer 21, so that the heat absorbing layer is minimized while ensuring that the defect at the cutting track can be reduced. The use of 20 endothermic materials saves resources and reduces production costs. Moreover, depending on the thickness of the substrate 10 to be cut, the thickness of the heat absorbing layer 20 is also different, thereby reducing the defects generated by the laser cutting position and reducing the heat absorbing material of the heat absorbing layer 20. Use, save resources and reduce production costs. When the thickness of the substrate 10 to be cut is thin, the thickness of the heat absorbing layer 20 may be thin; when the thickness of the substrate 10 to be cut is thick, the thickness of the heat absorbing layer 20 is relatively thick. In this embodiment, the heat absorbing layer 20 is formed on the substrate to be cut by coating one by one by coating, and the heat absorbing is controlled by controlling the number of layers to be coated. The thickness of layer 20. The heat absorbing layer 20 covered on the regular track is a plurality of layers, and the heat absorbing layer covered on the irregular track is at least one layer. In this embodiment, the number of layers of the heat absorbing layer 20 of the regular trajectory is less than the number of layers of the heat absorbing layer 20 of the irregular trajectory, so that the thickness of the first heat absorbing layer 21 is smaller than The thickness of the second heat absorption layer 22 is described. In this embodiment, the chamfering and the cutting track of the opening of the earpiece area and the camera area belong to the irregular track, and the second heat absorbing layer 22 is covered thereon.

When the laser 11 is irradiated onto the substrate 10 to be cut, a spot is generated, and the substrate 10 to be cut in the region irradiated by the laser 11 is vaporized due to an increase in temperature, thereby completing the cutting to be performed. Cutting of the substrate 10. In the present invention, the width of the heat absorbing layer 20 covering the cutting trajectory is larger than the spot diameter of the laser light 11, so that the position of the spot irradiation of the laser light 11 is covered by the heat absorbing layer 20, The heat of each spot of the spot of the laser light 11 is partially absorbed by the heat absorbing layer 20, avoiding a large temperature gradient between the cutting position irradiated by the spot and the non-cutting position around the spot, thereby reducing the cutting position and The concentration of stress between the surrounding non-cutting locations reduces the occurrence of defects on the substrate 10 to be cut. The width direction of the heat absorbing layer 20 is perpendicular to the extending direction of the heat absorbing layer 20 and parallel to the plane of the substrate 10 to be cut.

Step 120, referring to FIG. 4, laser light is irradiated to the heat absorption layer 20 and the substrate to be cut 10 is cut along the cutting track.

The laser 11 cuts the substrate 10 to be cut along the cutting trajectory, and at this time, the laser 11 is first irradiated onto the heat absorbing layer 20 covering the cutting trajectory. The heat absorbing layer 20 absorbs part of the thermal energy of the laser light 11 to be melted into a fluid, and flows into the cutting slit generated by the laser 11 to cut the substrate 10 to be cut. That is, the heat absorbing material of the heat absorbing layer 20 is always located at the cutting position of the substrate 10 to be cut, absorbs part of the heat energy of the laser light irradiated at the position, and reduces the temperature gradient generated by the laser irradiation, thereby reducing the heat treatment. The unevenness of the thermal stress on the surface and the inside of the cutting position of the substrate 10 is cut, thereby reducing defects such as cracks which may occur on the surface and the inside of the cutting position of the substrate 10 to be cut.

Step 130, removing the heat absorbing layer 20 on the substrate 10 to be cut after the cutting is completed.

After the cutting of the substrate 10 to be cut is completed, the heat absorbing layer 20 on the substrate 10 to be cut after the cutting is completed. This ensures that the substrate is cleaned for the next step. In this embodiment, the heat absorbing layer 20 absorbs the heat energy of the laser light 11 and melts into a liquid state. Therefore, the heat absorbing layer 20 can be removed by wiping or sweeping by a sweeper, and can be removed. The heat absorbing layer 20 is recycled and recycled, thereby saving resources and reducing production costs. It can be understood that when the heat absorbing layer 20 is other heat absorbing materials, the removing manner is that other operations such as cleaning or tearing may be selected according to the difference of the heat absorbing layer 20.

The laser 11 cutting method provided by the present invention covers the heat absorbing layer 20 on the cutting track of the substrate to be cut before the laser cutting, so that the laser cuts the substrate to be cut along the cutting track. At the same time, the heat absorbing layer 20 can partially absorb the thermal energy of the laser light 11, thereby reducing the magnitude of the temperature gradient at the cutting position of the tape cutting substrate 10 and the non-cutting position around the cutting substrate 10, and reducing the thermal stress. Produced, thereby reducing the occurrence of defects such as cracks, resulting in a better quality product.

The above disclosure is only a preferred embodiment of the present invention, and of course, the scope of the present invention is not limited thereto, and those skilled in the art can understand all or part of the process of implementing the above embodiments, and according to the present invention. The equivalent changes required are still within the scope of the invention.

Claims

A laser cutting method, comprising the steps of:

Covering the heat absorbing layer on the cutting track of the substrate to be cut;

Laser illuminating the heat absorbing layer and cutting the substrate to be cut along the cutting trajectory;

The heat absorbing layer on the substrate to be cut after the cutting is completed is removed.
The laser cutting method according to claim 1, wherein the cutting trajectory comprises a regular trajectory and an irregular trajectory, and the heat absorbing layer covered on the regular trajectory is a plurality of layers, and the irregular trajectory covers the The heat absorbing layer is at least one layer.
The laser cutting method according to claim 2, wherein the number of layers of the heat absorbing layer covered on the regular trajectory is smaller than the number of layers of the heat absorbing layer covered on the irregular trajectory.
The laser cutting method according to claim 3, wherein the irregular trajectory comprises a chamfer cutting trajectory, a perforated cutting trajectory; and the regular trajectory comprises a straight cutting trajectory.
The laser cutting method according to claim 1, wherein the heat absorbing layer is covered on a cutting trajectory of the substrate to be cut by any one of lamination, coating, sputtering, or vapor deposition.
The laser cutting method according to claim 1, wherein the heat absorbing layer is UV photo-debonding.
The laser cutting method according to claim 6, wherein said "laser irradiation to said heat absorbing layer and cutting said substrate to be cut along said cutting trajectory" comprises: said heat absorbing layer being irradiated by said laser light Melting and flowing into the cutting slit created by the laser cutting the substrate to be cut.
The laser cutting method according to claim 1, wherein the heat absorbing layer on the substrate to be cut after the cutting is completed by wiping or wind sweeping.
The laser cutting method according to claim 1, wherein a width of said heat absorbing layer covering said cutting trajectory is larger than a spot diameter of said laser light.
The laser cutting method according to claim 1, wherein the substrate to be cut is an OLED panel or an LCD panel.