Laser etching method, laser etching equipment and display panel

Abstract

The invention discloses a laser etching method, laser etching equipment and a display panel, and the method comprises the steps: forming a conductive material layer on a substrate; placing the substrate base plate in a liquid medium; and performing laser etching on the conductive material layer in the liquid medium to form wires. The conductive material layer on a certain surface of the substrate is subjected to laser etching in the liquid medium to form the wire, so that the divergence angle of the laser in the substrate can be expanded, and the laser beam can be diverged to the degree that the energy is lower than the damage threshold value of the film layer on the other side of the substrate under the short optical path; therefore, the thickness of the substrate can be reduced, etching residues can be reduced, and the reliability of the display panel can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical processing, and particularly relates to a laser etching method, a laser etching device and a display panel. Background Art

[0002] At present, due to the limitation of the yield of mass transfer, large-size mini light-emitting diode (Mini LED) display devices cannot be manufactured in one go. Therefore, a large-size display is usually achieved by splicing small-size display panels. The splicing of small-size display panels is realized through a connection lead technology. The wiring on the display surface of the display panel bypasses to the non-display surface through the side. Common connection lead processes include printing process, punching process, sputtering process, exposure process, etc. Among them, the sputtering process forms connection leads by laser etching after plating a conductive material layer on a substrate. However, when etching the wiring on the non-display surface, if the energy density of the laser exceeds the damage threshold of the display film layer after passing through the substrate, etching damage will be caused. Therefore, the thickness of the substrate needs to be set relatively large, which is not conducive to the thinning of display products. Summary of the Invention

[0003] The present invention provides a laser etching method, a laser etching device and a display panel. The laser etching method etches a conductive material layer on a substrate in a liquid medium, which can avoid damaging the front film layer when etching the wiring on the back of the substrate. The laser etching device can provide a liquid processing environment, and the display panel manufactured by the above laser etching method can have a smaller thickness and lower etching residues.

[0004] In a first aspect of the present invention, a laser etching method is provided, and the laser etching method includes:

[0005] Forming a conductive material layer on a substrate;

[0006] Placing the substrate in a liquid medium;

[0007] Laser etching the conductive material layer in the liquid medium to form a wiring.

[0008] In some embodiments of the present invention, the substrate includes a first surface and a second surface opposite to each other, and a third surface connecting the first surface and the second surface. Among them, the first surface is used to arrange driving circuits and light-emitting devices;

[0009] The laser etching the conductive material layer in the liquid medium to form a wiring includes:

[0010] Laser etching the conductive material layer on the second surface in the liquid medium.

[0011] In some embodiments of the present invention, before placing the substrate on the liquid medium, the laser etching method further includes:

[0012] Laser etching the conductive material layer on the first surface;

[0013] Laser etching the conductive material layer on the third surface.

[0014] In some embodiments of the present invention, the laser etching method further includes:

[0015] Performing a drying treatment on the etched substrate.

[0016] In some embodiments of the present invention, the liquid medium includes water or silicone oil.

[0017] In some embodiments of the present invention, the thickness of the substrate is 0.3 mm to 0.4 mm.

[0018] In some embodiments of the present invention, the power of the laser is 0.5 W to 0.9 W.

[0019] In some embodiments of the present invention, the temperature of the liquid medium is 20°C to 25°C.

[0020] The second aspect of the present invention provides a laser etching device, which includes:

[0021] A laser;

[0022] An optical mirror group located on the light output side of the laser;

[0023] A processing platform located on the light output side of the optical mirror group; the processing platform includes a water container for containing a liquid medium.

[0024] In some embodiments of the present invention, the water container further includes a water inlet and a water outlet;

[0025] The laser etching device further includes:

[0026] A circulating filtration device connected to the water inlet and the water outlet.

[0027] In some embodiments of the present invention, the laser etching device further includes:

[0028] A drying device for drying the etched substrate.

[0029] In some embodiments of the present invention, the etching accuracy of the laser etching device is ±15 μm.

[0030] The third aspect of the present invention provides a display panel, which is made by any of the above laser etching methods, or the display panel is made by any of the above laser etching devices.

[0031] The beneficial effects of the present invention are as follows:

[0032] The present invention provides a laser etching method, a laser etching device and a display panel. Among them, the laser etching method includes: forming a conductive material layer on a substrate; placing the substrate in a liquid medium; and laser etching the conductive material layer in the liquid medium to form a trace. Laser etching the conductive material layer on a certain surface of the substrate in the liquid medium to form a trace can expand the divergence angle of the laser in the substrate, so that the laser beam can diverge to a degree where the energy is lower than the damage threshold of the film layer on the other side of the substrate within a shorter optical path, which is beneficial to reducing the thickness of the substrate. At the same time, it can also reduce etching residues and improve the reliability of the display panel. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments of the present invention. Obviously, the following introduced drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0034] Figure 1 It is a schematic flowchart of the laser etching method provided by the embodiment of the present invention;

[0035] Figure 2 It is a schematic structural diagram of the substrate after completing step S1 provided by the embodiment of the present invention;

[0036] Figure 3 It is one of the schematic principle diagrams of the laser etching method provided by the embodiment of the present invention;

[0037] Figure 4 It is another schematic principle diagram of the laser etching method provided by the embodiment of the present invention;

[0038] Figure 5 It is a schematic structural diagram of the splicing display device provided by the embodiment of the present invention;

[0039] Figure 6 It is a schematic structural diagram of the display device provided by the embodiment of the present invention;

[0040] Figure 7 For Figure 6 It is a schematic structural diagram of the BB cross-section in

[0041] Figure 8One of the schematic diagrams of the structure on the second surface of the display panel provided by the embodiment of the present invention;

[0042] Figure 9 Another schematic diagram of the structure on the second surface of the display panel provided by the embodiment of the present invention;

[0043] Figure 10 Schematic diagram of the structure of the etching channel after etching in the related art;

[0044] Figure 11 Schematic diagram of the structure of the etching channel after etching provided by the embodiment of the present invention;

[0045] Figure 12 Schematic diagram of the structure of the laser etching equipment provided by the embodiment of the present invention;

[0046] Explanation of reference numerals:

[0047] 1 - Substrate, 2 - First electrode, 3 - Connection lead, 4 - Second electrode, 5 - Light-emitting device layer, 6 - Driving circuit layer, 1a - First surface, 1b - Second surface, 1c - Third surface, 31 - First lead segment, 32 - Second lead segment, 33 - Third lead segment, 51 - Light-emitting device, 52 - Pixel driving chip, 53 - Protective film, D - Conductive material layer, D1 - First region, D2 - Second region, D3 - Third region, W - Liquid medium, F - Focus, f - Defocus amount, V - Oscillation wave, Q - Air, 1000 - Mosaic display device, 100 - Display device, 10 - Display panel, 20 - Circuit board, AA - Display area, AN - Peripheral area, X - First direction, Y - Second direction, Z - Third direction, P - Sub-pixel, 7 - Laser, 8 - Optical lens group, 9 - Processing platform, 81 - Electro-optic modulator, 82 - Beam expander, 83 - Reflector, 84 - Galvanometer, 85 - Field lens, 91 - Adsorption platform, 92 - Water container, K - Etching channel, G - Residual particles. Detailed implementation manners

[0048] To make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described below with reference to the drawings and embodiments. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings represent the same or similar structures, and thus their repeated description will be omitted. The words expressing positions and directions described in the present invention are all illustrated by taking the drawings as examples, but can be changed according to needs, and all changes made are included in the protection scope of the present invention. The drawings of the present invention are only used to illustrate the relative positional relationship and do not represent the true scale.

[0049] To improve product reliability and reduce manufacturing and operation and maintenance costs, a large-sized display device can be assembled by splicing multiple small-sized display devices. To avoid the sense of display screen fragmentation caused by splicing, it is necessary to reduce the border size of a single small-sized display device and reduce the seam width.

[0050] The small-sized display device includes a display panel. The traces on one side of the display surface of the display panel can be connected to a circuit board provided on the non-display surface side of the display panel through connection leads. Thus, when multiple small-sized display devices are spliced to form a larger-sized display device, the distance between adjacent small-sized display devices can be smaller, thereby improving the display quality of the spliced large-sized display device.

[0051] The connection leads of the display panel go from the display surface around the side surface to the non-display surface. They can be fabricated by first plating a conductive material layer on the edge area of the display surface, the side surface, and the edge area of the non-display surface of the display panel and then laser etching it. When etching the traces on the non-display surface, if the energy density of the laser exceeds the damage threshold of the display film layer after passing through the substrate, etching damage will occur. Therefore, the thickness of the substrate needs to be set relatively large to avoid film layer damage, but this is not conducive to the thinning of the display product. Moreover, during the laser etching process, etching residues are likely to be generated in the etching channels, affecting the reliability of the product.

[0052] In view of this, an embodiment of the present invention provides a laser etching method, which can laser etch traces on a thinner substrate and reduce etching residues.

[0053] Figure 1 It is a schematic flow chart of the laser etching method provided by the embodiment of the present invention.

[0054] As Figure 1 shown, the laser etching method provided by the embodiment of the present invention may include the following steps:

[0055] S1. Form a conductive material layer on the substrate;

[0056] S2. Place the substrate in a liquid medium;

[0057] S3. Laser etch the conductive material layer in the liquid medium to form traces.

[0058] Among them, in step S1, the substrate can be made of a rigid material, such as glass, quartz, etc., or the substrate can also be made of a flexible material, such as polyethylene terephthalate (PET) or polyimide (PI), etc. The conductive material layer can be made of a metal material, a metal oxide or a composite material thereof, such as one or more of gold, silver, copper, titanium, aluminum, molybdenum, nickel gold, indium tin oxide (ITO), etc. The material of the substrate and the conductive material can be selected according to specific requirements, and the embodiments of the present invention do not limit this here.

[0059] Figure 2 It is a schematic structural diagram of the substrate after completing step S1 provided by the embodiment of the present invention.

[0060] As Figure 2 shown, the substrate 1 includes opposite first surface 1a and second surface 1b, and a third surface 1c connecting the first surface 1a and the second surface 1b. Among them, the first surface 1a of the substrate 1 is used to set functional film layers such as a driving circuit layer and a light-emitting device layer. In step S1, the conductive material layer D can be formed on the substrate 1 by a sputter process. The conductive material layer D includes a first region D1, a second region D2 and a third region D3. Among them, the first region D1 is located on the first surface 1a, the second region D2 is located on the second surface 1b, and the third region D3 is located on the selected third surface 1cc.

[0061] In steps S2 and S3, the liquid medium can be water with a refractive index of 1.33, or the liquid medium can be silicone oil with a refractive index of 1.4 - 1.5. The liquid medium can also be other light-transmitting, non-volatile and high-refractive-index liquid media, and the embodiments of the present invention do not limit this here. The refractive index of the liquid medium can be less than or close to the refractive index of the substrate 1 to avoid total reflection at the junction of the liquid medium and the substrate 1 during the laser etching process, which affects the flatness of the wiring edge.

[0062] Figure 3 It is one of the schematic diagrams of the principle of the laser etching method provided by the embodiment of the present invention.

[0063] As Figure 3As shown, in the embodiment of the present invention, step S3 performs laser etching on the conductive material in the liquid medium W, and the focus F of the laser spot has a certain vertical distance to the surface of the conductive material layer D, which is called the defocus amount f of the laser. In order to ensure the etching effect, the defocus amount f of the laser is usually very small. During the laser etching process, the liquid medium W at the position of the laser focus F will produce a boiling phenomenon due to the local high temperature, so that the position of the conductive material layer D to be etched is in the violent oscillation wave V caused by the boiling liquid medium W. Therefore, the conductive material sputtered by the laser etching will quickly break away from the surface of the conductive material layer D under the action of the violent oscillation wave V, and it will quickly cool in the liquid medium W and remain in the liquid medium W, so as to prevent the etched conductive material from remaining in the etching path, and avoid the problem of local short circuit caused by the conductive material remaining on the etching path. Exemplarily, the defocus amount f of the laser in the embodiment of the present invention is about 20μm.

[0064] Based on the above principles, the laser etching method provided in the embodiment of the present invention can have a better etching effect compared with other etching methods. For example, when etching a conductive material in the air, there may be residual conductive material in the etching path, which affects the conductive performance of the routing. Laser etching in a liquid medium W can avoid residual conductive material in the etching path. Alternatively, when etching a conductive material by a chemical method, chemical agent residues will inevitably appear on the surface of the conductive material layer D, and the surface roughness of the routing obtained by chemical etching is relatively large, that is, it is difficult to have a flat surface. However, when laser etching the conductive material layer D in a liquid medium W, the surface roughness of the routing obtained is relatively small and has a better morphology.

[0065] In the embodiment of the present invention, the temperature of the liquid medium W may be between 20° C. and 25° C. Considering that the liquid medium W has a certain absorption effect on the laser, the power of the laser may be between 0.5W and 0.9W.

[0066] For ease of description, the wiring formed after completing step S3 is referred to as a connecting lead. In an embodiment of the present invention, laser etching the conductive material layer D in the liquid medium W in step S3 to form a wiring may include: laser etching the conductive material layer D on the second surface 1b in the liquid medium W, that is, laser etching the conductive material layer D on the non-display surface of the display panel in the liquid medium W. At this time, the laser will propagate from the second surface 1b of the base substrate 1 to the first surface 1a (i.e., the display surface), and the display surface is provided with a plurality of functional film layers. If the energy attenuation of the laser in the base substrate 1 is not enough, then the intensity of the laser after passing through the second surface 1b may be greater than the damage threshold of the functional film layer, thereby causing damage to the functional film layer on the display side, affecting the reliability of the display panel.

[0067] Figure 4 The second schematic diagram of the principle of the laser etching method provided in the embodiment of the present invention.

[0068] Figure 4 (a) shows the optical path diagram of the laser incident on the substrate 1 from the air Q. Figure 4 (b) shows the optical path diagram of the laser incident on the substrate 1 from the liquid medium W. In the embodiment of the present invention, taking the substrate 1 as a glass substrate and the liquid medium W as water as an example, the divergence amount of the laser on one side is described. When the laser diverges to the extent that it will not damage the display surface functional film layer, its divergence amount on one side is L.

[0069] According to the law of refraction, Figure 4 (a) and Figure 4 (b) the optical paths shown satisfy the following conditions:

[0070] Sinθ 2 =(Sinθ 1 )*n 1 / n 2 ;

[0071] where θ 1 is the incident angle of the laser at the interface of the two media; θ 2 is the exit angle of the laser at the interface of the two media; n 1 is the refractive index of the medium where the laser is incident first; n 2 is the refractive index of the medium where the laser is incident later. Therefore, to make the laser diverge to the extent that it will not damage the display surface functional film layer, the minimum thickness of the required glass substrate is:

[0072] T = L * Cotθ 2 = L * Cosθ 2 / Sinθ 2 .

[0073] From the above relationship, it can be seen that to reduce the thickness T of the glass substrate, it is necessary to increase θ 2 , and increasing θ 2 can be achieved by increasing θ 1 or increasing n 1 / n 2 . Among them, θ 1 is related to the performance of the laser etching equipment and is difficult to achieve before upgrading the existing laser etching equipment. In the embodiment of the present invention, by increasing n 1 / n 2 the thinning of the substrate 1 can be achieved.

[0074] Specifically, in the optical path shown in Figure 4 (a), the laser is incident from the air Q to the glass substrate. The refractive index n 1 ' of the air Q is 1, and the refractive index n 2 ' of the glass is 1.5; in Figure 4In the optical path shown in (b), the laser is incident from water onto the glass substrate. The refractive index n of water 1 ” = 1.33, and the refractive index n of glass 2 ” = 1.5. n 1 ” / n 2 ” > n 1 ’ / n 2 ’.

[0075] At the junction where the laser is incident from water to glass, the incident angle θ 1 ” is more difficult to increase compared to the incident angle θ 1 ’ when the laser is incident from air Q to the glass junction. On the premise that the refractive index ratio n of water to glass 1 ” / n 2 ” is greater than the refractive index ratio n of air to glass 1 ’ / n 2 ’, it can be ensured that the incident angle θ 2 ” when the laser is incident from water to the glass junction is greater than the incident angle θ 2 ’ when the laser is incident from air to the glass junction. Furthermore, when the laser divergence reaches the level where it will not damage the functional film layer on the display surface, that is, when the laser has the same unilateral divergence amount of L, Figure 4 the thickness T” of the glass substrate in (b) can be less than Figure 4 the thickness T’ of the glass substrate in (a).

[0076] Based on this, the laser etching method provided by the embodiments of the present invention is beneficial to reducing the thickness of the substrate 1, realizing the thinning of the display product, and at the same time can avoid etching damage to the functional film layer on the display surface when etching the traces on the non-display surface. Exemplarily, the laser etching method provided by the present invention can be applied to a substrate with a thickness of 0.3 mm to 0.4 mm.

[0077] In this case, before placing the substrate in the liquid medium, it may further include:

[0078] S21. Laser-etch the conductive material layer on the first surface;

[0079] S22. Laser-etch the conductive material layer on the selected third surface.

[0080] Among them, after completing step S21, the first lead segments of each connection lead can be formed. After completing step S22, the second lead segments of each connection lead can be formed. After completing step S3, the third lead segments of each connection lead can be formed.

[0081] In the embodiments of the present invention, the conductive material layer D on the first surface 1a and the selected third surface 1cc can be etched in the air Q. This is because the control components such as the driving chip or the circuit board are bonded to the opposite surface of the first surface 1a (i.e., the second surface 1b) after the wire etching is completed. Therefore, when etching the conductive material layer D on the first surface 1a, no etching damage will be caused to the components on the second surface 1b. The selected third surface 1cc and its opposite surface usually have a relatively large distance, and the selected third surface 1cc is usually only used to set the connection leads. Therefore, there will also be no problem of etching damage.

[0082] In some embodiments of the present invention, the conductive material layer D on the first surface 1a and the selected third surface 1cc can also be etched after the conductive material layer D on the second surface 1b is etched, which is not limited herein.

[0083] In some embodiments of the present invention, the laser etching of the conductive material layer D in the liquid medium W in step S3 may include etching three regions of the conductive material layer D in the liquid medium W respectively to form a plurality of connection leads. Among them, etching the first region D1 of the conductive material layer D can form the first lead segments of the respective connection leads, etching the third region D3 of the conductive material layer D can form the second lead segments of the respective connection leads, and etching the second region D2 of the conductive material layer D can form the third lead segments of the respective connection leads. The connection leads are all etched in the liquid medium, which can reduce the etching residue to a greater extent and is beneficial to improving the reliability of the display panel.

[0084] In some embodiments of the present invention, the laser etching method may further include:

[0085] S4. Drying the etched substrate.

[0086] Laser etching in the liquid medium W is equivalent to cleaning the substrate 1 and the film layer above it once, which is beneficial to improving its surface cleanliness. After the etching is completed, the substrate 1 and the film layer above it can be dried, for example, by blowing air for drying.

[0087] Based on the same inventive concept, the embodiments of the present invention also provide a display panel. The display panel is manufactured by the above laser etching method, and the display panel can be applied to a display device or a large-size tiled display device.

[0088] Figure 5 It is a schematic structural diagram of the tiled display device provided by the embodiments of the present invention.

[0089] Such as Figure 5As shown in the figure, the tiled display device 1000 may include a plurality of display panels 10 that are tiled together. The display panel 10 has a display area AA and a peripheral area AN located on at least one side of the display area AA. Among them, the peripheral area AN may be located on one side of the display area AA, or the peripheral area AN may be located on opposite sides of the display area AA, or the peripheral area AN may surround the display area AA. The specific setting manner of the peripheral area AN can be designed according to actual needs, and the embodiments of the present invention do not limit this here.

[0090] In the embodiments of the present invention, an example is given in which the tiled display device 1000 includes a plurality of display panels 10 that are tiled together, and each display panel 10 has a peripheral area AN located on one side of the display area AA. As Figure 5 shown in the figure, the plurality of display panels 10 may be arranged in multiple columns along the first direction X and in multiple rows along the second direction Y.

[0091] Among the plurality of display panels 10 that are tiled together, the peripheral areas AN of the display panels 10 are all arranged along the first direction X. In this way, among the plurality of display panels 10 arranged in a row along the first direction X, there is basically no seam between two adjacent display panels 10 along the first direction X. Among the plurality of display panels 10 arranged in a column along the second direction Y, there is a splicing gap between two adjacent display panels 10.

[0092] That is to say, among the plurality of display panels 10 arranged in a row along the first direction X, the size of the splicing gap between two adjacent display panels 10 is smaller than the size of the splicing gap between two adjacent display panels 10 among the plurality of display panels 10 arranged in a column along the second direction Y. In this way, when viewing the tiled display device 1000, the seam between two adjacent display panels 10 is difficult to be found by the naked eye within the viewing distance, so that the display screen of the tiled display device 1000 is relatively complete and can present a better display effect.

[0093] Figure 6 It is a schematic structural diagram of the display device provided by the embodiment of the present invention; Figure 7 is Figure 6 a schematic structural diagram of the cross-section BB in

[0094] As Figure 6 and Figure 7As shown, the display panel 10 can also be directly applied to the display device 100. The display device 100 may include a display panel 10 and a circuit board 20. The display panel 10 is electrically connected to the circuit board 20. Exemplarily, the circuit board 20 includes, but is not limited to, a PCB (Printed Circuit Board), an FPC (Flexible Printed Circuit Board), etc. In some embodiments, the tiled display device 1000 may also include a plurality of display devices 100 that are tiled together.

[0095] As Figure 6 and Figure 7 shown, the display panel 10 includes: a substrate 1, a plurality of first electrodes 2, and a plurality of connection leads 3. Among them, the substrate 1 includes a first surface 1a and a second surface 1b that are oppositely arranged, and a third surface 1c that connects the first surface 1a and the second surface 1b. The plurality of first electrodes 2 are disposed on the first surface 1a, and the connection leads 3 are disposed at least on the selected third surface 1cc. Among them, the number of the selected third surfaces 1cc of the substrate 1 and the specific arrangement manners of the plurality of first electrodes 2 and the plurality of connection leads 3 can be designed according to actual needs, and the embodiments of the present invention do not limit this here.

[0096] As Figure 7 shown, the display panel 10 further includes functional film layers such as a light-emitting device layer 5 and a driving circuit layer 6 disposed in the display area AA. Among them, the light-emitting device layer 5 is located on the side of the driving circuit layer 6 away from the substrate 1 and is electrically connected to the driving circuit layer 6.

[0097] The light-emitting device layer 5 includes a plurality of light-emitting devices 51. The light-emitting devices 51 emit light under the control of a driving signal transmitted by the driving circuit layer 6. Exemplarily, the light-emitting devices 51 include, but are not limited to, OLEDs (Organic Light-Emitting Diodes), Mini LEDs (Mini Light-Emitting Diodes), Micro LEDs (Micro Light-Emitting Diodes), etc. Referring to Figure 6 , the display panel 10 includes a plurality of sub-pixels P that can emit light of different colors. The sub-pixels P include at least one light-emitting device 51.

[0098] The driving circuit layer 6 may include a plurality of signal lines. The plurality of signal lines are located in the display area AA. At least a part of the plurality of signal lines is electrically connected to the light-emitting device layer 5 to provide a driving signal to the light-emitting device layer 5. As Figure 6As shown, a plurality of first electrodes 2 are located in the peripheral region AN and are disposed close to the selected third surface 1cc. One end of each first electrode 2 can be electrically connected to a signal line, and the other end can be electrically connected to a connection lead 3, so as to transmit the driving signal transmitted by the connection lead 3 to the driving circuit layer 6.

[0099] As Figure 7 shown, in some embodiments, the light-emitting device layer 5 may further include a plurality of pixel driving chips 52 and a protective film 53.

[0100] Among them, the pixel driving chip 52 is used to provide a driving signal to the light-emitting device 51. In some embodiments, the light-emitting device layer 5 may not have the pixel driving chip 52, but instead use thin-film transistors provided in the driving circuit layer 6 to provide a driving signal to the light-emitting device 51.

[0101] The protective film 53 may include a portion covering a plurality of light-emitting devices 51 and a portion filling the gap regions between the plurality of light-emitting devices 51. The protective film 53 can protect the plurality of light-emitting devices 51 in the light-emitting device layer 5 from being damaged by bumps during subsequent manufacturing processes. The material of the protective film 53 includes but is not limited to black silicone or black resin.

[0102] As Figure 7 shown, among the plurality of connection leads 3, each connection lead 3 includes a first lead segment 31, a second lead segment 32, and a third lead segment 33 connected in sequence. The first lead segment 31 is disposed on the first surface 1a and is electrically connected to one of the plurality of first electrodes 2. The second lead segment 32 is disposed on the selected third surface 1cc, and the third lead segment 33 is disposed on the second surface 1b.

[0103] Figure 8 It is one of the schematic structural diagrams on the second surface of the display panel provided by the embodiment of the present invention.

[0104] As Figure 8 shown, the display panel 10 may further include a plurality of second electrodes 4 disposed on the second surface 1b of the substrate 1. One end of each second electrode 4 is electrically connected to the third lead segment 33 of a connection lead 3, and the other end is electrically connected to an external driving circuit layer (such as a circuit board 20). The second electrode 4 and the circuit board 20 can be connected by a Bonding process to transmit the driving signal from the circuit board 20 to the light-emitting device layer 5 through the second electrode 4, the connection lead 3, and the driving circuit layer 6 in sequence.

[0105] In this case, the connection lead 3 serves as a connection line to electrically connect the driving circuit layer disposed on the front surface of the display panel 10 and the external driving circuit layer disposed on the back surface of the display panel 10. The second electrode 4 serves as a bonding electrode and is electrically connected to the external driving circuit. At this time, the third lead segment 33 of the connection lead 3 is linear and extends along the second direction Y. The length d2 of the third lead segment 33 is the dimension of the third lead segment 33 in its extending direction.

[0106] Figure 9 FIG. 4 is a second schematic diagram of the structure on the second surface of the display panel provided by the embodiment of the present invention.

[0107] As Figure 7 and Figure 9 shown, the end of the third lead segment 33 away from the selected third surface 1cc can be directly electrically connected to the external driving circuit. In this case, while the third lead segment 33 serves as a connection line connecting the driving circuit layer on the front surface and the external driving circuit layer on the back surface, it also serves as a bonding electrode and is directly connected to the circuit board 20.

[0108] As Figure 9 shown, the third lead segment 33 of the connection lead 3 can be zigzag. The third lead segment 33 includes a plurality of sub-parts connected end to end in sequence with different extending directions. The angle range formed between the extending direction of any one sub-part of the third lead segment 33 and the second direction Y can be 0 to 70°. And, the third lead segment 33 generally extends along the second direction Y. Then, the length d2 of the zigzag third lead segment 33 is the dimension of the third lead segment 33 as a whole in the second direction Y.

[0109] Therefore, referring to Figures 7 - 9 , in the direction perpendicular to the selected third surface 1cc, the length d2 of the third lead segment 33 is greater than the length d1 of the first lead segment 31. And, referring to Figure 7 , the length d2 of the third lead segment 33 of the connection lead 3 can also be greater than the dimension d3 of the peripheral area AN in the extending direction of the third lead segment 33.

[0110] When preparing each connection lead 3, it is necessary to etch the conductive materials on the first surface 1a, the selected third surface 1cc, and the second surface 1b respectively. Since d2 > d3 and d2 > d1, the length of the part that needs to be laser-etched on the second surface 1b side is longer. Thus, during the process of etching to form the third lead segment 33 of the connection lead 3, when the laser irradiates the substrate 1 along the third direction Z, it may pass through the substrate 1 and irradiate the front functional film layer of the display panel 10, causing damage to the front functional film layer of the display panel 10 and resulting in problems such as local corrosion.

[0111] Exemplarily, if the laser irradiates the thin film transistor in the driving circuit layer 6, the active layer of the thin film transistor in the driving circuit layer 6 will be changed in characteristics after being irradiated by the laser. For example, the threshold current for turning off the thin film transistor increases, thus affecting the display effect.

[0112] Alternatively, if the laser irradiates the signal line in the driving circuit layer 6, it may cause damage to the signal line. For example, if a part of the signal line is etched by the laser irradiation, the line resistance of this part of the signal line will increase, affecting the signal transmission effect; or, when the width of the signal line is small, if the laser irradiates the signal line, it may cause local breakage of the signal line, making the signal unable to be transmitted normally.

[0113] Or, if the laser irradiates the light-emitting device 51, it may cause a change in the characteristics of the light-emitting device 51, such that the light-emitting effect of the light-emitting device 51 cannot reach the expected effect. For example, the light-emitting device 51 cannot emit light normally, or the light-emitting brightness, color, etc. change, thus affecting the display effect.

[0114] In view of this, the embodiment of the present invention adopts the laser etching method as Figure 1 shown, etching the third lead segment 33 on the second surface 1b in a liquid medium, increasing the energy attenuation degree of the laser when the thickness of the substrate 1 is smaller, so that the energy of the laser is lower than the damage threshold of the functional film layer such as the light-emitting device layer 5 and the driving circuit layer 6 on the first surface 1a when it reaches the first surface 1a, avoiding damage to the functional film layer on the display surface of the display panel, thereby ensuring the display effect of the display panel.

[0115] Figure 10 is a schematic structural diagram of the etching channel after etching in the related art; Figure 11 is a schematic structural diagram of the etching channel after etching provided by the embodiment of the present invention.

[0116] Figure 10 and Figure 11 respectively show the structures of the FF cross-section in the cases of directly etching the conductive material layer and etching the conductive material layer in a liquid medium Figure 9 as Figure 10 shown, in the related art, directly laser-etching the conductive material layer in the air, the etched conductive material may remain in the etching channel K, forming residual particles G, and the existence of the residual particles G will cause a problem of local short circuit.

[0117] In view of this, the embodiment of the present invention adopts the laser etching method as Figure 1 shown, etching the conductive material layer in a liquid medium to form the connection lead 3, referring to Figure 3 and Figure 11, in the embodiment of the present invention, the etched conductive material rapidly detaches from the surface of the conductive material layer under the action of the intense oscillation wave, and remains in the liquid medium after being rapidly cooled in the liquid medium, thereby greatly reducing or even avoiding the occurrence of residual particles G in the etching channel K.

[0118] Based on the same inventive concept, the embodiment of the present invention further provides a laser etching device, which can be used to implement the laser etching method as Figure 1 shown, and perform laser etching in a liquid medium.

[0119] Figure 12 It is a schematic structural diagram of the laser etching device provided by the embodiment of the present invention.

[0120] As Figure 12 shown, the laser etching device provided by the embodiment of the present invention includes a laser 7, an optical mirror group 8, and a processing platform 9.

[0121] Among them, the laser 7 can adopt a solid-state laser or a gas laser, such as a carbon dioxide (CO 2 ) laser, a helium-neon (He-Ne) laser, etc. The laser 7 can emit infrared light, ultraviolet light, or visible light.

[0122] The optical mirror group 8 is located on the light-emitting side of the laser 7, and is used to adjust the laser beam emitted by the laser 7 to the size required for etching and focus it to a set position for etching. The type of lens, the lens surface type parameters, and the arrangement method of the lenses in the optical mirror group 8 are not limited herein. Exemplarily, the embodiment of the present invention gives a possible structure of the optical mirror group 8.

[0123] As Figure 12 shown, the optical mirror group 8 may include an electro-optic modulator 81 (Electro Optic Modulator, abbreviated as EOM), a beam expander 82, a reflector 83, a galvanometer 84, and a field lens 85 arranged in sequence along the optical path propagation direction. Among them, the EOM includes an electro-optic crystal, and through its electro-optic effect, the phase, amplitude, intensity, and polarization state of the light emitted by the laser 7 can be adjusted. The beam expander 82 can be used for collimation and changing the size of the laser beam. The reflector 83 is used to reflect the laser beam in the direction of the processing platform 9. By controlling the movement trajectory of the galvanometer 84, stable and high-precision etching can be achieved. The field lens 85 can be used to form a uniformly sized focused spot near the material to be etched for etching.

[0124] The processing platform 9 is located on the light-emitting side of the optical lens group 8. The processing platform 9 may include an adsorption platform 91 for fixing the device to be etched, such as a vacuum adsorption platform, and a water container 92 for containing a liquid medium. Wherein, a waterproof adhesive can be coated on the adsorption platform 91, and the water container 92 is buckled into the area surrounded by the waterproof adhesive. In this way, the substrate 1 can sink into the liquid medium W and be adsorbed on the processing platform 9, so as to provide a stable processing environment.

[0125] In the laser etching device provided by the embodiment of the present invention, a water container 92 is arranged in the processing platform 9, and the etched conductive material can be directly impacted into the liquid medium W. Therefore, there is no need to set a dust suction module for sucking dust in the laser etching device, which helps to reduce costs. During the etching process, the substrate 1 is fixed in the liquid medium environment of the water container 92, and etching is performed by controlling the movement of the laser. The etching accuracy can reach ±15μm, meeting the use requirements.

[0126] In some embodiments of the present invention, the laser etching device may further include a circulating filtration device. At this time, the water container 92 may further include a water inlet and a water outlet, and the circulating filtration device is connected to the water inlet and the water outlet of the water container 92. Exemplarily, the circulating filtration device may include a circulating pump and a filter element. The water inlet and the water outlet of the water container 92 are led to the circulating pump and the filter element by water pipes. The circulating pump can provide power for the circulation of the liquid medium W, and the filter element is used to filter the liquid medium to ensure the cleanliness of the liquid medium. The water pump provides the power for the water bath circulation, and the filter element ensures the cleanliness of the water quality. Therefore, setting a circulating filtration device in the laser etching device can timely clean the etched conductive material in the liquid medium, thereby ensuring the cleanliness of the liquid medium and being beneficial to reducing etching residues.

[0127] In some embodiments of the present invention, the laser etching device may further include a drying device, and the drying device is used to perform a drying process on the etched substrate 1, for example, drying the etched substrate 1 by blowing air.

[0128] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0129] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A laser etching method, characterized in that, it includes: forming a conductive material layer on a substrate; placing the substrate in a liquid medium; laser etching the conductive material layer in the liquid medium to form a trace.

2. The laser etching method according to claim 1, characterized in that, the substrate includes opposite first and second surfaces, and a third surface connecting the first and second surfaces, wherein the first surface is used to arrange driving circuits and light-emitting devices; the laser etching the conductive material layer in the liquid medium to form a trace includes: laser etching the conductive material layer on the second surface in the liquid medium.

3. The laser etching method according to claim 2, characterized in that, before placing the substrate in the liquid medium, it further includes: laser etching the conductive material layer on the first surface; laser etching the conductive material layer on the third surface.

4. The laser etching method according to claim 1, characterized in that, it further includes: performing a drying treatment on the substrate after etching.

5. The laser etching method according to any one of claims 1 to 4, characterized in that, the liquid medium includes water or silicone oil.

6. The laser etching method according to any one of claims 1 to 4, characterized in that, the thickness of the substrate is 0.3 mm to 0.4 mm.

7. The laser etching method according to any one of claims 1 to 4, characterized in that, the power of the laser is 0.5 W to 0.9 W.

8. The laser etching method according to any one of claims 1 to 4, characterized in that, the temperature of the liquid medium is 20 °C to 25 °C.

9. A laser etching device, characterized in that, it includes: a laser; an optical mirror group located on the light output side of the laser; a processing platform located on the light output side of the optical mirror group; the processing platform includes a water container for containing a liquid medium.

10. The laser etching device according to claim 9, characterized in that, the water container further includes a water inlet and a water outlet; the laser etching device further includes: a circulating filtration device connected to the water inlet and the water outlet.

11. The laser etching device according to claim 9 or 10, characterized in that, it further includes: a drying device for performing a drying treatment on the substrate after etching.

12. The laser etching device according to claim 9, characterized in that, the etching accuracy of the laser etching device is ±15 μm.

13. A display panel, characterized in that, the display panel is manufactured by using the laser etching method according to any one of claims 1 to 8, or is manufactured by using the laser etching device according to any one of claims 9 to 12.

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