Display panel, manufacturing method thereof and display device

Abstract

The invention discloses a display panel, a manufacturing method of the display panel and a display device. The display panel comprises a back plate, a plurality of bonding electrodes, a plurality of first electrodes and a plurality of second electrodes, a plurality of light-emitting chips, wherein the light-emitting chips comprise chip electrodes; the chip electrodes are respectively fixed with the bonding electrodes through laser welding; the backboard comprises a first area and a second area, and the metal density of the first area is higher than that of the second area; the melting point of the bonding electrode in the first region is higher than that of the bonding electrode in the second region; and / or the melting point of the chip electrode in the first area is higher than that of the chip electrode in the second area. By means of the scheme, the risk that the back plate cracks during laser welding can be avoided, and the electrode welding quality is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of micro displays, and in particular to a display panel, a manufacturing method thereof, and a display device. Background Art

[0002] Micro LED (micron-sized light-emitting diode) display technology has attracted attention for its high brightness, high contrast, high resolution, and long life. The design concept of Micro LED display panels is to use Micro LED chips directly as display pixels, the basic unit of imaging, to achieve image display. After mass transfer, laser welding technology is typically used to bond the LED chip electrodes to the TFT (Thin Film Transistor) backplane bumps. Laser welding is usually performed using line scanning or surface scanning lasers, and the use of uniform laser parameters can easily lead to the following problems:

[0003] (1) Due to the uneven distribution of metal density on the backplane, for example, in special-shaped transparent display panels, the special-shaped areas around them usually have high-density VSR (Vertical Shift Register) circuits, which leads to high backplane temperature in the high metal density area during laser welding, and a high risk of backplane cracking.

[0004] (2) In Micro LED display panels, full-color display is usually achieved by directly arranging Micro LED chips of red, green, and blue. Since the materials and structures used for chips of different colors are different, the physical properties and process constraints of the corresponding electrode materials are also different. The electrodes of blue-green light chips are mainly made of highly reflective metals, while the electrodes of red light chips are mainly made of transparent conductive oxides or ultra-thin metals. This leads to different laser welding bonding strengths and solder overflow degrees. For example, high laser parameters may cause the red light chip electrodes to over-melt or solder overflow short circuit, while low laser parameters may cause blue and green chip electrodes to be poorly soldered. Summary of the Invention

[0005] Embodiments of the present invention provide a display panel and a manufacturing method thereof, and a display device, so as to avoid the risk of back panel cracking during laser welding and ensure electrode welding quality.

[0006] In one aspect, an embodiment of the present invention provides a display panel, including:

[0007] a back plate, wherein a plurality of bonding electrodes are provided on the back plate;

[0008] A plurality of light-emitting chips, each comprising a chip electrode; the chip electrodes are respectively fixed to the bonding electrodes by laser welding;

[0009] The back plate includes a first area and a second area, the metal density of the first area is higher than the metal density of the second area;

[0010] The melting point of the bonding electrodes in the first region is higher than that of the bonding electrodes in the second region; and / or the melting point of the chip electrodes in the first region is higher than that of the chip electrodes in the second region.

[0011] Optionally, the first area is an edge area of ​​the back panel, and the second area is a partial area of ​​the back panel display area.

[0012] Optionally, the light-emitting chip includes a first color light-emitting chip and a second color light-emitting chip;

[0013] The melting point of the bonding electrode connected to the chip electrode of the first color light-emitting chip is higher than the melting point of the bonding electrode connected to the chip electrode of the second color light-emitting chip; and / or

[0014] The melting point of the chip electrode of the first color light emitting chip is higher than the melting point of the chip electrode of the second color light emitting chip.

[0015] Optionally, the first color light-emitting chip is a red light Micro LED chip, and the second color light-emitting chip is a blue light Micro LED chip and a green light Micro LED chip.

[0016] On the other hand, an embodiment of the present invention further provides a display device including the display panel.

[0017] On the other hand, an embodiment of the present invention further provides a method for manufacturing a display panel, the method comprising:

[0018] Providing a back plate, the back plate comprising a first region and a second region, wherein the metal density of the first region is higher than the metal density of the second region; and a plurality of bonding electrodes are provided on the back plate;

[0019] Transferring the prefabricated light-emitting chip to the second area and the first area on the backplane;

[0020] The melting point of the bonding electrode in the first region is higher than that of the bonding electrode in the second region; and / or the melting point of the chip electrode of the light-emitting chip transferred to the first region is higher than that of the chip electrode of the light-emitting chip transferred to the second region;

[0021] The chip electrodes are fixedly connected to the bonding electrodes on the back plate by laser welding.

[0022] Optionally, the method further includes: providing a transfer substrate, generating a light-emitting chip having a first chip electrode and a light-emitting chip having a second chip electrode on the transfer substrate, wherein the melting point of the first chip electrode is higher than the melting point of the second chip electrode.

[0023] Optionally, transferring the prefabricated light-emitting chip to the second area and the first area on the backplane includes: transferring the light-emitting chip having the second chip electrode on the transfer substrate to the second area of ​​the backplane by mass transfer, and simultaneously transferring the light-emitting chip having the first chip electrode to the first area of ​​the backplane.

[0024] Optionally, transferring the prefabricated light-emitting chip to the second area and the first area on the backplane includes:

[0025] transferring the light-emitting chip having the second chip electrode on the transfer substrate to the second area of ​​the backplane by mass transfer;

[0026] The light-emitting chip having the first chip electrode on the transfer substrate is transferred to the first area of ​​the backplane by stamp transfer.

[0027] Optionally, the method further includes:

[0028] Providing a first transfer substrate, and generating a light-emitting chip having a first chip electrode on the first transfer substrate;

[0029] Providing a second transfer substrate, and growing a light-emitting chip having a second chip electrode on the second transfer substrate; the melting point of the first chip electrode is higher than the melting point of the second chip electrode;

[0030] The step of transferring the prefabricated light-emitting chip to the second area and the first area on the backplane comprises:

[0031] transferring the light-emitting chip on the second transfer substrate to the second area on the backplane;

[0032] The light emitting chip on the first transfer substrate is transferred to the first area on the backplane.

[0033] Optionally, the first area is an edge area of ​​the back panel, and the second area is a display area of ​​the back panel.

[0034] Optionally, the light-emitting chips in the first area and the light-emitting chips in the second area are chips of the same color.

[0035] Optionally, the light-emitting chip includes a first color light-emitting chip and a second color light-emitting chip;

[0036] The first area and the second area of ​​the back plate respectively include a first bonding electrode connected to the chip electrode of the first color light emitting chip and a second bonding electrode connected to the chip electrode of the second color light emitting chip;

[0037] The melting point of the first bonding electrode is higher than that of the second bonding electrode; and / or the melting point of the chip electrode of the first color light-emitting chip is higher than that of the chip electrode of the second color light-emitting chip.

[0038] Optionally, the first color light-emitting chip is a red light Micro LED chip, and the second color light-emitting chip is a blue light Micro LED chip and a green light Micro LED chip.

[0039] Optionally, the chip electrode and / or the bonding electrode includes a tin-based solder layer, and the method further includes: adjusting the melting point of the electrode by doping with different elements, doping the tin-based solder layer of the high-melting-point electrode with a high-melting-point element, and doping the tin-based solder layer of the low-melting-point electrode with a low-melting-point element.

[0040] Optionally, the tin-based solder layer is a tin-based alloy film; the method further comprises: forming the tin-based alloy film on the electrode by sputtering or evaporation.

[0041] Optionally, the high melting point element includes any one or more of the following: silver, copper; the low melting point element includes any one or more of the following: bismuth, tin, lead, indium.

[0042] Optionally, the chip electrode and / or the bonding electrode includes a soldering metal layer, and the method further includes: adjusting the melting point of the electrode by changing the content of a specific metal in the soldering metal layer.

[0043] Optionally, the welding metal layer is a gold-indium thin film, and the indium content in the gold-indium thin film of the high-melting-point electrode is lower than the indium content in the gold-indium thin film of the low-melting-point electrode.

[0044] Optionally, the method further includes: forming the gold-indium thin film on the electrode by sputtering or evaporation.

[0045] Optionally, the chip electrode includes a gold-plated layer, and the bonding electrode includes an indium-plated layer;

[0046] The thickness or area of ​​the indium plating layer of the bonding electrode with a high melting point is smaller than the thickness or area of ​​the indium plating layer of the bonding electrode with a low melting point.

[0047] Optionally, the chip electrode includes a gold-plated layer, and the bonding electrode includes an indium ball; the volume of the indium ball of the high-melting-point bonding electrode is smaller than the volume of the indium ball of the low-melting-point bonding electrode.

[0048] Compared with the existing technology, the technical solution provided by the present invention has at least the following advantages:

[0049] The display panel, its manufacturing method, and display device provided by the embodiments of the present invention are designed differently for the bonding electrodes and / or chip electrodes located in the first area with higher metal density and the bonding electrodes and / or chip electrodes located in the second area with lower metal density, in view of the different metal densities in different areas of the backplane and the fact that line scanning or surface scanning is usually used during electrode welding. This makes the melting point of the bonding electrodes in the first area higher than the melting point of the bonding electrodes in the second area, and / or the melting point of the chip electrodes in the first area higher than the melting point of the chip electrodes in the second area. By using high-melting-point metals as compensation design at high-temperature welding positions, the temperatures of different areas of the backplane can be kept as consistent as possible during laser welding, effectively avoiding the risk of cracking of the backplane due to different temperatures in different areas during laser welding, and ensuring the production yield and quality of the display panel.

[0050] Furthermore, in view of the differences in materials and structures between red light-emitting chips and blue-green light-emitting chips, the bonding electrodes connected to the chip electrodes of light-emitting chips of different colors are designed to have different melting points, and / or the chip electrodes of light-emitting chips of different colors are designed to have different melting points. This can ensure that under the same laser parameters, the electrodes of light-emitting chips of different colors will not over-melt, short-circuit or have cold solder joints, thereby improving the quality of laser welding and better ensuring product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0052] Figure 1 is a structural schematic diagram of a display panel provided by an embodiment of the present invention;

[0053] Figure 2 is another structural schematic diagram of a display panel provided by an embodiment of the present invention;

[0054] Figure 3 yes Figure 1 A schematic cross-sectional view of the display panel along the AA' direction is shown;

[0055] Figure 4 yes Figure 1 Another schematic cross-sectional view of the display panel along the AA' direction is shown;

[0056] Figure 5 yes Figure 1 Another schematic cross-sectional view of the display panel along the AA' direction is shown;

[0057] Figure 6 is another structural schematic diagram of a display panel provided by an embodiment of the present invention;

[0058] Figure 7 is another structural schematic diagram of a display panel provided by an embodiment of the present invention;

[0059] Figure 8 is another structural schematic diagram of a display panel provided by an embodiment of the present invention;

[0060] Figure 9 This is a flow chart of a method for manufacturing a display panel provided by an embodiment of the present invention;

[0061] Figure 10 is another flow chart of a method for manufacturing a display panel provided by an embodiment of the present invention;

[0062] Figure 11 is another flow chart of a method for manufacturing a display panel provided by an embodiment of the present invention;

[0063] Figure 12 It is a structural schematic diagram of a display device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0065] Electrode interconnection is a critical process in display manufacturing. Micro LED (micro light-emitting diode) display panels consist of a backplane and multiple micro-light-emitting chips electrically connected to the backplane. During the manufacturing process, the chip electrodes of the multiple light-emitting chips must be soldered to the bonding electrodes on the backplane. During soldering, the corresponding welding energy is absorbed by the circuits within the backplane. This energy increases the temperature of the circuits, causing them to overheat, which can lead to cracking in the backplane. This is particularly true in areas of the backplane with dense circuitry, which are more prone to cracking due to overheating.

[0066] Laser welding has become an important technology for achieving reliable connection after mass transfer of display chips due to its high precision, low thermal impact and fast processing.

[0067] There are three main methods for laser welding:

[0068] (1) Direct welding: Laser heating the chip electrode and the backplane bonding electrode metal to form a metallurgical bond.

[0069] (2) Solder assisted: A solder layer is pre-deposited on the chip electrodes and / or backplane bonding electrodes, and the connection is achieved by laser melting the solder layer (such as tin balls, gold-tin eutectic).

[0070] (3) Using ACF (Anisotropic Conductive Film): pre-attach the ACF film to the backplane or display chip array, locally heat the conductive adhesive with a laser to cure it, and then fix it by hot pressing.

[0071] In mass production, laser welding typically uses line scanning or surface scanning, making it difficult to adjust laser parameters for individual light-emitting chips in different array areas or for different colors. Therefore, regardless of the laser welding process used, the aforementioned issues of backplane cracking, poor solder joints, or short circuits can arise due to uneven metal density distribution on the backplane and the varying materials and structures used for Micro LED chips of different colors. These issues are particularly prominent in irregularly shaped transparent display panels.

[0072] Based on this, an embodiment of the present invention provides a display panel and a method for manufacturing the same. By using high-melting-point metal as a compensation design at high-temperature welding positions, the temperatures of different areas of the back panel can be kept as consistent as possible during laser welding, thereby reducing the risk of cracking of the back panel during laser welding.

[0073] like Figure 1 FIG. 1 is a schematic diagram of the structure of a display panel provided by an embodiment of the present invention. Figure 2 yes Figure 1 The AA' cross-sectional view of the display panel is shown.

[0074] The display panel 100 provided in an embodiment of the present invention includes a backplane 10 and multiple light-emitting chips 20 electrically connected to the backplane 10. The backplane 10 includes multiple bonding electrodes located on the first surface of the backplane 10; the light-emitting chips 20 include multiple chip electrodes located on the side of the light-emitting chip 20 facing the first surface of the backplane 10. Each chip electrode is secured to a corresponding bonding electrode on the first surface of the backplane 10 by laser welding. The light-emitting chips 20 can be, for example, light-emitting diodes, specifically Micro LEDs, Mini LEDs, and the like.

[0075] In an embodiment of the present invention, the backplane 10 may be composed of multiple metal layers or other structural layers. These metal layers or other structures may include circuits such as pixel circuits and scan drive circuits. The scan drive circuit is electrically connected to the pixel circuit, which is electrically connected to the light-emitting chip 20. The pixel circuit is used to provide corresponding drive signals to the light-emitting element 20, and the scan drive circuit is used to provide corresponding scan control signals to the pixel circuit. Both the scan drive circuit and the pixel circuit are composed of components such as transistors and capacitors connected together, which is the same as in the prior art and will not be further described here.

[0076] Reference Figure 2 FIG. 1 is a schematic structural diagram of a display panel provided by an embodiment of the present invention.

[0077] The backplane 10 includes a substrate 1001; a semiconductor layer 1002 located on the substrate 1001, the semiconductor layer 1002 including an active area forming a transistor TFT; a gate insulating layer 1003 located on the side of the semiconductor layer 1002 facing away from the substrate 1001; a gate metal layer 1004 located on the side of the gate insulating layer 1003 facing away from the substrate 1001, the gate metal layer 1004 including a gate electrode forming the transistor TFT; a capacitor insulating layer 1005 located on the side of the gate metal layer 1004 facing away from the substrate 1001; a capacitor metal layer 1006 located on the side of the capacitor insulating layer 1005 facing away from the substrate 1001, the capacitor metal layer 1006 including a plate forming a capacitor in the circuit, the other plate forming the capacitor can be located on the gate metal layer 1004, or the other plate forming the capacitor can be located on the source-drain metal layer 1008; an interlayer insulating layer located on the side of the capacitor metal layer 1006 facing away from the substrate 1001 an insulating layer 1007; a source-drain metal layer 1008 located on the side of the interlayer insulating layer 1007 facing away from the substrate 1001, the source-drain metal layer 1008 including a source and a drain forming the transistor TFT, and the source and the drain are in contact with the active area through respective vias; a passivation layer 1009 located on the side of the source-drain metal layer 1008 facing away from the substrate 1001; a circuit metal layer 1010 located on the side of the passivation layer 1009 facing away from the substrate 1001; a planarization layer 1011 located on the side of the circuit metal layer 1010 facing away from the substrate 1001; an electrode layer located on the side of the planarization layer 1011 facing away from the substrate 1001, the electrode layer including a first electrode 1A and a second electrode 1B, and a surface passivation layer 1013 located on the side of the electrode layer facing away from the substrate 1001, the surface passivation layer 1013 exposing the first electrode 1A and the second electrode 1B, and the surface of the backplane 10 having the surface passivation layer 1013 on the side is the first surface. Among them, the first electrode 1A is electrically connected to the transfer electrode in the circuit metal layer 1010 through a via, and the transfer electrode is electrically connected to the electrode of the transistor TFT in the source-drain metal layer 1008 (which can be a source electrode or a drain electrode, which needs to be specifically selected according to the actual application) through a via, and the second electrode 1B is electrically connected to the power supply electrode in the circuit metal layer 1010 through a via, thereby forming a circuit for providing a driving signal to the light-emitting chip 20.

[0078] Figure 2 In the example display panel shown, the transistor TFT in the backplane 10 is a top-gate transistor, that is, the gate of the transistor TFT is located above the active layer. In some other embodiments of the present invention, the transistor TFT in the backplane 10 may also be a bottom-gate transistor, that is, the gate of the transistor TFT is located below the active layer, which is not limited by the present invention.

[0079] like Figure 2As shown, the first electrode 1A is formed by laser welding the chip electrode 21a and the bonding electrode 11a, and the second electrode 1B is formed by laser welding the chip electrode 21b and the bonding electrode 11b.

[0080] It should be noted that Figure 2 The figure is merely an exemplary illustration of the internal structure of the backplane 10. In some embodiments, other variations are possible, which are not limited by the present invention. For example, a gate metal layer 1004, a gate insulating layer 1003, a semiconductor layer 1002, a capacitor insulating layer 1005, a capacitor metal layer 1006, an interlayer insulating layer 1007, a drain-source metal layer 1008, a passivation layer 1009, a circuit metal layer 1010, an electrode layer, and a surface passivation layer 1013 are sequentially formed on one side of the substrate 1001 from bottom to top.

[0081] Due to the presence of these circuits in the metal layer of the backplane 10, when the bonding electrodes of the backplane 10 and the chip electrodes of the light-emitting chip 20 are laser-welded after the mass transfer is completed, the circuits formed in the metal layer will absorb energy and heat up, thereby posing a risk of cracking the board. Moreover, these circuits in the metal layer are often unevenly distributed in the backplane 10, for example, Figure 1 In the illustrated embodiment, the pixel circuit, the scan drive circuit and other circuits are concentrated in the first area 101 of the back panel 10, resulting in a higher metal density in the first area 101, while the metal density in the second area 102 outside the first area 101 is relatively low. During laser welding, the first area 101 and the second area 102 heat up differently, and the temperature difference can easily cause cracking of the plate.

[0082] To this end, in the embodiment of the present invention, by differentiating the melting points of the bonding electrodes and / or chip electrodes in different areas of the backplane 10, during laser welding, while meeting the laser energy required for electrode bonding, the temperature rise in the area with higher metal density on the backplane 10 is reduced as much as possible, thereby reducing the risk of backplane cracking. Figures 3 to 5 This is explained in detail.

[0083] like Figure 3 As shown, Figure 1 A schematic cross-sectional view of the display panel 100 along the AA′ direction is shown.

[0084] Refer to 1 and Figure 3 , Figure 3 In the example shown, the light emitting chip 20A and the light emitting chip 20B each include two chip electrodes, and bonding electrodes connected to the chip electrodes are arranged on the back plate 10. Figure 1In the illustrated embodiment, the light emitting chip 20A is located in the first region 101 of the back plate 10 , and the light emitting chip 20B is located in the second region 102 of the back plate 10 . The metal density of the first region 101 is higher than that of the second region 102 .

[0085] It should be noted that, in some embodiments, the first area 101 may also be an area close to the edge of one or more sides of the back panel 10, and the second area 102 may be a partial display area of ​​the back panel 10, which is not limited in the present invention.

[0086] exist Figure 3 In the example shown, the two chip electrodes 201A of the light-emitting chip 20A and the two chip electrodes 201B of the light-emitting chip 20B are made of the same material and have the same melting point; the backplane 10 includes two bonding electrodes 101A connected to the two chip electrodes 201A, and two bonding electrodes 101B connected to the two chip electrodes 201B. The bonding electrodes 101A and the bonding electrodes 101B are made of different materials or have different ratios of elements contained in the materials, and the melting point of the bonding electrode 101A is higher than the melting point of the bonding electrode 101B.

[0087] Reference Figure 1 The melting points of the bonding electrodes in the first region 101 of the backplane 10 are all higher than those in the second region 102. Accordingly, during laser welding, the bonding electrodes in the first region 101 can absorb more energy. On the one hand, while the laser energy meets the energy requirements of the chip electrodes and bonding electrodes in the second region 102, the bonding electrodes in the first region 101 can quickly reach their melting points due to the heat generated by the high metal density in the first region 101, thereby ensuring welding quality. On the other hand, the absorption of heat by the high-melting-point bonding electrodes can better suppress the temperature rise of the plate in the first region 101, reducing the risk of cracking in the backplane 10.

[0088] like Figure 4 As shown, Figure 1 Another schematic cross-sectional view of the display panel along the AA' direction is shown.

[0089] and Figure 3 The example shown differs in that Figure 4 In the example shown, the two chip electrodes 202A of the light-emitting chip 20A and the two chip electrodes 202B of the light-emitting chip 20B are made of different materials or have different ratios of elements contained in the materials, and the melting point of the chip electrode 202A is higher than the melting point of the chip electrode 202B; the backplane 10 includes two bonding electrodes 102A connected to the two chip electrodes 201A, and two bonding electrodes 102B connected to the two chip electrodes 202B, and the bonding electrodes 102A and the bonding electrodes 102B are made of the same material and have the same melting point.

[0090] Similarly, refer to Figure 1 The melting points of the chip electrodes in the first region 101 of the backplane 10 are all higher than those of the chip electrodes in the second region 102. Accordingly, during laser welding, the chip electrodes in the first region 101 can absorb more energy. On the one hand, while the laser energy can meet the energy requirements of the chip electrodes and bonding electrodes in the second region 102, the chip electrodes in the first region 101 can quickly reach their melting points thanks to the heat generated by the high metal density in the first region 101, thereby ensuring welding quality. On the other hand, the absorption of heat by the high-melting-point chip electrodes can better suppress the temperature rise of the plate in the first region 101, reducing the risk of cracking in the backplane 10.

[0091] like Figure 5 As shown, Figure 1 Another schematic cross-sectional view of the display panel along the AA' direction is shown.

[0092] and Figure 3 and Figure 4 The difference is that in Figure 5 In the illustrated embodiment, the two chip electrodes 203A of the light-emitting chip 20A and the two chip electrodes 203B of the light-emitting chip 20B are made of different materials or have different ratios of elements contained in the materials, and the melting point of the chip electrode 203A is higher than the melting point of the chip electrode 203B; similarly, the bonding electrode 103A on the backplane 10 connected to the chip electrode 203A and the bonding electrode 103B on the backplane 10 connected to the chip electrode 203B are made of different materials or have different ratios of elements contained in the materials, and the melting point of the bonding electrode 103A is higher than the melting point of the bonding electrode 103B.

[0093] Similarly, refer to Figure 1 The melting points of the chip electrodes in the first region 101 on the backplane 10 are all higher than the melting points of the chip electrodes in the second region 102, and the melting points of the bonding electrodes in the first region 101 on the backplane 10 are all higher than the melting points of the bonding electrodes in the second region 102. Accordingly, during laser welding, the chip electrodes and bonding electrodes in the first region 101 can absorb more energy. On the one hand, the laser energy can meet the energy requirements of the chip electrodes and bonding electrodes in the second region 102, so that the chip electrodes in the first region 101 and the heat generated by the high metal density in the first region 101 can quickly reach their melting points, thereby ensuring welding quality. On the other hand, the absorption of heat by the high-melting-point chip electrodes can better suppress the temperature rise of the plate in the first region 101, reducing the risk of cracking of the backplane 10.

[0094] like Figure 6 , which is another structural schematic diagram of a display panel provided by an embodiment of the present invention.

[0095] The display panel 100 of this embodiment includes a back plate 10 and a plurality of light emitting chips located on a first surface of the back plate 100. The first surface includes a display area AA and a non-display area SA. Figure 6 The inner area of ​​the red frame is the non-display area SA. Figure 6 In some embodiments, the non-display area SA may be located on one side or at least on two sides of the display area AA, or may be arranged around the display area AA, which is not limited in the present invention.

[0096] The light emitting chips 20 are arranged in an array as pixel units and are located in the display area AA. For the convenience of description, the plurality of light emitting chips 20 arranged in an array are referred to as a pixel array, where each light emitting chip 20 is a pixel unit. Figure 1 As shown, a column of pixel units can be electrically connected to a data line DL, and a row of pixel units can be electrically connected to at least one strobe signal line SL. During the display period, the strobe signal line SL time-shares the scanning of a row of pixel units, and the data line DL time-shares the transmission of data signals to the column of pixel units. By controlling the light-emitting chip 20 through the strobe signal lines SL and the data lines DL, the display area AA displays an image.

[0097] At the same time, in order to further improve the signal uniformity of the display panel 100, the light emitting chip 20 also needs to be connected to a driving voltage line (not shown in the figure), which is used to lead out the positive and negative power supply signals PVDD and PVEE. The driving voltage line is usually arranged in the edge area of ​​the backplane, for example Figure 6 In a non-limiting embodiment shown, drive voltage lines are embedded in the non-display area SA near the bottom edge of the backplane, and are led out through pads 321 and 322, respectively. Specifically, one or more columns of light-emitting chips 20 correspond to a set of PVDD and PVEE signals. Furthermore, data signal pads 31 and other traces are also arranged in the non-display area SA, resulting in a higher metal density in the non-display area SA near the bottom edge of the backplane 10 than in the display area AA.

[0098] The light emitting chip 20 in the display panel 100 has a plurality of chip electrodes. Correspondingly, a corresponding bonding electrode is connected to the chip electrode corresponding to each light emitting chip 20 on the backplane 10 .

[0099] In the prior art, all bonding electrodes on the backplane 10 have the same melting point. When the light-emitting chip on the transient substrate is transferred to the backplane 10 and then laser welded, using the same laser parameters and energy, the non-display area SA near the lower edge of the backplane 10 has a higher metal density. Therefore, the energy absorbed by the circuits and pads in this area causes the temperature to be higher than that of the display area AA. To ensure the quality of the electrode bonding, this area must withstand higher temperatures, which can easily cause cracking in the plate.

[0100] To this end, a first area 101 and a second area 102 are set on the first surface of the backplane 10. By differentially designing the melting points of the bonding electrodes and / or chip electrodes in the first area 101 and the second area 102, during laser welding, the temperature rise in the metal density area on the backplane 10 is reduced as much as possible while meeting the laser energy required for electrode bonding, thereby reducing the risk of cracking of the backplane.

[0101] For example, for Figure 6 The light emitting chip 20A and other light emitting chips in the first area 101 of the display panel 100, as well as the light emitting chip 20B and other light emitting chips in the second area 102, can all be made of Figure 3 or Figure 4 or Figure 5 The different designs shown ensure that the temperature of the first region 101 and the temperature of the second region 102 are as close as possible during laser welding, and are conducive to using a laser beam with relatively low energy to ensure welding quality.

[0102] like Figure 7 , which is another structural schematic diagram of a display panel provided by an embodiment of the present invention.

[0103] In this embodiment, the light emitting chip 20 includes light emitting chips of multiple colors, which are red light emitting chip R, green light emitting chip G and blue light emitting chip B. In order to distinguish the light emitting chips of different colors, Figure 7 Each light emitting chip 20 is filled with red, green and blue color patterns to represent the three colors of light emitting chips. Similarly, the light emitting chips 20 are arranged in an array as pixel units and are located in the display area AA. Figure 7 As shown, a column of pixel units is electrically connected to at least three data lines. To make the diagram clear, Figure 7 In the figure, a data line DL is used to represent a row of pixel units. A row of pixel units can be electrically connected to at least one strobe signal line SL. During the display period, the strobe signal line SL time-shares the scan of a row of pixel units, while the data line DL time-shares the data signal to a column of pixel units. The strobe signal line SL and the data line DL control the light-emitting chip 20 to realize the display area AA.

[0104] In this example, the data signal pad 31 is arranged in the non-display area SA near the lower side of the first surface, and the pads 321 and 322 for leading out the driving voltage lines (not shown in the figure) of the positive and negative power supply signals PVDD and PVEE are arranged in the non-display area SA near the upper and left sides of the first surface.

[0105] Obviously, the metal density of the first area 101 outside the dotted line in the figure is higher than that of the second area 102 inside the dotted line. In order to avoid the back plate 10 from cracking due to the temperature difference between the two areas during laser welding, in the embodiment of the present invention, the metal density of the first area 101 outside the dotted line is higher than that of the second area 102 inside the dotted line. Figures 3 and 4 In the embodiment shown, the light emitting chip 20A and other light emitting chips in the first area 101, and the light emitting chip 20B and other light emitting chips in the second area 102 can all adopt Figure 3 or Figure 4 or Figure 5 The different designs shown ensure that the temperature of the first region 101 and the temperature of the second region 102 are as close as possible during laser welding, and are conducive to using a laser beam with relatively low energy to ensure welding quality.

[0106] Furthermore, considering that different colors of light-emitting chips use different semiconductor materials, for example, the substrate material of the red light-emitting chip (also called red light chip) is often AlGaInP (aluminum gallium indium phosphide) or GaAs (gallium arsenide) material, while the substrate material of the blue and green light-emitting chips (also called blue-green light chips) is often nGaN (indium gallium nitrogen) or GaN (gallium nitride), the different colors of light-emitting chips have different absorption and reflection capabilities for lasers, and the red light chip has a stronger absorption capacity for lasers. In addition, when laser welding the electrodes, the electrodes of the three colors of light-emitting chips are bonded at the same time. In the prior art, the three colors of light-emitting chips usually use chip electrodes of the same material. Therefore, during laser welding, if the laser intensity used is high, it is easy to cause the chip electrode of the red light-emitting chip to over-melt or the solder overflows and short-circuit; if the laser intensity used is low, it is easy to cause the chip electrodes of the blue and green light-emitting chips to be poorly soldered. For this reason, in Figure 7 In the illustrated embodiment, the melting points of the chip electrodes of light-emitting chips of different colors can also be designed differently, and / or the melting points of the bonding electrodes on the backplane 10 connected to the chip electrodes of light-emitting chips of different colors can be designed differently, so that the bonding quality of the electrodes of light-emitting chips of different colors remains consistent during welding.

[0107] Since the chip electrodes of the blue and green light-emitting chips have similar characteristics, for the convenience of description, the red light-emitting chip can be referred to as the first color light-emitting chip, and the blue light-emitting chip and the green light-emitting chip can be collectively referred to as the second light-emitting chip.

[0108] Accordingly, in a non-limiting embodiment, the melting points of the bonding electrodes on the back panel 10 connected to the light-emitting chips of different colors can be designed differently. Specifically, the melting point of the bonding electrode connected to the chip electrode of the first color light-emitting chip is higher than the melting point of the bonding electrode connected to the chip electrode of the second color light-emitting chip.

[0109] In another non-limiting embodiment, the melting points of chip electrodes of light-emitting chips of different colors may be designed differently. Specifically, the melting point of the chip electrode of the first color light-emitting chip is higher than the melting point of the chip electrode of the second color light-emitting chip.

[0110] In another non-limiting embodiment, the melting points of the bonding electrodes on the back panel 10 connected to the light-emitting chips of different colors and the melting points of the chip electrodes of the light-emitting chips of different colors can be designed differently at the same time, which can better ensure the electrode bonding quality of the light-emitting chips of different colors and thereby improve the quality of the display panel 100.

[0111] By designing the melting points of the chip electrodes of light-emitting chips of different colors and the bonding electrodes connected thereto differently, light-emitting chips of different colors can obtain better bonding quality during laser welding, thereby ensuring the quality of the display panel.

[0112] In some embodiments, the backplane 10 provided by the embodiment of the present invention can be rectangular, circular, etc., and the backplane 10 can even include some special-shaped areas. When the corresponding lines in the special-shaped areas are relatively dense, the above-mentioned various design methods can also be used to reduce the temperature of the special-shaped areas during laser welding, and improve the problems such as cracking of the backplane 10 caused by overheating due to absorption of laser energy by the lines in the special-shaped areas.

[0113] refer to Figure 8 , which is another structural schematic diagram of a display panel provided by an embodiment of the present invention.

[0114] The first surface of the back plate 10 includes a display area AA and a non-display area.

[0115] The non-display area SA includes a first area SA1 in a first direction X and located on at least one side of the display area AA, and / or a second area SA2 in a second direction Y and located on at least one side of the display area AA, and the first direction X and the second direction Y intersect (specifically, the first direction X and the second direction Y may be perpendicular to each other).

[0116] like Figure 8As shown, the first area SA1 and the second area SA2 are connected at the corner areas opposite to each other at the ends. For the convenience of description, the corner areas may also be referred to as special-shaped areas. The corners may be any shapes such as R angle (Corner Radius), broken line angle, etc. Assume that the scan drive circuit VSR is located in the special-shaped areas corresponding to the four corners. When the first area SA1 and the second area SA2 are connected through the special-shaped areas, it is equivalent to reducing the overall wiring area of ​​the non-display area, that is, the wiring area of ​​the special-shaped areas is more limited, so that when the scan drive circuit VSR is extended and arranged in the special-shaped areas, the line density at the special-shaped areas will be higher than that of other areas of the non-display area, such as the first area SA1. Accordingly, during laser welding, the lines in these special-shaped areas easily absorb laser energy and overheat, resulting in problems such as cracking of the backplane 10.

[0117] To this end, in an embodiment of the present invention, part of the display area and part of the special-shaped area close to the four special-shaped areas can be used as the first area 101, and the remaining display area can be used as the second area 102. Different melting points are designed for the chip electrodes of the light-emitting chip 20A in the first area and the light-emitting chip 20B in the second area, as well as the bonding electrodes corresponding to each chip electrode, so as to eliminate the different temperatures caused by different internal metal densities in different areas of the backplane during laser welding, and / or the different welding qualities caused by different light-emitting materials of chips of different colors, effectively avoiding the occurrence of cracks in the backplane 10 and ensuring the quality of the display panel 100.

[0118] Accordingly, an embodiment of the present invention further provides a method for manufacturing a display panel, such as Figure 9 FIG. 1 is a flow chart of the method of the present invention. The manufacturing process of the display panel is as follows:

[0119] In step S91, a backplane is provided, which includes a first area and a second area, wherein the metal density of the first area is higher than the metal density of the second area; a plurality of bonding electrodes are provided on the backplane, and the melting point of the bonding electrodes in the first area is higher than the melting point of the bonding electrodes in the second area.

[0120] In step S92 , the prefabricated light-emitting chips are transferred to the second area and the first area on the backplane.

[0121] In step S93, the chip electrodes are fixedly connected to the bonding electrodes on the backplane by laser welding.

[0122] like Figure 10 FIG. 1 is another flow chart of a method for manufacturing a display panel provided by an embodiment of the present invention, comprising the following steps:

[0123] In step S101 , a backplane is provided, the backplane comprising a first region and a second region, wherein the metal density of the first region is higher than the metal density of the second region; and a plurality of bonding electrodes are provided on the backplane.

[0124] In step S102 , the prefabricated light emitting chip is transferred to the second area and the first area on the backplane, wherein the melting point of the chip electrode of the light emitting chip transferred to the first area is higher than the melting point of the chip electrode of the light emitting chip transferred to the second area.

[0125] In step S103, the chip electrodes are fixedly connected to the bonding electrodes on the backplane by laser welding.

[0126] In some embodiments, the following conditions may also be met simultaneously: the melting point of the bonding electrode in the first region is higher than the melting point of the bonding electrode in the second region, and the melting point of the chip electrode of the light-emitting chip transferred to the first region is higher than the melting point of the chip electrode of the light-emitting chip transferred to the second region.

[0127] In the above embodiments, the light-emitting chips with different electrode melting points can be provided by the same transfer substrate or by different transfer substrates. Accordingly, the transfer method can be one or more of laser transfer, stamp transfer, or other transfer methods, which are not limited in this embodiment of the present invention.

[0128] In some non-limiting embodiments, the first area may be an edge area of ​​the backplane, and the second area may be a display area of ​​the backplane. The light-emitting chips in the first area and the light-emitting chips in the second area may be chips of the same color or chips of different colors.

[0129] By designing the differentiated melting points of the bonding electrodes in different areas of the backplane and / or the chip electrodes connected thereto, the risk of cracking of the backplane due to different temperatures in different areas during laser welding can be better avoided, thereby ensuring the production yield and quality of the display panel.

[0130] like Figure 11 FIG. 1 is another flow chart of a method for manufacturing a display panel provided by an embodiment of the present invention, comprising the following steps:

[0131] In step S111 , a backplane is provided, wherein the backplane includes a first region and a second region, wherein the metal density of the first region is higher than the metal density of the second region; and a plurality of bonding electrodes are provided on the backplane.

[0132] In step S112, a first transfer substrate is provided, and a light-emitting chip having a first chip electrode is generated on the first transfer substrate; and a second transfer substrate is provided, and a light-emitting chip having a second chip electrode is generated on the second transfer substrate; the melting point of the first chip electrode is higher than the melting point of the second chip electrode.

[0133] The light-emitting chip having the first chip electrode may be a red light chip, and the light-emitting chip having the second chip electrode may be a green light chip or a blue light chip.

[0134] In step S113, the light emitting chip on the second transfer substrate is transferred to the second area on the backplane, and then the light emitting chip on the first transfer substrate is transferred to the first area on the backplane.

[0135] In some embodiments, the transfer can be accomplished by one or more methods such as laser transfer and stamp transfer, which is not limited in this embodiment of the present invention.

[0136] In step S14, the chip electrodes are fixedly connected to the bonding electrodes on the backplane by laser welding.

[0137] It should be noted that in some embodiments, the light-emitting chips with the first chip electrodes and the light-emitting chips with the second chip electrodes can be prefabricated on the same transfer substrate. During transfer, the light-emitting chips with the second chip electrodes on the transfer substrate can be transferred to the second area of ​​the backplane by mass transfer, while the light-emitting chips with the first chip electrodes can be transferred to the first area of ​​the backplane at the same time; or the light-emitting chips with the second chip electrodes on the transfer substrate can be first transferred to the second area of ​​the backplane by mass transfer, and then the light-emitting chips with the first chip electrodes on the transfer substrate can be transferred to the first area of ​​the backplane by stamp transfer.

[0138] In some embodiments, the light-emitting chip may include a first color light-emitting chip and a second color light-emitting chip; wherein the first color light-emitting chip may be a red light-emitting chip, and the second color light-emitting chip may be a green light-emitting chip and a blue light-emitting chip. Accordingly, the first and second regions of the backplane may respectively include a first bonding electrode connected to the chip electrode of the first color light-emitting chip and a second bonding electrode connected to the chip electrode of the second color light-emitting chip. Furthermore, in this embodiment, the melting point of the first bonding electrode is higher than the melting point of the second bonding electrode; and / or the melting point of the chip electrode of the first color light-emitting chip is higher than the melting point of the chip electrode of the second color light-emitting chip.

[0139] In some embodiments, the chip electrode and / or the bonding electrode may include a tin-based solder layer. In the above-mentioned embodiments of the manufacturing method of each display panel, the melting point of the electrode can be adjusted by doping with different elements, and the tin-based solder layer of the high-melting-point electrode is doped with a high-melting-point element, and the tin-based solder layer of the low-melting-point electrode is doped with a low-melting-point element. For example, in a non-limiting embodiment, the tin-based solder layer is a tin-based alloy film. Accordingly, the tin-based alloy film can be formed on each electrode by sputtering or evaporation. Among them, the high-melting-point element may include, but is not limited to, any one or more of the following: silver, copper, etc.; the low-melting-point element may include, but is not limited to, any one or more of the following: bismuth, tin, lead, indium, etc.

[0140] In some embodiments, the chip electrode and / or the bonding electrode may include a soldering metal layer. In the aforementioned display panel manufacturing method embodiments, the melting point of the electrode can be adjusted by varying the content of a specific metal in the soldering metal layer. For example, in one non-limiting embodiment, the soldering metal layer is a gold-indium thin film, and the indium content of the gold-indium thin film of the high-melting-point electrode is lower than the indium content of the gold-indium thin film of the low-melting-point electrode. Accordingly, the gold-indium thin film can be formed on the electrode by sputtering or evaporation.

[0141] In some embodiments, the chip electrode may include a gold plating layer, and the bonding electrode may include an indium plating layer; the thickness or area of ​​the indium plating layer of the high melting point bonding electrode is smaller than the thickness or area of ​​the indium plating layer of the low melting point bonding electrode.

[0142] In some embodiments, the chip electrode may include a gold-plated layer, and the bonding electrode may include an indium ball; the volume of the indium ball of the high-melting-point bonding electrode is smaller than the volume of the indium ball of the low-melting-point bonding electrode.

[0143] Through the above-mentioned various electrode manufacturing processes, the doping of different elements in the solder layer, or the adjustment of the content of specific metals in the welding metal layer, the electrodes in the high metal density area on the backplane have a higher melting point, and the melting point of the chip electrodes of the red light chip is made higher than the melting point of the chip electrodes of the blue-green light chip. In addition, in combination with different laser welding processes, it can avoid the risk of cracking of the backplane due to different temperatures in different areas during laser welding, and can also ensure that under the same laser parameters, the electrodes of light-emitting chips of different colors will not over-melt, short-circuit or have cold solder joints, thereby effectively improving product quality.

[0144] Based on the same inventive concept, an embodiment of the present invention further provides a display device. Figure 12 , which is a schematic structural diagram of a display device provided in an embodiment of the present invention, wherein the display device 120 provided in an embodiment of the present invention includes a display panel provided in any one of the above embodiments.

[0145] In some embodiments, the display device 120 provided in the embodiment of the present invention can be any electronic device with a display function, such as a mobile terminal, notebook, tablet computer, computer, wearable device, vehicle-mounted display device, etc., and is particularly suitable for electronic devices with special-shaped transparent display panels, which the present invention does not specifically limit.

[0146] It is understandable that Figure 12 The display device is illustrated as a rectangular structure only. In some other embodiments of the present disclosure, the display device 120 may also be circular, elliptical, or any other feasible shape, which is not specifically limited in the present disclosure.

[0147] The display device 120 provided in the embodiment of the present invention has the beneficial effects of the display panel 100 provided in the embodiment of the present invention. For details, reference may be made to the detailed description of the display panel 100 in the above embodiments, which will not be repeated in this embodiment.

[0148] It should be understood that in the description of the embodiments of the present invention, the term "and / or" is merely used to describe an association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Furthermore, the character " / " in this document indicates that the associated objects are in an "or" relationship.

[0149] In addition, the orientations or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0150] In addition, the terms "first" and "second" are used for descriptive purposes only, and are only used to illustrate and distinguish the objects being described. There is no order, and they cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, and cannot constitute any limitation on the embodiments of the present invention. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of such features. In the description of the embodiments of the present invention, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0151] In the embodiments of the present invention, unless otherwise specified or limited, terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication between them; direct connections or indirect connections through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0152] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0153] In the embodiments of the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0154] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. Any person skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments without departing from the spirit and scope of the present invention.

Claims

1. A display panel, characterized in that: include: a back plate, wherein a plurality of bonding electrodes are provided on the back plate; A plurality of light-emitting chips, each comprising a chip electrode; the chip electrodes are respectively fixed to the bonding electrodes by laser welding; The back plate includes a first area and a second area, the metal density of the first area is higher than the metal density of the second area; The melting point of the bonding electrodes in the first region is higher than that of the bonding electrodes in the second region; and / or the melting point of the chip electrodes in the first region is higher than that of the chip electrodes in the second region.

2. The display panel according to claim 1, wherein: The first area is an edge area of ​​the back panel, and the second area is a partial area of ​​the back panel display area.

3. The display panel according to claim 1, wherein: The light emitting chip includes a first color light emitting chip and a second color light emitting chip; The melting point of the bonding electrode connected to the chip electrode of the first color light-emitting chip is higher than the melting point of the bonding electrode connected to the chip electrode of the second color light-emitting chip; and / or The melting point of the chip electrode of the first color light emitting chip is higher than the melting point of the chip electrode of the second color light emitting chip.

4. The display panel according to claim 3, wherein: The first color light-emitting chip is a red light Micro LED chip, and the second color light-emitting chip is a blue light Micro LED chip and a green light Micro LED chip.

5. A display device, characterized in that: The display panel comprises the display panel according to any one of claims 1 to 4.

6. A method for manufacturing a display panel, characterized in that: The method comprises: Providing a back plate, the back plate comprising a first region and a second region, wherein the metal density of the first region is higher than the metal density of the second region; and a plurality of bonding electrodes are provided on the back plate; Transferring the prefabricated light-emitting chip to the second area and the first area on the backplane; The melting point of the bonding electrode in the first region is higher than that of the bonding electrode in the second region; and / or the melting point of the chip electrode of the light-emitting chip transferred to the first region is higher than that of the chip electrode of the light-emitting chip transferred to the second region; The chip electrodes are fixedly connected to the bonding electrodes on the back plate by laser welding.

7. The method for manufacturing a display panel according to claim 6, wherein: The method further comprises: A transfer substrate is provided, on which a light-emitting chip having a first chip electrode and a light-emitting chip having a second chip electrode are generated, wherein the melting point of the first chip electrode is higher than the melting point of the second chip electrode.

8. The method for manufacturing a display panel according to claim 7, wherein: The step of transferring the prefabricated light-emitting chip to the second area and the first area on the backplane comprises: The light-emitting chip with the second chip electrode on the transfer substrate is transferred to the second area of ​​the backplane through mass transfer, and the light-emitting chip with the first chip electrode is transferred to the first area of ​​the backplane at the same time.

9. The method for manufacturing a display panel according to claim 7, wherein: The step of transferring the prefabricated light-emitting chip to the second area and the first area on the backplane comprises: transferring the light-emitting chip having the second chip electrode on the transfer substrate to the second area of ​​the backplane by mass transfer; The light-emitting chip having the first chip electrode on the transfer substrate is transferred to the first area of ​​the backplane by stamp transfer.

10. The method for manufacturing a display panel according to claim 6, wherein: The method further comprises: Providing a first transfer substrate, and generating a light-emitting chip having a first chip electrode on the first transfer substrate; Providing a second transfer substrate, and growing a light-emitting chip having a second chip electrode on the second transfer substrate; the melting point of the first chip electrode is higher than the melting point of the second chip electrode; The step of transferring the prefabricated light-emitting chip to the second area and the first area on the backplane comprises: transferring the light-emitting chip on the second transfer substrate to the second area on the backplane; The light emitting chip on the first transfer substrate is transferred to the first area on the backplane.

11. The method for manufacturing a display panel according to claim 6, wherein: The first area is an edge area of ​​the back panel, and the second area is a display area of ​​the back panel.

12. The method for manufacturing a display panel according to claim 6, wherein: The light-emitting chips in the first area and the light-emitting chips in the second area are chips of the same color.

13. The method for manufacturing a display panel according to any one of claims 6 to 12, wherein: The light emitting chip includes a first color light emitting chip and a second color light emitting chip; The first area and the second area of ​​the back plate respectively include a first bonding electrode connected to the chip electrode of the first color light emitting chip and a second bonding electrode connected to the chip electrode of the second color light emitting chip; The melting point of the first bonding electrode is higher than that of the second bonding electrode; and / or the melting point of the chip electrode of the first color light-emitting chip is higher than that of the chip electrode of the second color light-emitting chip.

14. The method for manufacturing a display panel according to claim 13, wherein: The first color light-emitting chip is a red light Micro LED chip, and the second color light-emitting chip is a blue light Micro LED chip and a green light Micro LED chip.

15. The method for manufacturing a display panel according to any one of claims 6 to 12, wherein: The chip electrode and / or the bonding electrode comprises a tin-based solder layer, and the method further comprises: The melting points of the electrodes are adjusted by doping with different elements. The tin-based solder layer of the high-melting-point electrode is doped with a high-melting-point element, and the tin-based solder layer of the low-melting-point electrode is doped with a low-melting-point element.

16. The method for manufacturing a display panel according to claim 15, wherein: The tin-based solder layer is a tin-based alloy film; the method further comprises: The tin-based alloy film is formed on the electrode by sputtering or evaporation.

17. The method for manufacturing a display panel according to claim 16, wherein: The high melting point element includes any one or more of the following: silver, copper; the low melting point element includes any one or more of the following: bismuth, tin, lead, indium.

18. The method for manufacturing a display panel according to any one of claims 6 to 12, wherein: The chip electrode and / or the bonding electrode includes a welding metal layer, and the method further includes: The melting point of the electrode is adjusted by changing the content of a specific metal in the weld metal layer.

19. The method for manufacturing a display panel according to claim 18, wherein: The welding metal layer is a gold-indium thin film, and the indium content in the gold-indium thin film of the high-melting-point electrode is lower than the indium content in the gold-indium thin film of the low-melting-point electrode.

20. The method for manufacturing a display panel according to claim 19, wherein: The method further comprises: The gold-indium thin film is formed on the electrode by sputtering or evaporation.

21. The method for manufacturing a display panel according to any one of claims 6 to 12, wherein: The chip electrode includes a gold-plated layer, and the bonding electrode includes an indium-plated layer; The thickness or area of ​​the indium plating layer of the bonding electrode with a high melting point is smaller than the thickness or area of ​​the indium plating layer of the bonding electrode with a low melting point.

22. The method for manufacturing a display panel according to any one of claims 6 to 12, wherein: The chip electrode includes a gold-plated layer, and the bonding electrode includes an indium ball; The volume of the indium ball of the bonding electrode with a high melting point is smaller than the volume of the indium ball of the bonding electrode with a low melting point.

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