Micro light emitting diode display panel, preparation method thereof and display device

Abstract

The application provides a micro light emitting diode display panel and a preparation method thereof and a display device. The micro light emitting diode display panel comprises a substrate, a plurality of integrated units, and a plurality of signal lines. The substrate comprises a panel circuit and a plurality of integrated units. Each integrated unit comprises a pixel group, a pixel driving chip, and a bridge electrode. The pixel group and the pixel driving chip are respectively fixed on the surface of the substrate. The two ends of the bridge electrode are respectively electrically connected to the pixel group and the pixel driving chip. The pixel driving chip and the signal line are electrically connected. Each pixel group comprises at least one micro light emitting diode chip.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of display, in particular to a micro light emitting diode display panel, a preparation method thereof and a display device. BACKGROUND

[0002] With the continuous expansion of the demand and application field of display and illumination, the demand for light emitting diodes (LED) and the related performance requirements are also increasingly high. Among them, the micro light emitting diode is to miniaturize the traditional LED to below 100 microns, which has the advantages of self-luminous, low power consumption, high brightness, long service life and other good photoelectric characteristics. In recent years, with the increasingly wide application field of light emitting diodes, micro light emitting diodes (Micro LED) are the focus of the industry.

[0003] At present, the display panel based on micro light emitting diode generally adopts massive transfer technology to transfer massive micro light emitting diodes to a driving backboard containing driving circuits, and after completing the electrical connection, the driving circuits drive the micro light emitting diodes to display. However, since the process of the micro light emitting diode and the process of the driving backboard are not compatible, there are problems such as poor electrical consistency and large electrical drift between the micro light emitting diode transferred to the driving backboard and the driving circuit.

[0004] Therefore, it is necessary to propose a new improved micro light emitting diode display panel. SUMMARY

[0005] In order to solve the technical problems in the prior art, the present application provides a micro light emitting diode display panel, a preparation method thereof and a display device.

[0006] In order to solve the above problems, the technical scheme of the present application provides a micro light emitting diode display panel, which comprises: a substrate, the substrate comprising a panel circuit and a signal line which are electrically connected to each other; and a plurality of integrated units arranged in an array on one side surface of the substrate, each integrated unit comprising a pixel group, a pixel driving chip and a bridge electrode, both ends of the bridge electrode being electrically connected to the pixel group and the pixel driving chip respectively, the pixel group comprising at least one micro light emitting diode chip, and the pixel driving chip being electrically connected to the signal line; wherein the projection of the pixel group on the substrate and the projection of the pixel driving chip on the substrate do not overlap.

[0007] As an optional technical scheme, each integrated unit further comprises a planar layer, the planar layer covering the pixel group and the pixel driving chip, one side of the planar layer towards the substrate comprising a planar surface, and the bridge electrode being arranged on the planar surface.

[0008] As an optional technical solution, the flat layer is an optical absorption type flat layer.

[0009] As an optional technical solution, each integrated unit further comprises a dielectric layer and a plurality of pads, the dielectric layer is arranged on the flat surface, the plurality of pads are arranged on a side of the dielectric layer away from the flat surface, the dielectric layer comprises a plurality of dielectric layer through holes, the plurality of dielectric layer through holes are filled with conductive posts, the conductive posts are electrically connected with the plurality of pads and a plurality of pins on the pixel driving chip; wherein the plurality of pads and the signal lines are electrically connected.

[0010] As an optional technical solution, the electrodes of the at least one micro light emitting diode chip and the pins on the pixel driving chip are respectively exposed from the flat surface.

[0011] As an optional technical solution, each integrated unit further comprises a first intermediate substrate, the pixel group and the pixel driving chip are arranged between the first intermediate substrate and the flat layer, wherein a first bonding layer is arranged on a side of the first intermediate substrate facing the pixel group and the pixel driving chip.

[0012] The application further provides a display device comprising the display panel.

[0013] The application further provides a preparation method of a micro light emitting diode display panel, the preparation method comprising:

[0014] providing a substrate, the substrate comprising a panel circuit and a signal line which are electrically connected with each other;

[0015] preparing a plurality of integrated units, each integrated unit comprising a pixel group, a pixel driving chip and a bridge electrode, two ends of the bridge electrode being electrically connected with the pixel group and the pixel driving chip respectively;

[0016] transferring the plurality of integrated units to a surface of a side of the substrate, the pixel driving chip and the panel circuit being electrically connected;

[0017] wherein the plurality of integrated units are arranged in an array.

[0018] As an optional technical solution, the preparation integrated unit comprises: providing a first intermediate substrate, a plurality of pixel groups are temporarily fixed on the first intermediate substrate, each pixel group comprises at least one micro light emitting diode, and there is a gap between any adjacent pixel groups; providing a second intermediate substrate, a plurality of pixel driving chips are temporarily fixed on the second intermediate substrate; bonding the first intermediate substrate and the second intermediate substrate, each pixel driving chip is located in the corresponding gap; peeling off the second intermediate substrate; forming a plurality of bridge electrodes, each bridge electrode is electrically connected to the corresponding pixel group and pixel driving chip at opposite ends; and cutting to form a single integrated unit.

[0019] As an optional technical solution, after peeling off the second intermediate substrate, further comprising: forming a planar layer above the plurality of pixel groups and the plurality of pixel driving chips; and forming a plurality of bridge electrodes above the planar layer.

[0020] As an optional technical solution, further comprising: forming a dielectric layer above the planar layer; patterning the dielectric layer to form a plurality of dielectric layer through holes, a plurality of pins of the pixel driving chip are exposed from the corresponding plurality of dielectric layer through holes; filling a conductive post in each of the plurality of dielectric layer through holes; and forming a plurality of pads above the dielectric layer, the plurality of pads are electrically connected to the plurality of pins through the conductive posts.

[0021] Compared with the prior art, the present application provides a micro light emitting diode display panel and a preparation method thereof, and a display device. The substrate of the micro light emitting diode display panel is provided with a plurality of integrated units arranged in an array. The integrated unit comprises a pixel group, a pixel driving chip and a bridge electrode. The pixel group and the pixel driving chip are arranged horizontally on the plane of the substrate. The electrical connection between the two is realized through the bridge electrode. On the one hand, the light emitting efficiency of the pixel group is not affected after the integration of the two. On the other hand, the electrical connection mode of pre-bonding the electrodes of the micro light emitting diode chip in the pixel group and the pins of the pixel driving chip is avoided. The electrical connection is realized through a wiring process (bridge electrode), which has low process difficulty and high electrical connection stability. Further, the above integrated units are subjected to electrical and optical performance consistency tests before being transferred to the substrate, and are sorted on this basis. Therefore, the electrical driving signals between each pixel group and its corresponding pixel driving chip are consistent. When they are applied to the micro light emitting diode display panel as pixels, the problems of poor electrical consistency and large electrical drift between the micro light emitting diodes and the driving circuit on the existing driving backplane can be overcome.

[0022] The present application will be described in detail below in conjunction with the drawings and specific embodiments, but is not limited to the present application. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0024] Figure 1 It is a partial cross-sectional schematic view of a micro-LED display panel in an embodiment of the present application.

[0025] Figure 2 It is a partial cross-sectional schematic view of a micro-LED display panel in another embodiment of the present application.

[0026] Figure 3 It is a partial cross-sectional schematic view of a micro-LED display panel in still another embodiment of the present application.

[0027] Figure 4 It is a flow chart of a preparation method of a micro-LED display panel provided by the present application.

[0028] Figures 5 to 7 It is a cross-sectional schematic view of a preparation process of an integrated unit in a micro-LED display panel provided by the present application.

[0029] Figure 8 It is a top view schematic view of a bridge electrode connecting a micro-LED chip and a pixel driving chip in the present application. Figure 7

[0030] It is a top view schematic view of a pad formed on a dielectric layer in the present application. Figure 9 Specific embodiments Figure 7 In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with examples and drawings. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0031] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with examples and drawings. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0032] ​It is to be understood that the terminology used herein such as first and second, and the like, is only used to distinguish one entity or action from another entity or action, and does not necessarily require or imply such a relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by an "includes" statement does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0033] It should be understood that when describing the structure of a component, when one layer, one region is referred to as being "on" or "above" another layer, another region, it can mean being directly on or above the other layer, another region, or other layers or regions are included therebetween. Moreover, if the component is turned over, the one layer, one region will be "under" or "below" the other layer, another region.

[0034] The driving technology of driving the micro light emitting diode display includes two ways of active driving and passive driving. The active driving way has large display information amount, high display image quality, and high integration degree of display terminal, and is particularly suitable for the micro light emitting diode display technology. At present, in the micro light emitting diode display technology of the active driving way, there are problems of poor electrical consistency of thin film transistors (TFT) of a driving backplane, large electrical drift, and the like.

[0035] To overcome the above technical problems, the present application provides a micro light emitting diode display panel, a preparation method thereof, and a display device.

[0036] As shown in Figure 1 The micro light emitting diode display panel 100 includes a substrate 110 and a plurality of integrated units 120 arranged in an array on one side surface of the substrate 110, the substrate 110 includes a panel circuit 112 and a signal line 111 which are electrically connected to each other; each integrated unit 120 includes a pixel group 121, a pixel driving chip 122, and a bridge electrode 123, two ends of the bridge electrode 123 are electrically connected to the pixel group 121 and the pixel driving chip 122 respectively, the pixel driving chip 122 is electrically connected to the signal line 111, and each pixel group 121 includes at least one micro light emitting diode chip; wherein the projection of the pixel group 121 on the substrate 110 and the projection of the pixel driving chip 122 on the substrate 110 do not coincide.

[0037] In a preferred embodiment, each pixel group 121 includes three micro light-emitting diode chips of different light-emitting colors, for example, a red micro light-emitting diode chip, a green micro light-emitting diode chip, and a blue micro light-emitting diode chip, wherein the red micro light-emitting diode chip can also be composed of a blue micro light-emitting diode chip and a red quantum dot material, and the green micro light-emitting diode chip can also be composed of a blue micro light-emitting diode chip and a green quantum material.

[0038] The pixel driving chip 122 corresponding to each pixel group 121 includes a silicon substrate body 122a and a pixel driving circuit 122b formed inside the silicon substrate body 122a, and the silicon substrate body 121a includes a single crystal silicon substrate body, a low-temperature polysilicon substrate body, etc., wherein the pixel driving circuit 122b can be a single crystal silicon semiconductor transistor, a low-temperature polysilicon semiconductor transistor, etc.

[0039] In the micro light-emitting diode display panel 100 provided by the present application, the projection of the pixel group 121 on the substrate 110 and the projection of the pixel driving chip 122 on the substrate 110 do not coincide, that is, the pixel group 121 and the pixel driving chip 122 are horizontally expanded and arranged on the surface of the substrate 110 in the plane of the substrate 110, and the pixel group 121 and the pixel driving chip 122 are electrically connected through the bridge electrode 123. Since the pixel group 121 and the pixel driving chip 122 are horizontally expanded in the plane of the substrate 110, they are electrically connected through external wiring (bridge electrode 123). On the one hand, the horizontal expansion arrangement makes the integration of the pixel driving chip 122 and the pixel group 121 not block the light emission of the pixel group 121, and does not affect the original light emission efficiency of the pixel group. On the other hand, compared with the pre-bonding method of forming electrical connection in the thickness direction (vertical direction) between the pixel driving chip and the pixel group, the present application adopts the connection method of forming electrical connection between the pixel driving chip and the pixel group in the plane direction of the substrate 110 through the bridge electrode, which has lower process complexity and more stable electrical connection. Specifically, the horizontal bridge connection method using the bridge electrode is compatible with the existing semiconductor process, and does not require high-temperature and high-pressure welding process, which effectively protects the device. The selection window of the bridge metal material is wide, and the existing metal material in the semiconductor process can meet the requirements, such as Mo, Al, Ti, etc.

[0040] Further, in the present application, the manufacturing process of the pixel driving chip 122 including the pixel driving circuit 122b is separated from the manufacturing process of the substrate 110 including the signal line 111, wherein the manufacturing process of the substrate 110 only needs to perform simple wiring in the substrate 110, thus significantly reducing the processing difficulty of the substrate 110.

[0041] In some embodiments, the substrate 110 can be a glass substrate, or can be a flexible substrate such as a polyimide (PI) substrate.

[0042] In some embodiments, the panel circuit 112 can include a scan control circuit, a data control circuit, and the like. The panel circuit 112 can be an integrated circuit (IC). The integrated circuit (IC) can be bonded on the substrate 110 through a flexible printed circuit (FPC).

[0043] In some embodiments, the signal line 111 can include a scan line, a data line, a reference voltage line (Vref), a power supply line (Vdd), a common ground power supply line (Vss), and the like. For the purpose of clearly showing the overall structure of the micro light emitting diode display panel 100, Figure 1 only one signal line 111 is shown in the figure.

[0044] In some embodiments, the circuit structure of the pixel driving circuit 122b can be any one of a 2T1C circuit, a 4T1C circuit, a 5T1C circuit, a 6T1C circuit, a 7T1C circuit, a 7T2C circuit, or a 9T1C circuit, or the circuit structure of the pixel driving circuit 122b can also be other circuit structures, which are not specifically limited herein. In this document, “2T1C circuit” refers to a pixel driving circuit including 2 thin film transistors (T) and 1 capacitor (C), and other “7T1C circuit”, “7T2C circuit”, “9T1C circuit” and the like are similarly defined.

[0045] In addition, in the present embodiment, the pad 114 electrically connected to the panel circuit 112 is located at the edge of the substrate 110, but is not limited thereto.

[0046] Continuing to refer to Figure 1 , the integrated unit 120 further includes a planar layer 124 covering the pixel group 121 and the pixel driving chip 122, wherein the planar layer 124 has a planar surface facing the substrate 110, the bridge electrode 123 is disposed on one side of the planar surface 1241 and is electrically connected to the electrode of the micro light emitting diode chip in the pixel group 121 and the pin 122c of the pixel driving chip 122.

[0047] In some embodiments, the planar layer 124 is, for example, a light-absorbing type planar layer, and is preferably a black or gray resin material with a light transmittance of less than 10%.

[0048] In addition, the back side (the side without electrodes) of each micro LED chip in the pixel group 121 is exposed from the side of the planarization layer 124 away from the substrate 110. With the light-absorbing planarization layer 124, each micro LED chip in the pixel group 121 can emit light from the back side.

[0049] In this embodiment, the planarization layer 124 is used to cover the pixel group 121 and the pixel driver chip 122 to provide a flat surface 1241 for the bridging electrode 123, which can improve the connection stability between the bridging electrode 123 and the pixel group 121 and the pixel driver chip 122; and reduce the manufacturing difficulty of the bridging electrode 123.

[0050] A dielectric layer 125 is also provided on one side of the flat surface 1241 of the planarization layer 124. The dielectric layer 125 includes a plurality of dielectric layer vias 1251. The pad 126 is disposed on the side of the dielectric layer 125 away from the planarization layer 124, and is electrically connected to the pin 122c of the pixel driver chip 122 through the dielectric layer vias 1251.

[0051] Furthermore, the pads 126 and the pads 113 on the surface of the substrate 110 are electrically connected, thereby making the pixel driver chip 122 and the signal line 111 electrically connected.

[0052] In this embodiment, the integrated unit 120 is fabricated on the first intermediate substrate 127 and formed by cutting. The integrated unit 120 further includes the first intermediate substrate 127 and the first bonding layer 128 disposed on the side of the pixel group 121 away from the substrate 110. The first intermediate substrate 127 and the first bonding layer 128 are a transparent carrier plate and an optical adhesive, respectively. Preferably, the first intermediate substrate 127 and the first bonding layer 128 can be used together as an encapsulation layer to isolate and protect the micro-light-emitting diode chip in the pixel group 121.

[0053] like Figure 2 As shown, another embodiment of the present invention also provides a micro-light-emitting diode display panel 200, which differs from the micro-light-emitting diode display panel 100 in that the pads 201 for connecting the panel circuit 112 on the substrate 110 are disposed on the back side of the substrate 110 and electrically connected through vias and signal lines 111.

[0054] like Figure 3 As shown, in another embodiment of the present invention, a micro-light-emitting diode display panel 300 is also provided, which differs from the micro-light-emitting diode display panel 100 in that the solder pads 301 for connecting the panel circuit 112 on the substrate 110 extend from the upper surface of the substrate 110 through the sidewall to the back surface.

[0055] The solder pads for connecting the panel circuit are guided to the back of the substrate 110, so that the large-size display panel formed by splicing the micro-LED display panels has no obvious splicing seam when displaying images and videos.

[0056] As shown in Figure 4 The application further provides a preparation method 400 of a micro-LED display panel, which comprises the following steps:

[0057] providing a substrate comprising a panel circuit and a signal line which are electrically connected to each other;

[0058] preparing a plurality of integrated units, each integrated unit comprising a pixel group, a pixel driving chip and a bridge electrode, two ends of the bridge electrode being electrically connected to the pixel group and the pixel driving chip, respectively;

[0059] transferring the plurality of integrated units to a surface on one side of the substrate, the pixel driving chip and the panel circuit being electrically connected;

[0060] wherein the plurality of integrated units are arranged in an array.

[0061] In a preferred embodiment, the process of preparing the integrated unit comprises the following steps:

[0062] providing a first intermediate substrate, the first intermediate substrate temporarily fixed with a plurality of pixel groups, each pixel group comprising at least one micro-LED, and any adjacent pixel groups having a gap part therebetween;

[0063] providing a second intermediate substrate, the second intermediate substrate temporarily fixed with a plurality of pixel driving chips;

[0064] bonding the first intermediate substrate and the second intermediate substrate, each pixel driving chip being located in a corresponding gap part;

[0065] stripping the second intermediate substrate;

[0066] forming a plurality of bridge electrodes, each bridge electrode having two opposite ends electrically connected to a corresponding pixel group and a pixel driving chip, respectively;

[0067] cutting to form a single integrated unit.

[0068] Specifically, after stripping the second intermediate substrate, the process further comprises the following steps: forming a planar layer above the plurality of pixel groups and the plurality of pixel driving chips; and forming a plurality of bridge electrodes above the planar layer.

[0069] In addition, the above preparation method further includes: forming a dielectric layer above the planarization layer; patterning the dielectric layer to form a plurality of dielectric layer vias, wherein a plurality of pins of the pixel driver chip are exposed from the corresponding plurality of dielectric layer vias; filling the plurality of dielectric layer vias with conductive pillars respectively; forming a plurality of pads above the dielectric layer, wherein the plurality of pads are electrically connected to the plurality of pins through the conductive pillars.

[0070] by Figure 1 Taking the micro-light-emitting diode display panel 100 illustrated in the figure as an example, combined with Figures 5 to 9 Detailed description Figure 4 The fabrication method of the micro-light-emitting diode display panel described in the article 400.

[0071] like Figure 5 As shown, the process of fabricating pixel group 121 on the first intermediate substrate 127 includes:

[0072] A first growth substrate 1000 is provided, on which a plurality of first micro light-emitting diode chips 121a are distributed; a first transfer substrate 2000 is provided, on which a first adhesive layer 2100 is provided on one side surface; the first growth substrate 1000 and the first transfer substrate 2000 are bonded together, and the electrodes of the plurality of first micro light-emitting diode chips 121a are attached to the first adhesive layer 2100; the first growth substrate 1000 is selectively irradiated with a laser, and the first micro light-emitting diode chips 121a on the first growth substrate 1000 are selectively peeled off, and some of the first micro light-emitting diode chips 121a are transferred to the first adhesive layer 2100 of the first transfer substrate 2000.

[0073] Continuing, a first intermediate substrate 127 is provided, the first intermediate substrate 127 including a first bonding layer 128, the first transfer substrate 2000 and the first intermediate substrate 127 are temporarily bonded, and the first micro light-emitting diode chip 121a on the first transfer substrate 2000 is transferred to the first intermediate substrate 127.

[0074] The second micro-LED chip 121b and the third micro-LED chip 121c are transferred to the first intermediate substrate 127 using the same operating steps.

[0075] Specifically, a second growth substrate 1000' is provided, and a plurality of second micro LED chips 121b are distributed on the second growth substrate 1000'; a second transfer substrate 2000' is provided, and a second adhesive layer 2100' is arranged on one side surface of the second transfer substrate 2000'; the second growth substrate 1000' and the second transfer substrate 2000' are bonded, and electrodes of the plurality of second micro LED chips 121b are adhered to the second adhesive layer 2100'; the second growth substrate 1000' is selectively irradiated by laser, and the plurality of second micro LED chips 121b on the second growth substrate 1000' are selectively peeled off, and part of the plurality of second micro LED chips 121b are transferred to the second adhesive layer 2100' of the second transfer substrate 2000'.

[0076] Continuing, a first intermediate substrate 127 is provided, and the first intermediate substrate 127 comprises a first bonding layer 128 and a plurality of first micro LED chips 121a; the second transfer substrate 2000' and the first intermediate substrate 127 are temporarily bonded, and the plurality of second micro LED chips 121b on the second transfer substrate 2000' are transferred to the first intermediate substrate 127.

[0077] A third growth substrate 1000'' is provided, and a plurality of third micro LED chips 121c are distributed on the third growth substrate 1000''; a third transfer substrate 2000'' is provided, and a third adhesive layer 2100'' is arranged on one side surface of the third transfer substrate 2000''; the third growth substrate 1000'' and the third transfer substrate 2000'' are bonded, and electrodes of the plurality of third micro LED chips 121c are adhered to the third adhesive layer 2100''; the third growth substrate 1000'' is selectively irradiated by laser, and the plurality of third micro LED chips 121c on the third growth substrate 1000'' are selectively peeled off, and part of the plurality of third micro LED chips 121c are transferred to the third adhesive layer 2100'' of the third transfer substrate 2000''.

[0078] Continuing, a first intermediate substrate 127 is provided, and the first intermediate substrate 127 comprises a first bonding layer 128 and a plurality of first micro LED chips 121a, second micro LED chips 121b; the third transfer substrate 2000'' and the first intermediate substrate 127 are temporarily bonded, and the plurality of third micro LED chips 121c on the third transfer substrate 2000'' are transferred to the first intermediate substrate 127.

[0079] At this time, the plurality of first micro LED chips 121a, the plurality of second micro LED chips 121b, and the plurality of third micro LED chips 121c constitute a pixel group 121, and any adjacent pixel groups 121 have a reserved gap part.

[0080] It should be noted that in other embodiments of the present application, if the micro light emitting diode chips transferred onto the first intermediate substrate 127 are all blue micro light emitting diode chips, 3 or more than 3 blue micro light emitting diode chips are transferred onto the first intermediate substrate 127 at one time, at this time, the 3 or more than 3 blue micro light emitting diode chips constitute a pixel group, and the gap part is also provided between any pixel groups.

[0081] As shown in Figure 6 , the process of preparing the pixel driving chip 122 on the second intermediate substrate includes:

[0082] The pixel driving circuit 122b is completed in the silicon substrate body 122a, and the pins 122c are completed on the surface of the silicon substrate body 122a. The pins 122c and the pixel driving circuit 122b are electrically connected, and the input and output of the electrical signal of the pixel driving circuit 122 are realized through the pins 122c.

[0083] Firstly, the first temporary substrate 4000 is provided, the first temporary substrate 4000 includes a first adhesive layer 4100, and the silicon substrate body 122a is temporarily fixed on the first adhesive layer 4100;

[0084] Secondly, the back surface of the silicon substrate body 122a is thinned;

[0085] Then, the second temporary substrate 5000 is provided, the second temporary substrate 5000 includes a second adhesive layer 5100;

[0086] Then, the second temporary substrate 5000 is bonded to the back surface of the silicon substrate body 122a, the first temporary substrate 4000 and the silicon substrate body 122a are peeled off, so that the pins 122a are exposed; through a photoetching process, the silicon substrate body 122a is patterned to form a plurality of isolation grooves 1221, and a plurality of pixel driving chips 122 are prepared.

[0087] Finally, the second intermediate substrate 6000 is provided, the second intermediate substrate 6000 includes a third adhesive layer 6100, the pixel driving chip 122 is selectively separated from the second temporary substrate 5000, and part of the pixel driving chip 122 is transferred to the second intermediate substrate 6000.

[0088] As shown in Figure 7 , Figure 8 and Figure 9 , the process of preparing the integrated pixel group 121 and the pixel driving chip 122 includes:

[0089] First, the second intermediate substrate 6000 and the first intermediate substrate 128 are bonded, wherein the pixel driving chip 122 is located in the gap between any pixel group 121; second, the pixel driving chip 122 and the second intermediate substrate 6000 are separated; then, the planar layer 124 is formed, which covers the pixel group 121 and the pixel driving chip 122, and through the thinning process, the first micro LED chip 121a, the second micro LED chip 121b, the third micro LED chip 121c in the pixel group 121 and the pin 122c of the pixel driving chip 122 are respectively exposed from the planar surface 1241 of the planar layer 124; then, the bridge electrode 123 is formed on the planar surface 1241, which is electrically connected to the pixel group 121 and the pixel driving chip 122; the dielectric layer 125 is formed on the planar surface 1241 of the planar layer 124, and the dielectric layer via 1251 is obtained by patterning the dielectric layer 125; the conductive pillar is formed by filling the metal material in the dielectric layer via 1251, and the pad 126 is formed on the surface of the dielectric layer 125 away from the planar layer, and the opposite ends of the conductive pillar are respectively connected to the pin 122c and the pad 126. Finally, the integrated unit 120 including one pixel group 121 and one corresponding pixel driving chip 122 is obtained by the cutting process.

[0090] As shown in Figure 8 the first electrode (for example, the cathode) of the first micro LED chip 121a, the second micro LED chip 121b and the third micro LED chip 121c in the pixel group 121 is respectively connected to the common electrode 121d, and the second electrode of the first micro LED chip 121a, the second micro LED chip 121b and the third micro LED chip 121c is respectively electrically connected to the bridge electrode 123, that is, the number of the bridge electrode 123 is multiple, which is respectively electrically connected to the second electrode of each micro LED chip and one pin 122c on the pixel driving chip 122.

[0091] It should be noted that the number of pins 122c on the pixel driving chip 122 is multiple, preferably, the number of pins 122c is greater than 6.

[0092] As shown in Figure 9As shown, due to the small size of the pin 122c of the pixel driving chip 122, it is inconvenient to externally bond other electrical elements, so the pin 122c is required to be led out to a larger pad 126 for facilitating the bonding operation. In some embodiments, the number of pads 126 on each integrated unit 120 is at least 6, and the 6 pads are respectively used to transmit a first data line driving signal (data1), a second data line driving signal (data2), a third data line driving signal (data3), a scanning line driving signal (gate), a power line (Vdd), and a common ground power line (Vss).

[0093] As shown in Figure 7 and Figure 1 After the prepared integrated unit 120 is subjected to electrical and optical detection before being transferred to the substrate 110, it enters the sorting process. That is, for each integrated unit 120, the same following 6 electrical signals are given, and the optical parameters including brightness and chrominance are tested, and the sorting is performed according to the brightness and chrominance data.

[0094] In addition, during the testing process, the input data1, data2, and data3 values are changed, and when the same brightness value is measured, the data1, data2, and data3 values required by each integrated unit 120 to reach the same brightness value are recorded. After the integrated unit 120 is transferred to the substrate 110 and bonded with the pads on the substrate 100, when the panel circuit 112 is driven, the above-mentioned data1, data2, and data3 values are referred to for compensation, thereby overcoming the problems of poor electrical consistency and large electrical drift between the micro light emitting diode and the driving circuit on the existing driving backplane.

[0095] The present application also provides a display device comprising any of the above-mentioned micro light emitting diode display panel 100, 200, 300.

[0096] In summary, the present application provides a micro light emitting diode display panel, a preparation method thereof and a display device, the substrate of the micro light emitting diode display panel is provided with a plurality of arrayed integrated units, the integrated unit includes a pixel group, a pixel driving chip and a bridge electrode, the pixel group and the pixel driving chip are arranged horizontally on the plane of the substrate, and the electrical connection relationship therebetween is realized through the bridge electrode, on the one hand, after integration, the light emitting efficiency of the pixel group is not affected, on the other hand, the electrical connection mode of pre-bonding the electrodes of the micro light emitting diode chip in the pixel group and the pins of the pixel driving chip is avoided, and the electrical connection is realized through a wiring process (bridge electrode), so that the process difficulty is low, and the electrical connection stability is high; further, the integrated units are subjected to electrical and optical performance consistency tests before being transferred to the substrate, and are sorted on this basis, therefore, the electrical driving signals between each pixel group and the corresponding pixel driving chip are consistent, when they are applied to the micro light emitting diode display panel as pixels, the problems of poor electrical consistency, large electrical drift and the like between the micro light emitting diode and the driving circuit on the existing driving backplane can be overcome.

[0097] The present application has been described by the above-mentioned related embodiments, however, the above-mentioned embodiments are only examples for implementing the present application. In addition, the technical features involved in the different embodiments of the present application described above can be combined with each other as long as they do not conflict with each other. It must be pointed out that the present application can also have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the claims attached to the present application.

Claims

1. A micro-light-emitting diode display panel, characterized in that, The micro-light-emitting diode display panel includes: A substrate, the substrate including panel circuitry and signal lines electrically connected to each other; and A plurality of integrated units are arranged in an array on one side surface of the substrate. Each integrated unit includes a first intermediate substrate, a pixel group, a pixel driver chip and a bridging electrode disposed on the first intermediate substrate. The two opposite ends of each bridging electrode are electrically connected to the corresponding pixel group and the pixel driver chip. The pixel group includes at least one micro light-emitting diode chip. The pixel driver chip and the signal line are electrically connected. The projections of the pixel group onto the substrate and the projections of the pixel driving chip onto the substrate do not overlap. Each integrated unit further includes a planarization layer, which is a light-absorbing planarization layer. The planarization layer covers the pixel group and the pixel driver chip. The side of the planarization layer facing the substrate includes a flat surface. The bridging electrode is a metal wiring disposed on the flat surface. The bridging electrode spans the gap between the pixel group and the pixel driver chip and bridges the electrodes of the micro light-emitting diode chip and the pins of the pixel driver chip. The pixel group and the pixel driver chip are sandwiched between the first intermediate substrate and the planarization layer, wherein the first intermediate substrate is a transparent carrier plate.

2. The micro-light-emitting diode display panel according to claim 1, characterized in that, Each integrated unit further includes a dielectric layer and multiple pads. The dielectric layer is disposed on the flat surface, and the multiple pads are disposed on the side of the dielectric layer away from the flat surface. The dielectric layer includes multiple dielectric vias, and the multiple dielectric vias are filled with conductive pillars. The conductive pillars are electrically connected to the multiple pads and multiple pins on the pixel driver chip. The multiple pads are electrically connected to the signal lines.

3. The micro-light-emitting diode display panel according to claim 2, characterized in that, The electrodes of the at least one micro LED chip and the pins on the pixel driver chip are exposed from the flat surface, respectively.

4. The micro-light-emitting diode display panel according to claim 1, characterized in that, in, A first bonding layer is provided on the side of the first intermediate substrate facing the pixel group and the pixel driver chip.

5. A display device, characterized in that, The display device includes a display panel as claimed in any one of claims 1-4.

6. A method for fabricating a micro-light-emitting diode display panel, characterized in that, The preparation method includes: A substrate is provided, the substrate including panel circuitry and signal lines electrically connected to each other; A plurality of integrated units are fabricated, each integrated unit including a pixel group, a pixel driver chip and a bridging electrode, wherein the two ends of the bridging electrode are electrically connected to the pixel group and the pixel driver chip respectively. The plurality of integrated units are transferred to a surface on one side of the substrate, and the pixel driving chip and the panel circuit are electrically connected; The plurality of integrated units are arranged in an array; Fabrication of the plurality of integrated units includes: A first intermediate substrate is provided, on which a plurality of pixel groups are temporarily fixed, each pixel group including at least one micro light-emitting diode, and there is a gap between any adjacent pixel groups. A second intermediate substrate is provided, on which a number of pixel driver chips are temporarily fixed; The first intermediate substrate and the second intermediate substrate are bonded together, and each pixel driver chip is located in the corresponding gap. Peel off the second intermediate substrate; A planarization layer is formed over the plurality of pixel groups and the plurality of pixel driving chips; A plurality of bridging electrodes are formed above the planarization layer, and the two ends of each bridging electrode are electrically connected to the corresponding pixel group and the pixel driver chip. The integrated unit is formed by cutting.

7. The method for fabricating a micro-light-emitting diode display panel according to claim 6, characterized in that, Also includes: A dielectric layer is formed above the planar layer; The dielectric layer is patterned to form multiple dielectric layer vias, and multiple pins of the pixel driver chip are exposed from the corresponding multiple dielectric layer vias; Conductive pillars are filled into the plurality of dielectric layer vias, respectively; Multiple pads are formed above the dielectric layer, and the multiple pads are electrically connected to the multiple pins through the conductive pillars.

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