Driving backplane, display panel and display device

The present disclosure provides a driving backplane, including: a base substrate, a driving circuit arranged on the base substrate, an insulation layer on a side of the driving circuit facing away from the base substrate, a plurality of first tip structures arranged on a side of the insulation layer facing away from the base substrate, and a plurality of contact electrodes arranged on the side of the insulation layer facing away from the base substrate. The driving circuit includes a plurality of output terminals, the insulation layer includes a plurality of openings and the output terminals and the openings are in a one-to-one correspondence. The contact electrodes are electrically connected with the output terminals through the openings. Each of the contact electrodes covers the plurality of first tip structures to constitute a plurality of second tip structures having the same appearance as the first tip structures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 201910683539.4, filed on Jul. 26, 2019, the entire content thereof is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of display technologies and, more particularly, to a driving backplane, a display panel and a display device.

BACKGROUND

With the development of Light-Emitting Diode (LED), the Micro-Light-Emitting Diode (Micro-LED) display technology will become a next-generation revolutionary technology. Compared with the Organic Light-Emitting Diode (OLED), the Micro-LED display has a higher brightness, a better luminous efficiency, and lower power consumption.

At present, when a micro light-emitting diode is bound to a driving backplane, that is, when a leading-out electrode of the micro light-emitting diode is bound to a contact electrode, the adhesive used between the leading-out electrode and the contact electrode is not easy to be completely discharged to the outside of the contact electrode, so that the binding effect of the micro light-emitting diode and the driving backplane is poor.

SUMMARY

An embodiment of the disclosure provides a driving backplane, a display panel and a display device to solve the problem of poor binding effect of the micro light-emitting diode and the driving backplane in the related art.

In a first aspect, an embodiment of the present disclosure provides a driving backplane, including: a base substrate, a driving circuit arranged on the base substrate, an insulation layer on a side of the driving circuit facing away from the base substrate, a plurality of first tip structures arranged on a side of the insulation layer facing away from the base substrate, and a plurality of contact electrodes arranged on the side of the insulation layer facing away from the base substrate; the driving circuit includes a plurality of output terminals, the insulation layer includes a plurality of openings, and there is a one-to-one correspondence between the output terminals and the openings, and the contact electrodes are electrically connected with the output terminals through the openings. Each of the contact electrodes includes a plurality of second tip structures, and each of the second tip structures is configured to cover one of the first tip structures.

In a possible implementation manner, in the above driving backplane provided by the embodiment of the present disclosure, the contact electrode is an integral structure arranged on a side of a film layer where the first tip structures are located, facing away from the base substrate.

In an optional implementation manner, in the above driving backplane provided by the embodiment of the present disclosure, the contact electrode further includes: a planar portion located between the insulation layer and the first tip structures. The planar portion is electrically connected with each of the second tip structures belonging to the same contact electrode, respectively.

In an optional implementation manner, in the above driving backplane provided by the embodiment of the present disclosure, each of the second tip structures corresponding to the same contact electrode are arranged along a plurality of straight lines crossing each other.

In an optional implementation manner, in the above driving backplane provided by the embodiment of the present disclosure, some of the second tip structures corresponding to the same contact electrode are distributed on a circle or concentric circle with one of the second tip structures being located at a center.

In an optional implementation manner, in the above driving backplane provided by the embodiment of the present disclosure, the second tip structure is a cone or a pyramid.

In an optional implementation manner, in the above driving backplane provided by the embodiment of the present disclosure, a height of the second tip structure in a direction perpendicular to the base substrate is within a range of 1 μm˜3 μm, and the maximum width of a bottom surface of the second tip structure is within a range of 1 μm˜3 μm.

In an optional implementation manner, in the above driving backplane provided by the embodiment of the present disclosure, the driving circuit includes: a plurality of thin film transistors and a plurality of power supply voltage signal lines arranged on the base substrate. The contact electrodes are divided into a first contact electrode and a second contact electrode. The first contact electrode is electrically connected with a drain electrode of the thin film transistor, and the second contact electrode is electrically connected with the power supply voltage signal line.

In a second aspect, an embodiment of the present disclosure provides a display panel, including: the driving backplane described above and a plurality of micro light-emitting diodes. A leading-out electrode of the micro light-emitting diode is bound to the contact electrode of the driving backplane.

In a third aspect, an embodiment of the present disclosure provides a display device including the display panel described above.

Beneficial effects of the present disclosure are described below.

The embodiments of the present disclosure provide a driving backplane, a display panel and a display device. The driving backplane includes: a base substrate, a driving circuit arranged on the base substrate, an insulation layer on the side of the driving circuit facing away from the base substrate, a plurality of first tip structures arranged on the side of the insulation layer facing away from the base substrate, and a plurality of contact electrodes arranged on the side of the insulation layer facing away from the base substrate; where the driving circuit has a plurality of output terminals, the insulation layer has a plurality of openings and there is a one-to-one correspondence between the out terminals and the openings, and the contact electrodes are electrically connected with the output terminals through the openings; the contact electrodes cover the plurality of first tip structures to constitute a plurality of second tip structures having the same appearance as the first tip structures. In the above driving backplane provided by the embodiment of the present disclosure, the surface of the contact electrode is formed with a plurality of second tip structures, so that the adhesive is smoothly discharged outward when the leading-out electrode of the micro light-emitting diode is bound to the contact electrode. Therefore, the leading-out electrode can be in good contact with the contact electrode, and the binding effect is improved.

DETAILED DESCRIPTION

In view of the problem in the related art that the binding effect of the micro light-emitting diode and the driving backplane is poor, embodiments of the present disclosure provide a driving backplane, a display panel and a display device.

Specific embodiments of a driving backplane, a display panel and a display device provided by embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The thickness and shape of each film layer in the accompanying drawings do not reflect an actual scale and are only intended to illustrate the content of the present disclosure.

In a first aspect, an embodiment of the present disclosure provides a driving backplane. As shown inFIG. 1, the driving backplane includes: a base substrate101, a driving circuit102arranged on the base substrate101, an insulation layer103arranged on a side of the driving circuit102facing away from the base substrate101, a plurality of first tip structures104arranged on a side of the insulation layer103facing away from the base substrate101, and a plurality of contact electrodes105arranged on the side of the insulation layer103facing away from the base substrate101.

The driving circuit102includes a plurality of output terminals (for example, one of the output terminals is located at a position where the contact electrode105is contact with the drain electrode D), the insulation layer103includes a plurality of openings M. The openings M and the output terminals are in a one-to-one correspondence. The contact electrode105is electrically connected with the output terminal through the opening M.

The contact electrode105covers the plurality of first tip structures104to constitute a plurality of second tip structures106having the same appearance as the first tip structures104.

In the above driving backplane provided by the embodiment of the present disclosure, the surface of the contact electrode is formed with a plurality of second tip structures, so that the adhesive is smoothly discharged outward when the leading-out electrode of the micro light-emitting diode is bound to the contact electrode. Therefore, the leading-out electrode can be in good contact with the contact electrode, and the binding effect is improved.

As shown inFIG. 1, the plurality of first tip structures104are provided on the side of the insulation layer103facing away from the base substrate base101, after the plurality of first tip structures104is covered by the contact electrode105, the second tip structures106having the same appearance as the first tip structures104are formed, and the second tip structures106are a part of the contact electrode105. Accordingly, the second tip structure106is electrically connected with the output terminal of the driving circuit102. Therefore, in the binding process, as long as the second tip structure106punctures the adhesive, direct contact electrical connection between the leading-out electrode of the micro light-emitting diode and the contact electrode can be achieved.

The micro light-emitting diode has a very small size, and the leading-out electrode of the micro light-emitting diode is on the order of micrometers. Accordingly, the size of the contact electrode of the driving backplane is about 25 μm×25 μm. In the binding process of the leading-out electrode of the micro light-emitting diode and the contact electrode, an adhesive, which is generally a non-conductive adhesive, is required to be dripped to the surface of the contact electrode, so as to adhere the leading-out electrode to the contact electrode. Then, in a manner that a side of the micro light-emitting diode with the leading-out electrode faces the driving backplane, the leading-out electrode is aligned to a corresponding contact electrode and pressed against the contact electrode. When the leading-out electrode and the corresponding contact electrode are pressed against each other, the second tip structure may puncture the adhesive to realize the contact between the leading-out electrode and the contact electrode, and the leading-out electrode can be fixed on the contact electrode through the adhesive. In this way, the binding connection of the leading-out electrode and the contact electrode is realized, and excess adhesive may be discharged along a gap between the second tip structures to avoid the contact effect between the leading-out electrode and the contact electrode being influenced by the excess adhesive. Therefore, the binding effect between the micro light-emitting diode and the driving backplane is improved.

In an actual implementation, the second tip structures in the contact electrode may also be elastic. Therefore, after the binding connection of the micro light-emitting diode and the contact electrode is achieved by pressing, the contact area between the second tip structures and the leading-out electrode may be increased.

Optionally, the above driving backplane provided by the embodiment of the present disclosure is bound to the micro light-emitting diode. The micro light-emitting diode generally has two leading-out electrodes, namely an anode and a cathode, and the two leading-out electrodes may be arranged on the same side of an epitaxial structure or on different sides of the epitaxial structure. In practical application, the structure of the driving backplane may be configured according to the structure of the micro-light emitting diode to be bound. For example, the driving backplane as shown inFIG. 1may be bound to a micro-light emitting diode with two leading-out electrodes arranged on the same side of the epitaxial structure.

Specifically, in the above driving backplane provided by the embodiment of the present disclosure, as shown inFIG. 1, the driving circuit102includes: a plurality of thin film transistors TFT and a plurality of power supply voltage signal lines V arranged on the base substrate101. The contact electrode105is divided into a first contact electrode and a second contact electrode. The first contact electrode is electrically connected with a drain electrode D of the thin film transistor TFT, and the second contact electrode is electrically connected with the power supply voltage signal line V. The first contact electrode is electrically connected with the drain electrode D through an opening M, in which the position where the first contact electrode is in contact with the drain electrode D is the output terminal of the driving circuit. The second contact electrode is electrically connected with the power voltage signal line V through an opening M, in which the position where the second contact electrode is in contact with the power voltage signal line V is also the output terminal of the driving circuit.

Specifically, the thin film transistor TFT includes an active layer A, a gate electrode G, a source electrode S, a drain electrode D and the like. The power supply voltage signal line V may be a Vss signal line. Only one thin film transistor TFT and one power supply voltage signal line V are shown inFIG. 1. However, in actual implementation, the number of the thin film transistors TFT and the number of the power supply voltage signal lines V may be configured according to actual needs, which are not limited herein.

As shown inFIG. 1, a buffer layer107is further provided between the driving circuit102and the base substrate101. In the thin film transistor TFT, a first gate insulation layer201is provided between the active layer A and the gate electrode G, a second gate insulation layer202and an interlayer insulation layer203are further provided between the gate electrode G and the source electrode S. The source electrode S and the drain electrode D are electrically connected with the active layer A through through-holes penetrating through the first gate insulation layer201, the second gate insulation layer202and the interlayer insulation layer203, respectively.

In the actual implementation, in the above driving backplane provided by the embodiment of the present disclosure, the surface of the contact electrode may be formed with a plurality of second tip structures by adopting at least the following two structures.

As shown inFIG. 1, the contact electrode105is an integral structure arranged on a side of a film layer where the first tip structure104is located facing away from the base substrate101.

Specifically, in a manufacturing process of the above driving backplane, as shown inFIG. 2a, the buffer layer107, each film layer of the thin film transistor TFT, and the insulation layer103are patterned on the base substrate101. As shown inFIG. 2b, a plurality of first tip structures104are formed on the insulation layer103at positions where contact electrodes are to be formed later, for example, the first tip structures104may be made of an organic material. Next, a metal layer is deposited on the film layer where the first tip structures104are located. Referring toFIG. 1, the metal layer forms a plurality of second tip structures106at positions of the first tip structures104, and is patterned, to form the plurality of contact electrodes105, thereby obtaining the structure as shown inFIG. 1. Specifically, the metal layer may be formed by laminating an aluminum (Al) metal layer and a titanium (Ti) metal layer. The aluminum metal layer has a high conductivity, so that a good conductivity between the formed contact electrode and the lead-out electrode may be ensured. The titanium metal layer has a high hardness and may be used as a supporter.

As shown inFIG. 3, the contact electrode105further includes: a planar portion108arranged between the insulation layer103and the film layer where the first tip structures104are located. The planar portion108is electrically connected with each of the second tip structures106belonging to the same contact electrode105, respectively.

In contact electrode105, the planar portion108is electrically connected with each of the second tip structures106respectively, so that the electrical connection between the second tip structure106and the output terminal of the driving circuit can be achieved through the planar portion108. Therefore, it is ensured that the leading-out electrode is bound to the contact electrode105by being in contact with the second tip structure106subsequently.

Specifically, in the manufacturing process of the above driving backplane, as shown inFIG. 4a, a metal layer is formed on the insulation layer103and patterned to form the planar portions108of a plurality of contact electrodes, and the planar portions108are electrically connected with the corresponding output terminals through the openings M. Next, as shown inFIG. 4b, a plurality of first tip structures104are formed on the planar portions108, and then a plurality of metal structures are formed on the film layer of the first tip structures104at positions corresponding to the planar portions108, respectively, to form a plurality of second tip structures, thereby obtaining the structure as shown inFIG. 3, that is, each metal structure covers each of the first tip structures104corresponding to one planar portion108, so that the patterning process of the metal structure can be simplified. Specifically, similar to the metal layer in Structure I, the metal structure may also be formed by laminating an aluminum (Al) metal layer and a titanium (Ti) metal layer, and the thickness of the metal structure may be less than the thickness of the metal layer in Structure I.

Further, for the above driving backplane provided by the embodiment of the present disclosure,FIG. 5is a schematic diagram illustrating the distribution of the second tip structures corresponding to the same contact electrode,FIG. 6is a schematic diagram of an adhesive discharge process. InFIG. 5andFIG. 6, positions of the second tip structures are represented by circles without limiting the shapes of the second tip structures. As shown inFIG. 5, the second tip structures106corresponding to the same contact electrode105are arranged along a plurality of straight lines crossing each other. InFIG. 5, as an example, the second tip structures106of the same contact electrode105are arranged along straight lines L1, L2, L3and L4crossing each other. However, in the actual implementation, the second tip structures106may also be arranged according to the number and size of the second tip structures106of the contact electrode105, and the number of the straight lines in which the second tip structures106are arranged is not limited herein.

Since the second tip structures106corresponding to the same contact electrode105are arranged along a plurality of straight lines crossing each other, in the binding process, referring toFIG. 6, after the adhesive is dropped to the surface of the contact electrode105and then the micro light-emitting diode and the contact electrode105are pressed against each other, the adhesive109may be discharged outward along the gap between the second tip structures106arranged in the straight line. The direction indicated by the arrow inFIG. 6is the direction in which the adhesive is discharged outward. The adhesive109is not subjected to a restraining force during the discharge process. Further, since the second tip structures106are arranged in a straight line, the adhesive109does not squeeze the second tip structures106during the discharge process, and the second tip structures106are prevented from being damaged.

In a specific implementation, when the micro light-emitting diode and the contact electrode105are pressed against each other, the amount of the adhesive discharged in various directions is relatively uniform, and an included angle between adjacent straight lines formed by the second tip structures106may be the same, for example, an included angle between the straight lines L1and L2in the drawing is the same as an included angle between the straight lines L3and L4.

Further, for the above driving backplane provided by the embodiment of the present disclosure, as shown inFIG. 5, among the second tip structures106corresponding to the same contact electrode105, one of the second tip structures is arranged at a center, and the remaining second tip structures106are uniformly distributed on at least one concentric circle. InFIG. 5, with the second tip structure106in the middle as the center, the remaining second tip structures106are arranged on a circle C1and a circle C2, the circles C1and C2are concentric circles. As an example, the second tip structures106are arranged on two concentric circle in the drawing. However, in practical application, the second tip structures106may also be arranged according to the number and size of the second tip structures106of the contact electrode105, and the number of the concentric circles on which the second tip structures106are arranged is not limited herein.

Referring toFIG. 6, the second tip structures106of the contact electrode105are arranged on at least one concentric circle, so that the resistance of the adhesive109in various directions is substantially consistent during the outward diffusion process, facilitating the adhesive to spread outward uniformly.

In a specific implementation, in the driving backplane provided by the embodiment of the present disclosure, the second tip structure is a cone or a pyramid (as shown inFIG. 7). When the second tip structure is a pyramid, a schematic top view of the corresponding contact electrode can be as shown inFIG. 8, and as is apparent fromFIG. 8, the second tip structures106are arranged according to the arrangement shown inFIG. 5. In addition, the second tip structure may also have other shapes, which is not limited herein.

Specifically, in the driving backplane provided by the embodiment of the present disclosure, as shown inFIG. 7, a height H of the second tip structure106in a direction perpendicular to the base substrate is within a range of 1 μm˜3 μm. The maximum width B of a bottom surface of the second tip structure106is within a range of 1 μm˜3 μm. As shown inFIG. 7, when the second tip structure106is a pyramid, the maximum width B of the bottom surface of the second tip structure106is the bottom surface side length, and when the second tip structure106is a cone, the maximum width of the bottom surface of the second tip structure106is the bottom surface diameter. Generally, the size of the contact electrode105is about 25 μm×25 μm. Therefore, in order to ensure that the contact electrode has enough second tip structures, the maximum width of the bottom surface of the second tip structure is controlled within the range of 1 μm˜3 μm. For example, as shown inFIG. 8, the contact electrode105has 17 second tip structures106, so as to ensure the conductivity between the leading-out electrode of the micro light-emitting diode and the contact electrode and ensure the binding effect.

In a second aspect, based on the same concept, embodiments of the present disclosure provide a display panel. Since the display panel and the driving backplane adopt the same principle for solving the problem, the implementation of the display panel may refer to the implementation of the driving backplane, and thus the description is not repeated herein.

Specifically, the display panel provided in the embodiment of the present disclosure includes: the driving backplane described above and a plurality of micro light-emitting diodes. A leading-out electrode of the micro light-emitting diode is bound to the contact electrode of the driving backplane.

The leading-out electrode of the micro light-emitting diode is electrically connected with the contact electrode through direct contact, and the leading-out electrode and the contact electrode are adhered through adhesive so as to realize the binding connection between the leading-out electrode and the contact electrode.

In a third aspect, based on the same concept, embodiments of the present disclosure provide a display device including the display panel described above. The display device may be applied to any product or component having a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame and a navigator and the like. Since the display device and the display panel described above have the same principle for solving the problem, the implementation of the display device may refer to the implementation of the display panel, and thus the description is not repeated herein.

In the above driving backplane, display panel and display device provided by the embodiments of the present disclosure, the surface of the contact electrode is formed with a plurality of second tip structures, thus the adhesive is smoothly discharged outward when the leading-out electrode of the micro light-emitting diode is bound to the contact electrode. Therefore, the leading-out electrode is in good contact with the contact electrode, and the binding effect is improved.

It is apparent to those skilled in the art to make various modifications and variations to the disclosure without departing from the spirit and scope of the present disclosure. In this way, if these modifications and variations belong to the scope of the claims of the disclosure and their equivalents, then the disclosure is intended to cover these modifications and variations.