Double-sided display panel and manufacturing method thereof

Abstract

The present application provides a double-sided display panel and a manufacturing method thereof, which includes a substrate; a driving circuit layer disposed on the substrate; a first light-emitting element and a second light-emitting element electrically connected to the driving circuit layer, respectively, and the light emitting direction of the first light-emitting element is opposite to the light emitting direction of the second light-emitting element, and the driving circuit layer is used to individually control the light emission of the first light-emitting element and the second light-emitting element to achieve double-sided display; and an encapsulation layer connected to the substrate to seal the first light-emitting element and the second light-emitting element. The first light-emitting element and the second light-emitting element electrically connected to the driving circuit layer have opposite light emitting directions, and the driving circuit layer is used to individually control the light emission of the first light-emitting element and the second light-emitting element to achieve double-sided display, and the structure is simple, which can meet the requirements of thinning of double-sided display panels.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a double-sided display panel and a manufacturing method thereof. Background Art

[0002] At present, double-sided display screens have broad application prospects in the fields of commodity display, electronic bulletin boards, high-end exhibitions, etc. The current double-sided display usually uses two TFT-LCD substrates laminated back to back to achieve double-sided display through two panels. In the process of research and practice of the prior art, the inventors of the embodiments of the present invention found that since both display panels require separate backlights and due to the design requirements of heat dissipation, the manufactured double-sided display screen will have a large thickness, thereby occupying space and affecting the viewing experience, and the process is complex, the yield is low, and the production cost is high; and since two TFT-LCD substrates are laminated back to back, the thin and light effect of the product will be seriously affected.

[0003] Therefore, there are defects in the prior art, which need to be solved urgently. Summary of the invention

[0004] The present application provides a display panel that can solve the problem that a double-sided display panel formed by laminating two TFT-LCD substrates back to back is relatively heavy and is not conducive to thinning of the double-sided display panel.

[0005] To solve the above problems, the technical solutions provided by this application are as follows:

[0006] A double-sided display panel, comprising:

[0007] substrate;

[0008] A driving circuit layer disposed on the substrate;

[0009] a first light-emitting element and a second light-emitting element electrically connected to the driving circuit layer respectively, wherein the light emitting direction of the first light-emitting element is opposite to the light emitting direction of the second light-emitting element, and the driving circuit layer is used to individually control the light emission of the first light-emitting element and the second light-emitting element to realize double-sided display; and

[0010] The encapsulation layer is connected to the substrate to seal the first light emitting element and the second light emitting element.

[0011] In one embodiment of the present invention, the double-sided display panel is provided with a window penetrating the substrate and the driving circuit layer, and the second light emitting element is located in the window.

[0012] In one embodiment of the present invention, the driving circuit layer includes a thin film transistor device layer, the thin film transistor device layer includes at least two thin film transistors, and the first light emitting element and the second light emitting element are electrically connected to one thin film transistor respectively.

[0013] In one embodiment of the present invention, the driving circuit layer also includes an electrode layer arranged on a side of the thin film transistor device layer away from the substrate and electrically connected to the thin film transistor device layer, the electrode layer includes a first electrode pad, and the first light-emitting element is connected to the thin film transistor through the first electrode pad.

[0014] In one embodiment of the present invention, the electrode layer includes a second electrode pad, the size of the second electrode pad is larger than that of the first electrode pad, the window exposes the second electrode pad, and the second light-emitting element is connected to the second electrode pad exposed by the window.

[0015] In one embodiment of the present invention, a metal conductive sheet is further provided on the side of the second electrode pad away from the driving circuit layer, the thickness of the metal conductive sheet is greater than the thickness of the second electrode pad, the window also penetrates the second electrode pad to expose the metal conductive sheet, and the second light-emitting element is connected to the metal conductive sheet.

[0016] In one embodiment of the present invention, the packaging layer includes an upper packaging layer and a lower packaging layer, the upper packaging layer is connected to the upper surface of the substrate and covers the top surface and surrounding side surfaces of the driving circuit layer; the lower packaging layer covers the lower surface of the substrate and fills the window.

[0017] A method for manufacturing a double-sided display panel comprises the following steps:

[0018] providing a substrate;

[0019] forming a driving circuit layer on the substrate;

[0020] A first light emitting element and a second light emitting element are arranged to be electrically connected to the driving circuit layer, and a light emitting direction of the first light emitting element is opposite to a light emitting direction of the second light emitting element; and

[0021] A packaging layer connected to the substrate is provided to seal the first light emitting element and the second light emitting element.

[0022] In one embodiment of the present invention, a method for setting the second light emitting element includes:

[0023] A window is opened which penetrates the substrate and the driving circuit layer, and the second light emitting element is arranged in the window.

[0024] In one embodiment of the present invention, the driving circuit layer includes a thin film transistor device layer arranged on the substrate and an electrode layer arranged on a side of the thin film transistor device layer away from the substrate and electrically connected to the thin film transistor device layer, the electrode layer includes a first electrode pad and a second electrode pad; before opening the window, the step of arranging a first light-emitting element on the first electrode pad and a metal conductive sheet on the second electrode pad is also included, so that the metal conductive sheet is exposed in the window when the window is formed, and the second light-emitting element is arranged in the window and is connected to the metal conductive sheet.

[0025] The beneficial effects of the present application are as follows: the double-sided display panel and the manufacturing method thereof provided by the present application have light emitting directions of the first light-emitting element and the second light-emitting element electrically connected to the driving circuit layer opposite to each other. The driving circuit layer is used to individually control the light emission of the first light-emitting element and the second light-emitting element to achieve double-sided display, and has a simple structure, which can meet the requirements of thinning the double-sided display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0027] Figure 1 A cross-sectional schematic diagram of a substrate and a driving circuit layer formed on the substrate provided in the first embodiment of the present application;

[0028] Figure 2 for Figure 1 The structural diagram of the driving circuit layer provided;

[0029] Figure 3 A plan view of forming a driving circuit layer on a substrate;

[0030] Figure 4 For Figure 1 A schematic diagram of forming a first light emitting element and a metal conductive sheet on the driving circuit layer based on the above;

[0031] Figure 5 For Figure 4 A schematic diagram of forming an upper encapsulation layer on the surface of the substrate and the driving circuit layer based on the above;

[0032] Figure 6 For Figure 5 A schematic diagram of the middle structure of the panel is obtained by peeling off the glass substrate;

[0033] Figure 7 is Figure 6 A cross-sectional view of forming a window in the middle structure of the panel and forming a second light-emitting element in the window;

[0034] Figure 8 It is a schematic diagram of forming a lower package on the lower surface of the substrate to seal the second light-emitting element to obtain a double-sided display panel;

[0035] Fig. 9 is a schematic diagram of a double-sided display panel provided by a second embodiment of the present invention.

[0036] Description of Reference Numerals

[0037] 100, 200-double-sided display panel; 1-substrate; 2-driving circuit layer; 203-drain;

[0038] 3-first light-emitting element; 4-second light-emitting element; 5-encapsulation layer; 6-metal conductive sheet;

[0039] 20-thin film transistor device layer; 22-electrode layer; 201-thin film transistor;

[0040] 220 - first electrode pad; 222 - second electrode pad; 11 - window; 10 - glass substrate;

[0041] 50-upper packaging layer; 52-lower packaging layer; 7-panel middle structure. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0043] In the description of the present application, it should be understood that the terms "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0044] The present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not indicate the relationship between the various implementations and / or settings discussed. The double-sided display panel and its manufacturing method of the present application are described in detail below in conjunction with specific embodiments.

[0045] See also Figure 2 and Figure 8 The first embodiment of the present invention provides a double-sided display panel 100, comprising: a substrate 1, a driving circuit layer 2, a first light-emitting element 3, a second light-emitting element 4, and a packaging layer 5 for sealing the first light-emitting element 3 and the second light-emitting element 4. The driving circuit layer 2 is provided with at least two thin film transistors 201, and the at least two thin film transistors 201 are respectively connected to the first light-emitting element 3 and the second light-emitting element 4 to control the first light-emitting element 3 and the second light-emitting element 4 to emit light independently, so as to realize double-sided display.

[0046] The double-sided display panel 100 provided in the embodiment of the present invention solves the technical problems that if double-sided display is achieved, the backlights of the two panels need to be manufactured separately, which results in a large thickness, occupies space and affects the visual experience, and the process is complex, the yield is low and the manufacturing cost is high. The double-sided display panel 100 provided in the embodiment of the present invention can include the following technical effects: at least two thin film transistors 201 that can provide light to the first light-emitting element 3 and the second light-emitting element 4 respectively are manufactured under the same process, which can reduce the manufacturing cost, and the double-sided display panel 100 does not increase its panel thickness to achieve ultra-thin display, thereby achieving a light and thin double-sided display panel 100.

[0047] Specifically, in this embodiment, the substrate 1 can be a flexible substrate or a hard substrate. If it is a flexible substrate, when manufacturing the double-sided display panel 100, the substrate 1 is formed on the glass substrate 10. The material of the flexible substrate includes at least one of polydimethylsiloxane (PDMS), polyimide film (Polyimide Film), and flexible printed circuit (Flexible Printed Circuit). The flexible substrate has good flexibility and can enable the mini-LED display panel to be flexibly bent. Preferably, it is a photosensitive polyimide, which is convenient for subsequent laser irradiation to peel off from the glass substrate 10.

[0048] The driving circuit layer 2 includes a thin film transistor device layer 20 and an electrode layer 22 disposed on a side of the thin film transistor device layer 20 away from the substrate 1 and electrically connected to the thin film transistor device layer 20 .

[0049] The thin film transistor device layer 20 includes at least two thin film transistors 201 (Thin Film Transistor, TFT). In other embodiments, the number of thin film transistors 201 is multiple and arranged in an array. In this embodiment, the active layer of the TFT can be LTPS (Low Temperature Poly-Silicon), HTPS (High Temperature Poly-Silico) or oxide, etc. The embodiment of the present application does not specifically limit the specific structure of the thin film transistor 201.

[0050] The electrode layer 22 includes a first electrode pad 220 and a second electrode pad 222 that are spaced apart. In this embodiment, both the first electrode pad 220 and the second electrode pad 222 can be connected to the drain electrode 203 of the thin film transistor 201 through a via hole.

[0051] Preferably, the size of the second electrode pad 222 is larger than that of the first electrode pad 220. If the size of the second electrode pad 222 is too small, the connection of the second light-emitting element 4 will be affected when openings are subsequently formed in the substrate 1 and the driving circuit layer 2, resulting in poor electrical properties of the second light-emitting element 4.

[0052] The double-sided display panel 100 is provided with a window 11 , and the window 11 penetrates through the substrate 1 and the driving circuit layer 2 to expose the second electrode pad 222 .

[0053] The first light emitting element 3 is connected to the first electrode pad 220, and the second light emitting element 4 is connected to the second electrode pad 222 exposed through the window 11. In this embodiment, the first light emitting element 3 and the second light emitting element 4 are both mini-LED (sub-millimeter light emitting diode) chips. The display panel formed by mini-LED as the backlight source has the advantages of fast response, high color gamut, low energy consumption, etc. compared with the current LCD and OLED display devices.

[0054] A conductive material (not shown) is coated on the electrode pad to further improve the conductivity between the mini-LED chip and the electrode pad. In the present embodiment, the conductive material includes at least one of glass paste, conductive silver paste, solder paste, solder, or anisotropic conductive paste.

[0055] The encapsulation layer 5 includes an upper encapsulation layer 50 and a lower encapsulation layer 52. The upper encapsulation layer 50 is connected to the edge of the upper surface of the substrate 1 and covers the driving circuit layer 2 and the first light-emitting element 3. The lower encapsulation layer 52 covers the lower surface of the substrate 1 and fills the opening 11, so that the first light-emitting element 3 is sealed between the upper encapsulation layer 50 and the driving circuit layer 2, and the second light-emitting element 4 is sealed between the lower encapsulation layer 52 and the driving circuit layer 2. The materials of the upper encapsulation layer 50 and the lower encapsulation layer 52 are both light-transmitting materials, which have good water and oxygen isolation capabilities, can effectively prevent external water vapor from invading the mini-LED, and improve the service life of the mini-LED. At the same time, the light-transmitting material will not cause light loss of the mini-LED.

[0056] See also Fig. 9 , Fig. 9 A double-sided display panel 200 is provided in the second embodiment. The double-sided display panel 200 provided in the second embodiment has a substantially same structure as the double-sided display panel 100 provided in the first embodiment, except that: in the present embodiment, a metal conductive sheet 6 is further provided on the side of the second electrode pad 222 away from the driving circuit layer 2, the thickness of the metal conductive sheet 6 is greater than the thickness of the second electrode pad 222, the window 11 also penetrates the second electrode pad 222, the window 11 exposes the metal conductive sheet 6, and the second light-emitting element 4 is connected and fixed to the metal conductive sheet 6 by a conductive material. The conductive material includes at least one of glass paste, conductive silver glue, solder paste, solder, or anisotropic conductive glue.

[0057] Furthermore, the metal conductive sheet 6 is formed during the process of binding the first light emitting element 3 , which does not require any additional manufacturing process and can achieve a good conduction effect.

[0058] The advantage of such a design is that, since the thickness of the second electrode pad 222 is relatively thin, when the window 11 is formed by laser, it is difficult to control the depth of the window 11 so that the second electrode pad 222 can be just exposed. Therefore, in this embodiment, a metal conductive sheet 6 is further provided on the side of the second electrode pad 222 away from the driving circuit layer 2, so that the second light-emitting element 4 is connected and fixed to the metal conductive sheet 6 through a conductive material.

[0059] In this embodiment, the metal conductive sheet 6 is preferably a copper sheet, which has strong conductivity and low cost.

[0060] In this embodiment, the thickness of the metal conductive sheet 6 is between 10 microns and 100 microns. If the thickness of the metal conductive sheet 6 is too thin, it is not easy to control the depth of the window 11 when forming the window 11, and the metal conductive sheet 6 is easily penetrated. If the thickness of the metal conductive sheet 6 is too thick, it is not conducive to the thinning of the double-sided display panel 100, and it is easy to cause a large difference in gravity between the first light-emitting element 3 and the second light-emitting element 4 of the substrate 1, resulting in damage and breakage of the double-sided display panel 100.

[0061] The present invention also relates to a method for manufacturing a double-sided display panel 200, the manufacturing method comprising the following steps:

[0062] S1: Please refer to Figure 1 , provide a substrate 1. In the present embodiment, the substrate 1 is a flexible substrate 1, so a glass substrate 10 is first provided, and the substrate 1 is formed on the glass substrate 10 so as to support the substrate 1 by using the glass substrate 10.

[0063] Please also read Figure 2-3 A thin film transistor device layer 20 and an electrode layer 22 arranged on a side of the thin film transistor device layer 20 away from the substrate 1 and electrically connected to the thin film transistor device layer 20 are sequentially formed on the substrate 1, wherein the electrode layer 22 includes a first electrode pad 220 and a second electrode pad 222 spaced apart, and the size of the second electrode pad 222 is larger than that of the first electrode pad 220.

[0064] S2: Please refer to Figure 4 , conductive materials are formed on the first electrode pad 220 and the second electrode pad 222, respectively, the first light emitting element 3 is attached to the conductive material on the first electrode pad 220, and the metal conductive sheet 6 is attached to the conductive material on the second electrode pad 222. Then, the mini-LED and the thin film transistor 201 are electrically connected, and the metal conductive sheet 6 and another thin film transistor 201 are electrically connected by one of the heating methods of reflow soldering, hot pressing, and oven.

[0065] S3: Please refer to Figure 5 An upper packaging layer 50 is formed on the surface of the driving circuit layer 2 , and the upper packaging layer 50 covers the edge of the upper surface of the substrate 1 , the driving circuit layer 2 , the first light-emitting element 3 and the metal conductive sheet 6 .

[0066] S4: Please refer to Figure 6 , peel off the glass substrate 10 to obtain the panel intermediate structure 7.

[0067] S5: Please refer to Fig. 9, a window 11 is formed in the panel intermediate structure 7, the window 11 penetrates the substrate 1, the thin film transistor device layer 20 and the second electrode pad 222, and the metal conductive sheet 6 is exposed by the window 11. In this embodiment, a window penetrating the substrate 1, the thin film transistor device layer 20 and the second electrode pad 222 is formed in the region between two adjacent thin film transistors 201, so as to avoid damaging the conductive circuit in the driving circuit layer 2.

[0068] S6: Please continue reading Fig. 9 , a conductive material is arranged on the metal conductive sheet 6 and a second light emitting element 4 is attached to the conductive material. Then, the second light emitting element 4 is electrically connected to the metal conductive sheet 6 by one of the heating methods of reflow soldering, hot pressing, and oven. Since the second electrode pad 222 is electrically connected to the drain 203 of the thin film transistor device layer 20, and the second electrode pad 222 is connected to the metal conductive sheet 6, the second light emitting element 4 is connected to the thin film transistor 201, so that the thin film transistor 201 can be used as a control switch to control the light emission of the second light emitting element 4. Figure 6 It only illustrates the connection and fixation between the second light-emitting element 4 and the metal conductive sheet 6. It can be understood that the electrode layer 22 also includes a common electrode, so that one of the electrodes of the first light-emitting element 3 and the second light-emitting element 4 can be electrically connected to the thin film transistor 201, and the other electrode of the first light-emitting element 3 and the second light-emitting element 4 is connected to the common electrode, thereby forming a loop to achieve conduction between the first light-emitting element 3 and the second light-emitting element 4.

[0069] S7: Please refer again Fig. 9 A lower encapsulation layer 52 is provided on the substrate 1, and the lower encapsulation layer 52 covers the lower surface of the substrate 1 and fills the window 11, so that the first light-emitting element 3 is sealed between the upper encapsulation layer 50 and the driving circuit layer 2, and the second light-emitting element 4 is sealed between the lower encapsulation layer 52 and the driving circuit layer 2, and a double-sided display panel 200 can be obtained.

[0070] In summary, the double-sided display panel and its manufacturing method provided by the present application have light emitting directions of the first light-emitting element and the second light-emitting element electrically connected to the driving circuit layer opposite to each other. The driving circuit layer is used to individually control the light emission of the first light-emitting element and the second light-emitting element to achieve double-sided display, and has a simple structure, which can meet the requirements of thinning the double-sided display panel.

[0071] In summary, although the present application has been disclosed as above with preferred embodiments, the above preferred embodiments are not intended to limit the present application. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. A double-sided display panel, characterized in that: include: substrate; A driving circuit layer disposed on the substrate; A first light-emitting element and a second light-emitting element electrically connected to the driving circuit layer respectively, wherein the light emitting direction of the first light-emitting element is opposite to the light emitting direction of the second light-emitting element, and the driving circuit layer is used to individually control the light emission of the first light-emitting element and the second light-emitting element to realize double-sided display; An encapsulation layer connected to the substrate to seal the first light emitting element and the second light emitting element; A metal conductive sheet, arranged on a side of the driving circuit layer away from the substrate; The double-sided display panel is provided with a window penetrating the substrate and the driving circuit layer, the window reveals the metal conductive sheet, and the second light emitting element is located in the window and connected to the metal conductive sheet.

2. The double-sided display panel according to claim 1, characterized in that: The driving circuit layer includes a thin film transistor device layer, the thin film transistor device layer includes at least two thin film transistors, and the first light emitting element and the second light emitting element are electrically connected to one thin film transistor respectively.

3. The double-sided display panel according to claim 2, characterized in that: The driving circuit layer also includes an electrode layer arranged on a side of the thin film transistor device layer away from the substrate and electrically connected to the thin film transistor device layer. The electrode layer includes a first electrode pad, and the first light-emitting element is connected to the thin film transistor through the first electrode pad.

4. The double-sided display panel according to claim 3, characterized in that: The electrode layer includes a second electrode pad, which is arranged between the thin film transistor device layer and the metal conductive sheet. The size of the second electrode pad is larger than that of the first electrode pad. The window also penetrates the second electrode pad to expose the metal conductive sheet.

5. The double-sided display panel according to claim 4, characterized in that: The encapsulation layer includes an upper encapsulation layer and a lower encapsulation layer, wherein the upper encapsulation layer is connected to the upper surface of the substrate and covers the driving circuit layer and the first light-emitting element; and the lower encapsulation layer covers the lower surface of the substrate and fills the opening.

6. A method for manufacturing a double-sided display panel, characterized in that: The steps include: providing a substrate; forming a driving circuit layer on the substrate; forming a metal conductive sheet on the driving circuit layer; A first light-emitting element and a second light-emitting element are arranged so as to be electrically connected to the driving circuit layer, and a light emitting direction of the first light-emitting element is opposite to a light emitting direction of the second light-emitting element; Disposing a packaging layer connected to the substrate to seal the first light-emitting element and the second light-emitting element; Wherein, the method of setting the second light emitting element comprises: A window is opened through the substrate and the driving circuit layer, the window reveals the metal conductive sheet, and the second light-emitting element is located in the window and connected to the metal conductive sheet.

7. The method for manufacturing a double-sided display panel according to claim 6, wherein: The driving circuit layer includes a thin film transistor device layer arranged on the substrate and an electrode layer arranged on a side of the thin film transistor device layer away from the substrate and electrically connected to the thin film transistor device layer, the electrode layer includes a first electrode pad and a second electrode pad, and the second electrode pad is arranged between the thin film transistor device layer and the metal conductive sheet.

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