Display panel manufacturing method, display panel and display device

Abstract

The present invention provides a display panel manufacturing method, a display panel and a display device. In the display panel manufacturing method, a plurality of independent connectors are first prepared, and then the connectors and a plurality of light-emitting chips are sequentially transferred to a back plate, and the light-emitting chips and the back plate are welded by the connectors, thereby avoiding the use of screen printing technology and solving the problems of circuit short circuit and poor connection of light-emitting chips caused by the bonding and drawing between solder paste and steel mesh and the inaccurate position of solder paste.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic display equipment, and in particular to a display panel preparation method, a display panel and a display device. Background Art

[0002] Mini-LED (mini light-emitting diode) and Micro-LED (micro light-emitting diode) are one of the hot spots of future display technology. As the panel resolution increases, the size of LED (light-emitting diode) chips gradually decreases, and the installation process requirements and process difficulty of LED chips also increase as the chip size decreases.

[0003] The existing Mini-LED chip installation is usually achieved through die bonding and reflow soldering, while for smaller Micro-LED chips, ACF (Anisotropic Conductive Film) pressing is usually used, that is, a layer of ACF glue is attached between the chip and the pad, and the chip is installed on the substrate by applying pressure or heat.

[0004] The die bonding and reflow soldering method requires the stencil printing to apply solder paste to the pad. The existing technology has many defects in the tinning process, such as inaccurate solder paste position, adhesion and wire drawing between solder paste and stencil, etc., which will cause circuit short circuits, poor connections and other problems. For smaller Micro-LED chips, the tinning and reflow soldering method cannot be used for soldering due to process accuracy and other issues. Summary of the invention

[0005] The purpose of the present invention is to provide a display panel preparation method, a display panel and a display device to solve the technical problems in the prior art such as circuit short circuit of the display panel and poor connection of the light-emitting chip caused by inaccurate solder paste positioning, wire drawing between the solder paste and the steel mesh, and low process precision.

[0006] To achieve the above-mentioned objectives, the present invention provides a method for preparing a display panel, which comprises the following steps: preparing a plurality of connectors on a substrate layer; transferring the connectors from the substrate layer to a backplane; transferring a light-emitting chip to a surface of the backplane away from the connectors; and welding the light-emitting chip and the backplane.

[0007] Furthermore, the step of preparing a plurality of connectors on the substrate layer includes the following steps: forming a sacrificial layer on a surface of the substrate layer; forming an insulating layer and a conductive layer on the sacrificial layer; dividing the insulating layer to form a plurality of the connectors, each connector comprising at least one conductive layer; and removing the sacrificial layer to separate the connectors from the substrate layer.

[0008] Furthermore, the step of forming an insulating layer and a conductive layer on the sacrificial layer includes the following steps: forming the insulating layer on a surface of the sacrificial layer away from the substrate layer; forming a plurality of through holes in the insulating layer; and filling the through holes with conductive materials to form the conductive layer.

[0009] Furthermore, the material of the insulating layer includes inorganic material, and the conductive material includes metal material.

[0010] Furthermore, before transferring the connector from the substrate layer to the backplane, the following step is also included: aligning the connector with the backplane so that the conductive layer of the connector corresponds to the pad of the backplane.

[0011] Furthermore, before transferring the light-emitting chip to the connecting member, the following steps are also included: aligning the light-emitting chip with the connecting member or the backplane so that the electrode pins of the light-emitting chip correspond to the conductive layer of the connecting member.

[0012] Furthermore, the number of the connecting members is twice or more than the number of the light-emitting chips.

[0013] The present invention also provides a display panel, which is manufactured by the display panel manufacturing method as described above. The display panel includes a backplane, a light-emitting chip and a connector. The light-emitting chip is arranged on the backplane. The connector is arranged between the light-emitting chip and the backplane, and is electrically connected to the light-emitting chip and the backplane.

[0014] Furthermore, the connector includes an insulating layer and a conductive layer. The insulating layer is provided between the light-emitting chip and the back plate. The insulating layer is provided with at least one through hole, and the conductive layer is filled in the through hole. Two ends of the conductive layer are electrically connected to the electrode pins of the light-emitting chip and the pads of the back plate, respectively.

[0015] The present invention further provides a display device, comprising the display panel as described above.

[0016] The advantages of the present invention are: a display panel preparation method, display panel and display device in the present invention adopt the method of preparing independent connectors and then welding, thus avoiding the use of screen printing technology, thereby solving the problems of circuit short circuit and poor connection of light-emitting chips caused by the bonding wire drawing between solder paste and steel mesh and the inaccurate position of solder paste. At the same time, the display panel preparation method provided in the embodiment of the present invention also improves the process accuracy, so that even Micro-LED chips with smaller sizes can be welded by reflow soldering. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a schematic diagram of a layered structure of a display panel in an embodiment of the present invention;

[0019] Figure 2 is a three-dimensional diagram of a connecting member in an embodiment of the present invention;

[0020] Figure 3 is a schematic flow chart of a method for preparing a display panel according to an embodiment of the present invention;

[0021] Figure 4 Schematic diagram of a layered structure after a sacrificial layer is formed in step S10 in an embodiment of the present invention;

[0022] Figure 5 Schematic diagram of a layered structure after an insulating layer is formed in step S10 in an embodiment of the present invention;

[0023] Figure 6 Schematic diagram of the layered structure after the through hole is formed in step S10 in an embodiment of the present invention;

[0024] Figure 7 Schematic diagram of a layered structure after a conductive layer is formed in step S10 in an embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of a layered structure after the insulating layer is separated in step S10 in an embodiment of the present invention;

[0026] Fig. 9 This is a schematic diagram of the layered structure after the connecting member is peeled off in step S10 in an embodiment of the present invention;

[0027] Fig.10 Schematic diagram of the layered structure of the display panel after step S20 in an embodiment of the present invention;

[0028] Fig.11 Schematic diagram of the layered structure of the display panel after step S30 in an embodiment of the present invention.

[0029] The components in the figure are shown as follows:

[0030] Display panel 1; Back panel 10;

[0031] Solder pad 11; Light emitting chip 20;

[0032] Electrode pin 21; Connector 30;

[0033] Insulating layer 31; Through hole 32;

[0034] Conductive layer 33; Substrate layer 40;

[0035] Sacrificial layer 50 . DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention are described below with reference to the drawings in the specification to prove that the present invention can be implemented. The embodiments of the invention can fully introduce the present invention to those skilled in the art, making its technical content clearer and easier to understand. The present invention can be embodied through many different forms of embodiments of the invention, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0037] In the drawings, components with the same structure are indicated by the same numerical reference numerals, and components with similar structures or functions are indicated by similar numerical reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0038] In addition, the following descriptions of the various embodiments of the invention refer to the attached drawings to illustrate specific embodiments of the invention that the present invention can be implemented. The directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for better and clearer description and understanding of the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0039] When some components are described as being "on" another component, the component may be directly placed on the other component; there may also be an intermediate component on which the component is placed, and the intermediate component is placed on the other component. When a component is described as being "mounted on" or "connected to" another component, the two may be understood to be directly "mounted on" or "connected", or one component may be indirectly "mounted on" or "connected to" another component via an intermediate component.

[0040] A display device is provided in an embodiment of the present invention. The display device may be an MLED display device, which includes: Figure 1 The self-luminous display panel 1 shown in FIG. The display device can be any display device with a display function, such as a mobile phone, a notebook computer, a tablet computer, etc.

[0041] like Figure 1As shown, the display panel 1 includes a back plate 10 , a plurality of light emitting chips 20 and a plurality of connectors 30 . The light emitting chips 20 are electrically connected to the back plate 10 through the connectors 30 and fixed on the back plate 10 .

[0042] The back plate 10 may be an array substrate, and a plurality of pads 11 are disposed on one surface thereof. The connectors 30 are disposed on the pads 11, and each pad 11 is provided with at least one connector 30. The back plate 10 is used to control the on or off of the light emitting chip 20, thereby controlling the display screen of the display panel 1.

[0043] The light emitting chip 20 is arranged on the connecting member 30, and two electrode pins 21 are arranged on the bottom surface thereof, and the two electrode pins 21 are respectively located at the two ends of the light emitting chip 20. At least one connecting member 30 is arranged under each electrode pin 21, and the electrode pin 21 is electrically connected to a pad 11 in the back plate 10 through the connecting member 30. The number of the connecting members 30 is twice or more than twice the number of the light emitting chips 20. The light emitting chip 20 can be an autonomous light emitting chip 20 such as Mini-LED, Micro-LED, etc., which is used to provide a display light source.

[0044] like Figure 1-2 As shown, the connector 30 includes an insulating layer 31 and a conductive layer 33. The insulating layer 31 is disposed between the light-emitting chip 20 and the back plate 10, and its top surface contacts the electrode pin 21 of the light-emitting chip 20, and its bottom surface contacts the pad 11 of the back plate 10. Two through holes 32 are disposed in the insulating layer 31, and the two through holes 32 are parallel to each other and are not the same. The through hole 32 passes through from the top surface of the insulating layer 31 to the bottom surface of the insulation, and can be cylindrical, prism-shaped, truncated cone-shaped, etc. The conductive layer 33 is filled in the through hole 32, so that the insulating layer 31 wraps the conductive layer 33 and protects the conductive layer 33 to prevent water and oxygen from invading and corroding. The top surface and bottom surface of the conductive layer 33 are flush with the top surface and bottom surface of the insulating layer 31, respectively, so that the top surface and bottom surface of the conductive layer 33 are also in contact with the electrode pin 21 and the pad 11, respectively, and are electrically connected, thereby lighting up the light-emitting chip 20.

[0045] The present invention also provides a method for preparing a display panel 1, which is used to prepare the above-mentioned display panel 1. The process of the method for preparing the display panel 1 is as follows: Figure 3 As shown, it includes the following implementation steps:

[0046] Step S10) preparing a plurality of connecting members 30 on a substrate layer 40:

[0047] like Figure 4As shown, a glass substrate is prepared as the substrate layer 40 , and a sacrificial layer 50 is formed on a surface of the substrate layer 40 .

[0048] like Figure 5 As shown, a layer of inorganic material is prepared on a surface of the sacrificial layer 50 away from the substrate layer 40 by a film forming method such as chemical vapor deposition or physical vapor deposition, thereby forming the insulating layer 31 on the sacrificial layer 50. The inorganic material may be an oxide or a nitride.

[0049] like Figure 6 As shown, the insulating layer 31 is patterned by a patterning method such as laser etching or wet etching, so as to form a plurality of through holes 32 in the insulating layer 31 .

[0050] like Figure 7 As shown, each through hole 32 is filled with a conductive material by electroplating or physical vapor deposition, thereby forming a conductive layer 33 in the through hole 32. The conductive material may be a high-conductivity metal such as tin, copper, gold, silver, or a solder filler containing a metal.

[0051] like Figure 8 As shown, the insulating layer 31 is divided by a patterning method such as laser etching or wet etching to form a plurality of independent connecting members 30 .

[0052] like Fig. 9 As shown, the sacrificial layer 50 is removed by an etching method such as wet etching or dry etching, so as to peel off the connecting member 30 and the substrate layer 40 .

[0053] Step S20) transferring the connecting member 30 from the substrate layer 40 to the backplane 10:

[0054] like Fig.10 As shown, the connectors 30 on the substrate layer 40 are transferred to the backplane 10 by a mass transfer method such as die bonding. Before releasing the connectors 30, an alignment operation is performed to place the connectors 30 corresponding to the pads 11 on the backplane 10, so that each connector 30 can fall on the pads 11 after being released.

[0055] Step S30) transferring the light emitting chip 20 to the connecting member 30:

[0056] like Fig.11As shown, a plurality of light emitting chips 20 are transferred to a surface of the connector 30 away from the back plate 10 by mass transfer again. In addition, before releasing the light emitting chip 20, an alignment operation is also performed to align the electrode pins 21 of the light emitting chip 20 with the connector 30, so that each electrode pin 21 of the light emitting chip 20 can fall on the connector 30 after being released.

[0057] Step S40) welding the light emitting chip 20 and the back plate 10:

[0058] The conductive layer 33 in the connector 30 is melted by the reflow soldering method, and due to the limitation of the insulating layer 31, the conductive layer 33 cannot overflow from the through hole 32, so that the conductive layer 33 can only connect the light emitting chip 20 and the back plate 10, reducing the risk of circuit short circuit. After the conductive layer 33 is solidified, the light emitting chip 20 is fixed on the pad 11 in the back plate 10 through the conductive layer 33 in the connector 30, forming a Figure 1 The display panel 1 shown in FIG.

[0059] The display panel preparation method provided in the embodiment of the present invention does not need to use screen printing technology, thereby solving the problem of circuit short circuit and poor connection of light-emitting chips caused by wire drawing between solder paste and steel mesh and inaccurate solder paste position. In addition, the insulating layer in the connector can also avoid short circuit failure caused by irregular flow of the conductive layer after melting, and reduce the risk of short circuit caused by solder paste remelting and flow during secondary reflow soldering. At the same time, the display panel preparation method provided in the embodiment of the present invention improves the process accuracy, so that even smaller Micro-LED chips can be soldered by reflow soldering.

[0060] In the embodiment of the present invention, each connector of the display panel is provided with only two conductive layers, but in other embodiments of the present invention, the number of the conductive layers is not limited, and one conductive layer or more than two conductive layers can be provided according to the performance and process requirements, and its structure is the same as the connector provided with two conductive layers in the embodiment of the present invention, so it will not be described in detail here. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0061] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A method for preparing a display panel, characterized in that: The following steps are involved: Preparing a plurality of connecting members on a substrate layer; transferring the connector from the substrate layer to a backplane; Transferring the light-emitting chip to a surface of the connecting member away from the back plate; Welding the light emitting chip and the back plate; The step of preparing a plurality of connectors on the substrate layer includes the following steps: forming a sacrificial layer on a surface of the substrate layer; forming an insulating layer and a conductive layer on the sacrificial layer; dividing the insulating layer to form a plurality of the connecting members, each of which includes at least one of the conductive layers; removing the sacrificial layer and separating the connecting member from the substrate layer; The step of forming an insulating layer and a conductive layer on the sacrificial layer includes the following steps: forming the insulating layer on a surface of the sacrificial layer away from the substrate layer; forming a plurality of through holes on the insulating layer; Filling the through hole with a conductive material to form the conductive layer; The step of transferring the light emitting chip to the connecting member further comprises: The light emitting chip is aligned with the connecting member or the back plate so that the electrode pins of the light emitting chip correspond to the conductive layer of the connecting member.

2. The method for preparing a display panel according to claim 1, wherein: The material of the insulating layer includes inorganic material; The conductive material includes a metal material.

3. The method for preparing a display panel according to claim 1, wherein: Before transferring the connecting element from the substrate layer to the backplane, the method further includes the following steps: The connecting member and the back plate are aligned so that the conductive layer of the connecting member corresponds to the pad of the back plate.

4. The method for preparing a display panel according to claim 1, wherein: The number of the connecting members is twice or more than the number of the light emitting chips.

5. A display panel, characterized in that: The display panel is manufactured by the method for manufacturing a display panel according to any one of claims 1 to 4; the display panel comprises: A light emitting chip is disposed on a back plate; The connecting member is disposed between the light emitting chip and the back plate, and is electrically connected to the light emitting chip and the back plate.

6. The display panel according to claim 5, wherein: The connecting piece comprises: An insulating layer, disposed between the light emitting chip and the back plate, wherein the insulating layer is provided with at least one through hole; A conductive layer filled in the through hole; Two ends of the conductive layer are electrically connected to the electrode pins of the light emitting chip and the pads of the back plate respectively.

7. A display device, characterized in that: Comprising a display panel as described in any one of claims 5-6.

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