WO2023122962A1

WO2023122962A1 - Display apparatus

Info

Publication number: WO2023122962A1
Application number: PCT/CN2021/142098
Authority: WO
Inventors: 叶岩溪
Original assignee: 厦门市芯颖显示科技有限公司
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2023-07-06

Abstract

Provided in the embodiments of the present application is a display apparatus. The display apparatus comprises a micro light-emitting diode; a driving substrate, which provided with a driving circuit; a pad structure, which is provided with a patterned structure, wherein the pad structure comprises a pin pad and a binding pad, the pin pad being arranged on the micro light-emitting diode and being electrically connected to the micro light-emitting diode, and the binding pad being arranged on the driving substrate and being electrically connected to the driving circuit; and a connection layer, which is arranged between the pin pad and the binding pad and comprises a plurality of conductive particles, wherein at least some of the conductive particles are scattered in the patterned structure, and the driving circuit is electrically connected to the micro light-emitting diode by means of the pad structure and the conductive particles electrically connected to the pad structure. By means of the technical solution, a patterned structure is provided on a pad structure, such that conductive particles can be scattered in the patterned structure, thereby improving the blocking effect of the pad structure on the deviation of the conductive particles, and the problem of poor contact occurring when a micro light-emitting diode is bound to a driving substrate is solved.

Description

display device

technical field

The present application relates to the field of display technology, and in particular to a display device.

Background technique

Compared with traditional LCD (Liquid Crystal Display, liquid crystal display) and OLED (Organic Light-Emitting Diode, organic electro-laser display), Micro-LED (miniature light-emitting diode) display device has higher brightness, wider color gamut, and more Fast response time, better transparency, special-shaped cutting, better reliability and other advantages.

In the existing display devices, the design of the Micro-LED bonding pad (welding pad) on the Micro-LED technology substrate (driver substrate) is a flat metal layer, and the Micro-LED bonding on the technology substrate is made of conductive glue. In the technology where the pin pad on the pad and the LED is used as the contact medium, the planar metal design of the Micro-LED binding pad on the technical substrate is easy to make the conductive particles in the conductive glue slide, resulting in the binding of the Micro-LED and the technical substrate. There is a bad contact.

application content

Therefore, in order to overcome at least some of the defects and deficiencies existing in the prior art, an embodiment of the present application provides a display device.

Specifically, the display device proposed by an embodiment of the present application includes, for example, micro light emitting diodes; a driving substrate provided with a driving circuit; a pad structure provided with a patterned structure, and the pad structure includes pin pads and bonding pads. Pad, the pin pad is arranged on the micro light emitting diode and electrically connected to the micro light emitting diode, the bonding pad is arranged on the driving substrate and electrically connected to the driving circuit; the connection layer is arranged on the Between the pin pad and the bonding pad, and including a plurality of conductive particles; wherein at least part of the conductive particles of the plurality of conductive particles are scattered in the patterned structure, and the driving circuit passes through the The pad structure and the conductive particles electrically connected to the pad structure are electrically connected to the micro light emitting diodes.

In one embodiment of the present application, the bonding pad is provided with the patterned structure, and the driving circuit passes through the bonding pad, the plurality of conductive particles and the bonding pad and The conductive particles electrically connected to the pin pads are electrically connected to the micro light emitting diodes; and/or the pin pads are provided with the patterned structure, and the micro light emitting diodes are connected to the micro light emitting diodes through the pin pads. The conductive particles electrically connected to the pin pads and the binding pads are electrically connected to the drive circuit.

In one embodiment of the present application, the patterned structure is a groove.

In one embodiment of the present application, the width of the groove is greater than 1 micron.

In one embodiment of the present application, the groove includes multiple sub-grooves, and the multiple sub-grooves are spaced apart from each other.

In one embodiment of the present application, the projection shape of the multiple sub-grooves on the bonding pad and/or the lead pad is one of a square shape, a rhombus shape, or a plurality of groups of stop grooves.

In one embodiment of the present application, the pad structure includes a smooth area and a rough area, the patterned structure is disposed in the rough area, and the surface roughness of the patterned structure is greater than the surface of the smooth area roughness, at least a portion of the plurality of conductive particles scattered on the roughened area.

In one embodiment of the present application, the projection shape of the rough region on the bonding pad and/or on the pin pad is in the shape of a square.

In one embodiment of the present application, the projection shape of the rough region on the bonding pad and/or the lead pad is rhombus.

In one embodiment of the present application, the projection shape of the rough region on the bonding pad and/or the lead pad is in the shape of multiple sets of grooves.

It can be seen from the above that the above-mentioned embodiments of the present application have the following beneficial effects: by providing a patterned structure on the pad structure, conductive particles can be scattered in the patterned structure, thereby increasing the resistance of the pad structure to the migration of conductive particles The function solves the problem of bad contact when the miniature light-emitting diode and the driving substrate are bonded. Further, by designing a patterned structure on the lead pad and/or the bonding pad so that the conductive particles can be scattered therein, the resistance of the lead pad and/or the bonding pad to the offset of the conductive particles is increased, Therefore, the problem of poor contact of the display device when the micro light-emitting diode and the driving substrate are bound is solved. In addition, the patterned structure is further set as a groove or a rough area, and the groove or rough area is designed to further enhance the resistance of the lead pad and/or the bonding pad to the offset of the conductive particles, increasing the Binding reliability.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a display device provided in the first embodiment of the present application.

FIG. 2 is a schematic structural diagram of another display device provided in the first embodiment of the present application.

FIG. 3 is a schematic structural diagram of another display device provided in the first embodiment of the present application.

4A-4C are schematic diagrams of the projected shape of the groove on the bonding pad in the first embodiment of the present application.

FIG. 5 is a schematic structural diagram of another display device provided in the first embodiment of the present application.

6A-6C are schematic diagrams of the projected shape of the rough region on the bonding pad in the first embodiment of the present application.

FIG. 7 is a schematic structural diagram of a display device provided by the second embodiment of the present application.

FIG. 8 is a schematic structural diagram of another display device provided by the second embodiment of the present application.

FIG. 9 is a schematic structural diagram of another display device provided in the second embodiment of the present application.

FIG. 10 is a schematic structural diagram of another display device provided in the second embodiment of the present application.

FIG. 11 is a schematic structural diagram of a display device provided by the third embodiment of the present application.

FIG. 12 is a schematic structural diagram of another display device provided by the third embodiment of the present application.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only part of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

It should be noted that all directional indications (such as up, down, left, right, front, and back) in the embodiments of the present application are only used to explain the relative positions of the components in a certain posture (as shown in the accompanying drawings) relationship, motion, etc., if the particular pose changes, the directional indication changes accordingly.

In the embodiments of the present application, the descriptions involving "first", "second", etc. are only for the purpose of description, and should not be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features.

【The first embodiment】

As shown in FIG. 1 , the first embodiment of the present application provides a display device 10 . Specifically, the display device 10 includes a driving substrate 11 , a pad structure 12 , a connection layer 13 , and micro light emitting diodes 14 . Wherein, the pad structure 12 is, for example, provided with a patterned structure. Specifically, the pad structure 12 includes, for example, lead pads 122 and bonding pads 121 . Wherein, the lead pads 122 are, for example, disposed on the micro LEDs 14 and electrically connected to the micro LEDs 14 . The bonding pads 121 are, for example, disposed on the driving substrate 11 .

Specifically, the driving substrate 11 is provided with, for example, a driving circuit for driving the micro light emitting diodes 14 electrically connected to the driving substrate 11 . The bonding pad 121 is electrically connected to the driving circuit, for example. The material of the pad structure 12 is, for example, copper, silver, gold and other metal materials with good electrical conductivity. The connection layer 13 is, for example, a conductive adhesive having a plurality of conductive particles 131 such as ACF (Anisotropic Conductive Film, Anisotropic Conductive Film). The connection layer 13 is, for example, disposed between the lead pad 122 and the bonding pad 121 . The driving circuit is electrically connected to the miniature LED 14 through the pad structure 12 and the conductive particles 131 electrically connected to the pad structure 12 , for example. At least part of the conductive particles 131 in the plurality of conductive particles 131 are scattered on the patterned structure, so that the movement of the part of the conductive particles 131 scattered on the patterned structure on the pad structure 12 is restricted, and then fall on the part of the conductive particles 131 The deviation of the conductive particles 131 between them is blocked. Therefore, the patterned structure acts as a barrier to the sliding of the plurality of conductive particles 131 on the pad structure 12 . It can be understood that, the miniature light emitting diodes 14 are, for example, existing flip-chip, front-mount or vertical micro-light emitting diodes, and the present application is not limited thereto.

In the display device provided by the above technical solution, a patterned structure is provided on the pad structure, so that conductive particles can be scattered in the patterned structure, thereby increasing the blocking effect of the pad structure on the offset of conductive particles, and solving the problem of The poor contact problem that occurs when the miniature light-emitting diode and the driving substrate are bonded.

Specifically, as shown in FIG. 2 , for example, a patterned structure 1211 is disposed on the bonding pad 121 . The connection layer 13 is, for example, disposed on the driving substrate 11 and covers the bonding pads 121 . The micro light emitting diodes 14 are, for example, disposed on a side of the connection layer 13 away from the driving substrate 11 . Wherein, the driving circuit in the driving substrate 11 is electrically connected to the miniature LEDs 14 through the bonding pad 121 and the connection layer 13 . Specifically, the driving circuit is electrically connected to the miniature light emitting diode 14 through the bonding pad 121 and the conductive particles 131 electrically connected to the bonding pad 121 and the lead pad 122 . At least some of the conductive particles 131 in the plurality of conductive particles 131 are scattered on the patterned structure 1211, so that the movement of some of the conductive particles 131 scattered on the patterned structure 1211 on the bonding pad 121 is restricted, and the part of the conductive particles The offset of 131 was blocked.

In the display device provided by the above technical solution, by setting a patterned structure on the bonding pad, conductive particles can be scattered in the patterned structure, thereby increasing the blocking effect of the bonding pad on the offset of conductive particles, and solving the problem of The poor contact problem that occurs when the micro light-emitting diode and the driving substrate are bonded is solved.

It can be understood that the display device 10 includes, for example, a plurality of miniature light emitting diodes 14 , and the plurality of miniature light emitting diodes 14 are bound to the driving substrate with reference to the above description, which will not be repeated in this application.

Further, the driving substrate 11 is, for example, a TFT (Thin Film Transistor, Thin Film Field Effect Transistor) driving substrate. Wherein, the TFT driving substrate includes a thin film transistor layer. The thin film transistor layer is used to provide a pixel driving circuit to control the display of the micro light emitting diodes bound on the TFT substrate. The thin film transistor layer includes, for example, a plurality of thin film transistors arranged in an array. The thin film transistor may be, for example, a polysilicon transistor, an amorphous silicon transistor, an organic thin film transistor, a metal oxide transistor, a carbon nanotube or graphene transistor, or other nanoparticle-based transistors, and the present application is not limited thereto. The thin film transistor layer also includes other circuit components such as capacitors, for example. More specifically, the pixel driving circuit provided by the thin film transistor layer is, for example, 2T1C (2transistor1capacitance, 2 thin film transistors and 1 storage capacitor Cst), 3T1C (3transistor1capacitance, 3 thin film transistors and 1 storage capacitor Cst), 4T1C (4transistor1capacitance, 4 A driving circuit such as a thin film transistor with 1 storage capacitor Cst) or a 4T2C (3transistor1capacitance, 4 thin film transistors and 2 storage capacitors Cst), the present application is not limited thereto.

The display device 10 further includes, for example, an encapsulation layer and a protective cover disposed on the micro LEDs 14 . The encapsulation layer is, for example, a composite material such as a thermoplastic film or a high molecular polymer, which can effectively protect a plurality of micro light emitting diodes and isolate external water and oxygen. The protective cover is, for example, a glass substrate with good light transmission and a layered structure that isolates water and oxygen and protects the micro light emitting diodes. The display device 10 further includes, for example, a Chip On Flex (COF) bonded to the driving substrate and a PCB driving circuit. The chip-on-chip and the PCB driving circuit are used to provide driving signals to the driving substrate. It can be understood that the display device 10 provided in the embodiment of the present application may also include other elements or structures that assist the display of the display device, and the present application is not limited thereto.

Further, as shown in FIG. 3 , the patterned structure 1211 is, for example, a groove 12111 . Specifically, the groove 12111 runs through the bonding pad 121 along the direction extending from the micro LED 14 to the driving substrate 12 , and the width of the groove 12111 in the direction parallel to the driving substrate 11 is a. Specifically, the width a is larger than 1 micrometer (μm). The conductive particles 131 are, for example, metal balls or polymer plastic balls coated with metal. Common metal balls and metal-coated materials are, for example, metal powder nickel (Ni), gold (Au), gold-plated nickel, silver, and tin alloys. The diameter of the conductive particles 131 is generally 2 to 3 microns, so setting the width of the groove 12111 to be greater than 1 micron can make the conductive particles 131 partly scattered on the groove 12111, so that the groove 12111 can block the movement of the conductive particles 131, Offset of the conductive particles 131 is prevented.

Further, as shown in FIGS. 4A-4C , the groove 12111 includes, for example, multiple sections of sub-grooves 121111 , and the multiple sections of sub-grooves 121111 are arranged at intervals from each other. Each sub-groove 121111 is, for example, an L-shaped groove, a strip-shaped groove or a groove of other shapes, and the present application is not limited thereto. Specifically, as shown in FIGS. 3 and 4A , the projection shape of the multi-segment sub-grooves 121111 on the bonding pad 121 is a square shape. A plurality of conductive particles 131 can be scattered on the groove 12111, so that the conductive particles 131 are fixed between the zigzag grooves, and the conductive particles 131 fixed between the zigzag grooves realize the bonding of the pads 121 and the pin pads 122 electrical connections. As shown in FIG. 3 and FIG. 4B , the projection shape of the multi-segment sub-grooves 121111 on the bonding pad 121 is rhombus. A plurality of conductive particles 131 can be scattered on the grooves 12111, so that the conductive particles 131 are fixed between the diamond-shaped grooves, and the conductive particles 131 fixed between the diamond-shaped grooves realize the binding of the bonding pads 121 and the pin pads 122. electrical connection. As shown in FIG. 3 and FIG. 4C , the projection shape of the multi-segment sub-grooves 121111 on the bonding pad 121 is the shape of multiple sets of stop grooves. A plurality of conductive particles 131 can be scattered on the groove 12111, so that the conductive particles 131 are fixed between multiple groups of groove-shaped grooves, and the conductive particles 131 fixed between multiple groups of groove-shaped grooves realize bonding pads 121 and the electrical connection of the pin pad 122. The above technical solution can prevent the movement of conductive particles in multiple directions by setting multiple sub-grooves, thereby improving the binding reliability. Furthermore, by designing the groove as a multi-segment sub-groove shape, the blocking effect of the bonding pad on the migration of conductive particles is further enhanced, and the bonding reliability is increased.

On the other hand, as shown in FIG. 5 , the bonding pad 121 includes, for example, a smooth area 1212 and a rough area 1213 . Wherein, the smooth region 1212 and the rough region 1213 are, for example, disposed on a side of the bonding pad 121 away from the driving substrate 11 and in contact with the connection layer 13 . The rough region 1213 is formed, for example, by pattern etching techniques such as GTM (Gray Tone Mask). It is of course understood that other patterning techniques for patterning the roughness can also be used. Wherein, the patterned structure 1211 is, for example, disposed in the rough region 1213 , and the patterned structure 1211 overlaps with the rough region 1213 , for example. The surface roughness of the rough area 1213 is greater than that of the smooth area 1212 , and the rough area 1213 and the smooth area 1212 are arranged at intervals, so that a plurality of conductive particles 131 can be scattered in the rough area 1213 and restricted by the rough area 1213 . In addition, since the conductive particles 131 scattered on the smooth area 1213 are blocked by the conductive particles 131 in the rough area 1213, their deviation will also be restricted, so that the movement of the conductive particles 131 on the bonding pad 121 is blocked, solving the problem of driving the substrate. 11. Poor contact with micro light emitting diodes 14. It can be understood that two rough regions 1213 and a plurality of smooth regions 1212 separated by the two rough regions 1213 are arranged on the bonding pad 121 shown in FIG. The conductive particles 131 can be blocked by the rough region 1213 and the conductive particles 131 falling on the rough region 1213 , thereby limiting the sliding of the conductive particles 131 on the bonding pad 121 . Of course, it can be understood that the number and distribution of the rough regions 1213 can also be in other forms, which are not limited in this application.

Specifically, as shown in FIG. 5 and FIGS. 6A-6C , the projection shape of the rough region 1213 on the bonding pad 121 is, for example, a square shape, a rhombus shape, or a plurality of sets of groove shapes. More specifically, as shown in FIG. 6A , the projection shape of the rough region 1213 on the bonding pad 121 is a square shape. As shown in FIG. 6B , the projection shape of the rough region 1213 on the bonding pad 121 is a rhombus. As shown in FIG. 6C , the projection shape of the rough region 1213 on the bonding pad 121 is the shape of multiple sets of grooves. A plurality of conductive particles 131 can be scattered on the rough region 1213 and the smooth region 1212, so that the plurality of conductive particles 131 can be fixed on the rough region 1213 or between the conductive particles 131 on the rough region 1213, thereby realizing bond welding Pad 121 and pin pad 122 are electrically connected. By setting the rough area and designing it into multiple shapes, the resistance of the bonding pad to the sliding of the conductive particles is further increased, and the bonding reliability is increased.

To sum up, the display device proposed in the first embodiment of the present application arranges a patterned structure on the bonding pad structure, so that conductive particles can be scattered in the patterned structure, thereby increasing the resistance of the bonding pad structure to the offset of conductive particles. The barrier solves the problem of poor contact that occurs when the micro light-emitting diode and the driving substrate are bonded. Furthermore, by designing a patterned structure on the bonding pad, the conductive particles can be scattered therein, increasing the blocking effect of the bonding pad on the migration of the conductive particles, thereby solving the problem of the display device in the micro light-emitting diode and driving. Poor contact problem during substrate bonding. In addition, the patterned structure is set as a groove or a rough area, and the groove or rough area is designed, which further enhances the resistance of the bonding pad to the offset of the conductive particles, thereby further solving the problem of the display device in the micro-luminescence. Poor contact problems during bonding of diodes and driver substrates increase bonding reliability.

【Second Embodiment】

Referring to FIG. 7 , the second embodiment of the present application proposes a display device 20 . The display device 20 includes, for example, micro light emitting diodes 24 , a driving substrate 21 , pad structures 22 and a connection layer 23 . Wherein, the bonding pad structure 22 is provided with a patterned structure, for example. Specifically, the pad structure 22 includes, for example, a pin pad 222 and a bonding pad 221 . The lead pads 222 are, for example, disposed on the micro LEDs 24 and electrically connected to the micro LEDs 24 .

Specifically, the drive substrate 21 is provided with a drive circuit, for example. The driving circuit is used to drive the micro LEDs 24 electrically connected to the driving substrate 21 . The bonding pads 221 are, for example, disposed on the driving substrate 21 and electrically connected to the driving circuit. The materials of the bonding pads 221 and the lead pads 222 are, for example, metal materials with good electrical conductivity such as copper, silver, and gold. The connection layer 23 is, for example, a conductive adhesive such as ACF having a plurality of conductive particles 231 . The connection layer 23 is, for example, disposed on the driving substrate 21 and covers the bonding pads 221 . The miniature light emitting diode 24 is electrically connected to the driving circuit, for example, through the lead pad 222 and the conductive particles 231 electrically connected to the lead pad 222 and the bonding pad 221 . At least some of the conductive particles 231 in the plurality of conductive particles 231 are scattered on the patterned structure, so that the movement of the part of the conductive particles 231 scattered on the patterned structure on the pad structure 22 is restricted, and then fall on the part of the conductive particles 231 The deviation of the conductive particles 231 between them is blocked. Therefore, the patterned structure acts as a barrier to the sliding of the plurality of conductive particles 231 on the pad structure 22 .

In the display device provided by the above technical solution, a patterned structure is provided on the pad structure, so that conductive particles can be scattered in the patterned structure, thereby increasing the resistance of the pad structure to the migration of conductive particles, and solving the problem of miniature The poor contact problem that occurs when the light-emitting diode and the driving substrate are bonded.

Specifically, as shown in FIG. 8 , for example, a patterned structure 2221 is disposed on the lead pad 222 . At least part of the plurality of conductive particles 231 is scattered on the patterned structure 2221 , so that the patterned structure 2221 acts as a barrier to the deviation of the plurality of conductive particles 231 on the lead pad 222 . The miniature light emitting diodes 24 are, for example, conventional flip chip, front chip or vertical micro light emitting diodes, which is not limited in this application. It can be understood that the number of pin pads 222 of each micro LED 24 is two, corresponding to the positive electrode and the negative electrode of the micro LED 24 respectively. The display device 20 includes, for example, a plurality of micro LEDs 24 , and each micro LED 24 is electrically connected to the driving circuit on the driving substrate 21 through the lead pads 222 , the conductive particles 231 and the bonding pads 221 . Specifically, the micro light emitting diode 24 is electrically connected to the driving circuit through the lead pad 222 and the conductive particles 231 electrically connected to the lead pad 222 and the bonding pad 221 .

In the display device provided by the above technical solution, by designing a patterned structure on the lead pads, the conductive particles can be scattered in the patterned structure, thereby increasing the resistance of the lead pads to the offset of the conductive particles, and solving the problem of Poor contact problem when bonding micro light emitting diodes and driving substrates.

It can be understood that, for example, the display device 20 further includes an encapsulation layer and a protective cover disposed on the micro LEDs 24 . The encapsulation layer is, for example, a composite material such as a thermoplastic film or a high molecular polymer, which can effectively protect the plurality of micro LEDs 24 and isolate external water and oxygen. The protective cover is, for example, a glass substrate with good light transmission and a layered structure that isolates water and oxygen and protects the micro LEDs 24 . The display device 20 further includes, for example, a chip-on-chip film bound to the driving substrate and a PCB driving circuit. The chip-on-chip and the PCB driving circuit are used to provide driving signals to the driving substrate. It can be understood that the display device 20 provided in the embodiment of the present application may also include other elements or structures that assist the display of the display device, and the present application is not limited thereto.

Further, referring to FIG. 9 , the patterned structure 2221 is, for example, a groove 22211 . Specifically, the groove 22211 runs through the lead pad 222 along the direction extending from the driving substrate 22 to the micro LED 24 , and the width of the groove 22211 in the direction parallel to the driving substrate 21 is b. The width b is greater than 1 micron. The conductive particles 231 are, for example, metal balls or polymer plastic balls coated with metal. Common metal balls and metal-coated materials are, for example, metal powder nickel (Ni), gold (Au), gold-plated nickel, silver, and tin alloys. The diameter of the conductive particles 231 is generally 2-3 microns, so setting the width of the groove 22211 to be greater than 1 micron can make the conductive particles 131 partly scattered on the patterned 2411, so that the patterned structure 2221 can block the sliding of the conductive particles 231 , preventing the offset of the conductive particles 231.

Further, the groove 22211 includes, for example, multiple sections of sub-grooves, and the multiple sections of sub-grooves are arranged at intervals from each other. Specifically, the projection shape of the multi-segment sub-grooves on the lead pad 222 is, for example, one of a square shape, a rhombus shape, and a plurality of groups of stop groove shapes. For the specific structure of the multi-segment sub-grooves, refer to the first embodiment and the description of the multi-segment sub-grooves 121111 in FIGS. 4A-4C , and the present application will not repeat them here. By designing the groove as a multi-segment sub-groove shape, the resistance of the lead pad to the deviation of the conductive particles is further enhanced, and the bonding reliability is increased.

On the other hand, as shown in FIG. 10 , the lead pad 222 includes, for example, a smooth area 22212 and a rough area 22213 . Wherein, the smooth area 22212 and the rough area 22213 are, for example, disposed on the side of the lead pad 222 in contact with the connection layer 23 . The rough region 22213 is formed, for example, by pattern etching techniques such as GTM (Gray Tone Mask). Of course, it can be understood that the rough region 22213 can also use other patterning techniques capable of etching a patterned rough structure. Wherein, the patterned structure 2221 is, for example, disposed in the rough region 22213 , specifically, the patterned structure 2221 overlaps with the rough region 22213 , for example. The surface roughness of the rough area 22213 is greater than that of the smooth area 22212 , and the rough area 22213 and the smooth area 22212 are arranged at intervals, so that a plurality of conductive particles 231 can be scattered in the rough area 22213 and restricted by the rough area 22213 . In addition, since the conductive particles 231 scattered on the smooth area 22212 are blocked by the conductive particles 231 in the rough area 22213, their offset will also be restricted, so that the movement of the conductive particles 231 on the pin pads 222 is blocked, which solves the problem of driving the substrate. 21 and the micro light emitting diode 24 poor contact problem. It can be understood that two rough regions 22213 and a plurality of smooth regions 22212 separated by the two rough regions 22213 are arranged on the lead pad 222 shown in FIG. The conductive particles 231 can be blocked by the rough area 22213 and the conductive particles 231 falling on the rough area 22213 , thereby limiting the sliding of the conductive particles 231 on the lead pad 222 . Of course, it can be understood that the number and distribution of the rough regions 22213 can also be in other forms, which are not limited in this application.

Specifically, the projected shape of the rough area 22213 on the lead pad 222 is, for example, a square shape, a rhombus shape, and multiple groups of grooves, so that the probability of a plurality of conductive particles 231 falling on the rough area 22213 can be increased, and the guiding force can be increased. The blocking effect of the foot pads 222 on the conductive particles 231 solves the problem of poor contact during the electrical connection between the driving substrate 21 and the micro LEDs 24 . Wherein, for the specific structural design of the rough region 22213, refer to FIGS. 6A-6C and the description of the rough region 1213 in the first embodiment. It can be understood that the projected shape of the rough region 22213 on the lead pad 222 can also be any other geometric shape, so as to prevent the conductive particles 231 from shifting in multiple directions.

In the second embodiment of the present application, a patterned structure is provided on the pad structure, so that conductive particles can be scattered in the patterned structure, thereby increasing the resistance of the pad structure to the migration of conductive particles, and solving the problem of micro light emitting diodes and drivers. Poor contact problems during substrate bonding. Specifically, by designing a patterned structure on the pin pads so that conductive particles can be scattered therein, the blocking effect of the pin pads on the offset of conductive particles is increased, and the binding of the display device on the micro light-emitting diode and the driving substrate is solved. When the poor contact problem. In addition, the patterned structure is further set as a groove or a rough area, and the groove or rough area is designed, which further enhances the resistance of the lead pad to the offset of the conductive particles, thereby further solving the problem of the display device in the miniature The problem of poor contact during bonding of light-emitting diodes and driving substrates increases bonding reliability.

[Third embodiment]

Referring to FIG. 11 , a display device 30 proposed in the third embodiment of the present application includes, for example, a driving substrate 31 , a bonding pad structure 32 , a connection layer 33 , and micro light emitting diodes 34 . Wherein, the bonding pad structure 32 is provided with a patterned structure, for example. Specifically, the pad structure 32 includes, for example, a pin pad 322 and a bonding pad 321 . The lead pads 322 are, for example, disposed on the micro LEDs 34 and electrically connected to the micro LEDs 34 . The bonding pads 321 are, for example, disposed on the driving substrate 31 .

Specifically, the drive substrate 31 is provided with a drive circuit, for example. The driving circuit is used to drive the micro LEDs 34 electrically connected to the driving substrate 31 . The bonding pads 321 are, for example, disposed on the driving substrate 31 and electrically connected to the driving circuit. The pad structure 32 is composed of metal materials with good electrical conductivity, such as copper, silver, and gold. The connection layer 33 is, for example, a conductive adhesive having a plurality of conductive particles 331 such as ACF. The connection layer 33 is, for example, disposed between the lead pad 322 and the bonding pad 321 . The driving circuit is electrically connected to the miniature LED 34 through the pad structure 32 and the conductive particles 331 electrically connected to the pad structure 32 , for example. Specifically, the connection layer 33 is, for example, disposed on the driving substrate 31 and covers the bonding pad 321 . At least some of the conductive particles 331 in the plurality of conductive particles 331 are scattered in the patterned structure, so that the movement of the conductive particles 331 scattered on the patterned structure on the pad structure 32 is restricted, and then fall on the conductive particles 331 The deviation of the conductive particles 331 between them is blocked. Therefore, the patterned structure acts as a barrier to the sliding of the plurality of conductive particles 331 on the pad structure 32 . It can be understood that the miniature light emitting diodes 34 are, for example, existing flip-chip, front-mount or vertical micro-light emitting diodes, and the present application is not limited thereto.

Specifically, as shown in FIG. 12 , for example, a patterned structure 3211 is disposed on the bonding pad 321 . For example, a patterned structure 3221 is disposed on the lead pad 322 . The first part of conductive particles in the plurality of conductive particles 331 is scattered on the patterned structure 3221 and the patterned structure 3211, so that the patterned structure 3211 and the patterned structure 3221 can bind the plurality of conductive particles 331 on the bonding pad 321 and the lead wire respectively. The offset of the foot pad 322 acts as a barrier. The miniature light emitting diodes 34 are, for example, existing flip chip, front chip or vertical micro light emitting diodes, which is not limited in this application. The micro light emitting diodes 34 are disposed on a side of the connection layer 33 away from the driving substrate 31 . It can be understood that the number of lead pads 322 of each micro LED 34 is two, corresponding to the positive electrode and the negative electrode of the micro LED 34 respectively. The display device 30 includes a plurality of micro light emitting diodes 34 , and the number of bonding pads 321 corresponds to the lead pads 322 provided on the plurality of micro light emitting diodes 34 . Wherein, each miniature LED 34 is electrically connected to the driving circuit on the driving substrate through the lead pad 322 , the conductive particles 331 and the bonding pad 321 . Specifically, the miniature light emitting diode 34 is electrically connected to the driving circuit by electrically connecting the conductive particles 331 through the lead pad 322 , the lead pad 322 and the binding pad 321 .

In the display device provided by the above technical solution, patterned structures are arranged on both the lead pads and the bonding pads, so that conductive particles can be scattered in the patterned structure, thereby preventing the conductive particles from being connected to the bonding pads and the lead pads. The sliding on the foot pad solves the problem of poor contact when the micro light-emitting diode and the driving substrate are bonded.

It can be understood that, for example, the display device 30 further includes an encapsulation layer and a protective cover disposed on the micro LEDs 34 . The encapsulation layer is, for example, a composite material such as a thermoplastic film or a high molecular polymer, which can effectively protect a plurality of micro light emitting diodes and isolate external water and oxygen. The protective cover is, for example, a glass substrate with good light transmission and a layered structure that isolates water and oxygen and protects the micro light emitting diodes. The display device 30 also includes, for example, a chip-on-chip film bound to the driving substrate and a PCB driving circuit. The chip-on-chip and the PCB driving circuit are used to provide driving signals to the driving substrate. It can be understood that a display device provided in an embodiment of the present application may further include other elements or structures that assist the display of the display device, and the present application is not limited thereto.

Further, the patterned structure 3221 and the patterned structure 3211 are, for example, grooves. Specifically, the grooves on the pin pads 322 penetrate through the pin pads 322 along the direction extending from the driving substrate 32 to the micro light emitting diodes 34 . The groove on the bonding pad 321 runs through the bonding pad 321 along the direction extending from the micro LED 34 to the driving substrate 32 . The width of the grooves obtained above is greater than 1 micron in the direction parallel to the driving substrate 31 . The conductive particles 331 are, for example, metal balls or polymer plastic balls whose surface is coated with metal. Commonly used metal balls and metal coating materials are, for example, metal powder nickel (Ni), gold (Au), gold plated on nickel, silver, and tin alloys. The diameter of the conductive particles 331 is generally 2 to 3 microns, so the width of the groove is set to be greater than 1 micron, so that the conductive particles 331 are partially scattered on the patterned structure 3221 and the patterned structure 3211, thereby patterning the structure 3221 and the pattern The chemical structure 3211 can respectively block the movement of the conductive particles 331 electrically connected to the bonding pad 321 and the lead pad 322 . Thus, the conductive particles 331 are prevented from being offset on the bonding pad 321 and the lead pad 322 . Further, the groove includes, for example, multiple sub-grooves, and the multiple sub-grooves are arranged at intervals from each other. Specifically, the projection shape of the multi-segment sub-grooves on the lead pad 322 or the bonding pad 321 is, for example, one of a square shape, a rhombus shape, and a plurality of sets of stop groove shapes. For the specific structure of the multi-segment sub-grooves, refer to the first embodiment and the description of the multi-segment sub-grooves 121111 in FIGS. 4A-4C , and the present application will not repeat them here. By arranging multiple sections of sub-grooves, the blocking effect of the grooves on conductive particles can be increased, thereby solving the problem of poor contact between the driving substrate and the electrical connection of the micro light-emitting diodes.

On the other hand, the bonding pad 321 and the lead pad 322 respectively include a smooth area and a rough area, for example. Wherein, the smooth area and the rough area on the bonding pad 321 are disposed on the side of the bonding pad 321 away from the driving substrate 31 and in contact with the connection layer 33 . The smooth area and the rough area on the lead pad 322 are disposed on the side of the lead pad 222 adjacent to the driving substrate 31 and in contact with the connection layer 33 . The rough region is formed, for example, by pattern etching techniques such as GTM (Gray Tone Mask). The aforementioned grooves are also obtained, for example, by this technique. Of course, it can be understood that other patterning techniques capable of etching the above-mentioned grooves and patterning the rough structure can also be used. The patterned structure 3221 and the patterned structure 3211 are, for example, disposed in the rough area. Specifically, the patterned structure 3221 coincides with the rough area on the lead pad 322 , for example. The patterned structure 3211 coincides with, for example, the rough region on the bonding pad 321 . The surface roughness of the rough area is greater than the surface roughness of the smooth area, and the rough area and the smooth area are arranged at intervals, so that a plurality of conductive particles 331 can be scattered in the rough area, and the plurality of conductive particles 331 are placed on the pin pad 322 and the bonding pad. The sliding on the fixed pad 321 will be blocked by the roughness on it. In addition, since the conductive particles 331 scattered in the smooth area are blocked by the conductive particles 331 in the rough area, their deviation will also be limited, so that the movement of the conductive particles 331 on the bonding pad 321 and the lead pad 322 is blocked. This solves the problem of bad contact when the driving substrate 31 is bonded to the micro light emitting diode 34, and also increases the bonding reliability. It can be understood that the projection shape of the rough area on the lead pad 322 and the bonding pad 321 is, for example, a square shape, a rhombus shape, and a plurality of sets of groove shapes, thereby increasing the probability that a plurality of conductive particles 331 fall on the rough area. probability, increase the blocking effect of the pin pads 322 on the conductive particles 331, and improve the problem of poor contact. 6A-6C and the description of the rough region 1213 in the first embodiment, the specific structural design of the rough region will not be repeated here.

Finally, it can be understood that the patterned structure 3221 and the patterned structure 3211 can be grooves or rough regions at the same time. The patterned structure 3221 and the patterned structure 3211 can also be grooves or rough regions respectively, and the present application is not limited thereto.

In the third embodiment of the present application, a patterned structure is provided on the bonding pad structure, so that conductive particles can be scattered in the patterned structure, thereby increasing the resistance of the bonding pad structure to the migration of conductive particles, and solving the problem of micro light emitting diodes and drivers. Poor contact problems during substrate bonding. Specifically, a patterned structure is designed on the lead pad and the bonding pad so that the conductive particles can be scattered therein, which increases the blocking effect of the bonding pad and the lead pad on the offset of the conductive particles, and solves the problem of the display device. The problem of bad contact in the bonding of micro light-emitting diodes and driving substrates. In addition, the patterned structure on the lead pad and the bond pad is further set as a groove or a rough area, and the groove or rough area is designed, which further enhances the lead pad and the bond pad. The pad blocks the offset of the conductive particles, thereby further solving the problem of poor contact of the display device when bonding the micro light-emitting diode and the driving substrate, and increasing the bonding reliability.

In addition, it can be understood that the above-mentioned embodiments are only exemplary illustrations of the present application. On the premise that the technical features do not conflict, the structures do not contradict, and the application objective of the present application is not violated, the technical solutions of the various embodiments can be combined arbitrarily, For use with.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

A display device, characterized in that it comprises:

miniature light-emitting diodes;

The driving substrate is provided with a driving circuit;

The pad structure is provided with a patterned structure, the pad structure includes a pin pad and a bonding pad, and the pin pad is arranged on the micro light emitting diode and electrically connected to the micro light emitting diode, so The bonding pad is arranged on the driving substrate and electrically connected to the driving circuit;

a connection layer, disposed between the pin pad and the bonding pad, and including a plurality of conductive particles;

Wherein, at least part of the conductive particles of the plurality of conductive particles are scattered in the patterned structure, and the driving circuit is electrically connected to the micro light-emitting diode through the pad structure and the conductive particles electrically connected to the pad structure. diode.
The display device according to claim 1, wherein the bonding pad is provided with the patterned structure, and the driving circuit connects the bonding pad, the plurality of conductive particles and the bonding pad. The conductive particles electrically connected to the fixed pad and the pin pad are electrically connected to the micro light emitting diode; and/or

The pin pad is provided with the patterned structure, and the micro light emitting diode is electrically connected to the Drive circuit.
The display device according to claim 2, wherein the patterned structure is a groove.
The display device according to claim 3, wherein the width of the groove is larger than 1 micron.
The display device according to claim 3, wherein the groove comprises a plurality of sub-grooves, and the plurality of sub-grooves are spaced apart from each other.
The display device according to claim 5, wherein the projection shape of the multiple sub-grooves on the bonding pad and/or the lead pad is a square, a rhombus, or a plurality of sets of grooves One of.
The display device according to claim 1, wherein the pad structure includes a smooth area and a rough area, the patterned structure is disposed in the rough area, and the surface roughness of the patterned structure is greater than the Surface roughness of the smooth area, at least part of the plurality of conductive particles scattered on the rough area.
The display device according to claim 7, wherein the projection shape of the rough region on the bonding pad and/or on the lead pad is a zigzag shape.
The display device according to claim 7, wherein a projection shape of the rough region on the bonding pad and/or on the lead pad is rhombus.
The display device according to claim 7, wherein the projection shape of the rough region on the bonding pad and/or the lead pad is in the shape of multiple sets of grooves.