CN217306498U

CN217306498U - Miniature LED chip and display device

Info

Publication number: CN217306498U
Application number: CN202220864716.6U
Authority: CN
Inventors: 姜建兴; 杨启伟
Original assignee: Shenzhen Stan Technology Co Ltd
Current assignee: Shenzhen Stan Technology Co Ltd
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2022-08-26
Anticipated expiration: 2032-04-14

Abstract

The utility model provides a miniature LED chip and display device. The micro LED chip comprises a driving circuit substrate, a light emitting chip array sheet and a conductive piece; the driving circuit substrate is provided with a first electrode; the light-emitting chip array sheet is provided with a second electrode corresponding to the first electrode and facing the driving circuit substrate; the conductive part comprises an insulating base material and conductive particles, the insulating base material is filled between the driving circuit substrate and the light-emitting chip array sheet, and at least part of the conductive particles are positioned between the first electrode and the second electrode and are electrically connected with the first electrode and the second electrode. In the miniature LED chip of this embodiment, through adopting electrically conductive piece to connect chip array piece and drive circuit base plate, compare in traditional miniature LED chip, can avoid appearing because the heat quantity difference leads to for example solder joint crack, solder joint to drop the solder joint degradation condition such as to guarantee miniature LED chip's structural strength and electric conductivity, simple structure, excellent in use effect.

Description

Miniature LED chip and display device

Technical Field

The utility model relates to a semiconductor photoelectric technology field especially relates to a miniature LED chip and display device.

Background

The Micro Light-Emitting Diode (Micro-LED) has self-luminous display characteristics, is an all-solid-state LED, has the excellent characteristics of long service life, high brightness, low power consumption, small volume, ultrahigh resolution and the like, and can be applied to extreme environments such as high temperature or radiation and the like. Compared with the traditional LED display technology, the Micro-LED has the advantages of high efficiency, long service life, relative stability due to the fact that the material is not easily influenced by the environment, and the phenomenon of ghost shadow can be avoided.

The conventional Micro-LED chip (Micro LED chip) is generally connected to the driving IC chip by flip chip bonding. To meet the requirement of high PPI display, it is usually necessary to provide several tens of thousands or even hundreds of thousands of Micro chips on a Micro-LED chip array sheet with the size of a nail cover of a regular person, and the size of a welding point at the bottom of the chip is only a micron level.

At present, for the welding point of the micron scale, metal is generally evaporated on the bottom of the chip and formed into a metal ball, and then the metal ball is pressed and welded with the driving IC chip. However, when the array chip and the driving IC chip are connected by the method, the welding strength is not high, and the welding spot is easy to loosen, so that the device fails.

Therefore, it is necessary to improve upon the above-described problems to change the present situation.

SUMMERY OF THE UTILITY MODEL

The utility model provides a miniature LED chip and display device for in solving traditional miniature LED chip structure, adopt evaporation metal sphere to connect array piece and the problem that the solder joint drops appears easily with the drive IC chip.

The utility model provides a miniature LED chip, include:

a first electrode is convexly arranged on the surface of one side of the driving circuit substrate;

the light emitting chip array sheet is arranged at intervals with the drive circuit substrate, and a second electrode corresponding to the first electrode is convexly arranged on one side, facing the drive circuit substrate, of the light emitting chip array sheet; and

the conductive part comprises an insulating base material and conductive particles, the insulating base material is filled between the driving circuit substrate and the light-emitting chip array sheet, the conductive particles are distributed in the insulating base material, and at least part of the conductive particles are positioned between the first electrode and the second electrode and are electrically connected with the first electrode and the second electrode.

According to an embodiment of the present invention, the insulating base material connects the light emitting chip array sheet and the driving circuit substrate by heating and/or pressing; the light-emitting chip array sheet comprises a plurality of pixel points which are arranged in an array mode, each pixel point corresponds to one first electrode, and at least part of conductive particles are located between the first electrodes and the second electrodes and are communicated with the first electrodes and the second electrodes.

According to an embodiment of the present invention, the diameter of the conductive particles is D, the width dimension of the pixel points is L1, and D < (1/5 × L1).

According to an embodiment of the present invention, the diameter of the conductive particles is D, and the distance between the adjacent two of the pixels is L2, and D < (1/3 × L2).

According to an embodiment of the present invention, there are at least three conductive particles between the first electrode and the second electrode, and all communicate with the first electrode and the second electrode.

According to the utility model discloses an embodiment, the material of conducting particle includes any one or more alloy in gold, tin, aluminium, silver.

According to an embodiment of the invention, the number of the first electrodes and the second electrodes is a plurality of groups.

According to an embodiment of the present invention, the conductive member includes anisotropic conductive adhesive.

According to the utility model discloses an embodiment, miniature LED chip still includes the light-shielding piece, the light-shielding piece encircles the periphery setting of emitting chip array piece, the light-shielding piece includes that black box dam glues.

The utility model also provides a display device, include as above-mentioned arbitrary one miniature LED chip.

Implement the embodiment of the utility model provides a, following beneficial effect has:

in the micro LED chip of the present embodiment, the conductive members are filled between the array sheet and the driving circuit substrate, and the conductive members only conduct the first electrode and the second electrode that are correspondingly and alternately disposed, so as to avoid the solder joint deterioration between the first electrode and the second electrode due to the heat difference when the first electrode and the second electrode are directly contacted, thereby ensuring the mechanical structure strength and the electrical conductivity of the micro LED chip.

In the miniature LED chip of this embodiment, through adopting electrically conductive piece to connect chip array piece and drive circuit base plate, compare in traditional miniature LED chip, can avoid appearing because the heat quantity difference leads to for example solder joint crack, solder joint to drop the solder joint degradation condition such as to guarantee miniature LED chip's structural strength and electric conductivity, simple structure, excellent in use effect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the description below are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Wherein:

fig. 1 is a schematic structural diagram of a micro LED chip according to an embodiment of the present invention;

FIG. 2 is a microscopic enlarged schematic view of detail A of FIG. 2;

fig. 3 is a schematic diagram of a process for manufacturing a micro LED chip according to an embodiment of the present invention;

reference numerals:

10. a micro LED chip; 100. a chip array sheet; 110. pixel points; 200. a connecting structure; 210. a first electrode; 220. a second electrode; 230. a conductive member; 231. an insulating base material; 2321. conductive particles; 2322. non-conductive particles; 300. a drive circuit substrate; 400. a light shielding member.

Detailed Description

To make the objects, technical solutions and advantages of the present invention clearer, the drawings of the present invention are combined to clearly and completely describe the technical solutions of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Referring to fig. 1 and 2, the present invention provides a micro LED chip 10, which includes a chip array sheet 100, a connection structure 200 and a driving circuit substrate 300, wherein the chip array sheet 100 is connected to the driving circuit substrate 300 through the connection structure 200, and specifically, the connection structure 200 includes a first electrode 210 and a second electrode 220: a first electrode 210 is convexly disposed on one side surface of the driving circuit substrate 300; the light emitting chip array sheet 100 and the driving circuit substrate 300 are arranged at an interval, and a second electrode 220 corresponding to the first electrode 210 is convexly arranged on one side of the light emitting chip array sheet 100 facing the driving circuit substrate 300; the conductive member 230 includes an insulating base material 231 and conductive particles 2321, the insulating base material 231 is filled between the driving circuit substrate 300 and the light emitting chip array sheet 100, the conductive particles 2321 are distributed in the insulating base material 231, and at least a part of the conductive particles 2321 is located between the first electrode 210 and the second electrode 220 and electrically connected to the first electrode 210 and the second electrode 220.

In the micro LED chip 10 of the present embodiment, the conductive member 230 is filled between the array sheet and the driving circuit substrate 300, and the conductive member 230 only conducts the first electrode 210 and the second electrode 220 which are correspondingly and separately disposed, so that the situation that the first electrode 210 and the second electrode 220 are directly contacted with each other and the solder joint of the two electrodes is degraded due to the heat difference can be avoided, thereby ensuring the mechanical structure strength and the electrical conductivity of the micro LED chip 10.

In the micro LED chip 10 of the present embodiment, the conductive member 230 is used to connect the chip array sheet 100 and the driving circuit substrate 300, so that compared with the conventional micro LED chip 10, the occurrence of solder joint deterioration conditions such as solder joint crack and solder joint drop caused by heat difference can be avoided, and thus the structural strength and the electrical conductivity of the micro LED chip 10 are ensured, the structure is simple, and the using effect is good.

In the present embodiment, the conductive member 230 includes anisotropic conductive paste.

When the anisotropic conductive adhesive is adopted, in the packaging process, firstly, the driving circuit substrate 300 is placed on a vacuum platform, the anisotropic conductive adhesive with normal temperature return is placed in a glue dispenser needle cylinder, the glue dispenser is used for uniformly dispensing the anisotropic conductive adhesive on the driving circuit substrate 300, then, a vacuum suction nozzle is used for adsorbing the light-emitting chip array sheet 100 and is in alignment fit with the driving circuit substrate 300, meanwhile, heating and pressurization are started, so that the insulating layer on the surface of the conductive particle in the anisotropic conductive adhesive is broken, the corresponding up-and-down conduction of the first electrode 210 and the second electrode 220 is realized, the anisotropic conductive adhesive can realize the Z-direction conduction, the XY-direction is not conducted, and the anisotropic conductive adhesive is solidified and ensures the strength between the light-emitting chip array sheet 100 and the driving circuit substrate 300; in the laid state shown in fig. 2, the vertical direction is the Z direction, and the horizontal direction is the XY direction. In this embodiment, the conductive member 230 may be an epoxy resin-based anisotropic conductive adhesive, and the temperature returns to normal temperature at normal temperature.

Referring to fig. 2, in the present embodiment, the first electrode 210, the second electrode 220 and the conductive member 230 form a connection structure 200 for connecting the light emitting chip array chip 100 and the driving circuit substrate 300.

Specifically, referring to fig. 3, the insulating base 231 connects the light emitting chip array sheet 100 and the driving circuit substrate 300 by heating and/or pressing; the light emitting chip array sheet 100 includes a plurality of pixel points 110 arranged in an array, each pixel point 110 corresponds to one of the first electrodes 210, and at least a portion of the conductive particles 2321 is located between and communicates the first electrode 210 and the second electrode 220.

In the conductive element 230 of the embodiment, the surface layer of the conductive particle 2321 adsorbs the insulating base material 231 and forms a thin film structure with an insulating function, and when the light emitting chip array sheet 100 and the driving circuit substrate 300 are thermally pressed, the thin film structure of the outer layer of the conductive particle 2321 is damaged, so that the conductive element 230 can be conducted in the Z direction, but not conducted in the horizontal XY direction.

Specifically, referring to fig. 3, the diameter of the conductive particle 2321 is defined as D, and the width of the pixel 110 is defined as L1 and D < (1/5 × L1).

In the embodiment, the size of the L1 is 2 μm to 40 μm, so that the size of D is 0.4 μm to 8 μm, thereby preventing the non-conductive particles 2322 suspended in the insulating base 231 from contacting the first electrode 210 and the second electrode 220 to cause different sets of the first electrode 210 and the second electrode 220 to be electrically connected, thereby ensuring the normal operation of the micro LED chip 10.

In one embodiment, the distance between two adjacent pixels 110 is defined as L2 and D < (1/3 × L2).

With this arrangement, it is further avoided that the non-conductive particles 2322 suspended in the insulating substrate 231 contact the first electrode 210 and the second electrode 220 to cause electrical connection between different groups of the first electrode 210 and the second electrode 220, and an electrical connection state between the corresponding group of the first electrode 210 and the second electrode 220 is ensured. In the present embodiment, the size of L2 may be approximately equal to the size of L1, i.e., the size of L2 is 2 μm to 40 μm, so that the size of D in the present embodiment is 2/3 μm to 40/3 μm, which is determined by the design requirements of the micro LED chip 10 and the performance of the conductive member 230.

In some embodiments, the insulating substrate 231 of the anisotropic conductive adhesive may be a single-component thermosetting epoxy resin, the conductive particles 2321 may be metal particles, the size D may be 0.1 μm to 5 μm, and the specific value may be different metal particles with different diameters according to the different pitches of the pixels 110 of the micro LED chip 10, which requires the diameters of the metal particles to be satisfied at the same time.

Further, referring to fig. 3, at least three conductive particles 2321 are disposed between the first electrode 210 and the second electrode 220 and are in communication with the first electrode 210 and the second electrode 220.

With this arrangement, at least one conductive particle 2321 can be connected between the first electrode 210 and the second electrode 220, thereby ensuring circuit continuity between the light emitting chip array sheet 100 and the driving circuit substrate 300; specifically, the density of the conductive particles 2321 in the insulating substrate 231 may be controlled during the adjustment of the conductive element 230, which is not described herein again.

Specifically, the material of the conductive particles 2321 includes any one or more alloys of gold, tin, aluminum, and silver.

In the present embodiment, the conductive particles 2321 are preferably a metal with a lower hardness (compared to cemented carbide), and when the first electrode 210 and the second electrode 220 are connected by applying pressure and/or heat, the soft conductive particles 2321 may flow or deform to a certain extent to ensure a lead effect between the first electrode 210 and the second electrode 220. In some embodiments, the conductive particles 2321 may also be an alloy of any more of gold, tin, aluminum, and silver, which is not limited herein only to satisfy the requirement of conductivity

In this embodiment, the conductive particles 2321 may be spherical, the inner core is made of one or more alloys of gold, tin, aluminum, copper, and the like, and the PI polyimide insulating layer or the resin insulating layer is wrapped by the outer layer of the conductive particles 2321.

Further, the micro LED chip 10 further includes a light shielding member 400, the light shielding member 400 is disposed around the periphery of the light emitting chip array sheet 100, and the light shielding member 400 includes a black dam adhesive.

According to the arrangement, after the light-emitting chip array sheet 100 is bonded with the driving circuit substrate 300 and the conductive member 230 is also cured and connected with the light-emitting chip array sheet 100, a dispenser is used for coating black dam adhesive on the edge point of the light-emitting chip array sheet 100, so that the light shading effect of the edge of the micro LED chip 10 is ensured, and light leakage is avoided; then, when the light shielding member 400 is dam glue, the micro LED chip 10 may be placed in a high temperature oven to bake the curing glue.

The utility model also provides a display device, it includes miniature LED chip 10 as in any one above-mentioned embodiment.

It can be understood that, in the display device of the present embodiment, by providing the above-mentioned micro LED chip 10, compared with the conventional micro LED chip 10, the solder joint deterioration conditions such as solder joint crack and solder joint falling caused by the heat quantity difference can be avoided, so as to ensure the display effect of the display device.

Referring to fig. 3, an embodiment of the present invention provides a method for packaging a micro LED chip, which can be used to prepare the micro LED chip 10 in any of the above embodiments, and the method includes the following steps:

step S100, providing a light emitting chip array sheet 100, wherein the light emitting chip array sheet 100 is provided with a plurality of groups of first electrodes 210;

step S200, providing a driving circuit to be attached to the light emitting chip array sheet 100, wherein a plurality of groups of second electrodes 220 are disposed on one side of the driving circuit facing the light emitting chip array sheet 100, after the light emitting chip array sheet 100 is attached to the driving circuit, the first electrodes 210 correspond to the second electrodes 220 one by one, and at least one group of the first electrodes 210 and the second electrodes 220 are disposed at intervals;

step S300, filling a conductive member 230 between the light emitting chip array sheet 100 and the driving circuit, wherein the conductive member 230 only conducts the corresponding first electrode 210 and the second electrode 220. Specifically, a layer of conductive member 230 may be covered on the driving circuit substrate 300 by a screen printing or dispensing method, and then the driving circuit substrate 300 and the light emitting chip array sheet 100 are bonded by a hot pressing method, where the conductive member 230 only conducts the corresponding first electrode 210 and the second electrode 220.

It should be noted that, when the conventional Micro-LED chip array chip is packaged with a driver IC chip, two chips are electrically connected through a solder joint, and the following two problems are often encountered: firstly, the Micro-LED chip also generates heat when emitting light, the heat is conducted to the driving IC chip through a welding spot and a gap between the welding spots, the material characteristics of the driving IC chip and the array sheet are different, and after the Micro-LED chip 10 generates heat, the welding spot between the Micro-LED chip and the array sheet can cause the welding spot to have deterioration conditions such as cracks, loosening and the like due to the fact that the thermal expansion coefficients of the Micro-LED chip and the array sheet are different, so that the Micro-LED chip 10 fails; secondly, the distance between welding spots under the Micro-LED chip array is in a micron level, the requirement on the equipment surface mounting precision is high, and short circuit abnormity is easily caused once the surface mounting is deviated.

When the micro LED chip 10 is manufactured by using the packaging method of the embodiment, the conductive member 230 is filled between the array sheet and the driving circuit substrate 300, and the conductive member 230 only conducts the first electrode 210 and the second electrode 220 which are correspondingly and alternately arranged, so that the situation that the first electrode 210 and the second electrode 220 are directly contacted and the welding point is degraded due to the heat difference can be avoided, and the mechanical structure strength and the electrical conductivity of the micro LED chip 10 can be ensured. In addition, when the first electrode 210 and the second electrode 220 are connected by the packaging method of the present application, when there is a deviation between the first electrode 210 and the second electrode 220, the conductive member 230 can still realize the circuit connection between the two electrodes, so that the precision requirement of the processing equipment of the micro LED chip 10 can be reduced, and the manufacturing cost and the equipment cost of the micro LED chip 10 can be reduced.

In the method for packaging the micro LED chip 10 of the embodiment, the conductive member 230 is used to connect the light emitting chip array sheet 100 and the driving circuit substrate 300, so that compared with the conventional micro LED chip 10, the solder joint deterioration conditions such as solder joint crack, solder joint falling and the like caused by the heat difference can be avoided, thereby ensuring the structural strength and the electrical conductivity of the micro LED chip 10, and having the advantages of simple structure, low precision requirement and good use effect.

In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing the embodiments of the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "connected" and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the embodiments of the present invention can be understood in specific cases by those skilled in the art.

In embodiments of the invention, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description of the present specification, references to the description of "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro LED chip, comprising:

a first electrode is convexly arranged on one side surface of the driving circuit substrate;

2. The micro LED chip according to claim 1, wherein the insulating base material connects the light emitting chip array sheet and the driving circuit substrate by heating and/or pressing; the light-emitting chip array sheet comprises a plurality of pixel points which are arranged in an array mode, each pixel point corresponds to one first electrode, and at least part of conductive particles are located between the first electrodes and the second electrodes and are communicated with the first electrodes and the second electrodes.

3. The micro LED chip of claim 2, wherein the conductive particles have a diameter D, and the pixels have a width dimension of L1 and D < (1/5 x L1).

4. The micro LED chip of claim 2, wherein the diameter of the conductive particles is D, the distance between two adjacent pixels is L2, and D < (1/3 x L2).

5. The micro LED chip of claim 2, wherein at least three of the conductive particles are between the first electrode and the second electrode and are in communication with the first electrode and the second electrode.

6. The micro LED chip of claim 2, wherein the conductive particles comprise an alloy of one or more of gold, tin, aluminum, and silver.

7. The micro LED chip of any one of claims 1-6, wherein the number of the first electrodes and the second electrodes is in a plurality of groups.

8. The micro LED chip of any one of claims 1 to 6, wherein the conductive member comprises anisotropic conductive paste.

9. The micro LED chip of claim 7, further comprising a light shield disposed around a periphery of said light emitting chip array sheet, said light shield comprising a black dam glue.

10. A display device comprising the micro LED chip according to any one of claims 1 to 9.