CN116779729A

CN116779729A - LED chip transfer structure, transfer method thereof and display device

Info

Publication number: CN116779729A
Application number: CN202210217317.5A
Authority: CN
Inventors: 韩赛赛; 宋玉华; 盛翠翠; 王岩; 董小彪; 葛泳
Original assignee: Chengdu Vistar Optoelectronics Co Ltd
Current assignee: Chengdu Vistar Optoelectronics Co Ltd
Priority date: 2022-03-07
Filing date: 2022-03-07
Publication date: 2023-09-19

Abstract

The invention discloses an LED chip transfer structure, a transfer method thereof and a display device, wherein the transfer structure comprises a transition substrate, the transition substrate comprises at least one supporting unit, the supporting unit comprises a barrier column and grooves positioned at two sides of the barrier column, and the grooves are matched with electrodes of an LED chip; the grooves are used for filling conductive adhesive so that the surfaces of the electrodes of the LED chips are covered by the conductive adhesive, and the barrier columns are used for isolating the conductive adhesive between the electrodes of the LED chips in the transfer process of the LED chips. According to the technical scheme provided by the embodiment of the invention, the anisotropic conductive adhesive can be applied to the bonding of the Micro-LED chip, and the problem that the electrode of the LED chip is short-circuited due to overlarge particle size of the conductive adhesive can be avoided.

Description

LED chip transfer structure, transfer method thereof and display device

Technical Field

The invention relates to the technical field of display, in particular to an LED chip transfer structure, a transfer method thereof and a display device.

Background

Micro-LEDs can be regarded as miniaturized LEDs, have the advantages of low power consumption, high brightness, high definition, long service life and the like, and become a novel display technology capable of being compatible with AMOLED display in the future.

Because the Micro-LED has smaller size, the bonding yield of the LED chip is lower in the current mass transfer or bit filling repair process, and the defective pixel is required to be removed and repaired to reach the standard of the yield required by display, which is not beneficial to the popularization of the Micro-LED display device.

Disclosure of Invention

The invention provides an LED chip transfer structure, a transfer method thereof and a display device, so as to improve the bonding yield of an LED chip.

According to an aspect of the present invention, there is provided an LED chip transfer structure including:

the LED chip comprises a transition substrate, wherein the transition substrate comprises at least one supporting unit, the supporting unit comprises a barrier column and grooves positioned on two sides of the barrier column, and the grooves are matched with electrodes of the LED chip;

the grooves are used for filling conductive adhesive so that the electrode surfaces of the LED chips are covered by the conductive adhesive, and the barrier columns are used for isolating the conductive adhesive between the electrodes of the LED chips in the LED chip transferring process.

Optionally, in the first direction, the width of the barrier rib is smaller than or equal to the distance between the two electrodes of the LED chip; along a second direction, the length of the barrier column is greater than or equal to the electrode size of the LED chip; the first direction and the second direction are perpendicular to each other and are perpendicular to the thickness direction of the transition substrate;

preferably, the barrier ribs have a width of less than 14 μm.

Optionally, the cross-sectional shape of the barrier rib comprises a rectangle, a trapezoid or a triangle along the thickness direction of the transition substrate;

preferably, the cross section of one end of the blocking column is arc-shaped.

Optionally, the grooving depth of the groove is in the range of 1.5-2.5 μm along the thickness direction of the transition substrate.

Optionally, when the transition substrate includes a plurality of the supporting units, the supporting unit arrays are arranged on the transition substrate; alternatively, the support units are arranged randomly on the transition substrate.

According to another aspect of the invention, an LED chip transferring method is provided, and the LED chip transferring structure provided by any embodiment of the invention is adopted to realize the transfer of the LED chip; the LED chip transferring method comprises the following steps:

providing the LED chip transfer structure;

coating conductive adhesive on the LED chip transfer structure, and enabling the conductive adhesive to cover the groove;

aligning the LED chip with the supporting unit so that the surface of the electrode of the LED chip is covered by the conductive adhesive in the groove;

providing a driving backboard;

and transferring the LED chip from the supporting unit to the driving backboard.

Optionally, the conductive paste comprises an anisotropic conductive paste.

Optionally, forming the LED chip transfer structure includes:

providing the transition substrate;

forming etching patterns corresponding to the LED chip structure on the transition substrate;

and etching the transition substrate according to the etching pattern to form the groove.

Optionally, after transferring the LED chip to the driving back plate, the method further comprises:

bonding the LED chip and the driving backboard; preferably, the step of bonding the LED chip to the driving back plate includes: and performing the local pressing operation on the LED chip, so that the conductive material in the conductive adhesive is in eutectic connection with the electrode of the LED chip and the electrode on the driving backboard.

According to another aspect of the present invention, there is provided a display device manufactured using the LED chip transfer method provided in any of the embodiments of the present invention.

According to the technical scheme provided by the embodiment of the invention, the LED chip is transited by forming at least one supporting unit matched with the electrode of the LED chip through the grooves on the transition substrate. Before the LED chip is transited to the supporting unit, the conductive adhesive is coated on the supporting unit so that the conductive adhesive flows into the grooves, when the LED chip is contacted with the supporting unit, the blocking columns are just positioned between two electrodes of the LED chip, and the chip electrodes are respectively positioned in the corresponding grooves, so that the LED chip electrodes are prevented from contacting the conductive adhesive while contacting the conductive adhesive, the phenomenon of short circuit of the chip electrodes is avoided, and the bonding yield of the LED chip is improved. In addition, the technical scheme provided by the embodiment can apply the anisotropic conductive adhesive to the bonding of the Micro-LED chip, and the LED chip transfer structure can be reused, so that the process cost is greatly reduced.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic top view of an LED chip transfer structure according to an embodiment of the present invention;

fig. 2 is a schematic perspective view of a supporting unit according to an embodiment of the present invention;

fig. 3 is an enlarged schematic structural view of a supporting unit according to an embodiment of the present invention;

fig. 4 is a schematic top view of an LED chip according to an embodiment of the present invention;

fig. 5 is a schematic cross-sectional structure of a supporting unit according to an embodiment of the present invention;

fig. 6 is a schematic cross-sectional structure of another support unit according to an embodiment of the present invention;

fig. 7 is a schematic top view of another LED chip transfer structure according to an embodiment of the present invention;

fig. 8 is a schematic top view of another LED chip transfer structure according to an embodiment of the present invention;

fig. 9 is a flowchart of an LED chip transferring method according to an embodiment of the present invention;

fig. 10 is a schematic top view of another LED chip transfer structure according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of alignment of an LED chip and an LED chip transfer structure according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of an LED chip bonded to a driving back plate in the prior art;

FIG. 13 is a flowchart of another LED chip transferring method according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of an LED chip bonded to a driving back plate according to an embodiment of the present invention;

fig. 15 is a schematic structural diagram of a display device according to an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

As described in the background art, the bonding yield of the LED chip, especially the Micro-LED chip in the prior art is low, and the yield standard required by display cannot be met. The inventors have found through careful study that the cause of the above problems is: micro-LED chips are typically smaller than 100 μm in size, while the electrode pitch of the LED chips is only a few microns or tens of microns, and Micro-LED chips are typically transferred from a growth substrate to a drive back plate for bonding using mass transfer techniques. The conventional bonding method of Micro-LED chips is metal bonding and anisotropic conductive adhesive film (Anisotropic Conductive Film, ACF) bonding, but the metal bonding method has the problems of insufficient viscosity, thermal mismatch caused by high temperature and the like, while the ACF bonding is to connect the LED chips and the driving backboard by means of conductive particles, so that the alignment precision requirement is high, and the ACF material is expensive, so that the possibility of applying the ACF bonding method to mass production is reduced. In the prior art, the anisotropic conductive adhesive can be used for bonding, the anisotropic conductive adhesive not only can keep the advantages of ACF, but also has the advantages of easy obtainment, low alignment precision requirement and the like, but the particle size of conductive particles in the anisotropic conductive adhesive is larger and is higher than the thickness of an electrode of a Micro-LED chip, so that the phenomenon of short circuit caused by transverse conduction between two electrodes of the Micro-LED chip is easy to occur when the conductive adhesive is coated, and the bonding yield of the LED chip is reduced. Therefore, the anisotropic conductive adhesive is generally applied to bonding of Mini-Led chips with larger sizes, and is not suitable for bonding process of Micro-LED chips.

Based on the above problems, the embodiment of the invention provides an LED chip transfer structure to solve the problem that short circuit is easy to occur between electrodes of an LED chip, so that anisotropic conductive adhesive can be applied to bonding of Micro-LED chips. Fig. 1 is a schematic top view of an LED chip transfer structure according to an embodiment of the present invention, fig. 2 is a schematic perspective view of a support unit according to an embodiment of the present invention, and referring to fig. 1 and 2, the LED chip transfer structure includes a transition substrate 10, the transition substrate 10 includes at least one support unit 20, the support unit 20 includes a barrier column 201 and grooves 202 located at two sides of the barrier column 201, and the grooves 202 are adapted to electrodes of an LED chip; the grooves 202 are used for filling conductive glue so that the electrode surfaces of the LED chips are covered by the conductive glue, and the barrier pillars 201 are used for isolating the conductive glue between the electrodes of the LED chips during the transfer process of the LED chips.

Wherein the LED chip and the conductive paste are not shown in the figure. In this embodiment, the LED chip may be a Micro-LED chip, and the Micro-LED chip is transferred to the driving back plate through the LED chip transfer structure to be bonded, where the driving back plate includes a welding electrode for connecting with an electrode of the LED chip. The conductive adhesive may be an anisotropic conductive adhesive for bonding the LED chip and the driving back plate.

Specifically, the transition substrate 10 is an insulating substrate for providing a supporting effect, and the transition substrate 10 has a certain thickness, and for example, the transition substrate 10 may be a silicon plate. At least one supporting unit 20 is disposed on the transition substrate 10, and the supporting unit 20 is used for supporting the LED chip during the LED chip transferring process. The support unit 20 includes a barrier rib 201 and grooves 202, wherein the grooves 202 are located at both sides of the barrier rib 201, and the shapes of the grooves 202 are adapted to the electrodes of the LED chip so that the electrodes of the LED chip can be placed in the grooves 202. In the process of transferring the LED chip, firstly, the conductive adhesive is coated on the LED chip transferring structure, and because the conductive adhesive has fluidity, the conductive adhesive flows into the groove 202 of the supporting unit 20 (in order to ensure that the conductive adhesive is positioned in the groove 202, the conductive adhesive on the barrier column 201 can be removed by adopting some auxiliary means); the LED chips are then transferred to the LED chip transfer structure such that the chip electrodes of the LED chips are in one-to-one correspondence with the grooves 202 on the support unit 20. Here, the barrier rib 201 plays a role in supporting the LED chip, and at the same time, can separate the conductive paste between the two chip electrodes of the LED chip, thereby preventing the contact between the chip electrodes of the LED chip and preventing the short circuit between the LED chip electrodes, so that the anisotropic conductive paste can be applied to the bonding of the Micro-LED chip.

In this embodiment, the barrier columns 201 in the support unit 20 and the transition substrate 10 are integrally formed, and the barrier columns 201 are part of the transition substrate 10. That is, the support unit 20 is obtained by etching the transition substrate 10, and in the region of one support unit 20, the grooves 202 are obtained by grooving the transition substrate 10, and the portion of the transition substrate 10 between the upper and lower grooves, which is not etched, forms the barrier rib 201.

It should be noted that, the LED chip transfer structure provided in this embodiment not only can be used in a huge amount of transfer stages of LED chips, but also can be used in repair and bit compensation stages of LED chips, so as to reduce repair difficulty of LED chips and ensure display yield.

Fig. 3 is an enlarged schematic structural view of a supporting unit provided by the embodiment of the present invention, and fig. 4 is a schematic structural view of an LED chip in a top view provided by the embodiment of the present invention, referring to fig. 3 and fig. 4, on the basis of the above technical solution, optionally, along a first direction, a width of a barrier pillar 201 is smaller than or equal to a distance between two electrodes of the LED chip; in the second direction, the length of the barrier pillars 201 is greater than or equal to the electrode size of the LED chip. The first direction may be an X direction, and the second direction may be a Y direction, when the support unit 20 is seen in a top view, the first direction and the second direction are both horizontal directions, and the first direction and the second direction are perpendicular to each other and are perpendicular to the thickness direction of the transition substrate 10.

As shown in fig. 4, the LED chip includes a substrate 311, on which a chip electrode including a first chip electrode 301 and a second chip electrode 302 is provided, the first chip electrode 301 and the second chip electrode 302 being arranged in the X direction. The first chip electrode 301 may be a P-type electrode, the second chip electrode 302 may be an N-type electrode, and a distance between the first chip electrode 301 and the second chip electrode 302 is D.

Referring to fig. 3, since the barrier rib 201 plays a role of preventing contact of the conductive paste between the first chip electrode 301 and the second chip electrode 302 of the LED chip, and the barrier rib 201 cannot shield the chip electrode, the width D of the barrier rib 201 cannot exceed the distance D between the first chip electrode 301 and the second chip electrode 302 in the X direction; in the Y direction, the length L of the barrier rib 201 cannot be smaller than the size of the chip electrode, that is, L is greater than or equal to a, so as to ensure that the chip electrode can be completely contacted with the conductive adhesive. Preferably, the width d of the barrier pillars 201 is less than 14 μm, which can meet the requirements of Micro-led chips.

Fig. 5 is a schematic cross-sectional structure of a supporting unit according to an embodiment of the present invention, specifically, a cross-sectional structure of the supporting unit shown in fig. 3 along a cutting line AA', and referring to fig. 5, based on the above technical solutions, optionally, a depth H of a groove 202 in a thickness direction of the transition substrate 10, i.e., a Z direction, ranges from 1.5 μm to 2.5 μm. The thickness of the chip electrode of the Micro-LED chip is usually 1-2 μm, so that the depth of the groove 202 is reasonably set according to the thickness of the chip electrode, effective contact between the LED chip electrode and the conductive adhesive 40 in the groove 202 can be ensured, the electrode surface of the LED chip is ensured to be covered by the conductive adhesive 40, and the etching difficulty of the transition substrate 10 is reduced.

Fig. 6 is a schematic cross-sectional structure of another support unit according to an embodiment of the present invention, and referring to fig. 5 and 6, a cross-sectional shape of the barrier rib 201 includes a rectangle, a trapezoid or a triangle along a thickness direction (Z direction) of the transition substrate 10. As a preferred implementation manner of this embodiment, the cross-sectional shape of one end of the blocking post 201 is circular arc, that is, one end of the blocking post 201 for supporting the LED chip is circular arc, so when the conductive adhesive 40 is coated on the supporting unit 20, the conductive adhesive 40 located on the blocking post 201 can flow into the groove 202 along the arc structure, which helps to further reduce the risk of being communicated by the conductive adhesive 40 between two chip electrodes of the LED chip.

The barrier column 201 with the arc structure can be obtained by adopting a mode of etching for a plurality of times, and the arc angle can be any angle smaller than or equal to 180 degrees.

Fig. 7 is a schematic top view of another LED chip transferring structure according to an embodiment of the present invention, and fig. 8 is a schematic top view of another LED chip transferring structure according to an embodiment of the present invention, and referring to fig. 1, fig. 7 and fig. 8, when the transition substrate 10 includes a plurality of support units 20, the support units 20 are arranged in an array on the transition substrate 10; alternatively, the support units 20 are randomly arranged on the transition substrate 10.

Specifically, when the LED chip transfer structure is used in the mass transfer stage, the plurality of support units 20 are arranged in an array on the transition substrate 10 (as shown in fig. 1), so that the mass transfer of the LED chips is facilitated. When the LED chip transferring structure is used in the repairing and repairing stage, the plurality of supporting units 20 may be arranged randomly on the transition substrate 10 (as shown in fig. 7 and 8), and the arrangement requirement is that the positions of the supporting units 20 need to be in one-to-one correspondence with the positions of the LED chips to be repaired so as to repair the corresponding LED chips.

Of course, in other embodiments, there may be only one supporting unit 20, and the single supporting unit 20 may be disposed at any position corresponding to the LED chip, so that the method can be applied to a one by one repair scheme of the display screen body.

The position and the quantity of the supporting units on the transition substrate can be set according to actual demands, so that one by one repair, line repair or surface repair of the display screen body can be realized, the display screen body can be repaired on the driving backboard in situ, the redundant position repair can be realized, and various repair demands of the display screen body can be met.

Optionally, the embodiment of the invention further provides an LED chip transferring method, and the LED chip transferring structure provided by any embodiment is used as a transition to realize the transfer of the LED chip. Fig. 9 is a flowchart of an LED chip transferring method according to an embodiment of the present invention, and referring to fig. 9, the LED chip transferring method includes:

s110, providing an LED chip transfer structure.

Specifically, as shown in fig. 1, the LED chip transfer structure includes a transition substrate 10, the transition substrate 10 includes at least one support unit 20, the support unit 20 includes a barrier column 201 and grooves 202 located at both sides of the barrier column 201, and the grooves 202 are adapted to electrodes of the LED chip.

S120, coating conductive adhesive on the LED chip transfer structure, and enabling the conductive adhesive to cover the grooves.

Specifically, fig. 10 is a schematic top view of another LED chip transfer structure according to an embodiment of the present invention, and referring to fig. 10, a conductive adhesive 40 is uniformly coated on the LED chip transfer structure by spraying or spin coating, so that the conductive adhesive 40 flows into the groove 202 at the position of the supporting unit 20. Along the thickness direction of the transition substrate 10, the grooving depth of the groove 202 ranges from 1.5 μm to 2.5 μm, and the conductive adhesive 40 covers the groove 202, so that the thickness of the LED chip electrode can be satisfied.

S130, aligning the LED chip with the supporting unit so that the surface of the electrode of the LED chip is covered by the conductive adhesive in the groove.

Specifically, fig. 11 is a schematic structural diagram of alignment of an LED chip and an LED chip transfer structure according to an embodiment of the present invention, referring to fig. 11, a transfer device (e.g., a transfer head) may be used to transfer the LED chip to a position above the LED chip transfer structure and align the LED chip with the supporting unit 20, so that the first chip electrode 301 and the second chip electrode 302 of the LED chip respectively correspond to a groove 202, and the substrate 311 of the LED chip contacts with the barrier column 201.

In this embodiment, one end of the barrier rib 201 for supporting the LED chip has a circular arc structure, so that when the conductive adhesive 40 is coated on the supporting unit 20, the conductive adhesive 40 on the barrier rib 201 can flow into the groove 202 along the arc structure. When the barrier rib 201 contacts with the LED chip, the first chip electrode 301 and the second chip electrode 302 in the LED chip are not completely contacted with the conductive adhesive 40 due to the barrier rib 201, so that the first chip electrode 301 and the second chip electrode 302 can be prevented from being communicated by the conductive adhesive 40.

S140, providing a driving backboard.

S150, transferring the LED chip from the supporting unit to the driving backboard.

The driving backboard is provided with a first welding electrode and a second welding electrode, the first welding electrode can be an anode and used for being correspondingly connected with a first connecting electrode 301 of the LED chip, the second welding electrode can be a cathode and used for being correspondingly connected with a second connecting electrode 302 of the LED chip, and the driving backboard is used for driving the LED chip to emit light. After the electrodes of the LED chip contact the conductive paste 40 (i.e., the surfaces of the electrodes of the LED chip are covered with the conductive paste 40 in the grooves 202), the LED chip is transferred from the support unit 20 to the driving back plate for subsequent bonding of the LED chip to the driving back plate.

According to the technical scheme provided by the embodiment of the invention, the transition LED chip is transferred through the LED chip transfer structure with the supporting unit, and the supporting unit comprises the blocking columns and the grooves which are positioned on two sides of the blocking columns and are matched with the electrodes of the LED chip. Before the LED chip is transited to the supporting unit, the conductive adhesive is coated on the supporting unit and flows into the grooves, when the LED chip is contacted with the supporting unit, the blocking columns are just positioned between the two electrodes of the LED chip, and the chip electrodes are respectively positioned in the corresponding grooves, so that the LED chip electrodes are ensured not to be completely contacted with the conductive adhesive while being contacted with the conductive adhesive, the phenomenon of short circuit of the chip electrodes is avoided, and the bonding yield of the LED chip is improved.

In the prior art, a metal bonding or ACF bonding mode is generally adopted to bond the Micro-LED chip, but the metal bonding mode has the problems of insufficient viscosity, thermal mismatch caused by high temperature and the like, so that the bonding yield is easy to be reduced, and the yield requirement cannot be met. The ACF bonding mode can effectively avoid the defects of the metal bonding. Fig. 12 is a schematic structural diagram of an LED chip bonded to a driving back plate in the prior art, as shown in fig. 12, the ACF itself relies on conductive particles 21 to realize electrical connection between the LED chip and the back plate 1, but the number of conductive particles 21 in the ACF is limited, and the conductive particles 21 are uniformly distributed in the adhesive layer 2, so that the P electrode 41 and N electrode 42 in the LED chip, the conductive particles 21, the anode 11 and the cathode 12 need higher alignment precision to ensure good conductive effect between the LED chip and the back plate 1. Moreover, since the conductive particles 21 are used to electrically connect the LED chip and the driving back plate 1, the point contact between the LED chip and the back plate 1 results in lower bonding strength, the LED chip is easy to drop, and these factors all result in reduced bonding yield.

In this embodiment, the LED chip may be a Micro-LED chip, and the anisotropic conductive adhesive may be applied to the bonding of the Micro-LED chip through the LED chip transfer structure, so as to ensure that the LED chip will not cause a short circuit between two electrodes of the LED chip due to too large particle size of the anisotropic conductive adhesive.

Fig. 13 is a flowchart of another method for transferring LED chips according to an embodiment of the present invention, and referring to fig. 13, the method for transferring LED chips includes:

s1101, providing a transition substrate.

S1102, forming an etching pattern corresponding to the LED chip structure on the transition substrate.

And S1103, etching the transition substrate according to the etching pattern to form a groove.

With continued reference to fig. 1, the support unit 20 is obtained by etching the transition substrate 10, and in a region of one support unit 20, the groove 202 is obtained by grooving the transition substrate 10, and a portion of the transition substrate 10 between the upper and lower grooves, which is not etched, forms a barrier pillar 201. For example, the transition substrate 10 may be a silicon plate, and an etching pattern corresponding to the LED chip is formed on the transition substrate 10, and the shape groove 202 corresponding to the shape of the LED chip is etched by deep silicon etching according to the etching pattern.

S140, providing a driving backboard.

S160, bonding the LED chip and the driving backboard.

Specifically, fig. 14 is a schematic structural diagram of an LED chip bonded to a driving back plate according to an embodiment of the present invention, and referring to fig. 14, the LED chip is subjected to a pressing operation, so that a conductive material in a conductive paste (anisotropic conductive paste) is eutectic-connected with electrodes (a first connection electrode 301 and a second connection electrode 302) of the LED chip and electrodes (a first welding electrode 601 and a second welding electrode 602) on the driving back plate 50. In the present embodiment, the materials of the electrodes (the first connection electrode 301 and the second connection electrode 302) of the LED chip and the electrodes (the first bonding electrode 601 and the second bonding electrode 602) on the driving back plate 50 may be metals such as gold, silver, or copper, or alloy materials formed of one or more of these metals.

In this embodiment, the anisotropic conductive adhesive is a colloid made of an anisotropic conductive material and an insulating material, for example, the anisotropic conductive adhesive may be a structure in which metal particles such as tin powder or nickel powder are coated with an insulating resin, and under a condition of tiny stress or heating, the metal particles may aggregate and are connected with a eutectic between an electrode of an LED chip and a welding electrode on a driving back plate, where the eutectic connection is a surface connection, so that the bonding strength between the LED chip and the driving back plate can be enhanced, and the conductivity can be increased advantageously. Meanwhile, the insulating material coated outside can spread outwards to wrap the electrode, so that the insulating effect is achieved. Therefore, the anisotropic conductive adhesive is adopted to bond the LED chip and the driving backboard, and in the bonding process, the micro acting force is applied to the LED chip, so that the anisotropic conductive adhesive is communicated with the LED chip electrode and the driving backboard 50, and the requirement on a transfer device or force application equipment is reduced.

According to the LED chip transferring method, through transition of the LED chip transferring structure, the anisotropic conductive adhesive is directly covered on the LED chip electrodes, the two electrodes of the LED chip are not communicated by the conductive adhesive, the problem of short circuit between the LED chip electrodes is effectively avoided, and therefore the anisotropic conductive adhesive can be applied to a bonding process of a Micro-LED chip. And the problems of high-precision alignment, high equipment requirement, weak bonding strength, reduced conductivity and the like in the bonding process of the ACF can be solved by adopting the anisotropic conductive adhesive, and the bonding yield of the LED chip is greatly improved.

Similarly, the method for transferring the LED chip provided in this embodiment may be applied to a repair and repair process of the LED chip, where after the LED chip is subjected to the present pressing operation, if the screen body is found to have adverse phenomena such as bright (dark) lighting, bright (dark) lines, or display residual shadows, the method for transferring the LED chip provided in the above embodiment may be used to repair and repair the LED chip at the dead point position after the LED chip is removed by using laser. The repair position repair supports one by one repair, line repair and surface repair, and can be repaired on the back plate in situ or on the redundant position, and only a proper LED chip transfer structure is needed.

It should be noted that, the method for transferring the LED chip provided in the embodiment of the present invention may be applied not only to an anisotropic conductive adhesive bonding method, but also to an ACF bonding method and a metal bonding method, which is not limited in this embodiment.

Optionally, fig. 15 is a schematic structural diagram of a display device according to an embodiment of the present invention, and the embodiment of the present invention further provides a display device, where the display device is manufactured by using the LED chip transferring method according to any embodiment of the present invention, so that the display device also has the beneficial effects described in any embodiment of the present invention. In this embodiment, the display device may be a mobile phone as shown in fig. 15, or any electronic product with a display function, including but not limited to the following categories: television, notebook computer, desktop display, tablet computer, digital camera, smart bracelet, smart glasses, vehicle-mounted display, medical equipment, industrial control equipment, touch interactive terminal, etc., which are not particularly limited in this embodiment of the invention.

It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.

The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims

1. An LED chip transfer structure, comprising:

2. The LED chip transfer structure of claim 1, wherein the width of the barrier posts is less than or equal to the spacing between the two electrodes of the LED chip in a first direction; along a second direction, the length of the barrier column is greater than or equal to the electrode size of the LED chip; the first direction and the second direction are perpendicular to each other and are perpendicular to the thickness direction of the transition substrate;

preferably, the barrier ribs have a width of less than 14 μm.

3. The LED chip transfer structure of claim 2, wherein the cross-sectional shape of the barrier ribs comprises a rectangle, trapezoid, or triangle along the thickness direction of the transition substrate;

preferably, the cross section of one end of the blocking column is arc-shaped.

4. The LED chip transfer structure of claim 1, wherein the groove has a groove depth in the thickness direction of the transition substrate in the range of 1.5-2.5 μm.

5. The LED chip transfer structure of claim 1, wherein when the transition substrate includes a plurality of the supporting units, the supporting unit array is arranged on the transition substrate; alternatively, the support units are arranged randomly on the transition substrate.

6. An LED chip transfer method, characterized in that the LED chip transfer is realized using the LED chip transfer structure according to any one of claims 1 to 5;

the LED chip transferring method comprises the following steps:

providing the LED chip transfer structure;

providing a driving backboard;

7. The LED chip transfer method of claim 6, wherein said conductive paste comprises an anisotropic conductive paste.

8. The LED chip transfer method of claim 6, wherein forming said LED chip transfer structure comprises:

providing the transition substrate;

9. The LED chip transfer method of claim 6, further comprising, after transferring said LED chip to said drive back plate:

bonding the LED chip and the driving backboard;

preferably, the step of bonding the LED chip to the driving back plate includes:

and performing the local pressing operation on the LED chip, so that the conductive material in the conductive adhesive is in eutectic connection with the electrode of the LED chip and the electrode on the driving backboard.

10. A display device, characterized in that it is manufactured by the LED chip transfer method according to any one of claims 6 to 9.