Manufacturing method of LED weakening structure and weakening structure

Abstract

The present application relates to the field of display technology and provides a method for manufacturing a weakened structure of an LED and the weakened structure. The manufacturing method includes: preparing multiple LEDs on a growth substrate, forming a step structure on one surface of a temporary substrate, covering the surface of the step structure away from the temporary substrate with an adhesion layer, laminating the surface of the growth substrate on which the LEDs are grown with the surface of the step structure with the adhesion layer, peeling off the growth substrate of each LED, and etching the adhesion layer in the area where a target LED among the multiple LEDs is located to form a weakened structure corresponding to the target LED; so that the target LED and the remaining LEDs have different weakened structures, thereby eliminating the need to use a stamped transfer head for selective picking, thereby reducing the cost of transferring a large number of LEDs.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and in particular relates to a manufacturing method and a weakening structure of an LED. Background Art

[0002] With the development of optoelectronic display technology and semiconductor manufacturing technology, display technology has evolved from liquid crystal display technology to organic light-emitting diode display technology and micro light-emitting diode chip (MicroLightEmitting Diode, MicroLED) display technology. Among them, micro light-emitting diode chips have the characteristics of small size, high integration and self-luminescence. Compared with liquid crystal display technology and organic light-emitting diode display technology, they have greater advantages in brightness, resolution, contrast, energy consumption, service life, response speed and thermal stability.

[0003] During the fabrication of Micro LED displays, millions or even tens of millions of Micro LED chips need to be transferred from a growth substrate to a driver backplane. This requires mass transfer printing (MTP). In the mass transfer process, each Micro LED on the existing growth substrate has the same weakening structure, and a high-precision stamping transfer head is required to selectively pick up the Micro LEDs. However, stamping transfer heads are difficult and costly to manufacture.

[0004] Therefore, each MicroLED in the conventional MicroLED mass transfer method has the same weakened structure, which requires a stamp-like transfer head for selective picking, increasing the cost of MicroLED mass transfer. Summary of the Invention

[0005] The purpose of this application is to provide a method for manufacturing a weakened structure of an LED and a weakened structure, aiming to solve the problem in the prior art that each MicroLED has the same weakened structure, resulting in the need to use a stamped transfer head for selective picking, resulting in high costs for mass transfer of MicroLEDs.

[0006] In a first aspect, an embodiment of the present application provides a method for manufacturing a weakened structure of an LED, comprising:

[0007] fabricating a plurality of LEDs on a surface of a growth substrate;

[0008] forming a step structure on a surface of a transient substrate;

[0009] Covering the surface of the step structure away from the temporary substrate with an adhesive layer;

[0010] Laminating the surface of the growth substrate on which the LED is grown to the surface of the step structure having the adhesion layer;

[0011] peeling off the growth substrate of each of the LEDs;

[0012] The adhesion layer in the region where the target LED among the plurality of LEDs is located is etched to reduce the adhesion force of the adhesion layer in the region where the target LED is located, thereby forming a weakened structure corresponding to the target LED.

[0013] In one embodiment, after etching the adhesion layer in the region where the target LED among the plurality of LEDs is located to reduce the adhesion force of the adhesion layer in the region where the target LED is located to form a weakened structure corresponding to the target LED, the method includes:

[0014] The target LED is transferred from the transient substrate to a receiving substrate.

[0015] In one embodiment, etching the adhesion layer in the region where a target LED among the plurality of LEDs is located to reduce the adhesion force of the adhesion layer in the region where the target LED is located to form a weakened structure corresponding to the target LED includes:

[0016] Using a target LED among the plurality of LEDs as a mask, etching the adhesion layer in the area where the target LED is located by a plasma etching process;

[0017] The etching time of the plasma etching process is adjusted to reduce the adhesion force of the adhesion layer in the area where the target LED is located to a preset adhesion force, thereby forming a weakened structure corresponding to the target LED.

[0018] In one embodiment, the predetermined adhesion force satisfies the following conditions:

[0019] F1 <F2<F3

[0020] Wherein, F1 is the first adhesion force of the adhesive layer in the area where the target LED is located to the target LED;

[0021] F2 is the second adhesion force of the transfer head to the target LED;

[0022] F3 is a third adhesion force of the adhesion layer in the area outside the target LED to the other LEDs among the plurality of LEDs except the target LED.

[0023] In one embodiment, the calculation formula for the first adhesion force is:

[0024] F1=S1×f1

[0025] Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer on the target LED adhering to the first side of the adhesion layer;

[0026] S1 is the contact area between the adhesion layer and the target LED adhered to the first side of the adhesion layer; the calculation formula of the third adhesion force is:

[0027] F3=S3×f1

[0028] Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer on the target LED adhering to the first side of the adhesion layer;

[0029] S3 is a contact area between the adhesion layer and the other LED adhered to the first side of the adhesion layer, and S3>S1.

[0030] In one embodiment, the calculation formula for the second adhesion force is:

[0031] F2=S2×f2

[0032] Wherein, f2 is the adhesion force per unit area of ​​the transfer head on the second side of the target LED away from the adhesion layer;

[0033] S2 is a contact area between the transfer head and the target LED at a second side away from the adhesive layer.

[0034] In one embodiment, the thickness of the adhesion layer ranges from 5 μm to 15 μm.

[0035] In one embodiment, forming a step structure on a surface of the transient substrate includes:

[0036] Depositing a dielectric layer of a preset thickness on one surface of the temporary substrate;

[0037] The dielectric layer is subjected to multiple photolithography processes to form the step structure.

[0038] In one embodiment, the preset thickness ranges from 2 μm to 5 μm;

[0039] The height of the steps of the step structure ranges from 0.5 μm to 1.5 μm.

[0040] In a first aspect, an embodiment of the present application provides a weakening structure, which is manufactured based on any one of the manufacturing methods in the first aspect above.

[0041] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0042] The manufacturing method of the weakened structure of the LED provided in the embodiment of the present application is carried out by preparing multiple LEDs on a growth substrate, forming a step structure on one surface of a temporary substrate, covering the surface of the step structure away from the temporary substrate with an adhesion layer, and fitting the surface of the growth substrate with the LEDs grown thereto with the surface of the step structure with the adhesion layer. The growth substrate of each LED is peeled off, and the adhesion layer in the area where the target LED is located among the multiple LEDs is etched to reduce the adhesion force of the adhesion layer in the area where the target LED is located to form a weakened structure corresponding to the target LED, so that the target LED has a different weakened structure from the remaining LEDs, and then an ordinary transfer head can be used for selective picking, thereby reducing the cost of transferring a large number of LEDs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic flow chart of a method for manufacturing a weakened structure of an LED provided in an embodiment of the present application;

[0044] Figure 2 A schematic diagram of a process for forming a step structure on a surface of a transient substrate provided in an embodiment of the present application;

[0045] Figure 3 A schematic diagram of a process for etching an adhesion layer in a region where a target LED among multiple LEDs is located, reducing the adhesion force of the adhesion layer in the region where the target LED is located, and forming a weakened structure corresponding to the target LED, provided in an embodiment of the present application;

[0046] Figure 4 A cross-sectional schematic diagram of fabricating an LED on one surface of a growth substrate according to an embodiment of the present application;

[0047] Figure 5 A cross-sectional schematic diagram of depositing a dielectric layer of a preset thickness on a surface of a transient substrate provided in an embodiment of the present application;

[0048] Figure 6 A cross-sectional schematic diagram of covering a dielectric layer with photoresist and performing exposure using a mask according to an embodiment of the present application;

[0049] Figure 7 A cross-sectional schematic diagram of photoresist development provided in an embodiment of the present application;

[0050] Figure 8 A schematic cross-sectional view of a temporary substrate provided in an embodiment of the present application having a stepped structure with N stepped surfaces formed on its upper surface;

[0051] Figure 9 A cross-sectional schematic diagram of an adhesive layer covering a surface of each step surface of a step structure away from a bottom surface of the step structure provided in an embodiment of the present application;

[0052] Figure 10A schematic cross-sectional view of laminating a surface of a growth substrate having LEDs grown thereon to a surface of a stepped structure having an adhesion layer, provided in an embodiment of the present application;

[0053] Figure 11 A schematic cross-sectional view of the LED after the growth substrate is peeled off according to an embodiment of the present application;

[0054] Figure 12 A cross-sectional schematic diagram of etching the adhesion layer in the area where a target LED is located among multiple LEDs provided in an embodiment of the present application to form a weakened structure corresponding to the target LED;

[0055] Figure 13 A cross-sectional schematic diagram of a transfer head picking up a target LED provided by an embodiment of the present application;

[0056] Figure 14 A cross-sectional schematic diagram of a transfer head according to an embodiment of the present application picking up a target LED and leaving the transient substrate;

[0057] Figure 15 A cross-sectional schematic diagram of a transfer head provided in an embodiment of the present application transferring an LED to a receiving substrate.

[0058] Reference numerals in the accompanying drawings:

[0059] 110, growth substrate; 101, target LED; 102, first other LED; 103, second other LED; 120, epitaxial layer; 130, electrode;

[0060] 200, transient substrate; 210, dielectric layer; 220, photoresist layer; 230, mask; 231, first sub-mask; 232, second sub-mask; 233, second sub-mask; 211, step structure; 240, adhesion layer; 241, weakening structure;

[0061] 300, transfer head; 310, flat adhesive material;

[0062] 400. Receive a substrate. DETAILED DESCRIPTION

[0063] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0064] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly specifying the number of technical features. "Multiple" means two or more, unless otherwise expressly specified.

[0065] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0066] The technical solution of this application is described below through specific embodiments.

[0067] Example 1

[0068] like Figure 1 As shown, this embodiment provides a method for manufacturing a weakened structure of an LED, comprising:

[0069] S100, such as Figure 4 As shown, a plurality of LEDs are prepared on one surface of a growth substrate 110 .

[0070] The growth substrate 110 includes at least one of sapphire (Al 2 O 3 ), silicon (Si), and silicon carbide (SiC). A buffer layer (not shown) is provided between the growth substrate 110 and the LED.

[0071] LED includes at least one component selected from the group consisting of light-emitting diode chip (LED), mini LED chip (Mini LED), and micro LED chip (MicroLED). The size of LED is 1μm to 500μm. The size of LED is not limited to the above size range and is determined according to the requirements of the LED to be transferred.

[0072] In one embodiment, the size of the LED is 1 μm to 50 μm.

[0073] In one embodiment, the size of the LED is also 5 μm to 25 μm.

[0074] In one embodiment, the LED is a micro LED chip, which includes two electrodes 130 and an epitaxial layer 120 , wherein the electrodes 130 are a first side of the LED and the epitaxial layer 120 is a second side of the LED.

[0075] S200, such as Figures 5 to 8 , a step structure 211 is formed on one surface of the temporary substrate 200 .

[0076] In application, a step structure 211 having a plurality of stepped surfaces is formed on one surface of the temporary substrate 200 . Each stepped surface of the step structure 211 is located in a plane parallel to the bottom surface of the step structure 211 and at a different height.

[0077] The temporary substrate 200 includes either sapphire (Al 2 O 3 ) or glass.

[0078] In one embodiment, Figure 2 As shown, a step structure 211 is formed on one surface of the temporary substrate 200, including:

[0079] S210, such as Figure 5 As shown, a dielectric layer 210 of a preset thickness is deposited on one surface of a temporary substrate 200;

[0080] In application, a dielectric layer 210 having a predetermined thickness is deposited on one surface of the temporary substrate 200 by a chemical vapor deposition (CVD) process. The dielectric layer 210 is made of silicon oxide (SiOx) or silicon nitride (SiNx).

[0081] In one embodiment, the preset thickness of the dielectric layer 210 is in the range of 2 μm to 10 μm. The thickness of the dielectric layer 210 is not limited to the above range, and the specific thickness is set according to the type of LED and the manufacturing cost.

[0082] In one embodiment, the preset thickness of the dielectric layer 210 is in the range of 2 μm to 5 μm.

[0083] S220 , performing photolithography multiple times on the dielectric layer 210 to form a step structure 211 .

[0084] In applications, such as Figure 6 As shown, the surface of the dielectric layer 210 away from the temporary substrate 200 is first covered with a photoresist layer 220. The thickness of the photoresist layer 220 is greater than or equal to half of the preset thickness.

[0085] like Figure 6 、 Figure 7 、 Figure 8 As shown, a mask 230 (Half Tone Mask, HTM) with multiple different transmittances is then used for exposure, development, and etching, so that the dielectric layer 210 forms a stepped structure 211 having N stepped surfaces, each of which is located on a plane parallel to the bottom surface of the stepped structure 211 and at a different height. Wherein, N is a positive integer, N≧2, and the number of stepped surfaces N is set according to the number of times the LEDs on each growth substrate 110 need to be transferred.

[0086] In one embodiment, N=3, that is, the stepped structure 211 has three stepped surfaces, and thus the stepped structure 211 has two steps.

[0087] It should be noted that the mask 230 includes a plurality of sub-masks with different transmittances.

[0088] In one embodiment, the mask 230 includes a first sub-mask 231 having a first transmittance, a second sub-mask 232 having a second transmittance, and a third sub-mask 233 having a third transmittance.

[0089] Among them, the etching process includes plasma dry etching. When the dielectric layer is silicon oxide (SiOx), a first etching gas is used for etching; when the dielectric layer is silicon nitride (SiNx), a second etching gas is used for etching; the first etching gas includes at least one of trifluoromethane (CHF3) and oxygen (O2); the second etching gas includes at least one of chlorine (Cl2), nitrogen trifluoride (NF3) and nitrogen hexafluoride (NF6).

[0090] In one embodiment, the height H of each step of the step structure 211 ranges from 0.5 μm to 5 μm. The height of the steps is not limited to the above range. The specific height of each step is set according to the height of the LED. The heights of each step can be equal or unequal.

[0091] In one embodiment, the height H of each step of the step structure 211 ranges from 0.5 μm to 1.5 μm.

[0092] The width of the step structure 211 is set according to the width of the LED and the distance between two LEDs on the growth substrate 110 to avoid interference and collision between adjacent LEDs during transfer, thereby improving the yield of LED mass transfer.

[0093] S300, such as Figure 9 As shown, the surface of the step structure 211 away from the temporary substrate 200 is covered with an adhesive layer 240 .

[0094] In use, the surface of each step surface of the step structure 211 away from the bottom surface of the step structure 211 is covered with an adhesive layer 240. The upper surface of the adhesive layer 240 on each step surface is in the same plane, and the surface of the adhesive layer 240 away from the step structure 211 is parallel to the bottom surface of the dielectric layer 210. Therefore, the thickness of each step surface from the surface away from the bottom surface of the step structure 211 to the surface of the adhesive layer 240 away from the bottom surface of the step structure 211 is inconsistent.

[0095] In one embodiment, the thickness of the adhesive layer 240 ranges from 5 μm to 15 μm. The thickness of the adhesive layer 240 is not limited to the above range, and the thickness of the adhesive layer 240 is specifically set according to the height of the LED.

[0096] Adhesion layer 240 comprises either a photoresist layer or an adhesive layer. The photoresist comprises at least one of a resin material, a photosensitizer, a solvent, and a binder. The resin comprises polyimide (PI) or polymethyl methacrylate (PMMA). The binder comprises at least one of acrylate, butadiene, and polyurethane, with the mass fraction of polyurethane in the photoresist being 5% to 10%. The binder is used to enhance the adhesion of adhesion layer 240 to the LED. The adhesive layer comprises hot melt adhesive or other adhesive materials.

[0097] S400, such as Figure 10 As shown, the surface of the growth substrate 110 on which the LEDs are grown is attached to the surface of the step structure 211 having the adhesion layer 240 .

[0098] In application, the surface of the growth substrate 110 with the LED is bonded to the surface of the step structure 211 on the temporary substrate 200 with the adhesion layer 240, which is equivalent to rotating the growth substrate 110 with the LED grown thereon by 180°, so that the side of the LED away from the growth substrate 110 adheres to the adhesion layer 240.

[0099] S500, such as Figure 10 、 Figure 11 As shown, the growth substrate 110 of each LED is peeled off.

[0100] In applications, such as Figure 10 As shown, a laser lift-off process (Laser Lift Off, LLO) is used to separate the buffer layer between the growth substrate 110 and each LED, thereby peeling off the growth substrate 110 and separating the LED from the growth substrate 110. Figure 11 As shown, after the growth substrate 110 is peeled off, each LED is still adhered to the adhesive layer 240 according to the arrangement on the growth substrate 110 , so that each LED is fixed on the temporary substrate 200 .

[0101] S600, such as Figure 12 As shown, the adhesion layer 240 in the area where the target LED among the multiple LEDs is located is etched to reduce the adhesion force of the adhesion layer in the area where the target LED is located, and form a weakened structure 241 corresponding to the target LED.

[0102] In application, the adhesion layer 240 where the target LED is located is etched to form a weakened structure 241 corresponding to the target LED, which facilitates picking up the target LED.

[0103] In a specific embodiment, Figure 3 As shown, etching the adhesion layer 240 in the region where the target LED among the multiple LEDs is located, reducing the adhesion force of the adhesion layer in the region where the target LED is located, and forming a weakened structure 241 corresponding to the target LED, including:

[0104] S610 , using a target LED among the multiple LEDs as a mask, a plasma etching process is used to etch the adhesion layer 240 in the area where the target LED is located.

[0105] In application, a plasma etching process is used to etch the adhesion layer 240 in the area where the target LED is located using a target LED among multiple LEDs as a mask, thereby reducing the contact area between the surface of the adhesion layer 240 away from the temporary substrate 200 and the target LED, thereby reducing the adhesion force of the adhesion layer 240 to the target LED.

[0106] The plasma etching process uses a third etching gas for etching, and the third etching gas includes at least one of oxygen (O2) and carbon tetrachloride (CCl4).

[0107] S620 , adjusting the etching time of the plasma etching process to reduce the adhesion of the adhesion layer in the area where the target LED is located to a preset adhesion, so as to form a weakened structure 241 corresponding to the target LED.

[0108] like Figure 12 As shown, the LED labeled 101 is a target LED, the LED labeled 102 is a first other LED in the first etching, and the LED labeled 103 is a second other LED in the first etching.

[0109] In practice, the plasma etching process time is adjusted based on the etching condition of the adhesion layer 240 where the target LED is located, reducing the contact area between the surface of the adhesion layer 240 away from the temporary substrate 200 and the target LED until the adhesion of the adhesion layer in the area where the target LED is located is reduced to a predetermined adhesion force, forming a weakened structure 241 corresponding to the target LED, allowing the target LED with the weakened structure 241 to be transferred. While the target LED is being transferred, other LEDs with weakened structures 241 that do not have the predetermined adhesion force on the adhesion layer 240 cannot be transferred and remain fixed to the adhesion layer 240. This facilitates the selective removal of the target LED from the other LEDs, preventing the transfer of other LEDs that are not the target LED, which could result in LED loss, thereby improving the yield rate of mass transfer.

[0110] The preset adhesion meets the following conditions:

[0111] F1 <F2<F3

[0112] Wherein, F1 is the first adhesion force of the adhesion layer 240 to the target LED in the area where the target LED is located;

[0113] F2 is the second adhesion force of the transfer head 300 to the target LED;

[0114] F3 is a third adhesion force of the adhesion layer 240 in the area outside the target LED to the other LEDs among the plurality of LEDs except the target LED.

[0115] The calculation formula for the first adhesion force is:

[0116] F1=S1×f1

[0117] Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer 240 to the target LED adhered to the electrode 130 of the adhesion layer;

[0118] S1 is the contact area between the adhesion layer 240 and the target LED Target LED is adhered to the electrode 130 of the adhesion layer.

[0119] The calculation formula of the third adhesion force is:

[0120] F3=S3×f1

[0121] Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer 240 to the target LED adhered to the electrode 130 of the adhesion layer;

[0122] S3 is the contact area between the adhesion layer 240 and the electrode 130 of other LEDs adhered to the adhesion layer, and S3>S1.

[0123] The calculation formula for the second adhesion force is:

[0124] F2=S2×f2

[0125] Wherein, f2 is the adhesion force per unit area of ​​the transfer head 300 to the epitaxial layer 120 of the target LED away from the adhesion layer;

[0126] S2 is the contact area between the transfer head 300 and the epitaxial layer 120 of the target LED away from the adhesion layer.

[0127] In a specific embodiment, the total electrode area of ​​the two LED electrodes of the micro LED chip is S0; the adhesion force f1 of the adhesive layer per unit area to the LED electrodes of the micro LED chip is 20 N / cm 2 The adhesion force f2 per unit area of ​​the transfer head to the LED epitaxial layer of the micro LED chip is 4N / cm 2 The contact area S1 between the adhesion layer and the LED electrode of the target micro LED chip is greater than or equal to one quarter of the total electrode area S0, that is, The contact area S3 between the adhesion layer and the LED electrode of the micro-LED chip other than the target micro-LED chip is greater than or equal to one-half of the total electrode area S0, that is

[0128] Taking a 30μm×30μm micro-LED chip as an example, based on the above parameter settings, F2 is obtained as 0.36×10 -4 N according to the second adhesion force calculation formula, that is, the condition satisfied by the preset adhesion force of the weakening structure 241 is F1 < 0.36×10 -4 N < F3, where F3 ≥ 2F1.

[0129] S700, such as Figure 13 、 Figure 14 、 Figure 15 As shown, the target LED is transferred from the transient substrate 200 to the receiving substrate 400.

[0130] In the application, the target LED corresponding to the weakening structure 241 that meets the preset adhesion force condition is picked up from the transient substrate 200 and transferred to the receiving substrate 400, while other LEDs with an adhesion force of the adhesion layer greater than the second adhesion force will not be picked up, thus realizing the massive transfer of the target LED. During the transfer process, since the weakening structure 241 corresponding to the target LED meets the condition of the preset adhesion force and can be picked up and transferred, while the adhesion force of the adhesion layer where the remaining LEDs are located does not meet the condition of the preset adhesion force and cannot be picked up and transferred, there is no need to use a stamping transfer head made with high precision for picking up and transferring, thereby reducing the cost of the massive transfer of LEDs.

[0131] In one embodiment, transferring the target LED from the transient substrate 200 to the receiving substrate 400 includes:

[0132] Picking up the target LED with a transfer head 300 having a second adhesion force and transferring it to the receiving substrate 400. Among them, the transfer head having a second adhesion force includes the transfer head 300 and the planar viscous material 310. Among them, the viscous material includes planar polydimethylsiloxane (PDMS) or other weakly viscous materials.

[0133] In one embodiment, after picking up the target micro-LED chip with a transfer head having a second adhesion force, the adhesion layer material remaining on the target LED is cleaned, and then the LED electrode of the target micro-LED chip is flip-chip bonded to the driving backplane.

[0134] It should be noted that when the stepped structure on the temporary substrate includes N stepped surfaces, the adhesion layer is etched a first time to form a weakened structure that meets the preset adhesion conditions, and the first target LED is picked up. Then, the adhesion layer on the temporary substrate is etched a second time to form a weakened structure that meets the preset adhesion conditions, and the second target LED is picked up. This process of etching to form weakened structures that meet the preset adhesion conditions and picking up target LEDs is repeated N times until all LEDs are picked up and transferred to the receiving substrate. For example, when the stepped structure on the temporary substrate includes three stepped surfaces, the process of etching to form weakened structures that meet the preset adhesion conditions and picking up target LEDs is repeated three times, and all LEDs can be picked up and transferred to the receiving substrate.

[0135] Compared with the prior art, this embodiment has the following beneficial effects:

[0136] The present embodiment provides a method for manufacturing a weakened structure of an LED, by preparing an LED on a growth substrate, forming a step structure on one surface of a temporary substrate, covering the surface of the step structure away from the temporary substrate with an adhesion layer, laminating the surface of the growth substrate on which the LED is grown with the surface of the step structure with the adhesion layer, peeling off the growth substrate of each LED, etching the adhesion layer in the area where the target LED is located, reducing the adhesion force of the adhesion layer in the area where the target LED is located, forming a weakened structure corresponding to the target LED, so that the target LED has a different weakened structure from the remaining LEDs, and then a common transfer head can be used for selective picking, thereby reducing the cost of transferring a large number of LEDs.

[0137] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0138] Example 2

[0139] This embodiment provides a weakening structure, such as Figure 12 As shown, the weakened structure is manufactured based on any one of the manufacturing methods in the first aspect above.

[0140] Compared with the prior art, this embodiment has the following beneficial effects:

[0141] The weakening structure provided in this embodiment enables the target LED to have a different weakening structure from the other LEDs, so that a common transfer head can be used for selective picking, thereby reducing the cost of transferring a large number of LEDs.

[0142] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0143] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for manufacturing a weakened structure of an LED, comprising: fabricating a plurality of LEDs on a surface of a growth substrate; forming a step structure on a surface of a transient substrate; The surface of the step structure away from the temporary substrate is covered with an adhesive layer; the thickness of each step surface from the surface away from the bottom surface of the step structure to the surface of the adhesive layer away from the bottom surface of the step structure is inconsistent; Laminating the surface of the growth substrate on which the LED is grown to the surface of the step structure having the adhesion layer; peeling off the growth substrate of each of the LEDs; The adhesion layer is etched to reduce the adhesion force of the adhesion layer in the area where the target LED is located, forming a weakened structure corresponding to the target LED, so that the target LED has a different weakened structure from other LEDs, wherein after etching, the contact area between the target LED and the adhesion layer in the area where it is located is smaller than the contact area between the adhesion layers of other LEDs and the areas where they are located, and the adhesion force of the adhesion layer in the area where the target LED is located is smaller than the adhesion force of the adhesion layers in the areas where other LEDs are located, thereby selectively picking up the target LED from the surface of the transient substrate, the target LED being the LED corresponding to the area of ​​the adhesion layer with the smallest thickness.

2. The production method according to claim 1, wherein: After etching the adhesion layer to reduce the adhesion force of the adhesion layer in the area where the target LED is located to form a weakened structure corresponding to the target LED, the method includes: The target LED is transferred from the transient substrate to a receiving substrate.

3. The production method according to claim 1, wherein The etching of the adhesion layer to reduce the adhesion force of the adhesion layer in the area where the target LED is located to form a weakened structure corresponding to the target LED includes: Using a target LED among the plurality of LEDs as a mask, etching the adhesion layer using a plasma etching process; The etching time of the plasma etching process is adjusted to reduce the adhesion force of the adhesion layer in the area where the target LED is located to a preset adhesion force, thereby forming a weakened structure corresponding to the target LED.

4. The production method according to claim 3, wherein: The preset adhesion force satisfies the following conditions: in, A first adhesion force of the adhesion layer in the area where the target LED is located to the target LED; is a second adhesion force of the transfer head to the target LED; The third adhesion force of the adhesion layer in the area outside the target LED to the other LEDs among the plurality of LEDs except the target LED is obtained.

5. The production method according to claim 4, characterized in that: The calculation formula of the first adhesion force is: in, is the adhesion force per unit area of ​​the adhesion layer to the target LED adhered to the first side of the adhesion layer; is the contact area between the adhesion layer and the target LED adhered to the first side of the adhesion layer; The calculation formula of the third adhesion force is: in, is the adhesion force per unit area of ​​the adhesion layer to the target LED adhered to the first side of the adhesion layer; is the contact area between the adhesive layer and the other LEDs adhered to the first side of the adhesive layer, and .

6. The production method according to claim 4, wherein: The calculation formula of the second adhesion force is: in, is the adhesion force per unit area of ​​the transfer head to the second side of the target LED away from the adhesion layer; is the contact area between the transfer head and the second side of the target LED away from the adhesion layer.

7. The production method according to any one of claims 1 to 6, characterized in that The thickness of the adhesion layer ranges from 5 μm to 15 μm.

8. The production method according to claim 1, wherein: The step structure is formed on a surface of the transient substrate, comprising: Depositing a dielectric layer of a preset thickness on one surface of the temporary substrate; The dielectric layer is subjected to multiple photolithography processes to form the step structure.

9. The production method according to claim 8, wherein: The preset thickness ranges from 2 μm to 5 μm; The step height of the step structure ranges from 0.5 μm to 1.5 μm.

10. A weakening structure, characterized in that: The weakened structure is manufactured based on the manufacturing method according to any one of claims 1 to 9.

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