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 comprises: preparing a plurality of LEDs on a growth substrate, forming an adhesion layer on a surface of a temporary substrate, bonding a surface of the growth substrate on which the LEDs are grown with a surface of the temporary substrate having the adhesion layer, peeling off the growth substrate of each LED, and etching the adhesion layer in a region where a target LED among the plurality of 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, and thus there is no 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 (Micro Light Emitting Diode, Micro LED) 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] In the process of preparing Micro LED display devices, it is necessary to transfer millions or even tens of millions of Micro LED chips from the growth substrate to the driving backplane, which requires mass transfer (Mass Transfer Printing, MTP) of Micro LEDs. In the mass transfer process, each Micro LED on the growth substrate of the prior art has the same weakening structure, and a high-precision stamp transfer head is required to selectively pick up the Micro LED, and the stamp transfer head is difficult and costly to manufacture.

[0004] Therefore, each Micro LED in the prior art Micro LED mass transfer method has the same weakened structure, which requires a stamp-like transfer head to be used for selective picking, thereby increasing the cost of Micro LED mass transfer. Summary of the invention

[0005] The purpose of the present 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 Micro LED 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 Micro LEDs.

[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 an adhesion layer on a surface of a transient substrate;

[0009] Laminating the surface of the growth substrate on which the LED is grown to the surface of the temporary substrate having the adhesion layer;

[0010] peeling off the growth substrate of each of the LEDs;

[0011] The adhesion layer in the region where the target LED among the multiple 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.

[0012] In one embodiment, the step of forming an adhesion layer on a surface of a temporary substrate comprises:

[0013] Coating an adhesive material on one surface of a temporary substrate to form an adhesive layer;

[0014] The adhesive layer is cured for the first time by vacuuming.

[0015] After the surface of the growth substrate on which the LED is grown is bonded to the surface of the temporary substrate having the adhesive layer, the method comprises:

[0016] The adhesive layer is cured for a second time.

[0017] In one embodiment, the second curing is performed by heating at a preset temperature, wherein the preset temperature ranges from 80°C to 120°C.

[0018] 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:

[0019] The target LED is transferred from the transient substrate to a receiving substrate.

[0020] In one embodiment, 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 includes:

[0021] Using a mask with multiple transmittances to perform photolithographic etching on the adhesion layer in the area where the target LED is located;

[0022] The process parameters of the photolithography etching are adjusted to reduce the adhesion of the adhesion layer in the area where the target LED is located to a preset adhesion to form a weakened structure corresponding to the target LED, wherein the process parameters include at least one of developer concentration and development time.

[0023] In one embodiment, the preset adhesion force satisfies the following conditions:

[0024] F1 <F2<F3

[0025] Wherein, F1 is the first adhesion force of the adhesion layer in the area where the target LED is located to the target LED;

[0026] F2 is the second adhesion force of the transfer head to the target LED;

[0027] F3 is a third adhesion force of the adhesion layer in the area outside the target LED to other LEDs among the plurality of LEDs except the target LED.

[0028] In one embodiment, the calculation formula of the first adhesion force is:

[0029] F1=S1×f1

[0030] Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer to the first side of the target LED;

[0031] S1 is the contact area between the adhesion layer and the first side of the target LED;

[0032] The calculation formula of the third adhesion force is:

[0033] F3=S3×f1

[0034] Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer to the first side of the target LED;

[0035] S3 is a contact area between the adhesion layer and the first side of the other LED, and S3>S1;

[0036] The calculation formula of the second adhesion force is:

[0037] F2=S2×f2

[0038] Wherein, f2 is the adhesion force per unit area of ​​the transfer head to the second side of the target LED away from the adhesion layer;

[0039] S2 is a contact area between the transfer head and the second side of the target LED away from the adhesive layer.

[0040] In one embodiment, the thickness of the adhesion layer ranges from 5 μm to 15 μm.

[0041] In a first aspect, an embodiment of the present application provides a weakened structure, which is manufactured based on any manufacturing method in the first aspect above.

[0042] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0043] 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 an adhesion layer on a surface of a temporary substrate, bonding the surface of the growth substrate with the LEDs grown thereon to the surface of the temporary substrate 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 among the multiple LEDs, 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of a process for manufacturing a weakened structure of an LED provided in an embodiment of the present application;

[0045] Figure 2 A schematic diagram of a process for forming an adhesion layer on a surface of a transient substrate provided in an embodiment of the present application;

[0046] Figure 3 A schematic diagram of a process for adding a second curing of the adhesion layer after laminating the surface of the growth substrate with the LEDs grown thereon with the surface of the transient substrate with the adhesion layer provided in an embodiment of the present application;

[0047] Figure 4 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;

[0048] Figure 5 A cross-sectional schematic diagram of preparing a plurality of LEDs on one surface of a growth substrate provided in an embodiment of the present application;

[0049] Figure 6 A schematic cross-sectional view of a surface of a transient substrate after an adhesion layer is formed according to an embodiment of the present application;

[0050] Figure 7 A cross-sectional schematic diagram of laminating a surface of a growth substrate with LEDs grown thereon with a surface of a transient substrate with an adhesion layer provided in an embodiment of the present application;

[0051] Figure 8 A cross-sectional schematic diagram of laser stripping of a growth substrate of each LED provided in an embodiment of the present application;

[0052] Fig. 9A schematic cross-sectional view of the LED growth substrate after peeling off according to the embodiment of the present application;

[0053] Fig.10 A cross-sectional schematic diagram of using masks with multiple transmittances to expose an adhesion layer according to an embodiment of the present application;

[0054] Fig.11 A schematic cross-sectional view of a weakened structure corresponding to the target LED formed in the adhesion layer in the region where the target LED among the multiple LEDs is located after the adhesion layer is developed provided in an embodiment of the present application;

[0055] Fig.12 A cross-sectional schematic diagram of a transfer head picking up a target LED provided by an embodiment of the present application;

[0056] Fig.13 A cross-sectional schematic diagram of a transfer head picking up a target LED from a transient substrate provided in an embodiment of the present application;

[0057] Fig.14 A cross-sectional schematic diagram of a transfer head provided in an embodiment of the present application transferring a target LED to a receiving substrate.

[0058] Markings 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, adhesive layer; 211, adhesive layer of first thickness; 212, adhesive layer of second thickness; 213, adhesive layer of third thickness; 214, weakened structure;

[0061] 220, mask; 221, first sub-mask; 222, second sub-mask; 223, third sub-mask; 224, light shielding portion;

[0062] 300, transfer head; 310, flat viscous material;

[0063] 400. Receive a substrate. DETAILED DESCRIPTION

[0064] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0065] The terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0066] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0067] The technical solution of the present application is described below through specific embodiments.

[0068] Example 1

[0069] like Figure 1 As shown, this embodiment provides a method for manufacturing a weakened structure of an LED, comprising:

[0070] S100, such as Figure 5 As shown, a plurality of LEDs ( 101 , 102 , 103 ) are prepared on one surface of a growth substrate 110 .

[0071] The growth substrate 110 includes at least one of sapphire (Al 2 O 3 ), silicon (Si), and silicon carbide (SiC), and a buffer layer (not shown in the figure) is arranged between the growth substrate 110 and the LED.

[0072] LED includes at least one of the components 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.

[0073] In one embodiment, the size of the LED is 1 μm to 50 μm.

[0074] In one embodiment, the size of the LED is also 5 μm to 25 μm.

[0075] In one embodiment, the LED is a micro LED chip, which includes two electrodes 130 and an epitaxial layer 120 , wherein the side where the electrodes 130 are located is the first side of the LED, and the side where the epitaxial layer 120 is located is the second side of the LED.

[0076] S200, such as Figure 6 As shown, an adhesive layer 210 is formed on one surface of a temporary substrate 200 .

[0077] In application, an adhesive layer 210 is formed on one surface of the temporary substrate 200 to facilitate the adhesion of LEDs.

[0078] The material of the temporary substrate 200 includes sapphire (Al2O3) or glass.

[0079] In one embodiment, Figure 2 As shown, forming an adhesion layer 210 on one surface of a temporary substrate 200 and performing a first curing process includes:

[0080] S210, coating an adhesive material on one surface of the temporary substrate 200 to form an adhesive layer 210;

[0081] In applications, an adhesive material is coated on one surface of the temporary substrate 200 through a coating process to form an adhesive layer 210 .

[0082] The material of the adhesive layer 210 includes any one of a photoresist material or an adhesive material, wherein the composition of the photoresist material includes at least one of a resin material, a photosensitizer, a solvent and a binder, wherein the resin material includes polyimide (PI) or polymethyl methacrylate (PMMA), and the binder includes at least one of acrylate, butadiene and polyurethane, and the mass fraction of polyurethane in the photoresist material is 5% to 10%. The binder is used to increase the adhesion of the adhesive layer 210 to the LED. The adhesive material includes hot melt adhesive or other adhesive materials with viscosity.

[0083] In one embodiment, the thickness of the adhesive layer 210 is in the range of 5 μm to 15 μm. The thickness of the adhesive layer 210 is not limited to the above range, and the thickness of the adhesive layer 210 is specifically set according to the height of the LED.

[0084] S220 , performing a first curing on the adhesive layer 210 by vacuuming.

[0085] In application, the adhesive layer 210 is evacuated to a preset vacuum level to allow the solvent in the adhesive layer 210 to evaporate, thereby making the adhesive layer 210 lose fluidity, making it easier to adhere the LED.

[0086] In one embodiment, the preset vacuum degree of the vacuum extraction is less than or equal to 10Pa.

[0087] S300, such as Figure 7 As shown, the surface of the growth substrate 110 on which the LED is grown is attached to the surface of the temporary substrate 200 having the adhesive layer 210 .

[0088] In application, the surface of the growth substrate 110 with the LED is bonded to the surface of the temporary substrate 200 with the adhesion layer 210, 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 is embedded in the adhesion layer 210, making it easier for the adhesion layer 210 to fix each LED.

[0089] In one embodiment, Figure 3 As shown, after the surface of the growth substrate 110 with the LED grown thereon is bonded to the surface of the temporary substrate 200 with the adhesive layer 210, the following steps are included:

[0090] S310 , performing a second curing on the adhesive layer 210 .

[0091] In application, the adhesive layer 210 is cured for the second time by heating to further increase the adsorption force of the adhesive layer 210 on each LED.

[0092] In one embodiment, the second curing is performed by heating at a preset temperature, and the preset temperature ranges from 80° C. to 120° C. The heating time is adjusted according to the specific heating temperature. When the heating temperature increases, the heating time is shortened, and when the heating temperature decreases, the heating time is increased.

[0093] S400, such as Figure 8 , Fig. 9 As shown, the growth substrate 110 of each LED is peeled off.

[0094] In applications, such as Figure 8 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 achieving the peeling of the growth substrate 110 and separating the LED from the growth substrate 110. Fig. 9 As shown, after the growth substrate 110 is peeled off, each LED is still adhered to the adhesive layer 210 according to the arrangement on the growth substrate 110 , so that each LED is fixed on the temporary substrate 200 .

[0095] S500, such as Fig.10 , Fig.11 As shown, the adhesion layer 210 in the area where the target LED 101 is located among the multiple LEDs is etched to reduce the adhesion force of the adhesion layer in the area where the target LED 101 is located, and form a weakened structure 214 corresponding to the target LED 101 .

[0096] In application, the adhesion layer 210 where the target LED 101 is located is etched to reduce the contact area between the surface of the adhesion layer 210 away from the temporary substrate 200 and the target LED 101, thereby reducing the adhesion force of the adhesion layer 210 to the target LED 101, and then forming a weakened structure 214 corresponding to the target LED 101, which facilitates the picking up of the target LED 101.

[0097] In one embodiment, Figure 4 As shown, etching the adhesion layer 210 in the region where the target LED 101 is located among the multiple LEDs, reducing the adhesion force of the adhesion layer 210 in the region where the target LED 101 is located, and forming a weakened structure 214 corresponding to the target LED 101, including:

[0098] S510, such as Fig.10 As shown, a mask 220 with multiple transmittances is used to perform photolithography etching on the adhesion layer 210 in the area where the target LED 101 is located.

[0099] In one embodiment, a mask 220 (Half Tone Mask, HTM) with multiple different transmittances is first used to expose the adhesion layer 210 through the transparent temporary substrate 200 .

[0100] It should be noted that the mask 220 includes a plurality of sub-masks with different transmittances and a shading portion 224. The shading portion 224 is located at the mask connection portion corresponding to the interval area between each LED chip, so as to facilitate independent exposure of the adhesion layer 210 in the area corresponding to each LED chip, and the LED chips are completely opaque.

[0101] The mask 230 includes a first sub-mask 221 with a first transmittance T1, a second sub-mask 222 with a second transmittance T2, and a third sub-mask 223 with a third transmittance T3, wherein when the adhesion layer 210 is made of a negative photoresist material, T1>T2>T3; when a positive photoresist material is used, T1>T2>T3. <T2<T3。

[0102] The adhesion layer 210 exposed to different degrees is then developed and etched, so that the amount of photoresist material remaining in the area corresponding to the target LED 101 in the adhesion layer 210 after development is the least, and the amount of photoresist material remaining in the areas corresponding to other LEDs (102, 103) in the adhesion layer 210 after development is greater than the amount of photoresist material remaining in the area corresponding to the target LED 101 after development.

[0103] In one embodiment, during the first development, the adhesion layer 210 uses a negative photoresist material, T1>T2>T3. Since the negative photoresist material is insoluble after exposure, the photoresist with the weakest exposure reacts the least, the photoresist material dissolved by development is the most, and the photoresist residue after development is the least.

[0104] In one embodiment, during the first development, the adhesion layer 210 uses a positive photoresist material, where T1 < T2 < T3. Since the exposed positive photoresist material is soluble, the photoresist with the strongest exposure undergoes the greatest reaction, the most photoresist material is dissolved during development, and the least amount of photoresist remains after development.

[0105] As Fig.11 shown, after the first development, the photoresist material remaining in the adhesion layer 213 with the third thickness in the area of the adhesion layer 210 corresponding to the second other LED 103 is the most, the photoresist material remaining in the adhesion layer 211 with the first thickness in the area of the adhesion layer 210 corresponding to the target LED 101 is the least, and the photoresist material remaining in the adhesion layer 212 with the second thickness in the area of the adhesion layer 210 corresponding to the first other LED 102 among the adhesion layer 210 is between the two.

[0106] S520, as Fig.11 shown, adjust the process parameters of photolithography etching to reduce the adhesion force of the adhesion layer 210 in the area where the target LED 101 is located to a preset adhesion force, forming a weakened structure 214 corresponding to the target LED 101.

[0107] Fig.11 In

[0108] application, according to the etching situation of the adhesion layer 210 where the target LED 101 is located, adjust the process parameters of photolithography etching to reduce the contact area between the surface of the adhesion layer 210 away from the transient substrate 200 and the target LED 101 until the adhesion force of the adhesion layer 210 in the area where the target LED 101 is located is reduced to the preset adhesion force, forming a weakened structure 214 corresponding to the target LED 101, so that the target LED 101 with the weakened structure 214 can be transferred. Among them, the process parameters include at least one of the developer concentration and the development time. For example, when the temperature is 23 °C, the developer uses a 2.38% TMAH (tetramethylammonium hydroxide) developer, and the development time ranges from 40 seconds to 100 seconds.

[0109] When the target LED 101 is transferred, other LEDs (102, 103) with the weakened structure 214 where the adhesion layer 210 has not been reduced to the preset adhesion force cannot be transferred and remain fixed to the adhesion layer 210, which is beneficial for selectively picking up the target LED 101 from each LED, avoiding transferring the remaining LEDs together, so as to avoid loss of LEDs, thereby improving the yield of mass transfer.

[0110] Among them, the preset adhesion force satisfies the following conditions:

[0111] F1 <F2<F3

[0112] Wherein, F1 is the first adhesion force of the adhesion layer 210 to the target LED 101 in the area where the target LED 101 is located;

[0113] F2 is the second adhesion force of the transfer head 300 to the target LED 101;

[0114] F3 is a third adhesion force of the adhesion layer 210 in the area outside the target LED 101 to other LEDs among the plurality of LEDs except the target LED 101 .

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

[0116] F1=S1×f1

[0117] Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer 210 to the first side of the target LED 101;

[0118] S1 is the contact area between the adhesion layer 210 and the first side of the target LED 101 .

[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 210 to the first side of the target LED 101;

[0122] S3 is the contact area between the adhesion layer 210 and the first side of other LEDs, 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 second side of the target LED 101 away from the adhesive layer;

[0126] S2 is the contact area between the transfer head 300 and the second side of the target LED 101 away from the adhesive layer.

[0127] In one embodiment, when the adsorption force of the adhesive layer on the side wall of the LED epitaxial layer is ignored, the adhesion force f1 of the adhesive layer on the LED per unit area is 15 N / cm 2 ~20N / cm 2 The adhesion force f2 of the transfer head per unit area to the epitaxial layer of the LED is less than 9N / cm 2; Set the radius of electrode 130 of the rod-shaped electrode of the LED as r, the height of electrode 130 of the rod-shaped electrode of the LED as h, and the area of electrode 130 of the rod-shaped electrode of the LED as S′0, then S′0 = πr 2 + 2πrh; The area of the LED epitaxial layer on the electrode side in the LED epitaxial layer is S″0, and the maximum contact area between the adhesion layer and the LED is S0, then S0 = S′0 + S″0. The contact area S1 between the adhesion layer and the target LED is greater than or equal to one-fourth of the maximum contact area S0 of the LED, that is The contact area S3 between the adhesion layer and the electrodes of other LEDs except the target LED is greater than or equal to one-half of the total maximum contact area S0 of the LED, 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 214 is F1 < 0.36×10 -4 N < F3, where F3 ≧ 2F1. Set the height of the adhesion layer covering the rod-shaped electrode of the LED as h1, S1 = πr 2 + 2πrh1, h1 < h.

[0129] S600, as Fig.12 、 Fig.13 、 Fig.14 shown, transfer the target LED101 from the transient substrate 200 to the receiving substrate 400.

[0130] In the application, pick up the target LED101 corresponding to the weakening structure 214 that satisfies the preset adhesion force condition from the transient substrate 200 and transfer it to the receiving substrate 400, and other LEDs with the adhesion force of the adhesion layer greater than the second adhesion force will not be picked up, thus realizing the massive transfer of LEDs. During the transfer process, since the weakening structure corresponding to the target LED satisfies 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 satisfy the condition of the preset adhesion force and cannot be picked up and transferred, there is no need to use a highly precise fabricated stamping transfer head for picking up and transferring, thereby reducing the cost of the massive transfer of LEDs.

[0131] In one embodiment, transferring the target LED101 from the transient substrate 200 to the receiving substrate 400 includes:

[0132] The transfer head 300 with the second adhesion force is used to pick up the target LED 101 and transfer it to the receiving substrate 400, wherein the transfer head with the second adhesion force includes the transfer head 300 and a planar adhesive material 310, wherein the adhesive material includes planar polydimethylsiloxane (PDMS) or other weakly adhesive materials.

[0133] In one embodiment, after the target micro LED chip is picked up by a transfer head having a second adhesive force, the residual adhesive layer material of the target LED is cleaned, and then the LED electrode of the target micro LED chip is flip-chip soldered on the driving backplane.

[0134] It should be noted that when multiple LEDs on a temporary substrate need to be selectively picked up N times, the adhesion layer is first photoetched to form a weakened structure that meets the preset adhesion conditions, and the first target LED is picked up, and then the adhesion layer on the temporary substrate is etched for a second time to form a weakened structure that meets the preset adhesion conditions, and then the second target LED is picked up, and the etching is repeated N times to form a weakened structure that meets the preset adhesion conditions and pick up the target LEDs until all LEDs are picked up and transferred to the receiving substrate. For example, when multiple LEDs on a temporary substrate need to be selectively picked up three times, the photoetching is repeated three times to form a weakened structure that meets the preset adhesion conditions and pick up the target LEDs, so that all LEDs can be picked up and transferred to the receiving substrate.

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

[0136] The method for manufacturing the weakened structure of an LED provided in the present embodiment prepares a plurality of LEDs on a growth substrate, forms an adhesion layer on one surface of a temporary substrate, fits the surface of the growth substrate on which the LEDs are grown with the surface of the temporary substrate with the adhesion layer, peels off the growth substrate of each LED, etches the adhesion layer in the area where the target LED is located, reduces the adhesion force of the adhesion layer in the area where the target LED is located, forms a weakened structure corresponding to the target LED, and makes the target LED have a different weakened structure from the remaining LEDs, so that 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 the present application.

[0138] Example 2

[0139] This embodiment provides a weakening structure, such as Fig.11As 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, the present embodiment has the following beneficial effects:

[0141] The weakening structure provided in this embodiment enables the target LED and other LEDs to have different weakening structures, 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 emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0143] The embodiments described above 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, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope 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 an adhesion layer on a surface of a transient substrate; Laminating the surface of the growth substrate on which the LED is grown to the surface of the temporary substrate having the adhesion layer; peeling off the growth substrate of each of the LEDs; Etching the adhesion layer 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 corresponding to the target LED; The etching of the adhesion layer in the region where the target LED among the plurality of 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, comprises: Using a mask with multiple transmittances to perform photolithographic etching on the adhesion layer in the area where the target LED is located; Adjusting the process parameters of the photolithography etching to reduce the adhesion of the adhesion layer in the area where the target LED is located to a preset adhesion to form a weakened structure corresponding to the target LED, wherein the process parameters include at least one of a developer concentration and a development time; The preset adhesion force satisfies the following conditions: F1<F2<F3 Wherein, F1 is the first adhesion force of the adhesion layer in the area where the target LED is located to the target LED; F2 is the second adhesion force of the transfer head to the target LED; F3 is a third adhesion force of the adhesion layer in the area outside the target LED to other LEDs among the plurality of LEDs except the target LED.

2. The method according to claim 1, characterized in that: The step of forming an adhesion layer on a surface of a transient substrate comprises: Coating an adhesive material on one surface of a temporary substrate to form an adhesive layer; The adhesive layer is cured for the first time by vacuuming.

3. The method according to claim 1, characterized in that: After the surface of the growth substrate on which the LED is grown is bonded to the surface of the temporary substrate having the adhesive layer, the method comprises: The adhesive layer is cured for a second time.

4. The method according to claim 3, characterized in that: The second curing is performed by heating at a preset temperature, wherein the preset temperature ranges from 80°C to 120°C.

5. The method according to claim 1, characterized in that: 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 comprises: The target LED is transferred from the transient substrate to a receiving substrate.

6. The method according to claim 4, characterized in that: The calculation formula of the first adhesion force is: F1=S1×f1 Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer to the target LED; S1 is the contact area between the adhesion layer and the target LED; The calculation formula of the third adhesion force is: F3=S3×f1 Wherein, f1 is the adhesion force per unit area of ​​the adhesion layer to the target LED; S3 is the contact area between the adhesion layer and the other LEDs, and S3>S1; The calculation formula of the second adhesion force is: F2=S2×f2 Wherein, f2 is the adhesion force per unit area of ​​the transfer head to the second side of the target LED away from the adhesion layer; S2 is a contact area between the transfer head and the second side of the target LED away from the adhesive layer.

7. The 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. A weakened structure, characterized in that: The weakened structure is manufactured based on the manufacturing method according to any one of claims 1 to 7.

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