Color micro led light color conversion module and manufacturing method thereof

Abstract

The application discloses a color Micro LED light color conversion module and a manufacturing method thereof. A black adhesive material layer is covered on one side of an integrated Micro LED chip with a common N-pole far from a substrate layer. The black adhesive material layer is etched to expose the electrode of the Micro LED chip, which can prevent light crosstalk between gallium nitride mesas. The substrate is peeled off and the N-type gallium nitride layer of the first Micro LED chip module is cut off, which can separate the N-type gallium nitride through the black adhesive material layer, prevent light crosstalk in the N-type gallium nitride material inside the common N-type chip and light crosstalk in the substrate part. In this way, the light crosstalk problem can be avoided in the light emitting path of the LED.

Description

[0001] The present application is a divisional application of the parent application with the application number 202211290900.5, the filing date of October 21, 2022, and the title of "Manufacturing method of an integrated anti-crosstalk structure of a color Micro LED". TECHNICAL FIELD

[0002] The present application relates to the field of semiconductor electronics, in particular to a color Micro LED light color conversion module and a manufacturing method thereof. BACKGROUND

[0003] Integrated Micro LEDs have all their pixels integrated on a substrate and do not undergo cutting or other segmentation operations, which leads to the problem of light crosstalk between adjacent pixels, affecting the display effect. Integrated Micro LEDs generally use common N-type gallium nitride, and the common N-type design also leads to the problem of light crosstalk in the N-type gallium nitride.

[0004] The existing integrated color Micro LED technology mainly uses an integrated blue and violet light gallium nitride (GaN) LED chip matrix light source and a quantum dot (QD, Quantum Dots) color conversion module to form a stack, and there are light crosstalk problems in the Mesa between the GaN LED chip matrix light source, the N-type GaN material inside the common N-type, and the sapphire substrate layer. There are also light crosstalk problems between the quantum dots of the QD module and the gap between the chip combination. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a color Micro LED light color conversion module and a manufacturing method thereof, which can avoid the problem of light crosstalk on the LED light path.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0007] A manufacturing method of a color Micro LED light color conversion module, comprising the steps of:

[0008] Covering a black adhesive material layer on the side of the common N-pole integrated Micro LED chip away from the substrate layer, etching the black adhesive material layer and exposing the electrode of the Micro LED chip to obtain a first Micro LED chip module;

[0009] Connecting the electrode of the first Micro LED chip module to the driving substrate through a bonding metal, removing the substrate layer of the first Micro LED chip module, and disconnecting the N-type gallium nitride layer of the first Micro LED chip module to obtain a second Micro LED chip module.

[0010] Filling insulating glue between the second Micro LED chip module and the driving substrate, and connecting all N-type gallium nitride of the second Micro LED chip module and N-pole of the driving substrate by using a transparent conductive layer;

[0011] Placing a light color conversion module on the transparent conductive layer on the surface of the N-type gallium nitride layer to obtain an anti-crosstalk structure of an integrated color Micro LED.

[0012] The present application has the beneficial effect that: covering a black glue material layer on the side of the integrated Micro LED chip away from the substrate layer, etching the black glue material layer and exposing the electrode of the Micro LED chip can prevent light crosstalk between gallium nitride mesas; peeling off the substrate and cutting off the N-type gallium nitride layer of the first Micro LED chip module can separate the N-type gallium nitride through the black glue material layer, preventing light crosstalk inside the N-type gallium nitride material of the common N-type chip and light crosstalk of the substrate part. In this way, light crosstalk problems can be avoided in the LED light path. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A flowchart of a manufacturing method of an anti-crosstalk structure of an integrated color Micro LED according to an embodiment of the present application;

[0014] Figure 2 A schematic diagram of a common N-pole integrated Micro LED chip according to an embodiment of the present application;

[0015] Figure 3 A schematic diagram of covering a black glue material layer on a common N-pole integrated Micro LED chip according to an embodiment of the present application;

[0016] Figure 4 A schematic diagram of etching a black glue material layer according to an embodiment of the present application;

[0017] Figure 5 A schematic diagram of combining a first Micro LED chip module and a driving substrate according to an embodiment of the present application;

[0018] Figure 6 A schematic diagram of peeling off a substrate of a first Micro LED chip module according to an embodiment of the present application;

[0019] Figure 7 A schematic diagram of etching an N-type gallium nitride layer of a first Micro LED chip module according to an embodiment of the present application;

[0020] Figure 8 A schematic diagram of covering a transparent conductive layer according to an embodiment of the present application;

[0021] Figure 9 FIG. 1 is a schematic diagram of a light color conversion module according to an embodiment of the present application;

[0022] Figure 10 FIG. 2 is a schematic diagram of an integrated color Micro LED anti-crosstalk structure according to an embodiment of the present application;

[0023] Label explanation:

[0024] 1, substrate layer; 2, buffer layer; 3, N-type gallium nitride layer; 4, P-type gallium nitride layer; 5, current expansion layer; 6, P electrode; 7, black adhesive material layer; 8, driving substrate; 9, bonding metal; 10, insulating adhesive; 11, transparent conductive layer; 12, N pole; 13, glass; 14, mirror layer; 15, red quantum dots; 16, green quantum dots; 17, light emitting hole; 18, protective layer; 19, black light shielding adhesive. DETAILED DESCRIPTION

[0025] In order to explain the technical content, the purpose and effect of the present application in detail, the following will be described in conjunction with the embodiments and the accompanying drawings.

[0026] Please refer to Figure 1 The embodiment of the present application provides a manufacturing method of a light color conversion module of a color Micro LED, comprising the following steps:

[0027] A black adhesive material layer is covered on the side of the integrated Micro LED chip far from the substrate layer, the black adhesive material layer is etched and the electrode of the Micro LED chip is exposed, and a first Micro LED chip module is obtained;

[0028] The electrode of the first Micro LED chip module is connected with the driving substrate through the bonding metal, the substrate layer of the first Micro LED chip module is removed, and the N-type gallium nitride layer of the first Micro LED chip module is cut off, and a second Micro LED chip module is obtained;

[0029] The insulating adhesive is filled between the second Micro LED chip module and the driving substrate, and the transparent conductive layer is used to connect all N-type gallium nitride of the second Micro LED chip module and the N pole of the driving substrate;

[0030] The light color conversion module is placed on the transparent conductive layer on the surface of the N-type gallium nitride layer, and an integrated color Micro LED anti-crosstalk structure is obtained.

[0031] From the above description, the beneficial effects of the present application are that: the black adhesive material layer is covered on the side of the integrated Micro LED chip far from the substrate layer, the black adhesive material layer is etched and the electrode of the Micro LED chip is exposed, which can prevent light crosstalk between gallium nitride mesas; the N-type gallium nitride layer of the first Micro LED chip module is separated from the substrate, which can separate the N-type gallium nitride through the black adhesive material layer, prevent light crosstalk in the N-type gallium nitride material of the common N-type chip and light crosstalk in the substrate part. In this way, the problem of light crosstalk can be avoided on the LED light-emitting light path.

[0032] Further, etching the black adhesive material layer and exposing the electrode of the Micro LED chip comprises:

[0033] The black adhesive material layer is etched until the P electrode of the Micro LED chip is exposed.

[0034] From the above description, the black adhesive material layer is selectively etched without etching the P electrode, so that the P electrode will be naturally exposed after a period of etching, and the manufacturing process has high reliability.

[0035] Further, connecting the electrode of the first Micro LED chip module to the driving substrate through the bonding metal comprises:

[0036] The first Micro LED chip module is placed in an inverted manner, the electrode of the first Micro LED chip module is connected to the bonding metal one by one, and the bonding metal is connected to the contact point of the driving substrate one by one.

[0037] From the above description, the first Micro LED chip module is combined with the driving substrate in a metal bonding manner after being inverted, and the bonding metal is used as a connection interface to ensure the reliability of the chip driving connection.

[0038] Further, separating the N-type gallium nitride layer of the first Micro LED chip module comprises:

[0039] The N-type gallium nitride layer is horizontally etched from the side far from the electrode until the black adhesive material layer is exposed.

[0040] From the above description, the N-type gallium nitride part of the common N-type chip is connected, and the N-type gallium nitride layer is horizontally etched, which can etch the connected part of the N-type gallium nitride, so that the remaining N-type gallium nitride is no longer connected and is separated by the black adhesive material layer, further preventing light crosstalk in the N-type gallium nitride material of the common N-type chip.

[0041] Further, the use of a transparent conductive layer to connect all the N-type gallium nitride layers and the N-pole of the driving substrate comprises:

[0042] A transparent conductive layer is evaporated on the surface of the black adhesive material layer, the etched N-type gallium nitride layer, the insulating adhesive, the driving substrate, and the N-pole thereof.

[0043] As described above, the transparent conductive layer is evaporated on the surface of the chip module and the driving substrate, so that a common N-type transparent electrode is obtained, and the conduction of the common N-pole is realized.

[0044] Further, before placing the light color conversion module on the transparent conductive layer on the surface of the N-type gallium nitride layer, the following steps are included:

[0045] A groove is etched on the glass according to the position of the quantum dot, and a mirror layer is made on the surface of the groove;

[0046] A light-out hole of a first color is etched on the mirror layer corresponding to the position of the first groove, and quantum dots of a second color and a third color are respectively arranged on the mirror layer corresponding to the second groove and the third groove, to obtain a light color conversion structure;

[0047] A protective layer is deposited on the side of the light color conversion structure away from the glass, and a black light shielding adhesive is made on the protective layer corresponding to the positions between the quantum dots and the positions between the quantum dots and the light-out hole, to obtain a light color conversion module.

[0048] As described above, the selective mirror layer is prefabricated on the glass substrate, and the light-out hole of the first color and the quantum dots of the second color and the third color are arranged, so that the light color conversion module only reflects the light segment of the first color; and the light color conversion module and the chip module are completely separated by the black light shielding adhesive, without leaving a light leakage gap, to prevent light crosstalk between the quantum dots of the light color conversion module and between the chip.

[0049] Further, the first color is blue;

[0050] The mirror layer includes silicon oxide and titanium oxide, and the mirror layer reflects light of 200-480 nm.

[0051] As described above, the first color is blue, and the mirror layer reflects light of 200-480 nm, so that the mirror layer that only reflects blue light and does not reflect red and green light can be made by simply stacking silicon oxide and titanium oxide on the light-out surface of the quantum dot.

[0052] Further, the placing of the light color conversion module on the transparent conductive layer on the surface of the N-type gallium nitride layer includes:

[0053] The light color conversion module is placed on the transparent conductive layer, and the positions of the quantum dots of the light color conversion module correspond one-to-one to the positions of the N-type gallium nitride of the second Micro LED chip module.

[0054] From the above description, the light color conversion module and the chip module are combined, and an integrated color Micro LED anti-crosstalk structure can be obtained.

[0055] Further, the black adhesive material layer is a black epoxy adhesive material layer.

[0056] From the above description, the black adhesive material layer uses epoxy adhesive as the base material, has a shaping ability, and facilitates the isolation of N-type gallium nitride.

[0057] Further, the transparent conductive layer is an indium tin oxide layer.

[0058] The color Micro LED light color conversion module and the manufacturing method thereof are suitable for preventing light crosstalk problems at the gap between Mesas, N-type gallium nitride materials of the same N-type, substrate layers, quantum dots of QD modules, and the combination of QD modules and chips in integrated color Micro LED chips.

[0059] Example 1

[0060] Please refer to Figure 1 A manufacturing method of an integrated color Micro LED anti-crosstalk structure, comprising the following steps:

[0061] S1, covering a black adhesive material layer 7 on the side of the integrated Micro LED chip of the same N-type away from the substrate layer 1, etching the black adhesive material layer 7 and exposing the electrode of the Micro LED chip to obtain a first Micro LED chip module.

[0062] S11, please refer to Figure 2 An integrated Micro LED chip of the same N-type is made of a GaN-based epitaxial wafer, the Micro LED chip includes a buffer layer 2, an N-type gallium nitride layer 3 and a P-type gallium nitride layer 4 grown on a substrate layer 1 in sequence, the N-type gallium nitride layer 3 and the P-type gallium nitride layer 4 are patterned and etched, so that the N-type gallium nitride layer 3 is partially connected; the P-type gallium nitride layer 4 has a current spreading layer 5 and a P electrode 6 grown in sequence.

[0063] S12, please refer to Figure 3 A black adhesive material layer 7 of an epoxy base is uniformly coated on the integrated Micro LED chip of the same N-type, and is ready for etching after leveling.

[0064] S13, please refer to Figure 4Etching the black adhesive material layer 7 until the P electrode 6 of the Micro LED chip is exposed; in this embodiment, ICP etching can be used to selectively etch away the adhesive without etching the electrode, so that the electrode is naturally exposed after a period of etching.

[0065] S2, connecting the electrode of the first Micro LED chip module to the driving substrate 8 through the bonding metal 9, removing the substrate layer 1 of the first Micro LED chip module, and isolating the N-type gallium nitride layer 3 of the first Micro LED chip module to obtain a second Micro LED chip module.

[0066] S21, please refer to Figure 5 The first Micro LED chip module is placed upside down, and the electrode of the first Micro LED chip module is connected one-to-one to the bonding metal 9, and the bonding metal 9 is connected one-to-one to the contact point of the driving substrate 8.

[0067] In this embodiment, the first Micro LED chip module and the driving substrate 8 are combined using a metal bonding method, and the bonding metal 9 is used as the connection interface.

[0068] S22, please refer to Figure 6 The substrate layer 1 is removed using a laser lift-off method.

[0069] S23, please refer to Figure 7 From the side far from the electrode, horizontally etch the N-type gallium nitride layer 3 until the black adhesive material layer 7 is exposed.

[0070] Specifically, the buffer layer 2 is removed using ICP etching, and part of the N-type gallium nitride layer 3 is etched away. The remaining N-type gallium nitride layer 3 after etching is not connected, and the black adhesive material layer 7 is filled in the middle of each N-type gallium nitride layer 3.

[0071] S3, filling the insulating adhesive 10 between the second Micro LED chip module and the driving substrate 8, and using the transparent conductive layer 11 to connect all N-type gallium nitride of the second Micro LED chip module and the N pole 12 of the driving substrate 8.

[0072] Specifically, please refer to Figure 8 The transparent conductive layer 11 is evaporated on the outer surface of the black adhesive material layer 7, the etched N-type gallium nitride layer 3, the insulating adhesive 10, the driving substrate 8, and the N pole 12 thereof.

[0073] In the embodiment, the transparent conductive layer 11 is an indium tin oxide layer, which is plated by sputtering or RPD (Radio Frequency Plasma Deposition); specifically, after etching, the insulating glue 10 is filled between the chip module and the driving substrate, and the N-type gallium nitride is connected to the N pole 12 of the driving substrate by using indium tin oxide material.

[0074] S4, placing the light color conversion module on the transparent conductive layer 11 on the surface of the N-type gallium nitride layer 3 to obtain the anti-crosstalk structure of the integrated color Micro LED.

[0075] S41, please refer to Figure 9 , the light color conversion module is manufactured:

[0076] S411, etching grooves on the glass 13 according to the positions of the quantum dots, and manufacturing a mirror layer 14 on the surface of the grooves, the depth of the grooves is 500-5000um;

[0077] S412, etching the light emitting hole 17 of the first color on the mirror layer 14 corresponding to the position of the first groove, and setting the quantum dots of the second color and the third color on the mirror layer 14 corresponding to the second groove and the third groove respectively to obtain the light color conversion structure;

[0078] In the embodiment, the first color is blue, the second color is red, and the third color is blue, that is, the blue light emitting hole 17 is reserved, and the red quantum dot 15 and the green quantum dot 16 are manufactured; wherein the light emitting positions corresponding to the red and green quantum dots are protected by a mask and are not etched;

[0079] The main material of the mirror layer 14 is silicon oxide and titanium oxide, which utilizes the optical principle of distributed Bragg reflector to reflect only the light between 200-480nm, and does not reflect the light between 480-800nm;

[0080] S413, depositing the protective layer 18 of temperature resistance, humidity resistance and corrosion resistance on the side of the light color conversion structure away from the glass 13 by using ALD (Atomic Layer Deposition) deposition method, and manufacturing the black light shielding glue 19 on the protective layer 18 corresponding to the positions between the quantum dots and the positions between the quantum dots and the light emitting hole 17 by photoetching to obtain the light color conversion module.

[0081] S42, please refer to Figure 10 , the light color conversion module and the chip module are combined to obtain the anti-crosstalk structure of the integrated color Micro LED. Wherein, the positions of the quantum dots of the light color conversion module correspond one by one to the positions of the N-type gallium nitride of the second Micro LED chip module.

[0082] Compared with the traditional Micro LED structure, the embodiment retains the convenience of integrated processing, avoids light crosstalk problems on all light emitting and light paths, is convenient to design, can combine RGB color distribution according to actual needs, has excellent protection, has good protection for QD (quantum dot) and gallium nitride chips, and has a reasonable chip module processing process, which utilizes the good setting performance of epoxy glue and the convenience of black doping.

[0083] In summary, the color Micro LED light color conversion module and the manufacturing method thereof provided by the application cover a black epoxy glue material layer on the side of the integrated Micro LED chip far from the substrate layer, etch the black glue material layer and expose the electrode of the Micro LED chip, which can prevent light crosstalk between gallium nitride mesas; the substrate is peeled off and the N-type gallium nitride layer of the first Micro LED chip module is cut off, which can separate the N-type gallium nitride through the black glue material layer, the separated N-type gallium nitride layer is connected with the N-pole on the driving substrate through a transparent conductive layer to form a transparent common N electrode, which prevents light crosstalk in the N-type gallium nitride material of the common N-type chip and light crosstalk in the substrate part; and the color LED is realized through a light color conversion device, wherein a reflection layer that only reflects blue light and does not reflect red and green light is made by simply stacking silicon oxide and titanium oxide materials on the light emitting surface of the quantum dot. In this way, the light crosstalk problem can be avoided on the light emitting path of the LED.

[0084] The above description is only an embodiment of the application, and does not limit the patent scope of the application, and any equivalent transformation or direct or indirect application in the related technical field based on the content of the specification and drawings is also included in the patent protection scope of the application.

Claims

1.A method for manufacturing a light color conversion module of a color Micro LED, characterized in that, The method comprises the steps of: etching grooves on the glass according to the positions of the quantum dots, and making a mirror layer on the surface of the grooves; etching a light-out hole of a first color on the mirror layer corresponding to the position of the first groove, and setting quantum dots of a second color and a third color on the mirror layer corresponding to the second groove and the third groove respectively, to obtain a light color conversion structure; depositing a protective layer on the side of the light color conversion structure away from the glass, and making black light-shielding glue on the protective layer corresponding to the positions between the quantum dots and the positions between the quantum dots and the light-out hole, to obtain a light color conversion module; the first color is blue; the mirror layer comprises silicon oxide and titanium oxide, and the mirror layer reflects light of 200-480 nm. 2.The method of claim 1, wherein, The depth of the groove is 500-5000 um. 3.The method of claim 1, wherein the method further comprises: forming a color conversion layer on the color conversion layer transfer substrate; and transferring the color conversion layer to the color conversion layer transfer substrate. After obtaining the light color conversion module, the method comprises the steps of: placing the light color conversion module on the transparent conductive layer on the surface of the N-type gallium nitride layer of the Micro LED chip module. 4.The method of claim 3, wherein the method further comprises: forming a color conversion layer on the color conversion layer transfer substrate; and transferring the color conversion layer to the color conversion layer transfer substrate. Placing the light color conversion module on the transparent conductive layer on the surface of the N-type gallium nitride layer of the Micro LED chip module comprises: placing the light color conversion module on the transparent conductive layer, and the positions of the quantum dots of the light color conversion module correspond one-to-one to the positions of the N-type gallium nitride of the Micro LED chip module. 5.The method of claim 3, wherein the method further comprises: forming a color conversion layer on the color conversion layer transfer substrate; and transferring the color conversion layer to the color conversion layer transfer substrate. The transparent conductive layer is an indium tin oxide layer. 6.A light color conversion module of a color Micro LED, characterized in that, The light color conversion module is prepared by using the manufacturing method of a color Micro LED light color conversion module according to any one of claims 1-5.

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