A light emitting diode chip package structure and a method of manufacturing the same

Abstract

The application relates to a light-emitting diode chip packaging structure and a preparation method thereof, and relates to the technical field of semiconductor light emission. In the preparation method of the light-emitting diode chip packaging structure, the light-emitting diode chip is pre-packaged, and then a plurality of spherical light scattering bumps are formed in the growth substrate of each light-emitting diode chip. The arrangement of the spherical light scattering bumps greatly improves the light emission efficiency of the light-emitting diode chip. In the process of forming the spherical light scattering bumps, a plurality of semispherical grooves and a first protective layer are formed on the surface of the growth substrate, so that the first protective layer is embedded in each of the spherical light scattering bumps, and the stability of the spherical light scattering bumps is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor light-emitting technology, specifically to a light-emitting diode chip packaging structure and its fabrication method. Background Technology

[0002] The fabrication process of light-emitting diode (LED) chips typically includes three main stages: epitaxial growth of the LED wafer, chip fabrication, and post-processing dicing and testing. Epitaxial growth primarily involves growing N-type semiconductor layers, multiple quantum well (QQL) light-emitting layers, and P-type layers on a growth substrate using metal-organic chemical vapor deposition (MOCVD). Chip fabrication mainly includes depositing a transparent conductive layer, photolithography to form electrode patterns, etching and vapor deposition to form electrodes, and passivation. Finally, substrate thinning and laser dicing of the wafer create individual LED chips. How to improve the stability and light extraction efficiency of LED chips by modifying their structure during subsequent packaging remains a key technological focus in the industry. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a light-emitting diode chip packaging structure and its fabrication method.

[0004] To achieve the above objectives, the present invention provides a method for fabricating a light-emitting diode chip packaging structure, comprising: A carrier substrate is provided, on which a plurality of light-emitting diode chips are disposed. Each light-emitting diode chip includes a growth substrate, an N-type semiconductor layer, a light-emitting layer, a P-type semiconductor layer, a first electrode, and a second electrode.

[0005] A first encapsulation layer is formed on the carrier substrate, and the first encapsulation layer is planarized to expose the growth substrate of each of the light-emitting diode chips.

[0006] Next, a plurality of hemispherical grooves are formed on the surface of the growth substrate of each of the light-emitting diode chips.

[0007] Next, the first sacrificial protrusions are filled into the plurality of hemispherical grooves respectively.

[0008] Next, a first protective layer is formed on the first encapsulation layer, and the first protective layer is patterned to form a plurality of first openings, each of which is corresponding to one of the hemispherical grooves.

[0009] Next, a plurality of second hemispherical sacrificial bumps are formed, each second hemispherical sacrificial bump being configured in correspondence with a corresponding first sacrificial bump, and a portion of each second hemispherical sacrificial bump being embedded in a corresponding first opening.

[0010] Next, a second protective layer is formed on the first encapsulation layer, and the second protective layer is patterned to form a plurality of second openings, each second opening being configured to correspond to a corresponding second hemispherical sacrificial bump.

[0011] Next, remove each of the first sacrificial bumps and each of the second hemispherical sacrificial bumps.

[0012] Then, a corresponding spherical light-scattering bump is formed through each of the second openings and each of the first openings.

[0013] Next, the second protective layer of each of the light-emitting diode chip package structures is removed.

[0014] Next, the first encapsulation layer is cut to form a multi-LED chip encapsulation structure.

[0015] As a preferred technical solution, before setting multiple light-emitting diode chips on the carrier substrate, a temporary adhesive layer is set on the carrier substrate, so that the first electrode and the second electrode of each light-emitting diode chip are respectively embedded in the temporary adhesive layer.

[0016] As a preferred technical solution, the plurality of hemispherical grooves formed on the surface of the growth substrate of each light-emitting diode chip are arranged in multiple rows, and the plurality of hemispherical grooves in adjacent rows are staggered.

[0017] As a preferred technical solution, the first protective layer and the second protective layer are made of the same material, the first sacrificial bump and the second hemispherical sacrificial bump are made of the same material, and the first protective layer and the first sacrificial bump are made of different materials.

[0018] As a preferred technical solution, the depth of the hemispherical groove is 300-1500 nanometers, and the distance between two adjacent hemispherical grooves in each row is 900-3000 nanometers.

[0019] As a preferred technical solution, in the step of removing the second protective layer of each of the light-emitting diode chip package structures, the etching time is controlled to avoid etching the first protective layer.

[0020] As a preferred technical solution, the spherical light scattering bump includes a resin matrix and light scattering particles, and is formed by a slit coating process, a scraping process, or a screen printing process.

[0021] As a preferred technical solution, the spherical light scattering bumps enclose a portion of the first protective layer.

[0022] The present invention also proposes a light-emitting diode (LED) chip packaging structure, which is prepared by the above-described method for preparing LED chip packaging structures.

[0023] The beneficial effects of this invention are as follows: In the method for fabricating a light-emitting diode (LED) chip packaging structure of the present invention, the LED chip is pre-packaged to form multiple spherical light-scattering bumps in the growth substrate of each LED chip. The spherical light-scattering bumps greatly improve the light extraction efficiency of the LED chip. In the process of forming the spherical light-scattering bumps, multiple hemispherical grooves are formed on the surface of the growth substrate, and first sacrificial bumps are filled in the multiple hemispherical grooves respectively. Then, a first protective layer with multiple first openings is formed, each first opening corresponding to a corresponding hemispherical groove. Next, multiple second hemispherical sacrificial bumps are formed, each second hemispherical sacrificial bump corresponding to a corresponding first sacrificial bump. Then, a second protective layer with multiple second openings is formed. Each first sacrificial bump and each second hemispherical sacrificial bump are removed, and a corresponding spherical light-scattering bump is formed through each second opening and each first opening. The spherical light-scattering bumps formed in the above manner have a first protective layer embedded in each spherical light-scattering bump, which greatly improves the stability of the spherical light-scattering bumps. Attached Figure Description

[0024] Figure 1 The diagram shows a structure in which multiple light-emitting diode chips are disposed on a carrier substrate in an embodiment of the present invention.

[0025] Figure 2 The diagram shows a structure in which multiple hemispherical grooves are formed on the surface of the growth substrate of each light-emitting diode chip in an embodiment of the present invention.

[0026] Figure 3 The diagram shown is a schematic diagram of the structure forming the first protective layer in an embodiment of the present invention.

[0027] Figure 4 The diagram shows a structure in an embodiment of the present invention that forms a plurality of second hemispherical sacrificial bumps.

[0028] Figure 5 The diagram shown is a schematic representation of the structure forming the second protective layer in an embodiment of the present invention.

[0029] Figure 6 The diagram shown is a schematic representation of the structure forming a spherical light scattering bump in an embodiment of the present invention.

[0030] Figure 7The diagram shows a structural schematic of the second protective layer of the LED chip package structure removed in an embodiment of the present invention.

[0031] Figure 8 The diagram shows a structural schematic of a multi-LED chip package structure formed by cutting the first encapsulation layer in an embodiment of the present invention. Detailed Implementation

[0032] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0033] like Figures 1 to 8 As shown, this embodiment provides a method for fabricating a light-emitting diode chip packaging structure, including: like Figure 1 As shown, a carrier substrate 100 is provided, on which a plurality of light-emitting diode chips 200 are disposed. Each light-emitting diode chip 200 includes a growth substrate 201, an N-type semiconductor layer 202, a light-emitting layer 203, a P-type semiconductor layer 204, a first electrode 205, and a second electrode 206.

[0034] In a specific embodiment, before a plurality of light-emitting diode chips 200 are disposed on the carrier substrate 100, a temporary adhesive layer 101 is disposed on the carrier substrate 100, thereby embedding the first electrode 205 and the second electrode 206 of each light-emitting diode chip 200 into the temporary adhesive layer 101 respectively.

[0035] In a specific embodiment, the carrier substrate 100 can be one of a glass substrate, a plastic substrate, a ceramic substrate, a metal substrate, and a semiconductor substrate. The first temporary adhesive layer 101 has reduced adhesion under light or heating conditions, which facilitates the subsequent peeling process. The first temporary adhesive layer 101 can be formed on the carrier substrate 100 by spin coating, spraying, printing, or lamination processes. Then, the light-emitting diode chip 200 is disposed such that the first electrode 205 and the second electrode 206 of each light-emitting diode chip 200 are respectively embedded in the temporary adhesive layer 101.

[0036] In a specific embodiment, the growth substrate 201 of the light-emitting diode chip 200 can be a sapphire substrate, a silicon substrate, a silicon carbide substrate, a gallium nitride substrate, a gallium arsenide substrate, or a gallium phosphide substrate. Any suitable substrate can be selected based on the different emission colors of the light-emitting diode chip. Furthermore, depending on the emission color, the N-type semiconductor layer 202, the light-emitting layer 203, and the P-type semiconductor layer 204 can be gallium nitride, aluminum indium gallium phosphide, or gallium arsenide systems. In a more specific embodiment, the N-type semiconductor layer 202 can be an N-type gallium nitride layer, the light-emitting layer 203 can be a quantum well light-emitting layer, more specifically, an alternating InGaN quantum well layer and a GaN quantum barrier layer, and the P-type semiconductor layer 204 can be a P-type gallium nitride layer. The N-type semiconductor layer 202, the light-emitting layer 203, and the P-type semiconductor layer 204 are formed using an MOCVD process.

[0037] In a specific embodiment, the formation process of the first electrode 205 and the second electrode 206 is as follows: Through-holes exposing the N-type semiconductor layer 202 are formed using laser drilling or photolithography; the sidewalls of the through-holes are passivated; then, a metal conductive layer is formed using thermal evaporation, magnetron sputtering, electroplating, or chemical plating; and finally, patterning is performed to form the first electrode 205 and the second electrode 206. The metal conductive layer is made of one or more of copper, aluminum, silver, titanium, gold, and palladium. This ensures that the first electrode 205 is electrically connected to the N-type semiconductor layer 202, and the second electrode 206 is electrically connected to the P-type semiconductor layer 204.

[0038] like Figure 1 As shown, a first encapsulation layer 300 is formed on the carrier substrate 100, and the first encapsulation layer 300 is planarized to expose the growth substrate 201 of each of the light-emitting diode chips 200.

[0039] In a specific embodiment, the first encapsulation layer 300 is formed by dispensing, spin coating, blade coating, screen printing, or injection molding. The first encapsulation layer 300 can be made of epoxy resin or silicone. After the first encapsulation layer 300 is formed, it is planarized by chemical mechanical polishing to expose the growth substrate 201 of each light-emitting diode chip 200.

[0040] like Figure 2 As shown, a plurality of hemispherical grooves 401 are then formed on the surface of the growth substrate 201 of each of the light-emitting diode chips 200. First sacrificial bumps 402 are then filled into each of the plurality of hemispherical grooves 401.

[0041] In a specific embodiment, the plurality of hemispherical grooves 401 formed on the surface of the growth substrate 201 of each light-emitting diode chip 200 are arranged in multiple rows, and the plurality of hemispherical grooves 401 in adjacent rows are staggered.

[0042] In a specific embodiment, the depth of the hemispherical groove is 300-1500 nanometers, and the distance between two adjacent hemispherical grooves in each row is 900-3000 nanometers.

[0043] In a specific embodiment, the hemispherical groove 401 is formed by a wet etching process or a dry etching process. More specifically, the depth of the hemispherical groove is 300 nanometers, 500 nanometers, 700 nanometers, 900 nanometers, 1000 nanometers, 1200 nanometers, or 1500 nanometers, and the spacing between two adjacent hemispherical grooves in each row is 900 nanometers, 1200 nanometers, 1500 nanometers, 1800 nanometers, 2000 nanometers, 2300 nanometers, 2500 nanometers, 2700 nanometers, or 3000 nanometers.

[0044] In a specific embodiment, the first sacrificial bump 402 may be made of silicon dioxide, phosphosilicate glass, borosilicate glass, photoresist or polymethyl methacrylate, and may be formed by PECVD, spin coating, spraying or printing processes.

[0045] like Figure 3 As shown, a first protective layer 500 is then formed on the first encapsulation layer 300, and the first protective layer 500 is patterned to form a plurality of first openings 501, each of which is correspondingly provided with one of the hemispherical grooves 401.

[0046] In a specific embodiment, the first protective layer 500 and the first sacrificial bump 402 are made of different materials. Therefore, in subsequent processes, the first sacrificial bump 402 can be removed by selective etching while the first protective layer 500 is retained.

[0047] In a specific embodiment, the first protective layer 500 may be silicon nitride or aluminum oxide, and is formed by PECVD or ALD process. The first protective layer 500 is then patterned by dry etching or wet etching process to form a plurality of first openings 501, each of which is correspondingly provided with a hemispherical groove 401.

[0048] like Figure 4As shown, a plurality of second hemispherical sacrificial bumps 502 are then formed, each second hemispherical sacrificial bump 502 being disposed in correspondence with a corresponding first sacrificial bump 402, and a portion of each second hemispherical sacrificial bump 502 being embedded in a corresponding first opening 501.

[0049] In a specific embodiment, the material of the second hemispherical sacrificial bump 502 can be silicon dioxide, phosphosilicate glass, borosilicate glass, photoresist, or polymethyl methacrylate, and then formed by PECVD, spin coating, spraying, or printing processes. Furthermore, multiple second hemispherical sacrificial bumps 502 are formed by patterning. More specifically, the first sacrificial bump 402 and the second hemispherical sacrificial bump 502 are made of the same material, and the first sacrificial bump 402 and the second hemispherical sacrificial bump 502 can be removed simultaneously by a one-step etching process.

[0050] like Figure 5 As shown, a second protective layer 600 is then formed on the first encapsulation layer 300, and the second protective layer 600 is patterned to form a plurality of second openings 601, each second opening 601 being correspondingly disposed with a corresponding second hemispherical sacrificial bump 502.

[0051] In a specific embodiment, the first protective layer 500 and the second protective layer 600 are made of the same material. The second protective layer 600 can be silicon nitride or aluminum oxide, and is formed by PECVD or ALD process. The second protective layer 600 is then patterned by dry etching or wet etching process to form a plurality of second openings 601, each second opening 601 corresponding to a corresponding second hemispherical sacrificial bump 502.

[0052] like Figure 6 As shown, each of the first sacrificial bumps 402 and each of the second hemispherical sacrificial bumps 502 are then removed.

[0053] In a specific embodiment, each of the first sacrificial bumps 402 and each of the second hemispherical sacrificial bumps 502 are removed by a selective etching process, thereby retaining the first protective layer 500 and the second protective layer 600.

[0054] like Figure 6 As shown, a corresponding spherical light scattering bump 700 is then formed through each of the second opening 601 and each of the first opening 501, the spherical light scattering bump 700 wrapping a portion of the first protective layer 500.

[0055] In a specific embodiment, the spherical light scattering bump 700 includes a resin matrix and light scattering particles. The spherical light scattering bump is formed by a slot coating process, a scraping process, or a screen printing process. More specifically, the resin matrix can be epoxy resin, PMMA, unsaturated polyester, or silicone resin, and the light scattering particles can be silicon dioxide particles, titanium dioxide particles, zinc sulfide particles, or zinc oxide particles.

[0056] like Figure 7 As shown, the second protective layer 600 of each of the light-emitting diode chip package structures is then removed.

[0057] In a specific embodiment, the second protective layer 600 is removed by a wet etching process, thereby causing the plurality of spherical light scattering bumps 700 to protrude from the light-emitting diode chip package structure.

[0058] In a specific embodiment, in the step of removing the second protective layer 600 of each of the light-emitting diode chip package structures, the etching time is controlled to avoid etching the first protective layer 500.

[0059] like Figure 8 As shown, the first encapsulation layer 300 is then cut to form a plurality of light-emitting diode chip encapsulation structures 800.

[0060] In a specific embodiment, the first encapsulation layer 300 is cut using a laser cutting process or a mechanical cutting process to form a plurality of light-emitting diode chip encapsulation structures 800.

[0061] In a specific embodiment, after the first encapsulation layer 300 is cut, the carrier substrate 100 is removed.

[0062] like Figure 8 As shown, the present invention also proposes a light-emitting diode chip packaging structure 800, which is prepared by the above-described method for preparing a light-emitting diode chip packaging structure.

[0063] In other preferred technical solutions, the present invention provides a method for fabricating a light-emitting diode chip packaging structure, comprising: A carrier substrate is provided, on which a plurality of light-emitting diode chips are disposed. Each light-emitting diode chip includes a growth substrate, an N-type semiconductor layer, a light-emitting layer, a P-type semiconductor layer, a first electrode, and a second electrode.

[0064] A first encapsulation layer is formed on the carrier substrate, and the first encapsulation layer is planarized to expose the growth substrate of each of the light-emitting diode chips.

[0065] Next, a plurality of hemispherical grooves are formed on the surface of the growth substrate of each of the light-emitting diode chips.

[0066] Next, the first sacrificial protrusions are filled into the plurality of hemispherical grooves respectively.

[0067] Next, a first protective layer is formed on the first encapsulation layer, and the first protective layer is patterned to form a plurality of first openings, each of which is corresponding to one of the hemispherical grooves.

[0068] Next, a plurality of second hemispherical sacrificial bumps are formed, each second hemispherical sacrificial bump being configured in correspondence with a corresponding first sacrificial bump, and a portion of each second hemispherical sacrificial bump being embedded in a corresponding first opening.

[0069] Next, a second protective layer is formed on the first encapsulation layer, and the second protective layer is patterned to form a plurality of second openings, each second opening being configured to correspond to a corresponding second hemispherical sacrificial bump.

[0070] Next, remove each of the first sacrificial bumps and each of the second hemispherical sacrificial bumps.

[0071] Then, a corresponding spherical light-scattering bump is formed through each of the second openings and each of the first openings.

[0072] Next, the second protective layer of each of the light-emitting diode chip package structures is removed.

[0073] Next, the first encapsulation layer is cut to form a multi-LED chip encapsulation structure.

[0074] In a more preferred technical solution, before the multiple light-emitting diode chips are disposed on the carrier substrate, a temporary adhesive layer is disposed on the carrier substrate, so that the first electrode and the second electrode of each light-emitting diode chip are respectively embedded in the temporary adhesive layer.

[0075] In a more preferred technical solution, the plurality of hemispherical grooves formed on the surface of the growth substrate of each light-emitting diode chip are arranged in multiple rows, and the plurality of hemispherical grooves in adjacent rows are staggered.

[0076] In a more preferred technical solution, the first protective layer and the second protective layer are made of the same material, the first sacrificial bump and the second hemispherical sacrificial bump are made of the same material, and the first protective layer and the first sacrificial bump are made of different materials.

[0077] In a more preferred technical solution, the depth of the hemispherical groove is 300-1500 nanometers, and the distance between two adjacent hemispherical grooves in each row is 900-3000 nanometers.

[0078] In a more preferred technical solution, in the step of removing the second protective layer of each of the light-emitting diode chip package structures, the etching time is controlled to avoid etching the first protective layer.

[0079] In a more preferred technical solution, the spherical light scattering bump includes a resin matrix and light scattering particles, and is formed by a slit coating process, a scraping process, or a screen printing process.

[0080] In a more advanced technical solution, the spherical light-scattering bumps enclose a portion of the first protective layer.

[0081] In a more preferred technical solution, the present invention also proposes a light-emitting diode (LED) chip packaging structure, wherein the LED chip packaging structure is prepared by the above-described method for preparing an LED chip packaging structure.

[0082] In the method for fabricating a light-emitting diode (LED) chip packaging structure of the present invention, the LED chip is pre-packaged to form multiple spherical light-scattering bumps in the growth substrate of each LED chip. The spherical light-scattering bumps greatly improve the light extraction efficiency of the LED chip. In the process of forming the spherical light-scattering bumps, multiple hemispherical grooves are formed on the surface of the growth substrate, and first sacrificial bumps are filled in the multiple hemispherical grooves respectively. Then, a first protective layer with multiple first openings is formed, each first opening corresponding to a corresponding hemispherical groove. Next, multiple second hemispherical sacrificial bumps are formed, each second hemispherical sacrificial bump corresponding to a corresponding first sacrificial bump. Then, a second protective layer with multiple second openings is formed. Each first sacrificial bump and each second hemispherical sacrificial bump are removed, and a corresponding spherical light-scattering bump is formed through each second opening and each first opening. The spherical light-scattering bumps formed in the above manner have a first protective layer embedded in each spherical light-scattering bump, which greatly improves the stability of the spherical light-scattering bumps.

[0083] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for fabricating a light-emitting diode chip packaging structure, characterized in that: include: A carrier substrate is provided, on which a plurality of light-emitting diode chips are disposed. Each light-emitting diode chip includes a growth substrate, an N-type semiconductor layer, a light-emitting layer, a P-type semiconductor layer, a first electrode, and a second electrode. A first encapsulation layer is formed on the carrier substrate, and the first encapsulation layer is planarized to expose the growth substrate of each of the light-emitting diode chips; Next, a plurality of hemispherical grooves are formed on the surface of the growth substrate for each of the light-emitting diode chips; Next, the first sacrificial protrusions are filled into the plurality of hemispherical grooves respectively; Next, a first protective layer is formed on the first encapsulation layer, and the first protective layer is patterned to form a plurality of first openings, each of which is corresponding to one of the hemispherical grooves. Next, a plurality of second hemispherical sacrificial bumps are formed, each second hemispherical sacrificial bump being configured in correspondence with a corresponding first sacrificial bump, and a portion of each second hemispherical sacrificial bump being embedded in a corresponding first opening; Next, a second protective layer is formed on the first encapsulation layer, and the second protective layer is patterned to form a plurality of second openings, each second opening being corresponding to a second hemispherical sacrificial bump; Next, remove each of the first sacrificial bumps and each of the second hemispherical sacrificial bumps; Then, a corresponding spherical light-scattering bump is formed through each of the second openings and each of the first openings; Next, the second protective layer of each of the light-emitting diode chip package structures is removed; Next, the first encapsulation layer is cut to form a multi-LED chip encapsulation structure.

2. The method for fabricating a light-emitting diode chip packaging structure according to claim 1, characterized in that: Before a plurality of light-emitting diode chips are disposed on the carrier substrate, a temporary adhesive layer is disposed on the carrier substrate, thereby embedding the first electrode and the second electrode of each light-emitting diode chip into the temporary adhesive layer.

3. The method for fabricating a light-emitting diode chip packaging structure according to claim 1, characterized in that: The hemispherical grooves formed on the surface of the growth substrate of each LED chip are arranged in multiple rows, with the hemispherical grooves in adjacent rows being staggered.

4. The method for fabricating a light-emitting diode chip packaging structure according to claim 1, characterized in that: The first protective layer and the second protective layer are made of the same material, the first sacrificial bump and the second hemispherical sacrificial bump are made of the same material, and the first protective layer and the first sacrificial bump are made of different materials.

5. The method for fabricating a light-emitting diode chip packaging structure according to claim 3, characterized in that: The depth of the hemispherical groove is 300-1500 nanometers, and the distance between two adjacent hemispherical grooves in each row is 900-3000 nanometers.

6. The method for fabricating a light-emitting diode chip packaging structure according to claim 1, characterized in that: In the step of removing the second protective layer from each of the light-emitting diode chip package structures, the etching time is controlled to avoid etching the first protective layer.

7. The method for fabricating a light-emitting diode chip packaging structure according to claim 1, characterized in that: The spherical light scattering bump comprises a resin matrix and light scattering particles, and is formed by a slit coating process, a scraping process, or a screen printing process.

8. The method for fabricating a light-emitting diode chip packaging structure according to claim 1, characterized in that: The spherical light-scattering bumps enclose a portion of the first protective layer.

9. A light-emitting diode chip packaging structure, characterized in that: The light-emitting diode chip packaging structure is prepared by the method for preparing the light-emitting diode chip packaging structure according to any one of claims 1-8.

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