Light-emitting chip manufacturing method and light-emitting chip

Abstract

The present invention discloses a method for manufacturing a light-emitting chip, firstly reducing the thickness of a first substrate having a porous structure to a target thickness, then filling quantum dots into at least part of the holes of the first substrate after the thickness is reduced to the target thickness, and bonding the first substrate to a second substrate having a plurality of crystal grains, and converting the first light color emitted by the crystal grains into the target light color through quantum dots. The present invention can avoid the failure or degradation of quantum dots due to the influence of high temperature conditions, grinding fluid, polishing fluid, etc. during grinding and polishing during the thinning of the first substrate, thereby ensuring the color conversion efficiency of quantum dots. At the same time, the present invention also provides a light-emitting chip manufactured by the manufacturing method.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a light-emitting chip manufacturing method and a light-emitting chip. Background Art

[0002] Quantum dot (QD) materials have excellent optoelectronic properties, such as high color purity, adjustable luminescent color and high fluorescence quantum yield. At present, the display application of quantum dot materials is mainly based on their color conversion characteristics. Usually, ultraviolet light or blue light is used as the excitation source, and green or red light quantum dots are used to convert the excitation light into the required green or red light.

[0003] However, when quantum dots come into contact with moisture or heat, their fluorescence performance will drop sharply and their stability will also be reduced. The fact that quantum dots are afraid of water and heat greatly restricts the process of quantum dot light-emitting chips. Summary of the invention

[0004] The object of the present invention is to provide a method for manufacturing a light-emitting chip that can prevent factors such as temperature and moisture from affecting quantum dots, and a light-emitting chip manufactured using the manufacturing method.

[0005] To achieve the above object, the present invention provides a method for manufacturing a light-emitting chip, comprising:

[0006] Thinning the first substrate having a porous structure to a target thickness;

[0007] filling quantum dots into at least a portion of the holes of the first substrate after the thickness is reduced to the target thickness,

[0008] And, the first substrate after being thinned to the target thickness is bonded to a second substrate having a plurality of crystal grains, and the first light color emitted by the crystal grains is converted into the target light color through the quantum dots.

[0009] In some embodiments, quantum dots are first filled into at least a portion of the holes of the first substrate after the thickness is thinned to the target thickness, and then the first substrate filled with quantum dots is bonded to the second substrate.

[0010] In some embodiments, the first substrate has a first surface and a second surface relative to each other, the porous structure is disposed on the first surface of the first substrate, the second substrate has a third surface and a fourth surface relative to each other, and the plurality of grains are disposed on the third surface of the second substrate; the first surface of the first substrate is bonded to the third surface of the second substrate.

[0011] In some embodiments, the first substrate thinned to the target thickness is first bonded to the second substrate, and then quantum dots are filled into at least a portion of the holes of the first substrate bonded to the second substrate.

[0012] In some embodiments, the first substrate has a first surface and a second surface relative to each other, the porous structure is disposed on the first surface of the first substrate, the second substrate has a third surface and a fourth surface relative to each other, and the plurality of grains are disposed on the third surface of the second substrate; the second surface of the first substrate is bonded to the third surface of the second substrate.

[0013] In some embodiments, the light-emitting chip manufacturing method also includes: preparing the second substrate having multiple grains, including: providing a growth substrate, preparing multiple grains on the growth substrate; bonding and fixing the multiple grains to a second substrate on one side away from the growth substrate; peeling off the growth substrate to obtain the second substrate having multiple grains.

[0014] In some embodiments, the plurality of crystal grains are bonded and fixed to the second substrate, and after bonding the first substrate having the porous structure to the second substrate having the plurality of crystal grains, the process further includes: releasing the bonding between the plurality of crystal grains and the second substrate.

[0015] In some embodiments, after filling quantum dots into at least part of the holes of the first substrate and releasing the bonding between the plurality of grains and the second substrate, the method further includes: cutting along the gaps between the grains to obtain a light-emitting chip including at least one of the grains.

[0016] In some embodiments, the first substrate has a first surface and a second surface opposite to each other, the porous structure is disposed on the first surface of the first substrate, and the step of thinning the thickness of the first substrate having a plurality of holes to a target thickness includes: providing a support structure, applying wax to fix the first surface of the first substrate to the support structure; grinding and polishing the second surface of the first substrate to thin the thickness of the first substrate to a target thickness; and removing the wax to separate the first surface of the first substrate from the support structure.

[0017] In some embodiments, the warpage value of the first substrate having the plurality of holes is less than or equal to 35 micrometers.

[0018] To achieve the above object, the present invention further provides a light-emitting chip, which is manufactured using the manufacturing method described above.

[0019] Compared with the prior art, the present invention firstly thins the thickness of the first substrate with a porous structure to a target thickness, and then performs quantum dot filling and bonding of the first substrate to a second substrate with multiple grains. This can avoid the failure of quantum dots or performance degradation caused by high temperature conditions, grinding fluid, polishing fluid, etc. during grinding and polishing during the thinning of the first substrate, thereby ensuring the color conversion efficiency of the quantum dots. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 1 is a schematic diagram of a process of manufacturing a light-emitting chip according to an embodiment of the present invention.

[0021] Figure 2 FIG. 4 is a schematic diagram of a process of manufacturing a light-emitting chip according to another embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to explain the content, structural features, achieved purposes and effects of the present invention in detail, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The technical solution of the embodiment of the present invention is described in detail below with reference to the accompanying drawings:

[0024] Embodiment 1:

[0025] See also Figure 1 , a method for manufacturing a light-emitting chip provided by an embodiment of the present invention includes the following steps S1-S5.

[0026] S1, providing a first substrate 2 having a porous structure 1, such as Figure 1 As shown in (a1); and the thickness of the first substrate 2 having the porous structure 1 is thinned to a target thickness, and the first substrate 2 after thinning to the target thickness is as shown in Figure 1 As shown in (a4).

[0027] Among them, the holes of the porous structure 1 account for more than 70% of the surface area of ​​the entire porous structure 1, the diameter of the hole is 500nm~1.5um, and the depth of the hole is 8-10um. The light can be continuously reflected in the hole, which can achieve a better light color conversion effect.

[0028] In one embodiment, the warpage value of the first substrate 2 having the porous structure 1 is less than or equal to 35 microns. Since the warpage value of the first substrate 2 is small, the thickness of the first substrate 2 is thinned to the target thickness before filling the quantum dots 7 and bonding the first substrate 2 to the second substrate 5 having the plurality of grains 4, and cracking will not occur during the thinning process due to the small overall thickness of the first substrate 2 and the weak strength and stability.

[0029] In one embodiment, a thickened growth substrate (such as a sapphire substrate, a silicon carbide substrate, etc.) is first provided, and the thickness of the thickened growth substrate can be, for example, 800um; then, a thickened AlN buffer layer is grown on the growth substrate by physical vapor deposition (PVD), and the thickness of the AlN buffer layer can be, for example, 200nm; then, an N-GaN epitaxial layer is grown on the AlN buffer layer by hydride vapor phase epitaxy (HVPE), and the thickness of the N-GaN epitaxial layer can be, for example, 5um; thus, a substrate without holes is prepared, and since the thickness of the AlN buffer layer is relatively thick, the stress effect when growing the N-GaN epitaxial layer can be reduced, thereby reducing the warpage value of the manufactured substrate; then, a plurality of holes are formed in the N-GaN epitaxial layer of the substrate by laser etching, electrochemical etching, photolithography, etc., to obtain a first substrate 2 with a warpage value less than or equal to 35 microns.

[0030] The first substrate 2 has a first surface (i.e., the surface of the N-GaN epitaxial layer facing away from the growth substrate) and a second surface (i.e., the surface of the growth substrate facing away from the N-GaN epitaxial layer), and the porous structure 1 is disposed on the first surface of the first substrate 2. In one embodiment, when thinning the first substrate 2, firstly, a support structure is provided, and wax is applied to fix the first surface of the first substrate 2 (the porous structure 1) to the support structure. The waxed first substrate 2 is as follows: Figure 1 Then, the second surface of the first substrate 2 is ground and polished by a polishing and grinding device, so that the thickness of the first substrate 2 is reduced to a target thickness. The thinned first substrate 2 is as shown in Figure 1 Then, the wax 3 is removed to separate the first surface of the first substrate 2 from the support structure. Specifically, the wax can be cleaned with a wax removal solution, and then the first substrate 2 is dried. After the wax is removed, the first substrate 2 is as shown in FIG. Figure 1 As shown in (a4).

[0031] In one embodiment, before thinning the first substrate 2, the total thickness of the first substrate 2 having the porous structure 1 is about 600-800 um, and after thinning the first substrate 2, the total thickness of the first substrate 2 having the porous structure 1 is less than 100 um, that is, the target thickness is less than 100 um. Of course, in the specific implementation, the specific thickness of the first substrate 2 before and after thinning is not limited.

[0032] S2, bonding the first substrate 2 after the thickness is reduced to the target thickness to a second substrate 5 having a plurality of crystal grains 4, the crystal grains 4 being used to emit a first light color, and the structure obtained by bonding the first substrate 2 to the second substrate 5 having a plurality of crystal grains 4 is as shown Figure 1 As shown in (c1).

[0033] A bonding glue 6, such as a 3-5 um bonding glue, can be spin-coated on the second surface of the first substrate 2 by using a glue spreader. Figure 1 When the bonding adhesive 6 is spin-coated, the rotation speed of the glue spreader can be, for example, 3500-4500 RPM, the spin-coating time can be, for example, 2 minutes, the bonding adhesive 6 can be a thermal curing adhesive, a UV curing adhesive, etc., and the first substrate 2 thinned to a target thickness is bonded to the second substrate 5 having a plurality of grains 4 by the bonding adhesive 6.

[0034] Of course, a layer of bonding glue may also be spin-coated on the surface of the second substrate 5 having the plurality of crystal grains 4 for bonding with the first substrate 2 .

[0035] In one embodiment, when the first substrate 2 after the thickness is thinned to the target thickness is bonded to the second substrate 5 having multiple crystal grains 4, the bonding glue 6 used is a heat-curing glue, and the bonding temperature is 80-150°C. Since the higher the temperature, the shorter the bonding curing time required, the bonding time can be more than 20 minutes. Since the quantum dots 7 have not been injected into the holes at this time, the high temperature will not affect the quantum dots 7. In one embodiment, when the first substrate 2 after the thickness is thinned to the target thickness is bonded to the second substrate 5 having multiple crystal grains 4, the bonding glue 6 used is a UV curing glue with an energy greater than 1000mj to achieve rapid bonding of the first substrate 2 and the second substrate 5 having multiple crystal grains 4. Similarly, since the quantum dots 7 have not been injected into the holes, the large energy will not affect the quantum dots 5.

[0036] In one embodiment, a plurality of crystal grains 4 are bonded to a second substrate 5, and the second substrate 5 may be a substrate with adhesive on one side, such as a glass substrate with adhesive on one side. The crystal grains 4 may be crystal grains capable of emitting blue light.

[0037] In some embodiments, the second substrate 5 having a plurality of crystal grains 4 is prepared in the following manner: first, a growth substrate 8 is provided, and a plurality of crystal grains 4 are prepared on the growth substrate 8, such as a sapphire substrate. Figure 1 Then, in a vacuum environment, the side of the plurality of grains 4 facing away from the growth substrate 8 is bonded and fixed to the second substrate 5, as shown in (b1). Figure 1 Finally, the growth substrate 8 is peeled off to obtain a second substrate 5 having a plurality of crystal grains 4, as shown in FIG. Figure 1 As shown in (b3).

[0038] S3, filling quantum dots 7 into at least part of the holes of the first substrate 2 bonded to the second substrate 5 having a plurality of crystal grains 4, and converting the first light color emitted by the crystal grains 4 into the target light color through the quantum dots 7. Figure 1 As shown in (c2).

[0039] The quantum dots 7 may be quantum dots that convert the first light color emitted by the crystal grain 4 into red light, or may be quantum dots that convert the first light color emitted by the crystal grain 4 into green light, etc. The first light color emitted by the crystal grain 4 may be, for example, blue light, etc.

[0040] All holes in the first substrate 2 may be filled with quantum dots 7, and all grains 4 corresponding to the manufactured light-emitting chip may have their first light color emitted converted into the target light color through the quantum dots 7; or only some holes in the first substrate 2 may be filled with quantum dots 7, and some grains 4 corresponding to the manufactured light-emitting chip may have their first light color emitted converted into the target light color through the quantum dots 7, while some grains 4 may remain in the original light color of emitting the first light color because no quantum dots 7 are arranged on the light-emitting side.

[0041] S4, disconnecting the plurality of crystal grains 4 from the second substrate 5, and obtaining a light-emitting module including the plurality of crystal grains 4 and the quantum dots 7, such as Figure 1 As shown in (c3). The connection between the plurality of dies 4 and the second substrate 5 is released to remove the second substrate 5, so as to facilitate cutting of the light emitting module in the subsequent step S5, and at the same time, the thickness of the manufactured light emitting chip is also made thinner. Of course, in some embodiments, the step S4 can also be omitted.

[0042] S5 , cutting the light-emitting module along the gaps between the crystal grains 4 to obtain a light-emitting chip including at least one crystal grain 4 .

[0043] The light emitting chip may include only one die 4, such as Figure 1As shown in (c4). The light-emitting chip may also include, for example, three crystal grains. For example, the first light color emitted by the crystal grains is blue light. The hole corresponding to one of the crystal grains in the light-emitting chip is filled with red light quantum dots, the hole corresponding to one of the crystal grains is filled with green light quantum dots, and the hole corresponding to one of the crystal grains is not filled with quantum dots. The light-emitting chip can realize RGB full-color display.

[0044] In the above embodiment, the porous structure 1 is arranged on the first surface of the first substrate 2, the second substrate 5 has a third surface and a fourth surface opposite to each other, the plurality of crystal grains 4 are arranged on the third surface of the second substrate 5, and the second surface of the first substrate 2 is bonded to the third surface of the second substrate 5. After the first substrate 2 is bonded to the second substrate 5 having the plurality of crystal grains 4, the porous structure 1 of the first substrate 2 is located on the side away from the second substrate 5 having the plurality of crystal grains 4, and the porous structure 1 is exposed, so the quantum dot injection hole step can be performed after the first substrate 2 is bonded to the second substrate 5 having the plurality of crystal grains 4, and the quantum dot 7 is not affected by the grinding and polishing in step S1 to thin the first substrate 2, such as the contact corrosion of the grinding liquid and the polishing liquid, the influence of the heat and water generated by the grinding and polishing, the influence of the temperature during the waxing and dewaxing process, and the corresponding processing conditions and bonding materials when the first substrate 2 is bonded to the second substrate 5 having the plurality of crystal grains 4 in step S2, which can effectively ensure the performance of the final quantum dot 7, and further ensure the color conversion efficiency of the quantum dot 7.

[0045] Embodiment 2:

[0046] See also Figure 2 , a method for manufacturing a light-emitting chip provided by an embodiment of the present invention includes the following steps S1-S5.

[0047] S1, providing a first substrate 2 having a porous structure 1, and thinning the first substrate 2 having the porous structure 1 to a target thickness. After thinning to the target thickness, the first substrate 2 is as follows: Figure 2 As shown in (a4).

[0048] S2, filling quantum dots 7 into at least part of the holes of the first substrate 2 after the thickness is reduced to the target thickness, and the first substrate 2 after the quantum dots 7 are filled is as follows Figure 2 As shown in (a5).

[0049] S3, bonding the first substrate 2 filled with quantum dots 7 to the second substrate 5 having a plurality of crystal grains 4, the crystal grains 4 being used to emit a first light color, converting the first light color into a target light color through the quantum dots 7, and the second substrate 5 having a plurality of crystal grains 4 being used to emit a first light color. Figure 2 As shown in (b3), the structure obtained by bonding the first substrate 2 and the second substrate 5 having a plurality of crystal grains 4 is as shown in FIG. Figure 2 As shown in (c1).

[0050] exist Figure 2 In the embodiment shown, the first substrate 2 has a first surface and a second surface opposite to each other, the porous structure 1 is arranged on the first surface of the first substrate 2, the second substrate 5 has a third surface and a fourth surface opposite to each other, a plurality of crystal grains 4 are arranged on the third surface of the second substrate 5, and the first surface of the first substrate 2 filled with quantum dots 7 is bonded to the third surface of the second substrate 5, as shown in FIG. Figure 2 As shown in (c1).

[0051] When bonding the first surface of the first substrate 2 to the third surface of the second substrate 5, a layer of bonding glue 6 may be firstly spin-coated on the first surface of the first substrate 2 using a glue spreader, such as Figure 2 As shown in (a6), the first substrate 2 is bonded to the third surface of the second substrate 5 by means of a bonding adhesive 6. Alternatively, a bonding adhesive may be spin-coated on the third surface of the second substrate 5 having a plurality of crystal grains 4 by means of a coating machine.

[0052] S4, disconnecting the plurality of crystal grains 4 from the second substrate 5, and obtaining a light-emitting module including the plurality of crystal grains 4 and the quantum dots 7, such as Figure 2 As shown in (c2).

[0053] S5, cutting the light-emitting module along the gaps between the crystal grains 4 to obtain a light-emitting chip including at least one crystal grain 4, such as Figure 1 As shown in (c3).

[0054] Different from the above-mentioned embodiment 1, in this embodiment, quantum dots 7 are first filled into at least part of the holes of the first substrate 2 after the thickness is thinned to the target thickness, and then the first substrate 2 filled with quantum dots 7 is bonded to the second substrate 5 having a plurality of grains 4. Since the quantum dot injection step is performed after thinning the first substrate 2 and before bonding the first substrate 2 to the second substrate 5 having a plurality of grains 4, it is not required to expose the holes of the first substrate 2. Therefore, the hole surface (first surface) of the first substrate 2 can be bonded to the second substrate 5 having a plurality of grains 4. After bonding, the distance between the grains 4 and the quantum dots 7 is smaller (no longer separated by the portion of the first substrate 2 where the porous structure 1 is not provided, such as the growth substrate), which can better avoid light leakage and improve the color conversion effect. At the same time, the portion of the first substrate 2 where the porous structure 1 is not provided covers the side of the quantum dots 7 away from the grains 4, which can protect the quantum dots 7. Of course, in some embodiments, when the first substrate 2 is bonded to the second substrate 5 having a plurality of crystal grains 4, the hole surface of the first substrate 2 may still be on the side away from the crystal grains 4, so as to further reduce the influence of the corresponding processing conditions and bonding materials on the quantum dots 7 during bonding.

[0055] As for the more specific manufacturing process of the light emitting chip, please refer to the description in the above embodiment 1, which will not be repeated here.

[0056] In summary, the present invention first thins the thickness of the first substrate 2 having a porous structure 1 to a target thickness, and then performs quantum dot filling and bonding of the first substrate 2 to a second substrate 5 having a plurality of grains 4. This can avoid the failure of the quantum dots 7 or degradation of their performance due to the high temperature conditions, grinding fluid, polishing fluid, etc. during grinding and polishing during the thinning process of the first substrate 2, thereby ensuring the color conversion efficiency of the quantum dots 7.

[0057] The above disclosure is only a preferred embodiment of the present invention, which cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are all within the scope of the present invention.

Claims

1. A method for manufacturing a light-emitting chip, characterized in that: include: Thinning the first substrate having a porous structure to a target thickness, wherein the target thickness is less than 100 um; filling quantum dots into at least a portion of the holes of the first substrate after the thickness is reduced to the target thickness, and bonding the first substrate thinned to the target thickness to a second substrate having a plurality of crystal grains, wherein the first light color emitted by the crystal grains is converted into the target light color by the quantum dots; The steps of preparing the first substrate having a porous structure include: providing a thickened growth substrate; A thickened AlN buffer layer is grown on the growth substrate by physical vapor deposition; Then, an N-GaN epitaxial layer is grown on the AlN buffer layer by hydride vapor phase epitaxy. Then, a plurality of holes are formed in the N-GaN epitaxial layer of the substrate to obtain a first substrate with a porous structure, wherein the warpage value of the first substrate with the porous structure is less than or equal to 35 micrometers, and the total thickness of the first substrate with the porous structure is 600-800um; Wherein, preparing the second substrate having a plurality of grains comprises: Providing a growth substrate, and preparing a plurality of crystal grains on the growth substrate; Bonding and fixing the side of the plurality of crystal grains away from the growth substrate to a second substrate; Peeling off the growth substrate to obtain the second substrate having a plurality of crystal grains; After bonding the first substrate having the multi-porous structure to the second substrate having the plurality of grains, the method further includes: Release the bonding between the plurality of dies and the second substrate; After filling quantum dots into at least part of the holes of the first substrate and releasing the bonding between the plurality of grains and the second substrate, the method further includes: Cutting is performed along the gaps between the crystal grains to obtain a light-emitting chip including at least one crystal grain.

2. The method for manufacturing a light-emitting chip according to claim 1, characterized in that: First, quantum dots are filled into at least a portion of the holes of the first substrate after the thickness is thinned to the target thickness, and then the first substrate filled with quantum dots is bonded to the second substrate.

3. The method for manufacturing a light-emitting chip according to claim 2, characterized in that: The first substrate has a first surface and a second surface opposite to each other, the porous structure is arranged on the first surface of the first substrate, the second substrate has a third surface and a fourth surface opposite to each other, the plurality of crystal grains are arranged on the third surface of the second substrate; the first surface of the first substrate is bonded to the third surface of the second substrate.

4. The method for manufacturing a light-emitting chip according to claim 1, characterized in that: First, the first substrate thinned to the target thickness is bonded to the second substrate, and then quantum dots are filled into at least a portion of the holes of the first substrate bonded to the second substrate.

5. The method for manufacturing a light-emitting chip according to claim 4, characterized in that: The first substrate has a first surface and a second surface opposite to each other, the porous structure is arranged on the first surface of the first substrate, the second substrate has a third surface and a fourth surface opposite to each other, the plurality of crystal grains are arranged on the third surface of the second substrate; the second surface of the first substrate is bonded to the third surface of the second substrate.

6. The method for manufacturing a light-emitting chip according to claim 1, characterized in that: The first substrate has a first surface and a second surface opposite to each other, the porous structure is disposed on the first surface of the first substrate, and the step of thinning the thickness of the first substrate having a plurality of holes to a target thickness comprises: Providing a support structure, and applying wax to fix the first surface of the first substrate to the support structure; Grinding and polishing the second surface of the first substrate to reduce the thickness of the first substrate to a target thickness; The wax is removed to separate the first surface of the first substrate from the support structure.

7. A light-emitting chip, characterized in that: The light-emitting chip is manufactured by the manufacturing method according to any one of claims 1 to 6.

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