CN114914347A - Light-emitting chip manufacturing method and light-emitting chip - Google Patents

Abstract

The invention discloses a method for manufacturing a light-emitting chip. First, the thickness of a first substrate having a porous structure is reduced to a target thickness, and then at least part of the holes of the first substrate after the thickness is reduced to the target thickness are filled with quantum and bonding the first substrate with 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. In the process of thinning the first substrate, the invention can avoid the failure or performance degradation of quantum dots caused by the influence of high temperature conditions during grinding and polishing, grinding liquid, polishing liquid, etc., and ensure 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

Light-emitting chip manufacturing method and light-emitting chip

technical field

The present invention relates to the field of display technology, in particular to a method for manufacturing a light-emitting chip and a light-emitting chip.

Background technique

Quantum dot (QD) materials have the characteristics of high color purity, tunable emission color and high fluorescence quantum yield due to their excellent optoelectronic properties. At present, the display application of quantum dot materials is mainly based on their color conversion properties, usually , using ultraviolet light or blue light as the excitation source, and using green light and red light quantum dots to convert the excitation light into the desired green or red light.

However, when quantum dots are exposed to moisture and heat, the fluorescence performance will drop sharply, and the stability will also be reduced.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a light-emitting chip fabrication method that can avoid factors such as temperature, moisture and other factors affecting quantum dots, and a light-emitting chip fabricated by the fabrication method.

To achieve the above purpose, the present invention provides a method for manufacturing a light-emitting chip, comprising:

reducing the thickness of the first substrate with the porous structure to a target thickness;

filling quantum dots into at least part of the holes of the first substrate after the thickness is reduced to the target thickness,

And, the first substrate after the thickness is reduced 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 through the quantum dots light color.

In some embodiments, quantum dots are filled in at least part of the holes of the first substrate after the thickness is reduced to the target thickness, and then the first substrate and the second substrate filled with quantum dots are filled with quantum dots. Bond.

In some embodiments, the first substrate has an opposite first surface and a second surface, the porous structure is disposed on the first surface of the first substrate, and the second substrate has an opposite third surface and the fourth surface, 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.

In some embodiments, the first substrate after being thinned to the target thickness is bonded to the second substrate, and then the first substrate after being bonded to the second substrate is bonded to the first substrate. At least some of the holes are filled with quantum dots.

In some embodiments, the first substrate has an opposite first surface and a second surface, the porous structure is disposed on the first surface of the first substrate, and the second substrate has an opposite third surface and a fourth surface, 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.

In some embodiments, the light-emitting chip manufacturing method further includes: preparing the second substrate having a plurality of crystal grains, including: providing a growth substrate, and preparing a plurality of crystal grains on the growth substrate; Adhering and fixing the side of the plurality of crystal grains away from the growth substrate with a second substrate; peeling off the growth substrate to obtain the second substrate with the plurality of crystal grains.

In some embodiments, the plurality of die and the second substrate are adhered and fixed, and the first substrate having the porous structure and the second substrate having the plurality of die are bonded together. After the bonding, the method further includes: releasing the bonding between the plurality of die and the second substrate.

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 die and the second substrate, the method further includes: along the gap between the die The gap is cut to obtain a light-emitting chip containing at least one of the die.

In some embodiments, the first substrate has opposite first and second surfaces, the porous structure is disposed on the first surface of the first substrate, and the first substrate will have a plurality of holes Thinning the thickness of the first substrate to the target thickness includes: providing a support structure, waxing to fix the first surface of the first substrate and the support structure; grinding and polishing the second surface of the first substrate to The thickness of the first substrate is reduced to a target thickness; the wax is removed to separate the first side of the first substrate from the support structure.

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

In order to achieve the above object, the present invention also provides a light-emitting chip, the light-emitting chip is manufactured by the above-mentioned manufacturing method.

Compared with the prior art, the present invention firstly reduces the thickness of the first substrate with the porous structure to the target thickness, and then performs quantum dot filling and bonding between the first substrate and the second substrate having a plurality of crystal grains. Bonding can avoid the failure or performance degradation of quantum dots caused by the influence of high temperature conditions during grinding and polishing, grinding fluid, polishing fluid, etc. in the process of thinning the first substrate, so as to ensure the color conversion efficiency of quantum dots.

Description of drawings

FIG. 1 is a schematic process diagram of a method for fabricating a light-emitting chip according to an embodiment of the present invention.

FIG. 2 is a schematic process diagram of a method for fabricating a light-emitting chip according to another embodiment of the present invention.

Detailed ways

In order to describe the content, structural features, achieved objects 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 with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described implementation The examples are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Hereinafter, the technical solutions of the embodiments of the present invention will be described in detail with reference to the accompanying drawings:

Example 1:

Referring to FIG. 1 , a method for fabricating a light-emitting chip provided by an embodiment of the present invention includes the following steps S1-S5.

S1, providing the first substrate 2 with the porous structure 1, as shown in FIG. 1 (a1); and reducing the thickness of the first substrate 2 with the porous structure 1 to the target thickness, and then to the target thickness The resulting first substrate 2 is shown in FIG. 1( a4 ).

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 holes is 500nm-1.5um, the depth of the holes is 8-10um, and the light can be continuously reflected in the holes, which can reach Better light-color conversion effect.

In one embodiment, the warpage value of the first substrate 2 with 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 reduced to The target thickness will not cause cracks during the thinning process because the overall thickness of the first substrate 2 is small and its strength and stability are weak.

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 may be, for example, 800 μm; , PVD) method to grow a thickened AlN buffer layer on the growth substrate, the thickness of the AlN buffer layer can be, for example, 200nm; An N-GaN epitaxial layer is grown on top of the layer, and the thickness of the N-GaN epitaxial layer can be, for example, 5um; so far, a substrate without holes is prepared. Due to the thick AlN buffer layer, the growth of N-GaN can be reduced. The stress of the epitaxial layer can reduce the warpage value of the fabricated substrate; then, multiple holes are formed in the N-GaN epitaxial layer of the substrate by laser etching, electrochemical etching, photolithography, etc. to obtain warpage. The value of the first substrate 2 is less than or equal to 35 microns.

The first substrate 2 has an opposite first side (that is, the side of the N-GaN epitaxial layer facing away from the growth substrate) and a second side (that is, the side of the growth substrate facing away from the N-GaN epitaxial layer), a porous structure 1 is provided on the first surface of the first substrate 2 . In one embodiment, when the first substrate 2 is thinned, first, a support structure is provided, and the first surface (the porous structure 1 ) of the first substrate 2 is fixed with the support structure by waxing. The substrate 2 is shown in (a2) in FIG. 1 ; then, the second surface of the first substrate 2 is ground and polished by a polishing and grinding device, thereby reducing the thickness of the first substrate 2 to the target thickness, and the thinned first substrate 2 The substrate 2 is shown in (a3) in FIG. 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 to remove the The first substrate 2 after waxing is shown in FIG. 1( a4 ).

In one embodiment, before the first substrate 2 is thinned, the total thickness of the first substrate 2 with the porous structure 1 is about 600-800 μm, and after the first substrate 2 is thinned, the first substrate 2 with the porous structure 1 The total thickness of a substrate 2 is less than 100um, that is, the target thickness is less than 100um. Of course, the specific implementation is not limited by the specific thickness of the first substrate 2 before and after the thinning.

S2, the first substrate 2 after the thickness is reduced to the target thickness is bonded to a second substrate 5 having a plurality of die 4, the die 4 is used to emit a first light color, the first substrate 2 is The structure obtained by bonding the crystal grains 4 to the second substrate 5 is shown in FIG. 1 ( c1 ).

It can be to spin a layer of bonding glue 6 on the second surface of the first substrate 2 with a glue dispenser, such as 3-5um bonding glue, and the first substrate 2 after spin-coating a layer of bonding glue 6 is shown in Figure 1 shown in (a5). When the bonding glue 6 is spin-coated, the rotational speed of the glue spinner can be, for example, 3500-4500 RPM, and the spin coating time can be, for example, 2 minutes, and the bonding glue 6 can be heat-curing glue, UV-curing glue, etc., and the thickness is reduced by the bonding glue 6. The first substrate 2 after being thinned to the target thickness is bonded to the second substrate 5 having the plurality of die 4 .

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

In one embodiment, when the first substrate 2 after the thickness is reduced to the target thickness is bonded to the second substrate 5 having a plurality of die 4, the bonding adhesive 6 used is a thermosetting adhesive, and the bonding temperature is 80-150℃, because the higher the temperature, the shorter the bonding curing time is, and the bonding time is more than 20min. 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 reduced to the target thickness is bonded to the second substrate 5 having a plurality of die 4, the bonding adhesive 6 used is UV curing adhesive, and the energy is greater than 1000 mj, so as to To achieve rapid bonding of the first substrate 2 and the second substrate 5 having a plurality of crystal grains 4 , similarly, since the quantum dots 7 have not been injected into the holes, the higher energy will not affect the quantum 5 .

In one embodiment, the plurality of die 4 are bonded on the 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 die 4 may be a die capable of emitting blue light.

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, As shown in FIG. 1 (b1); then, the side of the plurality of crystal grains 4 facing away from the growth substrate 8 is bonded and fixed to the second substrate 5 in a vacuum environment, as shown in FIG. 1 (b2); 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. 1 ( b3 ).

S3, filling quantum dots 7 into at least part of the holes of the first substrate 2 after bonding with the second substrate 5 having a plurality of crystal grains 4, and converting the first light color emitted by the crystal grains 4 into a target through the quantum dots 7 Light color, the first substrate 2 after filling the quantum dots 7 is shown in FIG. 1 ( c2 ).

The quantum dots 7 may be quantum dots that convert the first light color emitted by the die 4 into red light, or may be quantum dots that convert the first light color emitted by the die 4 into green light, or the like. The first light color emitted by the die 4 may be, for example, blue light or the like.

It can be that all the holes of the first substrate 2 are filled with quantum dots 7, and all the crystal grains 4 corresponding to the produced light-emitting chip can convert the first light color emitted by the quantum dots 7 into the target light color; The quantum dots 7 may be filled only in part of the holes of the first substrate 2, and some of the crystal grains 4 corresponding to the fabricated light-emitting chip can convert the first light color emitted by the quantum dots 7 into the target light color, and Since the quantum dots 7 are not provided on the light-emitting side, some of the die 4 remain in the original light color that emits the first light color.

S4 , releasing the connection of the plurality of die 4 and the second substrate 5 to obtain a light-emitting module including the plurality of die 4 and the quantum dots 7 , as shown in ( c3 ) in FIG. 1 . Disconnecting the plurality of die 4 from the second substrate 5 to remove the second substrate 5 is convenient for cutting the light-emitting module in the subsequent step S5, and at the same time, the thickness of the fabricated light-emitting chip is thinner. Of course, in some embodiments, this step S4 may also be omitted.

S5 , cutting the light-emitting module along the gaps between the die 4 to obtain a light-emitting chip including at least one die 4 .

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

In the above embodiment, the porous structure 1 is disposed on the first surface of the first substrate 2 , the second substrate 5 has opposite third and fourth surfaces, and the plurality of crystal grains 4 are disposed on the third surface of the second substrate 5 . 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 with 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 step of injecting quantum dots into holes can be performed after the first substrate 2 is bonded to the second substrate 5 having a plurality of crystal grains 4, and the quantum dots 7 are not subjected to grinding and polishing in step S1 to thin the first substrate 2. For example, the contact corrosion of grinding liquid and polishing liquid, the effect of heat and water generated by grinding and polishing, the effect of temperature during waxing and dewaxing, and in step S2, the first substrate 2 with a plurality of crystal grains The influence of the corresponding processing conditions and the bonding material when the second substrate 5 of 4 is bonded can effectively ensure the performance of the final quantum dots 7, and further ensure the color conversion efficiency of the quantum dots 7.

Embodiment 2:

Referring to FIG. 2 , a method for fabricating a light-emitting chip provided by an embodiment of the present invention includes the following steps S1-S5.

S1, providing the first substrate 2 with the porous structure 1, and reducing the thickness of the first substrate 2 with the porous structure 1 to the target thickness, and the first substrate 2 after thinning to the target thickness is shown in FIG. 2 (a4).

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 filling the quantum dots 7 is shown in FIG. 2 ( a5 ).

S3, bonding the first substrate 2 filled with the quantum dots 7 with the second substrate 5 having a plurality of crystal grains 4, the crystal grains 4 are used to emit a first light color, and the quantum dots 7 convert the first light color into For the target light color, the second substrate 5 with a plurality of crystal grains 4 is shown in FIG. 2 ( b3 ), and the structure obtained by bonding the first substrate 2 and the second substrate 5 with a plurality of crystal grains 4 is shown in FIG. 2 (c1).

In the embodiment shown in FIG. 2 , the first substrate 2 has opposite first and second surfaces, the porous structure 1 is disposed on the first surface of the first substrate 2 , and the second substrate 5 has opposite third surfaces and On the fourth surface, 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 the quantum dots 7 is bonded to the third surface of the second substrate 5, as shown in FIG. 2 shown in (c1).

When bonding the first surface of the first substrate 2 and the third surface of the second substrate 5, a layer of bonding glue 6 can be spin-coated on the first surface of the first substrate 2 with a glue dispenser, as shown in Figure 2 As shown in (a6), the first substrate 2 and the third surface of the second substrate 5 are bonded by bonding glue 6 . Alternatively, a layer of bonding glue may be spin-coated on the third surface of the second substrate 5 having the plurality of crystal grains 4 by a glue spinner.

S4 , releasing the connection of the plurality of die 4 and the second substrate 5 to obtain a light emitting module including the plurality of die 4 and the quantum dots 7 , as shown in ( c2 ) in FIG. 2 .

S5 , cutting the light-emitting module along the gaps between the die 4 to obtain a light-emitting chip including at least one die 4 , as shown in (c3) in FIG. 1 .

The difference from the above-mentioned first embodiment is that in this embodiment, the quantum dots 7 are first filled into at least part of the holes of the first substrate 2 after the thickness is reduced to the target thickness, and then the first substrate filled with the quantum dots 7 is filled. The substrate 2 is bonded to the second substrate 5 with the plurality of dies 4 , since the quantum dot implantation step is after the thinning of the first substrate 2 and before the bonding of the first substrate 2 and the second substrate 5 with the plurality of dies 4 , the holes of the first substrate 2 are not required to be exposed, so the hole surface (the first surface) of the first substrate 2 can be bonded to the second substrate 5 having a plurality of crystal grains 4, and the bonded crystal grains 4 and The distance between the quantum dots 7 is smaller (no longer separated by the part 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 effect of color conversion. The part of the substrate 2 that is not provided with the porous structure 1 is covered on the side of the quantum dots 7 away from the crystal 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 die 4, the hole surface of the first substrate 2 may still be on the side away from the die 4, so as to further reduce the The corresponding processing conditions and the influence of bonding materials on quantum dots 7 during small bonding.

As for the more specific manufacturing process of the light-emitting chip, reference may be made to the description in the above-mentioned first embodiment, which will not be repeated here.

To sum up, the present invention firstly reduces the thickness of the first substrate 2 with the porous structure 1 to the target thickness, and then performs quantum dot filling and the first substrate 2 and the second substrate 5 with a plurality of crystal grains 4 . In the process of thinning the first substrate 2, the influence of high temperature conditions during grinding and polishing, grinding liquid, polishing liquid, etc. can cause the quantum dots 7 to fail or deteriorate in performance, and ensure the color conversion efficiency of the quantum dots 7.

The above disclosures are only preferred examples of the present invention, and cannot be used to limit the scope of rights of the present invention. Therefore, the equivalent changes made according to the claims of the present invention all belong to the scope covered by the present invention.

Claims (11)

1. A method for making a light-emitting chip, comprising: reducing the thickness of the first substrate with the porous structure to a target thickness; filling quantum dots into at least part of the holes of the first substrate after the thickness is reduced to the target thickness, And, the first substrate after the thickness is reduced 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 through the quantum dots light color. 2 . The method of manufacturing a light-emitting chip according to claim 1 , wherein at least part of the holes of the first substrate whose thickness is reduced to the target thickness are filled with quantum dots, and then filled with quantum dots. 3 . The first substrate is bonded to the second substrate. 3 . The method for fabricating a light-emitting chip according to claim 2 , wherein the first substrate has an opposite first surface and a second surface, and the porous structure is disposed on the first surface of the first substrate. 4 . , the second substrate has an opposite third surface and a fourth surface, the plurality of crystal grains are arranged on the third surface of the second substrate; the first surface of the first substrate and the second The third side of the substrate is bonded. 4 . The method of manufacturing a light-emitting chip according to claim 1 , wherein the first substrate after thinning to the target thickness is bonded to the second substrate, and then the first substrate is bonded to the second substrate. 5 . Quantum dots are filled in at least part of the holes of the first substrate after the two substrates are bonded. 5 . The method of manufacturing a light-emitting chip according to claim 4 , wherein the first substrate has an opposite first surface and a second surface, and the porous structure is disposed on the first surface of the first substrate. 6 . , the second substrate has an opposite third surface and a fourth surface, the plurality of crystal grains are arranged on the third surface of the second substrate; the second surface of the first substrate and the second The third side of the substrate is bonded. 6. The method for manufacturing a light-emitting chip according to claim 1, further comprising: preparing the second substrate having a plurality of crystal grains, comprising: providing a growth substrate on which a plurality of crystal grains are prepared; bonding and fixing the side of the plurality of crystal grains away from the growth substrate with a second substrate; The growth substrate is peeled off to obtain the second substrate having the plurality of crystal grains. 7 . The method of manufacturing a light-emitting chip according to claim 1 , wherein the plurality of dies are bonded and fixed to the second substrate, After bonding the first substrate with the porous structure and the second substrate with the plurality of crystal grains, the method further includes: The bonding of the plurality of dies and the second substrate is released. 8 . The method for fabricating a light-emitting chip according to claim 7 , wherein quantum dots are filled into at least part of the holes of the first substrate and the bonding between the plurality of dies and the second substrate is released. 9 . After that, also include: Cutting along the gaps between the die to obtain a light-emitting chip including at least one of the die. 9 . The method of manufacturing a light-emitting chip according to claim 1 , wherein the first substrate has a first surface and a second surface opposite to each other, and the porous structure is disposed on the first surface of the first substrate. 10 . , the reducing the thickness of the first substrate with a plurality of holes to the target thickness includes: a support structure is provided, and the first surface of the first substrate is fixed with the support structure by waxing; 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 side of the first substrate from the support structure. 10 . The method for fabricating a light-emitting chip according to claim 1 , wherein the warpage value of the first substrate having a plurality of holes is less than or equal to 35 μm. 11 . 11 . 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 10 .

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