Method for manufacturing a light-emitting device and light-emitting device

Abstract

The present invention discloses a method for manufacturing a light-emitting device. A mixed glue containing quantum dots and an adhesive glue is used. First, the mixed glue is filled into the holes on the first surface of the substrate, and the mixed glue is also distributed on the first surface of the substrate. Then, the light-emitting surface of the light-emitting chip is attached to the first surface of the substrate, and then the mixed glue is cured, and the light-emitting chip and the first surface of the substrate are fixed together by using the mixed glue. When manufacturing a light-emitting device by using the manufacturing method of the present invention, the curing of the quantum dots and the fixing of the substrate and the light-emitting chip are realized only through one curing process, which can improve the manufacturing efficiency of the light-emitting device, save energy consumption, etc. At the same time, it can also prevent the problem of quantum dot quenching caused by high-temperature baking in the curing process due to multiple curing. In addition, the present invention also discloses a light-emitting device.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly relates to a method for manufacturing a light-emitting device and a light-emitting device. Background Art

[0002] Color conversion through quantum dots (QD for short) is currently the main method to achieve high-quality full-color. At present, generally, a complete color conversion structure is first fabricated, and then the color conversion structure is fixed to the light-emitting surface of the light-emitting chip to obtain a light-emitting device containing quantum dots. Whether in the process of fabricating the color conversion structure or in the process of fixing the color conversion structure to the light-emitting chip, it will involve the curing process of liquid substances (such as quantum dot solution, adhesive, etc.). Multiple curing processes lead to low efficiency, and the curing process involves high-temperature baking, which easily causes quantum dot quenching. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for manufacturing a light-emitting device with high manufacturing efficiency, not easily causing quantum dot quenching, and a light-emitting device with good color conversion effect.

[0004] To achieve the above purpose, the present invention provides a method for manufacturing a light-emitting device, including:

[0005] (1) Providing a substrate and a mixed glue, wherein the first surface of the substrate has a plurality of holes, and the mixed glue contains quantum dots and an adhesive;

[0006] (2) Filling the plurality of holes with the mixed glue and making the mixed glue distributed on the first surface of the substrate;

[0007] (3) Providing at least one light-emitting chip, and attaching the light-emitting surface of the at least one light-emitting chip to the first surface of the substrate;

[0008] (4) Curing the mixed glue, and using the mixed glue to fix the at least one light-emitting chip and the first surface of the substrate together.

[0009] In some embodiments, step (2) includes: adding the mixed glue on the first surface of the substrate, the mixed glue protruding from the first surface by a first thickness; making the mixed glue on the first surface penetrate into the plurality of holes; adding the mixed glue on the first surface of the substrate again, so that the thickness of the mixed glue distributed on the first surface reaches the target thickness.

[0010] In some embodiments, making the thickness of the mixed glue distributed on the first surface reach the target thickness means: making the thickness of the mixed glue distributed on the first surface be 1um to 10um.

[0011] In some embodiments, step (3) includes: providing a light-emitting structure, the light-emitting structure including a carrier and a plurality of light-emitting chips disposed on the carrier; attaching the light-emitting surfaces of the plurality of light-emitting chips to the first surface of the substrate; after step (4), further including: removing the carrier; cutting the substrate along the gaps between the light-emitting chips to obtain a light-emitting device including at least one of the light-emitting chips.

[0012] In some embodiments, step (3) includes: growing a chip structure layer on a growth substrate, and dividing the chip structure layer to fabricate a wafer including a plurality of light-emitting chips; providing a carrier having a bonding adhesive on its surface, and bonding the carrier to the plurality of light-emitting chips of the wafer; removing the growth substrate to obtain a light-emitting structure including the carrier and a plurality of light-emitting chips disposed on the carrier; attaching the light-emitting surfaces of the plurality of light-emitting chips to the first surface of the substrate.

[0013] In some embodiments, before step (2), further included are: drying the substrate, and / or cleaning stains on the surface of the substrate and / or inside the holes.

[0014] In some embodiments, the aperture of the holes is in the nanometer or micrometer range.

[0015] In some embodiments, the substrate includes a growth substrate and an epitaxial layer grown on the growth substrate, and the epitaxial layer has the plurality of holes.

[0016] To achieve the above object, the present invention further provides a light-emitting device fabricated by using the fabrication method as described above.

[0017] Compared with the prior art, the fabrication method of the light-emitting device provided by the present invention uses a hybrid adhesive containing quantum dots and a bonding adhesive. First, the hybrid adhesive is filled into the holes on the first surface of the substrate, and the hybrid adhesive is also distributed on the first surface of the substrate; then the light-emitting surface of the light-emitting chip is attached to the first surface of the substrate, and then the hybrid adhesive is cured, and the light-emitting chip is fixed to the first surface of the substrate by using the hybrid adhesive. When fabricating the light-emitting device by using the fabrication method of the present invention, the curing of the quantum dots and the fixing of the substrate and the light-emitting chip are achieved only through one curing process, which can improve the fabrication efficiency of the light-emitting device, save energy consumption, etc. At the same time, it can also prevent the problem of quantum dot quenching caused by high-temperature baking during multiple curing processes.

[0018] To achieve the above object, the present invention further provides a light-emitting device, including a substrate, a hybrid glue, and at least one light-emitting chip. The first surface of the substrate has a plurality of holes; the hybrid glue contains quantum dots and an adhesive glue, and the hybrid glue is filled in the plurality of holes and distributed and adhered to the first surface of the substrate; the light-emitting surface of the at least one light-emitting chip is adhered to the surface of the hybrid glue facing away from the substrate.

[0019] Compared with the prior art, the hybrid glue in the plurality of holes mainly plays a role in color conversion. The hybrid glue in the holes absorbs the excitation light and converts it into the target light for emission. The main function of the hybrid glue distributed on the first surface of the substrate is to adhere the substrate and the light-emitting chip, so as to fix the light-emitting chip and the substrate together. At the same time, it can also play a role in color conversion. By absorbing the excitation light through the hybrid glue on the first surface of the substrate, it can prevent some excitation light from directly transmitting through the area of the substrate without holes, thereby improving the color conversion effect. Description of the Drawings

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

[0021] Figure 2 is a schematic structural diagram of a light-emitting device according to an embodiment of the present invention. Detailed Embodiments

[0022] To describe the content, structural features, achieved object, 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 embodiments are only a part of the embodiments of the present invention, rather than all 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 belong to the scope of protection of the present invention.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, and thus cannot be construed as a limitation to the protected content of the present invention.

[0024] Hereinafter, the technical solutions in the embodiments of the present invention will be described in detail with reference to the accompanying drawings:

[0025] Please refer to Figure 1 , a method for manufacturing a light-emitting device according to an embodiment of the present invention includes the following steps:

[0026] S1. Provide a substrate 1 and a hybrid glue. The first surface of the substrate 1 has a plurality of holes 3, as shown in (a1) in Figure 1 , and the hybrid glue contains quantum dots and an adhesive glue.

[0027] Among them, the substrate 1 can be a sheet-like structural member having a plurality of holes 3. For example, the substrate 1 is a sapphire substrate having a plurality of holes 3. For another example, the substrate 1 includes a multi-layer structure, and a plurality of holes 3 are formed on one layer structure.

[0028] In one embodiment, the substrate 1 includes a growth substrate 11 and an epitaxial layer 12 grown on the growth substrate 11, and the epitaxial layer 12 has a plurality of holes 3. Among them, the epitaxial layer 12 may include a buffer layer, an intrinsic layer, an N-type epitaxial layer, etc. that are sequentially stacked on the growth substrate, and the N-type epitaxial layer has holes 3. The N-type epitaxial layer may be an N-type gallium nitride layer doped with substances such as silicon, and the N-type epitaxial layer can be etched by an electrochemical etching method to obtain a plurality of holes 3.

[0029] The holes 3 can be regular shapes, such as cylindrical shapes, or irregularly shaped pits, etc.; the inner walls of the holes 3 can be rough structures, and the rough inner walls can cause the excitation light to continuously scatter in the holes 3 to improve the absorption efficiency of the quantum dots for the excitation light and improve the color purity.

[0030] In one embodiment, the aperture of the holes 3 is nanoscale or micron-scale, and the number is extremely large. By providing a huge number of holes 3, the scattering of light can be improved, the optical path can be increased, thereby improving the absorption efficiency of the quantum dots for the excitation light, reducing the leakage of the excitation light, and further improving the color purity.

[0031] Among them, the mixed glue is liquid and includes quantum dots, solvents, adhesive glue, etc. Among them, the quantum dots can be one or more of CdS quantum dots, CdSe quantum dots, CdTe quantum dots, ZnSe quantum dots, PbS quantum dots, PbSe quantum dots, InAs quantum dots, InGaN quantum dots, GaAs quantum dots, InP quantum dots, ZnCdSe quantum dots, ZnS quantum dots, etc. The solvent can be an organic solvent, and the adhesive glue can be a UV glue, an epoxy glue, etc.

[0032] Among them, the quantum dots can be red-light quantum dots that can convert the excitation light into red light, or green-light quantum dots that can convert the excitation light into green light, etc., and the excitation light can be blue light, etc. For example, the quantum dots are red-light quantum dots that can convert blue light into red light.

[0033] In one embodiment, the mixed glue is prepared in this way: First, the quantum dots, the solvent, and the adhesive glue are added to a stirrer for stirring and mixing. The stirring speed is 50 RPM to 200 RPM, the stirring time is 20 minutes to 40 minutes, and the stirring temperature is 15°C to 30°C; then, the stirred and mixed mixed glue is transferred to a centrifugal device or a vacuum device for defoaming treatment, and finally the mixed glue that can be added to the holes and the first surface of the substrate 1 is obtained.

[0034] In one embodiment, the mass ratio of the quantum dots in the hybrid glue is 20% - 30%. In this way, the quantum dots can fully absorb the excitation light, and the adhesive glue can also have a higher proportion, ensuring that the cured hybrid glue can stably fix the light-emitting chip 4 to the first surface of the substrate 1.

[0035] S2, perform a drying treatment on the substrate 1, and / or clean the stains on the surface of the substrate 1 and / or in the holes 3. By performing a drying treatment on the substrate 1, the moisture in the substrate 1 is removed; by cleaning the stains on the surface of the substrate 1 and / or in the holes 3, the hybrid glue can be better injected into the holes 3 in the subsequent steps.

[0036] In one embodiment, bake the substrate 1 in a vacuum oven at 80°C - 100°C for 13 minutes - 17 minutes to dry the moisture in the substrate 1 without damaging the substrate 1; then, clean the substrate 1 with plasma, cleaning the stains on the surface of the substrate 1 and in the holes 3. Among them, the plasma can be generated by argon and oxygen, and the volume ratio of argon to oxygen can be Ar:O2 = 50:10 - 10:10, and the cleaning time can be 10 minutes - 15 minutes. By drying the substrate 1 in a vacuum environment, the gas in the holes 3 can be evacuated, avoiding the gas existing in the holes 3 from hindering the injection of the hybrid glue into the holes 3 due to the small size of the holes 3.

[0037] It can be understood that in some embodiments, this step S2 may not be executed, that is, step S2 is omitted and directly proceed to step S3.

[0038] S3, fill the hybrid glue 2 into the multiple holes 3 and make the hybrid glue 2 distributed on the first surface of the substrate 1, as Figure 1 shown in (a2).

[0039] When filling the hybrid glue 2 into the multiple holes 3, it can be by centrifugal injection method. Specifically: place the substrate 1 in a container filled with the hybrid glue, and make the container rotate centrifugally to generate a centrifugal force towards the openings of the holes 3, and by means of the centrifugal force, the hybrid glue in the container flows towards the holes 3 and is injected into the holes 3; it can also be by vacuum injection method. Specifically: arrange the hybrid glue on the first surface of the substrate 1, and then evacuate to make the environment where the substrate 1 is located a vacuum environment, and maintain the vacuum for a certain time, so that the hybrid glue on the first surface of the substrate 1 penetrates into the holes 3; it can also be by electric field injection method. Specifically: the hybrid glue is charged, place the substrate 1 in the hybrid glue, and then apply an electric field to the hybrid glue, and by means of the electric field, drive the charged hybrid glue to move towards the holes 3 in the substrate 1 and be injected into the holes 3; it can also be by spin coating injection method; it can also be any two or more combinations of centrifugal injection, vacuum injection, electric field injection, spin coating injection, etc. to achieve filling the hybrid glue into the multiple holes 3.

[0040] In one embodiment, first, a mixed glue is spin-coated on the first surface of the substrate 1, and the mixed glue protrudes from the first surface by a first thickness; then, the mixed glue on the first surface is infiltrated into a plurality of holes 3 by means of centrifugal injection, vacuum injection, electric field injection, etc.; again, a mixed glue is spin-coated on the first surface of the substrate 1 so that the thickness of the mixed glue distributed on the first surface reaches the target thickness. The first thickness is less than the final thickness of the mixed glue 2. The mixed glue is spin-coated in multiple times to reduce the spin-coating thickness of the mixed glue each time, so as to reduce the resistance of the mixed glue to infiltrate into the holes 3 in the subsequent process of injecting the mixed glue into the holes 3. In one embodiment, the first thickness is 0.1 um to 1 um. After spin-coating the mixed glue on the first surface of the substrate 1 again, the thickness of the mixed glue distributed on the first surface is 1 um to 10 um, that is, the target thickness is 1 um to 10 um.

[0041] In the foregoing embodiment, the mixed glue is spin-coated once, then centrifugal injection / vacuum injection / electric field injection is adopted, and then the mixed glue is spin-coated a second time, so as to fill the mixed glue into a plurality of holes 3 and make the mixed glue distributed on the first surface of the substrate 1. Of course, in other embodiments, spin-coating and centrifugal injection / vacuum injection / electric field injection can be repeated multiple times to improve the injection effect. For example, in some embodiments, first, a mixed glue is spin-coated on the first surface of the substrate 1, and the mixed glue protrudes from the first surface by a first thickness; then, the mixed glue on the first surface is infiltrated into a plurality of holes 3 by means of centrifugal injection, vacuum injection, electric field injection, etc.; then, a mixed glue is spin-coated on the first surface of the substrate 1 again, and the mixed glue protrudes from the first surface by a second thickness, and then the mixed glue on the first surface is infiltrated into a plurality of holes 3 by means of centrifugal injection, vacuum injection, electric field injection, etc. again; then, a mixed glue is spin-coated on the first surface of the substrate 1 again so that the thickness of the mixed glue distributed on the first surface reaches the target thickness.

[0042] S4, provide at least one light-emitting chip 4, and attach the light-emitting surface of the at least one light-emitting chip 4 to the first surface of the substrate 1, as Figure 1 shown in (c1).

[0043] In one embodiment, first, a chip structure layer is grown on the growth substrate 5, and the chip structure layer is divided to fabricate a wafer including a plurality of light-emitting chips 4, as Figure 1 shown in (b1), wherein the chip structure layer may include a buffer layer, an intrinsic layer, an N-type layer, a light-emitting layer, a P-type layer, etc. that are sequentially stacked; then, a carrier 7 with a bonding glue 6 on its surface is provided, and the carrier 7 is bonded to the plurality of light-emitting chips 4 of the wafer, as Figure 1 shown in (b2), and the light-emitting surface of the light-emitting chip 4 faces away from the carrier 7; the growth substrate 5 is removed to obtain a light-emitting structure including the carrier 7 and a plurality of light-emitting chips 4 provided on the carrier 7, as Figure 1As shown in (b3), the growth substrate 5 can be removed by laser lift-off (LLO) or the like; then, the light-emitting surfaces of the plurality of light-emitting chips 4 are attached to the first surface of the substrate 1, as Figure 1 shown in (c1).

[0044] In Figure 1 the illustrated embodiment, the light-emitting surfaces of the plurality of light-emitting chips 4 are attached to the first surface of the substrate 1. Of course, in other embodiments, it is also possible to attach only the light-emitting surface of a single light-emitting chip 4 to the first surface of the substrate 1.

[0045] Among them, the light-emitting chip 4 is preferably a flip chip, and both electrodes of the flip chip are provided on the side facing away from the light-emitting surface (as Figure 1 shown in (b1)), so as to tightly fix the light-emitting surface of the light-emitting chip 4 to the first surface of the substrate 1.

[0046] S5, cure the hybrid glue 2 to fix the light-emitting chip 4 and the first surface of the substrate 1 together.

[0047] It can be to put the light-emitting chip 4 and the substrate 1 that are attached together into an oven or other bonding equipment, and bake for a preset duration at a preset temperature, so that the hybrid glue in the holes 3 and the hybrid glue on the first surface of the substrate 1 are cured. The preset temperature can be, for example, 80°C to 100°C. The preset temperature should not be too high to avoid quenching of quantum dots at high temperatures. The preset duration can be, for example, 10 to 200 minutes, etc.

[0048] In some embodiments where the light-emitting structure adopted in step S4 includes a carrier 7 and a plurality of light-emitting chips 4 provided on the carrier 7, and the light-emitting surfaces of the plurality of light-emitting chips 4 are attached to the first surface of the substrate 1, after step S5, the following steps can further be performed:

[0049] S6, remove the carrier 7, and the obtained structure is as Figure 1 shown in (c2). Then, cut the substrate 1 along the gap (cutting line L) between the light-emitting chips 4, as Figure 1 shown in (c3), to obtain a light-emitting device including at least one light-emitting chip 4.

[0050] Among them, the light-emitting device can include only one light-emitting chip 4 or can include a plurality of light-emitting chips 4. Of course, in some embodiments, step S6 may not be performed.

[0051] In one embodiment, after removing the carrier 7 and before cutting the substrate 1 along the gap between the light-emitting chips 4, the side of the substrate 1 facing away from the first surface is also thinned, that is, the growth substrate 11 is thinned to reduce the thickness of the entire substrate 1, and finally the thickness of the manufactured light-emitting device can be made thinner.

[0052] Next, please refer toFigure 2 , Figure 2 shows a schematic structural diagram of a light-emitting device according to an embodiment of the present invention. As Figure 2 shown, the light-emitting device includes a substrate 1, a hybrid glue 2, and a light-emitting chip 4. The first surface of the substrate 1 has a plurality of holes 3; the hybrid glue 2 contains quantum dots and an adhesive glue, and includes a first glue layer 21 filled in the plurality of holes 3 and a second glue layer 22 adhered to the first surface of the substrate 1; the light-emitting surface of the light-emitting chip 4 is bonded to the surface of the second glue layer 22 facing away from the substrate 1.

[0053] The first glue layer 21 in the plurality of holes 3 mainly functions as color conversion. The first glue layer 21 absorbs the excitation light and converts it into the target light for emission. The main function of the second glue layer 22 is to adhere the substrate 1 and the light-emitting chip 4 to fix the light-emitting chip 4 and the substrate 1 together. At the same time, the second glue layer 22 can also function as color conversion. By absorbing the excitation light through the second glue layer 22, it can prevent some of the excitation light from directly transmitting through the area of the substrate 1 where the first glue layer 21 is not provided, improving the color conversion effect.

[0054] In one embodiment, the thickness of the second glue layer 22 is 1 um to 10 um to balance the total thickness of the entire light-emitting device while stably fixing the first surface of the substrate 1 and the light-emitting surface of the light-emitting chip 4 together.

[0055] In one embodiment, the aperture of the holes 3 is nanoscale or micron-scale, and the number is extremely large. The huge number of holes 3 can enhance the scattering of light, increase the optical path, thereby improving the absorption efficiency of the quantum dots for the excitation light, reducing the leakage of the excitation light, and further improving the color purity.

[0056] In Figure 2 the shown embodiment, a light-emitting device includes only one light-emitting chip 4. In other embodiments, a light-emitting device may include two or more light-emitting chips 4.

[0057] In summary, for the method for manufacturing a light-emitting device provided by the present invention, a hybrid glue 2 containing quantum dots and an adhesive glue is used. First, the hybrid glue 2 is filled into the holes 3 on the first surface of the substrate 1, and the hybrid glue 2 is also distributed on the first surface of the substrate 1; then the light-emitting surface of the light-emitting chip 4 is attached to the first surface of the substrate 1, and then the hybrid glue 2 is cured to fix the light-emitting chip 4 and the first surface of the substrate 1 together by using the hybrid glue 2. When manufacturing a light-emitting device using the manufacturing method of the present invention, the curing of the quantum dots and the fixing of the substrate 1 and the light-emitting chip 4 are achieved only through one curing process, which can improve the manufacturing efficiency of the light-emitting device, save energy consumption, etc. At the same time, it can also prevent the problem of quantum dot quenching caused by high-temperature baking in multiple curing processes.

[0058] The above-disclosed are only the preferred examples of the present invention and cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention all fall within the scope covered by the present invention.

Claims

1. A method for fabricating a light-emitting device, characterized in that, Comprising the steps of: (1) Providing a substrate and a mixed glue, wherein a first surface of the substrate has a plurality of holes, and the mixed glue contains quantum dots and an adhesive glue; the substrate includes a growth substrate and an epitaxial layer grown on the growth substrate, and the epitaxial layer has the plurality of holes; (2) Filling the plurality of holes with the mixed glue and distributing the mixed glue on the first surface of the substrate; (3) Providing at least one light-emitting chip and attaching a light-emitting surface of the at least one light-emitting chip to the first surface of the substrate; (4) Curing the mixed glue to fix the quantum dots in the holes and using the mixed glue to fix the at least one light-emitting chip and the first surface of the substrate together; Wherein, step (2) includes: Adding the mixed glue to the first surface of the substrate, the mixed glue protruding from the first surface by a first thickness, and the first thickness being 0.1 um to 1 um; Allowing the mixed glue on the first surface to penetrate into the plurality of holes; Adding the mixed glue to the first surface of the substrate again to make the thickness of the mixed glue distributed on the first surface reach a target thickness, and the target thickness being 1 um to 10 um.

2. The method for manufacturing a light-emitting device according to claim 1, wherein: Step (3) includes: Providing a light-emitting structure, the light-emitting structure including a carrier and a plurality of light-emitting chips provided on the carrier; Attaching the light-emitting surfaces of the plurality of light-emitting chips to the first surface of the substrate; After step (4), further including: Removing the carrier; Cutting the substrate along the gaps between the light-emitting chips to obtain a light-emitting device including at least one of the light-emitting chips.

3. The method for manufacturing a light-emitting device according to claim 1, wherein Step (3) includes: Growing a chip structure layer on the growth substrate and dividing the chip structure layer to fabricate a wafer including a plurality of light-emitting chips; Providing a carrier having a bonding glue on its surface and bonding the carrier to the plurality of light-emitting chips of the wafer; Removing the growth substrate to obtain a light-emitting structure including the carrier and a plurality of light-emitting chips provided on the carrier; Attaching the light-emitting surfaces of the plurality of light-emitting chips to the first surface of the substrate.

4. The method for manufacturing a light-emitting device according to claim 1, wherein Before step (2), further including: Performing a drying treatment on the substrate and / or cleaning stains on the surface of the substrate and / or in the holes.

5. The method for manufacturing a light-emitting device according to claim 1, wherein, The aperture of the holes is nanoscale or micron-scale.

6. A light-emitting device, characterized in that, The light-emitting device is fabricated by the manufacturing method according to any one of claims 1 to 5.

7. A light-emitting device, characterized in that, Including: A substrate, a first surface of the substrate having a plurality of holes; the substrate includes a growth substrate and an epitaxial layer grown on the growth substrate, and the epitaxial layer has the plurality of holes; A mixed glue, the mixed glue containing quantum dots and an adhesive glue, the mixed glue being filled in the plurality of holes and distributed and adhered to the first surface of the substrate, and the thickness of the mixed glue distributed on the first surface reaching a target thickness, and the target thickness being 1 um to 10 um; And At least one light-emitting chip, a light-emitting surface of the at least one light-emitting chip being bonded to a surface of the mixed glue facing away from the substrate.

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