Manufacturing method of LED light-emitting device and LED light-emitting device

Abstract

The present application relates to a manufacturing method of an LED light-emitting device and an LED light-emitting device manufactured by this manufacturing method, and relates to the technical field of semiconductor packaging, including: providing a substrate and an LED chip. On the premise that the LED chip is mounted on the substrate, a first transparent encapsulant is coated along the substrate, and the first transparent encapsulant wraps the light-emitting surface of the LED chip; the first transparent encapsulant is baked for the first time to semi-cure the first transparent encapsulant; phosphor is sprayed onto the semi-cured first transparent encapsulant so that the particle density of the phosphor increases in the direction of the top surface away from the light-emitting surface of the LED chip. The present application has the effects of higher light-emitting efficiency, higher light conversion efficiency, and better light color performance of the LED chip.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor packaging, and in particular to a manufacturing method of an LED lighting device and an LED lighting device. Background Art

[0002] A layer of phosphor is coated on the surface of an LED chip of an LED lighting device, and the light energy emitted from the light-emitting surface of the LED chip can excite the phosphor to form light of a specific color.

[0003] As the power of the LED increases, the temperature of the LED chip will become higher and higher. At the same time, with the further growth of the dimming demand, the temperature of the LED chip will also change under the corresponding current drive. The increase and change of the surface temperature of the LED chip will be conducted to the phosphor, exacerbating the thermal quenching of the phosphor, thereby affecting the light color performance of the LED chip.

[0004] In addition, a layer of phosphor on the surface of the LED chip is arranged in a high-concentration and dense manner. This densely arranged phosphor will reflect a large amount of light in the direction of the LED chip, and the reflected light will be absorbed by the LED chip again, resulting in a reduction in the actual light-emitting efficiency of the LED chip. Summary of the Invention

[0005] The present application aims to at least solve the technical problems in the prior art that the increase and change of the surface temperature of the LED chip will be conducted to the phosphor, exacerbating the thermal quenching of the phosphor, and the phosphor on the surface of the LED chip is arranged in a high-concentration and dense manner, resulting in a reduction in the actual light-emitting efficiency of the LED chip. For this purpose, the present application provides a manufacturing method of an LED lighting device and an LED lighting device.

[0006] In a first aspect, the present application provides a manufacturing method of an LED lighting device, including:

[0007] Providing a substrate;

[0008] Providing an LED chip, and flip-chip mounting the LED chip at a preset position on the substrate;

[0009] Coating a first transparent encapsulant on the substrate, and the first transparent encapsulant wraps the light-emitting surface of the LED chip;

[0010] Performing a first baking on the first transparent encapsulant to semi-cure the first transparent encapsulant; and

[0011] Injecting phosphor into the semi-cured first transparent encapsulant to form a phosphor layer, and the particle density of the phosphor in the phosphor layer increases from the direction close to the substrate to the direction away from the substrate.

[0012] By adopting the above technical solution, the particle density of the phosphor increases in the direction away from the top surface of the LED chip, that is, the gap between the phosphor particles near the top surface of the LED chip is large, and the light emitted from the top surface of the LED chip is less reflected on this part of the phosphor, thereby reducing the probability of the light reflected and scattered back to the LED chip through this part of the phosphor, and thus improving the light extraction efficiency of the LED chip.

[0013] At the same time, the gap between the phosphor particles far from the top surface of the LED chip is small, which can be better excited by the light emitted from the light-emitting surface of the LED chip, improving the light conversion efficiency; moreover, the distance between this part of the phosphor and the LED chip is far, and it is less affected by the temperature of the LED chip, so the luminous performance of the LED chip is better.

[0014] According to an embodiment of the present application, a first transparent encapsulant is coated on the substrate, and the first transparent encapsulant wraps the light-emitting surface of the LED chip, including:

[0015] A recessed area is formed on the provided substrate. On the premise that the LED chip is installed in the recessed area, the first transparent encapsulant is coated in the recessed area;

[0016] The first transparent encapsulant is left standing, and the distance H1 between the upper surface of the first transparent encapsulant and the top surface of the light-emitting surface of the LED chip satisfies: 20um - 200um.

[0017] By adopting the above technical solution, by coating the first transparent encapsulant in the recessed area, it is used to better cover the light-emitting surface of the LED chip; leaving the first transparent encapsulant standing ensures that the thickness of the encapsulant on the top surface of the LED chip is consistent, so as to ensure the consistent distribution of the subsequent phosphor and improve the luminous consistency of the LED chip.

[0018] According to an embodiment of the present application, the thickness of the phosphor layer on the side of the LED chip is greater than the thickness of the phosphor layer on the top surface of the LED chip.

[0019] By adopting the above technical solution, after soft baking, the viscosity of the first transparent encapsulant on the side of the LED chip is less than the viscosity of the first transparent encapsulant on the top surface of the LED chip.

[0020] For the same phosphor, the resistance it encounters when entering the first transparent encapsulant on the top surface of the LED chip is greater, and the traveling distance is smaller; the resistance it encounters when entering the first transparent encapsulant on the side of the LED chip is smaller, and the traveling distance is greater.

[0021] That is, the phosphor can be wrapped around the top surface and the side surface of the LED chip, thereby avoiding the light emitted by the LED chip from directly passing through the first transparent encapsulant, and further improving the light conversion efficiency of the light source and making the light source performance better.

[0022] According to an embodiment of the present application, before the first baking of the first transparent encapsulant to semi-cure the first transparent encapsulant and before spraying the phosphor into the semi-cured first transparent encapsulant to form a phosphor layer, the method further includes:

[0023] Providing a stencil, the stencil is used to cover the substrate, and the stencil has at least one mesh hole for exposing the LED chip, and the mesh hole corresponds to the recessed area.

[0024] By adopting the above technical solution, the stencil can make the directivity of the phosphor injected into the first transparent encapsulant in the subsequent steps better, that is, it can be injected into the first transparent encapsulant in the mesh hole directionally.

[0025] According to an embodiment of the present application, spraying the phosphor into the semi-cured first transparent encapsulant includes:

[0026] Providing a powder spraying machine, the powder spraying machine sprays the phosphor in the direction of the top surface of the light-emitting surface of the LED chip facing directly, and the concentration range of the phosphor in the powder spraying machine satisfies: 1 mol / L - 10 mol / L.

[0027] By adopting the above technical solution, after the phosphor enters the first transparent encapsulant, the particle density of the phosphor increases in the direction away from the top surface of the LED chip, thereby improving the light extraction efficiency and the color consistency of the emitted light. According to an embodiment of the present application, the semi-curing of the first transparent encapsulant satisfies: the viscosity of the first transparent encapsulant is 25000 centipoise - 100000 centipoise.

[0028] According to an embodiment of the present application, the distance H2 between the lower surface of the phosphor layer and the top surface of the light-emitting surface of the LED chip satisfies: 2 μm - 20 μm.

[0029] According to an embodiment of the present application, the thickness of the sprayed phosphor (the thickness of the phosphor layer) satisfies: 40 μm - 200 μm;

[0030] The spraying speed of the phosphor satisfies: 100 mm / s - 300 mm / s;

[0031] The number of times of spraying the phosphor satisfies: 1 - 5 times.

[0032] According to an embodiment of the present application, phosphor is sprayed onto the semi-cured first transparent encapsulant to form a phosphor layer. After the particle density of the phosphor in the phosphor layer increases in the direction away from the substrate towards the substrate, the method further includes:

[0033] Performing a second baking on the semi-cured first transparent encapsulant to cure the first transparent encapsulant;

[0034] Coating a second transparent encapsulant on the surface of the cured first transparent encapsulant;

[0035] Performing a third baking on the second transparent encapsulant to cure the second transparent encapsulant, and the first transparent encapsulant and the second transparent encapsulant together form a glue-sealing layer.

[0036] By adopting the above technical solution, the first transparent encapsulant is cured by the second baking, which can avoid the sedimentation of the phosphor in the first transparent encapsulant. When the first transparent encapsulant is cured, the distance between the phosphor closest to the top surface of the LED chip and the top surface of the LED chip should satisfy: 2um - 20um.

[0037] In a second aspect, the present application provides an LED lighting device, including: a substrate;

[0038] An LED chip, the LED chip is mounted on the substrate;

[0039] A glue-sealing layer, the glue-sealing layer wraps the LED chip, and phosphor is provided in the glue-sealing layer, and the particle density of the phosphor increases in the direction away from the substrate towards the substrate.

[0040] In summary, the present application includes at least one of the following beneficial technical effects:

[0041] 1. The density of the phosphor particles near the top surface of the LED chip is small, and the light emitted from the top surface of the LED chip is less reflected on this part of the phosphor, so the probability of the light reflected back to the LED chip through this part of the phosphor is small, and the light extraction efficiency of the LED chip is higher. At the same time, the density of the phosphor particles far from the top surface of the LED chip is large, and it can be better excited by the light emitted from the top surface of the LED chip, improving the light conversion efficiency; and the distance between this part of the phosphor and the LED chip is far, and it is less affected by the temperature of the LED chip, so the overall performance of the LED lighting device is better.

[0042] 2. The viscosity of the first transparent encapsulant on the side of the LED chip is less than that of the first transparent encapsulant on the top surface of the LED chip. This allows the phosphor to travel a greater distance into the first transparent encapsulant on the side of the LED chip, enabling the phosphor to wrap around the side of the LED chip and preventing the light emitted from the side of the LED chip from directly passing through the first transparent encapsulant, thereby improving the luminous uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a schematic structural diagram of an LED lighting device in the related art;

[0044] Figure 2 is a schematic optical path diagram of the light transmitted after the light emitted from the light-emitting surface of the LED chip in the LED lighting device in the related art encounters the phosphor particles;

[0045] Figure 3 is one of the schematic structural diagrams of the LED lighting device provided by an embodiment of the present application;

[0046] Figure 4 is a schematic diagram of the distribution of phosphor particles in the phosphor layer of the LED lighting device provided by an embodiment of the present application;

[0047] Figure 5 is a top view of the relative position of the substrate and the chip of the LED lighting device provided by an embodiment of the present application;

[0048] Figure 6 is a schematic structural diagram of forming the first transparent encapsulant on the light-emitting part of the LED chip in the method for manufacturing the LED lighting device provided by an embodiment of the present application;

[0049] Figure 7 is a schematic structural diagram of spraying phosphor into the first transparent encapsulant in the method for manufacturing the LED lighting device provided by an embodiment of the present application;

[0050] Figure 8 is another schematic structural diagram of the LED lighting device provided by an embodiment of the present application.

[0051] Reference numerals: 100, substrate; 110, recessed area; 200, LED chip; 210, light-emitting surface; 300, first transparent encapsulant; 310, phosphor; 400, second transparent encapsulant, a, screen; a1, mesh hole; b, powder spraying machine; c, phosphor layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] Embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as a limitation of the present application.

[0053] Reference will be made below Figures 3 - 8 to describe a manufacturing method of an LED lighting device and an LED lighting device according to an embodiment of the present application.

[0054] As Figure 3 and Figure 4 shown, an LED lighting device includes: a substrate 100, an LED chip 200, and a potting layer.

[0055] Among them, the substrate 100 includes, but is not limited to, an aluminum nitride substrate, an alumina substrate, and an aluminum substrate. The surface on one side of the substrate 100 may include circuits and pads connected to the circuits.

[0056] The LED chip 200 may be a flip chip, and the pins of the flip chip may be connected to the pads.

[0057] The potting layer may be an organic encapsulant, which includes, but is not limited to, silicone rubber, silicone resin, fluororesin, fluororubber, etc. The potting layer is coated along the substrate 100 and wraps the light-emitting surface of the LED chip 200.

[0058] The light-emitting surface of the LED chip 200 generally refers to the thickness part above the pn junction. In this embodiment, it refers to the top surface and the side surface of the LED chip 200.

[0059] The potting layer wraps the LED chip 200, and phosphor 310 is provided in the potting layer. The particle density of the phosphor 310 increases in the direction away from the top surface of the LED chip 200.

[0060] In the related art, as Figure 1 and Figure 2 shown, a high-density phosphor layer c covers the outside of the LED chip 200. The gaps between the phosphor 310 particles in the phosphor layer c are very small, and each single phosphor 310 particle is not a standard sphere. This causes each single phosphor 310 particle to not only absorb but also reflect the light emitted by the LED chip 200. After being reflected by multiple phosphor 310 particles, part of the light will be reflected back to the LED chip 200, which greatly reduces the light extraction efficiency of the LED chip 200.

[0061] In addition, the materials in the LED chip 200 will absorb a certain amount of light, that is, the light reflected back to the LED chip 200 can be absorbed by the LED chip 200, which will increase the temperature of the LED chip 200 and exacerbate the thermal quenching of the phosphor 310, thus seriously degrading the light-emitting performance of the LED lighting device.

[0062] In the above embodiments of the present application, as Figure 3 shown, the particle density of the phosphor 310 increases in the direction away from the top surface of the LED chip 200, that is, the gap between the phosphor 310 particles near the top surface of the LED chip 200 is large, and the light emitted from the top surface of the LED chip 200 is less reflected on this part of the phosphor 310, thereby reducing the probability of the light reflected and scattered back to the LED chip 200 through this part of the phosphor 310, and thus improving the light extraction efficiency of the LED chip 200.

[0063] At the same time, the gap between the phosphor 310 particles far from the top surface of the LED chip 200 is small, and it can be better excited by the light emitted from the top surface of the LED chip 200, improving the light conversion efficiency; and the distance between this part of the phosphor 310 and the LED chip 200 is far, and it is less affected by the temperature of the LED chip 200, so the light-emitting performance of the LED chip 200 is better.

[0064] It should be noted that taking the LED chip 200 emitting blue light as an example, the blue light is absorbed by the phosphor 310 particles and can excite yellow light to be emitted. The present application can reduce the amount of blue light reflected back to the LED chip 200, increase the amount of blue light absorbed by the phosphor 310 particles, and excite the amount of yellow light to be emitted, thereby improving the light conversion efficiency and light extraction efficiency of the light source, and making the light-emitting performance of the LED chip 200 better.

[0065] As Figures 3 - 8 shown, the present application also provides a manufacturing method of an LED lighting device, including the following steps: step 510, step 520, and step 530.

[0066] Step 510: Provide a substrate 100 and an LED chip 200. On the premise that the LED chip 200 is installed on the substrate 100, a first transparent encapsulant 300 is coated along the substrate 100, and the first transparent encapsulant 300 wraps the light-emitting surface of the LED chip 200.

[0067] In this step, the LED chip 200 is flip-chip mounted at a preset position on the substrate 100. The light-emitting surface of the LED chip 200 generally refers to the thickness part above the pn junction. In this step, it refers to the top surface of the LED chip 200 and the side surface of the LED chip 200.

[0068] Step 520: Bake the first transparent encapsulant 300 for the first time to make the first transparent encapsulant 300 semi-cured.

[0069] In this step, the first transparent encapsulant 300 is baked for the first time to weaken the fluidity of the first transparent encapsulant 300 and increase the resistance to the incident phosphor 310 to a certain extent.

[0070] Step 530: As Figure 4 shown, the phosphor 310 is sprayed onto the semi-cured first transparent encapsulant 300 to form a phosphor layer c, and the particle density of the phosphor 310 in the phosphor layer c increases in the direction away from the substrate 100 towards the substrate 100.

[0071] In this step, the phosphor 310 will be successively injected into the semi-cured first transparent encapsulant 300, and there will be an interaction between the phosphor 310 particles sprayed before and after on the surface of the first transparent encapsulant 300, showing a trend that the particle density of the phosphor 310 increases in the direction away from the substrate 100 towards the substrate 100.

[0072] At the same time, since the density of the phosphor 310 is greater than that of the first transparent encapsulant 300, the phosphor 310 will settle, and after settling, the phosphor 310 near the top surface of the LED chip 200 will be more dispersed.

[0073] Among them, the particle density of the phosphor 310 at a position far from the top surface of the LED chip 200 is greater, which will prevent the subsequent phosphor 310 from being injected into the position near the top surface of the LED chip 200, thus ensuring that the particle density of the phosphor 310 in the phosphor layer c increases in the direction away from the substrate 100 towards the substrate 100.

[0074] In the above embodiments of the present application, the particle density of the phosphor 310 increases in the direction away from the top surface of the LED chip 200, that is, the gap between the phosphor 310 particles near the top surface of the LED chip 200 is large, and the light emitted from the top surface of the LED chip 200 has less reflection on this part of the phosphor 310, thereby reducing the probability of the light reflected and scattered back to the LED chip 200 by this part of the phosphor 310, and thus improving the light extraction efficiency of the LED chip 200.

[0075] At the same time, the gap between the phosphor 310 particles far from the top surface of the LED chip 200 is small, which can be better excited by the light emitted from the top surface of the LED chip 200, improving the light conversion efficiency; and the distance between this part of the phosphor 310 and the LED chip 200 is far, and it is less affected by the temperature of the LED chip 200, so the luminous performance of the LED chip 200 is better.

[0076] In summary, for the phosphor 310 coating method for the LED light-emitting device provided by the present application, the density of the phosphor 310 particles near the top surface of the LED chip 200 is small, and the light emitted from the top surface of the LED chip 200 is less reflected on this part of the phosphor 310. Therefore, the probability of the light reflected back to the LED chip 200 through this part of the phosphor 310 is small, and the light extraction efficiency of the LED chip 200 is higher. At the same time, the density of the phosphor 310 particles far from the top surface of the LED chip 200 is large, which can be better excited by the light emitted from the top surface of the LED chip 200, improving the light conversion efficiency. Moreover, the distance between this part of the phosphor 310 and the LED chip 200 is far, and it is less affected by the temperature of the LED chip 200, so the overall performance of the LED light-emitting device is better.

[0077] In actual implementation, the refractive index of the first transparent encapsulant 300 satisfies: 1.2 - 1.8.

[0078] This can reduce the refraction of the light emitted from the light-emitting surface of the LED chip 200 at the interface of the first transparent encapsulant 300, so that the light transmitted through the first transparent encapsulant 300 is more uniform.

[0079] As a more preferred implementation method, the refractive index of the light-emitting surface of the LED chip 200 and the first transparent encapsulant 300 satisfies: 1.5 - 1.8.

[0080] In some embodiments, step 510, on the premise that the LED chip 200 is installed on the substrate 100, the first transparent encapsulant 300 is coated along the substrate 100, and the first transparent encapsulant 300 wraps the light-emitting surface of the LED chip 200, including: step 511 and step 512.

[0081] Step 511, as Figure 5 shown, a recessed area 110 is formed on the substrate 100, and on the premise that the LED chip 200 is installed in the recessed area 110, the first transparent encapsulant 300 is coated in the recessed area 110.

[0082] In this step, the recessed area 110 can be a dam provided on the substrate 100, and the area formed by the dam surrounding the substrate 100.

[0083] In specific implementation, a dam glue surrounding the LED chip 200 can be set, and the dam glue is cured to form a dam.

[0084] Of course, it can also be a groove opened on the substrate 100, and this embodiment is not limited.

[0085] As Figure 1As shown, in the related art, a first transparent encapsulant 300 with phosphor 310 is directly coated on the LED chip 200, and the light-emitting surface of the LED chip 200 is often not completely covered.

[0086] For example, the side surface of the light-emitting surface of the LED chip 200 is not covered by the first transparent encapsulant 300, and the light emitted from the side surface of the light-emitting surface of the LED chip 200 is not absorbed by the phosphor 310, which will result in poor color consistency of the light emitted by the LED chip 200.

[0087] In this step, the first transparent encapsulant 300 can be dot-coated in the recessed area 110, so that the first transparent encapsulant 300 can better cover the light-emitting surface of the LED chip 200.

[0088] Step 512, as Figure 6 shown, let the first transparent encapsulant 300 stand still, and the distance H1 between the top surface of the first transparent encapsulant 300 and the top surface of the LED chip 200 satisfies: 20um - 200um.

[0089] More preferably, the distance H1 between the top surface of the first transparent encapsulant 300 and the top surface of the LED chip 200 satisfies: 20um - 100um.

[0090] In this step, let the first transparent encapsulant 300 stand still to make the top surface of the first transparent encapsulant 300 flat, and avoid the situation that the first transparent encapsulant 300 is uneven.

[0091] In addition, if the number of LED chips 200 is multiple, the distance between the first transparent encapsulant 300 covered on each LED chip 200 and the LED chip 200 should also be the same or approximately the same to ensure the consistent distribution of the phosphor 310 in the subsequent steps and improve the color consistency of the light emitted by the LED chips 200.

[0092] In this embodiment, by coating the first transparent encapsulant 300 into the recessed area 110 to better cover the light-emitting surface of the LED chip 200, and letting the first transparent encapsulant 300 stand still to ensure that the thickness of the glue on the top surface of the LED chip 200 is consistent, so as to ensure the consistent distribution of the phosphor 310 in the subsequent steps and improve the light-emitting consistency of the LED chip 200.

[0093] In some embodiments, step 520, bake the first transparent encapsulant 300 to make the first transparent encapsulant 300 semi-cured, including:

[0094] Place the substrate 100, the LED chip 200 and the first transparent encapsulant 300 into an oven for soft baking. In actual implementation, the soft baking duration is 5min - 30min, and the soft baking temperature is 60°C - 100°C.

[0095] The first transparent encapsulant 300 is semi-cured to meet the requirement that the viscosity of the first transparent encapsulant 300 is 25,000 CP - 100,000 CP.

[0096] It should be noted that the thickness of the first transparent encapsulant 300 on the side of the LED chip 200 is greater than the thickness of the first transparent encapsulant 300 on the top surface of the LED chip 200.

[0097] As Figure 5 shown, for example, a stencil a can be provided. The substrate 100 is covered by the stencil a, and the stencil a has at least one mesh hole a1 for exposing the LED chip 200. Each side of the mesh hole a1 is 100 μm - 300 μm larger than the LED chip and is located in the recessed area 110.

[0098] The thickness of the first transparent encapsulant 300 that is within the mesh hole a1 and wraps the side of the LED chip 200 will be greater than the thickness of the first transparent encapsulant 300 that is within the mesh hole a1 and wraps the top surface of the LED chip 200.

[0099] In this way, after soft baking, the viscosity of the first transparent encapsulant 300 on the side of the LED chip 200 is less than the viscosity of the first transparent encapsulant 300 on the top surface of the LED chip 200.

[0100] And through the stencil a, the directivity of the phosphor 310 shot at the first transparent encapsulant 300 in subsequent steps can be better, that is, it can be shot into the first transparent encapsulant 300 within the mesh hole a1 directionally.

[0101] That is to say, for the same phosphor 310, the resistance it encounters when entering the first transparent encapsulant 300 on the top surface of the LED chip 200 is greater, and the traveling distance is smaller; the resistance it encounters when entering the first transparent encapsulant 300 on the side of the LED chip 200 is smaller, and the traveling distance is greater.

[0102] Through the above method, the phosphor 310 can wrap the top surface and the side of the LED chip 200, thereby avoiding the situation where the light emitted from the light-emitting surface 210 directly penetrates through the first transparent encapsulant 300, and further improving the light conversion efficiency of the light source and making the light source performance better.

[0103] It should be understood that the process of the phosphor 310 traveling in the first transparent encapsulant 300 includes the sedimentation of the phosphor 310 in the first transparent encapsulant 300. However, after baking, the viscosity of the first transparent encapsulant 300 is large, and the sedimentation of the phosphor 310 is small, which has little impact on the distribution of the phosphor 310 in the first transparent encapsulant 300 in this embodiment.

[0104] It should also be understood that after the phosphor 310 on the side of the LED chip 200 reaches the limit position within the first transparent encapsulant 300, there may be a small distance from the substrate 100. In this case, the phosphor 310 cannot completely wrap the side of the LED chip 200.

[0105] However, very little light is emitted from the side of the LED chip 200 at this small distance, and it often exits approximately horizontally. This part of the light is easily absorbed by the first transparent encapsulant 300, the adjacent LED chip 200, and the encapsulation material, and thus does not affect the light emission uniformity of the LED chip 200.

[0106] It should be noted that due to the high viscosity of the first transparent encapsulant 300 in the mesh hole a1, after spraying the phosphor 310, it may not be able to flow laterally and reach the same horizontal plane as the first transparent encapsulant 300 outside the mesh hole a1 in a short time.

[0107] That is, the height of the phosphor layer c formed by the phosphor 310 at the first transparent encapsulant 300 in the mesh hole a1 is slightly higher than the height of the first transparent encapsulant 300 outside the mesh hole a1.

[0108] In some embodiments, step 530, spraying the phosphor 310 into the semi-cured first transparent encapsulant 300, includes:

[0109] As Figure 6 and Figure 7 shown, provide a powder spraying machine b. The powder spraying machine b sprays a phosphor glue towards the top surface direction of the LED chip 200 directly. The phosphor glue includes but is not limited to a mixture of phosphor and encapsulant, and the concentration range of the phosphor 310 satisfies: 1 mol / L - 10 mol / L.

[0110] In actual implementation, the refractive index of the phosphor glue is the same as that of the first transparent encapsulant 300, so that the phosphor glue and the first transparent encapsulant 300 can be well miscible, which is more conducive to the stable propagation of light.

[0111] On the contrary, if the refractive index of the phosphor glue is different from that of the first transparent encapsulant 300, there may be multiple interfaces between the phosphor glue and the first transparent encapsulant 300. The existence of these interfaces will scatter light and change the propagation direction of light, which is not conducive to the stable propagation of light. In actual implementation, the concentration of the phosphor 310 in the phosphor glue should be appropriate.

[0112] If the concentration of the phosphor 310 is very high, the phosphor 310 will densely enter the first transparent encapsulant 300 on the top surface of the LED chip 200, resulting in a large amount of light being reflected by the phosphor 310 particles towards the top surface direction of the LED chip 200, thereby reducing the light emission efficiency.

[0113] If the concentration of the phosphor 310 is very low, it is not easy for the phosphor 310 to enter the first transparent encapsulant 300, and it is difficult to travel within the first transparent encapsulant 300 and wrap the LED chip. As a result, the color consistency of the light emitted by the LED chip 200 is very poor.

[0114] In this step, by making the concentration range of the phosphor 310 in the powder spraying machine b satisfy: 1 mol / L - 10 mol / L, after the phosphor 310 enters the first transparent encapsulant 300, the particle density of the phosphor 310 can increase in the direction away from the top surface of the LED chip 200, thereby improving the light extraction efficiency and the color consistency of the emitted light.

[0115] In actual implementation, the distance H2 between the phosphor 310 closest to the top surface of the LED chip 200 and the top surface of the LED chip 200 satisfies: 2 μm - 20 μm.

[0116] It should be noted that, as Figure 7 shown, the powder spraying machine b sprays the phosphor 310 towards the top surface of the LED chip 200, and the spraying direction of the phosphor 310 can be consistent with the traveling direction of the phosphor 310 after it enters the first transparent encapsulant 300.

[0117] Similarly, it should be noted that after the phosphor 310 enters the first transparent encapsulant 300, it cannot be too far from the top surface of the LED chip 200. If it is too far from the top surface of the LED chip 200, it is possible that this part of the phosphor 310 entering the first transparent encapsulant 300 still cannot cover the LED chip 200 after traveling to the limit position, resulting in very poor color consistency of the light emitted by the LED chip 200.

[0118] If it is too close to the top surface of the LED chip 200, this part of the phosphor 310 entering the first transparent encapsulant 300 will densely gather on the top surface of the LED chip 200 after traveling to the limit position, thereby reducing the light extraction efficiency of the LED chip 200.

[0119] In this embodiment, by making the distance between the phosphor 310 closest to the top surface of the LED chip 200 and the top surface of the LED chip 200 satisfy: 2 μm - 20 μm, the color consistency of the light emitted by the LED chip 200 and the light extraction efficiency of the LED chip 200 are improved.

[0120] It should be understood that the distance between the phosphor 310 closest to the top surface of the LED chip 200 and the top surface of the LED chip 200 can be measured through experiments.

[0121] For example, after the phosphor powder 310 is sprayed in the direction of the top surface of the LED chip 200 by the powder spraying machine b, the first transparent encapsulant 300 is cut, and the distance between the phosphor powder 310 closest to the top surface of the LED chip 200 and the top surface of the LED chip 200 can be measured.

[0122] In actual implementation, the spraying speed of the phosphor powder 310 by the nozzle of the powder spraying machine b can be increased uniformly, or the phosphor powder 310 can be sprayed at intervals. This embodiment does not make any restrictions.

[0123] Among them, the thickness of the sprayed phosphor powder 310 (the thickness of the phosphor layer c) satisfies: 40um - 200um; the spraying speed of the phosphor powder 310 satisfies: 100mm / s - 300mm / s; the spraying times of the phosphor powder 310 satisfy: 1 - 5 times.

[0124] The distance between the nozzle of the powder spraying machine b and the substrate is adjustable. For example, the nozzle of the powder spraying machine b can move towards the substrate, or the substrate can move towards the nozzle of the powder spraying machine b. This embodiment does not make any restrictions.

[0125] In some embodiments, after step 530, spraying the phosphor powder 310 onto the semi-cured first transparent encapsulant 300 to form a phosphor layer c, and the particle density of the phosphor powder in the phosphor layer c increases from the direction close to the substrate to the direction away from the substrate, the method further includes: step 540, step 550, and step 560.

[0126] Step 540: Bake the semi-cured first transparent encapsulant 300 for the second time to cure the first transparent encapsulant 300.

[0127] In this step, the first transparent encapsulant 300 is cured by the second baking, which can avoid the sedimentation of the phosphor powder 310 in the first transparent encapsulant 300.

[0128] When the first transparent encapsulant 300 is cured, the distance between the phosphor powder 310 closest to the top surface of the LED chip 200 and the top surface of the LED chip 200 should satisfy: 2um - 20um.

[0129] Among them, the temperature of the second baking satisfies: 120°C - 180°C, and the time of the second baking satisfies: 20min - 60min.

[0130] Step 550: As Figure 8 shown, coat the second transparent encapsulant 400 on the surface of the cured first transparent encapsulant 300.

[0131] In this step, the second transparent encapsulant 400 should completely cover the first transparent encapsulant 300 to prevent the phosphor 310 in the first transparent encapsulant 300 from being exposed to the ambient gas, thereby avoiding the erosion of the phosphor 310 by the ambient gas.

[0132] In actual implementation, the refractive indices of the first transparent encapsulant 300 and the second transparent encapsulant 400 are the same.

[0133] Step 560: Bake the second transparent encapsulant 400 for the third time to cure the second transparent encapsulant 400, and the first transparent encapsulant and the second transparent encapsulant together form a glue seal layer.

[0134] Among them, the temperature of the third baking satisfies: 120 - 180 °C, and the time of the third baking satisfies: 1.5 h - 3 h.

[0135] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A manufacturing method of an LED lighting device, characterized in that, Including: Providing a substrate; Providing an LED chip and flip - mounting the LED chip at a preset position on the substrate; Coating a first transparent encapsulant on the substrate, with the first transparent encapsulant wrapping the LED chip; Performing a first baking on the first transparent encapsulant to make the first transparent encapsulant semi - cured; And Spraying phosphor powder at a preset position on the semi - cured first transparent encapsulant to form a phosphor layer, the phosphor layer wrapping the light - emitting surface of the LED chip, the light - emitting surface including a positive light - emitting surface disposed opposite to the substrate and a side light - emitting surface connected to the positive light - emitting surface. Among them, the phosphor layer located on the side light - emitting surface of the LED chip is spaced from the substrate, and the particle density of the phosphor in the phosphor layer increases from the top surface close to the LED chip to the direction away from the top surface of the LED chip; Performing a second baking on the semi - cured first transparent encapsulant to cure the first transparent encapsulant to fix the position of the sprayed phosphor powder; Coating a second transparent encapsulant along the surface of the cured first transparent encapsulant, with the second transparent encapsulant covering the phosphor layer and the first transparent encapsulant; Performing a third baking on the second transparent encapsulant to cure the second transparent encapsulant, and the first transparent encapsulant and the second transparent encapsulant jointly form a glue - sealing layer.

2. The manufacturing method of the LED lighting device according to claim 1, characterized in that, Coating a first transparent encapsulant on the substrate, with the first transparent encapsulant wrapping the light - emitting surface of the LED chip, including: A recessed area is formed on the provided substrate. On the premise that the LED chip is installed in the recessed area, coating the first transparent encapsulant in the recessed area; and Letting the first transparent encapsulant stand, and making the distance H1 between the upper surface of the first transparent encapsulant and the top surface of the light - emitting surface of the LED chip satisfy: 20um - 200um.

3. The manufacturing method of the LED lighting device according to claim 1, characterized in that, The thickness of the phosphor layer on the side of the LED chip is greater than the thickness of the phosphor layer on the top of the LED chip.

4. The manufacturing method of the LED lighting device according to claim 1, characterized in that, The distance H2 between the lower surface of the phosphor layer and the top surface of the light - emitting surface of the LED chip satisfies: 2um - 20um.

5. The manufacturing method of the LED lighting device according to claim 2, characterized in that, Performing a first baking on the first transparent encapsulant to make the first transparent encapsulant semi - cured; Before spraying phosphor powder into the semi - cured first transparent encapsulant to form a phosphor layer, the method further includes: Providing a stencil, the stencil being used to cover the substrate, and having at least one mesh hole on the stencil for exposing the LED chip, and the mesh hole corresponding to the recessed area.

6. The manufacturing method of the LED lighting device according to claim 1, characterized in that, Spraying phosphor powder into the semi - cured first transparent encapsulant, including: Providing a powder - spraying machine, the powder - spraying machine spraying phosphor powder in the direction facing the light - emitting surface of the LED chip, and the concentration range of the phosphor powder in the powder - spraying machine satisfies: 1mol / L - 10mol / L.

7. The manufacturing method of the LED lighting device according to claim 1, characterized in that, The semi - curing of the first transparent encapsulant satisfies: the viscosity of the first transparent encapsulant is 25000 centipoises - 100000 centipoises.

8. The manufacturing method of the LED lighting device according to claim 1, characterized in that, The thickness of the sprayed phosphor powder satisfies: 40um - 200um; The speed of spraying the phosphor satisfies: 100 mm / s - 300 mm / s; The number of times of powder spraying the phosphor satisfies: 1 - 5 times.

9. An LED lighting device, which is manufactured by the manufacturing method of the LED lighting device according to any one of claims 1 - 8, characterized in that, The LED lighting device includes: a substrate; an LED chip, which is mounted on the substrate; a glue encapsulation layer, which includes a first transparent encapsulation glue located on the substrate and wrapping the LED chip, a phosphor layer located on the surface of the first transparent encapsulation glue and wrapping the light-emitting surface of the LED chip, and a second transparent encapsulation glue covering the phosphor layer and the first transparent encapsulation glue. The light-emitting surface includes a positive light-emitting surface disposed opposite to the substrate and a side light-emitting surface connected to the positive light-emitting surface. Among them, the phosphor layer located on the side light-emitting surface of the LED chip is spaced from the substrate, and the phosphor layer is provided with phosphor, and the particle density of the phosphor increases from the top surface close to the LED chip to the direction away from the top surface of the LED chip.

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