Light emitting device and method for manufacturing light emitting device

Abstract

The embodiment of the present application provides a light emitting device and a manufacturing method of the light emitting device. The light emitting device comprises a substrate, a light emitting chip arranged on the substrate, a first fluorescent glue layer covering an upper surface of the light emitting chip, the first fluorescent glue layer comprising fluoride fluorescent powder and silica gel, and the fluoride fluorescent powder being uniformly distributed in the silica gel, and a second fluorescent glue layer covering the first fluorescent glue layer. The light emitting device provided by the embodiment covers the upper surface of the light emitting chip with the first fluorescent glue layer, and the first fluorescent glue layer comprises fluoride fluorescent powder and silica gel, and the fluoride fluorescent powder is uniformly distributed in the silica gel, so that the fluoride fluorescent powder is close to the light emitting chip, the purity of the fluoride fluorescent powder in the silica gel is high, the excitation efficiency of the fluoride fluorescent powder can be improved, and the heat dissipation efficiency is improved.

Description

Technical Field

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

[0002] Currently, LED products packaged with fluoride phosphors (such as KSF and KGF) are becoming increasingly popular, mainly because the spectral efficiency of fluoride phosphors is much higher than that of traditional red phosphors such as nitride.

[0003] However, fluoride phosphors are less efficient at being excited by blue light. White LED packaging typically includes a variety of phosphors with varying structures (e.g., garnet, silicate, sialon, nitride, fluoride, etc.). These phosphors have varying densities. When using traditional adhesive mixing, dispensing, and precipitation processes, the various phosphors mix together and sink simultaneously. The heavier phosphors are more likely to fall to the bottom layer, closer to the chip's light-emitting surface. Ultimately, the fluoride phosphors occupy a smaller proportion near the chip's light-emitting surface than those further away. This further impacts the fluoride phosphor's excitation and conversion efficiency, and consequently, the light-emitting efficiency of the white LED product. Summary of the Invention

[0004] Therefore, in order to overcome at least some of the defects and deficiencies in the prior art, embodiments of the present invention provide a light-emitting device and a method for manufacturing the light-emitting device.

[0005] Specifically, on the one hand, the light-emitting device provided by an embodiment of the present invention includes: a substrate; a light-emitting chip, which is arranged on the substrate; a first fluorescent glue layer, which covers the upper surface of the light-emitting chip, and the first fluorescent glue layer includes fluoride phosphor and silica gel, and the fluoride phosphor is uniformly distributed in the silica gel; a second fluorescent glue layer, which covers the first fluorescent glue layer.

[0006] On the other hand, an embodiment of the present invention also provides a method for manufacturing a light-emitting device, comprising: arranging a light-emitting chip on a substrate; forming a first fluorescent glue layer on the upper surface of the light-emitting chip through a powder spraying process or a dispensing process, wherein the first fluorescent glue mixture includes fluoride phosphor, silica gel and a diluent; and forming a second fluorescent glue layer on the first fluorescent glue layer.

[0007] As can be seen from the above, the light-emitting device provided in the embodiment of the present invention is configured such that a first fluorescent adhesive layer covers the upper surface of the light-emitting chip, and a second fluorescent adhesive layer covers the first fluorescent adhesive layer. The first fluorescent adhesive layer includes fluoride phosphor and silica gel, and the fluoride phosphor is evenly distributed in the silica gel. This allows the fluoride phosphor to be close to the light-emitting chip, and the fluoride phosphor has a high purity in the silica gel. This can improve the excitation efficiency of the fluoride phosphor and improve the heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0009] Figure 1 A schematic flow chart of a method for manufacturing a light-emitting device provided in an embodiment of the present invention.

[0010] Figure 2 A schematic structural diagram of a light-emitting device provided in an embodiment of the present invention.

[0011] Figure 3 This is a schematic structural diagram of another light-emitting device provided by an embodiment of the present invention.

[0012] Figure 4 This is a schematic structural diagram of yet another light-emitting device provided by an embodiment of the present invention.

[0013] Figure 5 This is a schematic structural diagram of another light-emitting device provided by an embodiment of the present invention.

[0014] Figure 6 This is a schematic structural diagram of another light-emitting device provided by an embodiment of the present invention.

[0015] Figure 7 This is a schematic structural diagram of another light-emitting device provided by an embodiment of the present invention.

[0016] Main component numbers:

[0017] 10. Light-emitting device; 11. Main light-emitting area; 12. Peripheral area; 100. Substrate; 200. Light-emitting chip; 300. First fluorescent adhesive layer; 400. Second fluorescent adhesive layer; 410. Precipitation layer; 420. Clear adhesive layer. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments described in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work shall fall within the scope of protection of the present invention.

[0019] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, top, and bottom) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0020] In the embodiments of the present invention, references to "first," "second," and the like are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of these features.

[0021] See also Figure 1 and Figure 2 The embodiment of the present invention provides a light emitting device 10 and a method for manufacturing the light emitting device. Figure 2 The lighting device 10 shown can be used, for example, by Figure 1 The light emitting device is manufactured by the manufacturing method shown.

[0022] like Figure 1 As shown, the manufacturing method of the light emitting device 10 may include the following steps:

[0023] S10, placing a light-emitting chip on a substrate;

[0024] S20, forming a first fluorescent glue layer on the upper surface of the light-emitting chip by a powder spraying process or a dispensing process, wherein the first fluorescent glue mixture includes fluoride phosphor powder, silica gel and a diluent;

[0025] S30: forming a second fluorescent adhesive layer on the first fluorescent adhesive layer.

[0026] Specifically, a substrate 100 is provided. The upper surface of the substrate 100 may, for example, include a die-bonding region, and the light-emitting chip 200 is fixed to the die-bonding region on the substrate 100. In this embodiment, the light-emitting device 10 may be an SMD package (Surface Mounted Devices), a COB package (Chips on Board), or a filament package. The light-emitting chip 200 may, for example, be one or more. The manufacturing method of this embodiment has significant advantages in light-emitting devices 10 such as COB packages and filament packages that simultaneously have multiple (usually more than three) light-emitting chips 200 on a substrate 100. A first fluorescent glue layer 300 is formed on the upper surface (i.e., the main light-emitting surface) of the light-emitting chip 200. For example, fluoride fluorescent powder, silica gel and a diluent may be mixed to form a first fluorescent glue mixture. The diluent may be, for example, siloxane or toluene. The first fluorescent glue mixture is then applied to the upper surface of the light-emitting chip 200 by a powder spraying process or a dispensing process. Since the diluent is volatile, the first fluorescent glue layer 300 including fluoride fluorescent powder and silica gel is formed on the upper surface of the light-emitting chip after it evaporates.

[0027] By adding a diluent to the mixture of fluoride phosphor and silica gel, the viscosity of the first fluorescent glue mixture can be reduced, ensuring that the first fluorescent glue mixture can be formed more quickly and evenly on the main light-emitting surface of the light-emitting chip 200 by a powder spraying process, or evenly formed on the main light-emitting surface of the light-emitting chip 200 by a quick leveling method of dispensing, thereby reducing the amount of silica gel used and uniformly distributing the fluoride phosphor within the silica gel, thereby improving the excitation conversion effect of the fluoride phosphor and improving the light extraction efficiency of the light-emitting device 10. In this embodiment, the first fluorescent glue layer 300 can be formed only on the main light-emitting surface (i.e., the upper surface) of the light-emitting chip 200, or can be simultaneously formed on the substrate 100 around the light-emitting chip 200 and / or coated on the side surface of the light-emitting chip 200. Specific implementation methods are described below with different embodiments.

[0028] The second fluorescent glue layer 400 is formed on the first fluorescent glue layer 300, for example, by a method similar to the above-mentioned method of forming the first fluorescent glue layer 300, or by a conventional dispensing process. Specifically, in one embodiment of the present embodiment, for example, the yellow-green phosphor can be first mixed with other phosphors such as nitride red powder, silica gel and a diluent to form a second fluorescent glue mixture, and then the second fluorescent glue mixture is applied to the first fluorescent glue layer 300 by a powder spraying process or a dispensing process, and the second fluorescent glue layer 400 is formed after the diluent evaporates. In another embodiment of the present embodiment, for example, the yellow-green phosphor can first be mixed with other phosphors such as nitride red powder and silica gel to form a third fluorescent glue mixture, and then the third fluorescent glue mixture is applied to the first fluorescent glue layer 300 by a conventional dispensing process to form the second fluorescent glue layer 400. Of course, the present embodiment is not limited to this.

[0029] like Figure 2 As shown, the light-emitting device 10 provided in the embodiment of the present invention may, for example, include a substrate 100, a light-emitting chip 200, a first fluorescent glue layer 300, and a second fluorescent glue layer 400. The substrate 100 may, for example, be a metal substrate, a ceramic substrate, a glass substrate, a composite substrate, etc. The light-emitting chip 200 may, for example, be a blue light-emitting chip, and the light-emitting chip 200 is disposed on the substrate 100. The first fluorescent glue layer 300 covers the light-emitting chip 200, and the first fluorescent glue layer 300 includes fluoride phosphor and silica gel, and the fluoride phosphor is uniformly distributed in the silica gel. The fluoride phosphor is a manganese-activated fluoride series red phosphor. Commonly used fluoride phosphors include K2SiF6:Mn 4+ (KSF) 、 K2TiF6:Mn 4+ (KTF), K2GeF6:Mn 4+ (KGF), etc. The second fluorescent glue layer 400 is covered on the first fluorescent glue layer 300. The second fluorescent glue layer 400 may include other fluorescent powders such as yellow-green fluorescent powder and nitride red fluorescent powder, which is not particularly limited in the present invention. The light-emitting device 10 provided by the embodiment of the present invention is provided by covering the light-emitting chip 200 with the first fluorescent glue layer 300, and covering the second fluorescent glue layer 400 on the first fluorescent glue layer 300. The first fluorescent glue layer 300 includes fluoride fluorescent powder and silica gel. The first fluorescent glue layer 300 including fluoride fluorescent powder and the second fluorescent glue layer 400 including other fluorescent powders are sequentially layered on the light-emitting chip 200, so that the fluoride fluorescent powder with relatively low excitation efficiency is closer to the light-emitting chip 200, and in particular, closer to the main light-emitting surface of the light-emitting chip 200, thereby improving the excitation effect of the fluoride fluorescent powder, thereby further improving the light extraction efficiency of the light-emitting device 10.

[0030] Preferably, the first fluorescent glue layer 300 of the present invention is as follows Figure 1As shown, the fluoride phosphor is mixed with silica gel and a diluent and then formed on the light emitting chip 200 by spraying or dispensing. The first fluorescent glue layer 300 formed in this way after the diluent evaporates has specific structural characteristics, so that the first fluorescent glue layer 300 can more conveniently and evenly cover the main light emitting surface of the light emitting chip 200, and achieve better excitation conversion effect and light extraction efficiency with less fluorescent glue. Specifically, as Figure 2 As shown, the space above and on the upper surface of the light-emitting chip 200 is defined as the main light-emitting region 11, and the area outside the main light-emitting region 11 of the light-emitting chip 200 is defined as the peripheral region 12. The first fluorescent adhesive layer 300 covers the main light-emitting region 11 and the peripheral region 12. In some implementations of this embodiment, the first fluorescent adhesive layer 300 may, for example, cover the upper surface and side surfaces of the light-emitting chip 200 and cover the upper surface of the substrate 100. In some embodiments, with the top surface of the substrate 100 as a reference plane, the top surface height H1 of the first fluorescent glue layer 300 in the main light-emitting region 11 is greater than the top surface height H2 of the first fluorescent glue layer 300 in the peripheral region 12. Specifically, the height H1 between the top surface of the first fluorescent glue layer 300 in the main light-emitting region 11 and the top surface of the substrate 100 is greater than the height H2 between the top surface of the first fluorescent glue layer 300 in the peripheral region 12 and the top surface of the substrate 100. In other words, the first fluorescent glue layer 300 exhibits a top surface with a height difference in a cross-section of the light-emitting device 10 perpendicular to the top surface of the light-emitting chip 200. In some more preferred embodiments, the top surface height H2 of the first fluorescent glue layer 300 in the peripheral region 12 is even lower than the top surface height H3 of the light-emitting chip 200. Specifically, the top surface height of the first fluorescent glue layer 300 in the peripheral region 12 relative to the top surface of the substrate 100 is lower than the top surface height of the light-emitting chip 200 relative to the top surface of the substrate 100. From another perspective, in this embodiment, the second fluorescent glue layer 400 is formed on the first fluorescent glue layer 300, and is also simultaneously formed in the main light-emitting area 11 and the peripheral area 12, and the height of the lower surface of the second fluorescent glue layer 400 in the peripheral area 12 is lower than its height in the lower surface of the main light-emitting area 11. In some more preferred embodiments, the height of the lower surface of the second fluorescent glue layer 400 in the peripheral area 12 is even lower than the height H3 of the upper surface of the light-emitting chip 200.

[0031] In an embodiment of the present invention, the light-emitting device 10 is packaged in a form such as a COB (chip on board) package, an SMD (surface mounted device) package, or a filament package. However, it is particularly worth mentioning that for a light-emitting device 10 in a COB package or other multi-chip (three or more) package (i.e., one with a larger packaging area), the present invention employs a first phosphor adhesive layer 300 formed on the light-emitting chip 200 by mixing fluoride phosphor, silica gel, and a diluent and then applying the mixture by spraying or dispensing. This overcomes the difficulty of implementing conventional layered dispensing processes in larger packaging areas, thereby enabling the fluoride phosphor to more conveniently and evenly cover the primary light-emitting surface of the light-emitting chip 200, thereby improving the light output efficiency and uniformity of such products.

[0032] Furthermore, in some embodiments of the present invention, the fluoride phosphor powder is evenly distributed in the first phosphor layer 300 of the light-emitting device 10, without stratification. Furthermore, its mass percentage (i.e., the ratio of the mass of the fluoride phosphor powder to the total mass of the fluoride phosphor powder and the silica gel in the first phosphor layer 300) can be greater than 60%, or even greater than 70%. In traditional dispensing solutions, once the mass percentage of the fluoride phosphor paste exceeds 50%, poor fluidity and uniform dispensing become problematic. This allows the present invention to achieve high excitation conversion and light extraction efficiency while reducing the amount of fluoride phosphor paste used. This arrangement can, for example, prevent the impact of high silica gel content in the first phosphor layer 300 on heat dissipation of the light-emitting device 10. It should be noted that the mass percentage of the fluoride phosphor powder in the first phosphor layer 300 of the light-emitting device 10 of the present invention can be greater than 60%, and this is not intended to limit this percentage to 60% or higher in all embodiments. The specific percentage will depend on the light output requirements of the light-emitting device 10 and the other phosphors used.

[0033] In an embodiment of the present invention, the ratio of fluoride phosphor to silica gel in the first fluorescent adhesive layer 300 can be, for example, between 1:9 and 9:1, that is, the mass percentage of fluoride phosphor in the first fluorescent adhesive layer 300 is between 10% and 90%. Preferably, the mass percentage of fluoride phosphor in the first fluorescent adhesive layer 300 is between 60% and 90%. By such a configuration, for example, the effect of heat dissipation caused by a high silica gel content in the first fluorescent adhesive layer 300 can be avoided. In some embodiments of the present invention, such as Figure 3 As shown, when the amount of the first fluorescent adhesive layer 300 is large, or the ratio of the fluoride phosphor to the silica gel is low, the upper surface of the first fluorescent adhesive layer 300 will present a relatively smooth curved surface with a small height difference; Figure 2As shown, when the amount of the first fluorescent adhesive layer 300 is small, or the ratio of the fluoride phosphor to the silica gel is high, the upper surface of the first fluorescent adhesive layer 300 may present a larger height difference; Figure 4 As shown, when the amount of first fluorescent adhesive layer 300 used is small, or the ratio of fluoride phosphor to silica gel is high, the upper surface of the first fluorescent adhesive layer 300 may even be discontinuous. The above-mentioned different structures of the first fluorescent adhesive layer 300 are all specific structural features of the first fluorescent adhesive layer 300 formed by the manufacturing method of the light-emitting device 10 provided in the embodiments of the present invention, and are applicable to the corresponding different embodiments below.

[0034] See Figure 5 , Figure 5 This is another embodiment of the present invention. The light emitting device 10 provided in this embodiment includes a substrate 100, a light emitting chip 200, and a first fluorescent adhesive layer 300. The selection and arrangement are similar to those in Figure 2 The embodiment shown is the same as that shown in FIG. Figure 2 The main difference between the illustrated embodiments is that the second fluorescent adhesive layer 400 provided in this embodiment is disposed in layers on the first fluorescent adhesive layer 300. The preparation method can be based on the aforementioned method for forming the second fluorescent adhesive layer 400, with the addition of natural sedimentation and centrifugal / semi-centrifugal sedimentation steps. This allows the majority of the other phosphors in the second fluorescent adhesive layer 400 to deposit on the surface of the first fluorescent adhesive layer 300, resulting in the second fluorescent adhesive layer 400 exhibiting a layered structure. Specifically, the second fluorescent adhesive layer 400 can include, for example, a precipitate layer 410 proximal to the first fluorescent adhesive layer 300 and a clear adhesive layer 420 located distal to the precipitate layer 410, with the clear adhesive layer 420 located on the side of the precipitate layer 410 distal to the first fluorescent adhesive layer 300 and distal to the light-emitting chip 200. It should be noted that the clear adhesive layer 420 is not completely free of fluorescent adhesive; rather, the content / concentration of the phosphors visible to the naked eye in the clear adhesive layer 420 is lower than that in the precipitate layer 410.

[0035] To put it another way, in a cross-sectional view of the light-emitting device 10 of this embodiment perpendicular to the main light-emitting surface of the light-emitting chip 200, the fluorescent glue can, for example, be displayed as a three-layer structure, including a first fluorescent glue layer 300, a precipitation layer 410 and a clear glue layer 420, the precipitation layer 410 is located between the first fluorescent glue layer 300 and the clear glue layer 420, and the clear glue layer 420 is located on the side of the precipitation layer 410 away from the light-emitting chip 200. The second fluorescent glue layer 400 is formed on the first fluorescent glue layer 300 and is also simultaneously formed in the main light-emitting area 11 and the peripheral area 12. The height of the lower surface of the second fluorescent glue layer 400 in the peripheral area 12 is lower than the height of the lower surface of the second fluorescent glue layer 400 in the main light-emitting area 11. That is, the height between the lower surface of the second fluorescent glue layer 400 in the peripheral area 12 and the upper surface of the substrate 100 is lower than the height between the lower surface of the second fluorescent glue layer 400 in the main light-emitting area 11 and the upper surface of the substrate 100. This allows the phosphor in the second fluorescent glue layer 400 to be more concentrated and close to the substrate 100, which helps to dissipate heat from the phosphor in the second fluorescent glue layer 400 downward through the substrate 100, thereby improving the thermal stability of the light-emitting device 10. In some implementations of this embodiment, in order to ensure a better heat dissipation effect, a precipitation step is added when forming the second fluorescent glue layer 400, so that the second fluorescent glue layer 400 is better leveled, and the phosphor contained therein also tends to settle toward the substrate 100, and fills the difference between the first fluorescent glue layer 300 in the main light-emitting area 11 and the peripheral area 12, so that the interface between the first fluorescent glue layer 300 and the precipitation layer 410 presents a relatively larger height difference, while the interface between the precipitation layer 410 and the clear glue layer 420 presents a smaller undulation; from another perspective, the thickness W3 of the precipitation layer 410 of the second fluorescent glue layer 400 in the peripheral area 12 will be greater than the thickness W2 of the precipitation layer 410 in the main light-emitting area 11. For a CRI90 series light-emitting device 10, ensuring optimal light output (light color, display index, etc.) requires a suitable ratio of fluoride phosphor to other phosphors. Furthermore, for better thermal stability (for example, improved heat dissipation), the amount of first phosphor layer 300 must be controlled. Current experiments have found that when the ratio of the thickness W1 of the first phosphor layer 300 in the main light-emitting region 11 to the thickness W2 of the precipitation layer 410 is less than 2, these excellent results can be uniformly achieved. Preferably, the thickness W1 of the first phosphor layer 300 in the main light-emitting region 11 is less than the thickness W2 of the precipitation layer 410.

[0036] Please refer to Figure 6 , Figure 6 This is another embodiment of the present invention. The light emitting device 10 of this embodiment includes a substrate 100, a light emitting chip 200, and a second fluorescent adhesive layer 400. The selection and arrangement are similar to those of Figure 2 The light emitting device 10 of this embodiment is the same as that of the embodiment shown in FIG. Figure 2The main difference of the light-emitting device 10 shown is that the first fluorescent glue layer 300 only covers the main light-emitting area 11 and is not provided in the peripheral area 12. Therefore, when the second fluorescent glue layer 400 is formed on the first fluorescent glue layer 300, it is located on the side of the first fluorescent glue layer 300 away from the light-emitting chip 200 in the main light-emitting area 11, and is directly located on the substrate 100 in the peripheral area 12. However, in this case, the height H1 of the upper surface of the first fluorescent glue layer 300 in the main light-emitting area 11 is greater than the height H2 of the upper surface of the first fluorescent glue layer 300 in the peripheral area 12 (in this embodiment, this thickness is equal to 0); or more precisely, the height of the lower surface of the second fluorescent glue layer 400 in the peripheral area 12 is lower than the height of its lower surface in the main light-emitting area 11.

[0037] Refer again Figure 7 , Figure 7 This is another embodiment of the present invention. The light emitting device 10 of this embodiment includes a substrate 100, a light emitting chip 200, and a first fluorescent adhesive layer 300. The selection and arrangement are similar to those of Figure 6 The light emitting device 10 of this embodiment is the same as that of the embodiment shown in FIG. Figure 6 The main difference of the light-emitting device 10 shown is that the second fluorescent glue layer 400 of this embodiment is provided on the first fluorescent glue layer 300 in a layered manner. In terms of method, the steps of natural precipitation and centrifugal / semi-centrifugal precipitation can be added to the aforementioned method of forming the second fluorescent glue layer 400. This allows most of the other phosphors in the second fluorescent glue layer 400 of this embodiment to be deposited on the surface of the first fluorescent glue layer 300 and the surface of the substrate 100, so that the second fluorescent glue layer 400 exhibits a layered structure, that is, the second fluorescent glue layer 400 can, for example, include a precipitation layer 410 and a clear glue layer 420 located on the precipitation layer 410. The second fluorescent glue layer 400 of this embodiment is different from the first fluorescent glue layer 300. Figure 5 The main difference of the second fluorescent glue layer 400 provided in the illustrated embodiment is that the precipitation layer 410 is disposed on the substrate 100 in the peripheral region 12. However, the lower surface height of the second fluorescent glue layer 400 in the peripheral region 12 is lower than the lower surface height in the main light-emitting region 11. The thickness W3 of the precipitation layer 410 of the second fluorescent glue layer 400 in the peripheral region 12 is greater than the thickness W2 of the precipitation layer 410 in the main light-emitting region 11. As a result, the phosphor powder in the second fluorescent glue layer 400 can be more concentrated close to the substrate 100, which helps to dissipate heat from the phosphor powder in the second fluorescent glue layer 400 downward through the substrate 100, thereby improving the thermal stability of the light-emitting device 10.

[0038] In addition, it can be understood that the aforementioned embodiments are merely exemplary descriptions of the present invention. Under the premise that the technical features do not conflict, the structures do not contradict, and the purpose of the present invention is not violated, the technical solutions of the various embodiments can be arbitrarily combined and used in combination.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A light emitting device, characterized in that: include: substrate; A light-emitting chip is disposed on the substrate; a first fluorescent adhesive layer covering the upper surface of the light-emitting chip and the upper surface of the substrate, the first fluorescent adhesive layer comprising fluoride phosphor and silica gel, wherein the fluoride phosphor is evenly distributed in the silica gel, and the first fluorescent adhesive layer has an uneven upper surface; The second fluorescent adhesive layer covers the first fluorescent adhesive layer and the side surface of the light-emitting chip, and the second fluorescent adhesive layer is different from the first fluorescent adhesive layer.

2. The light emitting device according to claim 1, wherein Taking the upper surface of the substrate as a reference plane, the height of the upper surface of the first fluorescent glue layer covering the light-emitting chip is greater than the height of the upper surface of the first fluorescent glue layer covering the substrate.

3. The light emitting device according to claim 2, wherein: The height of the upper surface of the first fluorescent glue layer covering the substrate is smaller than the height of the upper surface of the light-emitting chip.

4. The light emitting device according to claim 1, wherein The second fluorescent glue layer includes a precipitation layer and a clear glue layer, and the clear glue layer is located on a side of the precipitation layer away from the substrate.

5. The light emitting device according to claim 4, wherein: The ratio of the thickness of the first fluorescent glue layer to the thickness of the precipitation layer is less than 2.

6. The light emitting device according to claim 5, wherein The thickness of the first fluorescent glue layer is smaller than the thickness of the precipitation layer.

7. A method for manufacturing a light emitting device, characterized in that: include: placing a light-emitting chip on a substrate; A first fluorescent glue layer is formed on the upper surface of the light-emitting chip by a powder spraying process or a dispensing process, wherein the first fluorescent glue mixture includes fluoride phosphor, silica gel and a diluent, and the first fluorescent glue layer covers the upper surface of the light-emitting chip and the upper surface of the substrate, and the first fluorescent glue layer has an uneven upper surface; A second fluorescent glue layer is formed on the first fluorescent glue layer, the second fluorescent glue layer covers the first fluorescent glue layer and the side surface of the light-emitting chip, and the second fluorescent glue layer is different from the first fluorescent glue layer.

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