Light-emitting device and method for manufacturing light-emitting device

Abstract

The embodiment of the invention provides a light-emitting device and a manufacturing method of the light-emitting device. The light emitting device includes: a substrate; the light-emitting chip is arranged on the substrate; the first fluorescent glue layer covers the upper surface of the light-emitting chip, the first fluorescent glue layer comprises fluoride fluorescent powder and silica gel, and the fluoride fluorescent powder is uniformly distributed in the silica gel; and the second fluorescent glue layer covers the first fluorescent glue layer. According to the light-emitting device provided by the embodiment of the invention, the first fluorescent glue layer covers the upper surface of the light-emitting chip, the first fluorescent glue layer comprises the fluoride fluorescent powder and the 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, and the purity of the fluoride fluorescent powder in the silica gel is relatively 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, the efficiency of fluoride phosphors excited by blue light is low, and the packaging of white light LED products usually includes a variety of phosphors with different structures (for example, selected from garnet, silicate, sialon powder, nitride, fluoride, etc.), and the density of these phosphors is different. When using traditional mixing, dispensing, and precipitation processes, various phosphors are mixed together and sink at the same time. Phosphors with higher specific gravity are more likely to fall to the bottom layer, close to the chip light-emitting surface, and finally the proportion of fluoride phosphors close to the chip light-emitting surface is smaller than the proportion of fluoride phosphors far from the chip light-emitting surface. This further affects the effect of fluoride phosphors being excited and converted, and then affects the light-emitting efficiency of white light LED products. Summary of the invention

[0004] Therefore, in order to overcome at least some of the defects and shortcomings 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 fluorescent powder and silica gel, and the fluoride fluorescent powder 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: setting 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 achieved by covering the upper surface of the light-emitting chip with a first fluorescent glue layer, and covering the first fluorescent glue layer with a second fluorescent glue layer, and the first fluorescent glue layer includes fluoride fluorescent powder and silica gel, and the fluoride fluorescent powder is evenly distributed in the silica gel, so that the fluoride fluorescent powder is close to the light-emitting chip, and the fluoride fluorescent powder has a higher purity in the silica gel, which can improve the excitation efficiency of the fluoride fluorescent powder 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 accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying 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 A schematic structural diagram of another light emitting device provided in an embodiment of the present invention.

[0012] Figure 4 A schematic structural diagram of yet another light emitting device provided in an embodiment of the present invention.

[0013] Figure 5 A schematic structural diagram of another light emitting device provided in an embodiment of the present invention.

[0014] Figure 6 A schematic structural diagram of another light emitting device provided in an embodiment of the present invention.

[0015] Figure 7 A schematic structural diagram of another light emitting device provided in an embodiment of the present invention.

[0016] Main component numbers: 10. Light-emitting device; 11. Main light-emitting area; 12. Peripheral area; 100. Substrate; 200. Light-emitting chip; 300. First fluorescent glue layer; 400. Second fluorescent glue layer; 410. Precipitation layer; 420. Clear glue layer. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments 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 belong to the protection scope of the present invention.

[0018] 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 components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0019] In the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0020] 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.

[0021] like Figure 1 As shown, the manufacturing method of the light emitting device 10 may include the following steps, for example: S10, placing a light-emitting chip on a substrate; 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 fluorescent powder, silica gel and a diluent; S30, forming a second fluorescent glue layer on the first fluorescent glue layer.

[0022] Specifically, a substrate 100 is provided, and the upper surface of the substrate 100 may include a solid crystal area, for example, and the light-emitting chip 200 is fixed to the solid crystal area on the substrate 100. In the present embodiment, the light-emitting device 10 may be an SMD package (Surface Mounted Devices), or a COB package (Chips on Board), or a filament package. The light-emitting chip 200 may be, for example, one or more. Among the light-emitting devices 10 such as COB packages and filament packages that have multiple (usually more than 3) light-emitting chips 200 on a substrate 100 at the same time, the manufacturing method of the present embodiment has more obvious advantages. 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 coated on 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.

[0023] By adding a diluent to the mixture of fluoride phosphor and silica gel, the viscosity of the first fluorescent glue mixture can be reduced, and the first fluorescent glue mixture can be ensured to be formed more quickly and evenly on the main light-emitting surface of the light-emitting chip 200 by the powder spraying process, or to be formed evenly on the main light-emitting surface of the light-emitting chip 200 by the fast leveling method of dispensing, thereby reducing the amount of silica gel used, and the fluoride phosphor is evenly distributed in the silica gel, thereby improving the effect of the excitation conversion 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 it 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. The specific implementation method is described in different embodiments below.

[0024] 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 implementation of the present embodiment, for example, the yellow-green fluorescent powder may be first mixed with other fluorescent powders such as nitride red powder, silica gel and diluent to form a second fluorescent glue mixture, and then the second fluorescent glue mixture may be applied to the first fluorescent glue layer 300 by a powder spraying process or a dispensing process, and the second fluorescent glue layer 400 may be formed after the diluent evaporates. In another implementation of the present embodiment, for example, the yellow-green fluorescent powder may be first mixed with other fluorescent powders such as nitride red powder and silica gel to form a third fluorescent glue mixture, and then the third fluorescent glue mixture may be 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 thereto.

[0025] 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, and the fluoride phosphor is a manganese-activated fluoride series red phosphor, and commonly used fluoride phosphors include K2SiF6:Mn 4+ (KSF) 、 K2TiF6:Mn 4+ (KTF), K2GeF6:Mn 4+ (KGF), etc. The second fluorescent glue layer 400 covers the first fluorescent glue layer 300, and 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 in the embodiment of the present invention is provided by covering the light-emitting chip 200 with the first fluorescent glue layer 300, and the second fluorescent glue layer 400 covers the first fluorescent glue layer 300, and the first fluorescent glue layer 300 includes fluoride fluorescent powder and silica gel, and by sequentially layering the first fluorescent glue layer 300 including the fluoride fluorescent powder and the second fluorescent glue layer 400 including other fluorescent powders 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.

[0026] Preferably, the first fluorescent glue layer 300 of the present invention is Figure 1As shown, the fluoride phosphor is mixed with silica gel and 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 presents a specific structural feature, 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 on and above the upper surface of the light emitting chip 200 is defined as the main light emitting area 11, and the area outside the main light emitting area 11 of the light emitting chip 200 is defined as the peripheral area 12, and the first fluorescent glue layer 300 covers the main light emitting area 11 and the peripheral area 12. In some implementations of this embodiment, the first fluorescent glue 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 upper surface of the substrate 100 as a reference plane, the upper surface height H1 of the first fluorescent glue layer 300 in the main light-emitting region 11 is greater than the upper surface height H2 of the first fluorescent glue layer 300 in the peripheral region 12, that is, the height H1 between the upper surface of the first fluorescent glue layer 300 in the main light-emitting region 11 and the upper surface of the substrate 100 is greater than the height H2 between the upper surface of the first fluorescent glue layer 300 in the peripheral region 12 and the upper surface of the substrate 100; in other words, the first fluorescent glue layer 300 will present a top surface with a height difference in a certain cross-sectional view of the light-emitting device 10 perpendicular to the upper surface of the light-emitting chip 200. In some more preferred embodiments, the upper surface height H2 of the first fluorescent glue layer 300 in the peripheral region 12 is even lower than the upper surface height H3 of the light-emitting chip 200, that is, the upper surface height of the first fluorescent glue layer 300 in the peripheral region 12 relative to the upper surface of the substrate 100 is lower than the upper surface height of the light-emitting chip 200 relative to the upper 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.

[0027] In the embodiment of the present invention, the packaging form of the light emitting device 10 is, for example, COB packaging (Chips on Board), SMD packaging (Surface Mounted Devices) or filament packaging, etc. However, it is particularly worth mentioning that for the light emitting device 10 with COB packaging or other multi-chip (three or more) packaging (i.e., with a larger packaging area), the first fluorescent glue layer 300 formed on the light emitting chip 200 by mixing fluoride phosphor, silica gel and diluent by spraying or dispensing in the present invention overcomes the problem that the traditional layered dispensing process is difficult to implement in a larger packaging area, and achieves the effect of fluoride phosphor covering the main light emitting surface of the light emitting chip 200 more conveniently and evenly, thereby improving the light output efficiency and light output uniformity of such products.

[0028] In addition, in the first fluorescent glue layer 300 of the light-emitting device 10 provided in some embodiments of the present invention, the fluoride fluorescent powder is evenly distributed and not layered; in addition, its mass percentage (i.e., the ratio of the mass of the fluoride fluorescent powder to the total mass of the fluoride fluorescent powder and the silica gel in the first fluorescent glue layer 300) can be greater than 60%, or even greater than 70%, while in the traditional dispensing solution, once the mass percentage of the fluoride fluorescent glue exceeds 50%, there is a problem of poor fluidity and difficulty in uniform dispensing. As a result, the present invention can reduce the amount of fluoride fluorescent glue while achieving high excitation conversion effect and high light extraction efficiency. Through such a setting, for example, when the silica gel content in the first fluorescent glue layer 300 is high, it can be avoided that the heat dissipation of the light-emitting device 10 is affected. However, it should be noted that the mass percentage of the fluoride fluorescent powder in the first fluorescent glue layer 300 of the light-emitting device 10 of the present invention can be achieved above 60%, and it is not used to limit the mass percentage to be above 60% in all embodiments. The specific selection will be adjusted according to the light extraction requirements of the light-emitting device 10 and other matching fluorescent powders.

[0029] In an embodiment of the present invention, the ratio of fluoride phosphor to silica gel in the first fluorescent glue layer 300 may be, for example, between 1:9 and 9:1, that is, the mass percentage of fluoride phosphor in the first fluorescent glue layer 300 is between 10% and 90%. Preferably, the mass percentage of fluoride phosphor in the first fluorescent glue layer 300 is between 60% and 90%. By such a setting, for example, when the silica gel content in the first fluorescent glue layer 300 is high, it can be avoided that the heat dissipation is affected. In some embodiments of the present invention, such as Figure 3 As shown, when the amount of the first fluorescent glue layer 300 is large, or the ratio of the fluoride fluorescent powder to the silica gel is low, the upper surface of the first fluorescent glue layer 300 will present a relatively smooth curved surface with a small height difference; Figure 2As shown, when the amount of the first fluorescent glue layer 300 is small, or the ratio of the fluoride fluorescent powder to the silica gel is high, the upper surface of the first fluorescent glue layer 300 may present a larger height difference; Figure 4 As shown, when the amount of the first fluorescent glue layer 300 is small, or the ratio of the fluoride phosphor to the silica gel is high, the upper surface of the first fluorescent glue layer 300 may even be discontinuous. The above-mentioned different structures of the first fluorescent glue layer 300 are all specific structural features presented by the first fluorescent glue layer 300 formed by the manufacturing method of the light-emitting device 10 provided in the embodiment of the present invention, and are applicable to the corresponding different embodiments below.

[0030] See also 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 glue layer 300. The selection and arrangement are the same as those of Figure 2 The embodiment shown is the same as that shown in FIG. 1 , and will not be described in detail here. Figure 2 The main difference between the embodiments shown is that the second fluorescent glue layer 400 provided in this embodiment is arranged on the first fluorescent glue layer 300 in a layered manner. In terms of the preparation method, the steps of natural precipitation and centrifugal / semi-centrifugal precipitation can be added on the basis of the aforementioned method for forming the second fluorescent glue layer 400. Most of the other fluorescent powders in the second fluorescent glue layer 400 in this embodiment are deposited on the surface of the first fluorescent glue layer 300, so that the second fluorescent glue layer 400 shows a layered structure, that is, the second fluorescent glue layer 400 can, for example, include a precipitation layer 410 close to the first fluorescent glue layer 300 and a clear glue layer 420 located in the precipitation layer 410 away from the first fluorescent glue layer 300, that is, the clear glue layer 420 is located on the side of the precipitation layer 410 away from the first fluorescent glue layer 300 and away from the light-emitting chip 200. It should be noted that the clear glue layer 420 does not completely contain fluorescent glue, but the content / concentration of the fluorescent powder visible to the naked eye in the clear glue layer 420 is less than that in the precipitation layer 410.

[0031] To put it another way, in a cross-sectional view of the light-emitting device 10 of the present 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 formed in the main light-emitting area 11 and the peripheral area 12 simultaneously, and the lower surface height of the second fluorescent glue layer 400 in the peripheral area 12 is lower than the lower surface height 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 smaller 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, so that the fluorescent powder in the second fluorescent glue layer 400 can be more concentrated and close to the substrate 100, which helps to conduct the heat of the fluorescent powder 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 the present 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 fluorescent powder contained therein also tends to precipitate toward the substrate 100, and fills the height difference between the main light-emitting area 11 and the peripheral area 12 of the first fluorescent glue layer 300, so that the interface between the first fluorescent glue layer 300 and the precipitation layer 410 presents a relatively larger height difference, and 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 the CRI90 series light-emitting device 10, in order to ensure the light emission effect (light color, display index, etc.), it is necessary to mix a suitable ratio of fluoride phosphor and other phosphors, and in order to achieve better thermal stability (for example, to improve the heat dissipation effect), it is necessary to control the amount of the first fluorescent glue layer 300. The current experiment found that when the ratio of the thickness W1 of the first fluorescent glue layer 300 located in the main light-emitting area 11 to the thickness W2 of the precipitation layer 410 is less than 2, the above-mentioned good effect can be uniformly achieved. Preferably, the thickness W1 of the first fluorescent glue layer 300 located in the main light-emitting area 11 is less than the thickness W2 of the precipitation layer 410.

[0032] Please refer to Figure 6 , Figure 6 Another embodiment of the present invention is provided. 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 the same as those of Figure 2 The light emitting device 10 of this embodiment is the same as 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 arranged in the peripheral area 12. Therefore, when the second fluorescent glue layer 400 is formed on the first fluorescent glue layer 300, it will be 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 directly on the substrate 100 in the peripheral area 12. However, in this case, it is also consistent with the upper surface height H1 of the first fluorescent glue layer 300 in the main light-emitting area 11 being greater than the upper surface height H2 of the first fluorescent glue layer 300 in the peripheral area 12 (this thickness is equal to 0 in this embodiment); or more precisely, it is also consistent with the lower surface height of the second fluorescent glue layer 400 in the peripheral area 12 being lower than its lower surface height in the main light-emitting area 11.

[0033] Refer to Figure 7 , Figure 7 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 glue layer 300. The selection and arrangement are the same as those of Figure 6 The light emitting device 10 of this embodiment is the same as 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 disposed 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 on the basis of the aforementioned method of forming the second fluorescent glue layer 400. This allows most of the other fluorescent powders 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 shows 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 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 area 12, but the lower surface height of the same second fluorescent glue layer 400 in the peripheral area 12 will be lower than the lower surface height in the main light-emitting area 11, and 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, so that the fluorescent powder in the second fluorescent glue layer 400 can be more concentrated and close to the substrate 100, which helps to conduct the heat of the fluorescent powder in the second fluorescent glue layer 400 downward through the substrate 100, thereby improving the thermal stability of the light-emitting device 10.

[0034] In addition, it can be understood that the aforementioned embodiments are only 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.

[0035] 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 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 glue layer, covering the upper surface of the light-emitting chip, wherein the first fluorescent glue layer comprises fluoride fluorescent powder and silica gel, and the fluoride fluorescent powder is evenly distributed in the silica gel; The second fluorescent glue layer covers the first fluorescent glue layer.

2. The light emitting device according to claim 1, characterized in that: The first fluorescent glue layer covers the upper surface of the light-emitting chip, and the second fluorescent glue layer covers the upper surface of the first fluorescent glue layer and the upper surface of the substrate.

3. The light emitting device according to claim 1, characterized in that: The first fluorescent glue layer covers the upper surface of the light-emitting chip, the upper surface of the substrate and the side surface of the light-emitting chip, and the second fluorescent glue layer covers the first fluorescent glue layer.

4. The light emitting device according to claim 1, characterized in that: The first fluorescent glue layer covers the upper surface of the light-emitting chip and the upper surface of the substrate, and the second fluorescent glue layer covers the first fluorescent glue layer and the side surface of the light-emitting chip.

5. The light emitting device according to claim 3 or 4, characterized in that: A height between an upper surface of the first fluorescent glue layer on the light-emitting chip and an upper surface of the substrate is greater than a height between an upper surface of the first fluorescent glue layer on the substrate and an upper surface of the substrate.

6. The light emitting device according to claim 5, characterized in that: A height between an upper surface of the first fluorescent glue layer on the substrate and an upper surface of the substrate is smaller than a height between an upper surface of the light-emitting chip and an upper surface of the substrate.

7. The light emitting device according to any one of claims 2 to 4, characterized in that: 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.

8. The light emitting device according to claim 7, characterized in that: The ratio of the thickness of the first fluorescent glue layer to the thickness of the precipitation layer is less than 2.

9. The light emitting device according to claim 8, characterized in that: The thickness of the first fluorescent glue layer is smaller than the thickness of the precipitation layer.

10. A method for manufacturing a light emitting device, characterized in that: include: Disposing a light emitting chip on a substrate; Forming a first fluorescent glue layer on the upper surface of the light-emitting chip by a powder spraying process or a dispensing process with a first fluorescent glue mixture, wherein the first fluorescent glue mixture includes fluoride fluorescent powder, silica gel and a diluent; A second fluorescent glue layer is formed on the first fluorescent glue layer.

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