Light emitting device

Abstract

The embodiment of the utility model provides a light-emitting device. The light emitting device includes: a substrate; the light-emitting chip is arranged on the substrate; the KSF or KGF fluorescent glue layer covers the upper surface of the light-emitting chip; and the first fluorescent glue layer covers the KSF or KGF fluorescent glue layer. According to the light-emitting device provided by the embodiment of the invention, the KSF or KGF fluorescent glue layer covers the upper surface of the light-emitting chip, and the first fluorescent glue layer covers the KSF or KGF fluorescent glue layer, so that the KSF or KGF fluorescent glue layer is close to the light-emitting chip, the excitation efficiency of fluoride fluorescent powder can be improved, and the heat dissipation efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to lighting technical field especially relates to a light emitting device. BACKGROUND

[0002] At present, the LED product using fluoride fluorescent powder (such as KSF, KGF) encapsulation is gradually popular, mainly because the spectral efficiency of fluoride fluorescent powder is greatly improved than traditional nitride red fluorescent powder.

[0003] However, the efficiency of fluoride fluorescent powder excited by blue light is low, and the packaging of white light LED product usually includes various fluorescent powders (for example, selected from garnet, silicate, sialon powder, nitride, fluoride, etc.), and the density of these fluorescent powders is different, when using traditional glue mixing, dispensing and sedimentation process, various fluorescent powders are mixed together and sink at the same time, the fluorescent powder with large specific gravity is more likely to fall to the bottom layer, close to the light emitting surface of the chip, and finally the proportion of fluoride fluorescent powder close to the light emitting surface of the chip is less than that far away from the light emitting surface of the chip. Further affect the conversion effect of fluoride fluorescent powder excited, and further affect the light efficiency of white light LED product. SUMMARY

[0004] Therefore, in order to overcome at least part of the defects and deficiencies existing in the prior art, the utility model embodiment provides a light emitting device.

[0005] Specifically, in one aspect, the utility model embodiment provides a light emitting device, which comprises: a substrate; a light emitting chip disposed on the substrate; a KSF or KGF fluorescent glue layer covering the upper surface of the light emitting chip; and a first fluorescent glue layer covering the KSF or KGF fluorescent glue layer.

[0006] On the other hand, the utility model embodiment provides a light emitting device, which comprises: a substrate; a light emitting chip disposed on the substrate; a KSF or KGF fluorescent glue layer covering the upper surface of the light emitting chip; a sedimentation layer covering the KSF or KGF fluorescent glue layer; and a glue removal layer covering the side of the sedimentation layer away from the substrate.

[0007] As can be seen from the above, the light emitting device provided by the utility model embodiment covers the KSF or KGF fluorescent glue layer on the upper surface of the light emitting chip, and the first fluorescent glue layer covers the KSF or KGF fluorescent glue layer, so that the KSF or KGF fluorescent glue layer is close to the light emitting chip, which can improve the excitation efficiency of fluoride fluorescent powder in the KSF or KGF fluorescent glue layer and improve the heat dissipation efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0008] In order to make the technical scheme of the embodiments of the present application clearer, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings described in the following are only some of the embodiments of the present application, and not all the embodiments. Based on the embodiments described in the present application, all the other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0009] Figure 1 The flowchart of the manufacturing method of the light emitting device provided by the embodiments of the present application.

[0010] Figure 2 The structural diagram of the light emitting device provided by the embodiments of the present application.

[0011] Figure 3 The structural diagram of another light emitting device provided by the embodiments of the present application.

[0012] Figure 4 The structural diagram of still another light emitting device provided by the embodiments of the present application.

[0013] Figure 5 The structural diagram of still another light emitting device provided by the embodiments of the present application.

[0014] Figure 6 The structural diagram of still another light emitting device provided by the embodiments of the present application.

[0015] Figure 7 The structural diagram of still another light emitting device provided by the embodiments of the present application.

[0016] Main element label:

[0017] 10, light emitting device; 11, main light emitting area; 12, peripheral area; 100, substrate; 200, light emitting chip; 300, KSF or KGF fluorescent glue layer; 400, first fluorescent glue layer; 410, sedimentation layer; 420, glue cleaning layer. DETAILED DESCRIPTION

[0018] In order to make the technical scheme of the embodiments of the present application clearer, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings described in the following are only some of the embodiments of the present application, and not all the embodiments. Based on the embodiments described in the present application, all the other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

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

[0020] In the embodiments of the present application, the description such as "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features.

[0021] Referring to Figure 1 and Figure 2 , the embodiments of the present application provide a light emitting device 10, Figure 2 as shown in the light emitting device 10 can be manufactured, for example, by Figure 1 the manufacturing method of the light emitting device.

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

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

[0024] S20, forming a KSF or KGF fluorescent glue layer on the upper surface of the light emitting chip by a powder spraying process or a point glue process, the first fluorescent glue mixture including fluoride fluorescent powder, silica gel and diluent;

[0025] S30, forming a first fluorescent glue layer on the KSF or KGF fluorescent glue layer.

[0026] Specifically, a substrate 100 is provided, and the upper surface of the substrate 100 can for example include a die-bonding area, and a light emitting chip 200 is fixed to the die-bonding area on the substrate 100. In the present embodiment, the light emitting device 10 can be an SMD package (Surface Mounted Device), a COB package (Chips on Board), or a filament package. The light emitting chip 200 can for example be one or more. In a COB package, a filament package, or the like, in which a plurality of (typically more than 3) light emitting chips 200 are simultaneously provided on a substrate 100, the manufacturing method of the present embodiment has more obvious advantages. The KSF or KGF 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, a first fluorescent glue mixture is first formed by mixing a fluoride fluorescent powder, a silica gel, and a diluent, and the diluent can for example be a siloxane or toluene. Then, the first fluorescent glue mixture is applied to the upper surface of the light emitting chip 200 by a powder spraying process or a dispensing process, and the like. Since the diluent has a volatile property, the KSF or KGF fluorescent glue layer 300 including the fluoride fluorescent powder and the silica gel is formed on the upper surface of the light emitting chip after the diluent evaporates.

[0027] By adding the diluent to the mixture of the fluoride fluorescent powder and the silica gel, the viscosity of the first fluorescent glue mixture can be reduced, and the first fluorescent glue mixture can be more quickly and uniformly formed on the main light emitting surface of the light emitting chip 200 by a powder spraying process, or uniformly formed on the main light emitting surface of the light emitting chip 200 in a dispensing and quick leveling manner. The amount of silica gel is reduced, and the fluoride fluorescent powder is uniformly distributed in the silica gel, so that the excitation conversion effect of the fluoride fluorescent powder can be improved, and the light emitting efficiency of the light emitting device 10 can be improved. In the present embodiment, the KSF or KGF 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 embodiments are described below in different embodiments.

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

[0029] As shown in Figure 2 The light emitting device 10 provided by the present embodiment can include, for example, a substrate 100, a light emitting chip 200, a KSF or KGF fluorescent glue layer 300, and a first fluorescent glue layer 400. The substrate 100 can be, for example, a metal substrate, a ceramic substrate, a glass substrate, a composite substrate, etc. The light emitting chip 200 can be, for example, a blue light emitting chip, and the light emitting chip 200 is disposed on the substrate 100. The KSF or KGF fluorescent glue layer 300 covers the light emitting chip 200, and the KSF or KGF fluorescent glue layer 300 does not necessarily contain only KSF or KGF fluorescent powder, but the mass ratio of KSF or KGF fluorescent powder to the total mass of all fluorescent powders in the KSF or KGF fluorescent glue layer is greater than 50%. The KSF or KGF fluorescent glue layer 300 can include, for example, a fluoride fluorescent powder and silica glue, and the fluoride fluorescent powder is uniformly distributed in the silica glue. The fluoride fluorescent powder is a manganese-activated fluoride series red fluorescent powder, and commonly used fluoride fluorescent powders include K2SiF6:Mn 4+ (KSF), K2TiF6:Mn 4+ (KTF), and K2GeF6:Mn 4+The first fluorescent glue layer 400 covers the KSF or KGF fluorescent glue layer 300, and the first fluorescent glue layer 400 may, for example, include yellow-green fluorescent powder and other fluorescent powder such as nitride red fluorescent powder, which is not particularly limited in the utility model. The light emitting device 10 provided by the utility model embodiment covers the KSF or KGF fluorescent glue layer 300 on the light emitting chip 200, covers the first fluorescent glue layer 400 on the KSF or KGF fluorescent glue layer 300, and the KSF or KGF fluorescent glue layer 300 includes fluoride fluorescent powder and silica gel. By sequentially layering the KSF or KGF fluorescent glue layer 300 containing fluoride fluorescent powder and the first fluorescent glue layer 400 containing other fluorescent powder on the light emitting chip 200, the fluoride fluorescent powder with relatively low excitation efficiency is closer to the light emitting chip 200, and in particular, is closer to the main light emitting surface of the light emitting chip 200, thereby improving the excitation effect of the fluoride fluorescent powder and further improving the light emitting efficiency of the light emitting device 10.

[0030] Preferably, the KSF or KGF fluorescent glue layer 300 of the utility model is formed on the light emitting chip 200 by mixing fluoride fluorescent powder, silica gel and diluent and then spraying or dispensing, as shown in the following formula (I): Figure 1 The KSF or KGF fluorescent glue layer 300 formed in this way after the diluent volatilizes has specific structural characteristics, so that the KSF or KGF fluorescent glue layer 300 can more conveniently and uniformly cover the main light emitting surface of the light emitting chip 200, and better excitation conversion effect and light emitting efficiency can be achieved with less fluorescent glue. Specifically, as shown in the following formula (II): Figure 2As shown, the space 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, then the KSF or KGF fluorescent glue layer 300 covers the main light emitting area 11 and the peripheral area 12. In some embodiments of the present embodiment, the KSF or KGF fluorescent glue layer 300 may, for example, cover the upper surface and the side surface of the light emitting chip 200, and cover the upper surface of the substrate 100. In some embodiments, taking the upper surface of the substrate 100 as the reference surface, the upper surface height H1 of the KSF or KGF fluorescent glue layer 300 in the main light emitting area 11 is greater than the upper surface height H2 of the KSF or KGF fluorescent glue layer 300 in the peripheral area 12, that is, the height H1 between the upper surface of the KSF or KGF fluorescent glue layer 300 on the main light emitting area 11 and the upper surface of the substrate 100 is greater than the height H2 between the upper surface of the KSF or KGF fluorescent glue layer 300 on the peripheral area 12 and the upper surface of the substrate 100; in other words, the KSF or KGF fluorescent glue layer 300 has a high-low difference in the upper surface 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 KSF or KGF fluorescent glue layer 300 in the peripheral area 12 is even lower than the height H3 of the upper surface of the light emitting chip 200, that is, the height of the upper surface of the KSF or KGF fluorescent glue layer 300 on the peripheral area 12 relative to the upper surface of the substrate 100 is lower than the height of the upper surface of the light emitting chip 200 relative to the upper surface of the substrate 100. From another perspective, in the present embodiment, the first fluorescent glue layer 400 is formed on the KSF or KGF fluorescent glue layer 300, and is also formed in the main light emitting area 11 and the peripheral area 12 at the same time, and the height of the lower surface of the first fluorescent glue layer 400 in the peripheral area 12 is lower than the height of the lower surface of the first fluorescent glue layer 400 in the main light emitting area 11, and in some more preferred embodiments, the height of the lower surface of the first 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 the embodiments of the utility model, the packaging form of the light emitting device 10 is for example COB packaging (Chips on Board, chip on board packaging), SMD packaging (Surface Mounted Devices, surface mount device) or filament packaging and the like. But particularly worth mentioning is that for the light emitting device 10 of COB packaging or other multi-chip (more than three) packaging (namely having larger packaging area), the KSF or KGF fluorescent glue layer 300 formed on the light emitting chip 200 by mixing the fluoride fluorescent powder, silica gel and diluent and then adopting powder spraying or point gluing and the like in the utility model overcomes the problem that the traditional layered point gluing process is difficult to implement in the larger packaging area, realizes the effect that the fluoride fluorescent powder covers the main light emitting surface of the light emitting chip 200 more conveniently and uniformly, and improves the light emitting efficiency and light emitting uniformity of such products.

[0032] In addition, in the KSF or KGF fluorescent glue layer 300 of the light emitting device 10 provided in some embodiments of the utility model, the fluoride fluorescent powder is uniformly distributed and not layered; in addition, the mass percentage (namely 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 KSF or KGF fluorescent glue layer 300) can be greater than 60%, even greater than 70%, and in the traditional point gluing scheme, once the mass percentage of the fluoride fluorescent glue exceeds 50%, there is a problem of poor flowability and difficult uniform point gluing. Thus, while realizing high excitation conversion effect and high light emitting efficiency, the utility model can reduce the amount of fluoride fluorescent glue. Through such a setting, for example, when the silica gel content in the KSF or KGF fluorescent glue layer 300 is high, the heat dissipation of the light emitting device 10 can be affected. However, it should be noted that the mass percentage of the fluoride fluorescent powder in the KSF or KGF fluorescent glue layer 300 of the light emitting device 10 of the utility model can be more than 60%, and is not limited to the mass percentage being more than 60% in all embodiments, and the specific selection will be adjusted according to the light emitting requirements of the light emitting device 10, the collocation of other fluorescent powders.

[0033] In the embodiments of the utility model, the ratio of the fluoride fluorescent powder and the silica gel in the KSF or KGF fluorescent glue layer 300 can be for example between 1:9~9:1, namely the mass percentage of the fluoride fluorescent powder in the KSF or KGF fluorescent glue layer 300 is between 10%~90%. Preferably, the mass percentage of the fluoride fluorescent powder in the KSF or KGF fluorescent glue layer 300 is between 60%~90%, through such a setting, for example, when the silica gel content in the KSF or KGF fluorescent glue layer 300 is high, the heat dissipation can be affected. In some embodiments of the utility model, for example, the mass percentage of the fluoride fluorescent powder in the KSF or KGF fluorescent glue layer 300 is 60%~90%, and the mass percentage of the silica gel in the KSF or KGF fluorescent glue layer 300 is 10%~40%. Figure 3As shown, when the KSF or KGF fluorescent glue layer 300 is in a large amount, or the ratio of the fluoride fluorescent powder and the silica gel is low, the upper surface of the KSF or KGF fluorescent glue layer 300 can present a relatively smooth curved surface with a small height difference; for example, Figure 2 As shown, when the KSF or KGF fluorescent glue layer 300 is in a small amount, or the ratio of the fluoride fluorescent powder and the silica gel is high, the upper surface of the KSF or KGF fluorescent glue layer 300 can present a larger height difference; for example, Figure 4 As shown, when the KSF or KGF fluorescent glue layer 300 is in a small amount, or the ratio of the fluoride fluorescent powder and the silica gel is high, the upper surface of the KSF or KGF fluorescent glue layer 300 can present a larger height difference; for example,

[0034] Please refer to Figure 5 , Figure 5 Another embodiment of the present application is provided, and the light emitting device 10 provided by the embodiment includes a substrate 100, a light emitting chip 200, and a KSF or KGF fluorescent glue layer 300. The selection and setting of the substrate 100, the light emitting chip 200, and the KSF or KGF fluorescent glue layer 300 are the same as those of the embodiment shown in Figure 2 The main difference between the embodiment and the embodiment shown in Figure 2 is that the first fluorescent glue layer 400 provided by the embodiment is arranged on the KSF or KGF fluorescent glue layer 300 in a layered manner. In the preparation method, the steps of natural precipitation and centrifugal / semi-centrifugal precipitation can be added on the basis of the method of forming the first fluorescent glue layer 400. Most of the other fluorescent powders in the first fluorescent glue layer 400 in the embodiment are deposited on the surface of the KSF or KGF fluorescent glue layer 300, so that the first fluorescent glue layer 400 presents a layered structure. For example, the first fluorescent glue layer 400 can include a deposition layer 410 close to the KSF or KGF fluorescent glue layer 300 and a glue cleaning layer 420 away from the KSF or KGF fluorescent glue layer 300, that is, the glue cleaning layer 420 is located on the side of the deposition layer 410 away from the KSF or KGF fluorescent glue layer 300 and away from the light emitting chip 200. It should be noted that the glue cleaning layer 420 does not completely contain fluorescent glue, but the content / concentration of the fluorescent powder visible to the naked eye in the glue cleaning layer 420 is less than that in the deposition layer 410.

[0035] In another aspect, 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 phosphor glue can be shown as a three-layer structure, including a KSF or KGF phosphor glue layer 300, a precipitated layer 410, and a clear glue layer 420, the precipitated layer 410 is located between the KSF or KGF phosphor glue layer 300 and the clear glue layer 420, and the clear glue layer 420 is located on the side of the precipitated layer 410 away from the light emitting chip 200. The first phosphor glue layer 400 is formed on the KSF or KGF phosphor glue layer 300, and is also formed in the main light emitting area 11 and the peripheral area 12 at the same time, and the height of the lower surface of the first phosphor glue layer 400 in the peripheral area 12 is lower than the height of the lower surface of the first phosphor glue layer 400 in the main light emitting area 11, that is, the height between the lower surface of the first phosphor glue layer 400 on the peripheral area 12 and the upper surface of the substrate 100 is less than the height between the lower surface of the first phosphor glue layer 400 on the main light emitting area 11 and the upper surface of the substrate 100, so that the fluorescent powder in the first phosphor glue layer 400 can be more concentrated close to the substrate 100, which helps the heat of the fluorescent powder in the first phosphor glue layer 400 to be conducted downward through the substrate 100, and improves the thermal stability of the light emitting device 10. In some embodiments of the present embodiment, in order to ensure better heat dissipation effect, a precipitated step is added when forming the first phosphor glue layer 400, so that the first phosphor glue layer 400 is better leveled, and the fluorescent powder contained therein also tends to precipitate towards the substrate 100, and fills the gap between the KSF or KGF phosphor glue layer 300 in the main light emitting area 11 and the peripheral area 12, so that the interface between the KSF or KGF phosphor glue layer 300 and the precipitated layer 410 presents a relatively larger undulating gap, while the interface between the precipitated layer 410 and the clear glue layer 420 presents a smaller undulation. In another aspect, the thickness W3 of the precipitated layer 410 of the first phosphor glue layer 400 in the peripheral area 12 is greater than the thickness W2 of the precipitated layer 410 in the main light emitting area 11. For the CRI90 series of light emitting devices 10, in order to ensure the light emitting effect (light color, indication, etc.), the appropriate ratio of fluoride fluorescent powder and other fluorescent powder needs to be adjusted, and in order to better the thermal stability (such as improving the heat dissipation effect), the amount of KSF or KGF phosphor glue layer 300 needs to be controlled. The current experiment finds that when the ratio of the thickness W1 of the KSF or KGF phosphor glue layer 300 in the main light emitting area 11 to the thickness W2 of the precipitated layer 410 is less than 2, the above-mentioned better effect can be uniformly achieved. Preferably, the thickness W1 of the KSF or KGF phosphor glue layer 300 in the main light emitting area 11 is less than the thickness W2 of the precipitated layer 410.

[0036] Please refer to Figure 6 , Figure 6 is another embodiment of the present application, the selection and setting of the substrate 100, the light emitting chip 200, and the first phosphor glue layer 400 included in the light emitting device 10 of the present embodiment are the same as those of the light emitting device 10 of the first embodiment of the present application. Figure 2The embodiments shown are the same, and will not be repeated here. The light emitting device 10 of the present embodiment is the same as the light emitting device 10 shown in Figure 2 The main difference between the light emitting device 10 shown in the present embodiment and the light emitting device 10 shown in the embodiment of the utility model is that the KSF or KGF fluorescent glue layer 300 only covers the main light emitting area 11 and is not arranged in the peripheral area 12, so that when the first fluorescent glue layer 400 is formed on the KSF or KGF fluorescent glue layer 300, the main light emitting area 11 is located on the side of the KSF or KGF fluorescent glue layer 300 away from the light emitting chip 200, and the peripheral area 12 is directly located on the substrate 100, but in this case, the height H1 of the upper surface of the KSF or KGF fluorescent glue layer 300 in the main light emitting area 11 is still greater than the height H2 of the upper surface of the KSF or KGF fluorescent glue layer 300 in the peripheral area 12 (in the present embodiment, the thickness is equal to 0); or more accurately, the height of the lower surface of the first fluorescent glue layer 400 in the peripheral area 12 is still lower than the height of the lower surface of the first fluorescent glue layer 400 in the main light emitting area 11.

[0037] Referring again to Figure 7 , Figure 7 The present embodiment is another embodiment of the utility model, and the light emitting device 10 of the present embodiment includes a substrate 100, a light emitting chip 200, and the selection and arrangement of the KSF or KGF fluorescent glue layer 300, which are the same as those of the light emitting device 10 shown in Figure 6 The light emitting device 10 of the present embodiment is the same as the light emitting device 10 shown in Figure 6 The main difference between the light emitting device 10 shown in the present embodiment and the light emitting device 10 shown in the embodiment of the utility model is that the first fluorescent glue layer 400 of the present embodiment is arranged on the KSF or KGF fluorescent glue layer 300 in a layered manner, and on the basis of the method for forming the first fluorescent glue layer 400 described above, the steps of natural precipitation and centrifugal / semi-centrifugal precipitation are additionally added. In the present embodiment, most of the other fluorescent powders in the first fluorescent glue layer 400 are deposited on the surface of the KSF or KGF fluorescent glue layer 300 and the surface of the substrate 100, so that the first fluorescent glue layer 400 exhibits a layered structure, that is, the first fluorescent glue layer 400 may, for example, include a precipitation layer 410 and a glue cleaning layer 420 located on the precipitation layer 410. The first fluorescent glue layer 400 of the present embodiment is the same as the first fluorescent glue layer 400 provided in the embodiment shown in Figure 5 The main difference between the first fluorescent glue layer 400 provided in the present embodiment and the first fluorescent glue layer 400 provided in the embodiment shown in the utility model is that the precipitation layer 410 in the peripheral area 12 is arranged on the substrate 100, but the height of the lower surface of the first fluorescent glue layer 400 in the peripheral area 12 is still lower than the height of the lower surface of the first fluorescent glue layer 400 in the main light emitting area 11, and the thickness W3 of the precipitation layer 410 of the first fluorescent glue layer 400 in the peripheral area 12 is greater than the thickness W2 of the precipitation layer 410 in the main light emitting area 11, so that the fluorescent powders in the first fluorescent glue layer 400 can be more concentratedly close to the substrate 100, which helps the heat of the fluorescent powders in the first fluorescent glue layer 400 to be conducted 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 foregoing various embodiments are only exemplary descriptions of the present application, and under the premise that the technical features do not conflict, the structures are not contradictory, and the purposes of the present application are not violated, the technical solutions of various embodiments can be arbitrarily combined and used.

[0039] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A light emitting device, characterized by, Comprising: a substrate; a light emitting chip disposed on the substrate; a KSF or KGF phosphor layer covering an upper surface of the light emitting chip; a first phosphor layer covering an upper surface of the KSF or KGF phosphor layer.

2. The light emitting device of claim 1, wherein The KSF or KGF phosphor layer covers an upper surface of the light emitting chip, and the first phosphor layer covers an upper surface of the KSF or KGF phosphor layer and an upper surface of the substrate.

3. The light emitting device of claim 1, wherein The KSF or KGF phosphor layer covers an upper surface of the light emitting chip, an upper surface of the substrate, and a side surface of the light emitting chip, and the first phosphor layer covers the KSF or KGF phosphor layer.

4. The light emitting device of claim 1, wherein The KSF or KGF phosphor layer covers an upper surface of the light emitting chip and an upper surface of the substrate, and the first phosphor layer covers the KSF or KGF phosphor layer and a side surface of the light emitting chip.

5. The light emitting device according to claim 3 or 4, wherein A height between an upper surface of the KSF or KGF phosphor layer on the light emitting chip and an upper surface of the substrate is greater than a height between an upper surface of the KSF or KGF phosphor layer on the substrate and an upper surface of the substrate.

6. The light emitting device of claim 5, wherein A height between an upper surface of the KSF or KGF phosphor layer on the substrate and an upper surface of the substrate is less than a height between an upper surface of the light emitting chip and an upper surface of the substrate.

7. The light emitting device of any of claims 2-4, wherein the first and second light emitting devices are arranged in a stacked configuration. The first phosphor layer includes a precipitated layer and a clean layer, and the clean layer is disposed on a side of the precipitated layer distal from the substrate.

8. The light emitting device of claim 7, wherein A ratio of a thickness of the KSF or KGF phosphor layer to a thickness of the precipitated layer is less than 2.

9. The light emitting device of claim 8, wherein the first and second light emitting devices are arranged in a vertical stack. The thickness of the KSF or KGF phosphor layer is less than the thickness of the precipitated layer.

10. A light-emitting device, characterized in that, Comprising: a substrate; a light emitting chip disposed on the substrate; a KSF or KGF phosphor layer covering an upper surface of the light emitting chip; a precipitated layer covering the KSF or KGF phosphor layer; and a clean layer covering a side of the precipitated layer distal from the substrate. ​

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