TWI626403B - Lighting apparatus - Google Patents

Abstract

A lighting device includes: a substrate; a plurality of light-emitting crystal grains disposed on the substrate and separated from each other, the light-emitting crystal grains are respectively coated with a fluorescent coating; a continuous structure disposed on the substrate and covering the plurality of light-emitting crystal grains; Light emitting grains; and a filler formed between the continuous structure and a fluorescent coating applied to each light emitting grain. The lighting device has a substantially white appearance in the off state.

Description

Lighting device

The invention relates to a light-emitting device, and more particularly to a light-emitting diode lighting device having an improved white appearance.

A light emitting diode is a semiconductor light emitting device that can emit light when a voltage is applied. Light emitting diodes have gradually become popular due to their good characteristics (such as small device size, long life, high performance, and good durability and reliability). In recent years, light emitting diodes have been widely used in various applications, including Indicator lights, light sensors, traffic signs, broadband data transmission, backlight units for liquid crystal displays, and other appropriate lighting devices. For example, light emitting diodes are often used in lighting devices to replace traditional incandescent light bulbs, such as those used in typical lamps.

One of the criteria for judging the efficacy of a light emitting diode lighting device includes its color appearance. For example, it is hoped that the light emitting diode lighting device can maintain a substantially white appearance even when it is turned off, because it is more comfortable for the human eye and is similar to the appearance of traditional non-light emitting diode lamps. However, the existing light emitting diode lighting device usually has a non-white appearance when it is turned off. For example, a conventional light emitting diode light bulb may still have a yellow appearance when it is turned off.

Therefore, although there are light-emitting diode lighting devices that can meet general needs, they have not been satisfactory in all aspects, so they continue to seek one light-emitting diode lighting device that can produce a substantially white appearance when closed. .

A lighting device includes: a substrate; a plurality of light-emitting crystal grains disposed on the substrate and separated from each other, the light-emitting crystal grains are respectively coated with a plurality of fluorescent coatings; a continuous structure disposed on the substrate and covering the plurality of Light emitting grains; and a filler formed between the continuous structure and a fluorescent coating applied to each light emitting grain. The lighting device has a substantially white appearance in the off state.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments in detail with the accompanying drawings, as follows:

40‧‧‧lighting device

50‧‧‧ substrate

60‧‧‧semiconductor light-emitting die

70‧‧‧Fluorescent film

80‧‧‧Horizontal size of light-emitting diode grains

90‧‧‧Optimized distance

110‧‧‧ Diffusion cover

120‧‧‧ Adhesive material (optical glue)

200‧‧‧heat dissipation structure

210‧‧‧ heat sink

300‧‧‧ Method

310, 320, 330, 340‧‧‧ steps

400‧‧‧lighting module

410‧‧‧base

420‧‧‧ Ontology

430‧‧‧Lighting

Figures 1 to 2 are partial cross-sectional diagrams made according to various forms of the present invention, and are used to explain an embodiment of a lighting device using a semiconductor light emitting device as a light source.

FIG. 3 is a schematic partial cross-sectional view made according to various forms of the present invention, and is used to describe an embodiment of the lighting device.

FIG. 4 is a flowchart according to various aspects of the present invention, and is used to explain an embodiment of a manufacturing method of a lighting device using a semiconductor light emitting device as a light source.

FIG. 5 is a schematic partial cross-sectional view made according to various forms of the present invention, and is used to explain an embodiment of a lighting module including the light-emitting device of FIGS. 1 to 3.

It is understood that the disclosure below this specification provides many different embodiments or examples to implement different features of the invention. The following disclosure in this specification is a specific example describing each component and its arrangement, in order to simplify the description of the invention. Of course, these specific examples are not intended to limit the present invention. For example, if the following disclosure of this specification describes forming a first feature on or above a second feature, it means that it includes the formed first feature and the first feature. The second feature is an embodiment in direct contact, and also includes an embodiment in which additional features can be formed between the first feature and the second feature, so that the first feature and the second feature may not be in direct contact. . In addition, related terms in space, such as "top", "bottom", "down", "up", etc., are used to easily express the relationship between the features and additional features in this specification. These spatially related terms cover different orientations of devices with specific characteristics. It can be understood that the following drawings are not drawn to scale and are provided for illustration purposes only. In addition, different examples in the description of the present invention may use repeated reference signs and / or words. These repeated symbols or words are for the purpose of simplicity and clarity, and are not intended to limit the relationship between the various embodiments and / or the appearance structure.

Semiconductor devices can be used to make light-emitting devices, such as light-emitting diode (LED) devices. When turned on, the light emitting diode can emit radiation, such as different color light in the visible spectrum and ultraviolet or infrared wavelength light. Compared with traditional light sources (such as incandescent light bulbs), lighting devices using light emitting diodes as light sources can provide, for example, smaller size, lower power consumption, longer life, multiple available colors, and higher durability And reliability. These advantages, along with the advancement of light emitting diode manufacturing technology that makes light emitting diodes cheaper and more reliable, have made light emitting diode system lighting devices more popular in recent years.

Nonetheless, existing light emitting diode system lighting devices may have certain disadvantages, one of which is related to their undesired color appearance when turned off. In detail, the light emitting diode can convert the output radiation into another color by using a fluorescent material. For example, the blue light emitted by the light emitting diode can be converted into a closer to white light by using a fluorescent material. However, the conventional technique of coating the fluorescent layer may cause the light emitting diode lighting device to have a non-white appearance even when it is turned off, which is not desirable.

According to various aspects of the present invention, a light emitting diode lighting device is described below, which has a substantially improved white appearance when it is turned off. Referring to FIG. 1, a schematic partial cross-sectional view of a lighting device 40 according to various embodiments of the present invention is shown. The lighting device 40 includes a substrate 50. In some embodiments, the substrate 50 includes a metal core printed circuit board (Metal Core Printed Circuit Board, MCPCB). The metal core printed circuit board includes a metal substrate, which can be made of aluminum (or an alloy thereof). The metal core printed circuit board may also include a dielectric layer that is thermally conductive but electrically insulated and disposed on a metal substrate. The metal core printed circuit board may also include a thin metal layer made of copper and disposed on a dielectric layer. In other embodiments, the substrate 50 may include other suitable materials, such as ceramic or silicon. The substrate 50 may include an active circuit and may also be used to establish interconnections.

The lighting device 40 includes a plurality of semiconductor light emitting dies 60 on a substrate 50. The semiconductor light-emitting crystal grains are used as the light source of the lighting device 40. The semiconductor light-emitting crystal grains 60 are light-emitting diode crystal grains in the embodiments described later, and therefore can be regarded as light-emitting diode crystal grains in the following paragraphs. In the embodiments discussed herein, the light emitting diode grains are physically separated from each other.

The light emitting diode grains include two oppositely doped semiconductor layers. In other words, these oppositely doped semiconductor layers have different conductivity types. For example, one of the semiconductor layers includes a material doped with an n-type dopant, and the other of the semiconductor layers includes a material doped with a p-type dopant. In some embodiments, each of the oppositely doped semiconductor layers comprises a III-V compound. In detail, the III-V compound includes a group III element of one periodic table and a group V element of another periodic table. For example, the group III element may include boron, aluminum, gallium, indium, osmium, and the group V element may include nitrogen, phosphorus, arsenic, antimony, and bismuth. In some embodiments, the oppositely doped semiconductor layer includes a p-type doped gallium nitride (GaN) material and an n-type doped gallium nitride material, respectively. The p-type dopant may include magnesium (Mg ), The n-type dopant may include carbon (C) or silicon (Si).

The light emitting diode grains also include a light emitting layer, such as a multiple-quantum well (MQW) layer, located between oppositely doped semiconductor layers. Multiple quantum well layers include alternating (or periodic) active material layers, such as gallium nitride and indium gallium oxide (InGaN). For example, the multiple quantum well layer may include a plurality of gallium nitride layers and a plurality of indium gallium nitride layers, wherein the gallium nitride layer and the indium gallium nitride layer are formed in an alternating or periodic manner. In some embodiments, the multiple quantum well layer includes ten gallium nitride layers and ten indium gallium nitride layers, wherein the indium gallium nitride layer is formed on the gallium nitride layer and another gallium nitride layer Formed on the indium gallium nitride layer, and so on. Luminous efficiency depends on the number and thickness of the alternating film layers. In other embodiments, an appropriate light emitting layer other than a multiple quantum well layer may be used instead.

Each light emitting diode die may also include a pre-strained layer and an electronic barrier layer. The pre-strained layer can be doped and can be used to release strain and reduce quantum confined Stark Effect (QCSE) in multiple quantum well layers-it describes the effect of an external electric field on the absorption spectrum of a quantum well layer . The electronic barrier layer may include a doped aluminum gallium nitride (AlGaN) material, wherein the dopant may include magnesium. The electron barrier layer helps to confine the carrier-electron hole recombination in the multiple quantum well layer, which can improve the quantum efficiency of the multiple quantum well layer and reduce unwanted frequency band radiation.

Both the doped layer and the multiple quantum well layer can be formed by one or more epitaxial growth processes known in the art. For example, these films can be formed by, for example, metal organic vapor phase epitaxy (MOVPE), molecular-beam epitaxy (MBE), or organic metal chemical vapor deposition ( Metal organic chemical vapor deposition (MOCVD), hydride vapor phase epitaxy (HVPE), liquid phase epitaxy (LPE), or other suitable methods. These processes can be performed in suitable deposition processing chambers and at high temperatures ranging from a few hundred degrees Celsius to over a thousand degrees.

After the epitaxial growth process is completed, multiple quantum well layers are deposited between the doped layers to form a light emitting diode. When a voltage (or charge) is applied to the doped layer of the light emitting diode grains, the multiple quantum well layer can emit radiation, such as light. The color of the light emitted by the multiple quantum well layer corresponds to its radiation wavelength, and this radiation may be visible (such as blue light) or invisible (such as ultraviolet light). The wavelength of light (and the color of light) can be adjusted by changing the composition and structure of the multiple quantum well layer material. For example, the light emitting diode crystals here can be blue light emitting diodes, in other words, they are configured to Emits blue light. The light emitting diode grains may also include electrodes or contact points for electrically connecting the light emitting diode grains to an external device.

As shown in FIG. 1, each light-emitting diode die (semiconductor light-emitting die 60) is also coated with a fluorescent film (or a phosphor coating) 70. In various embodiments, the fluorescent film 70 is conformally coated around the surface (such as the top surface and the side surface) of each of the light emitting diode crystal grains. The fluorescent film 70 may include a phosphorescent material and / or a fluorescent material. The fluorescent film 70 is used to convert the color of light emitted by the light-emitting diode grains. In some embodiments, the fluorescent film 70 includes yellow fluorescent particles, and can convert blue light emitted by the light-emitting diode grains into light of a different wavelength. By changing the material composition of the fluorescent film 70, a desired output light color (for example, approximately white) can be achieved. The fluorescent film 70 can be coated on the surface of the light-emitting diode grains in the form of a concentrated viscous fluid medium (such as a liquid adhesive). After the viscous fluid is hardened or cured, the fluorescent material exhibits a portion of the light-emitting diode packaging member.

Light-emitting diode grains (semiconductor light-emitting grains 60) each of the fluorescent films 70 are physically separated from the other fluorescent film 70 of the light-emitting diode grains, for example, from the adjacent light-emitting diodes The fluorescent film 70 around the die is separated. Therefore, the fluorescent film 70 can be regarded as a local coating on each light emitting diode crystal grain. In some embodiments, the bulk fluorescent film can be uniformly coated around a plurality of light-emitting diode crystal grains, and the light-emitting diode crystals coated with the fluorescent film can be separated and then disposed on the substrate 50. This ensures that the fluorescent films 70 do not contact each other. In other embodiments, the fluorescent films 70 may be separately coated on each light-emitting diode die to ensure physical separation between the fluorescent films 70.

According to the present invention, it is beneficial to coat each light-emitting diode die (semiconductor light-emitting die 60) with a corresponding localized fluorescent film 70. For example, the light-emitting diode die may have a white appearance when closed. . In detail, in many conventional light-emitting diode lighting devices, a bulk fluorescent material (or phosphor) is coated around a plurality of light-emitting diode crystal grains, so the fluorescent particles of the bulk fluorescent material are The color can affect the overall color appearance even when the light-emitting diode grains are not active light (ie, in the off state). For example, if the bulk fluorescent material mainly contains yellow fluorescent particles, the overall color appearance of the traditional light-emitting diode grains in the closed state may be dark yellow. In other words, traditional luminescence Diode grains appear pale yellow when not turned on. This is undesirable because the pale yellow appearance of the lighting device in the off state is not aesthetically pleasing to the naked eye.

In contrast, according to the various forms of the present invention, the fluorescent film 70 is partially coated around each light-emitting diode die (semiconductor light-emitting die 60), rather than all light-emitting diode die. The whole surroundings. This localized fluorescent coating method can reduce the number of overall fluorescent particles, such as the number of yellow fluorescent particles. For example, since there is no fluorescent coating in the space between adjacent light-emitting diode grains, no fluorescent particles are disposed between the adjacent light-emitting diode grains. In addition, the number of fluorescent particles provided on the light-emitting diode grains is also reduced due to the localized fluorescent coating. As a result, the overall color appearance of the light-emitting diode crystal grains can be less yellow and whiter than that of the conventional light-emitting diode crystal grains. Therefore, the lighting device of the present invention (that is, a person using a light-emitting diode die) can exhibit a substantially white appearance even in an off state.

It should be noted that the yellow fluorescent particles used here are only used as an example to illustrate the effect of the color of the fluorescent particles on the color appearance of the light-emitting diode grains. The same concept can also be applied to phosphors containing red, green, or other fluorescent particles of different colors.

Although the whiter appearance is one of the advantages of the embodiment of the lighting device of the present invention shown here, it is not the only advantage, nor is it necessary for all embodiments. Other embodiments may also provide different advantages and may not necessarily be the ones discussed here.

In some embodiments, the spacing between adjacent phosphor-coated light-emitting diode grains (semiconductor light-emitting grains 60) is configured in a manner that does not sacrifice too much grain area, so that The effect of fluorescent particles is minimized. In detail, the larger the distance separating adjacent light-emitting diode grains, the closer the overall color appearance is to white. However, a larger distance between adjacent light-emitting diode grains results in a larger grain area, which is expensive, cumbersome, and inefficient. Therefore, after the balance is selected, an optimal die separation distance range is selected, which can achieve a good white appearance and still maintain a sufficiently small chip package.

For example, as shown in Figure 1, each phosphor-coated light-emitting diode die (semiconductor light-emitting die 60) may have a horizontal or lateral dimension of 80, and an optimized adjacent The distance between the phosphor-coated light-emitting diode grains, that is, an optimized distance of 90, may indicate that adjacent phosphor-coated light-emitting diode grains are separated from each other by a first space. Therefore, the lateral dimension 80 between the light-emitting diode grains is related to the optimization distance 90 separating these grains. In other words, the optimization distance 90 can be defined by a function of the lateral dimension 80, and vice versa.

Referring to FIG. 2, a detailed sectional schematic view of the lighting device 40 is shown. The lighting device 40 includes a plurality of light emitting diode crystal grains (semiconductor light emitting crystal grains 60) provided on a substrate 50. As described above, the light-emitting diode grains are each partially coated with the fluorescent film 70, so that the fluorescent films 70 coated around different light-emitting diode grains are not in physical contact with each other.

The lighting device 40 also includes a diffusion cover 110. The diffusion cover 110 covers the light emitting diode grains (semiconductor light emitting grains 60) below it. In other words, the light-emitting diode die can be packaged with the diffusion cover 110 and the substrate 50 at the same time. The substrate 50 may be completely or partially covered by the diffusion cover 110. In some embodiments, the diffusion cover 110 has a curved surface or profile. In some embodiments, the curved surface may substantially follow a semi-circular profile, so that each light beam emitted by the light emitting diode crystals can reach the surface of the diffusion cover 110 at a substantially right angle of incidence, for example, about 90 degree. The curved shape of the diffusion cover 110 helps reduce the total internal reflection (TIR) of the light emitted by the light emitting diode grains. In some embodiments, the diffusion cover 110 has a patterned surface to further diffuse incident light.

In some embodiments, a space (also referred to as a second space) between the light-emitting diode die and the diffusion cover 110 may be filled with an optical-grade silicon-based adhesive material 120, which is also referred to as an optical glue 120. The diffusing particles may be mixed in the optical glue 120 in these embodiments to further diffuse the light emitted by the light emitting diode grains. In other embodiments, the space between the light emitting diode grains and the diffusion cover 110 may be filled with air.

The substrate 50 is disposed on the heat dissipation structure 200, which can also be regarded as a heat sink. The heat dissipation structure 200 is thermally connected to the light emitting diode die (semiconductor light emitting die 60) through the substrate 50. The heat dissipation structure 200 is configured to promote the dissipation of thermal energy into the ambient atmosphere. The heat dissipation structure 200 may include a thermally conductive material, such as a metal material. The shape and geometry of the heat dissipation structure 200 can be designed to provide a frame of a conventional light bulb, and at the same time, the heat energy can be dissipated or conducted away from the light emitting diode grains. In order to improve heat conduction, the heat dissipation structure 200 may have a plurality of heat sinks 210 protruding outward from the body of the heat dissipation structure 200. The heat sink 210 may have a substantial surface area exposed to the ambient atmosphere to promote heat conduction. In some embodiments, a thermally conductive material may be disposed between the substrate 50 and the heat dissipation structure 200. For example, the thermally conductive material may include thermally conductive glue, metal pads, solder, and the like. The thermally conductive material can further promote thermal conduction from the light emitting diode grains to the heat dissipation structure 200.

FIG. 3 is a schematic top view of a simplified lighting device 40 made according to some embodiments of the present invention. As an example, nine phosphor-coated light-emitting diode crystal grains (semiconductor light-emitting crystal grains 60) are fixed on the substrate 50 and arranged in three rows and three columns. In other embodiments, any other number of light emitting diode die arrangements may be used for other suitable configurations. The fluorescent film 70 corresponding to these light-emitting diode grains is covered with a transparent diffusion gel 120 and covered with a diffusion cover 110.

Since the light-emitting diode crystal grains (semiconductor light-emitting crystal grains 60) are respectively covered by the fluorescent film 70, they cannot be directly observed from the top view of FIG. Therefore, the luminescent diode crystals coated with phosphors are separately shown in the upper left corner of FIG. 3 to particularly illustrate the outline or boundary of the luminescent diode crystals. The boundary of the light-emitting diode crystal grains is shown as a dotted line to indicate that the light-emitting diode crystal grains are not directly visible because they are covered by the fluorescent film 70. Similarly, the fluorescent film 70 is not directly visible in a plan view because it is covered by the diffusion colloid 120. However, for the sake of illustration, the outline or boundary of the fluorescent film 70 is still shown here in dashed lines.

As described above, unlike the conventional lighting device of the light-emitting diode system, the fluorescent film 70 is partially coated around each light-emitting diode die (semiconductor light-emitting die 60) of the lighting device 40 instead of using a phosphor. Uniformly coated around all light-emitting diode grains. Therefore, the fluorescent film 70 here and other The fluorescent film is separated, thereby reducing the presence of colored fluorescent particles under the diffusion cover 110. Therefore, the overall color appearance of the light emitting diode grains may be less yellow than that of the conventional light emitting diode grains.

FIG. 4 is a flowchart according to various aspects of the present invention, and is used to describe an embodiment of a manufacturing method 300 of a lighting device using a semiconductor light emitting device as a light source. The method 300 includes step 310, in which a substrate is provided. The substrate may be a printed circuit board substrate, a ceramic substrate, a silicon substrate, or other suitable substrate. The method 300 includes a step 320 in which a plurality of light emitting diode crystal grains are disposed on a substrate, and each light emitting diode crystal grain is coated with a corresponding fluorescent film. A fluorescent film of each light emitting diode is conformally coated around the light emitting diode. The fluorescent film of each light emitting diode is physically separated from the fluorescent films of other light emitting diodes. In some embodiments, step 320 may include arranging an optimal separation distance between the light emitting diode and an adjacent light emitting diode, and the optimal separation distance is the distance between the light emitting diode particles coated with the phosphor A function of the horizontal dimension. The method 300 includes a step 330 in which a transparent diffusion colloid is coated on a substrate and a light-emitting diode coated with a fluorescent film. The method 300 includes step 340, in which a diffusion cover is mounted on the substrate, and the diffusion cover can cover the transparent diffusion colloid and the light-emitting diode coated with a fluorescent film.

Additional processes can be performed before, during, and after steps 310-340 discussed here to complete the manufacturing of the lighting device. For simplicity, these additional processes are not discussed here.

FIG. 5 is a simplified schematic diagram made according to various forms of the present invention, and is used to describe an embodiment of the lighting module 400 of the light-emitting device 40. The lighting module 400 has a base 410, a body 420 connected to the base 410, and a lamp 430 connected to the body 420. In some embodiments, the lamp 430 is a recessed light (or a lighting module for downward lighting).

The lamp 430 includes the lighting device 40 discussed above with reference to FIGS. 1 to 4. In other words, the lamp 430 of the lighting module 400 includes a light source of a light emitting diode system, in which the light emitting diode crystal grains are partially coated with a phosphor. Due to at least some of the above advantages, the light emitting diode package of the lamp 430 can have a substantially white appearance when closed, while the traditional light emitting diode lighting device usually looks yellow when closed.

A broader form of the invention relates to lighting devices. The lighting device includes: a substrate; a plurality of light-emitting crystal grains arranged on the substrate and separated from each other, the light-emitting crystal grains are respectively covered by a fluorescent coating; ; Wherein the lighting device has a substantially white appearance in the off state.

In some embodiments, the above-mentioned lighting device further includes a colloid disposed between the encapsulation structure and the light emitting die.

In some embodiments, the diffusion colloid is transparent and includes diffusion particles.

In some embodiments, the light-emitting crystals each include a light-emitting diode.

In some embodiments, the light emitting dies are each configured to emit blue light.

In some embodiments, the encapsulant structure includes a diffusion cover to scatter light.

In some embodiments, a fluorescent coating is applied conformally around each of these light emitting dies.

In some embodiments, the fluorescent coating of each of the light emitting grains is separated from the fluorescent coating of an adjacent light emitting grain by a distance.

In some embodiments, the distance is a function of the lateral size of the light emitting dies.

Another broad form of the present invention relates to a light-emitting lighting module. The light-emitting lighting module includes: a flat plate; one or a plurality of light-emitting diodes located on the flat plate; The light-emitting diodes have a substantially white appearance when they are not activated and emit light, and are respectively coated around each of the one or more light-emitting diodes; a diffusion cover is located on the plate and covers the one or more light-emitting diodes. Polar body.

In some embodiments, the light-emitting lighting module further includes a transparent diffusing material, which is located on one or a plurality of light-emitting diode dies and is covered in the diffusion cover.

In some embodiments, the aforementioned one or more light emitting diodes are respectively configured to emit blue light, and the fluorescent film contains a plurality of yellow fluorescent particles.

In some embodiments, the aforementioned one or more light emitting diodes include a plurality of light emitting diodes separated from each other.

In some embodiments, the fluorescent film used for the light emitting diode is not in physical contact with the fluorescent film used for other light emitting diodes.

In some embodiments, a distance between adjacently disposed light emitting diodes is related to the size of the light emitting diodes.

In some embodiments, the fluorescent film is conformally coated around each of the one or more light emitting diodes.

A more extensive form of the present invention relates to a method for manufacturing a lighting device. The method for manufacturing the lighting device includes: providing a substrate; and providing a plurality of light emitting diode crystal grains on the substrate. Correspond to one of the fluorescent films, wherein the fluorescent films of each of the light-emitting diodes are physically separated from the fluorescent films of other light-emitting diodes, and the light-emitting diodes are separated from the adjacent light-emitting diodes by one. The separation distance is set on the substrate; a transparent diffusion gel is coated on the substrate and the light-emitting diode coated with a fluorescent film; and a diffusion cover is mounted on the substrate to cover the transparent diffusion gel and the coating Light-emitting diode with fluorescent film.

In some embodiments, the fluorescent films for these light-emitting diodes are respectively conformally coated around the light-emitting diodes.

In some embodiments, the separation distance is a function of a lateral dimension of one of the light emitting diodes.

In some embodiments, the light emitting diodes are arranged in a manner such that the light emitting diode grains have a substantially white appearance when closed.

Although the present invention has been disclosed above with several preferred embodiments, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make any changes without departing from the spirit and scope of the present invention. And retouching, so the scope of protection of the present invention shall be determined by the scope of the attached patent application.

Claims (9)

An illumination device includes: a substrate; a plurality of light-emitting crystal grains disposed on the substrate and separated from each other; a plurality of fluorescent coatings, each covering the plurality of light-emitting crystal grains, and any two of the plurality of fluorescent coatings; Adjacent fluorescent coatings are separated from each other by a first space; a continuous structure covering the plurality of light-emitting crystal grains and a second space between at least one of the plurality of light-emitting crystal grains; and a filler Containing diffusion particles, the filler is located at least in the first space and the second space; wherein, in the closed state, the lighting device has an appearance of substantially white or a color different from the fluorescent coating. The lighting device according to item 1 of the patent application scope, wherein the filler comprises a bonding material. The lighting device according to item 2 of the patent application scope, wherein the bonding material is transparent and directly contacts the outer surface of the plurality of fluorescent coatings. The lighting device according to item 2 of the scope of patent application, wherein the bonding material is a silicone-based material. The lighting device according to item 1 of the scope of patent application, wherein the plurality of light emitting crystal grains include a light emitting diode. The lighting device according to item 1 of the scope of patent application, wherein the plurality of light emitting crystal grains are configured to emit blue light. The lighting device according to item 1 of the patent application scope, wherein the substrate comprises a printed circuit board substrate, a ceramic substrate, or a silicon substrate. The lighting device according to item 1 of the scope of patent application, wherein the plurality of fluorescent coatings are separated from each other according to a distribution pattern of the plurality of light emitting crystal grains. An illumination device includes: a substrate; a plurality of light-emitting crystal grains disposed on the substrate and separated from each other; a plurality of fluorescent coatings each covering the plurality of light-emitting crystal grains; and any two phases of the plurality of fluorescent coatings Adjacent fluorescent coatings are separated from each other by a first space; a continuous structure is disposed on the substrate and covers the light-emitting crystal grains, and has a second space between at least one of the light-emitting crystal grains; And a filler, including air, the filler is formed at least in the first space and the second space; wherein the lighting device has an appearance of substantially white or a color different from the fluorescent coating in the closed state.