White light LED device and preparation method thereof

Abstract

The invention relates to a white-light LED device and a preparation method thereof, and the white-light LED device comprises a support bowl cup (10) with an open accommodation cavity, at least three first light-emitting chips (200) disposed in the middle of the accommodation cavity of the support bowl cup (10), and at least one second light-emitting chip (300) disposed around the peripheral side of each first light-emitting chip (200). A first fluorescent glue layer and a second fluorescent glue layer are further arranged in the support bowl cup (10), the first fluorescent glue layer covers the top face and the inner side face of each first light-emitting chip (200), and the thickness of the first fluorescent glue layer is smaller than the depth of an accommodating cavity of the support bowl cup (10). And the second fluorescent glue layer is filled in the residual space in the accommodating cavity of the bracket bowl cup (10) and covers the top of the first fluorescent glue layer. According to the white light LED device, double color temperatures are achieved, light loss can be avoided, and the lighting effect is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of LEDs, and in particular to a white light LED device and a preparation method thereof. Background Art

[0002] White LED is a widely used lighting technology that is based on the principle of light-emitting diodes (LEDs) and can emit bright and energy-efficient white light. This LED efficiently converts electrical energy into light energy through the interaction between specific fluorescent substances and light-emitting chips, thereby generating white light. White LEDs not only have the advantages of long life, low energy consumption and environmental protection, but are also widely used in various lighting devices due to their small size and easy integration.

[0003] Among the diverse applications of white light LEDs, there is a design with adjustable color temperature, which can flexibly switch between a variety of different color temperatures. The adjustable color temperature range usually covers 2700K (warm light) to 5700K (cold light). Users can choose different color temperature modes according to their needs to adapt to different lighting environments and visual effects requirements, creating a comfortable and healthy lighting environment.

[0004] Traditional white light LEDs usually have a retaining wall inside the bracket cup to separate the bracket cup into two independent parallel spaces, and then different fluorescent glue layers are encapsulated in these two spaces to achieve two color temperatures. However, the presence of the retaining wall will reflect part of the light emitted by the light-emitting chip, causing light loss and reducing light efficiency. Therefore, how to achieve two color temperatures in one space while avoiding light loss and ensuring light efficiency is an urgent problem to be solved. Summary of the invention

[0005] Based on this, the purpose of the present invention is to overcome the defects or shortcomings of the prior art. On the one hand, a white light LED device is provided to achieve two color temperatures while avoiding light loss and ensuring light efficiency.

[0006] A white light LED device comprises a support bowl with an open accommodating cavity, at least three first light-emitting chips arranged in the middle of the support bowl accommodating cavity, and at least one second light-emitting chip arranged around the outer periphery of each first light-emitting chip; a first fluorescent glue layer and a second fluorescent glue layer are also provided in the support bowl, the first fluorescent glue layer covers the top surface and inner side surface of each first light-emitting chip, and the thickness of the first fluorescent glue layer is less than the depth of the support bowl accommodating cavity; the second fluorescent glue layer fills the remaining space in the support bowl accommodating cavity and covers the top of the first fluorescent glue layer.

[0007] Compared with the prior art, the white light LED device described in the present invention divides the accommodating cavity of the bracket bowl cup into a first area located in the middle and a second area surrounding the first area through multiple settings. The first light-emitting chip located in the first area is encapsulated with a first encapsulation glue, and the second light-emitting chip located in the second area is encapsulated with a second encapsulation glue. Finally, the LED device with a double layer of fluorescent glue layer can avoid light loss and ensure light efficiency while achieving dual color temperatures.

[0008] In one embodiment, the first light-emitting chips are arranged end to end to form a regular polygon and enclose a central recessed area, and a gap is provided between two adjacent first light-emitting chips.

[0009] In one embodiment, the white light LED device includes a plurality of second light emitting chips, and each of the second light emitting chips is arranged to form a regular polygon which is the same as each of the first light emitting chips.

[0010] In one embodiment, the top surface of the first fluorescent adhesive layer does not exceed a position in the accommodating cavity that is 50 μm away from the cup surface of the bracket bowl.

[0011] In another aspect, the present invention provides a method for preparing a white light LED device, comprising the following steps:

[0012] Installing chips: prepare a support cup, install at least three first light-emitting chips in the middle of the support cup cavity, and install at least one second light-emitting chip in the support cup cavity around the outer periphery of the first light-emitting chip;

[0013] First packaging: dispensing glue for the first time on the first light-emitting chip located in the middle of the bracket bowl-cup accommodating cavity, and then curing the glue by heating to form a first fluorescent glue layer, wherein the thickness of the first fluorescent glue layer is less than the depth of the bracket bowl-cup accommodating cavity and covers the top surface and inner side surface of each first light-emitting chip;

[0014] Second packaging: After completing the first packaging, the support bowl is glued for the second time, and then the colloid is cured by heating to form a second fluorescent glue layer. The second fluorescent glue layer fills the remaining space of the support bowl cavity and covers the top of the first fluorescent glue layer.

[0015] Compared with the prior art, the preparation method of the white light LED device described in the present invention divides the accommodating cavity into a first area located in the middle position and a second area surrounding the first area by means of a plurality of first light-emitting chips arranged in the accommodating cavity of the bracket bowl. The first light-emitting chips in the first area are firstly packaged with glue to form a first fluorescent glue layer, and then the light-emitting chips in the second area are packaged with glue to form a second fluorescent glue layer covering the first fluorescent glue layer. Finally, the LED device with a double-layer fluorescent glue layer is obtained, which can avoid light loss and ensure light efficiency while achieving dual color temperatures.

[0016] In one embodiment, in the chip installation step, the first light-emitting chips are arranged end to end to form a regular polygon and enclose a central recessed area, with a gap between two adjacent first light-emitting chips, and the first light-emitting chips enclose a first area of ​​the outer peripheral contour.

[0017] In one embodiment, the width of the gap is less than or equal to 100 μm.

[0018] In one embodiment, in the first packaging step, the first fluorescent glue layer is composed of a first glue solution, yellow-green fluorescent powder, red fluorescent powder and anti-precipitation powder, and the ratio of each component is first glue solution: yellow-green fluorescent powder: red fluorescent powder: anti-precipitation powder = 11: (9-30): (3-12): (0.1-0.2).

[0019] In one embodiment, the colloidal viscosity of the first glue is 1000-3000 mPa·s.

[0020] In one embodiment, the particle size of the yellow-green phosphor is 5 μm-10 μm, and the particle size of the red phosphor is 5 μm-15 μm.

[0021] In one embodiment, in the chip installation step, the number of the first light-emitting chips is 2n, wherein n≥2; when performing the first glue dispensing, glue is dispensed on the top surfaces of the two first light-emitting chips arranged opposite to each other.

[0022] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A top view of an embodiment of a white light LED device of the present invention;

[0024] Figure 2 This is a spectrum diagram of the white light LED device prepared by the preparation method of the present invention;

[0025] Figure 3 This is the appearance of the device with the first fluorescent glue layer protruding in the middle of the bracket bowl;

[0026] Figure 4A schematic diagram of the positions of dispensing glue on the top surfaces of two first light-emitting chips disposed opposite to each other during the first dispensing of glue in the preparation method of the present invention;

[0027] Figure 5 This is an appearance diagram of a device with a flat fluorescent glue layer obtained by the preparation method of the present invention;

[0028] Figure 6 This is a comparison diagram of the effects of dispensing the first fluorescent glue used in Example 1 of the preparation method of the present invention and dispensing the first fluorescent glue used in Comparative Example 1; Figure 6 a: The effect diagram of the first fluorescent glue after dispensing used in Example 1 of the preparation method of the present invention, Figure 6 b: Comparative effect diagram of the first fluorescent glue used in Example 1 after dispensing;

[0029] Figure 7 This is a comparison diagram of the effects of dispensing the first fluorescent glue used in Example 1 of the preparation method of the present invention and dispensing the first fluorescent glue used in Comparative Example 2; Figure 7 a: The effect diagram of the first fluorescent glue after dispensing used in Example 1 of the preparation method of the present invention, Figure 7 b: Comparative effect diagram of the first fluorescent glue used in Example 2 after dispensing;

[0030] Reference numerals:

[0031] 10. Bracket for bowls and cups;

[0032] 200. a first light-emitting chip;

[0033] 300. a second light-emitting chip;

[0034] A1, first area; A2, second area; C, middle recessed area; A3, area actually covered by the first fluorescent glue in comparative example 1;

[0035] K. Glue dispensing position. DETAILED DESCRIPTION

[0036] Dual color temperature LED devices usually include two types of fluorescent glue, namely high color temperature fluorescent glue and low color temperature fluorescent glue. The two fluorescent glues can emit light of different color temperatures after being excited. In order to accommodate two types of fluorescent glue at the same time, traditional white light LED devices usually set a baffle wall in the accommodating cavity of the bracket bowl to divide the accommodating cavity into two independent parallel spaces, and then encapsulate different fluorescent glue layers in the two independent spaces to achieve dual color temperature. However, the existence of the baffle wall will reflect part of the light emitted by the light-emitting chip, thereby causing light loss and reducing the light efficiency. In order to encapsulate two fluorescent glue layers in one space to achieve dual color temperature after removing the baffle wall, the present invention arranges a plurality of first light-emitting chips in the middle position of the bracket bowl accommodating cavity to divide the accommodating cavity into a first area located in the middle position and a second area surrounding the first area, and then encapsulates the fluorescent glue layers in the first area and the second area respectively to obtain a dual color temperature LED device. To prepare the white light LED device, the present invention first dispenses glue on the light-emitting chip in the first area to form a first fluorescent glue, then bakes and heats the first fluorescent glue to solidify the first fluorescent glue to form a first fluorescent glue layer, then dispenses glue on the second light-emitting chip in the second area to form a second fluorescent glue layer, then bakes and heats the second fluorescent glue to solidify the second fluorescent glue to form a second fluorescent glue layer, and finally obtains a dual-color temperature device. Furthermore, the present invention improves the colloidal component of the first fluorescent glue to match the chip arrangement in a regular polygonal shape, and tries to avoid part of the colloidal material flowing to the outer side of the first light-emitting chip during the first dispensing, so as to ensure that the light-emitting color of the prepared white light LED device is uniform and the device consistency is good.

[0037] The scheme of the present invention is described in detail below with reference to the accompanying drawings.

[0038] Example 1

[0039] like Figure 1 As shown, Embodiment 1 of the present invention provides a white light LED device, including a support bowl 10 having an open accommodating cavity, four first light-emitting chips 200 arranged in the middle position of the accommodating cavity of the support bowl 10, and four second light-emitting chips 300 arranged around the first light-emitting chip 200.

[0040] Specifically, four first light-emitting chips 200 are arranged end to end to form a regular quadrilateral, and there is a gap between two adjacent first light-emitting chips 200. The inner circumference of the first light-emitting chip 200 encloses a concave middle concave area C, and the outer circumferential contour line enclosed by each first light-emitting chip 200 is used as a boundary to form a first area A1, and the accommodating cavity part outside the first area A1 forms a second area A2. Four second light-emitting chips 300 are distributed in the second area A2 and arranged in the same quadrilateral as the four first light-emitting chips 200. The first area A1 is encapsulated with a first fluorescent glue layer (not shown in the figure), which fills the middle concave area C and the gap between two adjacent first light-emitting chips 200, and covers the top surface and inner side surface of each first light-emitting chip 200; the second area A2 is encapsulated with a second fluorescent glue layer (not shown in the figure), which fills the remaining space outside the first fluorescent glue layer (not shown in the figure) in the accommodating cavity, and covers the top of the first fluorescent glue layer (not shown in the figure).

[0041] In this way, by dividing the accommodating cavity into the first area A1 and the second area A2 from the inside to the outside, and encapsulating the first fluorescent glue layer and the second fluorescent glue layer in the first area A1 and the second area A2 respectively, the light emitted by the first light-emitting chip 200 in the first area A1 sequentially excites the first fluorescent glue layer and the second fluorescent glue layer and is emitted to form a first color temperature light (low color temperature); the light emitted by the second light-emitting chip 300 in the second area A2 excites the second fluorescent glue layer and is emitted to form a second color temperature light (high color temperature), thereby realizing two color temperatures in the accommodating cavity of a bracket bowl cup 10.

[0042] In order to prepare the above-mentioned white light LED device, the present invention provides a method for preparing a white light LED device, and the preparation method comprises the following steps:

[0043] S1: Installing chips: Prepare the support cup 10, install at least three first light-emitting chips 200 in the middle of the accommodating cavity of the support cup 10, and install at least one second light-emitting chip 300 in the accommodating cavity of the support cup 10 around the outer periphery of the first light-emitting chip 200;

[0044] Specifically, four first light-emitting chips 200 are arranged end to end to form a regular quadrilateral, and enclose a central recessed area C. The outer perimeter formed by the four first light-emitting chips 200 is the first area A1.

[0045] Here, the number of the first light-emitting chips 200 can be three, arranged end to end to form a regular triangle; or five or six, arranged end to end to form a regular polygon such as a regular pentagon or a regular hexagon.

[0046] S2: First packaging: The first light-emitting chip 200 located in the middle of the accommodating cavity of the support bowl 10 is firstly glued and then heated and cured to form a first fluorescent glue layer. The thickness of the first fluorescent glue layer is less than the depth of the accommodating cavity of the support bowl 10 and covers the top surface and inner side surface of each first light-emitting chip 200;

[0047] Specifically, glue is dispensed at the central position of the first area A1 so that the first fluorescent glue can be evenly diffused in the first area A1. The top surface of the first fluorescent glue diffused in the first area A1 is a gently curved surface that is slightly convex upward relative to the bottom surface of the support bowl 10, and the highest point of the top surface does not exceed the position of the accommodating cavity 50 μm away from the cup surface of the support bowl 10; the first fluorescent glue includes a first glue liquid, yellow-green fluorescent powder and a red fluorescent powder, and the first glue liquid: yellow-green fluorescent powder: red fluorescent powder = 11: (9-30): (3-12), preferably First glue: yellow-green phosphor: red phosphor = 11:17:7; wherein the first glue is specifically silica gel, and its viscosity is 1000-3000mPa·s; the yellow-green phosphor is a yellow-green phosphor with an emission peak wavelength in the range of 520nm-540nm, and its particle size is 5μm-10μm, and the red phosphor is a red phosphor with an emission peak wavelength in the range of 640-660nm, and its particle size is 5μm-15μm; then the first fluorescent glue is heated and cured by baking to form a first fluorescent glue layer. In this embodiment, the viscosity of the first glue is 1600mPa·s, the emission peak wavelength of the yellow-green phosphor is specifically 531nm, and the particle size is 6.2μm; and the emission peak wavelength of the red phosphor is 650nm, and the particle size is 9.4μm.

[0048] S3: Second packaging: After the first packaging is completed, the support bowl 10 is glued for the second time, and then the colloid is cured by heating to form a second fluorescent glue layer. The second fluorescent glue fills the remaining space of the support bowl 10 accommodating cavity and covers the top of the first fluorescent glue layer;

[0049] Specifically, the second fluorescent glue includes a second glue liquid, a cyan phosphor, a yellow-green phosphor and a red phosphor, wherein the mass percentage of the second glue liquid, the cyan phosphor, the yellow-green phosphor and the red phosphor is second glue liquid: cyan phosphor: yellow-green phosphor: red phosphor = 11: (1.5-5): (3-12): (0.1-0.3), preferably second glue liquid: cyan phosphor: yellow-green phosphor: red phosphor = 11: 1.175: 4.4: 0.23; wherein the second glue liquid is specifically silica gel, the cyan phosphor is specifically The cyan phosphor has an emission peak wavelength in the range of 480nm-500nm, and its particle size is 5μm-30μm. The yellow-green phosphor is specifically a yellow-green phosphor with an emission peak wavelength in the range of 520nm-540nm, and its particle size is 5μm-30μm. The red phosphor is specifically a red phosphor with an emission peak wavelength in the range of 650nm-670nm, and its particle size is 5μm-30μm. The second fluorescent glue completely covers the first fluorescent glue layer, and the second fluorescent glue is solidified after baking to form a second fluorescent glue layer with a basically flat surface.

[0050] In this embodiment, specifically, the emission peak wavelength of the cyan phosphor is 490 nm, and the particle size is 15 μm; the emission peak wavelength of the yellow-green phosphor is 529 nm, and the particle size is 16 μm; the emission peak wavelength of the red phosphor is 660 nm, and the particle size is 13 μm.

[0051] Preferably, in order to ensure that the two fluorescent adhesive layers have the same bonding force to prevent the adhesive layers from falling off, the first adhesive solution of the first fluorescent adhesive layer is the same as the second adhesive solution of the second fluorescent adhesive layer.

[0052] Figure 2 The spectrum of the LED device prepared by the above preparation method is shown in FIG. Figure 2 It can be seen that the highest color temperature of the LED device prepared by the preparation method of the above embodiment can be achieved at 5700K, and the lowest color temperature can be achieved at 2700. By adjusting the current of the first light-emitting chip 200 in the first area A1 and the second light-emitting chip 300 in the second area A2, any two color temperatures can be achieved within the range of 2700K-5700K.

[0053] In the process of preparing the above-mentioned white light LED devices, in order to ensure the uniformity of the light emitting color of each LED device and the consistency of the device, the first fluorescent glue layer preferably only covers the top surface and the inner side surface of the first light-emitting chip 200 (that is, the side of the first light-emitting chip 200 facing another adjacent or opposite first light-emitting chip 200), but does not cover the outer side surface of the first light-emitting chip 200 (that is, the side of the first light-emitting chip 200 facing the inner side wall of the accommodating cavity of the support bowl cup 10). However, since there is no partition around the middle area of ​​the support bowl cup 10, part of the colloid is easy to overflow from the top surface or the inner side surface of the first light-emitting chip 200 during the first dispensing of glue, resulting in the problems of uneven light emitting color and poor device consistency of the aforementioned LED device. In addition, when the first fluorescent glue layer does not cover the outer side of the first light-emitting chip 200, if the light converted by the first light-emitting chip 200 is to reach one of the target color temperatures, it is necessary to maximize the conversion efficiency of the first light-emitting chip 200 after exciting the fluorescent glue layer through its top surface and inner side surface. If the efficiency of converting the blue light excitation of the first light-emitting chip 200 into yellow-green light and red light is to be improved, it is necessary to increase the amount of fluorescent powder added to the first fluorescent glue or increase the amount of the first fluorescent glue dispensed. However, adding too much fluorescent powder will cause the first fluorescent glue to be too viscous to be stirred and dispensed when it is prepared. Since the dispensing position is usually selected at the center of the first area A1 during dispensing, so that the first fluorescent glue can be evenly diffused to the first area A1, if the amount of the first fluorescent glue dispensed is too large, it is easy to cause the fluorescent glue layer of the first area A1 to accumulate in the middle of the accommodating cavity and protrude to the cup surface of the bowl and cup holder (such as Figure 3 As shown), the appearance of the finished device is affected, and the second fluorescent glue layer cannot completely cover the first fluorescent glue layer, so that the light emitted by the first light-emitting chip 200 after excitation conversion cannot reach the first target color temperature (low color temperature).

[0054] In order to solve the problems of device luminous color uniformity and device consistency while achieving two color temperatures, the inventors of the present invention analyzed the composition of the first fluorescent glue and found in practice that the key factors affecting the fluidity of the first fluorescent glue colloid are the viscosity of the first glue and the particle size of the fluorescent powder. Therefore, the composition of the first fluorescent glue, the viscosity of the first glue in the first fluorescent glue, and the particle size of the fluorescent powder in the first fluorescent glue are improved, and the regular polygon shape of the first light-emitting chip 200 is arranged to avoid the fluorescent glue from overflowing from the top surface or inner side of the first light-emitting chip 200, while ensuring that the light emitted by the excitation conversion of the first light-emitting chip 200 can reach the target color temperature (low color temperature).

[0055] Specifically, the first glue liquid in the first packaging glue has a suitable viscosity: if the viscosity of the colloid is too high, it will affect the dispensing of the glue; if the viscosity of the glue liquid is too low, the fluidity of the colloid is too large, so that the first fluorescent glue is easy to overflow from the top surface of the first light-emitting chip 200 and the gap between two adjacent first light-emitting chips 200. Therefore, the colloid viscosity of the first glue liquid of the present invention is 1000-3000. In addition to the first glue liquid, the yellow-green fluorescent powder and the red fluorescent powder in the first fluorescent glue need to have a suitable particle size: if the particle size of the fluorescent powder is too large, it is necessary to increase the amount of fluorescent powder added, so that the concentration of the fluorescent powder in the colloid increases, thereby causing the viscosity of the fluorescent powder to be too large, affecting the dispensing of the glue; if the particle size of the fluorescent powder is too small, it will affect the excitation effect and reduce the brightness of the device. Therefore, the particle size of the yellow-green fluorescent powder in the first fluorescent glue of the present invention is 5μm-10μm; the particle size of the red fluorescent powder is 5μm-15μm. The first fluorescent glue mentioned above also adds a certain proportion of anti-precipitation powder, and the mass percentage of the anti-precipitation powder and other components is the first glue liquid: yellow-green fluorescent powder: red fluorescent powder: anti-precipitation powder = 11: (9-30): (3-12): (0.1-0.2). The anti-precipitation powder can promote the uniform dispersion of the fluorescent powder in the first glue liquid, avoid the aggregation and precipitation of the fluorescent powder in the colloid, and help improve the excitation conversion efficiency. At the same time, the anti-precipitation powder can cooperate with the first glue liquid with a viscosity of 1000-3000 to jointly adjust the viscosity of the final configured first fluorescent glue. In addition, in order to prevent the first fluorescent glue with fluidity from overflowing from the gap between two adjacent first light-emitting chips 200, the width of the gap between two adjacent first light-emitting chips 200 is less than or equal to 100μm, preferably 50μm. The gap within this width range can form surface tension on the first fluorescent glue, which can allow the first fluorescent glue to flow into the gap while preventing the first fluorescent glue from flowing out of the gap.

[0056] Thus, compared with the yellow-green phosphor with a particle size of 23 μm, the red phosphor with a particle size of 17 μm, and the glue with a viscosity of 4000-6500 mPa·s used in the traditional fluorescent glue, the present invention reduces the viscosity of the first glue, reduces the particle size of the yellow-green phosphor and the particle size of the red phosphor, and adds a certain proportion of anti-precipitation powder, and cooperates with the first light-emitting chips 200 arranged in a regular polygon and the synergistic effect between the gap width between two adjacent first light-emitting chips 200, so that the first fluorescent glue is not easy to flow to the outer side of the first light-emitting chip 200 or even overflow to the second area A2, and at the same time avoids the first fluorescent glue layer from bulging or even bulging out of the cup surface of the bracket bowl 10, so as to ensure the smooth appearance of the finished device, and at the same time ensure that the second fluorescent glue layer can cover the top of the first fluorescent glue layer, thereby ensuring that the light emitted by the first light-emitting chip 200 after excitation and conversion can reach the first target color temperature (low color temperature).

[0057] In other embodiments, to ensure that the first dispensing process does not cause the middle of the first fluorescent glue layer to bulge due to a large amount of glue, the first dispensing is performed at two locations. Figure 4 As shown in FIG. 1 , in this embodiment, the two dispensing positions K are the top surfaces of the two first light-emitting chips 200 disposed opposite to each other. In this way, by dispensing glue on the tops of the two first light-emitting chips 200 disposed opposite to each other, it is avoided that the glue is accumulated at the center position of the middle recessed area C after dispensing glue, resulting in the middle of the first fluorescent glue layer bulging, so that a first fluorescent glue layer with a relatively flat top surface can be obtained, and then after filling the second fluorescent glue layer, the following can be obtained: Figure 5 The appearance of the fluorescent glue layer is relatively smooth.

[0058] Preferably, the dispensing position K is located 50 μm from the center line of the first light emitting chip 200 parallel to the width direction thereof, so that the dispensing head can be prevented from touching the welding wire connecting the first light emitting chip 200 and the bracket cup 10 .

[0059] The technical effect of the method for preparing an LED device of the present invention is further illustrated by comparing Examples 1-2 with Example 1.

[0060] Comparative Example 1

[0061] Comparative Example 1 adopts the same preparation steps as Example 1, and the only difference between the two is that the first fluorescent glue used in Comparative Example 1 is different from that in Example 1. The main difference is that the viscosity of the first glue liquid in the first fluorescent glue used by the two is different, and the particle sizes of the yellow-green phosphor and the red phosphor in the first fluorescent glue are different.

[0062] Specifically, the viscosity of the first glue in comparative example 1 is 5500 mPa·s, the particle size of the yellow-green phosphor is 23 μm, and the particle size of the red phosphor is 17 μm. The other components and their proportions as well as the technical parameters used in dispensing are the same as those in example 1, and the gap between two adjacent first light-emitting chips 200 is also the same as that in example 1.

[0063] Figure 6 The effect comparison diagram of the first fluorescent glue used in Example 1 of the preparation method of the present invention after dispensing and the first fluorescent glue used in Comparative Example 1 after dispensing is shown. Among them, Figure 6 a is a diagram showing the effect of dispensing the first fluorescent glue used in Example 1 of the preparation method of the present invention, Figure 6 b is a comparative diagram of the effect of fluorescent glue dispensing in Example 1. Figure 6 a and Figure 6b It can be seen that after the first fluorescent glue used in the preparation method embodiment 1 of the present invention is dispensed, the colloid covers the entire first area A1, but does not overflow, so that the first fluorescent glue layer is square when viewed from a top view; while after the first fluorescent glue used in the comparative embodiment 1 is dispensed, the colloid only covers the third area A3, but does not completely cover the first area A1 (the area of ​​A3 is smaller than the area of ​​A1), so that the colloid cannot completely cover the top surface of each first light-emitting chip 200, and the middle position of the colloid obviously bulges upward ( Figure 6 b is shown by the dotted circle position). Thus, compared with the LED device prepared in Example 1, the excitation conversion efficiency of the LED device prepared in Comparative Example 1 is reduced, and the first target color temperature (low color temperature) cannot be achieved. In addition, the colloid in the middle of the device is easy to protrude from the cup surface of the support bowl 10, affecting the appearance of the device, and making it difficult for the device to achieve the second target color temperature (high color temperature).

[0064] Comparative Example 2

[0065] Comparative Example 2 also adopts the same preparation steps as Example 1. The only difference between the two is that the first fluorescent glue used in Comparative Example 2 is different from that in Example 1. The main difference is that the viscosity of the first glue liquid in the first fluorescent glue used by the two is different, and the first fluorescent glue used in Comparative Example 2 does not have anti-precipitation powder added.

[0066] Specifically, the viscosity of the first glue in comparative example 2 is 800 mPa·s, and no anti-precipitation powder is added. Other components and their proportions as well as technical parameters used in dispensing are the same as those in example 1, and the gap between two adjacent first light-emitting chips 200 is also the same as that in example 1.

[0067] Figure 7 The effect comparison diagram of the first fluorescent glue used in Example 1 of the preparation method of the present invention after dispensing and the first fluorescent glue used in Comparative Example 2 after dispensing is shown. Among them, Figure 7 a is a diagram showing the effect of dispensing the first fluorescent glue used in Example 1 of the preparation method of the present invention, Figure 7 b is a comparative diagram of the effect of fluorescent glue dispensing in Example 2. Figure 7 a and Figure 7 b It can be seen that after the first fluorescent glue used in Comparative Example 2 is dispensed, part of the glue overflows to the second area A2, making the first fluorescent glue layer appear irregular in shape when viewed from a top-down angle. This will cause the light emitted by the first light-emitting chip 200 in the final LED device to be difficult to reach the target color temperature, and the light emission of each LED device is uneven, resulting in poor device consistency.

[0068] Compared with the prior art, the white light LED device and the preparation method thereof of the present invention divide the accommodating cavity into a first area located in the middle position and a second area surrounding the first area by using a plurality of first light-emitting chips arranged in the accommodating cavity of the bracket bowl. The first light-emitting chips in the first area are firstly packaged by glue to form a first fluorescent glue layer, and then the light-emitting chips in the second area are packaged by glue to form a second fluorescent glue layer covering the first fluorescent glue layer. Finally, the LED device with a double-layer fluorescent glue layer can avoid light loss and ensure light efficiency while achieving dual color temperatures. Furthermore, by improving the colloidal composition of the first fluorescent glue layer and coordinating it with the chip arrangement in the form of a regular polygon, it is ensured that the first fluorescent glue completely covers the top surface and inner side surface of each light-emitting chip, and avoids a large amount of overflow of the first fluorescent glue, so that the light-emitting color of the prepared LED device is uniform and the device consistency is good.

[0069] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that, unless otherwise specified, "multiple" refers to two or more; the terms "first", "second", "third", etc. are only used to distinguish, rather than to describe a specific order or sequence, and cannot be understood as indicating or implying relative importance. The term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items. When the above description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of the present application, for those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0070] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A white light LED device, characterized in that: It comprises a support cup (10) having an open accommodating cavity, at least three first light-emitting chips (200) arranged in the middle of the accommodating cavity of the support cup (10), and at least one second light-emitting chip (300) arranged around the outer periphery of each first light-emitting chip (200); A first fluorescent glue layer and a second fluorescent glue layer are also provided in the support bowl (10), wherein the first fluorescent glue layer covers the top surface and the inner side surface of each first light-emitting chip (200), and the thickness of the first fluorescent glue layer is less than the depth of the accommodating cavity of the support bowl (10); The second fluorescent glue layer fills the remaining space in the accommodating cavity of the bracket bowl (10) and covers the top of the first fluorescent glue layer.

2. The white light LED device according to claim 1, characterized in that: The first light-emitting chips (200) are arranged end to end to form a regular polygon and enclose a central recessed area (C), with a gap between two adjacent first light-emitting chips (200).

3. The white light LED device according to claim 2, characterized in that: It comprises a plurality of second light-emitting chips (300), wherein each of the second light-emitting chips (300) is arranged to form a regular polygon which is the same as that of each of the first light-emitting chips (200).

4. The white light LED device according to claim 1, characterized in that: The top surface of the first fluorescent glue layer does not exceed a position in the accommodating cavity that is 50 μm away from the cup surface of the support bowl (10).

5. A method for preparing a white light LED device, characterized in that: The following steps are involved: Installing the chips: preparing a support cup (10), installing at least three first light-emitting chips (200) in the middle of the receiving cavity of the support cup (10), and installing at least one second light-emitting chip (300) in a position surrounding the outer periphery of the first light-emitting chip (200) in the receiving cavity of the support cup (10); First packaging: first dispensing glue on the first light-emitting chip (200) located in the middle of the accommodating cavity of the support bowl cup (10), and then curing the glue by heating to form a first fluorescent glue layer, wherein the thickness of the first fluorescent glue layer is less than the depth of the accommodating cavity of the support bowl cup (10) and covers the top surface and inner side surface of each first light-emitting chip (200); Second packaging: After the first packaging is completed, the support bowl cup (10) is glued for the second time, and then the colloid is cured by heating to form a second fluorescent glue layer, which fills the remaining space of the support bowl cup (10) accommodating cavity and covers the top of the first fluorescent glue layer.

6. The method for preparing a white light LED device according to claim 5, characterized in that: In the chip installation step, each first light-emitting chip (200) is arranged end to end to form a regular polygon and encloses a central recessed area (C), and there is a gap between two adjacent first light-emitting chips (200), and each first light-emitting chip encloses a first peripheral contour area (A1).

7. The method for preparing a white light LED device according to claim 6, characterized in that: The width of the gap is less than or equal to 100 μm.

8. The method for preparing a white light LED device according to claim 5, characterized in that: In the first packaging step, the first fluorescent glue layer is composed of a first glue solution, yellow-green fluorescent powder, red fluorescent powder and anti-precipitation powder, and the ratio of the components is first glue solution: yellow-green fluorescent powder: red fluorescent powder: anti-precipitation powder = 11: (9-30): (3-12): (0.1-0.2).

9. The method for preparing a white light LED device according to claim 8, characterized in that: The colloidal viscosity of the first glue solution is 1000-3000 mPa·s.

10. The method for preparing a white light LED device according to claim 8, characterized in that: The particle size of the yellow-green phosphor is 5 μm-10 μm, and the particle size of the red phosphor is 5 μm-15 μm.

11. The method for preparing a white light LED device according to claim 5, characterized in that: In the chip installation step, the number of the first light-emitting chips is 2n, wherein n≥2; when performing the first glue dispensing, glue is dispensed on the top surfaces of the two first light-emitting chips that are arranged opposite to each other.

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