LED packaging structure and packaging method

Abstract

The invention discloses an LED packaging structure and a packaging method, and relates to the technical field of LED packaging. The LED packaging structure comprises at least two flip chips and a fluorescent glue layer arranged on the flip chips. Each flip chip is provided with a first side surface opposite to the adjacent flip chip and a second side surface exposed outside, the upper surface and the second side surface of each flip chip are respectively provided with a fluorescent glue layer, and a white wall glue layer is arranged between the fluorescent glue layers of different flip chips. By adopting the packaging structure provided by the invention, the light emitting color of the lamp bead is uniform, the color coordinate concentration degree is high, and the yield and the reliability are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of LED packaging, and in particular to an LED packaging structure and a packaging method. Background Art

[0002] Conventional LED lamp beads produce light of different colors by stimulating different phosphors through LED chips. Specifically, fluorescent glue is applied to the bowl of the bracket, and the chip is wrapped and packaged into LED lamp beads. Each LED lamp bead is a single color, and multiple lamp beads are used in combination to achieve light of multiple colors.

[0003] Each lamp bead is equipped with a chip. In the chip processing stage, the number of cutting times needs to be increased. In addition, each LED chip needs to be packaged, which requires more raw materials such as substrates, and the chip manufacturing cost is high. Correspondingly, the volume of the encapsulated lamp bead is large. When multiple lamp beads are used in combination, mounting space needs to be left between two adjacent lamp beads. Therefore, when multiple color lamp beads are lit at the same time, the distance between the light-emitting centers is far, and the lamp cannot be made smaller and thinner, and it will also cause uneven light mixing. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an LED packaging structure and a packaging method, wherein the LED packaging structure has uniform light mixing and low manufacturing cost.

[0005] In order to solve the above problems, the present invention discloses an LED packaging structure, including at least two flip chips and a fluorescent glue layer arranged on the flip chips; each flip chip has a first side surface facing the adjacent flip chip and a second side surface exposed to the outside, and a fluorescent glue layer is provided on the upper surface and the second side surface of each flip chip, and a white wall glue layer is provided between the fluorescent glue layers of different flip chips.

[0006] As an improvement of the above technical solution, the thickness of the fluorescent glue layer is 100 μm to 300 μm; the thickness of the white wall glue layer is 100 μm to 300 μm, and the width of the white wall glue layer is 100 μm to 250 μm.

[0007] As an improvement of the above technical solution, the flip chip includes a first flip-chip blue-light chip and a second flip-chip blue-light chip, and the first flip-chip blue-light chip and the second flip-chip blue-light chip are symmetrically arranged;

[0008] A fluorescent glue layer is provided on the upper surface and the second side surface of the first flip-chip blue light chip, a fluorescent glue layer is provided on the upper surface and the second side surface of the second flip-chip blue light chip, and a white wall glue layer is provided between adjacent fluorescent glue layers.

[0009] As an improvement of the above technical solution, a first yellow fluorescent glue layer is provided on the upper surface and the second side surface of the first flip-chip blue light chip, and the color temperature of the first yellow fluorescent glue layer excited by the first flip-chip blue light chip is 2200K~3500K; a second yellow fluorescent glue layer is provided on the upper surface and the second side surface of the second flip-chip blue light chip, and the color temperature of the second yellow fluorescent glue layer excited by the second flip-chip blue light chip is 4000K~6500K; a white wall glue layer is provided between the first yellow fluorescent glue layer and the second yellow fluorescent glue layer.

[0010] As an improvement of the above technical solution, the flip chip includes a first flip chip, a second flip chip, a third flip chip and a fourth flip chip, and the first flip chip, the second flip chip, the third flip chip and the fourth flip chip are arranged in a field shape;

[0011] Among them, a fluorescent glue layer is provided on the upper surface and the second side surface of the first flip-chip blue light chip, a fluorescent glue layer is provided on the upper surface and the second side surface of the second flip-chip blue light chip, a fluorescent glue layer is provided on the upper surface and the second side surface of the third flip-chip blue light chip, and a fluorescent glue layer is provided on the upper surface and the second side surface of the fourth flip-chip blue light chip; a white wall glue layer is provided between adjacent fluorescent glue layers.

[0012] As an improvement of the above technical solution, a red fluorescent glue layer is provided on the upper surface and the second side surface of the first flip-chip blue light chip, a green fluorescent glue layer is provided on the upper surface and the second side surface of the second flip-chip blue light chip, a transparent glue layer is provided on the upper surface and the second side surface of the third flip-chip blue light chip, and a third yellow fluorescent glue layer is provided on the upper surface and the second side surface of the fourth flip-chip blue light chip; a white wall glue layer is provided between the red fluorescent glue layer and the green fluorescent glue layer, between the green fluorescent glue layer and the transparent glue layer, between the transparent glue layer and the third yellow fluorescent glue layer, and between the third yellow fluorescent glue layer and the red fluorescent glue layer.

[0013] As an improvement of the above technical solution, the thickness of the white wall glue layer is equal to the thickness of the fluorescent glue layer.

[0014] As an improvement of the above technical solution, the white wall glue layer is made of white wall glue, and the white wall glue includes reflective particles and silica gel, and the weight ratio of the reflective particles to the silica gel is 1:1.5 to 1:6;

[0015] The silica gel is composed of A glue and B glue, and the weight ratio of A glue to B glue is 1:1 to 10:1;

[0016] The A glue comprises the following raw materials in weight percentage: 25% to 45% vinyl silicone resin, 40% to 70% vinyl silicone oil, 2% to 15% fumed silica, 0.1% to 10% silane coupling agent, and 0.1% to 5% catalyst.

[0017] The B glue comprises the following raw materials in weight percentage: 70% to 90% of vinyl phenyl silicone resin, 5% to 25% of phenyl hydrogenated silicone oil, and 0.5% to 10% of a cross-linking agent.

[0018] Correspondingly, the present invention also discloses a LED packaging method for packaging the above-mentioned LED packaging structure, comprising the following steps:

[0019] integrating at least two flip chips and placing them upside down in a mold;

[0020] forming a fluorescent glue layer on the upper surface and the second side surface of the flip chip;

[0021] A white wall glue layer is formed on the upper surface and the second side surface at the junction of the flip chips, and the white wall glue layer is located between the fluorescent glue layers of different flip chips;

[0022] The flip chip formed with the fluorescent adhesive layer and the white wall adhesive layer is taken out from the mold to obtain an LED packaging structure.

[0023] As an improvement of the above technical solution, the white wall glue layer is obtained by curing white wall glue, and the curing temperature of the white wall glue is 120° C. to 150° C., and the curing time is 3 min to 5 min;

[0024] The fluorescent glue layer is obtained by curing the fluorescent glue, and the curing temperature of the fluorescent glue is 120° C. to 150° C., and the curing time is 3 min to 5 min.

[0025] The implementation of the present invention has the following beneficial effects: the present invention sets different fluorescent glue layers on different flip chips, so there is no need to perform bracket packaging on each flip chip separately, reducing the number of cutting times in chip processing, reducing chip manufacturing costs, and the distance between the luminous centers of different flip chips is close, and the mixed light is uniform. The luminous color of the lamp beads encapsulated by the encapsulation structure and encapsulation method of the present invention is uniform, the color coordinate concentration is high, and the yield and reliability are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a three-dimensional diagram of the LED packaging structure provided by Embodiment 1 of the present invention;

[0027] Figure 2 is a top view of the LED packaging structure provided by Embodiment 1 of the present invention;

[0028] Figure 3 yes Figure 2 The cross-sectional view of the AA surface;

[0029] Figure 4 is a bottom view of the LED packaging structure provided by Embodiment 1 of the present invention;

[0030] Figure 5 is a three-dimensional diagram of the LED packaging structure provided by Embodiment 2 of the present invention;

[0031] Figure 6 is a top view of the LED packaging structure provided by Embodiment 2 of the present invention;

[0032] Figure 7 yes Figure 6 The cross-sectional view of the AA surface;

[0033] Figure 8 is a bottom view of the LED packaging structure provided by Embodiment 2 of the present invention;

[0034] Fig. 9 is a schematic structural diagram of a first mold provided by an embodiment of the present invention;

[0035] Fig.10 is a top view of a first frame in a first mold provided by an embodiment of the present invention;

[0036] Fig.11 is a top view of a first ejector pin in a first mold provided by an embodiment of the present invention;

[0037] Fig.12 is a top view of the LED packaging structure after the white wall adhesive layer is formed by the LED packaging method provided by the embodiment of the present invention;

[0038] Fig.13 yes Fig.12 The cross-sectional view of the AA surface;

[0039] Fig.14 is a schematic structural diagram of a second mold provided by an embodiment of the present invention;

[0040] Fig.15 is a top view of a second frame in a second mold provided by an embodiment of the present invention;

[0041] Fig.16 is a top view of a second ejector pin in a second mold provided by an embodiment of the present invention;

[0042] Fig.17 is a color coordinate point diagram of the LED packaging structure provided by Example 1 of the present invention;

[0043] Fig.18 is a color coordinate point diagram of the LED packaging structure provided by Example 2 of the present invention;

[0044] Fig.19 This is a color coordinate point diagram of the LED packaging structure provided in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in further detail below.

[0046] See also Figures 1 to 8 The present invention provides an LED packaging structure, comprising at least two flip chips 1 and a fluorescent glue layer 2 arranged on the flip chips 1. Specifically, each flip chip 1 has a first side surface 11 facing the adjacent flip chip 1 and a second side surface 12 exposed to the outside, and a fluorescent glue layer 2 is provided on the upper surface 13 and the second side surface 12 of each flip chip 1, and a white wall glue layer 3 is provided between the fluorescent glue layers 2 of different flip chips 1. The second side surface 12 and the upper surface 13 of the flip chip are provided with a fluorescent glue layer 2, which can ensure the luminous effect of the flip chip. Different fluorescent glue layers 2 are spaced by the white wall glue layer 3 to avoid mutual interference of different colors when the flip chip 1 is lit alone, so that the luminous color is purer. Moreover, compared with encapsulating different flip chips on a bracket with fluorescent glue layers of different colors respectively, and then combining them to form an LED packaging structure, the LED packaging structure of the present invention has a small volume, a close distance between luminous centers, and uniform light mixing.

[0047] Among them, the thickness of the fluorescent glue layer 2 is 100μm to 300μm, and exemplarily is 120μm, 150μm, 200μm, 250μm or 280μm, but not limited to this. If the thickness of the fluorescent glue layer 2 is less than 100μm, the distribution of the fluorescent powder in the fluorescent glue layer is uneven; if the thickness of the fluorescent glue layer 2 is greater than 300μm, the overall thickness of the LED packaging structure will be too large, which is not conducive to the thinness of the lamp. The thickness of the white wall glue layer 3 is 100μm to 300μm, and exemplarily is 120μm, 150μm, 200μm, 250μm or 280μm, but not limited to this. If the thickness of the white wall glue layer 3 is less than 100μm, it is difficult to ensure the spacing effect between different fluorescent glue layers 2; if the thickness of the white wall glue layer 3 is greater than 300μm, the overall thickness of the LED packaging structure will be too large. It can be understood that if Figure 3 , Figure 4 , Figure 7 and Figure 8As shown, the thickness D1 of the fluorescent glue layer 2 refers to the thickness of the fluorescent glue layer on the upper surface 13 of the flip chip 1 or the thickness of the fluorescent glue layer on the second side 12 of the flip chip 1, and the thickness D2 of the white wall glue layer 3 refers to the thickness of the white wall glue layer on the upper surface 13 of the flip chip 1 or the thickness of the white wall glue layer on the second side 12 of the flip chip 1. In a preferred embodiment, on the upper surface 13 of the flip chip 1, the thickness of the white wall glue layer 3 is equal to the thickness of the fluorescent glue layer 2, so that on the upper surface 13 of the flip chip 1, the upper surface of the fluorescent glue layer 2 and the upper surface of the white wall glue layer 3 are flush. In a preferred embodiment, on the second side 12 of the flip chip 1, the thickness of the white wall glue layer 3 is equal to the thickness of the fluorescent glue layer 2, so that on the second side 12 of the flip chip 1, the side of the fluorescent glue layer 2 and the side of the white wall glue layer 3 are flush. The fluorescent glue layer 2 and the white wall glue layer 3 are arranged flush with each other on the surface, so that the overall structure of the LED packaging structure can be more regular, the combination of the fluorescent glue layer 2 and the white wall glue layer 3 can be more secure, and the application design of the LED packaging structure can be more flexible.

[0048] In a preferred embodiment, the width of the white wall glue layer 3 is 100μm to 250μm, and exemplary ones are 120μm, 140μm, 180μm, 200μm or 220μm, but not limited thereto. If the width of the white wall glue layer 3 is less than 100μm, it is difficult to achieve the isolation effect between different fluorescent glue layers 2; if the width of the white wall glue layer 3 is greater than 300μm, the area of ​​the fluorescent glue layer on the upper surface and the second side of the flip chip will be reduced, thereby affecting the luminous effect. Preferably, the width of the white wall glue layer 3 is 100μm to 250μm. It is understandable that if Figure 3 , Figure 4 , Figure 7 and Figure 8 As shown, the width D3 of the white glue layer 3 refers to the width of the white glue layer on the upper surface 13 of the flip chip 1 or the width of the white glue layer on the second side surface 12 of the flip chip 1 .

[0049] In a preferred embodiment, the white wall glue in the white wall glue layer 3 includes reflective particles and silica gel, and the weight ratio of the reflective particles to the silica gel is 1:1.5 to 1:6, and is exemplarily 1:2, 1:2.5, 1:3, 1:4 or 1:5, but not limited thereto. If the weight ratio of the reflective particles to the silica gel is too small, efficient reflection of the light emitted by the chip cannot be achieved; if the weight ratio of the reflective particles to the silica gel is too large, uneven distribution of the reflective particles in the silica gel will be caused. Optionally, the reflective particles are one or more of Al2O3, MgO, BaSO4, TiO2, SiO2, and ZrO2, but not limited thereto. The diameter of the reflective particles is 0.2μm to 0.8μm, and is exemplarily 0.3μm, 0.4μm, 0.5μm, 0.6μm or 0.7μm, but not limited thereto.

[0050] The silica gel is composed of A glue and B glue, and the weight ratio of A glue to B glue is 1:1 to 10:1, and exemplarily is 2:1, 4:1, 5:1, 6:1 or 8:1, but not limited thereto.

[0051] Glue A comprises the following raw materials in percentage by weight: 25% to 45% of vinyl silicone resin, 40% to 70% of vinyl silicone oil, 2% to 15% of fumed silica, 0.1% to 10% of silane coupling agent and 0.1% to 5% of catalyst.

[0052] The B glue comprises the following raw materials in weight percentage: 70% to 90% of vinyl phenyl silicone resin, 5% to 25% of phenyl hydrogen-containing silicone oil, and 0.5% to 10% of a cross-linking agent.

[0053] The cross-linking agent may be hydrogen-containing silicone oil, the silane coupling agent may be KH560 and / or KH570, and the catalyst may be a Pt catalyst, which are not specifically limited herein.

[0054] Specifically, the preparation method of the white wall glue is as follows:

[0055] Vinyl silicone resin, vinyl silicone oil, fumed silica and silane coupling agent are mixed, stirred and heated to 150°C to 200°C, kept warm for 1.5h to 2.5h, cooled to room temperature and then a catalyst is added to obtain glue A;

[0056] Mix vinyl phenyl silicone resin, phenyl hydrogen silicone oil and crosslinking agent, stir and heat to 150°C to 200°C, keep warm for 1.5h to 2.5h, and then cool to room temperature to obtain glue B;

[0057] Mix glue A and glue B to obtain silica gel;

[0058] Mix silica gel and reflective particles to get white wall glue.

[0059] The white wall glue layer 3 of the present invention is arranged between the fluorescent glue layers 2 of different colors, and the independent and efficient light emission of chips of different colors is realized by reflecting the light emitted by different chips. Since the fluorescent glue layer 2 and the white wall glue layer 3 are arranged after the LED chip is integrated in the present invention, the distance between different chips is relatively close, so the white wall glue needs to maintain good reflection performance and thermal conductivity at a relatively thin thickness. In the white wall glue prepared by the present invention, the gas phase silica can improve the distribution uniformity of the reflective particles in the white wall glue layer 3, so that it is effectively excited, which is conducive to the uniform transfer of heat. By adjusting the components and ratios of A glue and B glue, a modified silica gel with high thermal conductivity and good heat resistance can be obtained, which is mixed with reflective particles to prepare a white wall glue layer 3, which is applied between the fluorescent glue layers 2 of compactly integrated different chips, and the performance of the LED after encapsulation can be improved.

[0060] The fluorescent glue layer 2 can be obtained by mixing conventional fluorescent powder and silica gel, which is not specifically limited here.

[0061] It is understandable that the number of flip chips 1 is not fixed and can be selected according to actual conditions.

[0062] In one embodiment, Figure 1 to Figure 4 As shown, the flip chip includes a first flip blue light chip 1a and a second flip blue light chip 1b, and the first flip blue light chip 1a and the second flip blue light chip 1b are symmetrically arranged. A fluorescent glue layer is provided on the upper surface 13 and the second side surface 12 of the first flip blue light chip 1a, and a fluorescent glue layer is provided on the upper surface 13 and the second side surface 12 of the second flip blue light chip 1b, and a white wall glue layer is provided between adjacent fluorescent glue layers.

[0063] Specifically, a first yellow fluorescent glue layer 2a is provided on the upper surface 13 and the second side surface 12 of the first flip-chip blue light chip 1a, and the color temperature of the first yellow fluorescent glue layer 2a excited by the first flip-chip blue light chip 1a is 2200K-3500K, and low color temperature white light is emitted; a second yellow fluorescent glue layer 2b is provided on the upper surface 13 and the second side surface 12 of the second flip-chip blue light chip 1b, and the color temperature of the second yellow fluorescent glue layer 2b excited by the second flip-chip blue light chip 1b is 4000K-6500K, and high color temperature white light is emitted, and a white wall glue layer 3 is provided between the first yellow fluorescent glue layer 1a and the second yellow fluorescent glue layer 1b. By combining the first flip-chip blue light chip 1a and the second flip-chip blue light chip 1b with different yellow fluorescent glue layers, warm white light, cold white light, and white light mixed with cold and warm white light can be obtained respectively.

[0064] In one embodiment, Figures 5 to 8 As shown, the flip chip 1 includes a first flip chip 1a, a second flip chip 1b, a third flip chip 1c and a fourth flip chip 1d, and the first flip chip 1a, the second flip chip 1b, the third flip chip 1c and the fourth flip chip 1d are arranged in a field shape;

[0065] Among them, a fluorescent glue layer is provided on the upper surface 13 and the second side surface 12 of the first flip-chip blue light chip 1a, a fluorescent glue layer is provided on the upper surface 13 and the second side surface 12 of the second flip-chip blue light chip 1b, a fluorescent glue layer is provided on the upper surface 13 and the second side surface 12 of the third flip-chip blue light chip 1c, a fluorescent glue layer is provided on the upper surface 13 and the second side surface 12 of the fourth flip-chip blue light chip 1d, and a white wall glue layer is provided between adjacent fluorescent glue layers.

[0066] Specifically, a red fluorescent glue layer 2c is provided on the upper surface 13 and the second side surface 12 of the first flip-chip blue light chip 1a, a green fluorescent glue layer 2d is provided on the upper surface 13 and the second side surface 12 of the second flip-chip blue light chip 1b, a transparent glue layer 2e is provided on the upper surface 13 and the second side surface 12 of the third flip-chip blue light chip 1c, a third yellow fluorescent glue layer 2f is provided on the upper surface 13 and the second side surface 12 of the fourth flip-chip blue light chip 1d, and a white wall glue layer 3 is provided between adjacent fluorescent glue layers. By matching the first flip-chip blue light chip 1a, the second flip-chip blue light chip 1b, the third flip-chip blue light chip 1c and the fourth flip-chip blue light chip 1d with fluorescent glue layers of different colors, RGB monochromatic light and mixed light are obtained respectively.

[0067] Correspondingly, the present invention also discloses a LED packaging method for packaging the above-mentioned LED packaging structure, comprising the following steps:

[0068] S1, integrating at least two flip chips and placing them upside down in a mold;

[0069] S2, forming a fluorescent glue layer on the upper surface and the second side surface of the flip chip;

[0070] S3, forming a white wall glue layer on the upper surface and the second side surface at the junction of the flip chips, wherein the white wall glue layer is located between the fluorescent glue layers of different flip chips;

[0071] S4. Take out the flip chip with the fluorescent adhesive layer and the white wall adhesive layer from the mold to obtain an LED packaging structure.

[0072] It is understandable that the order of S2 and S3 can be adjusted.

[0073] In one embodiment, Figures 9 to 16 As shown, the white wall glue layer 3 is formed first and then the fluorescent glue layer 2 is formed. Specifically, the following steps are included:

[0074] S11 , integrating a plurality of flip chips 1 and placing them upside down in a first mold 100 .

[0075] S21 , filling the first mold 100 with white wall glue and curing it, forming a white wall glue layer 3 on the upper surface 13 and the second side surface 12 at the junction of the flip chip 1 .

[0076] like Figures 9 to 11As shown, the first mold 100 includes a first frame 101 and a first push rod 102. The first frame 101 is a rectangular frame formed by four side surfaces. The first push rod 102 fits with the four side surfaces and can move up and down in the first frame 101. The inner wall size of the first frame 101 is the same as the size of the integrated flip chip 1. The four side surfaces of the first frame 101 and the inner wall of the first push rod 102 are provided with grooves 103. After the integrated flip chip 1 is inverted and placed in the first mold 100, the cavity formed by the groove 103 and the flip chip 1 is used to fill the white wall glue, and the structure of the flip chip 1 with the white wall glue layer 3 is formed as shown in FIG. Fig.12 and Fig.13 shown.

[0077] S31, taking out the flip chip 1 with the white wall glue layer 3 from the first mold 100, and inverting it in the second mold 200. Specifically, the electrodes of the flip chip 1 are attached to the UV film, and the first ejector 102 is moved upward to eject the flip chip 1 with the white wall glue layer 3 from the first mold 100.

[0078] S32 , filling the second mold 200 with fluorescent glue and curing it to form a fluorescent glue layer 2 on the upper surface 13 and the second side surface 12 of the flip chip 1 .

[0079] like Figure 14 to Figure 16 As shown, the second mold 200 includes a second frame body 201 and a second top rod 202. The second frame body 201 is a rectangular frame body formed by four side surfaces. The second top rod 202 fits with the four side surfaces and can move up and down in the second frame body 201. After the flip chip 1 with a white wall glue layer 3 is formed and invertedly placed in the second mold 200, the cavity formed between the second mold 200 and the flip chip 1 is used to fill with fluorescent glue.

[0080] Specifically, before filling the fluorescent glue, the UV film in S31 is firstly debonded and removed.

[0081] S41 , taking out the flip chip 1 formed with the fluorescent adhesive layer 2 from the second mold 200 to obtain an LED packaging structure.

[0082] Specifically, the electrodes of the flip chip 1 are pasted to the UV film, and the second ejector pin 201 is moved upward to eject the flip chip 1 with the fluorescent adhesive layer 2 formed thereon from the second mold 200 .

[0083] It is understandable that, in one embodiment, the fluorescent glue layer 2 can be formed first and then the white wall glue layer 3 can be formed by controlling the specific shape of the mold.

[0084] In a preferred embodiment, the curing temperature of the white wall glue is 120° C. to 150° C., and the curing time is 3 min to 5 min. The curing temperature of the fluorescent glue is 120° C. to 150° C., and the curing time is 3 min to 5 min.

[0085] The present invention will be further described below with specific embodiments:

[0086] Example 1

[0087] The present embodiment provides an LED packaging structure, including two flip chips and a fluorescent glue layer arranged on the flip chips, each flip chip having a first side facing the adjacent flip chip and a second side exposed to the outside. The flip chips include a first flip blue chip and a second flip blue chip, and the first flip blue chip and the second flip blue chip are symmetrically arranged. Among them, a first yellow fluorescent glue layer is provided on the upper surface and the second side of the first flip blue chip, and the color temperature of the first yellow fluorescent glue layer excited by the first flip blue chip is 2500K; a second yellow fluorescent glue layer is provided on the upper surface and the second side of the second flip blue chip, and the color temperature of the second yellow fluorescent glue layer excited by the second flip blue chip is 4500K. A white wall glue layer is provided between the first yellow fluorescent glue layer and the second yellow fluorescent glue layer.

[0088] The thickness of the first yellow fluorescent adhesive layer is 200 μm, the thickness of the second yellow fluorescent adhesive layer is 200 μm, the thickness of the white wall adhesive layer is 200 μm, and the width of the white wall adhesive layer is 150 μm.

[0089] The white wall glue is composed of reflective particles and silica gel, and the weight ratio of reflective particles to silica gel is 1:4. The reflective particles are ZrO2.

[0090] Example 2

[0091] The present embodiment provides an LED packaging structure, including four flip chips and a fluorescent glue layer arranged on the flip chips, each flip chip having a first side facing the adjacent flip chip and a second side exposed to the outside. The flip chips include a first flip blue chip, a second flip blue chip, a third flip blue chip and a fourth flip blue chip, and the first flip blue chip, the second flip blue chip, the third flip blue chip and the fourth flip blue chip are arranged in a field shape. Among them, a red fluorescent glue layer is provided on the upper surface and the second side of the first flip blue chip, a green fluorescent glue layer is provided on the upper surface and the second side of the second flip blue chip, a transparent glue layer is provided on the upper surface and the second side of the third flip blue chip, and a third yellow fluorescent glue layer is provided on the upper surface and the second side of the fourth flip blue chip. White wall glue layers are provided between the red fluorescent glue layer and the green fluorescent glue layer, between the green fluorescent glue layer and the transparent glue layer, between the transparent glue layer and the third yellow fluorescent glue layer, and between the third yellow fluorescent glue layer and the red fluorescent glue layer.

[0092] The thickness of the red fluorescent glue layer is 200 μm, the thickness of the green fluorescent glue layer is 200 μm, the thickness of the transparent glue layer is 200 μm, the thickness of the third yellow fluorescent glue layer is 200 μm, the thickness of the white wall glue layer is 200 μm, and the width of the white wall glue layer is 150 μm.

[0093] The white wall glue is composed of reflective particles and silica gel, and the weight ratio of reflective particles to silica gel is 1:4. The reflective particles are ZrO2.

[0094] Example 3

[0095] This embodiment provides an LED packaging structure, which is different from the embodiment 2 in that the white wall glue layer is composed of reflective particles and silica gel, and the weight ratio of the reflective particles to the silica gel is 1:4. The reflective particles are MgO, ZrO2 and Al2O3, and the mass ratio is 1:5:3.

[0096] The silica gel is composed of A glue and B glue, and the weight ratio of A glue to B glue is 5:1. A glue is prepared from the following raw materials in weight percentage: 32% vinyl silicone resin, 60% vinyl silicone oil, 6% fumed silica, 1.3% silane coupling agent, and 0.7% catalyst. B glue is prepared from the following raw materials in weight percentage: 89% vinyl phenyl silicone resin, 9% phenyl hydrogenated silicone oil, and 2% crosslinking agent.

[0097] Comparative Example 1

[0098] This comparative example provides an LED packaging structure, including four bracket-type LED packaging structures, namely a first flip-chip blue light chip with a red fluorescent adhesive layer, a second flip-chip blue light chip with a green fluorescent adhesive layer, a third flip-chip blue light chip with a transparent adhesive layer, and a fourth flip-chip blue light chip with a yellow fluorescent adhesive layer. The four bracket-type LED packaging structures are mounted on the surface of the substrate in a field shape.

[0099] The performance of the LED packaging structures of Examples 1 to 3 and Comparative Example 1 was tested, and the luminous flux was measured and the luminous flux maintenance rate was calculated in several time periods. The results are shown in Table 1. The color coordinate point diagrams of Example 1, Example 2 and Comparative Example 1 were drawn. The results are shown in Table 1. Figure 17 to Figure 19 shown.

[0100] Table 1 Luminous flux maintenance rate

[0101] 0h 500h 1000h 1500h 2000h 2500h 3000h Example 1 100％ 99.7％ 99.5％ 98.9％ 98.7％ 98.4％ 97.6％ Example 2 100％ 99.8％ 99.6％ 99.1％ 98.9％ 98.5％ 97.8％ Example 3 100％ 99.8％ 99.6％ 99.2％ 99.1％ 98.8％ 98.0％ Comparative Example 1 100％ 99.6％ 98.7％ 97.4％ 96.6％ 95.2％ 94.3％

[0102] It can be seen from Table 1 that the luminous flux maintenance rate of the LED packaging structure provided by the embodiment of the present invention is still above 97% after 3000 hours, and the service life is long. Figure 17 to Figure 19 It can be seen from the figure that the color coordinates of the LED packaging structure provided by the embodiment of the present invention are concentrated and have high reliability.

[0103] The above is a preferred embodiment of the invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the invention. These improvements and modifications are also considered to be within the scope of protection of the invention.

Claims

1. An LED packaging structure, characterized in that: It comprises at least two flip chips and a fluorescent glue layer arranged on the flip chips; each flip chip has a first side surface facing the adjacent flip chip and a second side surface exposed to the outside, and a fluorescent glue layer is arranged on the upper surface and the second side surface of each flip chip, and a white wall glue layer is arranged between the fluorescent glue layers of different flip chips.

2. The LED packaging structure according to claim 1, characterized in that: The thickness of the fluorescent adhesive layer is 100 μm to 300 μm; the thickness of the white wall adhesive layer is 100 μm to 300 μm, and the width of the white wall adhesive layer is 100 μm to 250 μm.

3. The LED packaging structure according to claim 1, characterized in that: The flip chip comprises a first flip blue chip and a second flip blue chip, and the first flip blue chip and the second flip blue chip are symmetrically arranged; A fluorescent glue layer is provided on the upper surface and the second side surface of the first flip-chip blue light chip, a fluorescent glue layer is provided on the upper surface and the second side surface of the second flip-chip blue light chip, and a white wall glue layer is provided between adjacent fluorescent glue layers.

4. The LED packaging structure according to claim 3, characterized in that: A first yellow fluorescent glue layer is provided on the upper surface and the second side surface of the first flip-chip blue light chip, and the color temperature of the first yellow fluorescent glue layer excited by the first flip-chip blue light chip is 2200K~3500K; a second yellow fluorescent glue layer is provided on the upper surface and the second side surface of the second flip-chip blue light chip, and the color temperature of the second yellow fluorescent glue layer excited by the second flip-chip blue light chip is 4000K~6500K; a white wall glue layer is provided between the first yellow fluorescent glue layer and the second yellow fluorescent glue layer.

5. The LED packaging structure according to claim 1, characterized in that: The flip chip comprises a first flip chip, a second flip chip, a third flip chip and a fourth flip chip, wherein the first flip chip, the second flip chip, the third flip chip and the fourth flip chip are arranged in a shape of a field; Among them, a fluorescent glue layer is provided on the upper surface and the second side surface of the first flip-chip blue light chip, a fluorescent glue layer is provided on the upper surface and the second side surface of the second flip-chip blue light chip, a fluorescent glue layer is provided on the upper surface and the second side surface of the third flip-chip blue light chip, and a fluorescent glue layer is provided on the upper surface and the second side surface of the fourth flip-chip blue light chip; a white wall glue layer is provided between adjacent fluorescent glue layers.

6. The LED packaging structure according to claim 5, characterized in that: A red fluorescent glue layer is provided on the upper surface and the second side surface of the first flip-chip blue light chip, a green fluorescent glue layer is provided on the upper surface and the second side surface of the second flip-chip blue light chip, a transparent glue layer is provided on the upper surface and the second side surface of the third flip-chip blue light chip, and a third yellow fluorescent glue layer is provided on the upper surface and the second side surface of the fourth flip-chip blue light chip; a white wall glue layer is provided between the red fluorescent glue layer and the green fluorescent glue layer, between the green fluorescent glue layer and the transparent glue layer, between the transparent glue layer and the third yellow fluorescent glue layer, and between the third yellow fluorescent glue layer and the red fluorescent glue layer.

7. The LED packaging structure according to any one of claims 2 to 6, characterized in that: The thickness of the white wall adhesive layer is equal to the thickness of the fluorescent adhesive layer.

8. The LED packaging structure according to claim 1, characterized in that: The white wall glue layer is made of white wall glue, and the white wall glue includes reflective particles and silica gel, and the weight ratio of the reflective particles to the silica gel is 1:1.5 to 1:6; The silica gel is composed of A glue and B glue, and the weight ratio of A glue to B glue is 1:1 to 10:1; The A glue comprises the following raw materials in weight percentage: 25% to 45% vinyl silicone resin, 40% to 70% vinyl silicone oil, 2% to 15% fumed silica, 0.1% to 10% silane coupling agent, and 0.1% to 5% catalyst; The B glue comprises the following raw materials in weight percentage: 70% to 90% of vinyl phenyl silicone resin, 5% to 25% of phenyl hydrogenated silicone oil, and 0.5% to 10% of a cross-linking agent.

9. A method for packaging an LED, for packaging an LED packaging structure as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: integrating at least two flip chips and placing them upside down in a mold; forming a fluorescent glue layer on the upper surface and the second side surface of the flip chip; A white wall glue layer is formed on the upper surface and the second side surface at the junction of the flip chips, and the white wall glue layer is located between the fluorescent glue layers of different flip chips; The flip chip formed with the fluorescent adhesive layer and the white wall adhesive layer is taken out from the mold to obtain an LED packaging structure.

10. The LED packaging method according to claim 9, characterized in that: The white wall glue layer is obtained by curing white wall glue, the curing temperature of the white wall glue is 120° C. to 150° C., and the curing time is 3 min to 5 min; The fluorescent glue layer is obtained by curing the fluorescent glue, and the curing temperature of the fluorescent glue is 120° C. to 150° C., and the curing time is 3 min to 5 min.

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