Large-angle light-emitting light source, surface light source module, and method for preparing light-emitting light source

Abstract

The present invention relates to a method for preparing a large-angle light-emitting light source, a surface light source module and a light-emitting light source, wherein the large-angle light-emitting light source comprises an LED chip, the LED chip is a flip-chip structure, the LED chip comprises a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top, and a lower reflection layer is arranged on the bottom surface of the LED chip, a blue light re-excitation layer is arranged on the top surface and the side surface of the LED chip, an upper reflection layer is arranged on the top surface of the blue light re-excitation layer, the four sides of the blue light re-excitation layer are full light-emitting areas, and the top surface of the upper reflection layer is a full reflection or partial reflection area. The advantages of the present invention are: in the present invention, the reflection layer is directly arranged on the top and bottom of the flip-chip LED chip, the light emitted by the LED chip is reflected by the upper reflection layer and the lower reflection layer, so that the light is emitted from the four sides of the LED chip, and large-angle light emission is achieved; in addition, since the large-angle light-emitting light source of the present invention is a separate monomer, rather than making the reflection layer on the substrate as a whole, it can be applied to different substrates.

Description

Technical Field

[0001] The present invention relates to a large-angle light emitting light source, and also relates to a surface light source module using the large-angle light emitting light source and a method for preparing the light emitting light source. Background Art

[0002] Traditional front-mounted LED with reflector structure, such as Figure 1 As shown, it includes a reflective layer 11, a substrate 12, an N-GaN layer 13 and a P-GaN layer 14 arranged in sequence from bottom to top; a conventional flip-chip LED with a reflector structure, such as Figure 2 As shown, it includes a reflective layer 21, a P-GaN layer 22, a light-emitting layer 23, an N-GaN layer 24 and a substrate 25 arranged in sequence from bottom to top; if a reflective layer is applied to conventional face-mounted and flip-chip LED chips, they both emit light on five sides, and the reflective layer is arranged on the side close to the substrate, that is, on the bottom surface of the LED chip.

[0003] At present, in the light source structure formed by packaging LED chips with a reflector structure, the light output angle is only about 120°, and its use is subject to certain restrictions in the application of surface light sources in the backlight display and lighting industries.

[0004] For example, there are three main types of traditional direct-down surface-emitting modules:

[0005] (1) A light source array composed of conventional LED chips is used, and a diffusion plate is arranged at a certain distance above the LED light source array to convert the point light source into a surface light source;

[0006] (2) A light source array composed of conventional LED chips is used, and a lens is installed closely on each LED chip, so that the light emitted by the LED lamp beads passes through the lens, and then is transmitted through the air layer between the lens and the diffuser plate. After a certain degree of light intensity superposition, the light is irradiated onto the diffuser plate, thereby converting the point light source into a surface light source;

[0007] (3) A conventional LED chip light source array is used, and silica gel and phosphor are directly coated on the surface of the LED light source array to form a light-guiding medium layer, so that the point light source is transformed into a surface light source.

[0008] The above methods all have certain disadvantages or limitations:

[0009] (1) For the first method: Figure 3 , 4 As shown, the maximum light output angle of a conventional LED light source is about 120°. The LED light source 91 and the diffuser plate 92 must be spaced a large distance apart to achieve a more uniform light mixing effect. The entire surface light output module is usually very thick and can generally only be used in the lighting industry, such as panel lights, and its application is very limited.

[0010] (2) For the second method: Figure 5 , 6 As shown, after superimposing the lens 3 on the conventional LED light source 91, the light output angle can reach 135°. Although the light-emitting angle is increased and the light output from the top surface is greatly reduced, a more uniform light mixing effect can be achieved within a relatively shorter distance. Due to the need to use a secondary optical lens, a certain distance must be set between the diffuser plate 92 and the secondary optical lens 93. Although the thickness is reduced compared to the first method, the surface light output module cannot achieve an ultra-thin effect.

[0011] (3) For the third method, Figure 8 As shown, a phosphor layer 94 is coated on the surface of the light source array composed of several LED chips 91', which slightly increases the lateral propagation and mixing of white light; but from optical theory, we can find that when blue light is transmitted in a waveguide containing phosphor, the intensity of the blue light as excitation light will decrease rapidly due to the absorption and irregular scattering of the phosphor. Fig. 9 As shown, taking a point light source as an example, when its light intensity is transmitted in a waveguide containing phosphor, the intensity is numerically inversely proportional to the cube of the distance; Fig.10 As shown, when the light intensity of a line light source is transmitted in a waveguide containing phosphor, the intensity is numerically inversely proportional to the square of the distance; Fig.11 As shown, when the light intensity of a surface light source is transmitted in a waveguide containing phosphor, the intensity is inversely proportional to the distance.

[0012] The surface light source using the first and second methods is not only easy to form dark areas and poor light mixing uniformity due to the limitation of the light output angle of the LED chip, but also the entire direct-down surface light output module is relatively thick. If the thickness of the entire surface light output module is to be reduced, it can only be achieved by reducing the distance between adjacent LED chips (see Figure 7 ), but the number of LED chips required increases exponentially, and the cost increases significantly.

[0013] The third method of using surface light source can solve the problem of module thickness, but

[0014] Firstly, the light emission angle of the LED chip is limited, which makes it difficult for the light emitted by the LED chip to propagate horizontally in the phosphor layer, and the effect of horizontal propagation is limited;

[0015] Secondly, the white light obtained by mixing blue light and phosphors is severely attenuated during the propagation of the light-guiding medium, and the blue light that excites the phosphors is attenuated. Therefore, the blue light intensity is reduced, and the lateral propagation intensity along the waveguide direction is reduced; the chip light brightness is uneven, and the light mixing effect is poor, resulting in uneven brightness of the entire surface of the surface light source. Therefore, the chips are arranged relatively densely, which overall limits the arrangement of LED chips with larger spacing.

[0016] In summary, we need to develop a light source chip that increases the light output angle, and a surface light source module that can improve the light mixing effect, avoid uneven brightness, and reduce the overall thickness. Summary of the invention

[0017] The technical problem to be solved by the present invention is to provide a large-angle light source with increased light output angle and a preparation method thereof, and also to provide a surface light source module that can improve the light mixing effect, avoid uneven brightness and reduce the overall thickness.

[0018] In order to solve the above technical problems, the technical solution of the present invention is: a large-angle light source, characterized in that: it includes an LED chip, the LED chip is a flip-chip structure, the LED chip includes a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top, and a lower reflection layer is arranged on the bottom surface of the LED chip, a blue light re-excitation layer is arranged on the top surface and side surface of the LED chip, an upper reflection layer is arranged on the top surface of the blue light re-excitation layer, the four side surfaces of the blue light re-excitation layer are full light emitting areas, and the top surface of the upper reflection layer is a full reflection or partial reflection area.

[0019] Furthermore, a middle reflective layer is disposed on the top surface of the LED chip, and the middle reflective layer is a partially light-emitting and partially reflective structure.

[0020] Furthermore, a first dielectric transparent layer is disposed on the top surface and side surfaces of the blue light complex excitation layer, and the upper reflection layer is located on the upper surface of the first dielectric transparent layer.

[0021] A surface light source module for a large-angle light emitting light source is also provided, and its innovative point is that: the surface light source module comprises a substrate, a high-refractive-index transparent waveguide layer and a large-angle light emitting light source, a plurality of large-angle light emitting light sources are arranged on the substrate, a high-refractive-index transparent waveguide layer covering all the large-angle light emitting light sources is arranged on the substrate, and the height of the high-refractive-index transparent waveguide layer is equal to or higher than the top surface height of the large-angle light emitting light source;

[0022] The high refractive index transparent waveguide layer satisfies the following conditions simultaneously:

[0023] (1) The high refractive index transparent waveguide layer is a single medium and a uniformly distributed medium layer;

[0024] (2) defining a surface of the high refractive index transparent waveguide layer away from the substrate as the upper waveguide interface, and a medium located on one side of the upper waveguide interface away from the substrate as the outer medium layer, the refractive index of the high refractive index transparent waveguide layer is denoted as n2, and the refractive index of the outer medium layer is denoted as n3, and n2>n3;

[0025] (3) The other surface of the high refractive index transparent waveguide layer close to the substrate is defined as a lower waveguide interface, and a waveguide reflection layer is provided between the lower waveguide interface and the substrate.

[0026] Furthermore, a diffusion film layer is disposed above the upper waveguide interface of the high refractive index transparent waveguide layer, and an air layer or air gap exists between the diffusion film layer and the high refractive index transparent waveguide layer, and the air layer or air gap serves as an external medium layer.

[0027] Furthermore, when there is an air gap between the diffusion film layer and the high refractive index transparent waveguide layer, the lower surface of the diffusion film layer has an uneven microstructure, and the microstructure occupies 10 to 100% of the total area of ​​the diffusion film layer; the microstructure on the lower surface of the diffusion film layer is in close contact with the waveguide interface on the high refractive index transparent waveguide layer to form an air gap.

[0028] Furthermore, a local scattering microstructure is added between the substrate and the high refractive index transparent waveguide layer or between the high refractive index transparent waveguide layer and the diffusion film layer.

[0029] Furthermore, the substrate is a plurality of discontinuous strip substrates arranged at intervals, and the large-angle light emitting light sources are correspondingly arranged on the strip substrates.

[0030] A method for preparing a light source with a large light output angle is also provided, and its innovation lies in that the preparation method comprises the following steps:

[0031] Step S1: Select a qualified LED chip, wherein the LED chip has a lower reflection layer, a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top;

[0032] Step S2: Arrange a plurality of LED chips at equal intervals to form a fillable gap between adjacent LED chips, and then set a blue light re-excitation layer on the entire surface of the LED chips and in the fillable gap, and bake and solidify to obtain a semi-finished product;

[0033] Step S3: forming a mirror-like upper reflective layer with a clear interface on the top surface of the semi-finished product obtained in step S2;

[0034] Step S4: The semi-finished product with the upper reflective layer on the top surface is baked and solidified again, and then cut and split. After splitting, the chips are tested, sorted, and rearranged to obtain a large-angle light source.

[0035] Furthermore, in the step S1, the LED chip has a lower reflection layer, a P-GaN layer, a light-emitting layer, an N-GaN layer, a substrate and a middle reflection layer arranged in sequence from bottom to top. Before step S1, an LED wafer is selected, and the LED wafer has a lower reflection layer, a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top, and the LED wafer is inspected for qualification; and a middle reflection layer is arranged on the surface of the top substrate of the wafer that has passed the inspection, and the LED wafer with the middle reflection layer on the top surface is baked and cured, and then cut and split to obtain an LED chip having a lower reflection layer, a P-GaN layer, a light-emitting layer, an N-GaN layer, a substrate and a middle reflection layer arranged in sequence from bottom to top.

[0036] Furthermore, between steps S2 and S3, the semi-finished product is first cut and split to obtain a semi-finished product having a blue light complex excitation layer, and then the semi-finished products having a blue light complex excitation layer are rearranged equidistantly to form a fillable gap between adjacent semi-finished products, and then a first medium transparent layer is arranged on the entire surface of the semi-finished product and in the fillable gap as a whole, and the semi-finished product is baked and cured to obtain a semi-finished product having a blue light complex excitation layer and a first medium transparent layer.

[0037] Furthermore, in the step S3, a second dielectric transparent layer with a clear interface and a mirror-like upper reflection layer are sequentially formed on the top surface of the semi-finished product having the first dielectric transparent layer and the blue light complex excitation layer.

[0038] The advantages of the present invention are:

[0039] (1) In order to achieve a large-angle light output from the chip, theoretically, it is only necessary to add another reflective layer on the upper surface of the LED chip, so that part of the upward light can be reflected to the side of the chip through the reflective layer. However, Fig.12 As shown in the fluorescent emission spectrum stimulated by the blue light LED, the absorption rate of long-wavelength light such as green light, yellow light, and red light in the LED chip is low, while the blue light emitted by the LED chip itself has a shorter wavelength and the highest absorption rate, and its absorption is the most serious. Therefore, if this method is adopted, the blue light will be reflected and absorbed multiple times between the upper and lower reflection layers, and the light that can be smoothly emitted from all directions will be greatly reduced.

[0040] In the present invention, the reflective layer is directly set on the top and bottom of the flip-chip LED chip. When the light emitted by the LED chip is continuously reflected by the upper reflective layer and the lower reflective layer, due to the existence of the blue light re-excitation layer, for conventional blue light LED chips, the reflected blue light can be further excited by the blue light re-excitation layer (i.e., the phosphor layer), and then further mixed to obtain white light; in the fluorescent emission spectrum excited by the blue light LED, the absorption rate of long-wavelength light such as green light, yellow light, and red light in the LED chip is low, while the blue light emitted by the LED chip itself has a shorter wavelength, the highest absorption rate, and its absorption is the most serious; and in the present invention, the upper reflective layer and the blue light re-excitation layer are creatively set above the LED chip at the same time, and the blue light reflected by the upper reflective layer is excited again by the blue light re-excitation layer, and then further mixed to obtain white light, and the part of white light absorbed relative to the blue light is much less; on the basis of achieving large-angle light emission, light attenuation is avoided. The large-angle light emitting light source of the present invention is a separate monomer, rather than making the reflective layer on the substrate as a whole, so it can be conveniently applied to different substrates.

[0041] In the preparation process, in some light-emitting areas, we can control the thickness and transparency of the translucent reflective layer to control the amount of reflected light, thereby achieving regulation of the light output from the side of the chip; in addition, reflective particle fillers are provided in the translucent reflective layer, which helps to increase the light output from the edges and sides by controlling the thickness of the translucent reflective layer.

[0042] (2) The provision of the first or second dielectric transparent layer increases the light output angle of the LED chip, which is beneficial for guiding the light to the high refractive index transparent waveguide layer, increasing its light output angle and further improving the light mixing effect.

[0043] (3) In the surface light source module structure of the present invention, the microstructure of the lower surface of the diffusion film layer has gaps, that is, the air layer that occupies most of the area of ​​the diffusion film layer is used as a low refractive index layer, and then the white light emitted by the large-angle light source forms a waveguide in the high refractive index transparent waveguide layer, so that the point light source is transformed into a surface light source, thereby increasing the lateral propagation of white light.

[0044] (4) In the present invention, in order to improve the uneven light intensity and enhance the light mixing effect, a local scattering microstructure area can be provided on the upper surface of the substrate or the lower surface of the high refractive index transparent waveguide layer, or a local scattering microstructure area can be provided on the upper surface of the high refractive index transparent waveguide layer. The local scattering microstructure area is generally provided in the dark area of ​​the LED light source distributed in an array. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the structure of a traditional front-mounted LED with a reflector structure.

[0046] Figure 2This is a schematic diagram of the structure of a traditional flip-chip LED with a reflector structure.

[0047] Figure 3 This is a test chart of the light output angle of a traditional LED light source.

[0048] Figure 4 This is the principle diagram of the first type of light intensity superposition in the traditional direct-down surface light-emitting module.

[0049] Figure 5 This is a test chart of the light output angle after adding a lens to a traditional LED light source.

[0050] Figure 6 This is a schematic diagram of the light intensity superposition principle of the traditional direct-down surface light-emitting module using an LED light source plus a lens.

[0051] Figure 7 This is another light intensity superposition principle diagram of a traditional direct-down surface light module that uses closely arranged LED light sources and lenses.

[0052] Figure 8 This is a schematic diagram of the LED light source array plus phosphor method used in a traditional direct-type surface-emitting module.

[0053] Fig. 9 Schematic diagram of the light intensity loss of a point light source in a waveguide containing phosphor.

[0054] Fig.10 Schematic diagram of the loss of light intensity of a linear light source caused by a waveguide containing phosphor.

[0055] Fig.11 Schematic diagram of the light intensity loss of a surface light source due to a waveguide containing phosphors.

[0056] Fig.12 This is the fluorescence spectrum excited by blue LED.

[0057] Fig.13 This is a schematic structural diagram of a large-angle light emitting light source according to Example 1.

[0058] Fig.14 This is a test diagram of the light emission angle of the large-angle light emission light source according to the first embodiment of the present invention.

[0059] Fig.15 This is a schematic structural diagram of a large-angle light emitting light source according to Example 2.

[0060] Fig.16 Another schematic diagram of the structure of the LED chip in the present invention.

[0061] Figure 17 to Figure 19 They are respectively structural schematic diagrams of the surface light source module of Example 3.

[0062] Fig. 20 for Fig.18 A partial diagram of .

[0063] Figure 21-22 They are respectively structural schematic diagrams of the surface light source module of Example 4. DETAILED DESCRIPTION

[0064] Example 1

[0065] The large-angle light source of this embodiment, such as Fig.13 As shown, it includes an LED chip 1, and the LED chip 1 adopts a flip-chip structure with a reflector: the LED chip 1 includes a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top, and a lower reflection layer is arranged on the bottom surface of the LED chip 1, and a blue light re-excitation layer 2 is arranged on the top surface and side surface of the LED chip 1, and an upper reflection layer 3 is arranged on the top surface of the blue light re-excitation layer 2, the four side surfaces of the blue light re-excitation layer 2 are full light emitting areas, and the top surface of the upper reflection layer 3 is a full reflection or partial reflection area.

[0066] In a specific implementation, the upper reflective layer 3 contains granular fillers for refraction and reflection.

[0067] Take the large-angle light source with a semi-transparent and semi-reflective top surface reflection structure as an example. Fig.14 As shown in the figure, the structure successfully transforms the main energy angle of the main light-emitting direction of the normal Lambertian light type LED light source from 0° directly above to plus or minus 30° around. Secondly, from the light intensity distribution, it can be seen that the light intensity is successfully evenly distributed throughout the entire light-emitting angle. Even in the wide angle range of plus or minus 85°, the light intensity is still about 64% of the peak light intensity. In the normal Lambertian light type LED light source, if its light output angle is 120°, that is, when it is plus or minus 60°, its light output intensity is only half of the peak value (see Figure 3 ). However, in the large-angle light emitting light source structure using a semi-transparent and semi-reflective top surface reflection structure in this patent, the light intensity is still 64% of the peak light intensity even within a large angle range of plus or minus 85°.

[0068] The large-angle light source of this embodiment is prepared by the following steps:

[0069] Step S1: Select a qualified LED chip 1, wherein the LED chip 1 has a lower reflection layer, a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top;

[0070] Step S2: Arrange a plurality of LED chips 1 at equal intervals so that a fillable gap is formed between adjacent LED chips 1, and then set a phosphor layer on the entire surface of the LED chip 1 and in the fillable gap to form a blue light complex excitation layer 2, and bake and solidify to obtain a semi-finished product;

[0071] Step S3: forming a mirror-like upper reflection layer 3 with a clear interface on the top surface of the semi-finished product obtained in step S2; specifically, the upper reflection layer 3 is a metal layer disposed on the top surface of the blue light complex excitation layer 2 or a granular filler for refraction and reflection disposed on the top surface of the blue light complex excitation layer 2;

[0072] Step S4: The semi-finished product with the upper reflective layer on the top surface is baked and solidified again, and then cut and split. After splitting, the chips are tested, sorted, and rearranged to obtain a light source with a large angle of light.

[0073] The LED chip used in the wide-angle light source of this embodiment is more specifically implemented as follows: Fig.16 As shown, the top surface of the LED chip 1 is provided with a middle reflection layer 8, and the middle reflection layer 8 is a partial light emitting and partial reflection structure; for the preparation method of the large-angle light emitting light source using the LED chip of this structure, step S1 is further adjusted to: select an LED wafer, the LED wafer has a lower reflection layer, a P-GaN layer, a light emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top, and detect whether the LED wafer is qualified; and set a layer of middle reflection layer 8 on the surface of the substrate on the top surface of the wafer that has passed the test, bake and cure the LED wafer with the middle reflection layer on the top surface, and then cut and split it to obtain an LED chip with a lower reflection layer, a P-GaN layer, a light emitting layer, an N-GaN layer, a substrate and a middle reflection layer 8 arranged in sequence from bottom to top, and select a qualified LED chip 1 with a middle reflection layer 8; the remaining steps remain unchanged. In this way, the upper surface and the lower surface of the LED chip 1 have a middle reflection layer and a lower reflection layer respectively.

[0074] Taking a panel light of a certain specification as an example, the comparison parameters of the large-angle light source of this embodiment and the conventional light source are as follows:

[0075] 600*600mm Panel Light Application Case

[0076]

[0077] in conclusion:

[0078] It can be seen from the above table that, under the premise of the same luminous area and the same thickness of the panel light, in this embodiment, due to the use of a large-angle four-sided light source to shift the main luminous energy direction from directly above to the side, at the same time, the luminous angle is as high as more than 170°. Compared with the panel light combined with the conventional LED plus the diffuser, while ensuring the same mixed light effect, the distance between adjacent light sources is effectively increased, and the number of light source particles is greatly reduced; compared with the panel light combined with the conventional LED light source with a lens and a diffuser, not only the number of particles is reduced, but also the cost of the lens is saved.

[0079] Example 2

[0080] In this embodiment, Fig.15 As shown, the large-angle light source includes an LED chip 1, the bottom surface of the LED chip 1 has a lower reflection layer, the top surface and the side surface of the LED chip 1 are provided with a blue light re-excitation layer 2, and a first medium transparent layer 4 is provided on the top surface and the side surface of the blue light re-excitation layer 2, and an upper reflection layer 3 is provided on the upper surface of the first medium transparent layer 4.

[0081] The four side surfaces of the blue light complex excitation layer 2 are full light emitting areas, and the top surface of the upper reflection layer 3 is a full reflection or partial reflection area.

[0082] The large-angle light source of this embodiment is prepared by the following steps:

[0083] Step S1: Select a qualified LED chip 1, wherein the LED chip 1 has a lower reflection layer, a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top;

[0084] Step S2: Arrange a plurality of LED chips 1 at equal intervals so that a fillable gap is formed between adjacent LED chips 1, and then arrange a phosphor layer on the entire surface of the LED chip 1 and in the fillable gap as a whole to form a blue light complex excitation layer 2, and bake and solidify to obtain a semi-finished product; then cut and split the semi-finished product to obtain a semi-finished product with a blue light complex excitation layer 2, and then rearrange the semi-finished product with the blue light complex excitation layer 2 at equal intervals so that a fillable gap is formed between adjacent semi-finished products, and then arrange a first dielectric transparent layer 4 on the entire surface of the semi-finished product and in the fillable gap as a whole, and bake and solidify to obtain a semi-finished product with a blue light complex excitation layer 2 and a first dielectric transparent layer 4;

[0085] Step S3: forming a mirror-like upper reflection layer 3 with a clear interface on the top surface of the semi-finished product obtained in step S2; specifically, the upper reflection layer 3 is a metal layer disposed on the top surface of the blue light complex excitation layer 2 or a granular filler for refraction and reflection disposed on the top surface of the blue light complex excitation layer 2;

[0086] Step S4: The semi-finished product with the upper reflective layer on the top surface is baked and solidified again, and then cut and split. After splitting, the chips are tested, sorted, and rearranged to obtain a light source with a large angle of light.

[0087] The LED chip used in the large-angle light source of this embodiment can be selected to be an LED chip with a middle reflective layer. The implementation method thereof is as follows: Fig.16As shown, the top surface of the LED chip 1 is provided with a middle reflection layer 8, and the middle reflection layer 8 is a partially light-emitting and partially reflecting structure; for the preparation method of a large-angle light-emitting light source using an LED chip with this structure, step S1 is adjusted to: select an LED wafer, the LED wafer has a lower reflection layer, a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top, and detect whether the LED wafer is qualified; and a layer of middle reflection layer 8 is arranged on the surface of the top substrate of the wafer that has passed the inspection, and the LED wafer with the middle reflection layer on the top surface is baked and cured, and then cut and split to obtain an LED chip that is arranged with a lower reflection layer, a P-GaN layer, a light-emitting layer, an N-GaN layer, a substrate and a middle reflection layer 8 in sequence from bottom to top, and select a qualified LED chip 1 with a middle reflection layer 8; the remaining steps remain unchanged.

[0088] A second medium transparent layer is further arranged between the first medium transparent layer and the reflective layer, and the refractive index of the first medium transparent layer is higher than the refractive index of the second medium transparent layer.

[0089] For the large-angle light source of this structure, the preparation steps further optimize step S3 as follows: a second medium transparent layer with a clear interface and a mirror-like upper reflection layer 3 are sequentially formed on the top surface of the semi-finished product having the first medium transparent layer 4 and the blue light complex excitation layer 2; in this way, Fig.15 A second dielectric transparent layer is formed between the first dielectric transparent layer 4 and the mirror-like upper reflective layer 3, which further increases the light output angle of the LED chip, is beneficial to guide the light to the high refractive index transparent waveguide layer, increases its light output angle, and further improves the light mixing effect.

[0090] Example 3

[0091] The surface light source module of this embodiment includes a substrate 5, a high refractive index transparent waveguide layer 6, a diffusion film layer 7 and a large-angle light emitting light source. The large-angle light emitting light source of this embodiment adopts the large-angle light emitting light source of embodiment 1 or the large-angle light emitting light source of embodiment 2, such as Fig.17 and Fig.18 As shown, a plurality of large-angle light emitting sources are arranged on the substrate 5, and a high-refractive-index transparent waveguide layer 6 covering the large-angle light emitting sources is also arranged on the substrate 5, and the height of the high-refractive-index transparent waveguide layer 6 is equal to or higher than the height of the large-angle light emitting sources.

[0092] In this embodiment, the high refractive index transparent waveguide layer 6 is a single medium and uniformly distributed medium layer, and a surface of the high refractive index transparent waveguide layer 6 far from the substrate 5 is defined as an upper waveguide interface, that is, the upper waveguide interface in the figure is the upper surface of the high refractive index transparent waveguide layer 6; the medium located on the side far from the substrate on both sides of the upper waveguide interface is an outer medium layer, that is, the medium located above the upper surface of the high refractive index transparent waveguide layer 6 is an outer medium layer;

[0093] The refractive index of the high refractive index transparent waveguide layer 6 is recorded as n2, and the refractive index of the external medium layer is recorded as n3, n2>n3;

[0094] In addition, the other surface of the high refractive index transparent waveguide layer 6 close to the substrate 5 is defined as the lower waveguide interface, that is, the lower waveguide interface in the figure is the lower surface of the high refractive index transparent waveguide layer 6; a waveguide reflection layer 9 is arranged between the lower waveguide interface and the substrate 5.

[0095] In this embodiment, a diffusion film layer 7 is further provided above the upper waveguide interface of the high refractive index transparent waveguide layer 6, and an air gap exists between the diffusion film layer 7 and the high refractive index transparent waveguide layer 6, and the air gap serves as an external medium layer. Specifically: the lower surface of the diffusion film layer 7 has an uneven microstructure, and the microstructure occupies 10 to 100% of the total area of ​​the diffusion film layer 7; the microstructure on the lower surface of the diffusion film layer 7 is closely attached to the upper waveguide interface of the high refractive index transparent waveguide layer 6 to form an air gap.

[0096] As a preferred or optional method of this embodiment, when the large-angle light emitting light source having the first medium transparent layer 4 in Embodiment 2 is used to manufacture the surface light source module,

[0097] like Fig. 20 As shown, the thickness of the side of the first dielectric transparent layer 4 is recorded as a, the height of the first dielectric transparent layer 4 is recorded as h, the refractive index of the first dielectric transparent layer 4 is recorded as n1, the refractive index of the high refractive index transparent waveguide layer 6 is recorded as n2, and the refractive index of the outer medium layer is recorded as n3. In order to achieve total reflection of light, it is necessary to satisfy

[0098]

[0099] In this embodiment, the substrate 5 is a transparent flexible substrate, specifically a PI board, a PET board, or a PEV board, or the substrate 5 is a metal rigid board, specifically an aluminum board, a thin copper board, or a ceramic board.

[0100] like Fig.19 As shown, the substrate 5 is a plurality of discontinuous strip substrates arranged at intervals, and the large-angle light emitting light sources are correspondingly arranged on the strip substrates.

[0101] In this embodiment, a surface light source module in which the substrate 5 is a plurality of discontinuous strip substrates arranged at intervals is taken as an example to specifically describe its preparation method, which comprises the following steps:

[0102] (1) A continuous substrate is selected and integrally bonded on the substrate, that is, a large-angle light source is mounted on the substrate, and then cut into strip substrates 5 with a width of 0.2-3 mm, and one or both ends of each strip substrate 5 are connected by an electrode plate or an electrode device to form an integral structure;

[0103] (2) placing the overall structure in (1) on a reusable mold or backlight panel, and then coating the entire backlight panel with a high-refractive transparent material (silicone or acrylic material) so that the high-refractive transparent material covers the entire surface of the strip substrate and the area between adjacent strip substrates, and finally molding the entire structure to form a high-refractive index transparent waveguide layer 6 covering the large-angle light source;

[0104] (3) A diffusion film layer 7 is disposed on the upper surface of the high refractive index transparent waveguide layer 6 to form a backlight module, and finally the backlight module is peeled off from the backlight plate.

[0105] The product of this embodiment can be applied to ultra-thin displays, panel lights (with or without frames), bulb lamps, filament lamps, fluorescent lamps, and street lamps.

[0106] As a more specific implementation of this embodiment:

[0107] A local scattering microstructure is added between the substrate 5 and the high refractive index transparent waveguide layer 6 or between the high refractive index transparent waveguide layer 6 and the diffusion film layer 7 .

[0108] The diffusion particles of the local scattering microstructure can adopt a spherical structure, and its function is similar to that of a microlens. The microstructure includes holograms, cylindrical lenses, microlens arrays and stretchable diffraction gratings. The local scattering microstructure can be realized on the surface of the diffusion film by adopting the methods of extrusion roller embossing, diffusion photolithography, hot embossing, self-assembly and isotropic etching. When the light passes through these particles, it is focused and then scattered into a certain range of emission angles, which has the function of enhancing the brightness of the emitted light. In addition, the difference in the diameter of the diffusion particles and the refractive index with the film-forming resin also ensures that the light will not be directly emitted from the diffusion film, providing a uniform light mixing effect and uniform brightness. The diffusion film with a scattering microstructure involved in the present invention uses the refraction and reflection effect of the surface periodic or randomly distributed microstructures on light to modulate the optical state of the incident light. The surface light source module structure obtained by using this type of light diffusion film with a local scattering microstructure has the advantages of wide viewing angle, high transmittance, and uniform light mixing.

[0109] The parameters of the surface light source module made by using the large-angle light source of the first embodiment and the traditional direct-type backlight module are compared as follows:

[0110] 6-inch mobile phone backlight application case

[0111]

[0112] Conclusion: It can be seen from the above table that, under the premise of the same luminous area and the same thickness of the backlight module, in this embodiment, due to the use of a large-angle four-sided light source to shift the main luminous energy direction from directly above to the side, at the same time, the luminous angle is as high as more than 170°. Under the premise of ensuring the same mixed light effect, the distance between adjacent light sources is effectively increased and the number of light source particles is greatly reduced.

[0113] Example 4

[0114] The structure of the surface light source module of this embodiment is basically the same as that of embodiment 3, including a substrate 5, a high refractive index transparent waveguide layer 6, a diffusion film layer 7 and a large-angle light source. The large-angle light source of this embodiment adopts the large-angle light source of embodiment 1 or the large-angle light source of embodiment 2. Fig.21 and Fig. 22 As shown, a plurality of large-angle light emitting light sources are arranged on the substrate 5, and a high-refractive-index transparent waveguide layer 6 covering the large-angle light emitting light sources is also arranged on the substrate 5, and the height of the high-refractive-index transparent waveguide layer 6 is equal to or higher than the height of the large-angle light emitting light sources, and a diffusion film layer 7 is also arranged above the upper waveguide interface of the high-refractive-index transparent waveguide layer 6.

[0115] The difference is that the air gap between the diffusion film layer 7 and the high refractive index transparent waveguide layer 6 is changed into an air layer 10. Specifically:

[0116] In this embodiment, the high refractive index transparent waveguide layer 6 is a single medium transparent layer without phosphor, and a surface of the high refractive index transparent waveguide layer 6 away from the substrate 1 is defined as an upper waveguide interface, and an air layer 10 is provided between the upper waveguide interface and the diffusion film layer 4. The air layer 10 serves as an outer medium layer on the side away from the substrate on both sides of the upper waveguide interface. The refractive index of the outer medium layer is recorded as n3, and the refractive index of the high refractive index transparent waveguide layer 6 is recorded as n2, and n2>n3;

[0117] The other surface of the high refractive index transparent waveguide layer 6 close to the substrate 1 is defined as a lower waveguide interface, and a waveguide reflection layer 9 is provided between the lower waveguide interface and the substrate 1 .

[0118] The surface light source modules of Examples 3 and 4 can be applied to the backlight field. In the surface light source module structures of Examples 3 and 4, the white light emitted by the large-angle light source can form a waveguide in the high-refractive-index transparent waveguide layer, so that the point light source is transformed into a surface light source, which increases the lateral propagation of white light and can effectively improve the light mixing effect, which is very suitable for the high-performance display backlight field.

[0119] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A surface light source module using a large-angle light source, characterized by: The surface light source module includes a substrate, a high-refractive-index transparent waveguide layer, and a large-angle light source. The substrate is provided with a plurality of light sources with large light angles. The large-angle light emitting light source includes an LED chip, which has a flip-chip structure. The LED chip includes a P-GaN layer, a light-emitting layer, an N-GaN layer, and a substrate arranged in sequence from bottom to top. A lower reflection layer is provided on the bottom surface of the LED chip, a blue light complex excitation layer is provided on the top surface and side surfaces of the LED chip, and an upper reflection layer is provided on the top surface of the blue light complex excitation layer. The four side surfaces of the blue light complex excitation layer are full light emitting areas, and the top surface of the upper reflection layer is a full reflection or partial reflection area. A middle reflective layer is provided on the top surface of the LED chip, and the middle reflective layer is a partially light-emitting and partially reflective structure; A first dielectric transparent layer is provided on the top and side surfaces of the blue light complex excitation layer, and the upper reflection layer is located on the upper surface of the first dielectric transparent layer; The thickness of the side of the first medium transparent layer is recorded as a, the height of the first medium transparent layer is recorded as h, the refractive index of the first medium transparent layer is recorded as n1, the refractive index of the high refractive index transparent waveguide layer is recorded as n2, and the refractive index of the outer medium layer is recorded as n3. In order to achieve total reflection of light, it is necessary to meet ; A high-refractive-index transparent waveguide layer is provided on the substrate to cover all the large-angle light-emitting light sources, wherein the height of the high-refractive-index transparent waveguide layer is equal to or higher than the top surface height of the large-angle light-emitting light sources; The high refractive index transparent waveguide layer satisfies the following conditions simultaneously: (1) The high refractive index transparent waveguide layer is a single medium and a uniformly distributed medium layer; (2) The surface of the high-refractive-index transparent waveguide layer that is away from the substrate is defined as the upper waveguide interface, and the medium on the side away from the substrate on both sides of the upper waveguide interface is defined as the outer medium layer. The refractive index of the high-refractive-index transparent waveguide layer is denoted as n2, and the refractive index of the outer medium layer is denoted as n3, where n2>n3; (3) The other surface of the high refractive index transparent waveguide layer close to the substrate is defined as the lower waveguide interface, and a waveguide reflection layer is provided between the lower waveguide interface and the substrate.

2. The surface light source module according to claim 1, wherein: A diffusion film layer is further provided above the upper waveguide interface of the high refractive index transparent waveguide layer, and an air layer or air gap exists between the diffusion film layer and the high refractive index transparent waveguide layer, and the air layer or air gap serves as an outer medium layer.

3. The surface light source module according to claim 2, wherein: When an air gap exists between the diffusion film layer and the high-refractive-index transparent waveguide layer, the lower surface of the diffusion film layer has an uneven microstructure, and the microstructure occupies 10% to 100% of the total area of ​​the diffusion film layer; the microstructure on the lower surface of the diffusion film layer is in close contact with the waveguide interface on the high-refractive-index transparent waveguide layer to form an air gap.

4. The surface light source module according to claim 3, wherein: A local scattering microstructure is added between the substrate and the high-refractive-index transparent waveguide layer or between the high-refractive-index transparent waveguide layer and the diffusion film layer.

5. The surface light source module according to claim 4, characterized in that: The substrate is a plurality of discontinuous strip substrates arranged at intervals, and the large-angle light sources are correspondingly arranged on the strip substrates.

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