LED lamp bead, preparation method thereof and LED light source

Abstract

The invention provides an LED lamp bead, a preparation method thereof and an LED light source. The LED lamp bead comprises a substrate, at least two LED chips, a light conversion layer and a driving circuit. Wherein the LED chips are located on the substrate, the light conversion layer is located on the substrate and the LED chips, and the driving circuit can independently drive each LED chip. The LED lamp bead is provided with at least two LED chips, each LED chip can be independently driven by the driving circuit, the driving circuit can independently adjust the brightness of each LED chip, then the light-emitting angles of the LED lamp bead in at least two directions are adjusted, the LED lamp bead is easy to prepare, an optical lens and an optical film material do not need to be additionally arranged, the cost is low, the size is small, and the LED lamp bead is suitable for popularization and application. And the use is convenient. Besides, if the LED light source formed by the LED lamp beads generates a local darkening condition, the light-emitting angles of the LED lamp beads around the local darkening area in the corresponding directions can be adaptively adjusted, so that the problem of local darkening is solved.

Description

Technical Field

[0001] This application relates to the technical field of LEDs, and particularly to an LED lamp bead, a preparation method thereof, and an LED light source. Background Art

[0002] LED lamp beads have the characteristics of high brightness, low energy consumption, long lifespan, etc., and can meet the requirements of various different scenarios. They are widely used in fields such as displays, billboards, indoor and outdoor decorations, and automotive lighting. As the usage scenarios of LED lamp beads in various fields are increasing, traditional LED lamp beads with a luminous angle of 120° can no longer meet the usage requirements. Currently, LED lamp beads are required to have more uniform light emission, a larger luminous angle, and stronger stability. The conventional way to expand the luminous angle of LED lamp beads is to make the light refract and diverge by adding an external lens, thereby increasing the luminous angle. However, this method will cause the volume of the LED lamp bead to increase and the manufacturing process to be complicated.

[0003] In addition, currently, LED light sources made of common LED lamp beads are prone to local darkening, which may be caused by various factors. First, local darkening may be due to the large size of the LED light source, resulting in uneven brightness in different light-emitting areas. Especially at the edges or corners of the LED light source, the brightness will be lower. Second, local darkening may also be due to the damage of one or some LED lamp beads inside the LED light source. LED lamp beads are the main components of the LED light source. If an LED lamp bead is damaged, it will cause the brightness in the corresponding area to decrease, resulting in a darkening phenomenon. Existing products cannot solve the problem of local darkening. Summary of the Invention

[0004] In view of this, the embodiments of this application are committed to providing an LED lamp bead, a preparation method thereof, and an LED light source to solve the problems in the prior art such as the large volume and complicated manufacturing process of LED lamp beads with a large luminous angle, and the inability of LED light sources to improve local darkening.

[0005] On the one hand, this application provides an LED lamp bead, including:

[0006] A substrate;

[0007] At least two LED chips located on the substrate;

[0008] A light conversion layer located on the substrate and the LED chips; and,

[0009] A driving circuit for independently driving each of the LED chips.

[0010] In some embodiments, the LED lamp bead further includes:

[0011] At least two bowl cups are located on the substrate, and the LED chips are arranged on the substrate within each bowl cup. The light conversion layer is located on the substrate and the LED chips and fills the bowl cups.

[0012] In some embodiments, the light conversion layer at least includes:

[0013] A first light conversion layer, which is located on the substrate and the LED chips, and is used for absorbing the excitation light emitted by the LED chips and generating a first output light; and,

[0014] A second light conversion layer, which is located on the first light conversion layer, and is used for absorbing the excitation light emitted by the LED chips and generating a second output light, and the wavelength of the first output light is greater than the wavelength of the second output light.

[0015] In some embodiments, the top surface of the light conversion layer has a convex portion and a concave portion. The concave portion is located in the central region of the substrate, and the convex portion is located in the edge region of the substrate. The convex portion surrounds the concave portion.

[0016] In some embodiments, the virtual connection line between the center of the concave portion and the center of each LED chip is not perpendicular to the surface of the substrate.

[0017] In some embodiments, the LED lamp bead further includes:

[0018] A glass microsphere adhesive layer, which is located on the light conversion layer. The glass microsphere adhesive layer contains glass microspheres, and the glass microspheres are arranged close to the top surface of the glass microsphere adhesive layer.

[0019] In some embodiments, the top surface of the glass microsphere adhesive layer is a curved surface that bulges away from the substrate; and / or, the glass microsphere adhesive layer is located within the concave portion.

[0020] An embodiment of the present application further provides a method for manufacturing an LED lamp bead, including:

[0021] Providing a substrate and a driving circuit;

[0022] Die-bonding at least two LED chips on the substrate. Each LED chip is electrically connected to the driving circuit, and the driving circuit is used for independently driving each LED chip; and,

[0023] Forming a light conversion layer on the substrate and the LED chips.

[0024] In some embodiments, there are at least two bowl cups on the substrate. The LED chips are die-bonded on the substrate within the corresponding bowl cups, and a light conversion layer is formed on the substrate, on the LED chips, and within the bowl cups through a dispensing process.

[0025] In some embodiments, the substrate has at least two chip mounting areas. The LED chips are die-bonded in the corresponding chip mounting areas, and the light conversion layer is formed on the substrate and the LED chips at least through a molding process.

[0026] In some embodiments, after the light conversion layer is formed, the top surface of the light conversion layer has a convex portion and a concave portion. The concave portion is located in the central region of the substrate, and the convex portion is located in the edge region of the substrate. The convex portion surrounds the concave portion.

[0027] In some embodiments, the virtual connection line between the center of each concave portion and the center of each LED chip is not perpendicular to the surface of the substrate.

[0028] In some embodiments, after the light conversion layer is formed, the method for manufacturing the LED lamp bead further includes:

[0029] A glass microsphere adhesive layer is formed on the light conversion layer. The glass microsphere adhesive layer contains glass microspheres, and the glass microspheres are disposed near the top surface of the glass microsphere adhesive layer.

[0030] In some embodiments, the top surface of the glass microsphere adhesive layer is a curved surface convex in a direction away from the substrate; and / or, the glass microsphere adhesive layer is located within the concave portion.

[0031] An embodiment of the present application further provides an LED light source including at least one of the above-mentioned LED lamp beads.

[0032] The present application provides an LED lamp bead, a method for manufacturing the same, and an LED light source. The LED lamp bead includes a substrate, at least two LED chips, a light conversion layer, and a driving circuit. Among them, the LED chips are located on the substrate, the light conversion layer is located on the substrate and the LED chips, and the driving circuit can independently drive each LED chip. The LED lamp bead in the present application has at least two LED chips, and each LED chip can be independently driven by the driving circuit. The driving circuit can independently adjust the brightness of each LED chip, thereby adjusting the light-emitting angles of the LED lamp bead in at least two directions. Moreover, this kind of LED lamp bead is simple to manufacture, does not require additional optical lenses and optical films, has a low cost, a small volume, and is also convenient to use. In addition, if the LED light source composed of LED lamp beads has a situation of local dimming, the light-emitting angles of the LED lamp beads around the locally dimmed area can be adaptively adjusted in the corresponding directions, thereby solving the problem of local dimming. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 FIG. 1 is a plan view of an LED lamp bead provided in an embodiment of the present application.

[0034] Figure 2 is Figure 1 a cross-sectional view of the LED lamp bead in FIG. 1 along the A-A direction, as shown in

[0035] Figure 3 FIG. 2 is a plan view of an LED lamp bead provided in another embodiment of the present application.

[0036] Figure 4 FIG. 3 is a flowchart of a method for manufacturing an LED lamp bead provided in another embodiment of the present application.

[0037] Figures 5 to 7 FIG. 4 is a schematic structural view corresponding to the corresponding steps of a method for manufacturing an LED lamp bead provided in an embodiment of the present application.

[0038] Figures 8 to 10 FIG. 5 is a schematic structural view corresponding to the corresponding steps of a method for manufacturing an LED lamp bead provided in another embodiment of the present application.

[0039] Wherein, the reference numerals are as follows:

[0040] 101 - substrate; 102 - bowl cup; 200 - LED chip; 300 - light conversion layer; 301 - first light conversion layer; 302 - second light conversion layer; 400 - glass microsphere glue layer; 500 - glass microspheres. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0042] An embodiment of the present application provides an LED lamp bead. Figure 1 FIG. 1 is a plan view of an LED lamp bead provided in an embodiment of the present application, Figure 2 is Figure 1 a cross-sectional view of the LED lamp bead in FIG. 1 along the A-A direction, as shown in Figure 1 and Figure 2As shown in the figure, the LED lamp bead includes a substrate 101, at least two LED chips 200, a light conversion layer 300 and a driving circuit. Among them, at least two LED chips 200 are located on the substrate 101. The driving circuit can be located on the substrate 101 or on another substrate. Each LED chip 200 is electrically connected to the driving circuit, and the light conversion layer 300 is located on the substrate 101 and the LED chips 200. The LED lamp bead in this application has at least two LED chips 200, and each LED chip 200 can be independently driven by the driving circuit. The driving circuit can independently adjust the brightness of each LED chip 200, thereby adjusting the light emitting angles of the LED lamp bead in at least two directions. Moreover, this kind of LED lamp bead is simple to manufacture, does not require additional optical lenses and optical films, has a low cost, a small volume, and is also convenient to use.

[0043] Specifically, as Figure 2 shown in the figure, the substrate 101 can be a PCB board, and its material can be selected from ceramic materials (including one or more of AlN, Al2O3, SiO, SiO2, Si3N4 and SiON), aluminum, copper and other materials. In some embodiments, the substrate 101 has at least two bowl cups 102, and the material of the bowl cups 102 can be plastic (such as PPA plastic, PCT plastic or EMC plastic, etc.) or resin and other materials. The bowl cups 102 are annular and are closely arranged on the substrate 101. A corresponding LED chip 200 is arranged on the substrate 101 in each bowl cup 102. Each LED chip 200 in each bowl cup 102 is electrically connected to the driving circuit, and each LED chip 200 in each bowl cup 102 can be independently driven by the driving circuit to emit corresponding excitation light.

[0044] Further, the LED chip 200 can be attached to the substrate 101 by using die bonding glue, and then electrically connected to the pads on the substrate 101 by using leads. The driving circuit can be located on the substrate 101 outside the bowl cup 102. The driving circuit can be electrically connected to the corresponding LED chip 200 through the corresponding pads, so as to independently supply power to the corresponding LED chip 200. In some embodiments, the driving circuit can be a driving chip.

[0045] In some embodiments, the LED chip 200 can also be welded to the substrate 101 in a flip-chip manner, so as to get rid of the constraints of leads and die bonding glue, making the LED chip 200 have a high thermal conductivity, a small thermal resistance, can withstand large currents, and has stronger reliability, a higher light flux maintenance rate and a longer service life.

[0046] In some embodiments, the excitation light emitted by the LED chip 200 can be blue light, violet light, ultraviolet light, etc. Based on this, the LED chip 200 can be a blue LED chip, such as a GaN-based LED chip that emits blue light. The LED chip 200 can also be a purple or ultraviolet LED chip.

[0047] As Figure 2 shown, the light conversion layer 300 is located on the substrate 101 and the LED chip 200 and fills the bowl 102. The light conversion layer 300 has a light conversion material. After the excitation light emitted by the LED chip 200 irradiates the light conversion layer 300, the light conversion layer 300 absorbs the excitation light, and the light conversion material in the light conversion layer 300 is excited to generate light of a corresponding color. In some embodiments, the light conversion material can be a phosphor or a quantum dot, which is not limited in this application.

[0048] In some embodiments, the light conversion layer 300 can be a single-layer structure, and the light conversion layer 300 has at least one color of light conversion material. For example, the light conversion layer 300 can be a yellow light conversion layer 300. After the yellow light conversion layer 300 is excited by blue excitation light, yellow light can be generated, and the yellow light is mixed with the blue light to generate white light. At this time, the LED lamp bead can emit white light; of course, the light conversion layer 300 can also be a light conversion layer 300 of other colors, so that the LED lamp bead can emit light of other colors. Further, the light conversion material in the light conversion layer 300 not only has one color, but can also have multiple colors, thereby improving other properties such as the color rendering index of the LED lamp bead.

[0049] It should be noted that Figure 1 shows an embodiment with 4 bowls 102 and 4 LED chips 200. That is, there are 4 bowls 102 and 4 LED chips 200 on the substrate 101. One LED chip 200 is located in a corresponding one of the 4 bowls 102, and the 4 bowls 102 are arranged in an array, and the 4 LED chips 200 are also arranged in an array. In this way, the brightness of the 4 LED chips 200 can be independently controlled by the driving circuit, so that the light-emitting angles of the LED lamp bead in 4 directions can be adjusted. Taking Figure 1For example, if the drive current of an LED chip 200 in the upper left of the LED lamp bead is increased, the brightness of the LED chip 200 in the upper left becomes larger. At this time, the light-emitting angle of the LED lamp bead in the x1 direction will become larger; if the drive current of an LED chip 200 in the lower right of the LED lamp bead is increased, the brightness of the LED chip 200 in the lower right becomes larger. At this time, the light-emitting angle of the LED lamp bead in the x2 direction will become larger; if the drive current of an LED chip 200 in the upper right of the LED lamp bead is increased, the brightness of the LED chip 200 in the upper right becomes larger. At this time, the light-emitting angle of the LED lamp bead in the y1 direction will become larger; if the drive current of an LED chip 200 in the lower left of the LED lamp bead is increased, the brightness of the LED chip 200 in the lower left becomes larger. At this time, the light-emitting angle of the LED lamp bead in the y2 direction will become larger. That is to say, by controlling the drive current of each LED chip 200 separately through the drive circuit, the light-emitting angles of the LED lamp bead in four directions can be controlled, achieving the technical effect of controllable light-emitting angle of the LED lamp bead.

[0050] It can be understood that the LED lamp bead is not limited to having four bowl cups 102 and four LED chips 200, as long as it has at least two bowl cups 102 and at least two LED chips 200. Generally speaking, the bowl cups 102 and the LED chips 200 are in one-to-one correspondence. The LED chips 200 are not limited to being distributed in an array, and can also be distributed in other distribution ways. For example, the LED chips 200 can be evenly distributed circumferentially around the center of the substrate 101. In some embodiments, the light-emitting angle of the LED lamp bead can be adjusted by 360° by designing the number and distribution way of the LED chips 200.

[0051] Please continue to refer to Figure 2 , the inner side wall of the bowl cup 102 is inclined, and the opening width of the bowl cup 102 near the substrate 101 is smaller than the opening width of the side far from the substrate 101. Or it can also be understood in this way, the bowl cup 102 is frustum-shaped, its cross-sectional shape is trapezoidal, and its diameter gradually increases from bottom to top, so that the inner side wall of the bowl cup 102 is inclined. In this way, when the excitation light emitted by the LED chip 200 irradiates on the inner side wall of the bowl cup 102, the inner side wall of the bowl cup 102 can reflect the excitation light onto the light conversion layer 300, improving the light utilization rate, avoiding waste of light energy, and reducing power consumption.

[0052] Such as Figure 2As shown, the top surface of the light conversion layer 300 is uneven. Specifically, the top surface of the light conversion layer 300 has protrusions and depressions. The depressions are located in the central region of the substrate 101, and the protrusions are located in the edge region of the substrate 101. The protrusions surround the depressions. For example, the center of the depression can coincide with the center of the substrate 101, while the protrusions are arranged close to the edge of the substrate 101. This structure with a sunken middle and raised edges can spread the light emitted inside the LED lamp bead more ( Figure 2 The dotted arrows in it indicate the light emission direction), thereby overall expanding the light emission angle of the LED lamp bead. Of course, as an alternative embodiment, the top surface of the light conversion layer 300 can also be a flat surface.

[0053] In some embodiments, the virtual connection lines between the center of the depression and the center of each LED chip 200 are not perpendicular to the surface of the substrate. That is to say, the center of the depression does not coincide with the center of each LED chip 200 in the direction perpendicular to the substrate 101. The center of the depression and the center of each LED chip 200 are arranged in a staggered manner, making the light emission of the LED lamp bead more uniform. For example, for Figure 1 the LED lamp bead in, the center of the depression can be located at point Q; or, for the LED lamp bead with circumferentially distributed LED chips 200, the center of the depression can be located at the rotation center of the LED chips 200.

[0054] Furthermore, the top surface of the light conversion layer 300 is a curved surface, and the top surface of the light conversion layer 300 can be higher than the top surface of the bowl 102. In this way, the light-emitting surface of the LED lamp bead is more rounded, and the bowl 102 will not block the light emission of the LED lamp bead, which is conducive to the refraction and divergence of the light emitted by the LED lamp bead. Of course, as an alternative embodiment, the top surface of the light conversion layer 300 is not limited to being a curved surface, and can also be a combination of a flat surface and an inclined surface; in some embodiments, the top surface of the light conversion layer 300 is not limited to being higher than the top surface of the bowl 102, and can also be lower than the top surface of the bowl 102 or flush with the top surface of the bowl 102.

[0055] Please continue to refer to Figure 2, the LED lamp bead further includes a glass microsphere adhesive layer 400, the glass microsphere adhesive layer 400 is located on the light conversion layer 300, the glass microsphere adhesive layer 400 can be formed by mixing glass microspheres 500 and an adhesive material, the glass microspheres 500 are located within the glass microsphere adhesive layer 400, and since the glass microspheres 500 are of a hollow structure and will float on the surface of the adhesive material, the glass microspheres 500 will be disposed close to the top surface of the glass microsphere adhesive layer 400. After the light emitted from the light conversion layer 300 enters the glass microsphere adhesive layer 400, it can be refracted and scattered by the glass microspheres 500 in the glass microsphere adhesive layer 400, thereby further increasing the light-emitting angle and realizing an LED lamp bead with a large light-emitting angle. In some embodiments, when the top surface of the light conversion layer 300 has protrusions and depressions but there is no glass microsphere adhesive layer 400 on the light conversion layer 300, the light-emitting angle of the LED lamp bead can be greater than 120°, for example, it can reach about 150°. When the top surface of the light conversion layer 300 has protrusions and depressions and there is a glass microsphere adhesive layer 400 on the light conversion layer 300, the light-emitting angle of the LED lamp bead can be greater than 150°.

[0056] It should be noted that in order to prevent the glass microsphere adhesive layer 400 from blocking the light, the glass microspheres 500 still need to ensure a certain light transmittance so that a part of the light can exit from the glass microsphere adhesive layer 400. Optionally, the light transmittance of the glass microspheres 500 can be 75% - 95%, but it should not be limited thereto.

[0057] In some embodiments, the top surface of the glass microsphere adhesive layer 400 can be a curved surface protruding in a direction away from the substrate 101. For example, the top surface of the glass microsphere adhesive layer 400 can be semi-circular or other arc shapes, and this morphology can further increase the light-emitting angle.

[0058] It should be noted that the particle size of the glass microspheres 500 should preferably not vary too much, otherwise it is not conducive to the light output uniformity of the LED lamp bead. Optionally, the average particle size of the glass microspheres 500 can be 10μm - 80μm, and the concentration of the glass microspheres 500 in the glass microsphere adhesive layer 400 can be 2% - 5%. Further, the adhesive material in the glass microsphere adhesive layer 400 can be selected as a light-transmitting adhesive material such as UV glue, resin, silica gel or epoxy resin, etc. The glass microspheres 500 are preferably made of soda lime borosilicate glass (K20HS). This material is more water-resistant and has a stable chemical state, which can improve the performance and stability of the LED lamp bead.

[0059] Furthermore, the glass microsphere adhesive layer 400 can be located within the depression and will not block the protrusion. In this way, the glass microsphere adhesive layer 400 can refract and diverge the light in the depression and exit from the protrusion, increasing the brightness.

[0060] Figure 2The encapsulation method of the LED lamp beads therein is the encapsulation method with a bowl cup 102. Of course, there is also an encapsulation method for LED lamp beads without a bowl cup 102. Figure 3 It is a schematic structural diagram of an LED lamp bead provided by another embodiment of the present application. As Figure 3 shown, the LED lamp bead may not include a bowl cup 102. At this time, the substrate 101 may have at least two chip mounting areas. A corresponding LED chip 200 is arranged in each chip mounting area of the substrate 101. The LED chips 200 in each chip mounting area are electrically connected to the driving circuit. The LED chips 200 in the chip mounting area can be individually driven by the driving circuit to emit corresponding excitation light. The light conversion layer 300 is located on the substrate 101 and the LED chips 200.

[0061] In addition, in some embodiments, the light conversion layer 300 may be a double-layer or multi-layer structure. For example, the light conversion layer 300 may include a first light conversion layer 301 and a second light conversion layer 302. The first light conversion layer 301 may be located on the substrate 101 and the LED chips 200. The second light conversion layer 302 may be located on the first light conversion layer 301. Please continue to refer to Figure 3 , the first light conversion layer 301 may be hemispherical and may only cover a partial area of the substrate 101 and the LED chips 200. The second light conversion layer 302 may cover the remaining area of the substrate 101 and the first light conversion layer 301. In some embodiments, the first light conversion layer 301 may also completely cover the substrate 101 and the LED chips 200, and the second light conversion layer 302 may only cover the first light conversion layer 301.

[0062] Furthermore, after the first light conversion layer 301 absorbs the excitation light emitted by the LED chip 200, it can generate a first output light. After the second light conversion layer 302 absorbs the excitation light emitted by the LED chip 200, it can generate a second output light. The wavelength of the first output light is greater than the wavelength of the second output light. For example, the first light conversion layer 301 may be a red light conversion layer, and the second light conversion layer 302 may be a green light conversion layer. The excitation light emitted by the LED chip 200 first irradiates on the first light conversion layer 301. The red light conversion material in the first light conversion layer 301 is excited to generate red light. The remaining excitation light after passing through the first light conversion layer 301 irradiates on the second light conversion layer 302. The green light conversion material in the second light conversion layer 302 is excited to generate green light. Finally, blue light, red light, and green light are mixed to generate white light.

[0063] It can be understood that in the present application, the first light conversion layer 301 and the second light conversion layer 302 are arranged in layers, and the second light conversion layer 302 is arranged above the first light conversion layer 301. The excitation light will first excite the first light conversion layer 301 to generate red light. When the red light and the remaining excitation light pass through the second light conversion layer 302, the second light conversion layer 302 will only absorb the excitation light and will not absorb the red light, reducing the secondary absorption and conversion phenomenon, improving the light extraction efficiency. Moreover, the red light can be fully emitted, complementing the continuity of the spectrum, making the overall spectrum closer to natural light and having a higher color rendering index.

[0064] Of course, in some embodiments, the first light conversion layer 301 and the second light conversion layer 302 are not limited to having only one color of light conversion material. The light conversion material in the first light conversion layer 301 is not limited to a red light conversion material, and the light conversion material in the second light conversion layer 302 is not limited to a green light conversion material either.

[0065] Figure 3 In [description], the top surface of the second light conversion layer 302 is the top surface of the light conversion layer 300. Therefore, the convex portion and the concave portion are located on the top surface of the second light conversion layer 302.

[0066] It should be noted that Figure 2 the light conversion layer 300 in [description] can also be a double-layer or multi-layer structure, Figure 3 the light conversion layer 300 in [description] can also be a single-layer structure, and specific examples are not given here one by one.

[0067] Undoubtedly, the LED lamp beads provided above can be applied to various lighting fields. For example, they can be made into a backlight module for use in the display backlight field (which can be the backlight module of terminals such as TVs, monitors, mobile phones, etc.), and at this time, they can be applied to the backlight module. In addition to being applicable to the display backlight field, they can also be applied to the key backlight field, the shooting field, the household lighting field, the medical lighting field, the decoration field, the automotive field, the transportation field, etc. When applied to the key backlight field, they can be used as the key backlight light source for devices with keys such as mobile phones, calculators, keyboards, etc.; when applied to the shooting field, they can be made into the flash of a camera; when applied to the household lighting field, they can be made into floor lamps, table lamps, lighting lamps, ceiling lamps, downlights, projection lamps, etc.; when applied to the medical lighting field, they can be made into operating lamps, low-electromagnetic lighting lamps, etc.; when applied to the decoration field, they can be made into various decorative lamps, such as various colored lights, landscape lighting lamps, advertising lights; when applied to the automotive field, they can be made into automotive headlights, automotive indicator lights, etc.; when applied to the transportation field, they can be made into various traffic lights and can also be made into various street lamps. The above applications are only several examples shown in this embodiment, and it should be understood that the application of the LED lamp beads in this embodiment is not limited to the several fields shown in the above examples.

[0068] Based on this, some embodiments of the present application further provide an LED light source, which includes at least one LED lamp bead. The LED lamp beads in the LED light source can be arranged in one row or multiple rows and can be used in an LED backlight liquid crystal display. If the LED light source has a situation of local dimming, the emission angles in the corresponding directions of the LED lamp beads around the locally dimmed area can be adaptively adjusted, thereby solving the problem of local dimming.

[0069] Based on this, an embodiment of the present application further provides a preparation method for the above-mentioned LED lamp bead. Figure 4 The flowchart of the preparation method for the LED lamp bead is as Figure 4 shown, and the preparation method for the LED lamp bead includes:

[0070] Step S100: Provide a substrate 101 and a driving circuit;

[0071] Step S200: Fix at least two LED chips 200 on the substrate 101, and each LED chip 200 is electrically connected to the driving circuit. The driving circuit is used to independently drive each LED chip; and,

[0072] Step S300: Form a light conversion layer 300 on the substrate 101 and the LED chips 200.

[0073] Figures 5 to 7 is the structural schematic diagram corresponding to the corresponding steps of the preparation method for the LED lamp bead provided by an embodiment of the present application. Next, the preparation method for the LED lamp bead provided by an embodiment of the present application will be described in detail with reference to Figures 5 to 7 this.

[0074] As Figure 5 shown, first, execute step S100 to provide a substrate 101. There are at least two bowl cups 102 on the substrate 101. The bowl cups 102 are annular and located on the substrate 101. The driving circuit can be arranged on the substrate 101 outside the bowl cups 102 or on another substrate. The bowl cups 102 can be distributed in an array on the substrate 101 or circumferentially distributed relative to the center of the substrate 101. The present application does not limit the distribution manner of the bowl cups 102 on the substrate 101.

[0075] As Figure 6 shown, execute step S200 to fix at least two LED chips 200 on the substrate 101. One LED chip 200 is fixed on the substrate 101 inside one bowl cup 102 and is electrically connected to the pad inside the bowl cup 102. Each pad is further electrically connected to the driving circuit. Each LED chip 200 can be electrically connected to the pad inside the bowl cup 102 by using leads, or each LED chip 200 can also be soldered on the corresponding pad inside the bowl cup 102 in a flip-chip manner, so as to be electrically connected to the driving circuit through the pad.

[0076] As shown Figure 7 in FIG. 1, step S300 is performed to form a light conversion layer 300 on the substrate 101, on the LED chip 200, and inside the cup 102 through a dispensing process, so that the light conversion layer 300 covers the substrate 101 and the LED chip 200 and fills the cup 102. After the light conversion layer 300 is formed, the top surface of the light conversion layer 300 has a convex portion and a concave portion. The concave portion is located in the central region of the substrate 101, and the convex portion is located in the edge region of the substrate 101. The convex portion surrounds the concave portion. This structure with a concave middle and a convex edge can spread the light emitted inside the LED lamp bead more, thereby overall expanding the light-emitting angle of the LED lamp bead. Of course, as an alternative embodiment, after the light conversion layer 300 is formed, the top surface of the light conversion layer 300 may also be a flat surface.

[0077] In some embodiments, the virtual connection line between the center of the concave portion and the center of each LED chip 200 is not perpendicular to the surface of the substrate, that is to say, the center of the concave portion and the center of each LED chip 200 do not coincide in the direction perpendicular to the substrate 101. The center of the concave portion and the center of each LED chip 200 are misaligned, so that the light emission of the LED lamp bead is more uniform. For example, for the LED lamp bead in Figure 1 , the center of the concave portion may be located at point Q; or, for the LED lamp bead in which the LED chips 200 are circumferentially distributed, the center of the concave portion may be located at the rotation center of the LED chips 200.

[0078] It can be understood that due to the characteristics of the dispensing process, after the light conversion layer 300 is formed, the top surface of the light conversion layer 300 is a curved surface, and by controlling the dispensing amount of the dispensing process, the top surface of the formed light conversion layer 300 can be made higher than the top surface of the cup 102. In this way, the light-emitting surface of the LED lamp bead is more rounded, and the cup 102 does not block the light emission of the LED lamp bead, which is beneficial to the refraction and divergence of the light emitted by the LED lamp bead. Of course, as an alternative embodiment, the top surface of the light conversion layer 300 is not limited to being a curved surface. Through other processes such as molding processes, the top surface of the light conversion layer 300 can have other morphologies, for example, making the top surface of the light conversion layer 300 a combination of a flat surface and an inclined surface. In some embodiments, by controlling the dispensing amount of the dispensing process, the top surface of the formed light conversion layer 300 can be made lower than the top surface of the cup 102 or flush with the top surface of the cup 102.

[0079] As shown Figure 2As shown, a glass bead adhesive layer 400 is formed on the light conversion layer 300 using a dispensing process. The glass bead adhesive layer 400 contains glass beads 500. Because the glass bead adhesive layer 400 is formed by mixing the glass beads 500 with an adhesive material, and the glass beads 500 are hollow and float on the surface of the adhesive material (before the adhesive material solidifies), after the glass bead adhesive layer 400 is formed, the glass beads 500 are arranged close to the top surface of the glass bead adhesive layer 400. After the light emitted from the light conversion layer 300 enters the glass bead adhesive layer 400, it can be refracted and scattered by the glass beads 500 in the glass bead adhesive layer 400, thereby further increasing the light emission angle and realizing a wide-angle LED lamp bead.

[0080] It can be understood that due to the characteristics of the dispensing process, after the glass bead glue layer 400 is formed, the top surface of the glass bead glue layer 400 can be a curved surface that is convex in the direction away from the substrate 101. For example, the top surface of the glass bead glue layer 400 can be a semicircular or other arc shape. This morphology can further increase the light-emitting angle.

[0081] Furthermore, the glass bead adhesive layer 400 can be located in the recessed portion without blocking the protruding portion. In this way, the glass bead adhesive layer 400 can refract and disperse the light in the recessed portion and emit it from the protruding portion, thereby increasing brightness.

[0082] After that, you can test the LED lamp beads and select qualified LED lamp bead products.

[0083] Figures 8 to 10 This is a schematic diagram of the structure corresponding to the corresponding steps of the method for preparing LED lamp beads provided in another embodiment of the present application. Figures 8 to 10 A method for preparing an LED lamp bead provided in an embodiment of the present application is described in detail.

[0084] like Figure 8 As shown, step S100 is first performed to provide a substrate 101. Substrate 101 does not have a bowl 102. Substrate 101 has at least two chip mounting areas, and the driving circuit is located outside the chip mounting areas of substrate 101. The chip mounting areas can be distributed in an array on substrate 101 or distributed circumferentially relative to the center of substrate 101. This application does not limit the distribution method of the chip mounting areas on substrate 101.

[0085] like Figure 9As shown, step S200 is performed to fix at least two LED chips 200 on the substrate 101. One LED chip 200 is fixed on the substrate 101 within one chip mounting area and is electrically connected to the driving circuit. Each LED chip 200 can be electrically connected to the pad within the corresponding chip mounting area by leads. The pad is electrically connected to the driving circuit, and the driving circuit can independently supply power to each LED chip 200 through the pad. Each LED chip 200 can also be soldered to the pad within the corresponding chip mounting area in a flip-chip manner, so as to be electrically connected to the driving circuit through the pad.

[0086] As Figure 10 shown, step S300 is performed to form the light conversion layer 300 on the substrate 101 and the LED chips 200 at least through a molding process. In some embodiments, the light conversion layer 300 can be formed by a combination of a dispensing process and a molding process. For example, first, a first light conversion layer 301 can be formed on a partial area of the substrate 101 and the LED chips 200 through the dispensing process. The first light conversion layer 301 will cover a partial area of the substrate 101 and the LED chips 200. Then, a second light conversion layer 302 is formed on the first light conversion layer 301 through the molding process. The first light conversion layer 301 and the second light conversion layer 302 constitute the light conversion layer 300. After the second light conversion layer 302 is formed, the top surface of the second light conversion layer 302 has protrusions and depressions. The depressions are located in the central area of the substrate 101, and the protrusions are located in the edge area of the substrate 101. The protrusions surround the depressions. This structure with a sunken middle and raised edges can spread the light emitted inside the LED lamp beads more, thereby overall expanding the light-emitting angle of the LED lamp beads. Of course, as an alternative embodiment, the top surface of the first light conversion layer 301 and / or the second light conversion layer 302 can also be a flat surface.

[0087] In some embodiments, the virtual connection lines between the center of the depression and the center of each LED chip 200 are not perpendicular to the surface of the substrate, that is to say, the center of the depression and the center of each LED chip 200 do not coincide in the direction perpendicular to the substrate 101. The center of the depression and the center of each LED chip 200 are misaligned, so that the light emission of the LED lamp beads is more uniform. For example, for Figure 1 the LED lamp beads therein, the center of the depression can be located at point Q; or, for the LED lamp beads in which the LED chips 200 are circumferentially distributed, the center of the depression can be located at the rotation center of the LED chips 200.

[0088] In some embodiments, both the first light conversion layer 301 and the second light conversion layer 302 can be formed by a molding process. In this way, the first light conversion layer 301 can also completely cover the substrate 101 and the LED chip 200, while the second light conversion layer 302 can only cover the first light conversion layer 301.

[0089] It can be understood that due to the limitations of the dispensing process, the top surface of the first light conversion layer 301 is a curved surface. By designing the topography of the mold, the top surface of the second light conversion layer 302 can be made into a curved surface. In this way, the light-emitting surface of the LED lamp bead is more rounded, which is conducive to the refraction and divergence of the light emitted by the LED lamp bead. Of course, as an alternative embodiment, the top surfaces of the first light conversion layer 301 and the second light conversion layer 302 are not limited to being curved surfaces. By designing the topography of the mold, the top surfaces of the first light conversion layer 301 and the second light conversion layer 302 can have other topographies, such as making the top surface of the second light conversion layer 302 a combination of a flat surface and an inclined surface.

[0090] As Figure 3 shown, a glass microsphere glue layer 400 is formed on the second light conversion layer 302 by the dispensing process. The glass microsphere glue layer 400 contains glass microspheres 500. Since the glass microsphere glue layer 400 is formed by mixing glass microspheres 500 and a glue material, and the glass microspheres 500 are hollow structures and will float on the surface of the glue material (before the glue material cures), after the glass microsphere glue layer 400 is formed, the glass microspheres 500 will be disposed close to the top surface of the glass microsphere glue layer 400. After the light emitted from the light conversion layer 300 enters the glass microsphere glue layer 400, it can be refracted and scattered by the glass microspheres 500 in the glass microsphere glue layer 400, thereby further increasing the light-emitting angle and realizing a large-angle LED lamp bead.

[0091] It can be understood that due to the characteristics of the dispensing process, after the glass microsphere glue layer 400 is formed, the top surface of the glass microsphere glue layer 400 can be a curved surface protruding in a direction away from the substrate 101. For example, the top surface of the glass microsphere glue layer 400 can be semi-circular or other arc shapes, and this topography can further increase the light-emitting angle.

[0092] Furthermore, the glass microsphere glue layer 400 can be located in the recessed portion and will not block the protruding portion. In this way, the glass microsphere glue layer 400 can refract and diverge the light in the recessed portion and emit it from the protruding portion, increasing the brightness.

[0093] After that, the LED lamp beads can be tested to select qualified LED lamp bead products.

[0094] In summary, the embodiments of the present application provide an LED lamp bead, a preparation method thereof, and an LED light source. The LED lamp bead includes a substrate 101, at least two LED chips 200, a light conversion layer 300, and a driving circuit. Among them, at least two LED chips 200 are located on the substrate 101, the light conversion layer 300 is located on the substrate 101 and the LED chips 200, and the driving circuit is used to independently drive the LED chips 200. The LED lamp bead in the present application has at least two LED chips 200, and each LED chip 200 can be independently driven by the driving circuit. The driving circuit can independently adjust the brightness of each LED chip 200, and then adjust the light-emitting angles of the LED lamp bead in at least two directions. Moreover, this kind of LED lamp bead is simple to prepare, does not require additional optical lenses and optical films, has a low cost, a small volume, and is also convenient to use. In addition, if the LED light source composed of LED lamp beads has a situation of local dimming, the light-emitting angles in the corresponding directions of the LED lamp beads around the locally dimmed area can be adaptively adjusted, so as to solve the problem of local dimming.

[0095] It should be noted that the embodiments in this specification are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part. [[ID= +]]

[0096] It should also be noted that although the present application has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present application. For any person skilled in the art, without departing from the scope of the technical solution of the present application, many possible changes and modifications can be made to the technical solution of the present application by using the technical content disclosed above, or modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still belong to the scope of protection of the technical solution of the present application.

[0097] It should also be understood that unless otherwise specified or indicated, the terms "first", "second", "third", etc. in the specification are only used to distinguish each component, element, step, etc. in the specification, rather than to represent the logical relationship or sequential relationship, etc. between each component, element, step.

[0098] It should also be recognized that the terminology described herein is only used to describe specific embodiments and is not intended to limit the scope of the present application. It must be noted that the singular forms "a" and "an" used herein and in the appended claims include plural referents unless the context clearly dictates otherwise. For example, a reference to "a step" or "an apparatus" means a reference to one or more steps or apparatuses and may include sub-steps as well as sub-apparatuses. All conjunctions used should be understood in their broadest sense. Also, the word "or" should be understood to have the definition of a logical "or" rather than a logical "exclusive or" definition unless the context clearly dictates otherwise. In addition, the implementation of the methods and / or devices in the embodiments of the present application may include performing selected tasks manually, automatically, or in combination.

Claims

1. An LED lamp bead, characterized in that, Comprising: A substrate; At least two LED chips located on the substrate; A light conversion layer located on the substrate and the LED chips; And A driving circuit for independently driving each of the LED chips.

2. The LED lamp bead according to claim 1, wherein, The LED lamp bead further comprises: At least two bowl cups located on the substrate, with the LED chips disposed on the substrate within each bowl cup, and the light conversion layer located on the substrate and the LED chips and filling the bowl cups.

3. The LED lamp bead according to claim 1, wherein The light conversion layer at least comprises: A first light conversion layer located on the substrate and the LED chips, for absorbing the excitation light emitted by the LED chips and generating a first output light; and A second light conversion layer located on the first light conversion layer, for absorbing the excitation light emitted by the LED chips and generating a second output light, wherein the wavelength of the first output light is greater than that of the second output light.

4. The LED lamp bead according to claim 1, wherein The top surface of the light conversion layer has a convex portion and a concave portion, the concave portion is located in the central region of the substrate, the convex portion is located in the edge region of the substrate, and the convex portion surrounds the concave portion.

5. The LED lamp bead according to claim 4, wherein The virtual connection line between the center of the concave portion and the center of each LED chip is not perpendicular to the surface of the substrate.

6. The LED lamp bead according to claim 4, characterized in that: The LED lamp bead further comprises: A glass microsphere adhesive layer located on the light conversion layer, with glass microspheres within the glass microsphere adhesive layer, and the glass microspheres being disposed near the top surface of the glass microsphere adhesive layer.

7. The LED lamp bead according to claim 6, characterized in that, The top surface of the glass microsphere adhesive layer is a curved surface convex in a direction away from the substrate; and / or, the glass microsphere adhesive layer is located within the concave portion.

8. A preparation method of an LED lamp bead, characterized in that, Comprising: Providing a substrate and a driving circuit; Die-bonding at least two LED chips on the substrate, with each LED chip electrically connected to the driving circuit, and the driving circuit for independently driving each LED chip; and Forming a light conversion layer on the substrate and the LED chips.

9. The manufacturing method of the LED lamp bead according to claim 8, characterized in that, There are at least two bowl cups on the substrate, die-bonding the LED chips on the substrate within the corresponding bowl cups, and forming the light conversion layer on the substrate, on the LED chips, and within the bowl cups through a dispensing process.

10. The method for preparing an LED lamp bead according to claim 8, wherein: The substrate has at least two chip mounting areas, die-bonding the LED chips in the corresponding chip mounting areas, and forming the light conversion layer on the substrate and the LED chips at least through a molding process.

11. The preparation method of the LED lamp bead according to any one of claims 8 to 10, characterized in that, After forming the light conversion layer, the top surface of the light conversion layer has a convex portion and a concave portion, the concave portion is located in the central region of the substrate, the convex portion is located in the edge region of the substrate, and the convex portion surrounds the concave portion.

12. The preparation method of the LED lamp bead according to claim 11, wherein, The virtual connection line between the center of the concave portion and the center of each LED chip is not perpendicular to the surface of the substrate.

13. The preparation method of the LED lamp bead according to claim 11, wherein, After forming the light conversion layer, the method for manufacturing the LED lamp bead further comprises: Forming a glass microsphere adhesive layer on the light conversion layer, with glass microspheres within the glass microsphere adhesive layer, and the glass microspheres being disposed near the top surface of the glass microsphere adhesive layer.

14. The manufacturing method of the LED lamp bead according to claim 13, wherein, The top surface of the glass microsphere adhesive layer is a curved surface convex in a direction away from the substrate; and / or, the glass microsphere adhesive layer is located within the concave portion.

15. An LED light source, characterized in that, Comprising at least one LED lamp bead as described in any one of claims 1 to 7.

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