LED lamp bead, preparation method thereof and LED light source

Abstract

The invention provides an LED lamp bead and a preparation method thereof, and an LED light source. The LED lamp bead comprises a substrate; the at least one LED chip is positioned on the substrate; the first cofferdam is located on each LED chip; the light shielding layer is located on the area, outside the first cofferdam, of the substrate and the LED chips, and the light shielding layer and the first cofferdam jointly define the light emitting shape of the corresponding LED chips; and the light conversion layer is at least located on the LED chip in the first cofferdam. According to the invention, the first cofferdam and the shading layer are utilized to limit the light-emitting shape of the LED chip, so that the light-emitting shape of the LED chip is changed from a square shape to other required shapes, the cost is lower, the process is simpler to realize, and the batch production efficiency is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED lighting, in particular to an LED lamp bead, a preparation method thereof and an LED light source. BACKGROUND

[0002] An LED (Light Emitting Diode) is a kind of solid-state semiconductor device, which has the advantages of high brightness, low working voltage, small power consumption, easy matching with integrated circuits, simple driving, long service life, etc., and has been widely used as a light source in the lighting field.

[0003] Some LED products need special-shaped (such as circular, elliptical, etc.) light spots, but since the LED chip is usually square, it is difficult to achieve a special-shaped light spot by a lower cost and a simpler process. For example, in some LED products such as flashlights, the LED lamp bead needs to emit a circular light spot. Currently, there are mainly two kinds of LED lamp bead products that can produce a circular light spot. One is to make the LED chip in the LED lamp bead into a circular shape, which has a high cost. The other is to paste a circular glass sheet on the surface of a square LED chip, and the area outside the circular glass sheet is subjected to light shielding treatment. This solution requires a high light transmittance of the glass sheet, and also needs to consider the problem of glass bonding. SUMMARY

[0004] Therefore, the embodiments of the present application aim to provide an LED lamp bead, a preparation method thereof and an LED light source, so as to solve the problems of high cost and complex process of the existing LED lamp bead for producing a special-shaped light spot.

[0005] In one aspect, the present application provides an LED lamp bead, comprising:

[0006] a substrate;

[0007] at least one LED chip located on the substrate;

[0008] a first coffer located on each of the LED chips;

[0009] a light shielding layer located on the substrate and an area outside the first coffer of the LED chip, the light shielding layer and the first coffer jointly defining the shape of light emission of the corresponding LED chip; and

[0010] a light conversion layer located at least on the LED chip in the first coffer.

[0011] In some embodiments, the shape of the first coffer is at least one of a circle, an ellipse or a polygon; and / or, the edge of the first coffer does not exceed the edge of the corresponding LED chip.

[0012] In some embodiments, the height of the light shielding layer gradually decreases from the edge to the center of the substrate.

[0013] In some embodiments, the material of the first dam and the light shielding layer are both light shielding glue, and the viscosity of the light shielding glue used by the first dam is greater than the viscosity of the light shielding glue used by the light shielding layer.

[0014] In some embodiments, the light conversion layer is at least located on the LED chip, and the first dam is located on the light conversion layer.

[0015] In some embodiments, the method further comprises:

[0016] A second dam is located on the substrate and surrounds each of the LED chips, and the light shielding layer is filled in the gap between the first dam and the second dam.

[0017] In some embodiments, the top surface of the second dam is higher than the top surface of the first dam, and the top surface of the light shielding layer gradually transitions from flush with the top surface of the second dam to flush with the top surface of the first dam.

[0018] The present application also provides a preparation method of an LED lamp bead, comprising:

[0019] providing a substrate;

[0020] die bonding at least one LED chip on the substrate;

[0021] forming a first dam on each of the LED chips;

[0022] forming a light conversion layer on at least the LED chip in the first dam; and,

[0023] forming a light shielding layer on the substrate and on the area of the substrate where the LED chip is located outside the first dam, and the light shielding layer and the first dam jointly define the shape of light emission of the corresponding LED chip.

[0024] In some embodiments, before forming the first dam, the light conversion layer is formed on at least the LED chip, and then the first dam is formed on the light conversion layer; or,

[0025] after forming the first dam, the light conversion layer is formed on at least the LED chip in the first dam.

[0026] In some embodiments, before forming the first dam, the preparation method further comprises:

[0027] forming a second dam on the substrate, the second dam surrounding each of the LED chips; and,

[0028] After forming the light-shielding layer, the light-shielding layer also fills the gap between the first cofferdam and the second cofferdam.

[0029] In some embodiments, the top surface of the second cofferdam is higher than the top surface of the first cofferdam, the light-shielding glue is filled in the gap between the first cofferdam and the second cofferdam, and after curing, the top surface of the light-shielding layer gradually transitions from flush with the top surface of the second cofferdam to flush with the top surface of the first cofferdam.

[0030] In some embodiments, after forming the light-shielding layer, a cutting process is performed to separate individual LED lamp beads.

[0031] The application also provides an LED light source comprising the LED lamp bead.

[0032] The application provides an LED lamp bead and a preparation method thereof, and an LED light source. The LED lamp bead comprises a substrate, at least one LED chip located on the substrate, a first cofferdam located on each LED chip, a light-shielding layer located on the substrate and a region outside the first cofferdam where the LED chip is located, the light-shielding layer and the first cofferdam together defining the shape of light emission of the corresponding LED chip, and a light conversion layer located at least on the LED chip in the first cofferdam. The application uses the first cofferdam and the light-shielding layer to define the shape of light emission of the LED chip, so that the light emission of the LED chip changes from a square shape to other desired shapes, with low cost, simple process implementation, and high batch production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A flowchart of a preparation method of an LED lamp bead according to an embodiment of the application.

[0034] Figure 2 A structural schematic diagram of a flip-chip LED chip on a substrate according to an embodiment of the application.

[0035] Figure 3 And Figure 4 A structural schematic diagram of forming a second cofferdam on a substrate according to an embodiment of the application.

[0036] Figure 5 And Figure 6 A structural schematic diagram of forming a first cofferdam on an LED chip according to an embodiment of the application.

[0037] Figure 7 A structural schematic diagram of forming a light conversion layer on an LED chip according to an embodiment of the application.

[0038] Figure 8A cross-sectional view of an LED lamp bead according to an embodiment of the present application.

[0039] Figure 9 A plan view of an LED lamp bead according to an embodiment of the present application.

[0040] Figure 10 A structure diagram of forming a light conversion layer on an LED chip according to an embodiment of the present application.

[0041] Figure 11 A structure diagram of forming a first cofferdam on a light conversion layer according to an embodiment of the present application.

[0042] Figure 12 A cross-sectional view of another LED lamp bead according to an embodiment of the present application.

[0043] Figure 13 A structure diagram of die bonding a plurality of LED chips on a substrate according to an embodiment of the present application.

[0044] Figure 14 A structure diagram of forming a second cofferdam in a grid shape on a substrate according to an embodiment of the present application.

[0045] In the drawings, reference numerals:

[0046] 100 - substrate; 200 - LED chip; 301 - second cofferdam; 302 - first cofferdam; 400 - light conversion layer; 500 - light shielding layer. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0048] Figure 8 A cross-sectional view of an LED lamp bead according to an embodiment of the present application, Figure 9 A plan view of an LED lamp bead according to an embodiment of the present application. As Figure 8 and Figure 9As shown, the LED lamp bead comprises a substrate 100, at least one LED chip 200, a first coffer 302, a light shielding layer 500 and a light conversion layer 400. The LED chip 200 is located on the substrate 100, and the first coffer 302 is located on each LED chip 200. The light shielding layer 500 is located on the substrate 100 and the area outside the first coffer 302 of the LED chip 200, and the light shielding layer 500 and the first coffer 302 jointly define the shape of light emission of the corresponding LED chip 200. The light conversion layer 400 is located at least on the LED chip 200 in the first coffer 302. The present application uses the first coffer 302 and the light shielding layer 500 to define the shape of light emission of the LED chip 200, so that the light emission of the LED chip 200 changes from square to other required shapes, with lower cost, simpler process implementation and high batch production efficiency.

[0049] Specifically, the base material of the substrate 100 can be selected from ceramic materials (including one or more of AlN, Al2O3, SiO, SiO2, Si3N4 and SiON) or metal materials (including aluminum or copper). The substrate 100 can be provided with electrical connectors such as plugs and pads for leading out the LED chip 200.

[0050] The substrate 100 can have one LED chip 200 or more than two LED chips 200. When the substrate 100 has more than two LED chips 200, the LED chips 200 can be arranged in an array on the substrate 100. The LED chip 200 can be attached to the substrate 100 using die bonding glue, and then interconnected with the electrical connectors in the substrate 100 using leads. In some embodiments, the LED chip 200 can also be soldered to the substrate 100 in a flip-chip manner, which can eliminate the constraints of leads and die bonding glue, so that the LED chip 200 has a high thermal conductivity, a small thermal resistance, can withstand a large current, has stronger reliability, higher luminous flux maintenance rate and longer service life.

[0051] Further, the excitation light generated by the LED chip 200 can be blue light, purple light or ultraviolet light, based on which the LED chip 200 can be a blue LED chip, such as a GaN-based LED chip emitting blue light, or a purple or ultraviolet LED chip.

[0052] The first cofferdam 302 is located on each LED chip 200. Specifically, the first cofferdam 302 can be directly formed on the top surface (light emitting surface) of the LED chip 200, and the light emitted by the LED chip 200 can only be emitted from the inside of the first cofferdam 302, so the shape of the first cofferdam 302 determines the light emitting shape of the LED chip 200, and adjusting the shape of the first cofferdam 302 can adjust the light emitting shape of the LED chip 200. Further, the material of the first cofferdam 302 can be light shielding glue, for example, it can be black glue or white glue, etc. The material of the first cofferdam 302 can use light shielding glue with high viscosity, thereby simplifying the preparation difficulty of the first cofferdam 302.

[0053] In some embodiments, the shape of the first cofferdam 302 can be at least one of a circle, an ellipse, and a polygon (for example, it can be a triangle, a rectangle, a trapezoid, a pentagon, a hexagon, etc.), at this time, the light emitting of the LED chip 200 can also be adjusted to be a circle, an ellipse, or a polygon accordingly; the color of the first cofferdam 302 can be black or white, which is not limited in the present application.

[0054] It should be noted that the edge of the first cofferdam 302 is preferably not beyond the edge of the LED chip 200, for example, the edge of the first cofferdam 302 can be located within the edge of the LED chip 200, and the edge of the first cofferdam 302 can also partially coincide with the edge of the LED chip 200.

[0055] In some embodiments, the substrate 100 also has a second cofferdam 301, which surrounds each LED chip 200, and the second cofferdam 301 has a certain gap with the edge of the LED chip 200. For example, when the substrate 100 has 2 or more arrayed LED chips 200, the second cofferdam 301 can be in the form of a grid, and each LED chip 200 is exposed from the corresponding grid of the second cofferdam 301. Further, the material of the second cofferdam 301 can also be light shielding glue, for example, it can be black glue or white glue, etc. The material of the second cofferdam 301 can use light shielding glue with high viscosity, thereby simplifying the preparation difficulty of the second cofferdam 301.

[0056] Further, the top surface of the first cofferdam 302 can be lower than the top surface of the second cofferdam 301, which will make the light shielding layer 500 have the appearance of a bowl cup, and the light shielding layer 500 can reflect light, which is beneficial to the light emitting of the LED lamp bead. In some embodiments, the top surface of the first cofferdam 302 can also be flush with the top surface of the second cofferdam 301.

[0057] Further, the light conversion layer 400 is located on the LED chip 200 at least within the first cofferdam 302, and the conversion layer can receive the excitation light emitted by the LED chip 200 and generate corresponding output light. Specifically, the light conversion layer 400 has a light conversion material therein, which can absorb the excitation light generated by the LED chip 200 and generate light of a corresponding color, and finally mix to form the output light. The light conversion layer 400 in the present application can be formed by mixing a colloid with a light conversion material, and the light conversion material can be quantum dots or fluorescent powder, and the colloid can be a material such as silicone. That is, the light conversion layer 400 can be a quantum dot layer or a fluorescent powder layer.

[0058] In some embodiments, the light conversion layer 400 can also be located on the area outside the first cofferdam 302 where the LED chip 200 is located and on the substrate 100, but this does not affect the implementation of the present application.

[0059] In some embodiments, the top surface of the light conversion layer 400 within the first cofferdam 302 can be flush with the top surface of the first cofferdam 302, so that the surface of the LED lamp bead is relatively flat, but it should not be limited thereto, and the top surface of the light conversion layer 400 within the first cofferdam 302 can also be higher or lower than the top surface of the first cofferdam 302.

[0060] Figure 12 Another cross-sectional schematic diagram of an LED lamp bead is provided for an embodiment of the present application. As shown in Figure 12 , the light conversion layer 400 can also be directly formed on the LED chip 200, and the first cofferdam 302 is located on the light conversion layer 400. At this time, the first cofferdam 302 also needs to be located above the LED chip 200, and the edge of the first cofferdam 302 is preferably not beyond the edge of the LED chip 200. Moreover, the first cofferdam 302 can still define the shape of the light emitted by the LED chip 200, and adjusting the shape of the first cofferdam 302 can adjust the light-emitting shape of the LED chip 200.

[0061] Please continue to refer to Figure 8 or Figure 12 , the light shielding layer 500 is located on the substrate 100 and the area outside the first cofferdam 302 where the LED chip 200 is located, and it can be seen from Figure 9 that the light shielding layer 500 is annular and fills the gap between the first cofferdam 302 and the second cofferdam 301. At this time, the area outside the first cofferdam 302 where the LED chip 200 is located will also be covered by the light shielding layer 500, so only the light within the first cofferdam 302 can be emitted, and the light outside the first cofferdam 302 will be absorbed by the light shielding layer 500, thereby forming a light spot with the same shape as the first cofferdam 302, such as a circular light spot, an elliptical light spot or a polygonal light spot. The shape of the first cofferdam 302 is preferably circular, so that an LED lamp bead capable of generating a circular light spot can be formed, which can be applied in scenarios such as flashlights.

[0062] Of course, if the second cofferdam 301 is omitted, the light shielding layer 500 can extend from the first cofferdam 302 to the edge of the substrate 100. The material of the light shielding layer 500 can also be a light shielding glue, but the viscosity of the light shielding glue used in the light shielding layer 500 can be lower than the viscosity of the light shielding glue used in the first cofferdam 302 and the second cofferdam 301, thereby simplifying the preparation process of the light shielding layer 500 and allowing the light shielding layer 500 to have a bowl-like morphology.

[0063] Please continue reading Figure 8 or Figure 12 The height of the light shielding layer 500 gradually decreases from the edge to the center of the substrate 100. For example, the top surface of the light shielding layer 500 can gradually transition from being flush with the top surface of the second cofferdam 301 to being flush with the top surface of the first cofferdam 302. In this way, the light shielding layer 500 can have a cup-like morphology, acting as a cup to reflect light and improve light utilization efficiency.

[0064] Of course, in some embodiments, the top surface of the second cofferdam 301 may be flush with the top surface of the first cofferdam 302 . In this case, the top surface of the light shielding layer 500 may also be flush with the top surfaces of the second cofferdam 301 and the first cofferdam 302 .

[0065] There is no doubt that the LED lamp beads provided above can be applied to various lighting fields. For example, they can be made into backlight modules for display backlight fields (which can be backlight modules for terminals such as televisions, monitors, and mobile phones). In this case, they can be applied to backlight modules. In addition to being applicable to the display backlight field, they can also be applied to key backlight fields, shooting fields, home lighting fields, medical lighting fields, decoration fields, automotive fields, transportation fields, etc. When applied to the key backlight field, they can be used as key backlight light sources for mobile phones, calculators, keyboards, and other key devices; when applied to the shooting field, they can be made into camera flashlights; when applied to the home 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 surgical 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, and advertising lamps; when applied to the automotive field, they can be made into car lights, car indicator lights, etc.; when applied to the transportation field, they can be made into various traffic lights or various street lights. The above applications are merely examples of several applications in this embodiment. It should be understood that the application of the LED lamp beads in this embodiment is not limited to the several fields exemplified above.

[0066] Based on this, some embodiments of the present application further provide an LED light source, comprising at least one of the above-mentioned LED lamp beads. The LED lamp beads in the LED light source can be arranged in one row or multiple rows, and can be used in light sources such as direct-lit LED light sources and edge-lit LED light sources.

[0067] Based on this, an embodiment of the present application further provides a preparation method of the LED lamp bead. Figure 1 The flow chart of the preparation method of the LED lamp bead is shown in Figure 1 The preparation method of the LED lamp bead comprises the following steps:

[0068] Step S100: providing a substrate 100;

[0069] Step S200: die bonding at least one LED chip 200 on the substrate 100;

[0070] Step S300: forming a first cofferdam 302 on each LED chip 200;

[0071] Step S400: forming a light conversion layer 400 on the LED chip 200 at least in the first cofferdam 302; and

[0072] Step S500: forming a light shielding layer 500 on the substrate 100 and the area outside the first cofferdam 302 where the LED chip 200 is located, and the light shielding layer 500 and the first cofferdam 302 jointly define the shape of light emission of the corresponding LED chip 200.

[0073] Figures 2 to 14 The corresponding structure schematic diagram of the corresponding steps of the preparation method of the LED lamp bead provided by an embodiment of the present application. Next, the preparation method of the LED lamp bead will be described in detail. Figures 2 to 14

[0074] As shown in Figure 2 , step S100 is performed to provide the substrate 100, and the material of the substrate 100 can be selected from ceramic materials (including one or more of AlN, Al2O3, SiO, SiO2, Si3N4 and SiON) or metal materials (including aluminum or copper). The substrate 100 can be provided with electrical connectors such as plugs and pads for leading out the LED chip 200.

[0075] Please continue to refer to Figure 2 , step S200 is performed to die bond the LED chip 200 on the substrate 100, and the LED chip 200 can be attached to the substrate 100 by using die bonding glue, and then interconnected with the electrical connectors in the substrate 100 by using leads. In some embodiments, the LED chip 200 can also be soldered on the substrate 100 in a flip-chip manner, so as to get rid of the constraints of leads and die bonding glue, so that the LED chip 200 has a high thermal conductivity, a small thermal resistance, can withstand a large current, has stronger reliability, higher luminous flux maintenance rate and longer service life.

[0076] As shown in Figure 3 and Figure 4 ​As shown, a second cofferdam 301 is formed on the substrate 100. The second cofferdam 301 surrounds the LED chip 200, with a certain gap between the second cofferdam 301 and the edge of the LED chip 200. The material of the second cofferdam 301 can be a high-viscosity light-shielding adhesive. When the high-viscosity light-shielding adhesive is applied to the substrate 100, it can maintain a fixed shape on the substrate 100 without flowing. After curing, the second cofferdam 301 is formed.

[0077] like Figure 5 and Figure 6 As shown, step S300 is performed to form a first cofferdam 302 on each LED chip 200. The first cofferdam 302 can be formed directly on the top surface (light-emitting surface) of the LED chip 200. After the LED lamp bead is prepared, the light emitted by the LED chip 200 will only be emitted from the first cofferdam 302. Therefore, the first cofferdam 302 can determine the shape of the light emitted by the LED chip 200. Adjusting the shape of the first cofferdam 302 can adjust the light-emitting shape of the LED chip 200. The material of the first cofferdam 302 can be the same as that of the second cofferdam 301. For example, the material of the first cofferdam 302 can also be a light-shielding glue with a high viscosity. When the light-shielding glue with a high viscosity is applied to the LED chip 200, the light-shielding glue with a high viscosity can maintain a fixed morphology on the LED chip 200 without flowing. After solidification, the first cofferdam 302 is formed.

[0078] In some embodiments, the shape of the first cofferdam 302 can be at least one of a circle, an ellipse, and a polygon (for example, a triangle, a rectangle, a trapezoid, a pentagon, a hexagon, etc.), and the color of the first cofferdam 302 can be black or white, which is not limited in this application.

[0079] It should be noted that the edge of the first cofferdam 302 is preferably not beyond the edge of the LED chip 200 . For example, the edge of the first cofferdam 302 may be located within the edge of the LED chip 200 , or may partially overlap with the edge of the LED chip 200 .

[0080] Furthermore, after forming the first cofferdam 302, the top surface of the first cofferdam 302 can be lower than the top surface of the second cofferdam 301. This will give the subsequently formed light shielding layer 500 a bowl-like appearance. The light shielding layer 500 can reflect light, facilitating the emission of light from the LED lamp beads. In some embodiments, the top surface of the first cofferdam 302 can also be flush with the top surface of the second cofferdam 301.

[0081] like Figure 7As shown, step S400 is performed to form a light conversion layer 400 on the LED chip 200 in the first cofferdam 302. Specifically, glue made of light conversion material can be applied to the LED chip 200 in the first cofferdam 302, and after curing, the light conversion layer 400 can be formed on the LED chip 200 in the first cofferdam 302. The light conversion layer 400 can receive the excitation light emitted by the LED chip 200 and generate corresponding output light. Specifically, the light conversion layer 400 contains light conversion material, which can absorb the excitation light generated by the LED chip 200 and generate light of corresponding color, and finally mix to form output light. The light conversion layer 400 in the present application can be made of a mixture of colloid and light conversion material, the light conversion material can be quantum dots or phosphor powder, and the colloid can be materials such as silica gel. That is, the light conversion layer 400 can be a quantum dot layer or a phosphor powder layer.

[0082] In some embodiments, the glue prepared from the light conversion material can also be sprayed onto the LED chip 200. At this time, some glue prepared from the light conversion material may also be sprayed on the surface of the substrate 100, so that the light conversion layer 400 formed after curing is still located on the area of ​​the LED chip 200 outside the first cofferdam 302 and on the substrate 100, but this does not affect the implementation of the present application.

[0083] In some embodiments, the top surface of the light conversion layer 400 within the first cofferdam 302 can be flush with the top surface of the first cofferdam 302, so that the surface of the LED lamp bead is relatively flat, but it should not be limited to this. The top surface of the light conversion layer 400 within the first cofferdam 302 can also be higher or lower than the top surface of the first cofferdam 302.

[0084] like Figure 8 and Figure 9 As shown, step S500 is performed to form a light shielding layer 500 on the substrate 100 and on the area of ​​the LED chip 200 outside the first cofferdam 302. The material of the light shielding layer 500 can also be a light shielding glue, but the viscosity of the light shielding glue used in the light shielding layer 500 will be lower than the viscosity of the light shielding glue used in the first cofferdam 302 and the second cofferdam 301. When forming the light shielding layer 500, the light shielding glue with lower viscosity can be placed in the gap between the first cofferdam 302 and the second cofferdam 301. The light shielding glue with lower viscosity has stronger fluidity and can spontaneously flow in the gap between the first cofferdam 302 and the second cofferdam 301, thereby filling the gap between the first cofferdam 302 and the second cofferdam 301. After solidification, the light shielding layer 500 is formed, and the light shielding layer 500 can fill the gap between the first cofferdam 302 and the second cofferdam 301.

[0085] Further, when the top surface of the second cofferdam 301 is higher than the top surface of the first cofferdam 302, the light-shielding glue with a smaller viscosity will form a slope on the top surface when flowing in the gap between the first cofferdam 302 and the second cofferdam 301, and after solidification, the top surface of the light-shielding layer 500 gradually transitions from being flush with the top surface of the second cofferdam 301 to being flush with the top surface of the first cofferdam 302, which is similar to the appearance of a bowl cup, so that the light-shielding layer 500 can act as a bowl cup to reflect light.

[0086] Of course, if the top surface of the second cofferdam 301 is flush with the top surface of the first cofferdam 302, at this time, the top surface of the light-shielding layer 500 can also be flush with the top surface of the second cofferdam 301 and the top surface of the first cofferdam 302, which does not affect the implementation of the present application.

[0087] In some embodiments, after forming the second cofferdam 301, the light conversion layer 400 can be formed first, and then the first cofferdam 302 is formed. Specifically, as shown in Figure 10 After forming the second cofferdam 301, the light conversion layer 400 is formed on at least the LED chip 200. Specifically, glue mixed with light conversion material can be applied on the LED chip 200, and after solidification, the light conversion layer 400 is formed on the LED chip 200, or a film mixed with light conversion material can be pasted on the LED chip 200, thereby forming the light conversion layer 400.

[0088] In some embodiments, the glue mixed with light conversion material can also be sprayed on the LED chip 200 in a spraying manner, at this time, some glue mixed with light conversion material can also be sprayed on the surface of the substrate 100, so that the light conversion layer 400 formed after solidification is also located on the substrate 100, but this does not affect the implementation of the present application.

[0089] As shown in Figure 11 The first cofferdam 302 is formed on the light conversion layer 400, specifically, the first cofferdam 302 also needs to be located above the LED chip 200, and the edge of the first cofferdam 302 is preferably not beyond the edge of the LED chip 200. At this time, the first cofferdam 302 can still limit the light-emitting shape of the LED chip 200, and adjusting the shape of the first cofferdam 302 can adjust the light-emitting shape of the LED chip 200.

[0090] As shown in Figure 12 The light-shielding layer 500 is formed on the substrate 100 and the area of the LED chip 200 outside the first cofferdam 302, and the specific steps of forming the light-shielding layer 500 have been described above, and will not be repeated here.

[0091] In some embodiments, there can be more than two LED chips 200 on the substrate 100, in which case the first dam 302 is formed on each LED chip 200, and the second dam 301 is formed around each LED chip 200. Specifically, as shown in FIG. 2B, the substrate 100 can have more than two light emitting regions, which can be arranged in an array, and each light emitting region can have a LED chip 200 die-bonded therein. As shown in FIG. 2C, the second dam 301 can be formed on the substrate 100, and the second dam 301 can be in the form of a grid, so as to surround each LED chip 200, and there can still be a gap between the second dam 301 and the edge of the LED chip 200. Figure 13 Figure 14 As shown in FIG. 2C, the second dam 301 can be formed on the substrate 100, and the second dam 301 can be in the form of a grid, so as to surround each LED chip 200, and there can still be a gap between the second dam 301 and the edge of the LED chip 200.

[0092] Afterwards, the first dam 302 and the light conversion layer 400 can be formed on each LED chip 200 according to the steps described above, and the light blocking glue can be applied and cured in the gap between the first dam 302 and the second dam 301, so as to form the light blocking layer 500.

[0093] It should be noted that in some embodiments, the step of forming the second dam 301 can be omitted regardless of the number of LED chips 200 on the substrate 100, and when forming the light blocking layer 500, a mold can be used to cover the substrate 100, and then the light blocking glue with low viscosity can be applied on the substrate 100, and the light blocking glue with low viscosity can flow to the entire area of the substrate 100 outside the first dam 302 due to its strong flowability, and the light blocking layer 500 can be formed after the light blocking glue is cured, and then the mold can be removed. Even if the second dam 301 is omitted, since the light blocking layer 500 can separate adjacent LED chips 200, the problem of light crosstalk between adjacent LED chips 200 can also be avoided.

[0094] Further, when there are multiple LED chips 200 on the substrate 100, after the light blocking layer 500 is formed, a cutting process can be performed to separate single LED beads, and each LED bead can include a specific number of LED chips 200. In this way, a specific number of LED beads can be applied in a specific situation, for example, when applied in a flashlight, the single LED chip 200 can be cut and separated to form an LED bead including a single LED chip 200. Since the flashlight needs a circular light spot, the central light intensity needs to be large, and the light emitting surface needs to be small, otherwise the flashlight will have problems such as flooding, and it is difficult to illuminate a long distance. The LED bead packaged by using this single LED chip 200 can realize the illumination of the flashlight at a lower cost, and the illumination effect is better.

[0095] ​In summary, the embodiment of the present application provides an LED lamp bead, a preparation method thereof and an LED light source. The LED lamp bead comprises a substrate 100; at least one LED chip 200 located on the substrate 100; a first cofferdam 302 located on each LED chip 200; a light shielding layer 500 located on the substrate 100 and the area outside the first cofferdam 302 of the LED chip 200, the light shielding layer 500 and the first cofferdam 302 jointly define the shape of light emission of the corresponding LED chip 200; and a light conversion layer 400 located at least on the LED chip 200 in the first cofferdam 302. The first cofferdam 302 is used to define the shape of light emission of the LED chip 200, and the light shielding layer 500 is used to shield the light of the area outside the first cofferdam 302, so that the light emission of the LED chip 200 changes from a square to other required shapes, which is low in cost, simple in process implementation and high in batch production efficiency.

[0096] It should be noted that the embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between embodiments can be referred to each other.

[0097] It should also be noted that, although the present application has been disclosed as above with the preferred embodiments, the above embodiments are not intended to limit the present application. For any skilled person in the art, many possible changes and modifications of the technical content disclosed above, or equivalent embodiments of equivalent changes, can be made without departing from the scope of the technical solution of the present application. Therefore, any simple modification, equivalent change and modification of the above embodiments made according to the technical essence of the present application, without departing from the content of the technical solution of the present application, still belongs to the protection scope of the technical solution of the present application.

[0098] It should also be understood that, unless specifically described or indicated, the terms "first", "second", "third" and the like in the specification are only used to distinguish different components, elements, steps and the like in the specification, and not to indicate the logical relationship or sequence relationship between the components, elements, steps and the like.

[0099] It is also to be appreciated that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It must be noted that, as used herein, the articles "a", "an" and "the" are intended to include one or more items, and can be used interchangeably with "at least one" or "one or more." Where only one item is intended, the phrase "only one" or similar language is used. Also, as used herein, including in the claims, "or" as used in a list of items prefaced by "comprising" or "including" indicates a disjunctive list such that, for example, a list of "comprising at least one of A, B, or C" means that the list includes A alone; B alone; C alone; A and B together; A and C together; B and C together; or A, B, and C together.

Claims

1. An LED lamp bead, characterized in that: include: substrate(100); At least one LED chip (200) is located on the substrate (100); A first cofferdam (302) is located on each of the LED chips (200); a light shielding layer (500) located on the substrate (100) and the area where the LED chip (200) is located outside the first cofferdam (302), the light shielding layer (500) and the first cofferdam (302) jointly defining a shape of light emitted by the corresponding LED chip (200); and The light conversion layer (400) is located at least on the LED chip (200) within the first cofferdam (302).

2. The LED lamp bead according to claim 1, characterized in that: The shape of the first cofferdam (302) is at least one of a circle, an ellipse or a polygon; and / or the edge of the first cofferdam (302) does not exceed the edge of the corresponding LED chip (200).

3. The LED lamp bead according to claim 1, characterized in that: The height of the light shielding layer (500) gradually decreases from the edge to the center of the substrate (100).

4. The LED lamp bead according to claim 1, characterized in that: The materials of the first cofferdam (302) and the light-shielding layer (500) are both light-shielding glue, and the viscosity of the light-shielding glue used in the first cofferdam (302) is greater than the viscosity of the light-shielding glue used in the light-shielding layer (500).

5. The LED lamp bead according to claim 1, characterized in that: The light conversion layer (400) is at least located on the LED chip (200), and the first cofferdam (302) is located on the light conversion layer (400).

6. The LED lamp bead according to any one of claims 1 to 5, characterized in that: Also includes: The second cofferdam (301) is located on the substrate (100) and surrounds each of the LED chips (200), and the light shielding layer (500) is filled in the gap between the first cofferdam (302) and the second cofferdam (301).

7. The LED lamp bead according to claim 6, characterized in that: The top surface of the second cofferdam (301) is higher than the top surface of the first cofferdam (302), and the top surface of the light-shielding layer (500) gradually transitions from being flush with the top surface of the second cofferdam (301) to being flush with the top surface of the first cofferdam (302).

8. A method for preparing LED lamp beads, characterized in that: include: Providing a substrate (100); bonding at least one LED chip (200) onto the substrate (100); forming a first cofferdam (302) on each of the LED chips (200); forming a light conversion layer (400) at least on the LED chip (200) within the first cofferdam (302); and, A light shielding layer (500) is formed on the substrate (100) and on an area of ​​the LED chip (200) outside the first cofferdam (302), and the light shielding layer (500) and the first cofferdam (302) jointly define a shape of light emitted by the corresponding LED chip (200).

9. The method for preparing an LED lamp bead according to claim 8, wherein: Before forming the first cofferdam (302), the light conversion layer (400) is formed at least on the LED chip (200), and then the first cofferdam (302) is formed on the light conversion layer (400); or, After forming the first cofferdam (302), the light conversion layer (400) is formed at least on the LED chip (200) within the first cofferdam (302).

10. The method for preparing an LED lamp bead according to claim 8, wherein: Before forming the first cofferdam (302), the preparation method further comprises: forming a second cofferdam (301) on the substrate (100), wherein the second cofferdam (301) surrounds each of the LED chips (200); and After the light shielding layer (500) is formed, the light shielding layer (500) also fills the gap between the first cofferdam (302) and the second cofferdam (301).

11. The method for preparing an LED lamp bead according to claim 10, wherein: The top surface of the second cofferdam (301) is higher than the top surface of the first cofferdam (302), and light-shielding glue is applied in the gap between the first cofferdam (302) and the second cofferdam (301). After solidification, the light-shielding layer (500) is formed, and the top surface of the light-shielding layer (500) gradually transitions from being flush with the top surface of the second cofferdam (301) to being flush with the top surface of the first cofferdam (302).

12. The method for preparing an LED lamp bead according to claim 8, wherein: After the light shielding layer (500) is formed, a cutting process is performed to separate individual LED lamp beads.

13. An LED light source, characterized in that: The device comprises at least one LED lamp bead according to any one of claims 1 to 7.

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