LED light emitting device and method of manufacturing the same

Abstract

The application is suitable for the field of LED packaging technology, and provides an LED light emitting device and a manufacturing method thereof. The LED light emitting device comprises a support, an LED chip and an encapsulating glue layer. The support comprises a substrate and a dam part. The substrate has opposite front and back surfaces. The dam part has opposite bottom and top surfaces. The LED chip and the bottom surface of the dam part are arranged on the front surface of the substrate. The dam part surrounds the LED chip to form a chip mounting area for mounting the LED chip and bearing the encapsulating glue layer. The encapsulating glue layer is encapsulated above the LED chip. The dam part and the encapsulating glue layer are transparent or translucent. The top part of the encapsulating glue layer is provided with transparent or translucent hollow particles. The LED light emitting device and the manufacturing method thereof have high product brightness and good user experience.

Description

Technical Field

[0001] This invention belongs to the field of LED packaging technology, and particularly relates to an LED light-emitting device and its manufacturing method. Background Technology

[0002] With the rapid development of LCD technology in recent years, there is a trend towards larger screens. Driven by the demand for high dynamic range (HDR) and the "stay-at-home economy," Mini LED display technology is gradually penetrating medium and large-size application fields, including TVs, commercial displays, and e-sports. Currently, the mainstream Mini backlight technology is blue LEDs combined with quantum dot films, using white glue technology (such as CN112186090A) on the surface of the LED beads. Although this solution achieves a light emission angle of 160°, the light blocking layer (white glue) significantly obstructs the light, resulting in a large sacrifice of light intensity at the center of the LED beads. This leads to a severely low luminous flux of the LED beads, low product brightness, and a poor user experience.

[0003] In existing technologies, there are also solutions that use transparent brackets, such as the display device and its four-sided light-emitting LED disclosed in CN107086263B. The transparent bracket is formed on the substrate by thermoplastic molding. The transparent bracket is generally made of transparent plastic, such as PPA (poly(p-phenylene terephthalamide)), PCT (polyethylene terephthalate), or thermoplastic resin. Its light transmittance is insufficient, which affects the light intensity of the side light emission. In addition, due to the presence of a reflective white adhesive layer on the top, the light intensity loss at the top is relatively large, resulting in a poor actual user experience. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an LED light-emitting device and its manufacturing method, which can reduce the light intensity loss at the top of the LED light-emitting device, improve the brightness of the LED light-emitting device, and provide a better actual experience.

[0005] The technical solution of the present invention is as follows: an LED light-emitting device, comprising a bracket, an LED chip, and an encapsulating adhesive layer. The bracket includes a substrate and a dam portion. The substrate has a front side and a back side, and the dam portion has a bottom side and a top side. The bottom side of the LED chip and the dam portion is disposed on the front side of the substrate. The dam portion surrounds the LED chip, forming a chip mounting area for mounting the LED chip and supporting the encapsulating adhesive layer. The encapsulating adhesive layer is encapsulated above the LED chip. The dam portion and the encapsulating adhesive layer are transparent or semi-transparent. The top of the encapsulating adhesive layer is provided with transparent or semi-transparent hollow particles. The height of the dam portion is the distance from the front side of the substrate to the top side of the dam portion. The height of the encapsulating adhesive layer protruding from the bracket is the distance from the top side of the dam portion to the top of the encapsulating adhesive layer. The height of the encapsulating adhesive layer protruding from the bracket is greater than the height of the dam portion.

[0006] Optionally, the outer surface of the encapsulating adhesive layer is curved and has a shape that is larger at the bottom and smaller at the top; the top of the encapsulating adhesive layer is located directly above the chip mounting area, and the hollow particles cover directly above the LED light-emitting device.

[0007] Optionally, at least a portion of the encapsulating adhesive layer is not covered by hollow particles, and the hollow particles cover at least directly above the LED chip.

[0008] Optionally, the projected area of ​​the hollow particle coverage area on the bottom surface of the encapsulating adhesive layer accounts for 20%-80% of the bottom surface area of ​​the encapsulating adhesive layer; or the thickness of the surface of the encapsulating adhesive layer not covered by hollow particles is at least greater than the height of the dam portion.

[0009] Optionally, the encapsulating adhesive layer includes a first encapsulating adhesive layer and a second encapsulating adhesive layer, wherein the bottom of the first encapsulating adhesive layer is encapsulated on the front side of the substrate, and the bottom of the second encapsulating adhesive layer is encapsulated on the top of the first encapsulating adhesive layer; phosphor is disposed in the first encapsulating adhesive layer, and most of the phosphor is located at the bottom of the first encapsulating adhesive layer; the top surface of the first encapsulating adhesive layer is lower than the top surface of the dam portion.

[0010] Optionally, the mass content of the hollow particles in the second encapsulating adhesive layer is 1%-5%.

[0011] Optionally, the median particle size of the hollow particles is 15μm-100μm.

[0012] Optionally, the top surface of the dam section is inclined inward to the inside of the dam section.

[0013] The present invention also provides a method for manufacturing an LED light-emitting device, for manufacturing the above-mentioned LED light-emitting device, comprising the following steps:

[0014] A scaffold is prepared and an encapsulating adhesive layer with hollow particles is disposed on the scaffold;

[0015] The encapsulating adhesive layer protrudes beyond the bracket at a height greater than the height of the bracket.

[0016] Optionally, setting the encapsulating adhesive layer includes the following steps:

[0017] After a first encapsulating colloid containing phosphor is placed inside the dam section, the phosphor is settled by centrifugation, and the first encapsulating colloid is cured or semi-cured by a fast baking process.

[0018] A second encapsulating colloid containing hollow particles is placed above the first encapsulating colloid. The hollow particles are then baked to gather at the top of the second encapsulating colloid, forming a hollow particle gathering area.

[0019] The present invention provides an LED light-emitting device and its manufacturing method. Due to the low density and light weight of hollow particles, they can be concentrated in the area above the encapsulating colloid after heating. The hollow particles are white granules with reflective and refractive properties, allowing light directly above the LED chip to undergo secondary mixing through reflection and refraction. This causes the light intensity in the center of the LED chip to be refracted / reflected to both sides, increasing the light intensity on both sides of the LED chip. Furthermore, the hollow structure of the hollow particles increases light transmission, thus improving the light emission angle without significantly reducing the overall brightness of the LED chip. Moreover, since the hollow particles can be suspended above the LED chip and are a certain distance from the phosphor (the colloid of the second encapsulating layer separates the phosphor and the hollow particles), most of the light can be emitted from the colloid between the hollow particles and the phosphor, resulting in relatively enhanced light intensity on both sides. When applied to a display screen backlight panel, this can increase the pitch of the LED chips on the panel, reduce the number of LED chips on the same panel, lower the cost of the LED chips, and result in better brightness and user experience for the display screen, while also reducing application costs. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a cross-sectional schematic diagram of a bracket in an LED light-emitting device provided in an embodiment of the present invention;

[0022] Figure 2a This is a cross-sectional schematic diagram of the bracket and the first encapsulating adhesive layer in an LED light-emitting device provided by an embodiment of the present invention;

[0023] Figure 2b This is a cross-sectional schematic diagram of the bracket and the first encapsulating adhesive layer in an LED light-emitting device according to another embodiment of the present invention;

[0024] Figure 3a , 3b 3C is Figure 5a or Figure 5b Schematic diagram of AA section;

[0025] Figure 4 This is a schematic diagram showing the proportion of hollow particles to the bottom area of ​​the encapsulating adhesive layer in an LED light-emitting device from a top-view angle, according to an embodiment of the present invention.

[0026] Figure 5a This is a top view schematic diagram of an LED light-emitting device provided in an embodiment of the present invention;

[0027] Figure 5b This is a top view schematic diagram of another LED light-emitting device provided in an embodiment of the present invention;

[0028] Figure 6a yes Figure 3a A schematic diagram of the light effect;

[0029] Figure 6b yes Figure 3b A schematic diagram of the light effect;

[0030] Figure 7 This is a schematic diagram of the light effect in existing technology;

[0031] Figure 8 yes Figure 6b The diagram shows the light intensity distribution of an LED light-emitting device.

[0032] Figure 9 This is a schematic diagram of the light intensity distribution of an LED light-emitting device with white adhesive covering the top surface in the prior art;

[0033] Figure 10 This is a cross-sectional structural diagram of the LED light-emitting device in another embodiment;

[0034] Figure 11 This is a top view of the LED light-emitting device applied to the backlight panel in an embodiment of the present invention;

[0035] Figure 12 This is a schematic diagram of the light effect of the LED light-emitting device applied to the backlight panel in an embodiment of the present invention;

[0036] Figure 13 This is a cross-sectional view and luminous efficacy diagram of the LED light-emitting device in another embodiment;

[0037] Figure 14 This is a cross-sectional view and luminous efficacy diagram of the LED light-emitting device in another embodiment;

[0038] Figure 15 This is a cross-sectional structural diagram of the LED light-emitting device in another embodiment. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or may have an intervening component present. When a component is referred to as "connected to" another component, it can be directly connected to the other component or may have an intervening component present.

[0041] Furthermore, in embodiments of this invention, terms such as "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are used to indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, or in a conventional placement or usage state. These terms are merely for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the structures, features, devices, or elements referred to must have a specific orientation or positional relationship, nor that they must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0042] The various specific technical features and embodiments described in the detailed embodiments can be combined in any suitable manner without contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the various specific technical features / embodiments in this invention will not be described separately.

[0043] like Figure 1 , Figure 2a , Figure 2b , Figure 3a , Figure 3b and Figure 3c As shown, an embodiment of the present invention provides an LED light-emitting device (LED bead) 10, including a support 120, an LED chip 200, and an encapsulating adhesive layer 400. The support 120 includes a substrate 100 and a dam portion 110. The substrate 100 may be a metal substrate, a ceramic substrate with a metal coating, a glass substrate, or other substrates with conductive properties. The substrate 100 has opposing front and back sides, and the dam portion 110 has opposing bottom and top surfaces. The LED chip 200 and the dam portion 110 are disposed on the front side of the substrate 100, and the dam portion 110 surrounds the LED chip 200, forming a chip mounting area 130 for mounting the LED chip and carrying the encapsulating adhesive. The shape of the chip mounting area 130 can vary depending on different applications and luminous efficacy requirements, for example... Figure 5a The example chip mounting area 130 is rectangular; Figure 5bThe example chip mounting area 130 is circular; however, the chip mounting area 130 can also be other shapes, and this application does not limit the shape of the chip mounting area 130. The encapsulating layer 400 is encapsulated above the LED chip 200. The dam portion 110 and the encapsulating layer 400 are transparent or semi-transparent, allowing light to be emitted from the entire side of the LED light-emitting device (including the dam portion 110), with better light emission from the side. The encapsulating layer 400 can be made of epoxy resin, silicone resin, or other resins with high light transmittance. The dam portion 110 can be made of transparent material, including but not limited to EKE091, PPA, PCT, etc. A transparent or semi-transparent hollow particle is disposed on the top of the encapsulating layer 400. In this embodiment, the hollow particle is a hollow glass microsphere with chemical properties similar to a sodium-calcium borosilicate glass composition. It has excellent water resistance, is non-flammable, and non-porous, so the hollow particle does not absorb resin (encapsulating colloid), is compatible with resin, and has low application cost. In addition, because hollow particles have low density and light weight, they can be gathered in the area above the encapsulation layer 200 after heating and can be suspended above the LED chip 200. Hollow particles are transparent particles with reflective and refractive properties, so that the light directly above the LED bead is reflected and refracted by the hollow particles (because the hollow particles are transparent or semi-transparent hollow structures and have small particle size, they have the characteristics of refracting and reflecting light, and appear white visually) to the areas on both sides, thereby increasing the light intensity in the areas on both sides of the LED bead.

[0044] The height H1 of the dam 120 is the distance from the front surface of the substrate 100 to the top surface of the dam portion 110. The height H2 of the encapsulating adhesive layer 400 protruding from the support 120 is the distance from the top surface of the dam portion 110 to the top of the encapsulating adhesive layer 400. The height of the encapsulating adhesive layer 400 protruding from the support 120 is greater than the height of the support 120, that is, H2 is greater than H1 (preferably H2 is 1 to 2 times H1). This increases the proportion of the height of the encapsulating adhesive layer 400 protruding from the support 120 in the total height of the LED light-emitting device, causing hollow particles to concentrate at the top of the encapsulating adhesive layer 400 and located near the top of the LED chip 200. The hollow particles reflect the light emitted from the top surface of the LED chip 200. The encapsulating adhesive layer 400 protruding from the support 120 helps to arrange the hollow particles in a higher area (see reference). Figure 6a , Figure 6b and Figure 14 As shown), this reduces the obstruction of light reflected and refracted by the hollow particles, making it easier to reflect and refract light to the sides of the LED light-emitting device. This reduces the obstruction of the bracket to the light emitted from the LED chip. Combined with the hollow particles placed on top of the encapsulating layer 400, this appropriately reduces the top light emission of the LED light-emitting device and increases the side light emission. (Also, refer to...) Figure 6bAs shown, the dam section 110 is translucent, allowing light emitted from the LED chip to pass through the dam section 110 and reach the periphery of the LED light-emitting device 10. This light is then superimposed with the light reflected and refracted by the hollow particles, thus enhancing the light intensity around the LED light-emitting device 10 and improving light uniformity. (Reference) Figure 11 and Figure 12 The LED light-emitting device 10 can be arrayed on a PCB board to form a backlight board for the display screen, which makes the light intensity uniformity of the backlight board good, can increase the pitch of the LED beads on the board, reduce the number of LED beads on the same board, reduce the cost of LED beads, and make the display screen product have good brightness and good user experience.

[0045] Specifically, the outer surface of the encapsulating adhesive layer 400 is curved and has a shape that is larger at the bottom and smaller at the top; the top of the encapsulating adhesive layer 400 is located directly above the chip mounting area 130, and hollow particles cover the top of the LED chip 200, forming a hollow particle coverage area 410 on the top of the encapsulating adhesive layer 400. In some embodiments, the encapsulating adhesive layer 400 may be spherical, and the LED chip 200 is located at the bottom center or near the center of the encapsulating adhesive layer. The LED light-emitting device has good light uniformity and excellent effect.

[0046] like Figure 1 , Figure 3a , Figure 3b Figure 3c As shown, the encapsulating adhesive layer 400 at least covers the inner side and top of the dam portion 110, and at least fills the chip mounting area 130, thereby minimizing the obstruction of light emitted from the surface of the encapsulating adhesive layer 400 by the dam portion 110 and improving the peripheral light intensity of the LED light-emitting device. Since the encapsulating adhesive layer 400 can be formed through a dispensing process during production, and the protrusion height of the encapsulating adhesive layer 400 is too high, it may overflow the outside of the dam portion 110 due to its own gravity. In a preferred embodiment, the height H2 of the encapsulating adhesive layer 400 is lower than the length H4 and / or width H5 of the dam portion 110 (see reference). Figure 5a and 5b (As shown), to reduce the occurrence of adhesive overflow in the encapsulation layer 400 during the production process.

[0047] In practical applications, refer to Figure 5a and 5b As shown (the shaded area in the figure represents the area occupied by the dam portion 110), the dam portion 110 can be fixedly disposed or integrally disposed on the front side of the substrate 100, and the shapes of the dam portion 110 and the chip mounting area 130 can be flexibly arranged, which is not limited in this application. Figure 5a In the top view schematic diagram of an LED light-emitting device shown, the outer contour of the dam section 110 is square, and the chip mounting area 130 is also square; as shown Figure 5b In the top view of another LED light-emitting device shown, the outer contour of the dam portion 110 is square, and the chip mounting area 130 is circular. In other embodiments, such as this one, one LED chip 200 is provided in the chip mounting area 130, and the LED chip 200 is located at the center inside the chip mounting area 130. In other embodiments, two or more LED chips 200 may also be provided. In addition to mounting chips, the chip mounting area 130 may also mount protective elements, such as Zener diodes.

[0048] In specific applications, the encapsulating adhesive layer 400 can be a single-layer structure depending on the manufacturing process, for example... Figure 3c The encapsulating adhesive layer 400 shown is a single-layer structure, with hollow particles located on top of the single-layer encapsulating adhesive; the encapsulating adhesive layer 400 can also be a two-layer structure (with hollow particles located on top of the uppermost encapsulating adhesive layer), for example... Figure 3b The encapsulating layer 400 shown includes a first encapsulating layer 300 at the bottom and a second encapsulating layer 420 at the top, with hollow particles located on the top of the second encapsulating layer 420; the encapsulating layer 400 can also have a structure of three or more layers, for example... Figure 3a The encapsulating layer 400 shown includes a first encapsulating layer 300 at the bottom, a second encapsulating layer 420 in the middle, and a third encapsulating layer 430 at the top; hollow particles may be located on the top of the third encapsulating layer 430. The number of encapsulating layers 400 is not limited in this application.

[0049] In one embodiment, such as Figure 14 As shown, the hollow particle coverage area 410 can completely cover the encapsulating adhesive layer 400 (since there are gaps between the hollow particles, "complete coverage" here means that it visually appears to be basically covered, with no obvious blank areas); in another embodiment, as Figure 6a As shown in Figure 6b, the hollow particles may not completely cover the encapsulating adhesive layer 400; that is, at least part of the encapsulating adhesive layer 400 may not be covered by the hollow particles. This can be selected based on the light effect required by the product design, and this application does not impose any restrictions.

[0050] In practical applications, refer to Figure 3a , Figure 3b , Figure 3c and Figure 4 , Figure 6bIn one embodiment, the projected area of ​​the hollow particle covering region 410 on the bottom surface of the encapsulating adhesive layer 400 accounts for 20%-80% of the bottom surface area of ​​the encapsulating adhesive layer 400, preferably 24%-40%. This allows the light intensity in the center of the LED bead to be appropriately diverted to both sides to increase the light intensity on both sides of the LED bead. Furthermore, the hollow particle covering region 410 does not completely cover the upper surface of the encapsulating adhesive layer 400, reducing the obstruction of light emitted laterally by the LED and thus enhancing the lateral light from the LED (light intensity distribution reference). Figure 8 (As shown).

[0051] In another embodiment, the thickness H3 of the surface of the encapsulating adhesive layer 400 not covered by hollow particles is at least greater than the height of the dam portion H1. This ensures that a sufficient amount of light is directly refracted from the encapsulating adhesive layer 400, and then superimposed with the light reflected and refracted by the hollow particles, thereby enhancing the lateral light of the LED (light intensity distribution reference). Figure 8 (As shown).

[0052] Specifically, refer to Figure 3b Figure 6b In the illustrated embodiment, the encapsulating adhesive layer 400 includes a first encapsulating adhesive layer 300 and a second encapsulating adhesive layer 420. The bottom of the first encapsulating adhesive layer 300 is encapsulated on the front side of the substrate 100, and the bottom of the second encapsulating adhesive layer 420 is encapsulated on the top of the first encapsulating adhesive layer 300. Phosphor is disposed within the first encapsulating adhesive layer 300. The phosphor can be used to convert the wavelength of light emitted by the LED chip to produce white light or other desired light. Most of the phosphor is located at the bottom of the first encapsulating adhesive layer 300, that is, the first encapsulating adhesive layer 300 containing phosphor is disposed within the dam portion 110. The first encapsulating adhesive layer 300 can be a phosphor adhesive (containing phosphor).

[0053] like Figure 2a and Figure 2b As shown, the first encapsulating adhesive layer 300 may not protrude from the dam portion 110, and most or all of the phosphor is deposited on the upper surface of the substrate 100 and / or the LED chip 200, forming a phosphor deposition layer 320. Since the phosphor generates heat when excited, the phosphor deposition layer 320 being deposited on or near the substrate facilitates the dissipation of the heat generated by the phosphor through the substrate. The upper part of the first encapsulating adhesive layer 300 is a relatively transparent transparent layer 310, and the lower part is the phosphor deposition layer 320, which results in a high phosphor concentration near the LED chip. The light emitted by the LED chip can better excite the phosphor, improving the excitation efficiency, and reducing the light blocking by the phosphor when light passes through the transparent layer 310.

[0054] In specific applications, such as Figure 2a and Figure 2bAs shown, the height of the fluorescent adhesive (first encapsulating layer 300) is lower than the top surface of the dam portion 110, and it can be in the shape of a concave cup with a concave middle surface and protruding edges. Figure 2b (as shown) or a half-bowl structure with a flat surface and lower than the top surface of the dam section by 110 mm. Figure 2a As shown, the purpose is to leave space for the upper cup adhesive (i.e., the second encapsulating adhesive layer 420) formed in subsequent processes, so that the second encapsulating adhesive layer 420 can automatically flow to empty areas when there is a slight deviation in dispensing, avoiding the second encapsulating adhesive layer 420 from overflowing outside the dam portion 110, reducing the difficulty of the production process, improving the production yield, and increasing the contact area between the second encapsulating adhesive layer 420 and the first encapsulating adhesive layer 300 and the dam portion 110, which can enhance the bonding force between different layers. To ensure that at least some or all of the phosphor settles, after the semi-solid first encapsulating adhesive layer 300 is placed on the substrate, a centrifugal device can be used to settle the phosphor, forming a phosphor settling layer 320. A transparent layer is placed above the phosphor settling layer 320. After the centrifugation process is completed, a fast baking process is used to bake the phosphor adhesive (first encapsulating adhesive layer 300). The fast baking process includes baking at a low temperature of 43°C for 30-40 minutes, followed by baking at 130-150°C for 5-10 minutes, which can eliminate adhesive air bubbles and allow the adhesive surface to dry slightly.

[0055] In specific applications, such as Figure 3b and Figure 6b As shown, the central portion of the second encapsulating adhesive layer 420 arches upward relative to the outer periphery, forming a spherical shape. The second encapsulating adhesive layer 420 can be formed by a dispensing process. Furthermore, the hollow particle gathering region 410 is located at the crown portion at the top of the spherical shape. Figure 3b From the cross-sectional view, the hollow particle gathering region 410 is crescent-shaped (thin at the edges, thick in the center, and with an arc-shaped bottom), while the top is a planar structure (see reference). Figure 3a As shown in the figure, in this embodiment, only the spherical crown part (central part) is provided with hollow particles. The hollow particles do not need to be laid on the plane of the planar structure, and the amount of hollow particles can be relatively small. In some application scenarios that need to ensure the light intensity of the top surface of the LED, the light obstruction to the middle part of the LED can be reduced, and the light intensity loss at the top of the LED light-emitting device can be reduced. Moreover, the hollow particles can be gathered upwards at the upper end of the protruding part of the second encapsulating adhesive layer 420 by heating the second encapsulating adhesive layer 420, that is, a hollow particle gathering area 410 located directly above the LED chip 200 is formed in the top area of ​​the center, which is beneficial to manufacturing.

[0056] Specifically, Figure 1As shown, the width A of the top of the dam portion 110 is no greater than 200 μm, and the height H1 of the dam portion 110 is no greater than 450 μm. Limiting the height of the dam portion 110 can increase the light mixing area and distance above the substrate 100, increase the light emission angle and the light intensity on both sides, and reduce the obstruction of light by the dam portion 110.

[0057] Specifically, such as Figure 2a and Figure 2b As shown, the inner peripheral side of the dam section 110 is a vertical surface (reference). Figure 2a (as shown) or inwardly inclined surface (reference) Figure 2b As shown), the outer peripheral surface of the dam section 110 is a vertical surface (see reference). Figure 2a (as shown) or outwardly inclined surface (reference) Figure 2b (As shown). Figure 2b In the illustrated embodiment, the inclination angle of the inner sidewall of the dam portion 110 relative to the front side of the substrate 100 can increase the contact area between the dam portion and the encapsulating adhesive layer, improve the bonding force between the inner surface of the dam portion 110 and the adhesive of the encapsulating adhesive layer, reduce the occurrence of adhesive overflow when using more encapsulating adhesive, and the more encapsulating adhesive, the better the light-shaped effect.

[0058] refer to Figure 2b and Figure 10 As shown, the top surface of the dam portion 110 can be a plane 112 parallel to the plane of the substrate (see reference). Figure 2b ) or an inclined surface 114 that is not parallel to the substrate and tilts inward (reference) Figure 10 (As shown).

[0059] Figure 10 In the illustrated embodiment, the inward inclination of the top surface of the dam portion 110 increases the contact area between the dam portion and the encapsulating adhesive layer. This enhances the bonding force between the top surface of the dam portion 110 and the adhesive layer.

[0060] It can reduce the occurrence of adhesive overflow when using a larger amount of encapsulating colloid.

[0061] In another embodiment, such as Figure 13 As shown, the cross-section of the dam section 110 is triangular, that is, the top surface of the dam section 110 is pointed, which reduces the thickness of the top of the dam section 110 to increase the light transmittance, increase the light output on both sides, and reduce the material of the dam section 110. In addition, the inclined surface area of ​​the inner side surface 301 of the dam section 110 is larger, which can reflect some of the light that hits the inner side surface 301 to the periphery of the LED light-emitting device and increase the contact area between the encapsulating adhesive layer 400 and the dam section 110, thereby improving the bonding force and airtightness between the encapsulating adhesive layer 400 and the bracket 120.

[0062] Specifically, the first encapsulating colloid (first encapsulating layer) 300 and the second encapsulating colloid (second encapsulating layer) 420 use the same colloid material, that is, the second encapsulating layer 420 uses the same type of adhesive from the same manufacturer as the first encapsulating layer 300 (fluorescent adhesive), resulting in good bonding. In this embodiment, the first encapsulating layer can be silicone, and the second encapsulating layer can also be silicone.

[0063] Specifically, the content (by mass) of hollow particles in the second encapsulating adhesive layer 420 can be 1%-5%, which has a good effect.

[0064] Specifically, the median particle size of the hollow particles can be 15μm-100μm. The median particle size, also known as the D50 particle size or median diameter, refers to the particle size value corresponding to a cumulative distribution percentage of 50%. This is a typical value representing particle size, accurately dividing the total into two equal parts, meaning that 50% of the particles have a diameter greater than this value, and 50% of the particles have a diameter less than this value. If the D50 of a sample is 5μm, it means that among all the particles of different sizes that make up the sample, particles with a diameter greater than 5μm account for 50%, and particles with a diameter less than 5μm also account for 50%. In this embodiment, the median particle size of the hollow particles can be 40μm, meaning that hollow particles with a diameter greater than 40μm account for 50%, and hollow particles with a diameter less than 40μm also account for 50%.

[0065] Specifically, taking the 2835 LED bead as an example, the overall height of the LED light-emitting device can be 1.3mm-1.7mm, the thickness of the hollow particles in the hollow particle gathering area 410 can be 50-150μm, the shape of the hollow particle gathering area 410 can be roughly circular or elliptical, and its coverage diameter D can be 1800-2200μm.

[0066] like Figure 15 As shown, in one embodiment, multiple LED light-emitting devices 10 may also share a substrate 500. Multiple dams 110 can be formed on the substrate 500 to form an LED light panel or light strip. The substrate 500 can be a PCB board.

[0067] The present invention also provides a method for manufacturing an LED light-emitting device, for manufacturing the above-mentioned LED light-emitting device, comprising the following steps:

[0068] A side-transparent support is prepared and an encapsulating adhesive layer with hollow particles is disposed on the support 120, wherein the hollow particles are transparent or translucent.

[0069] The height of the encapsulating adhesive layer protruding from the bracket 120 is greater than the height of the bracket 120.

[0070] Hollow particles are white (transparent) granules with reflective and refractive properties. This allows light directly above the LED to be reflected and refracted by the hollow particles to the outside of the LED, where it undergoes secondary mixing with the light from the outside. This results in a slightly lower light intensity in the center of the LED, increasing the light intensity on both sides. Furthermore, the hollow structure of the hollow particles has good light transmittance, thus increasing the side light intensity without significantly reducing the overall brightness of the LED. When used in a display backlight panel, this enhances the light intensity in the areas between the LEDs, allowing for increased LED pitch on the backlight panel. This reduces the number of LEDs on the same panel, lowers LED costs, and results in display products with excellent brightness, good light uniformity, a superior user experience, and low application costs. The height of the dam section 110 is the distance from the front surface of the substrate 100 to the top surface of the dam section 110. The height of the encapsulating adhesive layer 400 protruding from the support 120 is the distance from the top surface of the dam section 110 to the top of the encapsulating adhesive layer. The height of the encapsulating adhesive layer 400 protruding from the support 120 is greater than the height of the dam section 110, which can reduce the proportion of the height of the dam section 110 in the total height of the LED light-emitting device. Combined with the hollow particles set on the top of the encapsulating adhesive layer, compared with the prior art, it can increase the light output of the top and sides of the LED light-emitting device, and at the same time improve the light output uniformity, resulting in a better user experience of the LED light-emitting device.

[0071] Specifically, in one embodiment, the fabrication of the support may include the following steps: fabricating a substrate 100 and integrally forming or fixing a dam portion 110 in an enclosed shape on the substrate 100 to form a chip mounting area 130;

[0072] The LED chip 200 is connected to the substrate 100 and the LED chip 200 is located inside the dam portion 110 (i.e., within the chip mounting area 130);

[0073] In one embodiment, setting the encapsulating adhesive layer includes the following steps: a semi-solid first encapsulating adhesive containing phosphor (i.e., the first encapsulating adhesive layer 300) is provided in the dam portion 110, and at least part or all of the phosphor is deposited on the upper surface of the substrate 100 and / or the LED chip 200; specifically, the phosphor can be deposited by centrifugation, and the first encapsulating adhesive layer 300 can be cured or semi-cured by a fast baking process.

[0074] After the first encapsulating adhesive layer 300 is cured or partially cured (i.e., semi-cured), a second encapsulating adhesive layer 420 mixed with hollow particles is disposed above the first encapsulating adhesive layer 300, and heated to cause at least some or all of the hollow particles to converge at the top of the second encapsulating adhesive layer 420 to form a hollow particle convergence area 410.

[0075] In this embodiment, the hollow particles are glass microspheres with a hollow center, which have the characteristics of low density and light weight. After heating, they are gathered in the upper region of the encapsulating colloid. The hollow particles are transparent or translucent particles with a hollow structure, which have reflective and refractive properties. This allows the light directly above the lamp bead to be reflected and refracted by the hollow particles, causing the light intensity in the middle of the lamp bead to be refracted / reflected to both sides, thereby increasing the light intensity on both sides of the lamp bead.

[0076] In one embodiment, the second encapsulating adhesive layer 420 is silicone. For example... Figure 7 In the prior art, the LED light-emitting device is covered with white glue 202 (hereinafter referred to as the white glue product), resulting in a significant loss of light intensity above the LED light-emitting device. This application, however, uses silicone combined with hollow particles above the LED beads (LED light-emitting device). Since the hollow particles are suspended above the LED chip 200 and protrude above the LED device, the brightness is improved compared to the existing white glue product. Furthermore, the transmittance of the silicone in this application is much higher than that of the transparent barrier. Therefore, the luminous flux of the existing white glue product is 30% lower than that of the product using hollow particles in this application at the same color point. Thus, the LED light-emitting device provided by this embodiment of the invention has relatively enhanced light intensity on both sides, which can increase the pitch of the LED beads on the lamp board, reduce the number of LED beads on the same lamp board, lower the cost of the LED beads, and result in better brightness and user experience for the display screen, while also reducing application costs.

[0077] Specifically, according to the manufacturing method of this embodiment, the height of the first encapsulating adhesive layer 300 containing phosphor disposed in the dam portion 110 is preferably lower than the top surface of the dam portion 110, so that when the phosphor settles to the bottom by centrifugation, the first encapsulating adhesive layer 300 will not be thrown out of the dam portion 110, so that the phosphor covers the upper surface of the substrate 100 and the LED chip 200. Then, a fast baking process can be used to cure the first encapsulating adhesive layer 300. The fast baking process is to bake at 43°C for 30-40 minutes, and then bake at 130-150°C for 5-10 minutes.

[0078] After a second encapsulating layer 420 containing hollow particles is placed above the first encapsulating layer 300, the hollow particles are baked to gather at the top of the second encapsulating layer 420 to form a hollow particle gathering area 410. The baking conditions are: baking at 43°C for 20-30 minutes, then heating to 100°C for 10-30 minutes to release stress, and then baking at 150°C for 150-180 minutes to cure.

[0079] This invention provides an LED light-emitting device and its manufacturing method. Because the LED light-emitting device uses phosphor in conjunction with an LED chip, the light emitted by the LED chip mixes with the light excited by the phosphor for wavelength conversion. Therefore, quantum dot films are unnecessary. Furthermore, the luminous intensity of the LED light-emitting device provided by this invention is higher than that of existing technologies. In certain application scenarios, it eliminates the need for or reduces the need for secondary brightening with DBEF film (brightness enhancement film), offering advantages such as low cost, high brightness, and ultra-wide-angle capability. Due to the low density and light weight of hollow particles, they are concentrated in the upper region of the encapsulating colloid after heating. The hollow particles exhibit reflectivity and refraction, causing light directly above the LED to be reflected and refracted, thus refracting / reflecting the light intensity in the center of the LED to the sides, thereby increasing the light intensity on both sides of the LED. Moreover, since the hollow particles are transparent, they do not absorb the original light energy of the LED, thus increasing the peripheral brightness of the LED without significantly reducing its overall brightness.

[0080] An embodiment of the present invention provides an LED light-emitting device with a large amount of light emitted from all sides, and the light-emitting effect is shown in Figure 6b. Figure 7 In the prior art shown, the fluorescent adhesive 201 of the LED light-emitting device 20 is covered with white adhesive 202. The white adhesive significantly blocks light, causing only a small portion of the light to escape from the top of the LED light-emitting device 20. The light transmission effect of the dam 203 is not as good as that of silicone, so less light is emitted from the side of the dam 203, resulting in poor light emission. Figure 8 The light intensity distribution diagram of the LED light-emitting device provided in this embodiment is as follows: Figure 9 This is a light intensity distribution diagram for white glue products in the prior art. The horizontal axis represents the emission angle, and the vertical axis represents the luminous intensity (unit: cd, candela). Figure 8 and Figure 9 As can be seen from the light intensity distribution diagram, Figure 9 The light intensity distribution diagram of the existing full-coverage white glue product shows that the light intensity on the side is small (the maximum value is less than 1.6). Figure 8 The light intensity distribution curve is slightly concave in the middle, with the maximum light intensity distributed on both sides of the normal. The extreme light intensity can reach above 1.8, which can improve brightness uniformity. Even when increasing the spacing between LEDs, the brightness uniformity can still meet customer specifications, thereby reducing the number of LEDs used and lowering application costs. The application effect is good. When designing a Mini POB backlight module, the number of LEDs can be reduced, such as... Figure 12 As shown, the ratio of OD (Optimal Distance, which is the distance from the LED to the illumination surface; in direct-lit backlight modules, OD is the distance between the diffuser plate and the upper surface of the lamp board PCB) to PITCH (LED pitch) can be increased to 1:1.6, resulting in low application cost.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An LED light-emitting device, characterized in that, The device includes a support, an LED chip, and an encapsulating adhesive layer. The support includes a substrate and a dam. The substrate has a front and a back side, and the dam has a bottom and a top side. The bottom side of the LED chip and the dam is located on the front side of the substrate. The dam surrounds the LED chip, forming a chip mounting area for mounting the LED chip and supporting the encapsulating adhesive layer. The encapsulating adhesive layer is encapsulated above the LED chip. The dam and the encapsulating adhesive layer are transparent or semi-transparent. The top of the encapsulating adhesive layer has transparent or semi-transparent hollow particles. The height of the dam is the distance from the front side of the substrate to the top surface of the dam. The encapsulating adhesive layer protrudes from the support by the distance from the top surface of the dam to the top of the encapsulating adhesive layer. The height of the encapsulating adhesive layer protruding from the support is greater than the height of the dam. The thickness of the encapsulating adhesive layer surface not covered by hollow particles is at least greater than the height of the dam. Phosphor is disposed within the encapsulating adhesive layer. The phosphor can be observed when viewed from the outside of the encapsulating adhesive layer where it is not covered by hollow particles.

2. The LED light-emitting device as described in claim 1, characterized in that, The outer surface of the encapsulating adhesive layer is curved and has a shape that is larger at the bottom and smaller at the top; the top of the encapsulating adhesive layer is located directly above the chip mounting area, and the hollow particles cover the top of the LED light-emitting device.

3. The LED light-emitting device as described in claim 1, characterized in that, The encapsulating adhesive layer is at least partially uncovered by the hollow particles, which at least cover the top of the LED chip.

4. The LED light-emitting device as described in claim 2, characterized in that, The projected area of ​​the hollow particle coverage area on the bottom surface of the encapsulating adhesive layer accounts for 20%-80% of the bottom surface area of ​​the encapsulating adhesive layer.

5. The LED light-emitting device as described in claim 1, characterized in that, The encapsulating adhesive layer includes a first encapsulating adhesive layer and a second encapsulating adhesive layer. The bottom of the first encapsulating adhesive layer is encapsulated on the front side of the substrate, and the bottom of the second encapsulating adhesive layer is encapsulated on the top of the first encapsulating adhesive layer. Phosphor is disposed in the first encapsulating adhesive layer, and most of the phosphor is located at the bottom of the first encapsulating adhesive layer. The top surface of the first encapsulating adhesive layer is lower than the top surface of the dam portion.

6. The LED light-emitting device as described in claim 5, characterized in that, The hollow particles in the second encapsulating adhesive layer have a mass content of 1%-5%.

7. An LED light-emitting device as described in claim 6, characterized in that, The median particle size of the hollow particles is 15μm-100μm.

8. An LED light-emitting device as described in any one of claims 1 to 7, characterized in that, The top surface of the dam section is inclined to the inside of the dam section.

9. A method for manufacturing an LED light-emitting device, characterized in that, The method for manufacturing an LED light-emitting device as described in any one of claims 1 to 8 comprises the following steps: A scaffold is prepared and an encapsulating adhesive layer with hollow particles is disposed on the scaffold; wherein the thickness of the surface of the encapsulating adhesive layer not covered by hollow particles is at least greater than the height of the dam portion, and phosphor is disposed within the encapsulating adhesive layer, and the phosphor can be observed when viewed from the outer part of the encapsulating adhesive layer not covered by hollow particles inward; The encapsulating adhesive layer protrudes beyond the bracket at a height greater than the height of the bracket.

10. A method for manufacturing an LED light-emitting device as described in claim 9, characterized in that, Setting the encapsulating adhesive layer includes the following steps: After a first encapsulating colloid containing phosphor is placed inside the dam section, the phosphor is settled by centrifugation, and the first encapsulating colloid is cured or semi-cured by a fast baking process. A second encapsulating colloid containing hollow particles is placed above the first encapsulating colloid. The hollow particles are then baked to gather at the top of the second encapsulating colloid, forming a hollow particle gathering area.

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