LED display unit

Abstract

The utility model provides a kind of LED display unit, comprising: substrate;LED chip is set on substrate;Encapsulation layer is covered on LED chip, and the outer surface of encapsulation layer includes the main light exit surface being arranged in parallel with substrate and multiple side light exit surfaces being connected between main light exit surface and substrate;Wherein, main light exit surface and each side light exit surface are all provided with multiple lenses connected in array.This application effectively solves the problem of more total reflection light proportion bouncing to the inside of encapsulation glue for brightness loss in related technology.

Description

Technical Field

[0001] This utility model relates to the field of LED display technology, and more specifically, to an LED display unit. Background Technology

[0002] In recent years, MIP (Mini or Micro in Package) packaging has gradually become a mature packaging method. Current packaging methods consist of an LED chip, a substrate, and encapsulating adhesive as a single package. This explanation of a single package involves using liquid adhesive or film to encapsulate and protect the LED chip structure through a lamination mechanism, and then using water jet or laser cutting to create a single-chip package structure.

[0003] However, the existing single-chip encapsulation structure is a square encapsulation. Observing from the angle of emission and the direction of brightness, Isnell's law states that when light travels from the encapsulating adhesive (high refractive index: 1.45) into the air (refractive index: 1), when the angle of incidence is greater than the critical angle, on a completely flat surface, a larger proportion of the light is reflected back into the encapsulating adhesive, resulting in brightness loss. This leads to a loss of brightness in the single-chip encapsulation structure. Utility Model Content

[0004] The main objective of this invention is to provide an LED display unit that solves the problem of brightness loss caused by a large proportion of total internal reflection light rebounding into the encapsulating adhesive in related technologies.

[0005] To achieve the above objectives, according to one aspect of the present invention, an LED display unit is provided, comprising: a substrate; an LED chip disposed on the substrate; and an encapsulation layer covering the LED chip, wherein the outer surface of the encapsulation layer includes a main light-emitting surface disposed parallel to the substrate and a plurality of side light-emitting surfaces connected between the main light-emitting surface and the substrate; wherein a plurality of lenses connected in an array are disposed on the main light-emitting surface and each side light-emitting surface.

[0006] Furthermore, there are four side-emitting light surfaces, which are connected sequentially along the circumference of the LED chip.

[0007] Furthermore, each side-emitting surface is a concave arc surface.

[0008] Furthermore, the encapsulation layer also includes an annular convex surface, the inner edge of which is connected to the edge of the main light-emitting surface, and the edge of each side light-emitting surface facing the main light-emitting surface is connected to the outer edge of the annular convex surface.

[0009] Furthermore, the edges of the two lenses at the junction of each side light-emitting surface and the main light-emitting surface are connected.

[0010] Furthermore, the shortest distance between the multiple side-emitting light surfaces and the substrate is less than 30 μm and greater than 0 μm.

[0011] Furthermore, the lens is hemispherical.

[0012] Furthermore, two of the four side-emitting light surfaces are symmetrically arranged.

[0013] Furthermore, the LED chip includes red, green, and blue lights arranged at intervals.

[0014] Furthermore, there is a first distance between the red and green lights, a second distance between the green and blue lights, and a third distance between any one of the red, green, and blue lights and the main light-emitting surface. The third distance is greater than the first distance and greater than the second distance.

[0015] The LED display unit, utilizing the technical solution of this utility model, includes a substrate, an LED chip, and an encapsulation layer. The LED chip is disposed on the substrate. The encapsulation layer covers the LED chip, and its outer surface includes a main light-emitting surface parallel to the substrate and multiple side light-emitting surfaces connected between the main light-emitting surface and the substrate. Multiple lenses are arranged in an array on the main light-emitting surface and each side light-emitting surface. When the LED chip emits light, when each ray of light reaches the boundary of a lens, each corner boundary of the lens is not planar, but becomes a single light-emitting surface into the air. This improves the limitation of the incident angle exceeding the critical angle, reduces the amount of total internal reflection light rebounding into the encapsulation material, lowers brightness loss, and increases light extraction efficiency and emission angle. Therefore, the technical solution of this application effectively solves the problem of a large proportion of total internal reflection light rebounding into the encapsulation material and causing brightness loss in related technologies. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0017] Figure 1 A side perspective view of an embodiment of an LED display unit according to the present invention is shown;

[0018] Figure 2 A simplified diagram is shown during the processing of the LED display unit according to the present invention, when the upper mold and the lower mold are separated, wherein the LED chip is not shown on the substrate of the upper mold;

[0019] Figure 3 A simplified diagram of the upper and lower molds before they are assembled during the processing of the LED display unit according to the present invention is shown, wherein the LED chip is not shown on the substrate of the upper mold;

[0020] Figure 4A simplified diagram of the upper and lower molds during the processing of the LED display unit according to the present invention is shown. The LED chip is not shown on the substrate of the upper mold, and the "lightning symbol" on the outside of the upper and lower molds indicates the heat curing process.

[0021] Figure 5 A simplified diagram of the upper and lower molds after they are fitted together during the processing of the LED display unit according to the present invention is shown, wherein the LED chip is not shown on the substrate of the upper mold;

[0022] Figure 6 A simplified diagram is shown in the process of manufacturing an LED display unit according to the present invention, wherein the LED chip is not shown on the substrate of the upper mold.

[0023] The above figures include the following reference numerals:

[0024] 10. Substrate;

[0025] 20. LED chip; 21. Red light; 22. Green light; 23. Blue light;

[0026] 30. Encapsulation layer; 31. Main light-emitting surface; 32. Side light-emitting surface; 33. Lens; 34. Annular convex surface;

[0027] 41. Upper mold; 42. Lower mold; 43. Dispensing head of dispensing mechanism; 44. Liquid glue. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0031] According to one aspect of this application, an LED display unit is provided, such as... Figure 1 As shown, an embodiment of the LED display unit includes a substrate 10, an LED chip 20, and an encapsulation layer 30. The LED chip 20 is disposed on the substrate 10. The encapsulation layer 30 covers the LED chip 20, and the outer surface of the encapsulation layer 30 includes a main light-emitting surface 31 arranged parallel to the substrate 10 and a plurality of side light-emitting surfaces 32 connecting the main light-emitting surface 31 and the substrate 10. A plurality of lenses 33 are arranged in an array on both the main light-emitting surface 31 and each side light-emitting surface 32.

[0032] The technical solution of the embodiment using the LED display unit has multiple lenses 33 connected in an array on the main light-emitting surface 31 and each side light-emitting surface 32. When the LED chip 20 emits light, when each ray of light reaches the boundary of the lens 33, each corner boundary of the lens 33 is not a plane, but becomes a single light-emitting surface into the air. This improves the limitation that the incident angle is greater than the critical angle, reduces the amount of total internal reflection light rebounding into the encapsulant, reduces brightness loss, and increases light emission efficiency and emission angle. Therefore, the technical solution of this application effectively solves the problem of a large proportion of total internal reflection light rebounding into the encapsulant and causing brightness loss in related technologies.

[0033] like Figure 1 As shown, there are four side-emitting light surfaces 32, which are connected sequentially along the circumference of the LED chip 20. This design ensures that the light from all around the LED chip 20 is guided reasonably in all directions, avoiding excessive concentration or lack of light in specific locations, thereby achieving a more uniform light distribution and improving the overall lighting effect.

[0034] like Figure 1As shown, each side-emitting light surface 32 is a concave arc surface. The concave arc surface can effectively capture the light emitted by the LED chip 20 and refract it into a wider range of angles. This means that even if the incident angle is close to the critical angle, the light can be diffused to a certain extent by the concave arc surface characteristics of the side-emitting light surface 32, reducing the proportion of total internal reflection light that directly returns to the encapsulant and enhancing the light utilization rate and the emission angle.

[0035] like Figure 1 As shown, the encapsulation layer 30 also includes an annular convex surface 34. The inner edge of the annular convex surface 34 is connected to the edge of the main light-emitting surface 31, and the edge of each side light-emitting surface 32 facing the main light-emitting surface 31 is connected to the outer edge of the annular convex surface 34. The annular convex surface 34 serves as a transition between the side light-emitting surface 32 and the main light-emitting surface 31, further optimizing the light path and enhancing the synergistic effect between the side-emitting and main light-emitting surfaces. When light passes through the side light-emitting surface 32, it undergoes additional refraction upon contact with the annular convex surface 34, effectively reducing the probability of total internal reflection and increasing the light emission angle, thereby improving brightness and luminous uniformity.

[0036] like Figure 1 As shown, the edges of the two lenses 33 at the junction of each side-emitting surface 32 and the main emitting surface 31 are connected. By ensuring that the lenses 33 are seamlessly connected at the junction of the side-emitting surface 32 and the main emitting surface 31, light loss between different interfaces can be minimized, improving light transmission efficiency and the overall visual effect of the LED display unit. This continuous design means that light can maintain the continuity and integrity of its initial path when passing through different lenses 33, reducing scattering and absorption.

[0037] like Figure 1 As shown, the shortest distance between the multiple side-emitting light surfaces 32 and the substrate 10 is less than 30 μm and greater than 0 μm. This tiny distance design ensures that the thickness of the encapsulant is controlled to the necessary and minimal level, which helps to improve the heat dissipation performance of the LED display unit, while reducing the material consumption of encapsulant and lowering production costs. Because the distance between the side-emitting light surfaces 32 and the substrate 10 is extremely close, the change in the medium encountered by the light before passing through the side-emitting light surfaces 32 is minimal, reducing brightness loss caused by refraction. The shortest distance between the multiple side-emitting light surfaces 32 and the substrate 10 is preferably 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, or 29 μm.

[0038] The shortest distance between the aforementioned multiple side-emitting light surfaces 32 and the substrate 10 is less than 30µm, which is lower than the target adhesive thickness, such as 120µm. If laser cutting is used, the laser light needs to be repeatedly applied to the cutting path to cut the semi-finished LED display unit into independent LED display units. However, with the new design concept, when the cutting path only contains the substrate thickness plus the guide adhesive thickness, the number of laser light repetitions will be reduced compared to traditional packaging methods. This shortens the adhesive surface cutting time, thereby improving the overall cutting efficiency.

[0039] like Figure 1 As shown, lens 33 is hemispherical. Compared to flat or other shaped lenses, the hemispherical lens 33 can more effectively collect and guide the light from the LED chip 20, causing it to diverge outwards. This structure not only maximizes light extraction efficiency but also reduces total internal reflection by changing the propagation angle of the light, resulting in a more uniform distribution of light over a wider angular range, thus improving lighting quality and visual experience.

[0040] like Figure 1 As shown, two of the four side-emitting light surfaces 32 are symmetrically arranged. The symmetrical arrangement of the side-emitting light surfaces 32 ensures that the light from the LED chip 20 receives the same refraction and guidance effect on both sides of the package, achieving consistency in brightness and balance in the emission angle on both sides of the package, thereby improving the overall visual harmony and the stability of the lighting effect.

[0041] like Figure 1 As shown, the LED chip 20 includes red LEDs 21, green LEDs 22, and blue LEDs 23 arranged at intervals. By arranging the red LEDs 21, green LEDs 22, and blue LEDs 23 in a sequential and spaced manner, RGB color mixing can be achieved in a smaller space, providing wide color gamut coverage and fine color control, suitable for high-resolution display applications. Furthermore, this layout helps improve color uniformity, reduce color shift, and provide a better visual experience when viewed at close range.

[0042] like Figure 1 As shown, there is a first distance between red light 21 and green light 22, a second distance between green light 22 and blue light 23, and a third distance between any one of the red, green, and blue lights 23 and the main light-emitting surface 31. This third distance is greater than both the first and second distances. By adjusting the distances of red light 21, green light 22, and blue light 23 relative to the main light-emitting surface 31, effective spatial isolation can be achieved between different colored light sources, preventing color mixing. Simultaneously, it ensures that each color of light can achieve optimal light efficiency conversion through its respective lens 33, resulting in purer and more saturated color performance. Furthermore, the setting of the third distance also helps improve the overall heat dissipation performance of the package and extends the lifespan of the LED chip 20.

[0043] The substrate in this embodiment is a circuit board.

[0044] like Figures 2 to 6 As shown, the equipment and materials used in the processing of the LED display unit in this embodiment include a pressing mold, a dispensing mechanism, liquid adhesive 44, and a strengthening curing device. The pressing mold includes an upper mold 41 and a lower mold 42, which can be fitted together and separated.

[0045] The substrates are designed with multiple LEDs (red LED 21, green LED 22, and blue LED 23) placed within a single sheet. Therefore, when designing the lamination mold, the flowability of the liquid adhesive 44 must be considered simultaneously. Thus, guide lines need to be left at the edge of each LED (red LED 21, green LED 22, or blue LED 23) to allow the liquid adhesive 44 to flow to the surface of each LED, ensuring that the space between the upper mold 41 and the lower mold 42 is filled with adhesive to achieve the required overall thickness. Therefore, see... Figure 2 As can be seen, the substrate is first placed in the upper mold. The dispensing head 43 of the dispensing mechanism dispenses liquid adhesive into a circular or (or) square shape on the lower mold. The upper and lower molds then mate. Due to the compression between the upper mold 41 and the lower mold 42, the liquid adhesive is fixed according to the shape of the lower mold 42. After the liquid adhesive is heated to the curing condition by the enhanced curing device, it bonds with the substrate to form the encapsulation layer 30. After the curing time is reached, the upper mold 41 and the lower mold 42 separate. At this point, the encapsulation layer 30 is on the same surface as the substrate, forming a semi-finished LED display unit.

[0046] In semi-finished LED display units, the residual adhesive (referred to as guide adhesive) thickness between individual LED display units is less than 30µm, lower than the target adhesive thickness (>120µm). Assuming laser cutting is used, the laser beam needs to be repeatedly applied to the cutting path to cut the semi-finished PKG into individual PKGs. However, with the new design concept, when the cutting path only contains the substrate thickness plus the guide adhesive thickness, the number of laser beam repetitions will be reduced compared to traditional packaging methods. This shortens the adhesive surface cutting time, improving overall cutting efficiency.

[0047] The technical solution in this embodiment achieves the following technical effects: the fine shavings produced on the substrate remain only on the side of the guiding adhesive and do not affect the overall brightness. The hemispherical lens design reduces the total internal reflection angle and increases light intensity. The irregular concave surface design on all four sides increases the refraction angle when light hits the concave surface, thus increasing the emission angle. The hemispherical lens design reduces laser cutting time and improves the removal of substrate shavings onto the side of the encapsulating adhesive during blade cutting. The reduced volume ratio of the encapsulating adhesive decreases adhesive usage and lowers costs.

[0048] In the description of this utility model, it should be understood that "multiple" means a quantity of two or more. Directional terms such as "front, back, up, down, left, right," "horizontal, vertical, perpendicular, horizontal," and "top, bottom" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are used solely for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself.

[0049] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0050] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0051] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An LED display unit, characterized in that, include: base(10); LED chip (20) is disposed on the substrate (10); An encapsulation layer (30) covers the LED chip (20). The outer surface of the encapsulation layer (30) includes a main light-emitting surface (31) arranged parallel to the substrate (10) and a plurality of side light-emitting surfaces (32) connecting the main light-emitting surface (31) and the substrate (10). The main light-emitting surface (31) and each of the side light-emitting surfaces (32) are provided with a plurality of lenses (33) connected in an array.

2. The LED display unit according to claim 1, characterized in that, There are four side-emitting light surfaces (32), and the four side-emitting light surfaces (32) are connected sequentially along the circumference of the LED chip (20).

3. The LED display unit according to claim 2, characterized in that, Each of the side-emitting light surfaces (32) is a concave arc surface.

4. The LED display unit according to claim 1, characterized in that, The encapsulation layer (30) further includes an annular convex surface (34), the inner edge of which is connected to the edge of the main light-emitting surface (31), and the edge of each side light-emitting surface (32) facing the main light-emitting surface (31) is connected to the outer edge of the annular convex surface (34).

5. The LED display unit according to claim 1, characterized in that, The edges of the two lenses (33) at the junction of each side light-emitting surface (32) and the main light-emitting surface (31) are connected.

6. The LED display unit according to claim 1, characterized in that, The shortest distance between the plurality of side-emitting light surfaces (32) and the substrate (10) is less than 30 μm and greater than 0 μm.

7. The LED display unit according to claim 1, characterized in that, The lens (33) is hemispherical.

8. The LED display unit according to claim 1, characterized in that, Two of the four side-emitting light surfaces (32) are symmetrically arranged opposite each other.

9. The LED display unit according to claim 1, characterized in that, The LED chip (20) includes a red light (21), a green light (22), and a blue light (23) arranged at intervals.

10. The LED display unit according to claim 9, characterized in that, There is a first distance between the red light (21) and the green light (22), a second distance between the green light (22) and the blue light (23), and a third distance between any one of the red light (21), the green light (22) and the blue light (23) and the main light-emitting surface (31), wherein the third distance is greater than the first distance and greater than the second distance.

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