LED package assembly and light emitting module

Abstract

The utility model discloses a kind of LED packaging assembly and light-emitting module, so that the upper surface of LED chip body is higher than the highest position of the upper surface of first light reflecting layer, and the upper surface of light conversion layer is higher than the upper surface of LED chip body, to this end, side light is guaranteed, and the intensity of side light is realized using bowl-shaped first light reflecting layer, to guarantee the utilization of light.

Description

Technical Field

[0001] This utility model relates to the field of LED light-emitting display packaging manufacturing, specifically to a light-emitting unit and light-emitting module that emits light from four sides. Background Technology

[0002] Chip-scale packaged (CSP) LEDs possess advantages such as small size, light weight, high integration, strong electrical performance, and high light density, making them highly sought after by display manufacturers. Currently, most CSP-LED packages are front-emitting, resulting in a large light-emitting area, uneven light emission, and higher brightness in the central region of the direct light source. Furthermore, due to the current demand for miniaturization, the thickness of the front phosphor layer of the LED is relatively small, leading to a shorter light mixing path and poorer color uniformity.

[0003] In existing technologies, there are two solutions: one is to directly set a reflective layer on the front to emit light from the side. However, the light utilization rate of this design is still not high, and there is still a light leakage problem on the back. The other is to directly set a reflective layer on the back to improve the light utilization rate. However, the light emission from the front is still relatively concentrated and the light mixing is uneven. Moreover, the reflective layer on the back reduces the light emission from the side of the package (or is not conducive to light emission from that side). It cannot guarantee the light utilization rate. Furthermore, the electrode layer of the LED bare chip is relatively thin, which limits the thinness of the reflective layer on the back. Utility Model Content

[0004] To address the aforementioned problems in the background art, this application provides an LED packaging component capable of four-sided light emission, which utilizes a thickened LED electrode layer to ensure the thickness of the reflective layer on the back side, as detailed below: This application provides an LED packaging assembly, including a packaging layer and an LED chip; the packaging layer encapsulates the LED chip; the packaging layer consists of a first reflective layer and a light conversion layer stacked vertically from bottom to top; along the vertical direction, the thickness of the central portion of the first reflective layer is less than the thickness of its surrounding portions, and the upper surface of the first reflective layer is recessed towards the lower surface of the first reflective layer, forming a bowl-shaped morphology; the LED chip includes an LED chip body and an electrode layer disposed on the lower surface of the LED chip body, the electrode layer including a first metal layer and a second metal layer, wherein the solderability of the second metal layer is greater than that of the first metal layer; wherein the LED chip body is completely encapsulated by the light conversion layer, and the electrode layer passes sequentially through the light conversion layer and the first reflective layer from the lower surface of the LED chip body and is exposed from the lower surface of the first reflective layer; the upper surface of the LED chip body is higher than the highest point of the upper surface of the first reflective layer, and the upper surface of the light conversion layer is higher than the upper surface of the LED chip body.

[0005] The beneficial effects of this application are as follows: The LED packaging component of this application makes the upper surface of the LED chip body higher than the highest position of the upper surface of the first reflective layer, and the upper surface of the light conversion layer higher than the upper surface of the LED chip body, thereby ensuring side light emission. At the same time, the bowl-shaped first reflective layer is used to achieve the intensity of side light emission and ensure the light utilization rate. Attached Figure Description

[0006] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0007] Figure 1 This is a cross-sectional view of the LED packaging assembly according to the first embodiment of this application; Figure 2 This is a side view of the LED packaging assembly according to the first embodiment of this application; Figure 3 This is a top view of the LED packaging assembly according to the first embodiment of this application; Figure 4 This is a cross-sectional view of the LED packaging assembly according to the second embodiment of this application; Figure 5 A schematic diagram of a bare LED chip; Figure 6 This is a schematic diagram of an LED chip (the electrode layer includes a first metal layer and a second metal layer); Figures 7A-7D This is a schematic diagram of the manufacturing process of the LED packaging component of this application; Figures 8A-8D This is a schematic diagram of the manufacturing process of the LED packaging component of this application.

[0008] Explanation of reference numerals in the attached figures: 1. Carrier board; 10. LED chip; 11. Upper surface of LED chip body; 12. LED chip body; 13. Side of LED chip body; 14. Electrode layer; 141. First metal layer; 142. Second metal layer; 20. Light conversion layer; 201. Phosphor layer; 202. Transparent resin layer; 23. Side of light conversion layer; 30. Second reflective layer; 31. Upper surface of second reflective layer; 33. Side of second reflective layer; 40. First reflective layer; 41. Upper surface of first reflective layer; 42. Lower surface of first reflective layer; 43. Side of first reflective layer; 60. Cutting equipment; C. Cutting line. Detailed Implementation

[0009] The following detailed description of the embodiments of this application, in conjunction with the accompanying drawings, will provide a thorough understanding of how this application uses technical means to solve technical problems and achieve corresponding technical effects, enabling its implementation. The embodiments of this application and the various features within them can be combined with each other without conflict, and the resulting technical solutions are all within the protection scope of this application. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0010] It should be understood that although the terms "first," "second," "third," etc., may be used to describe various elements, components, areas, layers, and / or parts, these elements, components, areas, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or part from another element, component, area, layer, or part. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or part discussed below may be referred to as the second element, component, area, layer, or part.

[0011] It should be understood that spatial relation terms such as "above," "located above," "below," "located below," etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as "below other elements" will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0012] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0013] Embodiments of this application are described herein with reference to cross-sectional views illustrating ideal embodiments (and intermediate structures). Thus, variations in the shape shown can be anticipated due to, for example, fabrication techniques and / or tolerances. Therefore, embodiments of this application should not be limited to the specific shape of the region shown herein, but should include shape deviations due to, for example, fabrication processes.

[0014] To fully understand this application, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0015] This application discloses an LED packaging assembly, including a packaging layer and an LED chip; the packaging layer encapsulates the LED chip; the packaging layer consists of a first reflective layer and a light conversion layer stacked vertically from bottom to top; along the vertical direction, the thickness of the central portion of the first reflective layer is less than the thickness of its surrounding portions, and the upper surface of the first reflective layer is recessed towards the lower surface of the first reflective layer, forming a bowl-shaped morphology; the LED chip includes an LED chip body and an electrode layer disposed on the lower surface of the LED chip body, the electrode layer including a first metal layer and a second metal layer, wherein the solderability of the second metal layer is greater than that of the first metal layer; wherein the LED chip body is completely encapsulated by the light conversion layer, and the electrode layer passes sequentially through the light conversion layer and the first reflective layer from the lower surface of the LED chip body and is exposed from the lower surface of the first reflective layer; the upper surface of the LED chip body is higher than the highest point of the upper surface of the first reflective layer, and the upper surface of the light conversion layer is higher than the upper surface of the LED chip body.

[0016] like Figure 1 , Figure 2 and Figure 3 As shown, the LED packaging assembly of the first embodiment of this application includes an LED chip 10 and a package encapsulating the LED chip 10. (Refer to...) Figure 1The LED package assembly is in the shape of a cuboid or frustum, and includes at least an upper surface and a lower surface arranged opposite each other, as well as four side surfaces connecting the upper and lower surfaces. At least a portion of the four side surfaces are used as light-emitting surfaces, that is, light is emitted from the side surfaces. The length (along the X direction) of the LED package assembly is between 300 and 800 micrometers, for example, 300 micrometers, 400 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, and 800 micrometers; its width (along the Y direction) is between 200 and 600 micrometers, for example, 200 micrometers, 300 micrometers, 400 micrometers, 500 micrometers, and 600 micrometers; and its height (along the Z direction) is between 80 and 500 micrometers, for example, 80 micrometers, 100 micrometers, 200 micrometers, 300 micrometers, 400 micrometers, and 500 micrometers.

[0017] The LED chip 10 has a generally rectangular parallelepiped structure, but other optional shapes are also possible. It is preferably a blue LED, which is a gallium nitride-based LED chip, and the LED chip 10 is a flip-chip LED chip, such as an In-doped GaN blue LED chip. The length of the LED chip 10 is between 200 and 500 micrometers, for example, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers, or 500 micrometers; the width of the LED chip 10 is between 100 and 400 micrometers, for example, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, or 400 micrometers; and the height of the LED chip 10 is between 50 and 200 micrometers, for example, 50 micrometers, 100 micrometers, 150 micrometers, or 200 micrometers.

[0018] It should be noted that the LED chip 10 includes an LED chip body 12 and an electrode layer 14 disposed on the lower surface of the LED chip body 12. The electrode layer 14 includes electrodes with positive and negative polarities and is made of, for example, a conductive metal material. In this application, the electrode layer 14 includes a first metal layer 141 directly bonded to the LED chip body 12 and a second metal layer 142 disposed on the side of the first metal layer 141 away from the LED chip body 12. In particular, the solderability of the second metal layer 142 is superior to that of the first metal layer 141, so that the second metal layer 142 can be directly used as a subsequent bonding material to connect other electronic components (e.g., external circuits). As a possible embodiment, the first metal layer 141 is preferably a material with good conductivity such as gold or silver, while the second metal layer 142 is selected as a material with good solderability containing tin, such as a tin-lead alloy, a tin-bismuth alloy, or a tin-silver alloy. Furthermore, the thickness of the second metal layer 142 is greater than the thickness of the first metal layer 141. This is for cost considerations and the reliability of subsequent welding. The thickness of the first metal layer 141 can be 10-50 micrometers, while the thickness of the second metal layer 142 can be 30-100 micrometers.

[0019] Furthermore, according to this embodiment, the encapsulation layer includes at least a three-layer structure, such as... Figure 1-3 As shown, it includes at least a first reflective layer 40, a light conversion layer 20, and a second reflective layer 30 stacked vertically (Z direction) from bottom to top. In this application, the LED chip body 12 is encapsulated by the light conversion layer 20, the lower surface of the LED chip body 12 contacts the first reflective layer 40, and the electrode layer 14 passes through the light conversion layer 20 and the first reflective layer 40 sequentially from the lower surface of the LED chip body 12 and is exposed from the lower surface 42 of the first reflective layer 40.

[0020] Generally, the light conversion layer 20 includes a light-transmitting resin material and fluorescent particles. Specifically, it includes a resin matrix material and a phosphor material dispersed in the resin matrix material. The phosphor material can be yellow phosphor, yellow-green phosphor, etc., and is uniformly dispersed in the resin matrix material. The resin matrix material can be a photocurable or thermocurable material.

[0021] The first reflective layer 40 includes a resin material and reflective particles dispersed in the resin material, such as titanium dioxide dispersed in silicone or epoxy resin. In this application, the first reflective layer 40 may have a curved upper surface 41. Vertically, the thickness of the central portion of the first reflective layer 40 is less than the thickness of its surrounding portions, and the upper surface 41 of the first reflective layer 40 is recessed towards the lower surface of the first reflective layer 20, forming a bowl-shaped morphology. Generally, the upper surface 41 of the first reflective layer 40 directly below the LED chip body 12 (i.e., the corresponding position of the central portion) is nearly planar, and this surface contacts the lower surface of the LED chip body 12; while in the surrounding portions outside the area directly below the LED chip body 12, the first reflective layer 40 has a convex shape (compared to a planar shape). This arrangement allows the light emitted by the LED chip 10 to be emitted more concentratedly. The upper surface of the first reflective layer 40 includes an annular surface surrounding the LED chip 10 (corresponding to the upper surface of the surrounding portion), the annular surface being a convex arc surface in the direction toward the LED chip body 12.

[0022] like Figure 1 As shown, the lower surface 42 of the first reflective layer 40 is formed as the backlight surface of the LED packaging assembly, wherein the backlight surface is flush with the lower surface of the electrode layer 14. Specifically, the distance H3 between the lower surface of the LED chip body 12 and the lower surface 42 of the first reflective layer 40 is between 30 and 150 micrometers, for example, it can be 30 micrometers, 50 micrometers, 65 micrometers, 80 micrometers, 100 micrometers, 120 micrometers, 150 micrometers, etc., while the height or thickness H2 of the central portion (also the position of minimum thickness) of the first reflective layer 40 is between 40 and 140 micrometers, for example, it can be 40 micrometers, 60 micrometers, 80 micrometers, 100 micrometers, 120 micrometers, 140 micrometers, etc., and H3-H2 is approximately 10-30 micrometers, and H3-H2 is greater than the thickness of the first metal layer 141.

[0023] The height H1 of the side surface 43 of the first reflective layer 40 is between 80 and 250 micrometers, and the height H4 of the side surface 23 of the light conversion layer 20 is between 100 and 400 micrometers. The side surface 43 of the first reflective layer 40 is approximately flush with the side surface 23 of the light conversion layer 20. Here, the side surface 23 of the light conversion layer 20 is used as the light-emitting area, and its height directly affects the light emission effect. In this application, the distance between the upper surface 11 of the LED chip body 12 and the upper surface of the light conversion layer 20 is between 50 and 200 micrometers. Verification shows that the absolute value of the difference between this distance and H4 should be between 50 and 100 micrometers. This ensures that the light from the LED chip 10 can be fully mixed and converted in the light conversion layer 20, while also ensuring that the light has a sufficient side light-emitting area to prevent excessive concentration of light in the central light-emitting area. Specifically, H1-H2 is less than or equal to 100 micrometers to ensure the cost advantage of the reflective material and prevent the package from becoming too thick.

[0024] In this application, the upper surface 11 of the LED chip body 12 is higher than the highest point of the upper surface 41 of the first reflective layer 40, and the upper surface of the light conversion layer 20 is higher than the upper surface 11 of the LED chip body 12. The lower surface of the light conversion layer 20 and the upper surface 41 of the first reflective layer 40 are conformally formed and closely fitted, and the upper surface of the light conversion layer 20 has a planar structure, which facilitates control of the emitted light shape. In some embodiments, the distance from the upper surface 11 of the LED chip body 12 to the highest point of the upper surface 41 of the first reflective layer 40 is H3, where H3 is greater than or equal to half the thickness of the LED chip body 12, and H3 needs to be greater than or equal to 50 micrometers, preferably greater than or equal to 50 micrometers, and less than or equal to 150 micrometers.

[0025] The second reflective layer 30 is formed on top of the light conversion layer 20. Its upper surface 31 is planar, while its lower surface is closely attached to the light conversion layer 20 and is also planar. The material of the second reflective layer 30 can be the same as that of the first reflective layer 40, thus forming a sandwich structure in which the light conversion layer 20 is sandwiched between the first reflective layer 40 and the second reflective layer 30. The light is emitted from four sides, that is, light is emitted from the four sides 23 of the light conversion layer 20. At this time, the side 23 of the light conversion layer 20 is sandwiched between the side 43 of the first reflective layer 40 and the side 33 of the second reflective layer 30.

[0026] Specifically, the maximum thickness of the first reflective layer 40 (i.e., the surrounding area) is greater than the thickness of the second reflective layer 30. Generally, the thickness of the second reflective layer 30 can be 50-100 micrometers. Furthermore, when viewed from above, the geometric center O of the LED chip body 12 coincides with the geometric center of the encapsulation layer to ensure the uniformity of light emission.

[0027] Figure 4This is a cross-sectional view of the LED packaging assembly according to the second embodiment of this application. The main difference is that the light conversion layer 20 includes a transparent resin layer 202 and a phosphor layer 201, wherein the transparent resin layer 202 is disposed between the phosphor layer 201 and the first reflective layer 40. Specifically, the upper surface 11 of the LED chip body 12 is flush with or lower than the upper surface of the transparent resin layer 202. This arrangement can ensure maximum light mixing effect while saving phosphor material, and at the same time ensure the uniformity of light output. Other structures and materials of the second embodiment can be found in the first embodiment, and will not be described again in this section.

[0028] The manufacturing method of the LED packaging component of this application will be described below with reference to the accompanying drawings. First, see... Figure 5 For the bare chip, it includes an LED chip body 12 and a first metal layer 141 on its electrode surface. The first metal layer 141 includes two electrodes of opposite polarity arranged at intervals, with a spacing between the two electrodes ranging from 80 to 200 micrometers. Each electrode is rectangular in shape, and the size of each electrode is approximately (50 to 200 micrometers) * (80 to 250 micrometers). See then. Figure 6 A second metal layer 142 is formed beneath the first metal layer 141 through processes such as ball bonding and reflow soldering. The second metal layer 142 is relatively thick, and can be much thicker than the first metal layer 141. The second metal layer 142 can be ellipsoidal or other suitable shapes. In this way, the LED chip 10 can be obtained.

[0029] The subsequent preparation process includes two methods, first see [link to previous text] Figures 7A-7D LED chips 10 are arranged in an array on a carrier plate 1, with electrode layers 14 in contact with the carrier plate 1. The carrier plate 1 may have a dissociation layer to facilitate subsequent separation. Then, reflective adhesive is applied between adjacent LED chips 10 using a dispensing device 60 (e.g., a dispensing head). The dispensing path for the reflective adhesive is described in [reference needed]. Figure 7B It travels along multiple intersecting paths. Due to its fluidity, the reflective adhesive flows between the LED chip body 12 and the carrier plate 1 and adheres to the lower surface of the LED chip body, and then cures to form the first reflective layer 40.

[0030] Then see Figure 7C A light conversion layer 20 and a second reflective layer 30 are sequentially stacked on the first reflective layer 40 and then cured and bonded to form a prefabricated structure.

[0031] See last. Figure 7D The prefabricated structure is cut horizontally and vertically along the cutting line C to form a single LED package component.

[0032] See another manufacturing method Figures 8A-8D First see Figure 8A A carrier plate 1 is provided, whose structure is consistent with that of 7A. See then... Figure 8B A first reflective layer 40 is formed on the carrier plate 1. The first reflective layer 40 can be shaped and can have the following properties: Figure 1 The multiple bowl-shaped morphologies shown each correspond to one LED chip 10. See next... Figure 8C Multiple LED chips 10 are arrayed on the first reflective layer 40, wherein the electrode layer 14 of the LED chip 10 is partially embedded in the first reflective layer, and then the first reflective layer 40 is cured. See next... Figure 8D The light conversion layer 20 and the second reflective layer 30 are stacked in sequence and cured. Then, they are cut horizontally and vertically along the cutting line C to be monolithized to obtain the final LED package component.

[0033] Both of the above manufacturing methods require the removal of the carrier plate 1 before cutting along the cutting line C, and... Figures 8A-8D In one embodiment, the lower surface 42 of the first reflective layer 40 also needs to be masked to expose the electrode layer 14.

[0034] In this application, a light-emitting module can be obtained by encapsulating multiple LED packaging components, such as encapsulating them in the same package or carrying them in the same carrier.

[0035] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An LED packaging assembly, comprising a packaging layer and an LED chip; wherein the packaging layer encapsulates the LED chip; The encapsulation layer consists of a first reflective layer and a light conversion layer stacked vertically from bottom to top. Along the vertical direction, the thickness of the central portion of the first reflective layer is less than the thickness of its surrounding portion, and the upper surface of the first reflective layer is recessed toward the lower surface of the first reflective layer, forming a bowl-shaped morphology. The LED chip includes an LED chip body and an electrode layer disposed on the lower surface of the LED chip body. The electrode layer includes a first metal layer and a second metal layer, wherein... The solderability of the second metal layer is greater than that of the first metal layer; The LED chip body is completely encapsulated by the light conversion layer, and the electrode layer passes through the light conversion layer and the first reflective layer sequentially from the lower surface of the LED chip body and is exposed from the lower surface of the first reflective layer. The upper surface of the LED chip body is higher than the highest point of the upper surface of the first reflective layer, and the upper surface of the light conversion layer is higher than the upper surface of the LED chip body.

2. The LED packaging assembly according to claim 1, characterized in that, The first metal layer is made of at least one of silver or gold; the second metal layer is made of tin.

3. The LED packaging assembly according to claim 1, characterized in that, The upper surface of the first reflective layer includes an annular surface surrounding the LED chip, the annular surface being a convex arc surface in the direction toward the LED chip body.

4. The LED packaging assembly according to claim 1, characterized in that, The lower surface of the LED chip body is covered by the first reflective layer.

5. The LED packaging assembly according to claim 1, characterized in that, The encapsulation layer further includes a second reflective layer disposed on the upper surface of the light conversion layer, with the side of the light conversion layer sandwiched between the side of the first reflective layer and the side of the second reflective layer.

6. The LED packaging assembly according to claim 5, characterized in that, The distance between the upper surface of the LED chip body and the highest point of the upper surface of the first reflective layer is greater than or equal to half the thickness of the LED chip body, and / or the upper surface of the light conversion layer is approximately planar, and the distance between the lower surface of the second reflective layer and the upper surface of the LED chip body is greater than or equal to 120 micrometers.

7. The LED packaging assembly according to claim 1, characterized in that, The minimum thickness of the first reflective layer is H2, and the maximum thickness of the first reflective layer is H1, wherein H1-H2 is less than or equal to 100 micrometers.

8. The LED packaging assembly according to claim 1, characterized in that, The light conversion layer includes a transparent resin layer and a fluorescent layer, wherein the transparent resin layer is disposed between the fluorescent layer and the first reflective layer.

9. The LED packaging assembly according to claim 8, characterized in that, The upper surface of the LED chip body is flush with or lower than the upper surface of the transparent resin layer.

10. A light-emitting module comprising a plurality of LED encapsulation components as described in any one of claims 1-9, wherein the plurality of LED encapsulation components are carried on the same carrier or encapsulated in the same encapsulation body.

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