LED packaging structure
By setting white adhesive walls and lens structures around the flip chip, the problems of inability to identify polarity and non-concentration of light color in CSP packaging are solved, improving the brightness and light-emitting angle adjustment capability of LED products.
Patent Information
- Application Number
- CN202422860702.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-22
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-11-22
AI Technical Summary
The existing CSP packaging method cannot identify the polarity of LED products from the front of a single packaged LED, and the light color is not concentrated, resulting in insufficient brightness.
White adhesive walls are placed around the flip chip, and a lens is placed above the phosphor layer. The white adhesive walls reflect light to the lens and the lens optimizes the optical path to adjust the emission angle.
It achieves an 8% to 10% increase in the brightness of LED products, and can identify the polarity from the front, with the light emission angle adjustable to be concentrated or diffused.
Smart Images
Figure CN223528435U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor packaging technology, and in particular to an LED packaging structure. Background Technology
[0002] In the field of light-emitting diode (LED) packaging, CSP (Chip Scale Package) is an integrated circuit packaging technology that encapsulates chips in a package close to chip size. Also known as chip-scale packaging, it aims to achieve the smallest possible size and highest integration. CSP packaging is of great significance in the microelectronics field and is widely used in mobile devices, communication equipment, consumer electronics, and automotive electronics.
[0003] To achieve single-sided light emission, such as Figure 1 As shown, the existing CSP packaging method involves fixing a flip chip 1 onto a phosphor layer 3 using die-attach adhesive, baking it to set, and then filling the area around the flip chip 1 with white glue 2. After the white glue 2 cures, the wafer is cut to obtain individual CSP chips. The surface of this CSP packaging solution is a phosphor film, making it impossible to identify the polarity of the LED product from the front of the packaged chip. Furthermore, this CSP packaging solution results in a large LED emission angle, leading to a lack of concentrated light color.
[0004] Therefore, in CSP LED packaging, how to improve the brightness of LED products while ensuring packaging performance has become one of the technical challenges that urgently needs to be solved by those skilled in the art. Utility Model Content
[0005] To address the shortcomings of the existing CSP LED packaging structure, this invention provides an LED packaging structure that can adjust the light emission angle to concentrate the light color and improve the brightness of the product.
[0006] To achieve at least one or more of the aforementioned advantages, this utility model provides an LED packaging structure, comprising at least: a flip-chip LED chip having a first surface and a second surface disposed opposite to each other; a phosphor layer disposed above the first surface of the flip-chip LED chip, the phosphor layer covering the first surface of the flip-chip LED chip; a white adhesive wall disposed on the peripheral side of the flip-chip LED chip and the phosphor layer, the thickness of the white adhesive wall being greater than or equal to the sum of the thicknesses of the flip-chip LED chip and the phosphor layer; and a lens disposed on the surface of the phosphor layer away from the flip-chip LED chip; wherein the lens completely covers the surface of the phosphor layer away from the flip-chip LED chip, and when viewed from above the first surface of the flip-chip LED chip, the projection surface of the lens is located within the projection surface of the white adhesive wall.
[0007] In some embodiments, the size of the core grain of the flip-chip LED chip ranges from 35mil*35mil to 45mil*45mil, and the thickness of the flip-chip LED chip ranges from 150 microns to 300 microns.
[0008] In some embodiments, the size of the fluorescent layer ranges from 38mil*38mil to 48mil*48mil as viewed from above the first surface of the flip-chip LED chip.
[0009] In some embodiments, the thickness of the lens ranges from 100 microns to 300 microns, and the diameter of the lens ranges from 1000 microns to 1500 microns as viewed from above the first surface of the flip-chip LED chip.
[0010] In some embodiments, the refractive index of the fluorescent layer is greater than the refractive index of the lens.
[0011] In some embodiments, the refractive index of the fluorescent layer ranges from 1.44 to 1.6, and the refractive index of the lens ranges from 1.35 to 1.44.
[0012] In some embodiments, the fluorescent layer is a preformed fluorescent gel sheet or a fluorescent film.
[0013] In some embodiments, the white glue wall is formed by introducing transparent silicone glue through glue injection and then curing.
[0014] In some embodiments, the side surface of the fluorescent layer and the white glue wall away from the first surface of the flip-chip LED chip are located in the same plane.
[0015] In some embodiments, an electrode is arranged below the second surface of the flip-chip LED chip, and the flip-chip LED chip is electrically connected to the PCB board through the electrode.
[0016] The LED packaging structure provided by the utility model has at least the following advantages compared with the prior art CSP LED packaging structure.
[0017] 1. In the LED packaging structure, the white glue wall is arranged around the flip-chip LED chip, so that the light emitted around is reflected to the lens and emitted, the brightness of the LED product device is improved, and the polarity of the product can be identified through the front surface.
[0018] 2. In the LED packaging structure, the lens structure is arranged above the light emitting surface of the flip-chip LED chip, the optical path of the light emitted by the flip-chip LED chip is optimized, the light emitting angle of the LED product is adjusted, and the light emitting angle of the LED product is concentrated or divergent according to actual needs. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.
[0020] Figure 1 A schematic diagram of a prior flip chip packaging structure is shown in the figure;
[0021] Figure 2 A schematic diagram of a sectional structure of a first embodiment of the LED packaging structure in the present application is shown in the figure;
[0022] Figure 3 A schematic diagram of a top view structure of an embodiment of the LED packaging structure in the present application is shown in the figure;
[0023] Figure 4 A schematic diagram of a sectional structure of a second embodiment of the LED packaging structure in the present application is shown in the figure;
[0024] Figure 5 A schematic diagram of a sectional structure of a second embodiment of the LED packaging structure in the present application is shown in the figure; Figure 2 A schematic diagram of light emission of the LED packaging structure shown in the figure is shown in the figure;
[0025] Figure 6 A schematic diagram of light emission of the LED packaging structure shown in the figure is shown in the figure; Figure 4 A schematic diagram of light emission of the LED packaging structure shown in the figure is shown in the figure;
[0026] Figure 7 A schematic diagram of the LED packaging structure in the present application with a light emission angle of 90° is shown in the figure; and
[0027] Figure 8 A schematic diagram of the LED packaging structure in the present application with a light emission angle of 130°-140° is shown in the figure.
[0028] The figure shows that 1 is a flip chip, 2 is white glue, 3 is a fluorescent layer, 100 is an LED packaging structure, 10 is a flip LED chip, 20 is a fluorescent layer, 30 is a white glue wall, 40 is a lens, and H1 / H2 is thickness. DETAILED DESCRIPTION
[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.
[0030] In the description of the utility model, need understanding is, the orientation or position relation that the terms "center", "transverse", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" indicate is based on the orientation or position relation shown in the drawing, is only for the convenience of describing the utility model and simplifying the description, and is not indicating or implying that the device or component indicated must have a particular orientation, or be constructed and operated in a particular orientation, therefore can not be understood as a limitation on the utility model. In addition, the terms "first", "second" are only for the purpose of description, and can not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included one or more features. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, the term "includes" and any variation thereof means "at least includes".
[0031] In the description of the utility model, it should be explained that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally formed connection, it can be mechanical connection, or electrical connection, it can be directly connected, or indirectly connected through intermediate medium, it can be the communication inside two components. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0032] The terms used herein are merely used to describe specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular form "a", "an", and "the" used herein is also intended to include the plural. It should also be understood that the terms "include" and / or "contain" used herein specify the existence of the stated features, integers, steps, operations, units and / or components, without excluding the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.
[0033] Please compare Figure 1 Refer to Figure 2 And Figure 3 , Figure 2 is the cross-sectional structure schematic diagram of the first embodiment of LED packaging structure in the utility model, Figure 3The utility model discloses a top view structure schematic diagram of one embodiment of LED packaging structure. In order to achieve at least one of the advantages or other advantages, an embodiment of the utility model provides a LED packaging structure 100, at least includes: flip chip LED chip 10, the fluorescent layer 20 of being located above flip chip LED chip 10, the white glue wall 30 of being located at the peripheral side of flip chip LED chip 10 and fluorescent layer 20, and the lens 40 of being located above fluorescent layer 20. It needs to be explained that generally on wafer piece one time is encapsulated to LED chip array on wafer piece, and then is cut into single LED chip. Embodiment and drawing are shown and explained with the packaging structure of single LED chip.
[0034] Flip chip LED chip 10 has oppositely arranged first surface 10a and second surface 10b. Figure 2 As shown, taking flip chip LED chip 10 as the reference, along the vertical direction, the first surface 10a of flip chip LED chip 10 is defined as upper, and the second surface 10b of flip chip LED chip 10 is defined as lower. The structure of flip chip LED chip 10 is not the key content of the application, and is not described here. The chip size range of flip chip LED chip 10 is 35mil*35mil to 45mil*45mil. The thickness range of flip chip LED chip 10 is 150 microns to 300 microns. Figure 2 Referring to Figure 3 Optionally, the chip of flip chip LED chip 10 can be cuboid or cube. From the upper side of the first surface 10a of flip chip LED chip 10, the cross section of flip chip LED chip 10 is quadrilateral structure, and the length-width size range of the quadrilateral is 35mil*35mil to 45mil*45mil. Optionally, flip chip LED chip 10 is a high-power LED chip. The LED packaging structure 100 can be used for device packaging of high-voltage LED products.
[0035] The second surface 10b of flip chip LED chip 10 is provided with an electrode (not shown in the figure), and flip chip LED chip 10 is electrically connected with the PCB board through the electrode.
[0036] The fluorescent layer 20 is arranged above the first surface 10a of flip chip LED chip 10. The fluorescent layer 20 covers the first surface 10a of flip chip LED chip 10. The fluorescent layer 20 does not cover the peripheral side of flip chip LED chip 10. Flip chip LED chip 10 is cuboid or square, and the peripheral side refers to the four sides between the first surface 10a and the second surface 10b.
[0037] The size range of the fluorescent layer 20 is 38mil*38mil to 48mil*48mil. In combination with Figure 2 Referring to Figure 3Optionally, as viewed from above the first surface 10a of the flip-chip LED chip 10, the cross section of the fluorescent layer 20 is in a quadrilateral structure, and the length and width of the quadrilateral ranges from 38 mil*38 mil to 48 mil*48 mil. The cross section of the fluorescent layer 20 is slightly larger than the cross section of the flip-chip LED chip 10, and can form full coverage on the first surface 10a of the flip-chip LED chip 10, thereby ensuring that the first surface 10a of the flip-chip LED chip 10 can achieve full light emission. Furthermore, the cross section of the fluorescent layer 20 is slightly larger than the cross section of the flip-chip LED chip 10, which can prevent the flip-chip LED chip 10 from being offset to cause blue light leakage, thereby ensuring the uniformity of the light color of the LED package structure 100.
[0038] Optionally, the fluorescent layer 20 is a preformed fluorescent gel sheet or fluorescent film. The fluorescent gel sheet or fluorescent film can be preformed according to the required size, and then attached to the first surface 10a of the flip-chip LED chip 10. The fluorescent layer 20 can adjust the light color of the flip-chip LED chip 10, and can also effectively prevent heat transfer of the flip-chip LED chip 10 to improve the luminous efficiency.
[0039] The white glue wall 30 is arranged on the side surface of the flip-chip LED chip 10 and the fluorescent layer 20, and the white glue wall 30 does not cover the top of the first surface 10a of the flip-chip LED chip 10. Optionally, the material of the white glue wall 30 is high-reflective white glue, which reflects the light emitted from the side surface of the flip-chip LED chip 10 to the first surface 10a of the flip-chip LED chip 10. The white glue wall 30 can be introduced by injection of transparent silicone glue, and then solidified to form.
[0040] Optionally, the thickness of the white glue wall 30 is greater than or equal to the sum of the thicknesses of the flip-chip LED chip 10 and the fluorescent layer 20, so as to completely block the non-light-emitting surface around the flip-chip LED chip 10, and make the light emitted as much as possible from the preset light-emitting surface. The side surface of the fluorescent layer 20 and the white glue wall 30 away from the first surface 10a of the flip-chip LED chip 10 is in the same plane. As shown in Figure 2 the upper surface of the fluorescent layer 20 and the upper surface (also referred to as the top surface) of the white glue wall 30 are in the same plane away from the first surface 10a of the flip-chip LED chip 10. In this way, the contact surface of the lens 40 with the fluorescent layer 20 and the white glue wall 30 is consistent, thereby improving the uniformity of the light emission of the LED package structure 100.
[0041] The lens 40 is arranged on the surface of the fluorescent layer 20 away from the flip-chip LED chip 10 and is located above the fluorescent layer 20. According to different actual requirements of the LED packaging structure 100, the lens 40 can have different angles and diameters. Alternatively, the lens 40 can be formed by molding. The lens 40 is a silicon lens. The silicon lens is easy to manufacture and has good airtightness, thermal stability and relatively high power. In addition, the silicon lens can be used in different molds to form silicon lenses with different requirements at a relatively low cost. Compared with the silicon lens, other materials (such as epoxy resin) have poor stability and low power.
[0042] The lens 40 completely covers the surface of the fluorescent layer 20 away from the flip-chip LED chip 10. When viewed from above the first surface 10a of the flip-chip LED chip 10, the projection surface of the lens 40 is located in the projection surface of the white glue wall 30. At this time, the gap between the lens 40 and the white glue wall 30 can be used as a space for laser coding. For example, the polarity during coding of the LED product on the white glue wall 30 by laser can be marked in the space, so that the polarity of the LED product device can be quickly identified by the coding on the white glue wall 30 after the flip-chip LED chip 10 is packaged.
[0043] As shown in Figure 2 Alternatively, the lens 40 has a spherical shape, and the surface of the lens 40 away from the fluorescent layer 20 is an arc surface. The thickness of the lens 40 ranges from 100 microns to 300 microns. The diameter of the lens 40 ranges from 1000 microns to 1500 microns. As shown in Figure 3 Alternatively, when viewed from above the first surface 10a of the flip-chip LED chip 10, the cross section of the lens 40 is circular, and the diameter of the circle ranges from 1000 microns to 1500 microns. In this way, the diameter of the lens 40 is slightly larger than the length (the longest side of the chip) of the flip-chip LED chip 10, which facilitates the lens 40 to absorb the light path of the flip-chip LED chip 10, thereby emitting more light to the light-emitting surface of the lens 40 (the side of the lens 40 away from the flip-chip LED chip 10 in the figure), improving the light-emitting efficiency and brightness.
[0044] Optionally, the refractive index of the fluorescent layer 20 is greater than the refractive index of the lens 40. When the light emitted from the first surface 10a of the inverted LED chip 10 is emitted from the fluorescent layer 20 to the lens, the change from the high refractive index layer to the low refractive index layer can reduce the total reflection of the light in the fluorescent layer 20 and the lens 40, increase the light emission amount of the arc-shaped light emission surface in the lens 40, and improve the light emission brightness of the LED. In some embodiments, the refractive index of the fluorescent layer 20 is 1.44-1.6, and the refractive index of the lens 40 is 1.35-1.44. When the refractive indices of the fluorescent layer 20 and the lens 40 are 1.44 respectively, the fluorescent layer 20 and the lens 40 can be regarded as the boundary line.
[0045] In combination Figure 3 Referring to Figure 4 , Figure 4 is a sectional structure schematic view of the second embodiment of the LED packaging structure in the utility model. Figure 4 With Figure 3 the same, the differences are described as follows. The thickness of the lens 40 ranges from 100 microns to 300 microns. Figure 3 In the first embodiment, the thickness of the lens 40 is H1, Figure 4 In the second embodiment, the thickness of the lens 40 is H2, and H2 is greater than H1. The thickness of the lens 40 is highly related to the light emission angle of the LED packaging structure 100. In combination Figure 3 , Figure 4 Referring to Figure 5 and Figure 6 , Figure 3 In the first embodiment, the thickness H1 of the lens 40 is small (low), and the light emitted from the arc-shaped surface of the lens 40 is divergent, and the light emission angle is about 120°-160°; Figure 4 In the second embodiment, the thickness H2 of the lens 40 is large (high), and the light emitted from the arc-shaped surface of the lens 40 is concentrated, and the light emission angle is about 60°-120°.
[0046] Compared with the existing CSP LED packaging structure, the LED packaging structure can be applied to the packaging field of high concentration and high directivity of CSP LED, and has at least the following advantages: (1) in the LED packaging structure, the white glue wall is arranged around the flip-chip LED chip, the light around the white glue wall is reflected to the lens, the brightness of the LED product device can be improved, and the polarity of the product can be identified through the front face. Through experimental comparison, compared with the existing product, the brightness of the LED product can be improved by 8% to 10% by using the LED packaging structure in the application. (2) in the LED packaging structure, the lens structure is arranged above the light emitting surface of the flip-chip LED chip, the optical path of the light emitted by the flip-chip LED chip can be optimized. The light emitted by the flip-chip LED chip is transmitted from the high-refractive fluorescent layer to the low-refractive lens, the proportion of total reflection of the emitted light in the packaging structure can be reduced, the transmission proportion can be increased, and the luminous brightness of the LED after packaging can be improved. At the same time, the light emitting angle of the LED product can also be adjusted, so that the light emitting angle of the LED product is concentrated or divergent according to actual needs.
[0047] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the utility model, but not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.
Claims
1. An LED package structure, characterized in that, At least comprising: a flip-chip LED chip having a first surface and a second surface arranged oppositely; a fluorescent layer arranged above the first surface of the flip-chip LED chip, the fluorescent layer covering the first surface of the flip-chip LED chip; a white glue wall arranged at the side of the flip-chip LED chip and the fluorescent layer, the thickness of the white glue wall being greater than or equal to the sum of the thicknesses of the flip-chip LED chip and the fluorescent layer; a lens arranged on the surface of the fluorescent layer away from the flip-chip LED chip; wherein the lens completely covers the surface of the fluorescent layer away from the flip-chip LED chip, and the projection plane of the lens is located in the projection plane of the white glue wall when viewed from above the first surface of the flip-chip LED chip.
2. The LED package structure of claim 1, wherein, The size of the flip-chip LED chip ranges from 35mil*35mil to 45mil*45mil, and the thickness of the flip-chip LED chip ranges from 150 microns to 300 microns.
3. The LED package structure of claim 1, wherein, The size of the fluorescent layer ranges from 38mil*38mil to 48mil*48mil when viewed from above the first surface of the flip-chip LED chip.
4. The LED package structure of claim 1, wherein, The thickness of the lens ranges from 100 microns to 300 microns, and the diameter of the lens ranges from 1000 microns to 1500 microns when viewed from above the first surface of the flip-chip LED chip.
5. The LED package structure of claim 1, wherein, The refractive index of the fluorescent layer is greater than that of the lens.
6. The LED package structure of claim 1, wherein, The refractive index of the fluorescent layer is 1.44-1.6, and the refractive index of the lens is 1.35-1.
44.
7. The LED package structure of claim 1, wherein, The fluorescent layer is a prefabricated fluorescent glue sheet or fluorescent film.
8. The LED package structure of claim 1, wherein, The white glue wall is formed by introducing transparent silicone glue and then curing.
9. The LED package structure of claim 1, wherein, The side surface of the fluorescent layer and the white glue wall away from the first surface of the flip-chip LED chip is located in the same plane.
10. The LED package structure of claim 1, wherein, An electrode is arranged below the second surface of the flip-chip LED chip, and the flip-chip LED chip is electrically connected to a PCB board through the electrode.