High-voltage LED packaging structure and display screen

Abstract

The invention relates to the field of chip packaging, in particular to a high-voltage LED packaging structure and a display screen. The high-voltage LED packaging structure comprises a bonding pad assembly, a chip assembly and a packaging layer. The chip assembly comprises a plurality of LED chips, and the plurality of LED chips form a series branch; the bottoms of the plurality of LED chips are connected with the bonding pad assembly; the packaging layer wraps the bonding pad assembly and the plurality of LED chips and fills gaps between the bonding pad assembly and the plurality of LED chips, and the packaging layer exposes light-emitting surfaces at the tops of the LED chips and pin surfaces of the bonding pad assembly. The bottoms of the LED chips connected in series are directly connected with the bonding pad assembly, and the bonding pad assembly is used for replacing a high-cost ceramic substrate, so that the cost is reduced. The flow guide area of the bonding pad assembly is large, the paster yield of the LED chip is improved, and the heat dissipation effect is good. And the packaging layer supports and fixes the LED chip and the bonding pad assembly, so that physical protection and insulation protection functions are provided.

Description

Technical Field

[0001] The present application relates to the field of chip packaging, and in particular, to a high-voltage LED packaging structure and a display screen. Background Art

[0002] LED packaging refers to the packaging of light-emitting chips, aiming to provide sufficient protection for the light-emitting chips.

[0003] Currently, the high-power LED packaging structure usually mounts the light-emitting chips on a ceramic substrate, and circuit design is carried out on the ceramic substrate to achieve electrical connection to the light-emitting chips. The existing structure has problems such as large volume, thick thickness, and high production cost. Summary of the Invention

[0004] The purpose of the present application is to provide a high-voltage LED packaging structure and a display screen, which are used to solve the problems of large volume, thick thickness, and high production cost existing in the existing high-power LED packaging structure.

[0005] The present application provides a high-voltage LED packaging structure, including a pad assembly, a chip assembly, and a packaging layer; The chip assembly includes a plurality of LED chips, and the plurality of LED chips form a series branch; the bottoms of the plurality of LED chips are connected to the pad assembly; The packaging layer wraps the pad assembly and the plurality of LED chips, fills the gap between the pad assembly and the plurality of LED chips, and the packaging layer exposes the light-emitting surface at the top of the LED chips and the pin surface of the pad assembly.

[0006] In the above technical solution, further, the pad assembly includes a first-polarity pad and a second-polarity pad, and the first-polarity pad and the second-polarity pad are arranged at intervals; The first-polarity end of the series branch is connected to the first-polarity pad, and the second-polarity end of the series branch is connected to the second-polarity pad; In the perspective of facing the light-emitting surface of the chip assembly, the area ratio of the pad assembly to the packaging layer is: 60% - 98%.

[0007] In the above technical solution, further, the pad assembly includes a connection pad; On the series branch, a connection pad is arranged between two adjacent LED chips; The connection pad is arranged at intervals from the first-polarity pad and the second-polarity pad; and when the number of connection pads is multiple, the adjacent connection pads are arranged at intervals.

[0008] In the above technical solution, further, a plurality of the LED chips form a plurality of series branches, and the plurality of series branches are connected in parallel between the first polarity pad and the second polarity pad.

[0009] In the above technical solution, further, the plurality of series branches are arranged at intervals in a first direction; On the series branch, a plurality of the LED chips are arranged at intervals in a second direction; The first direction is perpendicular to the second direction.

[0010] In the above technical solution, further, the connection pads, the first polarity pad, and the second polarity pad are arranged to form a rectangular outer contour.

[0011] In the above technical solution, further, the LED chip includes a light-emitting portion, a connection portion, and a reflective bowl cup; The connection portion includes a first electrode and a second electrode with opposite polarities. The first electrode and the second electrode are connected to the light-emitting portion, and the first electrode and the second electrode are connected to the pad assembly; The reflective bowl cup surrounds the circumferential direction of the light-emitting portion to reflect the light emitted from the side portion of the light-emitting portion toward the top direction.

[0012] In the above technical solution, further, the encapsulation layer is a high-reflectivity white glue layer.

[0013] In the above technical solution, further, it further includes a fluorescent layer; the top surface of the encapsulation layer is flush with the light-emitting surface of the chip assembly, and the fluorescent layer covers the top surface of the encapsulation layer and the light-emitting surface of the chip assembly.

[0014] This application also provides a display screen, including the high-voltage LED packaging structure described in the above solution.

[0015] Compared with the prior art, the beneficial effects of this application are as follows: The high-voltage LED packaging structure provided by this application directly connects the bottoms of a plurality of serially connected LED chips to the pad assembly, and uses the pad assembly to replace the high-cost ceramic substrate to reduce costs. The pad assembly has a large current-carrying area, which can improve the chip mounting yield of the LED chips. Even if the overall heat generation of the plurality of LED chips is large, the pad assembly has a good heat dissipation effect. Moreover, the encapsulation layer supports and fixes the LED chips and the pad assembly, providing physical protection and insulation protection functions.

[0016] This application also provides a display screen, including the high-voltage LED packaging structure described in the above solution. Based on the above analysis, it can be seen that the display screen also has the above beneficial effects, which will not be elaborated here. Description of the Drawings

[0017] To more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is the first structural schematic diagram of the high-voltage LED packaging structure provided by the present application; Figure 2 It is the second structural schematic diagram of the high-voltage LED packaging structure provided by the present application; Figure 3 It is the third structural schematic diagram of the high-voltage LED packaging structure provided by the present application; Figure 4 It is the fourth structural schematic diagram of the high-voltage LED packaging structure provided by the present application; Figure 5 It is the fifth structural schematic diagram of the high-voltage LED packaging structure provided by the present application; Figure 6 It is the sixth structural schematic diagram of the high-voltage LED packaging structure provided by the present application; Figure 7 It is the seventh structural schematic diagram of the high-voltage LED packaging structure provided by the present application.

[0019] In the figure: 101 - pad assembly; 102 - encapsulation layer; 103 - LED chip; 104 - first-polarity pad; 105 - second-polarity pad; 106 - connection pad; 107 - light-emitting part; 108 - connection part; 109 - reflecting bowl cup; 110 - first electrode; 111 - second electrode; 112 - fluorescent layer. Specific Embodiments

[0020] The following will clearly and completely describe the technical solutions of the present application in conjunction with the drawings. Obviously, the described embodiments are some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0021] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0022] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0023] Embodiment 1 Referring to Figures 1 to 7 As shown, the high-voltage LED packaging structure provided by the present application includes a pad assembly 101, a chip assembly, and a packaging layer 102.

[0024] The chip assembly includes a plurality of LED chips 103. In order to reduce the overall thickness of the device, the structure of the ceramic substrate is cancelled in the present application, and the bottoms of the plurality of LED chips 103 are directly connected to the pad assembly 101. The pad assembly 101 is used to replace the high-cost ceramic substrate, thereby reducing the cost. When the high-voltage LED packaging structure is placed horizontally, the projected area of the pad assembly 101 in the horizontal direction accounts for 60% - 98% of the projected area of the entire LED packaging structure in the horizontal direction. The outer contour of the pad assembly is similar to the outer contour of the packaging structure to support the chip assembly, and the current guiding area of the pad assembly 101 is large, which can improve the placement yield of the LED chips 103. Even if the overall heat generation of the plurality of LED chips 103 is large, the heat dissipation effect of the pad assembly 101 is also good.

[0025] Specifically, multiple LED chips 103 form a series branch, which can significantly increase the operating voltage of the entire LED packaging structure. The multiple LED chips 103 can be composed of chips emitting the same color or chips emitting different colors. However, in the series high-voltage structure, it is preferred that the multiple LED chips have the same emission color. Compared with the single-chip solution, the series structure is applied with a higher voltage under the same current, thus being suitable for application scenarios that require high-voltage drive. Integrating multiple LED chips 103 in one package can effectively reduce the number and complexity of external connection lines, thereby making the packaging structure more compact and suitable for the product requirements of miniaturization and lightweight.

[0026] Furthermore, the encapsulation layer 102 wraps the pad assembly 101 and multiple LED chips 103, fills the gap between the pad assembly 101 and multiple LED chips 103, and exposes the light-emitting surface at the top of the LED chip 103 and the pin surface of the pad assembly 101, so that the setting of the encapsulation layer 102 does not affect the light emission of the chip assembly and the electrical connection between the pad assembly 101 and external components. On the one hand, the encapsulation layer 102 can provide physical protection and insulation for the pad assembly 101 and multiple LED chips 103, preventing damage to the chips and pad assembly 101 from the external environment (such as moisture, dust, mechanical stress, etc.), and extending the service life of the LED. On the other hand, the encapsulation layer 102 fills all the gaps, can support and fix the pad assembly 101 and multiple LED chips 103, enhances the mechanical stability of the entire packaging structure, reduces the risk of internal connection failure caused by vibration or impact, and improves the reliability and durability of the product.

[0027] In an alternative embodiment of this example, specifically, the pad assembly 101 includes a first-polarity pad 104 and a second-polarity pad 105. The first-polarity pad 104 and the second-polarity pad 105 are respectively connected to the positive and negative electrodes of the power supply. The first-polarity pad 104 and the second-polarity pad 105 are arranged at intervals to ensure electrical isolation between the two and avoid the risk of short circuit. The first-polarity end of the series branch is connected to the first-polarity pad 104, and the second-polarity end of the series branch is connected to the second-polarity pad 105 to energize the multiple LED chips 103 in the series branch.

[0028] In an alternative embodiment of this example, the pad assembly 101 includes a connection pad 106. On the series branch, a connection pad 106 is arranged between two adjacent LED chips 103. The multiple LED chips 103 can be electrically connected in sequence through the connection pad 106. The connection pad 106 has a large current-carrying area, and the connection pad 106 can support the multiple LED chips 103 on the series branch, improving the chip mounting yield of the LED chips 103. The setting of the connection pad 106 can also increase the heat dissipation area and has a better heat dissipation effect.

[0029] It should be noted that the number of connection pads 106 is set according to the number of LED chips 103. The number of connection pads 106 set on the series branch is one less than the number of LED chips 103 set on the series branch. As Figures 5 to 7 shown, when two LED chips 103 are set on a series branch, one connection pad 106 is set on the series branch; when three LED chips 103 are set on a series branch, two connection pads 106 are set on the series branch; when four LED chips 103 are set on a series branch, three connection pads 106 are set on the series branch.

[0030] Furthermore, the connection pads 106 are arranged at intervals between the first-polarity pads 104 and the second-polarity pads 105; and when the number of connection pads 106 is multiple, the adjacent connection pads 106 are arranged at intervals, so as to ensure the electrical isolation between multiple pads and avoid the risk of short circuit of the LED chips 103.

[0031] In an alternative embodiment of this example, multiple LED chips 103 form multiple series branches, and the multiple series branches are connected in parallel between the first-polarity pads 104 and the second-polarity pads 105.

[0032] In this embodiment, Figures 5 to 7 the structures shown are all two series branches, and multiple series branches connected in parallel such as three or four can also be set according to actual requirements. The series branches are connected in parallel, so that the total current can be dispersed into each branch, and the current is evenly distributed in each branch, avoiding the problem of local overheating caused by uneven current, and improving the stability and reliability of the entire LED packaging structure. Even if a monochromatic chip in a certain series branch fails, the other series branches can still work normally, improving the fault tolerance and reliability of the system, and reducing the risk of the entire system failure caused by a single-point failure.

[0033] In an alternative embodiment of this example, the multiple series branches are arranged at intervals along the first direction; on the series branch, the multiple LED chips 103 are arranged at intervals along the second direction; the first direction is perpendicular to the second direction.

[0034] In this embodiment, for Figures 5 to 7 the structure shown, the first direction is the left-right direction, and the second direction is the up-down direction. The multiple LED chips 103 shown in the figure are arranged in a rectangular array, so that the overall high-voltage LED packaging structure is rectangular, which can achieve a more efficient and regular layout in a limited space, reduce the manufacturing cost, and improve the consistency of product quality; and the regular arrangement form makes the light-emitting point distribution of the high-voltage LED packaging structure more reasonable, ensuring more uniform and clear image output.

[0035] In an alternative solution of this embodiment, as Figures 5 to 7 shown, the connection pad 106, the first polarity pad 104, and the second polarity pad 105 are arranged to form a rectangular outer contour. Correspondingly, the overall high-voltage LED package structure after encapsulation is rectangular. The first polarity pad 104 and the second polarity pad 105 at both ends have a longer length so that multiple parallel branches can be connected to the first polarity pad 104 and the second polarity pad 105. The width direction of the connection pad 106 is the length direction of the first polarity pad 104 and the second polarity pad 105, and the length direction of the connection pad 106 is the length direction of the parallel branches. The two LED chips 103 connected to the same connection pad 106 are located at both ends of the length direction of the connection pad 106, so that there is a gap between the two LED chips 103 to avoid short circuit, and the connection area between the LED chip 103 and the connection pad 106 is larger, making their connection more reliable.

[0036] Embodiment Two The high-voltage LED package structure in this Embodiment Two is an improvement based on the above embodiment, and the technical content disclosed in the above embodiment will not be described repeatedly. The content disclosed in the above embodiment also belongs to the content disclosed in this Embodiment Two.

[0037] In an alternative solution of this embodiment, referring to Figure 3 and Figure 4 shown, the LED chip 103 includes a light-emitting portion 107 and a connection portion 108; the connection portion 108 includes a first electrode 110 and a second electrode 111 with opposite polarities. The first electrode 110 and the second electrode 111 are specifically copper electrodes. The first electrode 110, the second electrode 111 are connected to the light-emitting portion 107, and the first electrode 110, the second electrode 111 are connected to the pad assembly 101. In order to improve the conductive effect at the connection, the first electrode 110 and the second electrode 111 are provided with a Ti layer, a Ni layer or other metal layers.

[0038] As Figure 4 shown, the LED chip 103 further includes a reflecting bowl 109, which is specifically transparent silica gel and surrounds the circumference of the light-emitting portion 107. The light emitted from the side of the light-emitting portion 107 is reflected by the reflecting bowl 109 and can be emitted from the top direction of the LED chip 103, thereby improving the brightness of the entire package structure.

[0039] In an alternative solution of this embodiment, the encapsulation layer 102 is a high-reflectivity white glue layer. The light emitted from the side of the light-emitting portion 107 of multiple LED chips 103 is reflected by the encapsulation layer 102 and can be emitted from the top direction, improving the overall brightness of the high-voltage LED package structure.

[0040] In an alternative solution of this embodiment, as Figures 1 to 4As shown, the high-voltage LED packaging structure further includes a phosphor layer 112; the top surface of the encapsulation layer 102 is flush with the light-emitting surface of the chip component, and the phosphor layer 112 covers the top surface of the encapsulation layer 102 and the light-emitting surface of the chip component.

[0041] In this embodiment, the phosphor layer 112 covers the chip component and the surrounding encapsulation layer 102, which can ensure that the light emitted by the chip component can pass through the phosphor layer 112, and the light is not likely to leak out. The phosphor layer 112 is formed by doping a transparent glue with phosphors and particles such as SiO2 and TiO2. The light emitted by the monochromatic chip is wavelength-converted after passing through the phosphor layer 112, and light of another color can be emitted. Specifically, the monochromatic chip is a blue-light chip, and the phosphor layer 112 can convert the blue light emitted by the monochromatic chip into white light.

[0042] Embodiment III Embodiment III of the present application provides a display screen, which includes the high-voltage LED packaging structure of any of the above embodiments. Therefore, it has all the beneficial technical effects of the high-voltage LED packaging structure of any of the above embodiments, and will not be elaborated herein.

[0043] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some 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 present application. In addition, those skilled in the art can understand that although some embodiments herein include certain features included in other embodiments but not other features, the combination of the features of different embodiments means that it is within the scope of the present application and forms different embodiments.

Claims

1. A high-voltage LED packaging structure, characterized in that It includes a pad assembly, a chip assembly and a packaging layer; The chip assembly includes a plurality of LED chips, and the plurality of LED chips form a series branch; the bottoms of the plurality of LED chips are connected to the pad assembly; The packaging layer wraps the pad assembly and the plurality of LED chips, fills the gap between the pad assembly and the plurality of LED chips, and the packaging layer exposes the light-emitting surface at the top of the LED chips and the pin surface of the pad assembly.

2. The high-voltage LED packaging structure according to claim 1, wherein The pad assembly includes a first-polarity pad and a second-polarity pad, and the first-polarity pad and the second-polarity pad are arranged at intervals; The first-polarity end of the series branch is connected to the first-polarity pad, and the second-polarity end of the series branch is connected to the second-polarity pad; From the perspective facing the light-emitting surface of the chip assembly, the area ratio of the pad assembly to the packaging layer is: 60% - 98%.

3. The high-voltage LED packaging structure according to claim 2, characterized in that, The pad assembly includes connection pads; On the series branch, connection pads are arranged between two adjacent LED chips; The connection pads are arranged at intervals from the first-polarity pad and the second-polarity pad; and when the number of connection pads is multiple, adjacent connection pads are arranged at intervals.

4. The high-voltage LED packaging structure according to claim 2 or 3, characterized in that, The plurality of LED chips form a plurality of series branches, and the plurality of series branches are arranged in parallel between the first-polarity pad and the second-polarity pad.

5. The high-voltage LED packaging structure according to claim 4, characterized in that, The plurality of series branches are arranged at intervals in a first direction; On the series branch, the plurality of LED chips are arranged at intervals in a second direction; The first direction is perpendicular to the second direction.

6. The high-voltage LED packaging structure according to claim 3, wherein, The connection pads, the first-polarity pad and the second-polarity pad are arranged to form a rectangular outer contour.

7. The high-voltage LED packaging structure according to claim 1, characterized in that The LED chip includes a light-emitting part, a connection part and a reflecting bowl; The connection part includes a first electrode and a second electrode with opposite polarities, the first electrode and the second electrode are connected to the light-emitting part, and the first electrode and the second electrode are connected to the pad assembly; The reflecting bowl surrounds the circumference of the light-emitting part to reflect the light emitted from the side of the light-emitting part towards the top direction.

8. The high-voltage LED packaging structure according to claim 1, wherein, The packaging layer is a white glue layer with a high reflectivity.

9. The high-voltage LED packaging structure according to claim 1, wherein, It further includes a fluorescent layer; the top surface of the packaging layer is flush with the light-emitting surface of the chip assembly, and the fluorescent layer covers the top surface of the packaging layer and the light-emitting surface of the chip assembly.

10. A display screen, characterized in that, It includes the high-voltage LED packaging structure according to any one of claims 1 to 9.

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