A high-brightness and high-reliability LED device and its preparation method, and vehicle lamp

Abstract

The present application provides an LED device, a method for manufacturing the same, and a vehicle lamp. The LED device includes a carrier board, a flip-chip LED chip, a light-guiding transition layer, a wavelength conversion layer, and a reflective layer. The flip-chip LED chip is disposed on a carrier surface of the carrier board, with the light-emitting surface of the flip-chip LED chip located on the side of its backlight surface away from the carrier board. The light-guiding transition layer is disposed on the light-emitting surface and has a light incident surface, a light exit surface, and a light-guiding sidewall connecting the light incident surface and the light exit surface. The light exit surface is located on the side of the light incident surface away from the flip-chip LED chip, and the area of ​​the light incident surface is equal to the area of ​​the light exit surface and larger than the area of ​​the light exit surface. The wavelength conversion layer is disposed on the light exit surface, with the edge of the wavelength conversion layer flush with the edge of the light exit surface. The reflective layer is disposed around the periphery of the wavelength conversion layer and covers the chip sidewalls and the light-guiding sidewalls. The present application enables the LED device to achieve higher brightness and higher reliability while avoiding the use of vertical LED chips, which have more technical barriers.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a high-brightness and high-reliability LED device and a preparation method thereof. Background Art

[0002] Light emitting diode (LED) is an electroluminescent semiconductor light-emitting device. Due to its advantages of low energy consumption, small size, long life, good stability, fast response, and stable luminous wavelength, it has been widely used in automobiles, general lighting, displays, medical treatment, optical communications and other fields.

[0003] Taking the automotive sector as an example, the rise of new energy vehicles in recent years has driven the booming development of the automotive LED market. However, due to the specificity of automotive applications, national standards have clear requirements for the maximum brightness and reliability of LED devices used in headlights. To meet these requirements, international manufacturers' headlight LED devices currently typically use vertical LED chips with higher current stability to meet the brightness and reliability requirements. However, domestic LED manufacturers face significant technical barriers when using vertical LED chips. Therefore, there is an urgent need to provide LED devices that do not use vertical LED chips but can still meet the requirements for high brightness and high reliability. Summary of the Invention

[0004] The present application provides a high-brightness and high-reliability LED device, a preparation method thereof, and a car light, which can effectively solve the problem in related technologies that LED devices are difficult to meet the requirements of high brightness and high reliability without using vertical LED chips.

[0005] In a first aspect, the present application provides an LED device, comprising:

[0006] A carrier plate having a carrying surface;

[0007] A flip-chip LED chip is disposed on the carrier surface, the flip-chip LED chip having a backlight surface and a light-emitting surface that are oppositely disposed, and a chip sidewall connecting the backlight surface and the light-emitting surface, wherein the light-emitting surface is located on a side of the backlight surface away from the carrier board;

[0008] a light guide transition layer disposed on the light emitting surface, the light guide transition layer having a light incident surface and a light exit surface disposed opposite to each other, and a light guide side wall connecting the light incident surface and the light exit surface, the light exit surface being located on a side of the light incident surface away from the flip-chip LED chip, wherein an area of ​​the light incident surface is equal to an area of ​​the light exit surface and larger than an area of ​​the light exit surface;

[0009] a wavelength conversion layer, disposed on the light emitting surface, wherein an edge of the wavelength conversion layer is flush with an edge of the light emitting surface;

[0010] The reflective layer is arranged around the periphery of the wavelength conversion layer and covers the chip side wall and the light guide side wall.

[0011] Optionally, the reflective layer includes a first reflective portion and a second reflective portion, the first reflective portion covers the light guide sidewall, and the second reflective portion covers the chip sidewall and the sidewall of the wavelength conversion layer.

[0012] Optionally, the light exit surface has a first area, the light emitting surface has a second area, and the ratio of the first area to the second area is 1 to 0.4 to 0.6.

[0013] Optionally, the light exit surface and the light emitting surface are both square in shape, wherein the side length of the light exit surface is x, the side length of the light emitting surface is y, and the ratio of x to y is 1 to 0.68 to 0.74.

[0014] Optionally, the light-guiding transition layer includes a first optical portion and a first chamfered portion, wherein the first chamfered portion is arranged around the periphery of the first optical portion, wherein the material of the first optical portion is different from the material of the first chamfered portion, and the edge of the first optical portion is flush with the edge of the wavelength conversion layer.

[0015] Optionally, the wavelength conversion layer is a fluorescent glass sheet, the first optical portion is a transparent glass sheet, and the first chamfered portion is methyl silicone.

[0016] Optionally, the edge of the reflective layer is flush with the edge of the carrier, wherein, in a direction parallel to the light-emitting surface, the distance that the carrier extends beyond the edge of the light-emitting surface is a first distance, the distance that the light-incident surface extends beyond the edge of the light-emitting surface is a second distance, and the first distance is smaller than the second distance.

[0017] Optionally, a nano-array structure is provided on a surface of the wavelength conversion layer away from the light guiding transition layer.

[0018] In a second aspect, the present application provides a method for preparing an LED device, the method comprising the following steps:

[0019] Providing a carrier sheet, wherein the carrier sheet has a carrying surface;

[0020] Fixing a plurality of flip-chip LED chips on the carrying surface of the carrier, wherein the flip-chip LED chips have a backlight surface and a light-emitting surface that are oppositely disposed, and a chip sidewall connecting the backlight surface and the light-emitting surface, and the light-emitting surface is located on a side of the backlight surface away from the carrier;

[0021] Fixing a light guide transition layer on the light emitting surface of the LED chip, wherein the light guide transition layer has a light incident surface and a light emitting surface that are oppositely arranged, and a light guide side wall connecting the light incident surface and the light emitting surface, the light emitting surface is located on a side of the light incident surface away from the flip-chip LED chip, the area of ​​the light incident surface is equal to the area of ​​the light emitting surface and larger than the area of ​​the light emitting surface, and the light guide side wall is covered by a reflective layer;

[0022] Fixing a wavelength conversion layer on the light emitting surface of the light guide transition layer, wherein the edge of the wavelength conversion layer is flush with the edge of the light emitting surface;

[0023] forming a reflective layer on the periphery of the wavelength conversion layer and the periphery of the chip sidewall;

[0024] A cutting process is performed to remove the excess reflective layer and to separate the carrier into a plurality of carrier boards to form a plurality of independently arranged LED devices.

[0025] In a third aspect, the present application provides a vehicle lamp, comprising any one of the LED devices described above.

[0026] The present application provides a high-brightness and high-reliability LED device and its preparation method, and a vehicle lamp. The LED device includes a carrier board, a flip-chip LED chip, a light guide transition layer, a wavelength conversion layer, and a reflective layer. The carrier board has a carrying surface; the flip-chip LED chip is arranged on the carrying surface of the carrier board, and the flip-chip LED chip has a backlight surface and a light emitting surface that are arranged oppositely, and a chip side wall connecting the backlight surface and the light emitting surface, and the light emitting surface is located on the side of the backlight surface away from the carrier board; the light guide transition layer is arranged on the light emitting surface, and the light guide transition layer has a light incident surface and a light emitting surface that are arranged oppositely, and A light-guiding side wall connects the light incident surface and the light exit surface, wherein the light exit surface is located on the side of the light incident surface away from the flip-chip LED chip, wherein the area of ​​the light incident surface is equal to the area of ​​the light exit surface and is larger than the area of ​​the light exit surface; a wavelength conversion layer is arranged on the light exit surface, and the edge of the wavelength conversion layer is flush with the edge of the light exit surface; a reflective layer is arranged around the periphery of the wavelength conversion layer and covers the chip side wall and the light-guiding side wall. The present application can enable the LED device to achieve higher brightness and higher reliability while avoiding the use of vertical LED chips with more technical barriers. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0028] Figure 1 A schematic structural diagram of a high-brightness and high-reliability LED device provided in some embodiments of the present application.

[0029] Figure 2 This is a partially enlarged view of the wavelength conversion layer provided in some embodiments of the present application.

[0030] Figure 3 A schematic diagram of the preparation process of a high-brightness and high-reliability LED device provided in some embodiments of the present application.

[0031] Figure 4 This is a structural diagram corresponding to step S10 provided in some embodiments of the present application.

[0032] Figure 5 This is a schematic structural diagram corresponding to step S20 provided in some embodiments of the present application.

[0033] Figure 6 This is a structural diagram corresponding to step S30 provided in some embodiments of the present application.

[0034] Figure 7 This is a structural diagram corresponding to step S40 provided in some embodiments of the present application.

[0035] Figure 8 This is a structural diagram corresponding to step S50 provided in some embodiments of the present application.

[0036] Figure 9 This is a structural diagram corresponding to step S60 provided in some embodiments of the present application.

[0037] Figure 10 A flowchart of step S01 is provided for some embodiments of the present application.

[0038] Description of reference numerals:

[0039] Carrier 10; carrier 100; flip-chip LED chip 20; backlight surface 201; light emitting surface 202; chip sidewall 203; light guide transition layer 30; light incident surface 301; light emitting surface 302; light guide sidewall 303; first optical portion 31; first chamfered portion 32; wavelength conversion layer 40; nanometer array structure 41; reflective layer 50; first reflective portion 51; second reflective portion 52; first distance d1; second distance d2. DETAILED DESCRIPTION

[0040] The following will be combined with 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 embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0041] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the specified features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0043] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0044] Figure 1 This is a schematic diagram of the structure of a high-brightness and high-reliability LED device provided in some embodiments of the present application. Figure 1As shown, in the first aspect, the present application provides a high-brightness and high-reliability LED device, the LED device comprising a carrier 10, a flip-chip LED chip 20, a light-guiding transition layer 30, a wavelength conversion layer 40 and a reflective layer 50, the carrier 10 having a carrying surface; the flip-chip LED chip 20 is arranged on the carrying surface of the carrier 10, the flip-chip LED chip 20 having a backlight surface 201 and a light-emitting surface 202 arranged opposite to each other, and a chip sidewall 203 connecting the backlight surface 201 and the light-emitting surface 202, the light-emitting surface 202 being located on the side of the backlight surface 201 away from the carrier 10; the light-guiding transition layer 30 is arranged on the light-emitting surface 202, the light-guiding transition layer 30 It has a light incident surface 301 and a light exit surface 302 that are relatively arranged, and a light-guiding side wall 303 connecting the light incident surface 301 and the light exit surface 302, wherein the light exit surface 302 is located on the side of the light incident surface 301 away from the flip-chip LED chip 20, wherein the area of ​​the light incident surface 301 is equal to the area of ​​the light exit surface 202 and is larger than the area of ​​the light exit surface 302; the wavelength conversion layer 40 is arranged on the light exit surface 302, and the edge of the wavelength conversion layer 40 is flush with the edge of the light exit surface 302; the reflective layer 50 is arranged around the periphery of the wavelength conversion layer 40 and covers the chip side wall 203 and the light-guiding side wall 303.

[0045] In the high-brightness and high-reliability LED device provided in the embodiment of the present application, the flip-chip LED chip 20 arranged on the carrying surface of the carrier 10 can dissipate heat through the carrier 10, thereby enabling it to maintain high reliability in high-power and high-current working scenarios.

[0046] More importantly, the high-brightness and high-reliability LED device provided in the embodiment of the present application can replace the vertical LED chip with higher high-current stability but more technical barriers by adopting a larger-sized flip-chip LED chip 20 with a larger light-emitting surface 202 to obtain a larger luminous flux, stronger chip heat dissipation capability and higher reliability, and utilize a light-guiding transition layer 30 having a light incident surface 301 of the same size as the light-emitting surface 202 but a smaller light-emitting surface 302 to achieve light convergence and enhance luminous intensity, thereby making the LED device have higher brightness and higher reliability.

[0047] Furthermore, in the high-brightness, high-reliability LED device provided herein, since the wavelength conversion layer 40 is directly disposed on the light exit surface 302 of the light guide transition layer 30 and has the same dimensions as the light exit surface 302, light exiting through the light exit surface 302 of the light guide transition layer 30 can be fully wavelength-converted within the wavelength conversion layer 40, thereby ensuring accurate color temperature of the LED device and improving the safety of the vehicle lighting product in which it is used. Furthermore, to ensure that light generated by the flip-chip LED chip 20 is transmitted as efficiently and comprehensively as possible along the path of the flip-chip LED chip 20, the light guide transition layer 30, and the wavelength conversion layer 40, thereby reducing light energy waste and assisting the light guide transition layer 30 in guiding light from the large light incident surface 301 to the small light exit surface 302, the present invention provides a reflective layer 50 that covers the chip sidewalls 203 and the light guide sidewalls 303 and surrounds the wavelength conversion layer 40.

[0048] In some embodiments of the present application, the reflective layer 50 includes a first reflective portion 51 and a second reflective portion 52 . The first reflective portion 51 covers the light-guiding sidewall 303 , and the second reflective portion 52 covers the chip sidewall 203 and the sidewall of the wavelength conversion layer 40 .

[0049] In the high-brightness and high-reliability LED device provided in the embodiment of the present application, the first reflective portion 51 and the second reflective portion 52 are independently provided, thereby being able to improve the covering effect of the reflective layer 50 on the light-guiding side wall 303, thereby improving the light-guiding efficiency of the light-guiding transition layer 30, and improving the brightness and stability of the LED device. Specifically, the light-guiding side wall 303 is arc-shaped. The applicant found in actual research that due to the arc-shaped light-guiding side wall 303, during the process of integrally coating the reflective material, the reflective material is unable to completely cover the light-guiding side wall 303, thereby generating a gap between the reflective layer 50 and the light-guiding side wall 303, affecting the brightness and sealing performance of the LED device. Therefore, the present application separately prepares the first reflective portion 51 covering the light-guiding side wall 303, and independently provides the first reflective portion 51 and the second reflective portion 52.

[0050] In some embodiments of the present application, the light exit surface 202 has a first area, the light exit surface 302 has a second area, and the ratio of the first area to the second area is 1 to 0.4 to 0.6.

[0051] In the high-brightness and high-reliability LED device provided in the embodiment of the present application, the light-emitting surface 202 of the flip-chip LED chip 20 has a first area, and the light-emitting surface 302 has a second area. It can be understood that the original light-emitting area of ​​the flip-chip LED chip 20 is the first area, and the actual effective light-emitting area of ​​the flip-chip LED chip 20 after optical processing by the light-guiding transition layer 30 is the second area. With the auxiliary action of the reflective layer 50, light hardly attenuates when propagating in the light-guiding transition layer 30. That is, the luminous flux of the light emitted through the light-emitting surface 202 is basically equal to the luminous flux of the light emitted through the light-emitting surface 302, but the brightness of the light emitted through the light-emitting surface 302 is greater than the brightness of the light emitted through the light-emitting surface 202.

[0052] When taking the vertical LED chip with a light-emitting surface of a second area as an analogy object, the present application improves the heat dissipation capacity and power of the light-emitting chip by adopting a flip-chip LED chip 20 with a larger light-emitting surface 202, thereby being able to obtain a luminous flux that is not lower than that of the vertical LED chip with a light-emitting surface of a second area while ensuring the reliability of the light-emitting chip, thereby further reducing the actual effective light-emitting area with the help of the light-guiding transition layer 30, and achieving the same brightness level per unit area as the vertical LED chip.

[0053] The applicant has found through actual testing that the 2 The luminous flux and high current stability of the flip-chip LED chip 20 with the light emitting surface 202 are comparable to those of the 0.5mm 2 The luminous flux and high current stability performance of the vertical LED chip are close to or even better than those of 0.5mm 2 The luminous flux and high current stability of the vertical LED chip; with 1mm 2 The luminous flux and high current stability of the flip-chip LED chip 20 with the light emitting surface 202 are better than 0.4mm 2 The luminous flux and high current stability of the vertical LED chip; with 1mm 2 The luminous flux and high current stability of the flip-chip LED chip 20 with the light emitting surface 202 are comparable to those of the 0.6mm 2 The luminous flux and high current stability performance of the vertical LED chip are close to those of the predecessor.

[0054] Therefore, this application makes the area ratio of the light emitting surface 202 of the flip-chip LED chip 20 to the light emitting surface 302 be 1 to 0.4 to 0.6, so that the LED device using the flip-chip LED chip 20 can achieve the brightness level of the LED device using the vertical LED chip while taking into account the stability of the LED device, thereby meeting the reliability and brightness requirements of automotive products.

[0055] In some embodiments of the present application, the light exit surface 202 and the light exit surface 302 are both square in shape, wherein the side length of the light exit surface 202 is x, the side length of the light exit surface 302 is y, and the ratio of x to y is 1 to 0.68 to 0.74.

[0056] In the high-brightness, high-reliability LED device provided in the embodiments of the present application, the light-emitting surface 202 is square in shape, meaning that the sides of the light-emitting surface 202 of the flip-chip LED chip 20 are of equal length, which helps reduce the design difficulty and manufacturing cost of the flip-chip LED chip 20. The light-emitting surface 302 is square in shape, and the edge of the wavelength conversion layer 40 is flush with the edge of the light-emitting surface 302. Therefore, the cross-sectional shape of the wavelength conversion layer 40 in a direction parallel to the light-emitting surface 302 is also square, meaning that the length and width of the wavelength conversion layer 40 are equal, which helps reduce the design difficulty of the wavelength conversion layer 40.

[0057] More importantly, in the high brightness and high reliability LED device provided by the embodiment of the present application, since the side length of the light emitting surface 202 is x, accordingly, the area of ​​the light emitting surface 202 and the area of ​​the light incident surface 301 are both x. 2 Since the side length of the light emitting surface 302 is y, the area of ​​the light emitting surface 302 is y 2 On this basis, since the ratio of x to y is 1:0.68 to 0.74, the corresponding ratio of the area of ​​the light exit surface 202 to the area of ​​the light exit surface 302 is 1:0.4624 to 0.5476. This allows the LED device using the flip-chip LED chip 20 to achieve the brightness level of an LED device using a vertical LED chip while taking into account the stability of the LED device, thereby meeting the reliability and brightness requirements of automotive products.

[0058] In some embodiments of the present application, the size of the flip-chip LED chip 20 is 1 mm×1 mm; the size of the wavelength conversion layer 40 is 0.7-0.74 mm×0.7-0.74 mm.

[0059] In the high-brightness and high-reliability LED device provided in the embodiment of the present application, since the side length of the wavelength conversion layer 40 is greater than 0.7 mm, the precision requirements for processing equipment can be reduced, thereby reducing production costs.

[0060] In some embodiments of the present application, the light-guiding transition layer 30 includes a first optical portion 31 and a first chamfered portion 32, wherein the first chamfered portion 32 is arranged around the periphery of the first optical portion 31, wherein the material of the first optical portion 31 is different from the material of the first chamfered portion 32, and the edge of the first optical portion 31 is flush with the edge of the wavelength conversion layer 40.

[0061] In the high-brightness, high-reliability LED device provided in the embodiment of the present application, the first chamfered portion 32 is a component for achieving optical convergence and has an irregular shape. The applicant discovered during research that due to the relatively small overall size of the light-guiding transition layer 30, it is difficult for existing equipment to directly form the light-guiding transition layer 30 including the first chamfered portion 32 on an optical material through patterning. However, since the first chamfered portion 32 disposed on the periphery of the first optical portion 31 is made of a different material than the first optical portion 31, an independent preparation method can be adopted during the actual preparation process. First, a first optical portion 31 having the same size as the wavelength conversion layer 40 can be prepared. Then, using the first optical portion 31 as a carrier, the first chamfered portion 32 can be separately prepared on the periphery of the first optical portion 31. This can reduce the need for high-precision patterning equipment and reduce production costs.

[0062] In addition, since the first chamfered portion 32 is prepared separately, its design freedom is relatively higher. When the optical convergence effect is poor, it can be adjusted separately, thereby reducing the rework cost, reducing the product scrap rate, and improving the product yield.

[0063] In some embodiments of the present application, the wavelength conversion layer 40 is a fluorescent glass sheet, and the first optical portion 31 is a transparent glass sheet.

[0064] In the high-brightness, high-reliability LED device provided in the embodiments of the present application, since the wavelength conversion layer 40 is a fluorescent glass sheet and the first optical portion 31 is a transparent glass sheet, and the wavelength conversion layer 40 and the first optical portion 31 have the same dimensions, they can be manufactured using the same type of processing and manufacturing equipment and are suitable for the same processing techniques, such as glass sheet cutting. Furthermore, material costs can be reduced, as the primary raw materials include glass powder. Furthermore, since the fluorescent glass and transparent glass sheets have good heat resistance, with a glass transition temperature above 500 degrees Celsius, they can meet the temperature resistance requirements of automotive-grade products.

[0065] In some embodiments of the present application, the first chamfered portion 32 is made of methyl silicone.

[0066] In the high-brightness and high-reliability LED device provided in the embodiment of the present application, since methyl silicone has good heat resistance and long-term temperature resistance above 250 degrees Celsius, it can meet the temperature resistance requirements of automotive-grade products for materials.

[0067] In some embodiments of the present application, the edge of the reflective layer 50 is flush with the edge of the carrier 10, wherein, in a direction parallel to the light emitting surface 202, the distance that the carrier 10 extends beyond the edge of the light emitting surface 202 is a first distance d1, the distance that the light incident surface 301 extends beyond the edge of the light emitting surface 302 is a second distance d2, and the first distance d1 is smaller than the second distance d2.

[0068] In the high-brightness, high-reliability LED device provided in the embodiment of the present application, the edge of the reflective layer 50 is flush with the edge of the carrier 10, that is, the area where the reflective layer 50 is provided does not exceed the range of the carrier 10. Therefore, the space occupied by the carrier 10 in a direction parallel to the light-emitting surface 202 (which can be understood as a horizontal direction) is the inherent space occupied by the LED device in a direction parallel to the light-emitting surface 202. On this basis, in a direction parallel to the light-emitting surface 202, the smaller the distance that the carrier 10 exceeds the edge of the light-emitting surface 202, the larger the size of the flip-chip LED chip 20, and the heat dissipation capacity, luminous power, and luminous flux of the flip-chip LED chip 20 will be correspondingly improved. This is beneficial to improving the heat dissipation capacity and brightness of the LED device without additionally increasing the space occupied by the LED device in a direction parallel to the light-emitting surface 202.

[0069] The applicant has found that in current automotive lighting products that use vertical LED chips, the size of the carrier board 10 is often larger than the size of the vertical LED chip. The purpose is to quickly dissipate the heat generated by the vertical LED chip during operation through the larger carrier board 10. This also makes it possible to set a larger LED chip on the carrier board 10. Without changing the size of the carrier board 10 and the actual effective light-emitting area, the present application makes it possible to increase the size of the flip-chip LED chip 20 as much as possible by making the distance of the carrier board 10 beyond the edge of the light-emitting surface 202 in a direction parallel to the light-emitting surface 202 shorter than the distance of the light incident surface 301 beyond the edge of the light-emitting surface 302, thereby improving the heat dissipation capacity and brightness of the LED device.

[0070] In some embodiments of the present application, the reflective layer 50 includes white wall glue and thermal conductive particles mixed in the white wall glue.

[0071] The applicant further discovered that when the distance that the carrier 10 extends beyond the edge of the light emitting surface 202 is less than the distance that the light incident surface 301 extends beyond the edge of the light emitting surface 302, although the size of the flip-chip LED chip 20 is increased, it will also lead to a decrease in the thickness of the reflective layer 50 arranged on the outer side of the chip side wall 203. When the thickness of the reflective layer 50 is relatively small, the sealing performance of the reflective layer 50 on the flip-chip LED chip 20 will be reduced, thereby affecting the reliability of the LED device.

[0072] The applicant further discovered that, while reducing the thickness of the reflective layer 50 will reduce the sealing performance of the reflective layer 50 with the flip-chip LED chip 20, the direct cause of the reduced sealing performance of the reflective layer 50 is that the reflective layer 50 directly contacts the heated flip-chip LED chip 20, causing cracks in the reflective layer 50 due to excessive temperature. In other words, when the reflective layer 50 has excellent heat dissipation performance, it can still maintain strong sealing performance even when its thickness is reduced.

[0073] Therefore, in the high-brightness and high-reliability LED device provided in the embodiment of the present application, the heat dissipation performance is improved by mixing thermally conductive particles into the white wall glue, thereby improving the cracking problem of the reflective layer 50, thereby improving the reliability of the LED device when the size of the light-emitting chip is increased and the reflective layer 50 is thinned.

[0074] In some embodiments of the present application, the white wall glue includes reflective particles and colloid, wherein the reflective particles include at least one of TiO2, ZrO2, ZnO or BaSO4.

[0075] In some embodiments of the present application, the thermally conductive particles may be boron nitride nanosheets having high thermal conductivity, low expansion coefficient, and good chemical stability.

[0076] In some embodiments of the present application, the carrier 10 is a ceramic carrier to improve the thermal conductivity of the carrier 10 and thereby improve the reliability of the LED device.

[0077] Figure 2 This is a partial enlarged view of the wavelength conversion layer provided in some embodiments of the present application. Figure 2 As shown, in some embodiments of the present application, a nano-array structure 41 is provided on the surface of the wavelength conversion layer 40 away from the light guiding transition layer 30 .

[0078] In the high-brightness, high-reliability LED device provided in this embodiment, a nanometer array structure 41 is provided on the surface of the wavelength conversion layer 40 facing away from the light-guiding transition layer 30. This nanometer array structure 41 facilitates light emission, improves light efficiency, and converges the light emission angle. When used in a vehicle lamp, this LED device can meet the required brightness per unit area at a distance of 25 meters in high-beam mode, and even at further distances.

[0079] In a second aspect, the embodiments of the present application provide a method for preparing a high-brightness and high-reliability LED device. Figure 3 A schematic diagram of a preparation process of a high-brightness and high-reliability LED device provided in some embodiments of the present application, referring to Figure 3 As shown, the method for preparing the high-brightness and high-reliability LED device includes multiple steps, such as step S10, step S20, step S30, step S40, step S50, and step S60.

[0080] Figure 4 This is a schematic diagram of the structure corresponding to step S10 provided in some embodiments of the present application. Figure 3 and Figure 4 As shown, step S10 includes: providing a carrier 100, wherein the carrier 100 has a carrying surface.

[0081] Figure 5 This is a schematic diagram of the structure corresponding to step S20 provided in some embodiments of the present application. Figure 3 and Figure 5 As shown, step S20 includes: fixing a plurality of flip-chip LED chips 20 onto the supporting surface of the carrier 100, wherein the flip-chip LED chip 20 has a backlight surface 201 and a light-emitting surface 202 that are relatively arranged, and a chip side wall 203 connecting the backlight surface 201 and the light-emitting surface 202, and the light-emitting surface 202 is located on the side of the backlight surface 201 away from the carrier 100.

[0082] Figure 6 This is a schematic diagram of the structure corresponding to step S30 provided in some embodiments of the present application. Figure 3 and Figure 6As shown, step S30 includes: fixing the light-guiding transition layer 30 to the light-emitting surface 202 of the LED chip, wherein the light-guiding transition layer 30 has a light incident surface 301 and a light exit surface 302 that are relatively arranged, and a light-guiding side wall 303 connecting the light incident surface 301 and the light exit surface 302, the light exit surface 302 is located on the side of the light incident surface 301 away from the flip-chip LED chip 20, the area of ​​the light incident surface 301 is equal to the area of ​​the light exit surface 202, and is larger than the area of ​​the light exit surface 302, and the light-guiding side wall 303 is covered by the reflective layer 50.

[0083] Figure 7 This is a schematic diagram of the structure corresponding to step S40 provided in some embodiments of the present application. Figure 3 and Figure 7 As shown, step S40 includes: fixing the wavelength conversion layer 40 to the light emitting surface 302 of the light guide transition layer 30 , wherein the edge of the wavelength conversion layer 40 is flush with the edge of the light emitting surface 302 .

[0084] Figure 8 This is a schematic diagram of the structure corresponding to step S50 provided in some embodiments of the present application. Figure 3 and Figure 8 As shown, step S50 includes: forming a reflective layer 50 around the periphery of the wavelength conversion layer 40 and the periphery of the chip sidewall 203 .

[0085] Figure 9 This is a schematic diagram of the structure corresponding to step S60 provided in some embodiments of the present application. Figure 3 and Figure 9 As shown, step S60 includes: performing a cutting process to remove the redundant reflective layer 50 and dividing the carrier 100 into a plurality of carrier boards 10 to form a plurality of independently arranged LED devices.

[0086] The method for preparing an LED device provided in the embodiment of the present application can prepare an LED device with higher brightness and higher reliability without using vertical LED chips while ensuring high yield and low production cost.

[0087] In some embodiments of the present application, step S10 includes: laser drilling a hole in an aluminum nitride ceramic sheet with high heat dissipation performance, electroplating a metal layer on the front and back sides, and filling the metal layer in the hole to prepare a carrier 100.

[0088] In some embodiments of the present application, step S20 includes: eutectic welding a plurality of flip-chip LED chips 20 to the carrier 100. In addition, a Zener diode can be selectively welded in parallel to further improve reliability according to the actual application scenario.

[0089] In some embodiments of the present application, step S30 includes: applying silicone on the light-emitting surface 202 of the flip-chip LED chip 20, attaching the light-guiding transition layer 30 to the light-emitting surface 202 of the flip-chip LED chip 20, and baking and curing it, wherein a first reflective portion 51 made of white wall glue is provided on the light-guiding side wall 303 of the light-guiding transition layer 30.

[0090] In some embodiments of the present application, step S40 includes: applying silicone on the light emitting surface 302 of the light guide transition layer 30 , attaching the wavelength conversion layer 40 to the light emitting surface 302 of the light guide transition layer 30 , and baking and curing.

[0091] In some embodiments of the present application, step S50 includes: filling a reflective layer 50 made of white wall glue in the gap between two adjacent flip-chip LED chips 20, wherein the reflective layer 50 covers the side wall of the wavelength conversion layer 40, the chip side wall 203 and the first reflective portion 51.

[0092] In some embodiments of the present application, step S60 includes: attaching the carrier 100 to the UV film, using a water jet cutter to cut and remove excess white wall glue and the carrier 100 to form a plurality of independently arranged LED devices, wherein the LED device includes a carrier board 10, a flip-chip LED chip 20, a light guide transition layer 30, a wavelength conversion layer 40 and a reflective layer 50, and the carrier board 10 has a carrying surface; the flip-chip LED chip 20 is arranged on the carrying surface of the carrier board 10, and the flip-chip LED chip 20 has a backlight surface 201 and a light emitting surface 202 that are relatively arranged, and a chip side wall 203 connecting the backlight surface 201 and the light emitting surface 202, and the light emitting surface 202 is located on the side of the backlight surface 201 away from the carrier board 10; the light guide The transition layer 30 is arranged on the light emitting surface 202, and the light guiding transition layer 30 has a light incident surface 301 and a light exit surface 302 arranged opposite to each other, and a light guiding side wall 303 connecting the light incident surface 301 and the light exit surface 302, and the light exit surface 302 is located on the side of the light incident surface 301 away from the flip-chip LED chip 20, wherein the area of ​​the light incident surface 301 is equal to the area of ​​the light exit surface 202 and is larger than the area of ​​the light exit surface 302; the wavelength conversion layer 40 is arranged on the light exit surface 302, and the edge of the wavelength conversion layer 40 is flush with the edge of the light exit surface 302; the reflective layer 50 is arranged around the periphery of the wavelength conversion layer 40 and covers the chip side wall 203 and the light guiding side wall 303.

[0093] In some embodiments of the present application, step S10, step S20, step S30, step S40, step S50, and step S60 are performed sequentially.

[0094] In some embodiments of the present application, the method for preparing a high-brightness and high-reliability LED device provided by the present application further includes step S01 before step S10, and step S01 includes: preparing a light-guiding transition layer 30 and a wavelength conversion layer 40, wherein the light-guiding transition layer 30 includes a first optical portion 31 and a first chamfered portion 32, and the first chamfered portion 32 is arranged around the periphery of the first optical portion 31, wherein the material of the first optical portion 31 is different from the material of the first chamfered portion 32, the size of the first optical portion 31 is the same as the size of the wavelength conversion layer 40, and a reflective layer 50 is provided on the first chamfered portion 32.

[0095] The LED device manufacturing method provided in the embodiments of the present application can form the light-guiding transition layer 30 and the wavelength conversion layer 40 in a single process step, thereby improving component manufacturing efficiency and reducing production costs. Specifically, because the material of the first optical portion 31 is different from the material of the first chamfered portion 32, the first optical portion 31 can be manufactured separately. Furthermore, because the dimensions of the first optical portion 31 are the same as those of the wavelength conversion layer 40, the first optical portion 31 and the wavelength conversion layer 40 can be manufactured using the same equipment and the same mold opening parameters, thereby improving component manufacturing efficiency and reducing production costs.

[0096] In addition, in the preparation method of the LED device provided in the embodiment of the present application, step S01 is independent of step S50, that is, the present application includes two steps of preparing the reflective layer 50. The present application pre-prepares the reflective layer 50 (that is, the first reflective portion 51) covering the first chamfered portion 32 in step S01, thereby improving the covering effect of the reflective material on the light-guiding side wall 303, thereby avoiding the problem that the light-guiding side wall 303 cannot be tightly fitted with the reflective material due to the existence of a multi-step difference structure when executing step S50.

[0097] Figure 9 The flowchart of step S01 provided in some embodiments of the present application is shown in FIG. Figure 9 As shown, in some embodiments of the present application, step S01 includes step S011, step S012, step S013, step S014, step S015, and step S016.

[0098] Step S011 includes: preparing a first optical film.

[0099] Step S012 includes: preparing a wavelength conversion film.

[0100] Step S013 includes: using the same laser cutting equipment to cut the first optical film and the wavelength conversion film to form a plurality of first optical parts 31 and a plurality of wavelength conversion layers 40, wherein the first optical parts 31 are transparent glass sheets, and the wavelength conversion layers 40 are fluorescent glass sheets.

[0101] Step S014 includes: die-bonding the plurality of first optical parts 31 onto the high-temperature double-sided film.

[0102] Step S015 includes: forming first chamfered portions 32 on the peripheries of the plurality of first optical portions 31 .

[0103] Step S016 includes: forming a reflective layer 50 on the first chamfered portion 32 .

[0104] In some embodiments of the present application, step S011 includes: mixing, shaping, and heat-treating glass powder to form a first optical film.

[0105] In some embodiments of the present application, step S012 includes: mixing, molding, and heat treating glass powder, phosphor and anti-precipitation powder to form a wavelength conversion film, wherein the phosphor can be aluminate yellow phosphor; the anti-precipitation powder can be hydrophobic silica particles.

[0106] In some embodiments of the present application, step S012 also includes: spin-coating photoresist on the wavelength conversion film; covering the photoresist with a photoresist plate, wherein the photoresist plate includes micropores arranged in an array; exposing and developing the photoresist; etching the wavelength conversion film; removing the photoresist; and polishing the wavelength conversion film to form a nanoarray structure 41 on the surface of the wavelength conversion film.

[0107] In some embodiments of the present application, step S013 includes: using the same laser cutting equipment to cut the first optical film and the wavelength conversion film, cutting the first optical portion 31 and the wavelength conversion layer 40 into square sheets with a side length of 0.7 to 0.74 mm.

[0108] In some embodiments of the present application, step S014 includes: attaching a high-temperature double-sided film on a glass or stainless steel carrier 10, using a crystal bonding machine to array multiple first optical parts 31 onto the high-temperature double-sided film, and using a crystal expander to keep the first optical part 31 relatively fixed to the high-temperature double-sided film.

[0109] In some embodiments of the present application, step S015 includes: injecting methyl silicone between two adjacent first optical parts 31, and making the thickness of the methyl silicone thicker the closer to the side wall of the first optical part 31, but the thickest thickness does not exceed the thickness of the first optical part 31, so as to form a first chamfered portion 32 on the periphery of multiple first optical parts 31.

[0110] In some embodiments of the present application, step S016 includes: injecting white glue between two adjacent first optical parts 31, and using a water jet cutter to remove excess methyl silicone and / or white glue to form a reflective layer 50 on the first chamfered part 32.

[0111] In a third aspect, an embodiment of the present application provides a vehicle lamp, which includes the LED device described above. The LED device in the vehicle lamp can be manufactured by the method for manufacturing the LED device described above.

[0112] In some embodiments of the present application, the vehicle lamp may be a headlight in a car.

[0113] In summary, the present application provides a high-brightness and high-reliability LED device and its preparation method, and a vehicle lamp, wherein the LED device includes a carrier, a flip-chip LED chip, a light-guiding transition layer, a wavelength conversion layer, and a reflective layer, wherein the carrier has a carrying surface; the flip-chip LED chip is arranged on the carrying surface of the carrier, the flip-chip LED chip has a backlight surface and a light-emitting surface that are relatively arranged, and a chip side wall connecting the backlight surface and the light-emitting surface, the light-emitting surface is located on the side of the backlight surface away from the carrier; the light-guiding transition layer is arranged on the light-emitting surface, the light-guiding transition layer has a light incident surface and a light emitting surface that are relatively arranged, and a chip side wall connecting the backlight surface and the light-emitting surface, the light-emitting surface is located on the side of the backlight surface away from the carrier; A light-guiding side wall connected to the light incident surface and the light exit surface, the light exit surface is located on the side of the light incident surface away from the flip-chip LED chip, wherein the area of ​​the light incident surface is equal to the area of ​​the light exit surface and is larger than the area of ​​the light exit surface; the wavelength conversion layer is arranged on the light exit surface, and the edge of the wavelength conversion layer is flush with the edge of the light exit surface; the reflective layer is arranged around the periphery of the wavelength conversion layer and covers the chip side wall and the light-guiding side wall. The present application can enable the LED device to achieve higher brightness and higher reliability while avoiding the use of vertical LED chips with more technical barriers.

[0114] The above is a detailed introduction to a high-brightness and high-reliability LED device and its preparation method, and a car lamp provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. An LED device, characterized in that: The LED device comprises: A carrier plate having a carrying surface; A flip-chip LED chip is disposed on the carrier surface, the flip-chip LED chip having a backlight surface and a light-emitting surface that are oppositely disposed, and a chip sidewall connecting the backlight surface and the light-emitting surface, wherein the light-emitting surface is located on a side of the backlight surface away from the carrier board; a light guide transition layer disposed on the light emitting surface, the light guide transition layer having a light incident surface and a light exit surface disposed opposite to each other, and a light guide side wall connecting the light incident surface and the light exit surface, the light exit surface being located on a side of the light incident surface away from the flip-chip LED chip, wherein an area of ​​the light incident surface is equal to an area of ​​the light exit surface and larger than an area of ​​the light exit surface; a wavelength conversion layer, disposed on the light emitting surface, wherein an edge of the wavelength conversion layer is flush with an edge of the light emitting surface; a reflective layer, arranged around the periphery of the wavelength conversion layer and covering the chip sidewall and the light guide sidewall; In which, the edge of the reflective layer is flush with the edge of the carrier, and in the direction parallel to the light-emitting surface, the distance that the carrier extends beyond the edge of the light-emitting surface is a first distance, the distance that the light incident surface extends beyond the edge of the light-emitting surface is a second distance, and the first distance is smaller than the second distance.

2. The LED device according to claim 1, wherein The reflective layer includes a first reflective portion and a second reflective portion, wherein the first reflective portion covers the light guide sidewall, and the second reflective portion covers the chip sidewall and the sidewall of the wavelength conversion layer.

3. The LED device according to claim 1, wherein The light exit surface has a first area, the light emitting surface has a second area, and the ratio of the first area to the second area is 1 to 0.4 to 0.

6.

4. The LED device according to claim 3, characterized in that The light exit surface and the light emitting surface are both square in shape, wherein the side length of the light exit surface is x, the side length of the light emitting surface is y, and the ratio of x to y is 1 to 0.68 to 0.

74.

5. The LED device according to claim 1, wherein The light-guiding transition layer includes a first optical portion and a first chamfered portion, wherein the first chamfered portion is arranged around the periphery of the first optical portion, wherein the material of the first optical portion is different from the material of the first chamfered portion, and the edge of the first optical portion is flush with the edge of the wavelength conversion layer.

6. The LED device according to claim 5, characterized in that The wavelength conversion layer is a fluorescent glass sheet, the first optical portion is a transparent glass sheet, and the first chamfered portion is methyl silicone.

7. The LED device according to claim 1, wherein A nanometer array structure is provided on a surface of the wavelength conversion layer away from the light guide transition layer.

8. A method for preparing an LED device, characterized in that: The method for preparing the LED device comprises the following steps: Providing a carrier sheet, wherein the carrier sheet has a carrying surface; Fixing a plurality of flip-chip LED chips on the carrying surface of the carrier, wherein the flip-chip LED chips have a backlight surface and a light-emitting surface that are oppositely disposed, and a chip sidewall connecting the backlight surface and the light-emitting surface, and the light-emitting surface is located on a side of the backlight surface away from the carrier; Fixing a light guide transition layer on the light emitting surface of the LED chip, wherein the light guide transition layer has a light incident surface and a light emitting surface that are oppositely arranged, and a light guide side wall connecting the light incident surface and the light emitting surface, the light emitting surface is located on a side of the light incident surface away from the flip-chip LED chip, the area of ​​the light incident surface is equal to the area of ​​the light emitting surface and larger than the area of ​​the light emitting surface, and the light guide side wall is covered by a reflective layer; Fixing a wavelength conversion layer on the light emitting surface of the light guide transition layer, wherein the edge of the wavelength conversion layer is flush with the edge of the light emitting surface; forming a reflective layer on the periphery of the wavelength conversion layer and the periphery of the chip sidewall; Performing a cutting process to remove excess reflective layers and separate the carrier into a plurality of carrier boards to form a plurality of independently arranged LED devices; In which, the edge of the reflective layer is flush with the edge of the carrier, and in the direction parallel to the light-emitting surface, the distance that the carrier extends beyond the edge of the light-emitting surface is a first distance, the distance that the light incident surface extends beyond the edge of the light-emitting surface is a second distance, and the first distance is smaller than the second distance.

9. A vehicle lamp, characterized in that: The vehicle lamp comprises the LED device according to any one of claims 1 to 7.

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