High-brightness and high-reliability LED device and preparation method thereof, and vehicle lamp

Abstract

The invention provides an LED device and a preparation method thereof and a vehicle lamp, the LED device comprises a carrier plate, a flip LED chip, a light guide transition layer, a wavelength conversion layer and a reflection layer, the flip LED chip is arranged on the bearing surface of the carrier plate, the light emitting surface of the flip LED chip is located on the side, away from the carrier plate, of the backlight surface of the flip LED chip, the light guide transition layer is arranged on the light emitting surface, and the wavelength conversion layer is arranged on the reflection layer. The light guide transition layer is provided with a light incident surface, a light emergent surface and a light guide side wall connected with the light incident surface and the light emergent surface, the light emergent surface is positioned on one side, far away from the flip LED chip, of the light incident surface, and the area of the light incident surface is equal to that of the light emergent surface and is larger than that of the light emergent surface; the wavelength conversion layer is arranged on the light emitting surface, and the edge of the wavelength conversion layer is flush with the edge of the light emitting surface; the reflecting layer is arranged on the periphery of the wavelength conversion layer in a surrounding mode and covers the chip side wall and the light guide side wall. According to the invention, higher brightness and higher reliability of the LED device can be realized under the condition of avoiding the use of vertical LED chips with 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. It has been widely used in automotive, general lighting, display, medical, optical communication and other fields due to its advantages such as low energy consumption, small size, long life, good stability, fast response and stable luminous wavelength.

[0003] Taking the automotive field as an example, in recent years, the rise of new energy vehicles has driven the prosperity of the automotive LED market. However, based on the particularity of automotive application scenarios, national standards have clear requirements for the maximum brightness and reliability of LED devices for headlights. In order to meet the relevant requirements, international manufacturers' headlight LED devices usually use vertical LED chips with higher current stability to meet the requirements of brightness and reliability. However, domestic LED manufacturers have more technical barriers when using vertical LED chips. Therefore, it is urgent to provide an LED device that does not use vertical LED chips but can also meet the requirements of high brightness and high reliability. Summary of the invention

[0004] The present application provides a high-brightness and high-reliability LED device and a preparation method thereof, and a vehicle lamp, which can effectively solve the problem in the related art 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, the LED device comprising: A carrier plate having a carrying surface; A flip-chip LED chip is arranged on the carrying surface, the flip-chip LED chip has a backlight surface and a light-emitting surface arranged opposite to each other, and a chip side wall 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 carrying board; A light guide transition layer is arranged on the light emitting surface, the light guide transition layer has a light incident surface and a light emitting surface arranged opposite to each other, 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, wherein the area of ​​the light incident surface is equal to the area of ​​the light emitting surface and is larger than the area of ​​the light emitting surface; A wavelength conversion layer is disposed on the light emitting surface, and an edge of the wavelength conversion layer is flush with an edge of the light emitting surface; The reflective layer is disposed around the periphery of the wavelength conversion layer and covers the chip side wall and the light guide side wall.

[0006] Optionally, the reflective layer includes a first reflective portion and a second reflective portion, the first reflective portion covers the light guide side wall, and the second reflective portion covers the chip side wall and the side wall of the wavelength conversion layer.

[0007] Optionally, the light exit surface has a first area, the light exit surface has a second area, and the ratio of the first area to the second area is 1 to 0.4 to 0.6.

[0008] Optionally, the shape of the light emitting surface and the light exit surface are both square, wherein the side length of the light emitting surface is x, the side length of the light exit surface is y, and the ratio of x to y is 1 to 0.68 to 0.74.

[0009] 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 a material of the first optical portion is different from a material of the first chamfered portion, and an edge of the first optical portion is flush with an edge of the wavelength conversion layer.

[0010] 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.

[0011] 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 emitting surface extends beyond the edge of the light incident surface is a second distance, and the first distance is smaller than the second distance.

[0012] Optionally, a nano-array structure is provided on a surface of the wavelength conversion layer at a side away from the light guiding transition layer.

[0013] In a second aspect, the present application provides a method for preparing an LED device, the method for preparing an LED device comprising 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 chip has a backlight surface and a light-emitting surface that are arranged opposite to each other, and a chip side wall 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 which are arranged opposite to each other, 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 is larger than the area of ​​the light emitting surface, and the light guide side wall is covered by a reflective layer; Fixing the 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 around the periphery of the wavelength conversion layer and the periphery of the chip sidewall; A cutting process is performed to remove the redundant reflective layer and to separate the carrier into a plurality of carrier boards to form a plurality of independently arranged LED devices.

[0014] In a third aspect, the present application provides a vehicle lamp, comprising any one of the LED devices described above.

[0015] The present application provides a high-brightness and high-reliability LED device and a preparation method thereof, and a vehicle lamp. The LED device includes a carrier, a flip-chip LED chip, a light-guiding transition layer, a wavelength conversion layer, and a reflective layer. 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 arranged oppositely, and a chip side wall connecting the backlight surface and the light-emitting surface. The light-emitting surface is located on a 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 arranged oppositely, and A light-guiding side wall connects a light incident surface and a light emitting surface, wherein the light emitting surface is located on a side of the light incident surface away from a flip-chip LED chip, wherein an area of ​​the light incident surface is equal to an area of ​​the light emitting surface and is larger than an area of ​​the light emitting surface; a wavelength conversion layer is disposed on the light emitting surface, and an edge of the wavelength conversion layer is flush with an edge of the light emitting surface; a reflective layer is disposed 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

[0016] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0017] Figure 1 A schematic structural diagram of a high-brightness and high-reliability LED device provided in some embodiments of the present application.

[0018] Figure 2 A local enlarged view of the wavelength conversion layer provided in some embodiments of the present application.

[0019] 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.

[0020] Figure 4 A schematic structural diagram corresponding to step S10 provided in some embodiments of the present application.

[0021] Figure 5 A schematic structural diagram corresponding to step S20 provided in some embodiments of the present application.

[0022] Figure 6 A schematic structural diagram corresponding to step S30 provided in some embodiments of the present application.

[0023] Figure 7 A schematic structural diagram corresponding to step S40 provided in some embodiments of the present application.

[0024] Figure 8 A schematic structural diagram corresponding to step S50 provided in some embodiments of the present application.

[0025] Fig. 9 A schematic structural diagram corresponding to step S60 provided in some embodiments of the present application.

[0026] Fig.10 A flowchart of step S01 is provided for some embodiments of the present application.

[0027] Description of reference numerals: Carrier 10; carrier 100; flip-chip LED chip 20; backlight surface 201; light emitting surface 202; chip side wall 203; light guide transition layer 30; light incident surface 301; light emitting surface 302; light guide side wall 303; first optical portion 31; first chamfered portion 32; wavelength conversion layer 40; nano-array structure 41; reflective layer 50; first reflective portion 51; second reflective portion 52; first distance d1; second distance d2. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0029] The terms "first" and "second" in this document are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0032] 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 has a backlight surface 201 and a light-emitting surface 202 arranged opposite to each other, and a chip side wall 203 connecting the backlight surface 201 and the light-emitting surface 202, the light-emitting surface 202 is 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.

[0033] 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.

[0034] More importantly, the high-brightness and high-reliability LED device provided in the embodiment of the present application can obtain a larger luminous flux, a stronger chip heat dissipation capability and a higher reliability by adopting a larger flip-chip LED chip 20 with a larger light-emitting surface 202 while replacing the vertical LED chip with higher high-current stability but more technical barriers. It also utilizes a light-guiding transition layer 30 with 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.

[0035] In addition, in the high brightness and high reliability LED device provided by the present application, since the wavelength conversion layer 40 is directly arranged on the light exit surface 302 of the light guide transition layer 30 and has the same size as the light exit surface 302, the light emitted through the light exit surface 302 of the light guide transition layer 30 can be fully converted in wavelength in the wavelength conversion layer 40, thereby ensuring the color temperature of the LED device is accurate and improving the safety of the vehicle lamp product to which it is applied. On this basis, in order to ensure that the light generated by the flip-chip LED chip 20 can be transmitted in the path of the flip-chip LED chip 20, the light guide transition layer 30, and the wavelength conversion layer 40 as efficiently and comprehensively as possible, reduce the waste of light energy, and assist the light guide transition layer 30 to achieve the light guiding function from the large light incident surface 301 to the small light exit surface 302, the present application sets a reflective layer 50 covering the chip side wall 203, the light guide side wall 303, and surrounding the wavelength conversion layer 40.

[0036] In some embodiments of the present application, the reflective layer 50 includes a first reflective portion 51 and a second reflective portion 52 , wherein 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 .

[0037] 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 arranged, so that the coating effect of the reflective layer 50 on the light-guiding side wall 303 can be improved, 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 that covers the light-guiding side wall 303, and the first reflective portion 51 and the second reflective portion 52 are independently arranged.

[0038] 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.

[0039] 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 guide transition layer 30 is the second area. With the assistance of the reflective layer 50, light will hardly attenuate when propagating in the light guide transition layer 30, that is, the luminous flux of the light emitted through the light emitting surface 202 is substantially 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.

[0040] 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 the second area on the basis of 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 that of the vertical LED chip.

[0041] 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 a light emitting surface 202 are comparable to those of 0.5mm 2 The luminous flux and high current stability performance of the vertical LED chip are close to or even better than that 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 a 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 a light emitting surface 202 are comparable to those of 0.6mm 2 The luminous flux and high current stability performance of the vertical LED chip are close to those of the

[0042] Therefore, the present 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.

[0043] 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.

[0044] In the high-brightness and high-reliability LED device provided in the embodiment of the present application, the shape of the light-emitting surface 202 is a square, that is, the lengths of the sides of the light-emitting surface 202 of the flip-chip LED chip 20 are the same, which is conducive to reducing the design difficulty and production cost of the flip-chip LED chip 20. The shape of the light-emitting surface 302 is a square, and the edge of the wavelength conversion layer 40 is flush with the edge of the light-emitting surface 302, so the cross-sectional shape of the wavelength conversion layer 40 in the direction parallel to the light-emitting surface 302 is also a square, that is, the length and width of the wavelength conversion layer 40 are equal, which is conducive to reducing the design difficulty of the wavelength conversion layer 40.

[0045] More importantly, in the high-brightness and high-reliability LED device provided in 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, accordingly, the area of ​​the light emitting surface 302 is y 2 On this basis, since the ratio of x to y is 1 to 0.68 to 0.74, correspondingly, the ratio of the area of ​​the light emitting surface 202 to the area of ​​the light emitting surface 302 is 1: 0.4624 to 0.5476, thereby being able to take into account the stability of the LED device while enabling the LED device using the flip-chip LED chip 20 to reach the brightness level of the LED device using the vertical LED chip, thereby meeting the reliability and brightness requirements of automotive products.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] In the high-brightness and 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 its shape is irregular. The applicant found in the study that due to the 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 by patterning. Since the first chamfered portion 32 arranged on the periphery of the first optical portion 31 is made of a different material from the first optical portion 31, in the actual preparation process, an independent preparation method can be adopted, first preparing and forming the first optical portion 31 of the same size as the wavelength conversion layer 40, and then using the first optical portion 31 as a carrier, the first chamfered portion 32 is separately prepared on the periphery of the first optical portion 31, thereby reducing the need for the use of high-precision patterning equipment and reducing production costs.

[0050] 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.

[0051] 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.

[0052] In the high-brightness and high-reliability LED device provided in the embodiment of the present application, since the wavelength conversion layer 40 is a fluorescent glass sheet, the first optical part 31 is a transparent glass sheet, and the wavelength conversion layer 40 and the first optical part 31 have the same size, they can be manufactured using the same type of processing and manufacturing equipment and are suitable for the same processing technology, such as glass sheet cutting technology. In addition, the material cost can also be reduced, such as the main raw materials all include glass powder. In addition, since the fluorescent glass sheet and the transparent glass sheet have good heat resistance and the glass transition temperature is above 500 degrees Celsius, they can meet the temperature resistance requirements of automotive-grade products for materials.

[0053] In some embodiments of the present application, the first chamfered portion 32 is made of methyl silicone.

[0054] 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 performance is above 250 degrees Celsius, it can meet the temperature resistance requirements of automotive-grade products for materials.

[0055] 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 emitting surface 302 extends beyond the edge of the light incident surface 301 is a second distance d2, and the first distance d1 is smaller than the second distance d2.

[0056] In the high-brightness and high-reliability LED device provided by 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 setting area of ​​the reflective layer 50 does not exceed the range of the carrier 10, therefore, the space occupied by the carrier 10 in the direction parallel to the light-emitting surface 202 (which can be understood as the horizontal direction) is the inherent space occupied by the LED device in the direction parallel to the light-emitting surface 202. On this basis, in the direction parallel to the light-emitting surface 202, when the distance that the carrier 10 exceeds the edge of the light-emitting surface 202 is smaller, the size of the flip-chip LED chip 20 is larger, and the heat dissipation capacity, luminous power, and luminous flux of the flip-chip LED chip 20 will be correspondingly improved, which is beneficial to the improvement of the heat dissipation capacity and brightness of the LED device, and will not increase the space occupied by the LED device in the direction parallel to the light-emitting surface 202.

[0057] The applicant has found that in the current automotive lighting products using vertical LED chips, the size of the carrier 10 is often larger than the size of the vertical LED chip. The purpose is to quickly export the heat generated by the vertical LED chip during operation through the larger carrier 10. This also makes it possible to set a larger LED chip on the carrier 10. Without changing the size of the carrier 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 10 beyond the edge of the light-emitting surface 202 in a direction parallel to the light-emitting surface 202 smaller than the distance of the light-emitting surface 302 beyond the edge of the light-incident surface 301, thereby improving the heat dissipation capacity and brightness of the LED device.

[0058] 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.

[0059] 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 emitting surface 302 extends beyond the edge of the light incident surface 301, 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.

[0060] The applicant further discovered that, although the reduction in thickness of the reflective layer 50 will reduce the sealing performance of the reflective layer 50 to the flip-chip LED chip 20, the direct reason for the reduction in the sealing performance of the reflective layer 50 is that the reflective layer 50 directly contacts the heated flip-chip LED chip 20, and the reflective layer 50 is cracked due to excessive temperature. That is, when the reflective layer 50 has excellent heat dissipation performance, even when the thickness of the reflective layer 50 is reduced, the reflective layer 50 can still have a strong sealing performance.

[0061] 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 in 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.

[0062] In some embodiments of the present application, the white wall glue comprises reflective particles and colloid, wherein the reflective particles comprise TiO 2 、ZrO 2 , ZnO or BaSO 4 At least one of .

[0063] 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.

[0064] In some embodiments of the present application, the carrier 10 is a ceramic carrier to improve the thermal conductivity of the carrier 10 and further improve the reliability of the LED device.

[0065] 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 disposed on the surface of the wavelength conversion layer 40 away from the light guiding transition layer 30 .

[0066] In the high-brightness and high-reliability LED device provided in the embodiment of the present application, since the surface of the wavelength conversion layer 40 away from the light-guiding transition layer 30 is provided with a nano-array structure 41, and the nano-array structure 41 is conducive to the light emission of the product, improves the light efficiency, and can converge the light emission angle. When the LED device is used in a car lamp, the unit area brightness of the car lamp at 25 meters in the high beam mode, or even the unit area brightness at a farther distance, can meet the requirements.

[0067] In a second aspect, an embodiment of the present application provides 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.

[0068] 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 sheet 100 , wherein the carrier sheet 100 has a carrying surface.

[0069] Figure 5 The 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.

[0070] Figure 6 The 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.

[0071] Figure 7 The 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 guiding transition layer 30 , wherein the edge of the wavelength conversion layer 40 is flush with the edge of the light emitting surface 302 .

[0072] Figure 8 The 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 on the periphery of the wavelength conversion layer 40 and the periphery of the chip sidewall 203 .

[0073] Fig. 9 The schematic diagram of the structure corresponding to step S60 provided in some embodiments of the present application. Figure 3 and Fig. 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.

[0074] 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 a vertical LED chip while ensuring a high yield and low production cost.

[0075] 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.

[0076] 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 may be selectively welded in parallel to further improve reliability according to the actual application scenario.

[0077] 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, 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.

[0078] In some embodiments of the present application, step S40 includes: applying silicone on the light emitting surface 302 of the light guiding transition layer 30 , attaching the wavelength conversion layer 40 to the light emitting surface 302 of the light guiding transition layer 30 , and baking and curing.

[0079] 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 .

[0080] 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 transition layer 30 is arranged on the carrying surface of the carrier board 10, and ... 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 emitting surface 302 which are arranged opposite to each other, and a light guiding side wall 303 connecting the light incident surface 301 and the light emitting surface 302, and the light emitting 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 emitting surface 202 and is larger than the area of ​​the light emitting surface 302; the wavelength conversion layer 40 is arranged on the light emitting surface 302, and the edge of the wavelength conversion layer 40 is flush with the edge of the light emitting 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.

[0081] In some embodiments of the present application, step S10, step S20, step S30, step S40, step S50, and step S60 are performed sequentially.

[0082] In some embodiments of the present application, in the method for preparing a high-brightness and high-reliability LED device provided by the present application, before step S10, it also includes step S01, 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 arranged on the first chamfered portion 32.

[0083] The method for preparing the LED device provided in the embodiment of the present application can prepare and form the light-guiding transition layer 30 and the wavelength conversion layer 40 in one process step, thereby improving the preparation efficiency of parts and components and reducing the production and manufacturing costs. Specifically, since 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 prepared separately. In addition, since the size of the first optical portion 31 is the same as the size of the wavelength conversion layer 40, the first optical portion 31 and the wavelength conversion layer 40 can be prepared using the same set of equipment under the same mold opening parameters, thereby improving the preparation efficiency of parts and components and reducing the production and manufacturing costs.

[0084] 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 can enhance the covering effect of the reflective material on the light-guiding side wall 303 by pre-preparing the reflective layer 50 (i.e., the first reflective portion 51) covering the first chamfered portion 32 in step S01, 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.

[0085] Fig. 9 The flowchart of step S01 provided in some embodiments of the present application is shown in FIG. Fig. 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.

[0086] Step S011 includes: preparing a first optical film.

[0087] Step S012 includes: preparing a wavelength conversion film.

[0088] 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.

[0089] Step S014 includes: die-bonding a plurality of first optical parts 31 onto the high-temperature double-sided film.

[0090] Step S015 includes: forming a first chamfered portion 32 on the periphery of the plurality of first optical portions 31 .

[0091] Step S016 includes: forming a reflective layer 50 on the first chamfered portion 32 .

[0092] In some embodiments of the present application, step S011 includes: mixing, molding, and heat treating the glass powder to form a first optical film.

[0093] In some embodiments of the present application, step S012 includes: mixing, molding, and heat treating glass powder, fluorescent powder, and anti-precipitation powder to form a wavelength conversion film, wherein the fluorescent powder may be aluminate yellow fluorescent powder; and the anti-precipitation powder may be hydrophobic silica particles.

[0094] 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 microholes 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.

[0095] 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, and 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.

[0096] 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.

[0097] In some embodiments of the present application, step S015 includes: injecting methyl silicone between two adjacent first optical portions 31, and making the thickness of the methyl silicone thicker the closer to the side wall of the first optical portion 31, but the thickest thickness does not exceed the thickness of the first optical portion 31, so as to form a first chamfered portion 32 on the periphery of multiple first optical portions 31.

[0098] 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 .

[0099] 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 prepared by the method for preparing the LED device described above.

[0100] In some embodiments of the present application, the vehicle lamp may be a headlight in a car.

[0101] In summary, the present application provides a high-brightness and high-reliability LED device and a preparation method thereof, and a vehicle lamp, wherein the LED device comprises 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 arranged oppositely, and a chip side wall connecting the backlight surface and the light-emitting surface, the light-emitting surface is located on a 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 arranged oppositely, and a chip side wall 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; 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 arranged oppositely, and a chip side wall connecting the backlight surface and the light-emitting surface A light-guiding side wall connected to the light incident surface and the light exit surface, the light exit surface is located on a 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.

[0102] The above is a detailed introduction to a high-brightness and high-reliability LED device and its preparation method and car light 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, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. 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 arranged on the carrying surface, the flip-chip LED chip has a backlight surface and a light-emitting surface arranged opposite to each other, and a chip side wall 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 carrying board; A light guide transition layer is arranged on the light emitting surface, the light guide transition layer has a light incident surface and a light emitting surface arranged opposite to each other, 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, wherein the area of ​​the light incident surface is equal to the area of ​​the light emitting surface and is larger than the area of ​​the light emitting surface; A wavelength conversion layer is disposed on the light emitting surface, and an edge of the wavelength conversion layer is flush with an edge of the light emitting surface; The reflective layer is disposed around the periphery of the wavelength conversion layer and covers the chip side wall and the light guide side wall.

2. The LED device according to claim 1, characterized in that: The reflective layer includes a first reflective portion and a second reflective portion, the first reflective portion covers the light guide side wall, and the second reflective portion covers the chip side wall and the side wall of the wavelength conversion layer.

3. The LED device according to claim 1, characterized in that: 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 shapes of the light emitting surface and the light exit surface are both square, wherein the side length of the light emitting surface is x, the side length of the light exit 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, characterized in that: 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 that 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, characterized in that: 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 emitting surface extends beyond the edge of the light incident surface is a second distance, and the first distance is smaller than the second distance.

8. The LED device according to claim 1, characterized in that: A nano-array structure is disposed on a surface of the wavelength conversion layer at a side away from the light-guiding transition layer.

9. 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 chip has a backlight surface and a light-emitting surface that are arranged opposite to each other, and a chip side wall 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 which are arranged opposite to each other, 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 is larger than the area of ​​the light emitting surface, and the light guide side wall is covered by a reflective layer; Fixing the 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 around the periphery of the wavelength conversion layer and the periphery of the chip sidewall; A cutting process is performed to remove the redundant reflective layer and to separate the carrier into a plurality of carrier boards to form a plurality of independently arranged LED devices.

10. A vehicle lamp, characterized in that: The vehicle lamp comprises the LED device according to any one of claims 1 to 8.

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