Light emitting diode package and light emitting device

Abstract

The application relates to the technical field of semiconductor manufacturing, in particular to a light-emitting diode package and a light-emitting device. By arranging a heat-conducting auxiliary layer with a microstructure on one side of a first functional layer of a second functional layer, and then bonding the second functional layer with the heat-conducting auxiliary layer and the first functional layer through a first adhesive layer, the microstructure on the surface of the heat-conducting auxiliary layer can be embedded into the first adhesive layer, so that the heat-conducting distance from the first functional layer to the second functional layer or from the second functional layer to the first functional layer is shortened, and compared with the prior art without the heat-conducting auxiliary layer, the heat dissipation performance of the light-emitting diode package is greatly enhanced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a light-emitting diode package and a light-emitting device. Background Technology

[0002] LEDs, known as the fourth generation of lighting sources or green light sources, are characterized by energy saving, environmental friendliness, long lifespan, and small size. They are widely used in various fields such as indication, display, decoration, backlighting, general lighting, and urban nightscapes. Based on their function, they can be divided into five main categories: information display, signal lights, automotive lighting, LCD backlighting, and general lighting.

[0003] In the existing technology, LED packages can be used in various displays and LED lighting fixtures. LEDs have advantages such as long service life and energy saving and environmental protection. However, with the increase of LED current intensity and light output, the heat generated by LED chips also increases. Heat dissipation of LED chips will become a major problem, which has a great impact on the quality, service life and reliability of LED products.

[0004] Therefore, the purpose of this invention is to improve the heat dissipation problem of LED packages. Summary of the Invention

[0005] This invention provides a light-emitting diode package, comprising:

[0006] A substrate having a first surface and a second surface facing away from each other;

[0007] A light-emitting diode chip is disposed on the first surface;

[0008] The substrate includes a first functional layer and a second functional layer, which are bonded together by a first adhesive layer;

[0009] The substrate further includes a thermally conductive auxiliary layer, which is disposed on the side of the second functional layer opposite to the first functional layer, and the thermally conductive auxiliary layer has a microstructure on the surface of the first functional layer.

[0010] In some embodiments, the thermally conductive auxiliary layer is formed on the surface of the second functional layer by electro-evaporation or sputtering.

[0011] In some embodiments, the microstructure is formed naturally during the formation of the thermally conductive auxiliary layer.

[0012] In some embodiments, the microstructure is formed by etching the thermally conductive auxiliary layer.

[0013] In some embodiments, the microstructure is conical, conical-like, frustum-like, polygonal-like, frustum-like, cylindrical, or spherical.

[0014] In some embodiments, the difference in thermal expansion coefficients between the thermally conductive auxiliary layer and the first functional layer is no greater than 5 x 10⁻⁶. -6 / ℃.

[0015] In some embodiments, the thermally conductive auxiliary layer consists of several microstructures independently disposed on the surface of the second functional layer.

[0016] In some embodiments, the thermally conductive auxiliary layer comprises a material selected from one or more combinations of copper, aluminum, ceramic, or stainless steel.

[0017] In some embodiments, the thermally conductive auxiliary layer comprises the same material as the first functional layer.

[0018] In some embodiments, the thickness of the thermally conductive auxiliary layer is between 100-1000 nm.

[0019] In some embodiments, the height of the microstructure is between 50 and 950 nm.

[0020] In some embodiments, the thickness of the first adhesive layer is between 2 and 25 μm.

[0021] In some embodiments, the first functional layer is the substrate of the substrate, and the second functional layer is the reflective layer of the substrate.

[0022] In some embodiments, the first functional layer is a reflective layer of the substrate, and the second functional layer is a substrate of the substrate.

[0023] In some embodiments, the reflective layer is disposed on the substrate, the substrate comprising copper, the reflective layer comprising aluminum, the thickness of the substrate being between 1000-3000 μm, and the thickness of the reflective layer being between 100-1000 μm.

[0024] In some embodiments, the substrate further includes a first insulating layer, a conductive line layer, and a second insulating layer. The first insulating layer is disposed on the reflective layer via a second adhesive layer. The conductive line layer is disposed on the first insulating layer. The second insulating layer covers the conductive line layer. The second insulating layer has a plurality of openings to expose the conductive line layer to form a plurality of solder joints.

[0025] The present invention also provides a light-emitting device, comprising a light-emitting diode package as described in any of the above.

[0026] An embodiment of the present invention provides a light-emitting diode (LED) package. By providing a thermally conductive auxiliary layer with a microstructure on one side of a first functional layer at a second functional layer, and then bonding the second functional layer with the thermally conductive auxiliary layer to the first functional layer through a first adhesive layer, the microstructure on the surface of the thermally conductive auxiliary layer can be pressed and embedded into the first adhesive layer, thereby shortening the thermal conductivity distance between the first functional layer and the second functional layer or between the second functional layer and the first functional layer. Compared with the prior art without a thermally conductive auxiliary layer, the heat dissipation performance of the LED package of the present invention is greatly enhanced.

[0027] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a cross-sectional schematic diagram of an embodiment 1 of a light-emitting diode package provided by the present invention.

[0030] Figure 2 yes Figure 1 Enlarged view of a portion of region A in the middle;

[0031] Figure 3 These are temperature test images of LED packages at a specific power level in existing technology;

[0032] Figure 4 These are temperature test images of the LED package at a specific power level provided by this invention;

[0033] Figure 5 This is a top view schematic diagram of the light-emitting diode package provided by the present invention;

[0034] Figure 6 This is a cross-sectional schematic diagram of a second embodiment of a light-emitting diode package provided by the present invention;

[0035] Figure 7 This is a cross-sectional schematic diagram of a light-emitting diode package embodiment 3 provided by the present invention;

[0036] Figure 8 This is a cross-sectional schematic diagram of embodiment 4 of a light-emitting diode package provided by the present invention.

[0037] Figure label:

[0038] 10-Substrate; 11-Base; 12-Reflective layer; 13-First adhesive layer; 14-Thermal conductive auxiliary layer; 14a-Microstructure; 15-First insulating layer; 16-Conductive circuit layer; 17-Second insulating layer; 18-Second adhesive layer; 20-Light emitting diode chip; 16a-Bond point. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings; the technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] To achieve at least one or more of the aforementioned advantages, the light-emitting diode package provided by the present invention includes a substrate 10 and a light-emitting diode chip. The substrate 10 has a first surface S1 and a second surface S2 facing each other. In the placement state of the illustrated embodiment, the first surface S1 is the upper surface of the substrate 10, which is used to place the light-emitting diode chip 20.

[0041] The substrate 10 includes a first functional layer and a second functional layer with specific functions, which are bonded together by a first adhesive layer 13 disposed between them. To improve the heat dissipation capability of the LED package, the substrate 10 also includes a thermally conductive auxiliary layer 14 disposed between the first and second functional layers. The thermally conductive auxiliary layer 14 is attached to the surface of the second functional layer and has microstructures 14a on its surface facing the first functional layer. This arrangement allows the microstructures 14a on the surface of the thermally conductive auxiliary layer 14 to be pressed into the first adhesive layer, thereby shortening the thermal conduction distance between the first and second functional layers or between the second and first functional layers. Compared to the prior art without a thermally conductive auxiliary layer, the heat dissipation performance of the LED package of the present invention is greatly enhanced.

[0042] Example 1

[0043] Please see Figure 1 , Figure 1This is a cross-sectional schematic diagram of an embodiment 1 of a light-emitting diode (LED) package provided by the present invention. In this embodiment, to improve the luminous efficiency and heat dissipation efficiency of the LED package, the substrate 10 includes a first functional layer with a high reflectivity layered structure, called a reflective layer 12, which reflects the light emitted by the LED chip 20 so that the light is emitted as far as possible towards the direction facing the first surface S1. A second functional layer with certain mechanical strength and thermal conductivity is also included as the substrate 11 of the substrate 10. The substrate 11 serves as a carrier for supporting the reflective layer 12 and the LED chip 20 in the substrate 10, and also has good thermal conductivity to dissipate the heat generated by the LED chip 20 in a timely manner to ensure its normal operation. The reflective layer 12 is disposed on the substrate 11, and the substrate 11 and the reflective layer 12 are bonded together by a first adhesive layer 13 disposed between them. Preferably, the first adhesive layer 14 is, for example, a high-temperature resistant adhesive layer such as resin with a thickness between 2-25 micrometers, and preferably a thickness range of 15-20 micrometers, but the inventive concept is not limited to this.

[0044] To further improve the heat dissipation capability of the light-emitting diode package, the substrate 10 also includes a thermally conductive auxiliary layer 14. The thermally conductive auxiliary layer 14 is disposed on the side of the reflective layer 12 facing the substrate 11, and the surface of the thermally conductive auxiliary layer 14 facing the substrate 11 has microstructures 14a. In some embodiments, the thermally conductive auxiliary layer 14 may be formed on the surface of the reflective layer 12 by electron evaporation or sputtering. During the formation of the thermally conductive auxiliary layer 14, such as... Figure 2 As shown, an uneven microstructure 14a is naturally formed on its surface, with a height H between 50-950 nm. Since the first adhesive layer 13 is pressed and embedded into the gaps between the microstructures 14a, the thermally conductive auxiliary layer 14 shortens the thermal barrier distance from the reflective layer 12 to the substrate 11 caused by the first adhesive layer 13. This improves the heat dissipation capability of the LED package.

[0045] like Figure 3 and Figure 4 As shown, Figure 3 In the prior art, a light-emitting diode package that does not use the substrate 10 of this invention is subjected to a temperature test under a power condition of more than 1000 watts, and its average surface temperature reaches 140.6°C. Figure 4 The LED package using the structure of substrate 10 of this invention was subjected to temperature testing under power conditions exceeding 1000 watts, and its average surface temperature was only 119.6°C. This demonstrates that the structure of substrate 10 provided by this invention provides better heat dissipation for the package, making it suitable for higher power light-emitting devices. Preferably, the power density of the LED package provided by this invention can reach 0.6 W / mm². 2It is more than twice the size of a conventional package.

[0046] In some embodiments, the reflective layer 12 is, for example, made of aluminum with a thickness between 100-1000 μm, which has a high reflectivity of 99%, effectively improving the light extraction efficiency of the LED package. The substrate 11 can be made of materials including, but not limited to, one or more combinations of copper, aluminum, ceramic, or stainless steel, with a thickness between 1000-3000 μm, but is not limited thereto; the present invention does not impose any particular limitation on this. In the following description, the material of the substrate 11 is copper, therefore the material of the thermally conductive auxiliary layer 14 can also include copper. By using the same material as the substrate 11 for the thermally conductive auxiliary layer 14, the thermal conductivity from the thermally conductive auxiliary layer 14 to the substrate 11 can be improved by utilizing their similar material properties, i.e., their matching thermal conductivity. Furthermore, since the thermally conductive auxiliary layer 14 is made of the same material as the substrate 11, and their coefficients of thermal expansion are also the same, this effectively makes the coefficients of thermal expansion between the substrate 11 and the reflective layer 12 closer, reducing the adverse effects of delamination caused by the difference in thermal expansion between the two layers when heated. However, the present invention is not limited to this. In some embodiments, the material of the thermally conductive auxiliary layer 14 can also be a different material from the substrate 11. In order to enhance the thermal conductivity of the substrate 10, the difference in the coefficients of thermal expansion between the thermally conductive auxiliary layer 14 and the substrate 11 should not exceed 5 x 10. -6 / ℃, where the temperature condition for measuring the coefficient of thermal expansion is 20℃.

[0047] In some embodiments, such as Figure 2 As shown, the substrate 10 also includes a first insulating layer 15, a conductive line layer 16, and a second insulating layer 17 disposed on the reflective layer 12. The conductive line layer 16 is disposed on the upper surface of the first insulating layer 15, and the conductive line layer 16 is, for example, made of copper wire. The second insulating layer 17 covers the conductive line layer 16, and the upper surface of the second insulating layer 17 is also the first surface S1 of the substrate 10. Figure 5 As shown, Figure 5This is a top view of the LED package provided by the present invention. The second insulating layer 17 has several openings to expose portions of the conductive circuit layer 16, which serve as solder points 16a to the LED chip 20. Different types of encapsulation films can be applied over the LED chip 20 to provide mechanical protection or adjust the light emission effect, etc. The encapsulation film can be made of transparent materials such as silicone, but the concept of the present invention is not limited thereto. The first insulating layer 15 can be made of a high-temperature resistant transparent insulating material such as resin or glass fiber with a thickness between 50-400 micrometers, serving as a carrier for the conductive circuit layer 16 and the second insulating layer 17, and is connected to the reflective layer 12 via a second adhesive layer 18. Preferably, the second insulating layer 17 can be made of a high-temperature resistant transparent insulating material such as resin or glass fiber. The second insulating layer 17 can also be made of titanium dioxide, high-titanium powder, lithopone, or calcined white powder to cover the conductive circuit layer 16.

[0048] Example 2

[0049] This embodiment discloses a light-emitting diode package. The similarities with Embodiment 1, such as the structure above the reflective layer 12 and the selection of materials for each layer, will not be repeated here. Only the differences will be described in detail. The difference between this embodiment and Embodiment 1 is that the microstructure 14a is a regular pattern obtained by etching the thermally conductive auxiliary layer 14.

[0050] like Figure 6 As shown, Figure 6 This is a cross-sectional schematic diagram of an embodiment 2 of a light-emitting diode (LED) package provided by the present invention. In the fabrication process of the LED package shown in this embodiment, a thermally conductive auxiliary layer 14 with a thickness of 100-1000 nm can be deposited on the aluminum surface of the reflective layer 12. The thermally conductive auxiliary layer 14 is, for example, made of the same copper as the substrate 11. The thermally conductive auxiliary layer 14 is etched to form microstructures 14a with regular shapes, such as conical, quasi-conical, quasi-frustum, quasi-polygonal, quasi-frustum, cylindrical, or spherical shapes. Then, the reflective layer 12 with the thermally conductive auxiliary layer 14 is pressed onto the substrate 11 coated with a first adhesive layer 13. Preferably, the height H of the microstructure 14a can be controlled between 50-950 nm, and more preferably in the range of 200-500 nm. For example, forming... Figure 6 The conical microstructure 14a shown or as Figure 7 The spherical microstructure 14a is shown. In this embodiment, the height of the microstructure 14a to be fabricated can be better controlled by etching, and therefore the thickness of the thermally conductive auxiliary layer 14 to be deposited can also be better controlled to control costs.

[0051] Example 3

[0052] This embodiment discloses a light-emitting diode package. The similarities with Embodiment 1, such as the structure above the reflective layer 12 and the selection of materials for each layer, will not be repeated here. Only the differences will be described in detail. The difference between this embodiment and Embodiment 1 is that the thermally conductive auxiliary layer 14 is a structure in which several microstructures 14a are separated from each other.

[0053] like Figure 7 As shown, Figure 7 This is a cross-sectional schematic diagram of an embodiment 3 of a light-emitting diode package provided by the present invention. The thickness of the thermally conductive auxiliary layer 14 is controlled within the required thickness range of the microstructure 14a. Then, the thermally conductive auxiliary layer 14 is penetrated by etching, and the microstructure 14a directly contacts the lower surface of the reflective layer 12 and is separated from the adjacent microstructure 14a. In this way, while saving the material of the thermally conductive auxiliary layer 14, the stress between the thermally conductive auxiliary layer 14 and the reflective layer 12 when heated due to the difference in the thermal expansion coefficients of the materials of the thermally conductive auxiliary layer 14 and the reflective layer 12 can be reduced.

[0054] Example 4

[0055] This embodiment discloses a light-emitting diode package. The similarities with Embodiment 1, such as the structure above the reflective layer 12 and the selection of materials for each layer, will not be repeated here. Only the differences will be described in detail. The difference between this embodiment and Embodiment 1 is that the first functional layer in this embodiment is the substrate 11 and the second functional layer is the reflective layer 12.

[0056] like Figure 8 As shown, Figure 8 This is a cross-sectional schematic diagram of embodiment 3 of the light-emitting diode package provided by the present invention. An aluminum material with a thickness of 100-1000 nm can be deposited as a thermally conductive auxiliary layer 14 on a substrate 11, for example, using copper. The microstructure 14a can be formed naturally during the deposition process or formed by etching; the latter will be used as an example in this embodiment. Then, a first adhesive layer 13 is coated on the thermally conductive auxiliary layer 14. Finally, a reflective layer 12, for example made of aluminum, is pressed and bonded onto the substrate 11 with the thermally conductive auxiliary layer 14.

[0057] The LED package provided by the present invention, by providing a thermally conductive auxiliary layer with a microstructure on one side of the first functional layer in the second functional layer, and then bonding the second functional layer with the thermally conductive auxiliary layer to the first functional layer through a first adhesive layer, allows the microstructure on the surface of the thermally conductive auxiliary layer to be pressed and embedded into the first adhesive layer, thereby shortening the thermal conduction distance between the first functional layer and the second functional layer or between the second functional layer and the first functional layer. Compared with the prior art without a thermally conductive auxiliary layer, the LED package of the present invention has greatly enhanced heat dissipation performance.

[0058] It should be understood that the present invention is illustrated using the substrate 11 and the reflective layer 12 as the first and second functional layers, respectively. However, the present invention is not limited to this; the first and second functional layers can also be other structures within the encapsulation structure. The present invention is applicable to structures that require improved thermal conductivity.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light-emitting diode package, characterized in that, include: A substrate having a first surface and a second surface facing away from each other; A light-emitting diode chip is disposed on the first surface; The substrate includes a first functional layer and a second functional layer, which are bonded together by a first adhesive layer; The substrate further includes a thermally conductive auxiliary layer, which is disposed on the side of the second functional layer opposite to the first functional layer. The surface of the thermally conductive auxiliary layer opposite to the first functional layer has a microstructure; the microstructure is embedded in the first adhesive layer.

2. The light-emitting diode package according to claim 1, characterized in that: The thermally conductive auxiliary layer is formed on the surface of the second functional layer by electron evaporation or sputtering.

3. The light-emitting diode package according to claim 2, characterized in that: The microstructure is an irregular pattern that forms naturally during the formation of the thermally conductive auxiliary layer.

4. The light-emitting diode package according to claim 2, characterized in that: The microstructure is a regular pattern formed by etching the thermally conductive auxiliary layer.

5. The light-emitting diode package according to claim 4, characterized in that: The microstructure is conical, quasi-conical, quasi-frustum, quasi-polygonal, quasi-frustum, cylindrical, or spherical.

6. The light-emitting diode package according to claim 1, characterized in that: The difference in thermal expansion coefficients between the thermally conductive auxiliary layer and the first functional layer is no greater than 5 x 10⁻⁶. -6 / ℃.

7. The light-emitting diode package according to claim 1, characterized in that: The thermally conductive auxiliary layer comprises a material selected from one or more combinations of copper, aluminum, ceramic, or stainless steel.

8. The light-emitting diode package according to claim 1, characterized in that: The thermally conductive auxiliary layer contains the same material as the first functional layer.

9. The light-emitting diode package according to claim 1, characterized in that: The thickness of the thermally conductive auxiliary layer is between 100 and 1000 nm.

10. The light-emitting diode package according to claim 1, characterized in that: The height of the microstructure is between 50 and 950 nm.

11. The light-emitting diode package according to claim 1, characterized in that: The thickness of the first adhesive layer is between 2 and 25 μm.

12. The light-emitting diode package according to claim 1, characterized in that: The first functional layer is the substrate of the substrate, and the second functional layer is the reflective layer of the substrate.

13. The light-emitting diode package according to claim 1, characterized in that: The first functional layer is the reflective layer of the substrate, and the second functional layer is the substrate.

14. The light-emitting diode package according to claim 12 or 13, characterized in that: The reflective layer is disposed on the substrate, the substrate comprising one or more of the following materials: copper, aluminum, ceramic, or stainless steel, the reflective layer comprising the material aluminum, the thickness of the substrate being between 1000-3000 μm, and the thickness of the reflective layer being between 100-1000 μm.

15. The light-emitting diode package according to claim 14, characterized in that: The substrate further includes a first insulating layer, a conductive line layer, and a second insulating layer. The first insulating layer is disposed on the reflective layer through a second adhesive layer. The conductive line layer is disposed on the first insulating layer. The second insulating layer covers the conductive line layer. The second insulating layer has a plurality of openings to expose the conductive line layer to form a plurality of solder joints.

16. A light-emitting device, characterized in that: Includes a light-emitting diode package as described in any one of claims 1-15.

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