An LED chip structure, a manufacturing method thereof, and an electronic device

Abstract

The present invention provides an LED chip structure, a manufacturing method thereof, and an electronic device. Based on the conventional LED chip structure, the edge of the back metal plate is shrunk towards the center, that is, a part of the material containing irregular crystal phases at the edge of the back metal plate is removed. The present invention processes the irregular crystal phases in the conventional initial LED chip structure, effectively improves the surface flatness of the LED chip structure, enhances the fitting degree between the LED chip structure and the package body, reduces the void ratio after die bonding, facilitates the volatilization of organic pollutants during the packaging process, and improves the packaging effect of the LED chip structure.

Description

Technical Field

[0001] This application relates to the field of LED chip manufacturing, and particularly to an LED chip structure, a manufacturing method thereof, and an electronic device. Background Art

[0002] During the manufacturing process of LED chips, the chips are not independent but are integrally connected together. Laser cutting operation is carried out only after most of the manufacturing processes are completed to obtain independent LED chips, as Figure 1 shown. The laser is focused and irradiated onto the material, causing the surface temperature of the cut material to rise rapidly. The material heated by the laser starts to melt, forming a liquid phase and partial vaporization, forming high-pressure steam, which is ejected at an extremely high speed. At the same time, the high-concentration gas causes the liquid-phase processed material to move to the edge of the molten pool, forming a depression in the center of the molten pool and deepening the ablation effect. Since the laser cutting operation process is a high-temperature, high-heat, and high-speed process, irregular remelting is likely to occur after the liquid phase cools, and irregular crystal phases are likely to form at the chip edge, as Figure 2 shown. The existence of irregular crystal phases will cause the LED chips to not fit well with the encapsulation body during the encapsulation process, affecting the encapsulation effect. Summary of the Invention

[0003] To solve one of the above technical problems, the present invention provides an LED chip structure, a manufacturing method thereof, and an electronic device.

[0004] In a first aspect of an embodiment of the present invention, an LED chip structure is provided, including:

[0005] A first semiconductor layer, a second semiconductor layer, and an active layer located between the first semiconductor layer and the second semiconductor layer,

[0006] A first conductive layer forming an ohmic contact with the first semiconductor layer, a reflective layer electrically connected to the first conductive layer, a second conductive layer electrically connected to the reflective layer, and an electrode electrically connected to the second conductive layer. The first conductive layer, the reflective layer, the second conductive layer, and the electrode together form a first electrical connection layer,

[0007] A depression penetrating through the first semiconductor layer and the active layer and extending into the second semiconductor layer,

[0008] A first insulating layer in partial contact with the surface of the first semiconductor layer and partially exposed outside the second semiconductor layer, a second insulating layer covering the sidewall of the depression and one side of the first electrical connection layer, a third conductive layer partially contacting the surface of the second insulating layer and electrically connected to the second semiconductor layer, and a substrate contacting the third conductive layer,

[0009] A back metal plate covering the surface of the substrate,

[0010] The edge of the back metal plate shrinks toward the center, and no crystal phase exists on the surface of the back metal plate.

[0011] Preferably, the longitudinal section of the back metal plate is trapezoidal, and the lower bottom of the back metal plate is in contact with the substrate.

[0012] Preferably, the back metal plate is a multi-layer metal structure.

[0013] Preferably, the back metal plate includes a first back metal layer and a second back metal layer, and the second back metal layer is wrapped on the surface of the first back metal layer.

[0014] Preferably, the first conductive layer, the second conductive layer, the third conductive layer and the electrode are all multi-layer metal structures.

[0015] Preferably, when the substrate is made of a non-conductive material, the third conductive layer is a second electrical connection layer; when the substrate is conductive, the third conductive layer and the substrate together constitute an electrical connection layer.

[0016] A second aspect of an embodiment of the present invention provides a method for manufacturing an LED chip structure, the method being applied to the manufacture of an independent initial LED chip structure obtained by cutting an LED chip board, wherein a crystal phase protruding from the surface of the back metal plate is formed on the edge surface of the back metal plate of the initial LED chip structure;

[0017] The method comprises:

[0018] The edge of the back metal plate in the initial LED chip structure includes a portion of material containing the crystal phase protruding from the surface of the back metal plate, thereby obtaining a final LED chip structure in which the edge of the back metal plate shrinks toward the center and no crystal phase exists on the surface of the back metal plate.

[0019] A third aspect of the embodiments of the present invention provides an electronic device, wherein the electronic device comprises the LED chip structure described in the first aspect of the embodiments of the present invention.

[0020] The beneficial effects of the present invention are as follows: the LED chip structure and its manufacturing method proposed in the present invention can process the irregular crystal phase in the conventional initial LED chip structure, effectively improve the surface flatness of the LED chip structure, improve the fit between the LED chip structure and the packaging body, reduce the void rate after solid crystal, facilitate the volatilization of organic pollutants during the packaging process, and improve the packaging effect of the LED chip structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0022] Figure 1 It is a schematic diagram of the LED chip board cutting process;

[0023] Figure 2 It is a schematic structural diagram of the existing LED chip structure;

[0024] Figure 3 It is a schematic structural diagram of the LED chip structure described in Embodiment 1 of the present invention;

[0025] Figure 4 It is another schematic structural diagram of the LED chip structure described in Embodiment 1 of the present invention.

[0026] Reference numerals:

[0027] 1, the first semiconductor layer, 2, the second semiconductor layer, 3, the active layer, 4, the first conductive layer, 5, the reflective layer, 6, the second conductive layer, 7, the electrode, 8, the depression, 9, the first insulating layer, 10, the second insulating layer, 11, the third conductive layer, 12, the substrate, 13, the back metal plate, 14, the crystal phase;

[0028] 13-1, the first back metal layer, 13-2, the second back metal layer. Detailed implementation manners

[0029] In order to make the technical solutions and advantages in the embodiments of the present application clearer and more understandable, the following further details the exemplary embodiments of the present application with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than an exhaustive list of all embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0030] Embodiment 1

[0031] As Figure 2 shown, it is an LED chip structure, and the LED chip structure specifically includes:

[0032] The first semiconductor layer 1, the second semiconductor layer 2, and the active layer 3 located between the first semiconductor layer 1 and the second semiconductor layer 2,

[0033] A first conductive layer 4 that forms an ohmic contact with the first semiconductor layer 1, a reflective layer 5 that is electrically connected to the first conductive layer 4, a second conductive layer 6 that is electrically connected to the reflective layer 5, and an electrode 7 that is electrically connected to the second conductive layer 6. The first conductive layer 4, the reflective layer 5, the second conductive layer 6, and the electrode 7 together form a first electrical connection layer.

[0034] A recess 8 that penetrates through the first semiconductor layer 1 and the active layer 3 and extends into the second semiconductor layer 2.

[0035] A first insulating layer 9 that is in partial contact with the surface of the first semiconductor layer 1 and partially exposed outside the second semiconductor layer 2, a second insulating layer 10 that covers the sidewall of the recess 8 and one side of the first electrical connection layer, a third conductive layer 11 that is partially in contact with the surface of the second insulating layer 10 and forms an electrical connection with the second semiconductor layer 2, and a substrate 12 that is in contact with the third conductive layer 11.

[0036] A back metal plate 13 that covers the surface of the substrate 12.

[0037] Among them, the first conductive layer 4, the second conductive layer 6, the third conductive layer 11, and the electrode 7 are all multi-layer metal structures. When the substrate 12 is a non-conductive material, the third conductive layer 11 is a second electrical connection layer; when the substrate 12 is conductive, the third conductive layer 11 and the substrate 12 together form an electrical connection layer.

[0038] The above LED chip structure is a conventional structure of the existing LED chip structure. In the conventional structure of this LED chip structure, due to the influence of factors such as high temperature and high heat during the laser cutting process, irregular crystal phases 14 will be formed at the edge of the back metal plate 13. Therefore, in this embodiment, on the basis of the conventional LED chip structure, the back metal plate 13 is processed. Specifically, the edge of the back metal plate 13 is shrunk towards the center, that is, the part of the material containing the irregular crystal phase 14 at the edge of the back metal plate 13 is removed, as Figure 3 shown. Thereby improving the surface flatness of the back metal plate 13, enhancing the adhesion between the back metal plate 13 and the package, reducing the void ratio after die bonding, facilitating the volatilization of organic pollutants during the packaging process, and improving the packaging effect of the LED chip structure.

[0039] In this embodiment, the back metal plate 13 can be covered on the substrate 12 by evaporation. The longitudinal section of the back metal plate 13 is trapezoidal, and the long lower base of the back metal plate 13 is in contact with the substrate 12. Due to the height difference between the middle region and the edge region of the back metal plate 13 with this structure, during the packaging process, it helps the volatilization of organic pollutants in the middle region during die bonding.

[0040] Furthermore, in this embodiment, the back metal plate 13 may be a multi-layer metal structure. This embodiment takes a back metal plate 13 with a double-layer metal structure as an example. Figure 4 As shown. The back metal plate 13 includes a first back metal layer 13-1 and a second back metal layer 13-2. When there is only the first back metal layer 13-1, the surface area of the first back metal layer 13-1 is small. In order to improve the adhesion between the edge metal and the substrate 12 and improve the phenomenon of the back metal plate 13 falling off, the second back metal layer 13-2 is wrapped on the surface of the first back metal layer 13-1 to increase the effective area of the die bonding, which can further improve the packaging effect of the LED chip structure.

[0041] Example 2

[0042] This embodiment proposes a method for manufacturing an LED chip structure. The LED chip structure can refer to the content described in Embodiment 1, and this embodiment will not be repeated. The method proposed in this embodiment is applied to the manufacture of an independent initial LED chip structure obtained by cutting an LED chip board, and a crystal phase 14 protruding from the surface of the back metal plate 13 is formed on the edge surface of the back metal plate 13 of the initial LED chip structure;

[0043] The method includes:

[0044] The edge of the back metal plate 13 in the initial LED chip structure includes a portion of material containing the crystal phase 14 protruding from the surface of the back metal plate 13 , thereby obtaining a final LED chip structure in which the edge of the back metal plate 13 shrinks toward the center and no crystal phase 14 exists on the surface of the back metal plate 13 .

[0045] Specifically, in this embodiment, since the back metal plate 13 and the substrate 12 are made of two different materials, the adhesion between the bonding surfaces of the back metal plate 13 and the substrate 12 is relatively weak. Therefore, under the action of mechanical external force, the edge of the back metal plate 13 can be easily removed, thereby removing the crystal phase 14 on the surface of the back metal plate 13. Of course, this embodiment does not specifically limit the method of removing the material of the edge of the back metal plate 13, as long as the LED chip structure finally obtained in this embodiment can be achieved.

[0046] Example 3

[0047] This embodiment provides an electronic device, which includes the LED chip structure described in Embodiment 1, which will not be described in detail here.

[0048] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A manufacturing method of an LED chip structure, characterized in that, The method is applied to the fabrication of an independent initial LED chip structure obtained by cutting an LED chip board. A crystal phase protruding from the surface of the back metal plate is formed on the edge surface of the back metal plate of the initial LED chip structure. The method includes: Removing a part of the material of the back metal plate edge of the initial LED chip structure that contains the crystal phase protruding from the surface of the back metal plate, to obtain a final LED chip structure in which the edge of the back metal plate shrinks towards the center and there is no crystal phase on the surface of the back metal plate. The LED chip structure includes: A first semiconductor layer, a second semiconductor layer, and an active layer located between the first semiconductor layer and the second semiconductor layer. A first conductive layer forming an ohmic contact with the first semiconductor layer, a reflective layer electrically connected to the first conductive layer, a second conductive layer electrically connected to the reflective layer, and an electrode electrically connected to the second conductive layer. The first conductive layer, the reflective layer, the second conductive layer, and the electrode together form a first electrical connection layer. A depression penetrating through the first semiconductor layer and the active layer and extending into the second semiconductor layer. A first insulating layer in partial contact with the surface of the first semiconductor layer and partially exposed outside the second semiconductor layer, a second insulating layer covering the sidewall of the depression and one side of the first electrical connection layer, a third conductive layer partially contacting the surface of the second insulating layer and electrically connected to the second semiconductor layer, and a substrate contacting the third conductive layer. A back metal plate covering the surface of the substrate. The edge of the back metal plate shrinks towards the center, and there is no crystal phase on the surface of the back metal plate. The longitudinal section of the back metal plate is trapezoidal, and the lower base of the back metal plate is attached to the substrate. The back metal plate is a multi-layer metal structure. The back metal plate includes a first back metal layer and a second back metal layer, and the second back metal layer wraps around the surface of the first back metal layer. The first conductive layer, the second conductive layer, the third conductive layer, and the electrode are all multi-layer metal structures. When the substrate is a non-conductive material, the third conductive layer is a second electrical connection layer; when the substrate is conductive, the third conductive layer and the substrate together form an electrical connection layer.

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