LED chip and LED display panel

Abstract

The embodiment of the invention relates to the technical field of design and manufacturing of display devices, and discloses an LED chip and an LED display panel. The LED chip provided by the embodiment of the invention comprises an LED structure layer which comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer which are stacked in sequence; the electrode structure layer comprises a first conducting layer, a second conducting layer, a first electrode and a second electrode, and the first conducting layer and the second conducting layer are sequentially arranged on the LED structure layer at intervals; one end of the first conducting layer and one end of the second conducting layer are both connected with the first semiconductor layer, the other end of the first conducting layer and the other end of the second conducting layer are both connected with the second semiconductor layer, the first electrode is connected to the first conducting layer, and the second electrode is connected to the second conducting layer. The polarities of the two electrodes of the LED chip are not distinguished, and the LED chip can be flexibly pasted and manufactured, so that the manufacturing process of the LED display panel can be saved, the manufacturing efficiency of the LED display panel can be improved, and the material cost can be saved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of display device design and manufacturing, and in particular to an LED chip and an LED display panel. Background Art

[0002] Compared with other active light sources, light-emitting diodes (LEDs) have many advantages such as small size, long life, low power consumption, high brightness, and fast response speed, and are increasingly used in life.

[0003] At present, the electrodes of Micro LED chips are divided into positive and negative poles, which has many impacts on the production and packaging of LED chips. Among them, in the process of mass transfer of Micro LED chips, the orientation of the blue film needs to be adjusted according to the positive and negative poles of the chip. In addition, when packaging the Micro LED chip on the light board, the positive and negative poles of the chip must also be distinguished. In addition, when designing the light board, the chip pads also need to distinguish between positive and negative poles, fix the polarity of the chip pads, or transpose the chip for wiring convenience.

[0004] However, the steps of adjusting the orientation of the blue film, fixing the polarity of the chip pad, and transposing the chip will increase the manufacturing process of the LED display panel, resulting in low manufacturing efficiency and high material loss. Summary of the invention

[0005] In view of this, the embodiments of the present application provide an LED chip and an LED display panel. The two electrodes of the LED chip do not distinguish between polarities, and the LED chip can be flexibly patched, which can save the production process of the LED display panel, improve the production efficiency of the LED display panel, and save material costs.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the embodiment of the present application is implemented as follows:

[0007] One aspect of an embodiment of the present application provides an LED chip, including: an LED structure layer, including a first semiconductor layer, a light-emitting layer and a second semiconductor layer stacked in sequence, the polarity of the first semiconductor layer is opposite to the polarity of the second semiconductor layer; an electrode structure layer, including a first conductive layer, a second conductive layer, a first electrode and a second electrode, the first conductive layer and the second conductive layer are sequentially spaced above the LED structure layer, and one end of the first conductive layer and one end of the second conductive layer are both connected to the first semiconductor layer, the other end of the first conductive layer and the other end of the second conductive layer are both connected to the second semiconductor layer, the first electrode is connected to the first conductive layer, and the second electrode is connected to the second conductive layer.

[0008] The LED chip provided in the embodiment of the present application includes an LED structure layer and an electrode structure layer arranged on the LED structure layer, and the electrode structure layer is used to pass current to make the LED structure layer emit light. Among them, the electrode structure layer includes a first conductive layer, a second conductive layer, a first electrode and a second electrode, and the first conductive layer and the second conductive layer are arranged on the LED structure layer in sequence, and one end of the first conductive layer and one end of the second conductive layer are connected to the first semiconductor layer, and the other end of the first conductive layer and the other end of the second conductive layer are connected to the second semiconductor layer, and the first electrode is connected to the first conductive layer, and the second electrode is connected to the second conductive layer. In this way, no matter how the positive and negative polarity of the first electrode and the second electrode connected to the external circuit is, the current loop of the LED structure layer will be conducted through the first conductive layer and the second conductive layer to realize the light emission of the LED chip. Therefore, the electrodes of the LED chip do not distinguish between positive and negative polarity, and flexible patch bonding can be realized, saving the production process of the LED display panel and improving the production efficiency of the LED display panel. In addition, the material loss caused by the reverse polarity of the LED chip can be reduced, saving material costs.

[0009] In a possible implementation, an insulating layer is disposed between the first conductive layer and the second conductive layer, conductive vias are provided through the insulating layer and the second conductive layer, and the first electrode is connected to the first conductive layer through the conductive vias.

[0010] In this way, the insulating layer insulates and isolates the second conductive layer from the first conductive layer, thereby preventing the first conductive layer and the second conductive layer from short-circuiting. In addition, by forming conductive vias in the second conductive layer and the insulating layer, electrical connection between the first electrode and the first conductive layer is achieved.

[0011] In a possible implementation manner, the second conductive layer is disposed around the outer periphery of the conductive via, and the second conductive layer extends toward the edge of the electrode structure layer, and the second conductive layer and the conductive via are insulated and isolated.

[0012] In this way, the second conductive layer occupies a larger plane space, and there is no need to fill too much insulating material in the structural layer where the second conductive layer is located. The structural layer where the second conductive layer is located has better integrity and higher flatness, which is conducive to improving the flatness of the LED chip. In addition, the location of the second electrode is more flexible.

[0013] In a possible implementation, the first electrode and the second electrode are respectively located at opposite side edges of the electrode structure layer; or, the first electrode is located in the middle region of the electrode structure layer, and the second electrode is located at the edge of the electrode structure layer.

[0014] In a possible embodiment, the LED structure layer includes a first sub-pixel and a second sub-pixel arranged side by side, the first semiconductor layer of the first sub-pixel has a first extension portion, and the first extension portion extends to the side of the first sub-pixel, and the first semiconductor layer of the second sub-pixel has a second extension portion, and the second extension portion extends to the side of the second sub-pixel; the two ends of the first conductive layer are respectively connected to the first extension portion and the second semiconductor layer of the second sub-pixel, and the two ends of the second conductive layer are respectively connected to the second semiconductor layer of the first sub-pixel and the second extension portion.

[0015] In this way, the current can flow in different directions in the first conductive layer and the second conductive layer, and the first electrode and the second electrode can be realized without distinguishing between positive and negative polarities. When the first electrode is used as the positive electrode and the second electrode is used as the negative electrode, the second sub-pixel can be lit. When the second electrode is used as the positive electrode and the first electrode is used as the negative electrode, the first sub-pixel can be lit.

[0016] In a possible implementation manner, the first extending portion extends out from a side of the first sub-pixel close to the second sub-pixel, and the second extending portion extends out from a side of the second sub-pixel away from the first sub-pixel.

[0017] In this way, the distance between the first extension in the first sub-pixel and the second sub-pixel is small, and the first conductive layer can be connected between the two sides of the first sub-pixel and the second sub-pixel that are close to each other. The coverage area of ​​the first conductive layer is small, which can reduce the material usage of the first conductive layer and reduce the production cost of the LED chip.

[0018] In a possible embodiment, the first semiconductor layer has an extension portion, which extends to the side of the LED structure layer; one end of the first conductive layer and one end of the second conductive layer are both connected to the extension portion, and the other end of the first conductive layer and the other end of the second conductive layer are both connected to a side of the second conductive layer away from the extension portion.

[0019] In this way, the LED structure layer is an integral structure. No matter the first electrode is used as the positive electrode and the second electrode is used as the negative electrode, or the second electrode is used as the positive electrode and the first electrode is used as the negative electrode, the pixels in the LED structure layer can be lit. Moreover, the opening area of ​​the pixel is large, and the luminous efficiency of the LED chip is high.

[0020] In a possible implementation, the LED structure layer further includes: a substrate; a buffer layer disposed on the substrate, and the first semiconductor layer disposed on the buffer layer.

[0021] In this way, the substrate can be used as a basic support structure, and other structural layers of the LED chip can be formed on the substrate in sequence, and the substrate supports and protects the structural layers thereon. In addition, by arranging a buffer layer between the substrate and the first semiconductor layer, the buffer layer forms a transition between the substrate and the first semiconductor layer, weakens the interface stress between the two, and enhances the stability and reliability of the LED structural layer.

[0022] In a possible implementation, one of the first semiconductor layer and the second semiconductor layer is an n-type gallium nitride layer, and the other is a p-type gallium nitride layer.

[0023] In this way, the first semiconductor layer, the light-emitting layer and the second semiconductor layer together form a PN junction. Electrons dominate in the first semiconductor layer, and holes dominate in the second semiconductor layer. When current passes through, electrons and holes recombine in the light-emitting layer between the two and emit energy in the form of photons.

[0024] Another aspect of the embodiments of the present application provides an LED display panel, including a light board and a plurality of LED chips as described above, each LED chip being packaged in the light board.

[0025] The LED display panel provided in the embodiment of the present application includes the aforementioned LED chip and has all the technical effects of the LED chip, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art description are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of the structure of an LED chip provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of the structure of another LED chip provided in an embodiment of the present application;

[0029] Figure 3 for Figure 1 A or Figure 2 A partial enlarged view of point B in the middle;

[0030] Figure 4 A partial stereoscopic diagram of an electrode structure layer provided in an embodiment of the present application;

[0031] Figure 5-Figure 29 This is a flow chart of the manufacturing process of the LED chip provided in the embodiment of the present application.

[0032] Description of reference numerals:

[0033] 100-LED chips;

[0034] 110-LED structure layer;

[0035] 110a-first sub-pixel; 110b-second sub-pixel;

[0036] 111 - substrate; 112 - first semiconductor layer; 113 - light emitting layer; 114 - second semiconductor layer; 115 - buffer layer;

[0037] 1121-extending portion; 1121a-first extending portion; 1121b-second extending portion;

[0038] 120-electrode structure layer;

[0039] 121 - first conductive layer; 122 - second conductive layer; 123 - first electrode; 124 - second electrode; 125 - insulating layer; 126 - conductive via;

[0040] a-conductive contact part; b-flat layer; c-initial conductive layer; d-photosensitive film layer; e-etched opening; f-connecting hole; g-first electrode layer. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the specific technical solution of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0042] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more.

[0043] In addition, in the embodiments of the present application, directional terms such as "up", "down", "left" and "right" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they may change accordingly according to the changes in the orientation of the components in the drawings.

[0044] In the embodiments of the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0045] In the embodiments of the present application, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0046] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0047] As described in the background technology, the electrodes of existing Micro LED chips have positive and negative polarities. During the production and packaging process of Micro LED chips, it is necessary to distinguish the positive and negative poles of the chips.

[0048] For example, during the mass transfer of Micro LED chips to the blue film, the position of the blue film needs to be adjusted according to the positive and negative poles of the chips. Generally, N and / or S are marked on the blank positions on the blue film (positions where Micro LED chips do not need to be attached). When the blue film is put on the shelf, the operator needs to roughly adjust the position of N and / or S on the blue film, and then the mass transfer equipment will correct the position of the blue film.

[0049] For example, when transferring the Micro LED chip on the blue film to the light board, it is generally transferred monochrome in sequence according to the luminous color (for example, the red light emitting chip is transferred first, then the green light emitting chip, and finally the blue light emitting chip), and the positive and negative poles of each chip need to be identified.

[0050] In addition, when designing the light board, it is also necessary to screen print the chip pads to distinguish the positive and negative poles to fix the polarity of the chip pads. Sometimes, for the convenience of wiring, the polarity of the chip pads is also transposed. If the polarity direction of the chip pads is fixed, it will be inconvenient for the wiring of the light board and the number of layers of the light board will increase. If the chip pads are transposed, the transposition process during chip packaging will be increased, and the man-hours for chip packaging will increase.

[0051] Therefore, since the electrodes of the Micro LED chip need to distinguish between positive and negative polarities, it is necessary to adjust the orientation of the blue film, identify the positive and negative poles of the chip, and transpose the chip, which will increase the production process of the LED display panel and reduce the production efficiency of the LED display panel. In addition, the blue film or the chip itself will be lost due to the reverse polarity of the chip, affecting the process of the LED display panel.

[0052] In view of this, the embodiment of the present application provides an LED chip and an LED display panel, wherein the LED chip includes an LED structure layer and an electrode structure layer arranged on the LED structure layer, and the electrode structure layer is used to pass current to make the LED structure layer emit light. Wherein, the electrode structure layer includes a first conductive layer, a second conductive layer, a first electrode and a second electrode, by sequentially arranging the first conductive layer and the second conductive layer on the LED structure layer, and connecting one end of the first conductive layer and one end of the second conductive layer to the first semiconductor layer, connecting the other end of the first conductive layer and the other end of the second conductive layer to the second semiconductor layer, connecting the first electrode to the first conductive layer, and connecting the second electrode to the second conductive layer. In this way, regardless of the positive and negative polarity of the first electrode and the second electrode connected to the external circuit, the current loop of the LED structure layer will be conducted through the first conductive layer and the second conductive layer to realize the light emission of the LED chip. Thus, the electrodes of the LED chip do not distinguish between positive and negative polarity, and flexible patch bonding can be realized, saving the production process of the LED display panel and improving the production efficiency of the LED display panel. In addition, the material loss caused by the reverse polarity of the LED chip can be reduced, saving material costs.

[0053] The embodiment of the present application provides an LED display panel, which may include a light board and a plurality of LED chips, which are all packaged in the light board, and the plurality of LED chips may be arranged in an array on the light board, for example. Exemplarily, the light board may be a printed circuit board (PCB), or the light board may be a glass substrate or a plastic substrate with a circuit arranged thereon.

[0054] LED chips are the basic display units of LED display panels. For the entire LED display panel, by controlling whether each LED chip on the light board emits light and controlling the light brightness of each LED chip, the LED display panel can display images, text and other information.

[0055] Each LED chip arranged on the light board can be considered to be composed of a plurality of minimum display units. The display function of the LED display panel is realized by controlling the light-emitting state of each minimum display unit.

[0056] For example, the smallest display unit in an LED display panel can be composed of LED chips that emit red, green, and blue. By controlling the brightness of pixels of different colors in each smallest display unit, the smallest display unit can display a mixture of three colors. In this case, the LED display panel can display colorful images and videos, and can achieve full-color display of the LED display panel.

[0057] Alternatively, the smallest display unit in the LED display panel can be composed of LED chips that emit two colors. For example, the smallest display unit in the LED display panel is composed of LED chips that emit red and green, red and blue, or green and blue. By controlling the light luminance of the pixels of the two colors in each smallest display unit, the smallest display unit can display a mixed effect of the two colors. In this case, the LED display panel can display simple dynamic images.

[0058] Alternatively, the smallest display unit in the LED display panel can only emit a single color. For example, the smallest display unit is composed of a single-color LED chip that emits red, green or blue. By controlling the light-emitting brightness of the single-color pixel in each smallest display unit, the smallest display unit displays a monochrome effect. In this case, the LED display panel can only display images and texts in a single color.

[0059] The LED chip provided in the embodiment of the present application is described in detail below. The LED chip is, for example, a Micro LED chip.

[0060] Figure 1 A schematic diagram of the structure of an LED chip provided in an embodiment of the present application. Figure 2 A schematic diagram of the structure of another LED chip provided in an embodiment of the present application.

[0061] Reference Figure 1 or Figure 2 As shown, in this embodiment, the LED chip 100 includes an LED structure layer 110 and an electrode structure layer 120, and the electrode structure layer 120 is arranged on the LED structure layer 110. Pixels are formed in the LED structure layer 110, and the pixels can emit light. The electrode structure layer 120 is used to connect to an external circuit. For example, the electrode structure layer 120 is connected to the external circuit through the pads on the lamp board to light up the pixels in the LED structure layer 110.

[0062] Reference Figure 1 or Figure 2, the LED structure layer 110 may include a substrate 111 and an LED device formed on the substrate 111. The substrate 111 serves as the basic support structure of the LED chip 100, and other structure layers of the LED chip 100 may be sequentially formed on the substrate 111 to ensure the stability and reliability of the LED chip 100. The LED device is the core functional layer of the LED chip 100, and the function of the LED chip 100 is realized by the light emission of the LED device.

[0063] Exemplarily, the substrate 111 may be a rigid substrate, and the substrate 111 is made of a hard material. For example, the material of the substrate 111 may be silicon carbide (SiC), silicon (Si) or sapphire (Al2O3). In this case, a separate substrate 111 may be provided, and other structural layers of the LED chip 100 may be directly formed on the substrate 111.

[0064] Alternatively, the substrate 111 may be a flexible substrate, and the substrate 111 is made of a flexible material. For example, the material of the substrate 111 may be polyimide (PI for short), and the substrate 111 is a polyimide film. In this case, the flexible substrate 111 may be firstly pasted on a rigid substrate, and after other structural layers of the LED chip 100 are formed on the substrate 111, the substrate 111 may be peeled off from the rigid substrate.

[0065] The LED device may include a first semiconductor layer 112, a light-emitting layer 113, and a second semiconductor layer 114, wherein the first semiconductor layer 112, the light-emitting layer 113, and the second semiconductor layer 114 are sequentially stacked on the substrate 111. The polarity of the first semiconductor layer 112 is opposite to that of the second semiconductor layer 114. One of the first semiconductor layer 112 and the second semiconductor layer 114 is an n-type semiconductor layer, and the other is a p-type semiconductor layer. The light-emitting layer 113 is sandwiched between the n-type semiconductor layer and the p-type semiconductor layer, and the three together form a PN junction.

[0066] In the PN junction formed by the LED device, electrons dominate in the n-type semiconductor layer, and holes dominate in the p-type semiconductor layer. When current passes through the LED device, electrons and holes recombine in the light-emitting layer 113 between the two, and emit energy in the form of photons, thereby realizing the light-emitting function of the LED device. The light-emitting color of the LED device is determined by the material of the light-emitting layer 113. For example, the light emitted by the LED device can be red light, green light, or blue light.

[0067] When a forward voltage is applied to the LED device, that is, when the p-type semiconductor layer is connected to the positive electrode and the n-type semiconductor layer is connected to the negative electrode, the electrons in the n-type semiconductor layer are attracted and rush to the p-type semiconductor layer, and the holes in the p-type semiconductor layer move toward the n-type semiconductor layer, and current flows through the PN junction, and the LED device is lit. When a reverse voltage is applied to the LED device, that is, when the n-type semiconductor layer is connected to the positive electrode and the p-type semiconductor layer is connected to the negative electrode, the electrons in the n-type semiconductor layer gather in the n-type semiconductor layer, and the holes in the p-type semiconductor layer gather in the p-type semiconductor layer. The electrons do not move, and no current flows through the PN junction, and the LED device is turned off.

[0068] Exemplarily, in this embodiment, the semiconductor material selected for the LED device can be a third-generation semiconductor material. For example, the semiconductor material constituting the LED device can be gallium nitride (GaN), silicon carbide (SiC), aluminum nitride (AlN) or zinc oxide (ZnO). The bandgap width of these semiconductor materials is very large, generally greater than 2.3eV. For example, the bandgap width of GaN is 3.4eV, and the bandgap width of SiC is 3.2eV. The wide bandgap width makes these semiconductors have a large breakdown electric field. In addition, these semiconductors also have high thermal conductivity, high electron saturation rate, are more resistant to radiation than Si, and can be applied to high-power devices.

[0069] In this way, the breakdown electric field of the LED device is large, which can improve the reliability and service life of the LED device. In addition, the LED device has good thermal conductivity, which is conducive to improving the heat dissipation performance of the LED chip 100 and enhancing the stability of the LED chip 100. In addition, the LED chip 100 can be used in high-power LED display panels.

[0070] Continuing with the example that the first semiconductor layer 112 is an n-type semiconductor layer and the second semiconductor layer 114 is a p-type semiconductor layer, the first semiconductor layer 112 may be an n-type gallium nitride layer and the second semiconductor layer 114 may be a p-type gallium nitride layer. In this case, the light-emitting layer 113 disposed between the first semiconductor layer 112 and the second semiconductor layer 114 may be made of an indium gallium nitride (InGaN) material. In other words, the light-emitting layer 113 is an indium gallium nitride layer.

[0071] Reference Figure 1 or Figure 2 The LED structure layer 110 may further include a buffer layer 115, which is disposed between the substrate 111 and the first semiconductor layer 112. As a transition layer between the substrate 111 and the LED device, the buffer layer 115 may be made of a material similar to that of the LED device. The buffer layer 115 is used to reduce the interface stress between the substrate 111 and the LED device and enhance the stability and reliability of the LED structure layer 110.

[0072] Taking the first semiconductor layer 112 as an n-type gallium nitride layer as an example, the buffer layer 115 may also be made of gallium nitride material, and the buffer layer 115 may be an undoped gallium nitride layer.

[0073] Continue to refer to Figure 1 or Figure 2 In this embodiment, the electrode structure layer 120 disposed on the LED structure layer 110 includes a first conductive layer 121, a second conductive layer 122, a first electrode 123 and a second electrode 124. The first conductive layer 121 and the second conductive layer 122 are sequentially arranged on the LED structure layer 110 at intervals, one end of the first conductive layer 121 is connected to the first semiconductor layer 112, the other end of the first conductive layer 121 is connected to the second semiconductor layer 114, one end of the second conductive layer 122 is connected to the first semiconductor layer 112, and the other end of the second conductive layer 122 is connected to the second semiconductor layer 114. The first electrode 123 is connected to the first conductive layer 121, the second electrode 124 is connected to the second conductive layer 122, and the first electrode 123 and the second electrode 124 are both exposed on the surface of the LED chip 100.

[0074] After the LED chip 100 is packaged on the lamp board, it is connected to an external circuit by means of the first electrode 123 and the second electrode 124, and the current is transmitted in the LED structure layer 110 through the first conductive layer 121 and the second conductive layer 122 to light up the pixels in the LED structure layer 110. Among them, since the two ends of the first conductive layer 121 are respectively connected to the first semiconductor layer 112 and the second semiconductor layer 114, and the two ends of the second conductive layer 122 are also respectively connected to the first semiconductor layer 112 and the second semiconductor layer 114, the design of the current flow path in the first conductive layer 121, the LED structure layer 110 and the second conductive layer 122 is more flexible.

[0075] An insulating layer 125 is provided between the first conductive layer 121 and the second conductive layer 122. The insulating layer 125 is, for example, a silicon oxide layer, a silicon nitride layer, or a composite layer of silicon oxide and silicon nitride. The first conductive layer 121 and the second conductive layer 122 are insulated and isolated by the insulating layer 125 to avoid a short circuit between the first conductive layer 121 and the second conductive layer 122, thereby ensuring the working reliability of the LED chip 100.

[0076] In order to achieve the connection between the first electrode 123 and the first conductive layer 121, a conductive via 126 is provided in the second conductive layer 122 and the insulating layer 125, and the conductive via 126 penetrates the second conductive layer 122 and the insulating layer 125. The bottom end of the conductive via 126 is connected to the first conductive layer 121, and the first electrode 123 can be connected to the top end of the conductive via 126 to electrically connect the first electrode 123 to the first conductive layer 121 through the conductive via 126. The so-called conductive via 126 is a through-type via opened in the second conductive layer 122 and the insulating layer 125, and a conductive material is filled in the via to form the conductive via 126.

[0077] A flat layer (not shown) may also be provided on the second conductive layer 122, and the first electrode 123 and the second electrode 124 are exposed on the flat layer, so that the first electrode 123 and the second electrode 124 are electrically connected to an external circuit. The flat layer may also be formed of an insulating material, for example, the flat layer may be a silicon nitride layer, a silicon oxide layer, or a composite layer of silicon nitride and silicon oxide. The flat layer is used to flatten the entire LED chip 100 to improve the flatness of the LED chip 100. In addition, the structural layer located therebelow may be isolated and protected to isolate the LED chip 100 from the influence of external dust and water vapor.

[0078] With such a configuration, the current flow direction in the first conductive layer 121 and the second conductive layer 122 may not be fixed, and either the first electrode 123 or the second electrode 124 may be connected to the positive pole of the external circuit, and the other may be connected to the negative pole of the external circuit, and both may enable current to flow through the LED structure layer 110. Taking the first semiconductor layer 112 as an n-type semiconductor layer and the second semiconductor layer 114 as a p-type semiconductor layer as an example, regardless of the positive and negative polarities of the first electrode 123 and the second electrode 124 connected to the external circuit, it is possible to connect the second semiconductor layer 114 to the positive pole and the first semiconductor layer 112 to the negative pole, and apply a forward voltage to the LED structure layer 110 to light up the LED device.

[0079] Therefore, in this embodiment, the first electrode 123 and the second electrode 124 may not distinguish between positive and negative polarities, and the first electrode 123 may be used as a positive electrode and the second electrode 124 may be used as a negative electrode, or the second electrode 124 may be used as a positive electrode and the first electrode 123 may be used as a negative electrode.

[0080] In this way, in the process of transferring the LED chips 100 to the blue film, there is no need to manually adjust the position of the blue film, and the step of correcting the position of the blue film by the equipment can be omitted, and there is no need to locate the position of the LED chip 100 on the blue film. The process of mass transfer of LED chips 100 can be saved, and the efficiency of mass transfer of LED chips 100 can be improved. In addition, it can avoid the loss of blue film due to the wrong placement of one or several LED chips 100, saving the cost of using blue film.

[0081] Furthermore, in the process of transferring the LED chip 100 on the blue film to the lamp board, there is no need to identify the positive and negative poles of each LED chip 100. The LED chip 100 can be mounted on the lamp board at will by aligning the position of the LED chip 100 on the lamp board. The difficulty of transferring the LED chip 100 to the lamp board can be reduced, the efficiency of transferring the LED chip 100 to the lamp board can be improved, and the packaging efficiency of the LED display panel can be improved. Furthermore, the loss of the LED chip 100 or even the lamp board due to the polarity mounting error of one or several LED chips 100 can be avoided, the use cost of the LED chip 100 and the lamp board can be saved, and the packaging cost of the LED display panel can be reduced.

[0082] In addition, when designing the light board, there is no need to screen print the chip pads to distinguish the positive and negative poles, and there is no need to fix the polarity of the chip pads. In this way, even if the light board is wired, it is helpful to reduce the number of layers of the light board. In addition, there is no additional transposition process when packaging the LED chip 100, and the packaging time of the LED chip 100 is short and the packaging efficiency is high.

[0083] Reference Figure 1 As shown, as an implementation, the LED structure layer 110 can be divided into two parts, which are respectively defined as a first sub-pixel 110a and a second sub-pixel 110b in this embodiment. In the first sub-pixel 110a, the area of ​​the first semiconductor layer 112 can be larger than the area of ​​the second semiconductor layer 114 and the light-emitting layer 113, and the first semiconductor layer 112 has a first extension portion 1121a, and the first extension portion 1121a extends to the side of the first sub-pixel 110a. In the second sub-pixel 110b, the area of ​​the first semiconductor layer 112 can also be larger than the area of ​​the second semiconductor layer 114 and the light-emitting layer 113, and the first semiconductor layer 112 has a second extension portion 1121b, and the second extension portion 1121b extends to the side of the second sub-pixel 110b.

[0084] Among them, the two ends of the first conductive layer 121 can be respectively connected to the first extending portion 1121a of the first semiconductor layer 112 in the first sub-pixel 110a and the second semiconductor layer 114 in the second sub-pixel 110b, and the two ends of the second conductive layer 122 can be respectively connected to the second semiconductor layer 114 in the first sub-pixel 110a and the second extending portion 1121b of the first semiconductor layer 112 in the second sub-pixel 110b.

[0085] In this way, when the first electrode 123 is connected to the positive electrode of the external circuit and the second electrode 124 is connected to the negative electrode of the external circuit, that is, when the first electrode 123 is used as the positive electrode and the second electrode 124 is used as the negative electrode, the current flows along Figure 1 The second sub-pixel 110b can be lit by the thicker dotted arrow in the figure. When the second electrode 124 is connected to the positive electrode of the external circuit and the first electrode 123 is connected to the negative electrode of the external circuit, that is, the second electrode 124 is used as the positive electrode and the first electrode 123 is used as the negative electrode, the current flows along Figure 1 The first sub-pixel 110a can be lit by moving in the direction indicated by the thinner dotted arrow.

[0086] Since the first conductive layer 121 is connected between the first extension 1121a of the first semiconductor layer 112 in the first sub-pixel 110a and the second semiconductor layer 114 in the second sub-pixel 110b, the distance between the first extension 1121a and the second sub-pixel 110b can be reduced by designing the position of the first extension 1121a of the first sub-pixel 110a. Thus, the coverage area of ​​the first conductive layer 121 is reduced, the material usage of the first conductive layer 121 is reduced, and the manufacturing cost of the LED chip 100 is reduced.

[0087] For example, the first extension portion 1121a of the first semiconductor layer 112 in the first sub-pixel 110a extends out from a side of the first sub-pixel 110a close to the second sub-pixel 110b. In this way, the first conductive layer 121 can be connected between the two sides of the first sub-pixel 110a and the second sub-pixel 110b close to each other, and the coverage area of ​​the first conductive layer 121 can be minimized.

[0088] Reference Figure 2As shown, as another embodiment, the LED structure layer 110 can be an integral structure. In the LED structure layer 110, the area of ​​the first semiconductor layer 112 can be larger than the area of ​​the second semiconductor layer 114 and the light-emitting layer 113, and the first semiconductor layer 112 has an extension portion 1121, and the first semiconductor layer 112 extends to the side of the LED structure layer 110. Among them, the two ends of the first conductive layer 121 can be connected to the extension portion 1121 of the first semiconductor layer 112 and the second semiconductor layer 114 respectively, and the two ends of the second conductive layer 122 can also be connected to the extension portion 1121 of the first semiconductor layer 112 and the second semiconductor layer 114 respectively.

[0089] In this way, when the first electrode 123 is used as the positive electrode and the second electrode 124 is used as the negative electrode, the current flows along Figure 2 The current flows in the direction indicated by the thicker dotted arrow in the figure, and the pixels in the LED structure layer 110 can be lit. When the second electrode 124 is used as the positive electrode and the first electrode 123 is used as the negative electrode, the current flows in the direction indicated by the thicker dotted arrow in the figure, and the pixels in the LED structure layer 110 can be lit. Figure 2 The light flows in the direction indicated by the thinner dotted arrow, and the pixels in the LED structure layer 110 can also be illuminated.

[0090] Since the LED structure layer 110 is an integral structure, the pixels are not divided, so the opening area of ​​the pixels in the LED structure layer 110 is relatively large, and the luminous efficiency of the LED chip 100 is relatively high.

[0091] Figure 3 for Figure 1 A or Figure 2 A partial enlarged view of point B in the middle. Figure 4 This is a partial stereogram of the electrode structure layer provided in the embodiment of the present application. Figure 3 FIG. 2 shows the local structure of the height space where the second conductive layer 122 of the LED chip 100 is located. Figure 4 Schematic diagram of the spatial layout of the first electrode 123 and the second conductive layer 122 .

[0092] Combination Figure 3 and Figure 4 As shown, in this embodiment, the second conductive layer 122 is not arranged in a small area and occupies only a local area in the plane direction of the LED chip 100, but occupies a large area and is arranged according to the plane space of the LED chip 100. For example, in the plane direction of the LED chip 100, the contour edge of the second conductive layer 122 can extend to the edge of the substrate 111.

[0093] At this time, a connection hole with a smaller opening area may be opened in the second conductive layer 122 with a larger area, and the connection hole extends to communicate with the surface of the first conductive layer 121. The connecting hole is filled with insulating material, and a conductive via 126 is formed in the connecting hole. The cross-sectional area of ​​the conductive via 126 is smaller than the opening area of ​​the connecting hole, and there is a space between the outer wall of the conductive via 126 and the hole wall of the connecting hole, and the insulating material is filled in the space to insulate and isolate the conductive via 126 from the second conductive layer 122.

[0094] With such a configuration, the second conductive layer 122 occupies a larger plane space, and the second conductive layer 122 covers a larger area, so there is no need to fill too much insulating material in the structural layer where the second conductive layer 122 is located. The structural layer where the second conductive layer 122 is located has better integrity and higher flatness, which is beneficial to improving the flatness of the LED chip 100. In addition, the position design of the second electrode 124 is more flexible, and it is only necessary to ensure that the orthographic projection of the second electrode 124 on the electrode structural layer 120 is located within the coverage range of the second conductive layer 122, which does not have much impact on the manufacturing process of the electrode structural layer 120. In addition, the flow path of the current in the second conductive layer 122 is longer, so that the charge distribution in the LED structural layer 110 is more uniform, which helps to improve the uniformity of the light emission of the LED chip 100.

[0095] As for the layout design of the first electrode 123 and the second electrode 124 , a sufficient distance should be maintained between the first electrode 123 and the second electrode 124 to ensure that no short circuit occurs between the first electrode 123 and the second electrode 124 and to enable the LED chip 100 to be accurately packaged on the lamp board.

[0096] Among them, since the coverage area of ​​the second conductive layer 122 is large, the position of the second electrode 124 can be flexibly designed. When the second conductive layer 122 extends to the edge of the electrode structure layer 120, the second electrode 124 can be set at the edge of the electrode structure layer 120, and the second electrode 124 is connected to the edge area of ​​the second conductive layer 122. In this way, the position of the first electrode 123 can be designed according to the position of the second electrode 124, ensuring that there is a sufficient distance between the first electrode 123 and the second electrode 124.

[0097] As an embodiment, the first electrode 123 may be located in the middle region of the electrode structure layer 120 (see Figure 1 or Figure 2As shown in FIG. 1 ). In this way, when the coverage area of ​​the first conductive layer 121 is small, for example, the first conductive layer 121 only covers the middle area of ​​the electrode structure layer 120, it can also ensure that the first electrode 123 can be accurately and reliably connected to the first conductive layer 121. In addition, it is also easy to locate the formation position of the first electrode 123, so as to locate the position of the conductive via 126 in the second conductive layer 122, and form the first electrode 123 more quickly and accurately.

[0098] As another embodiment, the first electrode 123 may also be located at the edge region of the electrode structure layer 120, and the first electrode 123 and the second electrode 124 are arranged opposite to each other, and are respectively located at the edges of the electrode structure layer 120 on opposite sides. In this way, for the LED chip 100 of small size, the distance between the first electrode 123 and the second electrode 124 is relatively far, which ensures that there is no short circuit between the first electrode 123 and the second electrode 124, and also ensures that the LED chip 100 can be accurately and reliably packaged on the lamp board. In addition, it is also easier to perform performance testing on the LED chip 100. For example, when the LED chip 100 is plugged in and out, the distance between the first electrode 123 and the second electrode 124 is relatively far, which makes it easier to plug in and out the plug-in fixture.

[0099] For example, Figure 1 Taking the example of the first conductive layer 121 connected between the first sub-pixel 110a and the second sub-pixel 110b, the coverage area of ​​the first conductive layer 121 can be increased so that the first conductive layer 121 extends toward the edge of the electrode structure layer 120 (at least on the side opposite to the second electrode 124), so as to form the first electrode 123 in the edge area of ​​the electrode structure layer 120. Figure 2 Taking the example that the first conductive layer 121 shown in FIG. 1 is also connected between the two side edges of the LED structure layer 110 , the first conductive layer 121 covers a larger area, and the first electrode 123 can be formed in the edge area of ​​the electrode structure layer 120 .

[0100] Figure 5-Figure 29 This is a flowchart of the manufacturing process of the LED chip provided in the embodiment of the present application. Figure 5-Figure 29 As shown, the manufacturing process flow of the LED chip 100 provided in the embodiment of the present application is described in detail below.

[0101] It should be noted that Figure 1 The LED chip 100 shown is taken as an example for description. Figure 2 The LED chip 100 shown in FIG. Figure 1 The manufacturing process of the LED chip 100 is similar and will not be repeated here.

[0102] Reference Figure 5As shown, a substrate 111 is first provided, and an epitaxial layer is grown on the substrate 111. Specifically, a buffer layer 115 is first deposited on the substrate 111, and then an LED device is epitaxially grown on the buffer layer 115 to form an LED structure layer 110. Growing the LED device on the buffer layer 115 includes sequentially depositing a first semiconductor layer 112, a light-emitting layer 113, and a second semiconductor layer 114 on the buffer layer 115.

[0103] Reference Figure 6 As shown, the epitaxially grown LED device is etched using a photolithography process to expose a partial surface of the first semiconductor layer 112 of the LED device. Figure 1 Taking the LED chip 100 as an example, after etching the LED device, the LED device can be divided into a first sub-pixel 110a and a second sub-pixel 110b.

[0104] Reference Figure 7 As shown, then, a conductive material is used to form a conductive contact portion a on the epitaxial layer, and each conductive contact portion a is in contact with the first semiconductor layer 112 and the second semiconductor layer 114 of the LED device respectively. Figure 1 Taking the LED chip 100 as an example, the conductive contact portions a may include four, and the four conductive contact portions a are in contact with the first semiconductor layer 112 and the second semiconductor layer 114 of the first sub-pixel 110 a and the second sub-pixel 110 b respectively.

[0105] Reference Figure 8 As shown, after the conductive contact part a is formed, an insulating resin material is deposited on the epitaxial layer to form a flat layer b. The flat layer b fills the concave part of the epitaxial layer and fills between the conductive contact parts a to isolate the conductive contact parts a.

[0106] Reference Fig. 9 As shown, a conductive material is deposited to form a whole initial conductive layer c, so as to connect the conductive contact portions a through the initial conductive layer c.

[0107] Reference Fig.10 As shown, a photosensitive film layer d is formed on the initial conductive layer c.

[0108] Reference Fig.11 As shown, the photosensitive film layer d is exposed and developed to form an etching opening e on the photosensitive film layer d.

[0109] Reference Fig.12 As shown, the initial conductive layer c is etched along the etching opening e on the photosensitive film layer d to remove the unnecessary part of the initial conductive layer c, and the photosensitive film layer d is removed. At this time, a first conductive layer 121 is formed on the LED structure layer 110, and the first conductive layer 121 is connected to the two conductive contact parts a.

[0110] Reference Fig.13 As shown, a photosensitive film layer d is formed on the stacked structure, and the photosensitive film layer d covers the first conductive layer 121 and the remaining two conductive contact portions a.

[0111] Reference Fig.14 As shown, the photosensitive film layer d is exposed and developed to expose the top surfaces of the remaining two conductive contact portions a.

[0112] Reference Fig.15 As shown, the conductive material is continuously deposited, and the conductive material covers the top surfaces of the two exposed conductive contact portions a to increase the thickness of the two conductive contact portions a.

[0113] Reference Fig.16 As shown, the photosensitive film layer d is removed.

[0114] Reference Fig.17 As shown, an insulating resin material is deposited to form an insulating layer 125 on the first conductive layer 121 to planarize the surface of the first conductive layer 121 and to insulate and isolate the first conductive layer 121.

[0115] Reference Fig.18 As shown, a second conductive layer 122 is formed by depositing a conductive material.

[0116] Reference Fig.19 As shown, a photosensitive film layer d is formed on the second conductive layer 122 .

[0117] Reference Fig. 20 As shown, the photosensitive film layer d is exposed and developed to form an etching opening e on the photosensitive film layer d, and the etching opening e exposes a partial surface of the second conductive layer 122 .

[0118] Reference Fig.21 As shown, the second conductive layer 122 and the insulating layer 125 are etched along the etching opening e on the photosensitive film layer d to form a connecting hole f penetrating the second conductive layer 122 and the insulating layer 125, and the connecting hole f exposes a partial surface of the first conductive layer 121. Then the photosensitive film layer d is removed.

[0119] Reference Fig. 22 As shown, an insulating resin material is deposited. The insulating resin material adheres to the inner wall of the communication hole f to insulate the inner wall of the communication hole f. In addition, the insulating resin material covering the second conductive layer 122 forms a flat layer b.

[0120] Reference Fig.23 As shown, the insulating resin material attached to the bottom of the communicating hole f is removed until the surface of the first conductive layer 121 is exposed.

[0121] Reference Fig.24As shown, a conductive material is deposited in the connecting hole f to form a conductive via 126 to epitaxially extend the first conductive layer 121 .

[0122] Reference Fig.25 As shown, a conductive material is deposited on the flat layer b to form an initial first electrode layer g, so that the first electrode layer g is connected to the conductive via 126 .

[0123] Reference Fig.26 As shown, a photosensitive film layer d is formed on the first electrode layer g.

[0124] Reference Fig. 27 As shown, the photosensitive film layer d is exposed and developed to form an etching opening e on the photosensitive film layer d, and the etching opening e exposes a partial surface of the first electrode layer g.

[0125] Reference Fig.28 As shown, the first electrode layer g is etched along the etching opening e on the photosensitive film layer d to remove unnecessary conductive materials, thereby forming the final required first electrode 123. Afterwards, the photosensitive film layer d is removed.

[0126] Reference Fig.29 As shown, the planar layer b is partially etched to expose a local area of ​​the second conductive layer 122 . Then, a conductive material is continuously deposited to perform an epitaxial process on the local area of ​​the second conductive layer 122 to form a second electrode 124 .

[0127] Afterwards, the first electrode 123 and the second electrode 124 may be protected by, for example, electroplating a metal such as nickel or gold on the surface of the first electrode 123 and the second electrode 124 .

[0128] The serial numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments. The above are only preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An LED chip, characterized in that: include: An LED structure layer (110) comprises a first semiconductor layer (112), a light-emitting layer (113), and a second semiconductor layer (114) which are stacked in sequence, wherein the polarity of the first semiconductor layer (112) is opposite to the polarity of the second semiconductor layer (114); The electrode structure layer (120) comprises a first conductive layer (121), a second conductive layer (122), a first electrode (123) and a second electrode (124); the first conductive layer (121) and the second conductive layer (122) are sequentially arranged on the LED structure layer (110) and spaced apart from each other; one end of the first conductive layer (121) and one end of the second conductive layer (122) are both connected to the first semiconductor layer (112); the other end of the first conductive layer (121) and the other end of the second conductive layer (122) are both connected to the second semiconductor layer (114); the first electrode (123) is connected to the first conductive layer (121); and the second electrode (124) is connected to the second conductive layer (122).

2. The LED chip according to claim 1, characterized in that: An insulating layer (125) is provided between the first conductive layer (121) and the second conductive layer (122); conductive vias (126) are provided through the insulating layer (125) and the second conductive layer (122); and the first electrode (123) is connected to the first conductive layer (121) through the conductive vias (126).

3. The LED chip according to claim 2, characterized in that: The second conductive layer (122) is arranged around the periphery of the conductive via (126), and the second conductive layer (122) extends toward the edge of the electrode structure layer (120), and the second conductive layer (122) and the conductive via (126) are insulated and isolated.

4. The LED chip according to claim 2, characterized in that: The first electrode (123) and the second electrode (124) are respectively located at two opposite side edges of the electrode structure layer (120); Alternatively, the first electrode (123) is located in a middle region of the electrode structure layer (120), and the second electrode (124) is located at an edge of the electrode structure layer (120).

5. The LED chip according to any one of claims 1 to 4, characterized in that: The LED structure layer (110) comprises a first sub-pixel (110a) and a second sub-pixel (110b) arranged side by side and spaced apart from each other; the first semiconductor layer (112) of the first sub-pixel (110a) comprises a first extension portion (1121a), and the first extension portion (1121a) extends to the side of the first sub-pixel (110a); the first semiconductor layer (112) of the second sub-pixel (110b) comprises a second extension portion (1121b), and the second extension portion (1121b) extends to the side of the second sub-pixel (110b); The two ends of the first conductive layer (121) are respectively connected to the first extension portion (1121a) and the second semiconductor layer (114) of the second sub-pixel (110b), and the two ends of the second conductive layer (122) are respectively connected to the second semiconductor layer (114) of the first sub-pixel (110a) and the second extension portion (1121b).

6. The LED chip according to claim 5, characterized in that: The first extending portion (1121a) extends from a side of the first sub-pixel (110a) close to the second sub-pixel (110b), and the second extending portion (1121b) extends from a side of the second sub-pixel (110b) away from the first sub-pixel (110a).

7. The LED chip according to any one of claims 1 to 4, characterized in that: The first semiconductor layer (112) has a protruding portion (1121), and the protruding portion (1121) protrudes from the side of the LED structure layer (110); One end of the first conductive layer (121) and one end of the second conductive layer (122) are both connected to the protruding portion (1121), and the other end of the first conductive layer (121) and the other end of the second conductive layer (122) are both connected to a side of the second conductive layer (122) away from the protruding portion (1121).

8. The LED chip according to any one of claims 1 to 4, characterized in that: The LED structure layer (110) further includes: A substrate (111); A buffer layer (115) is disposed on the substrate (111), and the first semiconductor layer (112) is disposed on the buffer layer (115).

9. The LED chip according to any one of claims 1 to 4, characterized in that: One of the first semiconductor layer (112) and the second semiconductor layer (114) is an n-type gallium nitride layer, and the other is a p-type gallium nitride layer.

10. An LED display panel, characterized in that: It comprises a light board and a plurality of LED chips (100) according to any one of claims 1 to 9, wherein each of the LED chips (100) is packaged in the light board.

Images