Mini-LED chip preparation method and Mini-LED chip

Abstract

The present invention discloses a method for preparing a Mini-LED chip and a Mini-LED chip. The method comprises providing a first epitaxial wafer module, a second epitaxial wafer module, and a third epitaxial wafer module that can emit light of different colors; etching the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module to isolate multiple chip units in the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module; isolating each isolated chip unit into a single region, and after the regional isolation, fabricating electrode surfaces for the isolated regions and other regions of the multiple chip units according to preset rules; providing a first electrode on the electrode surface of the isolated region, and providing a second electrode electrically connected to the first electrode on the electrode surfaces of other regions of the chip unit. The present invention solves the problem in the prior art that chip fixing is difficult due to the small chip electrode area.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a method for preparing a Mini-LED chip and a Mini-LED chip. Background Art

[0002] Mini-LED is a type of LED that lies between Micro-LED and traditional LED. It is commonly used in mobile phones, laptops, iPads, TV backlighting, as well as LED displays, horticultural lighting, automotive lighting, and general lighting. Mini-LED chip size generally ranges from 50 to 200 microns. Mini-LED display products are manufactured by chipping small panels, which are then assembled into large screens. Mini-LED display products use the three primary colors of red (R), green (G), and blue (B). A set of RGB chips is the smallest display unit. Any color on the screen can be recorded and expressed by a set of RGB values.

[0003] An RGB display unit consists of a red chip, a green chip, and a blue chip fixed to the same aluminum substrate. Due to the small size of the chips and the even smaller electrode area, attaching the three chips together is difficult, and the large number of chips required is labor-intensive and resource-intensive. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a Mini-LED chip preparation method and a Mini-LED chip, aiming to solve the problem in the prior art that the chip is difficult to fix due to the small chip electrode area.

[0005] The embodiment of the present invention is implemented as follows:

[0006] In one aspect, a method for preparing a Mini-LED chip is provided, the method comprising:

[0007] Providing a first epitaxial wafer module, a second epitaxial wafer module, and a third epitaxial wafer module, each capable of emitting light of different colors, wherein the different colors of light include red, blue, and green, and each of the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module includes a plurality of chip units arranged at intervals;

[0008] Etching the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module respectively to isolate a plurality of chip units in the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module;

[0009] Isolating each of the isolated chip units into a single region, and after the region isolation, fabricating electrode surfaces on the isolated regions and other regions of the plurality of chip units according to preset rules;

[0010] A first electrode is provided on the electrode surface of the isolation region, and a second electrode electrically connected to the first electrode is provided on the electrode surface of other regions of the chip unit.

[0011] Furthermore, in the above-mentioned Mini-LED chip preparation method, the steps of isolating each of the isolated chip units into a single region and, after the regional isolation, fabricating electrode surfaces in the isolated regions and other regions of the multiple chip units according to preset rules include:

[0012] When the chip unit is a red light chip unit, a current blocking layer is deposited in the isolation region and other regions of the chip unit to form an electrode surface on the current blocking layer.

[0013] Furthermore, in the above-mentioned Mini-LED chip preparation method, the steps of isolating each of the isolated chip units into a single region and, after the regional isolation, fabricating electrode surfaces in the isolated regions and other regions of the multiple chip units according to preset rules include:

[0014] When the chip unit is a green light or blue light chip unit, etching the P-GaN layer in a portion of the isolation region of the chip unit to expose the N-GaN layer;

[0015] A conductive layer is deposited on the unetched area of the P-GaN layer, and then an insulating layer is deposited on the chip unit to form an electrode surface on the insulating layer.

[0016] Furthermore, in the above-mentioned Mini-LED chip preparation method, in which the first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module are respectively etched to isolate multiple chip units in the first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module, the etching depth is 12um~20um, and the isolation spacing is 10um~15um.

[0017] Furthermore, in the above-mentioned Mini-LED chip preparation method, in which each of the isolated chip units is isolated in a single area, and after the area isolation, the electrode surfaces of the isolation areas and other areas of the multiple chip units are made according to preset rules, the isolation spacing is 5um.

[0018] Furthermore, in the above-mentioned Mini-LED chip preparation method, the second electrode is arranged in a square shape.

[0019] Furthermore, in the above-mentioned Mini-LED chip preparation method, the first electrode and the second electrode are electrically connected via a welding wire.

[0020] Furthermore, in the above-mentioned Mini-LED chip preparation method, the chip units in the first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module are all arranged in a triangle.

[0021] On the other hand, an embodiment of the present invention further provides a Mini-LED chip, which is prepared by the above-mentioned Mini-LED chip preparation method, and the Mini-LED chip includes:

[0022] A first epitaxial wafer module, a second epitaxial wafer module and a third epitaxial wafer module can emit light of different colors. The first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module each include a plurality of chip units arranged at intervals. Each chip unit is provided with an isolation area and other areas. The isolation area is provided with an electrode surface for setting a first electrode, and the other area is provided with an electrode surface for setting a second electrode electrically connected to the first electrode.

[0023] Compared with the prior art: The embodiment of the present invention sets isolation areas and other areas on the chip unit, and then respectively makes electrode surfaces for setting the first electrode and the second electrode on the chip units in the isolation area and other areas. The first electrode realizes the conductive effect with the chip unit, and the second electrode set in other areas of the chip unit is electrically connected to the first electrode. The second electrode can be used to connect the chip unit to an external power supply. Moreover, since the second electrode is set outside the isolation area and is not affected by the size of the area of the chip unit used for chip production, it can be set to a size larger than the first electrode, thereby increasing the electrode area and reducing the difficulty of chip fixing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of the Mini-LED chip manufacturing method proposed in the first embodiment of the present invention;

[0025] Figure 2 Schematic diagram of cutting the RGB display unit in the Mini-LED chip manufacturing method proposed in the first embodiment of the present invention;

[0026] Figure 3 Schematic diagram of the structure of the red epitaxial chip in the Mini-LED chip preparation method proposed in the first embodiment of the present invention;

[0027] Figure 4 Schematic diagram of etching the P-type semiconductor layer of the blue and green epitaxial chips in the Mini-LED chip manufacturing method proposed in the first embodiment of the present invention;

[0028] Figure 5 Schematic diagram of fabricating the conductive layer of the blue and green epitaxial chips in the Mini-LED chip fabrication method proposed in the first embodiment of the present invention;

[0029] Figure 6 Schematic diagram of the insulating layer fabrication of the blue and green epitaxial chips in the Mini-LED chip fabrication method proposed in the first embodiment of the present invention;

[0030] Figure 7 Schematic diagram of electrode fabrication for blue and green epitaxial chips in the Mini-LED chip fabrication method proposed in the first embodiment of the present invention;

[0031] Figure 8 Schematic diagram of the structure of the isolation area and other areas in the Mini-LED chip proposed in the second embodiment of the present invention.

[0032] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0033] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0034] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to related embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0037] Embodiment 1

[0038] Please refer to Figure 1 , which shows the method for manufacturing a Mini-LED chip proposed in the first embodiment of the present invention. This manufacturing method includes steps S10 to S13.

[0039] Step S10: Provide a first epitaxial wafer module, a second epitaxial wafer module, and a third epitaxial wafer module that can emit different colors of light respectively. The different colors of light include red, blue, and green. The first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module each include a plurality of chip units arranged at intervals.

[0040] Among them, in specific implementation, the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module each include a plurality of chip units. The chip units can be arranged in various ways. For example, the plurality of chip units can be arranged in a rectangular array. In the specific implementation of this embodiment, each epitaxial wafer module includes three chip units, and the three chip units are arranged in a triangle. The advantage of doing this is that by arranging the three chip units in a triangle to form a "pin" character array, in the later production, one red-light, one green-light, and one blue-light epitaxial wafer module composed of three chip units can be respectively taken for arrangement and welding. Then, the second row is arranged and welded with dislocation, and the distance between the dislocated epitaxial wafer modules; each row is dislocated by half an epitaxial wafer module compared with the previous row, and an RGB display unit can be obtained. When cutting, as Figure 2 shown, cutting can be performed with the RGB display unit as a unit, thereby avoiding cutting each chip unit and then recombining to obtain the RGB display unit, and improving the packaging efficiency of the mini-LED chip.

[0041] Step S11: Etch the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module respectively to isolate the plurality of chip units in the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module.

[0042] Among them, as Figure 3As shown, taking the red light epitaxial wafer module as an example, the red light chip adopts a vertical structure of GaP. Through yellow light combined with dry etching process, isolation grooves 10 are formed to isolate the three red light chip units 1 in the red light epitaxial wafer module. Specifically, the etching depth is above 12 μm to completely etch through the P-type semiconductor layer and the N-type semiconductor layer in the red light chip unit 1, for example, 12 μm to 20 μm, and the isolation (width) spacing is 10 μm to 15 μm.

[0043] like Figures 4 to 7 As shown, taking the green and blue epitaxial wafer modules as an example, the green and blue chips adopt a common upright structure. Similarly, the isolation groove 20 is formed by yellow light combined with a dry etching process to isolate the green and blue chip units 2 in the green and blue epitaxial wafer modules. The etching depth is above 6um (all P / N-GaN is etched through), and the isolation (width) spacing is 10um.

[0044] Step S12 , isolating each of the isolated chip units into a single region, and after the region isolation, fabricating electrode surfaces on the isolated regions and other regions of the plurality of chip units according to preset rules.

[0045] Specifically, taking the red light epitaxial wafer module as an example, a single chip unit is isolated within the region to divide the single chip unit into an isolation region and other regions. More specifically, the etching depth is above 12um (all P / N-GaP is etched through), and the isolation spacing is 5um, in order to ensure that the core size is 100*100um. A current blocking layer 11 (SiO2) is made again with a thickness of 4000A to form an electrode surface in the isolation region and other regions. Attention should be paid to ensuring that the current blocking layer 11 at the isolation groove is well covered as much as possible to prevent the P electrode from contacting the N-type semiconductor layer and causing a short circuit.

[0046] Taking the green and blue epitaxial wafer modules as an example, a single chip unit is isolated within the region, the etching depth is above 12um (all P / N-GaN is etched through), and the isolation spacing is 5um, in order to ensure that the core particle size is 100*100um; then the N-region is produced, that is, the P-GaN in part of the region is etched away to expose the N-GaN layer 21; then the conductive layer 22 is produced, using ITO material with a thickness of 2500A; then the insulating layer 23 (SiO2) is produced with a thickness of 2500A to form electrode surfaces in the isolation region and other regions.

[0047] In step S13 , a first electrode is provided on the electrode surface of the isolation region, and a second electrode electrically connected to the first electrode is provided on the electrode surface of other regions of the chip unit.

[0048] Specifically, the first electrode is arranged in a circular shape and the second electrode is arranged in a square shape. The conductive effect with the chip unit is achieved by setting the first electrode on the electrode surface, and the second electrode is set in other areas of the chip unit to be electrically connected to the first electrode. The second electrode can be used to connect the chip unit with the outside. Since the second electrode is set outside the isolation area and is not affected by the size of the chip manufacturing area of the chip unit, it can be set to a size larger than the first electrode, thereby increasing the electrode area. When this embodiment is implemented, the first electrode and the second electrode are electrically connected through welding leads.

[0049] It should be noted that, taking the red light chip unit as an example, the red light chip adopts a vertical structure, with the P electrode 12 on the front and the N electrode on the other side, while the P electrode 241 and N electrode 242 of the blue and green light chips are both on the front side. After cutting, the connection between them and the aluminum substrate is generally made by wire bonding, that is, using a wire bonding machine to weld gold or silver wire on the chip electrode, and pulling out the other end to weld it to the bracket.

[0050] In summary, the Mini-LED chip preparation method proposed in the above embodiments of the present invention sets isolation areas and other areas on the chip unit, and then respectively makes electrode surfaces for setting the first electrode and the second electrode on the chip units in the isolation area and other areas. The first electrode realizes the conductive effect with the chip unit, and the second electrode set in other areas of the chip unit is electrically connected to the first electrode. The second electrode can be used to connect the chip unit to an external power supply. Moreover, since the second electrode is set outside the isolation area and is not affected by the size of the area of the chip unit used for chip production, it can be set to a size larger than the first electrode, thereby increasing the electrode area and reducing the difficulty of chip fixing.

[0051] Example 2

[0052] See also Figure 8 , which shows a Mini-LED chip proposed in a second embodiment of the present invention, comprising:

[0053] A first epitaxial wafer module, a second epitaxial wafer module and a third epitaxial wafer module can emit light of different colors. The first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module each include a plurality of chip units arranged at intervals. Each chip unit is provided with an isolation area 30 and other areas 31. The isolation area 30 is provided with an electrode surface for setting a first electrode, and the other area 31 is provided with an electrode surface for setting a second electrode electrically connected to the first electrode.

[0054] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a Mini-LED chip, characterized in that: The method comprises: Providing a first epitaxial wafer module, a second epitaxial wafer module, and a third epitaxial wafer module, each capable of emitting light of different colors, wherein the different colors of light include red, blue, and green, and each of the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module includes a plurality of chip units arranged at intervals; Etching the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module respectively to isolate a plurality of chip units in the first epitaxial wafer module, the second epitaxial wafer module, and the third epitaxial wafer module; Isolating each of the isolated chip units into a single region, and after the region isolation, fabricating electrode surfaces on the isolated regions and other regions of the plurality of chip units according to preset rules; A first electrode is provided on the electrode surface of the isolation region, and a second electrode electrically connected to the first electrode is provided on the electrode surface of other regions of the chip unit, wherein the first electrode and the second electrode are electrically connected via a welding wire; When the chip unit is a red light chip unit, depositing a current blocking layer in the isolation region and other regions of the chip unit to form an electrode surface on the current blocking layer; When the chip unit is a green light or blue light chip unit, etching the P-GaN layer in a portion of the isolation region of the chip unit to expose the N-GaN layer; A conductive layer is deposited on the unetched area of the P-GaN layer, and then an insulating layer is deposited on the chip unit to form an electrode surface on the insulating layer.

2. The method for preparing a Mini-LED chip according to claim 1, wherein: In the step of etching the first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module respectively to isolate multiple chip units in the first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module, the etching depth is 12um~20um and the isolation spacing is 10um~15um.

3. The method for preparing a Mini-LED chip according to claim 2, wherein: In the manufacturing step of isolating each of the isolated chip units into a single region, and after the regional isolation, manufacturing electrode surfaces for the isolation regions and other regions of the plurality of chip units according to preset rules, the isolation spacing is 5 μm.

4. The method for preparing a Mini-LED chip according to claim 1, wherein: The second electrodes are arranged in a square shape.

5. The method for preparing a Mini-LED chip according to claim 1, wherein: The chip units in the first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module are all arranged in a triangle.

6. A Mini-LED chip, characterized in that: Prepared by the Mini-LED chip preparation method according to any one of claims 1 to 5, the Mini-LED chip comprises: A first epitaxial wafer module, a second epitaxial wafer module and a third epitaxial wafer module can emit light of different colors. The first epitaxial wafer module, the second epitaxial wafer module and the third epitaxial wafer module each include a plurality of chip units arranged at intervals. Each chip unit is provided with an isolation area and other areas. The isolation area is provided with an electrode surface for setting a first electrode, and the other area is provided with an electrode surface for setting a second electrode electrically connected to the first electrode.

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