Patent Description:
In the current lighting market, with features such as high-luminance, energy-saving, multi-color, and fast-changing, LED (light-emitting diode) has been widely applied in technical fields of lighting that require light sources, particular in the field of vehicle lamp. Conventional arts include <CIT>, entitled "LED of generating various luminous colors on single wafer". This conventional art has disadvantages such as when attempting to have a single wafer to provide light effects of different colors, different color materials need to be used in conjunction during a manufacturing process of semiconductors. In other words, materials of different light wavelengths need to be used according to requirements of different colors. The process required in the entire production process becomes more complex. In addition, the conventional art does not allow RGB (red, green, blue) LED lamps of different shapes to be made according to requirements of customer on different lamp and display devices.

In response to the above-referenced technical inadequacies, the present invention provides a three-in-one RGB (red, green, blue) mini-LED (light-emitting diode) production method according to independent claims <NUM> or <NUM>, and the three-in-one RGB mini-LED device not only can have a light-emitting surface of a wafer to be partitioned into a plurality of light-emitting regions, but also effectively improve on disadvantages of existing technologies by only using a single light source wavelength material in the composition of product, in conjunction with a quantum dot filter to emit lights in three colors of RGB. In addition, through the design of flip-chip process in the present disclosure, the three-in-one RGB mini-LED device becomes an LED light-emitting component having RGB quantum dot materials, such that lateral sides of electrical semiconductor layers of the present disclosure are less likely to be damaged in a packaging process, thereby obtaining an RGB mini-LED structure having smaller size, higher light utilization rate, and precision controlled lighting pattern. Moreover, the three-in-one RGB mini-LED device of the present disclosure can also be cut into customized shapes according to requirements of customer and formed into displays of different sizes.

In one aspect, the three-in-one RGB mini-LED device provided in the present disclosure includes an arrangement of a plurality of display cells, and each of the display cells includes a substrate, a second electrical semiconductor layer, a plurality of multiple-quantum well layers, a plurality of first electrical semiconductor layers, a plurality of mirrors, a protecting layer, a plurality of first metal electrodes, a second metal electrode, and an RGB quantum dot filter. The second electrical semiconductor layer is disposed on the substrate. The multiple-quantum well layers are disposed on the second electrical semiconductor layer, an area of each of the multiple-quantum well layers is smaller than an area of the second electrical semiconductor layer, and a portion of the second electrical semiconductor layer is not covered by the multiple-quantum well layers. The first electrical semiconductor layers are correspondingly disposed on the multiple-quantum well layers, and an area of each of the first electrical semiconductor layers is equal to the area of each of the multiple-quantum well layers. The mirrors are correspondingly disposed on the first electrical semiconductor layers and are in electrical contact with the first electrical semiconductor layers, and an area of each of the mirrors is smaller than the area of each of the first electrical semiconductor layers. The protecting layer is covered on lateral sides of and above each of the mirrors and lateral sides of and above each of the first electrical semiconductor layers, and the protecting layer is covered on the second electrical semiconductor layer. The protecting layer exposes a plurality of first contact areas and a second contact area. Each of the first metal electrodes is correspondingly disposed on each of the first contact areas. The second metal electrode is disposed on the second contact area. The RGB quantum dot filter is disposed at a bottom of the substrate.

These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the scope of the invention as defined by the appended claims.

The present invention will become more fully understood from the following detailed description and accompanying drawings.

The present invention concerns a three-in-one RGB (red, green, blue) mini-LED (light-emitting diode) production method capable of effectively improving and elevating the quality of a lamp body. In a flip-chip process, after completing a cutting step, a three-in-one RGB mini-LED device can be formed into different RGB mini-LED light-emitting chips according to requirements of design, and become LED light-emitting components having RGB quantum dot materials. In the present disclosure, a variety of RGB LED bars or LED light strips having suitable shapes and sizes can also be selected according to requirements of design, in conjunction with other necessary electrical components, connector and driving integrated circuit, and mount the LED die on the circuit board selected according to requirements of design using surface-mount technology, thereby completing the production of an RGB light source mini-LED light-emitting device, and obtaining an RGB mini-LED structure having smaller size, higher light utilization rate, and precision controlled lighting pattern.

The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. In the drawings, sizes and relative positions and distances of RGB LED die, RGB LED member, LED, substrate, circuit board, etc., may be exaggerated for the purpose of clarity, however, like numbers in the drawings indicate like components throughout the views.

For a more clear description of the three-in-one RGB mini-LED production method of the present disclosure, steps of the production process of the three-in-one RGB mini-LED device is iterated first, and structures of the three-in-one RGB mini-LED device will be described in related descriptions of <FIG>, so as to have a more coherent and complete technical description of the present disclosure. Reference is made to <FIG>, which is a side schematic view of a first embodiment of production process of the three-in-one RGB mini-LED device of the present disclosure, and a structure of a display cell <NUM> (i.e., display unit) is disclosed. The structure contains, sequentially from bottom to top, a substrate <NUM>, a second electrical semiconductor layer <NUM>, a multiple-quantum well layer <NUM>, a first electrical semiconductor layer <NUM>, and a plurality of mirrors <NUM> (<FIG> shows a side view of the display cell <NUM>, therefore only one mirror is shown, and the plurality of mirrors <NUM> may be seen as in embodiments shown in <FIG>). That is, the second electrical semiconductor layer <NUM> is deposited on the substrate <NUM>, the multiple-quantum well layer <NUM> and the first electrical semiconductor layer <NUM> are sequentially deposited on the second electrical semiconductor layer <NUM>, and the plurality of mirrors <NUM> are deposited on the first electrical semiconductor layer <NUM>, such that the plurality of mirrors <NUM> are in electrical contact with the first electrical semiconductor layer <NUM>. The material of the substrate <NUM> may be sapphire or other oxide materials. The first electrical semiconductor layer <NUM> and the second electrical semiconductor layer <NUM> are epitaxial (EPI) silicone layers, or epitaxial layers. The multiple-quantum well (MQW) layer <NUM> may be an optical layer of a multiple-quantum well nanorod of indium gallium nitride or gallium nitride. The mirror <NUM> is made of metal, such as silver, aluminum, or nickel, or a laminated layer of silver-aluminum, aluminum-nickel, or silver-nickel, or a laminated layer of silver-aluminum-nickel, and the present disclosure is not limited thereto. In addition, in actual implementations, the mirror <NUM> of the present disclosure may also be a protecting layer capable of providing protection. Moreover, <FIG> also shows the first step of the production process of the three-in-one RGB mini-LED device of the present disclosure, which includes depositing the mirror <NUM> on the first electrical semiconductor layer <NUM>, such that the mirror <NUM> is in electrical contact with the first electrical semiconductor layer <NUM>.

It should be noted that, contents disclosed in <FIG> only take one component as an example, to facilitate a description to correlate figures to the text. In actual production, production steps are based on process for manufacturing a piece of semiconductor wafer.

<FIG> shows the second step in the process for producing the three-in-one RGB mini-LED device of the present disclosure, in which a dry etching manner or a wet etching manner is utilized to etch the first electrical semiconductor layer <NUM> and the multiple-quantum well layer <NUM>, thereby exposing the second electrical semiconductor layer <NUM>, and forming a plurality of first electrical semiconductor layers <NUM>, and an area of each of the first electrical semiconductor layers <NUM> is substantially greater than an area of each of the mirrors <NUM> (as shown in <FIG>).

<FIG> shows the third step in the process for producing the three-in-one RGB mini-LED device of the present disclosure, the step for depositing a protecting layer <NUM> includes depositing the protecting layer <NUM> after the second step, and exposing a first contact area 14a above the mirror <NUM>, and exposing a second contact area 12a above the second electrical semiconductor layer <NUM>. The depositing step deposits metal oxides or metal nitrides (e.g., silicon dioxide, silicon nitride, or titanium dioxide, etc.) at lateral sides of and above the above-mentioned metallic mirror <NUM>, and exposing the first contact area 14a above the metallic mirror <NUM>, that is, the first contact area 14a is an opening area of the protecting layer <NUM> above the mirror <NUM>. At the same time, metal oxides or metal nitrides are also deposited at lateral sides of and above the above-mentioned second electrical semiconductor layer <NUM>, and exposing the second contact area 12a above the second electrical semiconductor layer <NUM>, that is, the second contact area 12a is an opening area of the protecting layer <NUM> above the second electrical semiconductor layer <NUM>.

<FIG> shows the fourth step in the process for producing the three-in-one RGB mini-LED device of the present disclosure, which includes disposing and forming a first metal electrode <NUM> above the first contact area 14a, such that an area formed by the first metal electrode <NUM> is greater than the first contact area 14a. At the same time, a second metal electrode <NUM> is disposed above the second contact area 12a, such that an area formed by the second metal electrode <NUM> is greater than the second contact area 12a. During actual usage, the material of the first metal electrode <NUM> and the second metal electrode <NUM> may be titanium/platinum/gold, or chromium/platinum/gold.

<FIG> shows the fifth step in the process for producing the three-in-one RGB mini-LED device of the present disclosure. After the fourth step, a dry etching manner or a wet etching manner is utilized to etch edges of the second electrical semiconductor layer <NUM> of a component structure shown in <FIG>, and the substrate <NUM> is exposed to form a spacing region <NUM> (the spacing region <NUM> is as shown in <FIG>). A direction indicated by a dotted line at a left side of <FIG> represents etching along a direction toward a right side of <FIG>, and edges of the protecting layer <NUM> above the second electrical semiconductor layer <NUM> are etched. A direction indicated by a dotted line at the right side of <FIG> represents etching along a direction toward the left side of <FIG>, and the edges of the second electrical semiconductor layer <NUM>, the multiple-quantum well layer <NUM>, the first electrical semiconductor layer <NUM> and the protecting layer <NUM> are etched to form the spacing region <NUM>.

As shown in <FIG>, in one embodiment of the present disclosure, a covering layer <NUM> is further formed.

A layer of non-electrically-conductive layer (i.e., the covering layer <NUM>) is covered on a component structure shown in <FIG>, the covering layer <NUM> only exposes a partial area of the above-mentioned first metal electrode <NUM> and a partial area of the above-mentioned second metal electrode <NUM>, without covering on the spacing region <NUM>. That is, the covering layer <NUM> covers the lateral sides of and above the first metal electrode <NUM> and exposes the partial area of the first metal electrode <NUM> thereabove, and covers the lateral sides of and above the second metal electrode <NUM> and exposes the partial area of the second metal electrode <NUM> thereabove. In actual manufacturing, the material of the covering layer <NUM> is titanium dioxide or silicon dioxide.

As shown in <FIG>, a step of forming solder bumps is further performed on the embodiment shown in <FIG>. A first metal electrode bump <NUM> is formed above the first metal electrode <NUM>, and a second metal electrode bump <NUM> is formed above the second metal electrode <NUM>, as shown in <FIG>. After the step of forming solder bumps, a step of covering a dielectric material <NUM> above the covering layer <NUM> is performed, the dielectric material <NUM> is not covered on the spacing region <NUM>, and the dielectric material <NUM> is neither covered above the first metal electrode bump <NUM> nor above the second metal electrode bump <NUM>. In practical production, the dielectric material <NUM> can be such as epoxy or silicone. Furthermore, in <FIG>, technologies such as thin film process, chemical plating, or printing technology may be utilized to straighten spaces between electrodes of the first metal electrode bump <NUM> and the second metal electrode bump <NUM>.

It should be noted that, under different circumstances, such as when a manufacturer implements embodiments disclosed by <FIG>, according to actual requirements or requirements from different operational conditions, production process shown in <FIG> may be omitted. The above-mentioned production process shown in <FIG> may be operated by different manufacturers, or be processed and manufactured outside of core production process.

<FIG> shows the sixth step in the process for producing the three-in-one RGB mini-LED device of the present disclosure, and the sixth step includes preparing an RGB quantum dot filter <NUM>, and adhering the RGB quantum dot filter <NUM> at a bottom of the above-mentioned sapphire substrate <NUM>. The manner of preparing the RGB quantum dot filter <NUM> includes: forming a plurality of dams <NUM> on a transparent substrate <NUM> using an opaque material; the dams <NUM> are formed through performing photolithography on the opaque material, thereby forming the light-blocking dams <NUM>. In the dams <NUM>, in conjunction with quantum dot materials of various wavelengths, coating the quantum dot materials of various wavelengths between the dams <NUM> to form the RGB quantum dot filter (QD filter) <NUM> or an RGB wafer. In actual implementations, the quantum dot materials of various wavelengths include: red quantum dot material 50R, green quantum dot material <NUM>, and blue quantum dot material 50B.

Reference is made to <FIG>, which is a schematic view of the RGB quantum dot filter <NUM> adhering to the bottom of the substrate <NUM> as shown in <FIG>, and the RGB quantum dot filter <NUM> is adhered to the bottom of the substrate <NUM> by using adhering glue <NUM>. Afterwards, a cutting step is performed, and the above-mentioned spacing region <NUM> is cut along directions of arrows indicated by the phantom lines of the <FIG>. The cutting step is to perform customized cutting operation according to the shapes or sizes required by the customer, in order to meet aesthetic requirement of special lamp design by the customer. Therefore, steps of flip-chip process of an RGB mini-LED is completed, and the flip-chip structure of the RGB mini-LED is also completed at the same time. The material of the adhering glue <NUM> may be UV glue (ultraviolet curing glue), epoxy or silicone, etc. In addition, directions of arrows represented by the center lines of the <FIG> indicate the light-emitting directions of an LED through the RGB quantum dot filter <NUM>.

Reference is made to <FIG> and <FIG>, which represent another embodiment related to the production of the quantum dot material in <FIG> and <FIG>. In <FIG>, photolithography is performed directly on a back side of the above-mentioned substrate <NUM> to produce the plurality of dams <NUM>, which are also light-blocking dams, that is, the material of the transparent substrate <NUM> of <FIG> is omitted, thereby reducing a thickness of the entire component. In <FIG>, after the dams <NUM> are formed, the quantum dot materials of various wavelengths are coated between the dams <NUM>, respectively. In actual implementations, the quantum dot materials of various wavelengths include: the red quantum dot material 50R, the green quantum dot material <NUM>, and the blue quantum dot material 50B. As shown in <FIG>, packaging glue <NUM> is covered above the structure of a layer of the dams <NUM> as shown in <FIG>, and the material of the packaging glue, in actual production, may be a UV glue (ultraviolet curing glue), epoxy or silicone, etc. After packaging is completed, a cutting step is performed. The above-mentioned spacing region <NUM> is the baseline for cutting, and a customized cutting operation is performed according to the shapes or sizes required by the customer, in order to meet aesthetic requirement of special lamp design of the customer.

<FIG>, and <FIG> show one embodiment of an actual product, <FIG> is a schematic bottom view of a display cell 1a (i.e., display unit), <FIG> is a top view of <FIG>, and <FIG> is a perspective schematic view of <FIG> (to clearly explain a relative position of each of the layers, thicknesses of the layers are exaggerated as shown in <FIG>, and thickness of the actual product does not follow a ratio of thickness as shown in <FIG>). It should be noted that, the materials of each of the layers disclosed in <FIG> are basically transparent, such that an internal stacking relation can be observed in a top view or a bottom view of the component. As shown in <FIG>, a structure of the three-in-one RGB mini-LED device of the display cell 1a (i.e., display unit) is described as follows, which includes the substrate <NUM>, the second electrical semiconductor layer <NUM>, the multiple-quantum well layers <NUM>, the first electrical semiconductor layers <NUM>, and the mirrors <NUM>. Similarly, in <FIG>, the second electrical semiconductor layer <NUM> is disposed on the substrate <NUM>, an area of each of the multiple-quantum well layers <NUM> is smaller than an area of the second electrical semiconductor layer <NUM>, a portion of the second electrical semiconductor layer <NUM> is not covered by the multiple-quantum well layers <NUM>, and the portion is as shown by the phantom line in <FIG>. In <FIG>, the first electrical semiconductor layers <NUM> are correspondingly disposed on the multiple-quantum well layers <NUM>, and an area of each of the first electrical semiconductor layers <NUM> is equal to the area of each of the multiple-quantum well layers <NUM>. The plurality of mirrors <NUM> are correspondingly disposed on the first electrical semiconductor layers <NUM> and are in electrical contact with the first electrical semiconductor layers <NUM>, and an area of each of the mirrors <NUM> is smaller than the area of each of the first electrical semiconductor layers <NUM>.

In <FIG>, the mirrors <NUM> are shown, however, in actual production, <FIG> further includes the protecting layer <NUM> (as shown in <FIG>), that is, the protecting layer <NUM> is covered on lateral sides of and above each of the mirrors <NUM> and lateral sides of and above each of the first electrical semiconductor layers <NUM>, and the protecting layer <NUM> is covered on the second electrical semiconductor layer <NUM>. The protecting layer <NUM> also exposes a plurality of first contact areas 14a and a second contact area 12a (as shown in <FIG>). Furthermore, <FIG> includes a plurality of first metal electrodes <NUM>, and each of the first metal electrodes <NUM> is correspondingly disposed on each of the first contact areas 14a. <FIG> further includes the second metal electrode <NUM> disposed on the second contact area 12a (as shown in <FIG>). <FIG> further includes the RGB quantum dot filter <NUM> that is disposed at a bottom of the substrate <NUM> (as shown in <FIG>).

The RGB quantum dot filter <NUM> includes the transparent substrate <NUM>, the plurality of dams <NUM>, and the quantum dot materials of various wavelengths 50R, <NUM>, and 50B. The dams <NUM> are disposed on the transparent substrate <NUM>, and each of the dams <NUM> is an opaque dam. Each of the quantum dot materials of various wavelengths 50R, <NUM>, and 50B are correspondingly disposed in each of the dams <NUM>.

Furthermore, the first contact areas 14a indicate that the protecting layer <NUM> has an opening formed above each of the mirrors <NUM> and exposes an upper surface of each of the mirrors <NUM>, and edges of each of the mirrors <NUM> are still cladded by the protecting layer <NUM>. The second contact areas 12a indicate that the protecting layer <NUM> has an opening formed above a region above the second electrical semiconductor layer <NUM> that is not covered by the multiple-quantum well layers <NUM> and exposes a top surface of the second electrical semiconductor layer <NUM>. An area cladded by each of the first metal electrodes <NUM> is greater than each of the first contact areas 14a, and an area cladded by the second metal electrode <NUM> is greater than the second contact area 12a.

<FIG> includes the covering layer <NUM> that is covered on the protecting layer <NUM>, and covered on each of the first metal electrodes <NUM> and exposes partial areas of upper surfaces of each of the first metal electrodes <NUM>. The covering layer <NUM> is covered on the second metal electrode <NUM> and exposes a partial area of an upper surface of the second metal electrode <NUM>. <FIG> includes, in conjunction with <FIG>, the first metal electrode bumps <NUM>. Each of the first metal electrode bumps <NUM> is correspondingly disposed on the upper surfaces of each of the first metal electrodes <NUM> having the partial areas exposed. The second metal electrode bump is disposed on the upper surface of the second metal electrode <NUM> having the partial area exposed. <FIG> further includes the dielectric material <NUM> that covers on the covering layer <NUM>, and the dielectric material <NUM> does not cover upper sides of each of the first metal electrode bumps <NUM>, and does not cover an upper side of the second metal electrode bump <NUM>. In <FIG>, the spacing zone <NUM> is positioned between different adjacent display cells <NUM>. As for the embodiment of different RGB quantum dot filters of <FIG> and <FIG>, as iterated above, the dams <NUM> are disposed at the bottom of the substrate <NUM>, and each of the dams <NUM> is an opaque dam. This embodiment further include the quantum dot materials of various wavelengths 50R, <NUM>, and 50B, each of the quantum dot materials of various wavelengths 50R, <NUM>, and 50B are correspondingly disposed in each of the dams <NUM>.

<FIG> disclose another embodiment of a display cell 1b (i.e., display unit). <FIG> is a bottom view of another product implementation relative to the actual product of <FIG>, the difference is that the RGB is in a square-shaped matrix arrangement in <FIG>, and <FIG> shows a perpendicular arrangement (i.e., a horizontal arrangement when viewed from another angle). For the structure shown in <FIG>, the manufacturing steps of the substrate <NUM>, the second electrical semiconductor layer <NUM>, the multiple-quantum well layers <NUM>, the first electrical semiconductor layers <NUM>, and the mirrors <NUM> are the same as that of <FIG>. Similarly, <FIG> can further include the protecting layer <NUM>, the first metal electrode <NUM>, the second metal electrode <NUM>, and a stacking structure including the RGB quantum dot filter <NUM>. In addition, <FIG> is a top view of <FIG>.

<FIG> show that in actual embodiments of the present disclosure, individual cutting may be performed, such that the actual embodiments of the present disclosure are to be cut into a strip-shaped display or a square shaped display according to actual display device requirements of different user ends, or actual requirements for different shapes of terminal display from client ends. As shown in <FIG>, a piece of RGB semiconductor wafer can be cut into a single display cell, a dual display cell, a triple display cell, and up to a strip-shaped display cell. As shown in <FIG>, in addition to the display cells shown in <FIG>, one row of RGB display cells is further added to the components shown in <FIG>. As shown in <FIG>, in addition to the display cells shown in <FIG>, one row of RGB display cells is further added to the components shown in <FIG>. As shown in <FIG>, in addition to the display cells shown in <FIG>, one row of RGB display cells is further added to the components shown in <FIG>. Therefore, the three-in-one RGB mini-LED device of the present disclosure can meet different requirements of customized display from the customer, and through the cutting step, cutting operations for different structure and shape may be performed, thereby providing the RGB mini-LED device that is aesthetic and meets requirements of structure, appearance, and shape to the customer.

In conclusion, the three-in-one RGB mini-LED production method of the present invention to produce a three-in-one RGB mini-LED device that has a thin thickness, is capable of separating the light-emitting face of a wafer and a chip into three or more independent electrical regions (as shown in <FIG>) that adopt a common anode or common cathode design. The opaque dam can be disposed on the wafer to produce chips of RGB color by coating on the chip in conjunction with the quantum dot materials of various wavelengths (as shown in <FIG> and <FIG>), or the opaque dam can be disposed on the transparent substrate <NUM> and the quantum dot materials of various wavelengths is coated between the dams <NUM>, thereby forming the RGB quantum dot filter <NUM>. The RGB quantum dot filter <NUM> is then adhered to the wafer to form the three colors (as shown in <FIG> and <FIG>). The wafer having three colors is then cut into multiple-in-one die sizes according to requirements, or a packaging process is performed to protect the wafer. Therefore, through the present disclosure, the quality of the lamp body can be greatly improved, and an RGB mini-LED structure having smaller size, higher light utilization rate, and precision controlled lighting pattern can be obtained. The present disclosure can be adopted in fields of RGB-LED lamps or RGB-LED displays having different shapes. The technical contents of the present disclosure are strongly suitable for patent application.

The foregoing description of the exemplary embodiments of the invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed.

Claim 1:
A three-in-one RGB mini-LED production method, wherein the production method includes:
sequentially disposing a second electrical semiconductor layer (<NUM>), a multiple-quantum well layer (<NUM>), and a first electrical semiconductor layer (<NUM>) on a substrate (<NUM>);
depositing a plurality of mirrors (<NUM>) on the first electrical semiconductor layer (<NUM>) such that each of the mirrors (<NUM>) being in electrical contact with the first electrical semiconductor layer (<NUM>);
etching the first electrical semiconductor layer (<NUM>) and the multiple-quantum well layer (<NUM>),
exposing the second electrical semiconductor layer (<NUM>) and forming a plurality of the first electrical semiconductor layers (<NUM>), and an area of each of the first electrical semiconductor layers (<NUM>) being substantially greater than an area of each of the mirrors (<NUM>);
depositing a protecting layer (<NUM>), exposing a first contact area (14a) above each of the mirrors (<NUM>), and exposing a second contact area (12a) above the second electrical semiconductor layer (<NUM>);
disposing a first metal electrode (<NUM>) above the first contact areas (14a) the area of each first metal electrode (<NUM>) being greater than each first contact area (14a); and disposing a second metal electrode (<NUM>) above the second contact area (12a), the area of the second metal electrode (<NUM>) being greater than the second contact area (12a);
etching edges of the second electrical semiconductor layer (<NUM>), and exposing the substrate (<NUM>) to be taken as a spacing region (<NUM>);
covering, by a covering layer (<NUM>), and exposing only a partial area of the first metal electrode (<NUM>) and a partial area of the second metal electrode (<NUM>), without covering the spacing region (<NUM>);
preparing an RGB quantum dot filter (<NUM>), and adhering the RGB quantum dot filter (<NUM>) to a backside of the substrate (<NUM>); and
cutting according to the spacing region (<NUM>), thereby cutting out a strip shape or a rectangle shape, and forming a three-in-one RGB mini-LED structure;
wherein a portion of the second electrical semiconductor layer (<NUM>) is not covered by the multiple-quantum well layer (<NUM>);
wherein an area of the portion of the second electrical semiconductor layer (<NUM>) not covered by the multiple-quantum well layer (<NUM>) is larger than an area of the second metal electrode (<NUM>).