TWI890070B - Light-emitting element and method of manufacturing the same - Google Patents

Abstract

A light-emitting element is provided. The light-emitting element includes a supporting layer, a plurality of light emitting units, a control unit, an optical layer, and electrode pads. The light-emitting units are disposed on the supporting layer. The control unit is disposed on the supporting layer. The control unit is configured to control the light-emitting units. The optical layer is disposed on the supporting layer and covers the light-emitting units and the control unit. The electrode pads are disposed under the supporting layer. The electrode pads are electrically connected to the light-emitting units and the control element. The control unit includes a III-V material. The control unit includes a plurality of transistors, each of the transistors has a first electrode and a second electrode, and the transistors share a semiconductor layer and a third electrode.

Description

Light-emitting element and manufacturing method thereof

This application relates to light-emitting devices and their manufacturing methods, and more particularly to display pixels and their manufacturing methods.

The driving method for light-emitting diode (LED) displays involves placing the LED on a glass circuit board with thin-film transistors (TFTs). A driver IC controls the on/off state of the TFTs according to the desired brightness. When the TFTs are on, the driver IC controls the current flowing through the LEDs.

However, typical thin-film transistors are made of silicon, which can actually carry very low current and is insufficient to drive a single LED. Furthermore, glass circuit boards utilize a deposition process to deposit a silicon layer onto a single sheet of glass to create all the thin-film transistors. Because the thickness of the silicon layer on a glass circuit board is not uniform, the electrical properties of each thin-film transistor can vary significantly.

This application provides a light-emitting element having a control unit, a method for manufacturing the light-emitting element, a package including the light-emitting element, and a light-emitting diode display using the package.

According to an embodiment, a light-emitting element includes a carrier layer, a plurality of light-emitting units, a control unit, an optical layer, and a plurality of electrode pads. The light-emitting units are disposed on the carrier layer. The control unit is disposed on the carrier layer and is used to control the light-emitting units. The optical layer is disposed on the carrier layer and covers the light-emitting units and the control unit. The electrode pads are disposed below the carrier layer. The electrode pads electrically connect the light-emitting units and the control unit. The control unit includes a III-V material. The control unit includes a plurality of transistors, each having a first electrode and a second electrode. The transistors share a semiconductor layer and a third electrode.

The manufacturing method of a light-emitting device according to an embodiment includes the following steps. First, a temporary substrate is provided. A plurality of light-emitting units and a control unit are disposed on the temporary substrate. An optical layer is formed on the temporary substrate, the optical layer covering the light-emitting units and the control unit. A carrier layer is formed on the optical layer. A plurality of electrode pads are formed on the carrier layer. Then, the temporary substrate is removed.

According to an embodiment, a light-emitting package includes a packaging substrate and a plurality of the aforementioned light-emitting elements. The packaging substrate has a plurality of pixel regions. The plurality of light-emitting elements are disposed on the packaging substrate and are respectively located in the plurality of pixel regions.

9A; 9B: Display device

10: Light-emitting element package

10C; 10C’: Circuit

100: Light-emitting element

100T: Temporary packaging structure

100C; 100C’: Circuit

100a: Temporary substrate

104; 104A: Light-emitting element package

110: Carrier layer

110a: Second dielectric layer

112: Conductive connector

114: Routing

116: Through hole

116a: First through hole

116b: Second through hole

120; 120-B; 120-G; 120-R: Light-emitting unit

122: First electrode

124: Second electrode

130: Control unit

131: Transistor

132: First electrode

133: Second electrode

134: Semiconductor layer

135: Third electrode

140: Optical layer

142: First dielectric layer

144: Third dielectric layer

150; 150-1~150-5: Electrode pad

200; 200’: Package substrate

202: Pixel area

204-1~204-20: Upper pad

206-1 to 206-6; 206-8 to 206-11; 206-13 to 206-16; 206-18 to 206-20; 206’-1 to 206’-5; 206’-8 to 206’-11; 206’-13 to 20’6-15; 206-18 to 206-20: Bottom pad

500A; 500B: Circuit board

2001: Upper surface

2002; 2002’: Lower surface

D: Height difference

DD: Data Drive

DL: Data Line

g1; g2: spacing

O1: First opening

O2: Second opening

S1; S2; S3; S4; S5; S6: Steps

SL: Scan Line

Vcc: supply voltage

10-1~10-29: Electrode Nodes

104A: Light-emitting element package

10A-1~10A-29: Node

104C: Circuits

1004:Packaging substrate

1024: Pixel area

1044: Conductive Components

2004: Light-emitting device

2024: Carrier Layer

2044: Light-emitting unit

2044-B: Light-emitting unit

2044-G: Light-emitting unit

2044-R: Light-emitting unit

2064: Conductive Components

2084: Optical layer

2104: First electrode

2124: Second electrode

2144:Electrode pad

2144-1~2144-4: Electrode pads

300: Control unit

300A: Control unit

300-2~300-29: Electrode Nodes

300A-2~300A-29: Electrode Node

302: Transistor assembly

304: Transistor

306: First electrode

308: Second electrode

310: Semiconductor layer

312: Third electrode

314: Package

C-1~C-29: Electrode nodes

DL: Data Line

L1: Dashed Line

L2: Dashed Line

Figure 1A shows a side view of a light-emitting device according to one embodiment.

Figure 1B shows a top view of a light-emitting device according to one embodiment.

Figure 1C shows a bottom view of a light-emitting device according to one embodiment.

Figure 1D shows an equivalent circuit of a light-emitting device according to one embodiment.

Figure 1E shows an equivalent circuit of a light-emitting element according to another embodiment.

Figure 2 shows a manufacturing process flow chart of a light-emitting device according to one embodiment.

Figures 3A to 3G illustrate the manufacturing process of a light-emitting device according to one embodiment.

Figure 4A shows a top view of a light-emitting device package according to one embodiment.

Figure 4B shows a top view of a package substrate according to one embodiment.

Figure 4C shows a bottom view of a package substrate according to one embodiment.

Figure 4D shows the equivalent circuit of a light-emitting device package according to one embodiment.

Figure 4E shows a bottom view of a package substrate according to one embodiment.

Figure 4F shows an equivalent circuit of a light-emitting device package according to one embodiment.

Figure 5A shows a top view of a display device according to one embodiment.

Figure 5B shows a top view of a display device according to one embodiment.

Figure 6A shows the structure of a light-emitting device package according to one embodiment.

Figure 6B shows the equivalent circuit of a light-emitting device package according to one embodiment.

Figure 7A shows a top view of a light-emitting device according to one embodiment.

Figure 7B shows a side view of a light-emitting device according to one embodiment.

Figure 8 shows a schematic diagram of a control unit according to one embodiment.

Figure 9A shows a schematic diagram of a light-emitting device package according to one embodiment.

Figure 9B shows a schematic diagram of a control unit according to one embodiment.

Various embodiments are described in more detail below with reference to the accompanying drawings. For clarity, elements in the drawings may not be drawn to scale. Furthermore, some elements and/or symbols may be omitted in some drawings. Similar symbols are used throughout the description and drawings to indicate similar elements. It should be understood that the following description and the accompanying drawings are for illustrative purposes only and are not intended to be limiting. It is contemplated that elements and features of one embodiment may be beneficially incorporated into another embodiment without further elaboration.

Figures 1A-1C illustrate the structure of a light-emitting device 100. Figure 1A is a side view of the light-emitting device 100, Figure 1B is a top view of the light-emitting device 100, and Figure 1C is a bottom view of the light-emitting device 100. As shown in Figures 1A-1C, the light-emitting device 100 includes a carrier layer 110, a plurality of light-emitting units 120, a control unit 130, an optical layer 140, and a plurality of electrode pads 150. The light-emitting units 120 are disposed on the carrier layer 110. The control unit 130 is also disposed on the carrier layer 110. The control unit 130 is used to control the plurality of light-emitting units 120. The optical layer 140 is disposed on the carrier layer 110 and covers the plurality of light-emitting cells 120 and the control cell 130. The electrode pad 150 is disposed beneath the carrier layer 110. The electrode pad 150 electrically connects the light-emitting cells 120 and the control cell 130. The control cell 130 comprises an epitaxial structure made of III-V materials. The control cell 130 includes a plurality of transistors 131, each having a first electrode 132 and a second electrode 133. The transistors 131 share a semiconductor layer 134 and a third electrode 135.

Specifically, the carrier layer 110 may be formed of a dielectric material, such as, but not limited to, a photo-imageable dielectric (PID). According to some embodiments, the carrier layer 110 may include a plurality of conductive connectors 112 that electrically connect the plurality of light-emitting units 120 and the control unit 130 to the electrode pads 150. The conductive connectors 112 include, but are not limited to, traces 114 and vias 116.

A plurality of light-emitting cells 120 are disposed on the carrier layer 110. The light-emitting cells 120 may be light-emitting diode (LED) light-emitting cells, and the thickness of the light-emitting cells 120 may be 5 μm to 15 μm. As shown in FIG1B , each light-emitting cell 120 may have a first electrode 122 and a second electrode 124 . In a single light-emitting element 100 , the first electrode 122 of the light-emitting cells 120-R, 120-G, and 120-B may be electrically connected to an electrode pad 150-4 , as shown in FIG1C . The second electrodes 124 of the light-emitting cells 120-R, 120-G, and 120-B are electrically connected to electrode pads 150-1 to 150-3 , respectively. One of the first electrode 122 and the second electrode 124 is an anode, and the other is a cathode. According to some embodiments, the plurality of light-emitting elements 120 emit at least two different colors of light. For example, light-emitting elements 120-R, 1204-G, and 120-B emit red, green, and blue light, respectively. However, it will be appreciated that the plurality of light-emitting elements 120 may also employ other suitable combinations of light colors.

In one embodiment, the control unit 130 and the plurality of light-emitting units 120 are packaged together, significantly simplifying the system design. Furthermore, placing the control unit 130 and the plurality of light-emitting units 120 on the same side of the carrier layer 110 helps reduce costs and the thickness of the package. Furthermore, the height of the control unit 130 is preferably such that it does not block the light emitted by the light-emitting units 120. For example, the height difference D between the top surface of the control unit 130 and the top surface of the light-emitting units 120 is less than or equal to 5μm to 10μm. In another embodiment, the control unit 130 can be the same height as the light-emitting units 120.

As shown in FIG1B , control unit 130 includes a plurality of transistors 131 for controlling a plurality of light-emitting units 120. In one embodiment, control unit 130 includes three transistors 131. Each transistor 131 has a first electrode 132 and a second electrode 133. The three transistors 131 share a third electrode 135 and a semiconductor layer 134. The three first electrodes 132 of the three transistors 131 are connected to a single electrode pad, such as electrode pad 150-4 in FIG1C . The three second electrodes 133 of the three transistors 131 are connected to the second electrodes 124 of the light-emitting cells 120-R, 120-G, and 120-B, respectively. The three first electrodes 122 of the light-emitting cells 120-R, 120-G, and 120-B are connected to three electrode pads, for example, electrode pads 150-1 through 150-3 in FIG. 1C . The third electrode 135 shared by the three transistors 131 can be connected to a single electrode pad, for example, electrode pad 150-5 in FIG. 1C . One of the first electrode 132 and the second electrode 133 of the transistor 131 is a source, and the other is a drain. The third electrode 135 is a gate of the transistor 131. In one embodiment, the thickness of the control unit 130 can be 5μm to 15μm. According to one embodiment, the transistor 131 is made of III-V material, wherein the III-V material includes aluminum gallium nitride (AlGaN) and/or gallium nitride (GaN). Compared to polycrystalline silicon and amorphous silicon, III-V materials have higher electron mobility. At the same volume, gallium nitride transistors can conduct larger currents and withstand larger voltages than silicon transistors. In other words, a smaller III-V material transistor can achieve the same performance as a larger silicon transistor.

In one embodiment, the optical layer 140 can be passed through by light emitted by the light-emitting unit 120. In another embodiment, the portion of the optical layer 140 that directly contacts or is close to the side surface of the light-emitting unit 120 can block the light emitted by the light-emitting unit 120, while the portion that does not directly contact or is far from the side surface of the light-emitting unit 120 can be passed through by the light emitted by the light-emitting unit 120. For example, the portion of the optical layer 140 that directly contacts the side surface of the light-emitting unit 120 is made of a dark material (e.g., black or gray), while the portion that does not directly contact the side surface of the light-emitting unit 120 or above the light-emitting unit 120 is made of a light-transmitting material (e.g., transparent or translucent).

As shown in FIG1A , a plurality of electrode pads 150 are disposed under the carrier layer 110 . The light-emitting element 100 is electrically connected to a circuit board or electronic component via the electrode pads 150 using a connection method, such as surface mount technology (SMT). The number of electrode pads 150 is less than the total number of electrodes of the light-emitting unit 120 and the control unit 130 . For example, the light-emitting element 100 includes five electrode pads 150-1 to 150-5, and the light-emitting unit 120 and the control unit 130 include thirteen electrodes. Assuming that the projected area of the light-emitting element 100 is fixed, the fewer the number of electrode pads 150, the larger the area of each electrode pad 150. Larger electrode pads can tolerate greater displacement tolerances during the connection process and form a stronger connection to the circuit board.

Referring to FIG. 1D , circuit 100C illustrates an equivalent circuit of light-emitting element 100 . Referring to FIG. 1B , in one embodiment, first electrodes 122 of light-emitting cells 120-R, 120-G, and 120-B are anodes, second electrodes 124 are cathodes, and second electrodes 133 of three transistors 131 are drains connected to the second electrodes 124 (cathodes) of light-emitting cells 120-R, 120-G, and 120-B, respectively. First electrodes 122 (anodes) of light-emitting cells 120-R, 120-G, and 120-B are collectively connected to electrode pad 150-4 (drain pad) in FIG. 1C . The first electrodes 132 of the three transistors 131 serve as sources and are connected to electrode pads 150-1 through 150-3 (source pads) in Figure 1C , respectively. The third electrodes 135 of the three transistors 131 serve as gates and are commonly connected to electrode pad 150-5 (gate pad) in Figure 1C . Specifically, the anodes 122 of the light-emitting cells 120-R, 120-G, and 120-B in the light-emitting device 100 are commonly connected. The supply voltage Vcc is applied from electrode pad 150-4 to the first electrodes 122 (anodes) of the light-emitting cells 120-R, 120-G, and 120-B. The second electrodes 124 (cathodes) of light-emitting cells 120-R, 120-G, and 120-B are connected to the second electrodes 133 (drains) of three transistors 131, respectively. The first electrodes 132 (sources) of transistors 131 are connected to corresponding data lines DL via electrode pads 150-1 through 150-3. In one embodiment, the voltages input to light-emitting cells 120-R, 120-G, and 120-B can be adjusted via the corresponding data lines DL, thereby varying the current flowing through the light-emitting cells 120-R, 120-G, and 120-B to adjust their brightness. Furthermore, the three transistors 131 in the light-emitting element 100 share a common third electrode 135 (gate) and are connected to the scan line SL via an electrode pad 150-5. When the transistors 131 are turned on, the light-emitting cells 120-R, 120-G, and 120-B emit light. When the transistors 131 are turned off, the light-emitting cells 120-R, 120-G, and 120-B do not emit light.

FIG1E illustrates another equivalent circuit 100C' of the light-emitting element 100. Referring to FIG1B , in one embodiment, the first electrodes 122 of the light-emitting cells 120-R, 120-G, and 120-B are cathodes, and the second electrodes 124 are anodes. In one embodiment, the second electrodes 133 of the three transistors 131 are all sources, connected to the second electrodes 124 (anodes) of the light-emitting cells 120-R, 120-G, and 120-B, respectively. The first electrodes 122 (cathodes) of the light-emitting cells 120-R, 120-G, and 120-B are connected in common to the electrode pad 150-4 (source pad) shown in FIG1C . The first electrodes 132 of the three transistors 131 are drains, connected to electrode pads 150-1 through 150-3 (drain pads) in Figure 1C . The three transistors 131 share a third electrode 135 (gate), which is also connected to electrode pad 150-5 (gate pad). Specifically, the first electrodes 132 (drains) of the three transistors 131 are connected to three data drivers DD, which regulate the current flowing through the light-emitting cells 120-R, 120-G, and 120-B, thereby controlling the brightness of the light emitted by the light-emitting cells 120-R, 120-G, and 120-B. The third electrode 135 is connected to the scanning line SL via the electrode pad 150-5. When the transistor 131 is turned on, the light-emitting elements 120-R, 120-G, and 120-B emit light. When the transistor 131 is turned off, the light-emitting elements 120-R, 120-G, and 120-B do not emit light.

Figure 2 shows a flowchart of the manufacturing process of the light-emitting device 100. Figures 3A to 3G show exemplary structures of the light-emitting device 100 at different manufacturing stages.

Referring to Figures 2 and 3A , first, in step S1, a temporary substrate 100a is provided. The material of temporary substrate 100a is not particularly limited, as long as it can provide temporary support and be removed later, such as glass, sapphire, and metal.

In step S2, as shown in FIG3A , a plurality of light-emitting cells 120-R, 120-G, and 120-B and a control cell 130 are placed on a temporary substrate 100a. The first and second electrodes 122 and 124 of the light-emitting cells 120, and the first, second, and third electrodes 132, 133, and 135 of the control cell 130 are oriented toward a side of the temporary substrate 100a. According to one embodiment, a padding material (not shown) is pre-placed between the light-emitting units 120-R, 120-G, and 120-B and the temporary substrate 100a to ensure that the surfaces of the first and second electrodes 122 and 124 of the light-emitting units 120-R, 120-G, and 120-B and the first, second, and third electrodes 132, 133, and 135 of the control unit 130 are aligned (not shown). The padding material can refer to the material of the optical layer 140 described above. Furthermore, the padding material can also be used to secure the light-emitting units 120 to the temporary substrate 100a in step S2.

In step S3, as shown in FIG. 3B , a first dielectric layer 142 is formed on the temporary substrate 100a, covering the light-emitting elements 120-R, 120-G, 120-B, and the control element 130. Because the light-emitting elements 120-R, 120-G, 120-B, and the control element 130 are covered by the first dielectric layer 142, the light-emitting elements 120-R, 120-G, 120-B, and the control element 130 are represented by dashed lines. The first dielectric layer 142 can serve as the optical layer 140 alone or together with the third dielectric layer 144 described later. The first dielectric layer 142 can block or allow light from the light-emitting elements 120-R, 120-G, and 120-B to pass through. Next, as shown in FIG3B , a plurality of first openings O1 are formed in the first dielectric layer 142 to expose the first and second electrodes 122 and 124 of the light-emitting elements 120-R, 120-G, and 120-B, and the first, second, and third electrodes 132, 133, and 135 of the control element 130.

In step S4, referring to Figures 3C-3D, a carrier layer 110 (Figure 3D) is formed on the first dielectric layer 142.

As shown in Figure 3C , metal is filled into a plurality of first openings O1 to connect the first electrodes 122 and second electrodes 124 of the light-emitting cells 120-R, 120-G, and 120-B, and the first electrodes 132, second electrodes 133, and third electrodes 135 of the control cell 130. A plurality of first vias 116a are also formed. Next, based on the aforementioned circuits 100C and 100C', a plurality of traces 114 are formed on the first dielectric layer 142 to electrically connect the light-emitting cells 120 and the control cell 130. In one embodiment, the traces 114 can be formed using a semiconductor process, such as, but not limited to, yellow light development.

Next, as shown in FIG3D , a second dielectric layer 110a is formed on the first dielectric layer 142, covering the plurality of traces 114 and the plurality of first vias 116a. In one embodiment, the material of the second dielectric layer 110a can be the same as or different from that of the first dielectric layer 142. The material of the second dielectric layer 110a can be ABF (Ajinomoto Build-up Film), epoxy resin, BT (Bismaleimide Triazine) resin, or polyimide resin. Next, a plurality of second openings O2 are formed in the second dielectric layer 110a to expose the endpoints of the plurality of traces 114. Then, metal is filled into the plurality of second openings O2 to contact the endpoints of the plurality of traces 114, forming a plurality of second vias 116b. Specifically, the conductive connector 112 in Figure 1A includes traces 114, first vias 116a, and second vias 116b. The first vias 116a and the second vias 116b are collectively referred to as vias 116. The plurality of traces 114, vias 116, and second dielectric layer 110a together constitute the carrier layer 110. In other embodiments, the carrier layer 110 may include other components, such as passive components such as resistors and capacitors.

In step S5, as shown in FIG. 3E , a plurality of electrode pads 150 are formed on the carrier layer 110. According to one embodiment, the electrode pads 150 can be formed using a semiconductor process or a plating process, but are not limited thereto.

In step S6, the temporary substrate 100a is removed. Methods for removing the temporary substrate 100a include laser irradiation, heating, or etching. Figure 3F shows a cross-sectional view of the intermediate package structure 100T after the temporary substrate 100a is removed and awaiting further processing. The intermediate package structure 100T exposes the surface 142S of the first dielectric layer 142 and the control unit 130.

Figure 3G shows a cross-sectional view of the light-emitting device 100. After removing the temporary substrate 100a, a third dielectric layer 144 is formed on the surface 142S of the first dielectric layer 142 and the control unit 130 to cover the light-emitting units 120 and 130. The material of the third dielectric layer 144 is the same as that of the optical layer 140 described above. The optical layer 140 includes the first dielectric layer 142 and the third dielectric layer 144. In one embodiment, the first dielectric layer 142 and/or the third dielectric layer 144 have a transmittance greater than 70% for light emitted by the light-emitting units 120-R, 120-G, and 120-B.

FIG4A shows a top view of a light-emitting device package 10 according to one embodiment. The light-emitting device package 10 includes a package substrate 200 and a plurality of light-emitting devices 100 disclosed in the aforementioned embodiments located on the package substrate 200. The package substrate 200 has a plurality of pixel regions 202. The light-emitting devices 100 are disposed on the package substrate 200 and are respectively located in the pixel regions 202 to serve as pixels. For details of the light-emitting devices 100, please refer to the relevant paragraphs above. As shown in FIG4A , the number of light-emitting devices 100 is four, that is, the light-emitting device package 10 has four pixels. The light-emitting devices 100 can be controlled by an external controller (not shown) through connection elements (not shown) within the package substrate 200. In this embodiment, the light-emitting device package 10 includes more than four light-emitting devices 100 (not shown), that is, more than four pixels. For example, the light-emitting device package 10 includes n*m light-emitting devices 100 (pixels), where n is a positive integer equal to or greater than 3, m is a positive integer equal to or greater than 3, and n is equal to or not equal to m.

Figures 4B-4C illustrate a package substrate 200 according to one embodiment, wherein Figure 4B shows a top view of the package substrate 200, and Figure 4C shows a bottom view of the package substrate 200. As shown in Figure 4B, the package substrate 200 includes a plurality of upper pads 204-1-20 located on a top surface 2001 of the package substrate 200. As shown in FIG4C , package substrate 200 includes a plurality of lower pads 206-1 through 206-6, 206-8 through 206-11, 206-13 through 206-16, and 206-18 through 206-20 located on a lower surface 2002 of package substrate 200. Upper pads 204-1 through 204-20 are used to electrically connect to the four light-emitting elements 100, while lower pads 206-1 through 206-6, 206-8 through 206-11, 206-13 through 206-16, and 206-18 through 206-20 are used to electrically connect to circuit board 500B of display device 9B shown in FIG5B . According to one embodiment, at least two of the upper pads 204-1 to 204-20 can be electrically connected to a lower pad. For example, upper pads 204-2, 204-7, 204-12, and 204-17 are electrically connected to lower pad 206-2. The remaining upper pads 204-1, 204-3 to 204-6, 204-8 to 204-11, 204-13 to 204-16, and 204-18 to 204-20 are electrically connected to lower pads 206-1, 206-3 to 206-6, 206-8 to 206-11, 206-13 to 206-16, and 206-18 to 206-20, respectively.

FIG4D shows an equivalent circuit 10C of the light-emitting device package 10. As shown in FIG4D, circuit 10C of the light-emitting device package 10 is a combination of four circuits 100C (FIG1D). In conjunction with FIG4B-4C, FIG4B-4C illustrate the upper pads 204-1 through 204-20 and the lower pads 206-1 through 206-6, 206-8 through 206-11, 206-13 through 206-16, and 206-18 through 206-20 of the package substrate 200. Upper pads 204-2, 204-7, 204-12, and 204-17, along with lower pad 206-2, can serve as drain pads. Upper pads 204-3 to 204-5, 204-8 to 204-10, 204-13 to 204-15, 204-18 to 204-20 and lower pads 206-3 to 206-5, 206-8 to 206-10, 206-13 to 206-15, 206-18 to 206-20 can serve as source pads. Upper pads 204-1, 204-6, 204-11, 204-16 and lower pads 206-1, 206-6, 206-11, 206-16 can serve as gate pads. Lower pad 206-2 is used to connect to the supply voltage Vcc.

FIG4E shows a bottom view of a package substrate 200′ according to another embodiment. Package substrate 200′ similarly has a plurality of upper pads 204-1 through 204-20, as well as a plurality of lower pads 206′-1 through 206′-5, 206′-8 through 206′-11, 206′-13 through 206′-15, and 206′-18 through 206′-20, as shown in FIG4B . The difference between package substrate 200' and package substrate 200 is that upper pads 204-1 and 204-6 are electrically connected to lower pad 206'-1, and upper pads 204-11 and 204-16 are electrically connected to lower pad 206'-11. Therefore, compared to package substrate 200, package substrate 200' has two fewer lower pads on its lower surface 2002'. The upper and lower pad designs of the rest of package substrate 200' are the same as those of package substrate 200.

FIG4F shows an equivalent circuit 10C' of the light-emitting device package 10 according to another embodiment. Circuit 10C' differs from circuit 10C in that it further connects the gates 135 of the two light-emitting devices 100 to reduce the number of lower pads. The remainder of circuit 10C' is identical to circuit 10C. In circuit 10C', upper pads 204-2, 204-7, 204-12, 204-17, and lower pad 206'-2 can serve as drain pads. Upper pads 204-3 to 204-5, 204-8 to 204-10, 204-13 to 204-15, 204-18 to 204-20 and lower pads 206'-3 to 206'-5, 206'-8 to 206'-10, 206'-13 to 206'-15, 206'-18 to 206'-20 can serve as source pads. Upper pads 204-1, 204-6, 204-11, 204-16 and lower pads 206'-1 and 206'-11 can serve as gate pads. Lower pad 206'-2 is used to introduce the supply voltage Vcc into the circuit.

Figure 5A shows a top view of a display device 9A. Display device 9A comprises a circuit board 500A, on which a plurality of light-emitting elements 100 are arranged in an array at a fixed pitch g1. The plurality of light-emitting elements 100 are electrically connected to circuit board 500A, and the color of light emitted by each light-emitting element 100 is independently controlled by an external controller (not shown). In one embodiment, the plurality of light-emitting elements 100 are first subjected to a mixing process before being placed on circuit board 500A to ensure that the display device 9A can display relatively uniform colors.

Figure 5B shows a top view of a display device 9B. Display device 9B includes a circuit board 500B, on which a plurality of light-emitting device packages 10 are arranged in an array at a fixed pitch g2. The plurality of light-emitting device packages 10 are electrically connected to circuit board 500B, and each light-emitting device 100 within each light-emitting device package 10 is independently controlled by an external controller (not shown). In one embodiment, the plurality of light-emitting device packages 10 are first subjected to a mixing process before being placed on circuit board 500B to ensure that the display device 9B can display relatively uniform colors. Since the light-emitting device package 10 includes four or more light-emitting devices 100, the manufacturing process of the display device 9B can be simplified.

Figures 6A-6B schematically illustrate a light-emitting device package 104 according to one embodiment. Figure 6A illustrates the structure of the light-emitting device package 104, while Figure 6B shows an equivalent circuit 104C of the light-emitting device package 104. As shown in Figure 6A, the light-emitting device package 104 includes a package substrate 1004, a plurality of light-emitting devices 2004, and a control unit 300. Each light-emitting device 2004 represents a pixel, so the light-emitting device package 104 has four light-emitting devices 2004, or four pixels.

As shown in FIG. 6A , the package substrate 1004 has four pixel regions 1024, demarcated by dashed lines L1 and L2. The four light-emitting elements 2004 are located in each of the four pixel regions 1024. The control unit 300 is disposed on the package substrate 1004, generally at the intersection of the dashed lines L1 and L2. A plurality of conductive elements 1044 (shown in dashed lines) are used to connect the light-emitting elements 2004 and the control unit 300. In other embodiments, the control unit 300 may be configured in other suitable locations, for example, embedded within the package substrate 1004, placed at a non-center location of the package substrate 1004 (i.e., not at the intersection of the dashed lines L1 and L2), or placed on the backside of the package substrate 1004 (i.e., with the light-emitting element 2004 and the control unit 300 located on opposite sides of the package substrate 1004). FIG. 6A shows a plurality of electrode nodes 10-1 through 10-29, which correspond to electrode nodes C-1 through C-29 of the circuit 104C shown in FIG. 6B . Furthermore, electrode nodes 10-2 through 10-29 in FIG. 6A also correspond to electrodes 300-2 through 300-29 of the control unit 300 shown in FIG. 8 . As shown in Figures 6A and 6B, within a pixel region 1024, a light-emitting element 2004 includes at least three light-emitting units, such as light-emitting units 2044-R, 2044-G, and 2044-B. The anodes of light-emitting units 2044-R, 2044-G, and 2044-B are connected to electrode node C-1. A supply voltage Vcc is connected to electrode node C-1, and the supply voltage Vcc can be connected to the anodes of light-emitting units 2044-R, 2044-G, and 2044-B. The cathodes of light-emitting cells 2044-R, 2044-G, and 2044-B are respectively connected to electrode nodes C-2 through C-4 (or electrode nodes 300-2 through 300-4 shown in FIG8 ), e.g., drains, of the three transistors 304 of control unit 300. Electrode nodes C-14 through C-16 (or electrode nodes 300-14 through 300-16 shown in FIG8 ), e.g., sources, of the three transistors 304 are connected to data line DL. The three transistors 304 in the same pixel region 1024 share a common electrode node C-26 (or electrode node 300-26 shown in FIG8 ), e.g., a gate. Electrode node C-26 is connected to scan line SL. Similarly, within the light-emitting device package 104, the other three pixels are arranged in the same manner within the circuit 104C. In other embodiments, the pixels employ other suitable circuit designs, for example, where the cathodes of the light-emitting units 2044-R, 2044-G, and 2044-B are connected to the electrode node C-1.

Figure 7A shows a top view of light-emitting element 2004, and Figure 7B shows a side view of light-emitting element 2004. As shown in Figure 7B, light-emitting element 2004 includes a carrier layer 2024, a plurality of light-emitting units 2044, and a plurality of electrode pads 2144. The light-emitting units 2044 are disposed on the carrier layer 2024. The electrode pads 2144 are disposed beneath the carrier layer 2024 and are electrically connected to the light-emitting units 2044. In one embodiment, light-emitting element 2004 further includes a plurality of conductive elements 2064 (including at least vias or conductive traces) for electrically connecting the light-emitting units 2044 and the electrode pads 2144. According to one embodiment, the light-emitting element 2004 further includes an optical layer 2084. The optical layer 2084 is disposed on the carrier layer 2024 and covers the light-emitting unit 2044.

As shown in FIG7A , each of the plurality of light-emitting cells 2044 may include a first electrode 2104 and a second electrode 2124. Within a single light-emitting element 2004, the first electrodes 2104 of the plurality of light-emitting cells 2044 may be electrically connected to the same electrode pad 2144, such as electrode pad 2144-1 in FIG7A . The second electrodes 2124 of the plurality of light-emitting cells 2044 are electrically connected to corresponding electrode pads 2144-2 through 2144-4. According to one embodiment, one of the first electrode 2104 and the second electrode 2124 of each of the plurality of light-emitting cells 2044 is an anode, and the other is a cathode. Referring to circuit 104C shown in FIG. 6B , first electrode 2104 is an anode, and second electrode 2124 is a cathode. Light-emitting element 2044 may be a light-emitting diode. According to one embodiment, the plurality of light-emitting elements 2044 emit at least three different colors of light. For example, circuit 104C in FIG. 6B includes three light-emitting elements 2044-R, 2044-G, and 2044-B, which emit red, green, and blue light, respectively. In other embodiments, the plurality of light-emitting elements 2044 may also employ other suitable combinations of light colors.

FIG8 shows a schematic diagram of a control unit 300. The control unit 300 includes a plurality of transistor groups 302, each of which controls a plurality of light-emitting elements 2004 (not shown). Each transistor group 302 includes a plurality of transistors 304. In one embodiment, a transistor group 302 includes three transistors 304. Each transistor 304 has a first electrode 306 and a second electrode 308. The plurality of transistors 304 in a single transistor group 302 share a semiconductor stack 310 and a third electrode 312. According to one embodiment, one of the first electrode 306 and the second electrode 308 of each of the plurality of transistors 304 is a source, and the other is a drain. Referring to circuit 104C shown in FIG. 6B , second electrode 308 is a source, and first electrode 306 is a drain. Third electrode 312, shared by multiple transistors 304 in a single transistor group 302, is a gate. In another embodiment, control unit 300 includes four transistor groups 302, each used to control four light-emitting elements 2004. Each of the four transistor groups 302 has a total of twelve first electrodes 306 connected to electrode nodes 300-2 through 300-13, twelve second electrodes 308 connected to electrode nodes 300-14 through 300-25, and four third electrodes 312 connected to electrode nodes 300-26 through 300-29. According to one embodiment, the semiconductor stack 310 of the control unit 300 includes a III-V material. The III-V material includes aluminum gallium nitride (AlGaN) and/or gallium nitride (GaN). According to one embodiment, the control unit 300 may further include a package 314 for encapsulating the transistor assembly 302.

Figures 9A-9B schematically illustrate a light-emitting device package 10A and its control unit 300A according to one embodiment. As shown in Figure 9B , the difference between light-emitting device package 104A and light-emitting device package 104 lies in that, in control unit 300A, transistors 304 in two adjacent transistor groups 302 share a common semiconductor layer 310. In other words, the two adjacent transistor groups 302 are further integrated. The structure and circuit configuration of control unit 300A, as well as the circuit configuration of light-emitting device package 104A, are adjusted accordingly. Electrode nodes 10A-1 through 10A-29 in Figure 9A can also correspond, respectively, to electrode nodes C-1 through C-29 in circuit 104C shown in Figure 6B . Furthermore, electrode nodes 10A-2 to 10A-29 in FIG. 9A may also correspond to electrode nodes 300A-2 to 300A-29 of control unit 300A shown in FIG. 9B , respectively.

In summary, this application provides a light-emitting device including a control unit, a method for manufacturing the light-emitting device, and a light-emitting device package. These devices can be applied to micro-LED displays, offering advantages such as simplified system design. However, it is understood that the light-emitting device, method for manufacturing the light-emitting device, and light-emitting device package of this application may also be applied to other types of LED displays, even displays that do not use LEDs, without specific limitations.

While the embodiments of this invention are disclosed above, they are not intended to limit the scope of this invention. Those skilled in the art will readily appreciate that various modifications and improvements are possible without departing from the spirit and scope of this invention. Therefore, the scope of protection for this invention shall be determined by the scope of the patent application attached hereto.

100: Light-emitting element

110: Carrier layer

112: Conductive connector

114: Routing

116: Through hole

120: Light-emitting unit

130: Control unit

140: Optical layer

150: Electrode pad

D: Height difference

Claims (8)

A light-emitting element comprises: a carrier layer; a plurality of light-emitting units disposed on the carrier layer; a control unit disposed on the carrier layer, the control unit being used to control the light-emitting units; an optical layer disposed on the carrier layer and covering the light-emitting units and the control unit; and a plurality of electrode pads disposed beneath the carrier layer and electrically connecting the light-emitting units and the control unit; the control unit comprises a III-V material; the control unit comprises a plurality of transistors, each having a first electrode and a second electrode, and the transistors sharing a common semiconductor layer and a common third electrode. A light-emitting element as described in claim 1, wherein the light-emitting units are LED light-emitting units. A light-emitting element as described in claim 1, wherein the light-emitting units emit light of at least two different colors. The light-emitting device as described in claim 1, wherein the III-V material of the control unit is GaN. The light-emitting element as described in claim 1, wherein a height difference between an upper surface of the control unit and an upper surface of the light-emitting units is less than or equal to 10 μm. The light-emitting device as described in claim 1, wherein the first electrodes of the transistors are connected to the same electrode pad. The light-emitting element as described in claim 1, wherein one of the first electrode and the second electrode of each of the transistors is a source and the other is a drain, and the third electrode shared by the transistors is a gate. The light-emitting element as described in claim 1, wherein the carrier layer includes a plurality of conductive connectors that electrically connect the light-emitting units and the control unit to the electrode pads.