CN113179667A

CN113179667A - Composite micro light-emitting diode, display panel and electronic equipment

Info

Publication number: CN113179667A
Application number: CN201980004330.9A
Authority: CN
Inventors: 陈靖中
Original assignee: Chongqing Kangjia Photoelectric Technology Research Institute Co Ltd
Current assignee: Chongqing Kangjia Optoelectronic Technology Co ltd
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2021-07-27
Anticipated expiration: 2039-11-26
Also published as: CN113179667B; WO2021102665A1

Abstract

The invention provides a composite miniature light emitting diode, the composite miniature light emitting diode comprises a first micro light emitting diode and a second micro light emitting diode; the first micro light emitting diode comprises a first semiconductor layer, a second semiconductor layer and a first quantum well layer; the second micro light emitting diode includes a third semiconductor layer, a fourth semiconductor layer and a second quantum well layer; the first semiconductor layer and the fourth semiconductor layer have a first polarity, the second semiconductor layer and the third semiconductor layer The layer has a second polarity; the second semiconductor layer and the third semiconductor layer are of the same material, and the second semiconductor layer and the third semiconductor layer are combined together so that the first micro-LED and the second micro-LED are combined together; the first The quantum well layer and the second quantum well layer are doped with different materials. In addition, the present invention also provides a display panel and an electronic device.

Description

Composite micro light-emitting diode, display panel and electronic equipment

Technical Field

The invention relates to the technical field of display, in particular to a composite micro light-emitting diode, a display panel and electronic equipment.

Background

Light Emitting Diodes (LEDs) usually generate a white light effect by using monochromatic LEDs and wavelength conversion materials, for example, red LEDs, blue LEDs or green LEDs respectively generate a white light effect by carrying a quantum dot layer, a fluorescent powder layer or a phosphor layer, or chips of different materials are press-welded together by wafer transfer (wafer transfer) so that chips originally emitting different light rays are combined to emit composite light rays.

For example, a semiconductor layer made of GaN is used for manufacturing a green Micro LED or a blue Micro LED, and a semiconductor layer made of GaAsP is used for manufacturing a red Micro LED. Two chips emitting different monochromatic light are packaged in a pressure welding process mode, so that composite light can be emitted. That is, the materials used for different monochromatic lights are also different.

For another example, when the material of the semiconductor layer is GaN, the semiconductor device can emit blue light or green light. When two chips which are both blue or green are pressure-welded together, the bonding surfaces in the prior art are an N-type semiconductor layer and a P-type semiconductor layer respectively, the main component of the N-type semiconductor layer is Si, and the main component of the P-type semiconductor layer is Mg. That is, the N-type semiconductor layer and the P-type semiconductor layer are different in material.

In the prior art, in the manufacturing method for producing the composite light by bonding and welding the two micro light-emitting diode chips together, the bonding surfaces are made of different materials, and the lattice coefficients are not matched, so that the micro light-emitting diode chips are easy to crack in the bonding and welding process.

Disclosure of Invention

In view of the above, it is desirable to provide a compound micro light emitting diode that can prevent the micro light emitting diode from breaking.

In addition, it is necessary to provide a display panel and an electronic device using the composite micro light emitting diode.

In a first aspect, an embodiment of the present invention provides a composite micro light emitting diode. The composite micro light-emitting diode comprises a first micro light-emitting diode and a second micro light-emitting diode; the first micro light emitting diode comprises a first semiconductor layer, a second semiconductor layer and a first quantum well layer arranged between the first semiconductor layer and the second semiconductor layer; the second micro light emitting diode includes a third semiconductor layer, a fourth semiconductor layer, and a second quantum well layer disposed between the third semiconductor layer and the fourth semiconductor layer; the first semiconductor layer and the fourth semiconductor layer have a first polarity; the second semiconductor layer and the third semiconductor layer have a second polarity, the second semiconductor layer and the third semiconductor layer are made of the same material, and the second semiconductor layer and the third semiconductor layer are combined together to enable the first micro light-emitting diode and the second micro light-emitting diode to be combined together; the first quantum well layer and the second quantum well layer are of different materials.

In a second aspect, an embodiment of the invention provides a display panel, which includes a circuit board and the composite micro led mounted on the circuit board.

In a third aspect, an embodiment of the present invention provides an electronic device, which includes the display panel and a housing for fixing the display panel.

According to the composite type micro light-emitting diode, the first micro light-emitting diode and the second micro light-emitting diode are combined through the second semiconductor layer and the third semiconductor layer which have the same polarity and are made of the same material, so that the problem that the first micro light-emitting diode and the second micro light-emitting diode are broken due to the fact that the two semiconductor layers made of different materials are combined is avoided, and the yield of the composite type micro light-emitting diode is improved. In addition, the first quantum well layer and the second quantum well layer are made of different materials, so that the first micro light-emitting diode and the second micro light-emitting diode generate light with different wavelengths, and the composite micro light-emitting diode can emit composite light.

Drawings

Fig. 1 is a schematic view of a composite micro led according to a first embodiment.

Fig. 2 is a schematic diagram of a first embodiment of a composite micro led according to a first embodiment.

Fig. 3 is a schematic diagram of a second embodiment of the compound micro led according to the first embodiment.

Fig. 4 is a schematic diagram of light emitted from the first micro light-emitting diode and the second micro light-emitting diode shown in fig. 1.

FIG. 5 is a schematic diagram of the electrical connection of the hybrid micro LED shown in FIG. 2 according to the first embodiment.

FIG. 6 is a schematic diagram of the electrical connection of the composite micro LED shown in FIG. 2 according to a second embodiment.

Fig. 7 is a schematic view of a display panel according to a first embodiment.

Fig. 8 is a schematic diagram of an electronic device according to the first embodiment.

Detailed Description

The embodiment of the invention provides a composite micro light-emitting diode, a display panel using the same and electronic equipment. According to the combined type micro light-emitting diode, the two semiconductor layers of the two combined micro light-emitting diodes have the same polarity and material, so that the problem of breakage caused by combination of the two micro light-emitting diodes is avoided, and the yield of the combined type micro light-emitting diode is improved.

Please refer to fig. 1, which is a schematic diagram of a hybrid micro led 99 according to a first embodiment. The composite micro led 99 includes a first micro led 990 and a second micro led 992. The first micro light emitting diode 990 and the second micro light emitting diode 992 are integrated. The light emitted by the first micro light emitting diode 990 has the first wavelength 60 a. The light emitted by the second micro light emitting diode 992 has a second wavelength 60 b. The first wavelength 60a and the second wavelength 60b are different, preferably the first wavelength 60a and the second wavelength 60b do not overlap. As shown in FIG. 4, the first wavelength 60a is 380-430 mm; the second wavelength 60b is 450-550 mm. Thus, the first micro light emitting diode 990 and the second micro light emitting diode 992 can emit light with different wave bands, respectively, so that the composite micro light emitting diode 99 has a multi-band emission effect closer to natural light (Sun Beam).

The first micro light emitting diode 990 includes a first semiconductor layer 10, a second semiconductor layer 11, and a first quantum well layer (MQW)12 disposed between the first semiconductor layer 10 and the second semiconductor layer 11. The second micro light emitting diode 992 includes a third semiconductor layer 20, a fourth semiconductor layer 21, and a second quantum well layer 22 disposed between the third semiconductor layer 20 and the fourth semiconductor layer 21. The first semiconductor layer 10 and the fourth semiconductor layer 21 have a first polarity. The second semiconductor layer 11 and the third semiconductor layer 20 have the second polarity and are made of the same material. The second semiconductor layer 11 and the third semiconductor layer 20 are bonded to each other. Specifically, the first semiconductor layer 11 and the third semiconductor layer 20 are bonded by pressure welding. It can be seen that the two bonding surfaces have the same polarity and are made of the same material, and thus, the two bonding surfaces, i.e., the second semiconductor layer 11 and the third semiconductor layer 20, have the same material, so that when the first micro light emitting diode 990 and the second micro light emitting diode 992 are bonded, the probability of fracture of the bonding surfaces can be reduced.

In the embodiment, since the doping materials of the first quantum well layer 12 and the second quantum well layer 22 are different, when the polarity and the material of the second semiconductor 11 and the third semiconductor 20 are the same, the first wavelength 60a and the second wavelength 60b of the light emitted from the first micro light emitting diode 990 and the second micro light emitting diode 992 are different.

Preferably, the first wavelength 60a and the second wavelength 60b do not overlap. Specifically, in some possible embodiments, the materials doping the first quantum well layer 12 and the second quantum well layer 22 are different, specifically: the first quantum well layer 12 and the second quantum well layer 22 are doped with the same material composition but at different concentrations, so that the wavelengths of light emitted from the first micro light emitting diode 990 and the second micro light emitting diode 992 are different. The first quantum well layer 12 and the second quantum well layer 22 are doped with different concentrations of substances, which can be understood as follows: the doped substances have different component proportions; it may also be different for the total weight of the doped substances.

Please refer to fig. 2, which is a schematic diagram of a first embodiment of the hybrid micro light emitting diode 99 according to the first embodiment. The first polarity is P-type and the second polarity is N-type. The first semiconductor layer 10, the second semiconductor layer 11, the third semiconductor layer 20, and the fourth semiconductor layer 21 are made of gallium nitride. That is, the first semiconductor layer 10, the second semiconductor layer 11, the third semiconductor layer 20, and the fourth semiconductor layer 21 are specifically: p-type gallium nitride semiconductor layer 10a, N-type gallium nitride semiconductor layer 11a, N-type gallium nitride semiconductor layer 20a, and P-type gallium nitride semiconductor layer 21 a.

Please refer to fig. 3, which is a schematic diagram of a second embodiment of the hybrid micro light emitting diode 99 according to the first embodiment. In this embodiment, the first polarity may also be N-type, and the second polarity may be P-type. Specifically, the first semiconductor layer 10, the second semiconductor layer 11, the third semiconductor layer 20, and the fourth semiconductor layer 21 are an N-type gallium nitride semiconductor layer 10b, a P-type gallium nitride semiconductor layer 11b, a P-type gallium nitride semiconductor layer 20b, and an N-type gallium nitride semiconductor layer 21b, respectively, made of gallium nitride.

In some possible embodiments, the material used for the first semiconductor layer 10, the second semiconductor layer 11, the third semiconductor layer 20, and the fourth semiconductor layer 21 may also be, but is not limited to, gallium arsenide phosphide (GaAsP), which is not shown in the drawings.

Specifically, the first micro light emitting diode 990 and the second micro light emitting diode 992 are electrically connected through a circuit structure. The electrical connection structure between the first micro light emitting diode 990 and the second micro light emitting diode 992 will be described by taking the first micro light emitting diode 990 using the P-type gallium nitride semiconductor layer 10a and the N-type gallium nitride semiconductor layer 11a as the first conductive layer 10 and the second conductive layer 11, and the second micro light emitting diode 992 using the N-type gallium nitride semiconductor layer 20a and the P-type gallium nitride semiconductor layer 21a as the third semiconductor layer 20 and the fourth semiconductor layer 21 as examples.

Referring to fig. 5, the electrical connection structure of the composite micro-led 999 according to the second embodiment is shown. The composite micro led 999 further includes a connection layer 50, a first polarity electrode 30, and two second polarity electrodes 31 b. The connection layer 50 is provided on the second semiconductor layer 11a and the third semiconductor layer 20a and electrically connects the first quantum well layer 11a and the second quantum well layer 21a through the second semiconductor layer 11a and the third semiconductor layer 20a and the first quantum well layer 11a and the second quantum well layer 21a in parallel. The first polarity electrode 30 is disposed on the connection layer 50. One second polarity electrode 31a is provided on the first semiconductor layer 11a on the side away from the first quantum well layer 12. The other second polarity electrode 31b is disposed on the fourth semiconductor layer 21 a. The first polarity electrode 30 is an N-type electrode, and the second polarity electrode 30b is a P-type polarity electrode. The first polarity electrode 30 and the two second polarity electrodes 31a and b are respectively provided with leads 40a to 40 c.

Further, the second semiconductor layer 20a has a first surface 111, a second surface 113 opposite to the first surface 111, and a third surface 112 connected between the first surface 111 and the second surface 113. The first quantum well layer 12a is disposed on the first surface 111 and partially exposes the first surface 111 to form a first connection surface 1110. The third semiconductor layer 20a has a fourth surface 201. The second semiconductor layer 11a is bonded to the fourth surface 201 through the second surface 113 and exposes the second surface to form a second connection surface 2010. The connection layer 50 covers the first connection face 1110, the second connection face 2010 and the third surface 112. In this embodiment, the cross-section of the connecting layer 50 is generally right-angle two-step stepped. Specifically, the first polarity electrode is located at a position corresponding to the second connection surface 2010.

Specifically, the other second polarity electrode 31b is disposed on the side of the fourth semiconductor layer 21a away from the second quantum well layer 22a and the second polarity electrode 31b completely covers the side of the fourth semiconductor layer 21 away from the second quantum well layer. In this manner, the second polarity electrode 31b can be electrically connected by directly mounting a circuit board (not shown) without providing a wire.

Referring to fig. 6, an electrical connection structure of a composite micro-led 99 of a second embodiment is shown. The electrical connection structure of the second embodiment differs from that of the first embodiment in that the structure of the other second polarity electrode 31b and the fourth semiconductor layer 21a is different.

Specifically, the fourth semiconductor layer includes a fifth surface 211, and the second quantum well layer 21a is provided on the fifth surface 211 with the fifth surface partially exposed to form the third connection surface 2110. Another second polarity electrode 30b is disposed on the third connection face 2110. The other second polarity electrode 31b need not be provided with the wire 40 c.

In the above embodiment, the connection layer 50 can electrically connect the first quantum well layer 11a and the second quantum well layer 21a in parallel, which can be realized without using a via connection line, and thus the circuit structure is simpler and the processing process is more convenient.

In the above embodiment, the first micro light emitting diode and the second micro light emitting diode have the same polarity and material, and the second semiconductor layer and the third semiconductor layer are combined, so that the problem that the first micro light emitting diode and the second micro light emitting diode are broken due to the combination of the two semiconductor layers made of different materials is avoided, and the yield of the composite micro light emitting diode is improved. In addition, the first quantum well layer and the second quantum well layer are made of different materials, so that the first micro light-emitting diode and the second micro light-emitting diode generate light with different wavelengths, and the composite micro light-emitting diode can emit composite light.

Please refer to fig. 7, which is a schematic diagram of a display panel 999 applying the composite micro led 99 of the first embodiment. The display panel 999 includes the circuit board 70 and the composite micro led 99. The compound micro-leds 99 are mounted on the circuit board 70.

Please refer to fig. 8, which is a schematic diagram of an electronic device 9999 applying the display panel 999 according to the first embodiment. The electronic device 9999 includes a display panel 999 and a housing 80 that fixes the display panel 999. It is understood that the electronic device 9999 has an illumination or display function. The electronic device 9999 includes, but is not limited to, a display, a television, a computer, a notebook, a tablet, a wearable device, a lighting device, and the like.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, insofar as these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is intended to include these modifications and variations.

The above-mentioned embodiments are only examples of the present invention, which should not be construed as limiting the scope of the present invention, and therefore, the present invention is not limited by the claims.

Claims

A composite micro light emitting diode comprising:

a first micro light emitting diode comprising a first semiconductor layer, a second semiconductor layer, and a first quantum well layer disposed between the first semiconductor layer and the second semiconductor layer; and

a second micro light emitting diode comprising a third semiconductor layer, a fourth semiconductor layer, and a second quantum well layer disposed between the third semiconductor layer and the fourth semiconductor layer;

wherein the first semiconductor layer and the fourth semiconductor layer have a first polarity; the second semiconductor layer and the third semiconductor layer have a second polarity, the second semiconductor layer and the third semiconductor layer are made of the same material, and the second semiconductor layer and the third semiconductor layer are combined together to enable the first micro light-emitting diode and the second micro light-emitting diode to be combined together; and the first quantum well layer and the second quantum well layer are doped with different materials.
The composite micro led of claim 1, wherein the second and third semiconductor layers are N-type semiconductor layers, and the first and fourth semiconductor layers are P-type semiconductor layers.
The composite micro led of claim 2, wherein the second and third semiconductor layers are gan.
The composite micro led of claim 2, wherein the second and third semiconductor layers are P-type semiconductor layers, and the first and fourth semiconductor layers are N-type semiconductor layers.
The composite micro led of claim 4, wherein the second semiconductor layer and the third semiconductor layer are made of gan material.
The composite micro light-emitting diode of claim 1, wherein the first and second micro light-emitting diodes have no overlap in wavelength of the first and second micro light-emitting diodes through the first and second quantum well layers.
The composite micro light-emitting diode of claim 2, further comprising a connection layer, a first polarity electrode and two second polarity electrodes; the connection layer is disposed between the second semiconductor layer and the third semiconductor layer to electrically connect the first quantum well layer and the second quantum well layer in parallel through the second semiconductor and the third semiconductor layer, and the first polarity electrode is disposed on the connection layer; one of the second polarity electrodes is disposed on a side of the first semiconductor layer away from the first quantum well layer, and the other of the second polarity electrodes is disposed on the fourth semiconductor layer.
The composite micro led of claim 7, wherein the first polarity electrode is an N-type electrode and the second polarity electrode is a P-type polarity electrode.
The composite micro led of claim 7, wherein the second semiconductor layer has a first surface, a second surface opposite to the first surface, and a third surface connected between the first surface and the second surface, and the first quantum well layer is disposed on the first surface and partially exposes the first surface to form a first connection surface; the third semiconductor layer is provided with a fourth surface, the second semiconductor layer is combined with the fourth surface through the second surface, the second surface is exposed to form a second connecting surface, and the connecting layer covers the first connecting surface, the second connecting surface and the third surface.
The composite micro led of claim 9, wherein the first polarity electrode is disposed on the connection layer at a position corresponding to the second connection surface.
The composite micro led of claim 7, wherein the another second polarity electrode is disposed on a side of the fourth semiconductor layer away from the second quantum well layer.
The composite micro light-emitting diode of claim 11, wherein the second polarity electrode completely covers a side of the fourth semiconductor away from the second quantum well layer.
The composite micro led of claim 7, wherein the fourth semiconductor layer has a fifth surface, the second quantum well layer is disposed on the fifth surface, and the fifth surface is partially exposed to form a third connection surface, and the second polarity electrode is disposed on the third connection surface.
The composite micro led of claim 1, wherein the second semiconductor layer and the third semiconductor layer are bonded by pressure welding.
A display panel, comprising a circuit board and the composite micro light emitting diode according to any one of claims 1 to 14, wherein the composite micro light emitting diode is mounted on the circuit board.
An electronic device characterized by comprising the display panel according to claim 15 and a housing fixed to the display panel.