Packaging structure of micro light-emitting diode chip and construction method thereof

Abstract

The invention relates to the technical field of micro light-emitting diode chip packaging, and provides a packaging structure of a micro light-emitting diode chip and a construction method of the packaging structure. The packaging structure comprises a circuit board; the first surface of the micro light-emitting diode chip is exposed, the second surface of the micro light-emitting diode chip is provided with an active area, and the circuit board is electrically connected with the micro light-emitting diode chip; and the plastic package body is connected with the circuit board and the micro light-emitting diode chip, the plastic package body is arranged on the periphery of the micro light-emitting diode chip, and the active area is exposed. According to the invention, the manufacturing cost of the packaging body can be reduced, and the thickness of the packaging body is reduced.

Description

Technical Field

[0002] The present invention generally relates to the technical field of micro light emitting diode chip packaging, and in particular to a packaging structure of a micro light emitting diode chip and a construction method thereof. Background Art

[0004] Micro Light Emitting Diode technology is a high-pixel density LED flat display technology that uses micron-sized LEDs as pixel elements and is assembled on a control backplane at a micron-sized period. Compared with traditional light-emitting diodes (LEDs), micro light-emitting diodes have the advantages of high brightness, high contrast, high response speed, high efficiency, long life, wide color gamut, and small size, and have been widely used.

[0005] The packaging structure of the micro-LED chip is a bridge connecting the micro-LED chip and the external circuit, which is crucial to the performance of the micro-LED. However, the packaging structure of the micro-LED chip in the prior art usually requires a reinforcement sheet to be provided on the back of the chip, which not only increases the manufacturing cost, but also increases the thickness of the packaging structure. Summary of the invention

[0007] In order to at least partially solve the above problems in the prior art, the present invention provides a packaging structure of a micro light emitting diode chip, comprising: Circuit boards; a micro light emitting diode chip having an active area on its second surface, the circuit board being electrically connected to the micro light emitting diode chip; and A plastic package is connected to the circuit board and the micro-LED chip, wherein the plastic package is arranged at the periphery of the micro-LED chip and exposes the active area.

[0008] In one embodiment of the present invention, it is provided that a first surface of the micro-LED chip opposite to the second surface is exposed.

[0009] In one embodiment of the present invention, it is provided that the micro light emitting diode chip is arranged on the circuit board, wherein a first side of the micro light emitting diode chip is connected to the circuit board.

[0010] In one embodiment of the present invention, it is provided that a surface of the circuit board facing away from the micro-LED chip is exposed.

[0011] In one embodiment of the present invention, it is provided that the circuit board has: A circuit board body, which is arranged under the plastic package and the micro light emitting diode; and The extension portion extends beyond the circuit board body to electrically connect the micro light emitting diode chip to the outside.

[0012] In one embodiment of the present invention, it is provided that the circuit board includes a flexible circuit board or a rigid printed circuit board.

[0013] In one embodiment of the present invention, it is provided that the material of the plastic package body includes epoxy resin, silicone or ethylene-vinyl acetate copolymer.

[0014] In one embodiment of the present invention, it is provided that the micro light emitting diode chip is electrically connected to the circuit board via leads, and the plastic package body covers the leads.

[0015] In one embodiment of the present invention, a first connection portion is provided at an edge region of the second surface of the micro-LED chip, and a second connection portion is provided on the surface of the circuit board, wherein the lead connects the first connection portion and the second connection portion.

[0016] In one embodiment of the present invention, the material of the lead wire includes gold or aluminum.

[0017] In one embodiment of the present invention, it is provided that the micro light emitting diode chip comprises an integrated circuit backplane and the active area arranged on the integrated circuit backplane, the active area comprises a pixel array formed by micro light emitting diodes, the pixel array comprises a plurality of micro light emitting diode pixels, and each pixel comprises one or more micro light emitting diodes.

[0018] In one embodiment of the present invention, the micro light emitting diode comprises a micron-scale light emitting mesa structure, wherein the micron-scale light emitting mesa structure comprises a first type epitaxial layer, a second type epitaxial layer, and a light emitting layer between the first type epitaxial layer and the second type epitaxial layer. The first type epitaxial layer is a semiconductor material having a first conductivity type and includes a plurality of semiconductor layers; The second type epitaxial layer is a semiconductor material having a second conductivity type and includes a plurality of semiconductor layers.

[0019] In one embodiment of the present invention, it is provided that the packaging structure of the micro light emitting diode chip further includes: A light-transmitting cover plate is arranged on the active area of ​​the micro-light emitting diode chip.

[0020] In one embodiment of the present invention, it is provided that there is a gap between the bottom surface of the light-transmitting cover plate and the surface of the active area.

[0021] In one embodiment of the present invention, it is provided that the material of the light-transmitting cover plate includes: glass, silicon dioxide or magnesium fluoride.

[0022] In one embodiment of the present invention, it is provided that the top surface height of the plastic package body is higher than the top surface height of the active area. The light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surface of the plastic package body, and there is a gap between the bottom surface of the middle area and the surface of the active area.

[0023] In one embodiment of the present invention, a transparent cover plate adhesive is provided at a position where the transparent cover plate overlaps with the top surface of the plastic package body, and the transparent cover plate is fixed by the transparent cover plate adhesive to be located above the active area.

[0024] In one embodiment of the present invention, it is stipulated that the portion of the plastic encapsulation body adjacent to the active area of ​​the micro-light-emitting diode chip forms a downward plastic encapsulation step, the top surface of the plastic encapsulation step is lower than the top surface of the plastic encapsulation body, the light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surface of the plastic encapsulation step, and there is a gap between the bottom surface of the middle area and the surface of the active area.

[0025] In one embodiment of the present invention, it is provided that the top surface height of the molding step is higher than the surface height of the active area.

[0026] In one embodiment of the present invention, a transparent cover plate adhesive is provided at a position where the transparent cover plate overlaps with a top surface of the plastic sealing step, and the transparent cover plate is fixed by the transparent cover plate adhesive to be located above the active area.

[0027] In one embodiment of the present invention, it is provided that the light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surrounding surfaces of the active area, and there is a gap between the bottom surface of the middle area and the surface of the active area.

[0028] In one embodiment of the present invention, a transparent cover plate adhesive is provided at a position where the transparent cover plate overlaps with the outer top surface of the active area, and the transparent cover plate is fixed by the transparent cover plate adhesive to be located above the active area.

[0029] In one embodiment of the present invention, it is provided that the plastic encapsulation body is connected to the light-transmitting cover plate and the side surface of the light-transmitting cover plate adhesive.

[0030] In one embodiment of the present invention, it is provided that the top surface of the light-transmitting cover plate is flush with the top surface of the plastic package body.

[0031] In one embodiment of the present invention, it is provided that the material of the transparent cover plate adhesive is ethylene-vinyl acetate copolymer.

[0032] In one embodiment of the present invention, it is provided that the packaging structure of the micro light emitting diode chip further includes: A heat sink connected to the first surface of the micro-LED chip, wherein at least a portion of the circuit board is arranged on the heat sink, and the plastic package covers a portion of the top surface of the heat sink; or the heat sink is arranged on the surface of the circuit board facing away from the micro-LED chip.

[0033] In one embodiment of the present invention, it is provided that the material of the heat sink includes: graphite.

[0034] The present invention also provides a method for constructing a packaging structure of a micro light emitting diode chip, comprising: Providing a circuit board, and arranging the circuit board on the top surface of the carrier board; Arranging a micro-LED chip on the top surface of the carrier board at a position adjacent to the circuit board, wherein a first surface of the micro-LED chip is connected to the carrier board, and a second surface of the micro-LED chip opposite to the first surface has an active area; forming wires between the circuit board and the micro light emitting diode chip by a wire bonding process; forming a plastic package, wherein the plastic package covers all side surfaces and a portion of the top surface except the active area of ​​the micro-LED chip, a portion of the top surface and side surfaces of the circuit board adjacent to the micro-LED chip, and a portion of the top surface of the carrier, and exposes the active area; and The carrier is removed to expose the first surface of the micro-LED chip.

[0035] The present invention also provides a method for constructing a packaging structure of a micro light emitting diode chip, comprising: Provide circuit boards; Arranging a micro light emitting diode chip on the front side of the circuit board, wherein a first side of the micro light emitting diode chip is connected to the circuit board, and a second side of the micro light emitting diode chip opposite to the first side has an active area; forming wires between the circuit board and the micro light emitting diode chip by a wire bonding process; and A plastic package is formed, which covers all side surfaces and a portion of the top surface of the micro-LED chip except the active area, and a portion of the top surface of the circuit board, and exposes the active area.

[0036] The present invention further proposes a method for constructing the packaging structure of the micro-LED chip, further comprising: A light-transmitting cover plate is covered above the active area of ​​the micro-light-emitting diode chip.

[0037] In one embodiment of the present invention, the top surface height of the plastic package body is higher than the top surface height of the active area, and the transparent cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area. The support area is covered and fixed to the surface of the plastic package body by a transparent cover plate adhesive, and a gap is provided between the bottom surface of the middle area and the surface of the active area.

[0038] In one embodiment of the present invention, a downward plastic encapsulation step is formed at a portion of the plastic encapsulation body adjacent to the active area of ​​the micro-LED chip, the top surface of the plastic encapsulation step is lower than the top surface of the plastic encapsulation body, the light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area, The support area is covered and fixed to the surface of the plastic packaging step by a transparent cover plate adhesive, and a gap is provided between the bottom surface of the middle area and the surface of the active area.

[0039] In one embodiment of the present invention, the light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area. The support area is covered and fixed to the surrounding surfaces of the active area by adhesive of a transparent cover plate, and a gap is provided between the bottom surface of the middle area and the surface of the active area.

[0040] In one embodiment of the present invention, a light-transmitting cover plate is provided above the active area of ​​the micro-LED chip, and the light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area. The support area is covered and fixed to the surrounding surfaces of the active area by adhesive of a transparent cover plate, and a gap is provided between the bottom surface of the middle area and the surface of the active area.

[0041] In one embodiment of the present invention, it is provided that the method for constructing the packaging structure of the micro light emitting diode chip further comprises: Connecting a heat sink to the first surface of the micro-LED chip, wherein at least a portion of the circuit board is arranged on the heat sink, and the plastic package covers a portion of the top surface of the heat sink; or A heat sink is arranged on the back side of the circuit board.

[0042] The present invention also provides a light source device having the packaging structure of the micro light emitting diode chip.

[0043] The present invention has at least the following beneficial effects: the present invention provides a packaging structure of a micro-LED chip and a construction method thereof, which eliminates the provision of a reinforcing sheet, thereby reducing the manufacturing cost of the package and reducing the thickness of the package. In addition, the exposed back of the micro-LED chip or circuit board is also conducive to heat dissipation, thereby increasing the chip life and maintaining high-performance operation of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] To further illustrate the advantages and features of various embodiments of the present invention, a more detailed description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It will be understood that these drawings only depict typical embodiments of the present invention and are therefore not to be considered as limiting the scope thereof. In the accompanying drawings, for clarity, identical or corresponding parts will be represented by identical or similar reference numerals.

[0046] Figure 1A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a first embodiment of the present invention is shown.

[0047] Figure 1B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a first embodiment of the present invention is shown.

[0048] Figure 1C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a first embodiment of the present invention is shown.

[0049] Figure 2 A schematic cross-sectional view showing a construction process of a packaging structure of a micro light emitting diode chip according to a first embodiment of the present invention.

[0050] Figure 3A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a second embodiment of the present invention is shown.

[0051] Figure 3B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a second embodiment of the present invention is shown.

[0052] Figure 3C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a second embodiment of the present invention is shown.

[0053] Figure 4 A cross-sectional schematic diagram shows a construction process of a micro light emitting diode chip packaging structure according to a second embodiment of the present invention.

[0054] Figure 5A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a third embodiment of the present invention is shown.

[0055] Figure 5B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a third embodiment of the present invention is shown.

[0056] Figure 5C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a third embodiment of the present invention is shown.

[0057] Figure 6 A schematic cross-sectional view showing a construction process of a packaging structure of a micro light emitting diode chip according to a third embodiment of the present invention.

[0058] Fig. 7A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a fourth embodiment of the present invention is shown.

[0059] Figure 7B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a fourth embodiment of the present invention is shown.

[0060] Figure 7C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a fourth embodiment of the present invention is shown.

[0061] Figure 8 A schematic cross-sectional view showing a construction process of a packaging structure of a micro-LED chip in a fourth embodiment of the present invention.

[0062] Fig. 9A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a fifth embodiment of the present invention is shown.

[0063] Fig. 9B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a fifth embodiment of the present invention is shown.

[0064] Fig. 9C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a fifth embodiment of the present invention is shown.

[0065] Fig.10 A schematic cross-sectional view showing a construction process of a packaging structure of a micro-LED chip in a fifth embodiment of the present invention.

[0066] Fig.11A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a sixth embodiment of the present invention is shown.

[0067] Fig. 11B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a sixth embodiment of the present invention is shown.

[0068] Fig. 11C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a sixth embodiment of the present invention is shown.

[0069] Fig.12 A schematic cross-sectional view showing a construction process of a packaging structure of a micro-LED chip in a sixth embodiment of the present invention.

[0070] Fig.13A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a seventh embodiment of the present invention is shown.

[0071] Fig. 13B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a seventh embodiment of the present invention is shown.

[0072] Fig. 13C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a seventh embodiment of the present invention is shown.

[0073] Fig.14 A cross-sectional schematic diagram shows a construction process of a packaging structure of a micro light emitting diode chip according to a seventh embodiment of the present invention.

[0074] Fig.15 A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to an eighth embodiment of the present invention is shown.

[0075] Fig.16 A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a ninth embodiment of the present invention is shown.

[0076] Fig.17 A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a tenth embodiment of the present invention is shown.

[0077] Fig.18 A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to an eleventh embodiment of the present invention is shown.

[0078] Fig.19A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a twelfth embodiment of the present invention is shown.

[0079] Fig.19B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a twelfth embodiment of the present invention is shown.

[0080] Fig.19C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a twelfth embodiment of the present invention is shown.

[0081] Figures 20A-20D A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to other embodiments of the present invention is shown.

[0082] Fig.21 A cross-sectional schematic diagram shows a construction process of a packaging structure of a micro light emitting diode chip according to a twelfth embodiment of the present invention.

[0083] Fig.22A A schematic structural diagram of a light source machine according to an embodiment of the present invention is shown.

[0084] Fig. 22B A structural schematic diagram of a light source machine according to another embodiment of the present invention is shown.

[0085] Fig.23 A schematic structural diagram of a light combining assembly according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0087] It should be noted that the components in the figures may be shown exaggeratedly for the sake of illustration and are not necessarily true to scale. In the figures, identical or functionally identical components are provided with the same reference numerals.

[0088] In the present invention, unless otherwise specified, "arranged on...", "arranged above..." and "arranged above..." do not exclude the existence of an intermediate between the two. In addition, "arranged on or above..." merely indicates the relative positional relationship between two components, and in certain cases, such as after reversing the product direction, it can also be converted into "arranged below or below...", and vice versa.

[0089] In the present invention, each embodiment is only intended to illustrate the aspects of the present invention and should not be construed as limiting.

[0090] In the present invention, unless otherwise specified, the quantifiers "a" or "an" do not exclude the presence of multiple elements.

[0091] It should also be noted that in the embodiments of the present invention, for the sake of clarity and simplicity, only a portion of the parts or components may be shown, but those of ordinary skill in the art will understand that under the teachings of the present invention, the required parts or components may be added according to the needs of the specific scenario. In addition, unless otherwise specified, the features in different embodiments of the present invention may be combined with each other. For example, a feature in the second embodiment may be used to replace a corresponding or functionally identical or similar feature in the first embodiment, and the resulting embodiment also falls within the disclosure scope or recorded scope of the present application.

[0092] It should also be noted that within the scope of the present invention, the terms "same", "equal", "equal to", etc. do not mean that the values ​​of the two are absolutely equal, but allow a certain reasonable error, that is, the terms also cover "substantially the same", "substantially equal", "substantially equal to". By analogy, in the present invention, the terms "perpendicular to", "parallel to", etc., which indicate directions, also cover the meanings of "substantially perpendicular to" and "substantially parallel to".

[0093] In the present application, the term "configuration" refers to the setting of the shape, structure, material and / or function of the target object to achieve the desired technical effect, wherein "configuration" includes a variety of alternative technical means for achieving the technical effect, which become obvious under the teaching of the present application.

[0094] In addition, the numbering of the steps of the methods of the present invention does not limit the execution order of the method steps. Unless otherwise specified, the method steps can be executed in different orders.

[0095] The present invention will be further described below in conjunction with specific embodiments with reference to the accompanying drawings.

[0096] Figure 1A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a first embodiment of the present invention is shown. Figure 1B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a first embodiment of the present invention is shown. Figure 1C FIG. 4 is a schematic diagram showing the back side of the packaging structure of the micro-LED chip according to the first embodiment of the present invention. Figure 1A As shown in FIG. 1C , the packaging structure includes a circuit board 101, a micro-LED chip 102, a lead 103 and a plastic package 104. The packaging structure can minimize the packaging thickness.

[0097] In some embodiments, the thickness of the circuit board 101 is greater than or equal to 100 mm. The circuit board 101 can be connected to the driving circuit of the micro-light emitting diode chip 102 through the lead 103 to connect it to an external power supply or control source. The circuit board 101 may have a built-in conductive circuit, which is configured to connect the interface area of ​​the micro-light emitting diode chip 102 to an external interface. The circuit board 101 may also have an external interface (not shown), which is configured to connect an external power supply and / or control signal to power and / or control the micro-light emitting diode chip 102. The external interface can be a pin interface or a gold finger interface, and other forms of interfaces are also conceivable. The circuit board 101 is preferably a flexible circuit board (FPC) or a rigid printed circuit board (PCB), and the conductive circuit is a trace arranged on the flexible printed circuit board.

[0098] In some embodiments, the first surface of the micro LED chip 102 is exposed, and an active region 1021 is disposed on a second surface of the micro LED chip 102 opposite to the first surface. In some embodiments, the micro LED chip 102 is square, circular, or other optional shapes.

[0099] The size of the micro LED chip 102 is no more than 1 cm, preferably no more than 20 microns. The micro LED structure is formed in the micro LED chip 102 in an array form, with a resolution of, for example, 720*480, 640*480, 1920*1080, 1280*720, 2K or 4K. The diameter of the micro LED structure is at the nanometer level, for example, 20nm to 100nm.

[0100] The micro-LED chip 102 includes an integrated circuit (IC) backplane and an active area 1021 arranged on the integrated circuit backplane, wherein the active area 1021 includes a pixel array formed by micro-LEDs, and the pixel array includes a plurality of micro-LED pixels. Each pixel may include one or more micro-LEDs. That is, each micro-LED may form at least a portion of a pixel element on the micro-LED chip 102. For example, each pixel may include a micro-LED of one color, whereby the active area of ​​the micro-LED chip 102 is a monochrome pixel array. Alternatively, each pixel may include micro-LEDs of two or more colors, whereby the active area of ​​the micro-LED chip 102 is a color pixel array.

[0101] In some embodiments, the IC backplane can be electrically connected to each micro-LED in the micro-LED array via a separate metal interconnect. In some embodiments, each micro-LED can be electrically controlled individually by the IC backplane. In some embodiments, the IC backplane can be electrically connected to the electrodes of the micro-LED chip 102 via metal interconnects. In some embodiments, a dielectric layer can be formed in the gaps between the micro-LEDs. In some embodiments, a dielectric layer can also be formed in the gaps between the interconnects.

[0102] In some embodiments, the IC backplane is provided with an array of drive circuits. Each drive circuit is a pixel driver. In some cases, the drive circuit is a thin film transistor pixel driver or a silicon CMOS pixel driver. The drive circuits form individual pixel drivers to control the operation of individual multi-color Micro-LED pixels.

[0103] The micro-LED chip includes a plurality of micro-LED arrays, each of which includes a plurality of micro-LEDs. The driving mode of the micro-LEDs is, for example, passive matrix (PM) driving, in which the cathodes of all the micro-LEDs in each array are connected to the cathode line NL, and the micro-LEDs with the same number in each array are connected to the corresponding anode line PL. Thus, the on-off and the light emitting brightness of each LED can be individually controlled by controlling the model numbers on the corresponding cathode line and anode line.

[0104] In some embodiments, each micro-LED in the micro-LED array may include a micron-scale light-emitting mesa structure. In some embodiments, the micron-scale light-emitting mesa structure may include, from bottom to top, a first type epitaxial layer (or first epitaxial layer), a light-emitting layer, and a second type epitaxial layer (or second epitaxial layer). That is, in the three-layer structure, the first type epitaxial layer is closest to the IC backplane; the light-emitting layer is located above the first type epitaxial layer and further away from the IC backplane; the second type epitaxial layer is located above the light-emitting layer and farthest away from the IC backplane. In some embodiments, the light-emitting layer is formed by a plurality of stacked quantum well layers, in particular, quantum well layers stacked in a superlattice. Preferably, the quantum well layer stacked in a superlattice includes a plurality of pairs of quantum well layers stacked with quantum barrier layers. In one embodiment of the present invention, the quantum well layer is an InGaN / GaN multi-quantum well layer or an InGaN / AlGaN multi-quantum well layer or an InGaAs / AlGaAs multi-quantum well layer. In one embodiment of the present invention, the light-emitting layer further includes an electron blocking layer, which is disposed on a first side of the light-emitting layer, and the first side refers to a side along which electrons migrate out of the light-emitting layer.

[0105] In some embodiments, the first type epitaxial layer is a semiconductor material having a first conductivity type and includes a plurality of semiconductor layers. The main matrix material of the first type epitaxial layer may be, but is not limited to, Ga, N, As, P, In, or Al. In addition, the first type epitaxial layer may include, but is not limited to, a waveguide layer, a confinement layer, a transition layer, and a window layer from top to bottom; in addition, an ohmic contact layer may be formed below the window layer. In some embodiments, the second type epitaxial layer is a semiconductor material having a second conductivity type and includes a plurality of semiconductor layers. The main matrix material of the second type epitaxial layer may be, but is not limited to, Ga, N, As, P, In, or Al. In addition, the first type epitaxial layer may include, but is not limited to, a confinement layer and a waveguide layer from top to bottom; in addition, in some embodiments, an ohmic contact layer may be formed on the confinement layer. In one embodiment of the present invention, the first type epitaxial layer is an N-type GaN layer or an N-type AlGaN layer, and the second type epitaxial layer is a P-type GaN layer or a P-type AlGaN layer. In another embodiment of the present invention, the first type epitaxial layer may also be a P-type GaN layer or a P-type AlGaN layer, and the second type epitaxial layer may be an N-type GaN layer or an N-type AlGaN layer. In an embodiment of the present invention, the semiconductor light-emitting mesa 501 is in a step shape or a trapezoidal shape. In some embodiments, the micron-scale light-emitting mesa structure may emit red light, blue light, green light, or light of any other color.

[0106] In some embodiments, a top conductive layer can be formed on the top surface of the micro light emitting diode array. In some embodiments, the top conductive layer can be shared by all micro light emitting diodes in the micro light emitting diode array.

[0107] In one embodiment of the present invention, the top conductive layer can be shared by all micro-LEDs in the micro-LED array. In one embodiment of the present invention, the top conductive layer is disposed above the micro-LED array, and contacts and covers the top of each light-emitting mesa, and is in electrical contact with the second epitaxial layer of the light-emitting mesa, so as to connect the second epitaxial layers of each semiconductor light-emitting mesa 1 in series, and is a transparent conductive layer.

[0108] In one embodiment of the present invention, the micro-LED array further comprises a passivation insulating layer. The passivation insulating layer covers the surface and side of the light-emitting mesa, but exposes at least part of the surface of the second epitaxial layer, and the top conductive layer is arranged on the surface of the passivation insulating layer. In one embodiment of the present invention, the passivation insulating layer can be formed by CVD deposition of SiO2 or ALD deposition of Al2O3 film layer to effectively reduce the chip leakage rate. In some embodiments of the present invention, the passivation insulating layer only covers the side of the light-emitting mesa, but not the top surface of the light-emitting mesa, and the highest point of the passivation insulating layer is flush with the top surface of the light-emitting mesa. In these embodiments, the continuous top conductive layer covering the top of the light-emitting mesa is in a horizontal or substantially horizontal plane. In some embodiments of the present invention, the passivation insulating layer not only covers the side of the light-emitting mesa, but also covers the edge of the top surface of the light-emitting mesa, so that there is a bulge at the top edge of the light-emitting mesa, so that the continuous top conductive layer covering it also forms a bulge at the top edge of the light-emitting mesa.

[0109] As mentioned above, there is a partition between the pixels formed by each light-emitting mesa, and a second electrode is arranged at the partition, and the second electrode is arranged on the surface of the top conductive layer. In one embodiment of the present invention, the second electrode is a ring-shaped reflective electrode, which is arranged around the light-emitting mesa, and is formed by magnetron sputtering or evaporation, and its material, for example, can use Al or Al alloy metal as a side wall reflector, and the electrode stack metal can be Ni, Al, Ti, Ni, Pt, Au and other metal materials. In one embodiment of the present invention, each second electrode is connected to each other. In some embodiments of the present invention, a deep groove is arranged at the partition between two adjacent light-emitting mesas, and the deep groove runs through the micro-light-emitting diode array, and the second electrode is arranged at the deep groove. In some embodiments of the present invention, a deep groove is not arranged at the partition between two adjacent light-emitting mesas, but a passivation isolation layer and a top conductive layer are directly formed, so that the surface of the top conductive layer between two adjacent light-emitting mesas is a horizontal or substantially horizontal plane, and the second electrode is formed here, and its morphological interface is a trapezoid or approximately a trapezoid, and the surface of the second electrode is not higher than the highest point of the continuous top conductive layer.

[0110] In one embodiment of the present invention, the micro-LED array is bonded to the driving backplane through a metal bonding layer and is electrically connected to the IC copper pillar on the driving backplane. In one embodiment of the present invention, the IC copper pillar includes a first IC copper pillar and a second IC copper pillar, wherein the first IC copper pillar is electrically connected to the first epitaxial layer of the semiconductor light-emitting module in a one-to-one correspondence. The second IC copper pillar is electrically connected to the first electrode 6. In one embodiment of the present invention, the polarity of the first electrode is opposite to that of the second electrode. In one embodiment of the present invention, each semiconductor light-emitting module has a common first electrode. The first electrode may be, for example, a P electrode or an anode electrode, and the second electrode is an electrode with a polarity opposite to that of the first electrode 506, such as an N electrode or a cathode electrode. In one embodiment of the present invention, the first and second electrodes and their connecting parts may be made of materials such as graphene, ITO, aluminum-doped zinc oxide (AZO) or fluorine-doped tin oxide (FTO) or any combination of the above materials. In another embodiment of the present invention, the first and second electrodes and their connecting parts may be made of non-transparent or transparent conductive materials, such as indium tin oxide (ITO).

[0111] In some embodiments, the light emitting layer may include at least one quantum well layer. In some embodiments, the micro-LED array may include a single-layer micro-LED structure. In some embodiments, the micro-LED array may include multiple layers of vertically stacked micro-LED structures.

[0112] In some embodiments, the micro-LED array may include micro-LEDs of one or more colors. In some embodiments, the pitch of the micro-LED array, i.e., the minimum center-to-center distance between the micro-LEDs, may be between about 2 microns and about 50 microns. In some embodiments, the number of pixels on the micro-LED chip 102 may be between thousands and millions.

[0113] In some embodiments, the microlens is disposed on the micro-LED array, and the lateral dimension of the bottom of the microlens is larger than the lateral dimension of the light-emitting area of ​​the micro-LED, or the lateral dimension of the bottom of the microlens can be less than or equal to the lateral dimension of the light-emitting area of ​​the micro-LED.

[0114] In some embodiments, a microlens can cover one or more lens-less micro-LEDs. A plurality of microlenses constitute a microlens array. The microlenses in a microlens array are generally identical. Examples of microlenses include spherical microlenses, aspherical microlenses, Fresnal microlenses, and cylindrical microlenses. The individual microlenses in the microlens array of the micro-LED chip 102 may be identical or different in shape, curvature, optical power, size, base, spacing, etc.

[0115] In some embodiments, the microlens can be made of various materials that are transparent to the wavelengths of light emitted by the micro-LED. Exemplary transparent materials for the microlens include polymers, dielectric materials. In some embodiments, the dielectric material includes one or more materials such as silicon oxide, silicon nitride, silicon carbide, titanium oxide, zirconium oxide, aluminum oxide, etc. In some embodiments, the microlens is made of photoresist. In some embodiments, the microlens is directly deposited on the surface of the micro-LED by chemical vapor deposition (CVD) technology.

[0116] In some embodiments, the lead 103 electrically connects the circuit board 101 to the micro-LED chip 102. In some embodiments, the edge region of the second surface of the micro-LED chip is provided with a first connection portion (metal pad), and the surface of the circuit board 101 has a second connection portion, wherein the lead connects the first connection portion and the second connection portion. Here, the term "edge region" refers to an area with a physical boundary distance of 20 microns to 400 microns from the micro-LED chip. In some embodiments, the lead 103 is a gold wire, an aluminum wire, or other conductive metal material.

[0117] In some embodiments, the plastic encapsulation body 104 is connected to the circuit board 101 and the micro-LED chip. In some embodiments, the plastic encapsulation body 104 is disposed at the periphery of the micro-LED chip 102 and exposes the active area 1021 of the micro-LED chip 102. In other words, the plastic encapsulation body 104 covers all the side surfaces of the micro-LED chip 102 and part of the top surface except the active area 1021, and part of the top surface and side surfaces of the circuit board 101 adjacent to the micro-LED chip 102. A plastic encapsulation window is formed above the active area of ​​the micro-LED chip 102 not covered by the plastic encapsulation body 104. The plastic encapsulation body 104 covers the lead 103 to insulate and protect the lead 103. The top of the active area 1021 of the micro-LED chip 102 is not covered by the plastic encapsulation body 104. In some embodiments, the material of the plastic encapsulation body 104 includes epoxy resin, silicone and ethylene-vinyl acetate copolymer (EVA glue).

[0118] Figure 2 A schematic cross-sectional view showing a construction process of a packaging structure of a micro light emitting diode chip according to a first embodiment of the present invention.

[0119] like Figure 2 As shown, first, in step S1 , a circuit board 101 is provided.

[0120] Next, in step S2 , the circuit board 101 is placed on the carrier board 201 .

[0121] Next, in step S3 , the micro LED chip 102 is arranged on the carrier 201 . Specifically, the first surface of the micro LED chip 102 is connected to the carrier 201 , and the micro LED chip 102 is adjacent to the circuit board 101 .

[0122] Next, in step S4, wires 103 are formed between the circuit board 101 and the micro-LED chip 102 by a wire bonding process. The circuit board 101 is connected to the driving circuit of the micro-LED chip 102 through the wires 103 .

[0123] Next, in step S5, an injection molding process is performed to form a plastic package 104. The plastic package 104 is disposed on the periphery of the micro-LED chip 102 and exposes the active area 1021 of the micro-LED chip 102. That is, the plastic package 104 covers all the side surfaces of the micro-LED chip 102 and part of the top surface except the active area 1021, part of the top surface and side surfaces of the circuit board 101 adjacent to the micro-LED chip 102, and part of the top surface of the carrier 201. The plastic package 104 covers the lead 103 to insulate and protect the lead 103. The upper part of the active area 1021 of the micro-LED chip 102 is not covered by the plastic package 104.

[0124] Next, in step S6 , the carrier board 201 is removed, so that the first surface of the micro-LED chip 102 is exposed.

[0125] Figure 3A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a second embodiment of the present invention is shown. Figure 3B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a second embodiment of the present invention is shown. Figure 3C The back schematic diagram of the packaging structure of the micro-LED chip according to the second embodiment of the present invention is shown. Compared with the first embodiment, the packaging structure of the micro-LED chip in the second embodiment mainly differs in that a transparent cover plate 301 is added to reduce the thickness of the package while protecting the active area of ​​the micro-LED chip 102. The circuit board 101, the micro-LED chip 102, the lead 103, and the plastic package 104 are similar to the corresponding structures in the first embodiment, and will not be repeated for simplicity.

[0126] like Figure 3AAs shown in FIG. 3C , the light-transmitting cover plate 301 is arranged on the active area of ​​the micro-LED chip 102, wherein the light-transmitting cover plate 301 is used to protect the active area 1021 on the micro-LED chip 102. In some embodiments, a gap is left between the bottom surface of the light-transmitting cover plate 301 and the surface of the active area 1021 to prevent the light-transmitting cover plate 301 from contacting the surface of the active area 1021. In some embodiments, the material of the light-transmitting cover plate 301 can be glass or other light-transmitting materials such as silicon dioxide and magnesium fluoride.

[0127] In some embodiments, the top surface height of the plastic package 104 is higher than the top surface height of the active area 1021. The transparent cover plate 301 has a middle area corresponding to the active area and a support area located outside the middle area, the support area covers and is fixed to the surface of the plastic package 104, and there is a gap between the bottom surface of the middle area and the surface of the active area 1021. That is, when the transparent cover plate 301 is placed, the four sides of the transparent cover plate 301 are supported on the top surface of the plastic package 104, and the part opposite to the active area 1021 is suspended, so as to prevent the transparent cover plate 301 from contacting the surface of the active area 1021. The transparent cover plate 301 has an adhesive 302 at the position where it overlaps with the top surface of the plastic package 104, and the transparent cover plate 301 is fixed by the adhesive 302 so that it is located above the active area 1021. In some embodiments, the material of the adhesive 302 can be ethylene-vinyl acetate copolymer (EVA adhesive).

[0128] Figure 4 A cross-sectional schematic diagram of the construction process of the micro-LED chip package structure according to the second embodiment of the present invention is shown. The manufacturing process of the package structure in the second embodiment differs from that in the first embodiment mainly in step S6 and step S7. Steps S1 to S5 are similar to the corresponding steps in the first embodiment and will not be described in detail for simplicity.

[0129] like Figure 4As shown, in step S6, the light-transmitting cover plate 301 is covered above the active area of ​​the micro-light-emitting diode chip 103. Specifically, the top surface height of the plastic package 104 is higher than the surface of the active area. The light-transmitting cover plate 301 has a middle area corresponding to the active area and a supporting area located outside the middle area, and the supporting area covers and is fixed to the surface of the plastic package 104. There is a gap between the bottom surface of the middle area and the surface of the active area 1021. Therefore, when the light-transmitting cover plate 301 is placed, the four sides of the light-transmitting cover plate 301 are supported on the top surface of the plastic package 104. The position where the light-transmitting cover plate 301 overlaps with the top surface of the plastic package 104 has an adhesive 302, and the light-transmitting cover plate 301 is fixed by the adhesive 302.

[0130] Next, in step S7 , the carrier board 201 is removed, so that the first surface of the micro-LED chip 102 is exposed.

[0131] Figure 5A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a third embodiment of the present invention is shown. Figure 5B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a third embodiment of the present invention is shown. Figure 5C The back side schematic diagram of the packaging structure of the micro-LED chip according to the third embodiment of the present invention is shown. The packaging structure of the micro-LED chip in the third embodiment is different from that in the second embodiment mainly in the shape and position of the plastic package 104 and the transparent cover plate 301. The circuit board 101, the micro-LED chip 102 and the lead 103 are similar to the corresponding structures of the second embodiment, and will not be described again for simplicity.

[0132] like Figure 5A As shown in FIG. 5C , the plastic encapsulation body 104 is disposed at the periphery of the micro-LED chip 102, and exposes the active area of ​​the micro-LED chip 102. In other words, the plastic encapsulation body 104 covers all the side surfaces of the micro-LED chip 102 and part of the top surface except the active area, and part of the top surface and side surfaces of the circuit board 101 adjacent to the micro-LED chip 102. The plastic encapsulation body 104 covers the lead 103 to insulate and protect the lead 103. The upper part of the active area of ​​the micro-LED chip 102 is not covered by the plastic encapsulation body 104. A downward plastic encapsulation step 501 is formed at the portion of the plastic encapsulation body 104 adjacent to the active area of ​​the micro-LED chip 102, so that the top surface 5011 of the plastic encapsulation step 501 is lower than the top surface 1041 of the other parts of the plastic encapsulation body 104. In other words, in the region of the molding step 501 , the top surface of the molding body 104 drops from a first height to a second height, and the difference between the first height and the second height is the height of the molding step 501 .

[0133] In some embodiments of the present invention, the top surface height of the molding step 501 is higher than the surface height of the active area. The transparent cover plate 301 has a middle area corresponding to the active area and a support area located outside the middle area, the support area covers and is fixed to the surface of the molding step 501, and there is a gap between the bottom surface of the middle area and the surface of the active area. That is, the four sides of the transparent cover plate 301 are supported on the top surface of the molding step 501, and the part facing the active area is suspended, so as to prevent the transparent cover plate 301 from contacting the surface of the active area. The adhesive 302 is set at the position where the transparent cover plate 301 overlaps with the top surface of the molding step 501, and the transparent cover plate 301 is fixed by the adhesive 302 so that it is located above the active area.

[0134] In some embodiments of the present invention, a plastic encapsulation window is formed above the active area of ​​the micro-LED chip 102 not covered by the plastic encapsulation body 104, and a plastic encapsulation step 501 forms a support area for the light-transmitting cover plate 301 around the plastic encapsulation window. The edge of the plastic encapsulation step 501 is equal to or slightly larger than the outer edge of the light-transmitting cover plate 301, so that the light-transmitting cover plate 301 can be accommodated inside the recessed area formed by the plastic encapsulation step 501. The height of the plastic encapsulation step 501 is substantially equal to the sum of the thickness of the light-transmitting cover plate 301 and the adhesive 302, so that the top surface of the light-transmitting cover plate 301 is substantially flush with the top surface 1041 of the plastic encapsulation body 104, so as to reduce the overall thickness of the package. Compared with the second embodiment, the package thickness of the third embodiment is reduced by about 0.1 mm.

[0135] In other embodiments of the present invention, the top surface of the light-transmitting cover plate 301 may be higher or lower than the top surface 1041 of the plastic package body 104 .

[0136] Figure 6 A cross-sectional schematic diagram of the construction process of the packaging structure of the micro-LED chip according to the third embodiment of the present invention is shown. The construction process of the packaging structure in the third embodiment is different from that in the second embodiment mainly in step S5 and step S6. Steps S1 to S4 and step S7 are similar to the corresponding steps in the second embodiment, and will not be repeated for simplicity.

[0137] like Figure 6As shown, in step S5, an injection molding process is performed to form a plastic package 104. The plastic package 104 is arranged at the periphery of the micro-LED chip 102, and exposes the active area of ​​the micro-LED chip 102. In other words, the plastic package 104 covers all the side surfaces of the micro-LED chip and part of the top surface except the active area, part of the top surface and side surfaces of the circuit board adjacent to the micro-LED chip, and part of the top surface of the carrier. The plastic package 104 covers the lead to insulate and protect the lead. There is a downward plastic package step in the portion of the plastic package 104 adjacent to the active area of ​​the micro-LED chip. In the plastic package step area, the top surface of the plastic package 104 drops from a first height to a second height, and the difference between the first height and the second height is the height of the plastic package step.

[0138] In step S6, the light-transmitting cover plate 301 is covered above the active area of ​​the micro-LED chip. The top surface height of the plastic-sealed step 501 is higher than the surface height of the active area. The light-transmitting cover plate 301 has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surface of the plastic-sealed step 501, and there is a gap between the bottom surface of the middle area and the surface of the active area. Specifically, a plastic-sealed window is formed above the active area of ​​the micro-LED chip 102 not covered by the plastic-sealed body 104, and the plastic-sealed step forms a supporting area of ​​the light-transmitting cover plate around the plastic-sealed window. The edge of the plastic-sealed step 501 is slightly larger than the outer edge of the light-transmitting cover plate 301, so that the light-transmitting cover plate 301 can be accommodated in the recessed area formed by the plastic-sealed step 501. The light-transmitting cover plate 301 is fixed to the top surface of the plastic-sealed step 501 by adhesive.

[0139] Fig. 7A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a fourth embodiment of the present invention is shown. Figure 7B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a fourth embodiment of the present invention is shown. Figure 7C The back side schematic diagram of the packaging structure of the micro-LED chip according to the fourth embodiment of the present invention is shown. The packaging structure of the micro-LED chip in the fourth embodiment is different from that in the second embodiment mainly in the position of the transparent cover plate 301. The circuit board 101, the micro-LED chip 102, and the lead 103 are similar to the corresponding structures of the second embodiment, and will not be described again for simplicity.

[0140] like Fig. 7AAs shown in FIG. 7C , the plastic encapsulation body 104 is disposed at the periphery of the micro-LED chip 102, and the active area 1021 of the micro-LED chip 102 is exposed. In some embodiments of the present invention, a plastic encapsulation window is formed above the active area of ​​the micro-LED chip 102 not covered by the plastic encapsulation body 104, and the light-transmitting cover plate 301 is disposed above the active area 1021 of the micro-LED chip in the plastic encapsulation window. The top surface of the light-transmitting cover plate 301 is flush with the top surface of the plastic encapsulation body 104. In other embodiments of the present invention, the top surface of the light-transmitting cover plate 301 may be higher or lower than the top surface of the plastic encapsulation body 104.

[0141] In an embodiment of the present invention, the light-transmitting cover plate 301 has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surrounding surfaces of the active area 1021, and there is a gap between the bottom surface of the middle area and the surface of the active area 1021. Adhesive 302 is set at the position where the light-transmitting cover plate 301 overlaps with the outer top surface of the active area 1021, and the light-transmitting cover plate 301 is fixed by the adhesive 302 so that it is located above the active area. The top surface height of the adhesive 302 is higher than the surface of the active area 1021, thereby preventing the light-transmitting cover plate 301 from contacting the surface of the active area 1021. Compared with the third embodiment, the package thickness of the fourth embodiment is further reduced by about 0.05 mm.

[0142] Figure 8 FIG. 1 is a cross-sectional schematic diagram showing the construction process of the packaging structure of the micro-LED chip in the fourth embodiment of the present invention. The difference between the construction process of the packaging structure in the fourth embodiment and that in the second embodiment lies mainly in step S6. Steps S1 to S5 and step S7 are similar to the corresponding steps in the second embodiment and will not be described in detail for simplicity. Figure 8 As shown, compared with the second embodiment, the difference is that in step S6 , the transparent cover plate 301 is fixed to the top surface around the active area 1021 by means of adhesive 302 .

[0143] Fig. 9A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a fifth embodiment of the present invention is shown. Fig. 9B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a fifth embodiment of the present invention is shown. Fig. 9CFIG. 1 is a schematic diagram of the back side of the packaging structure of the micro-LED chip according to the fifth embodiment of the present invention. The packaging structure of the micro-LED chip in the fifth embodiment is different from that in the fourth embodiment mainly in the position of the plastic package 104. The circuit board 101, the micro-LED chip 102, the lead 103, and the transparent cover 301 are similar to the corresponding structures of the fourth embodiment, and will not be described in detail for the sake of simplicity. Fig. 9A As shown in FIG. 9C , compared with the fourth embodiment, the difference is that the plastic package body 104 is connected to the side of the transparent cover plate 301 and the adhesive 302 .

[0144] Fig.10 A cross-sectional schematic diagram of the construction process of the packaging structure of the micro-light-emitting diode chip in the fifth embodiment of the present invention is shown. The construction process of the packaging structure in the fifth embodiment is different from that in the fourth embodiment mainly in that the transparent cover plate 301 is fixed to the top surface of the four sides of the active area 1021 by the adhesive 302 in advance, and then the plastic package 104 is formed by the injection molding process. The plastic package 104 is connected to the side of the transparent cover plate 301 and the adhesive 302. Steps S1 to S2 are similar to the corresponding steps in the fourth embodiment, and are not repeated for simplicity.

[0145] like Fig.10 As shown, in step S3, the micro-LED chip 102 is arranged on the carrier 201. Specifically, the first surface of the micro-LED chip 102 is connected to the carrier 201, and the micro-LED chip 102 is adjacent to the circuit board 101. The second surface of the micro-LED chip 102 opposite to the first surface is provided with an active area 1021, and the light-transmitting cover plate 301 has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surrounding surfaces of the active area 1021, and there is a gap between the bottom surface of the middle area and the surface of the active area 1021. The adhesive 302 is set at the position where the light-transmitting cover plate 301 overlaps with the outer top surface of the active area 1021, and the light-transmitting cover plate 301 is fixed by the adhesive 302 so that it is located above the active area. The top surface of the adhesive 302 is higher than the surface of the active area 1021 , thereby preventing the transparent cover plate 301 from contacting the surface of the active area 1021 .

[0146] Next, in step S4, wires 103 are formed between the circuit board 101 and the micro-LED chip 102 by a wire bonding process. The circuit board 101 is connected to the driving circuit of the micro-LED chip 102 through the wires 103 .

[0147] Next, in step S5, an injection molding process is performed to form a plastic package 104. The plastic package 104 is disposed on the periphery of the micro-LED chip 102, exposing the active area 1021 of the micro-LED chip 102, and connected to the transparent cover 301 and the side of the adhesive 302. That is, the plastic package 104 covers all the side surfaces of the micro-LED chip 102 and part of the top surface except the active area 1021, part of the top surface and side surfaces of the circuit board 101 adjacent to the micro-LED chip 102, and part of the top surface of the carrier 201, and is connected to the transparent cover 301 and the side of the adhesive 302. The plastic package 104 covers the lead 103 to insulate and protect the lead 103. The top of the active area 1021 of the micro-LED chip 102 is not covered by the plastic package 104.

[0148] Next, in step S6 , the carrier board 201 is removed, so that the first surface of the micro-LED chip 102 is exposed.

[0149] In the packaging structure of the fifth embodiment, the transparent cover is attached to the micro LED chip in advance, which reduces the difficulty of attaching the transparent cover. In addition, the transparent cover is connected to the plastic package around, so that the overall strength of the package is improved.

[0150] Fig.11A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a sixth embodiment of the present invention is shown. Fig. 11B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a sixth embodiment of the present invention is shown. Fig. 11C The back side schematic diagram of the packaging structure of the micro-LED chip according to the sixth embodiment of the present invention is shown. The packaging structure of the micro-LED chip in the sixth embodiment is different from that in the first embodiment mainly in that a heat sink 1101 is added. The circuit board 101, the micro-LED chip 102, the lead 103, and the plastic package 104 are similar to the corresponding structures of the first embodiment, and will not be described again for simplicity.

[0151] like Fig.11AAs shown in FIG. 11C , the heat sink 1101 is connected to the first surface of the micro-LED chip 102, and at least a portion of the circuit board 101 is arranged on the heat sink 1101, and the plastic package 104 covers a portion of the top surface of the heat sink 1101. In some embodiments, the material of the heat sink 1101 includes graphite. This packaging structure reduces the thickness of the package body and attaches the heat sink without providing a die attach (DA) glue / die attach film (DAF) glue barrier, thereby enhancing the heat dissipation capacity of the package body. In other embodiments of the present invention, a heat sink 1101 can be additionally provided on the basis of the packaging structure of the micro-LED chip in the second to fifth embodiments of the present invention.

[0152] Fig.12 FIG. 1 is a cross-sectional schematic diagram showing the construction process of the packaging structure of the micro-LED chip in the sixth embodiment of the present invention. The difference between the construction process of the packaging structure in the sixth embodiment and the first embodiment is that step S7 is added. Steps S1 to S6 are similar to the corresponding steps in the first embodiment and will not be described in detail for simplicity. Fig.12 As shown, compared with the first embodiment, the difference lies in that, in step S7, after removing the carrier 201, the heat sink 1101 is connected to the first surface of the micro-LED chip 102, and at least a portion of the circuit board 101 is arranged on the heat sink 1101, and the plastic package 104 covers a portion of the top surface of the heat sink 1101.

[0153] Fig.13A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a seventh embodiment of the present invention is shown. Fig. 13B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a seventh embodiment of the present invention is shown. Fig. 13C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a seventh embodiment of the present invention is shown.

[0154] The packaging structure of the micro LED chip in the seventh embodiment is different from that in the first embodiment mainly in the relative position between the circuit board 101 and the micro LED chip 102. The lead 103 and the plastic package 104 are similar to the corresponding structures in the first embodiment and will not be described again for simplicity.

[0155] like Fig.13A - Fig. 13CAs shown, the micro-LED chip 102 is arranged on the circuit board 101, wherein the first surface of the micro-LED chip 102 is connected to the circuit board 101, and an active area 1021 is provided on the second surface of the micro-LED chip 102 opposite to the first surface. The surface of the circuit board 101 facing away from the micro-LED chip 102 is exposed. In some embodiments, the circuit board 101 has a circuit board body and an extension portion, wherein the circuit board body is arranged under the plastic package 104 and the micro-LED chip 102, and the extension portion extends beyond the circuit board body for electrically connecting the micro-LED chip 102 to the outside.

[0156] Fig.14 A cross-sectional schematic diagram shows a construction process of a packaging structure of a micro light emitting diode chip according to a seventh embodiment of the present invention.

[0157] like Fig.14 As shown, first, in step S1 , a circuit board 101 is provided.

[0158] Next, in step S2 , the micro LED chip 102 is arranged on the circuit board 101 . Specifically, the first surface of the micro LED chip 102 is connected to the circuit board 101 through a chip bonding adhesive 105 .

[0159] Next, in step S3 , wires 103 are formed between the circuit board 101 and the micro-LED chip 102 by a wire bonding process. The circuit board 101 is connected to the driving circuit of the micro-LED chip 102 via the wires 103 .

[0160] Next, in step S4, an injection molding process is performed to form a plastic package 104. The plastic package 104 is disposed on the periphery of the micro-LED chip 102, and exposes the active area 1021 of the micro-LED chip 102. That is, the plastic package 104 covers all side surfaces of the micro-LED chip 102 and part of the top surface except the active area 1021, and part of the top surface of the circuit board 101. The plastic package 104 covers the lead 103 to insulate and protect the lead 103. The upper part of the active area 1021 of the micro-LED chip 102 is not covered by the plastic package 104.

[0161] Fig.15The cross-sectional schematic diagram of the packaging structure of the micro-LED chip according to the eighth embodiment of the present invention is shown. Compared with the seventh embodiment, the packaging structure of the micro-LED chip in the eighth embodiment mainly differs in that a transparent cover plate 301 is added to protect the active area of ​​the micro-LED chip 102 while reducing the thickness of the package. The circuit board 101, the micro-LED chip 102, the lead 103, and the plastic package 104 are similar to the corresponding structures in the seventh embodiment, and the transparent cover plate 301 is similar to the corresponding structure in the second embodiment, and will not be repeated for simplicity.

[0162] Fig.16 A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a ninth embodiment of the present invention is shown.

[0163] The packaging structure of the micro-LED chip in the ninth embodiment is different from that in the eighth embodiment mainly in the shape and position of the plastic package 104 and the transparent cover 301. The circuit board 101, the micro-LED chip 102 and the lead 103 are similar to the corresponding structures in the eighth embodiment, and the shape and position of the plastic package 104 and the transparent cover 301 are similar to the corresponding structures in the third embodiment, and will not be repeated for simplicity.

[0164] Fig.17 FIG. 1 is a schematic cross-sectional view of a package structure of a micro-LED chip according to a tenth embodiment of the present invention. The package structure of the micro-LED chip in the tenth embodiment is different from that in the eighth embodiment mainly in the position of the light-transmitting cover plate 301. The circuit board 101, the micro-LED chip 102, and the lead 103 are similar to the corresponding structures in the eighth embodiment, and the light-transmitting cover plate 301 is similar to the corresponding structure in the fourth embodiment, and will not be described in detail for simplicity.

[0165] Fig.18 A cross-sectional schematic diagram of the packaging structure of a micro-LED chip according to the eleventh embodiment of the present invention is shown. The packaging structure of the micro-LED chip in the eleventh embodiment is different from that in the tenth embodiment, mainly in the position of the plastic package 104. The circuit board 101, the micro-LED chip 102, the lead 103, and the light-transmitting cover 301 are similar to the corresponding structures in the tenth embodiment, and the plastic package 104 is similar to the corresponding structure in the fifth embodiment, and will not be repeated for simplicity. Fig.19A A schematic cross-sectional view of a packaging structure of a micro light emitting diode chip according to a twelfth embodiment of the present invention is shown. Fig.19B A front schematic diagram of a packaging structure of a micro light emitting diode chip according to a twelfth embodiment of the present invention is shown. Fig.19C A schematic back side view of a packaging structure of a micro light emitting diode chip according to a twelfth embodiment of the present invention is shown.

[0166] The packaging structure of the micro-LED chip in the twelfth embodiment is different from that in the seventh embodiment mainly in that a heat sink 1101 is added. The circuit board 101, the micro-LED chip 102, the lead 103, and the plastic package 104 are similar to the corresponding structures of the seventh embodiment, and will not be described in detail for simplicity. Fig.19A - Fig.19C As shown, the heat sink 1101 is arranged on the back side of the circuit board 101. In some embodiments, the material of the heat sink 1101 includes graphite. Fig. 20A - Fig.20D FIG. 4 is a schematic cross-sectional view of a packaging structure of a micro-LED chip according to another embodiment of the present invention. Fig. 20A - Fig.20D As shown, in other embodiments of the present invention, a heat sink 1101 may be additionally provided on the basis of the packaging structure of the micro-LED chip in the eighth to the fourth exemplary embodiments of the present invention.

[0167] Fig.21 FIG. 1 is a cross-sectional schematic diagram showing the construction process of the packaging structure of the micro-LED chip according to the twelfth embodiment of the present invention. The main difference between the construction process of the packaging structure in the twelfth embodiment and the seventh embodiment is that step S5 is added. Steps S1 to S4 are similar to the corresponding steps in the first embodiment and will not be described in detail for simplicity. Fig.21 As shown, compared with the first embodiment, the difference is that in step S5, the heat sink 1101 is arranged on the back side of the circuit board 101.

[0168] The packaging structures of the micro-LED chips according to the first to twelfth embodiments of the present invention can play a role in reducing the size of a light source when applied to the light source. Fig.22A A schematic structural diagram of a light source machine according to an embodiment of the present invention is shown. Fig. 22B FIG. 2 shows a schematic diagram of the structure of a light source device according to another embodiment of the present invention. Fig.22A and Fig. 22B As shown, the light source machine includes a lens 2201, a first package 2202, a second package 2203 and a third package 2204, wherein the micro light emitting diode chips 102 in the first package 2202, the second package 2203 and the third package 2204 are output from the lens 2201 after being combined by a light combining component.

[0169] Fig.23 FIG. 2 shows a schematic diagram of the structure of a light combining assembly according to an embodiment of the present invention. Fig.23As shown, the light combining component 2300 includes a mirror body 2301, a first semi-reflective semi-transparent membrane 2302 and a second semi-reflective semi-transparent membrane 2303, and the first semi-reflective semi-transparent membrane 2302 and the second semi-reflective semi-transparent membrane 2303 are arranged alternately on the mirror body 2301. After the light emitted by the first micro-LED chip enters the light combining component 2300 through the first light incident surface 2300b, it passes through the first semi-reflective semi-transparent membrane 2302 and the second semi-reflective semi-transparent membrane 2303 and then exits through the light emitting surface 2300a. After the light emitted by the second micro-LED chip enters the light combining component 2300 through the second light incident surface 2300c, part of the light is first reflected by the first semi-reflective semi-permeable membrane 2302, then passes through the second semi-reflective semi-permeable membrane 2303, and is emitted through the light emitting surface 2300a; another part of the light first passes through the second semi-reflective semi-permeable membrane 2303, then reflects by the first semi-reflective semi-permeable membrane 2302, and is emitted through the light emitting surface 2300a. After the light emitted by the third micro-LED chip enters the light combining component 2300 through the third light incident surface 2300d, part of the light is first reflected by the second semi-reflective semi-permeable membrane 2303, then passes through the first semi-reflective semi-permeable membrane 2302, and is emitted through the light emitting surface 2300a; another part of the light first passes through the second semi-reflective semi-permeable membrane 2303, then reflects by the first semi-reflective semi-permeable membrane 2302, and is emitted through the light emitting surface 2300a.

[0170] In some embodiments, the shape of the light combining component 2300 is a cube, such as a cuboid or a cube, etc. In some embodiments, the light combining component 2300 can be formed by splicing four sub-prisms with triangular cross-sections, and sub-semi-reflective and semi-transparent membranes are attached to the preset surfaces of the four sub-prisms. When the four sub-prisms are spliced ​​together, the sub-semi-reflective and semi-transparent membranes are connected to each other to form a first semi-reflective and semi-transparent membrane 2302 and a second semi-reflective and semi-transparent membrane 2303.

[0171] In some embodiments, at least one of the first package body 2202, the second package body 2203, and the third package body 2204 has a package structure of the micro-LED chip according to the first to twelfth embodiments of the present invention. Fig.22A As shown, the back of the micro-LED chip 102 of the first package 2202, the second package 2203 and the third package 2204 has a reinforcing sheet 2205, and Fig. 22B The back of the micro-LED chip 102 of the first package 2202, the second package 2203 and the third package 2204 has no reinforcement sheet 2201, so that the back of the micro-LED chip 102 is exposed. Fig. 22B Compared with the light source Fig.22AIn the case where the first size L1 of the light source machine is the same, the second size L2 (due to the first package 2022 and the second package 2203 eliminating the reinforcing sheet) and the third size L3 (due to the third package 2204 eliminating the reinforcing sheet) are both reduced, so that the overall size of the light source machine can be reduced. For example, Fig.22A The first dimension L1 of the light source is 5 to 10 cm, the second dimension L2 is 5 to 10 cm, the third dimension LE is 10 to 15 cm, and the thickness of the reinforcing sheet is 0.1 to 0.2 cm. In the case of removing the reinforcing sheet, Fig. 22B The first size of the light source machine remains unchanged, the second size is reduced to 4.6 to 9.8 cm, and the third size is reduced to 9.8 to 14.9 cm.

[0172] Although various embodiments of the present invention are described above, it should be understood that they are presented as examples only and not as limitations. It is obvious to those skilled in the relevant art that various combinations, deformations and changes can be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should only be defined according to the attached claims and their equivalents.

Claims

1. A packaging structure of a micro light emitting diode chip, characterized in that: include: Circuit boards; A micro light emitting diode chip, the second surface of which is provided with an active area, the circuit board being electrically connected to the micro light emitting diode chip; as well as A plastic package is connected to the circuit board and the micro-LED chip, wherein the plastic package is arranged at the periphery of the micro-LED chip and exposes the active area.

2. The packaging structure of the micro light emitting diode chip according to claim 1, characterized in that: A first surface of the micro-LED chip opposite to the second surface is exposed.

3. The packaging structure of the micro light emitting diode chip according to claim 1, characterized in that: The micro light emitting diode chip is arranged on the circuit board, wherein a first side of the micro light emitting diode chip is connected to the circuit board.

4. The packaging structure of the micro light emitting diode chip according to claim 3, characterized in that: The surface of the circuit board facing away from the micro-LED chip is exposed.

5. The packaging structure of the micro light emitting diode chip according to claim 4, characterized in that: The circuit board has: A circuit board body, which is arranged under the plastic package and the micro light emitting diode; and The extension portion extends beyond the circuit board body to electrically connect the micro light emitting diode chip to the outside.

6. The packaging structure of the micro light emitting diode chip according to claim 1, characterized in that: The circuit board includes a flexible circuit board or a rigid printed circuit board.

7. The packaging structure of the micro light emitting diode chip according to claim 1, characterized in that: The material of the plastic package body includes epoxy resin, silica gel or ethylene-vinyl acetate copolymer.

8. The packaging structure of the micro light emitting diode chip according to claim 1, characterized in that: The micro light emitting diode chip is electrically connected to the circuit board via leads, and the plastic package body covers the leads.

9. The packaging structure of the micro light emitting diode chip according to claim 8, characterized in that: A first connection portion is disposed at an edge region of the second surface of the micro-LED chip, and a second connection portion is disposed on a surface of the circuit board, wherein the lead connects the first connection portion and the second connection portion.

10. The packaging structure of the micro light emitting diode chip according to claim 8, characterized in that: The material of the lead wire includes gold or aluminum.

11. The packaging structure of the micro light emitting diode chip according to claim 1, characterized in that: The micro light emitting diode chip comprises an integrated circuit backplane and the active area arranged on the integrated circuit backplane, wherein the active area comprises a pixel array formed by micro light emitting diodes, wherein the pixel array comprises a plurality of micro light emitting diode pixels, and each pixel comprises one or more micro light emitting diodes.

12. The packaging structure of the micro light emitting diode chip according to claim 11, characterized in that: The micro light emitting diode comprises a micron-scale light emitting mesa structure, wherein the micron-scale light emitting mesa structure comprises a first type epitaxial layer, a second type epitaxial layer and a light emitting layer between the first type epitaxial layer and the second type epitaxial layer. The first type epitaxial layer is a semiconductor material having a first conductivity type and includes a plurality of semiconductor layers; The second type epitaxial layer is a semiconductor material having a second conductivity type and includes a plurality of semiconductor layers.

13. The packaging structure of the micro light emitting diode chip according to claim 1, characterized in that: Also includes: A light-transmitting cover plate is arranged on the active area of ​​the micro-light emitting diode chip.

14. The packaging structure of the micro light emitting diode chip according to claim 13, characterized in that: There is a gap between the bottom surface of the light-transmitting cover plate and the surface of the active area.

15. The packaging structure of the micro light emitting diode chip according to claim 13, characterized in that: The material of the light-transmitting cover plate includes: glass, silicon dioxide or magnesium fluoride.

16. The packaging structure of the micro light emitting diode chip according to claim 13, characterized in that: The top surface height of the plastic package body is higher than the top surface height of the active area. The light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surface of the plastic package body, and there is a gap between the bottom surface of the middle area and the surface of the active area.

17. The packaging structure of the micro light emitting diode chip according to claim 16, characterized in that: A transparent cover plate adhesive is provided at a position where the transparent cover plate overlaps with the top surface of the plastic package body, and the transparent cover plate is fixed by the transparent cover plate adhesive so as to be located above the active area.

18. The packaging structure of the micro light emitting diode chip according to claim 13, characterized in that: The portion of the plastic encapsulation body adjacent to the active area of ​​the micro light-emitting diode chip forms a downward plastic encapsulation step, the top surface of the plastic encapsulation step is lower than the top surface of the plastic encapsulation body, the light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surface of the plastic encapsulation step, and there is a gap between the bottom surface of the middle area and the surface of the active area.

19. The packaging structure of the micro light emitting diode chip according to claim 18, characterized in that: The top surface height of the molding step is higher than the surface height of the active area.

20. The packaging structure of the micro light emitting diode chip according to claim 18, characterized in that: A transparent cover plate adhesive is provided at a position where the transparent cover plate overlaps with the top surface of the plastic sealing step, and the transparent cover plate is fixed by the transparent cover plate adhesive so as to be located above the active area.

21. The packaging structure of the micro light emitting diode chip according to claim 13, characterized in that: The light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area, the supporting area covers and is fixed to the surrounding surfaces of the active area, and there is a gap between the bottom surface of the middle area and the surface of the active area.

22. The packaging structure of the micro light emitting diode chip according to claim 21, characterized in that: A transparent cover plate adhesive is provided at a position where the transparent cover plate overlaps with the outer top surface of the active area, and the transparent cover plate is fixed by the transparent cover plate adhesive to be located above the active area.

23. The packaging structure of the micro light emitting diode chip according to claim 22, characterized in that: The plastic sealing body is connected to the light-transmitting cover plate and the side surface of the light-transmitting cover plate adhesive.

24. The packaging structure of the micro light emitting diode chip according to claim 18 or 21, characterized in that: The top surface of the light-transmitting cover plate is flush with the top surface of the plastic package body.

25. The packaging structure of the micro light emitting diode chip according to any one of claims 19, 20 and 22, characterized in that: The material of the transparent cover plate adhesive is ethylene-vinyl acetate copolymer.

26. The packaging structure of the micro light emitting diode chip according to claim 2 or 4, characterized in that: Also includes: A heat sink connected to the first surface of the micro-LED chip, wherein at least a portion of the circuit board is arranged on the heat sink, and the plastic package covers a portion of the top surface of the heat sink; or the heat sink is arranged on the surface of the circuit board facing away from the micro-LED chip.

27. The packaging structure of the micro light emitting diode chip according to claim 26, characterized in that: The material of the heat sink includes graphite.

28. A method for constructing a packaging structure of a micro light emitting diode chip, characterized in that: include: Providing a circuit board, and arranging the circuit board on the top surface of the carrier board; Arranging a micro-LED chip on the top surface of the carrier board at a position adjacent to the circuit board, wherein a first surface of the micro-LED chip is connected to the carrier board, and a second surface of the micro-LED chip opposite to the first surface has an active area; forming wires between the circuit board and the micro light emitting diode chip by a wire bonding process; forming a plastic package, wherein the plastic package covers all side surfaces and a portion of the top surface except the active area of ​​the micro-LED chip, a portion of the top surface and side surfaces of the circuit board adjacent to the micro-LED chip, and a portion of the top surface of the carrier, and exposes the active area; and The carrier is removed to expose the first surface of the micro-LED chip.

29. A method for constructing a packaging structure of a micro light emitting diode chip, characterized in that: include: Provide circuit boards; Arranging a micro light emitting diode chip on the front side of the circuit board, wherein a first side of the micro light emitting diode chip is connected to the circuit board, and a second side of the micro light emitting diode chip opposite to the first side has an active area; forming wires between the circuit board and the micro light emitting diode chip by a wire bonding process; as well as A plastic package is formed, which covers all side surfaces and a portion of the top surface of the micro-LED chip except the active area, and a portion of the top surface of the circuit board, and exposes the active area.

30. The method for constructing a packaging structure of a micro light emitting diode chip according to claim 28 or 29, characterized in that: Also includes: A light-transmitting cover plate is covered above the active area of ​​the micro-light-emitting diode chip.

31. The method for constructing a packaging structure of a micro light emitting diode chip according to claim 30, characterized in that: The top surface height of the plastic package body is higher than the top surface height of the active area, and the transparent cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area. The support area is covered and fixed to the surface of the plastic package body by a transparent cover plate adhesive, and a gap is provided between the bottom surface of the middle area and the surface of the active area.

32. The method for manufacturing the packaging structure of a micro light emitting diode chip according to claim 30, characterized in that: A downward plastic encapsulation step is formed at a portion of the plastic encapsulation body adjacent to the active area of ​​the micro light emitting diode chip, the top surface of the plastic encapsulation step is lower than the top surface of the plastic encapsulation body, the light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area, The support area is covered and fixed to the surface of the plastic packaging step by a transparent cover plate adhesive, and a gap is provided between the bottom surface of the middle area and the surface of the active area.

33. The method for manufacturing the packaging structure of a micro light emitting diode chip according to claim 30, characterized in that: The light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area. The support area is covered and fixed to the surrounding surfaces of the active area by adhesive of a transparent cover plate, and a gap is provided between the bottom surface of the middle area and the surface of the active area.

34. The method for constructing a packaging structure of a micro light emitting diode chip according to claim 28 or 29, characterized in that: A light-transmitting cover plate is provided above the active area of ​​the micro-LED chip, and the light-transmitting cover plate has a middle area corresponding to the active area and a supporting area located outside the middle area. The support area is covered and fixed to the surrounding surfaces of the active area by adhesive of a transparent cover plate, and a gap is provided between the bottom surface of the middle area and the surface of the active area.

35. The method for constructing a packaging structure of a micro light emitting diode chip according to claim 28 or 29, characterized in that: Also includes: Connecting a heat sink to the first surface of the micro-LED chip, wherein at least a portion of the circuit board is arranged on the heat sink, and the plastic package covers a portion of the top surface of the heat sink; or A heat sink is arranged on the back side of the circuit board.

36. A light source machine, characterized in that: A packaging structure of a micro light emitting diode chip as claimed in any one of claims 1 to 27.

Images