Micro-display light-emitting panel and packaging method thereof

Abstract

The embodiment of the invention provides a micro-display light-emitting panel and a packaging method thereof, and the panel comprises a light-emitting chip which comprises a light-emitting region and a non-light-emitting region, and the non-light-emitting region comprises a plurality of first pin pads; the circuit board comprises a plurality of second pin bonding pads corresponding to the first pin bonding pads, and the first pin bonding pads and the second pin bonding pads are attached in an aligned mode so that the circuit board can be electrically connected with the light-emitting chip. Due to the fact that the circuit board and the light-emitting chip are attached in an aligned mode through the pin bonding pad, bonding through a lead is not needed, the space of the micro-display light-emitting panel is saved, and the size of the micro-display light-emitting panel is reduced.

Description

Technical Field

[0001] This application relates to the field of Micro-LED manufacturing technology, and particularly relates to a packaging structure and a packaging method for a micro-display light-emitting panel. Background Art

[0002] . With the development of technology, a new generation of display technology with high efficiency, low power consumption, and high stability - Micro-LED has emerged as the times require.

[0003] . A Micro LED (Micro light emitting diode, a micro light-emitting diode structure) is a micro-LED array with multiple single-pixel elements, and the distance between the LED pixel points in the array is on the order of 100 nanometers to 100 micrometers. The Micro LED display based on MicroLED is much smaller in size than LCD and OLED displays. Due to the small size of the Micro LED display, it has been used in fields such as in-vehicle displays, wearable products, smart watches, VR / AR, etc.

[0004] . However, based on the existing chip packaging technology, the size of the Micro LED display panel cannot be made small enough. Summary of the Invention

[0005] . Embodiments of this application provide a micro-display light-emitting panel and its packaging method to reduce the size of the micro-display light-emitting panel.

[0006] On the one hand, this application provides a micro-display light-emitting panel, including: A light-emitting chip, the light-emitting chip includes a light-emitting area and a non-light-emitting area, and the non-light-emitting area includes a plurality of first pin pads; A circuit board, the circuit board includes a plurality of second pin pads corresponding to the first pin pads, and the first pin pads and the second pin pads are aligned and adhered to each other to electrically connect the circuit board and the light-emitting chip. In a possible implementation manner of this application, at least one surface of the circuit board can achieve the alignment and adhesion of the second pin pads and the first pin pads of the light-emitting chip.

[0007] In a possible implementation manner of this application, the circuit board has a hollowed-out area, and the hollowed-out area at least exposes the light-emitting area of the light-emitting chip.

[0008] In a possible implementation manner of this application, the hollowed-out area is of any planar geometric shape.

[0009] In a possible implementation manner of this application, the circuit board is L-shaped, or S-shaped or of any planar geometric shape, and the second pin pads are on at least one surface of the circuit board.

[0010] In a possible implementation manner of the present application, the circuit board is a flexible circuit board or a rigid circuit board; the materials of the circuit board include at least one of FR, PI, CEM, or ceramic.

[0011] In a possible implementation manner of the present application, the material of the first pin pad includes at least one of Cr, Ni, Al, Au, and Cu.

[0012] In a possible implementation manner of the present application, the material of the second pin pad includes at least one of Cr, Ni, Al, Au, and Cu.

[0013] In a possible implementation manner of the present application, the thickness of the first pin pad is greater than or equal to 0.1 micrometer and less than or equal to 20 micrometers.

[0014] In a possible implementation manner of the present application, the attachment includes at least one of bonding, gluing, and snap - fitting.

[0015] In a possible implementation manner of the present application, the gluing includes conductive film gluing.

[0016] In a possible implementation manner of the present application, the light - emitting chip is a Micro LED light - emitting chip; the Micro LED light - emitting chip includes: a substrate, the substrate includes a pixel driving circuit; a Micro LED array, the Micro LED array is located on the substrate, and each Micro LED in the Micro LED array is electrically connected to the pixel driving circuit.

[0017] In a possible implementation manner of the present application, the material of the substrate includes at least one of glass, silicon, alumina, and silicon nitride; the Mohs hardness grade of the substrate is greater than or equal to 5 and less than or equal to 8; the substrate is a silicon - based CMOS driving substrate or a TFT driving substrate; the Micro LED includes a first semiconductor layer, a second semiconductor layer, and a light - emitting layer formed between the semiconductor layer and the second semiconductor layer, and the conductivity type of the first semiconductor layer is different from that of the second semiconductor layer.

[0018] On the one hand, the present application provides a packaging method for a micro - display light - emitting panel, including: providing a light - emitting chip, the light - emitting chip includes a light - emitting area and a non - light - emitting area, and the non - light - emitting area includes a plurality of first pin pads; providing a circuit board, the circuit board includes a plurality of second pin pads corresponding to the first pin pads;

[0019] Align and fit the first pin pad with the second pin pad to electrically connect the circuit board to the light-emitting chip.

[0020] An embodiment of the present application provides a microdisplay light-emitting panel and its packaging method. The light-emitting chip of the present application includes a light-emitting chip, the light-emitting chip includes a light-emitting area and a non-light-emitting area, the non-light-emitting area includes a plurality of first pin pads; a circuit board, the circuit board includes a plurality of second pin pads corresponding to the first pin pads, and the first pin pads are aligned and fitted with the second pin pads to electrically connect the circuit board to the light-emitting chip. Since the light-emitting chip and the circuit board of the present application are electrically connected by aligning and fitting the first pad pin and the second pad pin, there is no need to electrically connect by wire bonding. Therefore, there is no need to place leads connecting the circuit board in the microdisplay light-emitting panel, saving the space of the microdisplay light-emitting panel, and thus reducing the size of the microdisplay light-emitting panel. Description of the Drawings

[0021] . To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1a It is a top view of the first light-emitting chip provided by the embodiment of the present application.

[0023] Figure 1b It is a top view of the first circuit board provided by the embodiment of the present application.

[0024] Figure 1c It is a top view of the second circuit board provided by the embodiment of the present application.

[0025] Figure 2a It is a top view of the second light-emitting chip provided by the embodiment of the present application.

[0026] Figure 2b It is the first top view of the third circuit board provided by the embodiment of the present application.

[0027] Figure 2c It is the first top view of the fourth circuit board provided by the embodiment of the present application.

[0028] Figure 3a It is a top view of the third light-emitting chip provided by the embodiment of the present application.

[0029] Figure 3b It is a top view of the fifth circuit board provided by the embodiment of the present application.

[0030] Figure 4aThe top view of the fourth light-emitting chip provided by the embodiment of the present application.

[0031] Figure 4b The top view of the sixth circuit board provided by the embodiment of the present application.

[0032] Figure 5a The top view of the fifth light-emitting chip provided by the embodiment of the present application.

[0033] Figure 5b The top view of the seventh circuit board provided by the embodiment of the present application.

[0034] Figure 6a The top view of the sixth light-emitting chip provided by the embodiment of the present application.

[0035] Figure 6b The top view of the eighth circuit board provided by the embodiment of the present application.

[0036] Figure 7a The top view of the seventh light-emitting chip provided by the embodiment of the present application.

[0037] Figure 7b The top view of the ninth circuit board provided by the embodiment of the present application.

[0038] Figure 8a The side view of the second light-emitting chip provided by the embodiment of the present application.

[0039] Figure 8b The second top view of the second circuit board provided by the embodiment of the present application.

[0040] Figure 8c The second side view of the second circuit board provided by the embodiment of the present application.

[0041] Figure 9 The flowchart of the light-emitting chip packaging method provided by the embodiment of the present application. Detailed implementation manners

[0042] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0043] The disclosure of the present application provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, components and settings of specific examples are described in the present application. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0044] Generally, terms can be understood at least in part based on their usage in the present application. For example, the term "one or more" used in the present application can be understood at least in part based on the present application and can be used to describe any component, structure, or feature in the singular form, or can be used to describe a combination of components, structures, or features in the plural form. Similarly, terms such as "a", "an", or "the" can also be understood at least in part based on the present application to convey singular usage or convey plural usage. Additionally, the term "based on..." can be understood as not necessarily intended to convey a set of exclusive factors, but can instead, at least in part based on the present application, allow for the existence of additional factors that do not necessarily have to be explicitly described.

[0045] It should be readily understood that the meanings of "on", "above", and "over" in the present application should be interpreted in the broadest sense, such that "on" not only means "directly on something", but also means "on something" including the existence of intermediate components or layers therebetween, and "above" or "over" not only mean the meaning of "above" or "over" something, but also include the meaning of "above" or "over" something without the existence of intermediate components or layers therebetween.

[0046] In addition, for ease of description, the present application may use spatial relative terms such as "below", "beneath", "lower", "above", "upper", etc. to describe the relationship between one element or component and another element or component shown in the drawings. In addition to the orientation described in the figures, spatial relative terms are also intended to cover different orientations of the device during use or operation. The device can be oriented in other ways, rotated 90° or in other orientations, and the spatial relative descriptive terms used in the present application can be interpreted accordingly in the same manner.

[0047] As used in this application, the term "layer" refers to a portion of a material that includes a region having a certain thickness. The layer may extend over the entire underlying or overlying structure, or may have an extent less than that of the underlying or overlying structure. In addition, the layer may be a region of a homogeneous or heterogeneous continuous structure, the thickness of which is less than the thickness of the continuous structure. For example, the layer may be located between the top and bottom surfaces of the continuous structure or between any pair of horizontal planes therebetween. The layer may extend horizontally, vertically, and / or along a conical surface. The substrate may be a layer, may include one or more layers therein, and / or may have one or more layers on, above, and / or below it. A layer may include multiple layers. For example, a semiconductor layer may include one or more doped or undoped semiconductor layers and may have the same or different materials.

[0048] As used in this application, the term substrate refers to a material on which subsequent material layers are added. The substrate itself may be patterned. The material added to the top of the substrate may be patterned or may remain unpatterned. In addition, the substrate may include a variety of semiconductor materials, such as silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, indium phosphide, etc. Alternatively, the substrate may be made of a non-conductive material, such as glass, plastic, or a sapphire wafer. Further alternatively, the substrate may have semiconductor devices or circuits formed therein.

[0049] In this application, a Micro LED (Micro light emitting diode, micro light emitting diode structure) is a micro LED array having a plurality of single pixel elements, and the distance between the LED pixel points in the array is on the order of 100 nanometers to 100 micrometers.

[0050] The "micro" LED and "micro" device used in this application refer to the descriptive dimensions of certain devices or structures according to the embodiments of this application. The term "micro" device or structure used herein is intended to represent a scale of 100 nanometers to 100 micrometers. However, it should be understood that the embodiments of this application are not necessarily limited thereto, and certain aspects of the embodiments may be applicable to larger and possibly smaller size scales.

[0051] In this application, the size of each micro light emitting diode chip does not exceed 1 cm, preferably does not exceed 20 micrometers. The micro light emitting diode structure is formed in an array in the micro light emitting diode chip, and the resolution is, for example, 720*480, 640*480, 1920*1080, 1280*720, 2K, or 4K. The diameter of the micro light emitting diode structure is at the nanometer level, for example, 20 nm to 100 nm.

[0052] In one embodiment, the micro light-emitting diode array may include a single-layer micro light-emitting diode structure. In some embodiments of the present invention, the micro light-emitting diode array may include a multi-layer vertically stacked micro light-emitting diode structure.

[0053] In one embodiment, the micro light-emitting diode array may include blue micro light-emitting diodes. In some embodiments of the present invention, the pitch of the micro light-emitting diode array, i.e., the minimum center-to-center distance between the micro light-emitting diodes, may be between about 2 micrometers and about 50 micrometers.

[0054] In one embodiment, the number of pixels on the micro light-emitting diode chip may be between several thousand and several million.

[0055] See Figure 1a and Figure 1b , Figure 1a is a top view of the first light-emitting chip 101 provided in the embodiment of the present application. Figure 1b is a top view of the first circuit board 101 provided in the embodiment of the present application. The light-emitting chip 101 includes a non-light-emitting area 1011 and a light-emitting area 1012. The non-light-emitting area 1011 includes a plurality of first pin pads 102, and the circuit board 103 includes a plurality of second pin pads 104. The first pin pads 102 are in alignment and fit with the second pin pads 104.

[0056] In the present application, the light-emitting chip may be a light-emitting chip of an organic light-emitting diode (OLED) or an inorganic light-emitting diode (LED), which is not limited herein and is selected according to the actual application scenario. In the present application, a Micro LED light-emitting chip is taken as an example for illustration.

[0057] In the present application, the material of the circuit board should meet the characteristics of high electrical insulation performance, good moisture and heat resistance performance, and high thermal conductivity.

[0058] In the present application, the pin pads have electrical conductivity and are usually used as contact points for electrical connection. The first pin pads are metal areas on the light-emitting chip and are used to connect the pins of the light-emitting chip to the external circuit. The second pin pads are metal areas on the circuit board and are used to connect the pins of the circuit board to the internal chip.

[0059] Since both the first pin pads and the second pin pads have electrical conductivity, the first pin pads and the second pin pads are in alignment and fit, so that the circuit board and the light-emitting chip can be electrically connected.

[0060] A microdisplay light-emitting panel provided by an embodiment of the present application includes a light-emitting chip. The light-emitting chip includes a light-emitting region and a non-light-emitting region. The non-light-emitting region includes a plurality of first pin pads; a circuit board, the circuit board includes a plurality of second pin pads corresponding to the first pin pads, and the first pin pads and the second pin pads are aligned and attached to each other to electrically connect the circuit board and the light-emitting chip. Since the light-emitting chip and the circuit board in the present application are electrically connected by aligning and attaching the first pad pins and the second pad pins, there is no need to electrically connect by wire bonding. Therefore, there is no need to place leads connecting the circuit board in the microdisplay light-emitting panel, saving the space of the microdisplay light-emitting panel, and thus reducing the size of the microdisplay light-emitting panel.

[0061] In one embodiment, at least one surface of the circuit board can achieve the alignment and attachment of the second pin pads and the first pin pads of the light-emitting chip. For example, Figure 1a As shown, when the light-emitting chip 101 is square and the first pin pads 102 are distributed on the four sides of the square; the circuit board 103 can be Figure 1b As shown, an integrally formed square circuit board, and the second pin pads 104 are distributed on the four sides of the square; it can also be Figure 1c As shown, formed by electrically connecting 4 separate circuit boards, and the second pin pads 104 are distributed on the surfaces of 4 cuboids.

[0062] Figure 2a 、 Figure 2b As shown, when the light-emitting chip 101 is square and the first pin pads 102 are distributed on the opposite sides of the square, the circuit board 103 can be Figure 2b As shown, an integrally formed square circuit board, and the second pin pads 104 are distributed on the opposite sides of the circuit board 103; it can also be Figure 2c As shown, formed by electrically connecting 2 separate circuit boards, and the second pin pads 104 are distributed on the surfaces of 2 cuboids.

[0063] The specific circuit board structure is not limited here, as long as it is ensured that at least one surface of the circuit board can achieve the alignment and attachment of the second pin pads and the first pin pads of the light-emitting chip.

[0064] In the present application, the circuit board 103 can be transparent or non-transparent, which is not limited here and is determined according to the actual application scenario.

[0065] In one embodiment, the circuit board has a transparent region, and the transparent region exposes at least the light-emitting region of the light-emitting chip.

[0066] In one embodiment, the circuit board has a hollowed-out region, and the hollowed-out region exposes at least the light-emitting region of the light-emitting chip.

[0067] For example, Figure 1bThe blank area 105 of the circuit board 103 shown can be a transparent area or a hollowed-out area, which is not limited herein and is determined according to the actual application scenario.

[0068] Among them, the hollowed-out area can be of any geometric shape, including but not limited to square, rectangle, hexagon, circle, etc.

[0069] In the actual production process, the shape of the circuit board 103 is related to the shape of the light-emitting chip 101 and the distribution of the first pin pads 102.

[0070] In one embodiment, the circuit board is L-shaped, S-shaped or any planar geometric shape, and the second pin pads are on at least one surface of the circuit board.

[0071] Refer to Figure 1a and Figure 1b , when the light-emitting chip 101 is square and the first pin pads 102 are distributed on the four sides of the square, the circuit board 103 can be a "hui"-shaped.

[0072] Refer to Figure 2a , Figure 2b , when the light-emitting chip 101 is square and the first pin pads 102 are distributed on the opposite sides of the square, the circuit board 103 can also be a "hui"-shaped.

[0073] Refer to Figure 3a and Figure 3b , Figure 4a and Figure 4b When the light-emitting chip 101 is square and the first pin pads 102 are distributed on two mutually perpendicular sides of the square, the circuit board 103 can be L-shaped.

[0074] In one embodiment, the circuit board is L-shaped, and the second pin pads are on at least one of the two L-shaped sides of the circuit board.

[0075] Refer to Figure 5a and Figure 5b , when the light-emitting chip 101 is square and the first pin pads 102 are distributed on one side of the square, the circuit board 103 can be rectangular.

[0076] Refer to Figure 6a and Figure 6b , when the light-emitting chip 101 is circular, the light-emitting area 1012 is also circular, and the first pin pads 102 are evenly distributed on the surface of the non-light-emitting area 1011, the circuit board 103 is annular.

[0077] Refer to Figure 7a and Figure 7bWhen the light-emitting chip 101 is square, the light-emitting area 1012 is circular, and the first pin pads 102 are distributed on three sides of the square, the circuit board 103 can be U-shaped.

[0078] In actual application scenarios, the shape of the light-emitting chip 101 can be any planar geometric shape such as square, rectangular, circular, hexagonal, etc. The shape of the circuit board 103 changes according to the shape of the light-emitting chip 101 and the distribution position of the first pin pads 102. The shape of the circuit board 103 can be L-shaped, S-shaped or any planar geometric shape. The second pin pads are on at least one surface of the circuit board, which is not limited herein.

[0079] In this application, designing the circuit board into geometric shapes such as a square frame, L-shaped, rectangular, circular, S-shaped, etc. can not only save production costs, but also facilitate the heat dissipation of the chip.

[0080] See Figure 8a 、 Figure 8b and Figure 8c , Figure 8a is the side view of the second light-emitting chip provided by the embodiment of the present application, Figure 8b is the second top view of the second circuit board provided by the embodiment of the present application, Figure 8c is the second side view of the second circuit board provided by the embodiment of the present application. The circuit board 103 is usually used in cooperation with a flexible circuit board 105 (FPC, Flexible Printed Circuit). The flexible circuit board 105 is used to connect the circuit board 103 to an external control host to realize the communication between the circuit board 103 and the external control host.

[0081] Among them, the flexible circuit board 105 can be connected to any side of the circuit board 103, which is not limited herein.

[0082] In one embodiment, the material of the circuit board includes at least one of FR, PI, CEM or ceramic.

[0083] The shapes of the first pin pads and the second pin pads include but are not limited to at least one of circular and rectangular.

[0084] In one embodiment, the material of the first pin pads includes at least one of Cr, Ni, Al, Au, Cu.

[0085] In one embodiment, the material of the second pin pads includes at least one of Cr, Ni, Al, Au, Cu.

[0086] Among them, the way of alignment and bonding is not limited and is selected according to the actual application scenario.

[0087] In one embodiment, the alignment bonding includes at least one of bonding, gluing, and snap - fitting. For example: There are 10 first pin pads 102 in the light - emitting chip 101, and there are also 10 second pin pads 104 in the corresponding circuit board 103. Among them, 5 first pin pads 102 and 5 second pin pads 104 are bonded by metal bonding, and the remaining 5 first pin pads 102 and the remaining 5 second pin pads 104 are bonded by gluing. Here is just an example to illustrate that the alignment bonding includes at least one of bonding, gluing, and snap - fitting, or any combination of multiple ones, and no limitation is made here.

[0088] In one embodiment, the bonding method includes but is not limited to metal bonding.

[0089] In one embodiment, gluing includes but is not limited to conductive film bonding. For example: Gluing is performed through an anisotropic conductive film (ACF, Adhesive Conductive Film).

[0090] Since the circuit board 103 needs to cover the surface of the non - light - emitting area 1011 of the light - emitting chip 101 and cannot affect the light output of the light - emitting area 1012, the thickness of the first pin pad 102 plus the second pin pad 104 is greater than or equal to the thickness of the light - emitting area 1012. If the thickness of the first pin pad is too small, it will affect the firmness of the bonding between the light - emitting chip 101 and the circuit board 103. If the thickness is too large, the size of the chip package will be too large. Therefore, the thickness of the first pin pad 102 needs to be in an appropriate range.

[0091] In one embodiment, the thickness of the first pin pad 102 is greater than or equal to 0.1 micrometer and less than or equal to 20 micrometers.

[0092] In one embodiment, the light - emitting chip is a Micro LED light - emitting chip.

[0093] In one embodiment, the Micro LED light - emitting chip includes: a substrate, the substrate includes a pixel driving circuit; a Micro LED array, the Micro LED array is located on the substrate, and each Micro LED in the Micro LED array is electrically connected to the pixel driving circuit.

[0094] In one embodiment, the substrate may include a semiconductor material, such as at least one of silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, and cobalt phosphide.

[0095] In one embodiment, the substrate can be made of a non - conductive material, such as glass, plastic, or a sapphire wafer.

[0096] Since the circuit board is bonded to the light - emitting chip, the substrate of the light - emitting chip needs to have a certain hardness to support the light - emitting chip.

[0097] In one embodiment, the Mohs hardness grade of the substrate is greater than or equal to 5 and less than or equal to 8.

[0098] The Mohs hardness grade of the substrate being between 5 and 8 can ensure that the light-emitting chip 101 will not be deformed due to the covering of the circuit board, improving the firmness of the micro-display light-emitting panel.

[0099] In one embodiment, the substrate includes a pixel driving circuit, and the substrate can be a CMOS backplane or a TFT glass substrate. The driving circuit provides an electrical signal to the Micro LED unit to control the brightness.

[0100] In one embodiment, the driving circuit may include an active matrix driving circuit, wherein each individual MicroLED unit has a corresponding independent driver.

[0101] In one embodiment, the driving backplane can be electrically connected to each micro-light-emitting diode in the micro-light-emitting diode array through separate metal interconnections. In some embodiments, each micro-light-emitting diode can be individually electrically controlled by the driving backplane. In some embodiments, the driving backplane can be electrically connected to the electrodes of the micro-light-emitting diode chips through metal interconnections. In some embodiments, a dielectric layer can be formed in the gaps between the micro-light-emitting diodes. In some embodiments, the dielectric layer can also be formed in the gaps between the interconnections.

[0102] The micro-light-emitting diode chip includes a plurality of micro-light-emitting diode arrays, and each micro-light-emitting diode array includes a plurality of micro-light-emitting diodes. The driving method of the micro-light-emitting diodes is, for example, passive matrix (PM) driving, wherein the cathodes of all the micro-light-emitting diodes in each array are commonly connected to the cathode line NL, and the micro-light-emitting diodes with the same number in each array are respectively connected to the corresponding anode lines PL. Thus, the on / off and the light-emitting brightness of each light-emitting diode can be individually controlled by controlling the signals on the corresponding cathode line and anode line.

[0103] In one embodiment, a frame buffer, a column driving circuit, and a row driving circuit are integrated in the above-mentioned substrate. The frame buffer includes a first pixel storage area, and the Micro LED array includes a second pixel storage area. A complete frame of pixel grayscale data from the outside can enter the first pixel storage area of the frame buffer. The column driving circuit can load the pixel grayscale data in the first pixel storage area of the frame buffer into the second pixel storage area of the Micro LED array. The row driving circuit can scan the pixel grayscale data in the second pixel storage area and generate a pulse modulation signal to achieve the purpose of displaying different grayscales. When driving multiple Micro LEDs in the Micro LED array, either a single Micro LED independent driving method or a multiple Micro LED independent driving method can be adopted. The specific driving method should not constitute a limitation to this application.

[0104] In one embodiment, the Micro LED includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in sequence from top to bottom. The first semiconductor layer, the light-emitting layer, and the second semiconductor layer form a light-emitting mesa. When the first semiconductor and the second semiconductor are energized, the light-emitting layer can emit light. The conductivity type of the first semiconductor layer is different from that of the second semiconductor layer.

[0105] Among them, the light-emitting mesa can be a regular trapezoid or an inverted trapezoid, which is not limited here. In this application, the light-emitting mesa is taken as a regular trapezoid for illustration.

[0106] Among them, the first semiconductor layer can be an N-type semiconductor and the second semiconductor layer is a P-type semiconductor, or the first semiconductor layer is a P-type semiconductor and the second semiconductor layer is an N-type semiconductor, which is not limited here.

[0107] In one embodiment, the first semiconductor layer and the second semiconductor layer can include one or more based on II-VI materials (such as ZnSe or ZnO) or III-V materials (such as GaN, AlN, InN, InGaN, GaP, AlInGaP, AlGaAs and their alloys).

[0108] In one embodiment, the first semiconductor layer is P-type gallium nitride and the second semiconductor layer is N-type gallium nitride.

[0109] In one embodiment, the first semiconductor layer is N-type gallium nitride and the second semiconductor layer is P-type gallium nitride.

[0110] In one embodiment, the light-emitting layer is formed by multiple stacked quantum well layers, especially superlattice-stacked quantum well layers. Preferably, the superlattice-stacked quantum well layers include multiple pairs of quantum well layers stacked with quantum barrier layers.

[0111] In one embodiment, the quantum well layer is an InGaN / GaN multiple quantum well layer, an InGaN / AlGaN multiple quantum well layer, or an InGaAs / AlGaAs multiple quantum well layer. In an embodiment of the present application, the light-emitting layer further includes an electron blocking layer, and the electron blocking layer is disposed on a first side of the light-emitting layer, where the first side refers to the side along which electrons migrate out of the light-emitting layer.

[0112] In one embodiment, a top conductive layer can be formed on the top surface of the micro light-emitting diode array.

[0113] Among them, the top conductive layer can be shared by all the micro light-emitting diodes in the micro light-emitting diode array. In an embodiment of the present application, the top conductive layer is disposed above the micro light-emitting diode 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 to connect the second epitaxial layers of the respective semiconductor light-emitting mesas in series, and it is a transparent conductive layer.

[0114] In one embodiment, the micro light-emitting diode array further includes a passivation isolation layer. The passivation isolation layer covers the surface and side surfaces of the light-emitting mesa, but exposes at least a part of the surface of the second epitaxial layer, and the top conductive layer is disposed on the surface of the passivation isolation layer. In an embodiment of the present application, the passivation isolation layer can be formed by CVD depositing SiO2 or ALD depositing an Al2O3 film layer to effectively reduce the chip leakage rate. In some embodiments of the present application, the passivation isolation layer only covers the side surface of the light-emitting mesa and does not cover the top surface of the light-emitting mesa, and the highest point of the passivation isolation 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 planar shape. In some embodiments of the present application, the passivation isolation layer not only covers the side surface of the light-emitting mesa, but also covers the edge part of the top surface of the light-emitting mesa. Furthermore, there is a protrusion at the top edge of the light-emitting mesa, and thus the continuous top conductive layer covering it also forms a protrusion at the top edge of the light-emitting mesa.

[0115] As described above, there is a partition between the pixel points formed by each light-emitting mesa. A second electrode is disposed at the partition, and the second electrode is disposed on the surface of the top conductive layer. In an embodiment of the present application, the second electrode is an annular reflective electrode, which is disposed around the light-emitting mesa. It is formed by magnetron sputtering or evaporation, and its material can be, for example, Al or an Al alloy metal as the sidewall reflective mirror surface, and the electrode stack metal can be metal materials such as Ni, Al, Ti, Ni, Pt, Au, etc. In an embodiment of the present application, the second electrodes are connected to each other. In some embodiments of the present application, a deep trench is disposed at the partition between two adjacent light-emitting mesas, and the deep trench penetrates through the micro light-emitting diode array, and the second electrode is disposed at the deep trench.

[0116] In one embodiment, instead of forming a deep trench at the partition between two adjacent light-emitting mesa regions, a passivation isolation layer and a top conductive layer are directly formed. Therefore, the surface of the top conductive layer between two adjacent light-emitting mesa regions is a horizontal or substantially horizontal plane. The second electrode is formed here, and its morphological interface is trapezoidal or approximately trapezoidal, and the surface of the second electrode is not higher than the highest point of the continuous top conductive layer.

[0117] In one embodiment, the micro light-emitting diode array is bonded to the driving backplane through a metal bonding layer and is electrically connected to the IC copper pillars on the driving backplane. In one embodiment of the present application, the IC copper pillars include 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 one by one. The second IC copper pillar is electrically connected to the first electrode. In one embodiment of the present application, the polarity of the first electrode is opposite to that of the second electrode.

[0118] In one embodiment, each semiconductor light-emitting module has a common first electrode. The first electrode can 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, such as an N electrode or a cathode electrode. In one embodiment of the present application, the first and second electrodes and their connecting components can 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 application, the first and second electrodes and their connecting components can be made of an opaque or transparent conductive material, such as indium tin oxide (ITO).

[0119] In one embodiment of the present application, the light-emitting region further includes a microlens array. The microlens array is disposed above the micro light-emitting diode array, wherein at least one microlens is disposed on the surface of the conductive layer at the top of the micro light-emitting diode, and the horizontal profile of the microlens is larger than the maximum horizontal profile of the micro light-emitting diode. The microlens is mainly used for converging and / or collimating optical fibers. For example, by adjusting parameters such as the thickness and curvature of the microlens, the focal point of the microlens can be located in the light-emitting mesa region of the micro light-emitting diode.

[0120] In one embodiment of the present application, the microlenses of the microlens array correspond one-to-one with the light-emitting mesa. In some embodiments of the present application, there is a gap between adjacent microlenses and their bottoms are connected to each other. The bottom of the gap can be lower than the top of the light-emitting mesa of the micro light-emitting diode, or lower than the bottom of the light-emitting layer of the light-emitting mesa, or above the second electrode, or between the two peaks of the second electrode. In some other embodiments of the present application, adjacent microlenses are completely connected, but there is a gap at the connecting portion, and the bottom of the connecting portion can be lower than the top of the light-emitting mesa of the micro light-emitting diode, or lower than the bottom of the light-emitting layer of the light-emitting mesa, or above the second electrode, or between the two peaks of the second electrode. In addition, in one embodiment of the present application, there is an air gap inside the microlens.

[0121] In one embodiment of the present application, the microlens can be formed by multiple depositions. During the formation of the microlens, first, a SiO2 film layer needs to be deposited, and then ion etching is carried out. The microlens is formed at the position on the surface of the passivation isolation layer corresponding to each light-emitting mesa.

[0122] In the present application, the above-mentioned Micro LED light-emitting chip has a very small volume, and the dimensions of its length and width are between 500 μm and 50,000 μm. The area of the light-emitting region of the Micro LED light-emitting chip is very small, such as 1 mm × 1 mm, 2.64 mm × 2.02 mm, 3 mm × 5 mm, etc. The light-emitting region of the Micro LED light-emitting chip includes a plurality of micro LED pixels arranged in an array, and the specific pixel arrangement can be one of 320 × 240, 640 × 480, 1600 × 1200, 1920 × 1080, 2560 × 1440. The size of a single micro LED pixel is between 100 nm and 100 μm.

[0123] In some embodiments, the size of a single Micro LED pixel is between 150 nm and 15 μm. In some embodiments, the size of a single Micro LED pixel can also be less than 10 μm.

[0124] See Figure 9 , the present application also provides a packaging method for a light-emitting chip, including:

[0125] Step 901, provide a light-emitting chip, the light-emitting chip includes a light-emitting region and a non-light-emitting region, and the non-light-emitting region includes a plurality of first pin pads;

[0126] Among them, the light-emitting chip can be an organic light-emitting chip or an inorganic light-emitting chip, which is not limited herein.

[0127] In one embodiment, the light-emitting chip is a Micro LED light-emitting chip.

[0128] In one embodiment, the Micro LED light-emitting chip includes:

[0129] A substrate, the substrate includes a pixel driving circuit;

[0130] A Micro LED array, the Micro LED array is located on the substrate, and each Micro LED in the Micro LED array is electrically connected to the pixel driving circuit.

[0131] Wherein, the Micro LED includes a first semiconductor layer, a second semiconductor layer, and a light-emitting layer formed between the semiconductor layer and the second semiconductor layer, and the conductivity type of the first semiconductor layer is different from that of the second semiconductor layer.

[0132] In one embodiment, the substrate is a silicon-based CMOS driving substrate or a TFT driving substrate.

[0133] In practical applications, the circuit board 103 will cover the non-light-emitting area 1011 of the light-emitting chip 101, and the circuit board 103 has a certain weight. Therefore, the light-emitting chip 101 needs to have a certain load-bearing capacity.

[0134] In one embodiment, the material of the substrate includes at least one of glass, silicon, alumina, and silicon nitride.

[0135] In one embodiment, the Mohs hardness grade of the substrate is greater than or equal to 5 and less than or equal to 8.

[0136] The Mohs hardness grade of the substrate is between 5 and 8, which can ensure that the light-emitting chip 101 will not be deformed due to the coverage of the circuit board, improving the firmness of the microdisplay light-emitting panel.

[0137] In one embodiment, the material of the first pin pad includes at least one of Cr, Ni, Al, Au, and Cu.

[0138] Furthermore, since the circuit board 103 needs to cover the surface of the non-light-emitting area 1011 of the light-emitting chip 101 and cannot affect the light output of the light-emitting area 1012, the thickness of the first pin pad 102 plus the second pin pad 104 is greater than or equal to the thickness of the light-emitting area 1012. If the thickness of the first pin pad is too small, it will affect the firmness of the bonding between the light-emitting chip 101 and the circuit board 103. If the thickness is too large, the size of the chip package will be too large. Therefore, the thickness of the first pin pad 102 needs to be in an appropriate range.

[0139] In one embodiment, the thickness of the first pin pad is greater than or equal to 0.1 micron and less than or equal to 20 microns.

[0140] Step 902: Provide a circuit board, the circuit board includes a plurality of second pin pads corresponding to the first pin pads;

[0141] In one implementation, at least one surface of the circuit board is capable of achieving alignment and fitting of the second pin pad and the first pin pad of the light-emitting chip.

[0142] In one implementation, the circuit board has a hollowed-out area that at least exposes the light-emitting area of the light-emitting chip.

[0143] Among them, the hollowed-out area is of any planar geometric shape.

[0144] In one implementation, the circuit board is L-shaped, S-shaped, or of any planar geometric shape, and the second pin pad is on at least one surface of the circuit board.

[0145] In this application, designing the circuit board into geometric shapes such as a square frame shape, L shape, rectangle, ring, S shape, etc. can not only save production costs, but also facilitate the heat dissipation of the chip.

[0146] In one embodiment, the material of the second pin pad includes at least one of Cr, Ni, Al, Au, and Cu.

[0147] In one embodiment, the material of the circuit board includes at least one of FR, PI, CEM, or ceramic.

[0148] Step 903: Align and fit the first pin pad and the second pin pad to electrically connect the circuit board and the light-emitting chip. In one embodiment, the fitting includes at least one of bonding, gluing, and clamping.

[0149] In one embodiment, the bonding method includes but is not limited to metal bonding.

[0150] In one embodiment, gluing includes but is not limited to conductive film bonding. For example, gluing is performed through an anisotropic conductive film (ACF, Adhesive Conductive Film).

[0151] The embodiment of this application provides a packaging method for a microdisplay light-emitting panel. First, a light-emitting chip is provided. The light-emitting chip includes a light-emitting area and a non-light-emitting area. The non-light-emitting area includes a plurality of first pin pads. Then, a circuit board is provided. The circuit board includes a plurality of second pin pads corresponding to the first pin pads. Finally, the first pin pads and the second pin pads are aligned and fitted to electrically connect the circuit board and the light-emitting chip. Since the light-emitting chip and the circuit board in this application are electrically connected by aligning and fitting the first pad pin and the second pad pin, there is no need for wire bonding for electrical connection. Therefore, there is no need to place leads connecting to the circuit board in the microdisplay light-emitting panel, saving the space of the microdisplay light-emitting panel and thus reducing the size of the microdisplay light-emitting panel.

[0152] The above has introduced the present application in detail. Specific examples are used in the present application to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A microdisplay light-emitting panel, characterized in that, Comprising: A light-emitting chip, the light-emitting chip including a light-emitting region and a non-light-emitting region, the non-light-emitting region including a plurality of first pin pads; A circuit board, the circuit board including a plurality of second pin pads corresponding to the first pin pads, the first pin pads and the second pin pads being aligned and adhered to each other to electrically connect the circuit board and the light-emitting chip.

2. The microdisplay light-emitting panel according to claim 1, wherein At least one surface of the circuit board can achieve the alignment and adhesion of the second pin pads and the first pin pads of the light-emitting chip.

3. The microdisplay light-emitting panel according to claim 2, characterized in that, The circuit board has a hollowed-out area, and the hollowed-out area at least exposes the light-emitting region of the light-emitting chip.

4. The microdisplay light-emitting panel according to claim 3, wherein The hollowed-out area is of any planar geometric shape.

5. The microdisplay light-emitting panel according to claim 3, characterized in that, The circuit board is L-shaped, S-shaped or of any planar geometric shape, and the second pin pads are on at least one surface of the circuit board.

6. The microdisplay light-emitting panel according to claim 1, wherein, The circuit board is a flexible circuit board or a rigid circuit board; the material of the circuit board includes at least one of FR, Pl, CEM or ceramic.

7. The microdisplay light-emitting panel according to claim 1, wherein The material of the first pin pads includes at least one of Cr, Ni, Al, Au, Cu.

8. The microdisplay light-emitting panel according to claim 1, wherein The material of the second pin pads includes at least one of Cr, Ni, Al, Au, Cu.

9. The microdisplay light-emitting panel according to claim 1, characterized in that, The thickness of the first pin pads is greater than or equal to 0.1 micron and less than or equal to 20 microns.

10. The microdisplay light-emitting panel according to claim 1, wherein, The adhesion includes at least one of bonding, gluing, and snap connection.

11. The microdisplay light-emitting panel according to claim 10, wherein, The gluing includes conductive film gluing.

12. The microdisplay light-emitting panel according to claim 1, wherein The light-emitting chip is a Micro LED light-emitting chip; The Micro LED light-emitting chip includes: A substrate, the substrate including a pixel driving circuit; A Micro LED array, the Micro LED array being located on the substrate, and each Micro LED in the Micro LED array is electrically connected to the pixel driving circuit.

13. The microdisplay light-emitting panel according to claim 12, wherein The material of the substrate includes at least one of glass, silicon, alumina, and silicon nitride; the Mohs hardness grade of the substrate is greater than or equal to 5 and less than or equal to 8; the substrate is a silicon-based CMOS driving substrate or a TFT driving substrate; the Micro LED includes a first semiconductor layer, a second semiconductor layer, and a light-emitting layer formed between the semiconductor layer and the second semiconductor layer, and the conductivity type of the first semiconductor layer is different from that of the second semiconductor layer.

14. A packaging method for a microdisplay light-emitting panel, characterized in that, Comprising: Providing a light-emitting chip, the light-emitting chip including a light-emitting region and a non-light-emitting region, the non-light-emitting region including a plurality of first pin pads; Providing a circuit board, the circuit board including a plurality of second pin pads corresponding to the first pin pads; aligning and adhering the first pin pads and the second pin pads to electrically connect the circuit board and the light-emitting chip.

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