Display module and manufacturing method thereof

Abstract

A display module according to an embodiment of the present disclosure may comprise: a substrate; a plurality of connection pads arranged in a grid form on the substrate; a plurality of micro LEDs, each of which is disposed to overlap a pair of connection pads adjacent to each other in a first direction; and a plurality of connection members respectively disposed between the micro LEDs and the connection pads and configured to electrically connect the substrate and the micro LEDs. The substrate may comprise: a plurality of first regions in which the plurality of connection pads are provided; and a second region which is provided between the plurality of first regions and in which the plurality of connection pads are not provided. The connection members may extend on the connection pads along a second direction perpendicular to the first direction in the first regions of the substrate.

Description

Display module and method of manufacturing the same

[0001] One embodiment disclosed in this document relates to a display module and a method for manufacturing the same.

[0002] LEDs (light emitting diodes) are being applied in various industrial fields due to their relatively high luminous efficiency and long lifespan. For example, LEDs are being put into practical use not only in general lighting but also in the display field.

[0003] Meanwhile, Micro LED, a next-generation light-emitting device, is more efficient than LCD or LED and, similar to OLED, does not require additional filtering or conversion to directly emit pure colors from subpixels. Display modules utilizing Micro LED can achieve wide viewing angles, high efficiency, vivid colors, and high definition.

[0004] Multiple pixels are arranged in a display module. Each pixel consists of three R / G / B subpixels. Subpixels are typically based on blue LEDs and are equipped with a phosphor formed on the light-emitting surface of the blue LED to emit a desired color (e.g., red, green) for each subpixel. For example, a blue-emitting LED uses only the blue LED without a separate phosphor.

[0005] The display module electrically or physically connects the substrate and the micro LED through a connection member, such as a conductive ball, provided between the connection pad of the substrate and the electrode pad of the LED.

[0006] As Micro LEDs become increasingly miniaturized, connecting components such as conductive balls are also required to be miniaturized; however, these components face challenges regarding yield stability and increased costs associated with such miniaturization. Therefore, there is a need for research on connecting components that can ensure both yield and economic viability in the context of Micro LED miniaturization.

[0007] The information described above may be provided as related art for the purpose of aiding understanding of the present disclosure. No claim or determination is made as to whether any of the foregoing may be applied as prior art related to the present disclosure.

[0008] A display module according to one embodiment of the present disclosure may include a substrate, a plurality of connection pads arranged in a grid shape on the substrate, a plurality of micro LEDs each disposed to overlap on a pair of connection pads adjacent in a first direction, and a plurality of connection members disposed between the micro LEDs and the connection pads, respectively, for electrically connecting the substrate and the micro LEDs. The substrate may include a plurality of first regions provided with the plurality of connection pads, and a second region provided between the plurality of first regions and not provided with the plurality of connection pads. The connection member may extend on the connection pads along a second direction perpendicular to the first direction in the first region of the substrate.

[0009] A method for manufacturing a display module according to one embodiment of the present disclosure may include: a process of applying a masking member in a second direction perpendicular to a first direction between adjacent connection pads in a first direction on a substrate having a plurality of connection pads arranged in a grid pattern; a process of printing a conductive paste along a first direction on the substrate and the connection pads; a process of removing the masking member; a process of curing the remaining conductive paste on the substrate to form a connection member; a process of laminating an insulating layer on the substrate; and a process of mounting a micro LED on a pair of adjacent connection pads in the second direction.

[0010] A display module according to one embodiment of the present disclosure may include a substrate, a plurality of connection pads arranged in a grid shape on the substrate, a plurality of micro LEDs each disposed to overlap on a pair of connection pads adjacent in a first direction, and a plurality of connection members disposed between the micro LEDs and the connection pads, respectively, for electrically connecting the substrate and the micro LEDs. The connection members may be composed of an anisotropic conductive material that is disposed to span the plurality of connection pads and has insulating properties with respect to the first direction and a second direction perpendicular to the first direction.

[0011] However, the problems to be solved in this disclosure are not limited to those mentioned above, and may be determined in various ways without departing from the spirit and scope of this disclosure.

[0012] FIG. 1 is a block diagram of an electronic device in a network environment according to various embodiments.

[0013] FIG. 2 is a plan view of a display module according to one embodiment of the present disclosure.

[0014] Figure 3 is an enlarged view of part A of Figure 2.

[0015] FIG. 4 is a cross-sectional view of a display module cut along line A-A' of FIG. 3 according to one embodiment of the present disclosure.

[0016] FIG. 5 is a cross-sectional view showing the connection member before and after pressurization according to one embodiment of the present disclosure.

[0017] FIG. 6 is a plan view showing the connection member before and after pressurization according to one embodiment of the present disclosure.

[0018] FIG. 7 is a plan view of a portion of a substrate showing a state before a micro LED is mounted, according to one embodiment of the present disclosure.

[0019] FIG. 8a is a cross-sectional view taken along line B-B' of FIG. 7 according to one embodiment of the present disclosure.

[0020] FIG. 8b is a vertical cross-sectional view of a portion of a substrate showing a state before a micro LED is mounted, according to one embodiment of the present disclosure.

[0021] FIG. 8c is a vertical cross-sectional view of a portion of a substrate showing a state before a micro LED according to one embodiment of the present disclosure is mounted.

[0022] FIG. 9 is a plan view of a portion of a substrate showing a state before a micro LED is mounted, according to one embodiment of the present disclosure.

[0023] FIG. 10 is a cross-sectional view taken along line C-C' of FIG. 9 according to one embodiment of the present disclosure.

[0024] FIG. 11 is a manufacturing process diagram of a display module according to one embodiment of the present disclosure.

[0025] FIG. 12 is a schematic diagram showing a manufacturing process of a display module according to one embodiment of the present disclosure.

[0026] FIG. 13 is a schematic diagram showing a masking process of a display module according to one embodiment of the present disclosure.

[0027] FIG. 14 is an enlarged view of a portion of a plan view of a display module according to one embodiment of the present disclosure.

[0028] FIG. 15 is a cross-sectional view taken along line D-D' of FIG. 14 according to one embodiment of the present disclosure.

[0029] FIG. 16 is an enlarged view of a portion of a plan view of a display module according to one embodiment of the present disclosure.

[0030] FIG. 17 is a cross-sectional view taken along line E-E' of FIG. 16 according to one embodiment of the present disclosure.

[0031] In the following description, the attached drawings are referenced, and specific examples of implementation are illustrated within the drawings. Additionally, other examples may be used and structural modifications may be made without departing from the scope of the various examples.

[0032] The terms used in this document are used merely to describe specific embodiments and are not intended to limit the technical features of this document. For example, a component expressed in the singular form should be understood as a concept including singular or plural components unless the context clearly indicates only the singular form.

[0033] In this document, each of the following phrases may include any one of the items listed with the corresponding phrase, or any combination thereof: "A or B," "at least one of A and B," "at least one of A or B," "A, B or C," "at least one of A, B and C," and "at least one of A, B, or C." The term "and / or" as used in this document should be understood to encompass any possible combination of one or more of the multiple items listed with the corresponding term. Terms such as "first," "second," "first," or "second" as used in this document may be used simply to distinguish a component from another component and do not limit the components in any other aspect (e.g., importance or order).

[0034] Where it is stated that any (e.g., 1st) component is “coupled,” “connected,” “linked,” “coupled,” “supported,” “connected,” or “contacted” with or without the terms “functionally” or “communicationly,” it includes not only cases where the component is directly coupled, connected, linked, coupled, supported, or contacted with the other component, but also cases where it is indirectly coupled, connected, linked, coupled, supported, or contacted through a third component.

[0035] Terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this Document, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. When a component is said to be located "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where another component exists between the two components.

[0036] As used in this document, the expression "configured to..." may be appropriately substituted depending on the context, for example, with "suitable for...", "capable of...", "designed to...", "modified to...", "made to...", or "capable of...". The term "configured to..." does not necessarily mean only that it is "specially designed" in hardware. Instead, in some situations, the expression "device configured to..." may mean that the device is "capable of..." in conjunction with other devices or components. For example, the phrase "device configured (or set) to perform A, B, and C" may refer to a device dedicated to performing the said operation, or it may refer to a general-purpose device capable of performing various operations, including the said operation.

[0037] Terms such as "upper side," "lower side," and "front-rear direction" used in this document are defined based on the drawings, and the shape and location of each component are not limited by these terms.

[0038] The description in this document is centered on specific embodiments, but this document is not limited to such specific embodiments and should be understood to encompass all various modifications, equivalents, and / or substitutions of the various embodiments described in this document. In relation to the description of the drawings, similar reference numerals may be used for similar or related components.

[0039] FIG. 1 is a block diagram of an electronic device (101) in a network environment (100) according to various embodiments.

[0040] Referring to FIG. 1, in a network environment (100), an electronic device (101) may communicate with an electronic device (102) through a first network (198) (e.g., a short-range wireless communication network) or with at least one of an electronic device (104) or a server (108) through a second network (199) (e.g., a long-range wireless communication network). According to one embodiment, the electronic device (101) may communicate with the electronic device (104) through a server (108). According to one embodiment, the electronic device (101) may include a processor (120), memory (130), input module (150), sound output module (155), display module (160), audio module (170), sensor module (176), interface (177), connection terminal (178), haptic module (179), camera module (180), power management module (188), battery (189), communication module (190), subscriber identification module (196), or antenna module (197). In some embodiments, at least one of these components (e.g., connection terminal (178)) may be omitted from the electronic device (101), or one or more other components may be added. In some embodiments, some of these components (e.g., sensor module (176), camera module (180), or antenna module (197)) may be integrated into a single component (e.g., display module (160)).

[0041] The processor (120) can control at least one other component (e.g., hardware or software component) of the electronic device (101) connected to the processor (120) by executing software (e.g., program (140)), for example, and can perform various data processing or operations. According to one embodiment, as at least part of the data processing or operations, the processor (120) can store commands or data received from other components (e.g., sensor module (176) or communication module (190)) in volatile memory (132), process the commands or data stored in volatile memory (132), and store the resulting data in non-volatile memory (134). According to one embodiment, the processor (120) may include a main processor (121) (e.g., central processing unit or application processor) or an auxiliary processor (123) that can operate independently or together with it (e.g., graphics processing unit, neural processing unit (NPU), image signal processor, sensor hub processor, or communication processor). For example, if the electronic device (101) includes a main processor (121) and an auxiliary processor (123), the auxiliary processor (123) may be configured to use less power than the main processor (121) or to be specialized for a designated function. The auxiliary processor (123) may be implemented separately from the main processor (121) or as part thereof.

[0042] The auxiliary processor (123) may control at least some of the functions or states associated with at least one component of the electronic device (101) (e.g., display module (160), sensor module (176), or communication module (190)) on behalf of the main processor (121) while the main processor (121) is in an inactive (e.g., sleep) state, or together with the main processor (121) while the main processor (121) is in an active (e.g., application execution) state. According to one embodiment, the auxiliary processor (123) (e.g., image signal processor or communication processor) may be implemented as part of another functionally related component (e.g., camera module (180) or communication module (190)). According to one embodiment, the auxiliary processor (123) (e.g., neural network processing unit) may include a hardware structure specialized for processing an artificial intelligence model. The artificial intelligence model may be generated through machine learning. Such learning may be performed, for example, on the electronic device (101) itself where the artificial intelligence model is executed, or through a separate server (e.g., server (108)). The learning algorithm may include, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning, but is not limited to the examples described above. The artificial intelligence model may include a plurality of artificial neural network layers.An artificial neural network may be a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), a bidirectional recurrent deep neural network (BRDNN), a deep Q-network, or a combination of two or more of the above, but is not limited to the examples described above. In addition to the hardware structure, the artificial intelligence model may include a software structure, either additionally or substantially.

[0043] The memory (130) can store various data used by at least one component of the electronic device (101) (e.g., processor (120) or sensor module (176)). The data may include, for example, input data or output data for software (e.g., program (140)) and related commands. The memory (130) may include volatile memory (132) or non-volatile memory (134).

[0044] The program (140) may be stored as software in memory (130) and may include, for example, an operating system (142), middleware (144), or an application (146).

[0045] The input module (150) can receive commands or data to be used for a component of the electronic device (101) (e.g., processor (120)) from outside the electronic device (101) (e.g., user). The input module (150) may include, for example, a microphone, a mouse, a keyboard, a key (e.g., a button), or a digital pen (e.g., a stylus pen).

[0046] The sound output module (155) can output a sound signal to the outside of the electronic device (101). The sound output module (155) may include, for example, a speaker or a receiver. The speaker may be used for general purposes, such as multimedia playback or recording playback. The receiver may be used to receive incoming calls. According to one embodiment, the receiver may be implemented separately from the speaker or as part thereof.

[0047] The display module (160) can visually provide information to an external (e.g., user) of the electronic device (101). The display module (160) may include, for example, a display, a holographic device, or a projector and a control circuit for controlling said device. According to one embodiment, the display module (160) may include a touch sensor configured to detect a touch, or a pressure sensor configured to measure the intensity of the force generated by the touch.

[0048] The audio module (170) can convert sound into an electrical signal or, conversely, convert an electrical signal into sound. According to one embodiment, the audio module (170) can acquire sound through the input module (150) or output sound through the sound output module (155) or an external electronic device (e.g., electronic device (102)) (e.g., speaker or headphones) connected directly or wirelessly to the electronic device (101).

[0049] The sensor module (176) can detect the operating state of the electronic device (101) (e.g., power or temperature) or the external environmental state (e.g., user state) and generate an electrical signal or data value corresponding to the detected state. According to one embodiment, the sensor module (176) may include, for example, a gesture sensor, a gyroscope sensor, a barometric pressure sensor, a magnetic sensor, an accelerometer sensor, a grip sensor, a proximity sensor, a color sensor, an IR (infrared) sensor, a biosensor, a temperature sensor, a humidity sensor, or an illuminance sensor.

[0050] The interface (177) may support one or more specified protocols that can be used for the electronic device (101) to be connected directly or wirelessly to an external electronic device (e.g., electronic device (102)). According to one embodiment, the interface (177) may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, or an audio interface.

[0051] The connection terminal (178) may include a connector through which the electronic device (101) can be physically connected to an external electronic device (e.g., electronic device (102)). According to one embodiment, the connection terminal (178) may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphone connector).

[0052] The haptic module (179) can convert an electrical signal into a mechanical stimulus (e.g., vibration or movement) or an electrical stimulus that can be perceived by the user through tactile or kinesthetic senses. According to one embodiment, the haptic module (179) may include, for example, a motor, a piezoelectric element, or an electric stimulation device.

[0053] The camera module (180) can capture still images and video. According to one embodiment, the camera module (180) may include one or more lenses, image sensors, image signal processors, or flashes.

[0054] The power management module (188) can manage power supplied to the electronic device (101). According to one embodiment, the power management module (188) can be implemented, for example, as at least part of a power management integrated circuit (PMIC).

[0055] The battery (189) can supply power to at least one component of the electronic device (101). According to one embodiment, the battery (189) may include, for example, a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell.

[0056] The communication module (190) can support the establishment of a direct (e.g., wired) communication channel or a wireless communication channel between an electronic device (101) and an external electronic device (e.g., electronic device (102), electronic device (104), or server (108)), and the performance of communication through the established communication channel. The communication module (190) may include one or more communication processors that operate independently of the processor (120) (e.g., application processor) and support direct (e.g., wired) communication or wireless communication. According to one embodiment, the communication module (190) may include a wireless communication module (192) (e.g., cellular communication module, short-range wireless communication module, or GNSS (global navigation satellite system) communication module) or a wired communication module (194) (e.g., LAN (local area network) communication module, or power line communication module). The corresponding communication module among these communication modules can communicate with an external electronic device (104) through a first network (198) (e.g., a short-range communication network such as Bluetooth, WiFi (wireless fidelity) direct, or IrDA (infrared data association)) or a second network (199) (e.g., a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or WAN)). These various types of communication modules may be integrated into a single component (e.g., a single chip) or implemented as multiple separate components (e.g., multiple chips). The wireless communication module (192) can identify or authenticate the electronic device (101) within a communication network such as the first network (198) or the second network (199) using subscriber information (e.g., International Mobile Subscriber Identifier (IMSI)) stored in the subscriber identification module (196).

[0057] The wireless communication module (192) can support 5G networks and next-generation communication technologies following 4G networks, for example, new radio access technology. NR access technology can support high-speed transmission of high-capacity data (enhanced mobile broadband (eMBB)), minimization of terminal power and connection of multiple terminals (massive machine type communications (mMTC)), or high reliability and low latency (ultra-reliable and low-latency communications (URLLC)). The wireless communication module (192) can support a high-frequency band (e.g., mmWave band) to achieve a high data transmission rate, for example. The wireless communication module (192) can support various technologies for securing performance in the high-frequency band, such as beamforming, massive MIMO (multiple-input and multiple-output), full-dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, or large-scale antenna. The wireless communication module (192) can support various requirements specified in the electronic device (101), external electronic device (e.g., electronic device (104)), or network system (e.g., second network (199)). According to one embodiment, the wireless communication module (192) may support a Peak data rate (e.g., 20 Gbps or more) for eMBB realization, loss coverage (e.g., 164 dB or less) for mMTC realization, or U-plane latency (e.g., downlink (DL) and uplink (UL) each 0.5 ms or less, or round trip 1 ms or less) for URLLC realization.

[0058] An antenna module (197) can transmit a signal or power to or from an external source (e.g., an external electronic device). According to one embodiment, the antenna module (197) may include an antenna comprising a radiator made of a conductor or a conductive pattern formed on a substrate (e.g., a PCB). According to one embodiment, the antenna module (197) may include a plurality of antennas (e.g., an array antenna). In this case, at least one antenna suitable for a communication method used in a communication network, such as a first network (198) or a second network (199), may be selected from the plurality of antennas, for example, by a communication module (190). A signal or power may be transmitted or received between the communication module (190) and an external electronic device through the selected at least one antenna. According to some embodiments, in addition to the radiator, other components (e.g., a radio frequency integrated circuit (RFIC)) may be additionally formed as part of the antenna module (197).

[0059] According to various embodiments, the antenna module (197) may form a mmWave antenna module. According to one embodiment, the mmWave antenna module may include a printed circuit board, an RFIC disposed on or adjacent to a first surface (e.g., bottom surface) of the printed circuit board and capable of supporting a specified high frequency band (e.g., mmWave band), and a plurality of antennas (e.g., array antennas) disposed on or adjacent to a second surface (e.g., top surface or side surface) of the printed circuit board and capable of transmitting or receiving a signal of the specified high frequency band.

[0060] At least some of the above components can be connected to each other via a communication method between peripheral devices (e.g., bus, GPIO (general purpose input and output), SPI (serial peripheral interface), or MIPI (mobile industry processor interface)) and exchange signals (e.g., commands or data) with each other.

[0061] According to one embodiment, commands or data may be transmitted or received between the electronic device (101) and an external electronic device (104) through a server (108) connected to a second network (199). Each of the external electronic devices (102, or 104) may be the same or a different type of device as the electronic device (101). According to one embodiment, all or part of the operations performed on the electronic device (101) may be performed on one or more of the external electronic devices (102, 104, or 108). For example, if the electronic device (101) needs to perform a function or service automatically or in response to a request from a user or another device, the electronic device (101) may request one or more external electronic devices to perform at least part of the function or service instead of performing the function or service itself or additionally. One or more external electronic devices that receive the above request may execute at least part of the requested function or service, or additional function or service related to the request, and transmit the result of the execution to the electronic device (101). The electronic device (101) may provide the result as is or additionally processed as at least part of the response to the request. For this purpose, for example, cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used. The electronic device (101) may provide ultra-low latency services using, for example, distributed computing or mobile edge computing. In another embodiment, the external electronic device (104) may include an Internet of Things (IoT) device. The server (108) may be an intelligent server using machine learning and / or neural networks. According to one embodiment, the external electronic device (104) or the server (108) may be included within a second network (199).The electronic device (101) can be applied to intelligent services (e.g., smart home, smart city, smart car, or healthcare) based on 5G communication technology and IoT-related technology.

[0062] FIG. 2 is a plan view of a display module (200) according to one embodiment of the present disclosure.

[0063] Figure 3 is an enlarged view of part A of Figure 2.

[0064] The embodiments of FIGS. 2 and 3 can be optionally combined with the embodiment of FIG. 1.

[0065] According to one embodiment, a display module (200) (e.g., the display module (160) of FIG. 1) may include a plurality of pixels (200P) arranged in a matrix (or grid) form on a substrate (210). Each pixel (200P) may include a plurality of micro LEDs (230) as subpixels. For example, one micro LED (230) may correspond to one subpixel. A pixel (200P) may refer to a minimum unit of a pixel that represents various colors. Each pixel (200P) may be electrically shorted to one another on the substrate (210) and may operate individually or independently.

[0066] Referring to FIGS. 2 and FIGS. 3, a display module (200) according to one embodiment may include a substrate (210), a plurality of connection pads (220), a plurality of micro LEDs (230), and a plurality of connection members (240).

[0067] According to one embodiment, the substrate (210) may include a glass substrate (not shown), a TFT layer formed on an upper surface (e.g., one surface facing the +z-axis) of the glass substrate and having a Thin Film Transistor (TFT) circuit formed thereon, and a driving circuit formed on a lower surface (e.g., one surface facing the -z-axis) of the glass substrate to drive the TFT circuit. The glass substrate may be formed in a quadrangle type. For example, the glass substrate may be formed in a rectangle or a square. The substrate (210) may correspond to a TFT substrate in which a TFT layer (or backplane) is laminated on the glass substrate.

[0068] According to one embodiment, the substrate (210) is not limited to a specific structure or type. For example, the substrate (210) can be implemented as an Oxide TFT, Si TFT (poly silicon, a-silicon), Organic TFT, Graphene TFT, etc., in addition to an LTPS (Low Temperature Polycystalline Silicon) TFT. For example, the substrate (210) may be used to create and apply only a P-type (or N-type) MOSFET (Metal oxide semiconductor field effect transistor) in a Si wafer CMOS (Complementary metal oxide semiconductor) process.

[0069] According to one embodiment, the substrate (210) may include a plurality of first regions (210a) having a plurality of pixels (200P) and a second region (210b) not having a plurality of pixels (200P). The plurality of second regions (210b) may be arranged alternately with the plurality of first regions (210a) based on a direction (e.g., a second direction) parallel to a short side (e.g., a side parallel to the ±y-axis) of the substrate (210). For example, the plurality of second regions (210b) may be arranged between the plurality of first regions (210a). A plurality of pads (220), a plurality of micro LEDs (230), and a plurality of connecting members (240) may be located in the first region (210a).

[0070] According to one embodiment, a plurality of connection pads (220) may be provided on a substrate (210). For example, the plurality of connection pads (220) may be arranged in a matrix (or grid) form on the substrate (210). The connection pads (220) may extend in a direction parallel to the short side (e.g., the side parallel to the ±y-axis) of the substrate (210) (e.g., a second direction). Among the plurality of connection pads (220), a single micro LED (230) may be disposed on a pair of connection pads (220) spaced apart along a direction parallel to the long side (e.g., the side parallel to the ±x-axis) of the substrate (210) (e.g., a first direction). For example, the micro LED (230) may be disposed so as to overlap a pair of connection pads (220) adjacent in the first direction.

[0071] According to one embodiment, the connection pad (220) may be composed of a conductive material. The connection pad (220) may be electrically connected to a thin-film transistor provided inside the substrate (210). The connection pad (220) may be electrically connected to a micro LED (230) through a connection member (240). The connection pad (220) may transmit an electrical signal from the thin-film transistor to the micro LED (230) mounted on the substrate (210).

[0072] According to one embodiment, the micro LED (230) may be composed of an inorganic light-emitting material having a size of 100 μm or less. The micro LED (230) may be a semiconductor chip capable of emitting light on its own when supplied with power. Both the organic light-emitting diode (OLED) and the inorganic light-emitting diode (micro LED (230) have good energy efficiency, but the micro LED (230) has a longer lifespan, higher brightness, and higher luminous efficiency than the OLED. A display module (200) equipped with a plurality of micro LEDs (230) can provide better contrast, faster response time, and higher energy efficiency compared to a liquid crystal display (LCD) panel that requires a backlight.

[0073] According to one embodiment, a plurality of micro LEDs (230) included in a single pixel (200P) may emit different colors. For example, the plurality of micro LEDs (230) may include a red (R) micro LED (230a) that emits red light, a green (G) micro LED (230b) that emits green light, and a blue (B) micro LED (230c) that emits blue light.

[0074] In the present disclosure, a plurality of subpixels are exemplified as being composed of three micro LEDs (230a, 230b, 230c) corresponding to R / G / B (red / green / blue) colors, but are not limited thereto. For example, the plurality of subpixels may be composed of two micro LEDs of R / B (red / blue), R / G (red / green), or G / B (green / blue), or three micro LEDs of R / B / W (red / blue / white), or four micro LEDs of R / G / B / W (red / green / blue / white), R / G / G / W (red / green / green / white), or R / G / B / Y (red / green / blue / yellow), or five micro LEDs of R / G / B / Y / C (red / green / blue / yellow / cyan). In this case, the number of pixel circuits corresponds to the number of subpixels.

[0075] According to one embodiment, the connection member (240) may be configured to electrically and / or physically connect the connection pad (220) of the substrate (210) and the micro LED (230). The connection member (240) may be provided on the connection pad (220). The connection member (240) may be positioned between the connection pad (220) of the substrate (210) and the micro LED (230). The connection member (240) may overlap at least a portion with the micro LED (230) when the display module (200) is viewed from above (e.g., in the +z-axis direction). The connection member (240) may extend in a direction parallel to the long side (e.g., the side parallel to the ±y-axis) of the connection pad (220) (e.g., a second direction). For example, the connection member (240) may extend in a second direction on a first region (210a) of the substrate (210). The connecting member (240) extends along a second direction on the connecting pad (220), but may be spaced apart in a straight line from another connecting member (240) provided on the connecting pad (220) adjacent to the second direction. For example, a plurality of connecting pads (220) may be shorted from each other based on the second region (210b) of the substrate (210). The specific configuration and manufacturing process of the connecting member (240) will be described below with reference to FIG. 4 and below.

[0076] FIG. 4 is a cross-sectional view of a display module (200) cut along line A-A' of FIG. 3 according to one embodiment of the present disclosure.

[0077] FIG. 5 is a cross-sectional view showing the connection member (240) before and after pressure application according to one embodiment of the present disclosure.

[0078] FIG. 6 is a plan view showing the connection member (240) before and after being pressed, according to one embodiment of the present disclosure.

[0079] The embodiments of FIGS. 4 to 6 can be optionally combined with the embodiments of FIGS. 1 to 3.

[0080] Referring to FIGS. 4 to 6, a display module (200) according to one embodiment may include a substrate (210), a plurality of connection pads (220), a plurality of micro LEDs (230), a plurality of connection members (240), and an insulating layer (250).

[0081] The configurations of FIGS. 4 to 6 may be all or part identical to the configurations of FIGS. 2 and FIG. 3.

[0082] According to one embodiment, a plurality of connection pads (220) may include a first connection pad (220a) facing a first electrode pad (232a) of a micro LED (230) and a second connection pad (220b) facing a second electrode pad (232b) of a micro LED (230). For example, two connection pads (220a, 220b) adjacent to each other form a pair, and each connection pad (220a, 220b) may be electrically connected to one micro LED (230) through a connection member (240).

[0083] According to one embodiment, the micro LED (230) may include a chip body (31) and a pair of electrode pads (232) provided on the lower side of the chip body (31). In one embodiment, the pair of electrode pads (232) may include a first electrode pad (e.g., an anode electrode pad) (232a) and a second electrode pad (e.g., a cathode electrode pad) (232b) for driving the chip body (31). The micro LED (230) may have a flip-chip structure in which the first and second electrode pads (232a, 232b) are formed on the same side (e.g., the lower side) and the light-emitting surface is formed on the opposite side of the electrode pads (232a, 232b) (e.g., the upper side).

[0084] According to one embodiment, the connecting member (240) may be composed of a material (e.g., conductive paste) containing conductive particles within a non-conductive material. For example, the connecting member (240) may be composed of a polymer material (241) containing nano or micro-sized conductive particles (242). The conductive particles (242) may include, for example, Ag, Ni, Au, Al, or Carbon. The conductive particles (242) may have the form of, for example, spheres, flakes, or dendrites. The conductive particles (242) may be arranged in alignment or randomly placed within the non-conductive material (e.g., polymer material (241)).

[0085] Referring to FIG. 5 (a) and (b), the connecting member (240) is pressed (or compressed) by a micro LED (230) mounted on a substrate (210) during the manufacturing process of the display module (200), so that conductive particles (242) come into contact with each other or are densely packed, and the connecting member (240) and the electrode pad (232) can be electrically connected by the contact or density between the conductive particles (242).

[0086] Referring to FIG. 6 (a) and (b), the connecting member (240) is printed on the substrate (210) in the form of a line by the EHD printing process, thereby making line or surface contact with the electrode pad (232) of the micro LED (230). During the manufacturing process of the display module (200), the contact area (or connection area) of the connecting member (240) is gradually expanded according to the degree of pressure (or compression) applied by the micro LED (230) mounted on the substrate (210), and the resistance on the surface is reduced due to the expanded contact area, thereby reducing heat generation. In addition, the possibility of connecting the micro LED (230) to the substrate (210) is increased due to the expanded contact area, so the reliability of securing LED yield can be increased.

[0087] According to one embodiment, the cross-section of the connecting member (240) may have a hemispherical shape overall.

[0088] According to one embodiment, the connection member (240) may be formed by an Electrohydrodynamic (EHD) printing process. For example, the connection member (240) may be formed by applying (or printing) a conductive paste (or conductive ink) in a straight line along the long side (e.g., the side parallel to the ±y-axis direction) of a plurality of connection pads (220) provided on a substrate (210). Accordingly, the connection member (240) may have a thin line width corresponding to the size (e.g., width) of the micro LED (230). The process of forming the connection member (240) by the EHD printing process will be described later with reference to FIG. 13 and below.

[0089] According to one embodiment, the width (w) of the connecting member (240) may be designed to be about 10 μm. The thickness (t) of the connecting member (240) may be designed to be at least 1 / 15 times the width (w) of the connecting member (240). For example, the ratio (t / w) of the thickness (t) of the connecting member (240) to the width (w) of the connecting member (240) may be at least 1 / 15.

[0090] According to one embodiment, the adhesive layer (250) may refer to a layer laminated on the substrate (210) to fix a plurality of micro LEDs (230) on the substrate (210). The adhesive layer (250) may be disposed between a plurality of connection pads (220) and a plurality of electrode pads (232) formed on the substrate (210). For example, in the manufacturing process of the display module (200), the adhesive layer (250) is cured while the micro LED (230) is pressed against the connection pad (220), and after curing, due to the residual stress of the adhesive layer (250) itself, the micro LED (230) can be fixed to the connection pad (220) while maintaining the pressed state of the micro LED (230) against the connection pad (220). Accordingly, the adhesive layer (250) can stably maintain the connection state between the micro LED (230) and a plurality of connection members (240) provided on the plurality of connection pads (220). The adhesive layer (250) can cover the upper surface of the substrate (210) excluding the plurality of micro LEDs (230).

[0091] According to one embodiment, the adhesive layer (250) may include a non-conductive material. For example, the adhesive layer (250) may include a Non Conductive Film (NCF). The adhesive layer (250) may be placed between a plurality of connection pads (220) and a plurality of electrode pads (232) to prevent an electrical short circuit. The adhesive layer (250) may also be named an insulating layer (250).

[0092] FIG. 7 is a plan view of a portion of a substrate (210) showing a state before a micro LED (230) is mounted, according to one embodiment of the present disclosure.

[0093] FIG. 8a is a cross-sectional view taken along line B-B' of FIG. 7 according to one embodiment of the present disclosure.

[0094] FIG. 8b is a vertical cross-sectional view of a portion of a substrate (210) showing a state before a micro LED (230) is mounted, according to one embodiment of the present disclosure.

[0095] FIG. 8c is a vertical cross-sectional view of a portion of a substrate (210) showing a state before a micro LED (230) according to one embodiment of the present disclosure is mounted.

[0096] The embodiments of FIGS. 7 to 8c can be optionally combined with the embodiments of FIGS. 1 to 6.

[0097] The configurations of FIGS. 7 to 8c may be all or part identical to the configurations of FIGS. 1 to 6.

[0098] Referring to FIGS. 7 and FIGS. 8a, a display module according to one embodiment (e.g., the display module (200) of FIG. 2) may include a substrate (210), a plurality of connection pads (220), a plurality of connection members (240), and a liquid-repellent material (261).

[0099] According to one embodiment, the substrate (210) may include a first region (210a) and a second region (210b) that are alternately arranged. The first region (210a) and the second region (210b) may be alternately arranged along a direction (e.g., a second direction) parallel to the short side (e.g., ±y-axis direction) of the substrate (210). The first region (210a) and the second region (210b) may extend along a direction (e.g., a first direction) parallel to the long side (e.g., ±x-axis direction) of the substrate (210).

[0100] According to one embodiment, the first region (210a) may be an area where a pixel (e.g., the pixel (200P) of FIG. 2) is placed. For example, a plurality of connection pads (220), a plurality of connection members (240), and a plurality of micro LEDs (e.g., the micro LED (230) of FIG. 2) may be placed in the first region (210a). The first region (210a) may be named a pixel region.

[0101] According to one embodiment, the second region (210b) may be an area where a material (e.g., a masking material or a liquid-repellent material) is applied to disconnect (or segment) the straight-line connecting member (e.g., the connecting member (240) of FIG. 15) in a predetermined section (e.g., the first region (210a)) to prevent short circuits in the connecting member (e.g., the connecting member (240) of FIG. 15) connected in a straight line by an EHD printing process. The second region (210b) may be named a short region, a masking region, or an insulating region. The masking process for disconnecting (or segmenting) the straight-line connecting member will be described later with reference to FIG. 13 and below.

[0102] According to one embodiment, a plurality of connection pads (220) and / or connection members (240) adjacent in the short side direction (e.g., second direction) of the substrate (210) may be spaced apart from each other with respect to the second region (220b).

[0103] According to one embodiment, a liquid-repellent material (261) may be provided in a second region (210b) of the substrate (210). The liquid-repellent material (261) may be applied in a horizontal direction (e.g., ±y-axis direction) along the second region (210b) of the substrate (210) prior to the EHD printing process of the connection member (240). The liquid-repellent material (261) is a material having lyophobic properties and may have the property of repelling the conductive paste (or conductive ink) constituting the connection member (240). For example, the conductive paste of the connection member (240) printed on the substrate (210) may not aggregate in the second region (210b) due to the liquid-repellent material (261), and may form a body portion (243) and an end portion (244) in contact with the liquid-repellent material (261) on the connection pad (220) only in the first region (210a). Accordingly, the connection members (240) printed in a straight line by the EHD process can be disconnected from each other on each connection pad (220). The liquid-repellent material (261) may be composed of, for example, a non-polar fluorine-based or silicon-based material. The liquid-repellent material (261) may be named a masking member.

[0104] Referring to FIG. 8b, a display module according to one embodiment (e.g., the display module (200) of FIG. 2) may include a substrate (210), a plurality of connection pads (220), a plurality of connection members (240), and a disconnection structure (262).

[0105] According to one embodiment, the disconnect structure (262) may be provided in a second region (210b) of the substrate (210). The disconnect structure (262) may be formed by extending horizontally (e.g., ±y-axis direction) along the second region (210b) of the substrate (210) prior to the EHD printing process of the connecting member (240). The disconnect structure (262) may be a structure made of a solid material. The disconnect structure (262) may have a triangular cross-section. The disconnect structure (262) may be a structure in which one side facing the connecting member (240) is an inclined surface (262a). The conductive paste of the connecting member (240) printed on the substrate (210) can form an end (244) in contact with the body portion (243) and the liquid-repellent material (261) on the connecting pad (220) only in the first region (210a) along the inclined surface (262a) of the disconnecting structure (262). Accordingly, the connecting members (240) printed in a straight line by the EHD process can be disconnected from each other on each connecting pad (220). The disconnecting structure (262) may be named a masking member.

[0106] Referring to FIG. 8c, a display module according to one embodiment (e.g., the display module (200) of FIG. 2) may include a substrate (210), a plurality of connection pads (220), and a plurality of connection members (240).

[0107] Unlike the embodiments of FIG. 8a and FIG. 8b described above, the embodiment of FIG. 8c may not include a separate masking member (e.g., liquid-repellent material (261) or a disconnecting structure (262)). According to one embodiment, in an EHD printing process, by controlling the physical properties of the conductive paste of the connecting member (240) printed on the substrate (210), the conductive pastes of the connecting member (240) printed in a straight line without a separate masking member can be disconnected by section (e.g., a first region (210a)). For example, by controlling the surface tension of the conductive paste of the connecting member (240), the end portion (244) in contact with the body portion (243) and the liquid-repellent material (261) on the connecting pad (220) can be formed only in the first region (210a) by the cohesive force of the conductive paste. Accordingly, the manufacturing process of the display module (200) can be simplified as the aforementioned liquid removal treatment, gradient structure, or masking process described later is omitted.

[0108] FIG. 9 is a plan view of a portion of a substrate (210) showing a state before a micro LED (230) is mounted, according to one embodiment of the present disclosure.

[0109] FIG. 10 is a cross-sectional view taken along line C-C' of FIG. 9 according to one embodiment of the present disclosure.

[0110] The embodiments of FIGS. 9 and 10 can be optionally combined with the embodiments of FIGS. 1 to 8.

[0111] The configurations of FIGS. 9 and 10 may be all or partly identical to the configurations of FIGS. 1 to 8.

[0112] Referring to FIGS. 9 and 10, a display module according to one embodiment (e.g., the display module (200) of FIG. 2) may include a substrate (210), a plurality of connection pads (220), a plurality of connection members (240-1), and a porous material (263).

[0113] According to one embodiment, a porous material (263) may be provided in a second region (210b) of a substrate (210). The porous material (263) may be applied in a horizontal direction (e.g., ±y-axis direction) along the second region (210b) of the substrate (210) prior to the EHD printing process of the connecting member (240-1). The porous material (263) is a material having insulating properties and may include a porous structure (263a) (e.g., hole, groove). The conductive paste of the connection member (240-1) printed on the substrate (210) is contained in the porous structure (263a) of the porous material (263) in the second region (210b), and can form an end portion (244) in contact with the body portion (243) and the liquid-repellent material (261) on the connection pad (220) only in the first region (210a). Accordingly, the connection members (240-1) printed in a straight line by the EHD process can be disconnected from each other on each connection pad (220). In this case, the manufacturing process of the display module (200) can be simplified as the masking process, etc., is omitted.

[0114] The porous material (263) may include, for example, porous polyimide (PPI), porous polytetrafluoroethylene (Porous PTFE), or porous polyurethane (Porous PU). The porous material (263) may be named a masking member.

[0115] FIG. 11 is a manufacturing process diagram of a display module (200) according to one embodiment of the present disclosure.

[0116] FIG. 12 is a schematic diagram showing a manufacturing process of a display module (200) according to one embodiment of the present disclosure.

[0117] FIG. 13 is a schematic diagram showing a masking process of a display module (200) according to one embodiment of the present disclosure.

[0118] The embodiments of FIGS. 11 to 13 can be optionally combined with the embodiments of FIGS. 1 to 11.

[0119] Referring to FIGS. 11 to 13, according to one embodiment, in process 1110, a masking member (264) can be extended horizontally (e.g., in the ±x-axis direction) in a region (e.g., a second region (210b)) located between a plurality of connection pads (220) provided on the upper surface of a substrate (210). Here, the masking member (264) may be a removable masking tape.

[0120] According to one embodiment, in process 1120, a connecting member (or conductive paste) (240) can be printed in a long line on a connecting pad (220) on a substrate (210) in the direction of the short side (or vertical direction) (e.g., ±y-axis direction) of the substrate (210) using EHD printing. Accordingly, a straight connecting member (240) passing over each connecting pad (220) can be formed.

[0121] According to one embodiment, in process 1130, a masking member (264) attached to a substrate (210) can be removed. Accordingly, a portion of a connecting member (240) printed on the masking member (264) can be removed together with the masking member (264), and the connecting member (240) is located only on the corresponding connecting pad (220), and the connecting member (240) can be segmented from one another only in one area (e.g., a first area (210a)). That is, the connecting member (240) can be provided only in the first area (210a) of the substrate (210) by the masking process.

[0122] According to one embodiment, in process 1140, a conductive paste printed on a substrate (210) can be cured to form a connecting member (240).

[0123] According to one embodiment, in process 1150, an insulating layer (250) for transferring and fixing a micro LED (230) can be laminated on a substrate (210).

[0124] According to one embodiment, in process 1160, a micro LED (230) can be positioned on a corresponding pair of connection pads (220a, 220b). Afterward, by pressing the micro LED (230), the substrate (210) and the micro LED (230) can be electrically coupled through a connection member (240). Additionally, a protective layer (260) for protecting the display module (200) may be provided on the insulating layer (250) and the micro LED (230). The protective layer (260) may be, for example, an ETFE (Ethylene Tetrafluoroethylene) film.

[0125] FIG. 14 is an enlarged view of a portion of the plan view of a display module (300) according to one embodiment of the present disclosure.

[0126] FIG. 15 is a cross-sectional view taken along line D-D' of FIG. 14 according to one embodiment of the present disclosure.

[0127] FIG. 16 is an enlarged view of a portion of the plan view of a display module (300) according to one embodiment of the present disclosure.

[0128] FIG. 17 is a cross-sectional view taken along line E-E' of FIG. 16 according to one embodiment of the present disclosure.

[0129] The embodiments of FIGS. 14 to 17 can be optionally combined with the embodiments of FIGS. 1 to 13.

[0130] According to one embodiment, a display module (300) (e.g., the display module (160) of FIG. 1, the display module (200) of FIG. 2) may include a plurality of pixels (300P) arranged in a matrix (or grid) form on a substrate (310). Each pixel (300P) may include a plurality of micro LEDs (330a, 330b, 330c) as a subpixel. The configuration of the display module (300) of FIG. 14 to 17 may be all or partly the same as the configuration of the display modules (160, 200) of FIG. 1 to 13.

[0131] Referring to FIGS. 14 to 17, a display module (300) according to one embodiment (e.g., the display module (160) of FIG. 1 or the display module (200) of FIG. 2) may include a substrate (310), a plurality of connection pads (320), a plurality of micro LEDs (330), a plurality of connection members (340, 340-1), and an insulating layer (not shown) (e.g., the insulating layer (250) of FIG. 4).

[0132] According to one embodiment, the configuration of the substrate (310) of FIGS. 14 to 17 may be all or part identical to the configuration of the substrate (210) of FIGS. 2 and 3. The configuration of the plurality of connection pads (320) of FIGS. 14 to 17 may be all or part identical to the configuration of the plurality of connection pads (220) of FIG. 3. The configuration of the plurality of micro LEDs (330) of FIGS. 14 to 17 may be all or part identical to the configuration of the plurality of micro LEDs (230) of FIG. 3. The configuration of the plurality of connection members (340, 340-1) of FIGS. 14 to 17 may be all or part identical to the configuration of the plurality of connection members (240) of FIG. 3.

[0133] According to one embodiment, a plurality of connection pads (320) may be arranged to form a group in each of a plurality of first regions (310a) of the substrate (310). For example, the plurality of connection pads (320) may include a plurality of connection pad groups (320-1, 320-2) spaced apart from each other with a plurality of second regions (310b) of the substrate (310) in between.

[0134] According to one embodiment, the connecting member (340) may be positioned to partially span a plurality of connecting pads (320). For example, the connecting member (340) may be positioned to span each connecting pad group (320-1, 320-2). For example, the connecting member (340) may extend in a direction perpendicular to the longitudinal direction (e.g., ±y-axis direction) of the connecting pads (320) belonging to each connecting pad group (320-1, 320-2) (e.g., ±x-axis direction).

[0135] According to one embodiment, the connection member (340) can be printed on the substrate (310) by an EHD printing process. For example, the connection member (340) can be printed by an EHD printing process to cross the connection pads (320) belonging to each connection pad group (320-1, 320-2, 320-3) in a horizontal direction, as shown in FIG. 14 and FIG. 15, in which case the connection member (340) can have a continuous straight line shape (e.g., a horizontal line). For example, the connecting member (340-1) can be printed by an EHD printing process to cross corresponding connecting pads (320a, 320b) in a vertical direction across a plurality of first regions (310a) and second regions (310b) of the substrate (310), as shown in FIGS. 16 and 17, in each connecting pad group (320-1, 320-2, 320-3), and in this case, the connecting member (340-1) can have a continuous straight line shape (e.g., a vertical line).

[0136] According to one embodiment, the connecting member (340, 340-1) may be composed of a material containing conductive particles within a conductive material. For example, the connecting member (340, 340-1) may be composed of a material of an anisotropic polymer (341) containing nano or micro-sized conductive particles (342). The connecting member (340, 340-1) may be an anisotropic conductive material that allows electricity to flow only in one direction (e.g., +z-axis direction). For example, the connecting member (340, 340-1) may be able to conduct electricity as a large amount of contact between the conductive particles (342) is formed by the pressure of the micro LED (330) in the area (or part) in contact with the micro LED (330), and may be unable to conduct electricity in other areas (or parts) as there is little contact between the conductive particles (342). That is, the connecting member (340, 340-1) has anisotropic characteristics having only conductivity in the Z-axis direction and no conductivity in the XY-axis direction. Accordingly, the connecting member (340) printed in a straight line by the EHD process can be electrically disconnected from each other between each connecting pad (320). In this case, the manufacturing process of the display module (300) can be simplified as the aforementioned masking process for electrical disconnection is omitted.

[0137] According to one embodiment, the connecting member may be formed by applying and curing an anisotropic conductive material that conducts electricity in only one direction (e.g., +z-axis direction) over the entire area of ​​the substrate (210), rather than being applied in a specific direction (e.g., horizontal or vertical direction) with respect to the substrate (310) as described above.

[0138] A display module (200) according to one embodiment of the present disclosure may include a substrate (210), a plurality of connection pads (220) arranged in a grid shape on the substrate (210), a plurality of micro LEDs (230) each disposed to overlap on a pair of connection pads (220) adjacent in a first direction, and a plurality of connection members (240, 240-1) each disposed between the micro LEDs (230) and the connection pads (220) and electrically connecting the substrate (210) and the micro LEDs (230). The substrate (210) may include a plurality of first regions (210a) where the plurality of connection pads (220) are provided, and a second region (210b) provided between the plurality of first regions (210a) where the plurality of connection pads (220) are not provided. The above connection member (240, 240-1) may extend over the connection pad (220) along a second direction perpendicular to the first direction in a first region (210a) of the substrate (210).

[0139] According to one embodiment, the connecting member (240, 240-1) may be composed of a polymer material (241) containing conductive particles (242).

[0140] According to one embodiment, the display module (200) may include an insulating layer (250) for covering the upper surface of the substrate (210) excluding the plurality of micro LEDs (230), fixing the plurality of micro LEDs (230) on the plurality of connecting members (240, 240-1), and maintaining the pressure state of the plurality of micro LEDs (230) on the plurality of connecting members (240, 240-1).

[0141] According to one embodiment, the ratio (t / w) of the thickness (t) of the connecting member (240, 240-1) to the width (w) of the connecting member (240, 240-1) may be 1 / 15 or more.

[0142] According to one embodiment, the width (w) of the connecting member (240, 240-1) may be 10 µm or less.

[0143] According to one embodiment, the display module (200) may include a fluorine-based or silicon-based liquid-repellent material (261) extending along the first direction between adjacent connection pads (220) along the second direction on the substrate (210).

[0144] According to one embodiment, the display module (200) may include a plurality of disconnected structures (262) that are respectively disposed between adjacent connection pads (220) along the second direction and extend along the first direction.

[0145] According to one embodiment, the disconnect structure (262) may include an inclined surface (262a) facing an adjacent connection pad (220).

[0146] According to one embodiment, the display module (200) may include a porous material (263) having a porous structure (263a) of insulating properties that extends along the first direction between adjacent connection pads (220) along the second direction on the substrate (210).

[0147] According to one embodiment, the connection member (240, 240-1) may be formed by printing a conductive paste along the second direction on the substrate (210) and the connection pad (220) by an EHD (Electrohydrodynamic) printing process.

[0148] A method for manufacturing a display module (200) according to one embodiment of the present disclosure may include: a process of applying a masking member (264) in a second direction perpendicular to the first direction between adjacent connection pads (220) in a first direction on a substrate (210) having a plurality of connection pads (220) arranged in a grid pattern; a process of printing a conductive paste along the first direction on the substrate (210) and the connection pads (220); a process of removing the masking member (264); a process of curing the remaining conductive paste on the substrate (210) to form a connection member (240); a process of laminating an insulating layer (250) on the substrate (210); and a process of mounting a micro LED (230) on a pair of adjacent connection pads (220) in the second direction.

[0149] According to one embodiment, the connecting member (240) may be composed of a polymer material (241) containing conductive particles (242).

[0150] According to one embodiment, the ratio (t / w) of the thickness (t) of the connecting member (240) to the width (w) of the connecting member (240) may be 1 / 15 or more.

[0151] According to one embodiment, the width (w) of the connecting member (240) may be 10 µm or less.

[0152] According to one embodiment, the printing process may be performed by an EHD (Electrohydrodynamic) printing process.

[0153] A display module (300) according to one embodiment of the present disclosure may include a substrate (310), a plurality of connection pads (320) arranged in a grid shape on the substrate (310), a plurality of micro LEDs (330) each disposed overlappingly on a pair of connection pads (320) adjacent in a first direction, and a plurality of connection members (340, 340-1) each disposed between the micro LEDs (330) and the connection pads (320) and electrically connecting the substrate (310) and the micro LEDs (330). The connection members (340, 340-1) may be composed of an anisotropic conductive material that is disposed to span the plurality of connection pads (320) and has insulation properties with respect to the first direction and a second direction perpendicular to the first direction.

[0154] According to one embodiment, the connecting member (340) may extend over the plurality of connecting pads (320) along the first direction.

[0155] According to one embodiment, the connecting member (340-1) may extend over the plurality of connecting pads (320) along the second direction.

[0156] According to one embodiment, the display module (300) may include an insulating layer for covering the upper surface of the substrate (310) excluding the plurality of micro LEDs (330), fixing the plurality of micro LEDs (230) on the plurality of connecting members (340, 340-1), and maintaining the pressure state of the plurality of micro LEDs (330) on the plurality of connecting members (340, 340-1).

[0157] According to one embodiment, the connection member (340, 340-1) may be formed by printing a conductive paste onto the substrate (310) and a plurality of connection pads (320) by an EHD (Electrohydrodynamic) printing process.

Claims

1. In the display module (200), Substrate (210); A plurality of connection pads (220) arranged in a grid shape on the substrate (210); A plurality of micro LEDs (230), each disposed overlappingly on a pair of adjacent connection pads (220) in a first direction; and It includes a plurality of connection members (240, 240-1) respectively disposed between the micro LED (230) and the connection pad (220) and electrically connecting the substrate (210) and the micro LED (230), and The above substrate (210) is, It includes a plurality of first regions (210a) provided with the plurality of connection pads (220), and a second region (210b) provided between the plurality of first regions (210a) and not provided with the plurality of connection pads (220). The above connecting member (240, 240-1) is, A display module extending over the connection pad (220) along a second direction perpendicular to the first direction in a first region (210a) of the substrate (210).

2. In Paragraph 1, The above connecting member (240, 240-1) is a display module composed of a polymer material (241) containing conductive particles (242).

3. In Paragraph 1 or 2, A display module comprising an insulating layer (250) for covering the upper surface of the substrate (210) excluding the plurality of micro LEDs (230), fixing the plurality of micro LEDs (230) on the plurality of connecting members (240, 240-1), and maintaining the pressure state of the plurality of micro LEDs (230) with respect to the plurality of connecting members (240, 240-1).

4. In any one of paragraphs 1 through 3, A display module in which the ratio (t / w) of the thickness (t) of the connecting member (240, 240-1) to the width (w) of the connecting member (240, 240-1) is 1 / 15 or greater.

5. In any one of paragraphs 1 through 4, A display module in which the width (w) of the above connecting member (240, 240-1) is 10 µm or less.

6. In any one of paragraphs 1 through 5, A display module comprising a fluorine-based or silicon-based liquid-repellent material (261) extending along the first direction between adjacent connection pads (220) along the second direction on the substrate (210).

7. In any one of paragraphs 1 through 5, A display module comprising a plurality of disconnected structures (262) each disposed between adjacent connection pads (220) along the second direction and extended along the first direction.

8. In Paragraph 7, The above-mentioned disconnect structure (262) is a display module comprising an inclined surface (262a) facing an adjacent connection pad (220).

9. In any one of paragraphs 1 through 6, A display module comprising a porous material (263) having a porous structure (263a) having insulating properties, extending along the first direction between adjacent connection pads (220) along the second direction on the substrate (210).

10. In any one of paragraphs 1 through 9, The above connection member (240, 240-1) is a display module formed by printing a conductive paste along the second direction on the substrate (210) and the connection pad (220) by an EHD (Electrohydrodynamic) printing process.

11. In the display module (300), Substrate (310); A plurality of connection pads (320) arranged in a grid shape on the substrate (310); A plurality of micro LEDs (330), each disposed overlappingly on a pair of adjacent connection pads (320) in a first direction; and It includes a plurality of connection members (340, 340-1) respectively disposed between the micro LED (330) and the connection pad (320) and electrically connecting the substrate (310) and the micro LED (330). The above connection member (340, 340-1) is arranged to span the plurality of connection pads (320) and is composed of an anisotropic conductive material having insulation with respect to the first direction and the second direction perpendicular to the first direction, in a display module.

12. In Paragraph 11, The above connection member (340) is a display module that extends over the plurality of connection pads (320) along the first direction.

13. In Paragraph 11, The above connection member (340-1) is a display module that extends over the plurality of connection pads (320) along the second direction.

14. In any one of paragraphs 11 through 13, A display module comprising an insulating layer for covering the upper surface of the substrate (310) excluding the plurality of micro LEDs (330), fixing the plurality of micro LEDs (230) on the plurality of connecting members (340, 340-1), and maintaining the pressure state of the plurality of micro LEDs (330) with respect to the plurality of connecting members (340, 340-1).

15. In any one of paragraphs 11 through 14, The above connection member (340, 340-1) is a display module formed by printing a conductive paste on the substrate (310) and a plurality of connection pads (320) by an EHD (Electrohydrodynamic) printing process.

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