Patent Publication Number: US-2023156944-A1

Title: Electronic device including flexible printed circuit board

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation application, claiming priority under § 365(c), of an International application No. PCT/KR2022/013540, filed on Sep. 8, 2022, which is based on and claims the benefit of a Korean patent application number 10-2021-0156106, filed on Nov. 12, 2021, in the Korean Intellectual Property Office, and of a Korean patent application number 10-2021-0174866, filed on Dec. 8, 2021, in the Korean Intellectual Property Office, the disclosure of each of which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     The disclosure relates to an electronic device including a flexible printed circuit board (FPCB). 
     2. Description of Related Art 
     Recently, electronic devices such as portable terminals have been developed to improve the convenience of use through miniaturization while having various functions to satisfy consumers&#39; purchasing desires. Various components and boards for performing functions are mounted inside an electronic device, and these components may be connected through a flexible printed circuit board (FPCB). 
     The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure. 
     SUMMARY 
     Electronic devices need to be miniaturized to improve portability and aesthetics. Various components are disposed inside an electronic device. Thus, technologies for effectively utilizing an internal space of a miniaturized electronic device are being developed. For example, a flexible printed circuit board (FPCB) for electrically connecting the components disposed at various positions may be disposed inside the electronic device. 
     Meanwhile, when the components inside the electronic device are connected through the FPCB, it is necessary to prevent moisture from entering through a path on which the FPCB is disposed. 
     Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide an electronic device including a FPCB. 
     one aspect of the disclosure is to prevent moisture from entering a FPCB by applying a waterproof structure to the FPCB. 
     one aspect of the disclosure is to form a FPCB in a multi-layer structure and improve the waterproof performance of the FPCB through an arrangement structure of multiple layers. 
     The technical goals to be achieved through embodiments of the disclosure are not limited to those described above, and other technical goals not mentioned above are clearly understood by one of ordinary skill in the art from the following description. 
     Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments. 
     In accordance with an aspect of the disclosure, an electronic device is provided. The electronic device includes a display including a first area and a second area, a first housing supporting the first area and forming a first space positioned on a rear surface of the first area, a second housing supporting the second area and forming a second space positioned on a rear surface of the second area, a hinge structure connecting the first housing and the second housing to be foldable about a folding axis and configured to change the first area and the second area between a first state of forming substantially the same plane and a second state of facing each other, a first bracket connecting the first housing and the hinge structure and having a first opening penetrating through a surface thereof, a second bracket connecting the second housing and the hinge structure and having a second opening penetrating through a surface thereof, and a FPCB extending from the first space to the second space across the hinge structure in an extending direction, and formed in a multi-layer structure in which a plurality of substrates having uneven surfaces according to metal patterns are stacked in a stacking direction, wherein the FPCB may include a first sealing portion positioned inside the first opening and a second sealing portion positioned inside the second opening, and a waterproof member for sealing a space between the plurality of substrates may be disposed in the first sealing portion and the second sealing portion. 
     In accordance with another aspect of the disclosure, a FPCB is provided. The FPCB includes a central portion, a first flexible portion connected to the central portion and configured to be partially bent. a second flexible portion connected to the central portion to be opposite to the first flexible portion and configured to be partially bent, a first sealing portion connected to the first flexible portion to be opposite to the central portion; a second sealing portion connected to the second flexible portion to be opposite to the central portion, a first extension portion connected to the first sealing portion to be opposite to the first flexible portion and configured to be partially bent, and a second extension portion connected to the second sealing portion to be opposite to the second flexible portion and configured to be partially bent, wherein the FPCB may be formed in a multi-layer structure in which a plurality of substrates having uneven surfaces according to metal patterns are stacked in a stacking direction, a stepped space by the uneven surfaces may be formed between the plurality of substrates, and a ratio of an area of the stepped space to a length of the first sealing portion and the second sealing portion may be less than or equal to a ratio of an area of the stepped space to a length of the first flexible portion and the second flexible portion. 
     In accordance with another aspect of the disclosure, an electronic device is provided. The electronic device includes a display including a first area and a second area, a first housing including a first surface on which the first area is disposed, and a second surface opposite to the first surface. a second housing including a third surface on which the second area is disposed, and a fourth surface opposite to the third surface, a hinge structure connecting the first housing and the second housing to be foldable about a folding axis and configured to change the first area and the second area between a first state of forming substantially the same plane and a second state of facing each other, a first bracket connecting the first housing and the hinge structure and including a first opening penetrating through a surface thereof, a second bracket connecting the second housing and the hinge structure and including a second opening penetrating through a surface thereof, a first printed circuit board (PCB) disposed between the first bracket and the second surface. a second PCB disposed between the second bracket and the fourth surface, a FPCB with at least a portion disposed between the hinge structure and the display, and both ends respectively connected to the first PCB and the second PCB by passing through the first opening and the second opening, a first sealing member surrounding a perimeter of a first sealing portion of the FPCB positioned inside the first opening, and sealing between the first opening and the first sealing portion, and a second sealing member surrounding a perimeter of a second sealing portion of the FPCB positioned inside the second opening, and sealing between the second opening and the second sealing portion, wherein the FPCB may be formed in a multi-layer structure in which a plurality of substrates having uneven surfaces according to metal patterns are stacked in a stacking direction, and a waterproof member for filling a stepped space formed by the uneven surfaces between the plurality of substrates may be disposed in the first sealing portion and the second sealing portion. 
     According to embodiments, it is possible to prevent moisture from entering a flexible printed circuit board (FPCB) by disposing a waterproof member in a sealing portion of the FPCB. 
     According to embodiments, it is possible to improve the service life of a FPCB by improving the bending performance of a portion of the FPCB adjacent to a sealing portion. 
     According to embodiments, it is possible to improve the waterproof performance inside an electronic device by sealing a space between an opening and a FPCB with a sealing member and sealing a space between layers of the FPCB with a waterproof member. 
     Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a block diagram of an electronic device in a network environment according to an embodiment of the disclosure; 
         FIG.  2 A  is a view illustrating an unfolded state of an electronic device according to an embodiment of the disclosure; 
         FIG.  2 B  is a view illustrating a folded state of an electronic device according to an embodiment of the disclosure; 
         FIG.  2 C  is an exploded perspective view of an electronic device according to an embodiment of the disclosure; 
         FIG.  3 A  is a view illustrating an arrangement of a flexible printed circuit board (FPCB) in an unfolded state of an electronic device according to an embodiment of the disclosure; 
         FIG.  3 B  is a cross-sectional view of the electronic device according to a line of  FIG.  3 A  according to an embodiment of the disclosure; 
         FIG.  3 C  is a partial perspective view illustrating a coupling state of a FPCB and a sealing member according to an embodiment of the disclosure; 
         FIG.  3 D  is a cross-sectional view illustrating an area A of  FIG.  3 B  according to an embodiment of the disclosure; 
         FIGS.  4 A,  4 B, and  4 C  are cross-sectional views illustrating a sealing portion of a FPCB according to various embodiments of the disclosure; 
         FIG.  5    is a view illustrating a sealing portion of a FPCB according to one embodiment of the disclosure; 
         FIGS.  6 A,  6 B, and  6 C  are views illustrating sealing portions of FPCBs according to various embodiments of the disclosure; 
         FIGS.  7 A,  7 B, and  7 C  are views illustrating sealing portions of FPCBs according to various embodiments of the disclosure; and 
         FIG.  8    is a cross-sectional view illustrating a sealing portion of a FPCB according to an embodiment of the disclosure. 
     
    
    
     Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. 
     DETAILED DESCRIPTION 
     The following description with reference to accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
     The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents. 
     It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces. 
       FIG.  1    is a block diagram illustrating an electronic device in a network environment according to an embodiment of the disclosure. 
     Referring to  FIG.  1   , the electronic device  101  in the network environment  100  may communicate with an electronic device  102  via a first network  198  (e.g., a short-range wireless communication network), or communicate with at least one of an electronic device  104  or a server  108  via 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  via the server  108 . According to one embodiment, the electronic device  101  may include a processor  120 , a memory  130 , an input module  150 , a sound output module  155 , a display module  160 , an audio module  170 , a sensor module  176 , an interface  177 , a connecting terminal  178 , a haptic module  179 , a camera module  180 , a power management module  188 , a battery  189 , a communication module  190 , a subscriber identification module (SIM)  196 , or an antenna module  197 . In some embodiments, at least one (e.g., the connecting terminal  178 ) of the above components may be omitted from the electronic device  101 , or one or more other components may be added in the electronic device  101 . In some embodiments, some (e.g., the sensor module  176 , the camera module  180 , or the antenna module  197 ) of the components may be integrated as a single component (e.g., the display module  160 ). 
     The processor  120  may execute, for example, software (e.g., a program  140 ) to control at least one other component (e.g., a hardware or software component) of the electronic device  101  connected to the processor  120 , and may perform various data processing or computation. According to one embodiment, as at least a portion of data processing or computation, the processor  120  may store a command or data received from another component (e.g., the sensor module  176  or the communication module  190 ) in a volatile memory  132 , process the command or the data stored in the volatile memory  132 , and store resulting data in a non-volatile memory  134 . According to one embodiment, the processor  120  may include a main processor  121  (e.g., a central processing unit (CPU) or an application processor (AP)), or an auxiliary processor  123  (e.g., a graphics processing unit (GPU), a neural processing unit (NPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)) that is operable independently from, or in conjunction with the main processor  121 . For example, when the electronic device  101  includes the main processor  121  and the auxiliary processor  123 , the auxiliary processor  123  may be adapted to consume less power than the main processor  121  or to be specific to a specified function. The auxiliary processor  123  may be implemented separately from the main processor  121  or as a portion of the main processor  121 . 
     The auxiliary processor  123  may control at least some of functions or states related to at least one (e.g., the display module  160 , the sensor module  176 , or the communication module  190 ) of the components of the electronic device  101 , instead of the main processor  121  while the main processor  121  is in an inactive (e.g., sleep) state or along with the main processor  121  while the main processor  121  is in an active state (e.g., executing an application). According to one embodiment, the auxiliary processor  123  (e.g., an ISP or a CP) may be implemented as a portion of another component (e.g., the camera module  180  or the communication module  190 ) that is functionally related to the auxiliary processor  123 . According to one embodiment, the auxiliary processor  123  (e.g., an NPU) may include a hardware structure specified for artificial intelligence (AI) model processing. An AI model may be generated by machine learning. Such learning may be performed by, for example, the electronic device  101  in which an artificial intelligence model is executed, or performed via a separate server (e.g., the server  108 ). Learning algorithms may include, but are not limited to, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning. The artificial intelligence model may include a plurality of artificial neural network layers. An artificial neural network may include, for example, 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), and a bidirectional recurrent deep neural network (BRDNN), a deep Q-network, or a combination of two or more thereof, but is not limited thereto. The artificial intelligence model may additionally or alternatively, include a software structure other than the hardware structure. 
     The memory  130  may store various data used by at least one component (e.g., the processor  120  or the sensor module  176 ) of the electronic device  101 . The various data may include, for example, software (e.g., the program  140 ) and input data or output data for a command related thereto. The memory  130  may include the volatile memory  132  or the non-volatile memory  134 . The non-volatile memory  134  may include an internal memory  136  and an external memory  138 . 
     The program  140  may be stored as software in the memory  130 , and may include, for example, an operating system (OS)  142 , middleware  144 , or an application  146 . 
     The input module  150  may receive a command or data to be used by another component (e.g., the processor  120 ) of the electronic device  101 , from the outside (e.g., a user) of the electronic device  101 . 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). 
     The sound output module  155  may 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 playing multimedia or playing record. The receiver may be used to receive an incoming call. According to one embodiment, the receiver may be implemented separately from the speaker or as a portion of the speaker. 
     The display module  160  may visually provide information to the outside (e.g., a user) of the electronic device  101 . The display module  160  may include, for example, a control circuit for controlling a display, a hologram device, or a projector and control circuitry to control a corresponding one of the display, the hologram device, and the projector. According to one embodiment, the display module  160  may include a touch sensor adapted to sense a touch, or a pressure sensor adapted to measure an intensity of a force incurred by the touch. 
     The audio module  170  may convert a sound into an electrical signal or vice versa. According to one embodiment, the audio module  170  may obtain the sound via the input module  150  or output the sound via the sound output module  155  or an external electronic device (e.g., an electronic device  102  such as a speaker or a headphone) directly or wirelessly connected to the electronic device  101 . 
     The sensor module  176  may detect an operational state (e.g., power or temperature) of the electronic device  101  or an environmental state (e.g., a state of a user) external to the electronic device  101 , 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 gyro sensor, an atmospheric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor. 
     The interface  177  may support one or more specified protocols to be used for the electronic device  101  to be coupled with the external electronic device (e.g., the electronic device  102 ) directly (e.g., wiredly) or wirelessly. According to one embodiment, the interface  177  may include, for example, a high-definition multimedia interface (HDMI), a universal serial bus (USB) interface, a secure digital (SD) card interface, or an audio interface. 
     The connecting terminal  178  may include a connector via which the electronic device  101  may be physically connected to an external electronic device (e.g., the electronic device  102 ). According to one embodiment, the connecting 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). 
     The haptic module  179  may convert an electrical signal into a mechanical stimulus (e.g., a vibration or a movement) or an electrical stimulus which may be recognized by a user via his or her tactile sensation or kinesthetic sensation. According to one embodiment, the haptic module  179  may include, for example, a motor, a piezoelectric element, or an electric stimulator. 
     The camera module  180  may capture a still image and moving images. According to one embodiment, the camera module  180  may include one or more lenses, image sensors, ISPs, or flashes. 
     The power management module  188  may manage power supplied to the electronic device  101 . According to one embodiment, the power management module  188  may be implemented as, for example, at least a portion of a power management integrated circuit (PMIC). 
     The battery  189  may supply power to at least one component of the electronic device  101 . According to one embodiment, the battery  189  may include, for example, a primary cell which is not rechargeable, a secondary cell which is rechargeable, or a fuel cell. 
     The communication module  190  may support establishing a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device  101  and the external electronic device (e.g., the electronic device  102 , the electronic device  104 , or the server  108 ) and performing communication via the established communication channel. The communication module  190  may include one or more communication processors that are operable independently of the processor  120  (e.g., an AP) and that support a direct (e.g., wired) communication or a wireless communication. According to one embodiment, the communication module  190  may include a wireless communication module  192  (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module  194  (e.g., a local area network (LAN) communication module, or a power line communication (PLC) module). A corresponding one of these communication modules may communicate with the external electronic device  104  via the first network  198  (e.g., a short-range communication network, such as Bluetooth™, wireless-fidelity (Wi-Fi) direct, or infrared data association (IrDA)) or the second network  199  (e.g., a long-range communication network, such as a legacy cellular network, a fifth generation (5G) network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or a wide area network (WAN)). These various types of communication modules may be implemented as a single component (e.g., a single chip), or may be implemented as multi components (e.g., multi chips) separate from each other. The wireless communication module  192  may identify and authenticate the electronic device  101  in a communication network, such as the first network  198  or the second network  199 , using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the SIM  196 . 
     The wireless communication module  192  may support a 5G network after a fourth generation (4G) network, and next-generation communication technology, e.g., new radio (NR) access technology. The NR access technology may support enhanced mobile broadband (eMBB), massive machine type communications (mMTC), or ultra-reliable and low-latency communications (URLLC). The wireless communication module  192  may support a high-frequency band (e.g., a mmWave band) to achieve, e.g., a high data transmission rate. The wireless communication module  192  may support various technologies for securing performance on a high-frequency band, such as, e.g., beamforming, massive multiple-input and multiple-output (massive MIMO), full dimensional MIMO (FD-MIMO), an array antenna, analog beam-forming, or a large scale antenna. The wireless communication module  192  may support various requirements specified in the electronic device  101 , an external electronic device (e.g., the electronic device  104 ), or a network system (e.g., the 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 implementing eMBB, loss coverage (e.g., 164 dB or less) for implementing mMTC, or U-plane latency (e.g., 0.5 ms or less for each of downlink (DL) and uplink (UL), or a round trip of 1 ms or less) for implementing URLLC. 
     The antenna module  197  may transmit or receive a signal or power to or from the outside (e.g., the external electronic device) of the electronic device  101 . According to one embodiment, the antenna module  197  may include an antenna including a radiating element including a conductive material or a conductive pattern formed in or on a substrate (e.g., a printed circuit board (PCB)). According to one embodiment, the antenna module  197  may include a plurality of antennas (e.g., array antennas). In such a case, at least one antenna appropriate for a communication scheme used in a communication network, such as the first network  198  or the second network  199 , may be selected by, for example, the communication module  190  from the plurality of antennas. The signal or the power may be transmitted or received between the communication module  190  and the external electronic device via the at least one selected antenna. According to one embodiment, another component (e.g., a radio frequency integrated circuit (RFIC)) other than the radiating element may be additionally formed as a portion of the antenna module  197 . 
     According to one embodiment, the antenna module  197  may form a mmWave antenna module. According to one embodiment, the mmWave antenna module may include a PCB, an RFIC disposed on a first surface (e.g., a bottom surface) of the PCB or adjacent to the first surface and capable of supporting a designated a high-frequency band (e.g., the mmWave band), and a plurality of antennas (e.g., array antennas) disposed on a second surface (e.g., a top or a side surface) of the PCB, or adjacent to the second surface and capable of transmitting or receiving signals in the designated high-frequency band. 
     At least some of the above-described components may be coupled mutually and communicate signals (e.g., commands or data) therebetween via an inter-peripheral communication scheme (e.g., a bus, general purpose input and output (GPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI)). 
     According to one embodiment, commands or data may be transmitted or received between the electronic device  101  and the external electronic device  104  via the server  108  coupled with the second network  199 . Each of the external electronic devices  102  or  104  may be a device of the same type as or a different type from the electronic device  101 . According to one embodiment, all or some of operations to be executed by the electronic device  101  may be executed at one or more of the external electronic devices  102  or  104 , or the server  108 . For example, if the electronic device  101  needs to perform a function or a service automatically, or in response to a request from a user or another device, the electronic device  101 , instead of, or in addition to, executing the function or the service, may request one or more external electronic devices to perform at least portion of the function or the service. The one or more external electronic devices receiving the request may perform the at least portion of the function or the service requested, or an additional function or an additional service related to the request, and may transfer an outcome of the performing to the electronic device  101 . The electronic device  101  may provide the outcome, with or without further processing of the outcome, as at least portion of a reply to the request. To that end, a cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used, for example. The electronic device  101  may provide ultra low-latency services using, e.g., distributed computing or mobile edge computing. In one 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 a neural network. According to one embodiment, the external electronic device  104  or the server  108  may be included in the second network  199 . The electronic device  101  may be applied to intelligent services (e.g., smart home, smart city, smart car, or healthcare) based on 5G communication technology or IoT-related technology. 
     The electronic device according to one embodiment may be one of various types of electronic devices. The electronic device may include, for example, a portable communication device (e.g., a smart phone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance device. According to one embodiment of the disclosure, the electronic device is not limited to those described above. 
     It should be appreciated that various embodiments of the disclosure and the terms used therein are not intended to limit the technological features set forth herein to particular embodiments and include various changes, equivalents, or replacements for a corresponding embodiment. In connection with the description of the drawings, like reference numerals may be used for similar or related components. As used herein, “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”, each of which may include any one of the items listed together in the corresponding one of the phrases, or all possible combinations thereof. Terms such as “first”, “second”, or “first” or “second” may simply be used to distinguish the component from other components in question, and do not limit the components in other aspects (e.g., importance or order). It is to be understood that if an element (e.g., a first element) is referred to, with or without the term “operatively” or “communicatively”, as “coupled with”, “coupled to”, “connected with”, or “connected to” another element (e.g., a second element), it means that the element may be coupled with the other element directly (e.g., wiredly), wirelessly, or via a third element. 
     As used in connection with various embodiments of the disclosure, the term “module” may include a unit implemented in hardware, software, or firmware, and may interchangeably be used with other terms, for example, “logic”, “logic block”, “part”, or “circuitry”. A module may be a single integral component, or a minimum unit or part thereof, adapted to perform one or more functions. For example, according to one embodiment, the module may be implemented in a form of an application-specific integrated circuit (ASIC). 
     Various embodiments as set forth herein may be implemented as software (e.g., the program  140 ) including one or more instructions that are stored in a storage medium (e.g., an internal memory  136  or an external memory  138 ) that is readable by a machine (e.g., the electronic device  101 ). For example, a processor (e.g., the processor  120 ) of the machine (e.g., the electronic device  101 ) may invoke at least one of the one or more instructions stored in the storage medium, and execute it. This allows the machine to be operated to perform at least one function according to the at least one instruction invoked. The one or more instructions may include a code generated by a compiler or a code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the term “non-transitory” simply means that the storage medium is a tangible device, and does not include a signal (e.g., an electromagnetic wave), but this term does not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium. 
     According to one embodiment, a method according to one embodiment of the disclosure may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed (e.g., downloaded or uploaded) online via an application store (e.g., PlayStore™), or between two user devices (e.g., smart phones) directly. If distributed online, at least portion of the computer program product may be temporarily generated or at least temporarily stored in the machine-readable storage medium, such as memory of the manufacturer&#39;s server, a server of the application store, or a relay server. 
     According to one embodiment, each component (e.g., a module or a program) of the above-described components may include a single entity or multiple entities, and some of the multiple entities may be separately disposed in different components. According to one embodiment, one or more of the above-described components may be omitted, or one or more other components may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, the integrated component may still perform one or more functions of each of the plurality of components in the same or similar manner as they are performed by a corresponding one of the plurality of components before the integration. According to various embodiments, operations performed by the module, the program, or another component may be carried out sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be executed in a different order or omitted, or one or more other operations may be added. 
       FIG.  2 A  is a view illustrating an unfolded state of an electronic device according to an embodiment of the disclosure. 
       FIG.  2 B  is a view illustrating a folded state of the electronic device according to an embodiment of the disclosure. 
       FIG.  2 C  is an exploded perspective view of the electronic device according to an embodiment of the disclosure. 
     Referring to  FIGS.  2 A,  2 B, and  2 C , an electronic device  201  may include a pair of housings  210  and  220  rotatably coupled to each other through a hinge structure (e.g., a hinge structure  334  of  FIG.  3 A ) to be folded with respect to each other, a hinge cover  265  for covering foldable portions of the pair of housings  210  and  220 , and a display  261  (e.g., a flexible display or a foldable display) disposed in a space formed by the pair of housings  210  and  220 . In the disclosure, a surface on which the display  261  is disposed may be defined as a front surface of the electronic device  201 , and a surface opposite to the front surface may be defined as a rear surface of the electronic device  201 . In addition, a surface surrounding a space between the front surface and the rear surface may be defined as a side surface of the electronic device  201 . 
     In one embodiment, the pair of housings  210  and  220  may include a first housing  210 , a second housing  220 , a first rear cover  240 , and a second rear cover  250 . The pair of housings  210  and  220  of the electronic device  201  are not limited to the shapes or the combination and/or coupling of components shown in  FIGS.  2 A and  2 B , and may be implemented in other shapes or by another combination and/or coupling of components. 
     In one embodiment, the first housing  210  and the second housing  220  may be disposed on both sides with respect to a folding axis A, and may be disposed substantially symmetrically with respect to the folding axis A. In one embodiment, an angle or a distance between the first housing  210  and the second housing  220  may vary depending on whether the electronic device  201  is in an unfolded state, a folded state, or an intermediate state. In one embodiment, the first housing  210  and the second housing  220  may have substantially symmetrical shapes. 
     In one embodiment, the first housing  210  may be connected to a hinge structure (e.g., the hinge structure  334  of  FIG.  3 A ). The first housing  210  may include a first surface  211  facing the front surface of the electronic device  201 , a second surface  212  facing a direction opposite to the first surface  211 , and a first side portion  213  enclosing at least a portion of a space between the first surface  211  and the second surface  212 . The first side portion  213  may include a first side surface  213   a  disposed substantially in parallel with the folding axis A, a second side surface  213   b  extending in a direction substantially perpendicular to the folding axis A from one end of the first side surface  213   a , and a third side surface  213   c  extending in a direction substantially perpendicular to the folding axis A from another end of the first side surface  213   a  and substantially parallel to the second side surface  213   b . The second housing  220  may be connected to the hinge structure (e.g., the hinge structure  334  of  FIG.  3 A ). The second housing  220  may include a third surface  221  facing the front surface of the electronic device  201 , a fourth surface  222  facing a direction opposite to the third surface  221 , and a second side portion  223  enclosing at least a portion of a space between the third surface  221  and the fourth surface  222 . The second side member  223  may include a fourth side surface  223   a  disposed substantially in parallel with the folding axis A, a fifth side surface  223   b  extending in a direction substantially perpendicular to the folding axis A from one end of the fourth side surface  223   a , and a sixth side surface  223   c  extending in a direction substantially perpendicular to the folding axis A from another end of the fourth side surface  223   a  and substantially parallel to the fifth side surface  223   b . The first surface  211  and the third surface  221  may face each other when the electronic device  201  is in the folded state. 
     In one embodiment, the electronic device  201  may include at least one sound output module (e.g., the sound output module  155  of  FIG.  1   ) disposed on the fifth side surface  223   b  and/or the sixth side surface  223   c  of the second housing  220 . 
     In one embodiment, the electronic device  201  may include a recessed accommodating portion  202  for accommodating the display  261  through the structural coupling of the first housing  210  and the second housing  220 . The accommodating portion  202  may have substantially the same size as the display  261 . 
     In one embodiment, at least a portion of the first housing  210  and the second housing  220  may be formed of a metal material or a non-metal material having a predetermined magnitude of rigidity appropriate to support the display  261 . 
     In one embodiment, the electronic device  201  may include at least one component disposed to be visually exposed on the front surface of the electronic device  201  to perform various functions. For example, the component may include at least one of a front camera module, a receiver, a proximity sensor, an illuminance sensor, an iris recognition sensor, an ultrasonic sensor, or an indicator. In one embodiment, the component included in the electronic device  201  may be disposed not to be visually exposed to the outside of the electronic device  201 . For example, the at least one component may be disposed on a rear surface of the display  261 . In one embodiment, the first rear cover  240  may be disposed on the second surface  212  of the first housing  210 , and may have a substantially rectangular periphery. At least a portion of the periphery of the first rear cover  240  may be surrounded by the first housing  210 . The second rear cover  250  may be disposed on the fourth surface  222  of the second housing  220 , and may have a substantially rectangular periphery. At least a portion of the periphery of the second rear cover  250  may be surrounded by the second housing  220 . 
     In one embodiment, the first rear cover  240  and the second rear cover  250  may have substantially symmetrical shapes with respect to the folding axis A. In one embodiment, the first rear cover  240  and the second rear cover  250  may have different shapes. In one embodiment, the first housing  210  and the first rear cover  240  may be integrally formed, and the second housing  220  and the second rear cover  250  may be integrally formed. 
     In one embodiment, the first housing  210 , the second housing  220 , the first rear cover  240 , and the second rear cover  250  may provide a space in which various components (e.g., a PCB, the antenna module  197  of  FIG.  1   , the sensor module  176  of  FIG.  1   , or the battery  189  of  FIG.  1   ) of the electronic device  201  may be arranged through a structure in which the first housing  210 , the second housing  220 , the first rear cover  240 , and the second rear cover  250  are coupled to one another. In one embodiment, at least one component may be visually exposed on the rear surface of the electronic device  201 . For example, at least one component may be visually exposed through a first rear area  241  of the first rear cover  240 . Here, the component may include a proximity sensor, a rear camera module, and/or a flash. 
     In one embodiment, the display  261  may be disposed in the accommodating portion  202  formed by the pair of housings  210  and  220 . For example, the display  261  may be arranged to occupy substantially most of the front surface of the electronic device  201 . The front surface of the electronic device  201  may include an area in which the display  261  is disposed, and a partial area (e.g., a periphery area) of the first housing  210  and a partial area (e.g., a periphery area) of the second housing  220 , which are adjacent to the display  261 . The rear surface of the electronic device  201  may include the first rear cover  240 , a partial area (e.g., a periphery area) of the first housing  210  adjacent to the first rear cover  240 , the second rear cover  250 , and a partial area (e.g., a periphery area) of the second housing  220  adjacent to the second rear cover  250 . In one embodiment, the display  261  may be a display in which at least one area is deformable into a planar surface or a curved surface. In one embodiment, the display  261  may include a flexible area  261   c , a first area  261   a  on a first side (e.g., the right side) of the flexible area  261   c , and a second area  261   b  on a second side (e.g., the left side) of the flexible area  261   c . For example, the first area  261   a  may be positioned on the first surface  211  of the first housing  210 , and the second area  261   b  may be positioned on the third surface  221  of the second housing  220 . However, the area division of the display  261  is merely an example, and the display  261  may be divided into a plurality of areas depending on the structure or functions of the display  261 . For example, as shown in  FIG.  2 A , the display  261  may be divided into areas based on the folding axis A or the flexible area  261   c  extending in parallel to a Y-axis, or the display  261  may be divided into areas based on another folding area (e.g., a folding area extending in parallel to an X-axis) or another folding axis (e.g., a folding axis parallel to the X-axis). The area division of the display  261  as above is merely physical division based on the pair of housings  210  and  220  and the hinge structure (e.g., the hinge structure  334  of  FIG.  3 A ), and the display  261  may display substantially one screen through the pair of housings  210  and  220  and the hinge structure (e.g., the hinge structure  334  of  FIG.  3 A ). In one embodiment, the first area  261   a  and the second area  261   b  may have substantially symmetrical shapes with respect to the flexible area  261   c.    
     In one embodiment, the hinge cover  265  may be disposed between the first housing  210  and the second housing  220  and configured to cover the hinge structure (e.g., the hinge structure  334  of  FIG.  3 A ). The hinge cover  265  may be hidden by at least a portion of the first housing  210  and the second housing  220  or exposed to the outside according to the operating state of the electronic device  201 . For example, when the electronic device  201  is in an unfolded state as shown in  FIG.  2 A , the hinge cover  265  may be hidden by the first housing  210  and the second housing  220  and not exposed to the outside, and when the electronic device  201  is in a folded state as shown in  FIG.  2 B , the hinge cover  265  may be exposed to the outside between the first housing  210  and the second housing  220 . Meanwhile, when the electronic device  201  is in an intermediate state in which the first housing  210  and the second housing  220  form an angle with each other, at least a portion of the hinge cover  265  may be exposed to the outside between the first housing  210  and the second housing  220 . In this case, an area of the hinge cover  265  exposed to the outside may be smaller than the area of the hinge cover  265  exposed when the electronic device  201  is in the folded state. In one embodiment, the hinge cover  265  may have curved surfaces. 
     Describing the operation of the electronic device  201  according to one embodiment, when the electronic device  201  is in an unfolded state (e.g., the state of the electronic device  201  of  FIG.  2 A ), the first housing  210  and the second housing  220  may form a first angle (e.g., about 180 degrees) with each other, and the first area  261   a  and the second area  261   b  of the display  261  may be oriented in substantially the same direction. The flexible area  261   c  of the display  261  may be on substantially the same plane as the first area  261   a  and the second area  261   b . In one embodiment, when the electronic device  201  is in the unfolded state, the first housing  210  may rotate at a second angle (e.g., about 360 degrees) relative to the second housing  220 , whereby the first housing  210  and the second housing  220  may be reversely folded such that the second surface  212  and the fourth surface  222  may face each other. Meanwhile, when the electronic device  201  is in the folded state (e.g., the state of the electronic device  201  of  FIG.  2 B ), the first housing  210  and the second housing  220  may face each other. The first housing  210  and the second housing  220  may form an angle of about 0 degrees to about 10 degrees, and the first area  261   a  and the second area  261   b  of the display  261  may face each other. At least a portion of the flexible area  261   c  of the display  261  may be deformed into a curved surface. Meanwhile, when the electronic device  201  is in the intermediate state, the first housing  210  and the second housing  220  may form a predetermined angle with each other. An angle (e.g., a third angle, about 90 degrees) formed by the first area  261   a  and the second area  261   b  of the display  261  may be greater than that when the electronic device  201  is in the folded state and less than that when the electronic device  201  is in the unfolded state. At least a portion of the flexible area  261   c  of the display  261  may be deformed into a curved surface. In this case, a curvature of the curved surface of the flexible area  261   c  may be smaller than that when the electronic device  201  is in the folded state. 
     In one embodiment, the electronic device  201  may be folded about the folding axis A by means of a hinge structure (e.g., the hinge structure  334  of  FIGS.  3 A to  3 D ). For example, it is shown in the drawings that the folding axis A is formed by the hinge structure in a vertical direction (e.g., the Y-axis direction) of the electronic device  201  for ease of description, but this is merely an example, and the direction in which the axis A is formed is not limited thereto. For example, the folding axis A may be formed by the hinge structure in a horizontal direction (e.g., the X-axis direction) of the electronic device  201 , or a plurality of folding axes may be formed all in the same direction or in different directions such that the electronic device  201  may be folded a plurality of times through the plurality of folding axes. Meanwhile, the various embodiments of the electronic device described herein are not limited to the form factor of the electronic device  201  described with reference to  FIGS.  2 A and  2 B , and may also apply to electronic devices with various form factors. 
     Referring to  FIG.  2 C , an electronic device  201  according to one embodiment may include a display module  260  (e.g., the display module  160  of  FIG.  1   ), a hinge assembly  230 , a substrate  270 , a first housing  210  (e.g., the first housing  210  of  FIGS.  2 A and  2 B ), the second housing  220  (e.g., the second housing  220  of  FIGS.  2 A and  2 B ), the first rear cover  240  (e.g., the first rear cover  240  of  FIGS.  2 A and  2 B ), and the second rear cover  250  (e.g., the second rear cover  250  of  FIGS.  2 A and  2 B ). 
     The display module  260  may include a display  261  (e.g., the display  261  of  FIGS.  2 A and  2 B ) and at least one layer or plate  262  on which the display  261  is seated. In one embodiment, the plate  262  may be disposed between the display  261  and the hinge assembly  230 . The display  261  may be disposed on at least a portion of one surface (e.g., a top surface) of the plate  262 . The plate  262  may be formed in a shape corresponding to the display  261 . 
     In one embodiment, the display  261  may include a flexible display substrate, a plurality of display elements coupled to the display substrate to form multiple pixels, one or more conductive lines coupled to the display substrate and electrically connected to other display elements, and a thin-film encapsulation layer configured to prevent an inflow of external oxygen and moisture. In one embodiment, the display  261  may include a touch panel or may be integrally formed therewith. 
     The display substrate may be formed of a flexible material, for example, a plastic material such as polyimide (PI), but the material of the display substrate is not limited thereto and may include various materials having flexible properties. The plurality of display elements may be arranged on the display substrate and form multiple pixels. For example, the plurality of display elements may be arranged in a matrix form on the display substrate to form pixels of the display  261 . In this case, the plurality of display elements may include a fluorescent material or an organic fluorescent material capable of expressing colors. For example, the display elements may include organic light emitting diodes (OLEDs). The conductive lines may include one or more gate signal lines or one or more data signal lines. For example, the conductive lines may include a plurality of gate signal lines and a plurality of data signal lines, and the plurality of gate signal lines and the plurality of data signal lines may be arranged in a matrix form. In this case, the plurality of display elements may be arranged adjacent to a point where a plurality of lines intersect, and may be electrically connected to each line. The thin film encapsulation layer may cover the display substrate, the plurality of display elements, and the conductive lines, thereby preventing an inflow of oxygen and moisture from an outside. In one embodiment, the thin film encapsulation layer may be formed by alternately stacking one or more organic film layers and one or more inorganic film layers. 
     In one embodiment, the touch panel may be formed as an integral body on the display substrate or attached thereto. For example, the touch panel may be formed by patterning an aluminum metal mesh sensor on the thin film encapsulation layer. 
     In one embodiment, the polarizing film may be stacked between the display substrate and the touch panel. The polarizing film may improve visibility of the display  261 . The polarizing film may change a phase of light passing through the display  261 . For example, the polarizing film may convert linearly polarized light into circularly polarized light or convert circularly polarized light into linearly polarized light, thereby preventing reflection of light incident to the display  261 . 
     The window layer may be formed of a transparent plastic film having high flexibility and high hardness. For example, the window layer may be formed of a polyimide (PI) or polyethylene terephthalate (PET) film. In one embodiment, the window layer may be formed as multiple layers including a plurality of plastic films. 
     In one embodiment, the plate  262  may support the rear surface of the display  261 , thereby improving the impact resistance of the display  261 . In one embodiment, the plate  262  may be divided into areas to support a rear surface of the first area  261   a  and a rear surface of the second area  261   b  of the display  261 , respectively. In this case, the respective areas of the plate  262  may be separately attached to the rear surface of the first area  261   a  and the rear surface of the second area  261   b  of the display  261  so as not to contact each other along the folding axis A. According to this structure, the plate  262  may not interfere with the folding operation of the display  261  performed along the folding axis A. 
     In one embodiment, the plate  262  may be formed of a conductive material, for example, copper or an alloy material including copper. In this case, the plate  262  may function as a heat transfer path that transfers heat generated in an internal component (e.g., an application processor (AP)) in the electronic device to the display panel  261 , at the same time improving the impact resistance of the display  261 . 
     The hinge assembly  230  may include a first bracket  231 , a second bracket  232 , a hinge structure  234  disposed between the first bracket  231  and the second bracket  232 , a hinge cover  265  for covering the hinge structure  234  when the hinge structure  234  is viewed from the outside, and a FPCB  290  that traverses the first bracket  231  and the second bracket  232 . In one embodiment, the FPCB  290  may be a flexible printed circuit board (FPCB). 
     In one embodiment, the hinge assembly  230  may be disposed between the plate  262  and the substrate  270 . For example, the first bracket  231  may be disposed between the first area  261   a  of the display  261  and a first PCB  271 . The second bracket  232  may be disposed between the second area  261   b  of the display  261  and a second PCB  272 . 
     In one embodiment, at least a portion of the hinge structure  234  and the FPCB  290  may be disposed inside the hinge assembly  230 . The FPCB  290  may be disposed in a direction (e.g., the X-axis direction) that traverses the first bracket  231  and the second bracket  232 . The FPCB  290  may be disposed in a direction (e.g., the X-axis direction) perpendicular to a folding axis (e.g., the Y-axis or the folding axis A of  FIG.  2 A ) of the flexible area  261   c  of the electronic device  201 . 
     The substrate  270  may include the first PCB  271  disposed on the first bracket  231  and the second PCB  272  disposed on the second bracket  232 . The first PCB  271  and the second PCB  272  may be disposed in a space formed by the hinge assembly  230 , the first housing  210 , the second housing  220 , the first rear cover  240 , and the second rear cover  250 . For example, the first PCB  271  may be disposed inside the first housing  210 , and the second PCB  272  may be disposed inside the second housing  220 . In this case, the first PCB  271  may be disposed between the first bracket  231  and the second surface  212  of the first housing  210 , and the second PCB  272  may be disposed between the second bracket  232  and the fourth surface  222  of the second housing  220 . Components for implementing various functions of the electronic device  201  may be disposed on the first PCB  271  and the second PCB  272 . 
     The first housing  210  and the second housing  220  may be assembled together to be coupled to both sides of the hinge assembly  230  in a state in which the display module  260  is coupled to the hinge assembly  230 . The first housing  210  and the second housing  220  may be respectively connected to both sides of the hinge assembly  230 . 
     In one embodiment, the first housing  210  may include a first rotation support surface  214 , and the second housing  220  may include a second rotation support surface  224  corresponding to the first rotation support surface  214 . The first rotation support surface  214  and the second rotation support surface  224  may include curved surfaces corresponding to the curved surfaces included in the hinge cover  265 . 
     In one embodiment, when the electronic device  201  is in an unfolded state (e.g., the electronic device  201  of  FIG.  2 A ), the first rotation support surface  214  and the second rotation support surface  224  may cover the hinge cover  265  such that the hinge cover  265  may not be exposed through the rear surface of the electronic device  201  or may be minimally exposed. Meanwhile, when the electronic device  201  is in a folded state (e.g., the electronic device  201  of  FIG.  2 B ), the first rotation support surface  214  and the second rotation support surface  224  may rotate along the curved surfaces included in the hinge cover  265  such that the hinge cover  265  may be maximally exposed through the rear surface of the electronic device  201 . 
       FIG.  3 A  is a view illustrating an arrangement of a FPCB in an unfolded state of an electronic device according to an embodiment of the disclosure. 
       FIG.  3 B  is a cross-sectional view of the electronic device according to a line of  FIG.  3 A  according to an embodiment of the disclosure. 
       FIG.  3 C  is a partial perspective view illustrating a coupling state of the FPCB and a sealing member according to an embodiment of the disclosure. 
       FIG.  3 D  is a cross-sectional view illustrating an area A of  FIG.  3 B  according to an embodiment of the disclosure. 
     Referring to  FIGS.  3 A to  3 D , an electronic device  301  (e.g., the electronic device  101  of  FIG.  1    or the electronic device  201  of  FIG.  2 A ) according to one embodiment may include a display  361 , a first housing  310 , a second housing  320 , a hinge structure  334 , a first bracket  331 , a second bracket  332 , a FPCB  390 , a first sealing member  380   a , and a second sealing member  380   b.    
     In one embodiment, the display  361  may include a first area  361   a , a second area  361   b , and a folding area  361   c  connecting the first area  361   a  and the second area  361   b.    
     In one embodiment, the first housing  310  may support the first area  361   a  and form a first space  310   a  positioned on a rear surface of the first area  361   a . In one embodiment, the second housing  320  may support the second area  361   b  and form a second space  320   a  positioned on a rear surface of the second area  361   b . In one embodiment, a first PCB (e.g., the first PCB  271  of  FIG.  2 C ) may be disposed in the first space  310   a  formed by the first housing  310 , and a second PCB (e.g., the second PCB  272  of  FIG.  2 C ) may be disposed in the second space  320   a  formed by the second housing  320 . In one embodiment, the hinge structure  334  may rotatably connect the first housing  310  and the second housing  320  about a folding axis. In one embodiment, the hinge structure  334  may include a hinge cover  365  disposed between the first housing  310  and the second housing  320 . In one embodiment, the hinge structure  334  may allow the first area  361   a  and the second area  361   b  of the display  361  to change between a first state (e.g., the unfolded state of  FIG.  2 A ) of forming substantially the same plane and a second state (e.g., the folded state of  FIG.  2 B ) of facing each other, through the folding operation of the first housing  310  and the second housing  320 . 
     In one embodiment, the first bracket  331  and the second bracket  332  may be rotatably connected to the hinge structure  334 . In one embodiment, the first bracket  331  may be disposed inside the first space  310   a  and connect the first housing  310  and the hinge structure  334 . In one embodiment, the second bracket  332  may be disposed inside the second space  320   a  and connect the second housing  320  and the hinge structure  334 . In this case, the first bracket  331  may be disposed between the first area  361   a  and the first PCB (e.g., the first PCB  271  of  FIG.  2 C ), and the second bracket  332  may be disposed between the second area  361   b  and the second PCB (e.g., the second PCB  272  of  FIG.  2 C ). 
     In one embodiment, the first bracket  331  and the second bracket  332  may have openings  331   a  and  332   a  penetrating through surfaces thereof, respectively. For example, the first bracket  331  may have one or more first openings  331   a  formed to penetrate therethrough toward the first area  361   a , and the second bracket  332  may have one or more second openings  332   a  formed to penetrate therethrough toward the second area  361   b . In one embodiment, the FPCB  390  may extend to the first space  310   a  and the second space  320   a  through the first opening  331   a  and the second opening  332   a.    
     In one embodiment, the FPCB  390  may electrically connect the component elements inside the electronic device  301 . In one embodiment, the FPCB  390  may have a longitudinal direction to extend from the first space  310   a  through the hinge structure  334  to the second space  320   a  along an extending direction. In this case, at least a portion of the FPCB  390  may be disposed between the hinge structure  334  and the display  361 , and both ends of the FPCB  390  may pass through the first opening  331   a  and the second opening  332   a  and extend to the first space  310   a  and the second space  320   a , respectively. For example, both ends of the FPCB  390  may be connected to the first PCB (e.g., the first PCB  271  of  FIG.  2 C ) disposed in the first space  310   a  and the second PCB (e.g., the second PCB  272  of  FIG.  2 C ) disposed in the second space  320   a.    
     In one embodiment, the FPCB  390  may include a central portion  3901 , a first flexible portion  3903   a , a second flexible portion  3903   b , a first sealing portion  3900   a , a second sealing portion  3900   b , a first extension portion  3904   a , and a second extension portion  3904   b . In one embodiment, at least a portion of the central portion  3901  may be disposed between the hinge structure  334  and the display  361 . For example, the central portion  3901  may be disposed in an inner space of the hinge cover  365 , and both ends thereof may extend in the direction of the first bracket  331  and in the direction of the second bracket  332 , respectively. In one embodiment, the first flexible portion  3903   a  may be connected to the central portion  3901  and extend to the first opening  331   a . In this case, the first flexible portion  3903   a  may be formed to be partially bent. In one embodiment, the second flexible portion  3903   b  may be connected to the central portion  3901  to be opposite to the first flexible portion  3903   a , and extend to the second opening  332   a . In this case, the second flexible portion  3903   b  may be formed to be partially bent. In one embodiment, a rigid portion  3902  may be formed between the central portion  3901  and the flexible portion  3903 . For example, a first rigid portion  3902   a  may be formed between the central portion  3901  and the first flexible portion  3903   a , and a second rigid portion  3902   b  may be formed between the central portion  3901  and the second flexible portion  3903   b.    
     In one embodiment, the first sealing portion  3900   a  may be connected to the first flexible portion  3903   a  to be opposite to the central portion  3901 , and the second sealing portion  3900   b  may be connected to the second flexible portion  3903   b  to be opposite to the central portion  3901 . In this case, the first sealing portion  3900   a  may be disposed inside the first opening  331   a , and the second sealing portion  3900   b  may be disposed inside the second opening  332   a . In one embodiment, the first extension portion  3904   a  may be connected to the first sealing portion  3900   a  to be opposite to the first flexible portion  3903   a . The first extension portion  3904   a  may extend from the first opening  331   a  toward the first space  310   a . In this case, the first extension portion  3904   a  may be formed to be partially bent. In one embodiment, the second extension portion  3904   b  may be connected to the second sealing portion  3900   b  to be opposite to the second flexible portion  3903   b , and extend from the second opening  332   a  toward the second space  320   a . In this case, the second extension portion  3904   b  may extend from the second opening  332   a  toward the second space  320   a.    
     In one embodiment, the first sealing member  380   a  may seal the first opening  331   a , and the second sealing member  380   b  may seal the second opening  332   a . In one embodiment, the first sealing member  380   a  may be inserted and fixed into the first opening  331   a , and the second sealing member  380   b  may be inserted and fixed into the second opening  332   a . In this case, in a state in which the FPCB  390  is disposed to pass through the first opening  331   a  and the second opening  332   a , the first sealing member  380   a  may seal a space between the first opening  331   a  and the first sealing portion  3900   a , and the second sealing member  380   b  may seal a space between the second opening  332   a  and the second sealing portion  3900   b . In one embodiment, based on a state in which the first opening  331   a  and the second opening  332   a  are viewed in the direction of the display  361 , the first sealing member  380   a  may be formed in a shape corresponding to the first opening  331   a , and the second sealing member  380   b  may be formed in a shape corresponding to the second opening  332   a . In this case, the first sealing member  380   a  may be connected to surround a perimeter of the first sealing portion  3900   a , and the second sealing member  380   b  may be connected to surround a perimeter of the second sealing portion  3900   b . In one embodiment, the first sealing member  380   a  and the second sealing member  380   b  may be formed of a compressible elastic material. In this case, in a state in which the first sealing member  380   a  and the second sealing member  380   b  are positioned in the first opening  331   a  and the second opening  332   a , respectively, the first sealing member  380   a  and the second sealing member  380   b  may compress the surface of the first sealing portion  3900   a  and the surface of the second sealing portion  3900   b , respectively, thereby preventing moisture from entering along the surface of the FPCB  390 . Meanwhile, a drawing (e.g.,  FIG.  3 C ) illustrates the first sealing member  380   a  and the second sealing member  380   b  as a single structure including an insertion hole into which the FPCB  390  is inserted, which, however, is only for ease of description. The shapes and structure of the first sealing member  380   a  and the second sealing member  380   b  are not limited thereto. For example, the first sealing member  380   a  and the second sealing member  380   b  may be elastic glue applied to the surface of the first sealing portion  3900   a  and the surface of the second sealing portion  3900   b  to seal the space between the FPCB  390  and the openings, or various known waterproof packing structures. In other words, various structures capable of sealing the space between the openings and the FPCB to prevent moisture from entering through the openings may be applied to the first sealing member  380   a  and the second sealing member  380   b.    
     In one embodiment, the FPCB  390  may extend from the first space  310   a  inside the first housing  310  to the second space  320   a  inside the second housing  320  as shown in  FIG.  3 C . In this case, since the FPCB  390  extends through the first opening  331   a  and the second opening  332   a , the first sealing member  380   a  and the second sealing member  380   b  may seal the first opening  331   a  and the second opening  332   a , thereby preventing moisture from entering the first space  310   a  and the second space  320   a  along the surface of the FPCB  390 . In one embodiment, the FPCB  390  may include a waterproof structure formed therein, thereby preventing moisture from entering the first space  310   a  and the second space  320   a  therethrough. Hereinafter, for ease of description, an internal waterproof structure of the FPCB  390  will be described based on the first sealing portion  3900   a  of the FPCB  390 . In addition, unless otherwise mentioned, a sealing portion  3900  may be construed as a collective term for the first sealing portion  3900   a  and the second sealing portion  3900   b , a sealing member  380  may be construed as a collective term for the first sealing member  380   a  and the second sealing member  380   b , and an opening  331   a ,  332   a  may be construed as a collective term for the first opening  331   a  and the second opening  332   a.    
       FIGS.  4 A,  4 B, and  4 C  are cross-sectional views illustrating a sealing portion of a FPCB according to various embodiments of the disclosure. 
     Referring to  FIGS.  4 A to  4 C , a FPCB (e.g., the FPCB  390  of  FIG.  3 B ) according to one embodiment may include a plurality of substrates  391 ,  392 ,  393 , and  394  each having a metal pattern for signal transmission. In one embodiment, the FPCB may be formed in a multi-layer structure in which the plurality of substrates  391 ,  392 ,  393 , and  394  are stacked in a stacking direction (e.g., in a Z-axis direction with respect to the central portion of  FIG.  3 C ). In this case, the metal patterns formed on the respective substrates  391 ,  392 ,  393 , and  394  may allow electrical signals to be transmitted between a plurality of components (e.g., the first PCB  271  and the second PCB  272  of  FIG.  2 A ) connected by the FPCB. In one embodiment, when the FPCB is formed in a multi-layer structure, components may be mounted with high density inside an electronic device through the arrangement of three-dimensional metal patterns. 
     In one embodiment, the plurality of substrates may each include a base layer  3911 ,  3921 ,  3931 , and  3941 , a metal layer  3912 ,  3922 ,  3932 , and  3942 , a dielectric layer  3914 ,  3924 ,  3934 , and  3944 , and a bonding layer  3913 ,  3923 ,  3933 , and  3943 . In one embodiment, the base layers  3911 ,  3921 ,  3931 , and  3941  may be provided in the form of a film and formed of a polyimide (PI) material. In one embodiment, the metal layers  3912 ,  3922 ,  3932 , and  3942  may be stacked on one surface of the bases layer  3911 ,  3921 ,  3931 , and  3941  and form a metal pattern for a circuit on the surface of the base layer. The metal layers  3912 ,  3922 ,  3932 , and  3942  may be formed of a highly conductive metal material, for example, copper. In one embodiment, the metal layers  3912 ,  3922 ,  3932 , and  3942  may be stacked on the surface of the base layers  3911 ,  3921 ,  3931 , and  3941  through various known methods. For example, the metal layers  3912 ,  3922 ,  3932 , and  3942  may be stacked on the surface of the base layers  3911 ,  3921 ,  3931 , and  3941  through various methods such as sputtering, plating, or laminating. In one embodiment, the surface of the metal layers  3912 ,  3922 ,  3932 , and  3942  may be etched to form a designed metal pattern. In this case, as shown in  FIG.  4 A , based on a cross section parallel to the stacking direction, the metal layers  3912 ,  3922 ,  3932 , and  3942  may include a portion protruding through the metal pattern and a portion removed through etching, thereby forming an uneven surface according to the metal pattern. In one embodiment, the dielectric layers  3914 ,  3924 ,  3934 , and  3944  may be stacked on an outer surface of the metal layers  3912 ,  3922 ,  3932 , and  3942  to cover the metal layers  3912 ,  3922 ,  3932 , and  3942 . The dielectric layers  3914 ,  3924 ,  3934 , and  3944  may include an insulating material, for example, a material such as polyester, polyimide, liquid crystal polymer (LCP), or fluoropolymer. In one embodiment, the bonding layers  3913 ,  3923 ,  3933 , and  3943  may bond the metal layers  3912 ,  3922 ,  3932 , and  3942  and the dielectric layers  3914 ,  3924 ,  3934 , and  3944 . 
     In one embodiment, when the plurality of substrates  391 ,  392 ,  393 , and  394  are stacked, a stepped space  396  by uneven surfaces may be formed inside the FPCB. In one embodiment, the stepped space  396  may be formed inside the FPCB to extend along an extending direction. In one embodiment, the FPCB may include a waterproof member  397  disposed between the plurality of substrates to fill the stepped space  396  formed in the sealing portion  3900 . In this case, the waterproof member  397  may fill the stepped space  396  formed in the sealing portion  3900 , at the same time bonding adjacent substrates forming the stepped space  396 . Accordingly, the sealing portion  3900  of the FPCB may prevent moisture from entering through the stepped space  396 , thereby preventing moisture from entering an extending portion disposed in the first space (or the second space) from a flexible portion (e.g., the flexible portion  3903  of  FIG.  3 B ) along the inside of the FPCB. In one embodiment, the waterproof member  397  may be a bonding material formed by applying a prepreg between the plurality of substrates. In one embodiment, the waterproof member  397  may be an elastic sheet inserted between the plurality of substrates. However, this is merely an example, and various materials having waterproof performance may be applied to the waterproof member  397 . In one embodiment, when a plurality of stepped spaces  396  are formed inside the sealing portion  3900  based on the cross section, a plurality of waterproof members  397  may be disposed between adjacent substrates inside the sealing portion  3900  to fill a plurality of stepped spaces, respectively. 
     In one embodiment, the waterproof member  397  may be omitted from another portion adjacent to the sealing portion  3900 , for example, a flexible portion (e.g., the flexible portion  3903  of  FIG.  3 B ) or an extension portion (e.g., the extension portion  3904  of  FIG.  3 B ). In this case, the stress according to the flexible portion and the extension portion being bent may decrease, which may improve the service life of the FPCB. 
     Referring to  FIG.  4 A , in one embodiment, the sealing portion  3900  may include a plurality of substrates  391 ,  392 ,  393 , and  394  sequentially stacked, based on a cross section. In this case, the plurality of substrates  391 ,  392 ,  393 , and  394  may be stacked so that respective uneven surfaces thereof may face the same direction. In one embodiment, the plurality of substrates  391 ,  392 ,  393 , and  394  may include a first substrate  391 , a second substrate  392 , a third substrate  393 , and a fourth substrate  394  that are sequentially stacked. In one embodiment, the first substrate  391  may include a first base layer  3911 , a first metal layer  3912 , a first bonding layer  3913 , and a first dielectric layer  3914 . The second substrate  392  may include a second base layer  3921 , a second metal layer  3922 , a second bonding layer  3923 , and a second dielectric layer  3924 . The third substrate  393  may include a third base layer  3931 , a third metal layer  3932 , a third bonding layer  3933 , and a third dielectric layer  3934 . The fourth substrate  394  may include a fourth base layer  3941 , a fourth metal layer  3942 , a fourth bonding layer  3943 , and a fourth dielectric layer  3944 . In this case, a first stepped space  396   a  may be formed between the first substrate  391  and the second substrate  392 . A second stepped space  396   b  may be formed between the second substrate  392  and the third substrate  393 . A third stepped space  396   c  may be formed between the third substrate  393  and the fourth substrate  394 . In one embodiment, the sealing portion  3900  may include a first waterproof member  3971  disposed between the first base layer  3911  and the second dielectric layer  3924  to fill the first stepped space  396   a , a second waterproof member  3972  disposed between the second base layer  3921  and the third dielectric layer  3934  to fill the second stepped space  396   b , and a third waterproof member  3973  disposed between the third base layer  3931  and the fourth dielectric layer  3944  to fill the third stepped space  396   c . In this case, the surface of the sealing portion  3900  may be sealed by the sealing member  380 , and the stepped space  396  therein may be sealed through the waterproof member  397 . Thus, effective waterproof performance may be secured. 
     Referring to  FIG.  4 B , in one embodiment, a sealing portion  3900 ′ may form a stacked structure of a plurality of substrates  391 ,  392 ,  393 , and  394  that reduces stepped spaces  396   d  and  396   e . For example, based on a cross section shown in  FIG.  4 B , outermost substrates  391  and  394  of the plurality of substrates  391 ,  392 ,  393 , and  394  may be disposed such that uneven surfaces thereof face the outside. In this case, a surface of the sealing portion  3900 ′ may be compressed by the sealing member  380 . Thus, when the uneven surfaces face the outside, moisture entering through the uneven surfaces may be effectively blocked. In one embodiment, the plurality of substrates  391 ,  392 ,  393 , and  394  may include a first substrate  391 , a second substrate  392 , a third substrate  393 , and a fourth substrate  394  that are sequentially stacked. 
     In one embodiment, the first substrate  391  may include a first base layer  3911 , a first metal layer  3912  stacked on the first base layer  3911  and forming a first uneven surface, a first bonding layer  3913 , and a first dielectric layer  3914 . The second substrate  392  may include a second base layer  3921 , a second metal layer  3922  stacked on the second base layer  3921  and forming a second uneven surface in a direction facing the first base layer  3911 , a second bonding layer  3923 , and a second dielectric layer  3924 . The third substrate  393  may include a third base layer  3931  facing the second base layer  3921 , a third metal layer  3932  stacked on the third base layer  3931  and forming a third uneven surface in a direction opposite to the second uneven surface, a third bonding layer  3933 , and a third dielectric layer  3934 . The fourth substrate  394  may include a fourth base layer  3941 , a fourth metal layer  3942  stacked on the fourth base layer  3941  and forming a fourth uneven surface in a direction opposite to the third uneven surface, a fourth bonding layer  3943 , and a fourth dielectric layer  3944 . In this case, a first stepped space  396   d  may be formed by the second uneven surface between the first substrate  391  and the second substrate  392 . A second stepped space  396   e  may be formed by the third uneven surface between the third substrate  393  and the fourth substrate  394 . In one embodiment, the sealing portion  3900 ′ may include a first waterproof member  3971   b  disposed between the first base layer  3911  and the second dielectric layer  3924  to fill the first stepped space  396   d , and a second waterproof member  3972   b  disposed between the third dielectric layer  3934  and the fourth base layer  3941  to fill the second stepped space  396   e . In this case, the second substrate  392  and the third substrate  393  may be stacked so that the third base layer  3931  and the fourth base layer  3941  face each other, whereby a stepped space therebetween may be removed. In addition, the first substrate  391  and the fourth substrate  394  may be stacked so that respective uneven surfaces thereof may face the outside, and the surfaces thereof may be compressed by the sealing member  380 . Thus, the sealing member  3900 ′ may secure effective waterproof performance by minimizing the stepped spaces  396   d  and  396   e  formed therein. 
     Referring to  FIG.  4 C , in one embodiment, a plurality of substrates  491 ,  492 ,  493 , and  494  may form a stacked structure for reducing a stepped space  496  formed therebetween. For example, of the plurality of substrates  491 ,  492 ,  493 , and  494 , a pair of substrates  492  and  493  stacked adjacent to each other may be stacked with respective uneven surfaces facing each other, such that a single stepped space  496  may be formed between the respective uneven surfaces. In this case, the pair of substrates  492  and  493  disposed with the respective uneven surfaces facing each other may be formed such that the respective uneven surfaces may have mutually matching cross sections. 
     In one embodiment, the first substrate  491  may include a first base layer  4911 , a first metal layer  4912  stacked on the first base layer  4911  and forming a first uneven surface, a first bonding layer  4913 , and a first dielectric layer  4914 . The second substrate  492  may include a second base layer  4921  stacked on the first base layer  4911 , a second metal layer  4922  stacked on the second base layer  4921  and forming a second uneven surface in a direction opposite to the first uneven surface, a second bonding layer  4923 , and a second dielectric layer  4924 . The third substrate  493  may include a third base layer  4931 , a third metal layer  4932  stacked on the third base layer  4931  and forming a third uneven surface in a direction facing the second uneven surface, a third bonding layer  4933 , and a third dielectric layer  4934 . The fourth substrate  494  may include a fourth base layer  4941  stacked on the third base layer  4931 , a fourth metal layer  4942  stacked on the fourth base layer  4941  and forming a fourth uneven surface in a direction opposite to the third uneven surface, a fourth bonding layer  4943 , and a fourth dielectric layer  4944 . In this case, a sealing portion  3900 ″ may include a single stepped space  496  formed between the second substrate  492  and the third substrate  493 . In one embodiment, the sealing portion  3900 ″ may include a waterproof member  497   c  disposed between the second dielectric layer  4924  and the third dielectric layer  4934  to fill the stepped space  496 . In this case, the second uneven surface and the third uneven surface of the first substrate  492  and the third substrate  493  may have mutually matching cross sections, whereby the waterproof member  497   c  may be formed in a simplified cross section to effectively seal the stepped space  496 . In one embodiment, the first substrate  491  and the fourth substrate  494  may be stacked so that the respective uneven surfaces may face outward, and the surfaces thereof may be compressed by the sealing member  380 . 
     Meanwhile, although  FIGS.  4 A to  4 C  illustrate a stacked structure of a plurality of substrates in a case in which a FPCB includes four substrates that are sequentially stacked, the shown stacked structure is merely an example, and the multi-layer structure of the FPCB is not limited thereto. For example, the FPCB may be formed in a multi-layer structure in which three or at least five substrates are stacked. In this case, the waterproof structure of the sealing portion disclosed herein may apply in the same or similar manner. 
       FIG.  5    is a view illustrating a sealing portion of a FPCB according to an embodiment of the disclosure. 
       FIGS.  6 A,  6 B, and  6 C  are views illustrating sealing portions of FPCBs according to various embodiments of the disclosure. 
       FIGS.  7 A,  7 B, and  7 C  are views illustrating sealing portions of FPCBs according to various embodiments of the disclosure. 
       FIG.  8    is a cross-sectional view illustrating a sealing portion of a FPCB according to an embodiment of the disclosure. 
     Referring to  FIGS.  5 ,  6 A to  6 C,  7 A to  7 C, and  8   , in one embodiment, a sealing portion  5900  of a FPCB  590  may be designed to have a structure for improving waterproof performance. In one embodiment, a surface of the sealing portion  5900  of the FPCB  590  may be surrounded by a sealing member  580  as shown in  FIG.  5   . In this case, the sealing member  580  may be connected to compress the surface of the sealing portion  5900 , thereby preventing moisture from entering through the surface of the sealing portion  5900 , for example, moisture from entering through an opening (e.g., the opening  331   a  of  FIG.  3 B ) as shown in  FIG.  3 B . In one embodiment, the sealing portion  5900  may have a longitudinal direction L parallel to an extending direction. In one embodiment, when the sealing portion  5900  is formed in a multi-layer structure in which a plurality of substrates are stacked, an area B shown in  FIG.  5    may be construed as illustrating a cross section of a pair of substrates stacked adjacent to each other to form a stepped space. 
     In one embodiment, the sealing portion  5900  may be formed to have a relatively high waterproof performance compared to another portion of the FPCB  590 , for example, a flexible portion (e.g., the flexible portion  3903  in  FIG.  3 B ) or the extension portion  3904 . For example, the sealing portion  5900  may be formed such that the uneven surfaces forming the stepped space may secure a relatively high waterproof performance compared to the uneven surfaces formed in the other portion of the FPCB  590 . 
     Referring to  FIG.  6 A , a FPCB  590   a  may include a first substrate  691  and a second substrate  692  stacked on the first substrate  691 . In one embodiment, the first substrate  691  may include a first base layer  6911 , a first metal layer  6912  forming an uneven surface according to a metal pattern on a surface of the first base layer  6911 , and a first dielectric layer  6913  covering the first metal layer  6912 . The second substrate  692  may include a second base layer  6921 , a second metal layer  6922 , and a second dielectric layer  6923 . In this case, a stepped space  696   a  may be formed by uneven surfaces between the first substrate  691  and the second substrate  692 . In one embodiment, when the first metal layer  6912  includes a first metal pattern  69121  and a second metal pattern  69122  that are spaced apart from each other in parallel as shown in  FIG.  6 A , the stepped space  696   a  may be formed between the first metal pattern  69121  and the second metal pattern  69122 . 
     In this case, resistance received in the process of moisture passing through the stepped space  696   a  may be proportional to an area of the stepped space  696   a  and inversely proportional to a distance of a travel path of the moisture as shown in the following equation. 
       Water Resistance(R)∝Length of Travel Path of Moisture/Area of Stepped Space
 
     In one embodiment, the FPCB  590   a  may have a ratio of the area of the stepped space to a length of the sealing portion  5900  in the extending direction that is less than a ratio of the area of the stepped space to a length of another portion (e.g., the flexible portion) of the FPCB  590   a  in the extending direction. In other words, the FPCB  590   a  may have a waterproof performance of the stepped space  696   a  formed in the sealing portion  5900  that is higher than the waterproof performance of the stepped space formed on the other portion. 
     In one embodiment, the sealing portion  5900  may include a waterproof member  697  disposed in the stepped space  696   a  as shown in  FIG.  6 A . In this case, the area within the stepped space  696   a  through which moisture may move through the waterproof member  697  may decrease, which may improve the waterproof performance of the sealing portion  5900 . 
     Referring to  FIG.  6 B , a FPCB  590   b  according to one embodiment may be formed to increase a travel distance of moisture through a stepped space  696   b  in a sealing portion  6700   b . For example, the stepped space  696   b  in the sealing portion  6700   b  may be formed to form a meander pattern. For example, the FPCB  590   b  may include a first metal pattern  69121   b  and a second metal pattern  69122   b  forming the stepped space  696   b , wherein the first metal pattern  69121   b  and the second metal pattern  69122   b  may be provided in the shape of being bent to form a meander pattern in the sealing portion  6700   b . In this case, the first metal pattern  69121   b  and the second metal pattern  69122   b  in another area of the FPCB  590   b  except for the sealing portion  6700   b  may be provided in the shape of straight lines to perform effective signal transmission. Accordingly, when moisture enters through the stepped space  696   b  formed in the sealing portion  6700   b , the length of travel path D of the moisture may increase, whereby the waterproof performance of the sealing portion  6700   b  may improve. 
     Referring to  FIG.  6 C , a FPCB  590   c  according to one embodiment may include a first metal pattern  69121   c  and a second metal pattern  69122   c  forming a stepped space  696   c  therebetween. In this case, the first metal pattern  69121   c  and the second metal pattern  69122   c  may include one or more stub shapes protruding toward the inside of the stepped space  696   c . In this case, an area of the stepped space  696   c  in the sealing portion may decrease through the stub shapes, and at the same time a length of travel path of moisture through the sealing portion  6700   c  may increase, which may improve the waterproof performance of the sealing portion  6700   c.    
     Referring to  FIGS.  7 A to  7 C , a FPCB  790   a ,  790   b ,  790   c  according to one embodiment may include a first metal pattern  79121   a ,  79121   b ,  79121   c  and a second metal pattern  79122   a ,  79122   b ,  79122   c  forming a stepped space  796   a ,  796   b ,  796   c  therebetween, and include one or more dummy patterns  7914   a ,  7914   b ,  7914   c  provided between the first metal pattern  79121   a ,  79121   b ,  79121   c  and the second metal pattern  79122   a ,  79122   b ,  79122   c  for interfering with travel of moisture through the stepped space  796   a ,  796   b ,  796   c , at the same time reducing a cross-sectional area of the stepped space  796   a ,  796   b ,  796   c . In this case, the first metal pattern  79121   a ,  79121   b ,  79121   c  and the second metal pattern  79122   a ,  79122   b ,  79122   c  may be provided in the shape of straight lines in the sealing portion  7700   a ,  7700   b ,  7700   c  to perform effective signal transmission. Accordingly, it is possible to maintain the signal transmission performance in the sealing portion  7700   a ,  7700   b ,  7700   c , at the same time effectively improving the waterproof performance through the dummy patterns  7914   a ,  7914   b ,  7914   c.    
     Referring to  FIG.  8   , a FPCB  890  according to one embodiment may include a first substrate  891  including a first base layer  8911 , a first metal layer  8912  forming a first uneven surface, and a first dielectric layer  8913 , and a second substrate  892  including a second base layer  8921 , a second metal layer  8922  forming a second uneven surface, and a second dielectric layer  8923 . In one embodiment, the first substrate  891  and the second substrate  892  may be stacked such that the first metal layer  8912  and the second metal layer  8922  may face each other. In this case, the facing uneven surfaces of the first substrate  891  and the second substrate  892  may be formed such that the respective metal patterns thereof do not overlap each other. In this case, a cross section of a stepped space formed between the first substrate  891  and the second substrate  892  may decrease, which may improve the waterproof performance of the FPCB  890 . 
     According to one embodiment, an electronic device  301  may include: a display  361  including a first area  361   a  and a second area  361   b ; a first housing  310  supporting the first area  361   a  and forming a first space  310   a  positioned on a rear surface of the first area  361   a ; a second housing  320  supporting the second area  361   b  and forming a second space  310   b  positioned on a rear surface of the second area  361   b ; a hinge structure  334  connecting the first housing  310  and the second housing  320  to be foldable about a folding axis and allowing the first area  361   a  and the second area  361   b  to change between a first state of forming substantially the same plane and a second state of facing each other; a first bracket  331  connecting the first housing  310  and the hinge structure  334  and having a first opening  331   a  penetrating through a surface thereof; a second bracket  332  connecting the second housing  320  and the hinge structure  334  and having a second opening  332   a  penetrating through a surface thereof; and a FPCB  390  extending from the first space  310   a  to the second space  310   b  across the hinge structure  334  in an extending direction, and formed in a multi-layer structure in which a plurality of substrates  391 ,  392 ,  393 , and  394  having uneven surfaces according to metal patterns are stacked in a stacking direction, wherein the FPCB  390  may include a first sealing portion  3900   a  positioned inside the first opening  331   a  and a second sealing portion  3900   b  positioned inside the second opening  332   a , and a waterproof member  397  for sealing a space between the plurality of substrates  391 ,  392 ,  393 , and  394  may be disposed in the first sealing portion  3900   a  and the second sealing portion  3900   b.    
     In one embodiment, the electronic device  301  may further include: a first sealing member  380   a  for sealing the first opening  331   a ; and a second sealing member  380   b  for sealing the second opening  332   a , wherein a surface of the first sealing portion  3900   a  may be compressed by the first sealing member  380   a , and a surface of the second sealing portion  3900   b  may be compressed by the second sealing member  380   b.    
     In one embodiment, the plurality of substrates  391 ,  392 ,  393 , and  394  may each include: a base layer  3911 ; a metal layer  3912  stacked on one surface of the base layer  3911 , and forming the uneven surface; and a dielectric layer  3914  stacked to cover the metal layer  3912 , wherein a stepped space  396  by the uneven surface may be formed between the plurality of substrates  391 ,  392 ,  393 , and  394 , and the waterproof member  397  may be disposed in the stepped space  396 . 
     In one embodiment, a pair of adjacent substrates  492  and  493  among the plurality of substrates may be stacked such that respective uneven surfaces thereof may face each other, and the waterproof member  497   c  may be disposed between the facing uneven surfaces of the pair of substrates  492  and  493 . 
     In one embodiment, based on a cross section parallel to the stacking direction, the facing uneven surfaces of the pair of substrates  492  and  493  may be formed to have mutually matching cross sections such that the stepped space  496  may be formed therebetween. 
     In one embodiment, based on a cross section parallel to the stacking direction, the facing uneven surfaces of the pair of substrates  492  and  493  may be formed not to overlap each other. 
     In one embodiment, the plurality of substrates  491 ,  492 ,  493 , and  494  may include: based on the cross section parallel to the stacking direction, a first substrate  491  including a first base layer  4911  and a first metal layer  4912  stacked on the first base layer  4911  and forming a first uneven surface; a second substrate  492  including a second base layer  4921  stacked on the first base layer  4911 , and a second metal layer  4922  stacked on the second base layer  4921  and forming a second uneven surface in a direction opposite to the first uneven surface; a third substrate  493  including a third base layer  4931  and a third metal layer  4932  stacked on the third base layer  4931  and forming a third uneven surface in a direction facing the second uneven surface; and a fourth substrate  494  including a fourth base layer  4941  stacked on the third base layer  4931 , and a fourth metal layer  4942  stacked on the fourth base layer  4941  and forming a fourth uneven surface in a direction opposite to the third uneven surface, wherein the waterproof member  497   c  may be disposed between the second uneven surface and the third uneven surface. 
     In one embodiment, the plurality of substrates  391 ,  392 ,  393 , and  394  may include: based on the cross section parallel to the stacking direction, a first substrate  391  including a first base layer  3911  and a first metal layer  3912  stacked on the first base layer  3911  and forming a first uneven surface; a second substrate  392  including a second base layer  3921 , and a second metal layer  3922  stacked on the second base layer  3921  and forming a second uneven surface in a direction facing the first base layer  3911 ; a third substrate  393  including a third base layer  3931  facing the second base layer  3921 , and a third metal layer  3932  stacked on the third base layer  3931  and forming a third uneven surface in a direction opposite to the second uneven surface; and a fourth substrate  394  including a fourth base layer  3941 , and a fourth metal layer  3942  stacked on the fourth base layer  3941  and forming a fourth uneven surface in a direction opposite to the third base layer  3931 , wherein a first waterproof member  3971   b  may be disposed between the first base layer  3911  and the second uneven surface, and a second waterproof member  3972   b  may be disposed between the fourth base layer  3941  and the third uneven surface. 
     In one embodiment, the FPCB  390  may include: a first flexible portion  3903   a  to be bent to an outer side of the first opening  331   a  from the first sealing portion  3900   a  toward the hinge structure  334 ; and a second flexible portion  3903   b  to be bent to an outer side of the second opening  332   a  from the second sealing portion  3900   b  toward the hinge structure  334 , wherein the waterproof member may be omitted from the first flexible portion  3903   a  and the second flexible portion  3903   b.    
     In one embodiment, the FPCB  390  may include: a first extension portion  3904   a  to be bent to the outer side of the first opening  331   a  from the first sealing portion  3900   a  toward the first space  310   a ; and a second extension portion  3904   b  to be bent to the outer side of the second opening  332   a  from the second sealing portion  3900   b  toward the second space  310   b , wherein the waterproof member may be omitted from the first extension portion  3904   a  and the second extension portion  3904   b.    
     In one embodiment, a stepped space  696   a  by the uneven surface may be formed between the plurality of substrates  691  and  692 , and a ratio of an area of the stepped space to a length of the first sealing portion  3900   a  and the second sealing portion  3900   b  in the extending direction may be less than a ratio of an area of the stepped space to a length of the first flexible portion  3903   a  and the second flexible portion  3903   b  in the extending direction. 
     In one embodiment, a stepped space  696   b  by the uneven surface may be formed between the plurality of substrates, and based on a state in which the stepped space  696   b  is viewed in the stacking direction, the stepped space  696   b  may form a meander pattern in the first sealing portion  3900   a  or the second sealing portion  3900   b.    
     In one embodiment, a stepped space by the uneven surface may be formed between the plurality of substrates, and based on a state in which the stepped space is viewed in the stacking direction, the metal patterns  69121   c  and  69121   b  may include one or more stub shapes protruding toward the inside of the stepped space, in the first sealing portion  3900   a  or the second sealing portion  3900   b.    
     In one embodiment, a stepped space  796   a  by the uneven surface may be formed between the plurality of substrates, and based on a state in which the stepped space  796   a  is viewed in the stacking direction, the metal patterns may include one or more dummy patterns  7914   a  formed to be positioned inside the stepped space, in the first sealing portion  3900   a  or the second sealing portion  3900   b.    
     In one embodiment, the waterproof member  397  may be formed by applying a prepreg between the plurality of substrates or may be an elastic sheet inserted between the plurality of substrates. 
     According to one embodiment, a FPCB  390  may include: a central portion  3901 ; a first flexible portion  3903   a  connected to the central portion  3901  and configured to be partially bent; a second flexible portion  3903   b  connected to the central portion  3901  to be opposite to the first flexible portion  3903   a  and configured to be partially bent; a first sealing portion  3900   a  connected to the first flexible portion  3903   a  to be opposite to the central portion  3901 ; a second sealing portion  3900   b  connected to the second flexible portion  3903   b  to be opposite to the central portion  3901 ; a first extension portion  3904   a  connected to the first sealing portion  3900   a  to be opposite to the first flexible portion  3903   a  and configured to be partially bent; and a second extension portion  3904   b  connected to the second sealing portion  3900   b  to be opposite to the second flexible portion  3903   b  and configured to be partially bent, wherein the FPCB  390  may be formed in a multi-layer structure in which a plurality of substrates  391 ,  392 ,  393 , and  394  having uneven surfaces according to metal patterns may be stacked in a stacking direction, a stepped space  396  by the uneven surfaces may be formed between the plurality of substrates  391 ,  392 ,  393 , and  394 , and a ratio of an area of the stepped space  396  to a length of the first sealing portion  3900   a  and the second sealing portion  3900   b  may be less than or equal to a ratio of an area of the stepped space  396  to a length of the first flexible portion  3903   a  and the second flexible portion  3903   b.    
     In one embodiment, the FPCB  390  may further include: a waterproof member  397  disposed between the plurality of substrates to fill the stepped space  396 , wherein the waterproof member  397  may be positioned in the first sealing portion  3900   a  and the second sealing portion  3900   b.    
     In one embodiment, the waterproof member  397  may be omitted from the first flexible portion  3903   a , the second flexible portion  3903   b , the first extension portion  3904   a , and the second extension portion  3904   b.    
     In one embodiment, in a state in which the stepped space formed in the first sealing portion  3900   a  and the second sealing portion  3900   b  is viewed in the stacking direction, the metal patterns may be formed to form a meander pattern. 
     According to one embodiment, an electronic device  301  may include: a display  361  including a first area  361   a  and a second area  361   b ; a first housing  310  including a first surface on which the first area  361   a  is disposed, and a second surface opposite to the first surface; a second housing  320  including a third surface on which the second area  361   b  is disposed, and a fourth surface opposite to the third surface; a hinge structure  334  connecting the first housing  310  and the second housing  320  to be foldable about a folding axis and allowing the first area  361   a  and the second area  361   b  to change between a first state of forming substantially the same plane and a second state of facing each other; a first bracket  331  connecting the first housing  310  and the hinge structure  334  and including a first opening  331   a  penetrating through a surface thereof; a second bracket  332  connecting the second housing  320  and the hinge structure  334  and including a second opening  332   a  penetrating through a surface thereof; a first PCB disposed between the first bracket  331  and the second surface; a second PCB disposed between the second bracket  332  and the fourth surface; a FPCB  390  with at least a portion disposed between the hinge structure  334  and the display  361 , and both ends respectively connected to the first PCB  271  and the second PCB  272  by passing through the first opening  331   a  and the second opening  332   a ; a first sealing member  380   a  surrounding a perimeter of a first sealing portion  3900   a  of the FPCB  390  positioned inside the first opening  331   a , and sealing between the first opening  331   a  and the first sealing portion  3900   a ; and a second sealing member  380   b  surrounding a perimeter of a second sealing portion  3900   b  of the FPCB  390  positioned inside the second opening  332   a , and sealing between the second opening  332   a  and the second sealing portion  3900   b , wherein the FPCB  390  may be formed in a multi-layer structure in which a plurality of substrates having uneven surfaces according to metal patterns are stacked in a stacking direction, and a waterproof member  397  for filling a stepped space  396  formed by the uneven surfaces between the plurality of substrates may be disposed in the first sealing portion  3900   a  and the second sealing portion  3900   b.    
     In one embodiment, the first bracket and the second bracket are rotatably connected to the hinge structure. 
     In one embodiment, the second bracket is disposed between the second area and the second PCB. 
     In one embodiment, the first bracket has one or more first openings formed to penetrate therethrough toward the first area, and the second bracket has one or more second openings formed to penetrate therethrough toward the second area. 
     While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.