Patent Publication Number: US-2022240384-A1

Title: Overlapping printed circuit boards and electronic device including same

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation application of prior application Ser. No. 17/132,484, filed on Dec. 23, 2020, which is a continuation application of prior application Ser. No. 16/413,797, filed on May 16, 2019, which is based on and claims priority under 35 U.S.C. § 119(a) of a Korean patent application Serial number 10-2018-0061270, filed on May 29, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     Certain embodiments relate to overlapping printed circuit boards and an electronic device including the printed circuit boards. 
     2. Description of Related Art 
     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. 
     With the development of digital technologies, electronic devices are being produced in various forms such as a smart phone, a tablet personal computer (PC), and a personal digital assistant (PDA). Electronic devices are also being developed in a user wearable form in order to improve portability and a user&#39;s accessibility. An electronic device may include a printed circuit board connecting electronic components, and the printed circuit board may support data input/output and data exchange between the electronic components. 
     SUMMARY 
     A printed circuit board may include, for example, an area having that is relatively thin, which may be more likely than other areas to be damaged (cracked) due to an impact when the printed circuit board is coupled to or separated from an electronic device. The thickness of the area may be increased to make the area more rigid. However, this may consume more of the internal space in the electronic device and make it difficult to install other elements. 
     Electronic components may transmit or receive data signals through signal lines etched on the printed circuit board. Due to current flow, an electric field is formed in the signal lines, and this electric field causes electromagnetic interference (EMI) that interferes with the normal operation of the electronic components by introducing noise to a nearby electronic component or signals transmitted to another nearby signal line. In order to suppress such electromagnetic interference (e.g., noise), the signal lines may be designed to be located as far as possible from the nearest signal lines and electronic components, or may be designed such that the signal strength is high. However, with portable electronic devices large numbers of electronic components for various functions and signal lines associated therewith are being added to relatively small-volume electronic devices. In this regard, it is becoming more difficult to design the signal lines in a printed circuit board (e.g., the area formed in a relatively narrow width in the printed circuit board). 
     An embodiment of the disclosure provides overlapping printed circuit boards disposed to reinforce the rigidity of at least a portion of the printed circuit boards and an electronic device including the printed circuit boards. 
     An embodiment of the disclosure provides overlapping printed circuit boards disposed to secure a wiring area and an electronic device including the printed circuit boards. 
     According to an embodiment of the disclosure, an electronic device comprises a first printed circuit board including a first electrical terminal exposed on one face of a first area, a second electrical terminal exposed on the one face of a second area and insulated from the first electrical terminal, and a first ground terminal exposed on the one face of a third area formed between the first area and the second area, the third area having a width narrower than a width of the first area or the width of the second area; and a second printed circuit board including a third electrical terminal exposed on one face of a fourth area, a fourth electrical terminal exposed on the one face of a fifth area and electrically connected to the third electrical terminal, and a second ground terminal exposed on the one face of a sixth area located between the fourth area and the fifth area, wherein the second printed circuit board is disposed on the first printed circuit board to overlap the third area, the first electrical terminal and the third electrical terminal are electrically coupled to each other, the second electrical terminal and the fourth electrical terminal are electrically coupled to each other, and the first ground terminal and the second ground terminal are electrically coupled to each other. 
     According to certain embodiments, it is easy to reinforce at least some areas of the first printed circuit board and to secure a wiring area using one or more second printed circuit boards that overlap and coupled to the first printed circuit board, without increasing the wiring density in the areas or without designing the areas so as to expand the width thereof. 
     In addition, effects obtainable or predicted by certain embodiments of the disclosure will be directly or implicitly disclosed in the detailed description of the embodiments of the disclosure. For example, various effects that are expected according to certain embodiments of the disclosure will be disclosed within the following detailed description. 
    
    
     
       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 front side perspective view of a mobile electronic device according to an embodiment; 
         FIG. 2  is a rear side perspective view of the electronic device of  FIG. 1 ; 
         FIG. 3  is an exploded perspective view of the electronic device of  FIG. 1 ; 
         FIG. 4A  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 4B  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 4C  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 4D  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 5A  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 5B  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 5C  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 5D  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 5E  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 5F  is a view related to a manufacturing flow of a second printed circuit board in  FIG. 3 ; 
         FIG. 6  is a view for explaining contouring of a printed circuit board according to certain embodiments; 
         FIG. 7  is an exploded perspective view of printed circuit boards according to an embodiment; 
         FIG. 8  is a cross-sectional view of a printed circuit board according to an embodiment; 
         FIG. 9  is a view illustrating an electronic device including overlappingly disposed printed circuit boards according to certain embodiments; 
         FIG. 10  is a view illustrating an electronic device including overlapping printed circuit boards according to certain embodiments; 
         FIG. 11A  is a front view of a second printed circuit board according to certain embodiments; 
         FIG. 11B  is a rear view of the second printed circuit board of  FIG. 11A ; 
         FIG. 12  is a view illustrating a second printed circuit board according to certain embodiments; 
         FIG. 13  is a view illustrating a printed circuit board according to certain embodiments; and 
         FIG. 14  is a block diagram of an electronic device, including overlapping printed circuit boards, within a network environment according to certain embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, certain embodiments of the disclosure will be described with reference to the accompanying drawings. The certain embodiments and the terms used herein are not intended to limit the technical features disclosed herein to specific embodiments, and should be understood to include various modifications, equivalents, and/or alternatives to the corresponding embodiments. In describing the drawings, similar reference numerals may be used to designate similar constituent elements. The singular form of a noun corresponding to an item may include one item or a plurality of items unless the relevant context clearly indicates otherwise. In the disclosure, the expression “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B, or C”, or “at least one of A, B, or C” may include all possible combinations of items enumerated together. The expression “a first”, “a second”, “the first”, or “the second” may modify corresponding elements regardless of the order or importance, and is used only to distinguish one element from another element, but does not limit the corresponding elements. When an element (e.g., first element) is referred to as being “coupled” or “connected” to another element (second element) with or without the term “functionally” or “communicatively”, the element may be connected directly (e.g., wiredly) to the another element or connected to the another element through yet another element (e.g., third element). 
     The electronic device according to certain embodiments disclosed herein may be various types of devices. The electronic device may, for example, include at least one of a portable communication device (e.g., smartphone) a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, and a home appliance. The electronic device according to one embodiment of the disclosure is not limited to the above described devices. In the disclosure, the term “user” may indicate a person using an electronic device or a device (e.g., an artificial intelligence electronic device) using an electronic device. 
       FIG. 1  is a front side perspective view of a mobile electronic device according to an embodiment.  FIG. 2  is a rear side perspective view of the electronic device of  FIG. 1 .  FIG. 3  is an exploded perspective view of the electronic device of  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , an electronic device  100  according to an embodiment may include a housing  110  including a first face (or a front face)  110 A, a second face (or a rear face)  110 B, and a side face  110 C surrounding a space between the first face  110 A and the second face  110 B. In another embodiment (not illustrated), the term “housing” may refer to a structure forming some of the first face  110 A, the second face  110 B, and the side face  110 C of  FIG. 1 . According to an embodiment, at least part of the first face  110 A may be formed of a substantially transparent front plate  102  (e.g., a glass plate or a polymer plate including various coating layers). The second face  110 B may be formed of a substantially opaque rear plate  111 . The rear plate  111  may be formed of, for example, coated or colored glass, ceramic, a polymer, or a metal (e.g., aluminum, stainless steel (STS), or magnesium), or a combination of two or more of these materials. The side face  110 C may be formed by a side bezel structure (or a “side member”)  118  coupled to the front plate  102  and the rear plate  111  and including a metal and/or a polymer. In some embodiments, the rear plate  111  and the side bezel structure  118  may be integrally formed, and may include the same material (e.g., a metal material such as aluminum). 
     In the illustrated embodiment, the front plate  102  may include two first areas  110 D, which are bent from the first face  110 A toward the rear plate  111  and extend seamlessly, at the long opposite side edges thereof. In the illustrated embodiment (see  FIG. 2 ), the rear plate  111  may include two second areas  110 E, which are bent from the second face  110 B toward the front plate  102  and extend seamlessly, at the long opposite side edges thereof. In some embodiments, the front plate  102  (or the rear plate  111 ) may include only one of the first areas  110 D (or the second areas  110 E). In another embodiment, some of the first areas  110 D and the second areas  110 E may not be included. In the above embodiments, when viewed from a side of the electronic device  100 , the side bezel structure  118  may have a first thickness (or width) on the side in which the first areas  110 D or the second areas  110 E are not included, and may have a second thickness (or width), which is thinner than the first thickness, on the side in which the first areas  110 D or the second areas  110 E are included. 
     According to an embodiment, the electronic device  100  may include one or more of a display  101 , audio modules  103 ,  107 , and  114 , sensor modules  104 , and  119 , camera modules  105 ,  112 , and  113 , key input devices  115 ,  116 , and  117 , an indicator  106 , and connector holes  108  and  109 . In some embodiments, in the electronic device  100 , at least one of the components ((e.g., the key input devices  115 ,  116 , and  117  or the indicator  116 ) may be omitted, or other components may be additionally included. 
     The display  101  may be exposed through, for example, a large portion of the front plate  102 . In some embodiments, at least a part of the display  101  may be exposed through the front plate  102  forming the first face  110 A and the first areas  110 D of the side faces  110 C. The display  101  may be coupled to or disposed adjacent to a touch-sensing circuit, a pressure sensor capable of measuring touch intensity (pressure), and/or a digitizer that detects a magnetic-field-type stylus pen. In some embodiments, at least some of the sensor modules  104  and  119  and/or at least some of the key input devices  115 ,  116 , and  117  may be disposed in the first areas  110 D and/or the second areas  110 E. 
     According to an embodiment, the audio modules  103 ,  107 , and  114  may include a microphone hole  103  and speaker holes  107  and  114 . The microphone hole  103  may include a microphone disposed therein so as to acquire external sound, and in some embodiments, the microphone hole  125  may include multiple microphones disposed therein so as to sense the direction of sound. The speaker holes  107  and  114  may include an external speaker hole  107  and a phone call receiver hole  114 . In some embodiments, the speaker holes  107  and  114  and the microphone hole  103  may be implemented as a single hole, or a speaker (e.g., a piezo speaker) may be included without the speaker holes  107  and  114 . 
     According to an embodiment, the sensor modules  104  and  119  may generate an electrical signal or a data value corresponding to the internal operating state of the electronic device  100  or an external environmental condition. The sensor modules  104  and  119  may include, for example, a first sensor module  104  (e.g., a proximity sensor) and/or a second sensor module (not illustrated) (e.g., a fingerprint sensor) disposed on the first face  110 A of the housing  110 , and/or a third sensor module  119  (e.g., an HRM sensor) disposed on the second face  110 B of the housing  110 . The fingerprint sensor may be disposed not only on the first face  110 A of the housing  110  (e.g., the home button  115 ), but also on the second face  110 B thereof. The electronic device  100  may further include at least one of sensors (not illustrated) such as a gesture sensor, a gyro sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, and an illuminance sensor. 
     According to an embodiment, the camera modules  105 ,  112 , and  113  may include a first camera device  105  disposed on the first face  110 A of the electronic device  100  and a second camera device  112  and/or a flash  113  disposed on the second face  110 B. The camera devices  105  and  112  may include one or more lenses, an image sensor, and/or an image signal processor. The flash  113  may include, for example, a light-emitting diode or a xenon lamp. In some embodiments, two or more lenses (e.g., an infrared camera lens, a wide-angle lens, and a telephoto lens) and image sensors may be disposed on one face of the electronic device  100 . 
     According to an embodiment, the key input devices  115 ,  116 , and  117  may include a home key button  115  disposed on the first face  110 A of the housing  110 , a touch pad  116  disposed in the vicinity of the home key button  115 , and/or a side key button  117  disposed on the side face  110   c  of the housing  110 . In another embodiment, the electronic device  100  may not include some or all of the above-mentioned key input devices  115 ,  116 , and  117 , and a key input device  115 ,  116 , or  117 , which is not included, may be implemented in another form such as a soft key on the display  101 . 
     The indicator  106  may be disposed on, for example, the first face  110 A of the housing  110 . The indicator  106  may include an LED as long as it can provide, for example, the state information of the electronic device  100  in an optical form. 
     According to an embodiment, the connector holes  108  and  109  may include a first connector hole  108  capable of accommodating a connector (e.g., a USB connector) for transmitting and receiving power and/or data to and from an external electronic device, and/or a second connector hole  109  capable of accommodating a connector (e.g., an earphone jack) for transmitting and receiving an audio signal to and from an electronic device. 
     Referring to  FIG. 3 , the electronic device  300  may include a side bezel structure  310 , a first support member  311  (e.g., a bracket), a front plate  320 , a display  330 , a printed circuit board(s) (PCB(s))  340 , a battery  350 , a second support member  360  (e.g., a rear case), an antenna  370 , and a rear plate  380 . In some embodiments, in the electronic device  300 , at least one of the components (e.g., the first support member  311  or the second support member  360 ) may be omitted, or other components may be additionally included. At least one of the components of the electronic device  300  may be the same as or similar to at least one of the components of the electronic device  100  of  FIG. 1 or 2 , and a redundant description is omitted below. 
     According to an embodiment, the first support member  311  may be disposed inside the electronic device  300  and may be connected to the side bezel structure  310 , or may be formed integrally with the side bezel structure  310 . The first support member  311  may be formed of, for example, a metal material and/or a non-metal (e.g., polymer) material. The display  330  may be coupled to one side of the first support member  311 , and the printed circuit board(s)  340  may be coupled to the other side of the first support member  311 . On the printed circuit board(s)  340 , a processor, a memory, and/or an interface may be mounted. The processor may include one or more of, for example, a central processing unit, an application processor, a graphic processor, an image signal processor, a sensor hub processor, or a communication processor. 
     The memory may include, for example, volatile memory or nonvolatile memory. 
     The interface may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, and/or an audio interface. The interface may electrically or physically connect, for example, the electronic device  300  to an external electronic device, and may include a USB connector, an SD card/an MMC connector, or an audio connector. 
     The battery  350  is a device for supplying power to at least one component of the electronic device  300 , and may include, for example, a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell. At least a part of the battery  350  may be disposed to be substantially flush with, for example, the printed circuit board(s)  340 . The battery  350  may be integrally disposed within the electronic device  300 , or may be mounted so as to be detachable from the electronic device  300 . 
     The second support member  360  may be coupled to, for example, the first support member  311 , and may be disposed between the printed circuit board(s)  340  and the first rear plate  380 . The second support member  360  may be coupled to the first support member  311  together with the printed circuit board(s)  340  using bolt fastening or the like, and may serve to cover and protect the printed circuit board(s)  340 . 
     According to an embodiment, the antenna  370  may be disposed between the rear plate  380  and the display  350 . The antenna  370  may include, for example, a near-field communication (NFC) antenna, a wireless charging antenna, and/or a magnetic secure transmission (MST) antenna. The antenna  370  is capable of, for example, performing short-range communication with an external device or transmitting and receiving power required for charging in a wireless manner. In another embodiment, an antenna structure may be formed by the side bezel structure  310 , a portion of the first support member  311 , or a combination thereof. 
     According to an embodiment, the printed circuit board(s)  340  may include a first printed circuit board  341  and at least one second printed circuit board  342  disposed to overlap the first printed circuit board  341 . 
     According to an embodiment, the first printed circuit board  341  or the second printed circuit board  342  may be a multilayer printed circuit board. The multilayer printed circuit board may be formed by forming a plurality of inner layers in which a circuit is formed using a copper-clad laminate (CCL) (or an original plate) and laminating the plurality of inner layers. According to some embodiments, the first printed circuit board  341  or the second printed circuit board  342  formed on the basis of the copper-clad laminate may be a single-side printed circuit board in which a circuit is formed on only one side and a double-sided printed circuit board in which circuits are formed on both sides. 
     The second printed circuit board  342  may reinforce, for example, the first printed circuit board  341 . According to an embodiment, the first printed circuit board  341  may include a first area  341 A, a second area  341 B, and a third area  341 C disposed between the first area  341 A and the second area  341 B. The third area  341 C may be disposed along the side of the battery. As a result, the third area  341 C may have a narrower width than the first area  341 A or the second area  341 B, and may be more likely than the first area  341 A of the second  341 B area to be damaged due to cracks or the like (it is noted that the third area  341 C may have a narrow width for other reasons). The second printed circuit board  342  may be disposed to overlap the third area  341 C so as to be used as a reinforcing member (e.g., a reinforcing plate) to reinforce the rigidity of the third area  341 C. According to certain embodiments, the second printed circuit board  342  may be coupled to overlap various other areas of the first printed circuit board  341  that require reinforcement. 
     The second printed circuit board  342  may provide an electric path connected to, for example, the first printed circuit board  341 . For example, the first printed circuit board  341  may include a first area  341 A, a second area  341 B, and a third area  341 C disposed between the first area  341 A and the second area  341 B, and may include a first electrical terminal exposed on one face of the first area  341 A, and a second electrical terminal exposed on one face of the second area  341 B and physically separated from the first electrical terminal. The second printed circuit board  342  may include a third electrical terminal exposed on one face of a fourth area and a fourth electrical terminal exposed on one face of a fifth area, and the third electrical terminal and the fourth electrical terminal are electrically connected to each other. When the first printed circuit board  341  and the second printed circuit board  342  are coupled to each other, the first electrical terminal is coupled to the third electrical terminal via solder, and the second electrical terminal is coupled to the fourth electrical terminal via solder. Thereby, the first electrical terminal and the second electrical terminal may be electrically connected to each other through the second printed circuit board  342 . The electrical terminals may include signal terminals, conductive terminals, contact terminals, or conductive pads. 
     For example, the first printed circuit board  341  may include a first ground terminal exposed at least in some areas (e.g., the third area disposed between the first area  341 A and the second area  341 B). The first ground terminal may be a part of a first ground included in the first printed circuit board  341  or may be electrically connected to the first ground. The second printed circuit board  342  may include a second ground terminal exposed on one face thereof, and the second ground terminal may be a part of the second ground (or a second ground circuit) included in the second printed circuit board  342 , or may be electrically connected to the second ground. When the second printed circuit board  342  is coupled to the first printed circuit board  341 , solder interconnecting the first ground terminal and the second ground terminal is disposed, by which the first ground and the second ground can be electrically connected to each other. The first ground and the second ground may be utilized as the ground of the corresponding potential, so that the noise or electromagnetic interference (EMI) generated in the electronic device  300  can be reduced. 
     According to certain embodiments, the second printed circuit board  342  may include a third ground that is physically separated from the first ground of the first printed circuit board  341 . The first ground may have a first potential, and the third ground may have a second potential different from the first potential. The noise generated in the electronic device  300  may be attenuated by being dispersed to the first ground and the third ground. For example, a relatively high noise floor (e.g., a measured value for the sum of noise) of the noise generated by the electronic device  300  may be attenuated either by the first ground or by the third ground. 
     According to certain embodiments, the second printed circuit board  342  may be utilized as a part (e.g., an antenna) of a transmission circuit for wireless communication. At least a part of the circuit formed on the second printed circuit board  342  is electrically connected to a communication circuit mounted on the first printed circuit board  341 , and the communication circuit may support various types of communication using the second printed circuit board  343 . For example, the communication circuit may be electrically connected to the circuit and to a processor (not shown) included in the second printed circuit board  342 . The communication circuit may include radio frequency (RF) components such as a radio frequency integrated circuit (RFIC) and a front-end module (FEM) between the second printed circuit board  342  and the processor. For example, the RFIC may receive external radio waves through the second printed circuit board  342 , and may modulate the received high-frequency waves to a low frequency band (e.g., a baseband) that can be processed by the processor. The RFIC is capable of modulating low-frequency waves to high-frequency waves for transmission in the processor. The FEM may connect the second printed circuit board  342  and the RFIC, and may separate transmitted and received signals. For example, the FEM may perform filtering and amplification, and may include a reception-end FEM in which a filter is embedded in order to filter a received signal and a transmission-end FEM in which a power amplifier module (PAM) is embedded in order to amplify a transmitted signal. 
     According to certain embodiments, the second printed circuit board  342  may be used for at least one communication system among single input multiple output (SIMO), multiple input single output (MISO), diversity, and multiple input multiple output (MIMO). 
     According to some embodiments, the second printed circuit board  342  may be utilized as an antenna-matching circuit. The radiation characteristics and impedance of an antenna (e.g., the antenna  370  in  FIG. 3 ) are related to antenna performance, and may vary depending on the shape, size, and material of the antenna. The radiation characteristics of the antenna may include an antenna radiation pattern (or an antenna pattern), which is a directional function indicating the relative distribution of power radiated from the antenna, and the polarization state of electromagnetic waves radiated from the antenna (e.g., antenna polarization). The impedance of the antenna may be related to the transmission of power from a transmitter to the antenna or from the antenna to a receiver. In order to minimize reflection at a transmission line and an antenna connection portion, the impedance of the antenna is designed to match the impedance of the transmission line, thereby enabling maximum power transmission (or minimization of power loss) or efficient signal transmission through the antenna. The impedance matching may induce efficient signal flow at a specific frequency (or a resonant frequency). Impedance mismatch may cause power loss or reduce the strength of transmitted/received signals, thereby degrading communication performance. According to an embodiment, the circuit included in the second printed circuit board  342  may be utilized as a frequency adjustment circuit in order to eliminate such impedance mismatch. 
     According to an embodiment, the frequency adjustment circuit may include a switching circuit that switches to at least one designated matching circuit (e.g., a circuit included in the second printed circuit board  342 ) or a circuit that adjusts impedance using the second printed circuit board  342 . For example, the frequency adjustment circuit may shift the resonant frequency to a designated frequency using the second printed circuit board  342 , or may shift the resonant frequency as specified. 
       FIG. 4A-5F  are views related to a manufacturing flow of a second printed circuit board, such as second printed circuit board  342  in  FIG. 3 . 
     Referring to  FIG. 4A , in an embodiment, a copper-clad laminate (or an original plate)  410  may be formed. The copper-clad laminate  410  is a laminate for use in a printed circuit, and may include a structure in which copper foils  412  and  413  are attached to both sides of an insulating layer (or an insulating plate)  411  composed of various basic insulating materials (e.g., a resin) and a binder. 
     The copper foils  412  and  413  may be, for example, electrolytic copper foils formed through a chemical-electrolytic reaction. According to an embodiment, in order to increase the adhesion with the resin of the insulating layer  411 , the copper foils  412  and  413  may be made to chemically react with the resin to partially (about 5 μm (micrometers)) penetrate into the resin when forming the copper foils  412  and  413 . The thickness of an electrolytic copper foil may be about 18 to 70 μm, but the copper foils  412  and  413  may be variously formed to have thicknesses of 5 μm, 7 μm, and 15 μm, which are thinner than the above-mentioned range, depending on wiring density or fineness. According to some embodiments, the copper foils  412  and  413  may be rolled copper foils that have been rolled and thinned. The thickness of the copper foils  412  and  413  may be variously determined depending on the current allowed in the pattern. 
     The insulating layer  411  of the copper-clad laminate  410  may include a resin such as phenol or epoxy. The copper-clad laminate  410  may further include a reinforcing base material (not illustrated) such as paper, glass fiber, or glass non-woven fabric. The reinforcing base material is able to increase rigidity of the insulating layer  411  (e.g., longitudinal and transversal rigidity), which may be insufficient when using only a resin, or to reduce the dimensional change rate of the insulating layer with respect to temperature. 
     The copper-clad laminate  410  may be, for example, a glass-epoxy copper-clad laminate including a base material in which a glass fiber is impregnated (or infiltrated) with an epoxy resin and copper foils  412  and  413  bonded thereto. According to an embodiment, the National Electrical Manufacturers Association (NEMA) classifies copper-clad laminates into classes of, for example, FR (flame retardant)-1, FR-2, FR-3, FR-5, and FR-6, on the basis of base materials and flame resistance (flame retardancy), and the glass-epoxy copper-clad laminate may be one of FR-4 and FR-5. According to an embodiment, FR-4 or FR-5 may include a base material in which woven glass fiber impregnated with an epoxy resin are stacked in several layers and copper foils bonded thereto. 
     The copper-clad laminate  410  may be a paper-phenol copper-clad laminate including, for example, a base material in which paper is impregnated with phenol resin and copper foils  412  and  413  bonded thereto. According to an embodiment, the paper-phenol copper-clad laminate may be one of FR-1, FR-2 and FR-3 as classified by the NEMA. 
     The copper-clad laminate  410  may be, for example, a composite copper-clad laminate formed by combining two or more reinforcing base materials. According to an embodiment, the composite copper-clad laminate may include CEM (composite type of laminate material bonded with a flame-retardant epoxy resin)-1, CEM-3, or the like as defined by the NEMA. CEM-1 may include a center base material (or a core) made of paper impregnated with an epoxy resin, outer base materials made of woven glass fiber impregnated with an epoxy resin, and copper foils bonded to the outer base materials. CEM-3 may include a core base material made of non-woven glass fiber (e.g., glass non-woven fabric) impregnated with an epoxy resin, outer base materials made of woven glass fiber impregnated with an epoxy resin, and copper foils bonded to the outer base materials. Glass fiber or paper is capable of improving mechanical workability, heat resistance, or dimensional stability. According to some embodiments, the copper-clad laminate may be FR-6, which includes a central base material made of non-woven glass fiber (e.g., glass non-woven fabric) impregnated with a polyester resin, outer base materials made of glass fiber impregnated with a resin, and copper foils bonded to the outer base materials. 
     According to certain embodiments, CEM-3 may be designed to replace FR-4 or FR-5. CEM-3 has relatively less glass fiber than FR-4 or FR-5, and thus the mechanical strength of CEM-3 may be relatively low. When CEM-3 is designed to replace FR-4 or FR-5, the mechanical strength may be considered. According to certain embodiments, when punching is required, CEM-3, which is more advantageous for punching, may be applied to the manufacture of printed circuit boards in place of FR-4. 
     According to certain embodiments, the copper-clad laminate  410  may be a high-frequency copper-clad laminate made of a material capable of withstanding high-speed signal transmission. For example, in a printed circuit board, a signal propagation speed is inversely proportional to the permittivity of a material, and thus it is possible to increase the signal propagation speed when a material with low permittivity is used. 
     According to some embodiments, the copper-clad laminate  410  may be in the form in which a film prepreg made of an insulating material is disposed on a plate formed of a metal such as aluminum or iron and then a copper foil is bonded to the film prepreg. 
     According to some embodiments, the copper-clad laminate  410  may include a flexible copper-clad laminate for use in a flexible printed circuit board (FPCB), or the like. The flexible copper-clad laminate may be, for example, in the form in which a flexible polyester film or polyimide film and a copper foil are bonded to each other with an adhesive. 
     According to certain embodiments, the copper clad laminate  410  may be formed in a structure including an insulating layer  411  of various other materials or structures. 
     The second printed circuit board (e.g., the second printed circuit board  342  in  FIG. 3 ) may be formed by forming a plurality of plates (hereinafter referred to as “inner layers” or “inner layer substrates”) each formed by processing the copper-clad laminate  410 , and stacking the plurality of inner layers. The second printed circuit board  342  may be formed through a series of flows including, for example, inner layer circuit printing, inner layer etching, resist peeling, lay-up, stacking, hole-processing, plating, outer layer circuit printing, resist peeling, solder mask printing, and contouring. 
     Referring to  FIGS. 4A and 4B , a structure  420  in which circuit patterns  421  and  422  are printed on the surfaces  414  and  415  of the inner layer copper-clad laminate  410  is formed by the inner layer circuit printing according to an embodiment. According to an embodiment, through a method including applying a photosensitive dry film to the surfaces  414  and  415  of the inner laminate copper-clad laminate  410  with heat and pressure, then irradiating the dry film with light using a master film having a pattern thereon, and then developing the dry film (e.g., a photographic printing method), the circuit patterns (e.g., the portions remaining on the dry film)  421  and  422  may be printed on the surfaces  414  and  415 . According to another embodiment, a circuit pattern corresponding to a circuit may be printed on the surfaces  414  and  415  through a method using a silkscreen having a circuit pattern thereon in place of the dry film (e.g., a screen-printing method). 
     Referring to  FIGS. 4B and 4C , through the inner layer etching according to an embodiment, only the portions  431  and  432  corresponding to the printed circuit patterns  421  and  422  of the copper foils  412  and  413  are left, and a remaining portion is removed using a corrosive substance, so that a structure  430  may be formed. The portions  431  and  432  remaining without being corroded by being covered by the circuit patterns  421  and  422  may be defined as circuits. Referring to  FIGS. 4C and 4D , through the resist peeling according to an embodiment, the circuit patterns (or the etching resists)  421  and  422  are separated, so that an inner layer  440  in which circuits  431  and  432  are coupled to the insulating layer  411  may be formed. The inner layer  440  may include a first circuit  431  and a second circuit  432  respectively disposed on the opposite sides of the insulating layer  411 . The first circuit  431  or the second circuit  432  is shown as a plurality of sectional areas when viewed in cross section, but may be formed as an integral conductive pattern. According to some embodiments, the first circuit  431  or the second circuit  432  may include a plurality of physically separated patterns. 
     According to some embodiments, an inner layer including a circuit may be formed by processing a copper-clad laminate having a structure in which a copper foil is attached to one side of an insulating layer. The inner layer formed by processing the copper-clad laminate may have a structure in which a circuit is disposed on one side thereof. 
     Referring to  FIGS. 5A and 5B , inner layers  540  and  550  having circuits formed through the lay-up according to an embodiment may be disposed between a first outer layer  511  and a second outer layer  512 , which are formed of a copper foil according to a designed stacking structure of respective layers in that order. Each inner layer  540  or  550  has a structure in which the circuits  542  and  543  or  552  and  553  are bonded to an insulating layer  541  or  551 , and may be formed by processing a copper-clad laminate according to the manufacturing flow described above with reference to  FIGS. 4A, 4B, 4C, and 4D . When the layers  511 ,  512 ,  540 ,  550 ,  531 ,  532 , and  533  are laid up, the circuits (or wires)  542 ,  543 ,  552 , and  553  located on the inner layers  540  and  550  may be aligned at designed positions. Through the stacking according to an embodiment, when prepregs  531 ,  532 , and  533  having the functions of adhesion and insulation are disposed between the layers (e.g., the first outer layer  511 , the second outer layer  512 , and the inner layers  540  and  550 ) and then high heat and pressure are applied, it is possible to form a first structure  501  in which the layers  511 ,  512 ,  540 ,  550 ,  531 ,  532 , and  533  are bonded to each other. The prepregs  531 ,  532 , and  533  may be a thermosetting resin including an epoxy resin or glass impregnated with an epoxy resin. According to certain embodiments, the first structure  501  may be formed to include three or more inner layers without being limited to the illustrated example. 
     According to an embodiment, one inner layer (hereinafter, referred to as a “first inner layer”)  540  includes a first circuit  542  and a second circuit  543  respectively disposed on the opposite sides of the insulating layer  541 , and another inner layer (hereinafter, referred to as a “second inner layer”)  550  may include a third circuit  552  and a fourth circuit  553  respectively disposed on the opposite sides of the insulating layer  551 . According to some embodiments, at least one of the first and second inner layers  540  and  550  may have a structure in which a circuit is disposed on one side of the insulating layer. 
     Referring to  FIGS. 5B and 5C , in an embodiment, by performing hole-processing (e.g., drilling) in a first structure  501 , a second structure  502  including a through-hole (or a via)  561  may be formed. The through hole may be defined as a hole perforated in a substrate (e.g., the first structure  501 ) including outer layers (e.g., the outer layers  511  and  512 ), prepregs (e.g., the prepregs  531 ,  532 , and  533 ), and inner layers (e.g., the inner layers  540  and  550 ) for the purpose of disposing a connection lead in order to electrically connect conductor layers disposed in different layers. Depending on the position at which the through hole is formed, or on the stacking structure corresponding to the position, the conductor layers penetrated by the through hole (e.g., the first outer layer  511  and the second outer layer  512  and one or more circuits included in the inner layers disposed therebetween) may vary. For example, as illustrated in the drawings, a through hole  561  may be formed to penetrate the first outer layer  511 , the first circuit  542  and the second circuit  543  of the first inner layer  540 , the third circuit  552  and the fourth layer  553  of the second inner layer  550 , and the second outer layer  512 . 
     Referring to  FIGS. 5C and 5D , in an embodiment, the second structure  502  is plated to form a third structure  503  in which the through hole  561  is coated with a conductive material  563  such as copper. Since the face  562  of the through hole  561  does not have an electrical property, electroless copper plating that does not require electricity is primarily performed using a chemical agent first, and then copper may be secondary plated thereon through electroplating. The plated conductive material  563  electrically interconnects conductive portions which are separated from each other as layers (e.g., the first outer layer  511 , the second outer layer  512 , and the circuits of the inner layers  540  and  550 ). Depending on the position at which the through hole is formed or the stacking structure corresponding to the position, the face of the through hole may include the inner walls formed in various layers. For example, as illustrated in the drawings, the face  562  of the through hole  561  has inner walls formed in the outer layers  511  and  512 , inner walls formed in the prepregs  531 ,  532 , and  533 , inner walls formed by the insulating layers  541  and  551 , an inner wall formed in the first circuit  542 , an inner wall formed in the second circuit  543 , an inner wall formed in the third circuit  552 , and an inner wall formed in the fourth circuit  543 . These inner walls are coated with the conductive material  563 , and the outer layers  511  and  512 , the first circuit  542 , the second circuit  543 , the third circuit  552 , and the fourth circuit  553  may be electrically connected by the conductive material  563 . According to some embodiments, a hole partially pitted from the first outer layer  511  toward the second outer layer  512  or a hole partially pitted from the second outer layer  512  toward the first outer layer  511  is formed, and a conductive material may be plated over the face of the hole. 
     Referring to  FIGS. 5D and 5E , in an embodiment, outer layer circuit printing for printing a circuit pattern on the surfaces of the first outer layer  511  and the second outer layer  512  of the third structure  503  may be performed by applying the same method as the inner layer circuit printing, and outer layer etching and resist peeling for removing a part of the first outer layer  511  and a part of the second outer layer  512  may be performed by applying the same methods as those used for the inner layer etching and the resist peeling. In the fourth structure  504  formed in this manner, portions remaining after partially removing the first outer layer  511  form a first outer layer circuit  571 , and portions remaining after partially removing the second outer layer  512  form a second outer layer circuit  572 . Depending on the position at which the through hole is formed, or the stacking structure corresponding to the position, the conductive layers in which the first outer layer  571  and the second outer layer  572  are electrically connected via the conductive material  563  (e.g., the first outer layer  511 , the second outer layer  512  and one or more circuits included in the inner layers disposed therebetween) may vary. For example, as illustrated in the drawings, the first outer layer circuit  571  and the second outer layer circuit  572  may be electrically connected to the first circuit  542  and the second circuit  543  of the first inner layer  540  and the third circuit  552  and the fourth circuit  543  of the second inner layer  550  via the conductive material  563 . 
     Referring to  FIGS. 5E and 5F , in an embodiment, by performing solder mask printing on the fourth structure  504 , a fifth structure  505  may be formed in which at least a part of the first outer layer circuit  571  or at least a part of the second outer layer circuit  572  is coated with insulating materials  581  and  582  such as solder mask insulating ink of epoxy component. The portions covered by the insulating materials  581  and  582  in the outer layer circuits  571  and  572  are not exposed to the outside, and thus oxidation thereof can be prevented. The insulating materials  581  and  582  may also serve to prevent solder bridges from being generated during component mounting. According to an embodiment, in solder mask printing, photosensitive ink (e.g., photo S/R) may be applied to the entire corresponding face through a silkscreen-printing method or a spray-coating method, unnecessary portions may be removed through exposure and development, and then a remaining portion may be cured. According to some embodiments, in the solder mask printing, thermosetting ink may be directly applied to the corresponding area through the silkscreen-printing method. The exposed portions (not illustrated) of the first outer layer circuit  571  and the second outer layer circuit  572  may be used as terminals for soldering connection with other elements. The structure  505  of  FIG. 5F  is subjected to post-processing such as contouring (e.g., cutting) or surface treatment, and thus the final second printed circuit board (e.g., the second printed circuit  342  in  FIG. 3 ) may be formed. The second printed circuit board according to the structure  505  of  FIG. 5F  is formed in a structure in which the first outer layer circuit  571  and the second outer layer circuit  572  are electrically connected to the first circuit  541  and the second circuit  542  of the first inner layer  540  and the third circuit  552  and the fourth circuit  553  of the second inner layer  550  via the conductive material  563 , but may be designed to have various other wiring forms without being limited thereto. 
     According to certain embodiments, referring to  FIG. 3  again, the first printed circuit board  341  may also be formed according to the multilayer printed circuit board manufacturing flow described above with reference to  FIGS. 4A, 4B, 4C, and 4D  and  FIGS. 5A, 5B, 5C, 5D, 5E, and 5F . 
     According to some embodiments, the second printed circuit board formed on the basis of the copper-clad laminate may be a single-side printed circuit board in which a circuit is formed on only one side or a double-sided printed circuit board in which a circuit is formed on both sides. The double-sided printed circuit board may include through holes or vias connecting upper and lower circuits. 
     For example, the single-sided printed circuit board may be formed through a series of flows including circuit printing, copper foil etching, resist peeling, solder mask printing, hole-processing, and contouring on the basis of a copper-clad laminate. Each process has been described in the flow of forming a multilayer printed circuit board, and a detailed description thereof will be omitted. 
     For example, the double-sided printed circuit board may be formed through a series of flows including hole-processing, plating, circuit printing, copper foil etching, resist peeling, solder mask printing, and contouring on the basis of a copper-clad laminate. According to some embodiments, the double-sided printed circuit board may be formed through a series of flows including hole-processing, plating, circuit printing, resist peeling, copper foil etching, solder mask printing, and contouring on the basis of a copper-clad laminate. Each process has been described in the flow of forming a multilayer printed circuit board, and a detailed description thereof will be omitted. 
       FIG. 6  is a view for explaining contouring of a printed circuit board according to certain embodiments. 
     Referring to  FIG. 6 , a printed circuit board  600  may include a first portion  610  in which areas  601  corresponding to a first printed circuit board are arranged, and a second portion  620  in which areas  602  corresponding to a second printed circuit board are arranged. The printed circuit board  600  may also be formed according to, for example, the multilayer printed circuit board manufacturing flow described above with reference to  FIGS. 4A, 4B, 4C, and 4D  and  FIGS. 5A, 5B, 5C, 5D, 5E, and 5F . 
     According to an embodiment, the areas  601  corresponding to the first printed circuit board and the areas  602  corresponding to the second printed circuit board may be separated from the printed circuit board  600  through the contouring. For example, press processing using a mold or a computer numerical control (CNC) type routing equipment may be utilized for the contouring. Further referring to  FIG. 3 , each of the areas  601  illustrated in  FIG. 6  corresponds to the first printed circuit board  341  of  FIG. 3 , and each of the areas  602  illustrated in  FIG. 6  corresponds to the second printed circuit board  342  of  FIG. 3 . According to an embodiment, due to the size of the original plate on which the printed circuit board  600  is formed, the second portion  620  may correspond to an area in which it is difficult to design an area corresponding to the first printed circuit board. The areas  602  corresponding to the second printed circuit board (e.g., the second printed circuit board  342  in  FIG. 3 ) are designed using this second part  620 , so that costs can be reduced. 
     According to some embodiments, the second printed circuit board (e.g., the second printed circuit board  342  in  FIG. 3 ) may be formed on the basis of another original plate different from the first printed circuit board (e.g., the first printed circuit board  341  in  FIG. 3 ). 
       FIG. 7  is an exploded perspective view of printed circuit boards according to an embodiment. 
     Referring to  FIG. 7 , in an embodiment, the printed circuit board  700  may include a first printed circuit board  710  and a second printed circuit board  720 , which are coupled to overlap each other. The first printed circuit board  710  (e.g., the first printed circuit board  341  in  FIG. 3 ) or the second printed circuit board  720  (e.g., the second printed circuit board  342  in  FIG. 3 ) may also be formed according to the multilayer printed circuit board manufacturing flow described above with reference to  FIGS. 4A, 4B, 4C, and 4D  and  FIGS. 5A, 5B, 5C, 5D, 5E, and 5F . 
     According to an embodiment, the first printed circuit board  710  may include a first area  711 , a second area  712 , and a third area  713  disposed between the first area  711  and the second area  712 . The third area  713  may be formed to have a narrower width than the first area  711  or the second area  712 . For example, the first area  711 , the second area  712 , and the third area  713  are arranged in the y-axis direction, and in the x-axis direction, the width W 3  of the third area  713  may be narrower than the width W 1  of the first area  711  or the width W 2  of the second area  712 . 
     According to an embodiment, the second printed circuit board  720  may include a fourth area  714 , a fifth area  715 , and a sixth area  716  disposed between the fourth area  714  and the fifth area  715 . The second printed circuit board  720  may be coupled to overlap the first printed circuit board  710  so as to be utilized as a reinforcing member for reinforcing the rigidity of the third area  713  of the first printed circuit board  710 . The first printed circuit board  710  may include a plurality of terminals  701 ,  702 , and  705  disposed, for example, on the front face  731  thereof facing the rear face (not illustrated) of the second printed circuit board  720 . The second printed circuit board  720  may include a plurality of terminals  703 ,  704 , and  706  disposed, for example, on the rear face thereof. When the plurality of terminals  701 ,  702 , and  705  of the first printed circuit board  710  and the plurality of terminals  703 ,  704 , and  706  of the second printed circuit board  720  are coupled through solder, the second printed circuit board  720  may be disposed to overlap the first printed circuit board  710  and may reinforce the third area  713 . For example, the third area  713  has a narrower width than the first area  711  or the second area  712 , while the second printed circuit board  720  may reduce an impact or load transmitted to the third area  713 . 
     According to an embodiment, the first printed circuit board  710  may include a first electrical terminal  701  disposed in the first area  711  and a second electrical terminal  702  disposed in the second area  712 . The second printed circuit board  720  may include a third electrical terminal  703  disposed in the fourth area  714  and a fourth electrical terminal  704  disposed in the fifth area  715 , and the third terminal  703  and the fourth electrical terminal  704  may be electrically connected through a circuit (not illustrated) included in the second printed circuit board  720 . When the first printed circuit board  710  and the second printed circuit board  720  are coupled to each other, the first electrical terminal  701  may be coupled to the third electrical terminal  703  via solder, and the second electrical terminal  702  may be coupled to the fourth electrical terminal  704  via solder. Thereby, the first electrical terminal  701  and the second electrical terminal  702  may be electrically connected to each other through the second printed circuit board  720 . According to some embodiments, the first printed circuit board  720  may include a circuit that electrically connects the first electrical terminal  701  and the second electrical terminal  702 , and this circuit may extend to the third area  713 . 
     According to an embodiment, the first printed circuit board  710  may include a first ground terminal  705  disposed in the third area  713 , and the first ground terminal  705  may be electrically connected to a first ground (or a first ground circuit) included in the first printed circuit board  710  or may be a part of the first ground (or the first ground circuit). According to an embodiment, the second printed circuit board  720  may include a second ground terminal  706  disposed in the sixth area  716 , and the second ground terminal  706  may be electrically connected to a second ground (or a second ground circuit) included in the second printed circuit board  720  or may be a part of the second ground (or the second ground circuit). When the first printed circuit board  710  and the second printed circuit board  720  are coupled, solder interconnecting the first ground terminal  705  and the second ground terminal  706  is disposed, by which the first ground and the second ground can be electrically connected to each other. 
     According to an embodiment, at least some of the first electrical terminal  701 , the second electrical terminal  702 , the third electrical terminal  703 , the fourth electrical terminal  704 , the first ground terminal  705 , and the second ground terminal  706  may be conductive pads. According to some embodiments, at least some of the first electrical terminal  701 , the second electrical terminal  702 , the third electrical terminal  703 , the fourth electrical terminal  704 , the first ground terminal  705 , and the second ground terminal  706  may be terminals utilizing through holes or vias, which are plated with a conductive material. In certain embodiments, electrical terminals can be conductive material disposed on a surface covering a large enough surface area to form electrical contact by physical placement of an external device. 
     According to certain embodiments, a side face  723  of the second printed circuit board  720  may be at least partially surrounded by a conductive material, and the conductive material may be utilized for reducing noise generated by an electronic device (e.g., the electronic device  100  in  FIG. 1 or 2 ) or electromagnetic interference (EMI). For example, the side face  723  of the second printed circuit board  720  may be plated with a conductive material. 
     According to some embodiments, the first ground terminal  705  and the second ground terminal  706  may be omitted. 
     According to some embodiments, the first ground terminal  705  may be replaced by a first metal pad (or a first dummy pad) physically separated from a conductive portion (e.g., circuits) included in the first printed circuit board  710 . The second ground terminal  706  may be replaced by a second metal pad (or a second dummy pad) physically separated from a conductive portion (e.g., circuits) included in the second printed circuit board  720 . According to an embodiment, when the first printed circuit board  710  and the second printed circuit board  720  are coupled, solder may be disposed to bond the first metal pad and the second metal pad to each other. According to certain embodiments, the first metal pad and the second metal pad may be coupled to each other via various other bonding members. 
     According to certain embodiments, the second metal pad may be expanded to an area in which the third electrical terminal  703  is not disposed in the fourth area  714  or an area in which the fourth electrical terminal  704  is not disposed in the fifth area  715 , or other metal pads disposed in these areas may be further formed. The first printed circuit board  710  may be formed to have metal pad (s) corresponding to such metal pad (s) of the second printed circuit board  720 . 
     According to some embodiments, the third area  713  and the sixth area  716  may be coupled via various bonding members (e.g., polymer or organic adhesive layers) without the first metal pad and the second metal pad. 
     According to certain embodiments, various other types of first bonding portions may be formed to replace the first metal pad, and various other types of second bonds may be formed to replace the second metal pad. For example, an optical adhesive member (e.g., a material cured by specified light) or a thermosetting material may be disposed between the first bonding portion and the second bonding portion. According to certain embodiments, the adhesive member may be designed to be included in the first or second bonding portion. According to some embodiments, the first bonding portion and the second bonding portion may be coupled through bolt fastening. 
       FIG. 8  is a cross-sectional view illustrating the coupled state of a first printed circuit board and a second printed circuit board according to an embodiment. 
     Referring to  FIG. 8 , in an embodiment, a first printed circuit board  810  (e.g., the first printed circuit board  341  in  FIG. 3  or the first printed circuit board  710  in  FIG. 7 ) and a second printed circuit board  820  (e.g., the second printed circuit board  342  in  FIG. 3  or the second printed circuit board  720  in  FIG. 7 ) may be coupled to overlap each other. The first printed circuit board  810  or the second printed circuit board  820  may also be formed according to the multilayer printed circuit board manufacturing flow described above with reference to  FIGS. 4A, 4B, 4C, and 4D  and  FIGS. 5A, 5B, 5C, 5D, 5E, and 5F . 
     According to an embodiment, the first printed circuit board  810  may include a first area  811 , a second area  812 , and a third area  813  disposed between the first area  811  and the second area  812 . The second printed circuit board  820  may include a fourth area  814 , a fifth area  815 , and a sixth area  816  disposed between the fourth area  814  and the fifth area  815 . The fourth area  814  may be disposed to at least partially overlap the first area  811 , the fifth area  815  may be disposed to at least partially overlap the second area  812 , and the sixth area  816  may be disposed to at least partially overlap the third area  813 . 
     According to an embodiment, the first printed circuit board  810  may include first electrical terminals  801  (e.g., the first electrical terminal  701  in  FIG. 7 ) disposed in the first area  811 , second electrical terminals  802  (e.g., the second electrical terminal  702  in  FIG. 7 ) disposed in the second area  812 , and first ground terminals  805  (e.g., the first ground terminal  705  in  FIG. 7 ) disposed in the third area  813 . The second printed circuit board  820  may include third electrical terminals  803  (e.g., the third electrical terminal  703  in  FIG. 7 ) disposed in the fourth area  814 , fourth electrical terminals  804  (e.g., the fourth electrical terminal  704  in  FIG. 7 ) disposed in the fifth area  815 , and second ground terminals  806  (e.g., the second ground terminal  706  in  FIG. 7 ) disposed in the sixth area  816 . The first electrical terminals  801  may be coupled to the third electrical terminals  803  via solder  841 , the second electrical terminals  802  may be coupled to the fourth electrical terminals  804  via solder  842 , and the first ground terminals  805  may be coupled to the second ground terminals  806  via solder  843 . According to an embodiment, the third electrical terminals  803  and the fourth electrical terminals  804  may be electrically connected by a circuit included in the second printed circuit board  820 , whereby the first electrical terminals  801  and the second electrical terminals  802  may be electrically connected through the second printed circuit board  820 . The first ground terminals  805  may be electrically connected to a first ground included in the first printed circuit board  810 , and the second ground terminals  806  may be electrically connected to a second ground included in the second printed circuit board  820 . 
     The amount of soldering material in solders  841 ,  842 , and  843  or the gaps between the electrical terminals  803 ,  804 , and  806  may an amount limited to prevent connection to each other (e.g., to form a solder bridge) when the first printed circuit board  810  and the second printed circuit board  820  are coupled. According to certain embodiments, it is natural that various other conductive bonding materials may be applied to replace the solders  841 ,  842 , and  843 , in which case the terminals of the first printed circuit board  810  and the second printed circuit board  820  may also be modified differently. 
     According to certain embodiments, the thickness T 1  of the first printed circuit board  810  and the thickness T 2  of the second printed circuit board  820  may be the same as or different from each other. 
     According to certain embodiments, the number of inner layers (e.g., structure  440  in  FIG. 4D ) included in the first printed circuit board  810  and the number of inner layers included in the second printed circuit board  820  may be the same as or different from each other. 
     According to some embodiments, the first ground terminal  805  and the second ground terminal  806  may be omitted. 
       FIG. 9  is a view illustrating an electronic device including overlapping printed circuit boards according to certain embodiments. 
     Referring to  FIG. 9 , in an embodiment, an electronic device  900  (e.g., the electronic device  100  in  FIG. 1 ) may include a first printed circuit board  910 , and a second printed circuit board  921  and a third printed circuit board  922 , which are coupled to overlap the first printed circuit board  910 . According to an embodiment, the first printed circuit board  910  may include the first printed circuit board  710  of  FIG. 7  or the first printed circuit board  810  of  FIG. 8 , and the second and third printed circuit boards  921  and  922  may include the second printed circuit board  720  of  FIG. 7  or the second printed circuit board  820  of  FIG. 8 . 
     According to one embodiment, the first printed circuit board  910  may be integrally formed with a side bezel structure  950  (e.g., the side bezel structure  310  in  FIG. 3 ) of the electronic device  900 , or may be coupled to a support member  960  (e.g., the first support member  311  in  FIG. 3 ) connected to the side bezel structure  950 . The side bezel structure  950  may include first to fourth side face member  951  to  954 . The first side member  951  may be disposed parallel to the second side member  952  in the y-axis direction at a distance from the second side member  952 . The third side members  953  may be disposed parallel to the fourth side member  954  in the x-axis direction at a distance from the fourth side member  954 . According to an embodiment, a connection portion between the first side member  951  and the third side member  953 , a connection portion between the first side member  951  and the fourth side member  954 , a connection portion between the second side member  952  and the third side member  953 , or a connection portion between the second side member  952  and the fourth side member  954  may provide a smoothly curved side face. 
     According to an embodiment, the first printed circuit board  910  may include an opening  914  that supports the placement of a camera  970  (e.g., the second camera device  112  in  FIG. 2 ). The camera  970  is an integrated component including a lens, an image sensor, and/or an image signal processor, and is inserted into the opening  914 . The camera  970  may include a flexible printed circuit (FPCB) electrically connected to the first printed circuit board  910 . According to an embodiment, the first printed circuit board  910  may include a third area  913  (e.g., the third area  713  in  FIG. 7 ) disposed between the opening  914  in the peripheral areas defining the opening  914  and the first side member  951 . According to an embodiment, the first printed circuit board  910  may include a first area  911  (e.g., the first area  711  in  FIG. 7 ) disposed between the third area  913  and the third side member  953 , and a second area  912  (e.g., the second area  712  in  FIG. 7 ) disposed between the third area  913  and the fourth side member  954 . According to an embodiment, the first area  911  and the second area  912  may extend to define an opening  914 . The third area  913  connects the first area  911  and the second area  912 , and according to an embodiment, the third area  913  may have a narrower width than the first area  911  or the second area  912  in the y-axis direction (e.g., the direction between the first side member  951  and the second side member  952 ). 
     According to an embodiment, the first printed circuit board  910  may include a first electrical terminal (e.g., the first electrical terminal  701  in  FIG. 7 ) disposed in the first area  911  and a second electrical terminal (e.g., the second electrical terminal  702  in  FIG. 7 ) disposed in the second area  912 . The first printed circuit board  910  may include a first ground terminal (e.g., the first ground terminal  705  in  FIG. 7 ) disposed in the third area  913 . The second printed circuit board  921  may include, on the rear face thereof, a third electrical terminal (e.g., the third electrical terminal  703  in  FIG. 7 ) coupled with the first electrical terminal, a fourth electrical terminal (e.g., the fourth electrical terminal  704  in  FIG. 7 ) coupled with the second electrical terminal, and a second ground terminal (e.g., the second ground terminal  706  in  FIG. 7 ) coupled with the first ground terminal. 
     According to an embodiment, the first electrical terminal, the first ground terminal, and the second electrical terminal may be arranged in the x-axis direction (e.g., the direction between the third side member  953  and the fourth side member  954 ). The second printed circuit board  921  may be in a form such that it is extended to overlap the third area  913  when connected to the first electrical terminal and the second electrical terminal. According to certain embodiments, the first electrical terminal or the second electrical terminal may be disposed in the vicinity of the third area  913  (e.g., within about 20 mm). 
     According to an embodiment, the first electrical terminal and the second electrical terminal may be electrically connected to each other through the second printed circuit board  921 . According to an embodiment, the third area  913  may be designed so as to obviate wiring for electrically connecting the first electrical terminal and the second electrical terminal, or according to some embodiments, so as to include wiring for connecting the first electrical terminal and the second electrical terminal. 
     According to certain embodiments, the first electrical terminal may be electrically connected to a first component mounted on the first area  911 , and the second electrical terminal may be electrically connected to a second component mounted on the second area  912 . 
     According to an embodiment, the second printed circuit board  921  is capable not only of reinforcing the third area  913  of the first printed circuit board  910 , but also of being used as a wiring area for supporting the first printed circuit board  910  without increasing the width of the third area  913  or without designing the third area  913  so as to increase the wiring density. 
     According to an embodiment, the first printed circuit board  910  may include a seventh area  917  extending from the second area  912  to a space between the battery  940  (e.g., the battery  350  in  FIG. 3 ) and the fourth side member  954 , an eighth area  918  disposed on the side of the second side member  952 , and a ninth area  919  between the seventh area  917  and the eighth area  918 . In the x-axis direction, the ninth area  919  (e.g., the third area  713  in  FIG. 7 ) may have a width narrower than that of the seventh area  917  (e.g., the first area  711  in  FIG. 7 ) or the eighth area  918  (e.g., the second area  712  in  FIG. 7 ). According to an embodiment, the third printed circuit board  922  may be coupled to overlap the first printed circuit board  910  and may be disposed to overlap the ninth area  919 . The third printed circuit board  922  is capable not only of reinforcing the ninth area  919  of the first printed circuit board  910 , but also of being used as a wiring area for supporting the first printed circuit board  910  without increasing the width of the ninth area  919  or without designing the ninth area  919  to increase the wiring density. 
     According to an embodiment, the ninth area  919  may be a portion on which a motor is mounted. The motor may be for causing the electronic device to mechanically oscillate. For example, the motor may be disposed between the ninth area  919  and the support member  960 . 
       FIG. 10  is a view illustrating an electronic device including overlapping printed circuit boards according to certain embodiments. 
     Referring to  FIG. 10 , in an embodiment, an electronic device  1000  (e.g., the electronic device  100  in  FIG. 1 ) may include a first printed circuit board  1010 , and one or more second printed circuit boards  1021 ,  1022 , and  1023 , which are coupled to overlap the first printed circuit board  1010 . The first printed circuit board  1010  may include, for example, a first area  1011  (e.g., the first area  711  in  FIG. 7 ), a second area  1012  (e.g., the second area  712  in  FIG. 7 ), which is spaced apart from the first area  1011  by a distance D 1 , and a third area  1013  (e.g., the third area  713  in  FIG. 7 ) connecting the first area  1011  and the second area  1012 . 
     According to an embodiment, the first printed circuit board  1010  may include the first printed circuit board  710  of  FIG. 7  or the first printed circuit board  810  of  FIG. 8 , and the second printed circuit boards  1021 ,  1022 , and  1023  may include the second printed circuit board  720  of  FIG. 7  or the second printed circuit board  820  of  FIG. 8 . 
     According to an embodiment, the first printed circuit board  1010  may be integrally formed with a side bezel structure  1050  (e.g., the side bezel structure  310  in  FIG. 3 ) of the electronic device (e.g., the electronic device  100  in  FIG. 1 or 2 ), or may be coupled to a support member  1060  (e.g., the first support member  311  in  FIG. 3 ) connected to the side bezel structure  1050 . The side bezel structure  1050  may include a first side member  1051  (e.g., the first side member  951  in  FIG. 9 ), a second side member  1052  (e.g., the second side member  952  in  FIG. 9 ), a third side member  1053  (e.g., the third side member  953  in  FIG. 9 ), and a fourth side member  1054  (e.g., the fourth side member  954  in  FIG. 9 ). According to an embodiment, a battery  1040  (e.g., the battery  350  in  FIG. 3 ) may be disposed between the first area  1011  and the second area  1012 , and between the third area  1013  and the fourth side member  1054 . The third area  1013  may have a shape protruding and extending from the first area  1011  or the second area  1012  to a space between the battery  1040  and the third side member  1053 . In a direction oriented from the third side member  1053  toward the fourth side member  1054  (e.g., the x-axis direction), the third area  1013  may have a width narrower than that of the first area  1011  or the second area  1012 . 
     According to an embodiment, the second printed circuit boards  1021 ,  1022 , and  1023  may include a printed circuit board  1021  coupled to overlap the third area  1013 , a printed circuit board  1022  coupled to overlap the first area  1011  and the third area  1013 , or a printed circuit board  1023  coupled to overlap the second area  1012  and the third area  1013 . The second printed circuit boards  1021 ,  1022 , and  1023  may be coupled to the first printed circuit board  1010  via solder, so that the second printed circuit boards  1021 ,  1022 , and  1023  are able to reinforce the third area  1013 . Since the third area  1013  has a narrower width than that of the first area  1011  or the second area  1012 , the third area  1013  may be vulnerable to breakage due to impact or load. However, the second printed circuit boards  1021 ,  1022 , and  1023  are able to suppress the impact or load from being applied to the third area  1013  and improve rigidity. Since the third area  1013  can have a narrower width, substantial rigidity, it is possible to secure a space  1041  required for disposing the battery  1040  therein. According to certain embodiments, some of the second printed circuit boards  1021 ,  1022 , and  1023  may be omitted. 
     According to certain embodiments, the third area  1013  of the first printed circuit board  1010  may include portions formed like the first area  711 , the second area  712 , and the third area  713  of  FIG. 7 . The second printed circuit board  1021  may be coupled to the third area  1013  of the first printed circuit board  1010 , like the second printed circuit board  720  of  FIG. 7 . 
     According to some embodiments, at least one of the second printed circuit boards  1021 ,  1022 , and  1023  may be disposed between the support member  1060  and the first printed circuit board  1010 . 
     For example, electronic components may transmit or receive signals or data through signal lines included in the first printed circuit board  1010 . Due to a current flow, an electric field is formed in the signal lines, and this electric field causes electromagnetic interference (EMI) that interferes with the normal operation of the electronic components by applying noise to a nearby electronic component or signals transmitted to another nearby signal line. In order to suppress such electromagnetic interference, the signal lines may be designed to be located as far away as possible from other nearby signal lines and electronic components, or may be designed to further increase the volume thereof. It may difficult to design the third area  1013  to have an expanded width due to the limited space between the third side member  1053  and the battery  1040 . Accordingly, in consideration of electromagnetic interference, it may be difficult to design the third area  1013  such that the number of signal lines in the third area  1013  is increased (e.g., the wiring density is increased) or such that the volume of the signal lines included in the third area  1013  is increased. In order to overcome such design constraints, according to an embodiment, the second printed circuit boards  1021 ,  1022 , and  1023  may be utilized as signal lines for data transmission/reception. 
     As another example, current may be set to be equal to or lower than the value that can safely flow in the signal lines (e.g., maximum current). The maximum current is a value allowed by the electronic components connected to the signal lines, and the signal lines can be designed to allow this maximum current. For example, when current flows through a signal line, heat may be generated due to the electrical resistance of the signal line. The heat raises the temperature of the signal line, and when the temperature rises above a certain limit, the signal line may be damaged (e.g., weakened or broken). As another example, incineration may be caused in the signal line and in the vicinity of the signal line due to the heat generated from the signal line. In order to prevent the signal line from being damaged due to the heat generated when the current flows through the signal line, the signal line may include a material having electrical resistance as low as possible, or may be designed to have as large a volume as possible. According to an embodiment, a connector (e.g., a USB connector)  1080  may be disposed in the second area  1012 . When current is supplied from the external power supply through the connector  1080 , the current may flow to the first area  1011  through the second area  1012  and the third area  1013 . It may difficult to design the third area  1013  to have an expanded width due to the limited space between the third side member  1053  and the battery  1040 , whereby it may be difficult to design a signal line included in the third area  1013  to have an expanded volume. According to an embodiment, in order to overcome such design constraints, according to an embodiment, the second printed circuit boards  1021 ,  1022 , and  1023  may be utilized as signal lines for current transmission/reception. 
     According to an embodiment, second grounds (or ground circuits) included in the second printed circuit boards  1021 ,  1022 , and  1023  may be electrically connected to a first ground included in the first printed circuit board  1010 . Since the grounds are expanded by the second printed circuit boards  1021 ,  1022 , and  1023 , performance in electromagnetic interference (EMI) may also be improved. 
       FIG. 11A  is a front view of a second printed circuit board according to certain embodiments.  FIG. 11B  is a rear view of the second printed circuit board of  FIG. 11A . 
     Referring to  FIGS. 11A and 11B , a second printed circuit board  1100  (e.g., the second printed circuit board  720  in  FIG. 7 ) according to an embodiment may include a fourth area  1114 , a fifth area  1115 , and a sixth area  1116  disposed between the fourth area  1114  and the fifth area  1115 . According to an embodiment, the sixth area  1116  may extend straight in a first direction  1121  (e.g., the x-axis direction), the fourth area  1114  may extend in a third direction  1123  perpendicular to the first direction  1121 , and the fifth area  1115  may extend in a fourth direction  1124  opposite the second direction  1122 . According to certain embodiments, the width W 4  of the sixth area  1116  extending in the second direction  1123  or the third direction  1124  may be the same as or different from the width W 5  of fourth area  1114  extending in the first direction  1121  or the width W 6  of the fifth area  1115  extending in the first direction  1121 . According to certain embodiments, the width W 5  of the fourth area  1114  may be the same as or different from the width W 6  of the fifth area  1115 . 
     According to some embodiments, the fourth area  1114  or the fifth area  1115  may be designed to extend at an acute or obtuse angle relative to the sixth area  1116 . 
     Referring to  FIG. 11A , in an embodiment, the second printed circuit board  1100  may include a plurality of terminals disposed on the rear face  1120  (or the back side). The plurality of terminals of the second printed circuit board  1100  may be coupled to a plurality of terminals formed on the first printed circuit board (e.g., the first printed circuit board  341  in  FIG. 3 , the first printed circuit board  910  in  FIG. 9 , or the first printed circuit board  1010  in  FIG. 10 ) via solder, whereby the second printed circuit board may be coupled to overlap the first printed circuit board. According to an embodiment, the second printed circuit board  1100  may include third electrical terminals  1103  (e.g., the third electrical terminals  803  in  FIG. 8 ) disposed in the fourth area  1114 , fourth electrical terminals  1104  (e.g., the fourth electrical terminals  804  in  FIG. 8 ) disposed in the fifth area  1115 , and second ground terminals  1106  (e.g., the second ground terminals  804  in  FIG. 8 ) disposed in the sixth area  1116 . 
     According to an embodiment, the third electrical terminals  1103  are disposed in a portion of the fourth area  1114  that protrudes in the second direction  1122  with respect to the sixth area  1116 , and the fourth electrical terminals  1104  may be disposed in a portion of the fifth area  1115 , which protrudes in the third direction  1123  with respect to the sixth area  1116 . 
     According to an embodiment, as illustrated in the drawing, the third electrical terminals  1103  or the fourth electrical terminals  1104  may be terminals utilizing through holes or vias plated with a conductive material. According to some embodiments, the third electrical terminals  1103  or the fourth electrical terminals  1104  may be designed as conductive pads. 
     According to an embodiment, as illustrated in the drawing, the second ground terminals  1106  may be formed as conductive pads. According to some embodiments, the second ground terminals  1106  may be designed as terminals that utilize through holes or vias plated with a conductive material. 
     According to an embodiment, as illustrated in the drawing, the second ground terminals  1106  may be arranged in a row in the first direction  1121 . According to some embodiments, the second ground terminals may be arranged in two or more rows, in which case the width W 4  of the sixth area  1116  may be increased. According to some embodiments, when the width W 4  of the sixth area  1116  is maintained, the size of or spacing between the second ground terminals may be reduced so that the second ground terminals may be arranged in two or more rows. 
     According to an embodiment, the third electrical terminals  1103  and the fourth electrical terminals  1104  may be electrically connected through a circuit included in the second printed circuit board  1100 . The second ground terminals  1106  may be electrically connected to a ground (or a ground circuit) included in the second printed circuit board  110 , or may be a part of the ground (or the ground circuit). 
     Referring to  FIG. 11B , in an embodiment, the second printed circuit board  1100  may include circuits  1131  and  1132  disposed on the front face  1110  thereof, and these circuits  1131  and  1132  may be utilized as antennas. An antenna may be defined as an element capable of converting an electromagnetic wave for transmission into a free space wave, or converting a free space wave for reception into an electromagnetic wave. According to an embodiment, the first printed circuit board (e.g., the first printed circuit board  341  in  FIG. 3 ) to which the second printed circuit board  1100  is overlappingly coupled may include a communication circuit (e.g., a communication module). The communication circuit may be electrically connected to the second printed circuit board  1100 . The communication circuit may perform various types of communication using circuits  1131  and  1132  of the second printed circuit board  1100 . 
     According to some embodiments, the circuits  1131  and  1132  of the second printed circuit board  1100  may be utilized as antenna-matching circuits. For example, the first printed circuit board (e.g., the first printed circuit board  341  in  FIG. 3 ) to which the second printed circuit board  1100  is overlappingly coupled may include a frequency adjustment circuit. The frequency adjustment circuit may adjust antenna impedance using the circuits  1131  and  1132  of the second printed circuit board  1100 . 
     According to certain embodiments, antennas may be designed in various forms at various locations on the second printed circuit board  1100  on the basis of the radiation characteristics or impedance thereof. 
       FIG. 12  is a view illustrating a second printed circuit board according to certain embodiments. 
     Referring to  FIG. 12 , a second printed circuit board  1200  (e.g., the second printed circuit board  720  in  FIG. 7 ) according to an embodiment may include a fourth area  1214 , a fifth area  1215 , and a sixth area  1216  disposed between the fourth area  1214  and the fifth area  1215 . The second printed circuit board  1200  may include a face  1237  facing the first printed circuit board when the second printed circuit board  1200  is coupled to overlap the first printed circuit board (e.g., the first printed circuit board  341  of  FIG. 3 ), and a plurality of terminals  1203 ,  1204 , and  1206  may be disposed on the face  1237 . The sixth area  1216  extends in a first direction  1216  and may include second ground terminals  1206  (e.g., the second ground terminal  706  in  FIG. 7 ). The fourth area  1214  may include a first portion  1231  extending in the first direction  1221  from the sixth area  1216  and a second portion  1232  extending in the third direction  1223  perpendicular to the first direction  1221  to protrude with respect to the sixth area  1216 . Some of the third electrical terminals  1203  (e.g., the third electrical terminal  703  in  FIG. 7 ) may be disposed in the first portion  1231 , and some of the third electrical terminals  1203  may be disposed in the second portion  1232 . The fifth area  1215  may be formed symmetrically with the fourth area  1214 , and may include fourth electrical terminals  1204  (e.g., the fourth electrical terminal  704  in  FIG. 7 ). The third electrical terminals  1203  and the fourth electrical terminals  1204  may be electrically connected through a circuit included in the second printed circuit board  1200 , and the second ground terminals  1206  may be electrically connected to a ground circuit included in the second printed circuit board  1200 . 
     According to an embodiment, the fourth area  1214 , the fifth area  1215 , and the sixth area  1216  may form a space portion  1235 , which is recessed in a fourth direction  1224  opposite a third direction  1223 . When the second printed circuit board  1200  is coupled to overlap the first printed circuit board (e.g., the first printed circuit board  341  in  FIG. 3 ), at least one component mounted on the first printed circuit board may be placed in the space  1235 . According to an embodiment, the side face of the second printed circuit board  1200 , which forms the space  1235 , may be formed as a smoothly curved face  1236 . 
     According to certain embodiments, the shape of the second printed circuit board and the arrangement structure of the terminals of the second printed circuit board may be variously designed according to the corresponding area of the first printed circuit board. 
       FIG. 13  is a view illustrating a printed circuit board according to certain embodiments. 
     Referring to  FIG. 13 , in an embodiment, a printed circuit board  1300  may include a fourth printed circuit board  1330  (e.g., the first printed circuit board  710  in  FIG. 7 ) and a fifth printed circuit board  1340  (e.g., the second printed circuit board  720  in  FIG. 7 ), and the fifth printed circuit board  1340  may be coupled such that a part of the fifth printed circuit board  1340  overlaps the fourth printed circuit board  1330 . According to an embodiment, the fourth printed circuit board  1330  may include a first area  1311 , a second area  1312 , and a third area  1313  disposed between the first area  1311  and the second area  1312 . According to an embodiment, the fifth printed circuit board  1340  may include a fourth area  1314 , a fifth area  1315 , and a sixth area  1316  disposed between the fourth area  1314  and the fifth area  1315 . The sixth area  1316  is separated from the fourth printed circuit board  1330 , the fourth area  1314  extending from a first position of the sixth area  1316  is coupled to the first area  1311  of the fourth printed circuit board  1330 , and the fifth area  1315  extending from a second position of the sixth area  1316  may be coupled to the second area  1312  of the fourth printed circuit board  1330 . A portion of the fourth area  1314 , which overlaps the fourth printed circuit board  1330 , and a portion of the fifth area  1315 , which overlaps the fourth printed circuit board  1330 , may include at least one terminal coupled to the fourth printed circuit board  1330  via a conductive bonding material such as solder. 
     According to an embodiment, the fifth printed circuit board  1340  coupled to the fourth printed circuit board  1330  may reinforce the fourth printed circuit board  1330 . For example, the third area  1313  may be formed to have a width W 7  narrower than that of the first area  1311  or the second area  1312 , and the fifth printed circuit board  1340  may have a resistance structure to bear an impact or load transmitted to the third area  1313 . In addition, the fifth printed circuit board  1340  may be utilized as a wiring area that supports the fourth printed circuit board  1330 . It is possible to reinforce the third area  1313  and secure a wiring area by the fifth printed circuit board  1340  without increasing the width of the third area  1313  or without designing the third area  1310  so as to increase the wiring density. 
       FIG. 14  is a block diagram of an electronic device  1401  (e.g., the electronic device  100  in  FIG. 1 or 2 , or the electronic device  300  in  FIG. 3 ), including overlappingly disposed printed circuit boards, in a network environment  1400 , according to certain embodiments. Referring to  FIG. 14 , the electronic device  1401  in the network environment  1400  may communicate with an electronic device  1402  via a first network  1498  (e.g., a short-range wireless communication network), or may communicate with an electronic device  1404  or a server  1408  via a second network  1499  (e.g., a long-range wireless communication network). According to one embodiment, the electronic device  1401  may communicate with the electronic device  1404  via the server  1408 . According to an embodiment, the electronic device  1401  may include a processor  1420 , a memory  1430 , an input device  1450 , a sound output device  1455 , a display device  1460  (e.g., the display  101  in  FIG. 1  or the display  330  in  FIG. 3 ), an audio module  1470  (e.g., the audio module  103 ,  107  or  114  in  FIG. 1 or 2 ), a sensor module  1476  (e.g., the sensor module  104  in  FIG. 1  or the sensor module  119  in  FIG. 2 ), an interface  1477 , a haptic module  1479 , a camera module  1480  (e.g., the first camera device  105 , the second camera device  112 , and/or the flash  113  of  FIG. 1 or 2 ) (e.g., the camera module  970  in  FIG. 9 ), a power management module  1488 , a battery  1489  (e.g., the battery  350  in  FIG. 3 , the battery  940  in  FIG. 9 , or the battery  1040  in  FIG. 10 ), a communication module  1490 , a subscriber identification module  1496 , and an antenna module  1497 . In some embodiments, among these components, at least one component (e.g., the display device  1460  or the camera module  1480 ) may be eliminated from the electronic device  1401  or other components may be added to the electronic device  101 . In some embodiments, some of these components may be implemented as a single integrated circuit. For example, the sensor module  1476  (e.g., a fingerprint sensor, an iris sensor, or an illuminance sensor) may be implemented in the state of being embedded in the display device  1460  (e.g., a display). 
     The processor  1420  may control one or more other components (e.g., a hardware or software component) of the electronic device  1401 , which are connected to the processor  1420 , and may perform various data processing or arithmetic operations by executing, for example, software (e.g., a program  1440 ). According to an embodiment, as a part of such data processing or operations, the processor  1420  may load instructions or data received from another component (e.g., the sensor module  1476  or the communication module  1490 ) in volatile memory  1432 , and may process instructions or data stored in the volatile memory  1432  and store the resulting data in nonvolatile memory  1434 . According to an embodiment, the processor  1420  may include a main processor  1421  (e.g., a central processing unit or an application processor), and an auxiliary processor  1423 , which operates independently from or together with the main processor  1421  (e.g., a graphic processing device, an image signal processor, a sensor hub processor, or a communication processor). Additionally or alternatively, the auxiliary processor  1423  may use less power than the main processor  1421 , or may be set to be specific to a specified function. The auxiliary processor  1423  may be implemented separately from, or as part of, the main processor  1421 . 
     The auxiliary processor  1423  may control at least some functions or states associated with at least one of the components of the electronic device  1401  (e.g., the display device  1460 , the sensor module  1476 , or the communication module  1490 ), on behalf of the main processor  1421 , for example, while the main processor  1421  is in an inactive (e.g., sleep) state, or together with the main processor  1421  while the main processor  1421  is in an active (e.g., application execution) state. According to one embodiment, the auxiliary processor  1423  (e.g., an image signal processor or a communication processor) may be implemented as a part of other functionally related components (e.g., the camera module  1480  or the communication module  1490 ). 
     The memory  1430  may store various data to be used by at least one component of the electronic device  1401  (e.g., the processor  1420  or the sensor module  1476 ). The data may include, for example, input data or output data for software (e.g., the program  1440 ) and instructions associated therewith. The memory  1430  may include, for example, volatile memory  1432  or nonvolatile memory  1434 . 
     The program  1440  may be stored in the memory  1430  as software, and may include, for example, an operating system  1442 , middleware  1444 , or application  1446 . 
     The input device  1450  may receive instructions or data for use in a component (e.g., the processor  1420 ) of the electronic device  1401  from the outside of the electronic device  1401  (e.g., the user). The input device  1450  may include, for example, a microphone, a mouse, or a keyboard. 
     The sound output device  1455  may output sound signals to the outside of the electronic device  1401 . The sound output device  1455  may include, for example, a speaker or a receiver. The speaker may be used for general purposes such as multimedia playback or record playback, and the receiver may be used for receiving incoming calls. According to an embodiment, the receiver may be implemented separately from or as part of the speaker. 
     The display device  1460  may provide visual information to the outside (e.g., the user) of the electronic device  1401 . The display device  1460  may include, for example, a display, a hologram device, or a control circuit for controlling a projector and a corresponding device. According to an embodiment, the display device  1460  may include a touch circuit configured to sense a touch, or a sensor circuit (e.g., a pressure sensor) configured to measure the strength of force of the touch. 
     The audio module  1470  may convert sound into an electrical signal, or vice versa. According to one embodiment, the audio module  1470  may acquire sound through the input device  1450  or may output sound through the sound output device  1455  or an external electronic device (e.g., the electronic device  1402  (e.g., a speaker or headphone)) connected with the electronic device  1401 , either directly or in a wireless manner. 
     The sensor module  1476  may sense the operating conditions (e.g., power or temperature) of the electronic device  1401  or the external environmental state (e.g., the user state), and may generate an electrical signal or a data value corresponding to the sensed state. According to an embodiment, the sensor module  1476  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  1477  may support one or more designated protocols that may be used by the electronic device  1401  so as to be directly or wirelessly connected to an external electronic device (e.g., the electronic device  1402 ). According to one embodiment, the interface  1477  may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, or an audio interface. 
     A connection terminal  1478  may include a connector through which the electronic device  1401  may be physically connected to an external electronic device (e.g., the electronic device  1402 ). According to an embodiment, the connection terminal  1478  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  1479  may convert an electrical signal into a mechanical stimulus (e.g., vibration or motion) or an electrical stimulus that may be perceived by the user through a tactile or kinesthetic sense. According to an embodiment, the haptic module  1479  may include, for example, a motor, a piezoelectric element, or an electrical stimulation device. 
     The camera module  1480  is a device that is capable of capturing, for example, a still image and a video image. According to an embodiment, the camera module  1480  may include one or more lenses, image sensors, image signal processors, or flashes. 
     The power management circuit  1488  may manage the power to be supplied to the external electronic device  1401 . According to an embodiment, the power management module  1488  may be implemented as at least a part of, for example, a power management integrated circuit (PMIC). 
     The battery  1489  is capable of supplying power to at least one component of the electronic device  1401 . According to an embodiment, the battery  1489  may include, for example, a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell. 
     The communication module  1490  may establish a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device  1401  and an external electronic device (e.g., the electronic device  1402 , the electronic device  1404 , or the server  1408 ), and may support communication via the established communication channel. The communication module  1490  may include one or more communication processors, which are operated independently from a processor  1420  (e.g., an application processor) and support direct (e.g., wired) communication or wireless communication. According to an embodiment, the communication module  1490  may include a wireless communication module  1492  (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  1494  (e.g., a local area network (LAN) communication module, or a power line communication module). A corresponding one of these communication modules may communicate with an external electronic device via a first network  1498  (e.g., a short-range communication network such as Bluetooth, Wi-Fi direct, or infrared data association (IrDA)) or a second network  1499  (e.g., a cellular network, the Internet, or a computer network (e.g., a telecommunication network such as a LAN or a WAN)). These various types of communication modules may be integrated into one component (e.g., a single chip) or may be implemented as a plurality of components (e.g., a plurality of chips) that are separate from each other. The wireless communication module  1492  may identify or authenticate the electronic device  1401  in a communication network such as the first network  1498  or the second network  1499  using subscriber information (e.g., an international mobile subscriber identity (IMSI)) stored in a subscriber identification module  1496 ). 
     The antenna module  1497  may transmit/receive signals or power to/from the outside (e.g., an external electronic device). According to an embodiment, the antenna module  1497  may include one or more antennas, from which at least one antenna suitable for a communication scheme used in a communication network, such as the first network  1498  or the second network  1499 , may be selected by, for example, the communication module  1490 . The signals or power may be transmitted or received between the communication module  1490  and the external electronic device via the selected at least one antenna. 
     Among the components described above, at least some components may be connected to each other via a communication scheme (e.g., a bus, a general-purpose input and output (GPIO), a serial peripheral interface (SPI), or a mobile industry processor interface (MIPI)), and may exchange signals (e.g., commands or data) therebetween. 
     According to an embodiment, the instructions or data may be transmitted or received between the electronic device  1401  and the external electronic device  1404  via the server  1408  connected to the second network  1499 . Each of the electronic devices  1402  and  1404  may be of a type that is the same as or different from that of the electronic device  1401 . According to an embodiment, all or some of the operations executed on the electronic device  1401  may be executed on one or more of the external electronic devices  1402 ,  1404 , and  1408 . For example, when the electronic device  1401  is to perform a function or service automatically, or in response to a request from a user or another device, the electronic device  1401  may request that one or more external electronic devices perform at least a part of the function or the service, in place of or in addition to performing the function or service by itself. The one or more external electronic devices that receive the request may execute at least a portion of the requested function or service, or an additional function or service associated with the request, and may deliver the result of the execution to the electronic device  1401 . The electronic device  1401  may process the result as it is or additionally so as to provide at least a portion of the response to the request. For this purpose, for example, cloud computing technology, distributed computing technology, or client-server computing technology may be used. 
     According to one embodiment, the electronic device  1401  may include a printed circuit board (e.g., the printed circuit board  340  in  FIG. 3 ), on which at least some of a processor  1420 , a memory  1430 , an input device  1450 , a sound output device  1455 , a display device  1460 , an audio module  1470 , a sensor module  1476 , an interface  1477 , a haptic module  1479 , a camera module  1480 , a power management module  1488 , a battery  1489 , a communication module  1490 , a subscriber identification module  1496 , and an antenna module  340  are mounted. According to an embodiment, the printed circuit board may include a first printed circuit board (the first printed circuit board  341  in  FIG. 3 ) and at least one second printed circuit board (the second printed circuit board  342  in  FIG. 3 ) disposed to overlap the first printed circuit board. The first printed circuit board or the second printed circuit board may also be formed according to the multilayer printed circuit board manufacturing flow described above with reference to  FIGS. 4A, 4B, 4C, and 4D  and  FIGS. 5A, 5B, 5C, 5D, 5E, and 5F . According to an embodiment, the second printed circuit board is capable not only of reinforcing the first printed circuit board, but also of being utilized as a wiring area. 
     The term “module” used herein may include a unit implemented with hardware, software, or firmware, and may be used interchangeably with, for example, the terms of “logic,” “logic block,” “component, “circuit,” or the like. The module may be an integrally constructed component or a minimum unit or a part of the component, which performs one or more functions. For example, according to an embodiment, the module may be implemented in the form of an application-specific integrated circuit (ASIC). 
     Certain embodiments disclosed herein may be implemented by software (e.g., the program  1440 ) including one or more instructions stored in a storage medium (e.g., internal memory  1436  or external memory  1438 ) readable by a machine (e.g., the electronic device  1401 ). For example, a processor (e.g., the processor  1420 ) of a device (e.g., the electronic device  1401 ) may call and execute at least one of the stored one or more instructions from a storage medium. This enables the device to be operated to perform at least one function in accordance with the at least one called instruction. The one or more instructions may include code generated by a compiler or code capable of being executed 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” merely means that the storage medium is a tangible device and does not contain a signal (e.g., electromagnetic waves), and this term is not intended to distinguish between the case where data is permanently stored on the storage medium and the case where data is temporarily stored thereon. 
     According to one embodiment, a method according to certain embodiments disclosed herein may be provided in the manner of being included in a computer program product. A computer program product may be traded between a seller and a purchaser as a commodity. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., a compact disc read only memory (CD-ROM)), or may be distributed through an application store (e.g., Play Store™), directly between two user devices (e.g., smart phones), or online (e.g., downloaded or uploaded). In the case of on-line distribution, at least a part of the computer program product may be temporarily stored in or temporarily produced from a machine-readable storage medium such as a manufacturer&#39;s server, a server of an application store, or a memory of a relay server. 
     According to certain embodiments, among the above-described components, each component (e.g., a module or a program) may include one or more entities. According to certain embodiments, among the components, one or more components or operations may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into one component. In such a case, the integrated component may perform one or more functions of each of the plurality of components in a manner the same as or similar to performance thereof by the corresponding one of the plurality of components prior to the integration. According to certain embodiments, operations performed by a module, a program, or other components may be performed sequentially, in parallel, repetitively, or heuristically, one or more of the operations may be performed in a different order or omitted, or one or more other operations may be added thereto. 
     According to an embodiment of the disclosure, an electronic device (e.g., the electronic device  100  in  FIG. 1 or 2 ) may include a first printed circuit board (e.g., the first circuit board  710  in  FIG. 7 ) including a first electrical terminal  701  exposed on one face of a first area (e.g., the first area  711  in  FIG. 7 ), a second electrical terminal  702  exposed on one face of a second area (e.g., the second area  712  in  FIG. 7 ) and not electrically connected to the first electrical terminal  701 , and a first ground terminal  705  exposed on one face of a third area (e.g., the third area  713  in  FIG. 7 ) formed between the first area  711  and the second area  712  to have a width narrower than that of the first area  711  or the second area  712 . The electronic device  100  may include a second printed circuit board (e.g., the second circuit board  720  in  FIG. 7 ) including a third terminal  703  exposed on one face of a fourth area (e.g., the fourth area  714  in  FIG. 7 ), a fourth electrical terminal  704  exposed on one face of a fifth area (e.g., the fifth area  715  in  FIG. 7 ) and electrically connected to the third electrical terminal  703 , and a second ground terminal  706  exposed on one face of a sixth area (e.g., the sixth area  716  in  FIG. 7 ) located between the fourth area  714  and the fifth area  715 . The second printed circuit board  720  may be disposed on the first printed circuit board  710  to overlap the third area  713 , the first electrical terminal  701  and the third electrical terminal  703  may be electrically coupled to each other, the second electrical terminal  702  and the fourth electrical terminal  704  may be electrically coupled to each other, and the first ground terminal  705  and the second ground terminal  706  may be electrically coupled to each other. 
     According to an embodiment of the disclosure, the first printed circuit board  710  or the second printed circuit board  720  may be a printed circuit board formed using a copper-clad laminate (CCL) (e.g., FR-4) including an insulating layer in which woven glass fiber impregnated with an epoxy resin is stacked in multiple layers and copper bonded to the insulating layer. 
     According to an embodiment of the disclosure, the first printed circuit board  710  or the second printed circuit board  720  may be a printed circuit board formed using a copper-clad laminate (e.g., CEM-3) including a center base material made of non-woven glass fiber impregnated with an epoxy resin, outer base materials made of woven glass fiber impregnated with an epoxy resin, and copper foils bonded to the outer base materials. 
     According to an embodiment of the disclosure, the second printed circuit board may include a multilayer printed circuit board. 
     According to an embodiment of the disclosure, the second printed circuit board may include a multilayer printed circuit board including inner layers formed on the basis of the copper-clad laminate, and the number of inner layers may be equal to that in the first printed circuit board. 
     According to an embodiment of the disclosure, the second printed circuit board may include a multilayer printed circuit board including inner layers formed on the basis of the copper-clad laminate, and the number of inner layers may be different from that in the first printed circuit board. 
     According to an embodiment of the disclosure, the second printed circuit board may include a double-sided printed circuit board. 
     According to an embodiment of the disclosure, the second printed circuit board may have a thickness different from that of the first printed circuit board. 
     According to an embodiment of the disclosure, at least a portion of a side face  723  of the second printed circuit board (e.g., the second printed circuit board  720  in  FIG. 7 ) may be surrounded by a conductive material. 
     According to an embodiment of the disclosure, the third area (e.g., the third area  913  in  FIG. 9 ) may be adjacent to an opening  914  formed in the first printed circuit board  910 . 
     According to an embodiment of the disclosure, the third area (e.g., the third area  913  in  FIG. 9 ) may be adjacent to a camera module  970  included in the electronic device. 
     According to an embodiment of the disclosure, the electronic device may further include a battery (e.g., the battery  1040  in  FIG. 10 ), and the third area (e.g., the third area  1013  in  FIG. 10 ) may be adjacent to the battery  1040 . 
     According to an embodiment of the disclosure, the electronic device may include a motor mounted on the third area (e.g., the ninth area  919  in  FIG. 9 ). 
     According to an embodiment of the disclosure, the electronic device may further include a solder (e.g., the solder  841 ,  842 , or  843  in  FIG. 8 ) disposed between the first electrical terminal and the third electrical terminal, between the second electrical terminal and the fourth electrical terminal, or between the first ground terminal and the second ground terminal. 
     According to an embodiment of the disclosure, at least one of the third electrical terminal, the fourth electrical terminal, and the second ground terminal may include a via. 
     According to an embodiment of the disclosure, the second printed circuit board may include an antenna (e.g., the antennas  1131  and  1132  in  FIG. 11B ) disposed on the face facing away from the face that faces the first printed circuit board. 
     According to an embodiment of the disclosure, the electronic device may further include a communication circuit mounted on the first printed circuit board, and the communication circuit may perform communication using the antenna. 
     According to an embodiment of the disclosure, the second printed circuit board may be electrically connected to a frequency adjustment circuit mounted on the first printed circuit board. 
     According to an embodiment of the disclosure, at least a part of the current provided from an external power source connected to the electronic device may flow from the first area to the second area through the second printed circuit board. 
     According to certain embodiment of the disclosure, an electronic device (e.g., the electronic device  100  in  FIG. 1 or 2 ) may include a first printed circuit board (e.g., the first circuit board  710  in  FIG. 7 ) including a first electrical terminal  701  exposed on one face of a first area (e.g., the first area  711  in  FIG. 7 ), a second electrical terminal  702  exposed on one face of a second area (e.g., the second area  712  in  FIG. 7 ) and not electrically connected to the first electrical terminal  701 , and a first metal pad formed on one face of a third area (e.g., the third area  713  in  FIG. 7 ) formed between the first area  711  and the second area  712  to have a width narrower than that of the first area  711  or the second area  712 . The electronic device  100  may include a second printed circuit board (e.g., the second circuit board  720  in  FIG. 7 ) including a third terminal  703  exposed on one face of a fourth area (e.g., the fourth area  714  in  FIG. 7 ), a fourth electrical terminal  704  exposed on one face of a fifth area (e.g., the fifth area  715  in  FIG. 7 ) and electrically connected to the third electrical terminal  703 , and a second metal pad formed on one face of a sixth area (e.g., the sixth area  716  in  FIG. 7 ) located between the fourth area  714  and the fifth area  715  to have a width narrower than that of the first area  711  or the second area  712 . The second printed circuit board  720  may be disposed on the first printed circuit board  710  to overlap the third area  713 , the first electrical terminal  701  and the third electrical terminal  703  may be electrically coupled to each other, the second electrical terminal  702  and the fourth electrical terminal  704  may be electrically coupled to each other, and the first metal pad and the second metal pad may be electrically coupled to each other. 
     The disclosure has been described above in connection with the exemplary embodiments thereof. It will be understood by those skilled in the art to which the disclosure belongs that the disclosure may be implemented in modified forms without departing from the essential characteristics of the disclosure. Therefore, the embodiments disclosed herein should be considered from an illustrative point of view, rather than a limitative point of view. The scope of the disclosure is found not in the above description but in the accompanying claims, and all differences falling within the scope equivalent to the claims should be construed as being included in the disclosure.