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EP-3903166-B1 - FOLDABLE ELECTRONIC DEVICE INCLUDING FLEXIBLE PRINTED CIRCUIT BOARD

EP3903166B1EP 3903166 B1EP3903166 B1EP 3903166B1EP-3903166-B1

Inventors

  • WOO, JEONG
  • An, Jungchul
  • CHOI, SEUNGKI

Dates

Publication Date
20260506
Application Date
20200213

Claims (14)

  1. A foldable electronic device (101) comprising: a hinge structure (510, 550) having a folding axis; a foldable housing (300) including a folding section where the electronic device (101) is folded about the folding axis, a first housing structure (310, 610), and a second housing structure (320, 620), wherein: the first housing structure (310, 610) is connected to the hinge structure (510, 550), includes a first surface (311) facing a first direction, a second surface (312) facing a second direction opposite to the first direction, and a first printed circuit board (821) having a first plurality of electronic components mounted thereon, the second housing structure (320, 620) is connected to the hinge structure (510, 550), includes a third surface (321) facing a third direction, a fourth surface (322) facing a fourth direction opposite to the third direction, and a second printed circuit board (822) having a second plurality of electronic components mounted thereon, the second housing structure (320, 620) being configured to be foldable on the first housing structure (310, 610) around the hinge structure (510, 550), and the first surface (311) faces the third surface (321) when the electronic device (101) is folded and the third direction coincides with the first direction when the electronic device (101) is unfolded; a flexible display (200) disposed in the foldable housing (300) and extending from the first surface (311) of the first housing structure (310, 610) to the third surface (321) of the second housing structure (320, 620); a first flexible printed circuit board (F1) configured to cross at least a portion of the hinge structure (510, 550) and configured to electrically connect the first printed circuit board (821) and the second printed circuit board (822) through first connection terminals (810, 820) at both ends thereof; and a second flexible printed circuit board (F2) configured to cross at least a portion (902') of the hinge structure (510, 550) and configured to electrically connect the first printed circuit board (821) and the second printed circuit board (822) through second connection terminals (910, 920) at both ends thereof, characterized in that wherein first signal lines having a first signal line characteristic are disposed on the first flexible printed circuit board (F1) and second signal lines having a second signal line characteristic are disposed on the second flexible printed circuit board (F2), and wherein the second flexible printed circuit board (F2) is longer than the first flexible printed circuit board (F1) and wherein a signal line for Mobile Industry Processor Interface, MIPI, is formed on the first flexible printed circuit board.
  2. The foldable electronic device (101) of claim 1, wherein a portion (902') of the second flexible printed circuit board (F2) is parallel with the first flexible printed circuit board (F1), and another portion (902') of the second flexible printed circuit board (F2) is not parallel with the first flexible printed circuit board (F1) and includes a bent portion (902').
  3. The foldable electronic device (101) of claim 2, wherein the other portion (902') of the second flexible printed circuit board (F2) overlaps the first plurality of electronic components or the second plurality of electronic components.
  4. The foldable electronic device (101) of claim 2, wherein the other portion (902') of the second flexible printed circuit board (F2) overlaps a battery (189, 851, 852).
  5. The foldable electronic device (101) of claim 1, wherein: the first connection terminals (810, 820) are disposed at a first end (1010) and a second end (1020) of the first flexible printed circuit board (F1), first rigid portions (801) for fixing the first flexible printed circuit board (F1) to the first printed circuit board (821) and the second printed circuit board (822) are formed at the first end (1010) and the second end (1020), the second connection terminals (910, 920) are disposed at a third end (910) and a fourth end (920) of the second flexible printed circuit board (F2), and second rigid portions (803) for fixing the second flexible printed circuit board (F2) to the first printed circuit board (821) and the second printed circuit board (822) are formed at the third end (910) and the fourth end (920).
  6. The foldable electronic device (101) of claim 5, wherein the first end (1010) and the second end (1020) face opposite directions, and the third end (910) and the fourth end (920) face directions perpendicular to each other.
  7. The foldable electronic device (101) of claim 5, wherein the first flexible printed circuit board (F1) further comprises at least one third rigid portion between the first end (1010) and the second end (1020), and the second flexible printed circuit board (F2) further comprises at least one fourth rigid portion (903) between the third end (910) and the fourth end (920).
  8. The foldable electronic device (101) of claim 7, wherein the at least one third rigid portion and the at least one fourth rigid portion (903) are configured to be connected and fixed to the hinge structure (510, 550).
  9. The foldable electronic device (101) of claim 1, wherein the first signal lines are signal lines that perform communication at a relatively higher speed than the second signal lines or are signal lines through which a relatively higher current than the second signal lines flows.
  10. The foldable electronic device (101) of claim 1, wherein the first flexible printed circuit board (F1) further comprises a first-first signal line and a first-second signal line disposed on different layers, and a ground between the first-first signal line and the first-second signal line.
  11. The foldable electronic device (101) of claim 1, wherein the first flexible printed circuit board (F1) further comprises a layer having a first connector formed at an end (1010) and a second connector corresponding to the first connector and formed at another end (1020), and the first connector and the second connector are parallel pin connectors each having at least two lines of pins.
  12. The foldable electronic device (101) of claim 11, wherein the first connector further comprises a first-first line of pins formed at an outermost side of the first flexible printed circuit board (F1) and a first-second line of pins formed inside the first-first line of pins, the second connector further comprises a second-first line of pins formed at the outermost side of the first flexible printed circuit board (F1) and a second-second line of pins formed inside the second-first line of pins, and wherein the first flexible printed circuit board (F1) further comprises a first signal line connected from the first-first line of pins to the second-second line of pins, and a second signal line connected from the first-second line of pins to the second-first line of pins.
  13. The foldable electronic device (101) of claim 12, wherein a layer on which the first signal line and the second signal line is disposed is stacked adjacent to a layer having the first connector and the second connector.
  14. The foldable electronic device (101) of claim 12, wherein the first signal line and the second signal line each correspond to a Mobile Industry Processor Interface, MIPI.

Description

[Technical Field] One or more embodiments disclosed herein generally relate to a foldable electronic device including a flexible printed circuit board. [Background Art] The electronic device related to the instant application may be a device that performs specific functions in accordance with programs installed therein, such as home appliances, electronic notepads, mobile multimedia players, mobile communication terminals, tablet PCs, video/sound devices, desktop/laptop computers, automobile navigation systems, etc. For example, these electronic devices can output information stored therein as sound or images. As development of these electronic devices have advanced and high-speed and large-capacity wireless communication networks have been popularized recently, an increasing number of functions can be integrated in a single electronic device such as a mobile communication terminal. These functions may include communication, entertainment such as gaming, multimedia such as playback of music/video, communication and security for mobile banking, calendar, electronic wallet, etc. These electronic devices are also increasingly miniaturized so that users can conveniently carry them. In similar regards, publication EP 2975489 A1 relates to an electronic device with a cover, wherein a first display is disposed on a first face of a first portion of the cover and a second display is disposed on a second portion of the cover, and a circuit board placed on the cover connects the two displays. As the above functions of the electronic devices have increased, users can not only make voice calls or write short text messages, but also use multimedia services of the electronic devices. In order to provide users with convenience when using the multimedia services, the electronic devices are being equipped with wider display panels. Further, recently, foldable electronic devices equipped with flexible display devices are being implemented. [Disclosure of Invention] [Technical Problem] A foldable electronic device according to an embodiment includes one display panel and two housings surrounding the display panel with the folding region of the display panel therebetween. The electronic device may include various electronic devices for performing various functions and operations such as communication, entertainment, multimedia, and security. These electronic parts may be separately disposed in the two housings subject to various design considerations, such as spatial mounting within the electronic devices. The electronic parts are mounted on a PCB (Printed Circuit Board) included in the housing and are electrically connected to one another through at least one FPCB (Flexible Printed Circuit Board). For example, the FPCB may be a C2C (connector to connector) FPCB connecting connectors respectively formed on two different substrates to each other. Various signal lines are disposed on the FPCB, such as signal lines for implementing various functions including high-quality displaying, operating a high-performance camera and/or stereo speakers, or power supply. According to a certain embodiment, when the FPCB is connected to two substrates disposed in different housings, some signal lines disposed on the FPCB that are sensitive to impedance may be subject to a greater possibility of signal loss. [Solution to Problem] The invention is directed to the subject-matter of the independent claim. Advantageous embodiments are set out in the dependent claims. [Advantageous Effects of Invention] According to certain embodiments, it is possible to provide a foldable electronic device that includes at least two flexible printed circuit boards connecting two substrates respectively included in two different housings, and includes a plurality of signal lines separately disposed on the at least two flexible printed circuit boards for improved signal characteristics. According to certain embodiments, since a plurality of signal lines are separately disposed on at least the two flexible printed circuit boards for improved signal characteristics, it is possible to implement a design that minimizes impedance influence. The placement of the plurality of signal lines is done in consideration of the various characteristics (e.g., sensitivity) of the signal lines. Thus it is possible to prevent deterioration of the performance of the electronic device. According to an embodiment, since there is provided a wiring method that gives approximately the same lengths to different signal lines formed on a layer, it is possible to prevent timing skew or delay and there is no need for an additional wiring to reduce timing skew or delay when designing the signal lines. [Brief Description of Drawings] The above and other aspects, features, and advantages of the disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a block diagram of an electronic device in a network environmen