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EP-4007463-B1 - RIGID FLEXIBLE PRINTED CIRCUIT BOARD AND ELECTRONIC DEVICE COMPRISING SAME

EP4007463B1EP 4007463 B1EP4007463 B1EP 4007463B1EP-4007463-B1

Inventors

  • LEE, YOUNGSUN
  • HONG, Eunseok
  • KIM, Byeongkeol
  • JEON, Jongmin
  • JANG, Donggon
  • JUNG, KISOO
  • HONG, Seounghyun
  • HWANG, Hyunsung

Dates

Publication Date
20260513
Application Date
20200730

Claims (11)

  1. An electronic device comprising: a first electrical element and a second electrical element; and a rigid flexible printed circuit board (400, 700, 740) configured to electrically connect the first electrical element to the second electrical element, wherein the rigid flexible printed circuit board (400, 700, 740) comprises: at least one flexible portion (410, 440, 720, 722, 724, 760, 762, 764, 766) comprising a first dielectric (401) which has a first dielectric constant and is flexible, at least one rigid portion (420, 430, 450, 710, 712, 714, 716, 750, 752, 754, 756) extending from the flexible portion (410, 440, 720, 722, 724, 760, 762, 764, 766) and comprising a second dielectric (402) which has a second dielectric constant and is less flexible than the first dielectric (401), multiple conductive patterns (610, 612) formed inside the first dielectric (401) and the second dielectric (402), multiple conductive layers (510, 512) formed on the first dielectric (401) and the second dielectric (402), and multiple conductive vias (530) which are formed in the rigid portion (420, 430, 450, 710, 712, 714, 716, 750, 752, 754, 756) and electrically connect the multiple conductive layers (510, 512) to each other or the multiple conductive patterns (610, 612) to each other; and wherein the at least one flexible portion (410, 440, 720, 722, 724, 760, 762, 764, 766) comprises a first air layer (732) and a second air layer (734), wherein the first air layer (732) and second air layer (734) are spaced apart from each other and are parallel to each other; wherein the multiple conductive patterns (610, 612) are positioned between the first air layer (732) and the second air layer (734); and wherein the first air layer (732) and the second air layer (734) are parallel to the multiple conductive patterns (610, 612) and the multiple conductive layers (510, 512).
  2. The electronic device of claim 1, wherein the first dielectric (401) is formed of a liquid crystal polymer, LCP,.
  3. The electronic device of claim 2, wherein the second dielectric (402) is formed of prepreg.
  4. The electronic device of claim 1, wherein the first dielectric (401) is formed of an insulation thermoplastic resin, and wherein the second dielectric (402) is formed of an insulation thermosetting resin.
  5. The electronic device of claim 1, wherein the first dielectric constant is identical to the second dielectric constant.
  6. The electronic device of claim 1, wherein a first glass transition temperature that a first insulation bonding material for forming the first dielectric (401) has is lower than a second glass transition temperature that a second insulation bonding material for forming the second dielectric (402) has.
  7. The electronic device of claim 1, wherein the flexible portion (410, 440, 720, 722, 724, 760, 762, 764, 766) and the rigid portion (420, 430, 450, 710, 712, 714, 716, 750, 752, 754, 756) form impedance having the same magnitude corresponding to a designated frequency.
  8. The electronic device of claim 1, wherein the first electrical element comprises: a first printed circuit board (310) comprising at least one antenna array (1270, 1280), and a first wireless communication circuit (340, 1240) disposed on the first printed circuit board (310) and electrically connected to the at least one antenna array (1270, 1280), wherein the second electrical element comprises: a second printed circuit board (370), and a second wireless communication circuit disposed on the second printed circuit board (370), and wherein one end of the rigid flexible printed circuit board (400, 700, 740) is electrically connected to the first printed circuit board (310), and another end of the rigid flexible printed circuit board (400, 700, 740) is electrically connected to the second printed circuit board (370).
  9. The electronic device of claim 8, wherein the at least one antenna array (1270, 1280) comprises: a first antenna element, and a second antenna element disposed to be spaced apart from the first antenna element, wherein the first wireless communication circuit (340, 1240) comprises: a first electrical path electrically connected to a first point on the first antenna element, and a second electrical path electrically connected to a second point on the second antenna element, and wherein a phase difference between a first signal at the first point and a second signal at the second point is provided.
  10. The electronic device of claim 1, wherein the rigid flexible printed circuit board (400, 700, 740) further comprises: a first cover layer (501) covering one side, and a second cover layer (502) covering the other side that is opposite to the one side wherein the first air layer (732) is formed between the first cover layer (501) and the conductive patterns (610, 612), and wherein the first air layer (732) is disposed to be spaced apart from each of the first cover layer (501) and the conductive patterns (610, 612).
  11. The electronic device of claim 10, wherein the second air layer (734) is formed between the second cover layer (502) and the conductive patterns (610, 612), and wherein the second air layer (734) is disposed to be spaced apart from each of the second cover layer (502) and the conductive patterns (610, 612).

Description

[Technical Field] Various embodiments of the disclosure relate to a rigid flexible printed circuit board and an electronic device including the same. [Background Art] With development of digital technology, an electronic device has been provided in different forms such as a smartphone, a tablet personal computer (PC), or a personal digital assistant (PDA). The electronic device has also been developed in a form wearable by a user so that portability and accessibility of the user can be enhanced. With development of wireless communication technology, an electronic device (e.g., a communication electronic device) is commonly used in a daily life, and accordingly, a trend of a content usage is exponentially increasing. The electronic device may include a rigid flexible printed circuit board (RFPCB) for electrically connecting elements (e.g., components or circuits) to each other. US 2011/203837 A1 relates to a flex-rigid wiring board and method for manufacturing the same. The flex-rigid wiring board includes an insulative substrate, a flexible connected body positioned beside the insulative substrate and including multiple flexible wiring boards, and an insulation layer positioned over the insulative substrate and the flexible connected body and having a portion exposing a portion of the flexible connected body. The flexible wiring boards include a double-sided flexible wiring board having a conductive layer on one surface of the double-sided flexible wiring board and a conductive layer on the opposite surface of the double-sided flexible wiring board. The flexible connected body has a conductor on one side of the flexible connected body, a conductor on the opposite side of the flexible connected body, and a through-hole conductor electrically connecting the conductors of the flexible connected body. The through-hole conductor is penetrating from one side through the opposite side of the flexible wiring boards. US 209/028497 A1 relates to an optoelectronic wiring board, optical communication device, and method of manufacturing the optical communication device. The optoelectronic wiring board includes a rigid, a flexible flex section made of an optical wiring, a flex rigid substrate section provided with an electric wiring, and optical wiring means. In the rigid section, a lamination which is formed of a conductive circuit and an insulating layer is formed on both sides of a substrate. The flexible flex section is made of an optical wiring. The flex rigid substrate section is provided with an electric wiring. The optical wiring means has an end face substantially perpendicular to the optical wiring means. The end face is arranged facing an optical element mounting region provided on the rigid section, and at least a part of the flex section is fixed on the rigid section. [Disclosure of Invention] [Technical Problem] A rigid flexible printed circuit board may include conductive vias. The conductive vias may include a conductive hole made for the purpose of disposing a connection wire for electrically connecting conductive layers arranged in different layers. When at least a part of the rigid flexible printed circuit board is disposed in the electronic device, conductive vias in the bent portion of the rigid flexible printed circuit board may be broken (e.g., a via crack) due to the bending stress. Various embodiments of the disclosure may provide a rigid flexible printed circuit board for securing reliability in transferring a signal while preventing a via crack which may be caused by bending when the rigid flexible printed circuit is disposed to be bent, and an electronic device including the same. Various embodiments of the disclosure may provide a rigid flexible printed circuit board having a reduced thickness by configuring the rigid flexible printed circuit board with one insulation layer, and an electronic device including the same. [Solution to Problem] The scope of protection conferred is determined from the claims. [Advantageous Effects of Invention] Various embodiments of the disclosure can prevent a via crack which may be caused by bending when a part of a rigid flexible printed circuit board is disposed in a bent form, and also secure reliability in transferring a signal (e.g., can achieve reduction in a signal loss or securing of signal integrity). Various embodiments of the disclosure can reduce the thickness of a rigid flexible printed circuit board. In addition, effects obtained or predicted by various embodiments of the disclosure will be directly or suggestively described in the detailed description of embodiments of the disclosure. For example, various effects predicted according to various embodiments of the disclosure will be described in the detailed description below. [Brief Description of Drawings] FIG. 1 is a block diagram illustrating an electronic device in a network environment according to an embodiment;FIG. 2 is a block diagram illustrating an electronic device in a network environm