US-12621925-B2 - Circuit board having electromagnetic shielding structures and electronic device including the same

Abstract

A circuit board electrically connected to an electronic device includes a base layer, a first conductive layer on a first surface of the base layer, a second conductive layer on a second surface of the base layer and including a terminal portion which is exposed outside of the circuit board and at which the circuit board is electrically connected to the electronic device, a first electromagnetic shield layer which faces the base layer with the first conductive layer therebetween and overlaps the terminal portion of the second conductive layer and a second electromagnetic shield layer which faces the base layer with the second conductive layer therebetween, and is spaced apart from the terminal portion of the second conductive layer in a direction along the base layer.

Inventors

• Cheuk PARK

Assignees

• SAMSUNG ELECTRONICS CO., LTD.

Dates

Publication Date

20260505

Application Date

20230206

Priority Date

20200804

Claims (19)

1. 1 . A circuit board electrically connected to an electronic device, the circuit board comprising: a base layer comprising a first surface and a second surface which is opposite to the first surface; a first conductive layer on the first surface of the base layer; a second conductive layer which is on the second surface of the base layer and electrically connected to the first conductive layer, the second conductive layer comprising: a terminal portion which is exposed outside of the circuit board and at which the circuit board is electrically connected to the electronic device, and the terminal portion extending along the base layer to define a line portion of the second conductive layer; a first electromagnetic shield layer which is on the first surface of the base layer, faces the base layer with the first conductive layer therebetween, and overlaps the terminal portion of the second conductive layer; and a second electromagnetic shield layer which is on the second surface of the base layer, faces the base layer with the line portion of the second conductive layer therebetween, and is spaced apart from the terminal portion of the second conductive layer in a direction along the base layer.
2. 2 . The circuit board of claim 1 , wherein in the direction along the base layer: the base layer comprises a side surface which is furthest from the second electromagnetic shield layer, and the terminal portion is spaced apart from the side surface.
3. 3 . The circuit board of claim 1 , wherein: the first conductive layer includes a first transmission line through which an electrical signal flows in the circuit board; and the second conductive layer includes a second transmission line through which an electrical signal flows in the circuit board.
4. 4 . The circuit board of claim 3 , further comprising a reinforcing line defined by the first conductive layer, the reinforcing line being electrically disconnected from the first transmission line.
5. 5 . The circuit board of claim 1 , further comprising a conductive via passing through the base layer, wherein the first conductive layer and the second conductive layer are electrically connected to each other by the conductive via.
6. 6 . The circuit board of claim 5 , wherein in the direction along the base layer: the base layer comprises a side surface which is furthest from the second electromagnetic shield layer, and the conductive via is closer to the side surface than the terminal portion of the second conductive layer.
7. 7 . The circuit board of claim 5 , wherein in the direction along the base layer: the base layer comprises a side surface which is furthest from the second electromagnetic shield layer, and the conductive via is further from the side surface than the terminal portion of the second conductive layer.
8. 8 . The circuit board of claim 1 , wherein the circuit board is a flexible circuit board or a flexible printed circuit board.
9. 9 . A circuit board electrically connected to an electronic device, the circuit board comprising: an edge of the circuit board; a base layer; a first conductive layer and a second conductive layer facing each other with the base layer therebetween; the first conductive layer comprising a first wiring defining a first terminal portion exposed outside of the circuit board, spaced apart from the edge of the circuit board and at which the circuit board is connected to the electronic device; the second conductive layer comprising a wiring having an end spaced apart from the edge of the circuit board; and a first conductive via which passes through the base layer, electrically connects the first conductive layer and the second conductive layer to each other and is non-overlapping the terminal portion along a thickness direction of the circuit board.
10. 10 . The circuit board of claim 9 , wherein in a direction along the base layer, the first conductive via is between the edge of the circuit board and the first terminal portion.
11. 11 . The circuit board of claim 9 , wherein in a direction along the base layer, the first terminal portion is between the edge of the circuit board and the first conductive via.
12. 12 . The circuit board of claim 11 , wherein the first conductive layer further comprises a second wiring defining a second terminal portion exposed outside of the circuit board, spaced apart from both the edge of the circuit board and the first terminal portion, and at which the circuit board is connected to the electronic device.
13. 13 . The circuit board of claim 12 , wherein the first wiring and the second wiring of the first conductive layer are electrically insulated from each other.
14. 14 . The circuit board of claim 9 , further comprising a first electromagnetic shield layer on the second conductive layer, wherein the first electromagnetic shield layer includes a side surface which is aligned with the edge of the circuit board.
15. 15 . The circuit board of claim 14 , further comprising a reinforcing plate on the first electromagnetic shield layer.
16. 16 . The circuit board of claim 9 , wherein the wiring of the second conductive layer comprises a first wiring pattern and a second wiring pattern spaced apart from each other in a direction along the base layer, the first wiring pattern closer to the edge of the circuit board than the second wiring pattern.
17. 17 . The circuit board of claim 16 , wherein the first conductive layer further comprises a second wiring electrically insulated from the first wiring, and the second wiring defines a second terminal portion exposed outside of the circuit board, spaced apart from both the edge of the circuit board and the first terminal portion, and at which the circuit board is connected to the electronic device.
18. 18 . The circuit board of claim 17 , wherein the first wiring of the first conductive layer is electrically connected to the first wiring pattern of the second conductive layer, by a first conductive via penetrating the base layer, and the second wiring of the first conductive layer is electrically connected to the second wiring pattern of the second conductive layer, by a second conductive via penetrating the base layer.
19. 19 . The circuit board of claim 9 , wherein the electronic device includes a connector, and the circuit board is connected to the connector, at the first terminal portion.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application of International Application No. PCT/KR2021/010197 designating the United States, filed on Aug. 4, 2021, at the Korean Intellectual Property Receiving Office and claiming priority to Korean Patent Application No. 10-2020-0097370 filed on Aug. 4, 2020, at the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entireties. BACKGROUND Field Due to the development of communication technology, various services using communication technology are being created. Some services may require very high throughput data communication. Accordingly, technologies for transmitting large amounts of data in various environments are being applied. A multiple input multiple output (MIMO) communication system may include a plurality of transmit antennas of a transmitting device (e.g., a base station) and a plurality of receiving antennas of a receiving device (e.g., a user terminal), and may improve throughput by simultaneously transmitting a plurality of streams by using the plurality of antennas. In addition, a mobile communication terminal may be connected to an external electronic device by wire (e.g., USB type C) and may process data at high speed. Description of the Related Art In a user terminal, at least one printed circuit board may be disposed on each of the upper and lower stages therein. An RF transceiver (radio-frequency transceiver) for processing wireless communication signals transmitted/received to/from a plurality of antennas located in the upper and lower stages therein may be disposed on a first printed circuit board on the upper stage in the terminal. Wireless communication signals transmitted to/received from the antennas in the lower stage of the terminal may be provided to an RF transceiver via a circuit board such as a flexible printed circuit board (FPCB) connecting the second printed circuit board in the lower stage of the terminal to the first printed circuit board. In addition, the processor of the terminal may be disposed on the first printed circuit board in the upper stage of the terminal. When the processor of the terminal located in the lower stage of the terminal transmits/receives data signals to/from the interface of the second printed circuit board located in the lower stage of the terminal, the flexible printed circuit board (FPCB) interconnecting the second printed circuit board and the first printed circuit board may be used. When the processor of the terminal located in the lower stage of the terminal transmits/receives data signals to/from an external device connected to the interface of the second printed circuit board located in the lower stage of the terminal, the flexible printed circuit board (FPCB) interconnecting the second printed circuit board and the first printed circuit board may be used. SUMMARY Technical Problem Mobile terminals often use higher-speed signals than conventional terminals in order to have high performance and fast network access performance. In addition, in order to ensure assembly flexibility, an FPCB may be designed to allow high-speed signals to flow therethrough, and for this reason, noise induced in high-speed signals through the FPCB often causes deterioration in radiation performance. A circuit board such as a FPCB or a flexible printed circuit (FPC) may be connected to a connector (e.g., a ZIF connector or a board-to-board connector) that enables connection with another component in an electronic device. The connector serves to connect two conductors in a circuit. In order to reduce signal noise generated in or affecting an FPCB, an electromagnetic interference (EMI) shield layer may be provided in a partial area of the FPCB. However, it is difficult to provide an EMI shield layer up to a portion connected to a connector of an FPCB for connection to a printed circuit board (PCB). In order to solve this, conventionally, there was a method of separately using insulating and laminated tapes for shielding. When a separate laminated tape is used instead of an EMI tape, shielding is possible, but a difference in performance may occur depending on a tape attachment deviation, and there is a problem in that the shielding performance of the laminated tape is not as good as that of the EMI tape. An embodiment according to the disclosure relates to a design of an FPCB pattern for applying an EMI shield layer up to an end of an FPCB to reduce noise induced in an FPCB that is designed to allow high-speed signals to flow therethrough. Based on the discussion, the disclosure discloses a structure of a circuit board such as a flexible printed circuit board (FPCB) configured to block noise induced in a high-speed signal designed in the FPCB. The disclosure also discloses a structure of an FPCB configured to block noise induced in a connector connecting portion. The disclosure also discloses a structure of an FPCB configured to p