US-12626961-B2 - Battery pack

US12626961B2US 12626961 B2US12626961 B2US 12626961B2US-12626961-B2

Abstract

A battery pack includes a battery cell; a main circuit board electrically connected to the battery cell; a flexible circuit board connected to the main circuit board and having an external connection terminal; a conductive compression layer between a first connection portion of the main circuit board and a second connection portion of the flexible circuit board, the conductive compression layer electrically connecting the first and second connection portion to each other, and including conductive particles and an insulating resin accommodating the conductive particles, wherein the first connection portion of the main circuit board includes a first insulating layer, first connection pads protruding from the first insulating layer, and accommodation spaces on the first insulating layer, between adjacent ones of the first connection pads and accommodating the insulating resin, and the second connection portion of the flexible circuit board includes second connection pads electrically connected to the first connection pads.

Inventors

Sanghun Park

Assignees

SAMSUNG SDI CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20230607
Priority Date: 20220608

Claims (17)

1 . A battery pack, comprising: a battery cell; a main circuit board electrically connected to the battery cell; a flexible circuit board connected to the main circuit board and having an external connection terminal therein; a conductive compression layer between a first connection portion of the main circuit board and a second connection portion of the flexible circuit board, the conductive compression layer: electrically connecting the first connection portion and the second connection portion to each other, and including a plurality of conductive particles and an insulating resin accommodating the plurality of conductive particles, wherein: the first connection portion of the main circuit board includes a first insulating layer, first connection pads protruding from the first insulating layer, and accommodation spaces on the first insulating layer, the accommodation spaces being between adjacent ones of the first connection pads and accommodating the insulating resin, and the second connection portion of the flexible circuit board includes second connection pads electrically connected to the first connection pads.
2 . The battery pack as claimed in claim 1 , wherein: the first connection pads are arranged in a first direction in which the main circuit board extends and arranged in a second direction intersecting the first direction, and the accommodation spaces have a channel shape extending in the first direction and the second direction between adjacent ones of the first connection pads.
3 . The battery pack as claimed in claim 2 , wherein the accommodation spaces are open toward an outside of the first connection portion.
4 . The battery pack as claimed in claim 2 , wherein each of the first connection pads is surrounded by the accommodation spaces and isolated from other adjacent first connection pads.
5 . The battery pack as claimed in claim 2 , wherein: the first connection pads protrude from the first insulating layer in a third direction intersecting the first direction and the second direction, and the accommodation spaces are on the first insulating layer.
6 . The battery pack as claimed in claim 1 , wherein the first connection pads, the second connection pads, and the conductive compression layer electrically connecting the first connection pads and the second connection pads to each other are between a surface of the main circuit board opposite to the first connection pads and a surface of the flexible circuit board opposite to the second connection pads.
7 . The battery pack as claimed in claim 6 , wherein the surface of the flexible circuit board is electrically insulating.
8 . The battery pack as claimed in claim 1 , wherein the first connection pads protrude above the first insulating layer and penetrate the first insulating layer.
9 . The battery pack as claimed in claim 8 , wherein the first connection pads have a uniform thickness protruding from the first insulating layer.
10 . The battery pack as claimed in claim 1 , wherein the first insulating layer has a flat surface across the first connection pads.
11 . The battery pack as claimed in claim 10 , wherein the first insulating layer forms a flat outer surface of the main circuit board in a third direction intersecting the first direction in which the main circuit board extends, extends from a position outside the first connection portion in the main circuit board, and is locally exposed in the first connection portion.
12 . The battery pack as claimed in claim 1 , wherein the second connection pads are recessed from a second insulating layer in the second connection portion.
13 . The battery pack as claimed in claim 12 , wherein: the second connection pads are recessed from the second insulating layer by a depth corresponding to a thickness of the second insulating layer, and a depth of the second connection pads provides a locking step for capturing the plurality of conductive particles between the first connection pads and the second connection pads.
14 . The battery pack as claimed in claim 12 , wherein the second connection pads are exposed through openings of the second insulating layer.
15 . The battery pack as claimed in claim 1 , wherein: the main circuit board and the flexible circuit board overlap each other at the first connection portion and the second connection portion in a first direction, and extend side by side with each other in the first direction, and the first connection pads and the second connection pads, in the first connection portion and the second connection portion, are arranged in the first direction and a second direction intersecting the first direction.
16 . The battery pack as claimed in claim 1 , wherein, among relative proportions of the plurality of conductive particles and the insulating resin of the conductive compression layer, a relative proportion of the plurality of conductive particles between the first connection pads and the second connection pads in the first connection portion and the second connection portion, respectively, is greater than a relative proportion of the plurality of conductive particles in the accommodation spaces.
17 . The battery pack as claimed in claim 1 , wherein, among relative proportions of the plurality of conductive particles and the insulating resin of the conductive compression layer, a relative proportion of the insulating resin in the accommodation spaces is greater than a relative proportion of the insulating resin between the first connection pads and the second connection pads in the first connection portion and the second connection portion, respectively.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2022-0069549, filed on Jun. 8, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. BACKGROUND 1. Field Embodiments relate to a battery pack. 2. Description of the Related Art In general, secondary batteries are rechargeable unlike non-rechargeable primary batteries. Secondary batteries may be used as energy sources of devices, such as mobile devices, electric vehicles, hybrid vehicles, electric bicycles, and uninterruptible power supplies, and depending on the type of an external device using a secondary battery, the secondary battery may be used as a single battery cell or as a module in which a plurality of battery cells are connected to each other to constitute a unit. SUMMARY The embodiments may be realized by providing a battery pack including a battery cell; a main circuit board electrically connected to the battery cell; a flexible circuit board connected to the main circuit board and having an external connection terminal therein; a conductive compression layer between a first connection portion of the main circuit board and a second connection portion of the flexible circuit board, the conductive compression layer electrically connecting the first connection portion and the second connection portion to each other, and including a plurality of conductive particles and an insulating resin accommodating the plurality of conductive particles, wherein the first connection portion of the main circuit board includes a first insulating layer, first connection pads protruding from the first insulating layer, and accommodation spaces on the first insulating layer, the accommodation spaces being between adjacent ones of the first connection pads and accommodating the insulating resin, and the second connection portion of the flexible circuit board includes second connection pads electrically connected to the first connection pads. The first connection pads may be arranged in a first direction in which the main circuit board extends and arranged in a second direction intersecting the first direction, and the accommodation spaces may have a channel shape extending in the first direction and the second direction between adjacent ones of the first connection pads. The accommodation spaces may be open toward an outside of the first connection portion. Each of the first connection pads may be surrounded by the accommodation spaces and isolated from other adjacent first connection pads. The first connection pads may protrude from the first insulating layer in a third direction intersecting the first direction and the second direction, and the accommodation spaces may be on the first insulating layer. The first connection pads, the second connection pads, and the conductive compression layer electrically connecting the first connection pads and the second connection pads to each other may be between a surface of the main circuit board opposite to the first connection pads and a surface of the flexible circuit board opposite to the second connection pads. The surface of the flexible circuit board may be electrically insulating. The first connection pads may protrude above the first insulating layer and penetrate the first insulating layer. The first connection pads may have a uniform thickness protruding from the first insulating layer. The first insulating layer may have a flat surface across the first connection pads. The first insulating layer may form a flat outer surface of the main circuit board in a third direction intersecting the first direction in which the main circuit board extends, extends from a position outside the first connection portion in the main circuit board, and is locally exposed in the first connection portion. The second connection pads may be recessed from a second insulating layer in the second connection portion. The second connection pads may be recessed from the second insulating layer by a depth corresponding to a thickness of the second insulating layer, and a depth of the second connection pads may provide a locking step for capturing the plurality of conductive particles between the first connection pads and the second connection pads. The second connection pads may be exposed through openings of the second insulating layer. The main circuit board and the flexible circuit board overlap each other at the first connection portion and the second connection portion in a first direction, and extend side by side with each other in the first direction, and the first connection pads and the second connection pads, in the first connection portion and the second connection portion, may be arranged in the first direction and a second direction intersecting the first direction. Among relative proportions of the plurality of conductive particles and the insulating resin of the co