Current control module, and battery and electronic apparatus equipped with same

Abstract

[Problem] To provide a current control module having a shortened current path. [Solution] A current control module 10 comprises: a multilayer circuit board 100; a switching element 200 embedded in the multilayer circuit board 100; an external terminal 331 connected to a current port P1 of the switching element 200 and exposed on one surface 101 of the multilayer circuit board 100; and an external terminal 382 connected to a current port P2 of the switching element 200 and exposed on the other surface 102 of the multilayer circuit board 100.

Description

Current control module, and battery and electronic device equipped with same

[0001] The present disclosure relates to a current control module, and a battery and electronic device including the same.

[0002] Current control circuits that control the charging and discharging of batteries are sometimes modularized by being integrated onto a multilayer circuit board.

[0003] International Publication No. 2010 / 041589

[0004] However, as described in Patent Document 1, a typical circuit module has external terminals on only one side, so when constructing a current control module, the current flows mainly in the planar direction, which tends to make the current path longer.

[0005] This disclosure describes a technique for shortening the current path in a current control module.

[0006] A current control module according to one aspect of the present disclosure includes a multilayer circuit board having a first surface and a second surface located opposite the first surface, a switching element embedded in the multilayer circuit board and having first and second current ports, a first external terminal connected to the first current port of the switching element and exposed at the first surface of the multilayer circuit board, and a second external terminal connected to the second current port of the switching element and exposed at the second surface of the multilayer circuit board.

[0007] According to the present disclosure, a technique for shortening a current path in a current control module is provided.

[0008] Fig. 1 is a schematic cross-sectional view illustrating the structure of a current control module 10 according to an embodiment of the technology disclosed herein. Fig. 2 is a schematic diagram illustrating the configuration of a first example of an electronic device 50 using the current control module 10. Fig. 3 is a schematic diagram illustrating the configuration of a second example of an electronic device 50 using the current control module 10.

[0009] Hereinafter, embodiments of the technology according to the present disclosure will be described in detail with reference to the accompanying drawings.

[0010] FIG. 1 is a schematic cross-sectional view illustrating the structure of a current control module 10 according to an embodiment of the technology disclosed herein.

[0011] As shown in FIG. 1, the current control module 10 according to this embodiment includes a multilayer circuit board 100 and a switching element 200 embedded in the multilayer circuit board 100. The multilayer circuit board 100 has a structure in which multiple conductor layers L1 to L4 and multiple insulating layers 111 to 113 are alternately stacked. The switching element 200 is embedded in the insulating layer 112. One surface 101 of the multilayer circuit board 100 is covered with a solder resist 121, except for the exposed portions of the external terminals. The other surface 102 of the multilayer circuit board 100 is covered with a solder resist 122, except for the exposed portions of the external terminals. The surfaces 101 and 102 are located on opposite sides of each other and are perpendicular to the stacking direction of the insulating layers 111 to 113. The overall thickness of the multilayer circuit board 100, including the solder resists 121 and 122, is approximately 350 μm, which is very thin.

[0012] The switching element 200 is a power semiconductor such as a transistor or a power IC, and has current ports P1 and P2. As an example, if the switching element 200 is a transistor, one of the current ports P1 and P2 is a source, and the other of the current ports P1 and P2 is a drain. The switching element 200 is controlled by a driver circuit (not shown). The driver circuit that controls the switching element 200 may be embedded in the multilayer circuit board 100, or may be mounted on the surface of the multilayer circuit board 100.

[0013] The current port P1 of the switching element 200 is connected to an external terminal 331 exposed on one surface 101 of the multilayer circuit board 100 via a via conductor 301, a conductor pattern 311, and a via conductor 321. The via conductors 301 and 321 are embedded in insulating layers 112 and 111, respectively. The conductor pattern 311 and the external terminal 331 are located on conductor layers L2 and L1, respectively. In the example shown in FIG. 1 , a large portion of the external terminal 331 overlaps with the switching element 200 in a plan view. Therefore, the wiring distance between the current port P1 of the switching element 200 and the external terminal 331 is very short.

[0014] The current port P2 of the switching element 200 is connected to an external terminal 382 exposed on the other surface 102 of the multilayer circuit board 100 via a via conductor 302, a conductor pattern 312, a via conductor 304, a conductor pattern 362, and a via conductor 372. The via conductors 302 and 304 are embedded in the insulating layer 112. The via conductor 362 is embedded in the insulating layer 113. The conductor pattern 312, the conductor pattern 362, and the external terminal 382 are located on conductor layers L2 to L4, respectively. In the example shown in FIG. 1 , the external terminal 382 is connected to a connector 352 via a conductive member 392 such as solder. The connector 352 is provided to establish an electrical connection with an external device by mating with another connector provided on the external device.

[0015] The conductor layer L1 further includes a heat dissipation terminal 333 exposed on one surface 101 of the multilayer circuit board 100. The heat dissipation terminal 333 is connected to the switching element 200 via a via conductor 323, a conductor pattern 313, and a via conductor 303. The via conductors 323 and 303 are embedded in the insulating layers 111 and 112, respectively. The conductor pattern 313 is located on the conductor layer L2. When the switching element 200 is a transistor, the via conductor 303 connected to the heat dissipation terminal 333 may be in contact with a semiconductor substrate constituting the transistor. This allows heat generated by switching of the transistor to be efficiently transferred to the heat dissipation terminal 333. When the switching element 200 is a power IC, the via conductor 303 connected to the heat dissipation terminal 333 may be connected to a ground terminal provided on the power IC. This allows heat generated by switching of the power IC to be efficiently transferred to the heat dissipation terminal 333 via the ground terminal. 1, the entire heat dissipation terminal 333 overlaps the switching element 200 in plan view, so the wiring distance between the switching element 200 and the heat dissipation terminal 333 is very short.

[0016] The conductor layer L4 is further provided with land patterns 381, 383, and 384 that are exposed on one surface 102 of the multilayer circuit board 100. In the example shown in Fig. 1, passive components 401 and 402 such as a capacitor and an inductor are mounted on one surface 102 of the multilayer circuit board 100. A pair of terminal electrodes provided on the passive component 401 is connected to the land patterns 381 and 384, respectively. A pair of terminal electrodes provided on the passive component 402 is connected to the land patterns 383 and 384, respectively.

[0017] The land pattern 383 is connected to a conductor pattern 363 located on the conductor layer L3 through a via conductor 373 embedded in the insulating layer 113. The land pattern 381 is connected to a shield pattern 361 located on the conductor layer L3 through a via conductor 371 embedded in the insulating layer 113. The shield pattern 361 is provided at a position overlapping with the switching element 200 in a plan view. The shield pattern 361 may cover most or the entire surface of the switching element 200. A ground potential may be applied to the shield pattern 361.

[0018] With this configuration, the current control module 10 according to this embodiment can pass current from the external terminal 331 to the external terminal 382, ​​or from the external terminal 382 to the external terminal 331, via the switching element 200. The amount of current is controlled by the switching element 200. Furthermore, because the external terminals 331 and 382 are located on the front and back sides of the multilayer circuit board 100, the current path within the current control module 10 is extremely short, resulting in low resistance. This makes it possible to suppress heat generation in the current path, even when the current amount is large, for example, 1 A or more. Furthermore, because the current path is short, electromagnetic noise generation from the current path is also suppressed. Furthermore, because a shield pattern 361 is provided between the switching element 200 and the passive components 401 and 402, electromagnetic interference between them is also suppressed.

[0019] FIG. 2 is a schematic diagram for explaining the configuration of a first example of an electronic device 50 using the current control module 10 according to this embodiment.

[0020] 2, the battery body 20 and the device body 30 are arranged so as to sandwich the current control module 10 in the stacking direction. The battery body 20 is, for example, a secondary battery, and serves to supply power to the device body 30 and is charged by a battery charger included in the device body 30.

[0021] The battery main body 20 has a power supply terminal 21 and a ground terminal 22. The power supply terminal 21 and the ground terminal 22 of the battery main body 20 are connected to an external terminal 331 and a heat dissipation terminal 333 of the current control module 10 via conductive members 391 and 393, respectively, such as solder. The current control module 10 and the battery main body 20 constitute a battery 40. In other words, the current control module 10 is a part of the battery 40. The device main body 30 has a connector 31 that constitutes a power supply terminal. The connector 31 of the device main body 30 fits into a connector 352 of the current control module 10.

[0022] This connects the battery body 20 and the device body 30 via the current control module 10. As described above, the multilayer circuit board 100 constituting the current control module 10 is very thin, which reduces the space required between the battery body 20 and the device body 30 to place the current control module 10 and also shortens the current path 60 between them. Furthermore, since the current control module 10 is provided with a shield pattern 361, electromagnetic interference between the battery body 20 and the device body 30 is also suppressed.

[0023] Furthermore, since the heat dissipation terminal 333 is disposed at a position overlapping the switching element 200, heat generated by the switching element 200 is efficiently transferred to the battery main body 20 via the heat dissipation terminal 333 and the ground terminal 22. This makes it possible to obtain high heat dissipation characteristics. Furthermore, since the heat generated by the switching element 200 is also dissipated via the external terminal 331, by disposing the external terminal 331 at a position overlapping the switching element 200, it is possible to obtain even higher heat dissipation characteristics. Heat generated by the switching element 200 is also dissipated to the device main body 30 side via the external terminal 382.

[0024] In the example shown in Figure 2, the current control module 10 and the device main body 30 are connected via a connector, so if the battery main body 20 deteriorates or breaks down, for example, it is possible to replace the battery 40 consisting of the battery main body 20 and the current control module 10 with a new one by disconnecting the connection via the connector.

[0025] FIG. 3 is a schematic diagram for explaining the configuration of a second example of an electronic device 50 using the current control module 10 according to this embodiment.

[0026] 3, contact pins 32 are provided in place of a connector on the device main body 30. The tips of the contact pins 32 come into contact with external terminals 382. This allows, for example, when the battery main body 20 deteriorates or breaks down, the battery 40 consisting of the battery main body 20 and the current control module 10 to be replaced with a new one.

[0027] The above describes embodiments of the technology according to the present disclosure, but the technology according to the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the technology, and it goes without saying that these modifications are also included within the scope of the technology according to the present disclosure.

[0028] The technology according to the present disclosure includes, but is not limited to, the following configuration examples.

[0029] A current control module according to one aspect of the present disclosure includes a multilayer circuit board having a first surface and a second surface opposite to the first surface, a switching element embedded in the multilayer circuit board and having first and second current ports, a first external terminal connected to the first current port of the switching element and exposed at the first surface of the multilayer circuit board, and a second external terminal connected to the second current port of the switching element and exposed at the second surface of the multilayer circuit board, thereby making it possible to shorten the current path between the first external terminal and the second external terminal.

[0030] In the current control module, the multilayer circuit board may include a shield pattern disposed between the switching element and the second surface, thereby reducing electromagnetic interference between the front and back surfaces of the multilayer circuit board.

[0031] In the current control module, at least one of the first and second external terminals may be disposed in a position overlapping with the switching element, thereby enabling the current path to be further shortened.

[0032] The current control module may further include a heat dissipation terminal connected to the switching element, positioned so as to overlap the switching element, and exposed on the first surface of the multilayer circuit board, thereby improving the heat dissipation characteristics of the switching element.

[0033] A battery according to one aspect of the present disclosure includes a battery body having a first power supply terminal and the current control module arranged to overlap the battery body, the first power supply terminal of the battery body being connected to the first external terminal of the current control module, thereby shortening the current path between the battery body and the switching element.

[0034] According to one aspect of the present disclosure, an electronic device includes a device body having a second power supply terminal and the battery, the current control module is disposed between the battery and the device body, and the second power supply terminal of the device body is connected to the second external terminal of the current control module, thereby shortening the current path between the battery and the device body.

[0035] In the electronic device described above, the second power terminal of the device body may be a connector or a contact pin, which makes it easy to attach and detach the battery to and from the device body.

[0036] This application claims the benefit of Japanese Patent Application No. 2023-219138, filed December 26, 2023, the entire disclosure of which is incorporated herein by reference.

[0037] 10 Current control module 20 Battery body 21 Power supply terminal 22 Ground terminal 30 Device body 31 Connector 32 Contact pin 40 Battery 50 Electronic device 60 Current path 100 Multilayer circuit board 101, 102 Surface of multilayer circuit board 111 to 113 Insulating layer 121, 122 Solder resist 200 Switching element 301 to 304, 321, 323, 362, 371 to 373 Via conductor 311 to 313, 362, 363 Conductive pattern 331, 382 External terminal 333 Heat dissipation terminal 352 Connector 361 Shield pattern 381, 383, 384 Land pattern 391 to 393 Conductive member 401, 402 Passive component 402 Passive component L1 to L4 Conductive layer P1, P2 current ports

Claims

1. A current control module comprising: a multilayer circuit board having a first surface and a second surface located on the opposite side of the first surface; a switching element embedded in the multilayer circuit board and having first and second current ports; a first external terminal connected to the first current port of the switching element and exposed on the first surface of the multilayer circuit board; and a second external terminal connected to the second current port of the switching element and exposed on the second surface of the multilayer circuit board.

2. The current control module according to claim 1, wherein the multilayer circuit board includes a shield pattern disposed between the switching element and the second surface.

3. The current control module according to claim 1, wherein at least one of the first and second external terminals is disposed at a position overlapping the switching element.

4. The current control module according to claim 1, further comprising a heat dissipation terminal connected to the switching element, disposed at a position overlapping the switching element, and exposed on the first surface of the multilayer circuit board.

5. A battery comprising: a battery body having a first power terminal; and the current control module according to any one of claims 1 to 4 disposed so as to overlap the battery body, wherein the first power terminal of the battery body is connected to the first external terminal of the current control module.

6. An electronic device comprising: a device body having a second power terminal; and the battery according to claim 5, wherein the current control module is disposed so as to be sandwiched between the battery and the device body, and the second power terminal of the device body is connected to the second external terminal of the current control module.

7. The electronic device according to claim 6, wherein the second power terminal of the device body is a connector or a contact pin.

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