Current control module, and battery and electronic device having the same

Abstract

The present invention provides a current control module with a shortened current path. A current control module 10 includes: 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 a surface 101 of one side 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 a surface 102 of the other side of the multilayer circuit board 100.

Description

Current control module, and the battery and electronic device thereof. This invention relates to a current control module, and a battery and electronic device having the same. Current control circuits that control the charging and discharging of batteries can be modularized by being stacked on a multilayer circuit board. [Prior Art Documents][Patent Documents] Patent Document 1: International Publication No. 2010 / 041589 (Problem to be solved by the invention) However, as described in Patent Document 1, a typical circuit module has external terminals on only one side. Therefore, when a current control module is constructed, the current mainly flows in the planar direction and tends to have a longer current path. This invention describes a technique for shortening the current path in a current control module. (Technical means to solve the problem) The current control module of this invention comprises: a multilayer circuit board having a first surface and a second surface located opposite to the first surface; a switching element embedded in the multilayer circuit board and having a first and a second current port; 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. (Effects compared to prior art) According to the present invention, it provides a technique for shortening the current path in a current control module. Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 is a schematic cross-sectional view illustrating the structure of a current control module 10 according to one embodiment of the present invention. As shown in Figure 1, the current control module 10 of 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 a plurality of conductor layers L1 to L4 and a plurality of insulating layers 111 to 113 are alternately stacked. The switching element 200 is embedded in the insulating layer 112. Surface 101 on one side of the multilayer circuit board 100, except for the exposed portion of the external terminals, is covered by a solder resist layer 121. Surface 102 on the other side of the multilayer circuit board 100, except for the exposed portion of the external terminals, is covered by a solder resist layer 122. Surfaces 101 and 102 are located on opposite sides and are perpendicular to the stacking direction of the insulating layers 111 to 113. The overall thickness of the multilayer circuit board 100 containing the solder resist layers 121 and 122 is approximately 350 μm, which is very thin. The switching element 200 is a power semiconductor such as a transistor or a power IC, and it has current ports P1 and P2. For example, when the switching element 200 is a transistor, one of the current ports P1 and P2 is the source, and the other is the drain. The switching element 200 is controlled by a driver circuit (not shown). The driver circuit controlling the switching element 200 can be embedded in the multilayer circuit board 100 or mounted on the surface of the multilayer circuit board 100. The current port P1 of the switching element 200 is connected to an external terminal 331 exposed on the 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 in conductor layers L2 and L1, respectively. In the example shown in Figure 1, most of the external terminal 331 overlaps with the switching element 200 when viewed from above. Therefore, the wiring distance between the current port P1 of the switching element 200 and the external terminal 331 is very short. The current port P2 of the switching element 200 is connected to an external terminal 382 exposed on the surface 102 of the multilayer circuit board 100 via through-hole conductor 302, conductor pattern 312, through-hole conductor 304, conductor pattern 362, and through-hole conductor 372. Through-hole conductors 302 and 304 are embedded in insulating layer 112. Through-hole conductor 362 is embedded in insulating layer 113. Conductor pattern 312, conductor pattern 362, and external terminal 382 are located in conductor layers L2 to L4, respectively. In the example shown in FIG1, the external terminal 382 is connected to connector 352 via conductive member 392 such as solder. Connector 352 is configured to establish an electrical connection with an external machine by engaging with other connectors located on the external machine. In the conductor layer L1, a heat dissipation terminal 333 is further provided on the 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 in the conductor layer L2. When the switching element 200 is a transistor, the via conductor 303 connected to the heat dissipation terminal 333 can also be connected to the semiconductor substrate constituting the transistor. Accordingly, the heat generated by the switching of the transistor can be efficiently transferred to the heat dissipation terminal 333. Furthermore, when the switching element 200 is a power IC, the via conductor 303 connected to the heat dissipation terminal 333 can also be connected to a ground terminal provided in the power IC. Accordingly, the heat generated by the switching of the power IC is efficiently transferred to the heat dissipation terminal 333 via the ground terminal. In the example shown in Figure 1, the entire heat sink terminal 333 overlaps with the switching element 200 when viewed from above. Therefore, the wiring distance between the switching element 200 and the heat sink terminal 333 is very short. Further, in the conductor layer L4, pad patterns 381, 383, and 384 are exposed on the surface 102 of the multilayer circuit board 100. In the example shown in FIG1, passive components 401 and 402, such as capacitors or inductors, are mounted on the surface 102 of the multilayer circuit board 100. A pair of terminal electrodes provided on the passive component 401 are respectively connected to the pad patterns 381 and 384. A pair of terminal electrodes provided on the passive component 402 are respectively connected to the pad patterns 383 and 384. Pad pattern 383 is connected to conductor pattern 363 located on conductor layer L3 via via conductor 373 embedded in insulating layer 113. Pad pattern 381 is connected to shield pattern 361 located on conductor layer L3 via via conductor 371 embedded in insulating layer 113. Shield pattern 361 is positioned overlapping the switching element 200 in top view. Shield pattern 361 may also cover most or all of the switching element 200. It is acceptable to assign a ground potential to shield pattern 361. With this configuration, the current control module 10 of this embodiment can allow current to flow from external terminal 331 to external terminal 382, ​​or from external terminal 382 to external terminal 331, via the switching element 200. The amount of current is controlled by the switching element 200. Furthermore, since external terminals 331 and 382 are disposed on the surface and back of the multilayer circuit board 100, the current path within the current control module 10 is very short and has low resistance. Therefore, even when the current is large, for example, above 1A, heat generation in the current path can be suppressed. Moreover, due to the shorter current path, electromagnetic noise from the current path can also be suppressed. In addition, since a shielding pattern 361 is provided between the switching element 200 and the passive elements 401 and 402, electromagnetic field interference between them can also be suppressed. Figure 2 is a schematic diagram illustrating the configuration of a first example of an electronic device 50 using the current control module 10 of this embodiment. In the example shown in Figure 2, the battery body 20 and the machine body 30 are arranged such that the current control module 10 is sandwiched in from the stacking direction. The battery body 20 is, for example, a secondary battery, which supplies power to the machine body 30 and is charged by a battery charger contained in the machine body 30. The battery body 20 has a power terminal 21 and a ground terminal 22. The power terminal 21 and ground terminal 22 of the battery body 20 are respectively connected to the external terminal 331 and the heat dissipation terminal 333 of the current control module 10 via conductive members 391 and 393 such as solder. The current control module 10 and the battery body 20 constitute the battery 40. That is, the current control module 10 is a part of the battery 40. The machine body 30 has a connector 31 that constitutes the power terminal. The connector 31 of the machine body 30 is engaged with the connector 352 of the current control module 10. In this way, the battery body 20 and the machine body 30 are connected via the current control module 10. As described above, the multilayer circuit board 100 constituting the current control module 10 is very thin, thus reducing the space required between the battery body 20 and the machine body 30 for arranging the current control module 10, and shortening the current path 60 between them. Furthermore, the current control module 10 is provided with a shielding pattern 361, thus suppressing electromagnetic field interference between the battery body 20 and the machine body 30. Furthermore, since a heat dissipation terminal 333 is disposed at the position overlapping with the switching element 200, the heat generated by the switching element 200 is efficiently transferred to the battery body 20 via the heat dissipation terminal 333 and the ground terminal 22. This results in superior heat dissipation characteristics. Additionally, the heat generated by the switching element 200 can also be dissipated via the external terminal 331. Therefore, by simply placing the external terminal 331 at the position overlapping with the switching element 200, even higher heat dissipation characteristics can be achieved. The heat generated by the switching element 200 can also be dissipated towards the machine body 30 via the external terminal 382. In the example shown in Figure 2, the current control module 10 and the machine body 30 are connected via a connector. Therefore, for example, when the battery body 20 deteriorates or fails, the battery 40, which consists of the battery body 20 and the current control module 10, can be replaced with a new one by disconnecting the connector. Figure 3 is a schematic diagram illustrating the configuration of a second example of an electronic device 50 using the current control module 10 of this embodiment. In the example shown in Figure 3, a contact pin 32 is provided on the machine body 30 to replace the connector. The front end of the contact pin 32 is in contact with the external terminal 382. In this way, for example, in the case of battery body 20 deterioration or failure, the battery 40, which is composed of battery body 20 and current control module 10, can be replaced with a new one. Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above. Various modifications can be made without departing from its spirit, and such modifications are of course included within the scope of the present invention. Although the present invention includes the following configuration examples, the present invention is not limited thereto. One embodiment of the current control module of the present invention comprises: a multilayer circuit board having a first surface and a second surface located opposite to the first surface; a switching element embedded in the multilayer circuit board and having a first and a second current port; 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. Accordingly, the current path between the first external terminal and the second external terminal can be shortened. In the aforementioned current control module, the multilayer circuit board may also contain a shielding pattern disposed between the switching element and the second surface. This reduces electromagnetic field interference between the front and back surfaces of the multilayer circuit board. In the aforementioned current control module, at least one of the first and second external terminals may be configured to overlap with the switching element. This further shortens the current path. The aforementioned current control module may further include a heat dissipation terminal, which is connected to the switching element and positioned overlapping with the switching element, and exposed on the first surface of the multilayer circuit board. This improves the heat dissipation characteristics of the switching element. One embodiment of the present invention provides a battery system comprising: a battery body having a first power terminal; and the aforementioned current control module configured to overlap with the battery body; the first power terminal of the battery body is connected to a first external terminal of the current control module. Accordingly, the current path between the battery body and the switching element can be shortened. One embodiment of the present invention comprises: a machine body having a second power terminal; and the aforementioned battery; and a current control module disposed between the battery and the machine body, wherein the second power terminal of the machine body is connected to a second external terminal of the current control module. Accordingly, the current path between the battery and the machine body can be shortened. In the aforementioned electronic devices, the second power terminal of the device body can also be a connector or a contact pin. This makes it easier to attach or detach the device body from the battery. 10: Current control module; 20: Battery body; 21: Power terminal; 22: Ground terminal; 30: Machine 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; 111~113: Insulating layer; 121, 122: Solder resist layer; 200: Switching element; 301~304, 321, 323, 362, 371~373: Through-hole conductor; 311~313, 362, 363: Conductor pattern; 331, 382: External terminal; 333: Heat dissipation terminal; 352: Connector; 361: Shielding pattern; 381, 383, 384: Pad pattern; 391~393: Conductive component; 401, 402: Passive component; L1~L4: Conductor layer; P1, P2: Current port. Figure 1 is a schematic cross-sectional view illustrating the structure of a current control module 10 according to one embodiment of the present invention. Figure 2 is a schematic diagram illustrating the configuration of a first example of an electronic device 50 using the current control module 10. Figure 3 is a schematic diagram illustrating the configuration of a second example of an electronic device 50 using the current control module 10. 10: Current control module 100: Multilayer circuit board 101, 102: Surface of multilayer circuit board 111~113: Insulation layer 121, 122: Solder resist layer 200: Switching element 301~304, 321, 323, 362, 371~373: Through-hole conductors 311~313, 362, 363: Conductor patterns 331, 382: External terminal 333: Heat dissipation terminal 352: Connector 361: Shielding pattern 381, 383, 384: Pad patterns 392: Conductive components 401, 402: Passive components L1~L4: Conductor layers P1, P2: Current ports

Claims

1. A current control module comprising: a multilayer circuit board having a first surface and a second surface located opposite to the first surface; a switching element embedded in the multilayer circuit board and having a first and a second current port; 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; wherein the multilayer circuit board includes a shielding pattern disposed between the switching element and the second surface.

2. As in request item 1, the current control module, wherein, At least one of the first and second external terminals is positioned to overlap with the switching element.

3. As in request item 1, the current control module, wherein, Furthermore, it includes a heat dissipation terminal, which is connected to the aforementioned switching element and is positioned overlapping the aforementioned switching element, and is exposed on the aforementioned first surface of the aforementioned multilayer circuit board.

4. A battery comprising: a battery body having a first power terminal; and a current control module of any one of claims 1 to 3, configured to overlap with the battery body; wherein the first power terminal of the battery body is connected to the first external terminal of the current control module.

5. An electronic device comprising: a device body having a second power terminal; and a battery of claim 4; wherein the current control module is configured 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.

6. The electronic machine as described in claim 5, wherein, The second power terminal of the aforementioned machine body is a connector or a contact pin.

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