CN211789255U

CN211789255U - Battery pack

Info

Publication number: CN211789255U
Application number: CN202020262007.1U
Authority: CN
Inventors: 曹圭晟; 权永焕; 尹澈重
Original assignee: Samsung SDI Co Ltd
Current assignee: Samsung SDI Co Ltd
Priority date: 2019-05-08
Filing date: 2020-03-05
Publication date: 2020-10-27
Anticipated expiration: 2030-03-05
Also published as: KR20200129461A

Abstract

The utility model provides a battery pack. The battery pack includes: a battery cell; a main circuit board connected to the battery cells; and a connection circuit board including a conductive pattern, the connection circuit board connecting the battery cell and the main circuit board to each other, wherein the conductive pattern includes a connection pattern and a fuse pattern having a smaller line width than the connection pattern. Accordingly, the battery pack may interrupt an overcurrent or short-circuit current without delay by rapidly responding to the overcurrent or short-circuit current to protect the battery cells, and thus prevent a safety accident such as a fire or explosion.

Description

Battery pack

This application claims the benefit of korean patent application No. 10-2019-0053893, filed by the korean intellectual property office at 5, 8, 2019, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

One or more embodiments relate to a battery pack.

Background

In general, a secondary battery refers to a battery capable of being repeatedly charged and recharged, unlike a primary battery that is not rechargeable. The secondary battery is used as an energy source for devices such as mobile devices, electric vehicles, hybrid vehicles, electric bicycles, or uninterruptible power supplies. Depending on the type of external device using the secondary battery, the secondary battery is used singly, or a plurality of secondary battery modules (groups) each including a plurality of secondary batteries connected as one unit are used.

Unlike small-sized mobile devices such as cellular phones, which can operate for a certain period of time using a single battery, devices such as electric vehicles or hybrid vehicles, which have a long operation time and consume a large amount of power, may require a plurality of battery modules (packs) each including a plurality of batteries (battery cells), in consideration of problems related to power and capacity. The output voltage or current of such battery modules may be increased by adjusting the number of batteries included in each battery module.

SUMMERY OF THE UTILITY MODEL

An object of one or more embodiments is to provide a battery pack configured to protect battery cells and prevent a safety accident such as fire or explosion by rapidly interrupting an overcurrent or short-circuit current without delay by responding to the overcurrent or short-circuit current.

Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosed embodiments.

According to one or more embodiments, a battery pack includes: a battery cell; a main circuit board connected to the battery cells; and a connection circuit board including a conductive pattern, the connection circuit board connecting the battery cell and the main circuit board to each other, wherein the conductive pattern includes a connection pattern and a fuse pattern having a smaller line width than the connection pattern.

For example, the fuse pattern may meander while alternately extending backward and forward along a second direction different from the first direction along which the connection pattern extends.

For example, the connection pattern may have a first line width and may extend in a first direction, an

The fuse pattern may have a second line width smaller than the first line width, and may meander while alternately extending backward and forward along a second direction crossing the first direction.

For example, the fuse pattern may include: a plurality of linear portions extending side by side in the second direction; and a bent portion connecting adjacent ends of the linear portions to each other in a bent shape.

For example, the curved portion may have a circular arc shape.

For example, a first end and a second end forming both ends of the fuse pattern may extend in the first direction parallel to the connection pattern.

For example, the first and second end portions may have a second line width smaller than the first line width of the connection pattern and may extend in the first direction parallel to the connection pattern.

For example, the connection circuit board may further include an insulating film in which the conductive pattern is embedded.

For example, the conductive pattern may include: a first conductive pattern providing a charge/discharge path; and a second conductive pattern, wherein a signal having information on the state of the battery cell is transmitted through the second conductive pattern.

For example, the battery cell may include a plurality of battery cells, and the second conductive pattern may provide a path for equalizing current for equalizing an unbalanced charge/discharge state of the plurality of battery cells.

For example, the second conductive pattern may be connected to an equalizing resistor of the main circuit board.

For example, the battery cell may include a plurality of battery cells, and the plurality of battery cells may be electrically connected to each other through a bus bar that connects terminals of different battery cells to each other.

For example, the first and second conductive patterns may be connected to terminals or bus bars of the plurality of battery cells.

For example, the conductive tabs may be disposed between the first and second conductive patterns and the terminals of the plurality of battery cells or between the first and second conductive patterns and the bus bars.

For example, the first conductive pattern may include: a low potential line connected to lowest potential terminals of the plurality of battery cells electrically connected to each other; and a high potential line connected to the highest potential terminal of the plurality of battery cells.

For example, the second conductive pattern may connect terminals of the plurality of battery cells having different potentials to the main circuit board.

For example, the second conductive pattern may include: a low potential line connected to a lowest potential terminal of the plurality of battery cells; a high potential line connected to the highest potential terminal of the plurality of battery cells; and an intermediate potential line connected to intermediate potential terminals of the plurality of battery cells.

For example, both the first conductive pattern and the second conductive pattern may be connected to the lowest potential terminal and the highest potential terminal of the plurality of battery cells.

For example, the second conductive pattern including the intermediate potential line may be connected to a bus bar that connects terminals of different battery cells to each other.

According to the embodiment, the battery pack may interrupt an overcurrent or short-circuit current without delay by rapidly responding to the overcurrent or short-circuit current to protect the battery cells, and thus prevent a safety accident such as a fire or explosion.

Drawings

The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings in which:

fig. 1 is an exploded perspective view illustrating a battery pack according to an embodiment;

fig. 2 is a plan view illustrating the battery pack shown in fig. 1;

fig. 3 is a schematic circuit diagram of the battery pack shown in fig. 1 according to an embodiment;

fig. 4 is an enlarged view illustrating the conductive pattern structure shown in fig. 1 according to an embodiment; and is

Fig. 5 is a view schematically illustrating melting and disconnection of the fuse pattern shown in fig. 4 according to an embodiment.

Detailed Description

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the presented embodiments may have different forms and should not be construed as being limited to the description set forth herein. Therefore, only the embodiments are described below to explain aspects of the present specification by referring to the figures. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Throughout this disclosure, the expression "at least one of a, b or c" means all or variations of a, b only, c only, both a and b, both a and c, both b and c, a, b and c.

The battery pack will now be described in detail with reference to the accompanying drawings in which embodiments are shown.

Fig. 1 is an exploded perspective view illustrating a battery pack according to an embodiment. Fig. 2 is a plan view illustrating the battery pack shown in fig. 1 according to the embodiment. Fig. 3 is a schematic circuit diagram of the battery pack shown in fig. 1 according to an embodiment.

Referring to fig. 1 and 2, the battery pack may include a battery cell C and a main circuit board 30 electrically connected to the battery cell C. In addition, the connection circuit board 20 may be disposed between the main circuit board 30 and the battery cells C.

The battery cell C may include an electrode assembly (not shown) and a case 11 accommodating the electrode assembly. The electrode assembly (not shown) may have a form in which first and second electrode plates having different polarities are stacked with a separator therebetween, or a form in which the first and second electrode plates are wound together with the separator, and terminals E having different polarities and electrically connected to the first and second electrode plates of the electrode assembly (not shown), respectively, may be disposed on the case 11.

The battery pack may include two or more battery cells C. For example, in an embodiment, the battery pack may include a first battery cell C1, a second battery cell C2, and a third battery cell C3. However, the technical scope of the present disclosure is not limited to the number of the battery cells C shown. In other embodiments, the battery pack may include four or more battery cells C. The battery cells C may be electrically connected to each other through the bus bar 15. For example, the bus bar 15 may connect different battery cells C in series by connecting the terminals E having opposite polarities of the different battery cells C to each other, or may connect different battery cells C in parallel by connecting the terminals E having the same polarity of the different battery cells C to each other. In an embodiment, the first, second, and third battery cells C1, C2, and C3 may be connected in series by the bus bar 15 connecting the terminals E of the adjacent battery cells C having opposite polarities to each other. In the present specification, the term "battery cell C" may collectively refer to any one of the first, second, and third battery cells C1, C2, and C3, or the first, second, and third battery cells C1, C2, and C3.

Referring to fig. 3, the main circuit board 30 may provide a charge/discharge path connecting the battery cell C to the positive output terminal P + and the negative output terminal P-, and may collect information on the state of the battery cell C to control charge and discharge operations of the battery cell C according to the collected state information. For example, the main circuit board 30 may connect a cell C (a first cell C1) having the lowest potential among the cells C electrically connected to each other to the negative output terminal P-, and may connect a cell C (a third cell C3) having the highest potential among the cells C to the positive output terminal P +, thereby providing a charge/discharge path. In addition, the main circuit board 30 may be connected to each of the battery cells C to collect information on the states of the battery cells C to perform an equalizing operation or control charging and discharging operations of the battery cells C based on the collected state information, and for example, the main circuit board 30 may turn on or off the charging/discharging path by controlling switching devices SW1 and SW2 disposed on the main circuit board 30 to provide the charging/discharging path of the battery cells C. With respect to the equalizing operation, the main circuit board 30 may include: equalizing resistors R1, R2, and R3 connected in parallel with the first, second, and third battery cells C1, C2, and C3; and switching devices SW3, SW4, SW5, and SW6 connected in series with the equalization resistors R1, R2, and R3, and the main circuit board 30 may discharge the first, second, and third battery cells C1, C2, and C3 through the equalization resistors R1, R2, and R3 by turning on the switching devices SW3, SW4, SW5, and SW 6.

The main circuit board 30 obtains status information such as the temperature and voltage of the battery cells C transmitted through the connection circuit board 20, and may function as a Battery Management System (BMS) that controls charging and discharging operations based on the obtained status information. In another embodiment, the BMS may be provided separately from the main circuit board 30. In this case, the main circuit board 30 may transmit the collected state information to the BMS such that the BMS may control the charging and discharging operation of the battery cell C, or the main circuit board 30 may control the charging and discharging operation of the battery cell C together with the BMS. For example, the main circuit board 30 may be provided in a form in which a plurality of circuit components (not shown) are disposed on a rigid insulating substrate.

The connection circuit board 20 may provide a charge/discharge path between the battery cell C and the main circuit board 30 by electrically connecting the battery cell C to the main circuit board 30. In addition, the connection circuit board 20 may transmit an electrical signal having information about the state of the battery cells C to the main circuit board 30, and may provide a path for equalizing current to solve the unbalanced charge/discharge state of the battery cells C.

With respect to the equalizing operation, the connection circuit board 20 may provide a discharge path for the battery cell C having a relatively high voltage and a charge path for the battery cell C having a relatively low voltage. According to the embodiment, the battery pack may perform various equalization operations without being limited to a specific equalization operation. For example, the connection circuit board 20 may equalize the voltage of the battery cells C by connecting the battery cells C having a relatively high voltage to the main circuit board 30 (e.g., the equalization resistors R1, R2, and R3 of the main circuit board 30). Referring to fig. 3, the equalization resistors R1, R2, and R3 may be connected in parallel to the first, second, and third battery cells C1, C2, and C3, respectively, and the first, second, and third battery cells C1, C2, and C3 may be discharged through the equalization resistors R1, R2, and R3 by turning on the switching devices SW3, SW4, SW5, and SW6 connected in series to the equalization resistors R1, R2, and R3. In another embodiment, the connection circuit board 20 may connect the battery cell C having a relatively high voltage to the battery cell C having a relatively low voltage through the main circuit board 30 (e.g., the balancing resistors R1, R2, and R3 of the main circuit board 30) to balance the unbalanced voltage of the battery cell C. As described above, the connection circuit board 20 may provide a discharging path or a charging path for equalizing current during the equalizing operation.

Referring to fig. 1, the connection circuit board 20 and the main circuit board 30 may be connected to each other by a plug-and-socket connector method. For example, the connector 25 provided on the end portion of the connection circuit board 20 and the connector 35 provided on the end portion of the main circuit board 30 may be fitted to each other to electrically connect the connection circuit board 20 and the main circuit board 30 to each other. For example, a plurality of connector pins (not shown) may be provided on one of the connector 25 of the connection circuit board 20 and the connector 35 of the main circuit board 30, and a plurality of connector holes (not shown) may be formed in the other of the connector 25 of the connection circuit board 20 and the connector 35 of the main circuit board 30, so that signals or outputs may be transmitted between the connection circuit board 20 and the main circuit board 30 in a one-to-one manner when the connector pins are fitted into the connector holes.

The connection circuit board 20 may be provided in the form of a relatively flexible film such as a Flexible Printed Circuit Board (FPCB). However, the technical scope of the present disclosure is not limited thereto, and in another embodiment, the connection circuit board 20 may be a rigid Printed Circuit Board (PCB) based on a relatively rigid insulation board.

The connection circuit board 20 may include an insulating film 21 (refer to fig. 2) and a conductive pattern L embedded in the insulating film 21. Referring to fig. 3, the conductive pattern L may include: first conductive patterns L11 and L12 providing a charge/discharge path between the battery cell C and the main circuit board 30; and second conductive patterns L21, L22, L31, and L32, which transmit an electrical signal having information on the state of the battery cell C from the battery cell C to the main circuit board 30, and provide an equalizing current path for equalizing the unbalanced charge/discharge state of the battery cell C.

For example, the second conductive patterns L21, L22, L31, and L32 may extend toward the main circuit board 30 and may be connected to a voltage measuring circuit (not shown) through the measuring terminals A, B, C and D, respectively, so that information on the voltages of the first, second, and third battery cells C1, C2, and C3 may be obtained from the voltage measuring circuit (not shown). In addition, the second conductive patterns L21, L22, L31, and L32 may extend to the main circuit board 30 and may be connected to the switching devices SW3, SW4, SW5, and SW6 and the equalization resistors R1, R2, and R3 connected in series to each other, and the first, second, and third battery cells C1, C2, and C3 may be discharged through the equalization resistors R1, R2, and R3 by turning on the switching devices SW3, SW4, SW5, and SW 6.

For example, the first conductive patterns L11 and L12 may include: a low potential line L11 connecting the main circuit board 30 to the lowest potential terminal E of the battery cells C electrically connected to each other; and a high potential line L12 connecting the main circuit board 30 to the highest potential terminal E of the battery cell C. For example, the first conductive patterns L11 and L12 may transmit electricity from the battery cell C to the main circuit board 30 while the low potential line L11 and the high potential line L12 are provided between the battery cell C and the main circuit board 30, and thus, the first conductive patterns L11 and L12 may supply driving power to an external load (not shown) through the main circuit board 30 (e.g., through the positive output terminal P + and the negative output terminal P-) of the main circuit board 30). In this case, the lowest potential terminal E and the highest potential terminal E of the battery cell C may refer to both end terminals E of the battery cell C electrically connected to each other, that is, may refer to a negative (-) terminal E of the battery cell C having the lowest potential (the first battery cell C1) and a positive (+) terminal E of the battery cell C having the highest potential (the third battery cell C3), respectively.

The electrode tab 22 (refer to fig. 2) may be disposed between the first conductive pattern L11 (the low potential line L11) and the lowest potential terminal E (the negative (-) terminal E of the first cell C1) for electrical connection therebetween, and the electrode tab 22 (refer to fig. 2) may be disposed between the first conductive pattern L12 (the high potential line L12) and the highest potential terminal E (the positive (+) terminal E of the third cell C3) for electrical connection therebetween. For example, the electrode tab 22 may form large conductive areas between the first conductive pattern L11 and the lowest potential terminal E and between the first conductive pattern L12 and the highest potential terminal E for stable connection therebetween, and may be welded to the lowest potential terminal E (the negative (-) terminal E of the first cell C1) and the highest potential terminal E (the positive (+) terminal E of the third cell C3), respectively. For example, the electrode tab 22 may include nickel.

Referring to fig. 3, the second conductive patterns L21, L22, L31, and L32 may connect terminals E having different potentials among the terminals E of the battery cells C to the main circuit board 30. The second conductive patterns L21, L22, L31, and L32 may include: a low potential line L21 connected to the lowest potential terminal E (the negative (-) terminal E of the first cell C1); a high potential line L22 connected to the highest potential terminal E (positive (+) terminal E of the third cell C3); and intermediate potential lines L31 and L32 connected to the intermediate potential terminal E (the positive (+) terminal E of the first cell C1, the positive (+) terminal E and the negative (-) terminal E of the second cell C2, the negative (-) terminal E of the third cell C3). Here, the term "intermediate potential terminal E" refers to a terminal E having a potential between the highest potential and the lowest potential among different potentials of the battery cell C, and the intermediate potential terminal E may include a plurality of terminals E having different potentials. The intermediate potential terminals E may be electrically connected to each other through the bus bars 15, and since different terminals E connected through the same bus bar 15 have the same potential, the second conductive patterns L31 and L32 may be respectively connected to the bus bars 15 connecting the different terminals E. In the present specification, the expression "the first conductive patterns L11 and L12 or the second conductive patterns L21, L22, L31 and L32 are connected to the terminal E of the battery cell C" may refer to both the case in which the first conductive patterns L11 and L12 or the second conductive patterns L21, L22, L31 and L32 are directly connected to the terminal E of the battery cell C and the case in which the first conductive patterns L11 and L12 or the second conductive patterns L21, L22, L31 and L32 are connected to the bus bar 15 connected to the terminal E of the battery cell C.

The second conductive patterns L21, L22, L31, and L32 may form lines having different potentials, and may transmit voltage information about the potentials of the second conductive patterns L21, L22, L31, and L32 to the main circuit board 30. For example, the second conductive patterns L21, L22, L31, and L32 may extend to the main circuit board 30 and may be connected to a voltage measuring circuit (not shown) through the measuring terminals A, B, C and D, respectively, so that information on the voltages of the first, second, and third battery cells C1, C2, and C3 may be obtained from the voltage measuring circuit (not shown).

In addition, the second conductive patterns L21, L22, L31, and L32 may provide a path for equalizing current while forming lines having different potentials to solve the unbalanced charge/discharge state. For example, the second conductive patterns L21, L22, L31, and L32 may extend to the main circuit board 30 and may be connected to the switching devices SW3, SW4, SW5, and SW6 and the equalization resistors R1, R2, and R3 connected in series to each other, and the first, second, and third battery cells C1, C2, and C3 may be discharged through the equalization resistors R1, R2, and R3 by turning on the switching devices SW3, SW4, SW5, and SW 6. For example, when the voltage of a specific cell C among the first, second, and third cells C1, C2, and C3 is relatively high, a switching device connected to the specific cell C among the switching devices SW3, SW4, SW5, and SW6 may be turned on to discharge the specific cell C through the balancing resistors R1, R2, and R3.

The electrode tabs 22 (refer to fig. 2) may be disposed between the second conductive patterns L21, L22, L31, and L32 and the terminal E having different potentials for electrical connection therebetween. For example, the electrode tab 22 may form a large conductive area between the second conductive patterns L21, L22, L31, and L32 and the terminal E for stable connection therebetween, and may be welded to the terminals E having different potentials, respectively. For example, the electrode tab 22 may include nickel.

The first and second conductive patterns L11 and L21 connected to the lowest potential terminal E (the negative (-) terminal E of the first battery cell C1) may be connected to the same electrode tab 22 (refer to fig. 2), and similarly, the first and second conductive patterns L12 and L22 connected to the highest potential terminal E (the positive (+) terminal E of the third battery cell C3) may be connected to the same electrode tab 22 (refer to fig. 2). In addition, the intermediate potential terminals E of the battery cells C may be connected through the bus bars 15, and since the intermediate potential terminals E connected through the same bus bar 15 have the same potential, the second conductive patterns L31 and L32 may be connected to the bus bars 15, respectively. In this case, the electrode tab 22 (refer to fig. 2) may be disposed between the second conductive patterns L31 and L32 and the bus bar 15.

Hereinafter, the structure of the conductive pattern L will be described. As described above, the conductive pattern L may include the first conductive patterns L11, L12 and the second conductive patterns L21, L22, L31 and L32. Hereinafter, the conductive pattern L may collectively refer to the first conductive patterns L11, L12 and the second conductive patterns L21, L22, L31 and L32, and the following description of the structure of the conductive pattern L may be equally applied to all of the first conductive patterns L11, L12 and the second conductive patterns L21, L22, L31 and L32, or selectively applied to one of the first conductive patterns L11, L12 and the second conductive patterns L21, L22, L31 and L32.

Fig. 4 is an enlarged view illustrating the structure of the conductive pattern L illustrated in fig. 1.

Referring to fig. 4, the conductive pattern L may include a connection pattern N and a fuse (fuse) pattern F connected to each other, and since the fuse pattern F is disposed in a middle portion of the connection pattern N, an overcurrent or a short-circuit current may be interrupted to prevent a safety accident such as overheating or explosion, which may be caused by the overcurrent or the short-circuit current.

For example, a short-circuit current may flow due to: for example, an internal short circuit between different wires on the main circuit board 30, a short circuit between different connector pins (not shown) or different connector holes (not shown) of the connector 25 of the connection circuit board 20 and the connector 35 (refer to fig. 1) of the main circuit board 30 caused by a conductive foreign substance, or an erroneous insertion between the connector 25 of the connection circuit board 20 and the connector 35 of the main circuit board 30. It is necessary to interrupt the flow of the short-circuit current due to such various causes to protect the battery cell C. In the embodiment, the fuse pattern F is included in the conductive pattern L to rapidly interrupt a short-circuit current or an overcurrent.

According to the present disclosure, the additional fuse device for interrupting an overcurrent or a short-circuit current is not provided on the connection circuit board 20 through which the battery cell C is connected to the main circuit board 30, but the fuse pattern F having a function of interrupting the overcurrent or the short-circuit current is provided by the shape design of the conductive pattern L, so that it is possible to eliminate the necessity of preparing a work space for connecting the additional fuse device to the conductive pattern L or a space for the additional fuse device, and eliminate the necessity of considering the aging of the additional fuse device or the behavior of the additional fuse device after the end of the service life of the additional fuse device. In addition, the components can be prevented from being damaged by an arc or the like that occurs when the additional fuse device interrupts current.

Referring to fig. 4, the connection pattern N may have a normal current conduction function, and unlike the fuse pattern F, the connection pattern N does not have a function of interrupting an overcurrent or a short-circuit current, and may have a different shape that is distinguishable from the fuse pattern F. For example, the connection pattern N and the fuse pattern F may have different line widths. For example, the connection pattern N may have a first line width t1 greater than the second line width t2 of the fuse pattern F, and thus the connection pattern N may have a relatively low resistance. In an embodiment, the first line width t1 or the second line width t2 may refer to a dimension measured in a width direction of the conductive pattern L perpendicular to a length direction of the conductive pattern L.

The fuse pattern F may perform an overcurrent interruption function in response to an overcurrent or a short-circuit current (hereinafter, the overcurrent may refer to the short-circuit current). The fuse pattern F may be connected to the connection pattern N at both ends thereof by the first and second end portions E1 and E2, and may have a relatively high resistance since the fuse pattern F connected to the connection pattern N has the second line width t2 smaller than the first line width t1 of the connection pattern N. As described later, the fuse pattern F may include a plurality of linear portions 1 extending parallel to each other and a bent portion 5 connecting adjacent ends of the linear portions 1. In the embodiment, both the straight line portion 1 and the bent portion 5 forming the fuse pattern F may have the same second line width t 2. In an embodiment, the second line width t2 of the fuse pattern F may be set to about 0.2mm to about 0.25 mm.

The fuse pattern F may have a relatively high resistance and may correspond to a portion of the conductive pattern L in which heat is concentrated. The fuse pattern F is shaped to prevent heat generated by overcurrent from being diffused to the surrounding environment and to concentrate heat generation to provide a fusing and breaking condition for interrupting overcurrent, and for this reason, the fuse pattern F may have a shape described below. That is, the fuse pattern F may have a serpentine shape that meanders while alternately extending backward and forward along the second direction Z2 intersecting the first direction Z1 of the connection pattern N. For example, the fuse pattern F may include a first end portion E1 and a second end portion E2 forming both ends of the fuse pattern F and a main body portion B between the first end portion E1 and the second end portion E2. In this case, the first end E1 and the second end E2 may extend in the first direction Z1 parallel to the connection pattern N, and the main body portion B may meander while alternately extending backward and forward in the second direction Z2.

For reference, in the present specification, unless the first end E1 and the second end E2 of the fuse pattern F are specifically mentioned, the fuse pattern F may refer to the body portion B. The fuse pattern F has a main function of interrupting an overcurrent by melting and breaking, which is performed by the main body portion B rather than the first and second end portions E1 and E2 because heat is concentrated in the main body portion B by a heat insulation effect. Accordingly, the fuse pattern F may mainly refer to the body portion B of the fuse pattern F.

The fuse pattern F does not extend in a straight line shape in parallel to the connection pattern N in the first direction Zl, but meanders and extends in a second direction Z2 intersecting the first direction Zl, thereby providing a heat insulation effect in which thermal interference between adjacent portions of the fuse pattern F prevents diffusion of heat generated in the fuse pattern F. For example, the fuse pattern F may include: linear portions 1 extending side by side in the second direction Z2; and a bent portion 5 connecting adjacent ends of the linear portions 1 to each other in a bent shape. In this case, the linear parts 1 may be arranged to face each other while extending side by side in the second direction Z2, so that thermal interference may occur between the linear parts 1 adjacent to each other to provide a heat-insulating environment in which heat generated in the linear parts 1 is prevented from being diffused to the surrounding environment due to the mutually facing structure of the linear parts 1. That is, due to the structure in which any one of the linear portions 1 is surrounded by the adjacent other linear portion 1, heat generated in the linear portion 1 is prevented from being diffused to the surrounding environment by heat generated in the adjacent other linear portion 1, and therefore, due to the heat insulating environment, the linear portion 1 can be immediately melted and broken in response to an overcurrent, thereby interrupting the overcurrent. If the fuse pattern F has only a small line width and extends straight in the first direction Z1 parallel to the connection pattern N, heat generated in the fuse pattern F in response to an overcurrent may be diffused to the surrounding environment, and thus the fuse pattern F may not be melted and disconnected, or may be slowly melted and disconnected, thereby increasing the possibility of a safety accident such as a fire or explosion caused by the overcurrent.

As the extension length h1 of the linear portions 1 increases, the area of mutual facing between the linear portions 1 adjacent to each other can be increased, and therefore the diffusion of heat generated in the linear portions 1 can be effectively prevented to improve the heat insulation effect. Here, the extension length h1 of the linear part 1 may be measured in the second direction Z2. In addition, the thermal interference between the linear portions 1 can be increased by reducing the gap s between the linear portions 1 adjacent to each other, and in this case, the heat generated in the linear portions 1 can be effectively prevented from being diffused to the surrounding environment. Here, the gap s between the linear portions 1 adjacent to each other may be measured in the first direction Z1.

As described above, the extended length h1 of the straight portion 1 and the gap s between the straight portion 1 can directly affect the heat insulation effect of the straight portion 1, and since the heat generated in the straight portion 1 is prevented from being diffused to the surrounding environment, the sensitivity to overcurrent can be improved to promptly interrupt the overcurrent by melting and breaking. In this case, the extension length h1 of the straight portion 1 is a design variable of the fuse pattern F that can be expressed as the height h of the fuse pattern F. In this case, the height h of the fuse pattern F may refer to a dimension of the fuse pattern F, which is the sum of the extension length h1 of the linear portion 1 and the height of the bent portions 5 provided on both ends of the linear portion 1. That is, the height h of the fuse pattern F may refer to a size of the fuse pattern F in the second direction Z2. The main factor determining the height h of the fuse pattern F is the extension length h1 of the straight portion 1, and the height of the bent portion 5 is smaller than the extension length h1 of the straight portion 1. In addition, since the extension length h1 of the straight portion 1 is set to be greater than the height of the bent portion 5 to increase the thermal insulation effect, the height h of the fuse pattern F may be mainly determined by the extension length h1 of the straight portion 1. In an embodiment, the height h of the fuse pattern F may be set to about 2mm to about 3 mm. In addition, the gap s between the linear portions 1 may be set to about 0.3 mm.

As the number of the linear portions 1 included in the fuse pattern F increases, the thermal insulation effect may increase due to the stacking of the linear portions 1, and thus, the number of turns of the fuse pattern F may be increased to increase the number of the linear portions 1 for effectively preventing the heat generated in the linear portions 1 from being diffused to the surrounding environment and increasing the thermal insulation effect. For example, the number of turns of the fuse pattern F may be counted by counting the number of identical unit patterns of the fuse pattern F from the first end E1 or the second end E2. For example, in the embodiment shown in fig. 4, the fuse pattern F has 5 turns, and in other embodiments, the fuse pattern F may have 2 to 6 turns.

The linear portions 1 adjacent to each other may be connected to each other by bent portions 5, and the bent portions 5 connect adjacent ends of the linear portions 1 in a bent shape. Since the straight line portions 1 adjacent to each other are connected to each other in a curved shape, electromagnetic interference (EMI) that may occur when the direction of current is abruptly changed can be prevented. For example, when the straight portions 1 adjacent to each other are connected by the angular connection portion instead of the bent portion 5, the direction of the current may be abruptly changed at the angular connection portion, so that the generation of electromagnetic waves (or reflected waves) causing EMI is increased, and thus the malfunction of the main circuit board 30 is caused. Therefore, in the present disclosure, the straight portions 1 adjacent to each other are connected to each other by the bent portion 5 to prevent malfunction caused by EMI. The curved portion 5 may have a circular arc shape, such as a semicircular shape having a gap s between the linear portions 1 as a diameter dr. For example, the curved portion 5 may have a semicircular shape with a diameter dr in the range of about 0.2mm to about 0.3 mm.

The fuse pattern F may be connected to the connection pattern N through the first and second end portions E1 and E2. In this case, as with the connection pattern N, the first end E1 and the second end E2 of the fuse pattern F may extend in the first direction Z1. That is, the first and second end portions E1 and E2 connecting the fuse pattern F and the connection pattern N to each other may have a second line width t2 smaller than the first line width t1 of the connection pattern N, and may extend in the first direction Z1 as with the connection pattern N. When the first and second ends E1 and E2 connected to the connection pattern N (having the first line width t1 and extending in the first direction Z1) are abruptly bent from the first direction Z1 toward the second direction Z2 with a reduction in width from the first line width t1 to the second line width t2, the structural stability of the first and second ends E1 and E2 may be deteriorated, and thus, the first and second ends E1 and E2 may be damaged, for example, by vibration or impact applied to the connection circuit board 20 provided in the form of a film. Accordingly, the first end E1 and the second end E2 may extend in the first direction Z1 as in the connection pattern N and may have a predetermined length d. For example, the first end E1 and the second end E2 may have a length d of about 0.3 mm.

Fig. 5 is a view schematically showing melting and breaking of the fuse pattern F shown in fig. 4.

Referring to fig. 5, the insulation effect at the central linear part 1, which is located at the center in the first direction Z1, of the linear part 1 may be the greatest because the other linear parts 1 overlap with both sides of the central linear part 1, and therefore, the temperature of the central linear part 1 may rapidly increase, and the central linear part 1 may be melted and broken prior to the other linear parts 1. That is, in the embodiment, when the fuse pattern F is melted and opened at a central position in the first direction Z1 (the first end E1 and the second end E2 extend from both ends of the fuse pattern F along the first direction Z1), the fuse pattern F may interrupt an overcurrent. This is because the thermal insulation effect is the largest at the center position of the fuse pattern F, and therefore, the temperature of the fuse pattern F can be increased to the melting/breaking temperature at the highest temperature increase rate at the center position.

According to the above-described embodiment, the additional fuse device for interrupting an overcurrent or a short-circuit current is not provided on the connection circuit board 20 through which the battery cell C is connected to the main circuit board 30, but the fuse pattern F having a function of interrupting an overcurrent or a short-circuit current is provided by the shape design of the conductive pattern L, so that it is possible to eliminate the necessity of preparing a work space for connecting the additional fuse device to the conductive pattern L or a space for the additional fuse device, and eliminate the necessity of considering the aging of the additional fuse device or the behavior of the additional fuse device after the end of the service life of the additional fuse device. In addition, the components can be prevented from being damaged by an arc or the like that occurs when the additional fuse device interrupts current.

It is to be understood that the embodiments described herein are to be considered in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope defined by the following claims.

Claims

1. A battery pack, characterized in that the battery pack comprises:

a battery cell;

a main circuit board connected to the battery cells; and

a connection circuit board including a conductive pattern, the connection circuit board connecting the battery cell and the main circuit board to each other,

wherein the conductive pattern includes a connection pattern and a fuse pattern having a smaller line width than the connection pattern.

2. The battery pack according to claim 1, wherein the fuse pattern meanders while alternately extending backward and forward along a second direction different from the first direction along which the connection pattern extends.

3. The battery pack of claim 2, wherein the connection pattern has a first line width and extends in a first direction, and

the fuse pattern has a second line width smaller than the first line width, and meanders while alternately extending backward and forward along a second direction crossing the first direction.

4. The battery pack of claim 2, wherein the fuse pattern comprises:

a plurality of linear portions extending side by side in the second direction; and

and a bent portion connecting adjacent ends of the linear portions to each other in a bent shape.

5. The battery pack according to claim 4, wherein the bent portion has a circular arc shape.

6. The battery pack according to claim 2, wherein a first end and a second end forming both ends of the fuse pattern extend in the first direction parallel to the connection pattern.

7. The battery pack according to claim 6, wherein the first end portion and the second end portion each have a second line width smaller than the first line width of the connection pattern and extend in the first direction parallel to the connection pattern.

8. The battery pack according to claim 1, wherein the connection circuit board further comprises an insulating film in which the conductive pattern is embedded.

9. The battery pack of claim 1, wherein the conductive pattern comprises:

a first conductive pattern providing a charge/discharge path; and

a second conductive pattern through which a signal having information on the state of the battery cell is transmitted.

10. The battery pack of claim 9, wherein the battery cell comprises a plurality of battery cells, and

the second conductive pattern provides a path for an equalization current for equalizing the unbalanced charge/discharge states of the plurality of battery cells.

11. The battery pack of claim 10, wherein the second conductive pattern is connected to an equalizing resistor of the main circuit board.

12. The battery pack of claim 9, wherein the battery cell comprises a plurality of battery cells, and

the plurality of battery cells are electrically connected to each other by a bus bar connecting terminals of different battery cells to each other.

13. The battery pack of claim 12, wherein the first and second conductive patterns are connected to terminals or bus bars of the plurality of battery cells.

14. The battery pack of claim 13, wherein the conductive tabs are disposed between the first and second conductive patterns and the terminals of the plurality of battery cells or between the first and second conductive patterns and the bus bars.

15. The battery pack of claim 9, wherein the first conductive pattern comprises:

a low potential line connected to lowest potential terminals of the plurality of battery cells electrically connected to each other; and

and a high potential line connected to the highest potential terminal of the plurality of battery cells.

16. The battery pack according to claim 15, wherein the second conductive pattern connects terminals of the plurality of battery cells having different potentials to the main circuit board.

17. The battery pack of claim 16, wherein the second conductive pattern comprises:

a low potential line connected to a lowest potential terminal of the plurality of battery cells;

a high potential line connected to the highest potential terminal of the plurality of battery cells; and

and an intermediate potential line connected to intermediate potential terminals of the plurality of battery cells.

18. The battery pack according to claim 17, wherein the first conductive pattern and the second conductive pattern are each connected to a lowest potential terminal and a highest potential terminal of the plurality of battery cells.

19. The battery pack according to claim 17, wherein the second conductive pattern including the intermediate potential line is connected to a bus bar that connects terminals of different battery cells to each other.