Patent Description:
Generally, a battery pack includes a plurality of battery cells, a busbar electrically connecting the battery cells to the outside (e.g., to an outside load), and a rigid circuit board that is electrically connected to the busbar and on which various circuits and components are mounted.

The busbar is mounted on the rigid circuit board by using bolts and insert nuts, which may cause the height of the battery pack to be increased. In addition, to absorb swelling of a battery cell, a separate terminal having a swelling-absorption structure should be bolted between the rigid circuit board and the battery cell. Further, a tox clinching process should be used for connecting the busbar, and thus, there are problems in that the structure of the battery pack and battery module becomes complicated, the costs increase, and it may be difficult to reduce the height of the module.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology, and therefore, it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

<CIT>, <CIT>, <CIT>, and <CIT> all make disclosures related to batteries.

According to a first aspect, there is provided a hybrid circuit board according to claim <NUM>. According to a second aspect, there is provided a battery pack according to claim <NUM>. Details of embodiments are provided in the dependent claims. BRIEF DESCRIPTION OF DRAWINGS.

Embodiments of the present disclosure are provided to assist in explaining the present disclosure, and the following embodiments may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided to convey the aspects and features of the present disclosure to a person skilled in the art.

In addition, in the accompanying drawings, sizes or thicknesses of various components may be exaggerated for brevity and clarity. In addition, it will be understood that when an element A is referred to as being "connected to" an element B, the element A can be directly connected to the element B or an intervening element C may be present therebetween such that the element A and the element B are indirectly connected to each other.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the disclosure. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms that the terms "have," "comprise," or "include" and variations thereof, such as "having," "comprising," or "including," when used in this specification, specify the presence of stated features, numbers, steps, operations, elements, and/or components but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and/or groups thereof.

It will be understood that, although the terms first, second, etc. may be used herein to describe various members, elements, regions, layers, and/or sections, these members, elements, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one member, element, region, layer and/or section from another. Thus, for example, a first member, a first element, a first region, a first layer, and/or a first section discussed below could be termed a second member, a second element, a second region, a second layer, and/or a second section without departing from the teachings of the present disclosure.

Spatially relative terms, such as "beneath," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. For example, if the element or feature in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "on" or "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below, etc. Further, the use of "may" when describing embodiments of the present disclosure relates to "one or more embodiments of the present disclosure. " Expressions, such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art.

Hereinafter, a hybrid circuit board and a battery pack having the same according to embodiments of the present disclosure will be described, in detail, with reference to the accompanying drawings.

<FIG> is a partially exploded perspective view of a battery pack according to an embodiment of the present disclosure, <FIG> is an exploded perspective view of the hybrid circuit board shown in <FIG>, <FIG> is a plan view of the hybrid circuit board shown in <FIG>, <FIG> is an enlarged plan view of the portion "A" of <FIG>, and <FIG> is an enlarged plan view of the portion "B" of <FIG>.

As shown in <FIG>, a battery pack <NUM> according to an embodiment of the present disclosure includes a plurality of battery cells <NUM>, a cell frame <NUM> which aligns and supports the battery cells <NUM>, a plurality of busbars <NUM>, which are electrically connected to the battery cells <NUM>, and a busbar holder <NUM>, which supports the busbars <NUM>. The battery pack <NUM> further includes a hybrid circuit board <NUM> on which various circuits and components are mounted. The busbars <NUM> are electrically connected to the hybrid circuit board <NUM>, and the hybrid circuit board <NUM> may be electrically connected to the outside of the battery pack <NUM> through a separate connector. The battery pack <NUM> may be referred to as a battery module.

The battery cells <NUM> may have a rectangular parallelepiped shape, and a plurality of battery cells <NUM> are arranged in a line along a direction (e.g., a predetermined direction). Here, each of the battery cells <NUM> may be arranged so that their relatively wide plate surfaces face each other. The cell frame <NUM> is provided to align the battery cells <NUM>. Each of the battery cells <NUM> may include a rectangular parallelepiped-shaped case, an electrode assembly accommodated together with an electrolyte in the case, and a cell cap <NUM> for sealing the case.

The electrode assembly may be formed by sequentially winding or stacking a negative electrode plate, a separator, and a positive electrode plate. A negative electrode active material, such as graphite or carbon, may be applied or coated on the negative electrode plate. The negative electrode plate may be formed of a metal foil, such as copper, copper alloy, nickel, or nickel alloy. An active material, such as a transition metal oxide, may be applied or coated on the positive electrode plate. The positive electrode plate may be formed of a metal foil, such as aluminum or an aluminum alloy. An uncoated region, that is, an area to which an active material is not applied, may be formed on the negative electrode plate and the positive electrode plate, respectively. A negative electrode tab may be connected to the negative electrode uncoated region, and a positive electrode tab may be connected to the positive electrode uncoated region. The negative electrode tab and the positive electrode tab, connected in this way, may be respectively electrically connected to the negative electrode terminal and the positive electrode terminal formed in the cell cap <NUM>. The negative and positive electrode terminals on the cell cap <NUM> are electrically connected to the busbars <NUM>.

The cell frame <NUM> includes a pair of end plates <NUM> that are in contact with the battery cells <NUM> at both ends along the arrangement direction of the battery cells <NUM>, a pair of side plates <NUM> coupled orthogonally to the end plates <NUM>, and a top plate <NUM> coupled to an upper portion of the hybrid circuit board <NUM>. On the basis of <FIG>, a bottom plate of the cell frame <NUM> is provided on the lower portion of the battery cells <NUM> to support the battery cells <NUM> from the lower portion. On the basis of <FIG>, the end plates <NUM> support the battery cells <NUM> in the front-rear direction, the side plates <NUM> support the battery cells <NUM> in the left-right direction, and the top plate <NUM> support the battery cells <NUM> in the upper direction, respectively. The end plate <NUM>, the side plates <NUM>, the top plate <NUM>, and the bottom plate (not shown) are coupled to one another to form a substantially rectangular parallelepiped frame, and the battery cells <NUM>, the busbar holder <NUM> and the busbars <NUM>, and the hybrid circuit board <NUM>, are accommodated therein.

The busbar holder <NUM> may be seated on top of the cell cap <NUM> on the basis of <FIG>. The busbar holder <NUM> is a substantially rectangular plate, and a plurality of openings (e.g., through holes), through which the positive and negative electrode terminals of the cell cap <NUM> are exposed, may be formed therein. The busbar holder <NUM> may be made of an insulating material. When the positive electrode terminal and the negative electrode terminal are exposed through the openings formed in the busbar holder <NUM>, the busbar <NUM> are electrically connected to the exposed positive electrode terminal and the negative electrode terminal.

The busbar <NUM> may electrically connect the positive electrode terminal and the negative electrode terminal (e.g., the positive electrode terminal of one of the battery cells <NUM> to the negative electrode terminal of another one of the battery cells <NUM>). The busbar <NUM> may connect the plurality of battery cells <NUM> in series and/or in parallel. To this end, a plurality of busbars <NUM> may be provided. In one example, the busbars <NUM> may electrically connect non-adjacent battery cells <NUM> from among the battery cells <NUM> arranged in a row. In other embodiments, the busbars <NUM> may electrically connect the positive electrode terminal of one battery cell <NUM> and a positive electrode terminal or a negative electrode terminal of another battery cell <NUM>. In addition, the busbar <NUM> may electrically connect the negative electrode terminal of one battery cell <NUM> and a positive electrode terminal or a negative electrode terminal of another battery cell <NUM>. The busbar <NUM> may be connected to the positive electrode terminal and the negative electrode terminal by welding or the like. Areas other than the busbar <NUM> and the positive and negative electrode terminals may be insulated by the busbar holder <NUM>. The hybrid circuit board <NUM> is disposed between the busbar(s) <NUM> and the top plate <NUM>.

As shown in <FIG>, the hybrid circuit board <NUM> includes a rigid substrate 50a and a flexible substrate 50b.

The rigid substrate 50a is coupled to the flexible substrate 50b to support the flexible substrate 50b and to reinforce (or improve) rigidity. The rigid substrate 50a may be simply formed of a reinforcing material for reinforcement without circuit mounting. In other embodiments, the rigid substrate 50a may be a printed circuit board (PCB) on which a circuit is mounted. Because the rigid substrate 50a supports the flexible substrate 50b, it may have a shape similar to that of the flexible substrate 50b. The rigid substrate 50a may have the same size as the flexible substrate 50b or a slightly smaller size. The rigid substrate 50a may have a substantially rectangular shape and may be disposed so that a long side direction coincides with an arrangement direction of the battery cells <NUM>. On the basis of <FIG>, the flexible substrate 50b is coupled to the upper portion of the rigid substrate 50a.

The flexible substrate 50b is a substrate made of a flexible material having lower strength than the rigid substrate 50a. The flexible substrate 50b may be (or may be referred to as) a flexible printed circuit assembly (FPCA) or a flexible printed circuit board (FPCB). In the flexible substrate 50b, various parts (or components or circuits) for measuring state information of the battery cells <NUM>, such as voltages and/or temperatures of the battery cells <NUM>, and various parts (or components or circuits) for controlling and/or managing the battery cells <NUM>, may be mounted.

As shown in <FIG>, the flexible substrate 50b may have a substantially rectangular shape, and a first tab connection portion <NUM> and a second tab connection portion <NUM> are formed at edges thereof in the long side (or length) direction. A substrate tab <NUM> is connected to the first tab connection portion <NUM> and the second tab connection portion <NUM>, respectively. The flexible substrate 50b may be disposed such that the long side direction coincides with an arrangement direction of the battery cells <NUM>. Because the flexible substrate 50b is to be connected to the busbars <NUM>, the flexible substrate 50b should cover a certain portion (or size) or more of the area of the busbar holder <NUM>. The flexible substrate 50b may have a different size than the busbar holder <NUM> but may have a size sufficient to be at least adjacent to the installation area for the busbars <NUM> for a smooth connection with the busbars <NUM>. For example, the flexible substrate 50b may have a short side (or width) length corresponding to an interval between the left busbars <NUM> and the right busbars <NUM> shown in <FIG>. In addition, the flexible substrate 50b may have a long side length equal to the sum of the widths of the left or right busbars <NUM> in the arrangement direction of the battery cells <NUM>.

As shown in <FIG>, a plurality of first and second tab connection portions <NUM> and <NUM> are formed on the edges of the flexible substrate 50b in the longitudinal (or long side or length) direction. However, the first tab connection portion <NUM> and the second tab connection portion <NUM> may also be formed on the edges of the flexible substrate 50b in the short side (or width) direction.

As shown in <FIG> , the first tab connection portion <NUM> is a portion of the flexible substrate 50b to which the substrate tab <NUM>, which is electrically connected to the busbar <NUM>, is connected. The first tab connection portion <NUM> may be formed to have a size the same as or slightly larger than the size of a portion to which the substrate tab <NUM> is welded (hereinafter, referred to as a first welding portion). A first shape portion <NUM> that is cut in an approximately water-droplet shape may be formed in the flexible substrate 50b at both sides of the first tab connection portion <NUM>.

The first shape portion <NUM> is concavely cut inwardly from an edge of the flexible substrate 50b in the long side direction and is provided on both sides of the first tab connection portion <NUM>. Because the first tab connection portion <NUM> is a free end due to the first shape portion <NUM> and is a flexible material, the first tab connection portion <NUM> can move with a degree of freedom in the vertical, horizontal, and horizontal directions, on the basis of <FIG>. The first tab connection portion <NUM> is connected to the busbar <NUM> by the substrate tab <NUM>, and the busbar <NUM> is connected to the cell cap <NUM>. Therefore, even if vibration is transmitted to the first tab connection portion <NUM> when swelling occurs in the battery cell <NUM>, the swelling can be absorbed by the first shape portion <NUM>. Accordingly, damage to the first tab connection portion <NUM> or damage to connection portions of the substrate tab <NUM> and the busbar <NUM> can be mitigated or prevented. The first shape portion <NUM> for absorbing swelling may be implemented in a different shape depending on a distance from the busbar <NUM> or interference with the busbar holder <NUM>.

As shown in <FIG>, and <FIG>, the second tab connection portion <NUM>, to which the substrate tab <NUM> is connected, is formed on the flexible substrate 50b, and a second shape portion <NUM> having an approximately 'S' shape is provided. For example, the second shape portion <NUM> includes an extension portion 522a extending in a straight line from one end of the edge of the flexible substrate 50b, a curved portion 522b integrally formed with the extension portion 522a and having an approximately 'S' curve shape, and a connection portion 522c formed integrally with the curved portion 522b and formed in a straight line to be connected to the second tab connection portion <NUM>. The second tab connection portion <NUM>, to which the substrate tab <NUM> is connected, is formed at an end of the connection portion 522c of the second shape portion <NUM>. In addition, the second shape portion <NUM> has a width smaller than the size of the second tab connection portion <NUM> and is spaced apart from the end of the flexible substrate 50b. Therefore, because the second tab connection portion <NUM> becomes a free end due to the second shape portion <NUM> and is a flexible material, the second tab connection portion <NUM> can move with a degree of freedom in the vertical, horizontal, left, and right directions, on the basis of <FIG>. Accordingly, swelling of the battery cells <NUM> may also be absorbed by the second shape portion <NUM>.

As such, the first tab connection portion <NUM> should be able to flow with a degree of freedom (e.g., a predetermined degree of freedom). Accordingly, when the rigid substrate 50a is coupled to the flexible substrate 50b, the extended length of the portion of the rigid substrate 50a supporting the first tab connection portion <NUM> (hereinafter, referred to as a support portion 50a') may be smaller than the extended length of the first tab connection portion <NUM>. As used herein, the extended length is a distance at which the first tab connection portion <NUM> protrudes from the end of the flexible substrate 50b. In other embodiments, the support portion 50a' of the rigid substrate 50a may not be fixed to the first tab connection portion <NUM>. For example, the extended length of the support portion 50a' may be the same as the extended length of the first tab connection portion <NUM>.

In addition, similar to the first tab connection portion <NUM>, the second tab connection portion <NUM> should be able to flow with a degree of freedom (e.g., a predetermined degree of freedom). To this end, the rigid substrate 50a may be shaped so as not to support a portion of the flexible substrate 50b where the second tab connection portion <NUM> is formed. For example, the rigid substrate 50a may be shaped such that the portion where the second tab connection portion <NUM> is formed is empty. <FIG> shows an embodiment in which the portion of the rigid substrate 50a corresponding to the second tab connection portion <NUM> of the flexible substrate 50b is empty.

As shown in <FIG>, the substrate tab <NUM> is a metal tab for connecting the first tab connection portion <NUM> and the second tab connection portion <NUM> to the busbars <NUM> , respectively. For example, the substrate tab <NUM> may be made of a nickel material. The substrate tab <NUM> may include a plurality of substrate tabs, and they may have a substantially rectangular shape. One end of the substrate tab <NUM> is coupled to the first tab connection portion <NUM> or the second tab connection portion <NUM>, and the other end thereof extends to the outside of the first tab connection portion <NUM> or the second tab connection portion <NUM>. Part or all of a region of the substrate tab <NUM>, except for one end thereof, may be coupled to the busbars <NUM>. One end of the substrate tab <NUM> that is coupled to the first tab connection portion <NUM> or the second tab connection portion <NUM> may be defined as a first welding portion <NUM>, and the remaining portion may be defined as a second welding portion <NUM>. For example, the first welding portion <NUM> may be connected to the first tab connection portion <NUM> or the second tab connection portion <NUM> by soldering, and the second welding portion <NUM> may be connected to the busbar <NUM> by laser welding. However, both the first welding portion <NUM> and the second welding portion <NUM> may be welded by ultrasonic welding or laser welding. For example, when the first welding portion <NUM> and the second welding portion <NUM> are physically coupled (e.g., are integrally formed) and electrically connected to the first tab connection portion <NUM>, the second tab connection portion <NUM>, or the busbars <NUM>, the coupling method is not limited. In addition, the first welding portion <NUM> and the second welding portion <NUM> may have different shapes than those shown in the drawings, which are provided by way of example. In other words, the shapes if the first welding portion <NUM> and the second welding portion <NUM> are not limited thereto.

As described above, because the flexible substrate 50b and the busbar <NUM> are electrically connected by the substrate tab <NUM>, a bolting process and bolting parts for connecting the substrate and the busbar holder <NUM> may be omitted. In addition, tox clinching, which is a type of riveting process for bonding dissimilar metals, for connecting a substrate and the busbars <NUM> may be omitted. Therefore, the assembly quality is improved, the quality can be stabilized, and the cost can be reduced by the omission of parts.

<FIG> is a cross-sectional view schematically illustrating a state in which a conventional busbar holder and a rigid circuit board are coupled. <FIG> is a cross-sectional view schematically illustrating a coupling state between a busbar holder and a hybrid circuit board of a battery pack according to an embodiment of the present disclosure.

As shown in <FIG>, conventionally, a busbar holder (b) is disposed on a cell cap (a), a rigid circuit board (e) is placed on the busbar holder (b), and the rigid circuit board (e) is then fixed to the busbar holder (b) by using an insert nut (c) and a bolt (d). Thereafter, a top plate (f) is fastened on the rigid circuit board (e). For example, a height ranging from the top plate (f) to the head of the bolt (d) may be about <NUM>, and a height ranging from the head of the bolt (d) to the bottom of the busbar holder (b) may be about <NUM> (hereinafter, the sum of the two heights is defined as a module height). That is, in the conventional structure, the module height is about <NUM>.

In contrast, when the hybrid circuit board <NUM> according to embodiments of the present disclosure is applied, the coupling structure is, according to an embodiment, as shown in <FIG>. As shown in <FIG>, a busbar holder <NUM> is placed on a cell cap <NUM>, and a hybrid circuit board <NUM> on which components are mounted is placed on the busbar holder <NUM>. Thereafter, a top plate <NUM> is disposed on the hybrid circuit board <NUM>. For example, a height ranging from the top plate <NUM> to the top end of a component mounted on the hybrid circuit board <NUM> may be about <NUM>, and a height ranging from the top end of the component mounted on the hybrid circuit board <NUM> to the bottom of the busbar holder <NUM> may be about <NUM>. Therefore, the module height according an embodiment of the present disclosure is about <NUM>, and thus, the module height can be greatly reduced compared to the conventional structure shown in <FIG>.

Hereinafter, a structure of a hybrid circuit board according to another embodiment of the present disclosure will be described, and a detailed description of the same configuration as that of the previous embodiment will be omitted.

<FIG> is a plan view of a hybrid circuit board according to another embodiment of the present disclosure, <FIG> is an enlarged perspective view of the portion "C" of <FIG>, and <FIG> is an enlarged bottom perspective view of portions of the portion "C" shown in <FIG>.

As shown in <FIG>, in the hybrid circuit board <NUM>' according to another embodiment of the present disclosure, a plurality of first tab connection portions <NUM> and a sensor connection portion <NUM> may be formed on a flexible substrate 50b'. Here, the first tab connection portion <NUM> may have the same shape and structure as that shown in <FIG>. As shown in <FIG>, however, the substrate tab <NUM> may be formed in a rectangular shape without a separate welding portion. A similar configuration of the substrate tab <NUM> may also be applied to the embodiment shown in <FIG>.

The sensor connection portion <NUM> may extend from one edge of the flexible substrate 50b' in an approximately 'S' shape. A foam pad <NUM> on which a temperature sensor <NUM> is mounted may be coupled to the extended (or distal) end of the sensor connection portion <NUM>. The foam pad <NUM> has a hexahedron shape having a thickness (e.g., a predetermined thickness), and an accommodation space in which the temperature sensor <NUM> is mounted may be formed on (or in) the foam pad <NUM>. For example, the foam pad <NUM> may be formed to surround (e.g., to surround in a plan view or to extend around a periphery of) the temperature sensor <NUM>. A metal tab <NUM> (see, e.g., <FIG>) electrically connected to the temperature sensor <NUM> and connected to the battery cell <NUM> or the cell cap <NUM> may be coupled to the lower portion of the foam pad <NUM> in the direction facing the busbar <NUM>. For example, the metal tab <NUM> may be made of an aluminum material. The temperature of the battery cell <NUM> may be measured by attaching the metal tab <NUM> to the surface of the battery cell <NUM> by using a double-sided tape or the like. Accordingly, the shape and length of the sensor connection portion <NUM> may vary depending on a position to which the metal tab <NUM> is attached. By including the sensor connection portion <NUM>, the processes and parts for connecting a temperature sensor to a board with a separate connector and wire, and welding the temperature sensor to a battery cell and installing the same, may be omitted. Accordingly, the cost can be reduced and the process can be simplified due to omission of parts. The above-described sensor connection portion <NUM> may also be applied to the hybrid circuit board <NUM> shown in <FIG>.

In the hybrid circuit board according to embodiments of the present disclosure having the above-described structure, components are not mounted on the edge of a flexible board having a swelling absorption structure formed thereon. The component is mounted on a portion that is less affected by swelling and is supported by a rigid substrate. For example, components may be disposed at a central portion spaced apart from the edge along the longitudinal direction of the flexible substrate.

According to embodiments of the present disclosure, by having both the characteristics of a rigid circuit board and a flexible circuit board, the rigidity of the substrate can be reinforced.

In addition, the hybrid circuit board according to embodiments of the present disclosure has a swelling absorption structure and can be connected to the busbar without a bolting process, and thus, a separate swelling absorption structure may be omitted and the busbar connection structure can be simplified. Accordingly, a cause of increased height of a battery pack is eliminated, thereby enabling a battery pack having a reduced or minimum height.

Claim 1:
A hybrid circuit board (<NUM>) for a battery pack (<NUM>), the battery pack (<NUM>) comprising a cell frame (<NUM>) and a plurality of battery cells (<NUM>) arranged in one direction, each of the battery cells (<NUM>) comprising a positive electrode terminal and a negative electrode terminal, and a plurality of busbars (<NUM>) electrically connected to the positive electrode terminal or the negative electrode terminal of each of the battery cells (<NUM>), the hybrid circuit board (<NUM>) comprising:
a flexible substrate (50b) comprising a flexible material, the flexible substrate being electrically connectable to a plurality of busbars (<NUM>), the busbars (<NUM>) electrically connecting a plurality of battery cells (<NUM>); and
a rigid substrate (50a) comprising a rigid material, the rigid substrate (50a) being coupled to the flexible substrate (50b) to support the flexible substrate (50b), wherein the flexible substrate (50b) comprises a plurality of tab connection portions (<NUM>, <NUM>) along an edge thereof, and
wherein a substrate tab (<NUM>) is electrically connected to each of the tab connection portions (<NUM>, <NUM>) and is electrically connectable to the busbars (<NUM>),
wherein the plurality of tab connection portions (<NUM>, <NUM>) comprise a plurality of first tab connection portions (<NUM>) and a plurality of second tab connection portions (<NUM>),
wherein the flexible substrate has a first shape portion formed at both sides of each of the first tab connection portions, the first shape portion being concavely cut inwardly from the edge of the flexible substrate, and
wherein each second tab connection portion (<NUM>) is connected to the edge of the flexible substrate (50b) by a second shape portion (<NUM>) extending from the edge of the flexible substrate in an 'S' shape and wherein the second shape portion is integrally formed with the second tab connection portion, wherein the second shape portion (<NUM>) comprises an extension portion (522a) extending in a straight line from one end of the edge of the flexible substrate (50b), a curved portion (522b) integrally formed with the extension portion (522a) and having an approximately 'S' curve shape, and a connection portion (522c) formed integrally with the curved portion (522b) and formed in a straight line to be connected to the second tab connection portion (<NUM>).