Battery pack

Abstract

This battery pack comprises a plurality of laminate batteries and a circuit board. The laminate batteries each comprise a terrace part from which an output tab is led out, and an upright wall that is connected to both ends of the terrace part. The plurality of laminate batteries are arranged side by side by linearly arranging the respective terrace parts in the longitudinal direction. The circuit board comprises: a plurality of linear parts that are arranged along the terrace parts; and a detour part that is disposed in a boundary region between adjacent terrace parts and takes a detour around the upright wall. The detour part comprises: a pair of rising parts that are respectively raised from opposing end parts of linear parts adjacent to each other; and a connection part which is disposed so as to face an upper end edge or a tip edge of the upright wall and connects the pair of rising parts to each other. The linear parts are integrally connected by the detour part.

Description

Battery pack

[0001] The present invention relates to a battery pack comprising a plurality of laminate batteries connected to a circuit board.

[0002] Laminated batteries are made by laminating positive and negative electrode plates and covering both sides of the electrode assembly with exterior film to form a sealed structure. This allows them to be manufactured thinner than prismatic batteries with metal exterior cases. Taking advantage of this feature, laminated batteries are widely used in thin battery packs. In laminated batteries, the positive and negative output tabs connected to the electrode plates are sandwiched between exterior film on both sides and extended to the outside. Because the output tab extensions do not incorporate electrode plates, they are thinner than the main body portion that incorporates the electrode plates, forming terrace portions. Battery packs incorporating laminated batteries are equipped with a protection circuit that protects the battery while charging and discharging, improving safety and preventing degradation and extending its lifespan. Battery packs that achieve this include a circuit board on which the protection circuit is mounted.

[0003] Thin battery packs equipped with laminated batteries are used as power sources for portable electronic devices such as smartphones, tablets, and laptops. In particular, in recent years, there has been an increasing demand for higher-capacity battery packs. To meet this demand, battery packs equipped with multiple laminated batteries have been developed. These battery packs, for example, have multiple laminated batteries arranged side-by-side on the same plane. These laminated batteries are connected in series via a circuit board to increase output voltage, or in parallel to increase output current and battery pack capacity.

[0004] In this manner, in a battery pack in which multiple laminate batteries are arranged side by side, as shown in FIG. 20, in order to connect multiple laminate batteries 91 in series or parallel, it is necessary to provide space for placing a circuit board 92 on the terrace portion 95 side from which the output tabs of the laminate batteries 91 are pulled out, which has the disadvantage of increasing the overall external dimensions of the battery pack 90 (see Patent Document 1).

[0005] JP 2013-80570 A

[0006] One object of the present invention is to provide a battery pack that has a structure in which multiple laminate batteries are arranged side by side, while the circuit board connecting these laminate batteries is arranged in a space-saving manner, thereby reducing the overall external dimensions of the battery pack and achieving compactness and high capacity.

[0007] A battery pack according to one embodiment of the present invention includes a plurality of laminate batteries packaged in an exterior film, and a circuit board connected to the plurality of laminate batteries and positioned in a fixed position. The laminate batteries each include a terrace portion formed by the peripheral sealing portion of the exterior film along the long side of a first end face, from which positive and negative output tabs are drawn, and upright walls connected to both ends of the terrace portion and extending along the short side of the first end face. The plurality of laminate batteries are arranged side by side with their terrace portions aligned linearly in the longitudinal direction. The circuit board is stacked on each terrace portion along the longitudinal direction of the terrace portion and includes a plurality of straight portions to which output tabs are connected, and a detour portion that is located in the boundary region between adjacent terrace portions and detours around the upright wall, and the detour portion includes a pair of upright portions that are respectively raised from the opposing ends of the adjacent straight portions in the raising direction of the upright wall, and a connecting portion that is located opposite the upper edge or tip edge of the upright wall and connects the pair of upright portions, and the adjacent straight portions are integrally connected by the detour portion.

[0008] According to the above configuration, the circuit board connected to multiple laminate batteries arranged side by side is composed of a straight section that is placed on the terrace section and a detour section that bypasses the upright walls that protrude into the boundary area of ​​the terrace section.When multiple laminate batteries are arranged side by side, the straight section can be placed on the terrace section while the detour section avoids the upright walls that protrude into the boundary area.By arranging the circuit board in a space-saving manner and reducing the external dimensions of the battery pack, it is possible to achieve a smaller battery pack with a higher capacity.

[0009] 1 is a perspective view of a battery pack according to one embodiment of the present invention. 1 is an exploded perspective view of the battery pack shown in FIG. 1 with the exterior label removed. 2 is an exploded perspective view of the battery pack shown in FIG. 2 with the cover case removed. 3 is an exploded perspective view of the battery pack shown in FIG. 3 further disassembled. 4 is a partially enlarged cross-sectional view taken along line V-V of the battery pack shown in FIG. 2. 5 is a partially enlarged cross-sectional view taken along line VI-VI of the battery pack shown in FIG. 2. 6 is a perspective view showing a manufacturing process of a laminated battery. 7 is an enlarged perspective view of the circuit board shown in FIG. 3. 8 is a perspective view showing the circuit board shown in FIG. 8 in an unfolded state. 9 is a front view of another example of a circuit board. 10 is a perspective view of another example of a circuit board. 11 is an unfolded view of the circuit board shown in FIG. 13. 11 is a perspective view of another example of a circuit board. 12 is an unfolded view of the circuit board shown in FIG. 15. 12 is a perspective view of another example of a circuit board. 13 is a perspective view of the circuit board shown in FIG. 17. 14 is a perspective view of a battery pack according to another embodiment of the present invention. 15 is a perspective view of the circuit board shown in FIG. 17. 16 is a perspective view of a conventional battery pack.

[0010] First, we will explain one of the key features of the present invention. A commonly used laminated battery is one in which the electrode assembly is covered with an exterior film, and the positive and negative output tabs connected to the electrode plates are pulled out from a peripheral sealing portion formed on one end face of the battery body to form a terrace portion. In a battery pack equipped with a laminated battery of this structure, a circuit board can be stacked on the terrace portion, thereby saving space and reducing the overall size of the battery pack.

[0011] In recent years, demand for higher capacity has led to the development of a battery pack 90 in which multiple laminated batteries 91 are arranged side-by-side on the same plane, as shown in Figure 20. However, in this battery pack 90, a circuit board 92 is placed outside the terrace portion 95 of the laminated battery 91 to connect the multiple laminated batteries 91 in series or parallel, which poses a problem of inability to store the circuit board 92 in a space-saving manner. This is because the circuit board cannot be placed on the terrace portion of the laminated battery in a space-saving manner, as is the case with battery packs that incorporate a single laminated battery. In laminated batteries 91 with a terrace portion 95 at one end, the peripheral seals formed on both sides are often folded along both sides, and in this laminated battery 91, the folded upright walls 96 are arranged so that they protrude from both ends of the terrace portion 95. As a result, in a battery pack 90 consisting of laminated batteries 91 of this structure arranged side by side, as shown in Figure 20, the upright walls 96 are arranged to protrude from the boundaries between the terrace sections 95 of adjacent laminated batteries 91, and these upright walls 96 get in the way, making it impossible to arrange a flat circuit board 92 across the terrace sections of adjacent laminated batteries. For this reason, as shown in Figure 20, it was necessary to arrange the circuit board 92 outside the terrace sections 95 of the laminated batteries 91, which created the problem of increasing the overall external dimensions of the battery pack 90.

[0012] The present invention was developed in consideration of these problems, and in a battery pack in which multiple laminated batteries are arranged side-by-side, the circuit board is arranged across adjacent terrace sections while avoiding the upright walls that protrude at the boundaries between adjacent terrace sections, thereby making effective use of the space in each terrace section and successfully reducing the external dimensions of the battery pack.

[0013] A battery pack according to one embodiment of the present invention comprises a plurality of laminated batteries packaged in an exterior film, and a circuit board connected to the plurality of laminated batteries and arranged in a fixed position. The laminated batteries each have a terrace portion formed by a peripheral sealing portion of the exterior film along the long side of a first end face, from which positive and negative output tabs are pulled out, and upright walls connected to both ends of the terrace portion and raised along the short side of the first end face. The plurality of laminated batteries are arranged side by side with each terrace portion aligned linearly in the longitudinal direction. The circuit board is stacked on each terrace portion along the longitudinal direction of the terrace portion and includes a plurality of straight portions to which the output tabs are connected, and a detour portion arranged in the boundary region between adjacent terrace portions and detours around the upright walls. The detour portion includes a pair of upright portions that respectively rise from opposing ends of adjacent straight portions in the direction in which the upright walls rise, and a connecting portion that is arranged opposite the upper edge or tip edge of the upright walls and connects the pair of upright portions, and adjacent straight portions are integrally connected by the detour portion.

[0014] With the above configuration, the straight sections of the circuit board are arranged on each terrace section of multiple laminated batteries arranged side by side, and the upright walls that protrude into the boundary areas of adjacent terrace sections are bypassed by the detour sections of the circuit board.This means that the circuit boards connected to multiple laminated batteries can be arranged by effectively utilizing the space of each terrace section, and by arranging the circuit boards in a space-saving manner, the external dimensions of the battery pack can be reduced.

[0015] In another embodiment of the present invention, the circuit board of the battery pack is formed by bending or curving a single flexible printed circuit board, and the straight portion and the detour portion are integrally formed. According to the above configuration, the straight portion and the detour portion are formed by bending or curving a single flexible printed circuit board, so that the circuit board can be manufactured inexpensively with a simple structure.

[0016] In another embodiment of the present invention, a circuit board of a battery pack includes a thin, strip-shaped flexible substrate that is bent or curved to form a rising portion connected to a straight portion and a connecting portion connected to the rising portion, the connecting portion being disposed opposite the upper edge of the upright wall. According to the above configuration, by bending or curving the thin, strip-shaped flexible substrate, a three-dimensional detour portion can be simply and easily formed relative to the straight portion.

[0017] In a battery pack according to another embodiment of the present invention, the detouring portion has an isosceles trapezoidal shape in a front view, the rising portion is connected to the straight portion at an obtuse angle, and the pair of rising portions are connected to the connecting portion at an obtuse angle. With this configuration, the bending portion of the circuit board is at an obtuse angle, so that the bending portion of the wiring formed on the circuit board can be protected by reducing the load on the bending portion.

[0018] In another embodiment of the battery pack of the present invention, the connecting portion has a curved surface that is curved so as to convex at the center, and the detour portion has a mountain shape, an arc shape, a parabolic shape, or an arch shape when viewed from the front. By making the connecting portion a curved surface that is convex at the center, it is possible to reduce the load on the wiring formed on the circuit board and to reliably avoid the upright wall while shortening the distance required to detour around the upright wall.

[0019] In another embodiment of the battery pack of the present invention, the bypass portion comprises a pair of rising portions connected to the opposing edges of adjacent straight portions, and a connecting portion whose both ends are connected to the side edges of the pair of rising portions, and the connecting portion is bent or curved relative to the pair of rising portions and is positioned opposite the tip edge of the rising wall.

[0020] In another embodiment of the battery pack of the present invention, the bypass portion comprises a pair of rising portions each connected to the side edges of adjacent straight portions, and a connecting portion whose both end edges are connected to the side edges of the pair of rising portions, the connecting portion being flush with the pair of rising portions and positioned opposite the leading edge of the rising wall.

[0021] In another embodiment of the battery pack of the present invention, the bypass portion comprises a pair of rising portions each connected to the side edges of adjacent straight portions, and a connecting portion whose side edge is connected to the upper edge of the pair of rising portions, and the connecting portion is bent relative to the pair of rising portions and is positioned opposite the upper edge of the rising wall.

[0022] In a battery pack according to another embodiment of the present invention, an output tab extending from a terrace portion is folded back from the rear side to the front side of a straight portion disposed on the terrace portion and connected to the front side of the straight portion. According to the above configuration, the output tab extending from the terrace portion is folded back from the rear side to the front side of the straight portion and connected to the front side of the straight portion, so that the output tab can be connected to the circuit board while the straight portion of the circuit board also serves as an insulating plate that insulates the output tab from the peripheral sealing portion. Furthermore, because the output tab extending from the terrace portion is folded back and connected to the circuit board, the output tab can be connected to the circuit board while being arranged in a space-saving manner without increasing the external size of the battery pack.

[0023] In a battery pack according to another embodiment of the present invention, the circuit board includes a reinforcing plate on a part of the straight portion or a part of the detour portion. With this configuration, the reinforcing plate arranged on a part of the straight portion keeps the straight portion arranged on the terrace portion flat, while the reinforcing plate arranged on a part of the detour portion maintains the shape of the detour portion, allowing the battery pack to reliably bypass the upright wall.

[0024] A battery pack according to another embodiment of the present invention further includes a holding case that holds multiple laminated batteries in a fixed position, the holding case including a frame case portion having openings that expose the first and second main surfaces of the laminated batteries, the frame case portion including a plurality of side wall portions that cover both side surfaces of the laminated battery, an end wall portion connected to one end of the plurality of side wall portions and covering the second end surface opposite the first end surface of the laminated battery, and a plate-shaped cover portion connected to the other end of the plurality of side wall portions and positioned opposite the back surface of the terrace portion, the cover portion including a positioning block that holds the bypass portion of the circuit board in a fixed position.

[0025] According to the above configuration, the laminated battery is positioned in a fixed position while being held by both side surfaces and the second end surface in a frame-shaped holding case having side wall portions and end wall portions, the terrace portion is held by a cover portion provided on the back side of the terrace portion, and the bypass portion of the circuit board can be held in a fixed position by a positioning block provided on the cover portion.

[0026] In another embodiment of the present invention, the battery pack includes a plurality of side walls, each of which includes a side wall disposed on a side surface of the battery pack and a middle wall disposed between adjacent laminate batteries, the ends of which are connected to a positioning block. With this configuration, the middle wall disposed between adjacent laminate batteries is connected to the positioning block at its end, thereby maintaining the middle wall in a stable upright position and enabling adjacent laminate batteries to be stably positioned.

[0027] In another embodiment of the battery pack of the present invention, the holding case includes a cover case that covers each terrace portion of a plurality of laminate batteries and the circuit board, and the cover case includes a first plate portion disposed opposite the terrace portion and a second plate portion formed in a bent position relative to the first plate portion and disposed on the leading end surface of the frame case portion, the second plate portion constituting the end surface of the holding case that faces the end wall portion of the frame case portion. With this configuration, the cover case covers the circuit boards disposed across adjacent terrace portions while defining the outer periphery of the holding case, thereby protecting the circuit boards and improving the surface appearance of the battery pack.

[0028] The present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper," "lower," and other terms including these terms) will be used as necessary. However, the use of these terms is intended to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Furthermore, parts that appear with the same reference numerals in multiple drawings indicate the same or equivalent parts or members.

[0029] Furthermore, the embodiments shown below are specific examples of the technical concept of the present invention and are not intended to limit the present invention thereto. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended as examples and are not intended to limit the scope of the present invention thereto. Furthermore, the content described in one embodiment or example can also be applied to other embodiments or examples. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity of explanation.

[0030] The battery pack of the present invention is suitable for use primarily as a power source for portable electronic devices such as laptop computers, tablets, smartphones, etc. However, the present invention does not specify the use of the battery pack, and it can also be used as a power source for various other electronic devices.

[0031] (Embodiment 1) A battery pack according to one embodiment of the present invention is shown in Figures 1 to 4. Figure 1 is a perspective view of the battery pack, Figure 2 is an exploded perspective view of the battery pack shown in Figure 1, Figure 3 is a perspective view of the battery pack shown in Figure 2 with the cover case removed, Figure 4 is a further exploded perspective view of Figure 3, Figure 5 is a cross-sectional view of the battery pack shown in Figure 2 taken along line V-V, Figure 6 is an enlarged cross-sectional view of the battery pack shown in Figure 2 taken along line VI-VI, and Figure 7 shows a manufacturing process for a laminated battery. The battery pack 100 shown in Figures 1 to 4 includes multiple laminated batteries 1 packaged in an exterior film 11 and a circuit board 2 connected to these laminated batteries 1 and positioned in a fixed location. The battery pack 100 also includes a holding case 3 that holds the multiple laminated batteries 1 and circuit board 2 in their fixed locations, and an exterior label 5 that covers the holding case 3 in which the laminated batteries 1 and circuit board 2 are positioned.

[0032] (Laminated Battery 1) As shown in FIG. 7, the laminated battery 1 has an electrode assembly 13, which is composed of positive and negative electrode plates stacked with separators in between, and is covered on both sides with exterior films 11. The exterior films 11 are made of aluminum foil with insulating plastic films laminated on both sides. In the laminated battery 1 of FIG. 7, the electrode assembly 13 is sandwiched between a first exterior film 11A and a second exterior film 11B, which are wrapped around the outer periphery of the electrode assembly 13, and the wrapped portions are joined to seal the electrode assembly 13 inside. The laminated battery 1 is a lithium-ion polymer battery with a thickness of 3 mm to 10 mm. However, the present invention does not limit the laminated battery to a lithium-ion polymer battery. The laminated battery can be any laminated battery that can be charged and discharged.

[0033] In the laminated battery 1 shown in Figure 7, the electrode assembly 13 has a rectangular outer shape, and the exterior film 11 is folded over along one edge of the rectangle. The exterior film 11 is provided with lapped sections along the two edges on either side of the lapped section and along one edge from which the positive and negative output tabs 14, respectively connected to the positive and negative electrode plates, are pulled out. The first exterior film 11A and the second exterior film 11B are hermetically bonded at the lapped sections by adhesive bonding, welding, or other methods to form a peripheral seal 12. In the laminated battery 1 shown in Figure 7, a single exterior film 11 is folded over along one edge of the electrode assembly 13, with the first exterior film 11A covering one side of the electrode assembly 13 and the second exterior film 11B covering the other side of the electrode assembly 13. Because the exterior film 11 is folded over along one edge of the electrode assembly 13, the laminated battery 1 with this structure has peripheral seal 12 on three sides, but not on one side. Although not shown, laminated batteries may have a structure in which peripheral sealing portions are provided around the four outer edges of the battery. Such laminated batteries are manufactured by placing two separate exterior films on both sides of an electrode body and joining the four edges of the electrode body with peripheral sealing portions.

[0034] The laminated battery 1 shown in Figure 7 has a planar second exterior film 11B. To achieve this, the first exterior film 11A is folded around the periphery of the electrode assembly 13 and then tightly joined to the second exterior film 11B at the lapped portion to form a peripheral seal 12. The laminated battery 1 shown in Figure 7 has opposing wide surfaces of the battery body 10 as the first and second principal surfaces 1A and 1B, each with a rectangular outer shape. Furthermore, the peripheral seal 12 formed along the long side of the first end surface 1D of the battery body 10 is planar and parallel to the surface of the electrode assembly 13, forming a terrace 15 from which the positive and negative output tabs 14 extend to the outside. Furthermore, in the laminated battery 1, the peripheral sealing portions 12 formed on both sides of the battery body 10 are folded along both side surfaces of the battery body 10, and the ends of these folded peripheral sealing portions 12 that protrude toward the first end face 1D form standing walls 16 that rise from both ends of the terrace portion 15 along the short sides of the first end face 1D. In the laminated battery 1 with the above structure, the height of the folded peripheral sealing portions 12 on the side surfaces of the battery body 10 is lower than the thickness of the battery body 10, and as a result, the height (h) of the standing walls 16 formed on both ends of the terrace portion 15 is lower than the thickness (t) of the laminated battery 1.

[0035] (Output Tabs 14) As shown in FIG. 7 , the terrace portion 15 sandwiches the positive and negative output tabs 14 between two exterior films 11 and extends them to the outside. The positive and negative output tabs 14 are thin metal plates and connected to the positive and negative electrode plates inside the exterior film 11. A resin tab 17 is disposed between the output tab 14 and the exterior film 11. The resin tab 17 is strip-shaped and wider and shorter than the output tab 14, covering both sides of the output tab 14. The resin tab 17 is a film of thermoplastic resin such as modified polyethylene, and is sandwiched between the output tab 14 and the exterior film 11 to extend the output tab 14 from the terrace portion 15 to the outside in an airtight manner. The tip of the output tab 14 protrudes from the resin tab 17, exposing both sides. The output tab 14 extends linearly from the terrace portion 15 and is connected to a connection terminal 27 provided on the circuit board 2 stacked on the terrace portion 15, as shown in FIGS. 3 and 6 . The output tab 14 is connected to the connection terminal 27 by laser welding. However, the output tab 14 can also be connected to the connection terminal by soldering, spot welding, or other methods.

[0036] The battery pack 100 shown in Figures 2 to 4 includes two laminate batteries 1, which are arranged in a holding case 3 in a horizontally aligned position, facing in the same direction. The horizontally aligned laminate batteries 1 are arranged so that their first main surface 1A, second main surface 1B, first end surface 1D, and second end surface 1E are flush with each other, their terraces 15 are aligned linearly in the longitudinal direction, and their opposing side surfaces 1C are close to each other. However, the battery pack of the present invention is not limited to two laminate batteries. A battery pack can include three or more laminate batteries.

[0037] (Circuit Board 2) The circuit board 2 is located in an area that includes each terrace 15 of multiple laminate batteries 1 arranged side by side, and is connected to each of the laminate batteries 1. The circuit board 2 shown in Figures 2 to 5 is formed in an elongated shape that straddles the multiple terraces 15, and is connected to the output tabs 14 extending from each laminate battery 1, connecting the multiple laminate batteries 1 in series or parallel.

[0038] Here, circuit boards arranged across multiple terraces can be arranged in a space-saving manner by stacking them on the terraces, but the upright walls arranged between adjacent terraces get in the way, making it impossible to arrange the circuit boards as a single, elongated plate in a stacked state on the terraces. To solve this problem, the present invention uses the following structure for the circuit board, which allows it to be arranged in a stacked state on each terrace while avoiding the upright walls, making it possible to arrange the circuit boards across multiple terraces. The structure of the circuit board is described in detail below.

[0039] As shown in FIGS. 2 to 5 and 8 , the circuit board 2 includes a plurality of linear portions 21 stacked on the terrace portion 15 along the longitudinal direction of the terrace portion 15, and a detour portion 22 disposed in the boundary region between adjacent terrace portions 15 and bypassing the upright wall 16. In this circuit board 2, adjacent linear portions 21 are integrally connected by the detour portion 22. The circuit board 2 shown in FIGS. 8 and 9 is made of a flexible printed circuit (FPC). The circuit board 2 shown in the figures is formed by cutting a single planar flexible printed circuit (FPC) 20 into a predetermined shape and bending or curving the same to integrally form the linear portions 21 and the detour portion 22. Thus, the circuit board 2 formed of the flexible printed circuit (FPC) 20 is inexpensive, lightweight, and can be processed into a desired shape with a high degree of freedom.

[0040] The circuit board 2, which is made of a flexible printed circuit board (FPC) 20, has a conductive pattern of a predetermined thickness provided as wiring on the surface of a base material. The flexible printed circuit board (FPC) 20 can include wiring made of, for example, copper foil. The electrical resistance of this wiring is adjusted by adjusting the thickness and width of the copper foil. The thickness of the copper foil can be, for example, 5 to 50 μm, preferably 15 to 40 μm. Furthermore, the flexible printed circuit board (FPC) 20 can also have conductive patterns wired across multiple layers. The flexible printed circuit board (FPC) 20 may be a flexible printed circuit board (FPC) in its entirety, or it may be a rigid-flexible printed circuit board (rigid FPC) in which the detour section 22 is a flexible printed circuit board (FPC) and the component mounting section is integrated as a rigid board.

[0041] The straight section 21 is a long, narrow plate extending along the width of the laminated battery 1, or in other words, along the length of the terrace section 15, and is arranged so as to be stacked on the terrace section 15 of each laminated battery 1. The straight section 21 is preferably extended in a planar manner and stacked on the terrace section 15 to ensure stable placement in a fixed position. However, the straight section 21 may also be arranged in a slightly inclined or curved position relative to the terrace section 15. The straight section 21 shown in the figure includes connection terminals 27 to which the positive and negative output tabs 14 extending from the terrace section 15 are connected, and electronic components 19 that implement the protection circuits and elements that protect the laminated battery 1.

[0042] The detour portions 22 are connected between the linear portions 21 arranged on adjacent terrace portions 15 and are formed in a shape that detours around the upright walls 16 arranged between the adjacent terrace portions 15. Here, the detour portions 22 that detour around the upright walls 16 do not detour in the pull-out direction of the output tab 14 within the same plane as the terrace portions 15 to avoid the upright walls 16. This is because the circuit board 2 requires wiring of a certain width to allow for the flow of charge and discharge current. If the detour portions 22 detour around the upright walls 16 within the same plane as the terrace portions 15, the output tab 14 would protrude too much in the pull-out direction, making it impossible to arrange the circuit board 2 in a space-saving manner. For this reason, in the present invention, the detour portions 22 are formed in a three-dimensional shape that detours in the rising direction of the upright walls 16 relative to the planar linear portions 21 stacked on the terrace portions 15, thereby enabling the detour to avoid the upright walls 16 without increasing the protrusion of the output tab 14 in the pull-out direction.

[0043] The detour section 22 shown in Figures 2 to 5 and 8 includes a pair of rising portions 23 that rise from opposing ends of adjacent straight portions 21 toward the rising direction of the upright wall 16, and a connecting portion 24 that is disposed opposite the upper edge of the upright wall 16 and connects the pair of rising portions 23 to each other. The detour section 22 shown in Figure 8 is formed into a desired shape by bending or curving a long, narrow, strip-shaped flexible printed circuit (FPC) 20 at predetermined positions, as shown in Figure 9. The flexible printed circuit (FPC) 20 shown in Figure 9 has a shape in which the straight portions 21 provided at both ends are connected by a pair of rising portions 23 and connecting portions 24 that constitute the detour section 22. Because this circuit board 2 is formed from a single strip-shaped flexible printed circuit (FPC) 20, the straight portions 21, rising portions 23, and connecting portion 24 are rectangular and have the same width (S).

[0044] 9, this circuit board 2 is valley-folded at a boundary line 25 (shown by a dashed dotted line in the figure) between the straight portion 21 and the rising portion 23, and mountain-folded at a boundary line 26 (shown by a dashed two-dot line in the figure) between the rising portion 23 and the connecting portion 24, so that the detour portion 22 formed by the rising portion 23 and the connecting portion 24 has a shape that protrudes three-dimensionally from the planar straight portion 21. In the circuit board 2 shown in FIGS. 8 and 9, the three-dimensional shape of the detour portion 22 in a front view is an isosceles trapezoidal mountain shape, and the rising portion 23 is formed by being bent or curved so that the inclination angle (α) of the rising portion 23 with respect to the straight portion 21 is an obtuse angle, and the connecting portion 24 is formed by being bent or curved so that the inclination angle (β) of the connecting portion 24 with respect to the rising portion 23 is an obtuse angle. According to this configuration, the rising portion 23 is bent at an obtuse angle relative to the straight portion 21, and the connecting portion 24 is bent at an obtuse angle relative to the rising portion 23, which has the advantage of reducing the burden on the wiring provided on the circuit board 2 at the bent portion and protecting it.

[0045] As described above, the circuit board 2 formed from a single strip-shaped flexible printed circuit (FPC) board 20 preferably has the total length (L1, L2) of the straight portion 21 slightly shorter than the width (W) of the terrace portion 15 of the laminated battery 1, as shown in FIG. 9 , to allow smooth stacking on the surface of the terrace portion 15. The total length (L1, L2) of the straight portion 21 is preferably 0.5 to 1 times the length (W) of the terrace portion to allow connection of the output tab 14 extended from the laminated battery 1. Furthermore, increasing the length (L3) of the rising portion 23 increases the inclination angle (α, β), but this shortens the total length (L1, L2) of the straight portion 21. Therefore, the length (L3) of the rising portion 23 is preferably 1 to 3 times the height (h) of the upright wall 16. Here, the length (L3) of the rising portion 23 may be equal to the height (h) of the upright wall 16, and the inclination angle (α, β) of the rising portion 23 may be 90 degrees. Furthermore, by setting the length (L4) of the connecting portion 24 to a predetermined length, it becomes easier to bend or curve the connecting portion 24 relative to the standing portion 23. If the length (L4) of the connecting portion 24 is shortened, it becomes more difficult to bend or curve the connecting portion 24 relative to the standing portion 23, and conversely, if the length (L4) is lengthened, the overall length (L1, L2) of the straight portion 21 becomes shorter. Therefore, the length (L4) of the connecting portion 24 is preferably 0.5 to 3 times the height (h) of the standing wall 16.

[0046] In the circuit board 2 shown in Figures 5 and 8, the shape of the detour portion 22 in a front view is an isosceles trapezoid, but the shape of the detour portion 22 is not limited to this. For example, the detour portion 22 may have a rectangular wave shape in a front view by setting the inclination angles (α, β) of the rising portions 23 to 90 degrees. Furthermore, in the above example, the connecting portions 24 are flat, but the connecting portions 24 may also have a curved surface shape with a central convexity, as shown in Figure 10. The detour portion 22 having the connecting portions 24 in a curved surface shape may have a mountain shape with a curved apex folded back in a front view. Furthermore, the overall shape of the detour portion 22 formed by the pair of rising portions 23 and the connecting portions 24 may also have an arc shape, a parabolic shape, or an arch shape in a front view. As described above, the circuit board 2 in which the connecting portion 24 is curved into a central convex shape has the advantage of being able to reduce the burden on the wiring formed on the flexible printed circuit board (FPC) 20, and also being able to reliably avoid the standing wall 16 while shortening the distance required to bypass the standing wall 16.

[0047] (Connection Terminals 27) The circuit board 2 also has connection terminals 27 to which the positive and negative output tabs 14 of the laminated battery 1 connect. The circuit board 2 shown in Figures 4, 6, and 8 has connection terminals 27 on the surfaces of the straight sections 21 that are located on the terrace sections 15. The circuit board 2 shown in the figures has connection terminals 27 on the front side of the straight sections 21. When the straight sections 21 are stacked on the terrace sections 15 of the laminated battery 1, the output tabs 14 that extend from the terrace sections 15 on the back side of the straight sections 21 are connected to the connection terminals by folding back in a U-shape from the back side of the straight sections 21 to the front side. This structure has the advantage that the straight sections 21 also function as an insulating plate, allowing connection to the circuit board 2 while reliably preventing the metal output tabs 14 from coming into contact with the exposed metal parts of the exterior film 11 on the terrace sections 15 and causing a short circuit. The exterior film 11 of the laminated battery 1 is insulated by laminating insulating plastic films on both sides of the aluminum foil, but the aluminum foil is exposed at the cut surface, and there is a risk of the plastic film becoming partially non-insulated if it is damaged or perforated. This structure prevents the output tab 14 from coming into contact with the exterior film 11, thereby avoiding contact with the exposed metal parts of the exterior film 11.

[0048] Furthermore, with the above structure, the output tab 14 is connected to the circuit board 2 in a U-bent folded state, so that the output tab 14 can be connected to the circuit board 2 while being arranged in a space-saving manner, and it is possible to prevent the external size of the battery pack 100 from becoming larger. Note that in this specification, the term "U-bent" does not specifically refer to a state in which the output tab 14 is folded completely back into a U shape, but is used in a broad sense to include a state in which the output tab 14 is bent into a rectangular shape when viewed from the side, or a state in which the output tab is folded back in a partially curved or inclined state.

[0049] (Electronic Components 19) The circuit board 2 also mounts electronic components 19 that implement a protection circuit for the laminated battery 1. The protection circuit detects the temperature, voltage, current, and other factors of the laminated battery 1 and controls the charge and discharge current. To achieve this, the circuit board 2 mounts electronic components 19 such as a voltage detection circuit that detects the voltage of the laminated battery 1; current interruption devices such as breakers, PTC devices, and fuses that protect the laminated battery 1; a temperature sensor that detects the temperature of the laminated battery 1; and semiconductor switching devices such as FETs that control the current through the laminated battery 1. These electronic components 19 are fixed to the circuit board 2 and positioned in fixed positions. Examples of such electronic components 19 include protection devices such as current interruption devices.

[0050] (Reinforcing Plates 28) Furthermore, the circuit board 2 is provided with reinforcing plates 28 in parts of the straight sections 21 or parts of the detour sections 22. The circuit board 2 shown in Figures 8 and 9 has reinforcing plates 28 arranged on the undersides of the straight sections 21 and the connecting sections 24. The reinforcing plates 28 are provided to maintain the circuit board 2 in a predetermined shape, and are made of a hard plastic plate or a metal plate with an insulated surface. These reinforcing plates 28 are thin plates with widths approximately equal to the straight sections 21 and the connecting sections 24, and are fixed to the undersides of the straight sections 21 and the connecting sections 24 by adhesive or adhesion.

[0051] The reinforcing plate 28 fixed to the lower surface of the straight portion 21 is preferably disposed over an area that covers the rear side of the area where the connection terminals 27 and electronic components 19 are disposed. This protects the rear side of the welded portion between the output tab 14 and the connection terminal 27, which are connected by laser welding or the like, or reinforces the mounting portion of the electronic components 19 mounted on the flexible printed circuit board (FPC) 20. Furthermore, the reinforcing plate 28 fixed to the lower surface of the connecting portion 24 is disposed over, for example, substantially the entire lower surface of the connecting portion 24. As described above, the circuit board 2 having the reinforcing plate 28 on the lower surface of the straight portion 21 or the connecting portion 24 has the advantage that the rising portion 23 can be easily bent or curved relative to the straight portion 21 or the connecting portion 24 to which the reinforcing plate 28 is fixed, during the process of bending or curving the flat flexible printed circuit board (FPC) 20 shown in FIG. 9 . The reinforcing plate may also be fixed to the lower surface of the rising portion.

[0052] Furthermore, as shown in Figure 10, in a circuit board in which the connecting portion 24 is a curved surface with a central convexity or the entire detour portion is curved, a curved reinforcing plate 28 can be fixed to the underside of the connecting portion 24, or a curved reinforcing plate can be fixed to the underside of the entire detour portion. This structure has the advantage that the curved reinforcing plate 28 can maintain the detour portion 22, which is curved into a central convexity, in a predetermined shape.

[0053] (Terminal Portion 6) The circuit board 2 further includes a terminal portion 6. The terminal portion 6 is disposed so as to protrude from the circuit board 2. The terminal portion 6 is made of a flexible material, preferably a flexible printed circuit (FPC). In the example shown in FIG. 3, the circuit board 2 and the terminal portion 6 are integrally connected by a flexible printed circuit (FPC) 20. The terminal portion 6 shown in the figure is disposed on one edge side (the left end in the figure) of the circuit board 2. One end of the terminal portion 6 is connected to an electronic component 19 that implements a protection circuit, and the other end extends out of the battery pack 100, with a connector 61 connected to the tip. The terminal portion 6 shown in the figure is bent and extended to the outside of the battery pack 100. The connector 61 includes an output terminal for providing the output of the battery pack 100 to an external device to be powered, a signal terminal for exchanging signals with the external device, and the like. Although the terminal portion 6 is integrally connected to the circuit board 2 shown in the figure, the terminal portion may be a separate member from the circuit board and connected to the circuit board.

[0054] (Retaining Case 3) The retaining case 3 comprises a frame case portion 30 that holds the laminated battery 1 in place, and a cover case 40 that is connected to the end of the frame case portion 30 and protects the terrace portion 15 of the laminated battery 1 and the circuit board 2. The retaining case 3 shown in Figures 2 to 4 has an overall rectangular shape, with a storage portion 31 at the end along one side of the rectangle where the terrace portion 15 and circuit board 2 are located.

[0055] (Frame Case 30) The frame case 30 shown in Figures 2 to 4 is frame-shaped and holds the laminated battery 1 along its outer periphery. It has openings on both sides that expose the first and second main surfaces 1A and 1B of the laminated battery 1. The frame case 30 shown in the figures has insertion spaces 32 aligned along the extension of the circuit board 2, allowing two laminated batteries 1 to be inserted side-by-side. The two laminated batteries 1 are arranged side-by-side, with the output tabs 14 located on the terraces 15 of each laminated battery 1 connected to the circuit board 2. In the battery pack 100 shown in the figures, the two laminated batteries 1 are positioned opposite one side of the frame case 30 so that the terraces 15 of each laminated battery 1 are aligned in the same straight line. The frame case 30 holds the multiple laminated batteries 1 arranged on the same plane in place.

[0056] 2 to 4 includes side walls 33 that cover the side surfaces 1C of the laminated battery 1, end walls 34 that connect to one end of the side walls 33 and cover the second end surface 1E of the laminated battery 1, and a cover 35 that connects to the other end of the side walls 33 and faces the terraces 15. The frame case 30 shown in the figures has insertion spaces 32 for inserting the laminated batteries 1 inside the side walls 33 that cover both side surfaces 1C of the laminated battery 1 and the end walls 34 that cover the end surfaces 1D. The laminated batteries 1 inserted into each insertion space 32 are positioned in a fixed position by the side walls 33 and end walls 34, and the output tabs 14 located on the terraces 15 are positioned opposite a fixed position on the circuit board 2.

[0057] (Side Wall 33) The side wall 33 is positioned opposite the side 1C of the laminated battery 1, positioning and holding the side 1C of the laminated battery 1 in place. The side wall 33 shown in Figures 3 to 5 comprises a side wall 33A positioned opposite the outside of two adjacent laminated batteries 1, and an intermediate wall 33B positioned between the adjacent laminated batteries 1. Therefore, the two adjacent laminated batteries 1 are inserted into the insertion space 32 formed by the side wall 33A, intermediate wall 33B, and end wall 34. As shown in Figures 2 and 3, the frame case portion 30 into which the laminated battery 1 is inserted has the first main surface 1A of the laminated battery 1 exposed from an opening on one side of the insertion space 32 (the upper side in the figures), and the second main surface 1B of the laminated battery 1 exposed from an opening on the other side of the insertion space 32 (the lower side in the figures).

[0058] 4 to 6, the cover portion 35 is an end portion of the side wall portion 33, and is formed in a flat shape along the underside of the end portion where the terrace portion 15 is disposed. The cover portion 35 is in the shape of a thin plate, and supports the terrace portion 15 and the output tab 14 disposed on the upper surface while positioning them in the same plane.

[0059] (Connecting Blocks 36, Positioning Blocks 37) Furthermore, the cover portion 35 includes connecting blocks 36 at both ends to which the tips of the side wall portions 33A are connected, and a positioning block 37 at its middle portion to which the tips of the intermediate wall portions 33B are connected. The connecting blocks 36 and the positioning block 37 have a predetermined thickness and are integrally formed with the cover portion 35 and the side wall portions 33 to support the side wall portions 33 in an upright position. The connecting blocks 36 at both ends position the tips of the terrace portions 15 and also serve as members for connecting the cover case 40 (described later) in a fixed position. The intermediate positioning block 37 positions the tips of the terrace portions 15 and supports in a fixed position the detour portions 22 of the circuit board 2 that are arranged across adjacent terrace portions 15. The positioning block 37 shown in FIG. 5 is shaped to support the detour portions 22 from below. 5 is formed in a hexagonal shape when viewed from the front, and includes a horizontal surface 37a that supports the underside of the connecting portion 24, an inclined surface 37b that supports the underside of the inclined rising portion 23, and a vertical surface 37c that is formed in a vertical position relative to the cover portion 35. Note that this positioning block can be modified into various shapes depending on the shape of the detour portion.

[0060] (Cover Case 40) The cover case 40 is located at one end of the frame case portion 30 and covers and protects the terrace portion 15 of the laminated battery 1 and the area where the circuit board 2 is located. The cover case 40 is large enough to cover the end of the frame case portion 30 in which the circuit board 2 is housed, and is formed in a shape that extends in one direction along the extension direction of the set circuit board 2. The cover case 40 shown in Figures 3 and 6 includes a first plate portion 41 that is positioned horizontally facing the terrace portion 15, a second plate portion 42 that is connected vertically to one side of the first plate portion 41 and is positioned along the tip surface of the frame case portion 30, and end surface portions 43 that are connected vertically to both ends of the first plate portion 41 and the second plate portion 42. The cover case 40 shown in Figure 6 has a first plate portion 41 and a second plate portion 42 connected in an inverted L-shape in cross section, and forms a storage portion 31 for storing the circuit board 2 inside the first plate portion 41 and the second plate portion 42 while closing the end of the frame case portion 30.

[0061] The first plate 41 has its outer surface flush with the first main surface 1A of the laminated battery 1 and is connected to the frame case 30 in a fixed position with its inner surface abutting the upper surface of the connecting block 36. A gap 38 is provided between the inner surface of the first plate 41 and the horizontal surface 37a, which is the upper surface of the positioning block 37, to accommodate the connecting portion 24 of the bypass section 22. The second plate 42 is connected to the frame case 30 in a fixed position with its inner surface abutting the leading edge of the connecting block 36 or the leading edge of the positioning block 37. Furthermore, the cover case 40 is connected to the frame case 30 in a fixed position by fitting its end surface portions 43 at both ends into fitting portions 36a on both sides of the connecting block 36. When the cover case 40 is connected to the frame case 30 in a fixed position, the second plate 42 forms one end surface of the holder case 3, facing the end wall portion 34 of the frame case 30. The cover case 40 is fixed in a fixed position on the frame case part 30 by adhesive, a locking structure, or a fitting structure. At this time, the terminal part 6 drawn out from the circuit board 2 is drawn out to the outside through a drawer gap or a drawer opening provided at the boundary between the cover case 40 and the frame case part 30.

[0062] The above-described holding case 3 is composed of a frame case 30, which is formed by integrally molding the side wall 33, end wall 34, and cover 35 from plastic, and a cover case 40 connected to the frame case 30 and cover 35. The plastic used to form the holding case 3 is a resin with excellent heat resistance and strength, such as polycarbonate. Polycarbonate is characterized by its ease of molding and excellent strength. Furthermore, because polycarbonate has excellent flame retardancy, even when used as the material for the holding case 3, a thickness as thin as 0.8 mm can still meet flame retardancy standards set by UL standards and other standards. Therefore, polycarbonate allows the holding case to be made thinner while maintaining its flame retardancy, thereby enabling the battery pack to be made more compact. However, the plastic used for the holding case 3 is not limited to polycarbonate, as other plastics can also be used.

[0063] (Exterior Label 5) The exterior label 5 is a plastic sheet with an adhesive layer on its inner surface. The exterior label 5 in FIG. 2 includes a first label 5A and a second label 5B, each attached to both sides of the holding case 3. The first label 5A is attached to the upper surface of the holding case 3, on the first main surface 1A of the laminated battery 1, and the second label 5B is attached to the lower surface of the holding case 3, on the second main surface 1B of the laminated battery 1. The first label 5A has multiple fold-back strips 51 on its four sides, which are folded back around the outer periphery of the holding case 3 and attached to the lower surface of the holding case 3. The second label 5B is attached so that its outer shape conforms to the outer shape of the holding case 3, overlapping the fold-back strips 51 of the first label 5A attached to the lower surface of the holding case 3.

[0064] The battery pack 100 shown in Figure 2 has two labels, a first label 5A and a second label 5B, attached to both sides of the holding case 3. Although not shown, the battery pack can also be configured with the first and second labels as a single label that is folded back in the middle and attached to both sides of the holding case. This label can have an opening between the first and second labels that exposes the protruding portion of the holding case.

[0065] (Another Example of Circuit Board) As shown in Fig. 9, the above-described circuit board 2 is configured such that a single flexible printed circuit (FPC) 20 cut into a long, narrow strip is bent or curved to form a detour section 22, and this detour section 22 detours around the upper end of the standing wall 16. However, as shown in Figs. 11 and 12, the circuit board 2 can also be configured such that a single flexible printed circuit (FPC) 20 cut into a predetermined shape is bent or curved to detour around the tip end of the standing wall 16. Fig. 11 shows a state in which the circuit board is arranged on a terrace section, and Fig. 12 is a developed view of the circuit board, showing an example of a flexible printed circuit (FPC) 20 cut into a predetermined shape.

[0066] The detour portion 22 of the circuit board 2 shown in Figure 11 includes a pair of rising portions 23 connected to the opposing edges of adjacent straight portions 21 and each rising in the direction of the rising wall 16, and a connecting portion 24 whose both ends are connected to the side edges of the pair of rising portions 23. The connecting portion 24 is bent or curved in the horizontal plane relative to the pair of rising portions 23 and is disposed opposite the leading edge of the rising wall 16. Therefore, a gap (not shown) for locating the connecting portion 24 of the circuit board 2 is formed between the leading end surface of the positioning block 37 of the frame case portion 30 and the second plate portion 42 of the cover case 40. The circuit board 2 shown in Figure 11 is formed into the three-dimensional shape shown in Figure 11 by bending or curving a flexible printed circuit (FPC) 20 cut to a predetermined outline as shown in Figure 12.

[0067] The flexible printed circuit board (FPC) 20 shown in Figure 12 is a developed view in which two straight portions 21, each having a rectangular rising portion 23 connected to its end edge, are arranged in a parallel orientation, and the side edges of the pair of rising portions 23 are connected to both end edges of a rectangular connecting portion 24. As shown in Figure 12, this flexible printed circuit board (FPC) 20 is valley-folded at a boundary 25 (shown by a dashed line in the figure) between the straight portions 21 and the rising portions 23, and mountain-folded at a boundary 26 (shown by a dashed line in the figure) between the rising portions 23 and the connecting portion 24, so that a detour portion 22 formed by the rising portions 23 and the connecting portion 24 protrudes three-dimensionally from the planar straight portions 21. In the circuit board 2 shown in Figure 11, the detour portion 22 has a U-shape in plan view, and is shaped to detour around the tip side of the upright wall 16. 11 is arranged by positioning a pair of rising portions 23 and a connecting portion 24 along the outer peripheral surface of a rectangular prism-shaped positioning block 37 provided on the cover portion 35. For example, the length (L3) of the rising portions 23 and the width (S) of the connecting portion 24 of this detouring portion 22 can be made approximately equal to the height (h) of the upright wall 16. This circuit board 2 can be formed by cutting the unfolded flexible printed circuit (FPC) 20 while shortening its overall length, thereby forming a circuit board in which the straight portions and the detouring portions are integrally connected.

[0068] However, the shape of the developed view of the circuit board 2 in which the detour portion 22 detours around the tip side of the upright wall 16 is not limited to the shape shown in Fig. 12. As shown in Fig. 13, the circuit board 2 can also have a developed view in which straight portions 21 to which rising portions 23 are connected are connected at an angle (θ) with respect to the connecting portion 24. In a flexible printed circuit (FPC) 20 of this shape, the boundary line 25 between the straight portions 21 and the rising portions 23 is an inclined line that is angled with respect to the extension direction of the straight portions 21, and the rising portions 23 are triangular or have a shape that combines a triangle and a sector, and are connected to the side edges of the rectangular connecting portions 24. The flexible printed circuit board (FPC) 20 shown in this developed view is valley-folded at a boundary line 25 (shown by a dashed dotted line in the figure) between the straight portion 21 and the rising portion 23, and mountain-folded at a boundary line 26 (shown by a dashed two-dot line in the figure) between the rising portion 23 and the connecting portion 24, so that the detour portion 22 formed by the rising portion 23 and the connecting portion 24 has a shape that protrudes three-dimensionally from the planar straight portion 21 and detours around the tip end side of the rising wall 16, as shown in Figure 14. In this way, the shape of the developed view of the circuit board 2 in which the detour portion 22 detours around the tip end side of the rising wall 16 can be selected and designed to make effective use of the flexible printed circuit board (FPC).

[0069] Furthermore, the detour portion 22 of the circuit board 2 may have a shape shown in FIG. 15 . The detour portion 22 of the circuit board 2 shown in FIG. 15 includes a pair of rising portions 23 connected to the side edges of adjacent straight portions 21 and raised in the direction of raising the upright wall 16, and a connecting portion 24 whose both ends are connected to the side edges of the pair of rising portions 23. The connecting portion 24 is flush with the pair of rising portions 23 and is disposed opposite the leading edge of the upright wall 16. That is, the pair of rising portions 23 and the connecting portion 24 form a flat-plate-like connected detour portion 22, which is bent in an L-shape relative to the straight portions 21 and connects adjacent straight portions 21 at their opposing side edges. The adjacent straight portions 21 are connected by a separation gap 29, and the detour portion 22 is disposed on the leading edge side of the upright wall 16 in a state where the upright wall 16 is guided into the separation gap 29 to detour.

[0070] Fig. 16 shows a development of the circuit board shown in Fig. 15. The flexible printed circuit (FPC) 20 shown in this development can be realized as a simple structure in which two elongated, strip-like straight portions 21 are linearly arranged with a separating gap 29 provided, and the side edges of the opposing ends are connected by a single elongated detour portion 22. By valley-folding this flexible printed circuit (FPC) 20 at the boundary line 25 (shown by a dashed line in the figure) between the straight portions 21 and the detour portion 22, as shown in Fig. 15, the detour portion 22 can be made to protrude three-dimensionally from the planar straight portion 21 and to detour around the tip end of the upright wall 16.

[0071] Furthermore, the detour portion 22 of the circuit board 2 may have a shape shown in Fig. 17. The detour portion 22 of the circuit board 2 shown in Fig. 17 includes a pair of rising portions 23 connected to the side edges of adjacent straight portions 21 and raised in the rising direction of the upright wall 16, and a connecting portion 24 whose both side edges are connected to the upper edges of the pair of rising portions 23. The connecting portion 24 is bent with respect to the pair of rising portions 23 and disposed opposite the upper edge of the upright wall 16. The adjacent straight portions 21 are connected to the detour portion 22 by providing a separation gap 29, and the detour portion 22 is disposed on the upper end side of the upright wall 16 in a state in which the upright wall 16 is guided into this separation gap 29 to detour around it.

[0072] 18 is a development view of the circuit board shown in FIG. 17 . The flexible printed circuit (FPC) 20 shown in this development has two elongated, strip-like linear portions 21 linearly arranged with a separation gap 29 between them, with rectangular rising portions 23 connected to the side edges of the opposing ends, and with a rectangular connecting portion 24 connected to the side edges of the upper ends (right ends in the figure) of the pair of rising portions 23. By valley-folding this flexible printed circuit (FPC) 20 at a boundary 25 (shown by a dashed line in the figure) between the linear portions 21 and the rising portions 23, the rising portions 23 are positioned so as to protrude three-dimensionally from the planar linear portions 21, as shown in FIG. 17 . By valley-folding at a boundary 26 (shown by a dashed line in the figure) between the rising portions 23 and the connecting portion 24, the connecting portion 24 is bent relative to the rising portions 23, and the connecting portion 24 is positioned horizontally, thereby bypassing the upper end of the upright wall 16. A circuit board 2 with this structure has the advantage that even if the thickness (t) of the laminated battery 1 is small and the length (L3) of the rising portion 23 cannot be increased, the width (S) of the rising portion 23 and the connecting portion 24 can be made sufficiently wide to ensure space for wiring.

[0073] (Embodiment 2) Furthermore, as shown in Figure 19, the battery pack of the present invention can also include three laminate batteries 1 arranged side by side. The holding case 3 of this battery pack 200 has three insertion spaces 32 for inserting each laminate battery 1 inside the side wall portions 33 that cover both side surfaces 1C of the laminate battery 1 and the end wall portion 34 that covers the second end surface 1E. Of the three adjacent laminate batteries 1, the laminate batteries 1 on both sides are inserted into the insertion spaces 32 formed by the side wall portions 33A, middle wall portions 33B, and end wall portions 34, while the middle laminate battery 1 is inserted into the insertion space 32 formed by the pair of middle wall portions 33B and end wall portions 34.

[0074] 19, a battery pack 200 with this structure includes a circuit board 2 arranged across the terrace portions 15 of three laminate batteries 1. The circuit board 2 includes three straight sections 21 stacked on each terrace portion 15, and detour sections 22 arranged between adjacent straight sections 21 to connect them. The circuit board 2 is also arranged in a space-saving manner, with the three straight sections 21 stacked on each terrace portion 15, with the detour sections 22 avoiding the upright walls 16 that protrude between adjacent terrace portions 15. The three laminate batteries 1 are connected to each other in series or in parallel via the circuit board 2, and are output to the outside through the terminal section 6.

[0075] The battery pack 100 shown in Figures 1 to 4 is assembled in the following steps: 1. The laminated battery 1 is placed in the insertion space 32 of the frame case portion 30 of the holding case 3. In the holding case 3 shown in the figures, two laminated batteries 1 are placed in their designated positions in the insertion space 32 of the frame case portion 30. 2. The circuit board 2 is placed on the terrace portion 15 of the two laminated batteries 1 placed in the frame case portion 30. The circuit board 2 is placed so that each straight portion 21 is stacked on the terrace portion 15, and the detour portion 22 is positioned in the boundary area between adjacent terrace portions 15, facing the upright wall 16. The detour portion 22 is positioned along the positioning block 37, and the circuit board 2 is set in its designated position. 3. The output tab 14, which is pulled out from the back side of the straight portion 21, is bent in a U-shape at the side edge of the straight portion 21 and folded back, and connected to the connection terminal 27 on the front side of the straight portion 21. The output tab 14 is connected to the connection terminal 27 by laser welding or other means. 4. The circuit board 2 connected to the laminated battery 1 is covered with a cover case 40. The cover case 40 is positioned so that the inner surface of the second plate portion 42 is aligned with the leading edge of the frame case portion 30, and the outer surface of the first plate portion 41 is flush with the first main surface 1A of the laminated battery 1. The cover case 40 is fixed in place in the frame case portion 30 by adhesive, a locking structure, or a fitting structure. 5. A first label 5A is affixed to the top surface of the holding case 3 holding the laminated battery 1 in place, facing the first main surface 1A of the laminated battery 1. The first label 5A is affixed to the second main surface 1B of the laminated battery 1 on the back side of the holding case 3 by folding back the multiple fold-back pieces 51 protruding from the outer edge of the holding case 3 at the outer edge. 6. A second label 5B is then affixed to the underside of the holding case 3 to which the first label 5A was affixed. The second label 5B is attached so that its outer periphery coincides with the outer periphery of the holding case 3.

[0076] The battery pack of the present invention is conveniently used by being built into portable electronic devices such as notebook computers, tablets, smartphones, and game devices.

[0077] DESCRIPTION OF SYMBOLS 100, 200...Battery pack 1...Laminated battery 1A...First main surface 1B...Second main surface 1C...Side surface 1D...First end surface 1E...Second end surface 2...Circuit board 3...Retaining case 5...Exterior label 5A...First label 5B...Second label 10...Battery body 11...Exterior film 11A...First exterior film 11B...Second exterior film 12...Peripheral sealing portion 13...Electrode body 14...Output tab 15...Terrace portion 16...Upright wall 17...Resin tab 19...Electronic component 20...Flexible printed circuit board 21...Straight portion 22...Detour portion 23...Upright portion 24...Connecting portion 25...Boundary line 26...Boundary line 27...Connection terminal 28...Reinforcing plate 29...Separation gap 30...Frame case portion 31...Storage portion 32...Insertion space 33...Side wall portion 33A...Side wall portion 33B...Intermediate wall portion 34...End wall portion 35...Cover portion 36...Connecting block 37...Positioning block 37a...Horizontal surface 37b...Inclined surface 37c...Vertical surface 38...Gap 40...Cover case 41...First plate portion 42...Second plate portion 43...End surface portion 61...Connector 90...Battery pack 91...Laminated battery 92...Circuit board 95...Terrace portion 96...Upright wall

Claims

1. A battery comprising: two or more laminate batteries packaged in an exterior film; and a circuit board connected to the two or more laminate batteries and arranged in a fixed position, wherein each of the two or more laminate batteries comprises: a terrace portion formed by the peripheral sealing portion of the exterior film along the long side of a first end face, from which an output tab is pulled out; and a standing wall connected to both ends of the terrace portion and standing along the short side of the first end face, wherein each of the two or more adjacent laminate batteries is arranged side by side with the terrace portions aligned in a straight line in the longitudinal direction, and the circuit board comprises: a straight portion stacked on the terrace portion along the longitudinal direction of the terrace portion and to which the output tab is connected; and a detour portion arranged in the boundary region between the terrace portions of each of the two or more adjacent laminate batteries and detours around the standing wall, wherein the detour portion comprises: a pair of standing portions each standing in the rising direction of the standing wall from the opposing ends of the straight portions of each of the two or more adjacent laminate batteries, a connecting portion disposed opposite the upper end edge or tip edge of the upright wall and connecting the pair of upright portions together, wherein the straight portions of each of the two or more adjacent laminate batteries are integrally connected to each other by the detour portion.

2. A battery pack as described in claim 1, wherein the circuit board is a single flexible printed circuit board that is bent or curved, and the straight section and the detour section are integrally formed.

3. A battery pack as described in claim 2, wherein the circuit board is formed by bending or curving a long, thin, strip-shaped flexible board to form the pair of rising parts connected to the straight part and the connecting part connected to the pair of rising parts, and the connecting part is disposed opposite the upper edge of the upright wall.

4. A battery pack as described in claim 3, wherein the detour section has an isosceles trapezoidal shape when viewed from the front, and the pair of rising sections are connected at an obtuse angle to the straight section, and the pair of rising sections are connected at an obtuse angle to the connecting section.

5. A battery pack as described in claim 3, wherein the connecting portion is a curved surface that is curved so that the center is convex, and the detour portion is any one of a mountain shape, a circular arc shape, a parabolic shape, and an arch shape when viewed from the front.

6. A battery pack as described in claim 2, wherein the detour section comprises a pair of rising sections connected to opposing end edges of adjacent straight sections, and a connecting section having both end edges connected to side edges of the pair of rising sections, the connecting section being bent or curved relative to the pair of rising sections and positioned opposite the tip edges of the rising walls.

7. A battery pack as described in claim 2, wherein the bypass portion comprises a pair of rising portions each connected to the side edges of the straight portions of each of the two or more adjacent laminated batteries, and the connecting portion has both end edges connected to the side edges of the pair of rising portions, the connecting portion being flush with the pair of rising portions and positioned opposite the tip edges of the rising walls.

8. A battery pack as described in claim 2, wherein the bypass portion comprises a pair of rising portions each connected to the side edges of the straight portions of each of the two or more adjacent laminated batteries, and the connecting portion has a side edge connected to the upper edge of the pair of rising portions, and the connecting portion is in a bent position relative to the pair of rising portions and is positioned opposite the upper edge of the standing wall.

9. A battery pack as described in any one of claims 1 to 8, wherein the output tab pulled out from the terrace portion is folded back from the back side of the straight portion arranged on the terrace portion to the front side and connected to the front side of the straight portion.

10. A battery pack according to any one of claims 1 to 8, wherein the circuit board is provided with a reinforcing plate on a part of the straight section or a part of the roundabout section.

11. A battery pack as described in any one of claims 1 to 8, further comprising a holding case that holds the two or more laminate batteries in a fixed position, the holding case comprising a frame case portion having an opening that exposes a first main surface and a second main surface of each of the two or more laminate batteries, the frame case portion comprising: a plurality of side wall portions covering both side surfaces of each of the two or more laminate batteries; an end wall portion connected to one end of the plurality of side wall portions and covering a second end surface opposite the first end surface of each of the two or more laminate batteries; and a plate-shaped cover portion connected to the other end of the plurality of side wall portions and positioned opposite the back surface of the terrace portion of each of the two or more laminate batteries, the cover portion comprising a positioning block that holds the detour portion of the circuit board in a fixed position.

12. A battery pack as described in claim 11, wherein the plurality of side wall portions comprise side wall portions disposed on the sides of the battery pack, and intermediate wall portions disposed between the two or more adjacent laminate batteries, and the tip of the intermediate wall portion is connected to the positioning block.

13. A battery pack as described in claim 11, wherein the holding case comprises a cover case covering the terrace portion and the circuit board of each of the two or more laminated batteries, the cover case comprising: a first plate portion arranged opposite the terrace portion of each of the two or more laminated batteries; and a second plate portion formed in a bent position relative to the first plate portion and arranged on the tip surface of the frame case portion, the second plate portion constituting an end surface of the holding case that faces the end wall portion of the frame case portion.

Images