JP2013025951A - Battery unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a configuration such that the downsizing of a battery unit having a flat-type battery and a substrate is achieved while securing electrical connection between the flat-type battery and the substrate by applying various measures to a connection structure between the battery and the substrate.SOLUTION: A battery unit (1) includes: a flat-type battery (2) having a bottomed cylindrical positive electrode can (10) (outer can) and a bottomed cylindrical negative electrode can (20) (sealing can) covering an opening side of the positive electrode can (10); a circuit board (61) (substrate) which is fixed to a plane part (21) of the negative electrode can (20) and on which a circuit component (62) is mounted; and battery-side positive electrode terminals (82) (connection members) which are disposed between the flat-type battery (2) and the circuit board (61) and electrically connect the flat-type battery (2) and the circuit board (61). The battery-side positive electrode terminals (82) can be elastically deformed in the lamination direction of the flat-type battery (2) and the circuit board (61).

Description

  The present invention relates to a battery unit including a flat battery and a substrate.

  Conventionally, a configuration in which a battery and a protection circuit or the like are unitized is known. As such a configuration, for example, as disclosed in Patent Document 1, a configuration in which a protection circuit or the like is arranged on a battery case is known.

JP 2009-152183 A

  By the way, in the structure of the above-mentioned patent document 1, since the size of the battery itself is relatively large, even if the connection structure between the battery and the protection circuit or the like is somewhat large, the size of the battery pack is not significantly affected. do not do.

  On the other hand, since a device using a substantially circular flat battery is generally small, when a substantially cylindrical battery unit is configured using the flat battery, the battery unit is also small. Is required. In such a battery unit, the size of the battery unit increases due to the provision of the substrate on which the protection circuit and the like are formed, and the size of the entire battery unit may change depending on the connection structure between the flat battery and the substrate. is there.

  Here, in order to make the size of the battery unit as small as possible, it is preferable to connect the flat battery and the substrate with as small a terminal as possible. However, when such a small terminal is used, the contact between the terminal and the flat battery and the substrate becomes unstable, and the resistance may increase.

  Therefore, in the present invention, in a battery unit having a flat battery and a substrate, the connection structure between the flat battery and the substrate is devised to ensure electrical connection between the battery and the substrate. It aims at obtaining the structure which can achieve size reduction.

  A battery unit according to an embodiment of the present invention includes a bottomed cylindrical outer can and a bottomed cylindrical sealing can that covers the opening side of the outer can, and the opening side of the side wall of the outer can is the side A flat battery formed by combining the outer can and the sealing can so as to be positioned on the outer periphery of the side wall of the sealing can, a substrate fixed to the flat portion of the sealing can, and mounted with circuit components; A connecting member that is disposed between the flat battery and the substrate and electrically connects the flat battery and the substrate; and the connecting member is elastic in a stacking direction of the flat battery and the substrate. It is configured to be deformable (first configuration).

  With the above configuration, the flat battery and the substrate can be electrically connected by the connecting member disposed between the flat battery and the substrate. Thereby, since a connection member does not protrude outside a flat battery, size reduction can be achieved as the whole battery unit.

  In addition, since the connecting member is configured to be elastically deformable in the stacking direction of the flat battery and the substrate, the connecting member is more reliably brought into contact with the flat battery and the substrate by the elastic restoring force of the connecting member. Can be made. Thereby, the electrical connection of a flat battery and a board | substrate is securable with a connection member.

  Therefore, with the above configuration, the battery unit as a whole can be reduced in size while ensuring electrical connection between the flat battery and the substrate.

  In the first configuration, the connection member is formed in the shape of a coil spring, and is arranged in a compressed state between the flat battery and the substrate (second configuration).

  Thereby, a connection member can be made to contact a flat battery and a board | substrate more reliably. That is, since the connecting member is a spring member that can be expanded and contracted, when it is arranged in a compressed state between the flat battery and the substrate, both ends of the connecting member are brought into contact with the flat battery and the substrate by elastic restoring force. Pressed. Thereby, a flat battery and a board | substrate can be electrically connected more reliably by a connection member.

  In the first or second configuration, the connection member is fixed to at least one of the flat battery and the substrate by a conductive adhesive (third configuration). By doing so, the connecting member can be more reliably electrically connected to at least one of the flat battery and the substrate.

  In any one of the first to third configurations, a plurality of connection members are provided between the flat battery and the substrate (fourth configuration). Thereby, a flat battery and a board | substrate can be electrically connected more reliably by several connection members.

  In any one of the first to fourth configurations, the connection member is configured to electrically connect an opening side of a side wall of an exterior can in the flat battery and the substrate. It arrange | positions between the opening part side of the side wall of a can, and the said board | substrate (5th structure).

  Thus, the connecting member can electrically connect the outer can of the flat battery and the substrate disposed on the sealing can side, so that the connection structure between the flat battery and the substrate can be made simple and compact. it can. Therefore, the battery unit can be reduced in size by the above-described configuration.

  According to the battery unit of one embodiment of the present invention, the flat battery and the substrate are electrically connected by the connecting member that is elastically deformable in the stacking direction of the flat battery and the substrate. Thereby, size reduction of a battery unit can be achieved, ensuring the electrical connection of a flat battery and a board | substrate.

FIG. 1 is a cross-sectional view of components other than a flat battery in the battery unit according to the first embodiment. FIG. 2 is a top view of the battery unit. FIG. 3 is a cross-sectional view of components other than the electrode body in the flat battery. FIG. 4 is a plan view of the circuit board. FIG. 5 is a perspective view showing a state in which a battery-side negative electrode terminal is attached by overlapping spacers on the negative electrode can of the flat battery. FIG. 6 is a top view showing a state in which a circuit board is overlaid on the configuration of FIG. FIG. 7 is a partially enlarged cross-sectional view showing a schematic configuration of the battery-side positive terminal in the battery unit. FIG. 8 is a cross-sectional view showing a schematic configuration of a manufactured circuit board in an example of a battery unit manufacturing method. FIG. 9 is a diagram illustrating a state in which a battery-side positive terminal is attached after a spacer and a battery-side negative terminal are attached to a flat battery in an example of a battery unit manufacturing method. FIG. 10 is a cross-sectional view showing a state in which a circuit board is mounted on a spacer in an example of a battery unit manufacturing method. FIG. 11 is a view corresponding to FIG. 1 of the battery unit according to the second embodiment. FIG. 12 is a top view showing a schematic configuration of the spacer. FIG. 13 is a perspective view showing a state in which a battery-side positive terminal and a battery-side negative terminal are attached by overlapping spacers on the negative electrode can of the flat battery. FIG. 14 is a plan view showing a schematic configuration of the battery-side positive terminal. FIG. 15 is a view corresponding to FIG. 7 illustrating a schematic configuration of the battery-side negative electrode terminal in the battery unit. FIG. 16 is a perspective view showing a state in which a battery-side positive terminal and a battery-side negative terminal are attached by overlapping spacers on a negative electrode can of a flat battery in a battery unit according to another embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

<Embodiment 1>
(overall structure)
FIG. 1 is a diagram showing a schematic configuration of a battery unit 1 according to Embodiment 1 of the present invention. The battery unit 1 is a unit in which a coin-shaped flat battery 2 and a circuit unit 3 are integrated. The battery unit 1 is used as a power source for small devices using a coin-type battery, such as a pedometer, a hearing aid, an automobile electronic key, an IC tag, and a sensor unit. The battery unit 1 is a secondary battery unit that can charge the flat battery 2.

  Specifically, as shown in FIG. 1, in the battery unit 1, the circuit unit 3 is bonded and fixed on the flat battery 2 by, for example, an elastic adhesive. The circuit unit 3 has the same shape and size as the outer shape of the flat battery 2 when viewed from the stacking direction of the flat battery 2 and the circuit unit 3. As a result, the flat battery 2 and the circuit unit 3 are arranged compactly in the thickness direction, and the size of the battery unit 1 is viewed from the stacking direction of the flat battery 2 and the circuit unit 3, and the outer shape of the flat battery 2. Can be made the same size. In addition, by using an elastic adhesive for adhesion between the flat battery 2 and the circuit portion 3, even when members having different amounts of thermal deformation are connected, the members can be more reliably bonded with the elastic adhesive. .

  Moreover, although mentioned later in detail, the various terminals 66-69 mentioned later are formed in the surface on the opposite side to the flat battery 2 in the circuit board 61 of the circuit part 3 (for example, refer FIG. 2). Thereby, in the battery unit 1, only the various terminals 66 to 69 are exposed as shown in FIG. 2 in a state where the flat battery 2 and the circuit unit 3 are combined as shown in FIG. 1.

  Further, as shown in FIG. 1, the side surface of the laminate formed by fixing the flat battery 2 and the circuit portion 3 in a laminated state is a resin material that shrinks by heat, such as PET (polyethylene terephthalate). It is covered with the tube 4 which consists of. The tube 4 covers not only the side surface of the laminated body but also the outer peripheral side of the both end faces of the laminated body (the outer peripheral side of the circuit board 61 of the circuit unit 3 and the outer peripheral side of the bottom surface of the outer can 10 of the flat battery 2). . Thereby, while improving the intensity | strength of the said laminated body, the external appearance of the side surface of this laminated body can also be improved. Further, since a step is formed on the end surface of the laminated body by the thickness of the tube 4, various terminals 66 to 69 formed on the outer surface of the circuit unit 3 positioned on the end surface of the laminated body are provided from the tube 4. Is also located inward in the stacking direction. Thereby, various terminals 66-69 become difficult to receive damage.

  Below, the structure of the flat battery 2 is demonstrated using FIG.

  As shown in FIG. 3, the flat battery 2 includes a positive electrode can 10 as a bottomed cylindrical outer can, a negative electrode can 20 as a sealing can covering the opening of the positive electrode can 10, and an outer peripheral side of the positive electrode can 10. And the outer periphery of the negative electrode can 20, and an electrode body 40 accommodated in a space formed between the positive electrode can 10 and the negative electrode can 20. Therefore, the flat battery 2 is formed into a flat coin shape by combining the positive electrode can 10 and the negative electrode can 20 together. In the space formed between the positive electrode can 10 and the negative electrode can 20, in addition to the electrode body 40, a nonaqueous electrolytic solution (not shown) is also enclosed. In the present embodiment, the flat battery 2 is configured as a lithium ion battery.

  The positive electrode can 10 is made of a metal material such as stainless steel, and is formed into a bottomed cylindrical shape by press molding. As shown in FIG. 3, the positive electrode can 10 includes a circular bottom portion 11, and a cylindrical peripheral wall portion 12 (side wall) formed continuously with the bottom portion 11 on the outer periphery thereof. The peripheral wall portion 12 is provided so as to extend substantially vertically from the outer peripheral end of the bottom portion 11 in a longitudinal sectional view (the state illustrated in FIG. 1). As described later, the positive electrode can 10 is crimped to the negative electrode can 20 by bending the opening end side of the peripheral wall portion 12 inward with the gasket 30 sandwiched between the positive electrode can 20 and the negative electrode can 20. Therefore, the bottom 11 of the positive electrode can 10 constitutes the bottom surface of the flat battery 2.

  Similarly to the positive electrode can 10, the negative electrode can 20 is made of a metal material such as stainless steel and is formed in a bottomed cylindrical shape by press molding. As shown in FIG. 3, the negative electrode can 20 includes a cylindrical peripheral wall portion 22 (side wall) whose outer shape is smaller than that of the peripheral wall portion 12 of the positive electrode can 10, and a circular flat portion 21 that closes one of the openings. Have. Therefore, the flat part 21 of the negative electrode can 20 constitutes the upper surface of the flat battery 2.

  Similar to the positive electrode can 10, the peripheral wall portion 22 of the negative electrode can 20 is also provided so as to extend substantially perpendicular to the flat surface portion 21 in a longitudinal sectional view. The peripheral wall portion 22 is formed with an enlarged diameter portion 22b whose diameter is increased stepwise compared to the base end portion 22a on the flat surface portion 21 side. That is, the peripheral wall portion 22 is formed with a step portion 22c between the base end portion 22a and the enlarged diameter portion 22b. As shown in FIG. 3, the open end side of the peripheral wall portion 12 of the positive electrode can 10 is bent and caulked with respect to the step portion 22c. That is, the positive electrode can 10 has the opening end side of the peripheral wall portion 12 fitted to the step portion 22 c of the negative electrode can 20.

(Configuration of the circuit part)
As shown in FIG. 1, the circuit unit 3 includes a circuit board 61 (board) and a plurality of circuit components 62 mounted on the circuit board 61. The plurality of circuit components 62 are mounted together on one side of the circuit board 61. Examples of the circuit component 62 include a protection IC that forms a protection circuit, a charging IC that forms a charging circuit, and a DC / DC converter that performs voltage conversion. By providing this DC / DC converter in the battery unit 1, even if the rated voltage of the flat battery 2 is different from the rated voltage of the electric device to be used, the battery unit is matched to the rated voltage of the electric device. 1 can output a voltage. Therefore, the battery unit 1 can be configured using flat batteries having various rated voltages. Although not described in detail, the circuit unit 3 is configured to change the output voltage when the remaining capacity of the flat battery 2 decreases in order to detect the remaining capacity of the flat battery 2. .

  As shown in FIGS. 1, 2, and 4, the circuit board 61 is formed to have a shape (circular shape) and size equivalent to the outer shape of the flat battery 2 in plan view. Thereby, the circuit board 61 can prevent the battery unit 1 from becoming larger than the diameter of the flat battery 2.

  As shown in FIGS. 2 and 4, the circuit board 61 is provided with two substantially semicircular cutout portions 61 a on the outer peripheral portion thereof. In each notch 61a, a board-side terminal 63 is formed on the side surface of the circuit board 61 by, for example, tin plating. The board-side terminal 63 provided in each notch 61a is electrically connected to a circuit (not shown) constituted by circuit components 62 mounted on the circuit board 61, although not particularly shown.

  As described above, by providing the circuit board 61 with the substantially semicircular cutout portion 61a, the board-side terminal 63 formed on the cutout portion 61a and the battery-side negative electrode terminal of the flat battery 2 described later. When soldering 81, solder becomes easy to spread. Thereby, the board | substrate side terminal 63 of the circuit board 61 and the battery side negative electrode terminal 81 of the flat battery 2 can be more reliably connected with solder.

  As shown in FIG. 2, each notch 61 a is covered with a tube 4 that covers the side surface of the stacked body of the flat battery 2 and the circuit unit 3. Thereby, it can prevent that the board | substrate side terminal 63 provided in the notch part 61a is exposed.

  As shown in FIGS. 1, 2, 4, and 6, a GND terminal 66, an output terminal 67, a charging terminal 68, and a charging display signal terminal are provided on the surface of the circuit board 61 on which the circuit component 62 is not mounted. 69 is provided. That is, as shown in FIG. 1, a plurality of circuit components 62 are mounted on one surface side of the circuit board 61, and various terminals 66 to 69 are collectively provided on the other surface side. The circuit board 61 has a plurality of through-holes, and a circuit (not shown) formed by the circuit components 62 on the circuit board 61 and various kinds of metal materials filled in the through-holes. Terminals 66 to 69 are electrically connected. The various terminals 66 to 69 may be arranged other than those shown in FIGS. 2, 4, and 6.

  As described above, the circuit (not shown) constituted by the circuit component 62 and the various terminals 66 to 69 are electrically connected to the circuit board 61 and the circuit on the circuit board 61 and the circuit on the circuit board 61 as described above. By electrically connecting (not shown), the various terminals 66 to 69 and the board-side terminal 63 can be electrically connected. Thereby, as will be described later, by connecting the battery-side negative terminal 81 of the flat battery 2 to the substrate-side terminal 63, the flat battery 2 and the various terminals 66 to 69 can be electrically connected.

  The GND terminal 66, the output terminal 67, the charging terminal 68, and the charging display signal terminal 69 are arranged on the end surface of the stacked body so as not to overlap the tube 4 that covers the side surface of the stacked body of the flat battery 2 and the circuit unit 3. The circuit board 61 is formed on the radially inner side of the tube 4 positioned.

  As shown in FIG. 1, the circuit board 61 is held on the negative electrode can 20 of the flat battery 2 via a spacer 71. Specifically, the circuit board 61 is bonded and fixed to the negative electrode can 20 by an elastic adhesive in a state where the circuit board 61 is arranged at a predetermined distance from the negative electrode can 20 of the flat battery 2 by the spacer 71. Yes. That is, the elastic adhesive is filled between the circuit board 61 and the negative electrode can 20 of the flat battery 2. In this way, by providing the circuit board 61 on the negative electrode can 20 that is unlikely to be deformed in the flat battery 2, even when the flat battery 2 is deformed, the circuit portion 3 and the flat battery 2 are electrically connected. Secure connection.

  The spacer 71 is a member made of a resin material such as ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin) or phenol resin, and has a substantially donut shape. As shown in FIG. 1, the spacer 71 has a thick outer peripheral portion along the step portion so as to fill the step portion between the negative electrode can 20 and the positive electrode can 10 of the flat battery 2. Yes. That is, the spacer 71 is formed so that the outer peripheral side portion extends to a caulking portion (hereinafter also referred to as a shoulder portion) of the positive electrode can 10 with the negative electrode can 20.

  The spacer 71 has a thickness such that a predetermined interval is formed between the flat battery 2 and the circuit board 61 so that the circuit component 62 does not contact the flat battery 2 (see FIG. 1). As a result, while forming a space for disposing the circuit component 62 on the negative electrode can 20 of the flat battery 2, the circuit component 62 contacts the flat battery 2 even when the flat battery 2 is deformed. To prevent damage.

  Further, as shown in FIGS. 1 and 6, the spacer 71 has two through holes 71 a in a portion where the thickness on the outer peripheral side is large. These through holes 71 a are formed at positions facing each other across the hole at the center of the spacer 71. As will be described later, these through holes 71a are formed in a size that allows the coil-shaped battery-side positive terminal 82 to pass therethrough.

  The circuit board 61 is overlaid on the spacer 71 so that the circuit component 62 is positioned inside the substantially donut-shaped spacer 71 (see FIG. 1). Thereby, the circuit board 61 on which the circuit component 62 is mounted can be arranged compactly with respect to the flat battery 2. Moreover, since the circuit component 62 is not exposed to the outside of the battery unit 1 by adopting the configuration as described above, it is possible to prevent the user or the like from touching the circuit component 62.

  As described above, since the elastic adhesive is filled between the circuit board 61 and the negative electrode can 20 of the flat battery 2, the circuit component 62 disposed inside the substantially donut-shaped spacer 71. Is also filled with an elastic adhesive.

(Battery side terminal configuration)
As shown in FIGS. 1 and 5, a battery-side negative electrode terminal 81 is provided on the flat portion 21 of the negative electrode can 20 of the flat battery 2. The battery-side negative electrode terminal 81 is formed by bending a rectangular plate member made of a conductive metal material so that the central portion in the longitudinal direction swells in the thickness direction. That is, the battery-side negative electrode terminal 81 is integrally formed with a battery connection portion 81a connected to the flat portion 21 of the negative electrode can 20 of the flat battery 2 and substrate connection portions 81b located on both sides of the battery connection portion 81a. The battery connection portion 81a bulges in the thickness direction of the member with respect to the substrate connection portion 81b. The height at which the battery connection portion 81a bulges with respect to the substrate connection portion 81b is such that the battery connection negative electrode terminal 81 attached to the flat battery 2 with the spacer 71 overlapped on the flat battery 2 is connected to the substrate. The height is such that the portion 81 b is positioned on the spacer 71.

  The battery connection part 81a is fixed on the flat part 21 of the negative electrode can 20 of the flat battery 2 by welding. Specifically, as shown in FIG. 5, the battery connection portion 81 a has a surface on the bulging side of the battery side negative electrode terminal 81 so that the substrate connection portion 81 b of the battery side negative electrode terminal 81 is placed on the spacer 71. The flat plate 21 of the negative electrode can 20 is fixed by welding. Thereby, the battery side negative electrode terminal 81 can be fixed to the flat battery 2. Moreover, since the battery connection portion 81a forms a recess that is recessed from the substrate connection portion 81b, the circuit component 62 mounted on the circuit board 61 can be disposed in the recess. Therefore, more circuit components 62 can be compactly disposed between the circuit board 61 and the flat battery 2.

  The board connecting portion 81b is fixed to the circuit board 61 with solder. Specifically, as shown in FIG. 6, the board connection portion 81 b is placed on the board side terminal 63 and the solder with the board side terminal 63 provided in the notch 61 a of the circuit board 61 positioned thereon. Attached. As a result, the board connecting portion 81 b is connected to the side surface of the circuit board 61.

  On the other hand, as described above, the coil-shaped battery-side positive terminal 82 (connection member) is inserted into the through hole 71a formed in the spacer 71 (see FIGS. 1, 6, and 7). The battery side positive terminal 82 is constituted by a coil spring. In other words, the battery-side positive terminal 82 is formed as a so-called compression spring that attempts to return to its original length by an elastic restoring force when compressed.

  As shown in FIGS. 1 and 7, the battery side positive terminal 82 has a depth direction of the through hole 71 a and a compression direction of the battery side positive terminal 82 in the through hole 71 a formed in the spacer 71. Are arranged. Thereby, the battery side positive electrode terminal 82 has one end side in contact with the peripheral wall portion 12 of the positive electrode can 10 in the through hole 71a and the other end side protruding outward from the through hole 71a.

  That is, the battery side positive terminal 82 is formed longer than the length of the through hole 71 a of the spacer 71. Thereby, the other end side of the battery side positive terminal 82 can be protruded from the spacer 71 in a state where the battery side positive terminal 82 is inserted into the through hole 71 a of the spacer 71.

  As shown in FIG. 7, the other end side of the battery side positive terminal 82 is in contact with the circuit board 61. On the mounting surface of the circuit board 61, a substrate-side positive terminal (not shown) is formed at a position in contact with the battery-side positive terminal 82 disposed in the through hole 71 a of the spacer 71. Therefore, by arranging the circuit board 61 above the spacer 71, the circuit board 61 and the battery-side positive terminal 82 can be electrically connected. Thereby, the circuit board 61 and the positive electrode can 10 of the flat battery 2 can be electrically connected via the battery side positive terminal 82.

  As described above, by disposing the circuit board 61 on the spacer 71, the battery-side positive terminal 82 that protrudes from the through hole 71 a of the spacer 71 on the other end side can be compressed. That is, the battery-side positive terminal 82 is compressed in the stacking direction of the spacer 71 and the flat battery 2 in the through hole 71 a of the spacer 71. Therefore, both ends of the battery-side positive terminal 82 are pressed against the positive electrode can 10 and the circuit board 61 by the elastic restoring force of the battery-side positive terminal 82, so that the battery-side positive terminal 82 is pressed by the positive electrode can 10 and the circuit board 61. It can be reliably contacted.

  Further, as shown in FIG. 7, the battery-side positive electrode terminal 82 is bonded and fixed at one end side to the peripheral wall portion 12 of the positive electrode can 10 by a conductive adhesive 83, while the other end side is connected to the circuit board 61. The conductive adhesive 83 is bonded and fixed. By doing so, it is possible to prevent both end portions of the battery side positive terminal 82 from being separated from the positive electrode can 10 and the circuit board 61. Therefore, the battery side positive terminal 82, the positive electrode can 10, and the circuit board 61 can be more reliably brought into contact with the above-described configuration.

  Here, the conductive adhesive 83 has a conductive filler and a binder. Examples of the conductive filler include conductive metal particles such as gold powder, silver powder, copper powder, nickel powder, and aluminum powder, carbon particles, and carbon black. As the binder, for example, a resin material such as epoxy, urethane, silicon, acrylic, or polyimide is used.

  With the above-described configuration, the flat battery 2 and the flat battery 2 are disposed by the battery-side positive terminal 82 disposed between the flat battery 2 and the circuit board 61 in a state where the circuit board 61 is laminated on the flat battery 2. The circuit board 61 can be electrically connected. In addition, since the battery-side positive terminal 82 formed of a coil spring is disposed in a compressed state between the flat battery 2 and the circuit board 61, both ends of the battery-side positive terminal 82 are connected to the flat battery 2 and The circuit board 61 can reliably make contact. Further, both ends of the battery-side positive terminal 82 are bonded and fixed to the flat battery 2 and the circuit board 61 with the conductive adhesive 83, respectively, so that the battery-side positive terminal 82 is connected to the flat battery 2 and the circuit board 61. Can be more reliably brought into contact. Therefore, with the above-described configuration, the flat battery 2 and the circuit board 61 can be more reliably electrically connected by the battery side positive terminal 82.

(Battery unit manufacturing method)
Next, a method for manufacturing the battery unit 1 having the above-described configuration will be described with reference to FIGS.

  First, as shown in FIG. 8, the circuit unit 3 is formed by mounting a plurality of circuit components 62 on one surface side of the circuit board 61. At this time, various terminals 66 to 69 are formed on the other surface side of the circuit board 61 (only the output terminal 67 and the charging terminal 68 are shown in FIG. 8). Since the method of mounting the circuit component 62 on the circuit board 61 and the method of forming the various terminals 66 to 69 are the same as in the prior art, detailed description is omitted.

  On the other hand, as shown in FIG. 9, the spacer 71 is bonded and fixed on the flat battery 2 with an elastic adhesive, and the battery-side negative terminal 81 is fixed to the flat battery 2 by welding.

  Further, as shown in FIG. 9, after the conductive adhesive 83 is put into the through hole 71a provided in the spacer 71, the battery side positive terminal 82 is inserted (see the white arrow in the figure). As a result, one end side of the battery side positive terminal 82 is bonded and fixed to the outer can 10 of the flat battery 2 by the conductive adhesive 83. Thereafter, a conductive adhesive 83 is applied to the other end side of the battery side positive terminal 82.

  As illustrated in FIG. 10, the circuit board 61 of the circuit unit 3 is disposed on the flat battery 2 to which the spacer 71, the battery-side negative terminal 81, and the battery-side positive terminal 82 are attached. At this time, the circuit board 61 is mounted on the flat battery 2 such that the board-side terminal 63 contacts the battery-side negative terminal 81 and the board-side positive terminal (not shown) contacts the other end of the battery-side positive terminal 82. Be placed. As described above, since the conductive adhesive 83 is applied to the other end side of the battery side positive terminal 82, the other end side of the battery side positive terminal 82 is bonded and fixed to the circuit board 61. When the circuit unit 3 is combined with the flat battery 2, an elastic adhesive or the like is filled between the circuit board 61 and the flat battery 2.

  Then, the elastic adhesive is cured to integrate the flat battery 2, the spacer 71, and the circuit board 61. Then, the tube 4 is contracted by fitting and heating the tube 4 to the side surface of the laminated body of the flat battery 2 and the circuit unit 3 formed as described above. In addition, this tube 4 has such a length that it covers a part of the outer peripheral side of both end faces of the laminated body in a state of being fitted to the side surface of the laminated body.

  Thereby, the battery unit 1 having the configuration as shown in FIG. 1 is obtained.

(Effect of Embodiment 1)
As described above, according to this embodiment, since the battery-side positive terminal 82 constituted by the coil spring is disposed in a compressed state between the positive electrode can 10 and the circuit board 61 of the flat battery 2, the flat shape Both end portions of the battery-side positive terminal 82 can be more reliably brought into contact with the battery 2 and the circuit board 61. Thereby, the flat battery 2 and the circuit board 61 can be more reliably electrically connected by the battery side positive terminal 82.

  In addition, both ends of the battery-side positive terminal 82 are fixed to the flat battery 2 and the circuit board 61 by the conductive adhesive 83, respectively. Therefore, the flat battery 2 and the circuit board 61 can be more reliably electrically connected by the battery side positive terminal 82.

  The circuit board 61 of the circuit unit 3 is provided with a plurality of notches 61a on the outer peripheral portion thereof, and board-side terminals 63 are provided on the side surfaces of the circuit board 61 in the notches 61a. Thereby, the circuit board 61 and the flat battery 2 can be electrically connected by soldering the side surface of the circuit board 61 to the battery-side negative electrode terminal 81. Therefore, the thickness of the battery unit 1 as a whole can be reduced by the amount of protrusion of the terminal end portion and the thickness of the solder as compared with the configuration in which the terminal end portion is soldered in a state of being inserted through the substrate. In addition, since the tip of the terminal does not protrude from the substrate, it is possible to prevent a short circuit from occurring at the terminal.

  Further, since the battery-side negative electrode terminal 81 constitutes the battery connection portion 81a with the center portion in the longitudinal direction of the rectangular plate member being recessed, the battery substrate negative electrode terminal 81 is formed on the circuit board 61 in the recessed portion formed in the battery connection portion 81a. The mounted circuit component 62 can be arranged. Therefore, more circuit components 62 can be arranged more compactly between the circuit board 61 and the flat battery 2.

  Further, in the circuit board 61 of the circuit unit 3, various terminals 66 to 69 are collectively provided on the surface opposite to the flat battery 2, so that the various terminals 66 to 69 are disposed at positions overlapping the flat battery 2 in plan view. 69 can be provided, and the battery unit 1 can be downsized. Moreover, by mounting the circuit components 62 together on the surface of the flat battery 2 on the circuit board 61, it is possible to prevent the circuit components 62 and the like from being exposed to the outside of the battery unit 1. Thereby, it is possible to prevent a user touching the battery unit 1 from directly touching the circuit component 62 or the like.

<Embodiment 2>
In FIG. 11, schematic structure of the battery unit 100 which concerns on Embodiment 2 of this invention is shown. In this battery unit 100, the configurations of the battery-side positive terminal 101 and the battery-side negative terminal 102 are different from the configurations of the battery-side negative terminal 81 and the battery-side positive terminal 82 in Embodiment 1 described above. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  Specifically, as shown in FIGS. 11 and 13, the battery-side positive terminal is disposed on the bottom 11 and the spacer 111 of the positive electrode can 10 in a state where the spacer 111 is disposed on the negative electrode can 20 of the flat battery 2. 101 is arranged. The battery-side positive terminal 101 is made of a conductive film member in which an acrylic adhesive containing powdered nickel is applied to both sides of a copper foil. Therefore, the battery side positive electrode terminal 101 is fixed on the flat battery 2 by the acrylic adhesive applied on the surface. In this embodiment, the acrylic pressure-sensitive adhesive is applied to both surfaces of the copper foil. However, the present invention is not limited to this, and the acrylic pressure-sensitive adhesive is applied only to the surface of the copper foil located on the flat battery 2 side. Alternatively, the acrylic adhesive may not be applied to the surface of the copper foil. Further, the adhesive to be applied may be an adhesive made of another material. Furthermore, although nickel powder is put into the pressure-sensitive adhesive to improve conductivity, materials other than nickel may be put into the pressure-sensitive adhesive as long as the material can improve the conductivity of the pressure-sensitive adhesive.

  As shown in FIGS. 11, 13, and 14, the battery-side positive terminal 101 includes a battery connection portion 101 a positioned on the bottom portion 11 of the positive electrode can 10, a substrate connection portion 101 b positioned on the spacer 111, and the battery It has the connection part 101c which connects the connection part 101a and the board | substrate connection part 101b.

  Specifically, as shown in FIG. 14, the battery-side positive terminal 101 has two substrate connection parts 101b formed in an arc shape so as to sandwich the battery connection part 101a with respect to the donut-shaped battery connection part 101a. Each is connected via a connecting portion 101c. The battery-side positive terminal 101 is a member in which these battery connection portion 101a, substrate connection portion 101b, and connection portion 101c are integrally formed.

  The battery connection portion 101 a is formed such that its outer peripheral side is positioned on the outer peripheral side of the bottom 11 of the positive electrode can 10. That is, the outer diameter of the battery connection portion 101 a is equal to the diameter of the bottom portion 11 of the positive electrode can 10. Further, a concentric circular hole portion 101d is formed in the battery connection portion 101a. Here, when the positive electrode can 10 is deformed outward due to a pressure change in the flat battery 2, the deformation amount is greatest at the central portion of the positive electrode can 10. As described above, since the hole 101d is provided in the central portion of the battery connecting portion 101a, the battery connecting portion 101a is not fixed to the central portion of the positive electrode can 10, so that the battery connecting portion 101a becomes positive electrode can by deformation of the central portion. Peeling from 10 can be prevented. In the present embodiment, the hole 101d is provided in the battery connection portion 101a. However, the present invention is not limited to this, and the hole 101d may not be provided.

  Each of the board connection portions 101b is formed in a shape that leaves only the arc portion on the outer peripheral side of a substantially semicircle. That is, the board connecting portion 101b has a shape in which a semicircular cutout is provided on the center side of a substantially semicircular circle. The outer diameter of the substrate connecting portion 101b is equal to the outer diameter of the donut-shaped spacer 111 attached on the negative electrode can 20. The inner diameter of the substrate connecting portion 101b is equal to the inner diameter of the spacer 111. Thereby, the board | substrate connection part 101b can be arrange | positioned on the spacer 111, without protruding from this spacer 111. FIG. The shape of the spacer 111 is the same as the shape of the spacer 71 in the first embodiment. In the spacer 111, two through holes 111a are formed in the inner portion having a small thickness at positions facing each other across the hole portion of the central portion of the spacer 111. As will be described later, these through holes 111a are formed so that a coil-shaped battery-side negative electrode terminal 102 can pass therethrough.

  In addition, each substrate connecting portion 101b is arranged on the spacer 111 as shown by a one-dot chain line in FIG. 12, and both end portions in the circumferential direction corresponding to both ends of the arc are formed in the through holes 111a formed in the spacer 111. It is formed so as not to overlap. That is, each substrate connecting portion 101b is formed in an arc shape such that both end portions in the circumferential direction do not reach the peripheral portion of the through hole 111a of the spacer 111. That is, each substrate connecting portion 101 b has a circumferential length shorter than the circumferential length of the semicircle of the spacer 111.

  The connecting portion 101c is formed so as to connect the battery connecting portion 101a and the substrate connecting portion 101b on a line connecting the respective circle centers of the battery connecting portion 101a and the substrate connecting portion 101b. The connecting portion 101c has a length in the connecting direction between the battery connecting portion 101a and the substrate connecting portion 101b that is equal to the thickness of the flat battery 2 and the spacer 111 in a state where the spacer 111 is stacked on the flat battery 2. Is formed.

  With the above configuration, as shown in FIG. 13, the battery connector 101 a is positioned on the bottom 11 of the positive electrode can 10 and the substrate connector 101 b is positioned on the spacer 111, while the connecting portion 101 c is positioned on the positive electrode 10 and the spacer 111. Can be positioned on the side of the. Therefore, the battery-side positive terminal 101 electrically connected to the positive electrode can 10 of the flat battery 2 can be routed to the spacer 111 disposed on the negative electrode can 20. As shown in FIG. 13, the circuit board 61 is arranged on the mounting surface of the circuit board 61 by arranging the circuit board 61 so that the mounting surface is on the lower side with respect to the board connecting portion 101b arranged on the spacer 111. The formed substrate-side positive terminal (not shown) can be electrically connected to the substrate connecting portion 101b. Thereby, the circuit board 61 and the positive electrode can 10 of the flat battery 2 can be electrically connected.

  On the other hand, as shown in FIGS. 11, 12, and 15, a coil-shaped battery-side negative electrode terminal 102 (connection member) is inserted into the through hole 111 a formed in the spacer 111. The battery-side negative electrode terminal 102 is configured by a coil spring as in the first embodiment. That is, the battery-side negative electrode terminal 102 is formed as a so-called compression spring that, when compressed, tries to return to its original length by elastic restoring force.

  As shown in FIGS. 11 and 15, the battery-side negative electrode terminal 102 has a depth direction of the through-hole 111 a and a compression direction of the battery-side negative electrode terminal 102 in the through-hole 111 a formed in the spacer 111. Is arranged. As a result, the battery-side negative electrode terminal 102 has one end in contact with the flat portion 21 of the negative electrode can 20 in the through hole 111a and the other end protruding outward from the through hole 111a.

  That is, the battery-side negative terminal 102 of the present embodiment is also formed longer than the length of the through hole 111a of the spacer 111, like the battery-side positive terminal 82 of the first embodiment. Thereby, the other end side of the battery side negative terminal 102 can be protruded from the spacer 111 in a state where the battery side negative terminal 102 is inserted into the through hole 111 a of the spacer 111.

  As shown in FIGS. 11 and 15, the other end side of the battery-side negative terminal 102 is in contact with the circuit board 61, similarly to the battery-side positive terminal 82 of the first embodiment. On the mounting surface of the circuit board 61, a substrate-side negative terminal (not shown) is formed at a position in contact with the battery-side negative terminal 102 disposed in the through hole 111 a of the spacer 111. Therefore, by arranging the circuit board 61 above the spacer 111, the circuit board 61 and the battery-side negative electrode terminal 102 can be electrically connected. Thereby, the circuit board 61 and the negative electrode can 20 of the flat battery 2 can be electrically connected via the battery-side negative electrode terminal 102.

  As described above, by disposing the circuit board 61 on the spacer 111, the battery-side negative electrode terminal 102 whose other end protrudes from the through hole 111a of the spacer 111 can be compressed. That is, the battery-side negative electrode terminal 102 is compressed in the stacking direction of the spacer 111 and the flat battery 2 in the through hole 111 a of the spacer 111. Therefore, both ends of the battery-side negative terminal 102 are pressed against the positive electrode can 10 and the circuit board 61 by the elastic restoring force of the battery-side negative terminal 102, so that the battery-side negative terminal 102 is moved by the positive electrode can 10 and the circuit board 61. It can be reliably contacted.

  Further, as shown in FIG. 15, the battery-side negative electrode terminal 102 is bonded and fixed at one end side to the flat portion 21 of the negative electrode can 20 by a conductive adhesive 83, while the other end side is connected to the circuit board 61. The conductive adhesive 83 is bonded and fixed. By doing so, both end portions of the battery-side negative electrode terminal 102 can be prevented from being separated from the planar portion 21 of the negative electrode can 20 and the circuit board 61. Therefore, the battery-side negative electrode terminal 102, the negative electrode can 20, and the circuit board 61 can be brought into contact with each other more reliably with the above-described configuration.

  In the present embodiment, the battery-side positive terminal 101 has two arc-shaped board connection parts 101b connected to the battery connection part 101a via the connecting part 101c so as to sandwich the donut-shaped battery connection part 101a. It has a configuration. However, the battery-side positive electrode terminal 101 may have any shape as long as the bottom 11 of the positive electrode can 10 of the flat battery 2 and the circuit board 61 can be electrically connected. That is, the battery-side positive terminal may have any shape as long as it has a battery connection part, a substrate connection part, and a connecting part that connects them.

(Effect of Embodiment 2)
With the above configuration, in the present embodiment, the flat battery 2 is disposed between the flat battery 2 and the circuit board 61 in a state where the circuit board 61 is stacked on the flat battery 2. The battery 2 and the circuit board 61 can be electrically connected.

  Moreover, the battery-side negative terminal 102 is constituted by a coil spring. Therefore, by arranging the battery-side negative electrode terminal 102 in a compressed state between the flat battery 2 and the circuit board 61, the flat battery 2 and the circuit board 61 can be reliably brought into contact with each other.

  Further, both ends of the battery-side negative terminal 102 are bonded and fixed to the flat battery 2 and the circuit board 61 with the conductive adhesive 83, respectively, so that the battery-side negative terminal 102 is fixed to the flat battery 2 and the circuit board 61. Can be more reliably brought into contact. Therefore, with the above-described configuration, the flat battery 2 and the circuit board 61 can be more reliably electrically connected by the battery-side negative electrode terminal 102.

  Further, in the present embodiment, in the battery unit 1 in which the circuit unit 3 is disposed on the flat unit 21, the bottom 11 of the positive electrode can 10 and the circuit board 61 of the flat battery 2 are made of a conductive film member. The battery side positive terminal 101 was electrically connected. Since the thickness of the battery-side positive terminal 101 is small, the battery-side positive terminal is formed on the side of the flat battery 2 when the battery-side positive terminal 101 is drawn from the bottom 11 of the positive electrode can 10 to the flat surface 21 side of the negative electrode can 20. It is possible to prevent the terminal 101 from protruding greatly to the outside of the battery. Moreover, the battery unit 1 can be prevented from increasing in the thickness direction by configuring the battery-side positive terminal 101 with a conductive film member as described above. Therefore, the battery unit 1 can be reduced in size by the above-described configuration.

  In addition, since the battery-side positive terminal 101 is coated with an acrylic adhesive on the surface of the copper foil, the battery-side positive terminal 101 can be easily fixed to the flat battery 2 and the spacer 111.

(Other embodiments)
While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented without departing from the spirit of the invention.

  In the first embodiment, the battery-side negative electrode terminal 81 has a shape that is bent so that the central portion in the longitudinal direction of the rectangular plate member bulges in the thickness direction. However, the present invention is not limited to this, and the negative electrode of the flat battery 2 As long as the can 20 and the circuit board 3 can be electrically connected, the battery-side negative electrode terminal may have any shape.

  In the second embodiment, the battery-side positive terminal 101 is constituted by a conductive film member in which an acrylic pressure-sensitive adhesive containing powdered nickel is applied to both surfaces of a copper foil. However, the battery-side positive electrode terminal 101 may have any configuration, for example, a configuration formed by bending a plate member as shown in FIG.

  In the example shown in FIG. 16, the battery-side positive terminal 151 is provided so as to sandwich the flat battery 2 and the spacer 111 in the thickness direction. The battery-side positive terminal 151 is constituted by a plate member made of a conductive metal material, and one end of the battery-side positive terminal 151 is fixed to the bottom 11 of the positive electrode can 10 of the flat battery 2 by welding. The end is located on the upper surface of the spacer 111.

  More specifically, as shown in FIG. 16, the battery-side positive terminal 151 includes a battery connection part 151 a connected to the bottom part 11 of the positive electrode can 10, and a board connection part 151 b connected to the circuit board 61 on the spacer 111. And a connecting portion 151c that connects the battery connecting portion 151a and the substrate connecting portion 151b. The battery connection part 151a and the board connection part 151b are bent in the same direction with respect to the connection part 151c. Thereby, the battery side positive electrode terminal 151 can be arrange | positioned so that the flat battery 2 and the spacer 111 may be inserted | pinched in the thickness direction.

  The battery-side positive terminal 151 is electrically connected to a substrate-side terminal of a notch formed on a circuit board (not shown), like the battery-side negative terminal 81 of the first embodiment.

  In each of the above embodiments, only one of the battery-side positive terminal and the battery-side negative terminal is configured by a coil spring, but this is not a limitation, and both the battery-side positive terminal and the battery-side negative terminal are configured by a coil spring. May be.

  In each of the embodiments described above, the battery-side positive terminal 82 and the battery-side negative terminal 102 are configured by coil springs. However, the present invention is not limited to this. As long as the shape battery 2 and the circuit board 61 can be electrically connected, another shape such as a pin shape or a leaf spring shape may be used.

  In each of the embodiments, the battery-side positive terminal 82 and the battery-side negative terminal 102 are fixed to the flat battery 2 and the circuit board 61 with the conductive adhesive 83. However, the battery-side positive terminal 82 and the battery-side negative terminal 102 may be brought into contact with the flat battery 2 and the circuit board 61 without being fixed by the conductive adhesive 83.

  In each of the embodiments described above, the various terminals 66 to 69 of the battery unit 1 are formed in a rectangular shape, but may have other shapes such as a concentric shape. In addition, by forming the various terminals 66 to 69 of the battery unit 1 concentrically, when the battery unit 1 is attached to an electric device, the alignment of the battery unit 1 becomes unnecessary.

  In each of the embodiments, the circuit board 61 has the same shape and size as the outer shape of the flat battery 2, but this is not restrictive, and the circuit board 61 may be smaller or larger than the flat battery 2. May be.

  In each of the above embodiments, the positive electrode can 10 and the negative electrode can 20 are each formed in a bottomed cylindrical shape, and the circuit board 61 is formed in a circular shape. However, the positive electrode can and the negative electrode can may be formed in a bottomed cylindrical shape other than the bottomed cylindrical shape, and the circuit board 61 may have a shape other than a circular shape.

  In each said embodiment, although the side surface of the laminated body of the circuit part 3 and the flat battery 2 is covered with the tube 4, it is not restricted to this, The tube 4 does not need to cover. By doing so, the battery unit can be reduced in size by not providing the tube 4. Further, instead of using the tube as in the embodiment, the side surface of the laminate may be coated with a resin material.

  In each said embodiment, although the circuit part 3 is arrange | positioned at the negative electrode can 20 side which is a sealing can of the flat battery 2, you may arrange | position not only in this but the positive electrode can 10 side which is an exterior can. . Furthermore, the circuit component 62 of the circuit unit 3 may be mounted on the surface of the circuit board 61 opposite to the flat battery 2 side. The circuit unit 3 may be configured by a circuit board on which the circuit component 62 is not mounted.

  In each of the embodiments described above, the flat battery 2 and the circuit unit 3 are bonded and fixed by an elastic adhesive. However, the present invention is not limited to this, and the both may be fixed using another bonding member such as a tape.

  In each of the above embodiments, the outer can is the positive electrode can 10 and the sealed can is the negative electrode can 20. However, the present invention is not limited to this, and the outer can may be the negative electrode can and the sealed can may be the positive electrode can. In this case, the battery-side negative terminals 81 and 102 may be battery-side positive terminals, and the battery-side positive terminals 82 and 101 may be battery-side negative terminals.

  In each of the embodiments described above, the flat battery 2 is configured as a lithium ion battery. However, the flat battery 2 may be a battery other than a lithium ion battery as long as it is a rechargeable secondary battery. The flat battery 2 may be a primary battery. When the flat battery 2 is a primary battery, a capacitor or the like is mounted as a circuit unit.

  The battery unit according to the present invention can be used in a configuration including a substrate on which a circuit is formed and a flat battery mounted on a small device.

1: battery unit, 2: flat battery, 3: circuit part, 10: positive electrode can (exterior can), 11: bottom part, 12: peripheral wall part (side wall), 20: negative electrode can (sealing can), 21: flat part 22: peripheral wall portion (side wall), 61: circuit board (substrate), 62: circuit component, 71, 111: spacer, 82: battery side positive terminal (connection member), 83: conductive adhesive, 102: battery side Negative terminal (connecting member)

Claims (5)

It has a bottomed cylindrical outer can and a bottomed cylindrical sealing can covering the opening side of the outer can, so that the opening side of the side wall of the outer can is located on the outer periphery of the side wall of the sealed can A flat battery formed by combining the outer can and the sealed can;
A substrate on which circuit components are mounted, fixed to the flat surface of the sealing can,
A connecting member disposed between the flat battery and the substrate, and electrically connecting the flat battery and the substrate;
The connection member is a battery unit configured to be elastically deformable in a stacking direction of the flat battery and the substrate. The battery unit according to claim 1,
The connection member is formed in the shape of a coil spring, and is arranged in a compressed state between the flat battery and the substrate. The battery unit according to claim 1 or 2,
The battery unit is a battery unit, wherein the connection member is fixed to at least one of the flat battery and the substrate by a conductive adhesive. The battery unit according to any one of claims 1 to 3,
A battery unit in which a plurality of connection members are provided between the flat battery and the substrate. In the battery unit according to any one of claims 1 to 4,
The connection member is disposed between the opening side of the side wall of the outer can and the substrate so as to electrically connect the opening side of the side wall of the outer can in the flat battery and the substrate. The battery unit.

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