JP5710287B2 - Electrochemical cell with terminal and manufacturing method thereof - Google Patents

Description

  The present invention relates to an electrochemical cell with a terminal formed by connecting a plurality of small electrochemical cells and a method for producing the same.

  Electrochemical cells such as lithium secondary batteries and electric double layer capacitors are not limited to the deterioration of their electrical characteristics when a voltage exceeding the withstand voltage of the electrolyte used is applied, and gas is generated by electrolysis of the electrolyte. As a result, the internal pressure rises, and there is a possibility that the mounted electronic apparatus will be greatly affected by package damage or leakage. Therefore, in these electrochemical cells, a working voltage that does not exceed the withstand voltage characteristic is determined and used. For example, in an electric double layer capacitor, the maximum operating voltage is about 0.8 to 0.9 V for an aqueous solvent and about 3.2 to 3.3 V for a non-aqueous solvent.

  On the other hand, when these electrochemical cells are mounted on an electronic device that operates at a higher voltage than the above voltage characteristics, a high voltage response may be required. In that case, the operating voltage can be increased by connecting a plurality of cells in series, but compared to the case of using a single cell, the connection method between cells and the method of maintaining the voltage balance between cells during charging. Etc. need to be devised.

  For example, in a conventional electric double layer capacitor module, a plurality of conventional electric double layer capacitors (capacitors) covered with a laminate film are stacked in the thickness direction and stored in a case, and adjacent terminals are connected by screwing or caulking. (For example, Patent Document 1). Since the capacitors are juxtaposed in a plane and accommodated in the case, a space for arranging the welding head around the positive electrode terminal and the negative electrode terminal derived from the capacitor body can be secured. As a result, the positive electrode terminal of one adjacent capacitor and the negative electrode terminal of the other capacitor can be electrically connected by welding, and the contact resistance between the positive electrode terminal and the negative electrode terminal is minimized. Therefore, it is easy to reduce the resistance.

  As another example, a structure for maintaining a voltage balance between cells is disclosed (for example, Patent Document 2). In the patent document, in an electrochemical cell connected in series, a resistance difference between each single cell becomes large due to a temperature change or the like while being used, a difference in charging voltage occurs and the operating voltage is exceeded. It increases the risk of failure. For this reason, in order to charge the charging voltage of each single cell equally, the single cells are connected to each other, an intermediate contact is provided at a serial connection portion between the cells, and a balance resistance is provided between each terminal and the intermediate contact. . As a cell produced by this method, as shown in FIG. 15, the cells 3 and 4 are connected, the positive and negative terminals 45 and 46, and the intermediate potential tab 24 are attached, and the resistance balance 1 having a resistor is further provided. The mounting structure is shown.

  On the other hand, for each electronic component, reflow mounting support has been strongly demanded in recent years from the viewpoint of improving the efficiency of the component mounting process. This requirement also extends to electrochemical cells, and products that respond to this demand include an electric double layer capacitor, a lithium secondary battery, etc., for mounting on a small coin-type outer package comprising a positive electrode can, a negative electrode can and a gasket. Electrochemical cells with terminals formed by welding a pair of external terminals are well known. These are used as a backup power source for a memory or a clock function of a small electronic device (for example, Patent Document 3).

JP 2009-164468 A JP 2006-517733 A JP 2002-190427 A

  However, the power source of the instantaneous voltage drop countermeasure device shown in Patent Document 1 is not an electrochemical cell in a field where reflow compatibility is originally required, and there is no suggestion or proposal regarding surface mounting.

  Moreover, the low resistance electric double layer capacitor used for leveling the load of the portable device shown in the conventional example of Patent Document 2 is composed of an exterior body having a very low heat resistance such as a laminate film (for example, Patent Document 2). For this reason, the mounting of this capacitor is unavoidably performed by soldering or the like after other components are mounted by reflow processing. Moreover, since the exterior body is a laminate film, the drop impact characteristics after mounting are not satisfactory.

  In applications such as leveling the load of the portable device, a current of several A is instantaneously discharged or a current of several + mA is discharged for several seconds to drive a motor, blink a light emitter, piezoelectric Perform actions such as vibrating the body and generating radio waves. Therefore, an internal resistance value of a capacity suitable for an electrochemical cell (in the range of several tens of mF to 1F) and several hundred milliohms, preferably 100 milliohms or less is required.

  The small coin-type electrochemical cell with a terminal having an external terminal disclosed in Patent Document 3 has a capacity and an internal resistance value that do not reach the above-mentioned use, and since it is circular, a mounting area increases. There was a problem.

  The present invention has been made in consideration of such circumstances, and the object thereof is to correspond to the operating voltage of a small electronic device to be mounted, can be easily and firmly connected to a circuit board, and has low internal resistance. Another object is to provide an electrochemical cell capable of surface mounting by automatic reflow mounting.

The present invention provides the following means in order to solve the above problems.
An electrochemical cell with a terminal according to the present invention includes an exterior body that is a metal cuboid provided with a terminal, a power generation element that includes a lead connected to the terminal, and an electrolyte that is accommodated in the exterior body. The electrochemical cell with a terminal in which a plurality of electrochemical cells are connected in series, wherein the electrochemical cells connected in series are opposed to each other and provided with the terminals of the electrochemical cells. was surface is fixed so as to be substantially flush with the said terminals to be connected to each other, are welded to one balanced terminal, the said terminal not connected to each other, are welded to the external terminals, respectively, provided in the terminal of one another A surface facing the formed surface is fixed by a fixed terminal, and the balance terminal, the external terminal, and the fixed terminal each include a bottom surface portion that is a mounting surface with a circuit board. .

According to this structure, each single cell is connected by aligning the side surface which is one side surface which comprises an exterior body, and is equipped with a terminal. A fixed terminal is provided on the exterior body of the plurality of connected cells, and an external terminal and a balance terminal are electrically connected to the terminals of each single cell. Thereby, a cell and a circuit board are firmly connected in several places. Since the external terminal and the balance terminal are arranged in the vicinity of the side surface including the terminals, the circuit board pattern to be mounted is simple and compact.
Further, according to this configuration, the fixed terminal is disposed on the side of the side that forms the exterior body and that faces the side including the terminal. The circuit board is mounted on the circuit board in two areas, the area where the fixed terminal is connected.
Therefore, the electrochemical cell can be used for surface mounting by automatic reflow mounting that can be easily designed on the circuit board, can be firmly connected to the circuit board, and has low internal resistance, corresponding to the operating voltage of the small electronic devices to be mounted. Can be obtained.

Furthermore, the electrochemical cell with a terminal according to the present invention includes an exterior body that is a metal rectangular parallelepiped provided with a terminal, a power generation element that includes a lead connected to the exterior body, and an electrolyte that is accommodated in the exterior body. The electrochemical cell with a terminal in which two electrochemical cells consisting of the above are connected in series, wherein the electrochemical cells connected in series are opposed to each other, and each of the electrochemical cells The surface on which the terminals are provided is fixed so as to be substantially the same surface, the exterior body is connected to a balance terminal, the terminals are welded to external terminals, and face each other on the surface on which the terminals are provided. A surface is fixed by a fixed terminal, and the balance terminal, the external terminal, and the fixed terminal each include a bottom surface portion that is a mounting surface with a circuit board .

According to this structure, each single cell is connected by aligning the side surface which is one side surface which comprises an exterior body, and is equipped with a terminal. A fixed terminal is connected to the exterior body of the two connected cells, and an external terminal is electrically connected to a terminal of each single cell. On the other hand, the balance terminal is connected across two linked exterior bodies. Thereby, a cell and a circuit board are firmly connected in several places. Since the external terminal and the balance terminal are arranged in the vicinity of the side surface including the terminals, the circuit board pattern to be mounted is simple and compact.
Further, according to this configuration, the fixed terminal is disposed on the side of the side that forms the exterior body and that faces the side including the terminal. The circuit board is mounted on the circuit board in two areas, the area where the fixed terminal is connected.
Therefore, the electrochemical cell can be used for surface mounting by automatic reflow mounting that can be easily designed on the circuit board, can be firmly connected to the circuit board, and has low internal resistance, corresponding to the operating voltage of the small electronic devices to be mounted. Can be obtained.

Furthermore, in the terminal with the electrochemical cell according to the present invention, it is characterized in that it is welded at a plurality of locations and the said terminal external terminal.
According to this configuration, two or more welding points are formed at intervals in the welding location. As a result, for external forces in handling and mounting on jigs in each process after welding, handling and impact at the time of mounting by automatic mounting machine on circuit board, drop impact after being incorporated in electronic equipment, etc. It becomes possible to have excellent durability.
In particular, in a cell using a metal outer package as in the present invention, the weight is about 2 to 3 times larger than that of an aluminum laminate package or the like of the same size. When the number of welding points at each welding point is one, there is a possibility that the external terminal or the like is peeled off at the welding point. This can be avoided by connecting a plurality of welding points with a space.
Therefore, the circuit board and the terminal-attached electrochemical cell can be firmly connected.

Furthermore, an electrochemical cell with terminals according to the present invention, the assumed horizontal plane formed by the bottom part of the external terminal, and assumes a horizontal surface formed by the bottom surface portion of said balance terminal, in substantially the same plane There is a space between the plane and the surface of the exterior body facing the substrate.
According to this configuration, external forces in handling and mounting on jigs in each process after welding, handling and impact during mounting by an automatic mounting machine on a circuit board, drop impact after being incorporated into an electronic device, etc. On the other hand, it is possible to have excellent durability.

Furthermore, in the terminal with the electrochemical cell according to the present invention, the said electrochemical cells connected in balanced terminal is characterized in that it is fixed to the surface provided with the said pin connecting plate.
According to this configuration, the single cells are mechanically firmly connected to each other and are also electrically connected with low resistance. Further, since the position and parallelism of the single cells are accurately aligned, the external terminals and the balance terminals can be easily aligned.

Furthermore, the electrochemical cell with a terminal according to the present invention is characterized in that a surface having a connection portion between the terminal and the external terminal intersects the substrate surface perpendicularly.
According to this configuration, the bottom surface of the external terminal can be set horizontally even when the terminal is inclined downward.

Furthermore, in the terminal with the electrochemical cell according to the present invention, said balance terminal, and wherein in cross section is crank-shaped.
According to this configuration, alignment between the balance terminal and the terminal or the exterior body is easy, and the connection work can be simplified.
Furthermore, in the terminal with the electrochemical cell according to the present invention, said balance terminal has two balanced terminals mounting surface, the two balanced terminal mounting surface is arranged on the outside of two of the terminals that are welded It is a feature.
According to this configuration, even when the terminal is not parallel to the bottom surface of the exterior body, the balance terminal can be connected to the terminal so that the bottom surface of the balance terminal is parallel to the bottom surface of the exterior body. Thereby, it can connect in parallel with the circuit board which mounts the electrochemical cell with a terminal.

Furthermore, in the terminal with the electrochemical cell according to the present invention, the external terminal is characterized in that cross-section is rectangular.
According to this configuration, it is possible to use a flat plate-like external terminal that is not bent depending on the shape of the exterior body.
Furthermore, in the terminal with the electrochemical cell according to the present invention, the external terminal is characterized in that cross-section is U-shaped.
According to this configuration, in addition to simple connection work, since the horizontal portion connected to the circuit board is folded, the dimension of the cell terminal in the extending direction can be shortened, which is practically preferable.

Furthermore, in the terminal with the electrochemical cell according to the present invention, the external terminal is characterized in that cross-section is L-shaped.
According to this configuration, even when the terminal is not parallel to the bottom surface of the exterior body, the bottom surface of the L-shaped external terminal can be connected to the terminal so as to be parallel to the bottom surface of the exterior body. It can be connected in parallel to the circuit board to be mounted.
Furthermore, in the terminal with the electrochemical cell according to the present invention, the external terminal is characterized in that cross-section is crank-shaped.
According to this configuration, it is easy to align the external terminal and the terminal, and the connection work can be simplified.

  Furthermore, the electrochemical cell with a terminal according to the present invention includes a first material in which at least one of the balance terminal or the external terminal is the same kind of metal as the terminal, and a resistivity lower than that of the first material. It is characterized by having a multilayer structure composed of two materials.

  According to this configuration, the resistance value of the balance terminal or the external terminal compared to the case where only the first material is used as the material of the balance terminal or the external terminal due to the second material layer having a low resistivity. Is reduced. In addition, since the first material of the terminal and the balance terminal or the external terminal is the same type, the shape is maintained even by heating during reflow.

Furthermore, the manufacturing method of the electrochemical cell with a terminal according to the present invention includes an exterior body manufacturing step for manufacturing a metal exterior body having a terminal, a power generation element housed in the exterior body, and a lead for the power generation element A connecting step for connecting the outer body to the outer body, a connecting step for aligning and connecting the surfaces of the outer bodies provided with the terminals, and a plurality of the outer body surfaces connected by the connecting step , A step of welding a fixed terminal to a surface opposite to a surface provided with the terminal, an external terminal welding step of welding the terminal and the external terminal at a plurality of welding points, and a balance terminal for welding the exterior body and the balance terminal. a welding step, wherein possess the step of sealing accommodating exterior body inside the electrolyte, and a said balance terminal, the external terminal, wherein the fixed terminal, a bottom portion is a mounting surface of the circuit board, respectively Rukoto equipped with a And features.

Furthermore, the manufacturing method of the electrochemical cell with a terminal according to the present invention includes an exterior body manufacturing step for manufacturing a metal exterior body having a terminal, a power generation element housed in the exterior body, and a lead for the power generation element A connecting step for connecting the outer body to the outer body, a connecting step for aligning and connecting the surfaces of the outer bodies provided with the terminals, and a plurality of the outer body surfaces connected by the connecting step , A step of welding a fixed terminal to a surface opposite to a surface provided with the terminal, an external terminal welding step of welding the terminal and the external terminal at a plurality of welding points, and a balance terminal for welding the exterior body and the balance terminal. a welding step, wherein possess the step of sealing accommodating exterior body inside the electrolyte, and a said balance terminal, the external terminal, wherein the fixed terminal, a bottom portion is a mounting surface of the circuit board, respectively Rukoto equipped with a And features.

Further, in the method of manufacturing the terminal-connected electrochemical cells according to the present invention, the step of welding the coupling step and the fixed terminals, characterized by connecting at least two positions by a connecting plate and the fixed terminal the electrochemical cell It shall be the.
Furthermore, in the method for manufacturing an electrochemical cell with a terminal according to the present invention, the connecting step is characterized in that the outer packaging body of the electrochemical cell is directly welded and connected.

Furthermore, in the method for manufacturing an electrochemical cell with a terminal according to the present invention, the external terminal welding step includes a gap between a surface of the external terminal connected to the substrate and a surface of the exterior body facing the substrate. And the said balance terminal welding process has a space | gap between the surface connected to the said board | substrate of the said balance terminal, and the surface facing the said board | substrate of the said exterior body, It is characterized by the above-mentioned.

  According to the present invention, it is compatible with the operating voltage of the mounted small electronic device, can be easily designed on the circuit board, can be firmly connected to the circuit board, and has low internal resistance, and can be surface mounted by automatic reflow mounting. An electrochemical cell can be obtained.

1 is an external perspective view of an electric double layer capacitor showing a first embodiment according to the present invention. It is an external appearance perspective view of the external terminal which comprises the electric double layer capacitor shown in FIG. It is an external appearance perspective view of the balance terminal which comprises the electric double layer capacitor shown in FIG. It is a schematic diagram of the connection form of the external terminal and terminal which comprise the electric double layer capacitor shown in FIG. It is an external appearance perspective view of the fixed terminal which comprises the electric double layer capacitor shown in FIG. It is an external appearance perspective view which shows the modification of the electrical double layer capacitor shown in FIG. It is a schematic diagram which shows arrangement | positioning when the electric double layer capacitor shown in FIG. 1 is mounted in a circuit board. It is an external appearance perspective view which shows the modification of the electrical double layer capacitor shown in FIG. It is an external appearance perspective view which shows the modification of the electrical double layer capacitor shown in FIG. It is an external appearance perspective view of the electric double layer capacitor which shows 2nd Embodiment concerning this invention. It is an external appearance perspective view which shows the modification of the electrical double layer capacitor shown in FIG. It is an external appearance perspective view of the electric double layer capacitor which shows 3rd Embodiment concerning this invention. It is an external appearance perspective view of the balance terminal which comprises the electric double layer capacitor shown in FIG. It is an external appearance perspective view of the external terminal which comprises the electric double layer capacitor shown in FIG. It is a schematic diagram of the connection form of the external terminal and terminal which comprise the electric double layer capacitor shown in FIG. It is an external appearance perspective view of the electric double layer capacitor which shows the comparative example which concerns on this invention.

(First embodiment)
Embodiments according to the present invention will be described below with reference to FIGS. In the present embodiment, an electric double layer capacitor will be described as an example of an electrochemical cell. In addition, a primary battery or a secondary battery can be configured.

  FIG. 1 is an external perspective view of an electric double layer capacitor showing a first embodiment according to the present invention. FIG. 1A is an external perspective view of the electric double layer capacitor 10 with a terminal. FIG. 1B is a cross-sectional view of the terminal-attached electric double layer capacitor 10 along the line A-A ′ shown in FIG. FIG. 1C is an external perspective view shown from the back of FIG.

  As shown in FIG. 1A, the electric double layer capacitor 10 with a terminal of this embodiment is a series connection body of two small electric double layer capacitor single cells, and each single cell is a metal box type. And a pair of terminals 14 fixed thereto by an insulating member 15, a power generation element 16 composed of a positive electrode, a negative electrode and a separator, and an electrolyte E. The positive electrode and the negative electrode are terminals inside the exterior. 14 is electrically connected. In FIG. 1A, the case 13 is shown as a transparent body in order to show the inside of the exterior body 11.

  As will be described later, the single cells are juxtaposed so that the side surfaces of the exterior body 11 and the side surfaces including the terminals are aligned, and are fixed via the connecting plate 8. Furthermore, the external terminal 5 and the balance terminal 7 are connected in series.

  In the present embodiment, the metal exterior body 11 is made of stainless steel, specifically SUS316L, and is a small rectangular parallelepiped container having a long side of 20 mm, a short side of 10 mm, a height of 4 mm, and a case thickness of 0.3 mm. It is. The exterior body 11 is composed of a plurality of constituent members. Specifically, the case 13 and the lid member 12 are fixed so as to close the opening of the case 13 by seam welding or the like, and the inside is airtight. Is sealed.

  The pair of terminals 14 are fixed to the lid member 12 with an interval in the width direction. The terminal 14 is a solid round bar thin wire formed of stainless steel (SUS316L), similar to the lid member 12, and is disposed so as to penetrate the lid member 12. The pair of terminals 14 have a hermetic seal structure made of an insulating member 15 obtained by baking glass, and are hermetically fixed to the lid member 12.

  In particular, the material of the exterior body 11 and the terminal 14 is made of the stainless steel having corrosion resistance to the electrolyte E, and having high heat resistance and durability, so that a reflow mountable and highly reliable cell is manufactured. can do.

  In this embodiment, as shown to Fig.1 (a), the surface of each cover member 12 provided with the terminal 14 is arrange | equalized, and the connection board 8 is made into the cover member in the state which closely contacted the side surfaces of case 13 side by side. 12 are arranged across the 12 surfaces, and each single cell is mechanically connected.

  Further, out of a total of four terminals 14, the outermost two terminals are connected to the external terminal 5 that is positive and negative, and the balance terminal 7 is connected to the remaining two adjacent terminals.

  In the present embodiment, the lid member 12 is “a side surface that forms the exterior body 11 and includes the terminals 14”. Further, as shown in FIG. 1C, the bottom surface of the case 13 and the surface to which the sealing plug 9 is welded is “opposite side surface that is one side surface that forms the exterior body 11 and that includes the terminal 14. Surface ".

  FIG. 2 is an external perspective view of an external terminal constituting the electric double layer capacitor shown in FIG. In FIG. 2, (a) shows a crank shape in cross section, (b) shows a U-shaped cross section, (c) shows an L-shaped cross section, and (d) shows the shape of the external terminal 5 having a rectangular cross section. As shown in FIG. 2A, the external terminal 5 of the present embodiment is formed by bending a stainless steel (SUS304) flat plate having a thickness of 0.15 mm into a crank shape, and is used for connection to a circuit board. A bottom surface portion 5b and a terminal connection portion 5a connected to the upper portion of the terminal are formed. Moreover, nickel plating and gold plating are given to the bottom face part 5b. The external terminal 5 and the upper part of the terminal 14 are connected by laser spot welding. In particular, as shown in FIG. 1, by providing a plurality of welding points 25 by laser spot welding, the connection is mechanically strong, and the electrical resistance value by the connection is extremely low. Can be suppressed.

  Regarding the shape of the external terminal 5, in addition to the crank shape shown in FIG. 2 (a), surface mounting such as a U-shape, L-shape, flat plate shape, etc. as shown in FIGS. 2 (b) to 2 (d) is possible. Various suitable shapes can be applied.

  3 is an external perspective view of a balance terminal constituting the electric double layer capacitor shown in FIG. 3A is a balance terminal having a crank shape in cross section, FIG. 3B is a balance terminal having a cross-sectional shape, and FIG. 3C is a balance terminal having an inverted U-shape having a horizontal portion at the opening end. (D) is a U-shaped balance terminal, and (e) is a flat-type balance terminal. As shown in FIG. 3A, the balance terminal 7 of the present embodiment is formed by bending a flat plate of stainless steel (SUS304) having a thickness of 0.15 mm into a crank shape, and is used for connection to a circuit board. A bottom surface portion 7b and a terminal connection portion 7a connected to the upper portion of the terminal are formed. Moreover, nickel plating and gold plating are applied to the bottom surface portion 7b. The balance terminal 7 and the upper part of the terminal 14 are connected by laser spot welding. In particular, as shown in FIG. 1, by providing a plurality of welding points 25 by laser spot welding, as described above, the mechanical connection becomes strong and the electrical resistance value by the connection is reduced. It can be suppressed to an extremely low value.

  As for the shape of the balance terminal 7, in addition to the crank shape shown in FIG. 3 (a), a U-shape, a flat plate shape, a U-shape, or an open end as shown in FIGS. 3 (b) to 3 (e) Various shapes suitable for surface mounting, such as a shape obtained by inverting the U-shape having a portion, can be applied.

  FIG. 4 is a schematic diagram of a connection form between the external terminals and the terminals constituting the electric double layer capacitor shown in FIG. In FIG. 4, (a) is a crank shape, (b) is a U-shape, (c) is an L shape, and (d) is a rectangular shape, showing the connection form of each external terminal 5. The external terminal 5 and the terminal 14 shown in FIG. 2 can be connected in various ways as shown in FIGS. In FIG. 1A, a crank-shaped external terminal 5 is disposed so as to cover the terminal 14 and is laser spot welded from above, but as shown in FIG. However, the respective upright portions may be shortened while maintaining the crank shape, and the terminal connection portion 5a may be connected to the lower side of the terminal 14. Further, as shown in FIG. 4B, a connection between the U-shaped external terminal 5 and the terminal 14 may be used. Alternatively, as shown in FIG. 4C, the L-shaped external terminal 5 and the end face of the terminal 14 may be connected to each other, or the side face of the terminal 14 may be connected to the side face of the terminal 14 as in a modified example of FIG. Connection may be used. Furthermore, as shown in FIG. 4D, when the exterior body is thin, it is also possible to use a flat plate-like external terminal 5.

  Further, the connection form between the balance terminal 7 and the terminal 14 can be various forms similar to those of the external terminal 5 and the terminal 14.

  FIG. 5 is an external perspective view of a fixed terminal constituting the electric double layer capacitor shown in FIG. In FIG. 5, (a) shows the L-shaped, (b) U-shaped, and (c) shows the rectangular fixed terminal 11. As shown in FIG. 5A, the fixed terminal 6 of the present embodiment is formed by bending a stainless steel (SUS304) plate having a thickness of 0.15 mm into an L-shaped structure, and is connected to a circuit board. Bottom surface portion 6 b and an upright portion 6 a for connecting to the exterior body 11. Regarding the shape of the fixed terminal 6, as shown in FIG. 5, in addition to the L shape, various shapes such as a U shape and a flat plate shape are possible according to the structure of the exterior body and the arrangement of the circuit board. . The fixed terminal 6 is connected to the exterior body 11 by laser spot welding.

  As shown in FIG. 1C, the fixed terminal 6 is connected across the plurality of single cells on the bottom surface of the case 13 of each single cell. Therefore, in the present embodiment, the fixed terminal 6 plays the role of mechanically connecting the two unit cells at the same time as the connecting plate 8 described below, so the two unit cells are more firmly connected to each other. Is done.

  In the present embodiment, the fixed terminal 6 is made of metal (conductive material), so that the two single-cell exterior bodies 11 have the same potential. Therefore, if the bottom surface portion 6b of the fixed terminal 6 is electrically connected to a predetermined pattern of the circuit board, the potential of the outer package 11 of the two single cells can be controlled by the potential of the pattern. .

  The connecting plate 8 is a flat plate made of stainless steel (SUS304) having a thickness of 0.15 mm, and is connected across two single-cell lid members 12 as shown in FIG. The connecting plate 8 is connected to the cover member 12 of the exterior body, and the fixed terminals 6 are connected to the bottom surface of the facing case 13 across the plurality of single cells, so that the single cells are more firmly fixed, The position and parallelism between single cells are aligned.

  Further, in the present embodiment, the attachment position of the connecting plate 8 is the top surface and bottom surface of the exterior body and the bottom surface of the case 13 in addition to the lid member 12 in the exterior body as shown in FIG. It doesn't matter. In particular, as shown in FIG. 6, when the connecting plate 8 is attached to the upper surface of the exterior body 2, the parallelism between the two single cells and the parallelism between the terminals 14 are further sufficiently maintained. It is. Here, FIG. 6 is an external perspective view showing a modification of the electric double layer capacitor shown in FIG.

  The sealing plug 9 is used to block an electrolyte injection hole provided at one location of the outer package 11 shown in FIG. Further, since the sealing plug 9 is in contact with the electrolyte E, the sealing plug 9 is formed of a disc made of the same stainless steel (SUS316L) as the outer package 11.

  The bottom surface portion 5b of the external terminal 5, the bottom surface portion 7b of the balance terminal 7, and the bottom surface portion 6b of the fixed terminal 6 are equal in height so as to be mounted horizontally on the circuit board. The assumed horizontal plane formed by these bottom surface portions, that is, the horizontal plane formed by the surface of the circuit board to be mounted is designed and disposed so as to be lower than the bottom surface of the exterior body. It is preferable that the clearance H between the assumed horizontal plane and the bottom surface of the exterior body shown in FIG. However, when the mounting height as a surface mounting component is limited, the numerical value of this clearance can be adjusted.

  The power generation element 16 is housed inside the exterior body 11. The power generation element 16 is provided with a positive electrode and a negative electrode with a separator interposed therebetween, and these are alternately stacked and manufactured by winding or stacking. The positive electrode and the negative electrode are made of a material that has corrosion resistance to the electrolyte E and can withstand a high temperature environment in the reflow mounting process. In the present embodiment, an aluminum current collector is used in which a positive electrode active material and a negative electrode active material made of activated carbon or the like are supported. In addition, a resin having mechanical strength and heat resistance is used for the separator. For the separator, glass fiber, ceramic porous body, and the like can be used in addition to the above-described resin.

  The electrolyte E is housed inside the hermetic outer package 11 and penetrates into the power generation element 16. In the present embodiment, an electrolytic solution in which a supporting salt is dissolved in a non-aqueous solvent having a high boiling point is used so as to withstand a high temperature environment in the reflow mounting process. Examples of the non-aqueous solvent include cyclic esters, chain esters, cyclic ethers, chain ethers, and the like. In the present embodiment, a single compound or a composite selected from solvents having a high boiling point such as γ-butyrolactone, propylene carbonate, and ethylene carbonate is used. Thereby, the pressure inside the exterior body 11 can be suppressed in a high temperature environment. In addition, as the supporting salt, among the various salts having durability against the reflow temperature, those having the optimum conductivity by the combination with the solvent are used.

  As the electrolyte E, in addition to the above electrolytic solution, a polymer electrolytic solution, an inorganic solid electrolyte, an ionic liquid, a room temperature molten salt, or the like can be used.

  The electric double layer capacitor 10 in which the power generation element 16 and the electrolyte E are accommodated in the above-described size has an internal resistance value of less than 50 mΩ in a single cell, and this is connected in series via a connection terminal. It has an internal resistance value of 100 mΩ or less. Accordingly, it can be suitably used as an auxiliary power source for a main power source in various electronic devices such as instantaneously discharging a current of several A or discharging a current of several tens of mA for several seconds. In addition, by providing excellent heat resistance, changes in electrical characteristics can be suppressed even when exposed to high temperatures during the reflow mounting process.

  Furthermore, the fabricated electric double layer capacitor 10 was heat-treated at the reflow temperature and then incorporated into a mobile phone, and a drop impact test was performed to drop it onto concrete from a height of 1.5 m. Even if it repeated below, the external terminal did not come off from the terminal, and the connection was maintained.

  The terminal-attached electric double layer capacitor 10 in this embodiment is mounted on the circuit board 18 in an arrangement as shown in FIG. Here, FIG. 7 is a schematic diagram showing an arrangement when the electric double layer capacitor shown in FIG. 1 is mounted on a circuit board. The pair of external terminals 5 are connected to the pattern marked + V and the pattern marked 0V on the circuit board. The balance terminal 7 is connected to a pattern (indicated as Bal.) Arranged in the middle of the + V and 0V patterns. Thus, the pair of external terminals 5 and the balance terminal 7 are arranged in the vicinity of the lid member, which is a side surface including the terminals, so that the circuit board pattern is simple and compact. On the other hand, the outer package of each cell connected to the fixed terminal 6 is electrically connected to a dummy pattern provided on the circuit, and the potential is in a floating state.

  The balance resistor 19 is disposed on the circuit to which the balance terminal 7 is connected. The balance resistor 19 uses a high-resistance resistor in units of kΩ to MΩ according to the leakage resistance value of two single cells and the circuit design of the device, and the voltage is equally divided during charging, so that each single cell It is possible to equalize the charging voltages of the two.

  In FIG. 7, the electric double layer capacitor with terminal 10 is connected to the circuit board at the side surface including the terminal and the opposite surface side thereof, that is, at a total of four locations on the external terminal, balance terminal side, and fixed terminal side. As a result, the adhesion force to the substrate is excellent even with respect to the external force and bending moment applied perpendicularly to the longitudinal direction of the cell. In addition, it is excellent against the peeling force acting in the vertical direction of the cell, and has sufficient durability against the mechanical impact that the mounted device receives by dropping or the like after mounting.

  Next, a method for manufacturing the terminal-attached electric double layer capacitor 10 configured as described above will be described below.

  The manufacturing method of this embodiment includes an exterior body manufacturing process, a single cell manufacturing process, a cell connecting process, a welding process of a fixed terminal, an external terminal, and a balance terminal, and a sealing process. Each of these steps will be described in detail.

  First, an exterior body manufacturing process for manufacturing the case 13 and the lid member 12 constituting the exterior body is performed. The case 13 is created by deep drawing of stainless steel. Here, the transfer process is gradually deepened and finally the sizing process is performed to precisely finish the opening surface of the case.

  On the other hand, the lid member 12 is first prepared by preparing a glass tablet (sintered product) for forming a hermetic seal, a thin rod for terminals, and a plate with a hole for the lid member. A glass tablet through which a thin rod is passed is attached to the hole of the plate with holes, and is placed on a firing jig for positioning them, and heat-treated in a firing furnace. In this manner, the lid member 12 having a pair of hermetic seal structures in which the terminals 14 are fixed by the insulating member 15 is produced.

  Next, a single cell manufacturing process is performed. First, the positive electrode, the negative electrode, and the separator which comprise the electric power generation element 16 are prepared, respectively. Then, a step of welding a pair of leads 17 to the positive and negative electrode current collectors is performed.

Subsequently, the positive and negative electrode current collectors to which the leads 17 are connected are alternately stacked with the separator interposed therebetween, and then the power generation element 16 is manufactured by winding, stacking, and the like. Subsequently, a pair of leads 17 are connected to the terminals 14 respectively. Thereby, the electric power generation element 16 and the cover member 12 are integrated. Furthermore, the power generation element 16 to which the lid member 12 is connected is pushed into the case 13, and the lid member 12 and the case 13 are seam welded to produce the exterior body 11.
At this point, the single cell manufacturing process is completed.

  Next, the process of connecting each single cell is performed. First, the connecting plate 8 is punched out of a stainless plate with a press or the like and finished to a predetermined size. Subsequently, the plurality of unit cells to be connected are juxtaposed with the surface of the lid member 12 aligned. Thereafter, the connecting plate 8 is overlapped so as to straddle the lid members 12 of the plurality of single cells, YAG laser light is irradiated from the front direction of the connecting plate, and the two adjacent exterior bodies 11 and the connecting plate 8 are welded. As welding conditions, for example, YAG laser light is applied to four rectangular peripheral portions of the connecting plate 8 at an output of 1.2 kW and an irradiation time of 1.5 msec. By providing at least two to three welding points, the connecting plate 8 and the exterior body 11 can be firmly connected.

  Next, a process of welding the fixed terminal 6 to the exterior body 11 is performed. First, the fixed terminal 6 is prepared. Specifically, after nickel and gold are partially plated on a stainless steel flat plate, punching and bending are performed by a press or the like. Thereby, the fixed terminal 6 shown in FIG. 5 can be obtained.

  Then, the process of welding the upright part 6a of the fixed terminal 6 to the exterior body 11 by laser spot welding is performed. Specifically, the upright portion 6 a is overlaid on the bottom surface of the case 13. Then, the upright portion 6a is irradiated with YAG laser light from a vertical direction, and the upright portion 6a and the exterior body 11 are welded. As a welding condition, for example, YAG laser light is irradiated to four rectangular peripheral portions of the upright portion 6a at an output of 1.2 kW and an irradiation time of 1.5 msec. By providing at least 2 to 3 or more welding points, the fixed terminal 6 and the exterior body 11 can be firmly connected.

  Next, a welding process is performed in which the external terminal 5 and the balance terminal 7 are welded to the terminal 14 fixed to the exterior body 11. First, the external terminal 5 and the balance terminal 7 are produced and prepared. Specifically, after nickel and gold are partially plated on a stainless steel flat plate, it is punched and bent by a press or the like. Thereby, the external terminal 5 shown in FIG. 2 and the balance terminal 7 shown in FIG. 3 can be obtained.

  Then, the process of welding the terminal connection part 5a and 7a of the external terminal 5 and the balance terminal 7 to the terminal 14 fixed to the exterior body 11 by laser spot welding is performed. Hereinafter, the welding between the external terminal 5 and the terminal 14 will be described as an example, but the same applies to the welding between the balance terminal 7 and the terminal 14.

  Specifically, the terminal connection portion 5a of the external terminal 5 is overlaid on the terminal 14 by the arrangement as shown in FIG. Then, YAG laser light is irradiated from above, and the terminal connecting portion 5a and the terminal 14 are welded. As welding conditions, for example, YAG laser light is irradiated to two adjacent points as shown in the irradiation spot 25 at an output of 1.2 kW and an irradiation time of 1.5 msec. In particular, by providing two or more welding points, the external terminal 5 and the terminal 14 can be mechanically firmly connected and can be electrically connected with a sufficiently low connection resistance.

  In the present embodiment, the external terminal 5 and the balance terminal 7 are disposed so as to cover the terminal 14. The external terminal 5 and the balance terminal 7 may be shortened in the upright portion while maintaining the crank shape, and the terminal connection portions 5a and 7a may be connected below the terminal 14.

  Subsequently, sealing the electrolyte E into the outer package 11 and welding the case 13 and the sealing plug 9 to produce the outer package 11 containing the electrolyte E and the power generation element 16 therein. Stop process.

This sealing step will be specifically described.
First, in the present embodiment, an electrolyte solution made of a supporting salt dissolved in a nonaqueous solvent is used as the electrolyte E, and the inside of the exterior body 11 is formed from an injection hole formed in one place of the case 13 of the exterior body 11. Inject a fixed amount. In order to inject the predetermined amount, the work of defoaming the electrolyte, the work of depressurizing the inside of the exterior body, and the work of pressurizing are performed to sufficiently penetrate the positive and negative electrode materials of the power generation element. In the case of this example, about 0.2 g of electrolyte was injected.

  Thereafter, the electrolytic solution adhering to the opening of the injection hole is wiped off, and the sealing plug 9 is disposed in the injection hole. Then, the outer periphery of the sealing plug 9 is sealed by seam welding.

  As a result, the terminal-attached electric double layer capacitor 10 shown in FIG. 1 in which the electrolyte E and the power generation element 16 are accommodated in the exterior body 11 can be obtained.

  In addition, the welding conditions shown by the said manufacturing process are examples, and conditions, such as an output and irradiation time, are not limited to this but can be implemented. However, in the welding process of the terminal 14 and the external terminal 5 and the welding process of the terminal 14 and the balance terminal 7, the insulating member 15 made of glass having a hermetic structure is cracked by a thermal shock caused by laser irradiation, and leaks. There is a possibility. It is desirable to carry out welding in an appropriate range in which the crack does not occur.

  Next, a modified example of the connection between the external terminal and the balance terminal and the terminal will be shown. In the embodiment described above, as shown in FIG. 1A, the crank-shaped external terminal 5 and the balance terminal 7 are connected to the upper part of the terminal, and the bottom surface parts 5 b and 7 b extend in the long side direction of the exterior body 11. As shown in FIG. 8 (a), the L-shaped external terminal 51, the balance terminal 71 having a U-shaped shape having a horizontal portion at the open end, and the side surface of the terminal 14 are shown. Alternatively, the electric double layer capacitor 20 may be welded. Here, FIG. 8 is an external perspective view showing a modification of the electric double layer capacitor shown in FIG.

  In the exterior body manufacturing process described above, when the terminal 14 is fixed by the insulating member 15, the terminal 14 may be inclined and fixed. For the purpose of miniaturization, the length of the terminal is about 4 to 5 mm, the diameter is also selected to be 1 mm or less, and the clearance tolerance with the firing jig such as carbon that fixes the position of the terminal during firing is slightly large. In some cases, the angle of the terminal is apt to occur although it is a slight angle. In that case, when the shape of the external terminal 5 and the balance terminal 7 is a crank shape as shown in FIG. 1A, the bottom surface height of the external terminal and the balance terminal varies due to the inclination of the terminal 14 with respect to the horizontal plane. There is a possibility that it may occur, and it may not be mounted horizontally on the circuit board, or the connection strength may be insufficient.

  Therefore, in such a case, it is preferable that the external terminal and the balance terminal have the shape shown in FIG. 8A, and the welding position with the terminal 14 is not the top surface of the terminal 14 but the side surface. In this way, as will be described later, it is possible to suppress variations in the height direction that occur due to the inclination of the terminals.

  If the external terminal 51 and the balance terminal 71 are arranged so that they can be welded without exceeding the length of the terminal 14, the long side of the electric double layer capacitor 20 with a terminal as in the example shown in FIG. Since the length in the direction can be shortened, the mounting area can be reduced.

  Here, the connection between the external terminal 51 and the balance terminal 71 and the terminal 4 will be described. The two external terminals 51 and the balance terminal 71 are arranged on the side surface of the terminal 14 so that the bottom surfaces 51b and 71b are in contact with one horizontal plane, and then the laser on the side surface of the terminal in consideration of the inclination of the terminal. Spot weld. In the case of the balance terminal 71, welding is performed by irradiating a laser from a slightly oblique lateral direction. The external terminal 51 is welded by laser irradiation from the lateral direction. At this time, if the inclination of the terminal is recognized in advance by an image processing technique or the like, the height of the welding position can be finely adjusted according to the angle of inclination of the terminal.

  FIG. 8B is a schematic diagram for explaining this situation, and is a cross-sectional view taken along line B-B ′ shown in FIG. The terminal 14 fixed to the insulating member 15 is slightly inclined downward from the horizontal plane (the inclination is θ), but is exaggerated in the drawing. The external terminal 51 is welded to the terminal 14 at the two welding points 25a and 25b. The center of the second welding point 25b is in contact with the first welding point 25a in consideration of the inclination θ of the terminal 14. The distance is set to the lower side by a distance of m × tan (θ) taking into account the horizontal distance m and the inclination θ.

  In this way, even when the terminal is inclined, the bottom surface 51b of the external terminal 51 can be set horizontally and can be maintained at a predetermined height. The same applies to the balance terminal.

  The shape of the balance terminal 71 in FIG. 8A is a shape in which a U-shape having a horizontal portion at the opening end is turned upside down, and the horizontal portion at the opening end is connected to the circuit board. In addition, although not shown, a U-shaped balance terminal may be used. In this case, the U-shaped opening is connected to the side surface of the terminal 14, and the U-shaped bottom portion is connected to the circuit board.

  In the above embodiment, two single cells are connected in series, but more single cells can be connected in series. For example, as shown in the electric double layer capacitor 30 with a terminal shown in FIG. 9, by connecting three single cells, a voltage up to three times the withstand voltage of the single cell can be used. More series connections are possible.

  In detail, the surface of the lid member 12 which is one side surface forming a single cell outer package and the side surface including the terminals is aligned and closely juxtaposed in three rows in a horizontal plane, and the outer terminals of the cells on both sides are connected. The external terminal 5 is connected, and the other terminals are connected by the balance terminal 7 between two adjacent terminals. Further, the exterior bodies are connected by welding or the like via the connecting plate 8 and the fixed terminal 6.

  In this way, even when the number of single cells is further increased, an electric double layer capacitor with terminals can be configured. Since the external terminals and the balance terminals are concentrated on the side surface including the terminals, the circuit board pattern to be mounted can be simple and compact even when the number of single cells is increased.

  Furthermore, in the present embodiment, the single cells are juxtaposed in the horizontal plane and connected in series, but the single cells may be stacked in series in the height direction.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described with reference to FIGS. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the electric double layer capacitor 40 with a terminal as shown in FIG. 10, the terminal 14 is fixed at only one place from the outer casing 21 of two single cells, and one of the positive and negative electrodes of the power generation element 16 is connected to the terminal 14. The other electrode is electrically connected to the exterior body 21, and the single cells are connected to each other via the connecting plate 8. Further, positive and negative external terminals 53 and 52 are connected to the terminal 14 of the single cell, and a balance terminal 72 is connected so as to straddle the exterior body 21. In FIG. 10, the case 23 is shown as a transparent body in order to show the inside of the exterior body 21.

  In the present embodiment, when the external terminal 52 is set to 0V and the external terminal 53 is set to + V, the external body has a half potential (+ V / 2). For example, when the external terminal 53 is 5.2V, the potential of the exterior body is 2.6V. In the first embodiment, the potential of the exterior body is basically different from that of the floating body.

  The arrangement of the external terminals 52 and 53 and the balance terminal 72 is gathered in the vicinity of the side surface that forms the exterior body and that includes the terminal. This makes the circuit board pattern simple and compact.

  Furthermore, the fixed terminal 6 is connected to the opposite surface of the side surface including the terminal, and can be firmly connected to the circuit board by a pair of external terminals, a balance terminal, and a fixed terminal.

  A method for manufacturing the electric double layer capacitor 40 according to the present embodiment will be briefly described. The manufacturing method includes an exterior body manufacturing process, a single cell manufacturing process, a cell connecting process, a welding process of a fixed terminal, an external terminal, and a balance terminal, and a sealing process.

  First, an exterior body manufacturing process for manufacturing an exterior body is performed. In the present embodiment, unlike the first embodiment, there is only one terminal. Therefore, it is only necessary to form one hermetic seal structure on the lid member. The other structure is the same as that of the first embodiment, and is manufactured according to the above-described production method.

  Next, a single cell manufacturing process is performed. First, the power generation element 16 to which the lead 17 is connected is manufactured in the same manner as in the first embodiment, and then one of the positive and negative leads 17 of the power generation element 16 is connected to the terminal 14 fixed to the lid member 22, and the other Is electrically connected to the surface of the lid member on the side to which the lead 17 is connected. Thereby, the electric power generation element 16 and the cover member 22 are integrated.

  Further, the power generation element 16 to which the lid member 22 is connected is pushed into the case 23, and the lid member 22 and the case 23 are seam welded to produce the exterior body 21. At this point, the single cell manufacturing process is completed.

  Next, the cell connection process which connects each single cell is performed. As shown in FIG. 10, two single cells are placed in close contact with each other in a horizontal plane with the surface of the lid member, which is one side surface forming the exterior body and the side surface including the terminals, being aligned. Then, the connecting plate 8 and the lid member 22 are welded by overlapping the connecting plate 8 so as to straddle two single cells and irradiating the connecting plate 8 with a YAG laser from a vertical direction.

  Next, the fixed terminal 6 and the exterior body 21 are connected by welding. Subsequently, the terminal 14 and the external terminals 52 and 53 are connected by welding. In this embodiment, the external terminals 52 and 53 are laser spot welded at the upper part of the terminal 14, respectively. Next, the terminal connection part 72a of the balance terminal 72 is welded with the upper part of the exterior body 21, and is electrically connected. Thus, unlike the first embodiment, the balance terminal 72 is connected to the exterior body 21 in the second embodiment. Note that the order of connection of the fixed terminal, the external terminal, and the balance terminal may be changed.

For each of the above welding conditions, the YAG laser irradiation conditions described in the first embodiment may be used. Further, at the time of welding the terminal 14 and the external terminal, at least two or more welding points are provided so that the mechanical connection can be strengthened and the connection can be electrically made with a sufficiently low connection resistance.
Subsequently, a sealing process is performed. In this step, as in the first embodiment, after the electrolyte E is sealed in the outer package 21, the sealing plug is seam welded and sealed.

  Thus, the electric double layer capacitor 40 with a terminal in which the electrolyte E and the power generation element 16 are accommodated in the exterior body 21 shown in FIG. 10 can be obtained.

  This embodiment is not limited to the case where the single cells are juxtaposed in the horizontal plane and connected in series as shown in FIG. 10, but the single cells are vertically oriented like the electric double layer capacitor 50 with a terminal shown in FIG. 11. It may be a structure in which they are stacked and connected in series. In that case, since the height from the circuit board on which the terminal 14 of each single cell is mounted is different, the dimensions of the positive and negative external terminals 54 and 55 in the height direction are also different. In FIG. 11, in order to show the external terminal 54, the balance terminal 73 is shown by a transparent body.

  On the other hand, the dimension in the height direction of the upright portion 61a of the fixed terminal 61 is designed to be longer than that of the upright portion 6a of FIG. 10, and plays the role of mechanically joining two single cells. As a result, the circuit board can be firmly connected, and the mounting is highly durable against a mechanical load due to a drop impact or the like.

  In the case of the structure shown in FIG. 11, the height dimension of the electric double layer capacitor with a terminal increases, while the mounting area can be reduced to about half. Two cells can be connected in series either in the horizontal plane or in the vertical direction, depending on the method preferred for the design of the electronic equipment to be used.

  Also in the second embodiment, since the external terminals and the balance terminals are concentrated on the side surface including the terminals, the circuit board pattern to be mounted can be made simple and compact.

(Third embodiment)
Next, a third embodiment according to the present invention will be described with reference to FIGS. In addition, in this embodiment, since it is substantially the same as the component in 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In the electric double layer capacitor 60 with a terminal as shown in FIG. 12, the difference from the components in the first embodiment is an external terminal 56 and a balance terminal 74.

  As for the main material of the external terminal 56 in the present embodiment, a clad material produced by cold-welding a first material 57 made of stainless steel and a second material 58 made of copper over the entire surface. The total thickness is 0.2 mm, the thickness of the first material is 0.15 mm, and the thickness of the second material is 0.05 mm. The base material is punched into a flat plate and bent into a crank shape to form an external terminal 56. As shown in FIG. 12, a bottom surface portion 56b for connecting to a circuit board and an upper portion of the terminal are formed. A terminal connection portion 56a to be connected is formed.

The resistivity of copper as the second material at 293K is 1.68 × 10 ⁻⁸ Ωm, which is one tenth or less of the resistivity of stainless steel (7.2 × 10 ⁻⁷ Ωm). When used as a material, the resistance value is greatly reduced. Furthermore, copper is a material used for wiring of a circuit board, and has good wettability during soldering, and thus is suitable as a material for an external terminal in contact with the circuit board.

For example, the resistance value of an external terminal manufactured by bending a stainless steel plate having a long side of 8 mm, a width of 2 mm, and a thickness of 0.15 mm is calculated as follows.
(Resistance value) = (resistivity) × ((long side) / (width × thickness))
= 7.2 × 10 ⁻⁷ Ωm × (8 × 10 ⁻³ m / (2 × 10 ⁻³ m × 0.15 × 10 ⁻³ m))
= 19.2mΩ
On the other hand, in the external terminal 56 in the present embodiment, the first material 57 and the second material 58 are in pressure contact with each other. Similarly, when formed from a flat plate having a length of 8 mm and a width of 2 mm, the resistance value is calculated as follows, and is greatly reduced as compared with the case of being made of stainless steel.
(Resistance value of the first material) = (resistivity) × ((long side) / (width × thickness))
= 7.2 × 10 ⁻⁷ Ωm × (8 × 10 ⁻³ m / (2 × 10 ⁻³ m × 0.15 × 10 ⁻³ m))
= 19.2mΩ
(Resistance value of second material) = (resistivity) × ((long side) / (width × thickness))
= 1.68 × 10 ⁻⁸ Ωm × (8 × 10 ⁻³ m / (2 × 10 ⁻³ m × 0.05 × 10 ⁻³ m))
= 1.3mΩ
(Resistance value) = 1 / (1 / (resistance value of the first material) + 1 / (resistance value of the second material))
= 1.3mΩ
Further, as shown in FIG. 14, for the external terminal 56, the first material 57 and the second material 58 are entirely layered, and the second material 58 is the first material 58. There may be a layer only of the first material 57 in contact with the material 57. In this case, the terminal connecting portion 56a is composed of only the first material 57, and is laser spot welded to the upper portion of the terminal 14. As a result, welding between the same kind of metals becomes possible, and a plurality of welding points by laser spot welding are provided, so that the connection is strong.

  The main material of the balance terminal 74 is a clad material produced by cold-welding the first material 75 formed of stainless steel (SUS304) and the second material 76 formed of copper over the entire surface. The total thickness is 0.2 mm, the thickness of the first material is 0.15 mm, and the thickness of the second material is 0.05 mm. The base material is punched into a flat plate and bent into a crank shape to form a balance terminal 74. As shown in FIG. 12, a bottom surface portion 74b for connection to a circuit board and an upper portion of the terminal are formed. A terminal connection portion 74a to be connected is formed. The balance terminal 74 and the upper part of the terminal 14 are connected by laser spot welding. In particular, by providing a plurality of welding points by laser spot welding, as described above, the mechanical connection becomes strong and the electrical resistance value due to the connection can be suppressed to an extremely low value. Is possible.

  In the balance terminal 74 shown in FIG. 12, the first material 75 and the second material 76 are in pressure contact with each other. When formed from a flat plate with a length of 8 mm and a width of 6 mm, the resistance value is calculated to be 0.4 mΩ as in the case of the external terminal 5 in FIG. Reduced to

  Similar to the external terminal 56, the balance terminal 74 has a first material 75 and a second material 76 that are entirely layered, and in particular, as shown in FIG. However, a layer of only the first material 75 may be present partially in contact with the first material 75. In this case, the terminal connection portion 74a is composed of only the first material 75 and is laser spot welded to the upper portion of the terminal. As a result, welding between the same kind of metals becomes possible, and a plurality of welding points by laser spot welding are provided, so that the connection is strong.

  As for the shape of the external terminal 56, as shown in FIG. 12, in addition to the crank shape shown in FIG. 14A, a U shape, an L shape, a flat plate shape, etc. Various shapes suitable for surface mounting can be applied as shown in FIG.

  Similarly, the balance terminal 74 has a U-shape, a flat plate shape, or a U-shape having a horizontal portion at the opening, in addition to the crank shape as shown in FIG. Various shapes suitable for surface mounting can be applied, for example, as shown in FIGS.

  The external terminal 56 and the terminal 14 shown in FIG. 14 can be connected in various ways as shown in FIGS. In FIG. 12A, a crank-shaped external terminal 56 is disposed so as to cover the terminal 14 and is laser spot welded from above, but as shown in FIG. However, each of the upright portions may be shortened while maintaining the crank shape, and the terminal connection portion 56a may be connected to the lower side of the terminal 14. Further, as shown in FIG. 15B, a connection between the U-shaped external terminal 56 and the terminal 14 may be used. Alternatively, as shown in FIG. 15C, the L-shaped external terminal 56 may be connected to the end face of the terminal 14, or may be connected to the side face of the terminal 14 although not shown. Furthermore, as shown in FIG. 15D, when the exterior body is thin, it is also possible to use a flat plate-like external terminal 56.

  Further, the connection form between the balance terminal 74 and the terminal 14 can be various forms similar to those of the external terminal 56 and the terminal 14.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in each of the above embodiments, an electric double layer capacitor has been described as an example of an electrochemical cell. It can also be applied to other electrochemical cells.

  In each of the above embodiments, the thickness and outer dimensions of the external terminal, balance terminal, fixed terminal, and connecting plate, and the outer dimensions of the terminals and the pitch between the terminals are appropriately set to have optimum dimensions and shapes. It is possible to design.

  In each of the above embodiments, the cross-sectional shape in the depth direction of the exterior body is illustrated as a quadrangle, but is not limited thereto, and may be other shapes such as a cylindrical shape or a track shape. . Even in the case of a cylindrical or track-shaped exterior body, the connecting plate and the fixed terminal described above can be similarly applied, and a plurality of single cells can be firmly connected.

  Furthermore, for the case of the exterior body, the manufacturing method by deep drawing has been described, but the case is not limited to the case of pressing or deep drawing with a bottomed shape, and a hollow corner or cylindrical pipe is used. What cut | disconnected to fixed length and joined the member used as a baseplate by welding may be used.

  Moreover, in each said embodiment, the material of the exterior body and the terminal was set to SUS316L which is austenitic stainless steel from a viewpoint of intensity | strength and corrosion resistance. However, it is not limited to this. For example, SUS329J4L, which is a two-phase stainless steel, may be used, and other stainless steels can be selected. It is also possible to select the material of the exterior body and the material of the terminal separately.

  Furthermore, materials other than stainless steel can be selected as materials for the outer package and the terminal. For example, cold rolled steel plated with a corrosion-resistant material such as nickel can be selected as the exterior body. The terminal can be made of a material such as Kovar.

  In each of the above embodiments, the external terminal, the balance terminal, and the fixed terminal are made of stainless steel that is easy to weld with the terminal and has good workability and corrosion resistance. The material is not limited to this as long as it can be welded to the exterior body. In addition, various metal films such as gold, tin, copper, and nickel may be formed on the bottom surface by plating so as to facilitate electrical connection with the circuit board.

  Further, in each of the above embodiments, the fixed terminal is made of a stainless steel flat plate. A partially formed structure may be used. As a result, similar to the plate-like fixed terminal, the circuit board can be mounted in a plurality of regions, and the external body potential can be set to a specific potential or grounded on the circuit board. In that case, it is desirable that the plurality of single cells are firmly connected by a connecting plate or the like so as to withstand a drop impact after mounting.

  Moreover, in each said embodiment, although the terminal and the external terminal were welded by laser spot welding, if it is a method which can be connected by local energy irradiation, it will not necessarily be limited to laser spot welding. For example, if it is the same non-contact type, electron beam welding capable of irradiating a sufficient amount of energy can be employed. Alternatively, connection by resistance welding may be used.

  Moreover, in each said embodiment, although it is supposed that it welds via a connection board about the connection method of exterior bodies, For example, various welding, such as resistance welding, laser welding, electron beam welding, arc welding, is carried out. Alternatively, the exterior bodies can be directly fixed using brazing or resin bonding. In each welding process, the welding conditions are set so as to avoid the heat effect on the power generation element and the electrolyte inside the exterior body. In that case, in order to improve weldability, it is desirable that the exterior bodies are adjacent to each other without a gap. On the other hand, if the exterior bodies are firmly connected via the connecting plate, the exterior bodies do not necessarily have to be in close contact with each other.

10, 20, 30, 40, 50, 60 ... Electric double layer capacitor 11, 21 ... Exterior body 12, 22 ... Cover member 13, 23 ... Case 14 ... Terminal 15 ... Insulating member 16 ... Power generation element 17 ... Lead E ... Electrolyte DESCRIPTION OF SYMBOLS 18 ... Circuit board 19 ... Balance resistance 5, 51, 52, 53, 54, 55, 56 ... External terminal 5a, 51a, 52a, 53a, 54a, 55a, 56a ... Terminal connection part 5b, 51b, 52b, 53b, 54b , 55b, 56b ... bottom surface portion 6, 61 ... fixed terminal 6a, 61a ... upright portion 6b ... bottom surface portion 7, 71, 72, 73, 74 ... balance terminal 7a, 71a, 72a, 73a, 74a ... terminal connection portion 7b, 71b, 72b, 73b, 74b ... bottom surface portion 57, 75 ... first material 58, 76 ... second material 8 ... connecting plate 9 ... sealing plug

Claims (18)

A plurality of electrochemical cells made of a metal cuboid provided with terminals, a power generation element having a lead connected to the terminals, and an electrolyte housed in the package were connected in series. An electrochemical cell with terminals,
It said electrochemical cells connected in series, are opposed to side surfaces of each other, and a surface of the terminal is provided for each electrochemical cell is fixed so as to be substantially flush,
The terminals connected to each other are welded to one balance terminal,
The terminals that are not connected to each other are each welded to an external terminal ,
The surface opposite to the surface on which the terminals are provided is fixed with a fixed terminal,
The terminal-equipped electrochemical cell , wherein the balance terminal, the external terminal, and the fixed terminal each include a bottom surface that is a mounting surface with a circuit board . Two electrochemical cells comprising an exterior body, which is a metal cuboid provided with terminals, a power generation element having a lead connected to the exterior body, and an electrolyte housed in the exterior body, are connected in series. Electrochemical cell with terminal,
It said electrochemical cells connected in series, are opposed to side surfaces of each other, and a surface of the terminal is provided for each electrochemical cell is fixed so as to be substantially flush,
The exterior body is connected to a balance terminal,
The terminal is welded to an external terminal ;
The surface opposite to the surface on which the terminals are provided is fixed with a fixed terminal,
The balance terminal, the external terminal, and the fixed terminal each include a bottom surface portion that is a mounting surface with a circuit board,
An electrochemical cell with terminals, characterized in that   The terminal-equipped electrochemical cell according to claim 1 or 2, wherein the terminal and the external terminal are welded at a plurality of locations. And assumes a horizontal surface formed by the bottom part of the external terminal, and assumes a horizontal surface formed by the bottom part of the balance terminal are substantially coplanar, facing the substrate of the with the planar outer package The terminal-attached electrochemical cell according to any one of claims 1 to 3, wherein a gap is formed between the surface and the surface.   The said electrochemical cell connected with the said balance terminal has the surface in which the said terminal was provided fixed with the connection board, The terminal attachment as described in any one of Claim 1 to 4 characterized by the above-mentioned. Electrochemical cell. The electrochemical cell with a terminal according to any one of claims 1 to 5 , wherein a surface having a connection portion between the terminal and the external terminal intersects the substrate surface perpendicularly. The electrochemical cell with a terminal according to any one of claims 1 to 6 , wherein the balance terminal has a crank shape in cross section. It said balance terminal has two of said bottom portion, either the bottom surface portion of claims 1 to 7, wherein it is located outside of two of the terminal to which the balance terminal are welded The electrochemical cell with a terminal as described in one. The electrochemical cell with a terminal according to any one of claims 1 to 8 , wherein the external terminal has a rectangular cross section. The electrochemical cell with a terminal according to any one of claims 1 to 8 , wherein the external terminal has a U-shaped cross section. The electrochemical cell with a terminal according to any one of claims 1 to 8 , wherein the external terminal has an L-shaped cross section. The electrochemical cell with a terminal according to any one of claims 1 to 8 , wherein the external terminal has a crank shape in cross section. At least one of the balance terminal or the external terminal has a multilayer structure including a first material that is the same kind of metal as the terminal and a second material having a resistivity lower than that of the first material. The terminal-attached electrochemical cell according to any one of claims 1 to 12 . An exterior body production process for producing a metal exterior body comprising a terminal;
A power generation element is housed inside the exterior body, and a connection step of connecting a lead of the power generation element to a terminal attached to the exterior body,
A connecting step of aligning and connecting the surfaces provided with the terminals of the plurality of exterior bodies;
Welding a fixed terminal to a surface facing the surface provided with the terminal among the surfaces of the plurality of exterior bodies connected by the connection step;
An external terminal welding step of welding the terminal and the external terminal not directly connected to the other exterior body at a plurality of welding points;
A balance terminal welding process of welding the terminal directly connected to the other exterior body and the balance terminal at a plurality of welding points;
Storing and sealing the electrolyte inside the exterior body;
I have a,
The balance terminal, the external terminal, wherein the fixed terminal, a method of producing the mounting surface and is provided with a bottom portion with a terminal electrochemical cell, wherein Rukoto the respective circuit board. An exterior body production process for producing a metal exterior body comprising a terminal;
A power generation element is housed inside the exterior body, and a connection step of connecting a lead of the power generation element to the exterior body,
A connecting step of aligning and connecting the surfaces provided with the terminals of the plurality of exterior bodies;
Welding a fixed terminal to a surface facing the surface provided with the terminal among the surfaces of the plurality of exterior bodies connected by the connection step;
An external terminal welding step of welding the terminal and the external terminal at a plurality of welding points;
A balance terminal welding step of welding the exterior body and the balance terminal;
Storing and sealing the electrolyte inside the exterior body;
I have a,
The balance terminal, the external terminal, wherein the fixed terminal, a method of producing the mounting surface and is provided with a bottom portion with a terminal electrochemical cell, wherein Rukoto the respective circuit board. The connecting step and the step of welding the fixed terminal, with the terminal according to 請 Motomeko 14 or claim 15 you comprises ligating at least two places the electrochemical cell by a connecting plate and the fixed terminal Electrochemical cell manufacturing method. The method of manufacturing an electrochemical cell with a terminal according to claim 14 or 15 , wherein the connecting step includes connecting the outer casings of the electrochemical cell by direct welding. The external terminal welding step has a gap between the surface of the external terminal connected to the substrate and the surface of the exterior body facing the substrate,
The said balance terminal welding process has a space | gap between the surface connected to the said board | substrate of the said balance terminal, and the surface facing the said board | substrate of the said exterior body, The Claim 14 or Claim 15 characterized by the above-mentioned. Manufacturing method of electrochemical cell with terminal.

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