JP6965164B2 - Battery pack and battery pack manufacturing method - Google Patents

Description

The present invention relates to a battery pack in which a circuit board is connected to a secondary battery cell, and more particularly to a battery pack in which a plurality of leader wires are connected to the circuit board and pulled out to the outside, and a method for manufacturing the same.

With the widespread use of mobile devices such as notebook personal computers and slate-type personal computers (so-called tablets), there is a demand for battery packs equipped with rechargeable and dischargeable secondary battery cells as their power sources. Some such battery packs have a plurality of leader lines drawn out to the outside in order to supply power and transmit signals to and from a mobile device or the like. The plurality of leader lines generally consist of positive and negative power lines and signal lines, and have a connector at the tip for connection. The battery pack is connected to a mobile device via this connector. As described above, in the battery pack provided with the leader wire, it is not necessary to provide the battery pack with a connector and connect the lead wire to the connector. Therefore, it is not necessary to connect the battery pack and the lead wire with a connector, and it is possible to prevent adverse effects such as poor contact of the connector.

However, in a battery pack in which a plurality of leader wires are connected to a circuit board and pulled out from the resin mold portion, it is difficult to mold the resin mold portion for insert molding the circuit board, and defective products occur in this process. The probability is high. This is because the leader wire is pinched by the mold and damaged when the circuit board is temporarily fixed and the mold is closed.

FIG. 21 is a front view showing a state in which the mold 140 sandwiches and clamps the leader wire 106 in the conventional battery pack manufacturing process. The mold 140 needs to seal the molding chamber with the leader wire 106 sandwiched between the upper and lower molds 140 so that the molten resin to be injected does not leak. The leader wire 106 connected to the circuit board is pulled out to the outside of the molding chamber in a state of being temporarily fixed to the mold 140, so that there is no gap between the mold 140 and the leader wire 106. Need to tighten. In order to realize this, the mold 140 of FIG. 21 is provided with a plurality of rows of guide grooves 141 for guiding the leader line 106 in the lower mold 140A. The guide groove 141 has a semicircular bottom along the leader line 106. The upper die 140B is provided with a plurality of rows of ridges 142 to be inserted into the guide groove 141, and the tip surface of the ridges 142 is semicircular. In this mold 140, the leader wire 106 is inserted into the guide groove 141 and arranged at a fixed position, the ridge 142 is inserted into the guide groove 141, and the upper and lower sides of the leader wire 106 are sandwiched between the upper mold 140B and the lower mold 140A. After wearing, the mold 140 is in close contact with the surface of the leader wire 106.

In the mold 140 of FIG. 21, the leader wire 106 is guided to the guide groove 141 of the lower mold 140A having a comb-shaped upper surface, the upper mold 140B is sealed in the lower mold 140A, and the leader wire 106 is tightly formed in the molding chamber. However, in the state of mold clamping, the leader wire 106 may be caught between the upper mold 140B and the lower mold 140A and may be damaged. When the resin mold portion is formed by sandwiching the leader wire 106 with the mold 140, the molten resin leaks from between the leader wire 5 and the mold 140, or the leader wire 106 sandwiched between the leader wires 140 is damaged. Then, the battery pack becomes defective. If a defective product is generated in this process, all the parts including the secondary battery cell cannot be used, so that the economic loss becomes extremely large.

Therefore, in the conventional manufacturing of the battery pack, the tip portion is soldered to the circuit board while specifying the lead length for each leader wire. For this reason, it takes time and effort to solder a plurality of leader wires to fixed positions on the circuit board, and there is a problem that efficient manufacturing cannot be performed. In addition, since the leader lines are connected while specifying the leader length, the connection position may deviate slightly. In this case, an error occurs in the lead-out amount of the plurality of leader lines, and the arrangement of the plurality of leader lines is unbalanced. In some cases, the appearance became worse.

Japanese Patent Application No. 2014-201583

The present invention has been made in view of such a conventional background. One object of the present invention is a battery pack capable of easily and easily arranging a tip portion connected to a circuit board at a predetermined position on a circuit board while allowing a plurality of leader wires to have a predetermined lead amount. And its manufacturing method.

In order to achieve the above object, according to the battery pack of the present invention, the secondary battery cell 1, the circuit board 5 electrically connected to the secondary battery cell 1 and equipped with a protection circuit, and the circuit board 5 are provided. The resin mold portion 4 formed by insert molding and the circuit board are arranged in the substrate storage portion , one end of which is connected to the circuit board 5, and the connector 69 is connected to the other end by being pulled out from the resin mold portion 4. It is provided with a plurality of leader lines 6 and the like. Further, the battery pack includes positioning mechanisms 60 and 90 for arranging the leader wire 6 at a fixed position on the circuit board 5. The positioning mechanism is provided on the outer peripheral surface of the substrate housing portion, and the positioning mechanisms 60 and 90 include a plurality of rows of comb-shaped ribs 61 and 91, and each drawer is provided between the adjacent comb-shaped ribs 61 and 91. The guide grooves 62 and 92 are provided with a plurality of rows of guide grooves 62 and 92 in which the wires 6 can be inserted separately and independently and the inserted leader wires 6 can be moved along the comb-shaped ribs 61 and 91. The upper end openings 63 and 93 are smaller than the outer shape of the leader wire 6 and larger than the thickness of the core wire 6a of the leader wire 6. In the battery pack, a circuit board 5 in which a plurality of leader wires 6 are connected at fixed positions via positioning mechanisms 60 and 90 is embedded in an insulating molding resin, and the leader wires 6 are pulled out from the resin mold portion 4 to the outside. There is.

With the above configuration, since a plurality of leader wires are arranged at a fixed position on the circuit board via a positioning mechanism, the plurality of leader wires are easily and easily connected to the circuit board while being pulled out so as to have a predetermined leader amount. The tip of the circuit board can be accurately placed at a predetermined position on the circuit board. This positioning mechanism is provided with a multi-row guide groove in which each leader wire can be inserted separately and independently between the multi-row comb-shaped ribs, and the upper end opening of the guide groove is inserted from the outer shape of the leader wire. It is also small and larger than the thickness of the core wire of the leader wire, so it is easy to insert the leader wire by pushing it from the upper end opening, but when it is inserted in the guide groove, move it so that it does not come out of the leader wire. Can be positioned.

In the battery pack of the present invention, the positioning mechanisms 60 and 90 can make the distance between the guide grooves 62 and 92 substantially equal to the distance between the plurality of leader wires 6 connected to the connector 69. With the above configuration, each leader wire connected to the connector can be quickly guided to the guide groove in the vicinity of the connector. This is because a plurality of leader wires can be arranged at intervals of the guide grooves via the connector, so that the plurality of leader wires can be inserted into the guide grooves at intervals specified by the connector.

In the battery pack of the present invention, the positioning mechanisms 60 and 90 can be provided with circular grooves 64 and 94 along the outer peripheral surface of the leader wire 6 at the ends of the guide grooves 62 and 92. With the above configuration, the gap between the circular groove and the leader wire can be narrowed, so that it is possible to effectively prevent the molten resin filled in the molding chamber from leaking to the outside from the guide groove when the resin mold portion is molded.

In the battery pack of the present invention, the circuit board 5 includes a plurality of connecting portions 55 for connecting the tip portions of the plurality of leader wires 6, and the positioning mechanisms 60 and 90 are positioned so as to face the plurality of connecting portions 55. A plurality of guide grooves 62 and 92 can be formed in the structure. With the above configuration, by arranging the positions of the tips of the plurality of leader wires at the positions of the guide grooves of the positioning mechanism, the tips of the plurality of leader wires are easily and easily opposed to the connection portions provided on the circuit board. Can be placed in position.

The battery pack of the present invention includes a holder case 2 for accommodating the secondary battery cell 1 and the circuit board 5, and the positioning mechanism 60 can be integrally molded with the holder case 2. With the above configuration, the secondary battery cell and the circuit board are housed and fixed in a fixed position of the holder case, so that the secondary battery cell and the circuit board are arranged on the same plane as an integrated structure, and the mechanical strength is increased. Can be enhanced. In particular, by protecting the entire outer shell of the battery pack with a holder case, high exterior strength can be realized and the strength against dropping and bending can be increased. Further, by integrally molding the positioning mechanism in the holder case, the number of parts and the manufacturing process can be reduced, and mass production can be performed efficiently.

The battery pack of the present invention includes a positioning holder 9 made of a separate member that constitutes the positioning mechanism 90, and the positioning holder 9 can be fixed to the circuit board 5 and inserted into the resin mold portion 4. With the above configuration, by fixing the positioning holder made of another member to the circuit board, a plurality of leader wires can be arranged at a fixed position on the circuit board while the positioning mechanism is arranged at a predetermined position on the circuit board.

The method for manufacturing a battery pack of the present invention is a method for manufacturing a battery pack in which a plurality of leader wires 6 are connected to fixed positions on a circuit board 5, and includes a plurality of rows of comb-shaped ribs 61 and 91 and adjacent combs. A plurality of rows of guide grooves 62 and 92 are provided between the ribs 61 and 91, and the upper end openings 63 and 93 of the guide grooves 62 and 92 are smaller than the outer shape of the leader wire 6 and the core wire of the leader wire 6 is formed. It is provided with positioning mechanisms 60 and 90 that are larger than the thickness of 6a. Further, the manufacturing method of the present invention includes an insertion step of individually inserting a plurality of leader wires 6 having a connector 69 connected to the other end into the multi-row guide grooves 62 and 92 of the positioning mechanisms 60 and 90, and a plurality of rows. A length adjusting step of adjusting the lead-out length of the leader line 6 by simultaneously moving a plurality of leader lines 6 inserted into the guide grooves 62 and 92 in the lead-out direction along the guide grooves 62 and 92, and a predetermined step. The connection step of soldering one end of the plurality of leader wires 6 drawn to the length of the above to the circuit board 5, and the circuit board 5 in which the secondary battery cell 1 and the plurality of leader wires 6 are connected are insert-molded. It includes a molding step of molding a resin mold portion 4 that pulls out the other ends of the plurality of leader wires 6 to the outside.

By simultaneously pulling out a plurality of leader wires along the guide groove of the positioning mechanism by the above method, the plurality of leader wires can be pulled out evenly and to a predetermined length, and on the circuit board side, the plurality of leader wires can be pulled out. The tip portions can be arranged at predetermined intervals on the connection portion of the circuit board, and a plurality of leader wires can be efficiently soldered to a fixed position on the circuit board for connection. In particular, while the leader wire is pushed in from the upper end opening and inserted easily, it can be moved so that it does not come out of the leader wire when it is inserted in the guide groove, so the connection position of multiple leader wires can be easily specified and work efficiency is improved. Can be improved.

It is a perspective view of the battery pack which concerns on one Embodiment of this invention. It is a perspective view which turned upside down the battery pack shown in FIG. FIG. 3 is a cross-sectional view taken along the line III-III of the battery pack shown in FIG. FIG. 2 is a sectional view taken along line IV-IV of the battery pack shown in FIG. It is an exploded perspective view of the battery pack shown in FIG. It is a top view which shows the state which set the secondary battery cell, a circuit board, and a leader wire in a holder case. It is an enlarged perspective view which shows an example of a secondary battery cell. FIG. 6 is a sectional view taken along line VIII-VIII of the holder case shown in FIG. FIG. 6 is an enlarged perspective view showing a connection portion between the circuit board of the holder case shown in FIG. 6 and the secondary battery cell. It is an enlarged cross-sectional view which shows the connection structure of a circuit board and a protection element. It is an enlarged plan view which shows the connection structure of a leader line and a circuit board. FIG. 11 is a cross-sectional view taken along the line XII-XII of the positioning mechanism shown in FIG. It is an enlarged perspective view of a positioning mechanism. It is a perspective view of the battery pack which concerns on other embodiment of this invention. It is a perspective view of the battery pack which concerns on other embodiment of this invention. It is a perspective view of the battery pack which concerns on other embodiment of this invention. It is an exploded perspective view of the battery pack shown in FIG. It is a top view excluding the exterior sheet and the resin mold of the battery pack shown in FIG. FIG. 8 is a sectional view taken along line IX-IX of the battery pack shown in FIG. FIG. 6 is an enlarged exploded perspective view of the battery pack shown in FIG. 17 as viewed from the opposite side. FIG. 5 is an exploded front view showing a state in which a mold sandwiches and clamps a lead wire holder in a conventional battery pack manufacturing process.

The battery pack according to the embodiment of the present invention is shown in FIGS. 1 to 6. The battery packs shown in these figures are mainly attached to thin portable electronic devices such as notebook personal computers and tablets, and are used as a power source for these devices. However, the battery pack of the present invention can be attached to an electric device other than a thin portable electronic device and used as a power source.

The battery pack 100 shown in FIGS. 1 to 6 is a circuit board 5 which is electrically connected to a thin secondary battery cell 1 and a secondary battery cell 1 and has a protection circuit mounted therein, and a secondary battery cell 1 and a circuit. A holder case 2 for accommodating the substrate 5, a resin mold portion 4 formed by insert-molding the circuit substrate 5 housed in the holder case 2, and one end connected to the circuit substrate 5, and from the resin mold portion 4 to the outside. It is provided with a plurality of leader wires 6 which are drawn out and have a connector 69 connected to the other end. The battery pack 100 shown in the figure includes two secondary battery cells 1, and these secondary battery cells 1 are arranged at both ends of the holder case 2 in a facing position, and the secondary batteries facing each other are arranged. The circuit board 5 is arranged between the cells 1, and the secondary battery cell 1 and the circuit board 5 are arranged on substantially the same plane.
(Secondary battery cell 1)

The secondary battery cell 1 has an outer shape smaller than the width and a thickness, and is a square battery having a thin shape as a whole. As shown in FIG. 7, the secondary battery cell 1 includes a bottomed cylindrical metal outer can 11 having an opening on one side, and a sealing plate 12 for closing the opening of the outer can 11. The opening of the outer can 11 is sealed by laser welding with a flat plate-shaped sealing plate 12 obtained by pressing a metal plate. The secondary battery cell 1 shown in the figure has curved surfaces on both sides of the outer can 11. However, as the thin secondary battery cell, not only a square battery but also a laminated battery in which electrodes are arranged inside a plastic exterior film can be used. The thin secondary battery cell 1 is a lithium ion secondary battery having a thickness of 3 mm to 10 mm. However, the secondary battery cell can be a non-aqueous electrolyte secondary battery other than the lithium ion secondary battery, or any other rechargeable secondary battery such as a nickel-hydrogen battery. The battery pack 100 in which the secondary battery cell 1 is a lithium ion secondary battery can increase the overall battery capacity.

The secondary battery cell 1 has a sealing plate 12 as a terminal surface 1X, and positive and negative electrodes 10 are provided on the terminal surface 1X. The secondary battery cell 1 shown in FIG. 7 is provided with a convex electrode 13 insulated from the sealing plate 12 at the center of the sealing plate 12. In the secondary battery cell 1, the convex electrode 13 provided on the sealing plate 12 is used as the first electrode 10A, and the sealing plate 12 is used as the second electrode 10B, and positive and negative electrodes 10 are provided on the terminal surface 1X. In the secondary battery cell 1 in the figure, the clad plate 14 is fixed to one end of the sealing plate 12 to form the second electrode 10B. The secondary battery cell 1 can reliably connect the connection lead plate 16 via the clad plate 14. In the secondary battery cell 1 shown in the figure, the convex electrode 13 (first electrode 10A) serves as a negative electrode, and the sealing plate 12 and the clad plate 14 (second electrode 10B) serve as a positive electrode.

Further, the secondary battery cell 1 is provided with a safety valve 15 on the sealing plate 12. The safety valve 15 opens when the internal pressure of the battery becomes higher than the set pressure to discharge the internal gas or the like to prevent the internal pressure from rising. However, the safety valve of the secondary battery cell may be provided in the outer can. In this case, the battery pack in which the sealing plate is embedded in the resin mold portion can easily discharge the gas or the like inside from the side surface of the outer can.

Further, in the secondary battery cell 1, a connection lead plate 16 for energization is connected to positive and negative electrodes 10 provided on the terminal surface 1X. The secondary battery cell 1 has a first connection lead plate 16A connected to the convex electrode 13 which is the first electrode 10A and a second connection lead plate 16B connected to the sealing plate 12 which is the second electrode 10B. It is connected to the circuit board 5 via. In the battery pack 100 shown in the figure, two secondary battery cells 1 are connected to the circuit board 5. The two secondary battery cells 1 are connected in series on the circuit board 5.

(Circuit board 5)
The circuit board 5 is equipped with electronic components that realize a protection circuit for the secondary battery cell 1 and the like. The protection circuit detects the temperature, voltage, current, etc. of the secondary battery cell 1 and controls the charging / discharging current. The protection circuits that realize this are a voltage detection circuit (not shown) that detects the voltage of the secondary battery cell 1, a current detection circuit (not shown) that detects the current, and the temperature of the secondary battery cell 1. (Not shown), a semiconductor switching element (not shown) such as an FET that controls the charge / discharge current of the secondary battery cell 1, and the temperature and overcurrent of the secondary battery cell 1 are detected. A protection element 7 such as a current cutoff element that operates in the same manner is mounted. Details of mounting the protective element 7 on the circuit board 5 and connecting the protective element 7 to the circuit board 5 will be described later.

The circuit board 5 can be made of epoxy resin. In the battery pack of the present invention, the overall strength can be increased by the holder case 2, so that the circuit board 5 can be manufactured at low cost without using a resin reinforced with reinforcing fibers such as glass fibers. However, it can also be manufactured with an epoxy resin reinforced with glass fiber or the like. The shape and size of the circuit board 5 arranged in the holder case 2 and the posture in which the circuit board 5 is arranged in the holder case are determined according to the outer shape and size required for the battery pack. The circuit board is formed so as to have an outer shape that can be arranged in the board storage portion formed in the holder case, which will be described in detail later.

(Holder case 2)
The holder case 2 houses the secondary battery cell 1 and the circuit board 5 and arranges them in a fixed position. The holder case 2 has a thin plate shape as a whole so that the thin secondary battery cell 1 and the circuit board 5 can be arranged on the same plane, and the secondary battery is on one side surface (upper surface in FIGS. 2 to 6). It is molded with resin into a shape having a storage opening that can store the cell 1 and the circuit board 5. The holder case 2 is made of a resin different from the resin for molding the resin mold portion 4, and is preferably molded with a resin having excellent heat resistance and strength, for example, a resin such as polycarbonate or ABS. The holder case 2 molded of these resins can improve the dimensional accuracy of the outer shape while keeping the heat resistant temperature at 70 ° C. or higher.

The holder case 2 has a battery arrangement area 21 in which the secondary battery cell 1 is arranged and a substrate arrangement area 22 in which the circuit board 5 is arranged in the same plane. The holder case 2 shown in FIG. 6 is provided with battery arrangement areas 21 at both ends so that two secondary battery cells 1 can be stored, and a substrate arrangement area 22 is provided between the opposite battery arrangement areas 21. There is. As described above, in the holder case 2 having the battery arrangement area 21 and the substrate arrangement area 22, the outer shape of the holder case 2 can be easily changed by adjusting the size of the substrate arrangement area 22. For example, since the outer shape of the secondary battery cell 1 is specified by its standard and capacity, it is difficult to change the design such as the size in the battery arrangement area 21, but the design of the substrate arrangement area 22 can be modified with a high degree of freedom. be. Therefore, the holder case 2 can be easily adapted to electronic devices by designing and deforming the substrate arrangement area 22 to an optimum size and shape in order to realize the outer shape required for the battery pack. Further, in a battery pack having a plurality of secondary battery cells, the outer shape of the holder case can be easily changed by adjusting the number of secondary battery cells to be stored and the arrangement of the battery arrangement area and the substrate arrangement area. Therefore, it is possible to easily support electronic devices to which a battery pack is mounted.

The holder case 2 shown in FIG. 6 has a rectangular shape extending in one direction as a whole. In this holder case 2, the battery arrangement areas 21 are formed at both ends in the longitudinal direction, and the substrate arrangement area 22 formed in the middle is formed to extend in the longitudinal direction, and the total length of the holder case 2 is adjusted. There is. In the board arrangement area 22, a circuit board 5 extending in the longitudinal direction is arranged so that both ends of the circuit board 5 are close to the terminal surfaces 1X of the secondary battery cells 1 arranged so as to face each other.

Here, in order to adjust the outer shape of the holder case 2, it is required to reduce the cost by reducing the size of the circuit board 5 and the resin mold portion 4 to be arranged in the substrate arrangement area 22 in which the area is widened. In order to realize this, in the holder case 2 shown in FIG. 6, the substrate arrangement region 22 is formed by molding the resin molding region 23 in which the circuit board 5 is arranged and the resin mold portion 4 is formed, and the resin mold portion 4. It is partitioned into a hollow region 24 that is not used. In the holder case 2 shown in the figure, the central portion of the substrate arrangement region 22, the region connecting the central portions of the terminal surfaces 1X of the facing secondary battery cells 1 is set as the resin molding region 23, and both sides of the resin molding region 23 are designated as the resin molding region 23. The hollow region 24 is used. The resin molding region 23 and the hollow region 24 are partitioned by a partition wall 33. In the holder case 2 shown in the figure, a pair of partition walls 33 are provided in the central portion of the substrate storage area 22 along the longitudinal direction, and a substrate storage portion 26 for storing the circuit board 5 is provided between the opposing partition walls 33. Is forming.

The hollow region 24 is provided with a plurality of reinforcing ribs 34 that intersect vertically and horizontally in a grid pattern, and the entire hollow region 24 is divided into a plurality of hollow chambers 28 for reinforcement. In this way, the structure in which the hollow region 24 is provided in the substrate arrangement region 22 and the plurality of hollow chambers 28 are provided can reduce the manufacturing cost by reducing the amount of the insulating molding resin used while making the holder case 2 lightweight. The holder case 2 of FIG. 6 is provided with hollow portions 24 on both sides of the substrate arrangement region 22, but the holder case is variously changed in arrangement, shape, size, etc. of the hollow portions according to the required outer shape. can. However, the holder case does not necessarily have to be provided with a hollow region in the substrate arrangement region, and the entire substrate arrangement region can be used as the substrate storage portion. For example, in a structure in which the substrate arrangement area is shortened in the overall length and lengthened in the width direction (the lateral direction of the holder case), the hollow region is not provided and the substrate is placed between the opposing secondary battery cells in the lateral direction. It is also possible to provide a board storage unit for storing the extending circuit board.

In the holder case 2 shown in FIGS. 3 to 6, a peripheral wall 30 is provided along the outer circumference of a rectangular shape, and a battery storage portion 25 for accommodating the secondary battery cell 1 and a substrate storage portion 26 for accommodating the circuit board 5 are provided inside. And are provided. As shown in FIG. 3, the holder case 2 is arranged with the circuit board 5 as a stepped structure in which the bottom plate 32, which is the bottom surface of the substrate placement area 22, is higher than the surface plate 31, which is the bottom surface of the battery placement area 21. The substrate storage portion 26 is formed shallower than the battery storage portion 25. With this structure, the amount of the insulating molding resin used by thinly molding the resin molding portion 4 for insert molding the circuit board 5 can be reduced. Further, the holder case 2 shown in the figure is provided by integrally molding a plurality of projecting pieces 38 projecting outward from the peripheral wall 30 provided on the outer periphery. The protruding piece 38 is used as a connecting portion for connecting to an electronic device to which the battery pack 100 is mounted.

The holder case 2 is provided with a frame portion 27 along the outer shape of the secondary battery cell 1 in the battery arrangement region 21, and the inside of the frame portion 27 is a battery storage portion 25. The frame portion 27 includes a holding wall 35 along the terminal surface 1X of the secondary battery cell 1, a peripheral wall 30 along the three sides excluding the terminal surface 1X, and a surface plate portion along one main surface 1A of the secondary battery cell 1. It has 31 and. As shown in FIG. 5, the holding wall 35 has a portion facing the substrate accommodating portion 26 cut so that the battery accommodating portion 25 and the substrate accommodating portion 26 communicate with each other. The surface plate portion 31 has a square ring shape along the outer peripheral edge portion of the main surface 1A of the secondary battery cell 1 with the central portion opened. The height of the peripheral wall 30 of the frame portion 27 is substantially equal to the thickness of the secondary battery cell 1, so that the secondary battery cell 1 can be stored in the battery storage portion 25. The inner shape of the frame portion 27 is substantially equal to the outer shape of the secondary battery cell 1, so that the secondary battery cell 1 housed therein can be arranged at a fixed position. The secondary battery cell 1 is housed in the frame portion 27 so that the terminal surface 1X provided with the pair of electrodes 10 faces the substrate arrangement portion 22.

As shown in FIG. 8, the substrate storage portion 26 is formed in a space surrounded by a pair of partition walls 33 facing each other and a bottom plate 32. In the substrate storage portion 26, the circuit board 5 is arranged, and the molten insulating molding resin is filled inside to mold the resin mold portion 4. The board accommodating portion 26 of FIG. 8 fixes the circuit board 5 in a fixed position via the connecting mechanism 19. The connecting mechanism 19 shown in the figure includes a locking rib 36 and a locking hook 37 provided on the holder case 2 to lock both side edges of the circuit board 5, and a locking portion 56 provided on the circuit board 5. doing. The holder case 2 is provided with vertical ribs 36a and horizontal ribs 36b protruding inward of the substrate storage portion 26 as locking ribs 36 on one partition wall 33 (right side in FIG. 8), and the partition wall 33 and the partition wall 33. A locking hook 37 that is located on the opposite side and projects from the bottom plate 32 is provided. The horizontal ribs 36b are arranged in the horizontal direction so that the side edge portion of the circuit board 5 can be inserted between the horizontal ribs 36b and the bottom plate 32. As shown in FIG. 5, the circuit board 5 is provided with a slit recess 56a at a position facing the vertical rib 36a and a locking recess 56b at a position facing the locking hook 37 as the locking portion 56. There is. The connecting mechanism 19 guides the vertical rib 36a to the slit recess 56a to specify the position of the circuit board 5 in the left-right direction. Further, the connecting mechanism 19 inserts one side edge portion of the circuit board 5 between the horizontal rib 36b and the bottom plate 32, and engages with the locking recess 56b provided on the side edge portion on the opposite side of the circuit board 5. The hook portion of the stop hook 37 is locked and fixed in a fixed position so as not to come off the circuit board 5.

Further, the holder case 2 shown in FIGS. 5 and 6 is a resin injection for injecting a molten insulating molding resin in order to insert-mold the circuit board 5 arranged in the substrate storage portion 26 into the resin mold portion 4. The guide 29 is provided in the substrate arrangement area 22. The holder case 2 of FIG. 5 is used as a resin injection guide 29 by providing a passage that communicates one end (left side in the drawing) of the substrate storage portion 26 with the outside. The resin injection guide 29 shown in FIG. 5 is partitioned from the hollow chamber 28 by an opposing passage wall 39. In the holder case 2 having this structure, when the resin mold portion 4 is molded, the opening side of the substrate arrangement region 22 is closed by a molding die (not shown) to form a molding chamber inside the substrate storage portion 26. NS. The resin injection guide 29 has an injection hole 29a opened in the peripheral wall 30, and when the resin is injected, the injection hole 29a is exposed to the outside in a state where the opening of the substrate arrangement region 22 is closed by a molding die. I am trying to do it.

Further, in the holder case 2, in addition to the resin injection guide 29 provided on one end side of the substrate storage portion 26, the holder case 2 has a second resin injection guide that communicates the opposite end portion of the substrate storage portion 26 with the outside. Can also be provided. Since this structure can inject the insulating molding resin from two places in the molding process of the resin molding portion, there is an advantage that the insulating molding resin can be filled in every corner of the molding chamber while shortening the injection time of the insulating molding resin.

(Resin mold part 4)
The resin mold portion 4 embeds a part or the whole of the circuit board 5, the electronic components mounted on the circuit board 5, and the terminal surface 1X of the secondary battery cell 1 in the insulating molding resin and fixes them at a fixed position. The resin mold portion 4 has a molding chamber in which the circuit board 5 and the secondary battery cell 1 are arranged at fixed positions of the holder case 2 and the storage opening of the holder case 2 is closed with a molding die (not shown). Is formed, and the molten insulating molding resin is injected into this molding chamber to form the mold.

The resin mold portion 4 is molded by heating a thermoplastic resin and injecting it into a molding chamber in a molten state. As the thermoplastic resin of the insulating molding resin, a resin that can be molded by heating it to a low temperature and injecting it into a molding chamber at a low pressure, for example, a polyamide resin or a polyolefin-based or urethane-based thermoplastic resin is used. The resin injected into the molding chamber at low temperature and low pressure has a characteristic that it does not adversely affect the mounting components of the secondary battery cell 1 and the circuit board 5 due to heat. The temperature of the molten resin injected into the molding chamber is preferably lower than the heat-resistant temperature of the holder case 2, for example, 70 ° C. or lower. Since the polyolefin-based resin has higher mechanical strength than the polyamide resin, it has a feature that the circuit board 5 and the secondary battery cell 1 can be more firmly connected. Since the polyamide resin has a wider operating temperature range of −40 ° C. to 150 ° C. than the polyolefin-based resin, it has a feature that it can be firmly connected even when the secondary battery cell 1 becomes hot during use. In the molten insulating molding resin injected into the molding chamber, the circuit board 5 is embedded, a part or the whole of the terminal surface 1X of the secondary battery cell 1 is embedded, and these are embedded and fixed in place. do.

The resin mold portion 4 in which the circuit board 5 is embedded also embeds a semiconductor switching element such as an FET mounted on the circuit board 5. With this structure, heat generated by the semiconductor switching element can be conducted to the resin mold portion 4 to dissipate heat. Therefore, the resin mold portion 4 absorbs heat generated by a heat generating member such as a semiconductor switching element to reduce the temperature rise, and further dissipates the absorbed heat energy from the surface to reduce the temperature rise of the semiconductor switching element. Further, since the terminal surface 1X of the circuit board 5 and the secondary battery cell 1 is embedded in the resin mold portion 4, there is also a feature that the circuit board 5 and the terminal surface 1X of the secondary battery cell 1 can have a waterproof structure.

Further, the resin mold portion 4 shown in FIG. 2 has a plurality of rows of groove portions 41 formed on the surface thereof. The plurality of rows of grooves 41 are provided along the longitudinal direction of the circuit board 5. As described above, the structure in which the groove portions 41 in a plurality of rows are provided on the surface of the resin mold portion 4 is characterized in that the amount of the insulating molding resin used can be reduced to reduce the manufacturing cost. As shown in the figure, the plurality of rows of grooves 41 are, for example, the inner surface of a molding chamber for molding the resin mold portion 4 with an insulating molding resin, and by forming a plurality of rows of ridges on the surface of the molding die. realizable. Here, in the resin mold portion 4 shown in FIG. 2, a plurality of rows of groove portions 41 are formed along the longitudinal direction of the circuit board 5. In this structure, as shown by the arrow A in FIG. 6, the insulated molding resin in the molten state supplied from the resin injection guide 29 flows smoothly along the longitudinal direction of the circuit board 5 as shown by the arrow B. There are features that can be done. That is, the insulating molding resin injected into the molding chamber can be flowed along a plurality of rows of ridges formed on the surface of the molding die and filled up to the opposite side of the injection side. As a result, while the insulating molding resin in the molten state is injected from one side of the circuit board 5 extended in one direction, it can be flowed to the other side to fill every corner of the molding chamber. In the structure in which the molten resin is injected from the end of the molding chamber, fine solder debris is generated when the leader wire 6 and the connecting lead plate 16 are soldered to the circuit board 5, and remains on the circuit board 5. Even if there is, the molten resin that flows can be flushed to the corners of the molding chamber, so that safety can be improved. Further, since the resin mold portion 4 provided with the plurality of rows of groove portions 41 on the surface can have a large surface area on the surface side, it is possible to realize a feature that heat dissipation characteristics from this portion can be improved and heat can be dissipated. However, the resin molded portion does not necessarily have to be provided with a groove portion on the surface, and the surface can be molded into a flat surface.

(Protective element 7)
The protective element 7 is an element that detects the temperature of the secondary battery cell 1 and cuts off the current when the detected temperature becomes higher than the set temperature, or detects an overcurrent flowing in the circuit and cuts off the current. , Breaker 71, fuse 72, PTC, etc. can be used. That is, in the present specification, the protective element 7 includes a wide range of current breaking elements such as a breaker 71, a fuse 72, and a PTC that detect a temperature rise of the secondary battery cell 1 and an overcurrent flowing in the circuit to cut off the current. Used in the sense. The circuit board 5 shown in the figure is both ends in the longitudinal direction, and the breaker 71 is arranged at a position facing the terminal surface 1X of the secondary battery cell 1, and a fuse 72 is provided on one side of the central portion of the circuit board 5. It is arranged.

(Circuit breaker 71)
The breaker 71, which is the protective element 7, is arranged for each secondary battery cell 1 built in the battery pack 100. Since the battery pack 100 shown in the figure includes two secondary battery cells 1, two breakers 71 are connected to each secondary battery cell 1. Each breaker 71 is mounted on the edge portion of the circuit board 5, and as shown in FIG. 5, the secondary batteries facing each other via the connection lead plate 16 that connects the secondary battery cell 1 to the circuit board 5. It is connected in series to cell 1.

As shown in FIGS. 9 and 10, the breaker 71 includes a main body portion 71X having a square outer shape, and a pair of lead plates 71A and 71B protruding from both ends of the main body portion. The breaker 71 in the figure is arranged in a state of being entirely housed in a notch 51 formed at an edge portion of the circuit board 5. The circuit board 5 in the figure is provided with a notch 51 in which an edge portion facing the terminal surface 1X is cut out in a U shape and the breaker 71 is housed in a state of being exposed on both sides of the circuit board 5. The breaker 71 is arranged in the notch 51, and the surface of the main body 71A is arranged on substantially the same plane as the surface of the circuit board 5. Further, the breaker 71 arranged in the notch 51 is electrically connected to the back surface which is the first surface of the circuit board 5. As shown in FIG. 10, the breaker 71 is connected to the circuit board 5 on the first surface of the circuit board 5 via a pair of connection plates 53 protruding inward from both sides of the notch 51 and fixed. There is. Specifically, one lead plate 71A of the breaker 71 is connected to the first connection plate 53A, and the other lead plate 71B is connected to the second connection plate 53B to be connected to the circuit board 5. For the connection plate 53, for example, a metal plate such as a nickel plate can be used.

Further, the first connection plate 53A fixed to the back side surface of the circuit board 5 is the front side surface which is the second surface of the circuit board 5 via the connection line 54 which is a metal pattern wired inside the circuit board 5. It is electrically connected to the first connection land 52A formed in. The circuit board 5 shown in FIG. 9 forms a pair of connection lands 52 at the ends of the second surface in order to connect the pair of connection lead plates 16 drawn out from the secondary battery cell 1. In the secondary battery cell 1, the first connection lead plate 16A is connected to the first connection land 52A, and the second connection lead plate 16B is connected to the second connection land 52B to supply electricity to the second surface of the circuit board 5. Be connected. On the second electrode 10B side, the secondary battery cell 1 is energized in the order of the flat electrode 14 → the second connection lead plate 16B → the second connection land 52B, and the positive side output line of the circuit board 5 (not shown). ). Further, in the secondary battery cell 1, on the first electrode 10A side, the electric power supplied from the negative side output line (not shown) of the circuit board 5 is the second connection plate 53B → lead plate 71B → breaker 71. The main body 71X → lead plate 71A → first connection plate 53A → connection line 54 → first connection land 52A → first connection lead plate 16A → convex electrode 13 is energized in this order and input to the secondary battery cell 1. As described above, in the structure in which the breaker 71 is connected to the first electrode 10A on the negative electrode side of the secondary battery cell 1, the protection element 7 can be connected to the ground side, so that safety can be ensured. However, the breaker can also be connected to the second electrode on the positive electrode side of the secondary battery cell.

In the above structure, the lead plates 71A and 71B of the breaker 71 are connected to the circuit board 5 on the back side surface which is the first surface of the circuit board 5, and the secondary battery cell 1 is connected to the front side surface which is the second surface of the circuit board 5. Since the connection lead plate 16 drawn from the above is connected to the circuit board 5, the connection lead plate 16 and the lead plates 71A and 71B are in contact with each other even when the breaker 71 and the connection lead plate 16 are brought close to each other for wiring. It has the feature of being able to reliably prevent short circuits. However, the breaker does not necessarily have to be arranged in the notch provided in the circuit board, and can be mounted on the surface of the circuit board. The breaker arranged in this way can be easily mounted on the circuit board by a method such as reflow soldering.

Further, in the battery pack 100, the connection lead plate 16 is laminated in a heat-bonded state on the surface of the main body 71X of the breaker 71 in order to reliably detect the heat generated by the secondary battery cell 1 by the breaker 71 which is the protective element 7. doing. In the structures shown in FIGS. 9 and 10, the first connection lead plate 16A connected to the convex electrode 13 which is the first electrode 10A is arranged in a state of being laminated on the surface of the main body portion 71X of the breaker 71. The main body 71X of the breaker 71 and the first connection lead plate 16A are thermally coupled. As a result, the heat generated by the secondary battery cell 1 is effectively conducted to the breaker 71, and when the temperature of the secondary battery cell 1 rises to the set temperature, the heat generated by the breaker 71 is reliably detected and the current is cut off. I am trying to do it.

The first connection lead plate 16A shown in the figure is arranged so as to intersect the main body 71X of the breaker 71, and the tip of the first connection lead plate 16A is connected to the first connection land 52A. The intermediate portion of the first connection lead plate 16A is ensured to be in contact with the surface of the main body portion 71X. In particular, the breaker 71 shown in the figure is arranged in the notch 51 provided in the circuit board 5, so that the surface of the main body 71X is substantially flush with the front side surface of the circuit board 5. Therefore, the connection lead plate 16 is ideally connected to the main body of the breaker 71 in a state where the connection lead plate 16 drawn from the electrode 10 of the secondary battery cell 1 is connected to the connection land 52 provided on the front side surface of the circuit board 5. It can be laminated and brought into contact with the surface of the portion 71X.

In the above battery pack 100, the connection lead plate 16 connected to the convex electrode 13 of the secondary battery cell 1 is laminated on the breaker 71. In this way, the structure in which the connection lead plate 16 connected to the convex electrode 13 of the secondary battery cell 1 is thermally coupled to the breaker 71 is effective in transmitting heat inside the secondary battery cell from the convex electrode 13 to the breaker 71. The breaker 71 can be reliably operated by conducting heat conduction to the battery. However, although not shown, the battery pack can also detect heat generation in the secondary battery cell by stacking a connection lead plate connected to the sealing plate of the secondary battery cell on the breaker.

(Fuse 72)
The fuse 72, which is the protection element 7, is connected between the secondary battery cells 1 connected in series, and is blown in a state where an overcurrent flows to cut off the current. The fuse 72 shown in FIG. 6 is arranged in a region on one side of the central portion of the circuit board 5 and in a region away from the resin injection guide 29 into which the molten insulating molding resin is injected. As shown by arrows A and B in FIG. 6, this structure can increase the flow distance of the molten resin supplied from the resin injection guide 29, so that it is effective that the fuse 72 is erroneously blown by the heat of the molten resin. Can be prevented.

Further, the resin mold portion 4 shown in FIGS. 2 and 3 is provided with a shielding groove 42 in order to prevent the molten resin injected from the resin injection guide 29 from directly contacting the fuse 72. The shielding groove 42 is formed by a shielding rib 91 (indicated by a chain line in FIG. 6) provided so as to project from the inner surface of the molding die in a state where the molten resin is injected into the molding chamber. The shielding rib 91 shown in FIG. 6 has a U-shape in a plan view, and is provided in a posture of closing the inflow side of the molten insulating molding resin and arranging an opening on the opposite side. The insulating molding resin supplied to the molding chamber by the shielding rib 91 is filled up to the periphery of the fuse 72 in a state of bypassing the shielding rib 91 without directly contacting the fuse 72. Therefore, the high-temperature insulating molding resin in the molten state does not come into direct contact with the fuse 72, but comes into contact with the fuse 72 in a state where the temperature has dropped to some extent, thereby preventing the fuse from malfunctioning. However, when the distance between the resin injection guide 29 and the fuse 72 can be widened to increase the flow distance of the molten resin, it is not always necessary to provide a shielding groove in the resin mold portion.

(Leader line 6)
Further, in the battery pack 100 shown in FIGS. 1 to 6, a plurality of leader wires 6 are connected to the circuit board 5 and pulled out from the resin mold portion 4 to the outside. One end of the plurality of leader wires 6 is connected to the circuit board 5, and the other end is connected to the connector 69. The leader wire 6 is embedded and fixed in an insulating molding resin with one end connected to the circuit board 5, and the circuit board 5 is pulled out from the insert-molded resin mold portion 4. As shown in FIG. 11, the plurality of leader lines 6 have their ends connected to the circuit board 5 arranged at fixed positions via the positioning mechanism 60.

(Positioning mechanism 60)
The positioning mechanism 60 shown in FIGS. 11 to 13 is integrally molded with the holder case 2. The holder case 2 shown in the figure is an outer peripheral surface of the board storage unit 26 and is a part of the partition wall 33 in order to arrange a plurality of leader lines 6 at fixed positions of the circuit board 5 arranged in the board storage unit 26. Is provided with a positioning mechanism 60. The positioning mechanism 60 shown in FIGS. 11 to 13 includes a plurality of rows of comb-shaped ribs 61 formed in parallel postures so that the plurality of leader lines 6 can be arranged in parallel postures at predetermined intervals. , A plurality of rows of guide grooves 62 are provided between the adjacent comb-shaped ribs 61 by inserting a leader line 6 and arranging them at a fixed position. The plurality of rows of guide grooves 62 allow each leader line 6 to be inserted independently and independently, and the inserted leader line 6 can be moved along the comb-shaped rib 61. The comb-shaped ribs 61 do not necessarily have to be formed in a parallel posture, and may be appropriately inclined to each other if necessary.

In the positioning mechanism 60 shown in FIG. 13, a plurality of rows of comb-shaped ribs 61 are arranged side by side at equal intervals, and a plurality of rows of guide grooves 62 are provided at equal intervals. The positioning mechanism 60 inserts leader lines 6 into each guide groove 62 and arranges the leader lines 6 at regular intervals. The distance between the guide grooves 62 can be substantially equal to the distance between the leader wires 6 connected to the connector 69 at the tip. The positioning mechanism 60 can quickly guide each leader wire 6 connected to the connector 69 to the guide groove 62 in the vicinity of the connector 69. Since a plurality of leader wires 6 can be arranged at intervals of the guide grooves 62 via the connector 69, the plurality of leader wires 6 can be pushed into the guide grooves 62 and all the leader wires 6 can be easily inserted into the guide grooves 62. Because.

The guide groove 62 has a depth and width into which the leader line 6 can be inserted, and the upper end opening 63 is made slightly narrower than the thickness of the leader line 6 to prevent the leader line 6 inserted therein from coming out. ing. The guide groove 62 shown in FIGS. 12 and 13 is formed so that the upper end portion of the comb-shaped rib 61 protrudes inward to narrow the upper end opening 63. The guide groove 62 has an opening width of the upper end opening 62 smaller than the outer shape of the leader wire 6 and larger than the thickness of the core wire 6a of the leader wire 6. The leader wire 6 can be easily inserted into the guide groove 62 by pushing the leader wire 6 through the upper end opening 63, and when the leader wire 6 is inserted into the guide groove 62, the leader wire 6 is slid along the guide groove 62. be able to. Although not shown, the plurality of leader lines 6 can be easily inserted by using a jig having a plurality of rows of ridges along the plurality of rows of guide grooves 62 provided in the positioning mechanism 60.

Further, the positioning mechanism 60 shown in FIGS. 12 and 13 is a circular groove along the outer peripheral surface of the leader line 6 on the partition wall 33 which is on the circuit board 5 side of the guide groove 62 and is a boundary with the board storage portion 26. 64 is provided. In this way, the circular groove 64 formed on the end surface on the circuit board side can narrow the gap between the circular groove 64 and the leader wire 6 inserted therein. It is possible to effectively prevent the molten resin to be filled from leaking to the outside from the guide groove 62. Further, the holder case 2 shown in the figure is provided with a drawer recess 66 for passing the leader line 6 between the peripheral wall 30 on the side where the leader line 6 is drawn out and the positioning mechanism 60.

The positioning mechanism 60 described above allows the leader wire 6 to slide in the axial direction while the leader wire 6 is inserted into each of the guide grooves 62 from the upper end opening 63. In this positioning mechanism 60, after inserting the leader wire 6 into the guide groove 62 in the vicinity of the connector 69, the connector 69 is moved in a direction away from the guide groove 62, and the length of the leader wire 6 drawn out from the holder case 2 is reduced. Adjust to the specified length. The plurality of leader wires 6 are connected by soldering their tip portions to the circuit board 5 in a state where a predetermined length is pulled out from the holder case 2. Further, the positioning mechanism 60 arranges a plurality of leader wires 6 at regular intervals in a state where the tip portion of the leader wire 6 soldered to the circuit board 4 is moved to the connection portion with the circuit board 5. As shown in FIG. 11, the circuit board 4 is provided with a plurality of connecting portions 55 at positions where the tip portions of the leader wires 6 held at regular intervals by the positioning mechanism 60 can be soldered. Since the spacing between the plurality of connecting portions 55 is equal to the spacing at which the positioning mechanism 60 arranges the leader wires 6, the tips of the leader wires 6 are arranged at the connecting portions 55 to be soldered, and the leader wires 6 are efficiently soldered. Can be attached. The plurality of leader wires 6 connected to the fixed positions of the circuit board 5 via the positioning mechanism 60 are fixed in a state where the circuit board 5 is embedded in the insulating molding resin, and are drawn out from the resin mold portion 4.

The above positioning mechanism 60 is integrally molded with the holder case 2. However, the positioning mechanism 60 can be connected to and fixed to the holder case as a positioning holder that is a separate member from the holder case 2. The positioning holder can have the same shape as the positioning mechanism described above, and the holder case can be provided with a connecting portion for arranging the positioning holder at a fixed position. For example, this positioning holder can be fixed at a fixed position on the circuit board, a leader wire can be connected, and then the circuit board can be placed in the board storage portion of the holder case to be placed at the fixed position on the holder case. ..

(Exterior sheet 8)
Further, in the battery pack 100, the periphery of the secondary battery cell 1 is covered with the exterior sheet 8. In the battery pack 100 of FIG. 1, the secondary battery cell 1 and the frame portion 27 housed in the frame portion 27 of the holder case 2 are covered with the exterior sheet 8 and fixed. The exterior sheet 8 is an insulating sheet that firmly connects the frame portion 27 and the secondary battery cell 1 while insulating the outer periphery of the secondary battery cell 1.

The above battery pack 100 is manufactured as follows.
(1) The breaker 71, which is a protective element 7, is connected to the circuit board 5. As shown in FIG. 5, the circuit board 5 has breakers 71 fixed to both ends in the longitudinal direction and facing the terminal surface 1X of the secondary battery cell 1. As shown in FIGS. 9 and 10, the breaker 71 is arranged in the notch 51 provided at the end of the circuit board 5, and the lead plates 71A and 71B protruding from both ends of the main body 71X are formed on the circuit board 5. It is connected to the provided connection plate 53.

(2) The circuit board 5 is arranged in the holder case 2. The circuit board 5 is guided by the board storage portion 26 of the holder case 2 and is set at a fixed position in a locking structure via a connecting mechanism 19 as shown in FIG.

(3) A plurality of leader wires 6 having a connector 69 connected to the other end are individually inserted into the multi-row guide grooves 62 of the positioning mechanism 60 (insertion step). The leader wire 6 shown in FIGS. 4 and 6 has a connector 69 at the other end, and an intermediate portion on the connector side is inserted into the guide groove 62 of the positioning mechanism 60. In this state, the plurality of leader lines 6 inserted into the guide grooves 62 in the plurality of rows are simultaneously moved along the guide grooves 62 in the lead-out direction to adjust the lead-out length of the leader lines 6 (length adjusting step). ). One end of a plurality of leader wires 6 drawn to a predetermined length is soldered to the circuit board 5 (connection step).

(4) The secondary battery cell 1 is arranged in the battery storage portion 25 of the holder case 2. The holder case 2 shown in FIG. 5 is provided with frame portions 27 at both ends, and the secondary battery cell 1 is set inside the frame portions 27 and arranged at a fixed position. The two secondary battery cells 1 are arranged so that the terminal surfaces 1X face each other.

(5) A pair of connection lead plates 16 connected to the terminal surface 1X of the secondary battery cell 1 are connected to the circuit board 5. In the secondary battery cell 1, as shown in FIG. 9, the first connection lead plate 16A connected to the first electrode 10A is arranged in a state of being laminated on the surface of the breaker 71, and the first circuit board 5 is arranged. The second connection lead plate 16B connected to the connection land 52B and connected to the second electrode 10B is connected to the second connection land 52B of the circuit board 5.

(6) The opening side of the substrate arrangement area 22 of the holder case 2 is closed with a molding die (not shown) to form a molding chamber inside the substrate accommodating portion 26. In this state, the molten insulation molding resin is injected through the injection hole 29a of the resin injection guide 29 to mold the resin mold portion 4. The circuit board 5 to which the secondary battery cell 1 and the plurality of leader wires 6 are connected is inserted into the insulating molding resin, and the resin mold portion 4 for pulling out the other ends of the plurality of leader wires 6 to the outside is formed (molding step). ).

(7) After the insulating molding resin is cured and the molding die is removed, the frame portion 2 of the holder case 2 and the secondary battery cell 1 are covered with the exterior sheet 8.

The above battery pack 100 has a structure in which opposing secondary battery cells 1 are arranged at both ends and a circuit board 5 is arranged between them. However, the battery pack has a plurality of secondary battery cells as terminals. It is also possible to arrange the circuit boards side by side so that the surfaces are located on the same plane, and arrange the circuit boards at positions facing a plurality of terminal surfaces.

Further, the battery pack 100 of the above embodiment has a structure in which two secondary battery cells 1 are arranged at both ends of the holder case 2 and a circuit board 5 is arranged between the opposing secondary battery cells 1. However, the battery pack of the present invention may include one secondary battery cell or may include three or more secondary battery cells. Hereinafter, as a battery pack according to another embodiment of the present invention, an example of a battery pack 200 including one secondary battery cell 1 is shown in FIG. 14, and a battery pack 300 including four secondary battery cells 1 is shown in FIG. An example is shown in FIG. 15, respectively. Here, the battery packs 200 and 300 shown in FIGS. 14 and 15 show a state in which the resin mold portion and the exterior sheet are removed. Further, in the embodiments shown in these figures, the same components as those in the above-described embodiment are designated by the same reference numerals, and detailed description thereof is omitted.

In the battery pack 200 shown in FIG. 14, the holder case 2B is provided on a battery arrangement area 21B composed of a frame portion 27B on which one secondary battery cell 1 is arranged and a terminal surface 1X of the secondary battery cell 1. It includes a board arrangement area 22B on which the circuit board 5B is arranged along the line. The substrate arrangement region 22B shown in the figure is provided with only the resin molding region 23B without providing the hollow portion, and the circuit board 5B is arranged using the resin molding region 23B as the substrate storage portion 26B. However, as shown by the chain line in the figure, the holder case may be provided with a hollow portion when the area is widened due to a design change of the substrate storage portion or the like. The circuit board 5B in the figure has a shape extending in the lateral direction of the holder case 2B, and a breaker 71, which is a protective element 7, is mounted on a side edge portion of the secondary battery cell 1 facing the terminal surface 1X. There is. Further, in this battery pack 200, a plurality of leader wires 6 are connected to fixed positions of the circuit board 5B via a positioning mechanism 60B provided on the peripheral wall 30B of the holder case 2B, and the leader wires 6 to which the connector 69 is connected are externally connected. It has a structure that pulls out to.

Further, in the battery pack 300 shown in FIG. 15, the holder case 2C has a battery arrangement area 21C composed of a frame portion 27C in which two secondary battery cells 1 are arranged at both ends thereof, and these. The circuit board 5 is arranged by providing the substrate arrangement area 22C between the battery arrangement areas 21C. The battery arrangement area 21C includes two batteries, a peripheral wall 30C surrounding three sides and an intermediate wall 40 arranged between adjacent secondary battery cells 1 so that two secondary battery cells 1 can be accommodated. The storage portion 25 is formed. Further, the substrate arrangement region 22C is formed with a resin molding region 23C on which a resin mold portion is formed and a hollow region 24C. In the battery pack 300 shown in FIG. 15, the circuit board 5 is arranged by providing the substrate accommodating portion 26 between the two secondary battery cells 1 arranged in the front in the drawing, and the two are arranged in the rear in the drawing. No circuit board is arranged between the secondary battery cells 1 of the above, and the hollow region 24C is formed almost entirely.

Further, in the battery pack 300 shown in FIG. 15, the circuit board 5 is arranged at a position facing the terminal surface 1X of the two secondary battery cells 1 arranged in the front, and the two two are arranged in the rear. The next battery cell 1 has a structure in which it is connected to the circuit board 5 via an extension lead plate 17. In this battery pack 300, the region where the extension lead plate 17 is arranged is set as the resin molding region 23C, and the terminal surface 1X and the extension lead plate 17 of the secondary battery cell 1 arranged behind the battery pack 300 are filled with the insulating molding resin. Can be inserted into the resin mold and fixed.

Further, the battery pack of the present invention may have the structure shown in FIGS. 16 to 20. The battery pack 400 shown in FIGS. 16 to 20 includes two secondary battery cells 1, a circuit board 5D electrically connected to each of the secondary battery cells 1, and a mold in which the circuit board 5D is embedded. It has a molded resin mold portion 4D. The battery pack 400 shown in these figures has a resin mold portion 4D in which the terminal surfaces 1X of the two secondary battery cells 1 are arranged at positions facing the circuit board 5D and the circuit board 5D is embedded. A plurality of secondary battery cells 1 arranged on the same plane are connected.

In the secondary battery cell 1 shown in FIG. 17, a connection lead plate 46 welded to the convex electrode 13 which is a positive or negative electrode 10 is embedded in the resin mold portion 4D as an anchor portion 47. The connection lead plate 46 is bent into an L shape, one end of which is fixed to the convex electrode 13 of the secondary battery cell 1, and the other end of which is fixed to the circuit board 5D. The L-shaped connection lead plate 46 is connected by embedding a portion protruding from the convex electrode 13 toward the circuit board 5D in the resin mold portion 4D so as not to come off the resin mold portion 4D. The connection lead plate 46 to be the anchor portion 47 may be provided with a projecting portion having a long overall length or a projecting portion having a wide width, and this may be embedded in the resin mold portion 4D.

The circuit board 5D is an epoxy resin reinforced with glass fiber, and has sufficient strength as compared with the resin molded portion 4D. This circuit board 5D is embedded in the resin mold portion 4D to reinforce the resin mold portion 4D.

The resin mold portion 4D is molded by temporarily fixing the circuit board 5D and the secondary battery cell 1 at a fixed position of the mold and injecting molten resin into the molding chamber of the mold. In the resin mold portion 4D, the circuit board 5D is embedded, and the circuit board 5D and each secondary battery cell 1 are insert-molded and connected and fixed at a fixed position. The resin mold portion 4D is molded by heating a thermoplastic resin and injecting it into a molding chamber of a mold in a molten state. As such a thermoplastic resin, the above-mentioned ones can be used.

The resin mold portion 4D of FIG. 17 is provided by integrally molding the wrap portions 4a extending on both sides of the secondary battery cell 1. The wrap portion 4a is in close contact with both sides of the secondary battery cell 1 to firmly connect the resin mold portion 4D to the secondary battery cell 1. The wrap portion 4a is provided in the vicinity of the terminal surface 1X of the secondary battery cell 1 and is connected to the resin mold portion 4D.

In the battery pack 400 of FIGS. 17 and 18, the secondary battery cells 1 are arranged on both sides of the circuit board 5D, and the circuit board 5D between the secondary battery cells 1 is embedded in the resin mold portion 4D to form a resin. Each of the secondary battery cells 1 arranged on the same plane is connected by the mold portion 4D. Since the secondary battery cells 1 are connected to both sides of the circuit board 5D, the total length of the battery pack 400 is twice that of one secondary battery cell 1, but a resin mold for connecting the secondary battery cells 1 on both sides. Since the portion 4D has sufficient bending strength, it has excellent strength.

Further, in the battery pack 400, the periphery of the secondary battery cell 1 is covered with the exterior sheet 8D. In the battery pack 400 of FIG. 16, the periphery of each secondary battery cell 1 is covered with an exterior sheet 8D. By covering the exterior sheet 8D over the boundary portion between the secondary battery cell 1 and the resin mold portion 4D, the connection strength between the secondary battery cell 1 and the resin mold portion 4D can be strengthened.

The circuit board 5D connects a plurality of leader wires 6 and pulls them out to the outside. In the battery pack 400 shown in FIG. 16, the leader wire 6 connected to the circuit board 5D is pulled out from the resin mold portion 4D to the outside. The leader wire 6 connects the connector 69 to the tip. The leader wire 6 is connected to a circuit board 5D that is insert-molded into the insulation molding resin, and is insert-molded and fixed to the insulation molding resin. As shown in FIGS. 17 to 20, the leader line 6 is positioned at a fixed position by a positioning holder 9 in which the end portion connected to the circuit board 5D is molded with plastic separately from the insulating molding resin of the resin mold portion 4D. The positioning holder 9 is used as the positioning mechanism 90. The positioning holder 9 is insert-molded into an insulating molding resin and fixed. The positioning holder 9, which is the positioning mechanism 90, includes a plurality of rows of comb-shaped ribs 91 formed in parallel positions so that the plurality of leader lines 6 can be arranged in parallel positions at predetermined intervals, and is adjacent to each other. A plurality of rows of guide grooves 92 are provided so that the leader wire 6 is inserted between the comb-shaped ribs 91 to be arranged at a fixed position. The plurality of rows of guide grooves 92 allow each leader line 6 to be inserted independently and independently, and the inserted leader line 6 can be moved along the comb-shaped rib 91.

The positioning holder 9 inserts the leader lines 6 into the respective guide grooves 92 and arranges the leader lines 6 at regular intervals. The guide groove 92 has a depth and a width into which the leader wire 6 can be inserted, and the opening width of the upper end opening 93 is smaller than the outer shape of the leader wire 6 and larger than the thickness of the core wire 6a of the leader wire 6. Therefore, it is difficult to pull out the inserted leader line 6. The distance between the guide grooves 92 is equal to the distance between the leader wires 6 connected to the connector 69 at the tip. The positioning holder 9 moves to the end of the leader wire 6 soldered to the circuit board 5D by inserting the leader wire 6 in the vicinity of the connector 69 and then moving the connector 69 away from the positioning holder 9. In this state, the leader lines 6 are arranged at regular intervals. The circuit board 5D is provided with a plurality of connecting portions 55 at positions where the ends of the leader wires 6 held at regular intervals by the positioning holder 9 can be soldered. Since the spacing between the plurality of connecting portions 55 is equal to the spacing at which the positioning holder 9 arranges the leader wires 6, the tips of the leader wires 6 are arranged at the connecting portions 55 to be soldered, and the leader wires 6 are efficiently soldered. Can be attached. The circuit board 5D is insert-molded and fixed to the insulating molding resin in a state where it is arranged at a fixed position by the positioning holder 9 and soldered to the circuit board 5D. The positioning holder 9 shown in FIG. 19 is provided with a circular groove 94 along the outer peripheral surface of the leader line 6 on a side surface located outside the guide groove 92. In this way, the circular groove 94 formed on the side surface of the positioning holder 9 can narrow the gap between the circular groove 94 and the leader wire 6 inserted therein, so that the molten resin filled in the molding chamber at the time of molding the resin molding portion 4D can be formed. It is possible to effectively prevent leakage from the guide groove 92 to the outside.

The positioning holder 9 is fixed at a fixed position on the circuit board 5D, and a plurality of guide grooves 92 are arranged so as to face the plurality of connecting portions 55. The positioning holder 9 shown in FIG. 20 includes a fitting recess 97 for fitting the end portion of the circuit board 5D and fixing it in a fixed position. The positioning holder 9 shown in the figure is inside surrounded by the bottom plate 95 and the side wall 96, and forms a groove-shaped recess extending in the horizontal direction below the comb-shaped ribs 91 arranged in a plurality of rows to form a fitting recess 97. It is said. The positioning holder 9 is fixed at a fixed position on the circuit board 5 by inserting the end portion of the circuit board 5 into the fitting recess 97.

In the above embodiment, a structure in which a circuit board to which one end of the leader wire is connected is inserted into a resin mold portion is described in detail as a battery pack formed by pulling out a plurality of leader wires having a connector connected to the tip to the outside. However, the battery pack does not necessarily have to insert the circuit board into the resin mold portion, and may have a structure without the resin mold portion. In the battery pack in which the resin mold portion is not formed, the circuit board to which the leader wire is connected can be covered with, for example, an outer case or an outer sheet. Even in such a battery pack, by specifying the positions of the tips of the plurality of leader wires via the positioning mechanism in the same manner as described above, it is possible to accurately connect to the fixed positions of the circuit board.

The embodiments or examples of the present invention have been described above with reference to the drawings. However, the above-described embodiments to examples are examples for embodying the technical idea of the present invention, and the present invention is not specified as described above. Further, the present specification does not specify the members shown in the claims as the members of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention to the specific description unless otherwise specified, and are merely explanatory examples. It's just that. The size and positional relationship of the members shown in each drawing may be exaggerated to clarify the explanation. Further, in the above description, members of the same or the same quality are shown with the same name and reference numeral, and detailed description thereof will be omitted as appropriate. Further, each element constituting the present invention may be configured such that a plurality of elements are composed of the same member and the plurality of elements are combined with one member, or conversely, the function of one member is performed by the plurality of members. It can also be shared and realized.

In the battery pack of the present invention, a thin secondary battery cell and a circuit board can be arranged on the same plane and firmly connected to each other. Suitable for portable electronic devices.

100, 200, 300, 400 ... Battery pack 1 ... Secondary battery cell 1A ... Main surface 1X ... Terminal surface 2, 2B, 2C ... Holder case 4, 4D ... Resin mold part 4a ... Wrap part 5, 5B, 5D ... Circuit Substrate 6 ... Leader wire 6a ... Core wire 7 ... Protective elements 8, 8D ... Exterior sheet 9 ... Positioning holder 10 ... Electrode 10A ... First electrode 10B ... Second electrode 11 ... Exterior can 12 ... Seal plate 13 ... Convex electrode 14 ... Clad plate 15 ... Safety valve 16 ... Connection lead plate 16A ... First connection lead plate 16B ... Second connection lead plate 17 ... Extension lead plate 19 ... Connection mechanism 21, 21B, 21C ... Battery arrangement area 22, 22B, 22C ... Board arrangement Regions 23, 23B, 23C ... Resin molding regions 24, 24C ... Hollow regions 25 ... Battery storage parts 26, 26B ... Board storage parts 27, 27B, 27C ... Frame parts 28 ... Hollow chambers 29 ... Resin injection guide 29a ... Injection holes 30 , 30B, 30C ... Circumferential wall 31 ... Surface plate 32 ... Bottom plate 33 ... Partition wall 34 ... Reinforcing rib 35 ... Holding wall 36 ... Locking rib 36a ... Vertical rib 36b ... Horizontal rib 37 ... Locking hook 38 ... Protruding piece 39 ... Passage wall 40 ... Intermediate wall 41 ... Groove 42 ... Shielding groove 46 ... Connection lead plate 47 ... Anchor 51 ... Notch 52 ... Connection land 52A ... First connection land 52B ... Second connection land 53 ... Connection plate 53A ... First Connection plate 53B ... Second connection plate 54 ... Connection line 55 ... Connection part 56 ... Locking part 56a ... Slit recess 56b ... Locking recesses 60, 60B ... Positioning mechanism 61 ... Comb-shaped rib 62 ... Guide groove 63 ... Upper end opening 64 ... Circular groove 66 ... Drawer recess 69 ... Connector 71 ... Breaker 71A ... Lead plate 71B ... Lead plate 71X ... Main body 72 ... Fuse 90 ... Positioning mechanism 91 ... Comb-shaped rib 92 ... Guide rib 93 ... Upper end opening 94 ... Circular groove 95 ... Bottom plate 96 ... Side wall 97 ... Fitting recess 99 ... Shielding rib 106 ... Leader line 140 ... Mold 140A ... Lower mold 140B ... Upper mold 141 ... Guide groove 142 ... Convex

Claims (8)

With a rechargeable battery cell
A circuit board that is electrically connected to the secondary battery cell and has a protection circuit mounted on it.
A resin molded portion obtained by insert molding the circuit board and
The circuit board is arranged in the board storage portion and is arranged.
A battery pack including a plurality of leader wires that are connected to the circuit board at one end and are drawn out from the resin mold portion to the outside and a connector is connected to the other end.
Further, it is provided with a positioning mechanism for arranging the leader wire at a fixed position on the circuit board.
The positioning mechanism is provided on the outer peripheral surface of the substrate accommodating portion.
The positioning mechanism includes a plurality of rows of comb-shaped ribs, and each leader can be inserted separately and independently between adjacent comb-shaped ribs, and the inserted leaders can be inserted into the comb-shaped ribs. Equipped with multiple rows of guide grooves that can be moved along
The guide groove has an upper end opening smaller than the outer shape of the leader wire and larger than the thickness of the core wire of the leader wire.
The circuit board in which the plurality of leader wires are connected at a fixed position via the positioning mechanism is embedded in an insulating molding resin, and the leader wires are drawn out from the resin mold portion to the outside. Battery pack. The battery pack according to claim 1.
A battery pack in which the positioning mechanism makes the distance between the guide grooves substantially equal to the distance between the plurality of leader wires connected to the connector. The battery pack according to claim 1 or 2.
A battery pack in which the positioning mechanism has a circular groove along the outer peripheral surface of the leader wire at the end of the guide groove. The battery pack according to any one of claims 1 to 3.
The circuit board includes a plurality of connecting portions for connecting the tips of the plurality of leader wires.
A battery pack in which the positioning mechanism forms the plurality of guide grooves at positions facing the plurality of connecting portions. The battery pack according to any one of claims 1 to 4, and further.
It is provided with a holder case for accommodating the secondary battery cell and the circuit board.
A battery pack in which the positioning mechanism is integrally molded with the holder case. The battery pack according to any one of claims 1 to 4.
It is provided with a positioning holder made of a separate member that constitutes the positioning mechanism.
A battery pack in which the positioning holder is fixed to the circuit board and inserted into the resin mold portion. A method of manufacturing a battery pack that connects multiple leader wires to fixed positions on a circuit board.
A plurality of rows of comb-shaped ribs are provided, and a plurality of rows of guide grooves are provided between adjacent comb-shaped ribs, and the upper end opening of the guide groove is smaller than the outer shape of the leader wire and the leader wire is provided. Equipped with a positioning mechanism that is larger than the thickness of the core wire
An insertion step of individually inserting a plurality of leader wires having a connector connected to the other end into the multi-row guide groove of the positioning mechanism.
A length adjusting step of adjusting the lead-out length of the leader lines by simultaneously moving a plurality of leader lines inserted into the plurality of rows of guide grooves in the lead-out direction along the guide grooves.
A connection process in which one ends of the plurality of leader wires drawn to a predetermined length are soldered to a circuit board, and
A molding process in which the circuit board to which the secondary battery cell and the plurality of leader wires are connected is insert-molded, and a resin molded portion for pulling out the other ends of the plurality of leader wires is formed.
How to make a battery pack including. The battery pack according to claim 1.
The positioning mechanism is a battery pack that is insert-molded into the resin mold portion.

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