JP2003162987A - Board-integrated battery and battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a board-integrated battery in which a secondary battery and a circuit board are integrated with a mold resin, and to provide a battery pack. <P>SOLUTION: The resin is filled in between a battery body 101 and a circuit board 102 electrically connected to the battery body to integrate both. Notched parts are formed at both ends of the board 120, and the outer peripheral shape except the notched parts agrees with a shape of both side-faces of the secondary battery. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack having improved external connectivity and safety, and an improved robustness of a battery pack which is made compact and thin so as to be suitable for a battery power source for small portable electronic devices and the like. It is a thing.

[0002]

2. Description of the Related Art Miniaturization or thinning of portable electronic devices,
Further, the progress of higher functionality is remarkable, and accordingly, a battery or a battery pack serving as a power source thereof is required to be small and thin and have a high capacity. A lithium-based battery is effective as a battery that is small and enables high capacity, and among them, a flat prismatic lithium-ion secondary battery is suitable for thinning the device,
As a rechargeable secondary battery, its application to mobile electronic devices such as mobile phones is increasing.

Since the lithium-based battery has a high energy density and uses a flammable organic solvent as an electrolytic solution,
Consideration of safety is important. It is necessary to ensure safety so as not to damage the human body or equipment even if an abnormality occurs for some reason. For example, when a short circuit occurs between the positive electrode and the negative electrode of the battery for some reason, an excessive short-circuit current flows in the battery having high energy density, Joule heat is generated due to internal resistance, and the temperature of the battery rises. When the temperature of the battery rises, the reaction between the positive electrode active material and the electrolytic solution, vaporization and decomposition of the electrolytic solution may occur, and the gas pressure inside the battery may rise rapidly, which may cause the battery to burst or ignite. Not only the above-mentioned external short circuit causes the battery to fall into a high temperature state, but also when the secondary battery is overcharged, the portable electronic device with the battery placed near the heater, or left in the car parked in the hot sun. And so on.

The lithium-based battery is provided with a function of preventing the battery from falling into an abnormal state and preventing a dangerous state even if the battery falls into an abnormal state. The function of the battery itself is to prevent excessive reaction of the active material and electrolyte of the electrode plate, and the polyolefin microporous film used as a separator softens and closes its pores at abnormally high temperatures. It has a shutdown function. In addition, a temperature fuse that shuts off the input / output circuit when the temperature rises abnormally and a safety valve that releases the abnormal internal pressure to the outside are provided. In a cylindrical lithium battery, the PTC (connected to the input / output circuit in series at the sealing part) Posit
Ive Temperature Coeffcien
t) An element is provided to provide a protection function for limiting an excessive current due to an external short circuit.

In the case of a small battery or a prismatic battery in which the thermal fuse or the PTC element cannot be provided in the battery, the PTC element or the thermal fuse is connected by wiring as an external circuit component, and the secondary battery is overcharged or overcharged. A circuit board that constitutes a battery protection circuit that protects the secondary battery from over-discharge is provided, and these components are housed in a pack case together with the secondary battery to form a battery pack.

However, since the pack case is manufactured by resin molding, the manufacturing cost of the molding die is high, the cost is added to the cost of the pack case, and the cost is increased, and the development period of the mold is long. For this reason, it is difficult to support a battery pack of a portable electronic device such as a mobile phone in which a new model has a short insertion interval. Also,
There is a limit to the wall thickness that can be molded in resin molding, and conversely it is necessary to increase the wall thickness in order to maintain strength, and there is a limit to downsizing and thinning the battery pack.

Further, it can be seen that the battery or the battery pack is constructed so that it is difficult to disassemble or that it has been disassembled in order to prevent the danger of disassembling the battery, the wrong use, or the use of the battery in an interesting manner. It is important to ensure the safety of the structure. Further, considering that it is applied to portable electronic devices, it is required to have a robust structure capable of withstanding shock and vibration due to a drop or the like and moisture resistance of electronic circuit parts. In order to realize such a structure that is hard to disassemble, is robust, and has moisture resistance, it is envisioned that the circuit board that constitutes the battery protection circuit and the battery are integrated by resin molding.

Battery packs using the above resin molding are disclosed in Patent Documents 1 and 2, and an intermediate finished product in which a secondary battery and a circuit board are fixed by a connecting member is placed in a mold, A resin is filled around the intermediate finished product so that the external connection terminals formed on the circuit board are exposed to the outside to integrate the secondary battery and the circuit board.

Further, in Patent Document 3, a secondary battery and a circuit board connected by a connecting member are placed in a mold,
There is disclosed a configuration in which a circuit board is resin-sealed and fixed on a secondary battery or a pack case (battery lid), or a circuit board and a secondary battery are resin-sealed.

[0010]

[Patent Document 1] Japanese Patent Laid-Open No. 2002-134077

[0011]

[Patent Document 2] Japanese Patent Laid-Open No. 2002-166447

[0012]

[Patent Document 3] Japanese Patent Laid-Open No. 2000-315483

[0013]

In order to connect the electronic components such as the above-mentioned temperature fuse and PTC element to a small battery used as a power source for portable electronic equipment, the battery and the electronic components are housed in a case. It is necessary to form the battery pack, which leads to an increase in cost. Further, it is important that the heat sensitive element such as the thermal fuse and the PTC element is arranged in a state of being thermally coupled to the battery, and it is necessary to form a structure integrated with the battery. Therefore, there is a demand for a battery having a structure in which a heat sensitive element is integrated with the outside of the battery without forming the battery pack.

In the case of a secondary battery, the battery temperature is detected and used for charging control, safety control and the like. In order to detect the battery temperature, a temperature detection sensor such as a thermistor is arranged in contact with the secondary battery, and the detection output is input to the control circuit and is also provided to the charger from the external connection terminal. The temperature detection sensor is arranged in the form of a battery pack, but not only the number of manufacturing steps of the battery pack is increased, but also a structure for arranging so as to accurately detect the battery temperature is provided. There was a problem with the increase in cost.

A small battery has a positive electrode because of its structure,
The negative electrodes are formed on different surfaces. If the positive electrode and the negative electrode can be formed on the same plane or on a surface that facilitates connection, convenience in use is improved. For example, in a cylindrical battery, a positive electrode is formed at one end and a negative electrode is formed at the other end. Therefore, on the equipment side using this battery, connecting members for connecting to the positive electrode and the negative electrode of the battery are arranged on both sides of the accommodation space of the battery. Further, in the prismatic battery, the positive electrode and the negative electrode can be provided in the sealing portion, but since both electrodes are not on the same plane and there is a step, there is a problem that the external connection structure becomes complicated. Along with the downsizing and thinning of devices, there is an increasing demand for a simple structure of an external connection structure for the positive electrode and the negative electrode of a battery.

Further, when the battery and the circuit board are integrated with the resin mold, the resin is not joined to the battery or the circuit board, so that the integration is not sufficient and it is necessary to wrap the battery and the circuit board with the resin mold. As a result, the battery pack has the same form as a battery pack in which a battery and a circuit board are housed in a resin-molded pack case, and there is a problem that miniaturization and thinning cannot be achieved.

In the structure disclosed in Patent Document 3, the circuit board is fixed to the battery with the double-sided tape and then resin-molded, and the resin is molded over at least three surfaces of the battery. However, since the resin and the metal are basically not bonded to each other as described above, there is a possibility that the resin mold may peel off from the battery when subjected to vibration or shock.
Batteries and battery packs are mainly applied to portable electronic devices, vibration and shock are unavoidable, and it is necessary to obtain a state in which a resin mold is engaged with a metal such as a battery.

Further, in the above prior art, in the external connection structure of the battery pack, the connector is provided at the tip of the lead wire drawn out from the resin-molded circuit board, and the connection with the device is made by the device. It is made by fitting between the connector on the side and the male and female. This external connection structure is not a problem when the battery accommodation space is relatively large in a relatively large device, but it is natural that the battery accommodation space is small in the small device mainly intended by the battery pack of the present invention. Therefore, it is difficult to apply this connection structure. The connection structure with the device side of the battery or battery pack of the present invention, when the battery or battery pack is stored in the battery storage space of the device side,
A device side contact terminal (probe) provided there is pressed against an external connection terminal exposed to a predetermined position of a battery or a battery pack. A circuit board on which external connection terminals are formed and a battery are resin-molded to form a battery pack, and the device-side connection terminals provided in the battery-accommodating space on the device side and the external connection terminals are pressure-welded to each other with a low contact resistance To do so, the external dimensions of the battery pack and the positions of the external connection terminals must be formed with high accuracy. In the case of connection by such contact, if the forming accuracy is low, the contact resistance between the device-side connection terminal and the external connection terminal becomes large, resulting in abnormalities such as poor contact and voltage drop.

An object of the present invention is to provide a battery and a battery pack in which a battery and a substrate are integrated by resin molding.

[0020]

According to the present invention for achieving the above object, one or a plurality of battery main bodies and at least external connection terminals are formed in parallel with the upper surface of the battery main body. A substrate, a connecting member for electrically connecting the substrate and the battery main body, a resin molded body in which the filled and molded resin is fixed to arbitrary surfaces of the battery main body and the substrate to integrate them, and An engaging battery for engaging a resin molded body with a battery body and / or a substrate, wherein the outer peripheral edge of the substrate has a flat one side surface shape. It is characterized by conforming to.

In the substrate-integrated battery having the above structure, the battery main body and the substrate are integrated by the resin mold body, and in addition, the shape of the outer peripheral edge of the substrate matches the shape of one flat side surface of the battery main body. Therefore, the robustness of the integrated portion can be improved.

Further, according to the present invention for achieving the above object, one or a plurality of battery main bodies, and a substrate which is arranged in parallel with an upper surface of the battery main body and on which at least external connection terminals are formed, A connecting member for electrically connecting the substrate and the battery main body, a resin molded body in which the filled and molded resin is adhered to arbitrary surfaces of the battery main body and the substrate to integrate them, and the resin molded body. An upper resin molding for exposing at least the external connection terminal to the outside and covering the substrate and the resin molded body with respect to the substrate integrated battery configured to include the battery main body and / or the engaging means for engaging with the substrate. A body, a lower resin molded body that covers the surface of the battery main body opposite to the surface on which the substrate is provided, a part of the upper resin molded body and the lower resin molded body, and a body part of the battery body Outside with the wearing sheet The constructed by coating the lower resin molded body is made of preformed resin molded plate, the resin molded plate is characterized by coating the opposite surface entire surface of the substrate arrangement surface of the cell body.

In the battery pack having the above-mentioned structure, the battery main body and the substrate are integrated by a resin mold body, and at least the external connection terminals on the substrate are exposed to the outside to provide an exterior coating. An upper resin molded body that exposes the connection terminals to the outside and covers the substrate and the resin molded body, and a lower resin molded body that covers the surface of the battery opposite to the substrate mounting surface are formed. By making the body into a pre-molded resin molded plate and covering the entire surface of the battery main body opposite to the substrate mounting surface, the strength of the lower resin molded body can be further increased, thus improving the robustness of the battery pack. Can be improved.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The embodiments described below are examples of embodying the present invention and do not limit the technical scope of the present invention.

FIG. 1 shows a battery 100 according to the first embodiment.
2A and 2B show the appearance of a and 100b, and are configured as a flat prismatic lithium ion secondary battery. The battery body 101 is a terminal plate (substrate) connected to its positive and negative electrodes
102 and the resin molded body 103 are integrated, and the positive electrode external connection terminal 104 and the negative electrode external connection terminal 105 are formed on the outer surface of the terminal plate 102. The battery 100a is
The terminal plate 102 is arranged parallel to the sealing surface of the battery body 101, and the positive electrode external connection terminal 104 and the negative electrode external connection terminal 10 are arranged.
5 is provided on the upper surface. The battery 100b has a configuration in which the terminal plate 102 is arranged in parallel with the side surface of the battery body 101, and the positive electrode external connection terminal 104 and the negative electrode external connection terminal 105 are provided at the side surface ends.

As shown in FIG. 2, the battery body 101 accommodates a power generating element in an aluminum battery can 22 formed in a bottomed cylindrical shape having an oval cross section, and its open end is sealed. The plate 23 is sealed by laser welding. The sealing plate 23, which is joined to the battery can 22 and serves as a battery positive electrode, has a rivet 2 serving as a battery negative electrode, which is insulated at its center by an upper gasket 24a and a lower gasket 24b.
5 has been concluded. Further, a part of the sealing plate 23 is formed as a clad plate obtained by laminating foil-shaped plates, and the safety valve 20 in which the discharge port 20a is formed in the clad plate portion is configured. Further, the resin mold body 1 is provided on both sides of the sealing plate 23.
A pair of engaging members 26 for engaging 03 with the battery main body 101 are formed. The method of forming the engaging member 26 is the method of forming the sealing plate 23 by pressing, and the engaging member 26.
Any of the methods of welding and joining the sealing plate 23 to the sealing plate 23 can be adopted. Reference numeral 27 is a sealing plug that closes the electrolytic solution inlet. After the electrolytic solution is injected into the battery can 22, the electrolytic solution inlet is closed by the sealing plug 27, and the sealing plug 27 is welded to the sealing plate 23.

The battery main body 101 having the above-mentioned structure is shown in FIG.
As shown in FIG.
The TC element 110 is arranged, the other electrode plate of the PTC element 110 is arranged on the insulating sheet 21 stuck on the sealing plate 23, and a positive electrode connection lead plate (connection member) 108 described later is provided.
Is joined with. The heat insulating sheet 16 is disposed on the PTC element 110 so that the PTC element 110 is not thermally destroyed during the filling and molding of a resin described later. Further, the resin sheet 40 is attached to cover the discharge port 20a of the safety valve 20.

As shown in FIG. 4, the terminal plate 102 has a positive electrode external connection terminal 104 and a negative electrode external connection terminal 105 formed on one surface which is the outer surface side, and the other is the inner surface side which faces the battery body 101. A positive electrode connection land 106 and a negative electrode connection land 107 that are connected to the battery body 101 are formed on the direction. The positive electrode external connection terminal 104 and the negative electrode external connection terminal 105 can be formed by etching a copper foil attached on the plate surface, but can also be configured by attaching a terminal member to the plate surface. Since the configuration in which the positive electrode external connection terminal 104 and the negative electrode external connection terminal 105 are provided on the side surface like the battery 100b is suitable for sliding contact with the connection terminal on the device side, a plate-shaped terminal member is used as the terminal board 1.
It is desirable to attach it to 02. In addition, important points are connected between one surface and the other surface of the terminal board 102 by through holes and circuit patterns (not shown).

As shown in FIG. 4C, the positive electrode connecting land 106 and the negative electrode connecting land 107 respectively have a positive electrode connecting lead plate 108 and a negative electrode connecting lead plate (connecting member).
One end of 109 is joined by soldering. As shown in FIG. 5, this terminal board 102 has a positive electrode connection lead plate 108.
The other end of the negative electrode connection lead plate 109 is joined to the sealing plate 23.
The other end is joined to the other electrode plate of the PTC element 110 and connected to the battery body 101. When the battery 100a shown in FIG.
As shown in (a), the positive electrode connecting lead plate 108 and the negative electrode connecting lead plate 109 are bent so as to be parallel to the sealing plate 23. When the battery 100b shown in FIG. 1B is constructed, the battery 100b may remain in a state orthogonal to the sealing plate 23 as shown in FIG. 5A.

As described above, the battery body 101 and the terminal plate 10
2 is connected to the battery main body 101, as shown in FIG.
The battery main body 1 is formed by filling and molding resin between the terminal plate 102 and the terminal plate 102.
01 and the terminal board 102 are integrated. Most of the surface of the battery main body 101 is a metal body, and it is difficult to join the resin molded body 103 that has been filled and molded, but the engagement member 26 mounted on the sealing plate 23 is wrapped in the resin molded body 103, The resin molded body 10 in the undercut portion
3, the anchor effect for the resin mold body 103 is obtained, and the resin mold body 103 is connected to the battery main body 101.
It will be in a state of being joined to. In the terminal plate 102, the positive electrode connecting lead plate 108 and the negative electrode connecting lead plate 109 are the resin molded body 1.
Although it is wrapped in 03 and engages with the resin mold body 103, in order to further improve the engaging property, a rivet-shaped projection is provided, and the same effect as the engaging member 26 can be obtained. A thermoplastic polyamide resin is used as the resin to be filled and molded. This resin has excellent adhesiveness, electrical insulation, chemical resistance, and can be molded in the range of 190 ° C. to 230 ° C., so that it can suppress the thermal influence on the battery body 101, the PTC element 110, and the like. it can.

As shown in FIG. 5, the terminal plate 102 has a shape in which notches are provided at arc corners that match the arcs on both sides of the battery body 101, and the outer peripheral edge excluding the notches is the battery body. The shape is substantially the same as that of 101. Further, as shown in FIG. 1A, the resin mold body 103 has rectangular cutouts at the arc corners that conform to the shape of the terminal plate 102 and the arcs on both side surfaces of the battery body 101. The terminal plate 102 has a circular shape and is formed so that the arcuate corner portion of the terminal plate 102 is exposed from the resin mold body 103.

Further, by applying an adhesive having a good adhesive property to the resin and the metal to the surfaces of the terminal plate 102 and the battery body 101 which are in contact with the resin molded body 103, the resin mold body 103 and the battery body 101 and the terminal plate 102 are connected to each other. It is also possible to improve the bondability of. As this adhesive, a hot-melt adhesive of polyamide resin, an epoxy resin-based adhesive,
A silicone modified resin adhesive is used.

Batteries 100a and 100b having the above structure
Is a positive electrode external connection terminal 104 and a negative electrode external connection terminal 105.
If an external short circuit occurs between the
When the temperature of the PTC element 110 rises due to an excessive short-circuit current due to a short circuit and the temperature exceeds a set trip temperature, the PTC element 110, which has a small resistance value in a normal temperature state, rapidly increases the resistance value due to a trip phenomenon. Therefore, the short-circuit current is regulated at a stretch to prevent the battery main body 101 from rising in temperature due to an external short circuit and falling into a situation such as a rupture. Since the PTC element 110 trips due to the temperature rise even when the battery body 101 is exposed to a high temperature environment,
The battery body 101 is prevented from being used in a high temperature environment. That is, the batteries 100a and 100b are the PTC element 11
It will be equipped with 0 built-in safety function.

When the batteries 100a and 100b rise to an abnormal temperature and gas is generated in the battery body 101,
The battery main body 101 may burst, but when the pressure of the generated gas reaches the operating pressure of the safety valve 20, the safety valve 2
In the case of 0, the foil-like plate portion is broken and the abnormally increased internal pressure is released to the outside. Since the discharge port 20a of the safety valve 20 is covered with the resin sheet 40 and further covered with the resin mold body 103, the gas ejected from the discharge port 20a is generated between the resin sheet 40 and the resin mold body 103 and the battery body 101. It is released from the interface to the outside. Therefore, it is possible to prevent the battery main body 101 from rupturing due to the temperature rise.
Battery 1 with double safety function together with C element 110
00a, 100b.

Batteries 100a, 1 constructed as described above
00b can be improved in appearance and strength by further providing an exterior coating. The exterior coating is shown in FIG.
As shown in (b), the terminal plate 102 is formed by forming openings on the positive electrode external connection terminal 104 and the negative electrode external connection terminal 105.
The secondary mold body 120 that covers the upper surface and covers the side peripheral surface of the resin mold body 103 and the winding sheet 121 that is wound around the side peripheral surface of the battery body 101 have an appearance as shown in FIG. The batteries 100c and 100d can be finished. The winding sheet 121 is made of polypropylene resin, polyethylene terephthalate resin, polycarbonate resin,
Also, a resin or the like containing these is used, and by applying an adhesive layer to this resin, the resin is attached to the batteries 100a and 100b. In addition, by using a film having a desired function for the winding sheet 121, it is possible to enhance the function as a battery. For example, the effect of increasing the strength of the battery can be obtained by using a fiber reinforced film in which glass fibers or the like are dispersed instead of the resin. Further, by winding nickel powder and carbonyl iron powder in high concentration in the acrylic propolymer, the wound sheet 12
1 may be provided with an EMI (electromagnetic interference) shield layer. The winding sheet 121 having this shield layer is
In addition to the electromagnetic interference to the electronic parts mounted on the terminal board 102, the electromagnetic interference to the equipment in which this battery is mounted is suppressed. Further, the winding sheet 121 can be decorated with colors, patterns and the like. In particular, when applied to a device having a structure in which a battery is exposed to the outside, a wrapping sheet 121 according to the color and tone of the device is used.

Next, the battery pack according to the second embodiment will be described. This embodiment shows an example in which a flat-type lithium-ion secondary battery is used to configure a battery pack applied to a mobile phone. The battery pack applied to mobile phones is small, lightweight, thin, and has a high energy density that supports high functionality, mechanical strength that can withstand impacts such as drops that are inevitable as mobile devices, a structure that is difficult to disassemble, and a short circuit. It is required to have a safety function for protecting the secondary battery from overcharging, high temperature, etc., and the battery pack shown below is configured to meet these requirements.

FIG. 8 shows the external appearance of the battery pack 1 according to the embodiment. The external connection terminal 6 including a positive electrode terminal, a negative electrode terminal, and a temperature detection terminal is externally exposed on one end surface of the test terminal 30 to be described later. A submerged seal 9 is attached to the surface of the container to form a flat asymmetric shape. FIG. 9 shows the components of the battery pack 1 disassembled, and the details of the main components and the assembly procedure will be described below.

The secondary battery 2 used in the battery pack 1 is the first
The battery main body 101 has the same configuration as the battery main body 101 (see FIG. 2) applied to the battery shown in the embodiment, and the description thereof will be omitted.

In the secondary battery 2, as shown in FIG. 10, one connecting piece 10a of the temperature fuse 10 is welded to the rivet 25. A heat insulating sheet 16 is adhered to the upper surface of the thermal fuse 10 as shown by a broken line to prevent the thermal fuse 10 from being blown out at the time of resin filling described later. The other connecting piece 10b of the thermal fuse 10 is arranged on the insulating sheet 21 stuck on the sealing plate 23, and is joined to one end of a negative electrode lead plate 5 described later by spot welding. In addition, the thermal fuse 10 has a sealing plate 23 made of a heat conductive adhesive.
And is disposed in a state of being thermally coupled to the secondary battery 2. Although the thermal fuse 10 is applied here,
Like the batteries 100a and 100b described above, the PTC element 11
It is also possible to apply 0.

As shown in FIG. 11, the circuit board 3 constituting a protection circuit for protecting the secondary battery 2 from overcharge, overdischarge, and overcurrent has the external connection terminals 6 and the external connection terminals 6 on one surface which is the outer surface side. A test terminal 30 is formed, an electronic component 31 such as an integrated circuit component is mounted on the other surface of the secondary battery 2 side, and positive electrode soldering lands 32 for connecting to the secondary battery 2 and negative electrode solder are provided on both sides. The attachment land 33 is formed. One end of the positive electrode lead plate (connection member) 4 is soldered to the positive electrode solder land 32, and one end of the negative electrode lead plate (connection member) 5 is soldered to the negative electrode solder land 33. It should be noted that, in each drawing, the display of circuit patterns, through holes, etc. formed on the circuit board 3 is omitted.

With respect to the secondary battery 2, the circuit board 3 that has completed this connection process has the other end of the positive electrode lead plate 4 on the plate surface of the sealing plate 23 and the other end of the negative electrode lead plate 5 of the thermal fuse 10. Spot welding is performed on the other connection piece 10b.
In this connection state, since the circuit board 3 is in a direction orthogonal to the plate surface of the sealing plate 23, the lead plates 4 and 5 for the positive electrode and the negative electrode are bent as shown in FIG. A space is provided between the plate surface of the circuit board 3 and the plate surface of the sealing plate 23, and the circuit board 3 is shaped in a substantially parallel state. In this way, the circuit board 3 is connected to the secondary battery 2 to form the resin filling target 7 as shown in FIG.

A resin is filled in the gap between the secondary battery 2 and the circuit board 3 of the resin-filled object 7 to form a primary mold body (first frame) 11 to form a secondary battery 2. The circuit board 3 is integrated. The primary mold body 11 is formed by accommodating the resin-filled object 7 in the primary mold die as shown in FIG.
As shown in FIG. 3, resin is filled between the secondary battery 2 and the circuit board 3 and molded.

As shown in FIG. 14, in the lower die 36 of the primary molding die, the movable portion 41 is movable to the fixed portion 42 side by the urging means 45, and the movable portion 41 has the vacuum suction portion 43. It is provided. When the resin-filled object 7 is placed in the lower mold 36 with the movable portion 41 retracted and the movable portion 41 is moved forward, the bottom surface of the secondary battery 2 is pressed against the inner wall surface of the fixed portion 42. Positioned. on the other hand,
The circuit board 3 is positioned in close contact with the wall surface of the vacuum suction portion 43 by vacuum suction from the vacuum suction portion 43.

The height dimension H from the bottom surface of the secondary battery 2 to the external connection terminal forming surface of the circuit board 3 is such that the height dimension h of the secondary battery 2 varies and the circuit board 3 is fixed at a fixed position. Although it fluctuates due to the absence, the circuit board 3 is fixed at a fixed position by vacuum suction, and the moving amount of the movable portion 41 changes in accordance with the height dimension h of the secondary battery 2. The secondary battery 2 and the circuit board 3 positioned in the inside are changed by the change in the height dimension G of the gap between them.
The height dimension H from the bottom surface of the secondary battery 2 to the external connection terminal formation surface of the circuit board 3 becomes constant.

The lower mold 36 on which the secondary battery 2 and the circuit board 3 are positioned as described above is closed by the upper mold, and the resin is injected into the gap between the secondary battery 2 and the circuit board 3. As shown in FIG. 13, the injected resin also wraps around the electronic components 31 mounted on the circuit board 3 and the lead plates 4 and 5 for the positive and negative electrodes to bond to the circuit board 3, The undercut portion of the engaging projection 26 formed on the sealing plate 23 of the battery 2 is also wrapped around and joined to the sealing plate 23. The resin is preferably a thermoplastic polyamide resin that fluidizes at a temperature that does not adversely affect the electronic component 31, the secondary battery 2, or the thermal fuse 10 and solidifies when the temperature decreases. As an example of this resin, a thermoplastic polyamide resin cermelt 817 manufactured by TRL is used. Thermert 817 is 19
Since it can be molded at 0 to 210 ° C and the solidification time is as short as 5 seconds, it has a feature that heat influence on batteries and electronic parts can be eliminated.

Since the temperature of the resin exceeds 200 ° C. even if the temperature of the resin is relatively low, when the thermal fuse 10 whose melting temperature is set to 104 ° C. is touched, the thermal fuse 10 melts and the battery pack 1 itself. The function of will be stopped. The countermeasure is to attach the heat insulating sheet 16 on the thermal fuse 10 so that the heat of the resin is
It suppresses heat transfer to.

When the filled resin is solidified, FIG.
The intermediate finished product 8 as shown in (b) can be taken out from the lower mold 36. The intermediate finished product 8 can be formed into the battery pack 1 by applying an outer coating on the periphery thereof. Here, the exterior coating is applied by attaching a secondary molding and a wrapping sheet. Before performing the secondary molding, the insulator 1 is attached to the bottom surface of the secondary battery 2.
Stick 4 on.

In the secondary molding, as shown in FIG. 15, the intermediate finished product 8 is placed in the secondary molding die 46, and a resin is molded at a required portion of the intermediate finished product 8. The lower mold 47 of the secondary molding die 46 is formed with a recess 50 for accommodating the intermediate finished product 8, and one side wall surface of the recess 50 is for three external connection terminals that are biased inward. A protrusion 51 and a test terminal protrusion 52 are provided, and a bottom face protrusion 54 that is urged to move inward is provided on the other side wall surface facing each other. When the intermediate finished product 8 is placed in the recess 50 and the external connection terminal projection 51, the test terminal projection 52, and the bottom surface projection 54 are advanced, the external connection terminal projection 51 is formed on the circuit board 3. Press contact with the external connection terminals 6 at 3 places,
The test terminal projection 52 is pressed against the test terminal 30, and the bottom projection 54 is pressed against the insulator 14 attached to the bottom surface of the secondary battery 2.

The upper mold 48 is closed on the lower mold 47 in this state,
Resin is filled into the secondary molding die 46 from the gate 53 provided on the upper die 48. The resin is injected into the secondary molding die 46 from four places, and as shown in FIG. 16, the external connection terminals 6 and the test terminals 30 of the intermediate finished product 8 are exposed to the outside, and the central portion of the insulator 14 is exposed to the outside. Then, the primary mold body 11 and the circuit board 3 are covered, and the secondary battery 2
An upper molding portion 17 fixedly formed on the sealing plate 23 is formed, and a lower molding portion 18 wrapping around the insulator 14 and fixed to a predetermined thickness is formed on the bottom surface of the secondary battery 2, and the upper molding portion is further formed. A connection molding portion 19 is formed that connects the lower molding portion 17 and the lower molding portion 18 at a side surface corner of the secondary battery.

The types of resin selected in the primary molding and the secondary molding may be the same or different. When the types of resins are the same, the degree of adhesion between the resins is high, and the mechanical strength of the mold part can be increased. When different types of resin are used, the resin can be selected according to the characteristics required in each molding process. For example, the primary molding is mainly intended to insulate the circuit board 3 with resin and to integrate it with the secondary battery 2. Considering the heat influence on the circuit board 3 and the thermal fuse 10, low temperature molding is possible, In addition, a resin with excellent insulation and adhesion to metal parts is selected,
Since the secondary molding also serves as the exterior of the battery pack, it is required to have high mechanical strength and high surface properties. Since the resin in the secondary molding does not come into direct contact with the components (the electronic components 31 on the circuit board 3 and the thermal fuse 10) in which the resin in the molten state is significantly affected by heat, the resin in the secondary molding is more likely than the resin in the primary molding. The present invention can also be applied to resins that require high temperature molding (for example, resin materials such as ABS resin).

However, when different resin materials are selected, it is necessary to consider the adhesion between the resins, the mechanical strength, the chemical stability of the materials, and the like. Further, it is preferable that the color tone of the resin used for the secondary molding be substantially the same as or darker than the color tone of the resin used for the primary molding.
This is when using a light color resin for the secondary molding,
This is because the color tone of the primary molding resin is transmitted, and the appearance of the battery pack is impaired. For the same reason, the color of the secondary molding resin is similar to that of the circuit board 3 and the resist applied to the circuit board 3. Or, it is preferable that the color is dark.

As shown in FIG. 17, the connection molding portion 19 is formed of resin so that a 90 ° portion on one side of the arc side surface of the secondary battery 2 having an oval cross section is formed at a right angle. . By the upper molding part 17, the lower molding part 18, and the connection molding part 19, the secondary molding body shown in FIG.
Frame body 12 is formed.

As shown in FIG. 16, the upper molding part 17 is formed.
A stepped portion 38 is formed on the peripheral surface of the secondary battery near the secondary battery, and the winding sheet 13 is wound around the side peripheral surface of the secondary battery 2 using this as a sticking positioning line. After that, the operation state is inspected by using the test terminal 30, and the submerged seal 9 is attached in the recessed portion around the test terminal 30 to the product that passed the inspection, and the battery pack 1 as shown in FIG. 8 is formed. .

In the battery pack 1 thus formed, the flat shoulders on one side are formed at arc corners where the arcs on both sides of the secondary battery 2 appear on the surface, and the shoulders on the other side are connected. Since the molded portion 19 is formed in a rectangular corner, the external connection terminal 6 is formed in an asymmetrical position, and therefore the reverse loading to the device can be prevented. Further, the arcuate corner corresponds to the rounded shape of the corner of the device case, so that the device can be stored in the device without forming a useless space.

In the structure of the secondary molded body 12 in the above structure, only the upper molding part 17 is formed on the circuit board 3 and the primary molding body 11 as the secondary molding, and the lower molding part 18 is formed on the bottom surface of the secondary battery 2. Insulator 14 (ABS resin, ABS + PC resin, P
(C resin molded product) is affixed, and the connection molding portion 19 is not provided, and the winding sheet 13 is covered by covering the side peripheral surface of the secondary battery 2, the upper molding portion 17 and the end portion of the insulator 14. It can also be wrapped around. When the secondary molding body 12 is molded by the secondary molding, it is not necessary to mold the whole of the secondary molding, and therefore only the forming region can be put into the mold for molding. Therefore, since it is not necessary to dispose the entire secondary battery 2 in the mold, it is possible to minimize the heat effect on the battery, realize the downsizing of the mold, and effectively reduce the manufacturing cost. . Needless to say, the insulator 14 serves to insulate the bottom surface of the secondary battery 2, but the bottom surface of the secondary battery is not a resin molded body, but an insulator that is a separate molded product is used to form the battery. The strength of the bottom portion can be improved.

Further, the secondary molded body 12 is formed in advance by resin molding so as to have the same external shape as that of the upper molding portion 17, and the secondary molded body 12 is covered on the circuit board 3 to be attached so as to cover the primary molded body 11. On the bottom surface of the secondary battery 2, the insulator 14 described above is provided.
It is also possible to attach a, and to cover the end portions and the side peripheral surface of the secondary battery 2 and wind the winding sheet 13.

Next, a battery pack according to the third embodiment will be described. This embodiment shows a battery pack using a plurality of secondary batteries.

FIG. 18 shows the external appearance of the battery pack 200 according to the third embodiment. As shown in FIG. 19, two flat batteries 2a and 2b each having a flat rectangular shape are connected in series. Connected to the circuit board 203 to connect the two secondary batteries 2a,
2b and the circuit board 203 are integrated by a resin mold body 202.

The secondary batteries 2a and 2b have the same basic structure as that of the secondary battery 2 described above, but the secondary batteries 2a and 2b are provided on the bottom surface of the battery can 22 to ensure the integration between the secondary batteries 2a and 2b. Also, the engaging members 26, 26 are joined. The positive electrode connecting land of the circuit board 203 and the bottom surface of the battery can 22 of the secondary battery 2b are connected by a positive electrode connecting lead plate 204, and the temperature fuse 10 arranged on the negative electrode connecting land of the circuit board 203 and the secondary battery 2a. And the other connection piece 10b of the negative electrode connection lead plate 20
Connected at 5. Further, between the sealing plate 23 of the secondary battery 2a and the rivet 25 of the secondary battery 2b, the series connection lead plate 2 is provided.
It is connected at 07.

Two secondary batteries 2a, 2b connected in series
As shown in FIG. 19, the circuit board 203 and the circuit board 203 are arranged in a mold so as to be opposite to each other with a predetermined gap provided between them, and the primary molding is performed. In this process,
Resin is filled and molded between the upper and lower sides of the secondary batteries 2a and 2b and in parallel to form a resin mold body 202 in which the two secondary batteries 2a and 2b and the circuit board 203 are integrated. The engaging members 26 provided above and below the secondary batteries 2a and 2b have an anchoring effect on the resin mold body 202, and
The resin mold body 202 is fixed to a and 2b. Therefore, the secondary batteries 2a and 2b and the circuit board 203 which are unstable only by being connected to the positive and negative connection lead plates 204 and 205 and the serial connection lead plate 207 are firmly integrated.

Although it functions as a battery pack even in the state shown in FIG. 19, a battery pack 20 shown in FIG. 18 is provided by applying an outer coating to further improve strength and appearance.
Can be formed to 0. The exterior coating can be performed by the secondary mold and the winding sheet as in the battery pack 1 shown in the second embodiment. Further, the thermal fuse 10 is attached to the sealing plate 23 of the secondary battery 2a by being connected to the rivet 25 as in the case shown in FIG. 10, and the resin sheet 40 is attached to the safety valve 20.

The configuration of the battery pack in which a plurality of secondary batteries are connected in series and / or in parallel is not limited to the form in which the two secondary batteries 2a and 2b shown in the third embodiment are connected in series.
It can be configured by using an arbitrary number of secondary batteries as needed. For example, as shown in FIG. 20, it is possible to configure a battery pack in which four secondary batteries 2a to 2d are connected in series. Also in this case, the sealing plate 23 of each of the secondary batteries 2a to 2d
Further, when the engaging member 26 is provided on the bottom surface of the battery can 22 and the resin is filled and molded, the plurality of secondary batteries 2a to 2d and the circuit board 20 are formed.
3 can be firmly integrated.

[0063]

As described above, in the integrated battery according to the present invention, the battery main body and the substrate are integrated by the resin mold body, and in addition, the outer peripheral edge shape of the substrate is one flat side surface of the battery main body. Since it conforms to the shape of, the battery can be configured to have improved robustness of the integrated portion.

Further, the battery pack according to the present invention can be constructed as a battery pack in which the secondary battery, the circuit board and the like are integrated without using a resin-molded pack case.
In particular, it is possible to form a battery pack in which the robustness of the portion of the secondary battery main body opposite to the surface on which the substrate is provided is improved. This makes it possible to reduce the size and thickness, and due to the robust structure of the resin mold, it is suitable for application to a device such as a portable electronic device in which vibration or impact is unavoidable. Further, since the case formed by resin molding is not used, the period and cost for manufacturing the resin molding die are reduced, and it is possible to adapt to high-mix low-volume production.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of a battery according to an embodiment.

FIG. 2A is a plan view showing the configuration of a battery body, and FIG.
Is a cross-sectional view.

FIG. 3A is a plan view and FIG. 3B is a cross-sectional view with a PTC element attached to a battery body.

FIG. 4 is a perspective view showing the configuration of the terminal plate, where (a) is the outer surface side, (b) is the inner surface side, and (c) is the lead plate mounting state.

FIG. 5 is a perspective view showing how the terminal plate is attached to the battery body.

FIG. 6 is a cross-sectional view showing a state where a terminal plate and a battery body are integrated with a resin mold body.

FIG. 7 is a perspective view of a battery with an outer coating.

FIG. 8 is a perspective view showing the external appearance of the battery pack according to the embodiment.

FIG. 9 is an exploded perspective view showing each component of the battery pack.

FIG. 10A is a plan view showing a state in which a thermal fuse is attached to a secondary battery, and FIG. 10B is a sectional view.

FIG. 11 is a perspective view showing a state in which a circuit board is attached to the secondary battery.

FIG. 12 is a perspective view showing a state in each manufacturing process of the battery pack.

FIG. 13 is a cross-sectional view showing a state in which a circuit board is integrated with a secondary battery by a resin mold body.

FIG. 14 is a schematic diagram showing a configuration of a primary molding die.

FIG. 15 is a perspective view showing the configuration of a secondary molding die.

FIG. 16 is a sectional view showing a state in which a secondary mold body is formed.

FIG. 17 is a cross-sectional view illustrating a formation position of a connection molding portion.

FIG. 18 is a perspective view showing the appearance of a battery pack using a plurality of secondary batteries.

FIG. 19 is a schematic diagram illustrating an integrated structure of the battery pack of the same.

FIG. 20 is a schematic diagram illustrating an integrated structure of a battery pack using a plurality of secondary batteries.

[Explanation of symbols]

1 battery pack 2 Secondary battery 3 circuit board 4 Positive electrode lead plate (connection member) 5 Negative electrode lead plate (connecting member) 6 External connection terminal 7 Resin filling target 8 Intermediate finished products 10 Thermal fuse 11 Primary mold body 12 Secondary mold body 13 Wrapping sheet 14 Insulator (lower resin molding) 16 Insulation sheet 17 Upper molding part 18 Lower molding part 19 Connection molding part 23 Seal plate 26 Engagement protrusion 100a, 100b, 100c, 100d batteries 101 Battery body 102 terminal board (board) 103 Resin mold body 104 Positive electrode external connection terminal 105 Negative electrode external connection terminal

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kunio Tsuruta             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5H040 AA07 AA20 AS12 AY08 DD06                       DD08 DD10 DD24 JJ05

Claims (2)

[Claims] 1. One or a plurality of battery main bodies, a substrate disposed in parallel with an upper surface of the battery main body and provided with at least an external connection terminal, and the substrate and the battery main body electrically. A connecting member to be connected, a resin molded body in which the filled and molded resin is fixed to arbitrary surfaces of the battery main body and the substrate to integrate them, and an engagement for engaging the resin molded body with the battery and / or the substrate. And an outer peripheral edge shape of the substrate conforming to the shape of at least one flat side surface of the battery main body. 2. One or a plurality of battery main bodies, a substrate arranged in parallel to the upper surface of the battery main body and having at least external connection terminals formed thereon, and the substrate and the battery main body electrically. A connecting member to be connected, a resin molded body in which the filled and molded resin is fixed to arbitrary surfaces of the battery main body and the substrate to integrate them, and a member for engaging the resin molded body with the battery main body and / or the substrate. And an upper resin molded body that exposes at least the external connection terminal to the outside and covers the substrate and the resin mold body, and a battery mounting surface of the battery body. The outer surface is covered with a lower resin molded body that covers the opposite surface, and a wrapping sheet that is wound by covering a part of the upper resin molded body and the lower resin molded body and the body portion of the battery body. Battery pack, below 2. A battery pack, wherein the resin molded body comprises a resin molded plate which has been molded in advance, and the resin molded plate covers the entire surface of the battery main body opposite to the substrate mounting surface.