JP2003317679A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack in which a plurality of batteries are connected in series and/or in parallel by jointing a wiring board and integrated in one body and these are housed in a pack case. <P>SOLUTION: In the battery pack, a wiring board 15a, 15b in which an insulating sheet 12a, 12b is adhered on both faces of a conductor pattern 11a, 11b made of a metal thin plate is installed on both side end on which a plurality of batteries 2a-2i are arranged in parallel, and the portion of the conductor pattern 11a, 11b exposed to the outside is welded to each battery 2a-2i. And an internal structure element 10 that is connected to the circuit components, the circuit board 5, and the circuit plate and is made electrically connected and mechanically integrated is housed in a pack case. <P>COPYRIGHT: (C)2004,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 in which a plurality of batteries, circuit components, and other internal components connected by wiring are housed in a pack case.

[0002]

2. Description of the Related Art When a plurality of batteries are housed in a pack case to form a battery pack, wiring connections for connecting the plurality of batteries in series and / or in parallel are made and the wires are exposed from the pack case. A wiring structure for connecting to external connection terminals is required. Further, in a battery pack using a battery having a high energy density such as a lithium ion secondary battery, a protection circuit or a safety circuit is provided to protect the battery from a short circuit, overcharge, etc., and to ensure safety, a circuit board or Circuit parts and the like are housed in the pack case together with the battery. These internal components are required to be electrically wired and at the same time mechanically formed into a unitary structure. Further, since the battery pack is mainly used for portable electronic devices, it is required to have a robust structure capable of withstanding vibration and impact in addition to being downsized and thinned.

In order to construct an electrical and mechanical connection structure in the demand for miniaturization and thinning as described above, wiring leads in which lead members for connecting batteries in series and / or in parallel are formed of a thin metal plate. At the same time as connecting the wiring by the board,
It is known that components are integrated by wiring connection. Since the wiring lead plate is a thin metal plate,
An increase in the volume of the internal components is suppressed as compared with the wiring connection using the insulating coated lead wire, and the plurality of batteries can be integrated by the wiring connection. However, a metal lead plate arranged in a case where components are densely arranged in a case having a limited volume may cause a short circuit, and it is necessary to insulate the metal lead plate.

As a conventional technique in which a plurality of metal lead plates are formed as a wiring pattern and a plurality of batteries are integrated by subjecting a main portion thereof to an insulating treatment, Japanese Utility Model Laid-Open No. 22622/1995 and Japanese Patent Laid-Open No. 2663047/1992 are disclosed. The one disclosed in the above is known. In any of the technologies, a conductor pattern is formed by a metal lead plate on the array surface where a plurality of batteries are arranged, an insulating sheet or a resin insulating coating is provided on the surface of the conductor pattern that is in contact with the battery, and a plurality of insulating coatings are used. A wiring board in which the metal lead board is fixed in position is formed. A plurality of batteries connected in series are arranged on this wiring board, and parts are connected, and one end of the metal lead board is exposed outside the case as an external output terminal.

[0005]

In the above prior art, the metal thin plate is formed on the conductor pattern and the external connection terminals are formed by the metal thin plate. However, since the wiring for connecting a plurality of batteries in series requires connecting a lead plate different from the wiring pattern to the batteries, it is necessary to perform the process of connecting the batteries in series and / or in a separate process. . When the number of batteries increases, the step of connecting in series and / or parallel becomes the most complicated work, but another step is required to carry out this, which causes a problem of increasing the number of manufacturing steps of the battery pack.

Further, since the conductor pattern and the insulating means for insulating and supporting the conductor pattern according to the prior art are arranged on the surface where the batteries are arranged, the thickness of the battery pack is increased, and the battery pack is made thin like a portable electronic device. Is not a valid configuration when required.

Further, the outer surface of the battery is a live part that serves as a positive electrode or a negative electrode, and it is necessary to provide an insulating distance or to interpose an insulating member between the parts arranged close to the active part. If a distance is provided, it will be an obstacle to downsizing and thinning of the battery pack, and if an insulating member is interposed, management of another member and processing cost will be required in the manufacturing process, and there is a risk of failure due to forgetting to install the insulating member. is there.

[0008] Further, in the welded joint portion and the soldered joint portion of the conductor pattern, if the distance between the front and back is not provided to the insulating means so that heat at the time of joining is not dissipated to other portions, welding failure or It causes soldering failure. It has been difficult to achieve the trade-off between exposing metal and ensuring insulation in a narrow wiring space.

It is an object of the present invention to provide a battery pack provided with a wiring board for collectively wiring and connecting a plurality of batteries and circuit components.

[0010]

SUMMARY OF THE INVENTION To achieve the above object, the present invention relates to a battery circuit in which a plurality of batteries housed in a pack case are connected in series and / or in parallel by wiring leads and circuit components are connected. And a battery pack in which the battery circuit is connected to an external connection terminal exposed to the outside from the pack case, wherein the wiring lead connects at least a plurality of batteries in series and / or in parallel with each other. A conductor pattern for connecting parts to form a battery circuit is formed by a thin metal plate, and at least a welding part to be welded to a positive electrode or a negative electrode of the battery and front and back surfaces of a part connecting part for connecting the circuit parts are exposed to the outside and are both surfaces. It is characterized in that it is formed on a wiring board to which an insulating sheet is attached.

According to the above structure, when the welding portion and the connecting portion of the conductor pattern formed by the thin metal plate are exposed to the outside, the exposed portion of the wiring board having the insulating sheets adhered on both sides is joined to the battery and the circuit component. , A plurality of batteries are connected in series and / or in parallel, circuit parts are connected, and internal components are electrically connected and mechanically integrated at the same time. It can be configured into a battery pack.

In the above structure, the external connection terminal can be integrated with the internal component by extending and forming the terminal connection lead plate for connecting the external connection terminal from the wiring board.

In addition, a plurality of batteries arranged in parallel can be connected in series and / or in parallel by connecting a wiring board having a required conductor pattern formed on each end face side on which a positive electrode or a negative electrode is formed. It is easy to do so, and the thickness can be suppressed to form a thin battery pack.

In addition, by extending and forming an insulation allowance for covering the lead portion of the connected circuit component on the insulating sheet near the connection part of the circuit component, the insulation allowance is provided for covering the lead portion with the insulation allowance. It is possible to avoid forgetting the insulation process.

Further, the outer end of the insulating sheet is formed so as to be positioned outside the outer end of the conductor pattern, so that the edge portion of the conductor pattern is not exposed to the outside.
Insulation can be secured.

Further, by forming a conductor pattern on the metal thin plate so that the batteries connected in parallel can be arranged with an insulation gap therebetween, the batteries connected in series can be insulated.

Further, the circuit board is connected to the external connection terminals by wiring, and the external connection terminals are connected via the circuit board, thereby supporting the circuit board and forming a battery circuit including the circuit board. Can be done easily.

[0018]

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.

As shown in FIG. 1, the battery pack 1 according to the present embodiment has nine batteries 2a to 2i configured as a cylindrical lithium ion secondary battery connected in series and in parallel, and a battery protection circuit. A pack case 3 includes an internal component 10 that is integrated by an electrical and mechanical connection structure in which a circuit board 5 and circuit components that configure the above are connected to an external connection terminal board 4.
The terminal forming surface of the external connection terminal board 4 is exposed to the outside by accommodating it inside and closing the illustrated opening with a lid case (not shown) and joining the pack case 3 and the lid case by ultrasonic welding. Then, the internal component 10 is configured to be sealed in the pack case 3.

FIG. 2 shows the internal component 10 in a plane from the bottom surface side of the pack case 3 and each side surface thereof. The nine batteries 2a to 2i arranged in parallel have respective positive electrodes, Wiring boards 15a, 1 are provided on both end surfaces on which the negative electrode is formed.
5b is resistance-welded (series-welded) to batteries 2a, 2b, 2c, batteries 2d, 2e, 2f,
The batteries 2g, 2h, 2i are connected in parallel, and
The groups are connected in series and are connected in series and parallel. Further, the PTC element 7, the thermal fuse 8 and the thermostat 9 are connected to the required portions of the wiring boards 15a and 15b, and the thermal fuse 8 and the thermostat 9 are housed in an arc concave portion formed by arranging cylindrical batteries in parallel. The height of the internal component 10 is prevented from increasing. Wiring boards 15a, 1 in which batteries 2a to 2i are connected in series and parallel
The extension of 5b connects the PTC element 7 and
It is connected to the circuit board 5 by soldering. The circuit board 5 is integrally connected to the external connection terminal board 4 by being connected to each terminal of the external connection terminal board 4. By connecting the wiring boards 15a and 15b, the internal component 10 is mechanically integrated at the same time as being electrically connected. The configuration of the wiring boards 15a and 15b will be described in detail below.

FIG. 3 shows the conductor pattern 11a and the insulating sheets 12a, 12a constituting the wiring board 15a on one side separately. The conductor pattern 11a is formed by punching out a thin plate (t = 0.23) of a nickel-plated steel plate into the shape of the wiring pattern.
2i, a portion 20 connected by resistance welding, portions 21, 22 connected by soldering to the circuit board 5, a portion 23 connected by resistance welding to the PTC element 7, a thermal fuse 8.
Are connected to each other by soldering, and a portion 25 to which the thermostat 9 is connected by resistance welding is formed. In addition, the part shown by cross hatching is
This is a soldering part for facilitating soldering.

With respect to the conductor pattern 11a having the above structure, the insulating sheets 12 formed on both surfaces of the conductor pattern 11a have the same shape.
a and 12a are attached. The insulating sheet 12a is one in which an adhesive surface is formed on one side of a sheet made of aramid fiber having excellent heat resistance, chemical resistance, and flame resistance.
Resistance welding parts 20, 23, 25 and soldering part 2 of
A welding window 26 for attaching and covering the surfaces other than 1, 22, and 24 and for resistance welding to the batteries 2d to 2f in the main part.
Is formed, and insulating margins 27, 27 for insulating the soldered portion of the thermal fuse 8 and an extending piece 28 for insulating the resistance welding portion of the thermostat 9 are formed.

FIG. 4 shows a state in which insulating sheets 12a, 12a are attached to the conductor pattern 11a from both sides to form a wiring board 15a. The hatched portion is covered with the insulating sheets 12a, 12a of the conductor pattern 11a. The black solid portion is the portion where the conductor pattern 11a is exposed to the outside. Insulation sheet 12a as shown
Since the portion covering the conductor pattern 11a is formed to have an area located outside the conductor pattern 11a, the conductor pattern 11a is reliably insulated. The main part of the wiring board 15a thus formed is bent as shown in FIG.

FIG. 6 shows the conductor pattern 11b constituting the wiring board 15b on the other surface side and the insulating sheets 12b, 12b in a separated manner. The shape is different from that of the wiring board 15a on the one surface side. It is configured in the form of. The conductor pattern 11b is a thin plate of nickel-plated steel plate (t = 0.23).
Which is formed by punching into a shape of a wiring pattern and which is connected to the batteries 2a to 2i by resistance welding.
0, a portion 22 to be connected to the circuit board 5 by soldering,
Portions 23 connected to the PTC element 7 by resistance welding, and portions 24, 24 connected to the thermal fuse 8 by soldering
Are formed respectively. The cross-hatched portion is a solder-processed portion for facilitating soldering.

With respect to the conductor pattern 11b having the above structure, the insulating sheets 12 formed on both surfaces of the conductor pattern 11b have the same shape.
b and 12b are attached. The insulating sheet 12b is attached to and covers the surface of the conductor pattern 11b excluding the resistance welding portions 20, 23, 25 and the soldering portions 21, 22, 24, and the main portions of the battery 2a, 2b, 2c, 2g. A welding window 26 for resistance welding is opened, and insulating margins 27, 27 are formed to insulate the soldered portion of the thermal fuse 8.

FIG. 7 shows a state in which insulating sheets 12b, 12b are attached to both sides of the conductor pattern 11b to form a wiring board 15b. The hatched portion is covered with the insulating sheets 12b, 12b of the conductor pattern 11b. The black solid portion is the portion where the conductor pattern 11b is exposed to the outside. Wiring board 15 formed in this way
The main part of b is bent as shown in FIG.

As shown in FIG. 9, the wiring boards 15a and 15b having the above structure have a P between the welding portions 23 and 23.
The TC element 7 is resistance-welded, the leads of the thermostat 9 are resistance-welded to the pair of resistance-welded portions 25 of the wiring board 15a, respectively, and the two soldering portions 24, 24 of the wiring boards 15a, 15b facing each other are heated at different temperatures. Solder the lead of fuse 8 and solder part 2 at one end
1 and 22 are soldered to predetermined positions on the circuit board 5. After the thermostat 9 is welded and connected, the extension pieces 28 in which the insulating sheets 12a are extended on both sides of the welded portion 25 are folded back as shown in FIGS. 2 and 9 to enhance the insulation of the welded portion 25. ing. Further, the insulating sheets 12a, 1 formed on both sides of the soldering portion 24 of the thermal fuse 8
Insulation allowance 27 of 2b is between batteries 2a and 2b, batteries 2g and 2h.
It is inserted into the arcuate recess between them to enhance insulation.

To connect the batteries 2a to 2i to the wiring boards 15a and 15b, the wiring boards 15a and 15b are resistance-welded so that the batteries 2a to 2i are set in a jig and are in a predetermined parallel state. As described above, the wiring boards 15a and 15b are formed with the resistance welding portions 20 in which the conductor patterns 11a and 11b are exposed from the insulating sheets 12a and 12b to the outside, so that one of the batteries 2a to 2i set in the jig is formed. Wiring board 15a or wiring board 15b is arranged on the positive and negative electrodes on the end side,
Resistance welding is performed by pressing a pair of series welding electrodes against the wiring boards 15a and 15b for each of the batteries 2a to 2i. As shown in FIG. 2, by welding at 2 to 4 welding points S,
The batteries 2a to 2i are electrically connected in series and parallel and mechanically integrated. Further, the circuit board 5 is connected by the wiring boards 15a and 15b, and the circuit board 5 is connected to the external connection terminal board 4
, The internal component 10 is formed in which all the components are integrated.

As shown in FIG. 1, when the internal component 10 is housed in a pack case 3, the batteries 2a, 2b, 2c, the batteries 2d, 2e, 2f, and the battery 2 connected in parallel are connected.
The partition plates 6, 6 projectingly formed in the pack case 3 are inserted into the gaps G, G (see FIG. 2) formed between the parallel groups g, 2h, 2i to secure the insulation between the parallel groups and at the same time the battery. The strength of the pack 1 is improved.
The partition plate 6 formed on the pack case 3 is the battery 2
It is also inserted between a and the PTC element 7 to insulate the PTC element 7 from the battery 2a and at the same time secure the position of the battery in the pack case 3 to improve the strength.

[0030]

As described above, according to the present invention, both sides of the conductor pattern are insulated by the insulating sheets, and the welding and soldering portions are exposed to the outside. Sexuality is also secured. Further, since the extending portion of the insulating sheet can cover the joint portion of the circuit component, it is not necessary to separately insert an insulating member, and the occurrence of insulation failure due to forgetting to insert the insulating member can be avoided. Further, by disposing and bonding the insulating plates on both end faces of the plurality of batteries arranged in parallel, the plurality of batteries can be connected in series and / or in parallel, and the plurality of batteries can be integrated.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of a battery pack according to an embodiment.

2A and 2B are a plan view and a side view showing a configuration of an internal component of the same.

FIG. 3 is an exploded view showing the configuration of one wiring board.

FIG. 4 is a plan view showing the configuration of the above wiring board.

FIG. 5 is a perspective view showing a state after the wiring board is bent.

FIG. 6 is an exploded view showing the configuration of the other wiring board.

FIG. 7 is a plan view showing the structure of the above wiring board.

FIG. 8 is a perspective view showing a state after the wiring board is bent.

FIG. 9 is a perspective view showing a state in which a wiring board is assembled.

[Explanation of symbols]

1 battery pack 2a to 2i batteries 3 pack cases 4 External connection terminal board 5 circuit board 7 PTC element (circuit component) 8 Thermal fuse (circuit parts) 9 Thermostat (Circuit parts) 10 Internal components 11a, 11b conductor pattern 12a, 12b Insulation sheet 15a, 15b wiring board

Claims (7)

[Claims] 1. A battery circuit is configured by connecting a plurality of batteries housed in a pack case in series and / or in parallel by wiring leads and connecting circuit parts, and exposing the battery circuit to the outside from the pack case. A battery pack connected to an external connection terminal, wherein the wiring lead includes at least a plurality of batteries in series and / or
Or, a conductor pattern that is connected in parallel and that connects circuit components to form a battery circuit is formed by a thin metal plate, and a table of welded portions that are welded to at least the positive electrode or the negative electrode of the battery and component connection portions that connect the circuit components. A battery pack comprising a wiring board having a back surface exposed to the outside and insulating sheets attached to both surfaces. 2. The battery pack according to claim 1, further comprising a terminal connection lead plate extending from the wiring board and connected to the external connection terminal. 3. The battery pack according to claim 1, wherein a plurality of batteries arranged in parallel are connected to a wiring board having a required conductor pattern on both end surfaces on which the positive or negative electrodes are formed. 4. The battery pack according to claim 1 or 3, wherein an insulation sheet covering a lead portion of the connected circuit component is extendedly formed on an insulating sheet near the connection portion of the circuit component. 5. The battery pack according to claim 1, wherein the outer end of the insulating sheet is formed so as to be located outside the outer end of the conductor pattern. 6. The battery pack according to claim 1, wherein a conductor pattern is formed by a thin metal plate so that a plurality of batteries can be connected in series with an insulating gap provided between the batteries connected in parallel. . 7. The battery pack according to claim 1, wherein the circuit board is connected to the external connection terminal by wiring, and the external connection terminal is connected via the circuit board.