JP2007273242A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack which is compact and has high productivity. <P>SOLUTION: The battery pack is provided with a battery 1 and a card type end member 5 which houses a charge/discharge safety circuit and is provided with an external connecting terminal 10 and connecting lead parts 12a, 12b. The card type end member 5 is arranged on one end face 3 of the battery 1, and the connecting lead parts 12a, 12b are connected with an electrode terminal 4 of the battery 1 and a battery case 2 and the card type end member 5 is integrally fixed with the battery 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a battery pack including a battery and a charge / discharge safety circuit thereof.

  A battery pack including a battery and a charge / discharge safety circuit is widely used as a power source in various portable electronic devices. This battery pack is required to have a particularly compact configuration and high productivity in the manufacturing process.

  As shown in FIG. 5, a conventional battery pack has a protrusion 32 formed on the outer periphery of one end surface of the battery 31 and a recess 33 formed on the inside, a terminal plate 35 on the upper surface, and a battery end surface on the lower portion. A terminal holder 34 having a fitting convex part 34a to be fitted into the concave part is provided, and the protective element 36 is built in the terminal holder 34, and one end 36a thereof is an electrode terminal 37 of the battery 31 and the other end 36b is a terminal on the upper surface. After connecting to each of the plates 35 and connecting the terminal holder 34 to the battery 31 with an adhesive tape 38, a heat shrink film or the like, and then welding a lead plate (not shown) to the terminal plate 35 and the battery case, A battery pack 40 that is housed in a case 39 or covered with a heat-shrinkable tube or the like is known (for example, see Patent Document 1).

In addition, in a battery pack having a circuit board, the battery and the circuit board are mechanically and electrically connected to each other with a lead plate in a state where the circuit board is temporarily held by the battery with a holder. 6, a connecting projection 43 is provided on the sealing plate 41 a of the battery 41, the connecting projection 43 is connected to the circuit board 42, and the battery 41 and the circuit board 42 are mechanically and electrically connected by the connecting projection 43. A battery pack 50 in which the batteries 41 and the circuit board 42 are housed in a case 44 is known (for example, see Patent Document 2).
JP 2000-243360 A JP 2002-298809 A

  However, in the configuration described in Patent Document 1, the battery pack 40 is configured by forming the assembly of the terminal holder 34 including the battery 31 and the protective element 36 and then welding the lead plate and storing it in the case 39. However, there is a problem that it is difficult to ensure high productivity because the outer shape becomes larger and the number of assembly steps increases.

  Further, in the configuration described in Patent Document 2, the circuit board 42 is fixed to the sealing plate of the battery 41 using a special sealing plate 41a having the connecting convex portion 43, so that the lead plate is not used. Although the structure can reduce the number of assembly steps, the circuit board 42 and the battery 41 are housed in the case 44 to form the battery pack 50, and there is a problem that the outer shape is increased correspondingly.

  In view of the above-described conventional problems, the present invention provides a compact and highly productive battery pack.

  The battery pack of the present invention includes a battery, a card-type end member that has a built-in charge / discharge safety circuit and is provided with an external connection terminal and a connection portion for the electrode terminal of the battery. Are arranged, and a connection part is connected to the electrode terminal of the battery, and a card-type end member is integrally fixed to the battery.

  According to this configuration, the card type end member having a built-in charge / discharge safety circuit and having an external connection terminal and a connection portion is used, and the card type end member is integrally fixed to one end surface of the battery. Therefore, a battery pack with a compact configuration can be realized, and a card-type end member can be separately manufactured, so that when the card-type end member and the battery are assembled, the connecting portion is connected and fixed integrally. Therefore, the number of assembling steps is extremely small, and it can be manufactured with high productivity.

  In addition, it is preferable that an IC tag is built in the card-type end member because the history of the manufacturing and distribution process of the battery pack can be individually managed.

  In addition, when a thermal protection element is connected between the connection part of the card type end member and one electrode terminal of the battery, a higher protection mechanism against heat generation can be provided, and the safety of the battery pack Can be improved.

  Also, the card-type end member is a board or lead frame on which an external connection terminal is formed on the front surface, an electronic component is mounted on the back surface, and the connection lead portion is extended. When configured by adhering or welding between a case having a concave portion to be accommodated and a cover, the card-type end member itself having the above-described configuration can be manufactured with high productivity and at low cost.

  As the substrate, a low-temperature polyethylene terephthalate (which has a relatively low heat-resistant temperature is obtained by forming a circuit at low temperature using conductive ink, forming a resistive element, and electrically connecting an electronic component using a conductive adhesive. Preferred examples of the substrate include films such as PET) resin, polyethylene naphthalate (PEN) resin, norbornene-based amorphous polyolefin resin, cycloolefin polymer resin, liquid crystal polymer resin, and polyphenylene sulfide resin.

  Moreover, as a material of a lead frame, what plated the steel plate with nickel, a nickel plate, etc. are mentioned suitably.

  Also, the case of the card mold end member is provided with a protrusion for positioning the card mold end member by contacting at least the outer peripheral portions of one end surface of the battery, and the outer periphery of the battery and the card mold end member is covered with an exterior film. Thus, even when one electrode terminal protrudes from one end surface of the battery, the battery pack can be positioned by simply placing the card-type end member in contact with the one end surface of the battery, and covers the exterior film in that state. Thus, the battery and the card-type end member can be easily fixed together, and high productivity can be ensured.

  According to the battery pack of the present invention, the card-type end member is integrally fixed to one end surface of the battery, so that a compact configuration can be obtained, and a connecting portion is provided when the card-type end member and the battery are assembled. Since it is only necessary to connect and fix them together, the number of assembling steps is extremely small and it can be manufactured with high productivity.

  Hereinafter, an embodiment of a battery pack of the present invention will be described with reference to FIGS.

  In FIG. 1, reference numeral 1 denotes a rectangular battery having a flat cross-sectional shape, or a rounded rectangular or oval rectangular battery. The battery 1 is composed of a lithium ion battery, and an electrode plate group and an electrolytic solution as power generation elements are accommodated in a battery case 2. The electrode plate group is configured to be laminated in multiple layers by winding with a separator interposed between a belt-like positive electrode plate and a negative electrode plate. The positive electrode plate is made by applying and drying a positive electrode mixture to a core material made of aluminum foil, and the negative electrode plate is made by applying and drying a negative electrode mixture to a core material made of copper foil, and the separator is microporous. It is composed of a conductive polypropylene film.

  An electrode terminal 4 protrudes from the center of the one end surface 3 of the battery 1. The electrode terminal 4 seals and penetrates the one end surface 3 of the battery case 2 in an insulated state, and constitutes a negative electrode terminal of the battery 1. The electrode terminal of the positive electrode of the battery 1 is constituted by a battery case 2.

  Reference numeral 5 denotes a card-type end member disposed on the one end surface 3 of the battery 1, in which a charge / discharge safety circuit is built, and three external connection terminals 10 are provided on the surface thereof. Of the three external connection terminals 10, two are positive and negative external connection terminals, and the remaining one is a detection resistor for identification, I / O (input / output port) connection terminals of IC tags, and temperature detection. It is a connection terminal for identification that may be used as a connection terminal of the thermistor.

  As shown in FIG. 2, the card-type end member 5 has an electrode 10a to be an external connection terminal 10 formed on the front surface, various electronic components 11 mounted on the back surface, and connection lead portions 12a and 12b from both ends in the longitudinal direction. A substrate 6 made of an extended polyethylene terephthalate (PET) resin film, a case 7 having a recess 8 for accommodating an electronic component 11 mounted on the substrate 6, and a cover 9 covering the surface of the substrate 6. The case 7 and the cover 9 are integrally formed by being bonded or welded with the substrate 6 interposed therebetween. Suitable materials for the case 7 and the cover 9 include polyethylene terephthalate (PET) resin, polycarbonate (PC) resin, and the like. The external connection terminal 10 is exposed to the outside through three connection windows 9 a formed in the cover 9.

  As shown in FIG. 3A, an electrode 10a serving as the external connection terminal 10 is formed on the surface of the substrate 6, and the FET 13 and the control are formed on the back surface of the substrate 6 as shown in FIG. The IC 14 and the capacitive element 15 are mounted, and the resistor 16 is printed to form a charge / discharge safety circuit 17. In this embodiment, an IC tag 18 is mounted. In this embodiment, the electronic component 11 mounted on the substrate 6 is an FET 13, a control IC 14, a capacitive element 15, and an IC tag 18, and these electronic components 11 are electrically connected using a conductive adhesive. ing.

  One connection lead portion 12a extending from both ends in the longitudinal direction of the card-type end member 5 is connected to the electrode terminal 4 projecting from the central portion of the one end surface 3 of the battery 1 by spot welding or the like, The connection lead portion 12b is connected to one side of the battery case 2 by spot welding or the like. In addition, an insulating plate 19 is disposed between the card-type end member 5 and the one end surface 3 of the battery 1 in order to prevent one connection lead portion 12a from contacting the one end surface 3 of the battery 1 and causing a short circuit. ing.

  On both sides of the lower surface of the case 7 of the card-type end member 5, the planar view of positioning the card-type end member 5 at a predetermined position that contacts the one end surface 3 of the battery 1 and does not interfere with the electrode terminal 4 on the one end surface 3 is omitted. A U-shaped protrusion 20 is provided. The protrusion 20 on one side is provided with a notch 20a for extending the connection lead portion 12a along the lower surface of the case 7. The card-type end member 5 is positioned with respect to the battery 1 by this protrusion 20 and the outer periphery of the battery 1 and the card-type end member 5 is a cylindrical heat-shrinkable film with the connection lead portions 12a and 12b connected. The battery pack 22 is formed by covering the battery 1 and the card-type end member 5 integrally with each other.

  Next, an assembly process of the battery pack 22 having the above configuration will be described. First, the card-type end member 5 is positioned on the one end surface 3 of the battery 1, one connection lead portion 12 a is spot welded to the electrode terminal 4, and then the insulating plate 19 is disposed on the one end surface 3 of the battery 1. Thereafter, the projecting portion 20 is brought into contact with both side portions of the one end surface 3 to position the card-type end member 5, and the other connecting lead portion 12b is spot welded to the side surface of the battery case 2, and then the exterior film 21 is attached to the battery. The battery pack 22 is completed by being fitted over the outer periphery of the card-type end member 5 and covered with heat shrinkage.

  The manufacturing process of the card-type end member 5 will be described. First, the substrate 6 on which the circuit pattern is formed including the electrodes 10a to be the external connection terminals 10 and the connection lead portions 12a and 12b and the resistor 16 is printed. The electronic components 11 such as the FET 13, the control IC 14, the capacitor element 15, and the IC tag 18 constituting the charge / discharge safety circuit 17 are mounted on the substrate 6. The substrate 6 is placed on the case 7 so that the mounted electronic component 11 is accommodated in the recess 8, and the substrate 6 is sandwiched between the case 7 and the cover 9 and bonded or welded integrally. It can be manufactured with good performance.

  In addition, by forming a circuit pattern or resistance on the substrate with a conductive ink at a low temperature, a polyethylene terephthalate (PET) resin, a polyethylene naphthalate (PEN) resin, or a norbornene-based non-resistant material that cannot withstand the temperature of a high temperature furnace for solder reflow. A crystalline polyolefin resin, a cycloolefin polymer resin, a liquid crystal polymer resin, a polyphenylene sulfide resin, or the like can be used for a film or sheet substrate.

  According to the battery pack 22 having the above-described configuration, the card-type end member 5 having the built-in charge / discharge safety circuit 17, the external connection terminal 10 and the extended connection lead portions 12 a and 12 b is used. Since the battery pack 22 is configured by integrally fixing the card-type end member 5 to the one end face 3, the battery pack 22 having a compact configuration can be realized. In addition, by separately manufacturing the card mold end member 5, when the card mold end member 5 and the battery 1 are assembled, it is only necessary to connect the connecting lead portions 12 a and 12 b and to integrally fix them with the exterior film 21. Therefore, the number of assembling steps is extremely small, and it can be manufactured with high productivity.

  Further, since the IC tag 18 is built in the card-type end member 5, it is possible to individually manage the manufacturing and distribution process history of the battery pack 22 and the like.

  In the above description, an example in which the protrusion 20 is integrally formed on the case 7 is shown. However, a separate mounting frame is provided between the one end surface 3 of the battery 1 and the card-type end member 5. The battery 1, the mounting frame, and the card-type end member 5 may be integrally fixed with the exterior film 21 after being interposed and fixed or temporarily fixed as necessary.

  In the above description of the embodiment, an example in which the connection lead portion 12a is directly connected to the electrode terminal 4 is shown. However, as shown in FIG. 4, a temperature fuse is connected between the connection lead portion 12a and the electrode terminal 4. Alternatively, a heat-sensitive protective element 23 such as a PTC element may be connected. According to this configuration, a higher protection mechanism against heat generation can be provided, and the safety of the battery pack 22 can be improved.

  Further, in the card type end member 5 of the above embodiment, the connection lead portions 12a and 12b provided on the substrate 6 are extended from both ends in the longitudinal direction to the both sides. However, the present invention is not limited to this. For example, when a connection terminal serving as a connection portion is insert-molded in the case 7 and the substrate 6 is sandwiched between the case 7 and the cover 9, the card-type end member 5 is configured. Alternatively, the circuit pattern of the substrate 6 may be connected to the connection terminal, and the connection terminal of the card-type end member 5 may be connected to the electrode terminal provided on the one end surface 3 of the battery 1.

  Further, in the card type end member 5 of the above embodiment, the example using the substrate 6 has been shown, but a lead frame in which a circuit pattern is formed including the electrode 10a serving as the external connection terminal 10 instead of the substrate 6 is used. A lead frame on which an IC element such as FET 13 and control IC 14 is mounted and coated on the lead frame, and then a chip part such as a resistor or capacitor element 16 is mounted and reflow soldered, and this part is mounted. The card-type end member 5 may be configured by covering with a case 7 and a cover 9.

  Thus, the configuration using the lead frame can be configured at a lower cost than the substrate 6 made of a film using an expensive heat-resistant polyimide resin or the like.

  The battery pack of the present invention has a configuration in which a card-type end member is integrally fixed to one end surface of the battery, so that it can have a compact configuration, and a connecting portion is connected when the card-type end member and the battery are assembled. Therefore, since it is only necessary to fix them integrally, the number of assembly steps is extremely small, and it can be manufactured with high productivity, which is useful for small battery packs for portable electronic devices.

The principal part structure of the battery pack of one Embodiment of this invention is shown, (a) is a top view, (b) is a partial cross section front view. The disassembled perspective view of the card type | mold end member in the battery pack. The board | substrate in the card type | mold end member is shown, (a) is a top view, (b) is a bottom view. The fragmentary sectional front view which shows the principal part structure of the battery pack of other embodiment of this invention. The longitudinal cross-sectional front view which shows the principal part structure of the battery pack of a prior art example. The longitudinal cross-sectional front view which shows the principal part structure of the battery pack of another prior art example.

Explanation of symbols

1 Battery 2 Battery case (electrode terminal)
3 End face 4 Electrode terminal 5 Card type end member 6 Substrate 7 Case 8 Recess 9 Cover 10 External connection terminal 12a, 12b Connection lead part (connection part)
17 Charge / Discharge Safety Circuit 18 IC Tag 20 Projection 21 Exterior Film 22 Battery Pack 23 Thermal Protection Element

Claims (8)

  A battery and a card-type end member having a built-in charge / discharge safety circuit and having an external connection terminal and a connection to the electrode terminal of the battery, the card-type end member being disposed on one end surface of the battery, and a battery electrode A battery pack characterized in that a connecting portion is connected to a terminal and a card-type end member is integrally fixed to a battery.   2. The battery pack according to claim 1, wherein an IC tag is built in the card-type end member.   The battery pack according to claim 1, wherein a thermal protection element is connected between the connection part of the card type end member and one electrode terminal of the battery.   The card-type end member has a substrate or lead frame on which an external connection terminal is formed on the front surface, an electronic component is mounted on the back surface, and a connection lead portion is extended. The battery pack according to claim 1, wherein the battery pack is configured by being sandwiched and bonded or welded.   5. The battery pack according to claim 4, wherein the substrate has a wiring pattern printed on the base material using a conductive ink.   The substrate has a resin base material, a wiring pattern printed on the base material using conductive ink, and a resistance element printed on the base using conductive ink having a high resistivity. The battery pack according to claim 4.   The substrate has a wiring pattern printed on the base material using a conductive ink on the base material, and the electrical connection of the electronic component is made using a conductive adhesive. The battery pack according to claim 4. The card type end member case is provided with a protrusion for positioning the card type end member in contact with at least the outer peripheral portions of one end surface of the battery, and the outer periphery of the battery and the card type end member is covered with an exterior film. The battery pack according to any one of claims 1 to 7, characterized in that

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