JP2004221024A - Battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery allowing a circuit board to be properly installed in a unit cell, and capable of reducing the cost of a die used for coating the circuit board. <P>SOLUTION: The opening of an armoring material 3 is closed by a sealing member 8 with an electrode body housed in the armoring material 3 of the unit cell 1. The circuit board 2 is installed in the unit cell 1. By disposing the sealing member 8 at a position of the armoring material 3 receding inward relative to the opening surface of the armoring material 3, a space 9 surrounded by the armoring material 3 with the front face opened is formed on the front side of the sealing member 8. A tip part of a negative electrode terminal 14 of the unit cell 1 pierces the sealing member 8. The space 9 is filled with a resin material 11 with the circuit board 2 housed in the space 9 by fitting the tip side of a lead body 18 of a negative electrode of the circuit board 2 to the terminal 14 of the unit cell 1. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a battery, such as a thin lithium-ion secondary battery, which is suitable for use as a power source for small electronic devices such as a mobile phone.
[0002]
[Prior art]
2. Description of the Related Art A battery is known in which a circuit board having a protection circuit and the like is attached to a unit cell and integrated. In this conventional example, a circuit board is arranged on a unit cell, a lead body of the circuit board is connected to an electrode terminal of the unit cell, and then the circuit board is fixed to the unit cell with an insulating holder, and the circuit board is mounted on the unit cell. There is one integrated with a battery (see Patent Document 1).
[0003]
Also, after attaching a circuit board to the outer surface of the unit cell and connecting the lead body of the circuit board to the electrode terminals of the unit cell, the entire circuit board is covered with a synthetic resin together with the unit cell, and the circuit board is assembled. Some are integrated with a battery (see Patent Document 2).
[0004]
[Patent Document 1]
JP 2001-196048 A (paragraph number 0024, FIG. 1)
[Patent Document 2]
JP 2000-315483 A (paragraph number 0027, FIG. 4)
[0005]
[Problems to be solved by the invention]
In the batteries of Patent Documents 1 and 2, since there is no means for positioning the circuit board on the unit cell, the circuit board may move before the circuit board is integrated into the unit cell. As a result, there is a possibility that the lead body of the circuit board may be connected in a state of being shifted from the electrode terminal of the unit cell, and a step such as bending may be involved in assembling the battery, making it difficult to automate the battery assembling step. There is a problem somewhere.
[0006]
Furthermore, in the battery of Patent Document 2, since a wide area of the outer surface of the unit cell is covered with the synthetic resin, there is a problem in that a cost is required to prepare a mold for molding the cover.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a battery in which a circuit board can be appropriately arranged on a unit cell, a cost of a mold used for covering the circuit board can be reduced, and the battery assembly process can be easily automated. Is to do.
[0008]
[Means for Solving the Problems]
As shown in FIG. 2, the battery to which the present invention is applied includes a unit cell 1 in which an electrode body is accommodated in a bottomed cylindrical exterior member 3 having an opening, and a circuit board 2 integrated with the unit cell 1. An opening of the exterior material 3 is closed by a sealing body 8, an electrode terminal 14 is connected to the electrode body, and a tip end of the electrode terminal 14 penetrates the sealing body 8; A lead body 18 is connected to the circuit board 2, and a tip side of the lead body 18 extends from the circuit board 2. In the present invention, the sealing body 8 is disposed at a position retracted inward of the exterior material 3 from the opening surface of the exterior material 3, so that the sealing body 8 and the opening surface of the exterior material 3 A space 9 surrounded by the exterior material 3 is formed therebetween, and the lead body 18 is formed in a shape that can be fitted to the tip of the electrode terminal 14. The space 9 is filled with a resin material 11 in a state where the circuit board 2 is housed in the space 9 while being fitted to the tip of the electrode terminal 14.
[0009]
The unit cell 1 here corresponds to a lithium ion secondary battery, a primary battery, or the like. The electrode terminal 14 includes a case of a positive terminal and a case of a negative terminal. The circuit board 2 has an output terminal or the like for a communication device as a small electronic device, is covered with a synthetic resin or the like to form a module, and the case where the leading end side of the lead body 18 extends from the module is also included. . The resin material 11 corresponds to a synthetic resin such as a polyamide resin, a polyurethane resin, a polycarbonate resin, and an acrylonitrile butadiene styrene resin.
[0010]
Specifically, as shown in FIG. 2, the lead body 18 has a shape that fits by covering the electrode terminal 14. Further, the exterior material 3 regulates the movement of the circuit board 2.
[0011]
Further, the circuit board 2 may have a protection circuit and a charging circuit. With the protection circuit, the unit cell 1 can be protected from overcharge or overdischarge, and with the charge circuit, the unit cell 1 can be charged and its charging current can be controlled.
[0012]
Effects of the Invention
According to the present invention, the circuit board 2 can be positioned by fitting the lead body 18 of the circuit board 2 to the tip of the electrode terminal 14 of the unit cell 1. Therefore, the circuit board 2 is disposed at an appropriate position, the lead 18 of the circuit board 2 can be accurately connected to the electrode terminal 14 of the unit cell 1, and the battery assembly can be as much as the circuit board 2 can be positioned. Automation of the process becomes easy.
[0013]
Moreover, since the space 9 is provided by using the exterior material 3 of the unit cell 1 and the circuit board 2 is accommodated in the space 9 and filled with the resin material 11, the resin material 11 is placed on the front side of the battery. It is only necessary to mold only. Therefore, it is sufficient to use a mold having a simple shape for molding the resin material 11, and the cost of the mold can be reduced.
[0014]
When the lead body 18 of the circuit board 2 is shaped to cover the electrode terminals 14 of the unit cell 1, accurate positioning can be achieved, and the contact area between the lead body 18 and the electrode terminals 14 of the unit cell 1 increases. This makes spot welding easier.
[0015]
When the movement of the circuit board 2 is regulated by the exterior material 3, the circuit board 2 is positioned more accurately.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 3 show a battery according to the present invention. The battery has a unit cell 1 formed in a rectangular thin shape as shown in FIG. 1, and a circuit board 2 (FIG. 2) disposed on the unit cell 1.
[0017]
The unit cell 1 is a chargeable / dischargeable lithium ion secondary battery, and a bottomed cylindrical aluminum can or iron can with an open front surface is used as the exterior material 3. As shown in FIG. 1, the front and rear sides 4 and 5 of the battery are vertically short and vertically long, and the left and right sides 6 and 7 are vertically short and vertically long. .
[0018]
As shown in FIG. 2, the opening of the exterior material 3 is closed by a sealing body 8 made of aluminum, iron, or the like. The sealing body 8 is disposed at a position retracted inward (downward in FIG. 2) of the packaging material 3 from the front opening surface of the packaging material 3. A space 9 (see FIG. 3) that is enclosed and has an open front surface is provided. The resin material 11 is filled in the space 9 with the circuit board 2 accommodated therein.
[0019]
The circuit board 2 is a COB (Chip On Board) module having a protection circuit, a charging circuit, a polyswitch (PTC), and the like, and is attached to the front side of the sealing body 8 with the insulating tape 12 interposed in the space 9. .
[0020]
The electrode body is accommodated in the exterior material 3 in a liquid-tight state together with the electrolytic solution. The tip of a rectangular parallelepiped negative electrode terminal (electrode terminal) 14 penetrates through the right side of the sealing body 8, and the tip of the negative electrode terminal 14 has a square shape provided at the right side of the insulating tape 12. It fits into the fitting hole 15. The exterior material 3 of the unit cell 1 also serves as a positive electrode. In addition, the negative electrode terminal 14 is insulated from the sealing body 8 by the insulating packing 16.
[0021]
The electrode body is spirally wound with a sheet-shaped insulating separator sandwiched between a sheet-shaped positive electrode and a sheet-shaped negative electrode. In this state, the flat shape is crushed into a substantially elliptical cross section. It has become. The protection circuit protects the unit cell 1 from overcharge or overdischarge. The charging circuit controls the charging current while charging the unit cell 1. The polyswitch cuts off the current flowing through the unit cell 1 when the temperature of the unit cell 1 rises excessively.
[0022]
The front ends of the positive and negative leads 17 and 18 extend from the left and right sides of the circuit board 2, and the front ends of the positive leads 17 are connected to the front surface of the sealing body 8. As shown in FIG. 3, the lead body 18 of the negative electrode has a distal end side bent in a convex shape toward the front, and the distal end portion 18 a covers and fits the negative electrode terminal 14 of the unit cell 1. The lead members 17 and 18 of the positive and negative electrodes are formed of a thin plate such as elongated nickel.
[0023]
The upper and lower widths of the circuit board 2 are only slightly smaller than the distance between the upper and lower side walls 21 and 22 of the exterior material 3. When the circuit board 2 is stored in the space 9, the upper and lower side walls of the exterior material 3 The vertical positioning of the circuit board 2 is performed at 21 and 22.
[0024]
The vertical width L1 of the circuit board 2 is larger than the vertical width L2 of the negative electrode lead body 18. Thus, even if the circuit board 2 rattles up and down in the space 9 before the resin material 11 is filled, the upper and lower side walls 21 and 22 of the exterior material 3 are placed before the lead 18 of the negative electrode. , And the short circuit between the negative electrode lead body 18 and the exterior material 3 can be reliably prevented.
[0025]
As shown in FIG. 2, a negative electrode connector 19 for supplying power to a small electronic device protrudes from the front surface of the circuit board 2. The resin material 11 is formed of a synthetic resin such as a polyamide resin, a polyurethane resin, a polycarbonate resin, or an acrylonitrile butadiene styrene resin, and the circuit board 2, the leads 17 and 18, and the negative electrode terminals 14 are formed by the resin material 11. Are insulated and protected. The front end of the negative electrode connector 19 protrudes forward (upward in FIG. 2) from the front surface of the resin material 11.
[0026]
Next, a method for manufacturing the unit cell 1 will be described. In the space 9 of the unit cell 1, the fitting hole 15 of the insulating tape 12 is fitted to the tip of the negative electrode terminal 14 of the unit cell 1, and the insulating tape 12 is arranged on the front surface of the sealing body 8. Further, the distal end portion 18a of the lead 18 of the negative electrode of the circuit board 2 is fitted over the negative electrode terminal 14 of the unit cell 1 by covering the same, and the circuit board 2 is positioned. At this time, the circuit board 2 is housed in the space 9.
[0027]
In this state, the distal end portion 18a of the negative electrode lead body 18 of the circuit board 2 is connected to the negative electrode terminal 14 of the unit cell 1 by spot welding or the like, and the distal end side of the positive electrode lead body 17 is spot welded to the sealing body 8 or the like. Connect with. Thus, the circuit board 2 is fixed to the unit cell 1.
[0028]
Thereafter, the unit cell 1 is mounted in a mold, and a molten synthetic resin is injected into the space 9 of the unit cell 1 and solidified, so that the circuit board 2 and the leads 17 and 18 are covered with the resin material 11. (The state of FIG. 2), and the battery of FIG. 1 is completed.
[0029]
As described above, the circuit board 2 is positioned by fitting the negative electrode lead 18 of the circuit board 2 over the tip of the negative electrode terminal 14 of the unit cell 1 so that the positive and negative electrodes of the circuit board 2 can be positioned. The leads 17 and 18 can be accurately connected to the positive and negative electrodes of the unit cell 1.
[0030]
Further, since the space 9 is provided in the unit cell 1 by using the exterior material 3 of the unit cell 1 and the circuit board 2 is accommodated in the space 9 and filled with the synthetic resin, only the front side surface 2 of the unit cell 1 The circuit board 2 can be covered only by molding the mold with a mold.
[0031]
Instead of bending the lead 18 of the negative electrode of the circuit board 2 into a convex shape and fitting it to the negative terminal 14 of the unit cell 1, a fitting hole is provided in the lead 18 of the negative electrode, May be fitted to the negative electrode terminal 14 of the unit cell 1.
[0032]
In the above embodiment, the circuit board 2 is a COB module, but a discrete module as the circuit board 2 may be accommodated in the space 9 and filled with a synthetic resin.
[Brief description of the drawings]
FIG. 1 is a perspective view of a battery according to the present invention.
FIG. 2 is a sectional view of a main part of a battery.
FIG. 3 is an exploded perspective view of a main part of the battery.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Unit cell 2 Circuit board 3 Exterior material 8 Sealing body 9 Space 11 Resin material 14 Negative terminal 18 of unit cell Negative lead 18a Tip of the negative lead

Claims (5)

A unit cell containing the electrode body in a bottomed cylindrical exterior material having an opening, and a circuit board integrated with the unit cell,
The opening of the exterior material is closed by a sealing body,
An electrode terminal is connected to the electrode body, and a tip end of the electrode terminal penetrates the sealing body,
In a battery, a lead body is connected to the circuit board, and a tip side of the lead body extends from the circuit board.
The sealing body is disposed at a position retracted inward of the exterior material from the opening surface of the exterior material, so that the sealing material is surrounded by the exterior material between the sealing body and the opening surface of the exterior material. Space is formed,
The lead body is formed in a shape that can be fitted to the tip of the electrode terminal,
The battery is characterized in that the space is filled with a resin material in a state in which the lead body is fitted to the tip of the electrode terminal and the circuit board is housed in the space. The battery according to claim 1, wherein the lead body has a shape that fits by covering the electrode terminal. The battery according to claim 1, wherein the exterior member regulates movement of the circuit board. 4. The battery according to claim 1, wherein the circuit board has a protection circuit. 5. The battery according to claim 1, wherein the circuit board has a charging circuit.

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