JP3766001B2 - Battery and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery and a battery manufacturing method, and more particularly to a technique for improving battery reliability and productivity.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a battery used for a mobile terminal such as a mobile phone or a simple mobile phone includes a substantially rectangular parallelepiped battery cell and a circuit board that is electrically connected to each terminal of the battery cell. There is something fixed integrally.
[0003]
The battery cell is configured by enclosing, in a container formed by deep-drawing an aluminum material, a laminate of a plurality of positive electrode films and negative electrode films separated by a separator together with an electrolyte with a sealing plate. . In the sealing plate, a negative electrode terminal is disposed in a protruding state at the center.
[0004]
The circuit board is for charge control and electrical protection of the battery cell, and is bonded to the surface of the battery cell with double-sided tape. In order to prevent the battery thickness from increasing, the circuit board is attached to the side surface along the thickness direction of the battery cell in order to prevent the battery thickness from increasing. The flat side is selected. The circuit board is attached to the side surface adjacent to the negative electrode terminal because it needs to be connected to the negative electrode terminal protruding on one side surface of the battery cell.
[0005]
Furthermore, the circuit board is connected to each terminal of the battery cell by a metal connection plate. The connecting plate extends from both ends of the elongated circuit board arranged over the entire length of the battery cell toward the negative terminal and the positive terminal on the adjacent side surface, and the respective tips are soldered to the terminals. Thus, the circuit board and the battery cell are electrically and mechanically connected. Therefore, these connection plates are arranged so as to hold the battery cells. Then, the circuit board and the connection plate fixed in this manner are encased in a resin mold part and integrated with the battery cell.
[0006]
[Problems to be solved by the invention]
However, in the conventional battery configured as described above, since the circuit board and the connection plate are arranged on the side surface of the battery cell, the surface of the battery cell is covered with the circuit board and the connection plate, and the resin mold portion and There has been a problem that the bonding area of the is reduced. For this reason, the resin mold part may fall off due to an external force.
Moreover, since the resin mold part was shape | molded over 3 side surfaces of the battery cell, it was necessary to embed the battery cell in the inside of a metal mold | die, and to shape | mold a resin mold part. For this reason, there is a problem in that a die having a complicated cavity shape is used and the product cost of the battery is increased.
The present invention has been made in view of the above-described circumstances, and aims to improve battery reliability and productivity.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1, and the battery cell, and a circuit board electrically connected to the terminals of the battery cell, the resin mold portion enveloping the circuit board by molding bonded, a battery formed by integral, at least a portion of the wall of the container constituting the battery cells on the inner surface of the protruding wall portion which projects from one of the adjacent surface adjacent to the wall, the resin mold portion Has proposed a battery with glue .
[0008]
According to the present invention, the bonding area between the battery cell and the resin mold part can be increased by bonding the surface of the battery cell and the inner surface of the protruding wall part to the resin mold part. Moreover, the side surface of the resin mold part can be supported by the protruding wall part having high rigidity.
As a result, it is possible to increase the adhesive force between the battery cell and the resin mold portion, and to keep the resin mold portion from dropping from the battery cell against the external force applied to the resin mold portion from the side.
[0009]
The invention according to claim 2 proposes the battery according to claim 1, wherein the protruding wall portion is provided at two positions facing each other across the adjacent surface.
According to the present invention, the resin mold portion sandwiched between the two protruding wall portions facing each other supports the resin mold portion with respect to the external force applied in the facing direction of the protruding wall portions, and the external force in a direction orthogonal to the resin mold portion. In contrast, the adhesive strength between the resin mold portion and the protruding wall portion can be increased to further improve the attachment strength between the resin mold portion and the battery cell.
[0010]
The invention according to claim 3 proposes a battery according to claim 1 , wherein the protruding wall portion is provided over the entire circumference of the adjacent surface.
According to this invention, the side surface of the resin mold portion is covered with the protruding wall portion over the entire circumference, and external force can be prevented from being directly applied to the side surface.
[0011]
The invention according to claim 4 is the battery manufacturing method according to any one of claims 1 to 3, wherein the circuit board is electrically connected to each terminal of the battery cell. A battery manufacturing method is proposed in which molten resin is injected into a cavity defined around the circuit board by using the adjacent surface and the protruding wall portion and cured.
[0012]
According to this invention, by defining the cavity using the protruding wall portion, the cavity surface formed by the mold can be reduced, and the mold can be simplified. In particular, when the protruding wall portion is formed over the entire circumference of the adjacent surface, there is only one cavity surface to be formed by the mold, and instead of a mold that wraps the battery cell, a lid that closes the tip opening of the protruding wall portion. A simple mold having a simple shape can be used.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a battery according to the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing an appearance of a battery 1 according to the present embodiment. The battery 1 is used for a portable terminal such as a cellular phone, and includes a battery cell 2 and a resin mold portion 3.
[0014]
The battery cell 2 is, for example, a lithium ion battery, and includes a deep-drawn aluminum cuboid container and a sealing plate 2a as shown in FIG. Inside the container, a separator and an electrode (not shown) are sealed together with an electrolytic solution. The sealing plate 2a is a lid-like member for sealing the opening of the container.
[0015]
A negative electrode cap 2c is provided at the center of the sealing plate 2a so as to protrude from the surface of the sealing plate 2a. The negative electrode cap 2c is electrically insulated from the sealing plate 2a. The sealing plate 2 a constitutes one of the minimum area surfaces having the smallest projected area among the surfaces of the battery cells 2.
[0016]
The sealing plate 2a is inserted from the front end of the opening of the container to a position at a predetermined depth, and is circumferentially welded to the container to seal the container. That is, the sealing plate 2a constitutes an adjacent surface adjacent to the container wall surface of the battery cell, and a portion of the container side wall from the sealing plate 2a to the tip of the opening constitutes a protruding wall portion 2b protruding from the adjacent surface. Yes.
In the battery cell 2 configured as described above, the negative electrode cap 2c functions as a negative electrode terminal, and all other surfaces including the sealing plate 2a and the protruding wall portion 2b function as a positive electrode terminal.
[0017]
As shown in FIG. 2, the resin mold portion 3 wraps the circuit board 4 and the connection members 5 and 6.
The circuit board 4 has an area that is less than the size of the sealing plate 2a of the battery cell 2, and is mounted with appropriate electronic components, an external connection connector 7, and the like. This electronic component is a component for performing charge control of the battery 1 or the like. The circuit board 4 is arranged to face the sealing plate 2 a of the battery cell 2 and is connected to the battery cell 2 via connection members 5 and 6. The circuit board 4 is provided with connection terminals 4a and connection holes 4b as shown in FIG. A wiring (not shown) led from the connector 7 or the like is connected to the connection terminal 4a and the connection hole 4b.
[0018]
As shown in FIG. 3, the connection members 5 and 6 are formed in an L shape by bending a metal plate, for example, and are electrically connected to the positive terminal and the negative terminal of the circuit board, respectively. It is what is done. Further, one end of the connection member 6 is provided with a connection protrusion 6a for insertion into the connection hole 4b of the circuit board 4. The circuit board is inserted by inserting the connection protrusion 6a into the connection hole 4b and soldering or the like. 4 is electrically connected to the wiring 4.
[0019]
According to the battery 1 of the present embodiment, the resin mold portion 3 is surrounded by the protruding wall portion 2 b of the battery cell 2. As a result, the side surface of the resin mold portion 3 is not exposed to the outside, and no external force is directly applied to the side surface. Further, since the protruding wall portion 2b having high rigidity supports the resin mold portion 3, the resin mold portion 3 is protected against an external force acting indirectly on the resin mold portion 3, and the resin mold portion 3 is connected to the battery cell. 2 can be prevented from falling off.
[0020]
In addition, since the circuit board 4 is disposed to face the surface of the minimum area of the battery cell 2, the volume of the resin mold portion 3 can be reduced as compared with any other surface. For this reason, an increase in the volume of the battery 1 can be minimized, and the battery 1 can be reduced in size and weight. Furthermore, since the amount of resin required for the resin mold portion 3 is small, the product cost can be reduced.
[0021]
Next, a method for manufacturing the battery 1 according to this embodiment will be described with reference to FIGS.
In order to manufacture the battery 1 of this embodiment, first, the connecting members 5 and 6 are attached to the inner surface of the protruding wall portion 2b of the battery cell 2 and the negative electrode cap 2c, respectively, by spot welding or soldering (FIG. 4). Next, the circuit board 4 is inserted into the projecting wall portion 2b, and the connection terminal 4a is slid from obliquely upward so as to contact the lower surface of the connection member 5 projecting from the projecting wall portion 2b. Are connected by spot welding or soldering. Further, after the connection protrusion 6a is inserted into the connection hole 4b of the circuit board 4, the connection member 6 is connected to the connection hole 4b by spot welding or soldering (FIG. 5).
[0022]
In this way, the resin mold portion 3 is molded in a state where the circuit board 4 is connected to each terminal of the battery cell 2. In order to mold the resin mold portion 3, as shown in FIG. 6, a fixture 11 and a close lid 12 for fixing the battery cell 2 are used. The fixing device 11 is, for example, an aluminum alloy container, and includes an accommodating portion 11a for supporting the battery cell 2 so as not to fall. The accommodating portion 11a has a volume enough to accommodate the battery cell 2 in a state where the opening end of the battery cell 2 is projected.
[0023]
The contact lid 12 is, for example, an aluminum alloy lid-like member, and includes an insulating member 12a and an injection nozzle 12b as shown in FIG. The insulating member 12 a is a member for preventing an electrical short circuit due to the external connection terminal of the connector 7 and the protruding wall portion 2 b coming into contact with the close-contact lid 12. It is provided on the surface where the edges of the wall 2b are in close contact. The injection nozzle 12 b is provided inside the contact lid 12. The injection port of the injection nozzle 12b is provided at the center of the surface on which the insulating member 12a is installed.
[0024]
As shown in FIG. 7, the battery cell 2 is accommodated in the accommodating portion 11 a of the fixing device 11. Then, as shown in FIGS. 8 and 9, the tight lid 12 is brought into close contact with the edge of the protruding wall portion 2 b of the battery cell 2 and the external connection terminal of the connector 7. Thereby, a cavity closed by the sealing plate 2a, the protruding wall portion 2b, and the contact lid 12 is formed. In this state, molten resin is injected from the injection nozzle 12b into the cavity. When the molten resin is filled in the cavity, the heat of the molten resin is immediately conducted to the projecting wall and the like, so that the molten resin in the cavity is rapidly cooled and cured.
[0025]
As a result, the battery 1 having the resin mold part 3 enclosing the circuit board 4 in the recess surrounded by the protruding wall part 2b of the battery cell 2 is manufactured. Thereafter, the contact lid 12 is separated from the battery 1 and the battery 1 is taken out from the fixture 11 to complete the manufacturing process. In the battery 1, since the contact lid 12 is in close contact with the connector 7 during manufacture, only the end surface of the connector 7 is exposed on the surface of the resin mold portion 3 of the battery 1.
[0026]
According to the manufacturing method of the battery 1 of the above embodiment, since the sealing plate 2a and the protruding wall portion 2b of the battery cell 2 are used for defining the cavity, there is an advantage that it is not necessary to use a mold having a complicated cavity shape. There is.
[0027]
In the battery 1 of the above embodiment, the positive and negative terminals are arranged on the external connection terminals of the connector 7 for connecting to the mobile terminal. However, instead of the connector 7, the battery 1 protrudes from the surface of the resin mold portion 3. While providing a negative electrode terminal part, you may make the whole surface of the battery cell 2 function as a positive electrode terminal. In this way, the negative electrode terminal and the positive electrode terminal are provided on the opposite surfaces of the battery, so that the battery can be attached to the portable terminal so as to sandwich the terminals.
Further, although the protruding wall portion 2b is provided around the entire periphery of the sealing plate 2a of the battery cell 2, the protruding wall is provided only at a part of the periphery of the sealing plate 2a or at a position facing the sealing plate 2a. The part 2b may be provided.
[0028]
Moreover, in the manufacturing method of the battery 1 according to the above embodiment, since the protruding wall portion 2b is provided around the entire circumference of the sealing plate 2a, the contact lid 12 that defines only one surface of the cavity is used. When the portion 2b is provided only in a part of the periphery of the sealing plate 2a, a mold that can define a cavity surface other than the cavity surface by the protruding wall portion 2b may be used.
In addition, although the insulating member 12a is provided on the surface of the contact lid 12 that contacts the external connection terminal of the connector 7, the insulating member may be directly attached to the external connection terminal.
[0029]
【The invention's effect】
As is clear from the above description, the present invention has the following effects.
According to the first aspect of the present invention, the side surface of the resin mold portion is supported by the protruding wall portion, the adhesion area between the battery cell and the resin mold portion is increased, and the resin mold portion may drop from the battery cell. Therefore, the soundness of the battery can be maintained.
[0030]
According to the invention which concerns on Claim 2, while supporting a resin mold with respect to the external force which acts on the opposing direction of these protrusion wall parts, a resin mold part and a protrusion wall part also with respect to the external force of the direction orthogonal to this Thus, the resin mold part and the battery cell can be more firmly fixed.
[0031]
According to the invention of claim 3, since all the side surfaces of the resin mold portion are protected by the protruding wall portion, it is possible to avoid the external force from acting directly on the side surfaces, and therefore the resin mold portion is detached from the battery cell. The effect that it can prevent more reliably is produced.
[0032]
According to the invention which concerns on Claim 4, since the cavity shape of a metal mold | die can be made simple, there exists an effect that reduction of product cost can be aimed at.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a battery according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the battery of FIG.
3 is an exploded perspective view showing an exploded resin mold portion of the battery shown in FIG. 1; FIG.
4 is a perspective view showing a procedure for assembling the battery shown in FIG. 1. FIG.
FIG. 5 is a perspective view showing a state of the battery of FIG. 1 before molding a resin mold part.
6 is a perspective view showing a manufacturing process for molding a resin mold part of the battery of FIG. 1; FIG.
7 is a perspective view showing a manufacturing process for molding a resin mold part of the battery of FIG. 1. FIG.
8 is a perspective view showing a manufacturing process for forming a resin mold part of the battery of FIG. 1. FIG.
9 is a cross-sectional view showing a manufacturing process for forming a resin mold part of the battery shown in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Battery 2 Battery cell 2a Adjacent surface 2b Projection wall part 3 Resin mold part 4 Circuit board

Claims (4)

A battery cell and a circuit board that is electrically connected to each terminal of the battery cell are bonded by a resin mold part that wraps the circuit board by molding , and is a battery that is integrated,
It said battery at least a portion of the wall of the container constituting the cell on the inner surface of the protruding wall portion which projects from one of the adjacent surfaces adjacent to this wall, a battery in which the resin mold portion is adhered. The battery according to claim 1, wherein the projecting wall portion is provided at two positions facing each other across the adjacent surface. The battery according to claim 1, wherein the protruding wall portion is provided over the entire circumference of the adjacent surface. 4. The method of manufacturing a battery according to claim 1, wherein the adjacent surface and the protruding wall portion are used in a state where the circuit board is electrically connected to each terminal of the battery cell. 5. A method of manufacturing a battery in which molten resin is injected into a cavity defined around a circuit board and cured.

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