JP4108184B2 - Manufacturing method of thin temperature fuse - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a thin temperature fuse, and is useful, for example, in manufacturing a temperature fuse used to protect a lithium ion secondary battery from overcharge and overdischarge.
[0002]
[Prior art]
Recently, large capacity batteries such as lithium ion secondary batteries have been used as power sources for portable electric devices.
In such a large-capacity battery, a considerably large current may flow during charging or discharging, and abnormal heat generation may occur due to overcharging or failure of the main device.
[0003]
Therefore, it has been studied to detect this abnormal heat generation with a temperature fuse and to shut off the battery from the charging power source or between the battery and the main device.
The battery protection temperature fuse is required to be thin, and the tips of a pair of strip-shaped lead conductors are fixed on one side of a resin-based film, and between the tips of the strip-shaped lead conductors. A low melting point soluble alloy piece is connected, a resin cover film is placed on one side of the resin base film, and the film around the resin film and between the resin cover film and the strip-shaped lead conductor are bonded. A thin temperature fuse sealed with an agent is known.
[0004]
[Problems to be solved by the invention]
However, in the sealing with the above-mentioned adhesive, the adhesive is cast inward and adheres to the low melting point soluble alloy piece, which inhibits the melting of the low melting point soluble alloy piece and impairs the operation of the temperature fuse. There is a fear.
Thus, it is conceivable to use heat seal or ultrasonic fusion instead of the adhesive, but the resin cover is more in comparison with the fusion between the resin base film and the resin cover film. -The resin-to-metal fusion between the film and the strip-shaped lead conductor is poor, and there is a step at the edge of the strip-shaped lead conductor, so there is a gap between the resin cover film and the strip-shaped lead conductor. In order to ensure the fusion of heat, it is necessary to significantly increase the heat output of the heating jig used or the horn output of the ultrasonic horn to be used. There is concern about damage to the fusible alloy pieces due to heat or vibration.
[0005]
An object of the present invention is to place a low melting point soluble alloy piece in a space between resin films superimposed on each other, and at least one of the strip-shaped lead conductors for the low melting point soluble alloy piece is from the space between the resin films. When manufacturing a thin temperature fuse that is drawn out and sealed between the films around both resin films and between each film and the strip-shaped lead conductor, a low-melting-point soluble alloy from heat or vibration is produced. A thin temperature fuse manufacturing method capable of securely holding a piece and sealing between a film around both resin films and between each film and a strip-shaped lead conductor by heat sealing or ultrasonic fusion Is to provide.
[0006]
[Means for Solving the Problems]
In one thin temperature fuse manufacturing method according to the present invention, a resin layer is coated on a sealed portion of a pair of strip-shaped lead conductors, and a low melting point soluble alloy piece is connected between the tips of the strip-shaped lead conductors. After that, the belt-shaped lead conductor end including the low-melting-point soluble alloy piece and the sealed portion is sandwiched with a resin film, and the resin film and the strip-shaped lead conductor sealed portion are surrounded by the resin film. It is the structure characterized by fuse | melting between resin layers .
[0007]
According to another method of manufacturing a thin temperature fuse according to the present invention, the tip of one strip-shaped lead conductor is fixed to the resin base film by exposing it from the back side to the front side, and the other strip-shaped fuse is fixed. The leading end portion of the lead conductor is fixed to the surface side of the resin base film, a low melting point soluble alloy piece is connected between the leading ends of both strip-shaped lead conductors, and the resin is placed on the surface of the resin base film. In the method for manufacturing a temperature fuse by arranging a cover film and sealing between the films around both resin films and between the resin cover film and the other strip lead conductor, A resin layer is previously coated on the sealed portion of the conductor, and the sheet between the two resin films and between the resin cover film and the other strip-shaped lead conductor sealed portion resin layer is heated. Or by ultrasonic welding or laser irradiation. That.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 (a) and FIG. 1 (b) [a cross-sectional view of FIG. 1 (b)] are drawings showing an example of a thin temperature fuse manufactured by the invention according to claim 1. is there.
In FIG. 1, 1 indicates a resin film, 2 indicates a strip-shaped lead conductor, 3 indicates a low melting point soluble alloy piece, 4 indicates a flux, and the strip-shaped lead sealed between the resin films 1 and 1. The sealed portion 20 of the conductor 2 is previously coated with a resin layer a as shown in FIG. 2, and a in FIG. 1 indicates the resin layer.
For example, copper, aluminum, nickel or the like can be used for the strip-shaped lead conductor 2, and for example, polyethylene terephthalate, polyamide, or the like can be used for the resin film 1 or a resin base film or a resin cover film described later. Engineering plastics such as polyimide, polybutylene terephthalate, polyphenylene oxide, polyethylene sulfide, and polysulfone can be used.
The resin a covering the sealed portion 20 of the strip-shaped lead conductor 2 has a fusion property equivalent to or higher than that of a resin film, and has a fusion property equivalent to or higher than that of a resin film. Any suitable resin can be used, but it is preferable to use the same resin as the resin film 1.
In order to coat the encapsulated portion 20 of the strip-shaped lead conductor 2 with resin, as shown in FIG. 3A, the lead conductor encapsulated portion 2 ′ is made of resin films a ′ and a ′. As shown in (b) of FIG. 3 by heat pressing or induction heating, a method of heat-sealing or a method of applying and baking a resin liquid can be used.
[0009]
In order to manufacture a thin temperature fuse by the invention according to claim 1, in FIG. 1, one end surface of a pair of strip-shaped lead conductors 1, 1 in which a sealed portion shown in FIG. A low melting point soluble alloy piece 3 is connected between them by welding or the like, and a flux is applied onto the connected low melting point soluble alloy piece. Next, the flux-coated low-melting-point soluble alloy piece is squeezed with the resin films 1 and 1, and the resin films 1 and 1 around the resin film 1 and the resin film 1 and the belt-shaped lead conductor sealed portion resin layer a The space is fused by heat sealing, ultrasonic welding or laser irradiation, and the production of the thin temperature fuse according to the invention of claim 1 is completed.
[0010]
For the heat seal, a method in which a frame-shaped hot plate that is in contact with the peripheral portion of the resin film is brought into contact with the portion to be sealed at a predetermined temperature, pressure, and time can be used.
In the ultrasonic fusion, a frame-shaped horn that is in contact with the peripheral portion of the resin film is pressed against a portion to be sealed, and this pressing horn is vibrated with a predetermined ultrasonic output by operating an oscillator. Can be used.
[0011]
In the above, the fusion of the resin films 1 and 1 around the resin film and the fusion of the resin film 1 and the belt-shaped lead conductor sealed portion resin layer a are both easy fusion of the resins. It can be fused well with low energy. In this case, since the belt-shaped lead conductor sealed portion 20 and the resin layer a coated on the sealed portion are already securely sealed, the resin films 1 and 1 around the resin film are fused together. In addition, it is not necessary to set the conditions at the time of fusion between the resin film 1 and the belt-shaped lead conductor sealed portion resin layer a as high energy as possible to enable fusion between the metal and the resin. Accordingly, when performing heat fusion between the resin films around the resin film and fusion between the resin film and the belt-shaped lead conductor encapsulated portion resin layer with a heat seal, the temperature, pressure and time are reduced, or When using ultrasonic welding, the ultrasonic output of the oscillator can be lowered.When using laser irradiation, the irradiation time can be shortened, and the low melting point soluble alloy piece can be damaged by heat or vibration. Can be well controlled.
[0012]
The periphery of the resin film is formed at the time of fusion, but it may be previously formed and fused.
[0013]
4 (a) and 4 (b) (a cross-sectional view of the roll in FIG. 4 (a)) are drawings showing an example of a thin temperature fuse manufactured by the invention according to claim 2. FIG. is there.
In order to manufacture a thin temperature fuse by the invention according to claim 2, in FIG. 4, the front end portion of one strip-shaped lead conductor 21 is applied to the resin base film 11 from the back side to the front side by hot pressing or the like. The other end of the strip-shaped lead conductor 2 is fixed to the surface of the resin base film 11 by hot pressing or the like, and the sealed portion 20 of the strip-shaped lead conductor 2 is fixed. The resin film a is fused, and then the low melting point soluble alloy piece 3 is joined between the ends of the belt-like lead conductors 2 and 21 by welding or the like, and the flux 4 is further applied on the low melting point soluble alloy piece 3. Apply. Next, a resin cover film 12 is disposed on one side of the resin base film 11, and the resin cover film 12 around the resin cover film 12 and between the resin base film 11 and the resin cover film 12. The sealed portion resin layer (film) a of the other strip-shaped lead conductor 2 is joined by heat sealing, ultrasonic fusion or laser irradiation, and according to claim 3 The production of the thin temperature fuse according to the invention is terminated.
[0014]
Also in the case of the invention according to claim 2 , as in the case of the invention according to claim 1, a low melting point is possible between the sealed portion 20 of the strip-shaped lead conductor 2 and the resin layer (film) a thereon. The molten alloy piece 3 can be firmly fused without having any influence, and the resin cover film 12 and the resin cover film 12 around the resin cover film 12 and between the resin cover film 12 and the belt-shaped ribbon. -Since the conductor-sealed portion resin layer (film) a can be fused with sufficiently low thermal energy or ultrasonic output for fusion between the resins, the heat of the low melting point soluble alloy piece 3 Or damage due to vibration can be well suppressed.
[0015]
In the first and second aspects of the invention, the periphery of the resin cover film is formed at the time of fusing. However, it can be formed and fused in advance.
[0016]
The thin temperature fuse manufactured in accordance with the present invention is used, for example, to protect a lithium ion secondary battery from abnormal heat generation. For example, one strip-shaped lead conductor and a temperature fuse main body are attached to the negative electrode can of the battery. The belt-shaped lead conductor and the negative electrode can are electrically connected to each other, and the other belt-shaped lead conductor is insulated from the negative electrode can by separating or interposing an insulating film in series with the battery. The battery can be electrically disconnected from the main unit by inserting and fusing the low melting point soluble alloy piece due to abnormal heat generation of the battery.
[0017]
FIG. 5 shows a lithium ion secondary battery, in which a spiral wound body E of a positive electrode 52 and a negative electrode 53 interposing a separator 51 is accommodated in a negative electrode can 54, and the negative electrode 53 and the bottom surface of the negative electrode can 54 are electrically connected. The positive electrode collector 55 is disposed at the upper end in the negative electrode can 54 to electrically connect the positive electrode 52 to the collector electrode 55, and the upper end 541 of the negative electrode can 54 is connected to the outer periphery of the outer explosion-proof valve plate 56. The end portion and the outer peripheral end portion of the positive electrode lid 57 are caulked through a packing 58, and the central concave portion of the explosion-proof valve plate 56 is electrically connected to the positive electrode collector electrode 59, and is manufactured according to the invention of claim 1 or 2. In the thin temperature fuse, as shown in the figure, the thin temperature fuse is disposed in the space between the explosion-proof valve plate 56 and the positive electrode cover 57 of the lithium ion secondary battery, and the outer peripheral end of the explosion-proof valve plate 56 An insulating spacer r is interposed between the outer peripheral end of the positive electrode cover 57. One strip-shaped lead conductor 2 is held between the outer peripheral end portion of the explosion-proof valve plate 56 and the insulating spacer ring r, and the other strip-shaped lead conductor 2 is sandwiched between the outer peripheral end portion of the positive electrode lid 57 and the insulating spacer ring. It can be used by being held in r and incorporated in series in the battery.
[0018]
6 (a) and 6 (b) (a cross-sectional view of the roll in FIG. 6 (a)) are drawings showing another embodiment of a thin temperature fuse manufactured by the invention according to claim 2. FIG. is there.
In FIG. 6, F is frame - indicates the beam, in FIG. 7 the inner one strip re the circumference of the annular portion 201 shown in (a) - the foil electrode f ₁ while having a de conductor 21, in FIG. 7 ( an annular resin space shown in b) - foil electrodes f ₀ having de conductor 2 Toori - - Sa film s and, strip re inner periphery to the other of the annular portion 200 shown in (c) of FIG. 7 de section 2, 21 are staggered 180 ° and overlapped by heat fusion or the like. Of these strip-shaped lead conductors 2 and 21, a resin layer (film) a is fused to the sealed portion 20 of the strip-shaped lead conductor 2, and the fusion of the resin film a is a foil. Can be performed by hot pressing at the time of fusion between the electrode f ₀ , f ₁ and the resin spacer film s.
[0019]
In FIG. 6, A is a temperature fuse main body arranged in the central space of the frame F, and fixes the leading end of one strip-shaped lead conductor 21 to one surface of the resin base film 11 and the film. 11 is locally exposed from one surface to the other surface, and the leading end portion of the other strip-shaped lead conductor 2 is fixed to the other surface of the resin base film 12 so as to be locally exposed to the leading end portion. The low melting point soluble alloy piece 3 is connected by welding or the like between the one end of the strip-shaped lead conductor 21 and the flux 4 is applied to the low melting point soluble alloy piece 3. A resin cover film 12 is arranged on the melting point soluble alloy piece, and between the resin base film 11 and the resin cover film 12 around the resin cover film 12 and between the resin cover film 12 and the other strip-shaped lead. Between the sealed portion resin layer (film) a of the conductor 2 Le or ultrasonic welding or Le - are joined by The irradiation.
[0020]
In this thin temperature fuse, in FIG. 5, the foil-shaped electrode f of the explosion-proof valve plate 56 and the frame F is held between the outer peripheral end portion of the explosion-proof valve plate 56 and the outer peripheral end portion of the positive electrode cover 57. electrical contact → Li foil-like electrode f1 of ₁ - de conductor 21 → the low melting-point fusible alloy piece 3 → foil electrodes f ₀ of the Li - de conductor 2 → frame - foil electrodes f ₀ of the beam F and the positive electrode Due to the electrical contact with the lid 57, the temperature fuse is electrically connected in series to the battery.
[0021]
【The invention's effect】
According to the thin temperature fuse manufacturing method of the present invention, the low melting point soluble alloy pieces are not affected between the resin films or the sealed portion of the strip-shaped lead conductor with respect to the resin base film. Before the low melting point soluble alloy piece is connected, the resin layer is fused to the sealed portion, and the sealing around the temperature fuse body is performed after the low melting point soluble alloy piece is connected. Since the resin is fused together, sealing around the temperature fuse body is good with a sufficiently low heat output hot plate, laser irradiation, or sufficiently low output ultrasonic horn. It can be performed, and excellent sealing properties can be ensured and damage to the low melting point soluble alloy piece due to heat or vibration can be well suppressed. Therefore, a good quality thin temperature fuse can be manufactured.
[Brief description of the drawings]
FIG. 1 is a view showing an example of a thin temperature fuse manufactured by the invention according to claim 1;
FIG. 2 is a drawing showing a sealing portion resin layer of a strip-shaped lead conductor used in the present invention.
FIG. 3 is a drawing showing a method for coating a sealing layer resin layer of a strip-shaped lead conductor used in the present invention .
4 is a view showing an example of a thin temperature fuse manufactured by the invention according to claim 2. FIG.
FIG. 5 is a view showing an example of a usage state of a thin temperature fuse manufactured according to the present invention.
6 is a view showing another example of a thin temperature fuse manufactured by the invention according to claim 2. FIG.
FIG. 7 is a view showing a frame used for the above-described another thin temperature fuse manufactured by the invention according to claim 2 ;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Resin film 11 Resin base film 12 Resin cover film 2 Strip-shaped lead conductor 20 Sealed part of strip-shaped lead conductor 2 a Sealed resin layer of strip-shaped lead conductor 2 3 Low melting point soluble Alloy piece 4 Flux

Claims (2)

The sealing portion of the pair of strip-shaped lead conductors is covered with a resin layer, and a low-melting-point soluble alloy piece is connected between the ends of these strip-shaped lead conductors. A thin temperature characterized by sandwiching the end of the strip-shaped lead conductor including the stop portion with a resin film and fusing between the films around both resin films and between the resin film and the resin layer of the strip-shaped lead conductor encapsulated portion Fuse manufacturing method. The front end of one strip-shaped lead conductor is fixed to the resin base film by exposing it from the back side to the front side, and the front end of the other strip-shaped lead conductor is fixed to the front side of the resin base film. The low melting point soluble alloy piece is connected between the ends of both strip-shaped lead conductors, a resin cover film is arranged on the surface of the resin base film, and between the films around both resin films and the resin In the method of manufacturing the temperature fuse by sealing between the cover film and the other strip-shaped lead conductor, a sealed portion of the other strip-shaped lead conductor is coated with a resin layer in advance, A method for producing a thin temperature fuse, characterized by fusing between a film around both resin films and between a resin cover film and the other belt-shaped lead conductor encapsulated portion resin layer.

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