JP2002197955A - Thermal fuse and battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal fuse and a battery pack minimizing characteristic deterioration and reliability degradation even though thinned and miniaturized. SOLUTION: The thermal fuse comprises a pair of terminal parts 4, 5, a fuse element 16 provided between the pair of terminals, and a body for containing the fuse element 16, and has the following dimensions of the whole body including the body: 2.0 mm<L1<7.5 mm, 1.5 mm<L2<3.5 mm, 0.4 mm<L3<1.5 mm, where L1=length, L2=width, and L3=thickness. The Young's modulus of the pair of terminals 4, 5 is in the range of 3×1010 Pa-8×1010 Pa, and the tensile strength is in the range of 4×108 Pa-6×108 Pa.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal fuse and a battery pack suitably used and used to prevent equipment damage due to excessive temperature rise.

[0002]

2. Description of the Related Art In recent years, the technical development of secondary batteries has been remarkably progressed. In particular, secondary batteries that are small and can be used for a long time with a single charge as batteries used in devices such as mobile phones, PHSs, and notebook computers. Secondary batteries are being developed and put into practical use.
More specifically, development and commercialization of Ni-Cd batteries, Ni-H batteries, Li-ion batteries, and Li-polymer batteries have progressed, and smaller and longer-lasting secondary batteries have been developed.

However, as a battery becomes smaller and has a longer life, the risk of the battery being damaged or exploding due to heat generated by rapid discharge due to a short circuit between the positive and negative electrodes of the battery increases. Therefore, in order to ensure the safety of the secondary battery, a thermal fuse that is disconnected due to heat generation at the time of a short circuit or the like is used. As the thermal fuse, one using a fusible material is generally used. Attach the fusible material to a portion of the battery or power supply device that may generate heat by contacting the insulating layer with an insulating layer, and melt the fusible material before the battery or power supply device generates heat and reaches a dangerous temperature level. Discharge of the battery or charging of the battery is interrupted to prevent abnormal heat generation of the battery and to prevent thermal destruction of the power supply device.

FIGS. 20, 21, and 22 are views showing a conventional thermal fuse. In FIGS.
1 is a lead conductor and 42 is an insulating plate. The conventional thin thermal fuse has a structure in which the width of the insulating plate 42 is wider than the width of the lead conductors 40 and 41.

[0005] Further, from the welding position 46 of the fusible alloy, 40,
Since the distance d between the terminals of 41 is smaller, the distance d between the terminals is smaller than the fusing distance when the thermal fuse is normally blown.

FIG. 19 is a perspective view showing a conventional battery pack. It is used for a rectangular battery pack having the same thickness as the width of the insulating plate 42.

[0007]

However, in recent years, with the miniaturization and thinning of mobile phones, conventional battery packs have been 6 mm to 5 mm thick, but small and thin type batteries having a thickness of 2.5 mm to 4 mm have been developed. Battery pack stuff has been needed. The conventional thin thermal fuse has a problem that the width of the insulating plate cannot be reduced while keeping the width of the lead conductors 40 and 41 unchanged. In addition, since the withstand voltage distance between the terminals is d in an air atmosphere, there is a limit to downsizing in the length direction of the insulating plate.

Further, merely reducing the size of the conventional thermal fuse necessarily results in deterioration of various characteristics such as bonding strength and thermal response of each member.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal fuse and a pack battery which have high reliability, high quality and low price even if they are miniaturized, and consume less power by wiring of a battery body.

[0010]

SUMMARY OF THE INVENTION The present invention comprises a pair of terminals, a fusible member provided between the pair of terminals, and a main body for housing the fusible member. Width L
2. When the thickness is L3, the thermal fuse satisfies 2.0 mm <L1 <7.5 mm 1.5 mm <L2 <3.5 mm 0.4 mm <L3 <1.5 mm, and the pair of terminals has a Young. rate is in the range of ^{3 × 10 10 Pa~8 × 10 10} Pa, the tensile strength was a structure is in the range of ^{4 × 10 8 Pa~6 × 10 8} Pa.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 includes a pair of terminal portions, a fusible member provided between the pair of terminal portions, and a main body for housing the fusible member, including the main body. When the size of the main body is length L1, width L2, and thickness L3, a thermal fuse with 2.0mm <L1 <7.5mm 1.5mm <L2 <3.5mm 0.4mm <L3 <1.5mm There, said the Young's modulus of the pair of terminal portions is in the range of ^{3 × 10 10 Pa~8 × 10 10} Pa, which is in the range of tensile strength ^{4 × 10 8 Pa~6 × 10 8} Pa By using a thermal fuse, the strength of the terminal can be secured even if the thermal fuse is made thinner and smaller, so that the terminal does not easily bend during handling or transportation during manufacturing, and there is no problem. The probability of product occurrence is extremely small, Without disconnection of the terminal portions not occur when subjected to bending a terminal part, it tends to be very productive.

According to a second aspect of the present invention, there is provided a battery, a main body for accommodating the battery, wiring derived from the main body and electrically connected to the battery, and provided between the wiring and in contact with the main body. And a temperature fuse provided so that the battery pack is characterized in that the temperature fuse according to claim 1 is used as the temperature fuse.
Even if the thickness of the battery pack is reduced to, for example, 2.5 mm to 4 mm, stable measures for preventing excessive heat generation can be taken.

An embodiment of the present invention will now be described with reference to the drawings, showing the manufacturing steps, and the configuration thereof.

As shown in FIG. 1, first, a strip-shaped or plate-shaped substrate film 1 is prepared.
3 are provided. The through holes 2 and 3 are provided so as to be aligned with another film to be laminated on the substrate film 1 later. In particular, by forming the substrate film 1 as a strip, a plurality of terminal portions described later can be aligned, so that productivity is greatly improved.

If there is no particular need for positioning, the through holes 2 and 3 need not be provided. Further, the substrate film 1 preferably has an insulating property,
In addition to the resin, a ceramic substrate or a metal plate whose surface is insulated may be used, but it is preferable to use a resin film in terms of productivity and handling.

The specific material of the substrate film 1 is as follows.
PET (polyethylene terephthalate), PEN (polyethylene naphthalate), ABS resin, SAN resin, polysamphon resin, polycarbonate resin, noryl, vinyl chloride resin, polyethylene resin, polyester resin, polypropylene resin, polyamide resin, PPS resin, polyacetal, Resin containing either fluorine resin or polyester as a main component (preferably thermoplastic resin)
Can be formed.

In the present embodiment, the substrate film 1 has a single-layer structure, but may be formed by laminating sheets of different materials. For example, a film made of PET (polyethylene terephthalate) and a film made of PEN (polyethylene terephthalate) may be used. By laminating the films made of polyethylene naphthalate), the strength of the substrate film 1 itself can be increased, and the mechanical strength can be improved. Further, by using the PEN sheet, the heat resistance can be increased, and a temperature fuse usable at 130 ° C. or higher can be provided. In the case where the substrate film 1 is manufactured in a laminated structure, it can be realized by using a combination of a material having low heat resistance and a material having high heat resistance in addition to the combination of the above-described materials.

As the substrate film 1, a disk-shaped or elliptical film can be used.

Next, as shown in FIG.
5 is disposed on the substrate film 1 between the through holes 2 and 3 so as to be opposed to each other and not to be in contact with each other.

By using the terminal portions 4 and 5 whose ends are narrower than the other portions, it is possible to reduce the size of the element itself. In the present embodiment, the terminal portions 4 and 5 are plate-shaped from the viewpoint of productivity and characteristics, but may be rod-shaped or linear.

Specific constituent materials of the terminal portions 4 and 5 include:
A conductive material is used, and in particular, a metal material is used in terms of strength and characteristics. Specific metal materials include nickel, iron, copper, silver, and other simple substances or alloys thereof, and furthermore, the above-mentioned simple metal materials to which other elements are added, and the above alloys containing other elements. What is added is used.

In particular, when the terminal portions 4 and 5 are made of a material in which nickel is 98% or more, the electric resistivity is 6.8 × 10
^-8 Ω · m to 12 × 10 ^-8 Ω · m, and reliability such as corrosion resistance can be dramatically improved.

Particularly, the terminal portions 4 and 5 are made of copper 90-99.
If prepared in 9% containing alloys, by the electric resistivity of the terminal portions 4 and 5 is ^{1.4 × 10 -8 Ω · m~8 ×} 10 -8 Ω · m, manufactured by nickel and nickel alloys As compared with the case where heat is applied, the thermal responsiveness can be improved by the action of heat conduction by electrons.

The thickness of the terminals 4 and 5 is 0.08.
When the thickness is in the range of mm to 0.25 mm, it is advantageous in terms of characteristics or handling. That is, the terminal portions 4 and 5
If the thickness of the film itself is less than 0.08 mm, the electrical resistance will be high, and the mechanical strength itself will be weak, causing problems such as easy bending when handling. On the other hand, if the thickness exceeds 0.25 mm, the thickness of the thermal fuse itself becomes large, and it is not suitable for miniaturization.

The width of the terminal portions 4 and 5 themselves is made larger than the width of the film bonding portions 8 and 9 and the width of the fusible body bonding portions 6 and 7, so that the resistance value is increased by the width of the terminal portions 4 and 5. The width of the welded portion 23 shown in FIG. 12 after cutting is reduced by making the widths of the film joining portions 8 and 9 and the fusible joining portions 6 and 7 smaller than the widths of the terminal portions 4 and 5. (Case width) can be made the same as the width of the terminal portions 4 and 5, and although the thermal fuse is small, the resistance value of the wiring does not decrease so much, which is advantageous with low power consumption. Terminals 4, 5
The most efficient way to reduce the width of the material itself is to perform cutting by pressing.

Furthermore, as the terminal portions 4 and 5, the Young's modulus is set to ^{3 × 10 10 Pa~8 × 10 10} Pa, tensile strength 4
By × 10 ⁸ Pa~6 × a 10 ⁸ Pa configuration, without thereby bending accidentally during handling or transportation, it is easy to pin bending, it is possible to prevent causing disconnection Moreover in bending. Terminal parts 4 and 5 have a Young's modulus of 3 ×
If the pressure is 10 ¹⁰ Pa or less, a part where the terminal is easily bent and a part which should not be bent (for example, a part for electrically connecting the terminal parts 4 and 5 ends) tends to be uneven, and the connection by welding becomes difficult. If the Young's modulus is 8 × 10 ¹⁰ Pa or more, the terminal portion to be bent (for example, the terminal portion 4 in FIG. 15).
(The middle part of the wire) is hard to bend or breaks and breaks. Furthermore, the terminal parts 4 and 5 have a tensile strength of 4
If the pressure is less than × 10 ⁸ Pa, it is easy to bend. If the pressure is more than 6 × 10 ⁸ Pa, the portion where the terminal is to be bent (for example, the middle part of the terminal 4 in FIG. 15) is difficult to bend or broken. Occurs. Table 1 shows Young's modulus, tensile strength, terminal bending test and drop test data.
Shown in

[0027]

[Table 1]

The measurement of the Young's modulus and the measurement of the tensile strength were carried out by conducting a tensile test of the material using Shimadzu Autograph AGS-500D manufactured by Shimadzu Corporation. Tensile test is 1mm
The elongation and the force of the test piece are measured at a pull rate of / min., And the Young's modulus is calculated from the range where the elongation and the force change almost linearly. The maximum force shown before the test piece breaks This was done by calculating the tensile strength from the ground (see FIG. 18). In the terminal bending test, a 90-degree bending jig was used once using a jig having a 90-degree angle. More than three times and less than three times were judged as △. In the drop test, the material was processed into individual pieces of 3 mm x 20 mm, placed in a plastic bag of 50 g and dropped on concrete six times from a height of 1 m. did. From (Table 1), the terminal portions 4 and 5, a Young's modulus of 3 × ^{10 10} Pa~8 ×
10 ¹⁰ Pa and the tensile strength is 4 × 10 ⁸ Pa to 6 × 1
When the pressure is 0 ⁸ Pa, the terminal can be easily bent without being erroneously bent at the time of handling or transportation, and furthermore, occurrence of disconnection or the like during bending can be prevented.

As described above, the substrate film 1 is made of PE.
When the T sheet and the PEN sheet have a laminated structure, it is preferable to mount the terminal portions 4 and 5 on the PET sheet side.

Further, at least on the opposite sides of the terminal portions 4 and 5 opposite to the surface facing the substrate film 1, fusible member joining portions 6 and 7 for improving the joining property with the fusible member described later are provided, respectively. In the present embodiment, the fusible member joints 6, 7
Is provided only on one main surface of the terminal portions 4 and 5,
It may be provided on one of the main surfaces, or may be provided on the entire periphery of the tip of the terminal portion 4 or 5. The fusible joints 6, 7 are plated,
It is manufactured by a thin film forming technique such as a sputtering method or a vapor deposition method, or by a method such as attaching a metal sheet. Moreover, preferable materials for the fusible joints 6 and 7 include gold, silver,
A material selected from copper, tin, lead, bismuth, indium, gallium, palladium (hereinafter abbreviated as a bonding material group) or a material obtained by adding other elements to the material alone, an alloy selected from a plurality of bonding material groups, and the like Examples include alloys in which other elements are added.

In particular, when the terminals 4 and 5 are made of nickel and a nickel alloy, good conductors are provided on the terminals 4 and 5 as shown in FIG. Parts 4a and 5a are provided, and their electric resistivity is 1.4 × 10
By that it is formed of a metal ^{-8 Ω · m~5 × 10 -8 Ω} · m, electrons due can improve the thermal response by the action of heat conduction, moreover, such as wiring or pattern containing nickel and Electric welding becomes easy.

Table 2 shows the relation between the terminal material and the terminal fusing temperature characteristics (thermal response).

[0033]

[Table 2]

As the thermal fuse, a fusible material showing a fusing temperature of 89 ± 2 ° C. at a rate of 1 ° C./min was used. Substrate film 1, adhesive film 10, and cover film 1
As for 8, a PET (polyethylene terephthalate) having a thickness of 0.125 mm was used. As the terminal parts 4 and 5,
A nickel terminal is used, and the nickel terminal is Ni + Co: 9
9.3 WT%, C: 0.1 WT%, Si: 0.1 WT
%, Mn: 0.1 WT%, Mg: 0.1 WT%, Fe
10. Electrical resistivity of 0.2 WT%, Cu: 0.1 WT%
A nickel alloy of 25 × 10 ⁻⁸ Ω · m was used.

The terminal heating fusing temperature is determined by installing a heater at a terminal position 8 mm from the center position of the thermal fuse body.
This is the heater temperature when the temperature fuse is blown by increasing the heater temperature at about 10 ° C./min. Judgment is based on the absence of the formed metal. When the terminal heating and fusing are performed at a temperature 5 degrees or more lower than the standard, the terminal heating and fusing temperature of less than ± 5 degrees is Δ, and when the terminal heating and fusing temperature is +5 degrees or more higher than the standard. X. According to Table 2, the electrical resistivity of the nickel terminal surface was 1.
4 × 10 ⁻⁸ Ω · m to 5 × 10 ⁻⁸ Ω · m metal,
It can be seen that thermal responsiveness is good when copper, silver, or the like is formed by plating.

The terminal portions 4 and 5 are provided with film bonding portions 8 and 9 so as to improve the bonding strength between the substrate film 1 and an adhesive film described later. By making the surfaces of the film bonding portions 8 and 9 rougher than other portions, the bonding strength with the substrate film 1 or the like can be increased. Specifically, the center line average roughness is 5 to
Roughness of about 100 μm is preferable, and it is produced by a blast polishing method in which fine hard particles are sprayed to roughen the surface, a grinding method in which a grindstone (blade) is rotated to roughen the surface, or a polishing method in which the surface is roughened by a wire brush. Further, in addition to the method of roughening the surface of the film bonding portions 8 and 9, a method of forming a bonding reinforcing layer such as a coupling material may be used.

Table 3 shows data showing the relationship between the surface roughness, the terminal width of the sealing portion, the torsional durability test, and the resistance value between terminals of 20 mm.

[0038]

[Table 3]

As the thermal fuse, a fusible material showing a fusing temperature of 89 ± 2 ° C. at a rate of 1 ° C./min was used. The substrate film 1 and the cover film 18 have a thickness of 0.
1 mm PET (polyethylene terephthalate) and 0.125 mm thick PEN (polyethylene naphthalate)
Was used. The heat resistance of PET is 1
20 ° C., and the heat resistance of PEN is 160 ° C. As the adhesive film 10, PET (polyethylene terephthalate) having a thickness of 0.125 mm was used. Nickel terminals are used as the terminal portions 4 and 5, and the nickel terminals are Ni + Co: 99.3WT%, C: 0.1WT.
%, Si: 0.1 WT%, Mn: 0.1 WT%, Mg:
0.1 WT%, Fe 0.2 WT%, Cu: 0.1 WT
%) Of a nickel alloy having an electric resistivity of 11.25 × 10 ⁻⁸ Ω · m, and the distance between the terminals of the terminal portions 4 and 5 is 1.7 mm.
And In the torsion endurance test, the terminal portions 4 and 5 were fixed, and the terminal portions 4 and 5 were moved 9
After 0-degree twisting was performed three times, a fusing test was performed and fusing was performed according to the standard. Sealing was confirmed by judging that flux leakage occurred after the fusing test of the torsional durability test, x, and that no flux leakage occurred. The resistance value between the terminals of 20 mm is based on the resistance value of a thermal fuse using a terminal having a terminal width of 3 mm and a thickness of 0.15 mm.
If the resistance was larger in the range of Ω, it was evaluated as × if the resistance was larger than the standard by more than 2 mΩ. From (Table 3), the terminal portions 4
5 includes film bonding portions 8 and 9 so as to improve the bonding strength between the substrate film 1 and an adhesive film described later.
By making the surface rougher than other parts,
Can increase the bonding strength with the film bonding portion 8,
9 and the width of the fusible joints 6 and 7 are made narrower than the widths of the terminals 4 and 5, so that the post-cut width (case width) of the welded portion 23 can be made the same as the terminal width. However, it was possible to obtain a structure in which the resistance value of the wiring was not increased so much while being small.

When the film joints 8 and 9 are mounted on the substrate film 1, it is preferable that the film joints 8 and 9 are mounted so that at least a part thereof is directly opposed to the substrate film 1.

The distal end portions of the terminal portions 4 and 5 where the fusible body joining portions 6 and 7 and the film joining portions 8 and 9 are present are configured to be thinner than other portions. Accordingly, when the terminal portions 4 and 5 are fixed by both the substrate film 1 and an adhesive film described later, the gap between each of the above-mentioned films and the terminal portions 4 and 5 can be reduced. The joining strength with each film can be improved. Moreover, corners and the like are chamfered so as not to generate burrs.

Next, the adhesive film 10 as shown in FIG.
Are placed on the substrate film 1 as shown in FIG. 4, and the terminal portions 4 and 5 are sandwiched between the substrate film 1 and the adhesive film 10.

As shown in FIG. 3, the adhesive film 19 has
Through holes 11 and 12 are provided.
A through-hole 13 having a rounded corner (an outer shape is substantially square) is provided between the two. The through holes 11 and 12 position the substrate film 1 and the adhesive film 10 so as to overlap the through holes 2 and 3 of the substrate film 1.

As shown in FIG. 4, the fusible body joining portions 6 and 7 of the terminal portions 4 and 5 are exposed from the through hole 13. In the present embodiment, the fusible body joints 6, 7 and the film joints 8,
9 are exposed from the through-hole 13, but only the fusible joints 6 and 7 may be exposed.
Since the film bonding portions 8 and 9 are exposed from the through holes 13, at least the adhesive film 10 slightly protrudes into the through holes 13 in a subsequent bonding process.
As in the present embodiment, it is preferable that a part of the film joints 8 and 9 is slightly exposed from the through hole 13.

The adhesive film 10 is preferably made of a material having an insulating property.
(Polyethylene terephthalate), PEN (polyethylene naphthalate), ABS resin, SAN resin, polysamphon resin, polycarbonate resin, noryl, vinyl chloride resin, polyethylene resin, polyester resin, polypropylene resin, polyamide resin, PPS resin, polyacetal, fluorine It is preferable to use a thermoplastic resin containing any one of a system resin and a polyester as a main component.

Next, as shown in FIG. 5, the terminal portions 4 and 5 are fixed with the substrate film 1 and the adhesive film 10. As a fixing method at this time, first, pressure is applied from the front surface and the back surface in a direction facing each other via the substrate film 1 and the adhesive film 10, and a current is caused to flow between both ends of the terminal portions 4 and 5. 5 itself is heated to melt the substrate film 1 and the adhesive film 10, and the terminal parts 4, 5 are fixed to the substrate film 1 and the adhesive film 10 by the melt, and the terminal parts 4, 5 are bonded to the substrate film 1. The films 10 are joined together.

At this time, the portion 10a between the through hole 13 and the side portion of the adhesive film 10 is wider than the other portions by applying heat and pressure, and furthermore, on the terminal portions 4 and 5, In addition, it protrudes in an arc shape toward the through hole 13 (projects toward the tip of the terminal portion 4, 5), and also protrudes in an arc shape toward the end opposite to the through hole 13. Further, also in the substrate film 1, the terminal portions 4, 5 are protruded in an arc shape toward a joint portion with another circuit pattern or the like. In this manner, by protruding the adhesive film 10 and the substrate film 1 in an arc shape in the longitudinal direction of the terminal portions 4 and 5, the substrate film 1 can be more heated than before the heating.
The bonding strength between the terminal portions 4 and 5 can be improved by increasing the bonding area between the terminal portions 4 and 5 of the adhesive fill 10.

The portions where the terminal portions 4 and 5 and the adhesive film 10 directly face each other are formed by melting the adhesive film 10 by heat, so that the terminal portions 4 and 5 and the adhesive film 1 are bonded.
0, and a part of the adhesive film 10 that is melted by heat flows in the longitudinal direction of the terminal portions 4 and 5 by the applied pressure, separately from the arc-shaped portion 10a,
The flow-out can further improve the sealing performance of the space defined by the outside, the through hole 13 and the substrate film 1. Similarly, the substrate film 1 and the terminal portions 4 and 5
Are directly opposed to each other, a part of the substrate film 1 melted by heat joins the substrate film and the terminal portions 4 and 5, and a part of the substrate film melted by heat is connected to the terminal portion. Flow starts in the longitudinal direction of 4, 5 and the sealing property can be improved as well.

Further, with respect to the side portions of the terminal portions 4 and 5, both the substrate film 1 and the adhesive film 10 are melted by the heat generated by the self-heating of the terminal portions 4 and 5, and the melted portions of both are mixed. The melted material fills the gap between the substrate film 1 and the adhesive film 10 on the side of the terminal portions 4 and 5, and the melt is directed to the inside where the through hole 13 exists and the outside on the opposite side. By providing the protruding portion 10b that protrudes into a spherical shape, the sealing performance can be further improved.

FIG. 6 is a cross-sectional view when the substrate film 1 and the adhesive film 10 are joined together. The thickness of the terminal portions 4 and 5 is T2, and a molten material in which both the substrate film 1 and the adhesive film are melted by heat. Assuming that the length of the terminal portions 10c in the lateral direction (referred to as welding size) of the terminal portions 4 and 5 is T1, 0.9 <T1
The heat value and pressure of the terminal portions 4 and 5 are adjusted so as to satisfy the relationship of /T2<4.0. If T1 / T2 is 0.9 or less, the sealing properties at the sides of the terminal portions 4 and 5 cannot be sufficiently improved, and if T1 / T2 is 4.0 or more, the terminal portions 4 and 5 cannot be improved.
Since the self-heating of No. 5 must be increased or the pressure to be applied must be increased, there are problems such as damage to the members and improvement in productivity.

Table 4 shows the welding dimensions and sealing evaluation.

[0052]

[Table 4]

The welding size was adjusted to the value of the welding size T1 by adjusting the current value, the energizing time and the pressure. Terminal is 3m wide
The prototype was made of a nickel alloy having a thickness of 0.15 mm (T2). As the substrate film 1, the adhesive film 10, and the cover film 18, PET (polyethylene terephthalate) having a thickness of 0.125 mm was used. Substrate film 1
The bonding between the adhesive film 10 and the cover film 18 was performed by an ultrasonic welding method having annular projections. In the sealing evaluation, as shown in FIG. 16, after completing as a thermal fuse, the flux 17 was allowed to stand at 150 ° C. for 10 minutes without leakage, and the leakage was evaluated as x.

According to Table 4, 0.9 <T1 / T2 <4.
By adjusting the heat values and the pressures of the terminal portions 4 and 5 so as to satisfy the relation of 0, a thermal fuse having excellent sealing properties can be manufactured.

Next, as shown in FIG. 7, welding fluxes 14 and 15 are provided on the distal ends (fusible joints 6 and 7) of the terminals 4 and 5 exposed in the through holes 13. The welding fluxes 14 and 15 are provided so that the terminal portions 4 and 5 and a fusible body to be described later can be joined well. In this embodiment, the welding fluxes 14 and 15 are provided separately, but may be provided integrally.

As a specific composition of the welding fluxes 14 and 15, for example, rosin is added to an alcohol-based solvent at 15 W.
T% to 60 WT% dissolved, and the rosin composition contains 50 WT% to 90 WT% abietic acid and 10 WT% to 50 WT% dehydroabietic acid. The welding fluxes 14 and 15 having the above composition are used. By using this, it is possible to obtain sufficient welding strength between the fusible body and the terminal portions 4 and 5, and to allow the alcohol to remain near the fusible body.

Therefore, the presence of the alcohol in the vicinity of the soluble material allows the solid flux described below to contain a small amount of alcohol, so that at a temperature higher than the boiling point of the alcohol, the activity of the solid flux described later is improved, The function as a thermal fuse is stabilized.

Next, as shown in FIG. 8, one or a plurality of fusible bodies 16 made of a low melting point fusible alloy or the like are mounted over the terminal portions 4 and 5, and the terminal portions 4 and 5 are welded or the like. The fusible member 16 is joined to the fusible member 16. Welding can be performed by soldering iron, electric welding, laser welding or soft beam welding.

At this time, the alloy constituting the fusible body 16 is defined as D2 / D1> 0.98 (preferably 0.995), where D1 is the theoretical density and D2 is the measured density after processing. Since the voids in the fusible body 16 are small and the residual oxide is sufficiently small, poor welding with the terminal portions 4 and 5 is unlikely to occur, and the yield can be improved. The theoretical density D1 of the fusible material is as follows: about 100 g of the fusible material is heated and melted in the welding flux to remove oxides, and then heated and melted in a vacuum to remove gas components in the molten metal. The mixture was cooled and solidified, and left for 168 hours in a desiccator at 25 ° C., and the density was measured by the Archimedes method. The measured density after processing is 16
The density of the fusible material processed into a plate shape or a linear shape in the shape of was measured by the Archimedes method.

Table 5 shows the relationship between D2 / D1 (abbreviated as density ratio) and welding yield.

[0061]

[Table 5]

The terminals 4 and 5 are 3 mm wide and 0.15 thick.
The fusible member joints 6 and 7 were made of a tin alloy having a thickness of 3 μm with a nickel alloy having a length of 13 mm and a length of 13 mm. 0.125 mm thickness for substrate film 1 and adhesive film 10
PET (polyethylene terephthalate) was used.
As the fusible body 16, a material that melts at 89 ± 2 ° C. when a quaternary alloy of Sn, In, Bi, and Pb is used as a thermal fuse is used. The size of the fusible body 16 is 0.14 mm in thickness, 0.91 mm in width, and 3 mm in length.
Was 1.7 mm. The welding was performed by a laser welding method. The welding yield is calculated as the non-defective one within the resistance value range of 13 ± 1 mΩ when 1000 welding operations are performed, and calculated from the number of non-defective parts / 1000 pieces. The following were rated as Δ, and 90% or more. According to Table 5, by setting the density ratio D2 / D1> 0.98 (preferably 0.995), the voids in the fusible body 16 are small, and the residual oxides are sufficiently small. And the yield was improved.

In the present embodiment, the fusible body 16 is a plate-like body having a rectangular cross section, but the fusible body 1 of a linear body or a rod-like body is used.
6 may be used.

Further, specific materials of the fusible body 16 include:
It is generally known that the main component is an alloy such as Sn, In, Bi, Pb, and Cd. This time, the harmful substance Cd
The fusible member 16 was made of an alloy containing no Sn, In, Bi, and Pb.

Next, as shown in FIG. 9, a solid flux 17 is provided so as to cover the fusible body 16. It is preferable to completely cover the fusible body 16 with the solid flux 17, but 50% of the exposed surface area of the fusible body 16 is preferable.
Even if the solid flux 17 is provided so as to cover the above, sufficient fusing characteristics can be obtained.

The solid flux 17 is provided by applying heat or dissolving it in a solvent to make it liquid, applying it on the fusible body 16 and solidifying it.

The solid flux 17 contains rosin, and its rosin composition is 50 wt% abietic acid.
~ 90 WT%, dehydroabietic acid 10 WT% ~ 50
Those containing WT% are mentioned. That is, the fusing characteristics can be improved by using the same components as the rosin contained in the welding fluxes 14 and 15. Further, by providing the solid flux containing the rosin, the yellow color can be recognized, and the quantitative recognition can be performed by the image judgment. In addition, as described above, the alcohol contained in the welding fluxes 14 and 15 contains the alcohol. It is inactive at a temperature lower than the softening point when it enters, and is therefore most suitable as a solid flux for a thermal fuse.

Next, a cover film 18 as shown in FIG. 10 is placed on the adhesive film 10 as shown in FIG. The cover film 18 has a through hole 1 for positioning.
A recess 21 is provided between the through holes 9 and 20 and the through holes 19 and 20 and is recessed from other portions. In the present embodiment, the recess 21 has a substantially square outer shape, but may have a circular shape, an elliptical shape, a triangular shape, or the like. With the concave portion 21, a space can be formed around the fusible member 16, and the fusible member 16 can be reliably cut.

As shown in FIG.
The cover film 18 is provided on the adhesive film 10 so that the through holes 19, 20 are opposed to each other.
It is arranged so as to overlap with 1 and 12. In FIG. 11, 2
Reference numeral 2 denotes a raised portion provided with a concave portion 21.
On the raised portion 22, a product number, a display as a safety component, and the like are described by printing or the like. The UV drying ink (ultraviolet curable ink) mainly composed of an acrylic oligomer having a heat resistance of 150 ° C. was used for the product number on the raised portion 22 and the display printing as a safety component. Ink is white, black, red, green,
A pigment colored with a pigment such as orange, blue, purple, ash or silver can be used. The printing was performed by transferring ink from the relief printing plate to a rubber roller and further transferring the ink to the cover film 18. The pressure between the rubber roller and the cover film 18 was adjusted so that the thickness of the ink on the cover film 18 was in the range of 1 to 5 μm. UV drying is
The irradiation was performed by irradiating an ultraviolet ray having a wavelength of about 365 nm for 5 to 15 seconds in an atmosphere of 90 ± 10 ° C. Ink thickness is 1μ
If it is less than m, the density of the ink becomes too thin to be readable, and if it exceeds 5 μm, when UV drying, it is difficult for ultraviolet rays to reach the inside of the ink. I do. (Table 6) shows the relationship between the product number, the ink thickness of the display as a safety component, the readability of the display, and the fusing temperature.

[0070]

[Table 6]

The terminals 4 and 5 are 3 mm wide and 0.15 thick.
Prototype was manufactured using a nickel alloy of mm (T2). As the substrate film 1, the adhesive film 10, and the cover film 18, PET (polyethylene terephthalate) having a thickness of 0.125 mm was used. As the soluble body 16, 102 ± 7
Pb, Bi, and Sn alloys that melt at ℃ were used. As the display, G is displayed on the raised portion 22 as the product number and the fusing temperature.
T102 and 00A were printed as the production number, and finished in the form of FIG. The adhesion strength test was performed on each of the 100 thermal fuses by bringing a gum tape into close contact with the raised portions 22 in FIG. 16 and peeling them off. Judgment of readability was evaluated as follows: after the adhesion strength test was performed, when the displayed contents were readable by visual inspection or with a magnifier of 10 times magnification, and when one or more were not readable, the evaluation was x. In addition, the confirmation of the match between the displayed content and the fusing temperature is based on the case where all the parts are blown at the temperature corresponding to the read part number, and the case where there is one or more pieces whose fusing temperature and display cannot be matched because the part number cannot be read. X.
According to Table 6, the ink thickness on the cover film 18 is 1
By setting so as to be within the range of ５5 μm, the product number and the display as a safety component are reliably performed, and there is an effect that the characteristics of the contents (the fusing temperature of the fusible member 16) and the display can be surely matched.

This time, PET was used as the insulating case material.
Although a (polyethylene terephthalate) film was used, even if the surface is made of a ceramic material such as alumina or a metal material such as stainless steel, if the ink thickness is in the range of 1 to 5 μm, the display is excellent in legibility and adhesion strength. Is possible.

The cover film 18 is preferably made of a material having an insulating property. In particular, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), ABS resin, SAN resin, polysanphone resin, polycarbonate resin, noryl It is preferable to use a thermoplastic resin mainly containing any of vinyl chloride resin, polyethylene resin, polyester resin, polypropylene resin, polyamide resin, PPS resin, polyacetal, fluorine resin and polyester.

Next, as shown in FIG. 12, a horn of ultrasonic welding is pressed around the raised portion 22 of the cover film 18, and the cover film 18 and the adhesive film 10 are welded. 13 and 14 are cross-sectional views when the thermal fuse shown in FIG. 12 is cut at P1 and P2, respectively.
3, in FIG. 14, reference numeral 38 denotes a bubble formed between the substrate film 1 and the cover film 18 and formed in a space (hereinafter referred to as a sealed space) which is cut off from the outside world, and 39 denotes a melt protruding into the sealed space. is there. At least the substrate film 1,
The adhesive film 10 and the cover film 18 are collectively subjected to the ultrasonic welding as described above, so that the welding portion 23a formed along the longitudinal direction of the terminal portions 4 and 5 and sandwiching the body of the thermal fuse is formed. A welding portion 23b is provided so as to sandwich the main body of the thermal fuse and substantially perpendicular to the welding portion 23a. As shown in FIGS. 13 and 14, the boundary between the welded portion 13a and the portion sandwiched between the welded portions 23a is provided with an R or chamfer (R1) of 0.1 mm or more, so that sealing is ensured. A space can be created, and the probability of the seal breaking due to long-term use is very low, and the cover film 18 can be prevented from being broken during manufacturing. Similarly, although not shown, a welded portion 23b similarly formed on the terminal portions 4 and 5, and the welded portion 23b
By providing an R or chamfer (R1) of 0.1 mm or more at the boundary with the portion sandwiched by b, a more secure sealed space can be created, and the seal is broken by long-term use or the like. The probability is very small, and furthermore, the tearing of the cover film 18 during the production can be prevented.

In this case, the method for producing R1 is as follows.
As the horn to be ultrasonically welded, it is preferable to use a horn having a corner with a radius or chamfer of 0.1 mm or more.

As shown in FIG. 12, a corner portion of the outer peripheral portion of the raised portion 22 (a boundary portion between the raised portion 22 and the welded portions 23a and 23b from another viewpoint) (in the present embodiment, Since the outer shape is square, R
Is provided with an R of 0.3 mm or more (R2 in FIG. 12), it is possible to create a reliable sealed space, and the probability of breaking the seal due to long-term use is very low. It is possible to prevent the cover film 18 from being broken during manufacturing.

Finally, as shown in FIG. 15, an extra portion is cut to complete a thermal fuse.

In the present embodiment, the solid flux 17 is applied directly to the fusible member 16, but the solid flux 17 is provided in a solid state in advance in the concave portion 21 provided in the cover film 18. , Cover film 18
Is placed on the adhesive film 10 and then heated to melt the solid flux 17 and apply it on the fusible body 16, and then the cover film 18 is ultrasonically welded to the adhesive film 10.
May be joined.

As shown in FIG. 17, by installing the thermal fuse of the present embodiment on the side of the battery pack, the battery pack can be made thinner and smaller than the conventional product (shown in FIG. 19). In addition, there is an effect that the resistance value loss of the wiring portion 23 is suppressed to the level of a conventional product. In FIG. 17, reference numeral 29 denotes a battery pack body, and a battery is built in the battery pack body 29 (not shown). 26 is an external electrode of the built-in battery, 28 is a protection circuit board connected to the built-in battery, and 27 is a nickel strip wiring connected to the protection circuit board 28. The thermal fuse according to the present embodiment is provided between the external electrode 26 and the nickel strip-shaped wiring 27, and is blown when a predetermined amount of heat is generated from a built-in battery or the like. Cut off.

By providing the thermal fuse of the present embodiment on the side surface of the case containing the substantially rectangular parallelepiped battery, the battery can be downsized.

In the thermal fuse of the present embodiment, the size of the thermal fuse body (case) is set to length L1 and width L
2. When the thickness is L3 (FIG. 15), it is preferable that 2.0 mm <L1 <7.5 mm 1.5 mm <L2 <3.5 mm 0.4 mm <L3 <1.5 mm, and L1, L2, When L3 is less than the above range, it is difficult to secure insulation resistance and dielectric strength when the thermal fuse operates (when the temperature fuse is disconnected), and when L1, L2, L3 is more than the above range, it becomes large. It is too difficult to use for small battery packs.

[0082]

The present invention comprises a pair of terminal portions, a fusible member provided between the pair of terminal portions, and a main body for storing the fusible member. L3, 2.0 mm <L1 <7.5 mm 1.5 mm <L2 <3.5 mm 0.4 mm <L3 <1.5 mm, and the Young's modulus of the pair of terminals is 3 × is in the range of ^{10 10 Pa~8} × ^{10 10} Pa, the tensile strength is that where the structure is in the range of ^{4 × 10 8 Pa~6 × 10 8} Pa, even when thin-miniaturized temperature fuse,
Since the strength of the terminal portion can be ensured, the terminal portion is not easily bent during handling or transportation during manufacturing, the probability of occurrence of defective products is extremely small, and the terminal portion is bent. In this case, no disconnection of the terminal portion occurs, and the production becomes very easy.

[Brief description of the drawings]

FIG. 1 is a diagram showing a manufacturing process of a thermal fuse according to an embodiment of the present invention.

FIG. 2 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 3 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 4 is a view showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 5 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 6 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 7 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 8 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 9 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 10 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 11 is a view showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 12 is a view showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 13 is a partial cross-sectional view of a thermal fuse according to an embodiment of the present invention.

FIG. 14 is a partial cross-sectional view of the thermal fuse according to one embodiment of the present invention.

FIG. 15 is a diagram showing a manufacturing process of the thermal fuse in one embodiment of the present invention.

FIG. 16 is a perspective view showing a thermal fuse according to another embodiment of the present invention.

FIG. 17 is a perspective view showing a battery pack according to an embodiment of the present invention.

FIG. 18 is a graph showing a tensile force-elongation curve in a tensile test of a thermal fuse according to an embodiment of the present invention.

FIG. 19 is a perspective view showing a conventional battery pack.

FIG. 20 shows a conventional thermal fuse.

FIG. 21 shows a conventional thermal fuse.

FIG. 22 shows a conventional thermal fuse.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate film 2,3,11,12,13,19,20 Through hole 4a, 5a Good conductor part 4,5 Terminal part 6,7 Soluble body joint part 8,9 Film joint part 10 Adhesive film 14,15 Welding flux 16 Soluble body 17 Solid flux 18 Cover film 21 Depression 22 Ridge 23, 23a, 23b Welding part 24, 25 Welding part 26 External electrode 27 Nickel strip wiring 28 Protection circuit board 29 Pack battery body

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 13, 2001 (2001.12.
13)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010]

SUMMARY OF THE INVENTION The present invention comprises a pair of terminals, a fusible member provided between the pair of terminals, and a main body for housing the fusible member . Thickness L
If 3 were, 2.0mm <L1 <7.5m m 0 . 4 mm <L3 <a thermal fuse was 1.5 mm, the Young's modulus of the pair of terminal portions is in the range of ^{3 × 10 10 Pa~8 × 10 10} Pa, tensile strength 4 × 10 ⁸ Pa~6 The composition was in the range of × 10 ⁸ Pa.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011]

The invention according to claim 1 includes a pair of terminal portions, a fusible member provided between the pair of terminal portions, and a main body for storing the fusible member, and the size of the main body. the lengths L1, when a thickness of L3, 2.0mm <L1 <7.5m m 0. 4 mm <L3 <a thermal fuse was 1.5 mm, the Young's modulus of the pair of terminal portions is in the range of ^{3 × 10 10 Pa~8 × 10 10} Pa, tensile strength 4 × 10 ⁸ Pa~6 The temperature fuse is characterized by being within the range of × 10 ⁸ Pa. Even if the thermal fuse is reduced in thickness and size, the strength of the terminal portion can be secured, so that it is easy to handle during manufacture or transport. In addition, the terminal portion is not bent, and the probability that a defective product is generated is extremely small. Further, when the terminal portion is subjected to the bending process, the terminal portion does not break and the production becomes very easy.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

According to a second aspect of the present invention, a battery and the battery
DOO Electrical the bonded wire and the wire and electrically bonded
Is a thermal fuse was, and a battery pack characterized by using a thermal fuse of claim 1, wherein as said thermal fuse according to claim 1 as the thermal fuse
The thickness of the battery pack is set to, for example, 2.5 mm by making the battery pack characterized by using the described thermal fuse.
Even if the thickness is reduced to 4 mm, stable measures against excessive heat generation can be taken.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Change

[Correction contents]

[0082]

The present invention comprises a pair of terminal portions, a fusible member provided between the pair of terminal portions, and a main body for accommodating the fusible member, wherein the main body has a length L1 and a thickness L3. If you, 2.0mm <L1 <7.5m m 0 . 4 mm <L3 <a thermal fuse was 1.5 mm, the Young's modulus of the pair of terminal portions is in the range of ^{3 × 10 10 Pa~8 × 10 10} Pa, tensile strength 4 × 10 ⁸ Pa~6 With a configuration in the range of × 10 ⁸ Pa, even if the temperature fuse is made thinner and smaller,
Since the strength of the terminal portion can be ensured, the terminal portion is not easily bent during handling or transportation during manufacturing, the probability of occurrence of defective products is extremely small, and the terminal portion is bent. In this case, no disconnection of the terminal portion occurs, and the production becomes very easy.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shinichi Otsuka 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term in the company (reference) 5G502 AA01 AA02 BA02 BA04 BB06 BC01 BD08 BE01 FF08 JJ01 5H040 AA27 AS13 AS14 AT01 AT02 AY08 DD26 NN01

Claims (2)

[Claims] A fusible member provided between the pair of terminal portions; and a main body for storing the fusible body, wherein the main body has a length L1, a width L2, and a thickness. In the case where L3 is 2.0 mm <L1 <7.5 mm 1.5 mm <L2 <3.5 mm 0.4 mm <L3 <1.5 mm, the Young's modulus of the pair of terminals is 3 × ¹⁰ 10 Pa~8 × is in the range of ¹⁰ 10 Pa, a temperature fuse, characterized in that is in the range of tensile strength ^{4 × 10 8 Pa~6 × 10 8} Pa. 2. A battery, a main body for accommodating the battery, wiring derived from the main body and electrically connected to the battery, and a temperature provided between the wirings and in contact with the main body. A battery pack comprising: a fuse; and the thermal fuse according to claim 1 is used as the thermal fuse.