TW201707037A - Protection element and fuse element - Google Patents

Abstract

To provide a protection element wherein stress that increases with the size increase of a fuse element is mitigated, and stable fusing characteristics can be maintained even if the ambient temperature changes. The present invention is provided with: a first electrode 12 and a second electrode 13; a fuse element 17 connected between the first and second electrodes 12, 13; and a housing that supports the fuse element 17. The fuse element 17 is fixed by having an elastic member 20 between the fuse element and a configuration member on the housing side.

Description

Protection element, fuse element

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection element and a fuse element for a fuse unit that is configured to block a current path by self-heating or heat generation of a heat generating body when a current exceeding a rated current flows.

The present application claims priority based on Japanese Patent Application No. 2015-109098, filed on May 28, 2015, the disclosure of which is hereby incorporated by reference.

Most of the secondary batteries that can be reused after being charged are supplied to the user after being processed into a battery pack. Especially for lithium ion secondary batteries with high weight and energy density, in order to ensure the safety of users and electronic equipment, in general, several protection circuits such as charging protection and overdischarge protection are built in the battery pack. The function of interrupting the output of the battery pack in a given situation.

Among such protection elements, there is an ON/OFF output using a FET switch built in a battery pack to perform overcharge protection or overdischarge protection of the battery pack. However, even if the FET switch is short-circuited due to some reason, or a lightning surge or the like is applied, a large current flows instantaneously, or the output voltage is abnormally lowered due to the life of the battery cell, or the opposite output is excessively abnormal. When the situation is equal, the battery pack or electronic device must be protected from accidents such as fire. Therefore, in order to safely interrupt the output of the battery in all such unexpected abnormal states, a protective element composed of a fuse element having a function of interrupting the current path by an external signal is used.

As shown in FIG. 19(A) and FIG. 19(B), as such a protective element 100 for a protective circuit of a lithium ion secondary battery or the like, there is a type which is formed on the insulating substrate 101 and which is connected to the current path. 1 and the second electrodes 102, 103 and the fuse unit 104 spanning between the first and second electrodes 102, 103 as part of a current path, and the fuse unit 104 on the current path is generated by an overcurrent The self-heating or the heating element 105 provided inside the protective element 100 is blown. In the protective element 100, the molten liquid fuse unit 104 is concentrated on the first and second electrodes 102 and 103, and is connected to the heating element 105 provided between the first and second electrodes 102 and 103. The heating element is drawn on the electrode 107 to thereby block the current path.

Moreover, the protective element 100 shown in FIG. 19 is generally used as a fuse unit 104 in order to avoid melting by heating by reflow soldering or the like. Generally, a lead-containing high melting point solder having a melting point of 300 ° C or higher is used. Further, when the fuse unit 104 is heated, the oxidation is further aggravated to prevent the fuse, so that the deposition of the flux 106 is performed in addition to removing the oxide film formed in the fuse unit 104 and improving the wettability of the fuse unit 104.

Advanced technical literature

[Patent Document 1] Japanese Patent No. 2790433

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-003665

In recent years, lithium ion secondary batteries have been increased in capacity and output, and the protection element 100 for a protection circuit for a lithium ion secondary battery has been required to be rated. In order to increase the rating and allow more current to flow, it is required to reduce the conductor resistance of the fuse unit 104, the fuse single The large size of the yuan 104 is a must.

Here, since the fuse unit 104 is mainly composed of a metal such as Pb or Sn, the linear expansion coefficient is generally large. Therefore, the fuse unit 104 repeatedly expands and contracts due to the ambient temperature of the environment in which the electronic device of the protection element 100 is constructed. However, the fuse unit 104 is fixed to the first and second electrodes 102 and 103 and the heat generating body extraction electrode 107 by solder or the like for connection, and stress generated by expansion and contraction is applied to the solder for connection and the electrodes 102 and 103. , 107, or fuse unit 104. This stress increases as the volume of the fuse unit 104 increases.

Further, since the insulating substrate 101 is mainly made of ceramic, the coefficient of linear expansion is extremely small compared with the metal fuse unit 104. Therefore, stress is generated between the fuse unit 104 and the insulating substrate 101 due to the fluctuation of the ambient temperature, and stress strain is concentrated to the fuse unit 104 itself, and the first and second electrodes 102 and 103 and the heating element extraction electrode 107. The joint, or the fuse portion where the fuse unit 104 is not joined to each of the electrodes 102, 103, 107, is damaged.

As described above, when the fuse unit 104 or the joint portion with the fuse unit 104 is broken, the fuse characteristics fluctuate, and there is a possibility that the fuse cannot be blown at a predetermined temperature or overcurrent, or the fuse time is delayed. Failure to maintain the established fuse characteristics.

Accordingly, an object of the present invention is to provide a protection element and a fuse element which can alleviate the stress which is increased by the increase in the size of the fuse unit, and can maintain the stable fuse characteristics even if the ambient temperature changes.

In order to solve the above problems, the protective element of the present invention includes a first electrode and a second electrode, a fuse unit that is bridged between the first and second electrodes, and a case that supports the fuse unit, and the fuse unit It is fixed to the structural member on the side of the casing through the elastic member.

Further, the fuse element of the present invention includes a first electrode and a second electrode, a fuse unit that is bridged between the first and second electrodes, and a case that supports the fuse unit, and the fuse unit is The constituent members on the casing side are fixed by the elastic members.

According to the present invention, since the elastic member is disposed between the constituent member on the element case side and the fuse unit, the stress generated by the change in the temperature environment can be absorbed and alleviated, and the constituent member on the fuse unit or the component case side can be prevented. A situation of breaking.

10, 30, 40, 50, 60, 70‧‧‧protective components

11‧‧‧Insert substrate

11a‧‧‧ Surface of insulating substrate

11b‧‧‧Back of the insulating substrate

12‧‧‧1st electrode

12a‧‧‧1st external connection electrode

13‧‧‧2nd electrode

13a‧‧‧2nd external connection electrode

14‧‧‧heating body

15‧‧‧Insulation

16‧‧‧heating body extraction electrode

16a‧‧‧The heating element leads to the lower part of the electrode

16b‧‧‧The heating element leads to the upper part of the electrode

17‧‧‧Fuse unit

17a‧‧‧Fuse

18‧‧‧ Covering components

19‧‧‧Heating body electrode

19a‧‧‧Heating body power supply electrode

20‧‧‧Flexible components

20a‧‧‧ core material

20b‧‧‧ Conductive layer

21‧‧‧Connected solder

22‧‧‧ Flux

80‧‧‧Battery Pack

81a~81d‧‧‧Battery

82‧‧‧Battery stacking

83‧‧‧Charge and discharge control circuit

84‧‧‧Detection circuit

85‧‧‧ Current control components

86‧‧‧Charging device

87, 88‧‧‧ Current control components

89‧‧‧Control Department

90, 91, 92‧‧‧ fuse components

Fig. 1 is a view showing a protective element to which the present invention is applied, wherein (A) is a plan view in which the covering member is omitted, and (B) is a cross-sectional view taken along line X-X' of the system (A).

2 is a view showing a state in which the elastic member follows the expansion and contraction of the fuse unit due to a change in temperature, and the stress is relieved. (A) shows a cross-sectional view when the fuse unit is inflated, and (B) shows a state in which the fuse unit is shrunk. Sectional view.

Fig. 3 is a cross-sectional view showing a protective member of a core material using an elastic member impregnated with a flux.

4 is a cross-sectional view showing a protective element in which a fuse unit is joined by an elastic member provided on the first and second electrodes.

Fig. 5 is a cross-sectional view showing a protective element in which a heat generating body is provided on the back surface of an insulating substrate.

Fig. 6 is a cross-sectional view showing a protective element in which an elastic member is provided on the first and second electrodes and the heat generating body lead-out electrode.

Fig. 7 is a cross-sectional view showing the protective member provided with an elastic member on the insulating layer between the fuse portion and the fuse portion.

Figure 8 is a cross-sectional view showing the protective member disposed between the cover member and the fuse unit.

Fig. 9 is a cross-sectional view showing a protective member using a metal plate independently supported from the element case as the first and second electrodes.

Figure 10 is a cross-sectional view showing the protective member of the protective member shown in Figure 9 with an elastic member disposed on the insulating layer between the fuse portion and the fuse portion.

Figure 11 is a cross-sectional view showing the protective member of the protective member shown in Figure 9 with the elastic member disposed between the fuse member and the fuse unit.

Fig. 12 is a circuit diagram of a battery pack in which a protective element is mounted.

Figure 13 is a circuit diagram of the protection element, (A) showing the fuse unit before the fuse is blown, and (B) showing the fuse unit being blown.

Fig. 14 is a cross-sectional view showing an operation state of the protective element, wherein (A) shows a state in which the heating element starts to generate heat due to energization, (B) shows a state in which the fuse unit starts to be melted, and (C) shows a state in which the fuse unit is blown.

Figure 15 is a cross-sectional view showing a fuse element to which the present invention is applied.

Figure 16 is a circuit diagram of a fuse element, (A) showing the fuse unit before the fuse, and (B) showing the fuse unit being blown.

Figure 17 is a cross-sectional view showing a fuse element provided with an elastic member on an insulating substrate between a fuse portion and a fuse portion.

Figure 18 is a cross-sectional view showing the fuse element disposed between the fuse unit and the fuse member.

Fig. 19 is a view in which the covering member is omitted to display the previous protective member, and (A) is an external perspective view, (B) is a sectional view.

Hereinafter, the protective element and the fuse element to which the present invention is applied will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below, and various changes can of course be made without departing from the scope of the invention. In addition, the drawings are shown in a schematic manner, and the ratios of the respective dimensions and the like may differ from the actual ones. The specific dimensions and the like should be judged by referring to the following instructions. Moreover, it is of course possible for the drawings to include portions having different dimensional relationships and ratios.

[Composition of protective components]

As shown in FIGS. 1(A) and 1(B), the protective element 10 to which the present invention is applied includes an insulating substrate 11, a heat generating body 14 laminated on the insulating substrate 11 and covered with the insulating layer 15, and formed on both ends of the insulating substrate 11. The first electrode 12 and the second electrode 13 and the heat generating body lead electrode 16 which is laminated on the insulating layer 15 so as to overlap the heat generating body 14 and the both ends are connected to the first and second electrodes 12 and 13 and are respectively connected to the center portion. The fuse unit 17 connected to the heat generating body lead-out electrode 16 is attached to the insulating substrate 11 with a cover member 18 for protecting the inside.

The protective element 10 is composed of the first and second electrodes 12 and 13 formed on the insulating substrate 11, the heating element 14, the insulating layer 15, the heating element extraction electrode 16, and the covering member 18, and the fuse unit 17 is formed. The constituent members on the element case side are fixed by the elastic member 20.

The insulating substrate 11 is formed of, for example, a substantially square shape using an insulating member such as alumina, glass ceramic, mullite or zirconia. In addition to the insulating substrate 11, a material for a printed wiring board such as a glass epoxy substrate or a phenol substrate can be used.

First and second electrodes are formed on opposite ends of the insulating substrate 11 12, 13. Each of the first and second electrodes 12 and 13 is formed of a conductive pattern such as Ag or Cu. Further, the first and second electrodes 12 and 13 are continuous from the surface 11a of the insulating substrate 11 through the castellation and the first and second external connection electrodes 12a and 13a formed on the back surface 11b. The protective element 10 is connected to the connection electrode provided on the circuit board of the battery circuit or the like that constitutes the protective element 10 by the first and second external connection electrodes 12a and 13a formed on the back surface 11b, and is assembled and formed on the circuit substrate. One part of the current path.

The heating element 14 is a member having a high electrical resistance and a heat-generating property when energized, and is made of, for example, a nickel-chromium alloy, W, Mo, Ru, or the like. The heating element 14 can be formed by mixing the alloy or the composition or the powder of the compound with a resin binder or the like, and forming a paste-like substance on the insulating substrate 11 by a screen printing technique to burn. Formed in equal ways.

Further, the protective element 10 is provided with an insulating layer 15 so as to cover the heating element 14, and the heating element extracting electrode 16 is formed to face the heating element 14 through the insulating layer 15. The heating element extraction electrode 16 is connected to the fuse unit 17, whereby the heating element 14 is superposed on the insulating layer 15 and the heating element extraction electrode 16 and the fuse unit 17. The insulating layer 15 is provided to protect and insulate the heating element 14 and to transfer the heat of the heating element 14 to the fuse unit 17 with good efficiency, and is composed of, for example, a glass layer. Further, in order to transfer the heat of the heat generating body 14 to the fuse unit 17 with good efficiency, the protective element 10 may also be provided with an insulating layer 15 between the heat generating body 14 and the insulating substrate 11.

Further, in the protective element 10, the heat generating body 14 may be formed on the back surface 11b on the side opposite to the surface 11a of the insulating substrate 11 on which the first and second electrodes 12 and 13 are formed, or on the surface 11a and the surface of the insulating substrate 11. 1. The second electrodes 12 and 13 are formed adjacent to each other. Further, in the protective element 10, the heat generating body 14 may be formed inside the insulating substrate 11.

Further, the heating element 14 has one end connected to the heating element extraction electrode 16 and the other end connected to the heating element electrode 19. The heat generating body lead-out electrode 16 has a layer portion 16a formed on the surface 11a of the insulating substrate 11 and connected to the heat generating body 14, and a layer portion 16a opposed to the heat generating body 14 and laminated on the insulating layer 15 and connected to the fuse unit 17 16b. Accordingly, the heating element 14 is electrically connected to the fuse unit 17 through the heating element extraction electrode 16. Further, the heating element extraction electrode 16 may be disposed to face the heating element 14 through the insulating layer 15, and the fuse unit 17 may be melted to facilitate the condensation of the molten conductor.

Further, the heating element electrode 19 is continuous with the heat generating body power supply electrode 19a (see FIG. 13(A)) formed on the front surface 11a of the insulating substrate 11 and transmitted through the castle type contact and the back surface 11b formed on the insulating substrate 11.

The protective element 10 is connected to the fuse element 17 from the first electrode 12 through the heating element extraction electrode 16 across the second electrode 13. The fuse unit 17 is used as a fusible conductor of the protective element 10. In normal use, the first and second electrodes 12 and 13 are electrically connected to form a part of a current path in which an external circuit of the protective element 10 is assembled. The fuse unit 17 is blown by self-heating (joule heat) by a current exceeding a rated current or by heat generation of the heat generating body 14, and the first and second electrodes 12 and 13 are blocked.

The fuse unit 17 is made of a material that can be quickly blown by heat generation or self-heating of the heat generating body 14. For example, it is very suitable to use a low melting point metal such as lead-free solder containing Sn as a main component. Further, the fuse unit 17 may be an alloy of In, Pb, Ag, Cu, or the like, or a low-melting-point metal such as lead-free solder containing Sn as a main component, or an alloy containing Ag, Cu or the like as a main component. A laminate of high melting point metals.

The fuse unit 17 is permeable to the connection between the first and second electrodes 12 and 13 The solder 21 is easily connected by reflow soldering.

The protective element 10 is disposed at a position overlapping the heat generating body 14 through the insulating layer 15 and the heat generating body lead-out electrode 16 through the fuse unit 17, so that the heat generated by the heat generating body 14 can be transmitted to the fuse unit 17 with good efficiency. Quickly blown.

Further, the protection element 10 is required to lower the conductor resistance of the fuse unit 17 in order to increase the rating and allow more current to flow. Therefore, in the protective element 10, the volume of the fuse unit 17 is increased and increased in size.

The fuse unit 17 shown in FIG. 1 is connected to the first and second electrodes 12 and 13 through a connecting material such as solder 21 for connection, and the heat generating body lead electrode 16 provided on the element case side of the protective element 10. The elastic members 20 are connected.

[elastic member 20]

The elastic member 20 is for absorbing the temperature change of the use environment of the electronic device accompanying the protective element 10, and the fuse unit 17 and the heating element extraction electrode 16, the first and second electrodes 12, 13 and the like The difference between the linear expansion coefficients of the constituent members of the side causes the stress generated. That is, the fuse unit 17 may be formed of a metal material such as Sn, and has a linear expansion coefficient larger than that of the insulating substrate 11 formed of ceramics or the like. Therefore, when the ambient temperature rises, the fuse unit 17 fixed to the first and second electrodes 12 and 13 by the solder 21 for connection is formed on the first and second electrodes 12 and 13 formed on the insulating substrate 11. Stress is generated between the heating element extraction electrodes 16.

For example, when the protective element 10 is used for a lithium ion battery for an electric vehicle, it can be assumed that the temperature varies widely depending on the use environment. Therefore, the protective element 10 causes the constituent members on the element case side such as the fuse unit 17 and the insulating substrate 11 to repeatedly expand and contract due to the temperature cycle, and the reaction line expands between the fuse unit 17 and the component case side. Stress difference strain.

Since the elastic member 20 is interposed between the heat generating body lead electrode 16 on the element case side and the fuse unit 17, the stress can be absorbed and alleviated, and the heat generating body lead electrode 16 and the fuse unit 17 can be prevented from being broken.

For example, as shown in FIG. 2, in the protection element 10, the fuse unit 17 is expanded between the first electrode 12 and the heating element extraction electrode 16 and between the second electrode 13 and the heating element extraction electrode 16 due to temperature change ( 2(A)) or contraction (Fig. 2(B)), stress is concentrated on the heat generating body lead-out electrode 16, and on the other hand, with respect to the amount of change of the fuse unit 17, the component case side of the insulating substrate 11 or the like When the amount of change is small and the stress strain is large, the elastic member 20 provided on the heat generating body lead-out electrode 16 can be deformed following the expansion change of the fuse unit 17, that is, the fuse unit 17 and the heat generating body can be alleviated. The stress on the side of the element body such as the electrode 16.

As a result, the protective element 10, the fuse unit 17, or the first and second electrodes 12 and 13 on the element case side, and the heat generating body lead-out electrode 16 and the like are not broken at the joint portion with the fuse unit 17. Therefore, in the protective element 10, the fuse unit 17 is blown at a predetermined time due to the heat generation of the heat generating body 14, or is blown at a predetermined time during an overcurrent, and the fuse characteristics are maintained.

Further, the elastic member 20 may be any one having elasticity or viscoelasticity as long as it can alleviate the stress generated between the fuse unit 17 and the element case side.

The elastic member 20 has electrical conductivity when it is between the heating element extraction electrode 16 and the fuse unit 17. Accordingly, the fuse unit 17 is electrically connected to the heat generating body lead-out electrode 16 through the elastic member 20. The elastic member 20 can be elastically and electrically conductive by forming a conductive layer 20b by conductive coating with a solder coating or Ag plating or the like on the elastic core material 20a. Further, the elastic member 20 may be formed only of a member having elasticity and conductivity without forming the conductive layer 20b.

Further, in the elastic member 20, the conductive layer 20b can be formed by bonding a conductive material such as solder on the surface, and the fuse unit 17 can be bonded to the heat generating body lead-out electrode 16 by the conductive layer 20b.

The elastic member 20 is preferably a core material having elasticity to use a conductive material having elasticity. For example, the elastic member 20 can be formed by using a sheet-like woven fabric or a non-woven fabric using a linear conductive material such as conductive fibers, and appropriately performing a conductive coating such as a solder coating or Ag plating.

Further, the elastic member 20 may be made of a porous material. For example, a porous resin sheet such as PTFE (polytetrafluoroethylene) is used as the core material 20a, and solder coating or Ag plating is performed. A conductive coating is provided to form the conductive layer 20b.

Further, since the protective element 10 transmits the heat of the heat generating body 14 to the fuse unit 17 through the heat generating body lead-out electrode 16 and the elastic member 20 to perform heating, the elastic member 20 is made of a material excellent in thermal conductivity. good.

Further, as shown in FIG. 3, the elastic member 20 may be formed of a conductive fiber or a porous material, and may be impregnated with a melting accelerator for preventing oxidation of the fuse unit 17 and promoting the melting of the flux 22. Thus, when the elastic member 20 is heated by the heating element 14, the originally impregnated flux 22 is exuded, and oxidation of the fuse unit 17 can be prevented. As a result, in the protective element 10, the melting of the fuse unit 17 can be promoted, and the first and second electrodes 12 and 13 can be quickly blocked.

Further, as the core member 20a, a woven fabric or a non-woven fabric made of a linear insulating material may be used as the core member 20a, and a melting accelerator for promoting the melting of the fuse unit 22 such as the fuse unit 17 may be impregnated. In this case, the elastic member 20 can be electrically conductively coated by a solder coating or Ag plating or the like to form the conductive layer 20b, thereby providing conductivity.

[flux]

Further, the protective element 10 can be coated with the flux 22 on the front and back surfaces of the fuse unit 17 in order to prevent oxidation of the fuse unit 17, and removal of oxide during melting and improvement in solder fluidity. By the coating of the flux 22, not only the wettability of the fuse unit 17 (for example, solder) but also the oxide during the melting of the fuse unit 17 can be removed during the actual use of the protective member 10, and the rapid fusibility can be improved. .

Further, when the oxidation preventing film such as lead-free solder containing Sn as a main component is formed on the surface of the fuse unit 17 by the coating of the flux 22, the oxide of the oxidation preventing film can be removed and effectively prevented. The oxidation of the fuse unit 17 maintains and enhances the rapid fusibility.

Further, the first and second electrodes 12 and 13 and the heating element extraction electrode 16 and the heating element electrode 19 are formed, for example, by a conductive pattern such as Ag or Cu, and Sn plating, Ni/Au plating is formed on the surface as appropriate. A protective layer such as Ni/Pd plating or Ni/Pd/Au plating is preferred. In this manner, in addition to the oxidation of the surface, it is possible to suppress the etching of the first and second electrodes 12 and 13 and the heat generating body lead-out electrode 16 by the connecting material such as the solder 21 for connection of the fuse unit 17.

[covering member]

Further, in the protective element 10, a cover member 18 for protecting the inside and preventing the molten fuse unit 17 from scattering is attached to the surface 11a of the insulating substrate 11 on which the fuse unit 17 is provided. The covering member 18 can be formed using various insulating members such as engineering plastics and ceramics. The covering member 18 is attached to the surface 11a of the insulating substrate 11 with an insulating adhesive, thereby covering the fuse unit 17.

The protective element 10 is formed to be heated to the heating element supply electrode 19a, the heating element electrode 19, the heating element 14, the heating element extraction electrode 16, the elastic member 20, and the fuse unit 17. The power path of the body 14. Further, the protective element 10 is connected to the external circuit through which the heating element electrode 19 is supplied with the heating element feeding electrode 19a to the heating element 14, and the external circuit controls the energization of the heating element electrode 19 and the fuse unit 17.

Further, the protective element 10 is connected to the heating element extraction electrode 16 via the fuse unit 17, and constitutes a part of the energization path to the heating element 14. Therefore, when the fuse unit 17 is melted and the connection to the external circuit is blocked, the protective element 10 is also blocked from the energization path of the heat generating body 14, so that the heat generation can be stopped.

[Modification 1]

Further, in the protective element 10 shown in FIG. 1, the elastic member 20 is provided only on the heating element extraction electrode 16, and the fuse unit 17 is supported. However, as shown in FIG. 4, the first and second electrodes 12 may be provided. The elastic member 20 is provided on the 13th, and the solder for connection 21 is provided on the heating element extraction electrode 16. The protective element 30 shown in FIG. 4 absorbs and relaxes the stress between the first electrode 12 and the heating element extraction electrode 16 by the elastic member 20 provided on the first electrode 12, and is provided in the second The elastic member 20 on the electrode 13 absorbs and relaxes the stress between the second electrode 13 and the heating element extraction electrode 16.

Further, in the protective element 30, the heat generating body 14 may be formed on the back surface 11b of the insulating substrate 11 as described above. At this time, as shown in FIG. 5, the protective element 30 is formed by superposing the heat generating body lead electrode 16 on the heat insulating body 14 with the insulating substrate 11 interposed therebetween, and connecting the fuse unit 17 to the heat generating body lead electrode 16 through the connection solder 21. good. In this way, the heat of the heating element 14 can be transmitted to the fuse unit 17 with good efficiency through the heating element extraction electrode 16 and the connection solder 21, and the fuse unit 17 is quickly melted after the heat generation of the heating element 14.

[Modification 2]

Further, as shown in FIG. 6, the protective member may be provided with the elastic member 20 on which the conductive layer 20b is formed by the bonding material such as solder on the first and second electrodes 12 and 13, and the heating element extraction electrode 16. In the protective element 40 shown in Fig. 6, the fuse unit 17 is bonded to the first and second electrodes 12 and 13 and the heat generating body lead-out electrode 16 by the conductive layer 20b of the elastic member 20, and is electrically connected. Further, the protective element 40 shown in FIG. 6 absorbs and relaxes the fuse unit 17 and the element case side by the respective elastic members 20 provided on the first and second electrodes 12 and 13 and the heat generating body lead-out electrode 16. Stress between.

[Modification 3]

Further, as shown in FIG. 7, the elastic member 20 may be provided on the insulating layer 15 in the protective member. In the protective element 50 shown in FIG. 7, the fuse unit 17 is bonded to the first and second electrodes 12 and 13 and the heat generating body lead-out electrode 16 by the solder 21 for connection, and is electrically connected. Further, in the protective element 50, the elastic member 20 provided on the insulating layer 15 is connected between the first electrode 12 and the heating element extraction electrode 16 and the fuse portion 17a between the second electrode 13 and the heating element extraction electrode 16. . The fuse portion 17a of the fuse unit 17 is a fuse that is bridged between the heat generating body lead electrode 16 and the first and second electrodes 12 and 13, and specifically refers to the heat generating body lead electrode 16. Between the first electrode 12 and the heating element extraction electrode 16 and the second electrode 13.

In the protective element 50, the fuse unit 17 is bonded to the first and second electrodes 12 and 13 and the heat generating body lead electrode 16 by the solder 21 for connection, so that the expansion and expansion and contraction portions are not fixed to the respective electrodes. Since the fuse portions 17a of 12, 13, and 16 are provided with the elastic member 20 in the fuse portion 17a, the stress between the fuse unit 17 and the element case side can be effectively absorbed and alleviated.

Moreover, the protective element 50 shown in FIG. 7 can be on the first and second electrodes 12 and 13 The elastic member 20 is provided at one or more places of the heating element extraction electrode 16 to engage the fuse unit 17.

[Modification 4]

Further, as shown in FIG. 8, the elastic member 20 may be provided on the covering member 18 covering the fuse unit 17 in the protective member. In the protective element 60 shown in FIG. 8, the fuse unit 17 is bonded to the first and second electrodes 12 and 13 and the heat generating body lead-out electrode 16 by the solder 21 for connection, and is electrically connected. Further, in the protective member 60, the elastic member 20 is joined to the covering member 18 and the covering member 18. The elastic member 20 provided on the covering member 18 does not necessarily have to be electrically conductive.

This protective member 60 is provided with the elastic member 20 between the fuse unit 17 and the constituent member covering member 18 on the component case side, and the stress between the fuse unit 17 and the component case side is pulled toward the covering member 18 side. It is absorbed and relaxed by the elastic member 20 connected to the covering member 18.

Further, the protective element 60 can be connected to the fuse unit 17 by providing the elastic member 20 on the heating element extraction electrode 16, so that both surfaces of the fuse unit 17 are sandwiched by the elastic member 20. As described above, the protective element 60 can effectively absorb and relax the stress between the fuse unit 17 and the element case side on both sides of the insulating substrate 11 side and the covering member 18 side.

Further, the protective member 60 may be provided with the elastic member 20 at one or more positions between the first and second electrodes 12 and 13 and the heat generating body lead-out electrode 16 and the insulating substrate 11 and the fuse portion 17a in addition to the cover member 18. Connected to the fuse unit 17, the both sides of the fuse unit 17 are sandwiched by the elastic member 20.

[Modification 5]

Further, as shown in FIG. 9, the first and second electrodes 12 and 13 may be formed of a metal plate that is independently supported from the element case in the protective element. Protective element 70, first and second shown in FIG. The electrodes 12 and 13 are formed of a metal plate that can be used for a large current, and are supported by a support member such as an external circuit board (not shown). The heat generating body 14, the insulating layer 15, the heat generating body lead electrode 16, and the elastic member 20 are provided on the insulating substrate 11. Further, in the protective element 70, the fuse unit 17 is connected to the first and second electrodes 12 and 13 through the connection solder 21, and is connected to the elastic member 20 provided between the heating element extraction electrode 16. The protective element 70 shown in FIG. 9 absorbs and relaxes the fuse unit 17 and the first and second electrodes 12 and 13 supported by a support mechanism (not shown) by the elastic member 20 provided on the heat generating body lead-out electrode 16. And the stress between the side of the component box.

Further, the protective member 70 is provided with the elastic member 20 on the first and second electrodes 12 and 13, and absorbs stress together with the elastic member 20 provided on the heat generating body lead-out electrode 16. Further, in the protective element 70, the elastic member 20 can be provided at one or more of the first and second electrodes 12 and 13 and the heat generating body lead-out electrode 16.

Further, as shown in FIG. 10, the protective member 70 may be provided with an elastic member 20 on the heating element extraction electrode 16, and an elastic member 20 may be disposed on the insulating layer 15 to absorb and alleviate the melting portion of the fuse unit 17. 17a stress. Further, the protective member 70 may be provided with the elastic member 20 only on the insulating layer 15, and the connecting solder 21 may be provided on the first and second electrodes 12 and 13 and the heating element extraction electrode 16. Alternatively, the protective member 70 may be provided with the elastic member 20 on the insulating layer 15, and the elastic member 20 may be provided at one or more of the first and second electrodes 12 and 13 and the heat generating body lead-out electrode 16.

Further, as shown in FIG. 11, the protective member 70 may be provided with the elastic member 20 in the covering member 18. The elastic member 20 provided on the covering member 18 does not necessarily have to be electrically conductive. Further, the protective member 70 may be provided with the elastic member 20 in the covering member 18, and the elastic member 20 may be provided at one or more of the first and second electrodes 12 and 13, the heating element extraction electrode 16, and the insulating layer 15.

[How to use protective components]

Next, the use forms of the protective elements 10, 30, 40, 50, 60, 70 will be described. Further, although the protective element 10 will be described below, the protective elements 30, 40, 50, 60, and 70 are also the same. The protective element 10, as shown in FIG. 12, is used, for example, in a circuit assembled in a battery pack 80 of a lithium ion secondary battery. The battery pack 80 has, for example, a battery stack 82 composed of a battery cells 81a to 81d of a total of four lithium ion secondary batteries.

The battery pack 80 includes a battery stack 82, a charge and discharge control circuit 83 for controlling charge and discharge of the battery stack 82, and a protective element 10 of the present invention which is used to block charging when the battery stack 82 is abnormal. The voltages of the respective batteries 81a to 81d are detected. The detection circuit 84 and the current control element 85 that controls the operation of the protection element 10 based on the detection result of the detection circuit 84.

The battery stack 82 is formed by connecting batteries 81a to 81d required for protection from overcharge and overdischarge conditions in series, and is detachably connected to the charging device 86 through the positive terminal 80a and the negative terminal 80b of the battery pack 80. The charging voltage from the charging device 86 is applied. The battery pack 80 charged by the charging device 86 can be operated by connecting the positive electrode terminal 80a and the negative electrode terminal 80b to an electronic device that operates with a battery.

The charge and discharge control circuit 83 includes two current control elements 87 and 88 connected in series to the current path from the battery stack 82 to the charging device 86, and a control unit 89 that controls the operation of the current control elements 87 and 88. The current control elements 87 and 88 are constituted by, for example, field effect transistors (hereinafter referred to as FETs), and the gate voltage is controlled by the control unit 89 to control conduction and blocking of the current path of the battery stack 82. The control unit 89 is operated by the power supply from the charging device 86, and controls the operation of the current control elements 87 and 88 so as to block the current path when the battery stack 82 is over-discharged or overcharged based on the detection result of the detection circuit 84.

The protection element 10 is, for example, connected to a charge and discharge current path between the battery stack 82 and the charge and discharge control circuit 83, the operation of which is controlled by the current control element 85.

The detection circuit 84 is connected to each of the batteries 81a to 81d, detects the voltage values of the batteries 81a to 81d, and supplies the respective voltage values to the control unit 89 of the charge and discharge control circuit 83. Further, the detection circuit 84 outputs a control signal for controlling the current control element 85 when any of the batteries 81a to 81d becomes an overcharge voltage or an overdischarge voltage.

The current control element 85 is constituted by, for example, an FET. When the voltage values of the batteries 81a to 81d become a voltage exceeding a predetermined over-discharge or over-charge state, the protection element 10 is operated in accordance with the detection signal output from the detection circuit 84, and the control is not dependent. The switching operation of the current control elements 87, 88 interrupts the charge and discharge current path of the battery stack 82.

In the battery pack 80 constructed as above, the protective element 10 to which the present invention is applied has the circuit configuration shown in FIG. In other words, the protective element 10 is electrically connected to the connection point of the fuse unit 17 which is connected in series between the first and second external connection electrodes 12a and 13a via the heat generating body lead-out electrode 16 and is heated by the connection point of the transmission fuse unit 17. A circuit configuration of the heating element 14 that fuses the fuse unit 17 is formed. Further, in the protective element 10, for example, the fuse unit 17 is connected in series to the charge and discharge current path of the battery pack 80 through the first and second external connection electrodes 12a and 13a, and the heat generating body 14 is transmitted through the heat generating body of the heat generating body electrode 19 19a is connected to current control element 85. The first external connection electrode 12a of the protection element 10 is connected to one of the open end sides of the battery stack 82, and the second external connection electrode 13a is connected to the positive terminal 80a side of the battery pack 80.

[fuse step]

The protective element 10 formed by such a circuit forms a current control element 85 provided in the battery pack 80 as shown in FIG. 14(A) when a current path that needs to block the battery pack 80 is generated. The heating element 14 is energized to generate heat. According to this, as shown in Fig. 14(B), the fuse element 17 assembled in the current path of the battery pack 80 is melted by the heat generation of the heat generating body 14, and the molten conductor of the fuse unit 17 is pulled to the wet state. The heater element 16 having high performance and the first and second electrodes 12 and 13 are drawn, and the fuse unit 17 is blown. As shown in FIG. 14(C), the protective element 10 can surely fuse the first electrode 12 to the heating element lead-out electrode 16 to the second electrode 13 (FIG. 13(B)), and the battery pack can be blocked. 80 current path. Further, by the fuse of the fuse unit 17, the power supply to the heating element 14 is also stopped.

Further, the protective element 10 of the present invention is not limited to the case of using a battery pack of a lithium ion secondary battery, and can of course be applied to various applications in which the current path is required to be interrupted by an electric signal.

[fuse element]

Next, a fuse element to which the present invention is applied will be described. The same components as those of the above-described protective element 10 are denoted by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 15, the fuse element 90 to which the present invention is applied includes an insulating substrate 11, first electrodes 12 and second electrodes 13 formed at both ends of the insulating substrate 11, and both ends of which are connected to the first and second electrodes, respectively. 12 and 13, a fuse member 17 that conducts between the first and second electrodes 12 and 13 is attached to the insulating substrate 11 with a cover member 18 for protecting the inside.

Further, in the fuse element 90, the element case is formed by the first and second electrodes 12 and 13 and the covering member 18 formed on the insulating substrate 11, and the fuse unit 17 is transmitted through the constituent members on the side of the element case. The elastic member 20 is fixed between.

For example, the fuse element 90 is connected to the fuse unit 17 via the elastic member 20 on the first and second electrodes 12 and 13. The elastic member 20 can be formed by a bonding material such as solder The conductive layer 20a is connected to the fuse unit 17 so as to be electrically conductive on the first and second electrodes 12 and 13.

Further, the fuse element 90 is provided with the elastic member 20 between the first and second electrodes 12, 13 on the element case side and the fuse unit 17, so that the fuse unit 17 is expanded even if the ambient temperature changes. In the case of contraction, the stress between the first and second electrodes 12 and 13 and the fuse unit 17 can be absorbed and alleviated, and the first and second electrodes 12 and 13 and the fuse unit 17 can be prevented from being broken.

[circuit configuration]

Such a fuse element 90 has a circuit configuration as shown in Fig. 16(A). The fuse element 90 is configured to be connected to an external circuit through the first and second external connection electrodes 12a and 13a, and is assembled on the current path of the external circuit. The fuse element 90 does not melt due to self-heating while the fuse unit 17 is flowing through the predetermined rated current. When the fuse element 90 flows over the rated overcurrent, the fuse unit 17 is blown by self-heating, and the first and second electrodes 12 and 13 are blocked, thereby interrupting the current path of the external circuit. (Fig. 16(B)).

[Modification 6]

Further, as shown in FIG. 17, the fuse element may be provided with an elastic member 20 on the insulating substrate 11. The fuse element 91 shown in FIG. 17 is provided with an elastic member 20 on the insulating substrate 11 instead of the first and second electrodes 12 and 13, and between the first electrode 12 and the second electrode 13 of the fuse unit 17. The fuse portion 17a is connected to the elastic member 20. In the fuse element 91, the fuse portion 17a of the fuse unit 17 is a fuse that is connected across the fuse unit 17 between the first and second electrodes 12, 13, specifically, the first electrode 12 and Between the second electrodes 13.

The fuse element 91 is bonded to the first and second electrodes 12 and 13 by the bonding solder 21 by the fuse unit 17, and the respective electrodes 12 are not fixed to the expanded and expanded portions. Since the fuse portion 17a is provided in the fuse portion 17a, the stress between the fuse unit 17 and the element case side can be effectively absorbed and alleviated by providing the elastic member 20 in the fuse portion 17a.

Further, in the fuse element 91, the elastic member 20 may be provided at one or more of the first and second electrodes 12 and 13, and the fuse unit 17 may be bonded.

[Modification 7]

Further, as shown in FIG. 18, the fuse element may be provided with the elastic member 20 on the covering member 18. In the fuse element 92 shown in FIG. 18, the fuse unit 17 is bonded to the first and second electrodes 12 and 13 by the solder 21 for connection, and is electrically connected. Further, in the fuse element 92, the elastic member 20 is joined to the cover member 18 at the fuse unit 17. The elastic member 20 provided on the covering member 18 does not necessarily need to have conductivity.

In the fuse element 92, by providing the elastic member 20 between the fuse unit 17 and the constituent member on the element case side, that is, the cover member 18, the stress between the fuse unit 17 and the side of the element case is pulled to cover. The member 18 side is absorbed and relaxed by the elastic member 20 attached to the covering member 18.

Further, in the fuse element 92, the elastic member 20 may be provided on the insulating substrate 11, and both surfaces of the fuse unit 17 may be sandwiched by the elastic member 20. In this manner, the fuse element 92 can effectively absorb and relax the stress between the fuse unit 17 and the element case side on both sides of the insulating substrate 11 side and the covering member 18 side.

Further, the fuse element 92 may be melted by providing the elastic member 20 at one or more places between the first and second electrodes 12 and 13 and the insulating substrate 11 and the fuse portion 17a in addition to the cover member 18. Both sides of the wire unit 17 are held by the elastic member 20.

10‧‧‧Protection components

11‧‧‧Insert substrate

11a‧‧‧ Surface of insulating substrate

11b‧‧‧Back of the insulating substrate

12‧‧‧1st electrode

12a‧‧‧1st external connection electrode

13‧‧‧2nd electrode

13a‧‧‧2nd external connection electrode

14‧‧‧heating body

15‧‧‧Insulation

16‧‧‧heating body extraction electrode

16a‧‧‧The heating element leads to the lower part of the electrode

16b‧‧‧The heating element leads to the upper part of the electrode

17‧‧‧Fuse unit

18‧‧‧ Covering components

19‧‧‧Heating body electrode

20‧‧‧Flexible components

20a‧‧‧ core material

20b‧‧‧ Conductive layer

21‧‧‧Connected solder

22‧‧‧ Flux

Claims (23)

A protection element comprising: a first electrode and a second electrode; a fuse unit spanning between the first and second electrodes; and a case supporting the fuse unit; the fuse unit being coupled to The constituent members on the casing side are fixed by the elastic members. A protective element according to claim 1, comprising: an insulating substrate, wherein the first and second electrodes are provided; a heat generating body is provided on the insulating substrate; and an insulating layer covering the heat And a heating element extraction electrode disposed on the insulating layer and connected to the heating element and connected to the fuse unit; the fuse unit and the first electrode, the second electrode or the heating element extraction electrode Between one or more of them, the elastic member having conductivity is present. The protective element according to claim 2, wherein the fuse unit is joined to one or more of the first electrode, the second electrode, or the heat generating body lead-out electrode by the elastic member. A protective element according to claim 1, comprising: an insulating substrate, wherein the first and second electrodes are provided; a heat generating body is provided on the insulating substrate; and an insulating layer covering the heat And a heating element extraction electrode disposed on the insulating layer, connected to the heating element and connected to the fuse unit; The fuse unit is fixed to the insulating layer through the elastic member. The protective member according to any one of claims 1 to 4, comprising: a cover member constituting the case covering the fuse unit; the fuse unit being fixed by the elastic member between the cover member and the cover member . The protective element according to any one of claims 1 to 4, wherein the first and second electrodes are metal plates independently supported by the case. The protective member according to any one of claims 1 to 4, wherein the elastic member is a porous material. The protective member according to any one of claims 1 to 4, wherein the elastic member is a woven or non-woven fabric composed of a linear conductive material. The protective member of claim 7, wherein the elastic member is impregnated with a material that promotes melting of the fuse unit. The protective member of claim 8, wherein the elastic member is impregnated with a material that promotes melting of the fuse unit. The protective member according to any one of claims 1 to 4, wherein the elastic member is a woven or non-woven fabric composed of a linear insulating material impregnated with a material which promotes melting of the fuse unit. The protective member of claim 5, wherein the elastic member is a woven or non-woven fabric composed of a linear insulating material impregnated with a material that promotes melting of the fuse unit. A fuse element comprising: a first electrode and a second electrode; The fuse unit is bridged between the first and second electrodes; and the case supports the fuse unit; the fuse unit is fixed to the constituent member on the case side through the elastic member. The fuse element of claim 13 having an insulating substrate constituting the case and having the first and second electrodes; the elastic member having electrical conductivity and present in the fuse unit and the first electrode And/or between the second electrodes. The fuse element of claim 14, wherein the fuse unit is bonded to the first electrode and/or the second electrode by the elastic member. A fuse element according to claim 13 which has an insulating substrate including the first and second electrodes, wherein the fuse unit is fixed to the insulating substrate through the elastic member. A fuse element according to any one of claims 13 to 16, which is provided with a covering member constituting the casing and covering the fuse unit; the fuse unit is transmitted through the elastic member between the covering member and the covering member fixed. The fuse element according to any one of claims 13 to 16, wherein the elastic member is a porous material. The fuse element according to any one of claims 13 to 16, wherein the elastic member is a woven or non-woven fabric composed of a linear conductive material. The fuse element of claim 18, wherein the elastic member is impregnated with a material that promotes melting of the fuse unit. The fuse element of claim 19, wherein the elastic member is impregnated The molten material entering the fuse unit. The fuse element according to any one of claims 13 to 16, wherein the elastic member is a woven or non-woven fabric composed of a linear insulating material impregnated with a material which promotes melting of the fuse unit. The fuse element of claim 17, wherein the elastic member is a woven or non-woven fabric composed of a linear insulating material impregnated with a material that promotes melting of the fuse unit.