TW201528305A - Protection element - Google Patents

Abstract

A cross-sectional area of a fusible conductor is increased to raise rated capacity of a protection element while keeping the insulating properties. The protection element includes an insulation substrate (11), a heating element (14) laminated on the insulation substrate (11), an insulating member (15) covering the heating element (14), a first and a second electrodes (12) laminated on the insulation substrate (11) where the insulating member (15) is laminated, a heating element extraction electrode (16) laminated on the insulating member (15) to overlap the heating element (14) and electrically connected to the heating element (14) through a current path between the first and the second electrodes (12), and a fusible conductor (13) laminated from the heating element extraction electrode (16) to the first and the second electrodes (12) and fusing the current path between the first electrode (12) and the second electrode (12) by heat. An inlet section (40) for allowing the melted fusible conductor (13) to flow through is installed beneath a fusing section (13a) of the fusible conductor (13).

Description

Protective component

The present invention relates to a protective element for suppressing thermal runaway of a battery by fusing the current path to stop charging and discharging the battery connected to the current path.

Most rechargeable secondary batteries that are used in reverse are processed into battery packs and supplied to the user. In particular, in order to ensure the safety of users and electronic equipment, lithium ion secondary batteries having a high weight and energy density are generally provided in a battery pack in a plurality of protection circuits such as overcharge protection and overdischarge protection. The function of interrupting the output of the battery pack.

Such a protection element has an ON/OFF output using a FET switch built in the battery pack, thereby performing an overcharge protection or an overdischarge protection operation of the battery pack. However, in the case where the FET switch is short-circuited and damaged for some reason, or a large current flows instantaneously when a lightning surge or the like is applied, or the output voltage is abnormally lowered due to the life of the battery unit, or vice versa. In the case of abnormal voltage, the battery pack or electronic equipment must still be protected from accidents such as fire. Therefore, in order to safely interrupt the output of the battery unit in any of the above-mentioned abnormal states, a protection element composed of a fuse element having a function of interrupting the current path with an external signal is used.

As such a protective element suitable for a protection circuit for a lithium ion secondary battery or the like, as disclosed in Patent Document 1, a soluble conductor is connected between the first and second electrodes on the current path to form a part of the current path. The fusible conductor on the current path leads to itself by overcurrent The heat generating body or the heating element provided inside the protective element is blown. Such a protective element blocks the current path by collecting the molten liquid-like soluble conductor on the first and second electrodes.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-003665

In order to improve the insulation performance when the current path is interrupted, it is preferable to use the protective element of the above-mentioned fusible conductor to pull apart the distance between the first and second electrodes. However, as the electronic device is reduced in size and thickness, it is required to further reduce the size and thickness of the protective element built in the battery pack. Therefore, it is difficult to pull apart the distance between the first and second electrodes. Further, as the secondary battery has a higher capacity and a higher output, the rating of the protective element is also required to be larger.

Here, in order to increase the rating of the protection element, it is necessary to obtain a balance between the decrease in the conductor resistance of the fusible conductor and the insulation performance in the interruption of the current path. That is, in order to allow more current to flow, the conductor resistance must be lowered, so that the cross-sectional area of the fusible conductor must be increased. On the other hand, when the current path is interrupted, the metal body constituting the fusible conductor is scattered around by the generated arc discharge, and a new current path is formed. The larger the sectional area of the meltable conductor, the higher the risk.

Further, when the protective element is melted by the heat of the heating element and introduced into the first and second electrodes to be melted, if the cross-sectional area of the fusible conductor is increased, the amount of the fusible conductor to be melted is also increased. Exceeding the tolerance that can be maintained on the electrode. In this case, there is a flaw in the fusible conductor that overflows from the electrode to short the electrodes.

As described above, development of a protective element that increases the sectional area of the fusible conductor and maintains the insulating performance at the same time is expected.

In order to solve the above problems, the protective element of the present invention includes: an insulating substrate; a heat generating body laminated on the insulating substrate; and an insulating member laminated on the insulating substrate to cover at least the insulating substrate a heating element; the first and second electrodes are laminated on the insulating substrate on which the insulating member is laminated; and the heating element extraction electrode is laminated on the insulating member to overlap the heating element, and between the first and second electrodes The current path is electrically connected to the heating element; and the fusible conductor is laminated so that the electrode is drawn from the heating element to the first and second electrodes, and the current between the first electrode and the second electrode is caused by heat The path is blown; and an inflow portion into which the meltable conductor flows is provided below the fuse portion of the fusible conductor.

According to the present invention, by providing the inflow portion, the path between the heating element extraction electrode and the first and second electrodes can be made longer, and even if the molten conductor which is melted or scattered by the arc discharge is attached, the melting can be prevented. The conductor forms a current path between the heating element extraction electrode and each of the first and second electrodes, and the insulation performance when the current path is blocked can be improved.

10,50,60,70,80‧‧‧protective components

11‧‧‧Insert substrate

12‧‧‧ electrodes

13‧‧‧Solid conductor

13a‧‧‧Fuse

14‧‧‧heating body

15‧‧‧Insulating components

16‧‧‧heating body extraction electrode

18‧‧‧Heating body electrode

19‧‧‧ Covering components

20‧‧‧Battery Pack

21~24‧‧‧ battery unit

26‧‧‧Detection circuit

27‧‧‧ Current control components

30‧‧‧Charge and discharge control circuit

31,32‧‧‧ Current control components

33‧‧‧Control Department

35‧‧‧Charging device

40‧‧‧Inflow Department

41‧‧‧ recess

42‧‧‧through holes

45‧‧‧heating body module

46‧‧‧ bottom substrate

47‧‧‧ concave face

1A is a cross-sectional view showing a protective member to which the present invention is applied, and FIG. 1B is a plan view showing a protective member to which the present invention is applied.

Fig. 2 is a circuit diagram of a battery pack in which a protective element to which the present invention is applied is assembled.

Figure 3 is an equivalent circuit of a protective element to which the present invention is applied.

Figure 4 is a cross-sectional view showing the fuse portion of the fusible conductor.

Fig. 5 is a cross-sectional view showing a modification of the protective member to which the present invention is applied.

Fig. 6 is a cross-sectional view showing a modification of the protective member to which the present invention is applied.

Fig. 7 is a cross-sectional view showing a modification of the protective member to which the present invention is applied.

Fig. 8 is a cross-sectional view showing a modification of the protective member to which the present invention is applied.

Fig. 9 is a cross-sectional view showing a modification of the protective member to which the present invention is applied.

Fig. 10 is a cross-sectional view showing a modification of the protective member to which the present invention is applied.

Hereinafter, the protective 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 modifications can be made without departing from the spirit and scope of the invention. Moreover, the drawings are shown in a schematic manner, and there are cases where the ratio of each size is different from the reality. The specific dimensions and the like should be judged by the following instructions. Further, the drawings naturally contain portions having different dimensional relationships or ratios from each other.

(Composition of protective components)

As shown in FIG. 1, the protective element 10 to which the present invention is applied includes an insulating substrate 11, a heating resistor 14 laminated on the insulating substrate 11 and covered by the insulating member 15, and an electrode 12 (A1) formed at both ends of the insulating substrate 11. 12 (A2), the heating element extraction electrode 16 laminated on the insulating member 15 so as to overlap the heating resistor 14, and both ends of which are connected to the electrodes 12 (A1), 12 (A2) and connected to the heating element at the center portion The fusible conductor 13 of the electrode 16.

The insulating substrate 11 is formed into 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 phenolic substrate may be used, but it is necessary to pay attention to the temperature at which the fuse is blown.

The heating resistor 14 is a conductive member having a high electric resistance value and generating heat when energized, and is made of, for example, W, Mo, Ru or the like. The alloy or the composition, the powder of the compound, the resin binder, and the like are mixed by a screen printing technique to form a paste, and a pattern is formed on the insulating substrate 11 and baked.

The insulating member 15 is disposed so as to cover the heating resistor 14, so as to be separated The edge member 15 and the heating resistor 14 are disposed to face the heating element extraction electrode 16. In order to efficiently transfer the heat of the heating resistor 14 to the fusible conductor, the insulating member 15 may be laminated between the heating resistor 14 and the insulating substrate 11.

One end of the heating element extraction electrode 16 is connected to the heating element electrode 18 (P1). Further, the other end of the heating resistor 14 is connected to the other heating element electrode 18 (P2).

The fusible conductor 13 is made of a low-melting-point metal which is rapidly melted by the heat generated by the heating resistor 14, and a Pb-free solder containing, for example, Sn as a main component can be preferably used. Further, the meltable conductor 13 may be a laminate of a low melting point metal and a high melting point metal such as Ag, Cu or an alloy containing the like as a main component.

When the protective element 5 is reflowed by laminating the high melting point metal and the low melting point metal, the reflow temperature exceeds the melting temperature of the low melting point metal layer, and even if the low melting point metal layer is melted, the fusible conductor 13 does not become Fuse. The meltable conductor 13 may be formed by forming a low melting point metal into a high melting point metal by a plating technique, and may be formed by using other well-known layering techniques or film formation techniques. Further, the fusible conductor 13 can be connected to the heat generating body lead electrode 16 and the electrodes 12 (A1), 12 (A2) using the low melting point metal solder constituting the outer layer.

Further, in order to prevent oxidation of the low-melting-point metal layer 13b of the outer layer, the protective element 5 may be coated with a flux on substantially the entire surface of the soluble conductor 13. Further, the protective member 5 may be placed on the insulating substrate 11 in order to protect the inside.

(How to use the protection component)

As shown in FIG. 2, the above protective element 10 is used in a circuit in a battery pack 20 of a lithium ion secondary battery.

For example, the protection element 10 is assembled to have a total of 4 lithium ion secondary power The battery packs 20 of the battery cells 21 to 24 of the pool are used and used.

The battery pack 20 includes a battery stack 25, a charge and discharge control circuit 30 for controlling charge and discharge of the battery stack 25, a protective element 10 applicable to the present invention when the battery stack 25 is abnormally interrupted, and a voltage for detecting each of the battery cells 21-24. The detection circuit 26 and the current control element 27 that controls the operation of the protection element 10 in accordance with the detection result of the detection circuit 26.

The battery stack 25 is connected in series to the battery cells 21 to 24 for protecting against the influence of overcharge and overdischarge conditions, and is detachably connected to the charging device through the positive terminal 20a and the negative terminal 20b of the battery pack 20. 35. Applying a charging voltage from the charging device 35. The positive electrode terminal 20a and the negative electrode terminal 20b of the battery pack 20 charged by the charging device 35 are connected to an electronic device that operates with a battery, whereby the electronic device can be operated.

The charge and discharge control circuit 30 includes two current control elements 31 and 32 connected in series to a current path flowing from the battery stack 25 to the charging device 35, and a control unit 33 that controls the operation of the current control elements 31 and 32. The current control elements 31, 32 are constituted by, for example, field effect transistors (hereinafter referred to as FETs), and the gate voltage is controlled by the control unit 33, thereby controlling the conduction and blocking of the current path of the battery stack 25. The control unit 33 receives the power supply from the charging device 35 and operates, and controls the operation of the current control elements 31 and 32 to interrupt the current path when the battery stack 25 is overdischarged or overcharged based on the detection result of the detection circuit 26.

The protection element 10 is, for example, connected to a charge and discharge current path between the battery stack 25 and the charge and discharge control circuit 30, the operation of which is controlled by the current control element 27.

The detection circuit 26 is connected to each of the battery cells 21 to 24, detects the voltage values of the battery cells 21 to 24, and supplies the respective voltage values to the control unit 33 of the charge and discharge control circuit 30. Further, the detection circuit 26 inputs when any of the battery cells 21 to 24 is an overcharge voltage or an overdischarge voltage. The control signal of the current control element 27 is controlled.

The current control element 27 is composed of, for example, an FET. When the voltage value of the battery cells 21 to 24 exceeds a predetermined over-discharge or over-charge state by the detection signal output from the detection circuit 26, the protection element 10 is operated and controlled. The charge and discharge current paths of the battery stack 25 are not interrupted by the switching action of the current control elements 31, 32.

In the battery pack 20 configured 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 constituted by a circuit composed of a fusible conductor 13 that is connected in series via the heat generating body lead-out electrode 16 and a heating resistor 14 that fuses the meltable conductor 13 by heat conduction through the connection point of the soluble conductor 13. Further, in the protective element 10, for example, the fusible conductor 13 is connected in series to the charge and discharge current path, and the heating resistor 14 is connected to the current control element 27. One of the two electrodes 12 of the protection element 10 is connected to A1 and the other is connected to A2. Further, the heating element extraction electrode 16 is connected to P1 to the heating element electrode 18 connected thereto, and the other heating element electrode 18 is connected to P2.

The protective element 10 composed of the above-described circuit can reliably fuse the fusible conductor 13 on the current path by the heat generated by the heating resistor 14.

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

(fuse part)

Next, a further specific configuration of the protective element 10 to which the present invention is applied will be described. The protective element 10 is provided with an inflow portion 40 in which a molten conductor that is melted and scattered by arc discharge flows in and is deposited under the fuse portion 13a of the blown fusible conductor 13. The fusible conductor 13 is connected to the heating element lead-out electrode 16 and between the electrodes 12 (A1) and 12 (A2), and generates self-heating (Joule heat) or a heating resistor due to an overcurrent. The heat of 14 is melted, and the heat generating body is taken out between the electrode 16 and the electrodes 12 (A1) and 12 (A2). Thereby, the protection element 13 interrupts the current path.

As shown in FIG. 4, the fuse portion 13a of the fusible conductor 13 is a fuse portion of the fusible conductor 13 connected between the heating element extraction electrode 16 and the electrodes 12 (A1), 12 (A2), specifically, The heating element is led between the electrode 16 and the electrode 12 (A1), and between the heating element extraction electrode 16 and the electrode 12 (A2).

(inflow)

Further, the protective element 10 is provided with an arc discharge generated when the fuse is blown by an overcurrent, under the fuse portion 13a of the soluble conductor 13 connected between the heating element lead-out electrode 16 and the electrodes 12 (A1) and 12 (A2). The inflow portion 40 in which the molten and scattered molten conductor flows into and accumulates. By flowing and depositing the molten and scattered molten conductor in the inflow portion 40, it is possible to prevent the current path between the heating element lead-out electrode 16 and the electrodes 12 (A1) and 12 (A2) by the molten conductor.

That is, the protective element 10 has an inflow portion 40 formed below the fuse portion 13a, and the path between the heat generating body lead electrode 16 and the electrode 12 (A1) and the electrode 12 (A2) is extended. Therefore, even if the protective element 10 has a molten conductor attached thereto, the path for adhering the molten conductor can be lengthened, and the heating element can be prevented from forming the heating element lead electrode 16 and the electrode 12 (A1), 12 (A2). The current path between).

In addition, when the protective element 10 is increased in the cross-sectional area of the soluble conductor 13 to increase the rated value, the molten conductor which is melted and scattered by the arc discharge generated during the fuse is also increased, but by providing the inflow portion 40, A current path formed by the molten conductor can be prevented. Further, the protective element 10 can maintain the insulating performance without setting the distance between the heating element lead-out electrode 16 and the electrode 12 (A1) and the electrode 12 (A2) to be long, and the size of the protective element can be reduced.

(Composition of the inflow part 1)

The inflow portion 40 is provided between the electrode 12 (A1) and the heating element extraction electrode 16 and between the electrode 12 (A2) and the heating element extraction electrode 16. That is, they are respectively formed below the two fuse portions 13a of the fusible conductor 13 connected between the heating element extraction electrode 16 and the electrodes 12 (A1) and 12 (A2).

Further, the inflow portion 40 may be provided only between the electrode 12 (A1) and the heating element extraction electrode 16 or between the electrode 12 (A2) and the heating element extraction electrode 16. The charge/discharge path of the device in which the protective element 10 is assembled can be interrupted as long as the current path formed by the molten conductor can be prevented. However, in order to reliably maintain the insulating performance, it is preferable that the inflow portion 40 is provided between the heating element extraction electrode 16 and the electrodes 12 (A1), 12 (A2).

(Composition of the inflow part 2)

As shown in FIG. 1 or FIG. 4, the inflow portion 40 may be constituted by a recess 41 formed in the insulating substrate 11. The concave portion 41 is formed in a groove shape between the electrode 12 (A1) of the insulating substrate 11 and the heating element extraction electrode 16 and between the electrode 12 (A2) and the heating element extraction electrode 16.

The concave portion 41 can be formed by a known method such as surface cutting or etching depending on the material of the insulating substrate 11, or a known method of laminating the substrate according to the shape of the concave portion 41. In the protective element 10, by forming the concave portion 41, the path between the heating element extraction electrode 16 and the electrodes 12 (A1) and 12 (A2) can be lengthened. Therefore, the current path formed by the molten conductor can be prevented by causing the molten conductor which is melted and scattered by the arc discharge during the overcurrent to flow. Further, in the case of an overvoltage or the like, the protective element 10 overflows from the electrode 12 (A1), 12 (A2) or the heating element lead-out electrode 16 even if the heat-melting consumable conductor 13 generated by the heating element extraction electrode 16 overflows. By causing the overflowed molten conductor to flow into the concave portion, it is possible to prevent short-circuiting between the heating element extraction electrode 16 and the electrodes 12 (A1) and 12 (A2).

Further, as shown in FIG. 5, the recessed portion 41 may be formed to expand toward the lower side of the insulating substrate 11. Thereby, the path between the heating element extraction electrode 16 and the electrodes 12 (A1) and 12 (A2) can be further extended, and the volume of the concave portion 41 can be increased. Therefore, even if the inflow amount of the molten conductor is large, the protective element 10 can more reliably prevent the formation of the current path.

Moreover, it is preferable that the recessed portion 41 has a larger volume than the accumulation portion of the fuse portion 13a of the fusible conductor 13. Thereby, even if the molten conductor of the fuse portion 13a flows into the concave portion 41, the molten conductor does not overflow from the concave portion 41, and the current path can be prevented from being formed by the overflowed molten conductor.

Further, as shown in FIG. 1B, the concave portion 41 is preferably formed to be extended to the outer side of the fusible conductor 13. By extending the concave portion 41 to the lower side of the soluble conductor 13 and the outside thereof, the arc discharge generated when the molten conductor of the melted fuse portion 13a is over-current is scattered to the outside of the soluble conductor 13, and it is also possible to prevent The molten conductor scattered to the outside forms a current path.

(Composition of the inflow section 3)

Further, as shown in FIG. 6, the protective element 50 may constitute the inflow portion 40 by the through hole 42 formed in the insulating substrate 11. Similarly to the concave portion 41, the through hole 42 is formed in a groove shape between the electrode 12 (A1) of the insulating substrate 11 and the heating element extraction electrode 16 and between the electrode 12 (A2) and the heating element extraction electrode 16.

The through hole 42 can be formed by a known method such as surface cutting or etching depending on the material of the insulating substrate 11, or a known method of laminating a substrate on which an opening groove corresponding to the shape of the through hole 42 is formed. By forming the through hole 42 in the protective element 50, the path between the heating element lead-out electrode 16 and the electrodes 12 (A1) and 12 (A2) can be lengthened, and melting and scattering can be caused by arc discharge during overcurrent. The molten conductor flows in and accumulates to prevent formation of a current composed of the molten conductor path. Further, when the protective element 50 is overvoltage or the like, even if the heat-meltable consumable conductor 13 generated by the heating element extraction electrode 16 overflows from the electrode 12 (A1), 12 (A2) or the heating element extraction electrode 16, By causing the overflowed molten conductor to flow into the through hole 42, it is possible to prevent a short circuit between the heating element extraction electrode 16 and the electrodes 12 (A1) and 12 (A2). At this time, since the inflow portion 40 is constituted by the through hole 42, even if the amount of the meltable conductor 13 overflowing from the electrode is large, the inflow portion 40 does not overflow.

Further, as shown in FIG. 7, the through hole 42 may be formed to expand in diameter below the insulating substrate 11. Further, it is preferable that the through hole 42 has a larger volume than the deposition portion 13a of the fusible conductor 13. Further, as shown in FIG. 1B, the through hole 42 is preferably formed to extend to the outer side of the fusible conductor 13.

(Composition of the inflow section 4)

Further, as shown in FIG. 8, the protective element 60 may be formed by providing the protruding portion 43 which is formed by the protruding portion 43 which is provided with the heat generating body lead-out electrode 16 of the insulating substrate 11 as compared with the electrode 12 (A1) and The heating element extraction electrodes 16 and the electrode 12 (A2) and the heating element extraction electrode 16 protrude between each other. Thereby, the protective element 60 forms a groove-like inflow portion 40 below the fuse portion 13a of the soluble conductor 13 between the protruding portion 43 and the electrodes 12 (A1), 12 (A2).

The protruding portion 43 can be formed by a known method such as surface cutting or etching depending on the material of the insulating substrate 11, or a known method of laminating the substrate at a portion where the heating element extraction electrode 16 is provided. By forming the protruding portion 43, the protective element 60 can lengthen the path between the heating element extraction electrode 16 and the electrodes 12 (A1) and 12 (A2), and can further improve the insulation performance.

Further, it is preferable that the inflow portion 40 between the protruding portion 43 and the electrodes 12 (A1), 12 (A2) has a larger volume than the deposition portion 13a of the fusible conductor 13. Further, the inflow portion 40 between the protruding portion 43 and the electrodes 12 (A1), 12 (A2) is preferably set to be fusible by providing the protruding portion 43 The outer side of the conductor 13 is elongated to form the outer side of the fusible conductor 13.

(Composition of the inflow part 5)

Further, as shown in FIG. 9, the protective element 70 may be formed by mounting the heat generating body module 45 on the insulating substrate 11 to form the inflow portion 40. Electrodes 12 (A1), 12 (A2) are formed on the insulating substrate 11. The heating element module 45 includes a base substrate 46, a heating resistor 14 laminated on the base substrate 46 and covered by the insulating member 15, and a heating element extraction electrode 16 formed to overlap the heating resistor 14. Similarly to the above-described insulating substrate 11, the base substrate 46 is formed into a substantially square shape using an insulating member such as alumina, glass ceramic, mullite, or zirconia. In addition, as the base substrate 46, a material for a printed wiring board such as a glass epoxy substrate or a phenolic substrate may be used. The heating resistor 14, the insulating member 15, and the heating resistor 16 are the same as described above.

The protective element 70 and the heat generating body module 45 are mounted between the electrodes 12 (A1) and 12 (A2) of the insulating substrate 11 by an adhesive. Thereby, the protective element 70 forms the inflow portion 40 between the electrode 12 (A1) and the electrode 12 (A2) and the heating element module 45. As described above, the protective element 70 can be easily formed into the inflow portion 40 by forming the heat generating body module 45 and mounting it on the insulating substrate 11.

Further, in the heating element module 45, it is preferable that the volume of the inflow portion 40 is larger than the melting portion 13a of the soluble conductor 13 by forming the base substrate 46 to be thick or the like. Further, in the heating element module 45, it is preferable that the inflow portion 40 is formed to extend to the outside of the soluble conductor 13 by making the length of the base substrate 46 longer than the soluble conductor 13.

(Composition of the inflow part 6)

Further, as shown in FIG. 10, the protective element 80 may have a concave portion 47 formed on a portion of the insulating substrate 11 on which the heating element module 45 is mounted. The concave surface portion 47 is provided to be wider than the bottom substrate 46 of the heat generating body module 45 between the electrodes 12 (A1) and 12 (A2) of the insulating substrate 11. Also, the concave portion 47 can be insulated The material of the substrate 11 is formed by a known method such as surface cutting or etching, or a known method such as laminating the substrate according to the positions at which the electrodes 12 (A1) and 12 (A2) are formed.

The heating element module 45 is provided with a gap between the electrodes 12 (A1) and 12 (A2) and is mounted on the concave surface portion 47 by an adhesive. Thereby, the protective element 80 forms the inflow portion 40 between the electrodes 12 (A1) and 12 (A2) and the heating element module 45. As described above, the protective element 80 can be easily formed into the inflow portion 40 by forming the heat generating body module 45 and mounting it on the insulating substrate 11, and the height of the concave portion 47 can be reduced.

Further, in the heating element module 45, it is preferable that the volume of the inflow portion 40 is larger than the melting portion 13a of the soluble conductor 13 by deepening the concave surface portion 47 and forming the base substrate 46 to be thick or the like. Further, in the heating element module 45, it is preferable that the inflow portion 40 is formed to extend to the outside of the soluble conductor 13 by making the length of the concave portion 47 and the base substrate 46 longer than the soluble conductor 13.

(depth of the inflow portion 40)

In any of the above protective elements 10, 50, 60, 70, 80, the deeper the depth of the inflow portion 40, the more the insulation performance can be improved. That is, the reason is that the protective elements 10, 50, 60, 70, 80 make the depth of the inflow portion 40 deeper, so that the heating element can be drawn between the electrode 16 and the electrodes 12 (A1), 12 (A2). The longer the path, the more easily the molten conductor that is melted and scattered by the arc discharge is attached to the current path between the heating element extraction electrode 16 and the electrodes 12 (A1) and 12 (A2).

10‧‧‧Protection components

11‧‧‧Insert substrate

12 (A1), 12 (A2) ‧ ‧ electrodes

13‧‧‧Solid conductor

13a‧‧‧Fuse

14‧‧‧heating body

15‧‧‧Insulating components

16‧‧‧heating body extraction electrode

18 (P1), 18 (P2) ‧ ‧ heating body electrode

19‧‧‧ Covering components

40‧‧‧Inflow Department

41‧‧‧ recess

42‧‧‧through holes

Claims (11)

A protective element comprising: an insulating substrate; a heating element laminated on the insulating substrate; and an insulating member laminated on the insulating substrate so as to cover at least the heating element; and the first and second electrodes are laminated on the laminated insulating member The insulating substrate; the heating element extraction electrode is laminated on the insulating member so as to overlap the heating element, electrically connected to the heating element in a current path between the first and second electrodes; and a fusible conductor The electrode of the heating element is laminated to the first and second electrodes, and a current path between the first electrode and the second electrode is melted by heat; and a fuse is provided below the fuse portion of the soluble conductor. The infused portion into which the meltable conductor flows. The protective element according to claim 1, wherein the inflow portion is provided between the first electrode and the heating element extraction electrode and/or between the second electrode and the heating element extraction electrode. The protective element of claim 1 or 2, wherein the inflow portion is formed in a recess of the insulating substrate. The protective element of claim 3, wherein the inflow portion is expanded toward the lower side of the insulating member. The protective element according to claim 1 or 2, wherein the inflow portion is formed in a through hole of the insulating substrate. The protective member of claim 5, wherein the inflow portion is expanded toward the lower side of the insulating member. For example, the protection element of claim 1 or 2, wherein the inflow part is A portion of the edge substrate on which the heating element extraction electrode is provided is formed to protrude from between the first electrode and the heating element extraction electrode, and between the second electrode and the heating element extraction electrode. The protective element according to claim 1 or 2, wherein the inflow portion is formed by mounting a heat generating body module on the insulating substrate, and the heat generating body module is formed with the heat generating body on the base substrate. The insulating member and the heating element lead the electrode. The protective element according to claim 7, wherein the portion of the insulating member on which the heat generating body module is mounted is lower than a portion where the first and second electrodes are laminated. The protective element of claim 1 or 2, wherein the volume of the inflow portion is larger than the volume of the fuse portion of the fusible conductor. The protective member of claim 1 or 2, wherein the inflow portion is formed to extend to the outer side of the fusible conductor.