WO2013146889A1

WO2013146889A1 - Protection element

Info

Publication number: WO2013146889A1
Application number: PCT/JP2013/059013
Authority: WO
Inventors: 吉弘米田
Original assignee: デクセリアルズ株式会社
Priority date: 2012-03-29
Filing date: 2013-03-27
Publication date: 2013-10-03

Abstract

The purpose of the present invention is to attain a protection element that can be made lead-free by using a multilayer body with a high melting-point metal layer and a low melting-point metal layer. A protection element (10) is provided with an insulation substrate (11), a heating element (14), an insulation member (15), two electrodes (12), a heating element draw-out electrode (16), and a fusible conductor (13). The fusible conductor (13) is composed of a multilayer body comprising at least a high melting-point metal layer (13a) and a low melting-point metal layer (13b). When being melted by the heat generated by the heating element (14), the low melting-point metal layer (13b) will erode the high melting-point metal layer (13a) while being pulled by surface tension towards the sides of the two electrodes (12) and the heating element draw-out electrode (16) to which the low melting-point metal layer (13b) has good wettability, causing the low melting-point metal layer (13b) to break.

Description

Protective element

The present invention relates to a protection element that stops charging of a battery connected on a current path by fusing the current path and suppresses thermal runaway of the battery.
This application is Japanese Patent Application No. 2012-076928 filed on March 29, 2012, Japanese Patent Application No. 2012-281442, and 2013 filed on December 25, 2012 in Japan. The priority is claimed on the basis of Japanese Patent Application No. 2013-008302 filed on Jan. 21, 2011, which is incorporated herein by reference.

Most of the secondary batteries that can be charged and used repeatedly are processed into battery packs and provided to users. In particular, in lithium ion secondary batteries with high weight energy density, in order to ensure the safety of users and electronic devices, a battery pack generally includes a number of protection circuits such as overcharge protection and overdischarge protection. It has a function of shutting off the output of the battery pack in a predetermined case.

・ The battery pack is overcharge protected or overdischarge protected by turning the output on and off using the FET switch built in the battery pack. However, when the FET switch is short-circuited for some reason, when a lightning surge or the like is applied and an instantaneous large current flows, the output voltage drops abnormally due to the life of the battery cell, or conversely an excessively abnormal voltage Even when a battery pack is output, battery packs and electronic devices must be protected from accidents such as fire. Therefore, in order to safely shut off the output of the battery cell in any possible abnormal state, a protection element made up of a fuse element having a function of cutting off the current path by an external signal is used.

As a protection element of such a protection circuit for a lithium ion secondary battery or the like, as described in Patent Document 1, the protection element has a heating element, and the heating element causes a soluble conductor on the current path. In general, a structure for fusing is used.

JP 2010-003665 A JP 2004-185960 A JP 2012-003878 A

In a protective element as described in Patent Document 1, in general, a soluble conductor contains Pb having a melting point of 300 ° C. or higher so that it is not melted by the heat of reflow when reflow mounting is used. High melting point solder is used. However, in the RoHS directive and the like, the use of Pb-containing solder is only limitedly recognized, and it is considered that the demand for Pb-free solder will increase in the future.

Here, “solder erosion” and “corrosion phenomenon” are well known as phenomena in which Au plating and Ag plating of electronic parts, etc. start to melt in the molten solder. A protective element corresponding to Pb-free solder material is described in Patent Document 2. However, as described in Patent Document 2, in the structure in which the refractory metal layer is closely attached to the insulating layer, the refractory metal layer only causes a erosion phenomenon due to melting of the low melting point metal layer. There is a problem that it may not be possible to completely block. Further, in order to surely melt the fusible conductor, it is preferable to form slits and film thickness steps in the refractory metal layer or the like, but there is a problem that the process for forming slits and film thickness steps increases. Yes (see, for example, Patent Document 3).

Therefore, an object of the present invention is to realize a protective element that can be made Pb-free by using a laminate of a high melting point metal layer and a low melting point metal layer.

As a means for solving the above-described problems, a protective element according to an embodiment of the present invention includes an insulating substrate, a heating element stacked on the insulating substrate, and a laminate on the insulating substrate so as to cover at least the heating element. Laminated on the insulating member so as to overlap the heating element, and the first and second electrodes laminated on the insulating substrate on which the insulating members are laminated. A heating element extraction electrode electrically connected to the heating element on the current path between the heating element extraction electrode and the first and second electrodes stacked from the heating element extraction electrode; And a soluble conductor that melts the current path between the two. The fusible conductor is composed of a laminate of a high melting point metal layer and a low melting point metal layer, and the low melting point metal layer is melted by the heat generated by the heating element, so that the high melting point metal layer is eroded and wetted. The first and second electrodes having high properties and the heating element extraction electrode are attracted and melted.

The low melting point metal layer is preferably made of Pb-free solder, and the high melting point metal layer is preferably made of a metal mainly composed of Ag or Cu.

Also, it is preferable that the volume of the low melting point metal layer is larger than the volume of the high melting point metal layer.

A protective element according to another embodiment of the present invention includes an insulating substrate, a heating element stacked on the insulating substrate, an insulating member stacked on the insulating substrate so as to cover at least the heating element, and an insulating member stacked A first and second electrodes stacked on the insulating substrate, a heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes, and a heating element extraction electrode To the first and second electrodes, and a soluble conductor that melts the current path between the first electrode and the second electrode by heating. The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer. The low melting point metal layer is attracted to the first and second electrodes and the heating element extraction electrode side where the low melting point metal has high wettability while being melted by the heat generated by the heating element while eroding the high melting point metal layer. Blown out.

A protection element according to another embodiment of the present invention includes an insulating substrate, a heating element stacked on the insulating substrate, an insulating member stacked on the insulating substrate so as to cover at least the heating element, and an insulating member. First and second electrodes stacked on a stacked insulating substrate, a heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes, and a heating element extraction A plurality of fusible conductors are stacked from the electrode to the first and second electrodes, and the current path between the first electrode and the second electrode is blown by heating. The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer. The low melting point metal layer is attracted to the first and second electrodes and the heating element extraction electrode side where the low melting point metal has high wettability while being melted by the heat generated by the heating element while eroding the high melting point metal layer. Blown out.

A protection element according to another embodiment of the present invention includes an insulating substrate, a heating element built in the insulating substrate, first and second electrodes stacked on the insulating substrate, and first and second electrodes. A heating element extraction electrode electrically connected to the heating element on the current path between the electrodes, and the first and second electrodes are laminated from the heating element extraction electrode to the first electrode by heating the heating element. And a soluble conductor that melts the current path between the second electrode and the second electrode. The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer. The low melting point metal layer is attracted to the first and second electrodes and the heating element extraction electrode side where the low melting point metal has high wettability while being melted by the heat generated by the heating element while eroding the high melting point metal layer. Is blown out.

A protection element according to another embodiment of the present invention includes an insulating substrate, a heating element stacked on the insulating substrate, and first and second layers stacked on opposite surfaces of the insulating substrate on which the heating element is stacked. And a heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes, and a stack from the heating element extraction electrode to the first and second electrodes. And a soluble conductor that melts a current path between the first electrode and the second electrode by heating the body. The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer. The low melting point metal layer is attracted to the first and second electrodes and the heating element extraction electrode side where the low melting point metal has high wettability while being melted by the heat generated by the heating element while eroding the high melting point metal layer. Blown out.

A protection element according to another embodiment of the present invention includes an insulating substrate, a heating element stacked on the insulating substrate, and first and second electrodes stacked on the same surface where the heating elements of the insulating substrate are stacked. And a heating element extraction electrode electrically connected to the heating element on the current path between the first and second electrodes, and a stack of the heating element from the heating element extraction electrode to the first and second electrodes. A soluble conductor that melts a current path between the first electrode and the second electrode by heating is provided. The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer. The low melting point metal layer is attracted to the first and second electrodes and the heating element extraction electrode side where the low melting point metal has high wettability while being melted by the heat generated by the heating element while eroding the high melting point metal layer. Blown out.

A protection element according to another embodiment of the present invention is stacked on an insulating substrate, first and second electrodes stacked on the insulating substrate, and a current path between the first and second electrodes. A heating element extraction electrode, a heating element mounted so as to be electrically connected to the heating element extraction electrode, and a first electrode and a second electrode are stacked from the heating element extraction electrode. A soluble conductor for fusing a current path between the electrode and the second electrode. The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer. The low melting point metal layer is attracted to the first and second electrodes and the heating element extraction electrode side where the low melting point metal has high wettability while being melted by the heat generated by the heating element while eroding the high melting point metal layer. Blown out.

A protective element according to another embodiment of the present invention includes an insulating substrate, a heating element stacked on the insulating substrate, an insulating member stacked on the insulating substrate so as to cover at least the heating element, and an insulating member stacked A first and second electrodes stacked on the insulating substrate, a heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes, and a heating element extraction electrode To the first and second electrodes, and a soluble conductor that melts the current path between the first electrode and the second electrode by heating. The fusible conductor is made of a high melting point metal, and is connected to each of the first electrode, the second electrode, and the heating element extraction electrode via the low melting point metal. The low melting point metal layer is melted by the heat generated by the heating element, so that the first and second electrodes and the heating element lead electrode having high wettability of the low melting point metal while eroding the soluble conductor made of the high melting point metal. Pulled to the side and blown.

In the protection element of the present invention, the low melting point metal layer is melted by the heat generated by the heating element by heating the soluble conductor composed of the laminate of the high melting point metal layer and the low melting point metal layer. Since the first and second electrodes having high wettability and the heating element lead-out electrode are melted and melted while being eroded, it can be surely melted. In addition, since the protection element of the present invention has a soluble conductor, it is clear that it functions as a normal current fuse, and it is possible to realize both current signal interruption and external signal and overcurrent interruption.

Further, the low melting point metal layer is made of Pb-free solder, and the high melting point metal layer is made of a metal containing Ag or Cu as a main component, so that it can correspond to Pb free.

Since the volume of the low melting point metal layer is larger than the volume of the high melting point metal layer, the erosion action of the high melting point metal layer can be performed effectively.

FIG. 1A is a plan view of a protection element to which the present invention is applied. 1B is a cross-sectional view taken along the line A-A ′ of FIG. 1A. FIG. 2 is a block diagram showing an application example of a protection element to which the present invention is applied. FIG. 3 is a diagram showing a circuit configuration example of a protection element to which the present invention is applied. FIG. 4 is a cross-sectional view of a protection element of a known example (Japanese Patent Laid-Open No. 2004-185960). FIG. 5 is a conceptual plan view for explaining the operation of the protection element to which the present invention is applied. FIG. 5A is a plan view showing the protection element before or just after the operation starts. FIG. 5B is a plan view showing a state in which the low melting point metal layer in the vicinity of the heat source is melted and eroded by the heating operation. FIG. 5C is a plan view showing a situation where erosion of the refractory metal layer has progressed. FIG. 5D is a plan view showing a state where the low melting point metal layer is drawn to the electrode and the heating element extraction electrode. FIG. 6A is a plan view showing one of the modifications of the embodiment of the protection element of the present invention. 6B is a cross-sectional view taken along the line A-A ′ of FIG. 6A. FIG. 7A is a plan view showing one of the modifications of the embodiment of the protection element of the present invention. FIG. 7B is a cross-sectional view taken along the line A-A ′ of FIG. 7A. FIG. 8A is a plan view showing one of the modifications of the embodiment of the protection element of the present invention. 8B is a cross-sectional view taken along the line A-A ′ of FIG. 8A. FIG. 9 is a conceptual plan view for explaining the operation of the protection element according to the modification of FIG. FIG. 9A is a plan view showing the protection element before or just after the operation starts. FIG. 9B is a plan view showing a state in which the low melting point metal layer in the vicinity of the heat source is melted and eroded by the heating operation. FIG. 9C is a plan view showing a situation where erosion of the refractory metal layer has progressed. FIG. 9D is a plan view showing a state where the low melting point metal layer is drawn to the electrode and the heating element extraction electrode. FIG. 10 is a perspective view showing an example in which soluble conductors having different shapes are configured. FIG. 10A shows an example in which a rectangular (square) shape is formed, and FIG. 10B shows an example in which a round line is formed. FIG. 11A is a plan view showing one of the modifications of the embodiment of the protection element of the present invention. FIG. 11B is a cross-sectional view taken along the line A-A ′ of FIG. 11A. FIG. 12A is a plan view showing one of the modifications of the embodiment of the protection element of the present invention. 12B is a cross-sectional view taken along the line A-A ′ of FIG. 12A. FIG. 13A is a top view which shows one of the modifications of embodiment of the protection element of this invention. 13B is a cross-sectional view taken along the line A-A ′ of FIG. 13A. FIG. 14A is a plan view showing one of the modifications of the embodiment of the protection element of the present invention. 14B is a cross-sectional view taken along the line A-A ′ of FIG. 14A. FIG. 15A is a plan view showing one of the modifications of the embodiment of the protection element of the present invention. FIG. 15B is a cross-sectional view taken along the line A-A ′ of FIG. 15A. FIG. 16 is a cross-sectional view showing a modification of the protection element in which the heating element is built in the insulating substrate. FIG. 17 is a cross-sectional view showing a modification of the protection element in which the heating element is formed on the back surface of the insulating substrate. FIG. 18 is a cross-sectional view showing a modification of the protection element in which the heating element is formed on the surface of the insulating substrate. FIG. 19 is a cross-sectional view showing a modified example of the protection element in which the heating element is mounted on the surface of the insulating substrate. FIG. 20 is a diagram showing a modification of the protection element using the soluble conductor in which a linear opening is provided in the high melting point metal layer and the low melting point metal layer is exposed, FIG. 20A is a plan view, and FIG. It is sectional drawing. FIG. 21 is a view showing a modification of the protective element using a soluble conductor in which a circular opening is provided in the high melting point metal layer and the low melting point metal layer is exposed, FIG. 21A is a plan view, and FIG. FIG. FIG. 22 is a diagram showing a modification of the protection element using the soluble conductor in which a linear opening is provided in the high melting point metal layer and the low melting point metal layer is exposed, FIG. 22A is a plan view, and FIG. 22B is a plan view. It is sectional drawing. FIG. 23 is a view showing a modified example of a protective element in which a soluble conductor having a two-layer structure of a high melting point metal layer and a low melting point metal layer is connected by a low melting point metal, FIG. 23A is a plan view, and FIG. It is sectional drawing. FIG. 24 is a diagram showing a modified example of a protection element using a soluble conductor having a four-layer structure in which high-melting point metal layers and low-melting point metal layers are alternately stacked. FIG. 24A is a plan view, and FIG. It is sectional drawing. FIG. 25 is a view showing a modification of the protective element in which a soluble conductor composed of a single high melting point metal layer is connected by a low melting point metal, FIG. 25A is a plan view, and FIG. 25B is a cross-sectional view. FIG. 26 is a plan view showing a protection element in which a plurality of soluble conductors are provided and an insulating layer is formed on the heating element extraction electrode. FIG. 27 is a plan view showing a state in which a soluble conductor is blown in a protective element in which a plurality of soluble conductors are provided and an insulating layer is formed on a heating element extraction electrode. FIG. 28 is a plan view showing a protection element in which a plurality of soluble conductors are provided and a narrow portion is formed on the heating element extraction electrode. FIG. 29 is a plan view showing a state where a soluble conductor is blown in a protective element in which a plurality of soluble conductors are provided and a narrow portion is formed on a heating element extraction electrode.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited only to the following embodiment, Of course, a various change is possible in the range which does not deviate from the summary of this invention.

[Configuration of protection element]
As shown in FIG. 1, a protection element 10 to which the present invention is applied is formed on an insulating substrate 11, a heating element 14 laminated on the insulating substrate 11 and covered with an insulating member 15, and both ends of the insulating substrate 11. Electrodes 12 (A1) and 12 (A2), a heating element extraction electrode 16 laminated on the insulating member 15 so as to overlap the heating element 14, and both ends of the electrodes 12 (A1) and 12 (A2), respectively. And a soluble conductor 13 connected to the heating element extraction electrode 16 at the center. In addition, external terminals connected to the electrodes 12 (A1) and 12 (A2) are formed on the back surface of the insulating substrate 11.

The rectangular insulating substrate 11 is formed of an insulating member such as alumina, glass ceramics, mullite, zirconia, and the like. In addition, although the material used for printed wiring boards, such as a glass epoxy board | substrate and a phenol board | substrate, may be used, it is necessary to pay attention to the temperature at the time of fuse blowing.

The heating element 14 is a conductive member that has a relatively high resistance value and generates heat when energized, and is made of, for example, W, Mo, Ru, or the like. These alloys, compositions, or compound powders are mixed with a resin binder or the like to form a paste on the insulating substrate 11 by patterning using a screen printing technique and firing.

An insulating member 15 is disposed so as to cover the heating element 14, and a heating element extraction electrode 16 is disposed so as to face the heating element 14 through the insulating member 15. In order to efficiently transfer the heat of the heating element 14 to the fusible conductor, an insulating member 15 may be laminated between the heating element 14 and the insulating substrate 11.

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

The soluble conductor 13 is a laminated structure composed of an inner layer and an outer layer, and preferably has a high melting point metal layer 13a as an inner layer and a low melting point metal layer 13b as an outer layer. As will be described later, the low melting point metal layer 13b may be provided as the inner layer, and the high melting point metal layer 13a may be provided as the outer layer. The soluble conductor 13 may be a two-layer laminated structure of an upper layer and a lower layer, and may have a high melting point metal layer 13a as an upper layer and a low melting point metal layer 13b as a lower layer. The refractory metal layer 13a is preferably made of Ag, Cu, or a metal containing either of them as a main component, and has a high melting point that does not melt even when board mounting is performed in a reflow furnace. The low melting point metal layer 13b is preferably a metal containing Sn as a main component, and is a material generally called “Pb-free solder” (for example, M705 manufactured by Senju Metal Industry). The melting point of the low melting point metal layer 13b is not necessarily higher than the temperature of the reflow furnace, and may be melted at about 200 ° C. By laminating the high melting point metal layer 13a and the low melting point metal layer 13b, even if the reflow temperature exceeds the melting temperature of the low melting point metal layer 13b and the low melting point metal is melted, as the soluble conductor 13 It does not lead to fusing. The fusible conductor 13 may be formed by forming the low melting point metal layer 13b on the high melting point metal layer 13a by using a plating technique, or by using another known lamination technique or film forming technique. The soluble conductor 13 in which the low melting point metal layer 13b is laminated on the layer 13a can be formed. Further, when the reverse refractory metal layer 13a is used as the outer layer, it can be formed by the same film formation technique. The fusible conductor 13 is connected to the heating element lead electrode 16 and the electrodes 12 (A1) and 12 (A2) by soldering using the low melting point metal layer 13b.

In order to prevent oxidation of the outer low-melting-point metal layer 13b, the flux 17 may be applied to almost the entire surface of the soluble conductor 13.

A cover member may be placed on the insulating substrate 11 in order to protect the inside of the protective element 10 thus configured.

[How to use protection elements]
As shown in FIG. 2, the protection element 10 described above is used for a circuit in a battery pack of a lithium ion secondary battery.

For example, the protective element 10 is used by being incorporated in a battery pack 20 having a battery stack 25 composed of battery cells 21 to 24 of a total of four lithium ion secondary batteries.

The battery pack 20 includes a battery stack 25, a charge / discharge control circuit 30 that controls charging / discharging of the battery stack 25, a protection element 10 to which the present invention that cuts off charging when the battery stack 25 is abnormal, and each battery cell. A detection circuit 26 for detecting voltages 21 to 24 and a current control element 27 for controlling the operation of the protection element 10 according to the detection result of the detection circuit 26 are provided.

The battery stack 25 is a series of battery cells 21 to 24 that need to be controlled to protect against overcharge and overdischarge states, and is detachable via the positive terminal 20a and the negative terminal 20b of the battery pack 20. Are connected to the charging device 35, and a charging voltage from the charging device 35 is applied thereto. The electronic device can be operated by connecting the positive electrode terminal 20a and the negative electrode terminal 20b of the battery pack 20 charged by the charging device 35 to the electronic device operated by the battery.

The charge / 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 operations of the

current control elements

31 and 32. Is provided. The

current control elements

31 and 32 are configured by, for example, field effect transistors (hereinafter referred to as FETs), and control the gate voltage by the control unit 33 to control conduction and interruption of the current path of the battery stack 25. . The control unit 33 operates by receiving power supply from the charging device 35, and according to the detection result by the detection circuit 26, when the battery stack 25 is overdischarged or overcharged, current control is performed so as to cut off the current path. The operation of the

elements

31 and 32 is controlled.

Protective element 10 is connected, for example, on a charge / discharge current path between battery stack 25 and charge / discharge control circuit 30, and its operation is controlled by current control element 27.

The detection circuit 26 is connected to the battery cells 21 to 24, detects the voltage values of the battery cells 21 to 24, and supplies the voltage values to the control unit 33 of the charge / discharge control circuit 30. The detection circuit 26 outputs a control signal for controlling the current control element 27 when any one of the battery cells 21 to 24 becomes an overcharge voltage or an overdischarge voltage.

The current control element 27 is constituted by, for example, an FET, and when the voltage value of the battery cells 21 to 24 exceeds a predetermined overdischarge or overcharge state by a detection signal output from the detection circuit 26, the protection element 10 is operated to control the charge / discharge current path of the battery stack 25 to be cut off regardless of the switch operation of the

current control elements

31 and 32.

In the battery pack 20 having the above configuration, the configuration of the protection element 10 will be specifically described.

First, the protection element 10 to which the present invention is applied has a circuit configuration as shown in FIG. 3, for example. That is, the protective element 10 generates heat by melting the soluble conductor 13 by causing the soluble conductor 13 connected in series via the heating element lead electrode 16 and the connection point of the soluble conductor 13 to generate heat. This is a circuit configuration comprising the body 14. In the protection element 10, for example, the fusible conductor 13 is connected in series on the charge / discharge current path, and the heating element 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 and the heating element electrode 18 connected thereto are connected to P1, and the other heating element electrode 18 is connected to P2.

The protective element 10 having such a circuit configuration can surely blow the soluble conductor 13 on the current path by the heat generation of the heating element 14 while realizing the Pb-free and the low profile.

The protection element of the present invention is not limited to use in a battery pack of a lithium ion secondary battery, and can of course be applied to various uses that require interruption of a current path by an electric signal.

[Operation of protection element]
First, for comparison, a known example (Japanese Patent Laid-Open No. 2004-185960) is used as a conventional protection element, and the configuration thereof will be described.

As shown in FIG. 4, in the conventional protection element 40, a glass layer 41a is formed as a base insulating layer on a rectangular substrate 41, and a heating element 44 is laminated on the glass layer 41a. An insulating member 45 is formed so as to cover the heat generating member 44, a refractory metal layer 43a is stacked so as to face the heat generating member 44 via the insulating member 45, and a low melting point metal layer 43b is further stacked. Electrodes 42 are stacked and connected to both ends of the high melting point metal layer 43a and the low melting point metal layer 43b so as to be sandwiched between the high melting point metal layer 43a and the low melting point metal layer 43b. A flux 47 is applied on the low melting point metal layer 43b.

Thus, in the conventional protection element 40, the entire refractory metal layer 43a is formed in direct contact with the insulating member 45. In this structure, the circuit is interrupted only by the action of the low melting point metal layer 43b being melted by the heat generation of the heating element 44 and eroding the high melting point metal layer 43a. Even if the cut-off state is not complete, the heat generation is stopped because the energization of the heating element 44 is suppressed when the soluble conductor becomes high resistance. That is, there may occur a case where the circuit cannot be completely shut off.

In the protection element 10 according to the present invention as shown in FIG. 1, the high melting point metal layer 13 a and the low melting point metal layer 13 b are connected so as to straddle between the heating element extraction electrode 16 and the electrode 12. For this reason, in addition to the erosion action of the high melting point metal layer due to the melting of the low melting point metal layer 13b, it is surely soluble by the physical pull-in action due to the surface tension of the molten low melting point metal layer 13b on each connected electrode 12 The conductor 13 can be melted.

Hereinafter, the operation of the protection element 10 according to the present invention will be described.

FIG. 5 schematically shows how the fusible conductor 13 behaves by energizing the heating element 14 of the protective element 10 as shown in FIG.

FIG. 5A shows a state in which a power source is connected so that a voltage is applied between the heating element electrode 18 (P2) and the electrodes 12 (A1) and (A2), before the heating element 14 is energized, and at the beginning of energization. FIG. It is desirable to set the resistance value of the heating element 14 according to the applied voltage so that the temperature of the heat generated by the heating element 14 is higher (300 ° C. or higher) than the normal reflow temperature (˜260 ° C.).

As shown in FIG. 5B, the low melting point metal layer 13b of the outer layer of the soluble conductor 13 directly above the heating element 14 starts melting, and the molten low melting point metal diffuses into the inner high melting point metal layer 13a, A erosion phenomenon occurs, and the refractory metal layer 13a is eroded and disappears. In the circle of the broken line, the high melting point metal layer 13a disappears and is mixed with the molten low melting point metal layer 13b.

As shown in FIG. 5C, the temperature of the heating element 14 further rises, and the erosion region of the high melting point metal layer 13a due to melting of the low melting point metal layer 13b of the outer layer of the soluble conductor 13 is expanded. In this state, by adopting a metal having a high thermal conductivity as the material of the refractory metal layer 13a, the temperature including the electrode 12 becomes high, and the entire low melting point metal layer 13b is in a molten state. At this time, when the refractory metal layer 13a is completely eroded on the heating element extraction electrode 16, as shown in FIG. 5D, the low melting point metal layer 13b, that is, the solder, depends on its wettability (surface tension). The heating element extraction electrode 16 and the two electrodes 12 (A1) and 12 (A2) are attracted to each other. As a result, the electrodes are cut off.

[Modification 1]
As shown in FIG. 6, the protection element 50 according to one modification of the present invention includes an insulating substrate 11, a heating element 14 stacked on the insulating substrate 11 and covered with an insulating member 15, and both ends of the insulating substrate 11. The formed electrodes 12 (A1) and 12 (A2), the heating element extraction electrode 16 laminated on the insulating member 15 so as to overlap the heating element 14, and both ends of the electrodes 12 (A1) and 12 (A2) And a fusible conductor 13 having a central portion connected to the heating element extraction electrode 16. In addition, external terminals connected to the electrodes 12 (A1) and 12 (A2) are formed on the back surface of the insulating substrate 11.

In the case of a soluble conductor using a general high melting point solder (Pb-containing solder), since the thermal conductivity is low, the electrodes at both ends of the protective element do not reach the melting temperature in a short time. On the other hand, in the case of a soluble conductor having a refractory metal layer made of a metal mainly composed of Ag or Cu or one of them, like the protective element according to the present invention, the thermal conductivity is low. Since it is high, in order to reach the melting temperature of the sufficiently low melting point metal layer also at the electrode portions at both ends of the protective element, it becomes possible to obtain more stable fusing characteristics by providing the solder pool portion described below. .

The soluble conductor 13 is a laminated structure composed of an inner layer and an outer layer, and preferably has a high melting point metal layer 13a as an inner layer and a low melting point metal layer 13b as an outer layer. Or you may make it have the low melting metal layer 13b as an inner layer, and the high melting metal layer 13a as an outer layer. The refractory metal layer 13a is preferably made of Ag, Cu, or a metal containing either of them as a main component, and has a high melting point that does not melt even when board mounting is performed in a reflow furnace. The low melting point metal layer 13b is preferably a metal containing Sn as a main component, and is a material generally called “Pb-free solder” (for example, M705 manufactured by Senju Metal Industry). The melting point is not necessarily higher than the temperature of the reflow furnace, and may be melted at about 200 ° C. The fusible conductor 13 may be formed by depositing the low melting point metal layer 13b on the high melting point metal layer 13a by using a plating technique, or by using another well-known lamination technique or film forming technique. The low melting point metal layer 13b may be stacked on the metal layer 13a. Further, when the reverse refractory metal layer 13a is used as the outer layer, it can be formed by the same film formation technique.

Here, at both ends of the fusible conductor 13, solder reservoirs 51 made of the same material as that of the low melting point metal layer 13b are provided at portions connected to the electrodes 12 (A1) and 12 (A2). During the operation of the protective element, the low melting point metal layer 13b including the pool portion 51 is in a molten state. Since the erosion of the refractory metal layer 13a occurs in the entire soluble conductor 13, the melted soluble conductor 13 is easily attracted to the

respective reservoir portions

51 and 51 on the electrodes 12 (A1) and 12 (A2) side. Therefore, the soluble conductor can be blown out more reliably.

[Modification 2]
As shown in FIG. 7, the protection element 60 includes an insulating substrate 11, a heating element 14 laminated on the insulating substrate 11 and covered with an insulating member 15, and electrodes 12 (A1) formed on both ends of the insulating substrate 11. , 12 (A2), a heating element extraction electrode 16 laminated on the insulating member 15 so as to overlap the heating element 14, and both ends thereof are connected to the electrodes 12 (A1) and 12 (A2), and the central portion generates heat. A soluble conductor 13 connected to the body extraction electrode 16. In addition, external terminals connected to the electrodes 12 (A1) and 12 (A2) are formed on the back surface of the insulating substrate 11.

The soluble conductor 13 is a laminated structure composed of an inner layer and an outer layer, and preferably has a high melting point metal layer 13a as an inner layer and a low melting point metal layer 13b as an outer layer. As in the above-described modification, the

reservoir portions

51 and 51 may be provided at both ends of the soluble conductor 13.

In this modification, a large number of openings 61 are provided in the refractory metal layer 13a, and the low melting point metal layer 13b is formed on the refractory metal layer 13a having a large number of openings using, for example, a plating technique. As a result, the area of the refractory metal layer 13a in contact with the molten low melting point metal layer 13b increases, so that the low melting point metal layer 13b can erode the refractory metal layer 13a in a shorter time. Therefore, the soluble conductor can be blown out more quickly and reliably.

[Modification 3]
FIG. 8 shows a modification in the case where the above-described structure of the soluble conductor 13 is used.

As shown in FIG. 8, the protection element 70 includes an insulating substrate 11, a heating element 14 stacked on the insulating substrate 11 and covered with an insulating member 15, and electrodes 12 (A1) formed on both ends of the insulating substrate 11. , 12 (A2), a heating element extraction electrode 16 laminated on the insulating member 15 so as to overlap the heating element 14, and both ends thereof are connected to the electrodes 12 (A1) and 12 (A2), and the central portion generates heat. A soluble conductor 13 connected to the body extraction electrode 16. In addition, external terminals connected to the electrodes 12 (A1) and 12 (A2) are formed on the back surface of the insulating substrate 11.

The soluble conductor 13 has an inner layer that is a low melting point metal layer 13b and an outer layer that is a high melting point metal layer 13a. Similarly to the above, Pb-free solder containing Sn as a main component can be used for the low melting point metal layer 13b. The high melting point metal layer 13a contains Ag, Cu, or any one of them as a main component. The metal to be used can be used. In the case of the modified example of FIG. 8, the flux 17 is soluble to prevent the melting temperature from rising due to oxidation of the surface of the soluble conductor 13 and to maintain the surface tension of the solder during exothermic melting. It is applied on the conductor 13.

As in the case of the configuration example shown in FIG. 1, the inner high-melting point metal layer 13a can be formed by applying a plating technique or the like to the inner low-melting point metal layer 13b. The molten conductor 13 can be formed.

FIG. 9 conceptually shows the operation of the configuration example shown in FIG.

In FIG. 9A, a power source is connected so that a voltage is applied between the heating element electrode 18 (P2) and the electrodes 12 (A1) and (A2), and before the heating element 14 is energized and at the beginning of energization. Show the state.

As shown in FIG. 9B, the low melting point metal layer 13b of the inner layer of the soluble conductor 13 immediately above the heating element 14 starts melting, and the low melting point metal diffuses into the outer high melting point metal layer 13a due to the corrosion phenomenon. To do. Therefore, the outer high-melting point metal layer 13a is eroded and disappears, and the inner low-melting point metal layer 13b starts to be exposed. The low melting point metal layer 13b is exposed in the solid circle in the figure, and the other part is the outer high melting point metal layer 13a.

As shown in FIG. 9C, the temperature of the heating element 14 further rises, the melting of the low melting point metal layer 13b of the soluble conductor 13 proceeds, and the erosion area of the high melting point metal layer 13a expands. In this state, since the entire low melting point metal layer 13b is in a molten state, when the high melting point metal layer 13a is completely eroded on the heating element extraction electrode 16, as shown in FIG. 13b, that is, the solder is attracted to the heating element extraction electrode 16 and each of the two electrodes 12 (A1) and 12 (A2) by the wettability (surface tension). As a result, the electrodes are interrupted.

The soluble conductor 13 may be a rectangular soluble conductor 13 as shown in FIG. 10A, or a round wire-like soluble conductor as shown in FIG. 10B. In FIG. 10, the low melting point metal layer 13b is used as the inner layer and the high melting point metal layer 13a is used as the outer layer, but the inner layer and the outer layer may be reversed.

Further, even when the low melting point metal layer 13b is used as the inner layer and the high melting point metal layer 13a is used as the outer layer, the electrodes 12 (A1) and 12 (A2) are maintained while maintaining the thickness of the soluble conductor 13. You may make it provide the pool part which consists of the low melting metal layer 13b thicker than the low melting metal layer 13b of the soluble conductor 13 on it.

[Modification 4]
FIG. 11 shows a modification in the case where the structure of the soluble conductor 13 is changed.

As shown in FIG. 11, the protection element 80 includes an insulating substrate 11, a heating element 14 laminated on the insulating substrate 11 and covered with an insulating member 15, and electrodes 12 (A1) formed on both ends of the insulating substrate 11. , 12 (A2), a heating element extraction electrode 16 laminated on the insulating member 15 so as to overlap the heating element 14, and both ends thereof are connected to the electrodes 12 (A1) and 12 (A2), and the central portion generates heat. A soluble conductor 13 connected to the body extraction electrode 16. In addition, external terminals connected to the electrodes 12 (A1) and 12 (A2) are formed on the back surface of the insulating substrate 11.

The soluble conductor 13 has a two-layer structure in which the lower layer is a low melting point metal layer 13b and the upper layer is a high melting point metal layer 13a. Similarly to the above, Pb-free solder containing Sn as a main component can be used for the low melting point metal layer 13b. The high melting point metal layer 13a contains Ag, Cu, or any one of them as a main component. The metal to be used can be used.

In the case of the modification of FIG. 11, in order to improve the fusing characteristics by suppressing the erosion of the electrode itself by the low melting point metal layer 13b, the external terminal connected to the electrode 12, the heating element and the heating element The surface of the extraction electrode 16 is plated to form a Ni / Au plating layer 52. A known plating process such as Ni / Pd plating or Ni / Pd / Au plating can be used instead of Ni / Au plating.

[Modification 5]
FIG. 12A and FIG. 12B are modifications in the case where the configuration of the soluble conductor is further changed.

The soluble conductor 91 of the protective element 90 shown in FIG. 12 is a laminated structure composed of an inner layer and an outer layer, and has a low melting point metal layer 91b as an inner layer and a refractory metal layer 91a as an outer layer. And as for the soluble conductor 91 of the protection element 90, the whole surface of the low melting metal layer 91b is coat | covered with the high melting metal layer 91a.

Such a soluble conductor 91 is formed by, for example, laminating a sheet of Pb-free solder containing Sn as a main component on a sheet of a high melting point metal such as Ag, or applying a paste of Pb-free solder containing Sn as a main component, Furthermore, it can be formed by laminating refractory metal sheets and performing hot pressing. The soluble conductor 91 can be formed by applying Ag plating to the entire surface of the sheet-like Pb-free solder.

The soluble conductor 91 is connected to the electrode 12 and the heating element extraction electrode 16 via a low melting point metal 92 such as Pb-free solder. In addition, the flux 17 is applied to almost the entire upper surface of the soluble conductor 91. The electrode 12 and the heating element extraction electrode 16 have a Ni / Pd / Au plating layer 93 formed on the surface in order to suppress the erosion of the electrode itself and improve the fusing characteristics.

By using the soluble conductor 91 in which the entire surface of the inner low melting point metal layer 91b is covered with the outer high melting point metal layer 91a, the protective element 90 uses the low melting point metal layer 13b having a melting point lower than the reflow temperature. Even in this case, it is possible to suppress the outflow of the inner low-melting-point metal layer 91b to the outside during reflow mounting. Therefore, in the protection element 90, the low melting point metal layer 91b erodes the high melting point metal layer 91a in a shorter time by the heat of the heating element 14, and the soluble conductor 91 can be blown out quickly and reliably.

Also, the protective element 90 can suppress deformation of the soluble conductor 91 by suppressing the outflow of the inner low melting point metal layer 91b during reflow mounting.

[Modification 6]
FIG. 13A and FIG. 13B are modified examples when the connection configuration of the fusible conductor 91 shown in FIG. 12 and the electrode 12 and the heating element extraction electrode 16 is changed.

The protective element 100 shown in FIG. 13 connects the soluble conductor 91, the electrode 12 and the heating element extraction electrode 16 with a conductive paste 95. As the conductive paste 95, a metal nano paste such as a silver nano paste is preferably used. Silver nanopaste forms a refractory metal film at a firing temperature of 200 ° C. or higher, that is, at a reflow temperature. Further, the fired film of silver nanopaste has conductivity and thermal conductivity that are inferior to bulk silver by about 50%.

Since the protective element 100 connects the soluble conductor 91 using the conductive paste 95 made of such a metal nanopaste, the conductive paste 95 is baked during reflow mounting to form a metal film. The corrosion of the refractory metal layer 91a constituting the outer layer of the conductor 91 can be suppressed. That is, when the fusible conductor 91 is connected by a low melting point metal such as solder, the outer refractory metal layer 91a is melted during reflow mounting and the outer refractory metal layer 91a is eroded. There was a need to form. However, if the refractory metal layer 91a is formed thick, it takes a long time to melt the soluble conductor 91.

On the other hand, in the protective element 100, the soluble conductor 91 is connected using the conductive paste 95 made of metal nanopaste, so that the refractory metal layer 91a as an outer layer is not corroded, and the refractory metal layer 91a is formed. It can be formed thin. Therefore, the protection element 100 can surely melt the soluble conductor 91 in a short time by the corrosion caused by the low melting point metal layer 91b as the inner layer.

In addition to using the soluble conductor 91 in which the entire surface of the inner low-melting-point metal layer 91b shown in FIG. 12 is covered with the high-melting-point metal layer 91a as the soluble conductor, the protective element 100 is shown in FIG. It is also possible to use a soluble conductor 13 in which high-melting-point metal layers 13a are stacked above and below an inner-layer low-melting-point metal layer 13b, which is not completely covered.

[Modification 7]
FIG. 14A and FIG. 14B are modified examples when the connection configuration of the soluble conductor 13 shown in FIG. 8 and the electrode 12 and the heating element extraction electrode 16 is changed.

The protection element 110 shown in FIG. 14 connects the fusible conductor 13 to the electrode 12 and the heating element extraction electrode 16 by welding such as ultrasonic waves. As shown in FIG. 8, the fusible conductor 13 has a high melting point metal layer 13a laminated on and under an inner low melting point metal layer 13b and is not completely covered.

In the protective element 110, it is preferable that an Ag plating layer is formed as the refractory metal layer 13a of the soluble conductor 13, and a Ni / Pd / Au plating layer 93 is formed on the surface of the electrode 12 or the heating element extraction electrode 16. . Since Ag and Ag and Au are excellent in adhesion by welding, the protective element 110 can reliably connect the soluble conductor 13 to the electrode 12 and the heating element extraction electrode 16. Further, since the protective element 110 connects the soluble conductor 13 to the electrode 12 and the heating element extraction electrode 16 by welding, the refractory metal layer 13a of the soluble conductor 13 may be eroded even by reflow mounting. As compared with the case where the soluble conductor 13 is connected by a low melting point metal such as solder, the high melting point metal layer 13a can be formed thinner. Therefore, the protection element 110 can surely melt the soluble conductor 13 in a short time by the corrosion by the inner low melting point metal layer 13b.

The protective element 110 uses, as a soluble conductor, a soluble conductor 13 in which a high melting point metal layer 13a is laminated above and below an inner low melting point metal layer 13b shown in FIG. 14 and is not completely covered. Alternatively, the soluble conductor 91 in which the entire surface of the inner low melting point metal layer 91b shown in FIG. 12 is covered with the high melting point metal layer 91a may be used.

[Modification 8]
FIG. 15 shows a modification in which the configuration of the soluble conductor is further changed.

The soluble conductor 121 of the protection element 120 shown in FIG. 15 has the entire surface of the inner low-melting-point metal layer 121b covered with the high-melting-point metal layer 121a, and the entire surface of the high-melting-point metal layer 121a is covered with the second low-melting-point metal layer. 121c is covered. The fusible conductor 121 is formed by coating the outer high-melting-point metal layer 121a with the second low-melting-point metal layer 121c, for example, even when a Cu plating layer is formed as the high-melting-point metal layer 121a. Can be prevented. Therefore, the soluble conductor 121 can prevent a situation where the fusing time is prolonged due to oxidation of Cu, and can be fused in a short time.

Further, the soluble conductor 121 can be made of an inexpensive but easily oxidized metal such as Cu as the high melting point metal layer 121a, and can be formed without using an expensive material such as Ag.

The second low melting point metal layer 121c can be made of the same material as the inner low melting point metal layer 121b, for example, Pb-free solder containing Sn as a main component. The second low melting point metal layer 121c can be formed by performing tin plating on the surface of the high melting point metal layer 121a.

The soluble conductor 121 may have the entire surface of the inner low-melting-point metal layer 121b covered with the high-melting-point metal layer 121a, or the high-melting-point metal layer 121a is laminated on the upper and lower sides of the inner-layer low-melting-point metal layer 121b. And may not be completely coated. Similarly, in the soluble conductor 121, the entire surface of the refractory metal layer 121a may be covered with the second low melting point metal layer 121c, or the second low melting point metal layer above and below the refractory metal layer 121a. 121c may be laminated and not completely covered.

[Modification 9]
Further, the soluble conductor 13 of the protective element to which the present invention is applied has a covering structure in which the inner layer is a low melting point metal layer 13b and the outer layer is a high melting point metal layer 13a. The layer thickness ratio may be low melting point metal layer: high melting point metal layer = 2.1: 1 to 100: 1. Thereby, the volume of the low melting point metal layer 13b can be surely made larger than the volume of the high melting point metal layer 13a, and the fusing of the high melting point metal layer 13a can be effectively performed in a short time. it can.

That is, since the high melting point metal layer 13a is laminated on the upper and lower surfaces of the low melting point metal layer 13b constituting the inner layer, the soluble conductor has a layer thickness ratio of low melting point metal layer: high melting point metal layer = 2.1. The volume of the low melting point metal layer 13b can be made larger than the volume of the high melting point metal layer 13a as the low melting point metal layer 13b becomes thicker than 1: 1. Further, the soluble conductor has a layer thickness ratio exceeding the low melting point metal layer: high melting point metal layer = 100: 1, the low melting point metal layer 13b is thick, and the high melting point metal layer 13a is thin, the high melting point metal layer 13a. However, there is a possibility that the low melting point metal layer 13b melted by heat during reflow mounting may be eroded.

The range of the layer thickness ratio is prepared by preparing samples of a plurality of soluble conductors having different layer thickness ratios, mounting them on the electrode 12 and the heating element extraction electrode 16 via solder paste, and then putting them in a reflow furnace. It was observed whether the soluble conductor was blown. As a result, if the layer thickness ratio is in the range of low melting point metal layer: high melting point metal layer = 2.1: 1 to 100: 1, it does not melt during reflow mounting, and heating by the heating element 14 is performed. As a result, it was confirmed that the low melting point metal layer 13b can be melted quickly with the corrosion of the high melting point metal layer 13a.

In the soluble conductor 91 in which the entire surface of the inner low-melting-point metal layer 91b is covered with the high-melting-point metal layer 91a, the layer thickness ratio between the same low-melting-point metal layer and the high-melting-point metal layer as in the soluble conductor 13 It is good. By setting the layer thickness ratio, even when the fusible conductor 91 is used, the volume of the low melting point metal layer 13b can be made larger than the volume of the high melting point metal layer 13a. Fusing in a short time by the corrosion of 13a can be performed.

[Modification 10]
FIG. 16 shows a modification in the case where a heat generating element 14 with a different arrangement position is used. As shown in FIG. 16, the protection element 130 includes an insulating substrate 11, a heating element 14 built in the insulating substrate 11, electrodes 12 (A1) and 12 (A2) formed on both ends of the insulating substrate 11, A heating element extraction electrode 16 laminated on the insulating substrate 11 so as to overlap with the heating element 14, both ends are connected to the electrodes 12 (A 1) and 12 (A 2), and a central part is connected to the heating element extraction electrode 16. The soluble conductor 13 is provided. The protective element 130 has the same configuration as the protective element 80 described above except that the heating element 14 is built in the insulating substrate 11 and the insulating member 15 is not provided.

The insulating substrate 11 has an external terminal 131 connected to the electrodes 12 (A1) and 12 (A2) on the back surface 11b. The protective element 130 is provided with a cover member 132 that protects the surface of the insulating substrate 11.

The soluble conductor 13 has a two-layer structure in which a high melting point metal layer 13a is provided in the upper layer and a low melting point metal layer 13b is provided in the lower layer, and the electrode 12 (A1) provided with the Ni / Au plating layer 52, respectively. , 12 (A2) and the heating element extraction electrode 16 are connected via the low melting point metal layer 13b. Moreover, the flux 17 is apply | coated to the soluble conductor 13 on the surface of the high melting-point metal layer 13a.

In the protection element 130, the heating element 14 is built in the insulating substrate 11, whereby the surface 11a of the insulating substrate 11 is flattened, whereby the heating element lead-out electrode 16 is connected to the electrodes 12 (A1) and 12 (A2). Can be formed on the same plane. The protective element 130 can connect the flattened soluble conductor 13 by setting the heating element extraction electrode 16 to the same height as the electrodes 12 (A1) and 12 (A2). Therefore, the protection element 130 can improve the fusing characteristics of the soluble conductor 13.

In addition, the protective element 130 uses a material having excellent thermal conductivity as the material of the insulating substrate 11, so that the heat generating element 14 heats the soluble conductor 13 in the same manner as when the insulating member 15 such as a glass layer is interposed. can do.

Further, the protective element 130 does not require the insulating member 15, and the conductive paste constituting the electrodes 12 (A 1), 12 (A 2) and the heating element extraction electrode 16 is applied to the surface 11 a of the flat insulating substrate 11. Thus, the electrodes 12 (A1), 12 (A2) and the heating element extraction electrode 16 can be formed in a lump, so that labor saving in the manufacturing process can be achieved.

[Modification 11]
FIG. 17 shows a modification in the case where a heat generating element 14 with a different arrangement position is used.

As shown in FIG. 17, the protection element 140 is laminated on the insulating substrate 11, the back surface 11 b of the insulating substrate 11 and covered with the insulating member 15, and the electrodes 12 formed at both ends of the insulating substrate 11. (A1), 12 (A2), the heating element extraction electrode 16 laminated on the insulating substrate 11 so as to overlap the heating element 14, and both ends are connected to the electrodes 12 (A1), 12 (A2), and the center And a soluble conductor 13 connected to the heating element extraction electrode 16. The protective element 140 has the same configuration as the protective element 80 described above except that the heating element 14 is laminated on the back surface 11b of the insulating substrate 11.

The insulating substrate 11 has an external terminal 131 connected to the electrodes 12 (A1) and 12 (A2) on the back surface 11b. The protective element 140 is provided with a cover member 132 that protects the surface of the insulating substrate 11.

In the protection element 140, the heating element 14 is laminated on the back surface 11b of the insulating substrate 11, so that the surface 11a of the insulating substrate 11 is flattened, whereby the heating element extraction electrode 16 is connected to the electrodes 12 (A1), 12 It can be formed on the same plane as (A2). And the protection element 100 can connect the soluble conductor 13 planarized by making the heat generating body extraction electrode 16 the same height as the electrodes 12 (A1) and 12 (A2). Therefore, the protection element 100 can improve the fusing characteristics of the soluble conductor 13.

In addition, the protective element 140 uses a material having excellent thermal conductivity as the material of the insulating substrate 11, so that the heating element 14 heats the soluble conductor 13 by the heating element 14 in the same manner as when laminated on the surface 11 a of the insulating substrate 11. can do.

Further, the protective element 140 is formed by applying the conductive paste constituting the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16 to the surface 11a of the flat insulating substrate 11 to thereby form the electrodes 12 (A1) and 12 Since (A2) and the heating element extraction electrode 16 can be formed in a lump, labor saving in the manufacturing process can be achieved.

[Modification 12]
FIG. 18 shows a modification in the case where a heat generating element 14 with a different arrangement position is used.

As shown in FIG. 18, the protection element 150 includes an insulating substrate 11, a heating element 14 laminated on the surface 11 a of the insulating substrate 11 and covered with the insulating member 15, and a heating element on the surface 11 a of the insulating substrate 11. 14 is laminated between the electrodes 12 (A 1) and 12 (A 2) formed adjacent to the electrode 14 and the electrodes 12 (A 1) and 12 (A 2) on the surface 11 a of the insulating substrate 11. A connected heating element extraction electrode 16 and a soluble conductor 13 whose both ends are connected to the electrodes 12 (A1) and 12 (A2) and whose central part is connected to the heating element extraction electrode 16 are provided. The protection element 150 has the same configuration as the protection element 80 described above except that the heating element 14 is laminated on the surface 11a of the insulating substrate 11.

The insulating substrate 11 has an external terminal 131 connected to the electrodes 12 (A1) and 12 (A2) on the back surface 11b. The protection element 150 is provided with a cover member 132 that protects the surface of the insulating substrate 11.

In the protection element 150, the heating element 14 is laminated on the surface 11 a of the insulating substrate 11 adjacent to the electrode 12 (A 1), so that the surface 11 a of the insulating substrate 11 is flattened. The electrode 16 can be formed on the same plane as the electrodes 12 (A1) and 12 (A2). And the protection element 150 can connect the soluble conductor 13 planarized by making the heat generating body extraction electrode 16 the same height as the electrodes 12 (A1) and 12 (A2). Therefore, the protective element 150 can improve the fusing characteristics of the soluble conductor 13.

In addition, the protection element 150 can efficiently transfer the heat generated to the soluble conductor 13 by laminating the heating element 14 adjacent to the electrode 12 (A1), and the heating element 14 can be transmitted via the insulating member 15. The soluble conductor 13 can be heated in the same manner as when the heating element 14 and the heating element extraction electrode 16 are overlapped.

Furthermore, the protective element 150 applies the conductive paste constituting the electrodes 12 (A 1) and 12 (A 2), the heating element 14 and the heating element extraction electrode 16 to the surface 11 a of the flat insulating substrate 11, whereby the electrode 12 ( Since A1), 12 (A2), the heating element 14 and the heating element extraction electrode 16 can be formed in a lump, labor saving in the manufacturing process can be achieved. Further, since the heating element 14 is formed on the surface 11a of the insulating substrate 11 and is not overlapped with the heating element extraction electrode 16, the protective element 110 is downsized by reducing the height of the insulating substrate 11 in the thickness direction. be able to.

[Modification 13]
FIG. 19 shows a case where a heating element is used instead of a configuration in which a heating paste 14 is formed by applying and baking a conductive paste, and this is adjacent to the vicinity of electrodes 12 (A1) and 12 (A2). It is a modified example of.

As shown in FIG. 19, the protection element 160 is formed adjacent to the insulating substrate 11, the heating element 161 mounted on the surface 11 a of the insulating substrate 11, and the heating element 161 on the surface 11 a of the insulating substrate 11. The heating element extraction electrode laminated between the electrodes 12 (A1) and 12 (A2) and the electrodes 12 (A1) and 12 (A2) on the surface 11a of the insulating substrate 11 and electrically connected to the heating element 161 16 and a soluble conductor 13 having both ends connected to the electrodes 12 (A 1) and 12 (A 2) and a central portion connected to the heating element extraction electrode 16. The protection element 160 is connected to the heating element lead electrode 16 laminated on the surface 11 a of the insulating substrate 11 in place of the heating element 14, except that the protection element 160 is connected to the heating element electrode 162. The configuration is the same as that of the protection element 80 described above. The heat generating element 161 is mounted on a land portion 163 formed on the surface 11 a of the insulating substrate 11.

The protection element 160 is connected to the heating element electrode 162 and the current control element 27 described above, and when an abnormal voltage is detected in any of the battery cells 21 to 24, the heating element 161 is operated to charge / discharge the battery stack 25. Shut off.

Also in this protective element 160, the heating element 161 is laminated on the surface 11a of the insulating substrate 11 adjacent to the electrode 12 (A1), so that the surface 11a of the insulating substrate 11 is flattened. The extraction electrode 16 can be formed on the same plane as the electrodes 12 (A1) and 12 (A2). The protective element 160 can connect the flattened soluble conductor 13 by setting the heating element extraction electrode 16 to the same height as the electrodes 12 (A1) and 12 (A2). Therefore, the protection element 160 can improve the fusing characteristics of the soluble conductor 13.

In addition, the protection element 160 can efficiently transmit the generated heat to the soluble conductor 13 by mounting the heating element 161 adjacent to the electrodes 12 (A1) and 12 (A2), and the insulating member 15 It is possible to heat the soluble conductor 13 in the same manner as when the heating element 14 and the heating element extraction electrode 16 are overlapped with each other.

Further, the protective element 160 is formed by applying the conductive paste constituting the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16 to the surface 11a of the flat insulating substrate 11 to thereby form the electrodes 12 (A1) and 12 Since (A2) and the heating element extraction electrode 16 can be formed in a lump, labor saving in the manufacturing process can be achieved. Further, since the protection element 160 is not formed by superimposing the heating element 14 on the surface 11a of the insulating substrate 11 with the heating element extraction electrode 16, the protection element 160 can be reduced in size by reducing the thickness of the insulating substrate 11 in the thickness direction. Can be planned.

Further, as the protection element 160, various elements can be selected and mounted as the heating element 161, and an element that generates heat at a high temperature suitable for fusing the soluble conductor 13 can be used.

[Modification 14]
20 to 22 are modified examples of the protection element in which the structure of the soluble conductor is changed.

20A and 20B uses a soluble conductor 173 having a three-layer structure in which a high melting point metal layer 172 is formed as an outer layer on both surfaces of a low melting point metal layer 171 as an inner layer. In the fusible conductor 173, a linear opening 172a is formed along the longitudinal direction in the high melting point metal layer 172 constituting the outer layer, and the low melting point metal layer 171 is exposed from the opening 172a. The fusible conductor 173 exposes the low melting point metal layer 171 from the opening 172a, thereby increasing the contact area between the molten low melting point metal and the high melting point metal layer 172, and further promoting the erosion action of the high melting point metal layer 172. The fusing property can be improved. The opening 172a of the refractory metal layer 172 can be formed, for example, by subjecting the low melting point metal layer 171 to partial plating of the metal constituting the refractory metal layer 172.

The protective element 170 has the same configuration as the protective element 10 described above except that the soluble conductor 173 is used instead of the soluble conductor 13. The fusible conductor 173 is connected to the electrodes 12 (A1) and 12 (A2) provided with the Ni / Au plating layer 52 and the heating element extraction electrode 16 via a low melting point metal 134 such as solder. . Further, the flux 17 is applied to the soluble conductor 173 on the surface of the refractory metal layer 172. The refractory metal layer 172 can be formed using the same material as the refractory metal layer 13a described above, and the low melting metal layer 171 is formed using the same material as the refractory metal layer 13b described above. be able to.

Further, the soluble conductor 173 may use solder as a metal constituting the low melting point metal layer 171 and may form a film containing Au or Au as a main component on the surface of the high melting point metal layer 172. Thereby, the soluble conductor 173 can further improve the wettability of the solder which comprises the low melting-point metal layer 171, and can promote an erosion effect | action.

21A and 21B uses a soluble conductor 183 having a three-layer structure in which a high melting point metal layer 182 is formed as an outer layer on both surfaces of a low melting point metal layer 181 as an inner layer. In the soluble conductor 183, a circular opening 182a is formed over the entire surface of the high melting point metal layer 182 constituting the outer layer, and the low melting point metal layer 181 is exposed from the opening 182a.

Other configurations of the protective element 180 are the same as those of the protective element 170 described above. The opening 182a of the refractory metal layer 182 can be formed, for example, by subjecting the low melting point metal layer 181 to partial plating of a metal constituting the refractory metal layer 182.

The soluble conductor 183 exposes the low melting point metal layer 181 from the opening 182a, thereby increasing the contact area between the molten low melting point metal and the high melting point metal layer 182 and further promoting the erosion action of the high melting point metal layer 182. The fusing property can be improved.

Also in the soluble conductor 183, solder may be used as a metal constituting the low melting point metal layer 181, and a film containing Au or Au as a main component may be formed on the surface of the high melting point metal layer 182. Thereby, the soluble conductor 183 can further improve the wettability of the solder constituting the low melting point metal layer 181 and promote the erosion action.

22A and 22B uses a soluble conductor 193 having a three-layer structure in which a high melting point metal layer 192 is formed as an outer layer on both surfaces of a low melting point metal layer 191 serving as an inner layer. In the fusible conductor 193, a plurality of linear openings 192a extending in the width direction are formed in the refractory metal layer 192 constituting the outer layer in the longitudinal direction, and the low melting point metal layer 191 is exposed from the openings 192a. .

Other configurations of the protection element 190 are the same as those of the protection element 170 described above. The opening 192a of the refractory metal layer 192 can be formed, for example, by subjecting the low melting point metal layer 191 to partial plating of a metal constituting the refractory metal layer 192.

The fusible conductor 193 exposes the low melting point metal layer 191 from the opening 192a, thereby increasing the contact area between the molten low melting point metal and the high melting point metal layer 192 and further promoting the erosion action of the high melting point metal layer. The fusing property can be improved.

Also in the soluble conductor 193, solder may be used as the metal constituting the low melting point metal layer 191, and Au or a film containing Au as a main component may be formed on the surface of the high melting point metal layer 192. Thereby, the soluble conductor 193 can further improve the wettability of the solder constituting the low melting point metal layer 191, and promote the erosion action.

[Modification 15]
FIG. 23 is a modified example of the protection element in which the configuration of the soluble conductor is changed.

23A and 23B uses a soluble conductor 203 in which a low-melting point metal layer 201 is disposed in an upper layer and a high-melting point metal layer 202 is formed in a lower layer. The fusible conductor 203 is connected to the electrodes 12 (A1) and 12 (A2) provided with the Ni / Au plating layer 52 and the heating element extraction electrode 16 via a low melting point metal 204 such as solder. Thereby, the soluble conductor 203 has a three-layer structure of the low melting point metal 204, the high melting point metal layer 202, and the low melting point metal layer 201 on the electrodes 12 (A 1) and 12 (A 2) and the heating element extraction electrode 16. .

In addition, the flux 17 is applied to the soluble conductor 203 on the surface of the low melting point metal layer 201. The protective element 200 has the same configuration as the protective element 10 described above except that the soluble conductor 203 is used instead of the soluble conductor 13. The refractory metal layer 202 can be formed using the same material as the above-described refractory metal layer 13a, and the low-melting metal layer 201 is formed using the same material as the above-described refractory metal layer 13b. Can be formed.

The protective element 200 has a three-layer structure in which a soluble conductor 203 is composed of a low melting point metal 204, a high melting point metal layer 202, and a low melting point metal layer 201 on the electrodes 12 (A 1) and 12 (A 2) and the heating element extraction electrode 16. Therefore, the molten conductor aggregates on the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16 by the erosion action of the high melting point metal layer 202 by the molten low melting point metal 204 and the low melting point metal layer 201. Can be further promoted, and the fusing property can be improved.

Further, the protective element 200 can be formed by a simple process in which the fusible conductor 203 is laminated on the surface of the low melting point metal layer 201 with the high melting point metal layer 202.

Also in the soluble conductor 203, solder may be used as the metal constituting the low melting point metal layer 201, and Au or a film mainly composed of Au may be formed on the surface of the high melting point metal layer 202. Thereby, the soluble conductor 203 can further improve the wettability of the solder which comprises the low melting-point metal layer 201, and can promote an erosion effect | action.

[Modification 16]
FIG. 24 shows a modification of the protection element in which the configuration of the soluble conductor is changed.

24A and 24B includes a first refractory metal layer 211, a first low melting point metal layer 212, a second refractory metal layer 213, and a second low melting point metal in order from the top layer. A soluble conductor 215 having a four-layer structure in which the layer 214 is laminated is used. The fusible conductor 215 is connected to the electrodes 12 (A1) and 12 (A2) provided with the Ni / Au plating layer 52 and the heating element extraction electrode 16 via the second low melting point metal layer 214, respectively. .

Note that the flux 17 is applied to the soluble conductor 215 on the surface of the first refractory metal layer 211. The protection element 210 has the same configuration as the protection element 10 described above except that the soluble conductor 215 is used instead of the soluble conductor 13. The first and second refractory metal layers 211 and 213 can be formed using the same material as the refractory metal layer 13a described above, and the first and second refractory metal layers 212 and 214 are formed. Can be formed using the same material as the low melting point metal layer 13b described above.

The protective element 210 has the electrodes 12 (A1), 12 (A2), and the electrodes 12 (A1), 12 (A2), and erosion action of the first and second refractory metal layers 211, 213 by the melted first and second low melting

point metal layers

212, 214 Aggregation of the molten conductor on the heating element extraction electrode 16 can be further promoted, and the fusing properties between the heating element extraction electrode 16 and the electrodes 12 (A1) and 12 (A2) can be improved.

In addition, by forming the second low melting point metal layer 214 as the lowermost layer, the second low melting point metal layer 214 is connected to the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16. An adhesive layer can also be used. In addition, the protection element 210 may use four or more layers as the soluble conductor as long as the high melting point metal layer and the low melting point metal layer are alternately laminated.

[Modification 17]
FIG. 25 is a modified example of the protection element in which the configuration of the soluble conductor is changed.

The protective element 220 shown in FIGS. 25A and 25B uses a single-layer soluble conductor 222 made of only the refractory metal layer 221. The fusible conductor 222 is connected to the electrodes 12 (A 1) and 12 (A 2) provided with the Ni / Au plating layer 52 and the heating element extraction electrode 16 via a low melting point metal 223 such as solder. Thereby, the soluble conductor 222 has a two-layer structure of the low melting point metal 223 and the high melting point metal layer 221 on the electrodes 12 (A 1) and 12 (A 2) and the heating element extraction electrode 16.

In addition, the flux 17 is applied to the soluble conductor 222 on the surface of the refractory metal layer 221. The protective element 220 has the same configuration as the protective element 10 described above except that the soluble conductor 222 is used instead of the soluble conductor 13. The refractory metal layer 221 can be formed using the same material as the above-described refractory metal layer 13a, and the low-melting metal 223 can be formed using the same material as the above-described low-melting metal layer 13b. can do.

The protective element 220 is melted because the fusible conductor 222 has a two-layer structure of a low melting point metal 223 and a high melting point metal layer 221 on the electrodes 12 (A1), 12 (A2) and the heating element extraction electrode 16. The erosion action of the high melting point metal layer 221 by the low melting point metal 223 further promotes the aggregation of the molten conductor on the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16 and improves the fusing property. it can. For this reason, the low melting point metal 223 is preferably formed thicker than the high melting point metal layer 221 of the soluble conductor 222.

In addition, the protective element 220 can be formed by a simple process because the soluble conductor 222 has a single-layer structure of the refractory metal layer 221.

In the soluble conductor 222, solder may be used as the metal constituting the low melting point metal 223, and a coating containing Au or Au as a main component may be formed on the surface of the high melting point metal layer 221. Thereby, the soluble conductor 222 can further improve the wettability of the solder which comprises the low melting-point metal 223, and can promote an erosion effect | action.

[Modification 18]
FIG. 26 is a modification of the protection element using a plurality of soluble conductors.

The protection element 230 shown in FIG. 26 is obtained by increasing the size of the fusible conductor 231 in order to increase the rating of the protection element 230 in a large current application. Here, when the size of the soluble conductor 231 is increased, the volume of the molten conductor at the time of melting increases, and the molten conductor aggregates between the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16 to cause fusing. It may not be possible.

Therefore, the protective element 230 is divided into a plurality of soluble conductors, and an insulating layer 232 is formed around the soluble conductor connecting portion 16a on the heating element extraction electrode 16. For example, as shown in FIG. 26, the protective element 230 is provided with first and second

soluble conductors

231a and 231b to improve the overall rating. The first and second

soluble conductors

231a and 231b are connected by a low melting point metal 233 such as solder from the electrode 12 (A1) to the electrode 12 (A2) through the heating element extraction electrode 16. The first and second

fusible conductors

231a and 231b are disposed at a predetermined distance apart.

The first and second

fusible conductors

231a and 231b have a laminated structure in which the low melting point metal layer constituting the inner layer is covered with the high melting point metal layer constituting the outer layer, as shown in FIG. The electrodes 12 (A 1) and 12 (A 2) and the heating element extraction electrode 16 are connected via the melting point metal 233. The first and second

fusible conductors

231a and 231b have a laminated structure in which a low melting point metal layer and a high melting point metal layer are laminated, and the electrode 12 (A1) is interposed via the low melting point metal layer constituting the lower layer. , 12 (A2) and the heating element extraction electrode 16 may be connected. The first and second

fusible conductors

231a and 231b have a single-layer structure having only a high melting point metal layer, and the electrodes 12 (A1) and 12 (A2) and the heating element lead electrode 16 are interposed through the low melting point metal 233. You may connect to the top. The first and second

fusible conductors

231a and 231b may have a configuration in which an opening is provided in the high melting point metal layer constituting the outer layer and the low melting point metal layer constituting the inner layer is exposed to the outside.

Further, in the protective element 230, an insulating layer 232 is formed in a region between the first and second

soluble conductors

231a and 231b on the heating element extraction electrode 16. The insulating layer 232 prevents the volume of the molten conductor from increasing due to the fusion between the melted first and second

soluble conductors

231a and 231b, and is formed by a known method using a known insulating material. Is done.

The fusible conductor 231 is coated with a flux (not shown) on the surface. Further, the protective element 230 uses a plurality of fusible conductors 231 instead of the fusible conductor 13 and a point that an insulating layer 232 is formed around the fusible conductor connecting portion 16a of the heating element extraction electrode 16. Thus, it has the same configuration as the protection element 10 described above. Further, the soluble conductor 231 can be formed as the refractory metal layer using the same material as the above-described refractory metal layer 13a, and the low-melting metal layer is the same as the refractory metal layer 13b described above. It can be formed using a material.

As shown in FIG. 27, the protective element 230 allows the molten conductor to be coupled by the insulating layer 232 along the heating element extraction electrode 16 even when the first and second

soluble conductors

231a and 231b are melted. Is prevented. Therefore, even when the protection element 230 increases the volume of the soluble conductor 231 to improve the rating, the molten conductor is drawn to one side along the heating element extraction electrode 16, and the electrodes 12 (A1), 12 (A2) and the heating element lead-out electrode 16 are aggregated between each other, so that a situation where the fusion cannot be performed can be prevented and the fusion can be surely performed.

In addition, the protective element 230 may provide the insulating layer 232 also around the soluble conductor connection part of the electrodes 12 (A1) and 12 (A2). As a result, the protection element 230 causes the molten conductor to be drawn to one side through the electrodes 12 (A1) and 12 (A2), and aggregates between the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16. In addition, it is possible to prevent a situation where fusing is not possible.

Note that when the fusible conductor 231 also has a structure in which a low melting point metal layer and a high melting point metal layer are laminated, solder is used as the metal constituting the low melting point metal, and Au or You may form the film | membrane which has Au as a main component. Thereby, the soluble conductor 231 can further improve the wettability of the solder constituting the low melting point metal and promote the erosion action.

Furthermore, as shown in FIG. 26, the protection element 230 may form an insulating layer 235 over the longitudinal direction of the electrodes 12 (A1) and 12 (A2). The insulating layer 235 prevents the molten conductor from aggregating to the external electrode beyond the electrodes 12 (A1) and 12 (A2), and the insulating conductor 235 of the soluble conductor 231 of the electrodes 12 (A1) and 12 (A2). It is formed outside the connection area. By providing the insulating layer 235, as shown in FIG. 27, in the protection element 230, the molten conductor does not aggregate on the electrodes 12 (A1) and 12 (A2) and does not flow to the external electrodes.

[Modification 19]
FIG. 28 is a modification of the protection element using a plurality of soluble conductors.

28, like the protection element 230 described above, the soluble conductor 241 is enlarged in order to increase the rating of the protection element 240 in a large current application.

The protective element 240 is divided into a plurality of fusible conductors, and the periphery of the fusible conductor connecting portion 16a on the heating element lead-out electrode 16 is narrower than the fusible conductor connecting portion 16a. Have For example, as shown in FIG. 28, the protection element 240 is provided with first and second

soluble conductors

241a and 241b to improve the overall rating. The first and second

soluble conductors

241a and 241b are connected by a low melting point metal 243 such as solder from the electrode 12 (A1) to the electrode 12 (A2) through the heating element extraction electrode 16. The first and second

fusible conductors

241a and 241b are disposed with a predetermined distance therebetween.

The first and second

fusible conductors

241a and 241b have a laminated structure in which the low melting point metal layer constituting the inner layer is covered with the high melting point metal layer constituting the outer layer, as shown in FIG. The electrodes 12 (A 1) and 12 (A 2) and the heating element extraction electrode 16 are connected via the melting point metal 243. The first and second

fusible conductors

241a and 241b have a laminated structure in which a low melting point metal layer and a high melting point metal layer are laminated, and the electrode 12 (A1) is interposed via the low melting point metal layer constituting the lower layer. , 12 (A2) and the heating element extraction electrode 16 may be connected. The first and second

fusible conductors

241a and 241b have a single-layer structure having only a high melting point metal layer, and are formed on the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16 through the low melting point metal. You may connect to. The first and second

fusible conductors

241a and 241b may have a structure in which an opening is provided in the high melting point metal layer constituting the outer layer and the low melting point metal layer constituting the inner layer faces outward.

The protective element 240 has a narrow portion 242 narrower than the soluble conductor connecting portion 16a in the region between the first and second

soluble conductors

241a and 241b on the heating element extraction electrode 16. The narrow portion 242 prevents the volume of the molten conductor from increasing due to the fusion between the melted first and second

soluble conductors

241a and 241b, and prints the heating element extraction electrode 16 in a predetermined pattern. It is formed by firing. The narrow portion 242 may be formed by providing an insulating layer on the heating element extraction electrode 16.

The fusible conductor 241 is coated with a flux (not shown) on the surface. Further, the protection element 240 has a point that a plurality of soluble conductors 241 are used instead of the soluble conductor 13 and that a narrow portion 242 is formed around the soluble conductor connecting portion 16a of the heating element extraction electrode 16. Except for this, it has the same configuration as the protection element 10 described above. In addition, the soluble conductor 241 can be formed as the refractory metal layer using the same material as the above-described refractory metal layer 13a, and the low-melting metal layer is the same as the refractory metal layer 13b described above. It can be formed using a material.

As shown in FIG. 29, when the first and second

soluble conductors

241a and 241b are melted, the protective element 240 does not flow into the narrow portion 242 but aggregates into the wide soluble conductor connection portion 16a. As a result, the molten conductor is prevented from being bonded through the heating element extraction electrode 16. Therefore, even when the protective element 240 has its rating increased by increasing the volume of the soluble conductor 241, the molten conductor is drawn to one side through the heating element extraction electrode 16, and the electrodes 12 (A1), 12 (A2) and the heating element lead-out electrode 16 are aggregated between each other, so that a situation where the fusion cannot be performed can be prevented and the fusion can be surely performed.

Note that the protective element 240 may be provided with a narrow portion 242 also around the soluble conductor connecting portion of the electrodes 12 (A1) and 12 (A2). Thereby, the protection element 240 is attracted to one side of the molten conductor along the electrodes 12 (A1) and 12 (A2), and is aggregated between the electrodes 12 (A1) and 12 (A2) and the heating element extraction electrode 16. In addition, it is possible to prevent a situation where fusing is not possible.

Note that when the fusible conductor 241 also has a structure in which a low melting point metal layer and a high melting point metal layer are laminated, solder is used as the metal constituting the low melting point metal and Au or You may form the film | membrane which has Au as a main component. Thereby, the soluble conductor 203 can further improve the wettability of the solder which comprises a low melting-point metal, and can promote an erosion effect | action.

Further, also in the protective element 240, as shown in FIG. 28, an insulating layer 245 may be formed over the longitudinal direction of the electrodes 12 (A1) and 12 (A2). The insulating layer 245 prevents the molten conductor from aggregating to the external electrode beyond the electrodes 12 (A1) and 12 (A2). The insulating layer 245 includes the soluble conductor 241 of the electrodes 12 (A1) and 12 (A2). It is formed outside the connection area. By providing the insulating layer 245, as shown in FIG. 29, in the protection element 240, the molten conductor does not aggregate on the electrodes 12 (A1) and 12 (A2) and does not flow to the external electrodes.

10, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240 Protection element, 11, 41 insulation Substrate, 12 (A1), 12 (A2), 42 electrodes, 13, 91, 121 soluble conductor, 13a, 43a, 91a, 121a high melting point metal layer, 13b, 43b, 91b, 121b, 121c low melting point metal layer, 14, 44 heating element, 15, 45 insulating member, 16 heating element extraction electrode, 17, 47 flux, 18 (P1), 18 (P2), 48 heating element electrode, 20 battery pack, 20a positive terminal, 20b negative terminal, 21 to 24 battery cells, 25 battery stacks, 26 detection circuits, 27, 31, 32 current control elements, 30 Charge and discharge control circuit, 33 control unit, 35 charging device, 41a glass layer, 51 reservoir, 52 Ni / Au-plated layer, 61 opening, 92 low-melting-point metal layer, 93 plating layer, 95 conductive paste, 132 cover member

Claims

An insulating substrate;
A heating element laminated on the insulating substrate;
An insulating member laminated on the insulating substrate so as to cover at least the heating element;
First and second electrodes stacked on the insulating substrate on which the insulating member is stacked;
A heating element extraction electrode laminated on the insulating member so as to overlap the heating element and electrically connected to the heating element on a current path between the first and second electrodes;
A laminate that extends from the heating element extraction electrode to the first and second electrodes, and includes a soluble conductor that melts a current path between the first electrode and the second electrode by heating;
The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer,
The low melting point metal layer is melted by the heat generated by the heating element, and the high melting point metal layer is eroded while the low melting point metal has high wettability, and the heating element extraction is performed. A protective element which is attracted to the electrode side and melted.
2. The protective element according to claim 1, wherein the low melting point metal layer is made of Pb-free solder, and the high melting point metal layer is made of Ag or Cu or a metal mainly composed of Ag or Cu.
3. The soluble conductor is connected with a low melting point metal at a position connected to the first and second electrodes and the heating element extraction electrode. Protection element.
4. The protective element according to claim 1, wherein the soluble conductor has a covering structure in which an inner layer is a high melting point metal layer and an outer layer is a low melting point metal layer.
The protective element according to claim 4, wherein the low melting point metal layer is formed so as to penetrate at least a part of the high melting point metal layer.
The protective element according to any one of claims 1 to 3, wherein the soluble conductor has a covering structure in which an inner layer is a low melting point metal layer and an outer layer is a high melting point metal layer.
The protective element according to any one of claims 1 to 3, wherein the soluble conductor has a two-layer structure in which an upper layer is a high melting point metal layer and a lower layer is a low melting point metal layer.
The surface of the first and second electrodes and the heating element extraction electrode is subjected to any one of Ni / Au plating, Ni / Pd plating, and Ni / Pd / Au plating. The protective element according to any one of claims 1 to 7.
The protective element according to any one of claims 1 to 8, wherein an insulating member layer is provided between the heating element and the insulating substrate.
10. The protective element according to claim 1, wherein the volume of the low melting point metal layer is larger than the volume of the high melting point metal layer.
2. The soluble conductor has a coating structure in which an inner layer is a low-melting point metal layer and an outer layer is a high-melting point metal layer, and the entire surface of the low-melting point metal layer serving as an inner layer is covered with the high-melting point metal layer. Protection element.
The soluble conductor has a coating structure in which an inner layer is a low melting point metal layer and an outer layer is a high melting point metal layer, and is connected to the first and second electrodes via a conductive paste. The protective element according to claim 11.
The soluble conductor has a coating structure in which an inner layer is a low melting point metal layer and an outer layer is a high melting point metal layer, and is connected to the first and second electrodes by welding. Item 12. The protective element according to Item 11.
The soluble conductor has a coating structure in which an inner layer is a low melting point metal layer and an outer layer is a high melting point metal layer, and the surface of the low melting point metal layer serving as an inner layer is coated with the high melting point metal layer. The protective element according to claim 1, wherein the surface is coated with a second low melting point metal layer.
The soluble conductor has a coating structure in which an inner layer is a low melting point metal layer and an outer layer is a high melting point metal layer, and the layer thickness ratio of the low melting point metal layer to the high melting point metal layer is 2.1: 1 to 100: The protective element according to claim 1, wherein the protective element is 1.
An insulating substrate;
A heating element laminated on the insulating substrate;
An insulating member laminated on the insulating substrate so as to cover at least the heating element;
First and second electrodes stacked on the insulating substrate on which the insulating member is stacked;
A heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes;
A laminate that extends from the heating element extraction electrode to the first and second electrodes, and includes a soluble conductor that melts a current path between the first electrode and the second electrode by heating;
The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer,
The low melting point metal layer is melted by the heat generated by the heating element, and the high melting point metal layer is eroded while the low melting point metal has high wettability, and the heating element extraction is performed. A protective element which is attracted to the electrode side and melted.
An insulating substrate;
A heating element laminated on the insulating substrate;
An insulating member laminated on the insulating substrate so as to cover at least the heating element;
First and second electrodes stacked on the insulating substrate on which the insulating member is stacked;
A heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes;
A plurality of fusible conductors laminated from the heating element extraction electrode to the first and second electrodes and fusing a current path between the first electrode and the second electrode by heating;
The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer,
The low melting point metal layer is melted by the heat generated by the heating element, and the high melting point metal layer is eroded while the low melting point metal has high wettability, and the heating element extraction is performed. A protective element which is attracted to the electrode side and melted.
The protective element according to claim 17, wherein the heating element extraction electrode in which the plurality of soluble conductors are laminated has an insulating layer formed between the soluble conductors of the plurality of soluble conductors.
The protection element according to claim 17, wherein the heating element extraction electrode is formed so that a width of a portion between the plurality of soluble conductors is narrower than a width of a portion where the plurality of soluble conductors are laminated.
An insulating substrate;
A heating element built in the insulating substrate;
First and second electrodes stacked on the insulating substrate;
A heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes;
A soluble conductor that is laminated from the heating element extraction electrode to the first and second electrodes, and that melts the current path between the first electrode and the second electrode by heating the heating element; ,
The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer,
The low melting point metal layer is melted by the heat generated by the heating element, and the high melting point metal layer is eroded while the low melting point metal has high wettability, and the heating element extraction is performed. A protective element which is attracted to the electrode side and melted.
An insulating substrate;
A heating element laminated on the insulating substrate;
A first electrode and a second electrode laminated on a surface opposite to a surface on which the heating element of the insulating substrate is laminated;
A heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes;
A soluble conductor that is laminated from the heating element extraction electrode to the first and second electrodes, and that melts the current path between the first electrode and the second electrode by heating the heating element; ,
The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer,
The low melting point metal layer is melted by the heat generated by the heating element, and the high melting point metal layer is eroded while the low melting point metal has high wettability, and the heating element extraction is performed. A protective element which is attracted to the electrode side and melted.
An insulating substrate;
A heating element laminated on the insulating substrate;
First and second electrodes stacked on the same surface on which the heating elements of the insulating substrate are stacked;
A heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes;
A soluble conductor that is laminated from the heating element extraction electrode to the first and second electrodes, and that melts the current path between the first electrode and the second electrode by heating the heating element; ,
The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer,
The low melting point metal layer is melted by the heat generated by the heating element, and the high melting point metal layer is eroded while the low melting point metal has high wettability, and the heating element extraction is performed. A protective element which is attracted to the electrode side and melted.
An insulating substrate;
First and second electrodes stacked on the insulating substrate;
A heating element extraction electrode stacked on a current path between the first and second electrodes;
A heating element mounted to be electrically connected to the heating element extraction electrode;
A soluble conductor that is laminated from the heating element extraction electrode to the first and second electrodes, and that melts a current path between the first electrode and the second electrode by heating the heating element; ,
The soluble conductor is composed of a laminate including at least a high melting point metal layer and a low melting point metal layer,
The low melting point metal layer is melted by the heat generated by the heating element, and the high melting point metal layer is eroded while the low melting point metal has high wettability, and the heating element extraction is performed. A protective element which is attracted to the electrode side and melted.
The low-melting-point metal layer is made of Pb-free solder, and the high-melting-point metal layer is made of Ag or Cu or a metal containing Ag or Cu as a main component. Protection element.
The protective element according to any one of claims 16 to 24, wherein a coating containing Au or Au as a main component is formed on a surface of the refractory metal layer.
26. The soluble conductor is connected with a low melting point metal at a position connected to the first and second electrodes and the heating element extraction electrode. Protection element.
The protective element according to any one of claims 16 to 26, wherein the soluble conductor has a covering structure in which an inner layer is a high melting point metal layer and an outer layer is a low melting point metal layer.
28. The protective element according to claim 27, wherein the low melting point metal layer is formed so as to penetrate at least a part of the high melting point metal layer.
The protective element according to any one of claims 16 to 26, wherein the soluble conductor has a coating structure in which an inner layer is a low melting point metal layer and an outer layer is a high melting point metal layer.
The protective element according to any one of claims 16 to 26, wherein the refractory metal layer has an opening on a surface thereof, and the low melting point metal layer is exposed.
27. The protection element according to claim 16, wherein the soluble conductor has a two-layer structure in which an upper layer is a high melting point metal layer and a lower layer is a low melting point metal layer.
27. The protection element according to claim 16, wherein the soluble conductor is a two-layer laminate in which an upper layer is a low melting point metal layer and a lower layer is a high melting point metal layer.
The protective element according to any one of claims 16 to 26, wherein the soluble conductor is formed by alternately laminating four or more layers of the high melting point metal layer and the low melting point metal layer.
The surface of the first and second electrodes and the heating element extraction electrode is subjected to any one of Ni / Au plating, Ni / Pd plating, and Ni / Pd / Au plating. The protective element according to any one of claims 16 to 33.
The protective element according to any one of claims 16 to 34, wherein an insulating member layer is provided between the heating element and the insulating substrate.
36. The protection element according to claim 16, wherein the volume of the low melting point metal layer is larger than the volume of the high melting point metal layer.
An insulating substrate;
A heating element laminated on the insulating substrate;
An insulating member laminated on the insulating substrate so as to cover at least the heating element;
First and second electrodes stacked on the insulating substrate on which the insulating member is stacked;
A heating element extraction electrode electrically connected to the heating element on a current path between the first and second electrodes;
A laminate that extends from the heating element extraction electrode to the first and second electrodes, and includes a soluble conductor that melts a current path between the first electrode and the second electrode by heating;
The soluble conductor is made of a high melting point metal, and is connected to each of the first electrode, the second electrode, and the heating element extraction electrode via a low melting point metal,
The first and second electrodes having high wettability of the low melting point metal while the low melting point metal layer is eroded by the soluble conductor made of the high melting point metal by being melted by heat generated by the heating element. In addition, the protective element is attracted to the heating element extraction electrode side and melted.