JP2022175540A - protective element - Google Patents

Abstract

To provide a fuse element having a low resistance value to reliably cut off a current flow during fuse operation, and to be mounted without distinguishing the front and back sides in assembly work for a protective element.SOLUTION: A protective element is provided with a heating element, at least a pair of main electrodes, and an energizing electrode of the heating element on an insulating substrate, a fuse element electrically connected by bridging between the main electrode and the energizing electrode, and the fuse element is a metal composite composed of a high-melting-point metal material 16 and a low-melting-point metal material 17, and the distribution of the high-melting-point metal material and the low-melting-point metal material has an isotropic distribution independent of the direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fuse element, a protection element for electrical/electronic equipment, and a protection circuit using the protection element.

In recent years, with the rapid spread of small electronic devices such as mobile devices, a small and thin protection element mounted on the protection circuit of the power supply to be mounted is being used. For example, a surface mount device (SMD) chip protection element is preferably used for a protection circuit of a secondary battery pack. These chip protection elements include non-resettable protection elements that detect excessive heat generated by overcurrent in the device being protected, or respond to abnormal overheating in the ambient temperature and operate a fuse under predetermined conditions to cut off the electrical circuit. be. In order to ensure the safety of the equipment, the protective element causes the resistance element to generate heat due to the signal current when the protective circuit detects an abnormality in the equipment. or by blowing a fuse element by overcurrent to break the circuit. Japanese Patent Application Laid-Open No. 2013-239405 (Patent Document 1) discloses a protective element in which a resistance element that generates heat in an abnormal state is provided on an insulating substrate such as a ceramic substrate.

Currently, there is a fuse element described in Japanese Patent Application Laid-Open No. 2015-079608 (Patent Document 2) as an example of a fusible alloy that constitutes the fuse element of the above-described protection element. The fuse element is composed of a low-melting-point metal material that is easily meltable at the soldering temperature when the protective element is surface-mounted on an external circuit board, and a low-melting-point metal material that is in a liquid phase at the soldering temperature. By integrally molding the low melting point metal and the high melting point metal, the liquid low melting point metal is soldered with the solid high melting point metal. It is characterized in that it is held until the attachment work is finished. The low melting point metal material and the high melting point metal material of the fuse element are fixed and molded to each other, and the low melting point metal material that has been liquefied by the heat of the soldering work is combined with the high melting point metal material that is solid at the soldering work temperature. The fuse element can be bonded to the electrode pattern of the protection element with a liquid-phase low-melting-point metal material while holding the fuse element so as not to melt. Furthermore, the fuse element is prevented from blowing at the soldering temperature when the protective element is surface-mounted on the circuit board. The protection element generates heat in a built-in resistance element, and the heat diffuses or melts the high-melting-point metal material of the fuse element into the low-melting-point metal material that is the medium, thereby performing a fusing operation.

These protective elements detect abnormalities in the protected device and cut off the current in the main circuit. It is preferable that the insulation resistance value is as large as possible when shutting down after operation. The internal resistance value of the conventional protective element described above was determined by the electrical conductivity of the fusible alloy bridged between the electrodes to which the fuse element was attached. However, the electrical conductivity of the fusible alloy is inferior to that of conductive metals such as silver and copper. is coated with a high melting point metal material such as silver or copper, or a silver or silver alloy that is soluble in a molten fusible alloy is coated on an electrode substrate as described in Japanese Patent Application Laid-Open No. 2017-228379 (Patent Document 3). It was necessary to provide a bypass electrode consisting of a sintered electrode. However, the refractory metal material such as silver or copper cannot be melted by simply heating the heating element of the protection element, and the sintered electrode material of silver or silver alloy must be completely melted into a fusible alloy. However, in any of the above-mentioned prior arts, a high melting point metal material such as silver or copper is laminated with a low melting point metal material such as a solder alloy. It cannot be said that the corrosion efficiency of metal to molten low-melting-point metal is always good. Also, when using a clad material with a high-melting point metal material and a low-melting point metal material, it may be placed upside down. It was possible. For this reason, a fuse element has been proposed in which the upper and lower surfaces of a high-melting-point metal material are sandwiched between low-melting-point metal materials so that there is no distinction between the front and back surfaces. There is a risk that it may become easier to induce

Patent Document 1: JP 2013-239405 Patent Document 2: JP 2015-079608 Patent Document 3: JP 2017-228379

In order to solve the above-mentioned drawbacks of the prior art, the present invention can remarkably improve the corrosion efficiency of the high-melting-point metal material constituting the fuse element to the low-melting-point metal material, thereby improving the breaking stability of the fuse element. To provide a protective element for an electrical/electronic device which has improved internal resistance and reduced internal resistance so as to reduce energization loss before fuse operation. At the same time, the present invention provides a fuse element of uniform properties that can be assembled regardless of the mounting direction without distinguishing between the front and back of the fuse element while using a high-melting-point metal material and a low-melting-point metal material in combination.

A first aspect of the fuse element according to the present invention is a metal composite composed of a high melting point metal material and a low melting point metal material, wherein the distribution of the high melting point metal material and the low melting point metal material is isotropic without depending on the direction. A fuse element having a distribution is provided. In the fuse element, the high melting point metal material and the low melting point metal material may be isotropically distributed.

As a second aspect of the fuse element according to the present invention, the metal body is a metal composite composed of a high-melting-point metal material and a low-melting-point metal material, and is a metal body in which the gaps in the grid made of the high-melting-point metal material are filled with the low-melting-point metal material. A fuse element is provided comprising: The fuse element may have a form in which a low-melting-point metal material is filled in a lattice gap formed by a high-melting-point metal material.

As a third aspect of the fuse element according to the present invention, it is a metal composite composed of a high melting point metal material and a low melting point metal material, wherein the ribbon-like or fibrous metal of the high melting point metal material is formed into a woven fabric or non-woven fabric. A fuse element is provided by filling the gaps of the formed cloth-like material with a low-melting-point metal material. The fuse element is a woven fabric or non-woven fabric formed by mixing a ribbon-like or fibrous metal made of a high-melting-point metal and a ribbon-like or fibrous-like metal made of a low-melting-point metal. may be filled with a low-melting-point metal material. The cloth-like material obtained by mixing the fibrous high-melting-point metal and the fibrous low-melting-point metal can promote the permeation of the low-melting-point metal when the gap is filled with the molten low-melting-point metal. .

The fuse element according to the present invention can secure a large contact area between the high-melting-point metal material and the low-melting-point metal material, thereby contributing to rapid operability of the fuse element and reduction of the internal resistance value of the fuse element.

As a first aspect of the protection element according to the present invention, a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element are provided on an insulating substrate. a bonded fuse element, wherein the fuse element is a metal composite composed of a high melting point metal material and a low melting point metal material, and the distribution of the high melting point metal material and the low melting point metal material does not depend on the direction A protective element having an isotropic distribution is provided.

A second aspect of the protection device according to the present invention is a protection device mounted with the fuse element of the second aspect described above, in which a heating element, at least a pair of main electrodes, and a current-carrying electrode for the heating element are provided on an insulating substrate. and a fuse element electrically connected by bridging between the main electrode and the conducting electrode, wherein the fuse element is a metal composite made of a high melting point metal material and a low melting point metal material, A protective element is provided in which a low-melting-point metal material is filled in the gaps of a grid made of a high-melting-point metal material.

A third aspect of the protection device according to the present invention is a protection device mounted with the fuse element of the third aspect described above, in which a heating element, at least a pair of main electrodes, and a current-carrying electrode for the heating element are provided on an insulating substrate. and a fuse element electrically connected by bridging between the main electrode and the conducting electrode, wherein the fuse element is a metal composite made of a high melting point metal material and a low melting point metal material, A protection element is provided in which a low-melting metal material is filled in the gaps of a cloth-like material formed by forming a ribbon-like or fibrous metal of a high-melting-point metal material into a woven or non-woven fabric. The fuse element of the protection element is a woven or non-woven fabric formed by mixing a ribbon-shaped or fibrous metal made of a high-melting metal material and a ribbon-shaped or fibrous metal made of a low-melting metal material. It may be formed by filling the gaps between the objects with a low-melting-point metal material.

As a first aspect of the protection circuit according to the present invention, a protection circuit for protecting a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A battery (assembled battery) to which one or more secondary battery cells are connected, a signal control section that outputs a control signal according to the voltage of the cell or battery, and a current circuit connected in parallel to the external terminal of the battery. and contains one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element, the fuse element being connected to a discharging circuit, a charging circuit, or both, and The heating element is provided with a protective element whose operation is controlled by the signal control unit,
The protective element has a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element provided on an insulating substrate, and further has a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode. The fuse element is a metal composite made of a high melting point metal material and a low melting point metal material, and the protection circuit has an isotropic distribution of the high melting point metal material and the low melting point metal material that does not depend on the direction. provided.

As a second aspect of the protection circuit according to the present invention, a protection circuit for protecting a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A battery (assembled battery) to which one or more secondary battery cells are connected, a signal control section that outputs a control signal according to the voltage of the cell or battery, and a current circuit connected in parallel to the external terminal of the battery. and contains one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element, the fuse element being connected to a discharging circuit, a charging circuit, or both, and The heating element is provided with a protective element whose operation is controlled by the signal control unit,
The protective element has a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element provided on an insulating substrate, and further has a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode. The fuse element is a metal composite made of a high-melting point metal material and a low-melting point metal material, and a protection circuit having a structure in which the low-melting-point metal material is filled in the gaps of the grid made of the high-melting-point metal material. is provided.

As a third aspect of the protection circuit according to the present invention, a protection circuit for protecting a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A battery (assembled battery) to which one or more secondary battery cells are connected, a signal control section that outputs a control signal according to the voltage of the cell or battery, and a current circuit connected in parallel to the external terminal of the battery. and contains one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element, the fuse element being connected to a discharging circuit, a charging circuit, or both, and The heating element is provided with a protective element whose operation is controlled by the signal control unit,
The protective element has a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element provided on an insulating substrate, and further has a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode. The fuse element is a metal composite composed of a high-melting metal material and a low-melting metal material, and is a cloth-like material formed by forming a ribbon-like or fibrous metal of the high-melting-point metal material into a woven or non-woven fabric. A protection circuit is provided in which the gap is filled with a low-melting-point metal material. The fuse element of the protection circuit is in the form of a woven fabric or non-woven cloth formed by mixing a ribbon-like or fibrous metal made of a high melting point metal material and a ribbon-like or fibrous metal made of a low melting point metal material. It may be formed by filling the gaps between the objects with a low-melting-point metal material.

According to one embodiment of the present invention, a fuse element with a low resistance value can be formed, and electricity can be cut off reliably during fuse operation. In addition, the fuse element can be mounted without distinguishing between the front and back sides of the protective element during assembly.

A fuse element 15 of the present invention, (a) showing a plan view and (b) showing a front view. The protective element 20 of the present invention, (a) shows a plan view of the cap-shaped lid body cut along the dd line of (b), and (b) shows the DD line of (a). (c) shows a bottom view thereof. 1 shows an equivalent circuit diagram of a protection circuit 30 of the present invention; FIG. 1 shows an equivalent circuit diagram of a protection circuit 40 of the present invention; FIG.

A first aspect of the fuse element according to the present invention is a metal composite composed of a high melting point metal material and a low melting point metal material, wherein the distribution of the high melting point metal material and the low melting point metal material is isotropic without depending on the direction. have a distribution. In the fuse element, the high melting point metal material and the low melting point metal material may be isotropically distributed.

A second aspect of the fuse element according to the present invention is a metal composite composed of a high-melting-point metal material and a low-melting-point metal material. It has a configuration that The fuse element may have a form in which a low-melting-point metal material is filled in a lattice gap formed by a high-melting-point metal material.

A third aspect of the fuse element according to the present invention is a metal composite composed of a high melting point metal material and a low melting point metal material, wherein the ribbon-like or fibrous metal of the high melting point metal material is formed into a woven or non-woven fabric. A fuse element is provided by filling the gaps of the formed cloth-like material with a low-melting-point metal material. The fuse element is a woven fabric or non-woven fabric formed by mixing a ribbon-like or fibrous metal made of a high-melting-point metal and a ribbon-like or fibrous-like metal made of a low-melting-point metal. may be filled with a low-melting-point metal material.

As an example of the fuse element according to the present invention, there is provided a fuse element composed of a high-melting-point metal material capable of absorbing and holding a molten metal material and a low-melting-point metal material solidified by entering the high-melting-point metal material. be. The high-melting-point metal material can be composed of a fibrous material. For example, by making a fibrous high-melting-point metal material into a felt-like material, it is possible to provide metal penetration and coagulability. The fuse element may be formed by infiltrating and solidifying a low melting point metal material in the felt-like high melting point metal material. The high-melting-point metal material according to the present invention only needs to allow the melted low-melting-point metal material to enter and solidify in the gaps between the fibers of the metal material. Instead of the high-melting-point metal material in the form of felt, that is, in the form of a non-woven fabric, a metal material formed in the shape of a net or woven fabric may be used.

The method for forming the high-melting-point metal material according to the present invention is not particularly limited, but the high-melting-point metal material in the form of felt, net, or woven fabric can be formed from a fibrous high-melting-point metal. Alternatively, a honeycomb material or a punching metal material having a large number of punched holes may be used as the high-melting-point metal material. When a honeycomb material or punching metal material is used as the high melting point metal material, at least the openings are filled with the low melting point metal material, and if necessary, the surface of the high melting point metal material is covered with the low melting point metal material. good too.

The high-melting-point metal material constituting the fuse element according to the present invention may be any metal that withstands the reflow soldering temperature and dissolves in the liquid-phase low-melting-point metal material. It is preferable to use wood. Silver, copper, a silver alloy, or a copper alloy may be used as the refractory metal material. Any metal may be used as the low-melting-point metal material constituting the fuse element according to the present invention as long as it melts at a lower temperature than the high-melting-point metal material and can corrode the high-melting-point metal material. . Tin, indium, bismuth, tin-based solder material, indium-containing solder material, bismuth-containing solder material, antimony-containing solder material, and lead-containing solder material may be used as the low melting point metal material. As an example, a Sn—Ag alloy containing 3 to 4% by mass of Ag and the balance being Sn, and 0.5 to 0.7% by mass of Cu and optionally containing 0 to 1% by mass of Ag and the balance being Sn Sn—Cu—Ag alloy (silver is not essential), containing 3 to 4% by mass of Ag and 0.5 to 1% by mass of Cu, the balance being Sn—Ag—Cu alloy, Bi Sn-Bi alloy and 96.5Sn-3.5Ag alloy, 99.25Sn-0.75Cu alloy, 96.5Sn-3Ag-0.5Cu alloy, 95.5Sn- Lead-free tin-based solder materials such as 4Ag-0.5Cu alloy and 42Sn-58Bi alloy can be suitably used. (The coefficients for alloy materials indicate mass % of elements.)

For example, as shown in FIG. 1, a fuse element 15 according to the present invention is composed of a high-melting-point metal material 16 having a metal-infiltration solidification property and a low-melting-point metal material 17 infiltrated and solidified in the high-melting-point metal material. The metal-penetrating solidifiable high-melting-point metal material 16 can be composed of a fibrous material. For example, by making a fibrous high-melting-point metal material into a felt-like material, it is possible to provide metal penetration and coagulability. The fuse element 15 may be formed by infiltrating and solidifying the low-melting-point metal material 17 in the felt-like high-melting-point metal material 16 . The high-melting-point metal material 16 having a metal-infiltration-solidification property according to the present invention is sufficient as long as the molten low-melting-point metal material 17 can be infiltrated and solidified in the gaps between the fibers of the metal material. Instead of the high-melting-point metal material 16 having a felt-like form, that is, a nonwoven fabric-like form, a metal material formed in a net-like or woven fabric-like form may be used.

The method of forming the metal-penetrating solidifiable high-melting-point metal material 16 according to the present invention is not particularly limited, but felt-like (non-woven fabric), net-like, and woven-like high-melting-point metal materials are formed from fiber-like high-melting-point metals. be able to.

A protection element according to the present invention is a protection element for an electric circuit or an electric device equipped with the fuse element described above.

A first aspect of a protective element according to the present invention is a protective element mounted with the fuse element of the first aspect described above, wherein an insulating substrate is provided with a heating element, at least a pair of main electrodes, and a conducting electrode of the heating element. and a fuse element electrically connected by bridging between the main electrode and the conducting electrode, wherein the fuse element is a metal composite made of a high melting point metal material and a low melting point metal material, The distribution of the high-melting-point metal material and the low-melting-point metal material does not depend on the direction and has an isotropic distribution.

A second aspect of the protection element according to the present invention is a protection element mounted with the fuse element of the second aspect described above, in which an insulating substrate is provided with a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heating element. and a fuse element electrically connected by bridging between the main electrode and the conducting electrode, wherein the fuse element is a metal composite made of a high melting point metal material and a low melting point metal material, A low-melting-point metal material is filled in the gaps of the lattice made of the high-melting-point metal material.

A third aspect of the protection element according to the present invention is a protection element mounted with the fuse element of the third aspect described above, in which a heating element, at least a pair of main electrodes, and a conducting electrode of the heating element are provided on an insulating substrate. and a fuse element electrically connected by bridging between the main electrode and the conducting electrode, wherein the fuse element is a metal composite made of a high melting point metal material and a low melting point metal material, A protection element is provided in which a low-melting metal material is filled in the gaps of a cloth-like material formed by forming a ribbon-like or fibrous metal of a high-melting-point metal material into a woven or non-woven fabric. The fuse element of the protection element is a woven or non-woven fabric formed by mixing a ribbon-shaped or fibrous metal made of a high-melting metal material and a ribbon-shaped or fibrous metal made of a low-melting metal material. It may be formed by filling the gaps between the objects with a low-melting-point metal material.

The protective element of the first to third aspects described above further includes through-holes penetrating through the insulating substrate, side electrodes provided on the side surface, and a A pad electrode may be provided. Also, any surface of the fuse element may be coated or filled with flux. A cover covering the upper portion of the fuse element may be provided to protect the mounting portion of the fuse element.

For example, the protective element 20 according to the present invention is a protective element mounted with the fuse element 15, and as shown in FIG. 22 current-carrying electrodes 24 are provided, and a fuse element 25 is electrically connected by bridging between the main electrodes 23a and 23b and the current-carrying electrodes 24, and the fuse element 25 has a metal penetration coagulation property. and a low-melting-point metal material 27 solidified by entering the high-melting-point metal material 26 . The fuse element 25 may be connected to the main electrodes 23 a and 23 b and the current-carrying electrode 24 using a solder material 200 . The metal-penetrating solidifiable high-melting-point metal material 26 can be composed of a fibrous material. For example, by making the fibrous high-melting-point metal material 26 into a felt-like material, it is possible to provide metal penetration and coagulability. The fuse element 25 may be formed by infiltrating and solidifying a low melting point metal material in the felt-like high melting point metal material. The high-melting-point metal material 26 having a metal-infiltration-solidification property according to the present invention is sufficient as long as the molten low-melting-point metal material 27 can be infiltrated and solidified in the gaps between the fibers of the metal material. Instead of the high-melting-point metal material in the form of felt, that is, in the form of a non-woven fabric, a metal material formed in the shape of a net or woven fabric may be used. Alternatively, a punching metal material having a large number of punched holes in the high melting point metal material 26 may be used. When a punching metal material is used as the high-melting-point metal material 26, at least the punched holes of the punching metal material are filled with the low-melting-point metal material 27, and the surface of the punching metal material is covered with the low-melting-point metal material 27 as necessary. may The high melting point metal material 26 may be silver, copper, a silver alloy, or a copper alloy. The low-melting-point metal material 27 may be tin, indium, bismuth, tin-based solder material, indium-containing solder material, bismuth-containing solder material, antimony-containing solder material, or lead-containing solder material. Examples of low-melting-point metal materials include Sn—Ag alloy containing 3 to 4% by mass of Ag and the balance being Sn, 0.5 to 0.7% by mass of Cu, and 0 to 1% by mass of Ag, if necessary. Sn--Cu--Ag alloy containing 3-4% by mass of Ag and the balance being Sn (although silver is not essential), containing 0.5-1% by mass of Cu and the balance being Sn-- Cu alloy, Sn—Bi alloy containing 10 to 60% by mass of Bi and the balance being Sn, 96.5Sn-3.5Ag alloy, 99.25Sn-0.75Cu alloy, 96.5Sn-3Ag-0.5Cu alloy , 95.5Sn-4Ag-0.5Cu alloy, 42Sn-58Bi alloy, and other lead-free tin-based solder materials can be suitably used. (The coefficients for alloy materials indicate mass % of elements.)

A protection circuit according to the present invention is a protection circuit that protects a battery pack of a secondary battery such as a lithium ion battery using the protection element described above from overcharging and overheating.

A first aspect of the protection circuit according to the present invention is a protection circuit that protects a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A battery (assembled battery) to which one or more secondary battery cells are connected, a signal control section that outputs a control signal according to the voltage of the cell or battery, and a current circuit connected in parallel to the external terminal of the battery. and contains one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element, the fuse element being connected to a discharging circuit, a charging circuit, or both, and The heating element is provided with a protective element whose operation is controlled by the signal control unit,
The protective element has a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element provided on an insulating substrate, and further has a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode. The fuse element is a metal composite composed of a high melting point metal material and a low melting point metal material, and the distribution of the high melting point metal material and the low melting point metal material is isotropic without depending on the direction.

A second aspect of the protection circuit according to the present invention is a protection circuit that protects a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A battery (assembled battery) to which one or more secondary battery cells are connected, a signal control section that outputs a control signal according to the voltage of the cell or battery, and a current circuit connected in parallel to the external terminal of the battery. and contains one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element, the fuse element being connected to a discharging circuit, a charging circuit, or both, and The heating element is provided with a protective element whose operation is controlled by the signal control unit,
The protective element has a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element provided on an insulating substrate, and further has a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode. The fuse element is a metal composite made of a high-melting point metal material and a low-melting point metal material, and has a structure in which the low-melting point metal material is filled in the gaps of the grid made of the high-melting point metal material.

A third aspect of the protection circuit according to the present invention is a protection circuit that protects a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A battery (assembled battery) to which one or more secondary battery cells are connected, a signal control section that outputs a control signal according to the voltage of the cell or battery, and a current circuit connected in parallel to the external terminal of the battery. and contains one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element, the fuse element being connected to a discharging circuit, a charging circuit, or both, and The heating element is provided with a protective element whose operation is controlled by the signal control unit,
The protective element has a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element provided on an insulating substrate, and further has a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode. The fuse element is a metal composite composed of a high-melting metal material and a low-melting metal material, and is a cloth-like material formed by forming a ribbon-like or fibrous metal of the high-melting-point metal material into a woven or non-woven fabric. A protection circuit is provided in which the gap is filled with a low-melting-point metal material. The fuse element of the protection circuit is in the form of a woven fabric or non-woven cloth formed by mixing a ribbon-like or fibrous metal made of a high melting point metal material and a ribbon-like or fibrous metal made of a low melting point metal material. It may be formed by filling the gaps between the objects with a low-melting-point metal material.

For example, the protection circuit 30 according to the invention is a secondary battery protection circuit using the protection element 20 . Like the equivalent circuit shown in FIG. 3, a protection circuit that protects a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A battery (assembled battery or battery stack) 302 to which one or more secondary battery cells 301 are connected, a signal control unit 303 that outputs a control signal according to the voltage of the cell or battery, and an external terminal 304 of the battery. One or more switching elements 305 that are connected in parallel to a current circuit between the a protection element 300 connected to a discharge circuit, a charge circuit, or both, and having a heating element 32 whose operation is controlled by a signal control unit 303;
The protection element 300 includes a heating element 32, at least a pair of main electrodes 33a and 33b, and an energizing electrode 34 of the heating element 32 provided on an insulating substrate. The fuse element 35 is made of a high-melting-point metal material having a metal infiltration and solidification property and a low-melting-point metal material infiltrated and solidified in the high-melting-point metal material.
The high-melting-point metal material with metal infiltration and solidification properties can be composed of a fibrous material. For example, by making a fibrous high-melting-point metal material into a felt-like material, it is possible to provide metal penetration and coagulability. The fuse element may be formed by infiltrating and solidifying a low melting point metal material in the felt-like high melting point metal material. The high-melting-point metal material of the present invention, which has a metal-infiltration-solidification property, should be capable of infiltrating and solidifying a molten low-melting-point metal material in the gaps between the fibers of the metal material. Instead of the high-melting-point metal material in the form of felt, that is, in the form of a non-woven fabric, a metal material formed in the shape of a net or woven fabric may be used. Alternatively, a punching metal material having a large number of punched holes in a high-melting-point metal material may be used. When a punching metal material is used as the high melting point metal material, at least the punched holes of the punching metal material may be filled with a low melting point metal material, and if necessary, the surface of the punching metal material may be covered with a low melting point metal material. . Silver, copper, a silver alloy, or a copper alloy may be used as the refractory metal material. Tin, indium, bismuth, tin-based solder material, indium-containing solder material, bismuth-containing solder material, antimony-containing solder material, and lead-containing solder material may be used as the low melting point metal material. Examples of low-melting-point metal materials include Sn—Ag alloy containing 3 to 4% by mass of Ag and the balance being Sn, 0.5 to 0.7% by mass of Cu, and 0 to 1% by mass of Ag, if necessary. Sn--Cu--Ag alloy containing 3-4% by mass of Ag and the balance being Sn (although silver is not essential), containing 0.5-1% by mass of Cu and the balance being Sn-- Cu alloy, Sn—Bi alloy containing 10 to 60% by mass of Bi and the balance being Sn, 96.5Sn-3.5Ag alloy, 99.25Sn-0.75Cu alloy, 96.5Sn-3Ag-0.5Cu alloy , 95.5Sn-4Ag-0.5Cu alloy, 42Sn-58Bi alloy, and other lead-free tin-based solder materials can be suitably used. (The coefficients for alloy materials indicate mass % of elements.)

As shown in FIG. 1, the fuse element 15 of Example 1 according to the present invention includes a high-melting metal material 16 made of silver material having metal infiltration and solidification properties, and a tin metal material infiltrated and solidified in the high-melting metal material. and a low-melting-point metal material 17 . The high-melting-point metal material 16 is formed by gathering fine ribbon-like silver foil materials into a sheet, and is like a sheet-like metal bundle. The fuse element 15 of Example 1 is obtained by infiltrating and solidifying molten tin in a high-melting-point metal material 16 having a metal-infiltrating and solidifying property. It is a composite metal material formed by infiltrating and solidifying the low-melting-point metal material 17 of . The silver material may be changed to a copper material that is soluble in the tin low-melting-point metal material 17 and has a higher melting point than the low-melting-point metal material 17 . The tin low-melting-point metal material 17 can be changed to a solder material. As a result, a low-resistance fuse element 15 made of a composite metal material composed of an isotropic non-laminated body in which the distribution of silver and tin is not unevenly distributed in a specific plane can be realized. Since it has no anisotropy, it can be assembled without worrying about the front and back. The fuse element 15 combines the high-melting-point metal material 16 made of fine silver fibers with the low-melting-point tin material 17, so that the fuse element 15 has a lower electric resistance than a fuse composed only of the low-melting-point metal material 17 made of tin. can be made lower and can withstand reflow soldering. The fuse element 15 can be used as a fuse element of a circuit protection element and used in a secondary battery protection circuit.

A protective element 20 of Example 2 according to the present invention is a protective element on which the fuse element 15 of Example 1 is mounted, and as shown in FIG. 22, a pair of main electrodes 23a and 23b made of sintered silver, and a current-carrying electrode 24 made of sintered silver for energizing the heating element 22 are provided on the insulating substrate 21. Further, the main electrodes 23a and 23b and the current-carrying electrode 24 The fuse element 25 is composed of a high-melting metal material 26 made of silver having a metal penetration solidification property, and a high-melting metal material 26 which is solidified by being penetrated into the high melting point metal material 26. and a low melting point metal material 27 made of tin. The fuse element 25 is made by infiltrating and solidifying molten tin in a high-melting-point metal material 26 having a metal-infiltrating and solidifying property. It is a composite metal material formed by infiltrating and solidifying the material 27 . The silver material may be changed to a copper material that is soluble in the tin low-melting-point metal material 27 and has a higher melting point than the low-melting-point metal material 27 . The tin low melting point metal material 27 may be changed to a solder material.
The main electrodes 23a and 23b and the conducting electrode 24 of the protective element 20 are connected to a sintered silver pad electrode 28 arranged on the lower surface of the insulating substrate 21 through a sintered silver half-through hole 29 provided on the side surface of the insulating substrate 21. It is installed and can be energized. The fuse element 25 is connected to the main electrodes 23 a and 23 b and the current-carrying electrode 24 using a solder material 200 . Although not shown, the fuse element has its surface coated with flux except for the solder joint surfaces with the main electrodes 23a and 23b and the current-carrying electrode 24. As shown in FIG. The insulating substrate 21 has a cover 210 covering the top of the fuse element.

A protection circuit 30 according to the third embodiment of the present invention is a secondary battery protection circuit using the protection element 20 of the second embodiment. As shown in FIG. 3, a protection circuit for protecting a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A current circuit between a battery stack 302 to which a secondary battery cell 301 is connected, a signal control unit 303 that outputs a control signal according to the voltage of the battery cell 301, and an external terminal 304 of the battery stack 302. One or more switching elements 305 connected in parallel and controlled on/off by receiving a signal from a signal control section 303, a heating element 32, and fuse elements 35a and 35b are incorporated, and the fuse elements 35 and 35b constitute a discharge circuit. or a protection element 300 connected to a charging circuit and having a heating element 32 whose operation is controlled by a signal control unit 303,
The protective element 300 includes an alumina insulating substrate, a heating element 32 made of a thick film resistor, a pair of sintered silver main electrodes 33a and 33b, and a sintered silver current-carrying electrode 34 for energizing the heating element 32. It is provided on an insulating substrate and further has fuse elements 35a and 35b electrically connected by bridging between the main electrodes 33a and 33b and the current-carrying electrode 34. The fuse elements 35a and 35b have a metal infiltration solidification property. and a low-melting-point metal material made of tin, which is immersed and solidified in the high-melting-point metal material. The fuse elements 35a and 35b are obtained by infiltrating and solidifying molten tin in a high-melting-point metal material having a metal-infiltrating and solidifying property. It is a composite metal material filled with material. The silver material forming the high-melting-point metal material may be changed to a copper material that is soluble in the low-melting-point metal material made of tin and has a higher melting point than the low-melting-point metal material. The tin low-melting-point metal material may be changed to a solder material.
The fuse element of the protection circuit 300 is formed by filling a low-melting-point metal material in the gaps of a cloth-like material obtained by forming an ultrafine ribbon-like metal of a high-melting-point metal material into a non-woven fabric. The fuse element is formed by filling the gaps of a non-woven fabric formed by mixing a fibrous metal made of a high melting point metal material and a fibrous metal made of a low melting point metal material with a low melting point metal material. good too.

A protection circuit 40 according to the fourth embodiment of the present invention is a secondary battery protection circuit using the protection element 20 of the second embodiment. As shown in FIG. 4, a protection circuit for protecting a battery pack of secondary batteries such as lithium ion batteries from overcharging and overheating,
A current circuit between a battery stack 402 to which a secondary battery cell 401 is connected, a signal control unit 403 that outputs a control signal according to the voltage of the battery cell 401, and an external terminal 404 of the battery stack 402. One or more switching elements 405 connected in parallel and controlled on/off by receiving a signal from a signal control section 403, a heating element 42, and fuse elements 45a and 45b are incorporated, and the fuse elements 45 and 45b constitute a discharge circuit. 406 and a charging circuit 407, and a protection element 400 in which the heating element 42 is controlled by the signal control unit 403,
The protection element 400 includes an alumina insulating substrate, a heating element 42 made of a thick film resistor, a pair of sintered silver main electrodes 43a and 43b, and a sintered silver current-carrying electrode 44 for energizing the heating element 42. It is provided on an insulating substrate and further has fuse elements 45a and 45b electrically connected by bridging between the main electrodes 43a and 43b and the current-carrying electrode 44. The fuse elements 45a and 45b have metal penetration and solidification properties. and a low-melting-point metal material made of tin, which is immersed and solidified in the high-melting-point metal material. The fuse elements 45a and 45b are obtained by infiltrating and solidifying molten tin in a high-melting-point metal material having a metal-infiltrating and solidifying property. It is a composite metal material filled with material. The silver material forming the high-melting-point metal material may be changed to a copper material that is soluble in the low-melting-point metal material made of tin and has a higher melting point than the low-melting-point metal material. The tin low-melting-point metal material may be changed to a solder material.
The fuse element of the protection circuit 400 is formed by filling a low-melting-point metal material in the gaps of a cloth-like material obtained by forming an ultrafine ribbon-like metal of a high-melting-point metal material into a non-woven fabric. The fuse element is formed by filling the gaps of a non-woven fabric formed by mixing a fibrous metal made of a high melting point metal material and a fibrous metal made of a low melting point metal material with a low melting point metal material. good too.

The protection element of the present invention can be mounted on another circuit board by reflow soldering, and can be used as a protection device for secondary batteries such as battery packs.

fuse element 15, high melting point metal material 16, low melting point metal material 17,
Protective element 20, insulating substrate 21, heating element 22, main electrodes 23a, 23b, conducting electrode 24, fuse element 25, high melting point metal material 26, low melting point metal material 27, pad electrode 28, half through hole 29, solder material 200, lid body 210,
protection circuit 30, heating element 32, fuse elements 35a, 35b, main electrodes 33a, 33b, conducting electrode 34, protection element 300, cell 301, battery stack 302, signal control section 303, external terminal 304, switching element 305,
Protection circuit 40, heating element 42, fuse elements 45a, 45b, main electrodes 43a, 43b, conducting electrode 44, protection element 400, cell 401, battery stack 402, signal control unit 403, external terminal 404, switching element 405, discharge circuit 406, charging circuit 407;

Claims (39)

A fuse element comprising a metal composite comprising a high melting point metal material and a low melting point metal material, wherein the distribution of the high melting point metal material and the low melting point metal material is isotropic without depending on the direction. A fuse element comprising a metal composite comprising a high-melting point metal material and a low-melting point metal material, the fuse element comprising a metal body in which the low-melting point metal material is filled in the gaps of a grid made of the high-melting point metal material. A fuse element comprising a high melting point metal material having a metal infiltration solidification property and a low melting point metal material infiltrated and solidified in the high melting point metal material. The fuse element according to any one of claims 1 to 3, wherein the high-melting-point metal material is made of fibrous material. 5. The fuse element according to claim 1, wherein said high-melting-point metal material is formed in any one of felt-like, mesh-like and woven fabric-like shapes. The high melting point metal material is a honeycomb material or a punching metal material having a large number of punched holes, and at least the openings are filled with the low melting point metal material. 3. The fuse element according to claim 2, wherein the fuse element is coated with the low melting point metal material. A metal composite comprising a high-melting-point metal material and a low-melting-point metal material, wherein a low-melting-point Fuse element filled with metal material A metal composite comprising a high melting point metal material and a low melting point metal material, wherein the ribbon-shaped or fibrous metal comprising the high melting point metal material and the ribbon-shaped or fibrous metal comprising the low melting point metal material are mutually combined. A fuse element formed by filling a low-melting-point metal material in the gaps between woven or non-woven cloth materials formed by mixing. 9. The fuse element according to claim 1, wherein said high-melting-point metal material is made of a metal material that withstands the temperature of reflow soldering and dissolves in said low-melting-point metal material in a liquid phase. 10. The fuse element according to any one of claims 1 to 9, wherein said refractory metal material is made of silver, copper, a silver alloy, or a copper alloy. The fuse element according to any one of claims 1 to 10, wherein the low-melting-point metal material is made of a metal material that melts at a lower temperature than the high-melting-point metal material and that can corrode the high-melting-point metal material. . The low-melting-point metal material is any one of tin, indium, bismuth, tin-based solder material, indium-containing solder material, bismuth-containing solder material, antimony-containing solder material, and lead-containing solder material. A fuse element according to any one of the preceding claims. The low melting point metal material contains 3 to 4% by mass of Ag and the balance is Sn—Ag alloy, 0.5 to 0.7% by mass of Cu, and 0 to 1% by mass of Ag if necessary. Sn--Cu--Ag alloy with the balance being Sn (however, silver is not essential), containing 3-4% by mass of Ag and 0.5-1% by mass of Cu, and the balance being Sn--Sn--Ag--Cu alloys, Sn—Bi alloys containing 10 to 60% by mass of Bi and the balance being Sn, 96.5Sn-3.5Ag alloys, 99.25Sn-0.75Cu alloys, 96.5Sn-3Ag-0.5Cu alloys, 12. The fuse element according to any one of claims 1 to 11, wherein the fuse element is made of any one of lead-free tin solder materials such as 95.5Sn-4Ag-0.5Cu alloy and 42Sn-58Bi alloy. a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element are provided on an insulating substrate; and a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode, A fuse element is a protective element which is a metal composite composed of a high melting point metal material and a low melting point metal material, wherein the distribution of the high melting point metal material and the low melting point metal material is isotropic without depending on the direction. a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element are provided on an insulating substrate; and a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode, A fuse element is a protective element which is a metal composite composed of a high melting point metal material and a low melting point metal material, and in which the low melting point metal material is filled in the gaps of a grid made of the high melting point metal material. 16. The protective element according to claim 14, wherein said fuse element is made of a high melting point metal material having a metal infiltration solidification property and a low melting point metal material infiltrated and solidified in said high melting point metal material. 17. The protection element according to any one of claims 14 to 16, wherein the high-melting-point metal material is composed of a fibrous material. 18. The protective element according to any one of claims 14 to 17, wherein the high-melting-point metal material is formed in any one of felt, net, and woven fabric. The high melting point metal material is a honeycomb material or a punching metal material having a large number of punched holes, and at least the openings are filled with the low melting point metal material. 16. The protective element according to claim 15, which is coated with the low-melting-point metal material. A heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element are provided on an insulating substrate, and a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode, wherein the fuse element is a metal composite consisting of a high-melting-point metal material and a low-melting-point metal material. A protective element filled with a melting point metal material. a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element are provided on an insulating substrate; and a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode, The fuse element is formed by mixing a ribbon-shaped or fibrous metal made of a high-melting metal material and a ribbon-shaped or fibrous metal made of a low-melting-point metal material into a gap between cloth-like materials in the form of a woven fabric or a non-woven fabric. A protective element formed by filling a low-melting-point metal material. 22. The protective element according to claim 14, wherein the high-melting-point metal material is made of a metal material that withstands reflow soldering temperatures and dissolves in the liquid-phase low-melting-point metal material. 23. The protective element according to any one of claims 14 to 22, wherein said high-melting-point metal material is made of silver, copper, a silver alloy, or a copper alloy. 24. The protective element according to any one of claims 14 to 23, wherein the low-melting-point metal material is made of a metal material that melts at a lower temperature than the high-melting-point metal material and that can corrode the high-melting-point metal material. . 25. The low-melting-point metal material is any one of tin, indium, bismuth, tin-based solder material, indium-containing solder material, bismuth-containing solder material, antimony-containing solder material, and lead-containing solder material. A protection element according to any one of the above. The low melting point metal material contains 3 to 4% by mass of Ag and the balance is Sn—Ag alloy, 0.5 to 0.7% by mass of Cu, and 0 to 1% by mass of Ag if necessary. Sn--Cu--Ag alloy with the balance being Sn (however, silver is not essential), containing 3-4% by mass of Ag and 0.5-1% by mass of Cu, and the balance being Sn--Sn--Ag--Cu alloys, Sn—Bi alloys containing 10 to 60% by mass of Bi and the balance being Sn, 96.5Sn-3.5Ag alloys, 99.25Sn-0.75Cu alloys, 96.5Sn-3Ag-0.5Cu alloys, 25. The protective element according to any one of claims 14 to 24, which is made of a lead-free tin-based solder material such as 95.5Sn-4Ag-0.5Cu alloy and 42Sn-58Bi alloy. A protection circuit for protecting a battery pack of secondary batteries from overcharging and overheating,
A current circuit is connected in parallel between a battery to which one or more secondary battery cells are connected, a signal control unit that outputs a control signal according to the voltage of the cell or the battery, and an external terminal of the battery. and one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element are incorporated, and the fuse element is connected to a discharge circuit or a charge circuit or both, and a protective element whose operation is controlled by the signal control unit,
The protection element includes the heating element, at least a pair of main electrodes, and an energizing electrode of the heating element provided on an insulating substrate, and the main electrode and the energizing electrode are electrically connected by bridging. a fuse element, wherein the fuse element is a metal composite made of a high melting point metal material and a low melting point metal material, and the distribution of the high melting point metal material and the low melting point metal material does not depend on the direction Protection circuit with isotropic distribution. A protection circuit for protecting a battery pack of secondary batteries from overcharging and overheating,
A current circuit is connected in parallel between a battery to which one or more secondary battery cells are connected, a signal control unit that outputs a control signal according to the voltage of the cell or the battery, and an external terminal of the battery. and one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element are incorporated, and the fuse element is connected to a discharge circuit or a charge circuit or both, and a protective element whose operation is controlled by the signal control unit,
The protection element includes the heating element, at least a pair of main electrodes, and an energizing electrode of the heating element provided on an insulating substrate, and the main electrode and the energizing electrode are electrically connected by bridging. a fuse element, wherein the fuse element is a metal composite composed of a high-melting-point metal material and a low-melting-point metal material, and the low-melting-point metal material fills a gap in a lattice made of the high-melting-point metal material. A protection circuit having a 29. The protection circuit according to claim 27, wherein said fuse element is made of a high melting point metal material having a metal infiltration solidification property and a low melting point metal material infiltrated and solidified in said high melting point metal material. 30. The protection circuit according to any one of claims 27 to 29, wherein said refractory metal material is made of fibrous material. 31. The protection circuit according to any one of claims 27 to 30, wherein said high-melting-point metal material is formed in any one of felt-like, mesh-like and woven fabric-like shapes. The high melting point metal material is a honeycomb material or a punching metal material having a large number of punched holes, and at least the openings are filled with the low melting point metal material. 29. The protection circuit according to claim 28, coated with said low melting point metal material. A protection circuit for protecting a battery pack of secondary batteries from overcharging and overheating,
A current circuit is connected in parallel between a battery to which one or more secondary battery cells are connected, a signal control unit that outputs a control signal according to the voltage of the cell or the battery, and an external terminal of the battery. and one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element are incorporated, and the fuse element is connected to a discharge circuit or a charge circuit or both, and a protective element whose operation is controlled by the signal control unit,
The protection element includes a heating element, at least a pair of main electrodes, and a current-carrying electrode of the heat-generating element provided on an insulating substrate, and further includes a fuse element electrically connected by bridging between the main electrode and the current-carrying electrode. The fuse element is a metal composite composed of a high-melting metal material and a low-melting metal material, and is a cloth-like material obtained by forming a ribbon-like or fibrous metal of the high-melting-point metal material into a woven or non-woven fabric. A protection circuit made by filling a low-melting-point metal material in the gap between A protection circuit for protecting a battery pack of secondary batteries from overcharging and overheating,
A current circuit is connected in parallel between a battery to which one or more secondary battery cells are connected, a signal control unit that outputs a control signal according to the voltage of the cell or the battery, and an external terminal of the battery. and one or more switching elements for on/off control in response to a signal from the signal control unit, a fuse element and a heating element are incorporated, and the fuse element is connected to a discharge circuit or a charge circuit or both, and a protective element whose operation is controlled by the signal control unit,
The protection element includes the heating element, at least a pair of main electrodes, and an energizing electrode of the heating element provided on an insulating substrate, and the main electrode and the energizing electrode are electrically connected by bridging. The fuse element is a woven fabric or non-woven fabric formed by mixing a ribbon-shaped or fibrous metal made of a high-melting metal material and a ribbon-shaped or fibrous metal made of a low-melting metal material. A protective circuit formed by filling a low-melting-point metal material in the gaps of a cloth-like material. 35. The protection circuit according to any one of claims 27 to 34, wherein the high-melting-point metal material is made of a metal material that withstands reflow soldering temperatures and dissolves in the low-melting-point metal material in a liquid phase. 36. The protection circuit according to any one of claims 27 to 35, wherein said refractory metal material is silver, copper, a silver alloy, or a copper alloy. 37. The protection circuit according to any one of claims 27 to 36, wherein the low-melting-point metal material is made of a metal material that melts at a lower temperature than the high-melting-point metal material and that can corrode the high-melting-point metal material. . 38. The low-melting-point metal material is any one of tin, indium, bismuth, tin-based solder material, indium-containing solder material, bismuth-containing solder material, antimony-containing solder material, and lead-containing solder material. A protection circuit according to any one of the preceding claims. The low melting point metal material contains 3 to 4% by mass of Ag and the balance is Sn—Ag alloy, 0.5 to 0.7% by mass of Cu, and 0 to 1% by mass of Ag if necessary. Sn--Cu--Ag alloy with the balance being Sn (however, silver is not essential), containing 3-4% by mass of Ag and 0.5-1% by mass of Cu, and the balance being Sn--Sn--Ag--Cu alloys, Sn—Bi alloys containing 10 to 60% by mass of Bi and the balance being Sn, 96.5Sn-3.5Ag alloys, 99.25Sn-0.75Cu alloys, 96.5Sn-3Ag-0.5Cu alloys, 38. The protection circuit according to any one of claims 27 to 37, which is made of any lead-free tin-based solder material such as 95.5Sn-4Ag-0.5Cu alloy and 42Sn-58Bi alloy.

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