HK1222039B - Temperature short circuit element and temperature switching element - Google Patents

Description

Temperature short-circuit elements, temperature switching elements

Technical Field

The present invention relates to a temperature short-circuit element that melts a fusible conductor according to a temperature atmosphere and physically and electrically shorts terminals in an open state, and a temperature switching element that physically and electrically shorts terminals in an open state and physically and electrically disconnects terminals in a connected state.

Background Art

Most secondary batteries, which can be recharged and reused repeatedly, are processed into battery packs and provided to users. Lithium-ion secondary batteries, with their high gravimetric energy density, are particularly prone to overcharge and overdischarge protection. To ensure the safety of both users and electronic devices, the battery packs typically incorporate numerous protection circuits, such as overcharge and overdischarge protection, which can shut down the battery pack's output under specific circumstances.

Some such protection elements utilize FET switches built into the battery pack to turn the output on and off, thereby protecting the battery pack from overcharge or overdischarge. However, battery packs and electronic devices must be protected to prevent fires and other accidents if the FET switch short-circuits and breaks down for some reason, if a lightning surge or other transient high current flows, or if the output voltage drops abnormally or even exceeds the output voltage due to the battery cell's lifespan, or if voltage variations between battery cells increase. Therefore, to safely shut off the battery cell output even in these potentially abnormal conditions, protection elements comprised of fuse elements that interrupt the current path in response to external signals are used.

As described in Patent Document 1, a protective element for a protection circuit for lithium-ion secondary batteries and the like is constructed by connecting a fusible conductor between a first electrode, a heating element lead electrode, and a second electrode along a current path, thereby forming a portion of the current path. The fusible conductor in this current path is melted by self-heating due to overcurrent, or by heating a heating element within the protective element. In this protective element, the melted liquid fusible conductor is concentrated on the conductive layer connected to the heating element, separating the first and second electrodes and interrupting the current path.

Prior art literature

Patent Literature

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

Patent Document 2: Japanese Patent Application Laid-Open No. 2004-185960

Patent Document 3: Japanese Patent Application Laid-Open No. 2012-003878.

Summary of the Invention

Problems to be solved by the invention

Furthermore, in recent years, HEVs (Hybrid Electric Vehicles) and EVs (Electric Vehicles), which utilize batteries and motors, have rapidly gained popularity. As the power source for HEVs and EVs, lithium-ion secondary batteries are often used due to their energy density and output characteristics. For example, automotive applications require high voltages and high currents. Therefore, specialized cells capable of withstanding these conditions have been developed. However, due to manufacturing cost constraints, in most cases, multiple battery cells are connected in series or parallel, resulting in the use of general-purpose cells to ensure the required voltage and current.

In high-speed vehicles, for example, a sudden drop in driving power or sudden stop can be dangerous, leading to the need for emergency battery management. For example, if a battery system anomaly occurs while driving, it would be ideal to be able to provide driving power to a repair shop or safe location, or to drive the hazard warning lights and air conditioning, thereby avoiding danger.

However, in a battery pack in which multiple battery cells are connected in series, as in Patent Document 1, if a protection element is provided only on the charge and discharge path, if an abnormality occurs in a portion of the battery cells and the protection element is activated, the charge and discharge path of the entire battery pack will be cut off, and power will no longer be supplied.

Therefore, in order to eliminate only abnormal battery cells in a battery pack composed of a plurality of cells and effectively utilize normal battery cells, a short-circuiting element capable of forming a bypass path for bypassing only the abnormal battery cells has been proposed.

Figure 40 shows an example of a short-circuit element configuration, and Figure 41 shows a circuit diagram of a battery circuit in which the short-circuit element is used. As shown in Figures 40 and 41, the short-circuit element 100 comprises: first and second short-circuit electrodes 102 and 103, which are connected in parallel with the battery cell 101 along the charge and discharge path and are normally open; two soluble conductors 104a and 104b, which melt to short-circuit the first and second short-circuit electrodes 102 and 103; and a heating element 105, which is connected in series with the soluble conductor 104a and melts the soluble conductors 104a and 104b.

The short-circuit element 100 includes a heating element 105 and an external connection electrode 111 connected to one end of the heating element 105 formed on an insulating substrate 110 such as a ceramic substrate. Furthermore, the short-circuit element 100 includes a heating element electrode 113 connected to the other end of the heating element 105, first and second short-circuit electrodes 102, 103, and first and second support electrodes 114, 115 that support soluble conductors 104a, 104b together with the first and second short-circuit electrodes 102, 103, formed on the heating element 105 via an insulating layer 112 such as glass.

The first supporting electrode 114 is connected to the heating element electrode 113 exposed on the insulating layer 112 and is adjacent to the first short-circuit electrode 102. Together with the first short-circuit electrode 102, the first supporting electrode 114 supports both sides of one soluble conductor 104a. Similarly, the second supporting electrode 115 is adjacent to the second short-circuit electrode 103 and, together with the second short-circuit electrode 103, supports both sides of the other soluble conductor 104b.

In the short-circuit element 100 , a power supply path to the heating element 105 is formed, which extends from the external connection electrode 111 through the heating element 105 , the heating element electrode 113 , and the soluble conductor 104 a to the first short-circuit electrode 102 .

The heating element 105 generates heat due to the current flowing through this power supply path, and the soluble conductors 104a and 104b melt due to this heat (Joule heat). As shown in Figure 41, the heating element 105 is connected to a current control element 106, such as a FET, via an external connection electrode 111. The current control element 106 controls the heating element 105 so that when the battery cell 101 is operating normally, it limits the power supply to the heating element 105. In the event of an abnormality, the current flows to the heating element 105 via the charge and discharge path.

In a battery circuit using short-circuit element 100, if an abnormal voltage or other condition is detected in battery cell 101, protection element 107 disconnects battery cell 101 from the charge/discharge path, and current control element 106 is activated, allowing current to flow into heating element 105. As a result, the heat from heating element 105 causes fusible conductors 104a and 104b to melt. Fusible conductors 104a and 104b melt as they drift toward the relatively large first and second short-circuit electrodes 102 and 103, spreading and coalescing between the two short-circuit electrodes 102 and 103. Consequently, the short-circuit electrodes 102 and 103 are short-circuited by the melted conductors of fusible conductors 104a and 104b, creating a current path that bypasses battery cell 101.

In the short-circuit element 100 , the soluble conductor 104 a moves toward the first short-circuit electrode 102 and melts, thereby opening the gap between the first support electrode 114 and the first short-circuit electrode 102 . This cuts off the power supply path to the heating element 105 , thereby stopping the heating element 105 from generating heat.

To operate such a short-circuit element, a fusible conductor and a heating element, which serves as a heat source to melt the fusible conductor, must be installed within the element. The short-circuit element must also be connected to a power path to the heating element. Furthermore, a control element must be provided in the power path to control the power flow to the heating element. The heating element is energized when predetermined operating conditions are met, such as when the battery cell voltage is abnormal.

If the fusible conductor can be melted using heat from a heat source external to the element, there is no need for a heating element within the short-circuit element, which can lead to miniaturization and simplified manufacturing processes. Furthermore, a current control element for controlling the flow of current to the heating element is also unnecessary, making it applicable to a wide range of applications. Furthermore, it can prevent the heating element from overheating due to a malfunction of the current control element for controlling the flow of current to the heating element.

Therefore, an object of the present invention is to provide a temperature short-circuit element and a temperature switching element that are operable in an atmosphere having a temperature equal to or higher than the melting point of a soluble conductor without including a heating element.

Solutions to Problems

In order to solve the above-mentioned problems, the temperature short-circuit element involved in the present invention comprises: a first electrode; a second electrode arranged adjacent to the above-mentioned first electrode; and a first soluble conductor, which melts and aggregates between the above-mentioned first and second electrodes to short-circuit the above-mentioned first and second electrodes, and the above-mentioned first soluble conductor melts in an atmosphere with a temperature above the melting point of the above-mentioned first soluble conductor.

In addition, the temperature switching element involved in the present invention comprises: a first electrode; a second electrode, which is arranged adjacent to the above-mentioned first electrode; a first soluble conductor, which is condensed between the above-mentioned first and second electrodes by melting and short-circuit the above-mentioned first and second electrodes; a third electrode and a fourth electrode; and a third soluble conductor, which is connected across the above-mentioned third and fourth electrodes and cuts off the above-mentioned third and fourth electrodes by melting, and the above-mentioned first and third soluble conductors melt in an atmosphere with a temperature above the melting point of the above-mentioned first and third soluble conductors.

Effects of the Invention

According to the present invention, the soluble conductor melts in an atmosphere at a temperature above its melting point. The soluble conductor aggregates around the first electrode and contacts the second electrode disposed adjacent to the first electrode, thereby short-circuiting the first and second electrodes. Furthermore, according to the present invention, the soluble conductor melts in an atmosphere at a temperature above its melting point, thereby disconnecting the third and fourth electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a diagram showing the structure of a temperature short-circuit element to which the present invention is applied, wherein (A) is a plan view and (B) is an AA' cross-sectional view.

FIG2 is a diagram showing a thermal short-circuit element after the first soluble conductor is melted, (A) is a plan view, and (B) is an AA' cross-sectional view.

FIG3 is a diagram showing the structure of a temperature short-circuit element to which the present invention is applicable, wherein (A) is a plan view, (B) is an AA’ cross-sectional view, and (C) is an external perspective view of the temperature short-circuit element including a heat transfer component.

FIG. 4 is a diagram showing an example of a circuit configuration of a temperature short-circuit element.

FIG. 5 is a diagram showing a circuit configuration example in which a switch of a temperature short-circuit element indicates an on state.

FIG6 is a diagram showing the structure of a temperature short-circuit element including a second fusible conductor, wherein (A) is a plan view and (B) is an AA' cross-sectional view.

FIG7 is a diagram showing a thermal short-circuit element after the first soluble conductor and the second soluble conductor are melted, (A) is a plan view, and (B) is an AA' cross-sectional view.

FIG8 is a diagram showing the structure of a surface-mounted thermal short-circuit element, wherein (A) is a plan view and (B) is an AA' cross-sectional view.

FIG9 is a diagram showing the structure of a surface mount type thermal short circuit element after the first soluble conductor is melted, (A) is a plan view, and (B) is an AA' cross-sectional view.

FIG10 is a diagram showing the structure of a temperature short-circuit element including a first supporting electrode, (A) is a plan view, and (B) is an AA' cross-sectional view.

FIG11 is a diagram showing a state in which a first soluble conductor of a temperature short-circuit element including a first supporting electrode is melted, (A) is a plan view, and (B) is an AA' cross-sectional view.

FIG12 is a diagram showing the structure of a temperature short-circuit element including first and second fusible conductors, wherein (A) is a plan view and (B) is an AA' cross-sectional view.

FIG13 is a diagram showing the structure of the thermal short-circuit element after the first and second soluble conductors are melted, (A) is a plan view, and (B) is an AA' cross-sectional view.

14 is a cross-sectional view showing a structure including first and second soluble conductors and a second support electrode supporting the first and second soluble conductors, wherein (A) shows before melting, and (B) shows after melting.

15 is a cross-sectional view showing a structure of a temperature short-circuit element in which a first soluble conductor is supported by a second insulating layer. (A) shows the first soluble conductor before melting, and (B) shows the first soluble conductor after melting.

FIG16 is a diagram showing a structure of a temperature short-circuit element in which a first fusible conductor is supported by first and second insulating layers, wherein (A) is a plan view, (B) is an AA' cross-sectional view, and (C) is a BB' cross-sectional view.

FIG17 is a plan view showing the thermal short-circuit element shown in FIG16 with the cover member and the first soluble conductor removed.

FIG18 is a diagram showing a state in which the first soluble conductor in the thermal short-circuit element shown in FIG16 is melted, wherein (A) is a plan view, (B) is an AA' cross-sectional view, and (C) is a BB' cross-sectional view.

FIG19 is a diagram showing a temperature short-circuit element including a cover electrode, wherein (A) is a plan view, (B) is an AA' cross-sectional view, and (C) is a BB' cross-sectional view.

FIG20 is a diagram showing a state in which the first soluble conductor in the thermal short-circuit element shown in FIG19 is melted, wherein (A) is a plan view, (B) is an AA' cross-sectional view, and (C) is a BB' cross-sectional view.

FIG21 is a diagram showing the structure of a temperature switching element to which the present invention is applied, (A) is a plan view, and (B) is an AA' cross-sectional view.

FIG22 is a diagram showing the temperature switching element after the first and third soluble conductors are melted, (A) is a plan view, and (B) is an AA' cross-sectional view.

23 is a diagram showing an example of a circuit configuration of a temperature switching element, wherein (A) shows before melting of the first and second soluble conductors, and (B) shows after melting of the first and second soluble conductors.

FIG. 24 is a diagram showing a circuit configuration example of a temperature switching element connected to an external circuit.

FIG25 is a diagram showing the structure of a surface-mounted temperature switching element, (A) is a plan view, and (B) is an AA' cross-sectional view.

FIG26 is a diagram showing the structure of the surface-mount temperature switching element after the first and third soluble conductors are melted, (A) is a plan view, and (B) is an AA' cross-sectional view.

FIG27 is a diagram showing a structure of a temperature switching element in which a first soluble conductor is supported by first and second insulating layers, wherein (A) is a plan view, (B) is an AA' cross-sectional view, and (C) is a BB' cross-sectional view.

FIG28 is a diagram showing the structure of a temperature switching element including first to third soluble conductors, wherein (A) is a plan view and (B) is an AA' cross-sectional view.

FIG29 is a diagram showing a state in which the first and third soluble conductors in the temperature switching element shown in FIG28 are melted, wherein (A) is a plan view and (B) is an AA' cross-sectional view.

30 is a plan view showing a temperature switching element that changes the thermal conductivity of the heat conduction path of the first and second electrodes and the heat conduction path of the third electrode.

FIG31 is a diagram showing a temperature switching element including a cover electrode, wherein (A) is a plan view, (B) is an AA' cross-sectional view, and (C) is a BB' cross-sectional view.

FIG32 is a diagram showing a state in which the first and third soluble conductors in the thermal short-circuit element shown in FIG31 are melted, wherein (A) is a plan view, (B) is an AA' cross-sectional view, and (C) is a BB' cross-sectional view.

33 is a diagram showing a structural example of a soluble conductor in which a low melting point metal layer covers a high melting point metal layer. (A) is a perspective view showing a long soluble conductor, and (B) is a perspective view showing a linear soluble conductor.

34 is a diagram showing a structural example of a soluble conductor having a low melting point metal layer and a high melting point metal layer stacked together, wherein (A) is a perspective view showing a two-layer structure and (B) is a perspective view showing a three-layer structure of the soluble conductor.

FIG. 35 is a perspective view showing a manufacturing process of a soluble conductor having a laminated structure.

FIG36 is a cross-sectional view showing a soluble conductor manufactured with a multilayer structure in which low-melting-point metal layers and high-melting-point metal layers are repeated to form four or more layers.

37 is a diagram showing a soluble conductor having stripe-shaped openings. (A) is a plan view showing a soluble conductor having openings arranged along the longitudinal direction, and (B) is a plan view showing a soluble conductor having openings arranged along the width direction.

FIG38 is a plan view showing a soluble conductor provided with a circular opening.

FIG39 is a plan view showing a soluble conductor in which a circular opening filled with a low-melting-point metal is provided in an inner high-melting-point metal layer.

FIG40 is a plan view showing a short-circuit element according to a reference example.

FIG41 is a circuit diagram of a battery pack incorporating a short-circuit element according to a reference example.

DETAILED DESCRIPTION

Hereinafter, with reference to the accompanying drawings, the temperature short-circuit element and the temperature switching element applicable to the present invention will be described in detail. In addition, the present invention is not limited to the following embodiments, and various modifications can obviously be made without departing from the gist of the present invention. In addition, the accompanying drawings are schematic, and the proportions of various dimensions may differ from those in reality. Specific dimensions, etc. should be determined with reference to the following description. In addition, it should be understood that the accompanying drawings also contain parts with different dimensional relationships or proportions.

[Temperature short circuit element 1]

As shown in Figures 1(A) and 1(B), a thermal short-circuit element 1 to which the present invention is applied comprises: a first electrode 11; a second electrode 12 disposed adjacent to the first electrode 11; and a first soluble conductor 13 that, upon melting, aggregates between the first and second electrodes 11 and 12, thereby short-circuiting the first and second electrodes 11 and 12. Furthermore, as shown in Figures 2(A) and 2(B), the thermal short-circuit element 1 does not require a heating element within the element. Instead, the first soluble conductor 13 is melted in an atmosphere at a temperature above the melting point of the first soluble conductor 13. The molten conductor 13a aggregates around the first electrode 11, thereby also contacting the second electrode 12 disposed adjacent to the first electrode 11, thereby short-circuiting the first and second electrodes 11 and 12.

[Temperature atmosphere]

The thermal short-circuit element 1 melts the first soluble conductor 13 using heat transferred from an external heat source. The term "temperature atmosphere" refers to the temperature environment in which the first soluble conductor 13 melts, created by a heat source external to the thermal short-circuit element 1. This temperature atmosphere can be created, for example, by transferring excess heat generated by abnormal heating of devices near the thermal short-circuit element 1 into the thermal short-circuit element 1. Alternatively, a temperature atmosphere above the melting point of the first soluble conductor 13 can be created by transferring heat from a fire in an electronic device or surrounding fire in which the thermal short-circuit element 1 is used. Furthermore, a temperature atmosphere above the melting point of the first soluble conductor 13 can be created by transferring heat from an external heat source into the thermal short-circuit element 1, not only in emergency situations such as accidents and disasters, but also for normal use to irreversibly turn on a switch.

[Heat transfer components]

Furthermore, the temperature atmosphere that causes the first soluble conductor 13 to melt is created by the air inside the thermal short-circuit element 1 or by components within the element functioning as a heat transfer member 14 that transfers heat from outside the element. The heat transfer member 14 transfers heat from a heat source external to the thermal short-circuit element 1. For example, the outer casing or insulating substrate of the thermal short-circuit element 1, the first and second electrodes 11 and 12, or other components described later can be directly or indirectly connected to the first soluble conductor 13 to heat the first soluble conductor 13. The heat transfer member 14 can be formed, for example, by an electrode pattern connected to the first electrode 11, a wire material, or a heat pipe. It transfers heat from the heat source 15 indirectly to the first soluble conductor 13 via the first electrode 11, causing it to melt.

Furthermore, as shown in FIG. 3 , when a conductive member such as a heat pipe is used as the heat transfer member 14 , it is preferable that at least the surface is covered with an insulating material 16 in order to achieve insulation from the surroundings.

[1st and 2nd electrodes]

The first and second electrodes 11 and 12 are formed on the same plane by printing and firing a high-melting-point metal paste on an insulating substrate such as alumina. Alternatively, the first and second electrodes 11 and 12 may be formed by using a structural member such as a wire material or a plate material made of a high-melting-point metal and supporting it in a predetermined position.

The first and second electrodes 11 and 12 are positioned close together and open. When the thermal short-circuit element 1 is activated, as shown in Figures 2(A) and 2(B), the switch 2 is formed, in which the meltable conductor 13a of the first meltable conductor 13, described later, coalesces and combines, short-circuiting the circuit via this meltable conductor 13a. The first and second electrodes 11 and 12 are provided with external connection terminals 11a and 12a at one end, respectively. These external connection terminals 11a and 12a connect the first and second electrodes 11 and 12 to external circuits such as power supply circuits and digital signal circuits connected by the operation of the thermal short-circuit element 1. When the first and second electrodes 11 and 12 are short-circuited via the meltable conductor 13a, the thermal short-circuit element 1 serves as a current path for the external circuit or a power supply path for the functional circuit.

[First insulation layer]

The second electrode 12 is provided with a first insulating layer 17 at least partially. Furthermore, the second electrode 12 not only overlaps the first soluble conductor 13 supported by the first electrode 11 but also supports the first soluble conductor 13 via the first insulating layer 17. In the thermal short-circuit element 1, the first soluble conductor 13 connected to the first electrode 11 is supported by the first insulating layer 17, leaving an open space between the first and second electrodes 11 and 12 ( FIG. 1 ).

First insulating layer 17 can be made of various insulating materials, such as a glass layer. Furthermore, when first fusible conductor 13 melts in thermal short-circuit element 1, fusible conductor 13a contacts the area of second electrode 12 excluding first insulating layer 17, short-circuiting the first and second electrodes 11 and 12. In this case, first insulating layer 17 controls the location of fusible conductor 13a on second electrode 12 toward the first electrode 12, allowing fusible conductor 13a to be more quickly and reliably aggregated between first and second electrodes 11 and 12.

[First fusible conductor]

The first soluble conductor 13 can be made of any metal that melts rapidly in the temperature atmosphere of the thermal short-circuit element 1 , and for example, low-melting-point metals such as Sn, SnBi-based solder, SnIn-based solder, or other lead-free solders containing Sn as a main component can be preferably used.

The first soluble conductor 13 may also contain a low-melting-point metal and a high-melting-point metal. The low-melting-point metal is preferably Sn or a lead-free solder containing Sn as a primary component, while the high-melting-point metal is preferably Ag, Cu, or an alloy containing these as primary components. By containing both a high-melting-point metal and a low-melting-point metal, even if the reflow temperature exceeds the melting point of the low-melting-point metal and the low-melting-point metal melts during reflow mounting of the short-circuit element 1, leakage of the low-melting-point metal to the outside is suppressed, and the shape of the first soluble conductor 13 is maintained. Furthermore, during a short circuit, the melting of the low-melting-point metal erodes the high-melting-point metal (the solder), allowing it to be rapidly melted at a temperature below the melting point of the high-melting-point metal. Furthermore, as will be described later, the first soluble conductor 13 can be formed in various configurations.

The first soluble conductor 13 is formed in a roughly rectangular plate shape and is connected to the first electrode 11 via a bonding material 18 such as solder. Furthermore, the first soluble conductor 13 protrudes toward the second electrode 12 and overlaps with it, while being supported and separated from the second electrode 12 by the aforementioned first insulating layer 17. Thus, the thermal short-circuit element 1 maintains the first and second electrodes 11 and 12 in an open state before operation. Furthermore, the first soluble conductor 13 melts due to heat from an external heat source creating an atmosphere with a temperature above its melting point. The molten conductor 13a condenses around the first electrode 11 and contacts the second electrode 12, located adjacent to the first electrode 11, creating a short circuit between the first and second electrodes 11 and 12.

For example, the first soluble conductor 13 uses a SnBi-based solder alloy and starts melting at a temperature of approximately 140° C. Alternatively, the first soluble conductor 13 uses a SnIn-based solder alloy and starts melting at a temperature of approximately 120° C.

Furthermore, the first soluble conductor 13 is coated with flux 24 (see FIG. 8 , etc.) for the purpose of preventing oxidation and improving wettability.

The first soluble conductor 13 does not necessarily need to be supported by the first electrode 11. For example, one end of the first soluble conductor 13 may be supported by the first insulating layer 17 described above, while the other end may be supported by a supporting member (not shown) or a fixing member provided on an insulating substrate, etc. In this case, the first soluble conductor 13 is supported at a position overlapping the first and second electrodes 11 and 12, with the soluble conductor 13a condensed between the first and second electrodes 11 and 12 (see Figure 15).

[Circuit Structure/Application]

The thermal short-circuit element 1 has the circuit configuration shown in Figure 4. Specifically, the thermal short-circuit element 1 forms a switch 2, and in its pre-operation state, the first electrode 11 and the second electrode 12 are brought into proximity and insulated by separation, resulting in a short circuit caused by the melting of the first soluble conductor 13. The first and second electrodes 11 and 12 are connected in series along a current path on a circuit board or the like on which the thermal short-circuit element 1 is mounted, thereby being incorporated between various external circuits 28A and 28B, such as power supply circuits and signal circuits.

External circuits 28A and 28B are physically and irreversibly short-circuited by the opening between first and second electrodes 11 and 12 before thermal short-circuit element 1 operates. These circuits can, for example, activate cooling devices, sprinklers, and other equipment, activate backup circuits, operate abnormality notification systems such as alarms, and establish bypass current paths in the event of abnormal heating or fire in an electronic device incorporating thermal short-circuit element 1. Alternatively, external circuits 28A and 28B can be used to bypass data servers to prevent hackers or crackers from accessing network communication equipment, or to activate standard devices and software.

In the thermal short-circuit element 1, if heat is transferred from an external heat source 15 due to abnormal heating caused by a device failure or fire, and the temperature reaches a temperature above the melting point of the first soluble conductor 13, the first soluble conductor 13 is heated and melted, as shown in Figures 2(A) and 2(B), short-circuiting the insulated first and second electrodes 11 and 12 via the molten conductor 13a. As a result, as shown in Figure 5, the switch 2 in the thermal short-circuit element 1 is turned on, connecting the external circuits 28A and 28B.

[Second fusible conductor]

6 , the temperature short-circuit element 1 may connect the second soluble conductor 21 to the second electrode 12 , connect the heat transfer member 14 and the first and second electrodes 11 and 12 to melt the second soluble conductor 21 via the second electrode 2 .

By also providing the second soluble conductor 21 in the second electrode 12, as shown in Figure 7, the thermal short-circuit element 1 can increase the amount of soluble conductor that aggregates between the first and second electrodes 11 and 12, thanks to the soluble conductors 13a and 21a of the first and second soluble conductors 13 and 21, thereby reliably short-circuiting. The second soluble conductor 21 is formed of the same material as the first soluble conductor 13, allowing it to melt at the same temperature as the first soluble conductor 13. Furthermore, as will be described later, the second soluble conductor 21 can be formed in various configurations. Furthermore, similarly to the first soluble conductor 13, the second soluble conductor 21 is bonded to the second electrode 12 using a bonding material 18 such as solder.

Furthermore, the second soluble conductor 21 is preferably provided so as to protrude from the second electrode 12 toward the first electrode 11, being spaced apart from the first electrode 11 and protruding to a position where it overlaps. Furthermore, by supporting the second soluble conductor 21 so as to also overlap the first soluble conductor 13, the soluble conductor 21a of the second soluble conductor 21 and the soluble conductor 13a of the first soluble conductor 13 are easily aggregated, thereby contributing to short-circuiting between the first and second electrodes 11 and 12.

The second electrode 12 to which the second soluble conductor 21 is joined transmits heat from the external heat source 15 via the heat transfer member 14, similarly to the first electrode 11. Thus, the second electrode 12 can melt the second soluble conductor 21 quickly.

[Surface mount type]

Furthermore, the temperature short-circuit element to which the present invention is applied can be formed so as to be surface-mounted on an external circuit substrate. As shown in Figures 8(A) and 8(B), the temperature short-circuit element 1 formed for surface mounting has first and second electrodes 11 and 12 stacked on the surface 10a of an insulating substrate 10. The first soluble conductor 13 is supported on the first electrode 11 by a bonding material 18 such as solder, and overlaps with the second electrode 12, supported by the first insulating layer 17 formed on the second electrode 12. Thus, the temperature short-circuit element 1 is formed with the first and second electrodes 11 and 12. Figure 8(A) is a plan view of the surface-mounted temperature short-circuit element 1, and Figure 8(B) is a cross-sectional view taken along line A-A' of Figure (A).

The insulating substrate 10 is formed in a generally rectangular shape using an insulating material such as alumina, glass ceramic, mullite, or zirconia. Alternatively, the insulating substrate 10 may be made of a material used for printed circuit boards, such as a glass epoxy substrate or a phenyl board. However, the temperature at which the first soluble conductor 13 melts must be carefully considered.

Furthermore, the insulating substrate 10 is preferably made of an insulating material with excellent thermal conductivity, such as a ceramic substrate, or a metal substrate coated with an insulating material. This allows the insulating substrate 10 to function as a heat transfer member 14 that transfers heat from an external heat source 15 to the first soluble conductor 13. Heat from the external heat source 15 is transferred via the insulating substrate 10 to the first electrode 11, directly to the first soluble conductor 13 via the bonding material 18, and indirectly to the first soluble conductor 13 as residual heat within the thermal short-circuit element 1. Consequently, the thermal short-circuit element 1 can create an atmosphere at a temperature above the melting point of the first soluble conductor 13, thereby melting the first soluble conductor 13.

The first and second electrodes 11 and 12 are conductive patterns formed on the front surface 10a of the insulating substrate 10. Furthermore, the first and second electrodes 11 and 12 are connected to external connection terminals (not shown) formed on the back surface 10b of the insulating substrate 10. The thermal short-circuit element 1 is incorporated into various external circuits, such as a power supply circuit, via these external connection terminals.

A first insulating layer 17 made of an insulating material such as glass is provided on the first and second electrodes 11 and 12, and a first soluble conductor 13 formed in a plate shape is mounted across the first and second electrodes 11 and 12. The first and second electrodes 11 and 12 support the first soluble conductor 13 on the first insulating layer 17 and are separated from the first soluble conductor 13. Furthermore, a bonding material 18 such as solder is provided on the first electrode 11, and the first soluble conductor 13 is connected via the bonding material 18.

Furthermore, the first insulating layer 17 is formed by removing the opposing portions of the adjacent first and second electrodes 11 and 12. This not only prevents the bonding material 18 and the molten conductor 13a from flowing out, but also ensures that the molten conductor 13a is concentrated between the first and second electrodes 11 and 12. Thus, the first insulating layer 17 prevents the molten conductor 13a from flowing out toward the external connection terminal and affecting the connection to the external circuit, while also reliably short-circuiting the first and second electrodes 11 and 12.

The first and second electrodes 11 and 12 can be formed by patterning a high-melting-point metal paste such as Ag on the surface 10 a of the insulating substrate 10 using screen printing technology and then firing the paste. Furthermore, the first and second electrodes 11 and 12 are formed using a material having excellent thermal conductivity such as Ag and can function as a heat transfer member 14 that transfers heat from an external heat source 15 to the first soluble conductor 13.

The first soluble conductor 13 is coated with flux 24 for the purpose of preventing oxidation, improving wettability, etc. In the thermal short-circuit element 1 , the cover member 25 covers the surface 10 a of the insulating substrate 10 .

When the thermal short-circuit element 1 is heated by an external heat source, as shown in Figures 9(A) and 9(B), heat is applied to the first soluble conductor 13 via heat transfer components such as the insulating substrate 10 and the first and second electrodes 11 and 12, causing the soluble conductor 13a to aggregate between the first and second electrodes 11 and 12, creating a short circuit. At this point, the thermal short-circuit element 1 is supported so that the first soluble conductor 13 and the second electrode 12 overlap. This allows the soluble conductor 13a to contact the second electrode 12 due to surface tension or gravity, thus reliably short-circuiting the first and second electrodes 11 and 12.

Furthermore, as shown in FIG8 , the thermal short-circuit element 1 may have the first fusible conductor 13 extending toward the side of the first electrode 11 opposite to the second electrode 12, and toward the side of the second electrode 12 opposite to the first electrode 11. This increases the amount of fusible conductor 13a that accumulates between the first and second electrodes 11 and 12, enabling reliable short-circuiting.

In the thermal short-circuit element 1, the plate-shaped first soluble conductor 13 preferably has an area larger than the area connected to the first electrode 11. This ensures a sufficient amount of soluble conductor for short-circuiting the first and second electrodes 11 and 12.

[Temperature short-circuit element 30]

The thermal short-circuit element according to the present invention may also include a support electrode for supporting the end of the first soluble conductor 13 supported by the first electrode 11. In the following description, the same components as those of the thermal short-circuit element 1 are denoted by the same reference numerals and their details are omitted.

The thermal short-circuit element 30 shown in FIG10 is similar to the thermal short-circuit element 1 described above. First and second electrodes 11 and 12 are formed on the surface 10a of an insulating substrate 10, and a first soluble conductor 13 is supported on the first electrode 11 via a bonding material 18. Furthermore, the first soluble conductor 13 is supported by a first insulating layer 17 provided on the first and second electrodes 11 and 12, thereby being separated from the first and second electrodes 11 and 12, thereby creating an open space between the first and second electrodes 11 and 12.

Furthermore, in the thermal short-circuit element 30, both ends of the first soluble conductor 13 protrude outward from the first and second electrodes 11 and 12, and are supported by a first support electrode 31 provided on the surface 10a of the insulating substrate 10. Like the first and second electrodes 11 and 12, the first support electrode 31 can be formed by patterning a high-melting-point metal paste such as Ag on the surface 10a of the insulating substrate 10 using screen printing technology and then firing the paste. It is preferably formed using the same process as the first and second electrodes 11 and 12.

The first support electrode 31 is provided with a bonding material 18 such as solder, thereby securing the two ends of the first soluble conductor 13. The thermal short-circuit element 30 includes a sufficient amount of soluble conductor 13a, allowing the first soluble conductor 13 to protrude outward from the first and second electrodes 11 and 12, to short-circuit the first and second electrodes 11 and 12. Furthermore, by securing the two ends of the first soluble conductor 13 to the first support electrode 31, the first soluble conductor 13 can be stably supported even under high-temperature conditions such as those encountered during reflow mounting. Furthermore, flux 24 is applied to the first soluble conductor 13 to prevent oxidation and improve wettability.

In the thermal short-circuit element 30, the first soluble conductor 13 melts in an atmosphere at a temperature above the melting point of the first soluble conductor 13 . As shown in FIG11 , the molten conductor 13 a aggregates on the first and second electrodes 11 and 12 . As a result, the molten conductor 13 a spreads and aggregates between the first and second electrodes 11 and 12 , creating a short circuit between the first and second electrodes 11 and 12 .

Furthermore, at this time, by forming the first insulating layer 17 between the first and second electrodes 11 and 12, the outflow of the bonding material 18 and the molten conductor 13a is prevented, and the molten conductor 13a is concentrated between the first and second electrodes 11 and 12, thereby reliably short-circuiting the first and second electrodes 11 and 12.

The plate-shaped first soluble conductor 13 has an area larger than the connection area with the first and second electrodes 11 and 12. Thus, the first soluble conductor 13 can ensure a sufficient amount of soluble conductor to short-circuit the first and second electrodes 11 and 12.

[Temperature short-circuit element 40]

Furthermore, the thermal short-circuit element to which the present invention is applied may have the first soluble conductor 13 supported by the first electrode 11, and the second soluble conductor 21 supported by the second electrode 12. In the following description, the same reference numerals are used for the same structures as those of the thermal short-circuit elements 1 and 30 described above, and their details are omitted.

The thermal short-circuit element 40 shown in FIG12 has first and second electrodes 11 and 12 formed on the surface 10a of the insulating substrate 10. The first electrode 11 supports a first soluble conductor 13, and the second electrode 12 supports a second soluble conductor 21. In the thermal short-circuit element 40, the first and second electrodes 11 and 12 independently support the soluble conductors, respectively, so that the first and second soluble conductors 13 and 21 are opened before melting.

A first insulating layer 17 is formed on each of the first and second electrodes 11 and 12, and a bonding material 18 is provided. The first and second soluble conductors 13 and 21 are separated and supported. The second soluble conductor 21 is made of the same material and structure as the first soluble conductor 13, and the first and second soluble conductors 13 and 21 melt in an atmosphere at approximately the same temperature. Furthermore, flux 24 is applied to the first and second soluble conductors 13 and 21 to prevent oxidation and improve wettability.

[Fixed parts]

Furthermore, the thermal short-circuit element 40 can also secure one end of the first soluble conductor 13 supported by the first electrode 11 to the insulating substrate 10 via a securing member 42. Similarly, one end of the second soluble conductor 21 supported by the second electrode 12 can be secured to the insulating substrate 10 via a securing member 42. The first and second soluble conductors 13 and 21 are secured to the bonding material 18 provided between the first and second electrodes 11 and 12 and the securing member 42 provided on the surface 10a of the insulating substrate 10, respectively. This prevents the first and second soluble conductors 13 and 21 from moving toward each other even when heated, such as during reflow mounting. Therefore, the thermal short-circuit element 40 can prevent the first and second soluble conductors 13 and 21 from moving toward each other and contacting each other, which could cause an initial short circuit, before the initial operation, such as during reflow mounting.

The fixing member 42 for fixing the first and second soluble conductors 13 and 21 can be made of the same material as the bonding material 18 , such as bonding solder.

The thermal short-circuit element 40 melts the first and second soluble conductors 13 and 21 in an atmosphere at a temperature equal to or higher than their melting points. As shown in FIG13 , the molten conductor 13a aggregates on the first electrode 11, and the molten conductor 21a aggregates on the second electrode 12. As a result, the molten conductors 13a and 21a aggregate across the space between the first and second electrodes 11 and 12, creating a short circuit between the first and second electrodes 11 and 12.

Furthermore, at this time, by forming the first insulating layer 17 between the first and second electrodes 11 and 12, the outflow of the bonding material 18 and the molten conductors 13a and 21a is prevented, and the aggregation position of the molten conductors 13a and 21a is made to fall between the first and second electrodes 11 and 12, thereby reliably short-circuiting the first and second electrodes 11 and 12.

Furthermore, the first and second soluble conductors 13 and 21 formed in a plate shape preferably have an area larger than the area of connection with the first and second electrodes 11 and 12. Thus, the first and second soluble conductors 13 and 21 can ensure a sufficient amount of soluble conductor to short-circuit the first and second electrodes 11 and 12.

Furthermore, as shown in FIG14 , the thermal short-circuit element 40 may also be provided with a second support electrode 43 that supports the ends of the first and second soluble conductors 13 and 21. The second support electrode 43, like the first and second electrodes 11 and 12, can be formed by patterning a high-melting-point metal paste such as Ag on the surface 10a of the insulating substrate 10 using screen printing technology and then firing the paste. It is preferably formed using the same process as the first and second electrodes 11 and 12.

The second support electrode 43 is also provided with a bonding material 18 such as solder, thereby securing the ends of the first and second soluble conductors 13 and 21. In the thermal short-circuit element 40, the first and second soluble conductors 13 and 21 are sized to protrude outward from the first and second electrodes 11 and 12, thereby providing sufficient soluble conductors 13a and 21a to short-circuit between the first and second electrodes 11 and 12. Furthermore, by securing both ends of the first and second soluble conductors 13 and 21 to the second support electrode 43, the first and second soluble conductors 13 and 21 can be stably supported even in temperature environments such as those encountered during reflow mounting.

[Temperature short-circuit element 50]

Furthermore, the thermal short-circuit element to which the present invention is applied may not support the first soluble conductor 13 by the first electrode 11. In the following description, the same components as those of the thermal short-circuit elements 1, 30, and 40 are denoted by the same reference numerals, and their details are omitted.

The temperature short-circuit element 50 shown in Figure 15 (A) includes: an insulating substrate 10; first and second electrodes 11 and 12 formed on the surface 10a of the insulating substrate 10; a second insulating layer 51 formed on the surface 10a of the insulating substrate 10 and thicker than the first and second electrodes 11 and 12; a first soluble conductor 13 supported by the second insulating layer 51 in a manner spanning the first and second electrodes 11 and 12; and a cover member 25 covering the surface 10a of the insulating substrate 10.

The second insulating layer 51 is composed of, for example, a glass layer and is formed on the surface 10a of the insulating substrate 10, covering the sidewall 25a of the cover member 25, the first and second electrodes 11 and 12, and the region excluding the electrically open gap separating the first and second electrodes 11 and 12. As a result, the second insulating layer 51 is formed with openings 52 that expose the surfaces and opposing side edges of the first and second electrodes 11 and 12. Furthermore, the second insulating layer 51 is formed thicker than the first and second electrodes 11 and 12, and the first soluble conductor 13 is mounted on its upper surface.

The first soluble conductor 13 is mounted on the second insulating layer 51 so as to straddle the first and second electrodes 11 and 12 facing the opening 52 of the second insulating layer 51. The first soluble conductor 13 is widely supported by the second insulating layer 51 except for both sides of the center portion overlapping the opening 52.

The cover member 25 is formed of an insulating material such as engineering plastic and includes side walls 25a mounted on the surface 10a of the insulating substrate 10 and a top surface 25b covering the surface 10a of the insulating substrate 10. The cover member 25 covers the second insulating layer 51 and the periphery of the first soluble conductor 13 via the side walls 25a.

In this thermal short-circuit element 50, when the first soluble conductor 13 melts in an atmosphere at a temperature above the melting point of the first soluble conductor 13, as shown in Figure 15(B), the movement position of the soluble conductor 13a is controlled to the first and second electrodes 11 and 12 facing the opening 52 provided in the second insulating layer 51. Specifically, in the thermal short-circuit element 50, the first soluble conductor 13 is closed by the second insulating layer 51 and the cover member 25, which do not wet the soluble conductor 13a of the first soluble conductor 13. Therefore, the soluble conductor 13a aggregates on the first and second electrodes 11 and 12, which have only wettability.

As a result, in the thermal short-circuit element 50 , the melting conductor 13 a spreads and aggregates between the first and second electrodes 11 and 12 , thereby reliably short-circuiting the first and second electrodes 11 and 12 .

[Temperature short-circuit element 60]

Furthermore, the thermal short-circuit element according to the present invention can be formed for surface mounting purposes, and the support area of the first soluble conductor 13 by the first and second electrodes 11 and 12 can be increased to prevent deformation of the first soluble conductor 13 and prevent initial short circuiting. In the following description, the same reference numerals are used for the same components as those of the thermal short-circuit elements 1, 30, 40, and 50 described above, and their details are omitted.

As shown in Figures 16 and 17 , the thermal short-circuit element 60 includes: an insulating substrate 10; first and second electrodes 11 and 12 formed on the surface 10a of the insulating substrate 10; a first insulating layer 17 laminated on the first and second electrodes 11 and 12, with their opposing tip portions 11b and 12b exposed; a second insulating layer 51 formed on the surface 10a of the insulating substrate 10 and thicker than the first and second electrodes 11 and 12; and a first soluble conductor 13 mounted on the first and second insulating layers 17 and 51. FIG. 16(A) is a plan view of the thermal short-circuit element 60 with the cover member 25 removed; FIG. 16(B) is a cross-sectional view taken along line AA' of FIG. 16(A); and FIG. 16(C) is a cross-sectional view taken along line BB' of FIG. 16(A). 17 is a plan view showing the temperature short-circuit element 60 with the cover member 25 and the first soluble conductor 13 removed.

The first and second electrodes 11 and 12 of the thermal short-circuit element 60 are formed broadly along the longitudinal direction of the rectangular insulating substrate 10, extending from both widthwise edges to the center of the insulating substrate 10 and facing each other at a predetermined interval. Furthermore, the first and second electrodes 11 and 12 are laminated with a first insulating layer 17 approximately in the center, with opposing tip portions 11b and 12b exposed.

The thermal short-circuit element 60 can improve short-circuit reliability by increasing the short-circuit length of the first and second electrodes 11 and 12 , and can also reduce the short-circuit resistance after the first and second electrodes 11 and 12 are short-circuited to cope with a high rated current.

The second insulating layer 51 is formed in the gap between the first and second electrodes 11 and 12 at both ends of the opposing side edges of the first and second electrodes 11 and 12. Furthermore, the second insulating layer 51 is formed thicker than the first and second electrodes 11 and 12 and is continuous with the first insulating layer 17 formed on the first and second electrodes 11 and 12. As a result, the first and second insulating layers 17 and 51 are formed with generally rectangular openings 61 that expose the opposing tip portions 11b and 12b of the first and second electrodes 11 and 12.

The first soluble conductor 13 is fixed to the first electrode 11 via a bonding material 18 such as solder. Furthermore, the first soluble conductor 13 is supported by the first insulating layer 17 and the second insulating layer 51 provided on the first and second electrodes 11 and 12, covering the opening 61. Specifically, in the thermal short-circuit element 60, the first and second electrodes 11 and 12 are extensively laminated on the insulating substrate 10 and, with the exception of the respective tip portions 11b and 12b of the first and second electrodes 11 and 12, are surrounded by the first and second insulating layers 17 and 51. Thus, the first soluble conductor 13 is supported throughout its periphery by the first and second insulating layers 17 and 51, preventing deflection in the longitudinal and width directions.

Therefore, the thermal short-circuit element 60 can reliably prevent the first soluble conductor 13 from being bent during reflow mounting, and can prevent an initial short circuit between the first and second electrodes 11 and 12 due to deformation of the first soluble conductor 13 .

Furthermore, the first soluble conductor 13 may be fixed to the first insulating layer 17 and/or the second insulating layer 51 via the bonding material 18 instead of the first electrode 11 or in addition to the first electrode 11. By fixing the first soluble conductor 13 at multiple locations, positional displacement and the like can be prevented even under temperature conditions such as during reflow mounting, and stable retention can be achieved.

In this thermal short-circuit element 60, when the first soluble conductor 13 melts in an atmosphere at a temperature above the melting point of the first soluble conductor 13, as shown in Figure 18, the movement position of the soluble conductor 13a is controlled to the respective tip portions 11b and 12b of the first and second electrodes 11 and 12, which face the openings 61 provided in the first and second insulating layers 17 and 51. In other words, the thermal short-circuit element 60 is supported by the first and second insulating layers 17 and 51, which are not wettable to the soluble conductor 13a of the first soluble conductor 13. Therefore, the soluble conductor 13a aggregates on the first and second electrodes 11 and 12, which are the only electrodes that have wettability.

As a result, in the thermal short-circuit element 60 , the molten conductor 13 a spreads between the first and second electrodes 11 and 12 and aggregates, thereby reliably short-circuiting the first and second electrodes 11 and 12 .

[Temperature short-circuit element 70]

Furthermore, the thermal short-circuit element to which the present invention is applied may be formed for surface mounting purposes and connected to a cover electrode provided on the cover member with the second electrode 12. In the following description, the same reference numerals are given to the same components as those of the thermal short-circuit elements 1, 30, 40, 50, and 60 described above, and their details are omitted.

As shown in Figure 19 , this thermal short-circuit element 70 includes a cover member 25 covering the surface of the insulating substrate 10. The second electrode 12 is connected to a cover electrode 71 formed on the top surface 25b of the cover member 25, facing the first electrode 11. Figure 19(A) is a plan view of the thermal short-circuit element 70 before the first soluble conductor 13 is melted, with the cover member 25 removed. Figure 19(B) is a cross-sectional view taken along the line AA' shown in Figure 19(A), and Figure 19(C) is a cross-sectional view taken along the line BB' shown in Figure 19(A). Figure 20 is a plan view of the thermal short-circuit element 70 after the first soluble conductor 13 is melted, with the cover member 25 removed. Figure 19(B) is a cross-sectional view taken along the line AA' shown in Figure 19(A), and Figure 19(C) is a cross-sectional view taken along the line BB' shown in Figure 19(A).

The cover member 25 has a side wall 25a connected to the outer edge of the surface 10a of the insulating substrate 10 and a top surface 25b, and can be formed using various engineering plastics or the same material as the insulating substrate 10. The cover member 25 has a cover electrode 71 formed from one side edge 25a to the top surface 25b of the cover member 25.

By mounting the cover member 25 on the insulating substrate 10, the cover electrode 71 is connected to the second electrode 12 formed on the front surface 10a of the insulating substrate 10. The first and second electrodes 11 and 12 are separated from each other and open. Furthermore, the first and second electrodes 11 and 12 are connected to external connection terminals 11a and 12a formed on the back surface 10b of the insulating substrate 10. The thermal short-circuit element 70 is incorporated into various external circuits such as a power supply circuit via these external connection terminals 11a and 12a.

The cover electrode 71 is opposed to the first electrode 11 formed on the surface 10a of the insulating substrate 10, and the first soluble conductor 13 is disposed between the cover electrode 71 and the first electrode 11. The first soluble conductor 13 is fixed to the first electrode 11 via a bonding material 18. Furthermore, the insulating substrate 10 may be provided with the aforementioned first supporting electrode 31, fixing member 42, and second insulating layer 51 so as to also support the first soluble conductor 13.

In this thermal short-circuit element 70, when the first soluble conductor 13 melts in an atmosphere at a temperature above the melting point of the first soluble conductor 13, as shown in FIG20, the molten conductor 13a aggregates on the first electrode 11 and also aggregates on the cover electrode 71 disposed on the top surface 25b opposite the first electrode 11. Thus, the thermal short-circuit element 70 can short-circuit the first and second electrodes 11 and 12 via the molten conductor 13a and the cover electrode 71.

[Temperature switching element]

In the description of the temperature switching element, the same components as those of the above-described thermal short-circuit elements 1 , 30 , 40 , 50 , 60 , and 70 are denoted by the same reference numerals and their details are omitted.

[Temperature switching element 80]

A temperature switching element 80 to which the present invention is applicable, as shown in FIG. 21(A) and FIG. 21(B), comprises: a first electrode 11; a second electrode 12 disposed adjacent to the first electrode 11; a first soluble conductor 13 that melts and aggregates between the first and second electrodes 11 and 12, thereby short-circuiting the first and second electrodes 11 and 12; a third electrode 83 and a fourth electrode 84; and a third soluble conductor 81 that spans and connects the third and fourth electrodes 83 and 84 and is disconnected between the third and fourth electrodes 83 and 84 by melting.

Furthermore, as shown in Figures 22(A) and 22(B), the temperature-switching element 80 does not require a heating element within the element, and the first and third soluble conductors 13 and 81 melt in an atmosphere at a temperature above the melting point of the first and third soluble conductors 13 and 81. As a result, in the temperature-switching element 80, the soluble conductor 13a aggregates around the first electrode 11 and also contacts the second electrode 12 adjacent to the first electrode 11, creating a short circuit between the first and second electrodes 11 and 12. Furthermore, the third soluble conductor 81 melts, disconnecting the third and fourth electrodes 83 and 84.

[Temperature atmosphere]

Similar to the thermal short-circuit element 1 described above, the temperature switching element 80 melts the first and third soluble conductors 13 and 81 using heat transferred from an external heat source 15. As described above, the temperature atmosphere refers to the temperature environment created by the external heat source 15 of the temperature switching element 80, which causes the first and third soluble conductors 13 and 81 to melt. This temperature atmosphere can be created, for example, by excess heat generated by abnormal heating of a device located near the temperature switching element 80 and transferred into the temperature switching element 80. Alternatively, a temperature atmosphere above the melting point of the first and third soluble conductors 13 and 81 can be created by heat transferred into the temperature switching element 80 from a fire in an electronic device using the temperature switching element 80 or a fire in the surrounding area. Furthermore, a temperature atmosphere above the melting point of the first and third soluble conductors 13 and 81 can be created not only in emergency situations such as accidents and disasters, but also in normal operation for irreversible switching by heat transferred from an external heat source into the temperature switching element 80.

[Heat transfer components]

Furthermore, the temperature atmosphere that melts the first and third soluble conductors 13 and 81 is created by allowing the air inside the temperature switching element 80 or components within the element to function as a heat transfer member 82 that transfers heat from outside the element. The heat transfer member 82 transfers heat from a heat source external to the temperature switching element 80. For example, the outer casing or insulating substrate of the temperature switching element 80, the first to fourth electrodes 11, 12, 83, 84, and other components described later can be used to heat the first and third soluble conductors 13 and 81 by being directly or indirectly connected to the first and third soluble conductors 13 and 81. The heat transfer member 82 can be formed, for example, by an electrode pattern, wire material, or heat pipe connected to the first electrode 11 or the third and fourth electrodes 83 and 84. It includes a first heat transfer member 82A that indirectly transfers heat from the heat source 15 to the first soluble conductor 13 via the first electrode 11, and a second heat transfer member 82B that directly transfers heat from the heat source 15 to the third soluble conductor 81.

Furthermore, similarly to the heat transfer member 14 shown in FIG. 3 , when a conductive member such as a heat pipe is used as the heat transfer member 82 , it is preferable that at least the surface be covered with an insulating material in order to achieve insulation from the surroundings.

[1st to 4th electrodes]

The first and second electrodes 11 and 12 are similar to the thermal short-circuit element 1 described above. The third and fourth electrodes 83 and 84 are also formed on the same plane as the first and second electrodes 11 and 12, for example, by printing and firing a high-melting-point metal paste on an insulating substrate such as alumina. Alternatively, the third and fourth electrodes 83 and 84 can be formed using a structural member such as a wire or plate made of a high-melting-point metal, supported at a predetermined position, or the like.

The third and fourth electrodes 83 and 84 are spaced apart at a predetermined distance, thus being open and always electrically connected via the third soluble conductor 81. The connection between the third and fourth electrodes 83 and 84 and the third soluble conductor 81 can be made using a bonding material 18 such as the aforementioned solder. Furthermore, as shown in Figures 22(A) and 22(B), when the temperature switching element 80 operates, the third soluble conductor 81 melts, thereby interrupting the conduction between the third and fourth electrodes 83 and 84. Each of the third and fourth electrodes 83 and 84 has an external connection terminal 83a or 84a at one end. These external connection terminals 83a and 84a connect the third and fourth electrodes 83 and 84 to an external circuit, such as a power supply circuit or digital signal circuit, that is interrupted by the operation of the temperature switching element 80. By interrupting the connection between the third and fourth electrodes 83 and 84, the temperature switching element 80 can interrupt the current path or functional circuit of the external circuit.

[Third fusible conductor]

As with the first soluble conductor 13, the third soluble conductor 81 can be made of any metal that melts rapidly due to the temperature atmosphere of the temperature switching element 80. Preferably, a low melting point metal such as Sn or SnBi solder, SnIn solder, or other lead-free solder containing Sn as the main component can be used.

In addition, the third soluble conductor 81 may contain a low melting point metal and a high melting point metal. The low melting point metal and the high melting point metal may be made of the same materials as those used for the first soluble conductor 13 described above.

Furthermore, the third soluble conductor 81 is coated with flux 24 for the purpose of preventing oxidation, improving wettability, and the like.

[Circuit Structure/Application]

The temperature switching element 80 has the circuit configuration shown in Figures 23(A) and 23(B). Specifically, the temperature switching element 80 forms the switch 2, such that, in its pre-operation state, the first electrode 11 and the second electrode 12 are close to each other, separated and insulated, and short-circuited by the melting of the first soluble conductor 13. Furthermore, the temperature switching element 80 connects the third and fourth electrodes 83 and 84 via the third soluble conductor 81, which is disconnected by the melting of the third soluble conductor 81.

As shown in FIG24 , the first and second electrodes 11 and 12 are connected in series on the current path of the circuit board on which the temperature switching element 80 is mounted, thereby interposing various external circuits 28A and 28B, such as power supply circuits and signal circuits. Similarly, the third and fourth electrodes 83 and 84 are also connected in series on the current path of the circuit board on which the temperature switching element 80 is mounted, thereby interposing various external circuits 85A and 85B, such as power supply circuits and signal circuits.

External circuits 28A and 28B are circuits that are physically and irreversibly short-circuited by the opening between first and second electrodes 11 and 12 before the temperature switching element 80 is activated. These circuits can, for example, activate cooling devices, sprinklers, and other equipment, activate backup circuits, operate abnormality notification systems such as alarms, and establish bypass current paths in the event of abnormal heating of the electronic device incorporating the temperature switching element 80, or in an emergency such as a fire. Alternatively, external circuits 28A and 28B can establish bypass signal paths to bypass data servers in network communication equipment, or activate standard devices and software.

Furthermore, the external circuits 85A and 85B are connected by connecting the third and fourth electrodes 83 and 84 via the third soluble conductor 81 before the temperature switching element 80 is operated, and are physically and irreversibly disconnected by disconnection between the third and fourth electrodes 83 and 84. These circuits are applicable to all circuits, such as power supply circuits of battery packs or electronic devices, signal circuits, and Internet circuits in network communication equipment.

When the temperature switching element 80 receives heat from abnormal heating associated with a device failure, fire, or external heat source 15, resulting in an atmosphere with a temperature exceeding the melting point of the first and third soluble conductors 13 and 81, the first and third soluble conductors 13 and 81 are heated and melted, as shown in Figures 22(A) and 22(B). As a result, the soluble conductor 13a in the temperature switching element 80 condenses around the first electrode 11 and also contacts the adjacent second electrode 11. The insulated first and second electrodes 11 and 12 are short-circuited via the soluble conductor 13a, connecting the external circuits 28A and 28B. Furthermore, the melting of the third soluble conductor 81 in the temperature switching element 80 interrupts the conduction between the third and fourth electrodes 83 and 84, disconnecting the external circuits 85A and 85B.

In the temperature switching element 80 , similarly to the temperature short-circuit element 1 , the second soluble conductor 21 may be connected to the second electrode 12 , the heat transfer member 82A may be continuous with the first and second electrodes 11 and 12 , and the second soluble conductor 21 may be melted via the second electrode 2 .

[Melting Order]

Furthermore, the temperature switching element 80 may limit the order of short-circuiting between the external circuits 28A and 28B and interrupting between the external circuits 85A and 85B by limiting the order of melting the first soluble conductor 13 and the third soluble conductor 81 .

Specifically, in the temperature switching element 80, by melting the first soluble conductor 13 before the third soluble conductor 81, the external circuits 85A and 85B can be disconnected after the external circuits 28A and 28B are short-circuited. This allows, for example, the external circuits 85A and 85B, which comprise a normal power supply circuit or a functional circuit, to be disconnected after the external circuits 28A and 28B, which comprise an emergency power supply circuit or a backup circuit, are activated.

Furthermore, in the temperature switching element 80, by melting the third soluble conductor 81 before the first soluble conductor 13, the external circuits 28A and 28B can be short-circuited after the external circuits 85A and 85B are disconnected. Thus, for example, after the external circuits 85A and 85B, which constitute the power supply circuit, are disconnected, the external circuits 28A and 28B, which constitute the alarm system circuit, can be activated.

The order in which the first soluble conductor 13 and the third soluble conductor 81 melt can be controlled by providing a difference in melting points between the first soluble conductor 13 and the third soluble conductor 81. For example, when the first soluble conductor 13 is formed using SnIn solder and the third soluble conductor 81 is formed using SnBi solder, the melting point of indium-tin alloy is 120°C and the melting point of tin-bismuth alloy is 138°C. Therefore, the first soluble conductor 13 has a lower melting point than the third soluble conductor 81 and can melt first.

Furthermore, the order in which the first and third soluble conductors 13 and 81 melt can be controlled by varying the cross-sectional areas of the first and third soluble conductors 13 and 81. As the cross-sectional area of a soluble conductor increases, it becomes more difficult to melt. Therefore, the cross-sectional area of the conductor that melts first can be reduced, while the cross-sectional area of the conductor that melts later can be increased.

Furthermore, the melting order of the first soluble conductor 13 and the third soluble conductor 81 may be controlled by providing a difference in thermal conductivity by changing the path length and thickness of the heat transfer member 82 .

[Surface mount type]

Furthermore, the temperature switching element to which the present invention is applied can be formed so as to be surface-mountable on an external circuit board. As shown in Figures 25(A) and 25(B), a temperature switching element 80 formed for surface mounting has first to fourth electrodes 11, 12, 83, and 84 stacked on the surface 10a of an insulating substrate 10. The first soluble conductor 13 is supported on the first electrode 11 by a bonding material 18 such as solder. It overlaps with the second electrode 12 and is supported by the first insulating layer 17 formed on the second electrode 12. Thus, the temperature switching element 80 has the first and second electrodes 11 and 12 exposed. The third soluble conductor 81 is connected across the third and fourth electrodes 83 and 84 using the bonding material 18. Figure 25(A) is a plan view of the surface-mount temperature switching element 80, and Figure 25(B) is a cross-sectional view taken along line A-A' of Figure 25(A).

The insulating substrate 10 can be similar to the insulating substrate 10 of the thermal short-circuit element 1 described above. By using an insulating material with excellent thermal conductivity, such as a ceramic substrate, or a metal substrate coated with an insulating material, the insulating substrate 10 functions as a heat transfer member 82 that transfers heat from an external heat source 15 to the first and third soluble conductors 13 and 81. Heat from the external heat source 15 is transferred via the insulating substrate 10 to the first, third, and fourth electrodes 11, 83, and 84, directly to the first and third soluble conductors 13 and 81 via the bonding material 18, and indirectly to the first and third soluble conductors 13 and 81 as waste heat within the temperature switching element 80. Consequently, the temperature switching element 80 can create an atmosphere at a temperature above the melting point of the first and third soluble conductors 13 and 81, thereby melting the first and third soluble conductors 13 and 81.

The first to fourth electrodes 11, 12, 83, and 84 are formed as a conductive pattern on the front surface 10a of the insulating substrate 10. Furthermore, the first to fourth electrodes 11, 12, 83, and 84 are connected to external connection terminals (not shown) formed on the back surface 10b of the insulating substrate 10. The temperature switching element 80 is incorporated into various external circuits, such as power supply circuits and backup circuits, via these external connection terminals.

The first to fourth electrodes 11, 12, 83, and 84 can be formed by patterning a high-melting-point metal paste such as Ag on the surface 10a of the insulating substrate 10 using screen printing technology and then firing the paste. Furthermore, the first to fourth electrodes 11, 12, 83, and 84 can be formed using a material having excellent thermal conductivity such as Ag, and can function as a heat transfer member 82 that transfers heat from the external heat source 15 to the first soluble conductor 13.

A first insulating layer 17 made of an insulating material such as glass is provided on the first and second electrodes 11 and 12, and a first soluble conductor 13 formed in a plate shape is mounted across the first and second electrodes 11 and 12. The first insulating layer 17 supports the first soluble conductor 13, and the first and second electrodes 11 and 12 are separated from each other. Furthermore, a bonding material 18 such as solder is provided on the first electrode 11, and the first soluble conductor 13 is connected via the bonding material 18.

Furthermore, a first insulating layer 17 made of an insulating material such as glass is provided on the third and fourth electrodes 83 and 84 in the vicinity of the connection portion with the third soluble conductor 81 .

The first insulating layer 17 is formed between the third and fourth electrodes 83 and 84 and the external connection terminals to prevent the bonding material 18 and the molten conductor 81a from flowing out. Thus, the first insulating layer 17 prevents the molten conductor 81a from flowing toward the external connection terminals and affecting the connection to the external circuit.

Furthermore, the first and third soluble conductors 13 and 81 are coated with flux 24 to prevent oxidation, improve wettability, etc. In the temperature switching element 80 , the cover member 25 covers the surface 10 a of the insulating substrate 10 .

When the temperature-switching element 80 is heated by an external heat source, as shown in Figures 26(A) and 26(B), heat is applied to the first and third soluble conductors 13 and 81 via heat transfer components such as the insulating substrate 10 and the first to fourth electrodes 11, 12, 83, and 84. Furthermore, in the temperature-switching element 80, the soluble conductor 13a aggregates between the first and second electrodes 11 and 12, creating a short circuit between the first and second electrodes 11 and 12. Furthermore, the third soluble conductor 81 melts, disconnecting the third and fourth electrodes 83 and 84.

Furthermore, as shown in FIG25 , the temperature switching element 80 may extend the first soluble conductor 13 toward the side of the first electrode 11 opposite to the second electrode 12, and also toward the side of the second electrode 12 opposite to the first electrode 11. Thus, the temperature switching element 80 can increase the amount of soluble conductor 13a that aggregates between the first and second electrodes 11 and 12, thereby reliably short-circuiting them.

In the temperature switching element 80, the plate-shaped first soluble conductor 13 preferably has an area larger than the connection area with the first electrode 11. This ensures a sufficient amount of soluble conductor for short-circuiting the first and second electrodes 11 and 12.

Furthermore, similar to the above-described temperature short-circuit element 30 , the temperature switching element 80 may be provided to support the end portion of the first soluble conductor 13 supported by the first electrode 11 .

[Temperature switching element 87]

Furthermore, the temperature switching element according to the present invention may be formed for surface mounting purposes, and the support area for the first soluble conductor 13 formed by the first and second electrodes 11 and 12 may be increased to prevent deformation of the first soluble conductor 13 and prevent initial short circuiting. In the following description, components identical to those of the aforementioned temperature short-circuit elements 1, 30, 40, 50, 60, 70 and the temperature switching element 80 are denoted by the same reference numerals, and their details are omitted.

As shown in Figure 27 , the temperature switching element 87 includes: an insulating substrate 10; first to fourth electrodes 11, 12, 83, and 84 formed on the surface 10a of the insulating substrate 10; a first insulating layer 17 laminated on the first and second electrodes 11 and 12, with the opposing tip portions 11b and 12b of the first and second electrodes 11 and 12 exposed; a second insulating layer 51 thicker than the first and second electrodes 11 and 12 formed on the surface 10a of the insulating substrate 10; a first soluble conductor 13 mounted on the first and second insulating layers 17 and 51; and a third soluble conductor 81 connected between the third and fourth electrodes 83 and 84. Figure 27(A) is a plan view of the temperature switching element 87 with the cover member 25 removed, Figure 27(B) is a cross-sectional view taken along line AA' of Figure 27(A), and Figure 27(C) is a cross-sectional view taken along line BB' of Figure 27(A).

The first and second electrodes 11 and 12 in the temperature switching element 87 are formed widely throughout the longitudinal direction of the insulating substrate 10 formed in a rectangular shape, similar to the temperature short-circuit element 60, and are formed from the two side edges in the width direction of the insulating substrate 10 to the central part, separated by a predetermined interval and opposite to each other, and the opposite front end portions 11b and 12b are exposed from the first insulating layer 17 stacked in the approximately central part.

The first and second insulating layers 17 and 51 of the temperature switching element 87 are formed similarly to the temperature short-circuit element 60 , and have a substantially rectangular opening 61 exposing the opposing tip portions 11 b and 12 b of the first and second electrodes 11 and 12 .

The first soluble conductor 13 is mounted on the first and second insulating layers 17 and 51 so as to cover the opening 61 and is fixed to the first electrode 11 via a bonding material 18 such as solder. As a result, the first soluble conductor 13 is entirely supported by the first and second insulating layers 17 and 51, preventing deflection in the longitudinal and width directions.

Therefore, the temperature switching element 87 can reliably prevent the first soluble conductor 13 from being bent during reflow mounting, and can prevent an initial short circuit between the first and second electrodes 11 and 12 due to deformation of the first soluble conductor 13 .

Furthermore, the first soluble conductor 13 may be fixed to the first insulating layer 17 and/or the second insulating layer 51 via the bonding material 18 instead of the first electrode 11 or in addition to the first electrode 11. By fixing the first soluble conductor 13 at multiple locations, positional displacement and the like can be prevented even under temperature conditions such as during reflow mounting, and stable retention can be achieved.

In this temperature-switching element 87, when the first and third soluble conductors 13 and 81 melt in an atmosphere at a temperature above their melting points, the molten conductor 13a spreads and aggregates between the tip portions 11b and 12b of the first and second electrodes 11 and 12, facing through the opening 61. Consequently, in the temperature-switching element 87, the molten conductor 13a spreads and aggregates between the first and second electrodes 11 and 12, reliably short-circuiting the first and second electrodes 11 and 12. Furthermore, in the temperature-switching element 87, the melting of the third soluble conductor 81 isolates the third and fourth electrodes 83 and 84.

[Temperature switching element 90]

Furthermore, in the temperature switching element to which the present invention is applied, the first soluble conductor 13 may be supported by the first electrode 11, and the second soluble conductor 21 may be supported by the second electrode 12. In the following description, the same reference numerals are used for the same components as those of the above-described temperature short-circuit elements 1, 40, 50, 60, 70 and the temperature switching element 80, and their details are omitted.

The temperature-switching element 90 shown in Figure 28 is similar to the temperature short-circuit element 40 described above. First and second electrodes 11 and 12 are formed on an insulating substrate 10. A first soluble conductor 13 is supported on the first electrode 11, and a second soluble conductor 21 is supported on the second electrode 12. Because the first and second electrodes 11 and 12 independently support the soluble conductors, the temperature-switching element 90 opens before the first and second soluble conductors 13 and 21 melt. The first, second, and third soluble conductors 13, 21, and 81 are made of the same material and structure and melt in an atmosphere at approximately the same temperature. Furthermore, flux 24 is applied to the first, second, and third soluble conductors 13, 21, and 81 to prevent oxidation and improve wettability.

Furthermore, similarly to the aforementioned thermal short-circuit element 40, the temperature-switching element 90 may have one end of the first soluble conductor 13 supported by the first electrode 11 fixed to the insulating substrate 10 via a fixing member 42. Similarly, one end of the second soluble conductor 21 supported by the second electrode 12 may be fixed to the insulating substrate 10 via a fixing member 42. Furthermore, similarly to the aforementioned thermal short-circuit element 40, the temperature-switching element 90 may have a second supporting electrode 43 provided on the insulating substrate 10 to support the ends of the first and second soluble conductors 13 and 21 via a bonding material 18.

The temperature-switching element 90 melts the first to third soluble conductors 13, 21, and 81 in an atmosphere at a temperature above their melting points. As shown in FIG29 , in the temperature-switching element 90, the molten conductor 13a aggregates on the first electrode 11, and the molten conductor 21a aggregates on the second electrode 12. Consequently, the molten conductors 13a and 21a aggregate across the first and second electrodes 11 and 12, creating a short circuit between the first and second electrodes 11 and 12. Furthermore, the third soluble conductor 81 melts, disconnecting the third and fourth electrodes 83 and 84.

Furthermore, the first and second soluble conductors 13 and 21 formed in a plate shape preferably have a larger area than the connection area with the first and second electrodes 11 and 12. Thus, the first and second soluble conductors 13 and 21 can ensure a sufficient amount of soluble conductor to short-circuit the first and second electrodes 11 and 12.

[Heat conduction path]

Furthermore, as described above, the temperature switching element 90, like the temperature switching element 80, can also control the order in which the external circuits 28A and 28B are short-circuited and the external circuits 85A and 85B are disconnected by controlling the order in which the first soluble conductor 13 and the third soluble conductor 81 melt. The order in which the first soluble conductor 13 and the third soluble conductor 81 melt can be controlled by setting a difference in melting point between the first soluble conductor 13 and the third soluble conductor 81 or by changing the cross-sectional area.

In addition, the temperature switching element 90 can also limit the melting order of the first soluble conductor 13 and the third soluble conductor 81 by changing the thermal conductivity of the heat conduction path to the first soluble conductor 13 of the first electrode 11 functioning as the heat transfer component 82 and the heat conduction path to the third soluble conductor 81 of the third electrode 83 functioning as the heat transfer component 82.

Specifically, as shown in FIG30 , in the temperature switching element 90, the first and second electrodes 11 and 12 function as heat transfer members that transfer heat from an external heat source to the first soluble conductor 13, and the third electrode 83 functions as a heat transfer member that transfers heat from an external heat source to the third soluble conductor 81. In this case, for example, in the temperature switching element 90, the heat transfer paths P1 and P2 from the external heat source of the first and second electrodes 11 and 12 are formed to be narrow and long, while the heat transfer path P3 from the external heat source of the third electrode 83 is formed to be wide and short.

As a result, the thermal conductivity of the heat transfer paths P1 and P2 that transfer heat to the first soluble conductor 13 is relatively lower than that of the heat transfer path P3 that transfers heat to the third soluble conductor 81. Consequently, when the temperature of the atmosphere reaches a temperature above the melting point of the first and third soluble conductors 13 and 81 due to heat from the external heat source 15, the temperature switching element 90 transfers heat to the third soluble conductor 81 before the first soluble conductor 13. Consequently, the temperature switching element 90 can melt the third soluble conductor 81 first, thereby disconnecting the external circuits 85A and 85B, and then melt the first soluble conductor 13, thereby short-circuiting the external circuits 28A and 28B.

In addition, the temperature switching element 90 may change the thermal conductivity of the heat transfer paths P1 and P2 and the heat transfer path P3 from the external heat source by forming the first and second electrodes 11 and 12 and the third electrode 83 with materials having different thermal conductivities.

[Temperature switching element 97]

Furthermore, the temperature switching element to which the present invention is applied may be formed for surface mounting and connected to a cover electrode provided on the cover member with the second electrode 12. In the following description, components identical to those of the aforementioned temperature short-circuit elements 1, 30, 40, 50, 60, 70 and temperature switching elements 80, 90 are denoted by the same reference numerals, and their details are omitted.

As shown in Figure 31 , the temperature-switching element 97 comprises first to fourth electrodes 11, 12, 83, and 84 stacked on the surface 10a of the insulating substrate 10. The third soluble conductor 81 is connected across the third and fourth electrodes 83 and 84 via a bonding material 18. Furthermore, the temperature-switching element 97 includes a cover member 25 covering the surface of the insulating substrate 10. The second electrode 12 is connected to a cover electrode 71 formed on the top surface 25b of the cover member 25, facing the first electrode 11. Figure 31(A) is a plan view of the temperature-switching element 97 before the first soluble conductor 13 is melted, with the cover member 25 removed. Figure 31(B) is a cross-sectional view taken along line AA' of Figure 31(A), and Figure 31(C) is a cross-sectional view taken along line BB' of Figure 31(A). 32 is a plan view showing the temperature switching element 97 after the first soluble conductor 13 is melted, with the cover member 25 removed. FIG32 (B) is a cross-sectional view taken along line AA' shown in FIG32 (A), and FIG32 (C) is a cross-sectional view taken along line BB' shown in FIG32 (A).

The cover member 25 has a cover electrode 71 formed from one side edge 25a to the top surface 25b. By being mounted on the insulating substrate 10, the cover electrode 71 is connected to the second electrode 12. Furthermore, the first and second electrodes 11 and 12 are separated from each other and open. Furthermore, the first and second electrodes 11 and 12 are connected to external connection terminals 11a and 12a formed on the back surface 10b of the insulating substrate 10. The temperature switching element 97 is incorporated into various external circuits such as a power supply circuit via these external connection terminals 11a and 12a.

The cover electrode 71 faces the first electrode 11 formed on the insulating substrate 10, and the first soluble conductor 13 is disposed between the cover electrode 71 and the first electrode 11. The first soluble conductor 13 is fixed to the first electrode 11 via a bonding material 18. Alternatively, the first soluble conductor 13 may be supported by providing the aforementioned fixing member 42, the first supporting electrode 31, or the second insulating layer 51 on the insulating substrate 10.

In this temperature-switching element 97, when the first and third soluble conductors 13 and 81 melt in an atmosphere at a temperature above their melting points, as shown in FIG32 , the molten conductor 13a aggregates on the first electrode 11 and also on the cover electrode 71 disposed on the top surface 25b opposite the first electrode 11. Thus, the temperature-switching element 97 can short-circuit the first and second electrodes 11 and 12 via the molten conductor 13a and the cover electrode 71. Furthermore, in the temperature-switching element 97, the third soluble conductor 81 melts, thereby isolating the third and fourth electrodes 83 and 84.

[Other structures]

Furthermore, in each of the above-described temperature short-circuit elements 1, 30, 40, 50, 60, 70 and temperature switching elements 80, 90, and 97, the plate-shaped first soluble conductor 13 preferably has an area at least twice the area of connection with the first electrode 11. This ensures that the first soluble conductor 13 has a sufficient amount of soluble conductor 13a to short-circuit between the first electrode 11 and the second electrode 12 or the cover electrode 71, and also allows for rapid melting even when the end portion is supported by the fixing member 42 or the first support electrode 31.

Furthermore, in each of the above-described temperature short-circuit elements 1, 30, 40, 50, 60, 70 and temperature-switching elements 80, 90, and 97, the first soluble conductor 13 may be formed of a wire material. In this case, the first soluble conductor 13 is preferably at least twice as long as the length of the connection to the first electrode 11. This ensures that the first soluble conductor 13 has a sufficient amount of soluble conductor 13a to short-circuit between the first electrode 11 and the second electrode 12 or the cover electrode 71, and also allows for rapid melting even when the end portion is supported by the fixing member 42 or the first support electrode 31.

Furthermore, in each of the aforementioned thermal short-circuit elements 1, 30, 40, 50, 60, 70 and temperature-switching elements 80, 90, and 97, the distance between the first and second electrodes 11 and 12 is preferably less than or equal to the width of the first electrode 11 along an extension of the distance between the first and second electrodes. For example, as shown in FIG1 , in the thermal short-circuit element 1, the distance _W1 between the first and second electrodes 11 and 12 is preferably less than _or equal to the width W2 of the first electrode 11 along an extension of the distance between the first and second electrodes. This allows the first and second electrodes 11 and 12 to be positioned closer together, allowing the melted conductor 13a of the first soluble conductor 13 to more reliably contact the second electrode 12 when it condenses around the first electrode 11, allowing the melted conductor 13a to condense between the first and second electrodes 11 and 12.

Furthermore, the first to fourth electrodes 11, 12, 83, 84, the first and second support electrodes 31, 43, and the cover electrode 71 of each of the thermal short-circuit elements 1, 30, 40, 50, 60, 70 and the temperature switching elements 80, 90, 97 can be formed using a common electrode material such as Cu or Ag. Preferably, a coating such as Ni/Au plating, Ni/Pd plating, or Ni/Pd/Au plating is applied to the surface using a known method such as plating. This prevents oxidation of the first to fourth electrodes 11, 12, 83, 84, the first support electrode 31, and the cover electrode 71, while reliably retaining the first to third soluble conductors 13, 21, 81. Furthermore, when the temperature short-circuit elements 1, 30, 40, 50, 60, 70 and the temperature switching elements 80, 90, 97 are reflow mounted, the first to fourth electrodes 11, 12, 83, 84, the first and second support electrodes 31, 43 and the cover electrode 71 can be prevented from being eroded (solder erosion) by the bonding material 18 such as the connecting solder connecting the first to third soluble conductors 13, 21, 81 or by the melting of the low-melting-point metal forming the outer layer of the first to third soluble conductors 13, 21, 81.

[Structure of fusible conductor]

As described above, the first to third soluble conductors 13, 21, and 81 may contain both a low-melting-point metal and a high-melting-point metal. In the following description, except where specifically distinguished, the first to third soluble conductors 13, 21, and 81 are collectively referred to as "soluble conductors 13, 21, and 81." As the low-melting-point metal, preferably, solder such as lead-free solder containing Sn as a primary component is used. As the high-melting-point metal, preferably, Ag, Cu, or alloys containing these as primary components is used. In this case, as shown in Figures 33(A) and 33(B), the soluble conductors 13, 21, and 81 may have a low-melting-point metal layer 92 as an inner layer and a high-melting-point metal layer 91 as an outer layer. In this case, the soluble conductors 13, 21, and 81 may have a structure in which the low-melting-point metal layer 92 is entirely covered by the high-melting-point metal layer 91, or a structure in which all but a pair of opposing side surfaces are covered.

The covering structure of the low-melting-point metal layer 92 formed by the high-melting-point metal layer 91 can be formed using known film-forming techniques such as plating. Among them, electrolytic plating, which can continuously apply high-melting-point metal plating to linear or long-length low-melting-point metal materials, is advantageous in terms of operating efficiency and manufacturing cost.

Furthermore, the soluble conductors 13, 21, and 81 may be those having a low-melting-point metal layer 92 as an outer layer and a high-melting-point metal layer 91 as an inner layer. In this case, the soluble conductors 13, 21, and 81 may be configured such that the entire surface of the high-melting-point metal layer 91 is covered with the low-melting-point metal layer 92, or may be configured such that only a pair of opposing side surfaces are covered.

34 , the soluble conductors 13 , 21 , and 81 may have a laminated structure in which a high-melting-point metal layer 91 and a low-melting-point metal layer 92 are laminated.

In this case, as shown in FIG34(A), the soluble conductors 13, 21, and 81 may be formed as a two-layer structure consisting of a lower layer connected to the first to fourth electrodes 11, 12, 83, and 84 or the first and second supporting electrodes 31 and 43, and an upper layer laminated on the lower layer, with the low-melting-point metal layer 92 being laminated on the upper surface of the high-melting-point metal layer 91 being the lower layer, or conversely, the high-melting-point metal layer 91 being laminated on the upper surface of the low-melting-point metal layer 92 being the lower layer. Alternatively, as shown in FIG34(B), the soluble conductors 13, 21, and 81 may be formed as a three-layer structure consisting of an inner layer and outer layers laminated on the upper and lower surfaces of the inner layer, with the low-melting-point metal layer 92 being laminated on the upper and lower surfaces of the high-melting-point metal layer 91 being the inner layer, or conversely, the high-melting-point metal layer 91 being laminated on the upper and lower surfaces of the low-melting-point metal layer 92 being the inner layer.

The laminated structure of the high-melting-point metal layer 91 and the low-melting-point metal layer 92 can be formed by laminating a sheet of low-melting-point metal material and a sheet of high-melting-point metal material. For example, as shown in FIG35 , a laminated structure in which the high-melting-point metal layer 91, forming the outer layer, is laminated on the upper and lower surfaces of the inner low-melting-point metal layer 92 can be formed by laminating Ag foil 91a, forming the sheet of high-melting-point metal layer 91, on the upper and lower surfaces of solder foil 92a, forming the sheet of low-melting-point metal layer 92. The laminated structure is then hot-pressed or hot-rolled at a predetermined temperature and pressure. In the soluble conductor 13, 21, or 81 formed by the laminated structure of the high-melting-point metal layer 91 and the low-melting-point metal layer 92, the interface between the low-melting-point metal material and the high-melting-point metal material is alloyed and integrated by stamping or rolling at a predetermined temperature and pressure. Furthermore, the soluble conductors 13 , 21 , and 81 are laminated on the high melting point metal layer 91 with a substantially uniform thickness over the entire surface of the low melting point metal layer 92 .

Alternatively, the stacked structure of the high melting point metal layer 91 and the low melting point metal layer 92 can be formed by stacking the metal material constituting the high melting point metal layer 91 on the upper and lower surfaces of the solder foil 92a constituting the sheet-shaped low melting point metal layer 92 using a well-known thin film forming process such as evaporation and sputtering.

Furthermore, as shown in FIG36 , the soluble conductors 13, 21, and 81 may have a multilayer structure having four or more layers alternately stacked with high-melting-point metal layers 91 and low-melting-point metal layers 92. In this case, the soluble conductors 13, 21, and 81 may have a structure in which the metal layer constituting the outermost layer covers the entire surface or covers only a pair of opposing side surfaces.

Furthermore, the soluble conductors 13, 21, and 81 may have the high melting point metal layer 91 partially laminated in stripes on the surface of the low melting point metal layer 92 constituting the inner layer.

The soluble conductors 13, 21, and 81 shown in FIG37(A) are constructed by forming a plurality of linear high-melting-point metal layers 91 on the surface of a low-melting-point metal layer 92 at predetermined intervals along the width direction and along the longitudinal direction. Linear openings 93 are then formed along the longitudinal direction, exposing the low-melting-point metal layer 92 through these openings 93. Exposing the low-melting-point metal layer 92 through the openings 93 increases the contact area between the molten low-melting-point metal and the high-melting-point metal, further promoting the erosion of the high-melting-point metal layer 91 and improving the fuse performance of the soluble conductors 13, 21, and 81. The openings 93 can be formed, for example, by partially plating the low-melting-point metal layer 92 with the metal constituting the high-melting-point metal layer 91.

37B , the soluble conductors 13 , 21 , and 81 may be formed by forming a plurality of linear high melting point metal layers 91 on the surface of the low melting point metal layer 92 at predetermined intervals along the longitudinal direction and along the width direction, thereby forming linear openings 93 along the width direction.

Alternatively, as shown in FIG38 , the soluble conductors 13, 21, and 81 may be configured such that a high-melting-point metal layer 91 is formed on the surface of a low-melting-point metal layer 92, and a circular opening 94 is formed over the entire surface of the high-melting-point metal layer 91, exposing the low-melting-point metal layer 92 from the opening 94. The opening 94 can be formed by, for example, partially plating the low-melting-point metal layer 92 with a metal constituting the high-melting-point metal layer 91.

The soluble conductors 13 , 21 , and 81 expose the low melting point metal layer 92 from the opening 94 , thereby increasing the contact area with the molten low melting point metal and high melting point metal, further promoting the erosion of the high melting point metal, and improving the melting property.

Alternatively, as shown in FIG39 , the soluble conductors 13, 21, and 81 may have a plurality of openings 95 formed in a high-melting-point metal layer 91 serving as an inner layer. A low-melting-point metal layer 92 may be formed on the high-melting-point metal layer 91 using a plating technique or the like, and then filled into the openings 95. This increases the area of contact between the molten low-melting-point metal and the high-melting-point metal in the soluble conductors 13, 21, and 81, thereby enabling the low-melting-point metal to dissolve the high-melting-point metal in a shorter time.

Furthermore, the soluble conductors 13, 21, and 81 are preferably formed so that the volume of the low-melting-point metal layer 92 is greater than the volume of the high-melting-point metal layer 91. When heated in an atmosphere at a temperature above its melting point, the low-melting-point metal melts and erodes the high-melting-point metal, allowing the soluble conductors 13, 21, and 81 to melt and fuse rapidly. Therefore, by forming the soluble conductors 13, 21, and 81 so that the volume of the low-melting-point metal layer 92 is greater than the volume of the high-melting-point metal layer 91, this erosion is promoted, enabling a rapid short circuit between the first and second electrodes 11 and 12.

Furthermore, in order to prevent degradation of the melting characteristics due to oxidation, the soluble conductors 13 , 21 , and 81 may be provided with an anti-oxidation film such as a CuO film or an Au film on the surface.

Description of labels

1 Temperature short-circuit element; 10 Insulating substrate; 11 First electrode; 11a External connection terminal; 12 Second electrode; 12a External connection terminal; 13 First fusible conductor; 13a Fusible conductor; 14 Heat transfer component; 15 Heat source; 17 First insulating layer; 18 Bonding material; 21 Second fusible conductor; 24 Solder; 25 Cover component; 25a Side wall; 25b Top surface; 28 External circuit; 30 Temperature short-circuit element; 31 First supporting electrode; 40 Temperature short-circuit element; 42 Fixing component; 43 Second supporting electrode; 50 Temperature 1. Temperature short-circuit element; 51. Second insulating layer; 52. Opening; 60. Temperature short-circuit element; 61. Opening; 70. Temperature short-circuit element; 71. Cover electrode; 80. Temperature switching element; 81. Third fusible conductor; 82. Heat transfer component; 83. Third electrode; 83a. External connection terminal; 84. Fourth electrode; 84a. External connection terminal; 85. External circuit; 87. Temperature switching element; 90. Temperature switching element; 91. High-melting-point metal layer; 92. Low-melting-point metal layer; 93. Opening; 94. Opening; 95. Opening; 97. Temperature switching element.

Claims (72)

1. A temperature-controlled short-circuit element, comprising: Electrode 1; The second electrode is disposed adjacent to the first electrode; and The first fusible conductor, through melting, condenses between the first and second electrodes, causing a short circuit between the first and second electrodes. The first fusible conductor melts in an atmosphere at a temperature above the melting point of the first fusible conductor. At least a portion of the second electrode is provided with a first insulating layer. The first fusible conductor overlaps with the second electrode and is supported by the first insulating layer, thereby opening the first and second electrodes. 2. The temperature short-circuit element as described in claim 1, wherein, It has heat transfer components that transfer heat from a heat source. The heat transfer component is continuous with the first electrode or the first fusible conductor. 3. The temperature short-circuit element as claimed in claim 2, wherein at least the surface of the heat transfer component is an insulating material. 4. The temperature short-circuit element according to any one of claims 1 to 3, wherein the first fusible conductor is supported on the first electrode. 5. The temperature short-circuit element as described in any one of claims 1 to 3, wherein, It has an insulating substrate, The first and second electrodes are conductor patterns formed on the insulating substrate. 6. The temperature short-circuit element as described in claim 4, wherein, It has an insulating substrate, The first and second electrodes are conductor patterns formed on the insulating substrate. 7. The temperature short-circuit element as described in claim 5, wherein, A second insulating layer, which is thicker than the first and second electrodes, is provided on the insulating substrate. The first fusible conductor overlaps with the first and second electrodes and is supported by the second insulating layer, thereby opening the first and second electrodes. 8. The temperature short-circuit element as described in claim 6, wherein, The first insulating layer is stacked on the first and second electrodes, and by providing a second insulating layer on the insulating substrate that is thicker than the first and second electrodes, openings are provided to expose the opposing front ends of the first and second electrodes. The first fusible conductor is mounted on the first and second insulating layers in a manner that covers the opening. 9. The temperature short-circuit element according to any one of claims 1 to 3, wherein a first support electrode is provided to support the first fusible conductor. 10. The temperature short-circuit element as claimed in claim 6, wherein a first support electrode is provided to support the first fusible conductor. 11. The temperature short-circuit element according to any one of claims 1 to 3, wherein it has a cover member that at least covers the first fusible conductor. 12. The temperature short-circuit element as claimed in claim 11, wherein, The top surface of the cover component has an internally provided cover electrode that overlaps with the first electrode and the first fusible conductor and is continuous with the second electrode. The first fusible conductor is melted in an atmosphere at a temperature above the melting point of the first fusible conductor, and the first and second electrodes are short-circuited via the cover electrode. 13. The temperature short-circuit element as claimed in claim 5, wherein the insulating substrate, the first electrode, or the housing becomes a heat transfer component for transferring heat from the heat source to the first fusible conductor. 14. The temperature short-circuit element as claimed in claim 5, wherein the insulating substrate is a ceramic substrate or a metal substrate with an insulating coating on its surface. 15. The temperature short-circuit element according to any one of claims 1 to 3, wherein it comprises a second fusible conductor connected to the second electrode. 16. The temperature short-circuit element as claimed in claim 5, wherein it comprises a second fusible conductor connected to the second electrode. 17. The temperature short-circuit element according to any one of claims 1 to 3, wherein the first fusible conductor has an area larger than the area connected to the first electrode. 18. The temperature short-circuit element as claimed in claim 5, wherein the first fusible conductor is fixed to the insulating substrate at least at a portion other than the connection portion with the first electrode by a fixing member. 19. The temperature short-circuit element of claim 15, wherein the second fusible conductor has an area larger than the area connected to the second electrode. 20. The temperature short-circuit element as claimed in claim 15, wherein a second support electrode is provided to support the first and second fusible conductors. 21. The temperature short-circuit element as claimed in claim 16, wherein the second fusible conductor is fixed to the insulating substrate at least at a portion other than the connection portion with the second electrode by a fixing member. 22. The temperature short-circuit element according to any one of claims 1 to 3, wherein at least a portion of the first fusible conductor is coated with flux. 23. The temperature short-circuit element according to any one of claims 1 to 3, wherein the first fusible conductor has a low-melting-point metal and a high-melting-point metal. 24. The temperature short-circuit element of claim 23, wherein the first fusible conductor is a laminate of the low-melting-point metal and the high-melting-point metal. 25. The temperature short-circuit element of claim 23, wherein the first fusible conductor is a covering structure in which the surface of the low-melting-point metal is covered by the high-melting-point metal. 26. The temperature short-circuit element as described in claim 23, wherein the low-melting-point metal is solder, and the high-melting-point metal is Ag, Cu, or an alloy with Ag or Cu as the main component. 27. The temperature short-circuit element as claimed in claim 26, wherein the low-melting-point metal is Sn or an alloy with Sn as the main component. 28. The temperature short-circuit element as claimed in claim 26, wherein the low-melting-point metal is a low-melting-point alloy of SnBi or SnIn type. 29. The temperature short-circuit element as claimed in claim 23, wherein the volume of the low-melting-point metal is greater than that of the high-melting-point metal. 30. The temperature short-circuit element of claim 23, wherein the high-melting-point metal is formed by plating the surface of the low-melting-point metal. 31. The temperature short-circuit element of claim 23, wherein the high-melting-point metal is formed by attaching a metal foil to the surface of the low-melting-point metal. 32. The temperature short-circuit element as claimed in claim 23, wherein the high-melting-point metal is formed on the surface of the low-melting-point metal by a thin film forming process. 33. The temperature short-circuit element as claimed in claim 23, wherein an anti-oxidation film is further formed on the surface of the high melting point metal. 34. The temperature short-circuit element of claim 23, wherein the low-melting-point metal and the high-melting-point metal are alternately stacked in multiple layers. 35. The temperature short-circuit element as claimed in claim 23, wherein the outer periphery, except for the two opposing end faces of the low-melting-point metal, is covered by the high-melting-point metal. 36. A temperature switching element, comprising: Electrode 1; The second electrode is disposed adjacent to the first electrode; The first fusible conductor melts and condenses between the first and second electrodes, thereby short-circuiting the first and second electrodes; The third and fourth electrodes; and A third fusible conductor, which is connected across the third and fourth electrodes, is melted to sever the connection between the third and fourth electrodes. The first and third fusible conductors melt in an atmosphere at a temperature above their melting points. At least a portion of the second electrode is provided with a first insulating layer. The first fusible conductor overlaps with the second electrode and is supported by the first insulating layer, thereby opening the first and second electrodes. 37. The temperature switching element as claimed in claim 36, wherein, It has heat transfer components that transfer heat from a heat source. The heat transfer component is continuous with the first electrode or the first fusible conductor and the third electrode or the third fusible conductor. 38. The temperature switching element as claimed in claim 37, wherein at least the surface of the heat transfer component is an insulating material. 39. The temperature switching element according to any one of claims 36 to 38, wherein the first fusible conductor is supported on the first electrode. 40. The temperature switching element according to any one of claims 36 to 38, wherein, It has an insulating substrate, The first to fourth electrodes are conductor patterns formed on the insulating substrate. 41. The temperature switching element as claimed in claim 39, wherein, It has an insulating substrate, The first to fourth electrodes are conductor patterns formed on the insulating substrate. 42. The temperature switching element as claimed in claim 40, wherein, A second insulating layer, thicker than the first and second electrodes, is provided on the insulating substrate. The first fusible conductor overlaps with the first and second electrodes and is supported by the second insulating layer, thereby opening the first and second electrodes. 43. The temperature switching element as claimed in claim 41, wherein, The first insulating layer is stacked on the first and second electrodes, and by providing a second insulating layer on the insulating substrate that is thicker than the first and second electrodes, openings are provided to expose the opposing front ends of the first and second electrodes. The first fusible conductor is mounted on the first and second insulating layers in such a way that it covers the opening of the first insulating layer. 44. The temperature switching element according to any one of claims 36 to 38, wherein a first support electrode is provided to support the first fusible conductor. 45. The temperature switching element as claimed in claim 41, wherein a first support electrode is provided to support the first fusible conductor. 46. The temperature switching element according to any one of claims 36 to 38, wherein it has a cover member that at least covers the first fusible conductor. 47. The temperature switching element as claimed in claim 46, wherein, The top surface of the cover component has an internally provided cover electrode that overlaps with the first electrode and the first fusible conductor and is continuous with the second electrode. The first fusible conductor is melted in an atmosphere at a temperature above the melting point of the first fusible conductor, and the first and second electrodes are short-circuited via the cover electrode. 48. The temperature switching element of claim 40, wherein the insulating substrate, the first electrode, the third electrode, or the housing becomes a heat transfer component for transferring heat from the heat source to the first fusible conductor and/or the third fusible conductor. 49. The temperature switching element as claimed in claim 40, wherein the insulating substrate is a ceramic substrate or a metal substrate with its surface covered by an insulating layer. 50. The temperature switching element according to any one of claims 36 to 38, wherein it comprises a second fusible conductor connected to the second electrode. 51. The temperature switching element as claimed in claim 40, wherein a second fusible conductor is connected to the second electrode. 52. The temperature switching element according to any one of claims 36 to 38, wherein the first fusible conductor has an area larger than the area connected to the first electrode. 53. The temperature switching element as claimed in claim 40, wherein the first fusible conductor is fixed to the insulating substrate at least at the portion other than the connection portion with the first electrode by a fixing member. 54. The temperature switching element of claim 50, wherein the second fusible conductor has an area larger than the area connected to the second electrode. 55. The temperature switching element as claimed in claim 50, wherein a second support electrode is provided to support the first and second fusible conductors. 56. The temperature switching element as claimed in claim 51, wherein the second fusible conductor is fixed to the insulating substrate at least at the portion other than the connection portion with the second electrode by a fixing member. 57. The temperature switching element according to any one of claims 36 to 38, wherein at least a portion of the first fusible conductor and the third fusible conductor is coated with flux. 58. The temperature switching element according to any one of claims 36 to 38, wherein the first fusible conductor and the third fusible conductor have a low-melting-point metal and a high-melting-point metal. 59. The temperature switching element of claim 58, wherein the first fusible conductor and the third fusible conductor are a stack of the low-melting-point metal and the high-melting-point metal. 60. The temperature switching element of claim 58, wherein the first fusible conductor and the third fusible conductor are a covering structure in which the surface of the low-melting-point metal is covered by the high-melting-point metal. 61. The temperature switching element as described in claim 58, wherein the low-melting-point metal is solder, and the high-melting-point metal is Ag, Cu, or an alloy with Ag or Cu as the main component. 62. The temperature switching element as claimed in claim 61, wherein the low-melting-point metal is Sn or an alloy with Sn as the main component. 63. The temperature switching element as claimed in claim 61, wherein the low-melting-point metal is a low-melting-point alloy of SnBi or SnIn type. 64. The temperature switching element as claimed in claim 58, wherein the volume of the low-melting-point metal is greater than that of the high-melting-point metal. 65. The temperature switching element of claim 58, wherein the high-melting-point metal is formed by plating the surface of the low-melting-point metal. 66. The temperature switching element of claim 58, wherein the high melting point metal is formed by attaching a metal foil to the surface of the low melting point metal. 67. The temperature switching element of claim 58, wherein the high melting point metal is formed on the surface of the low melting point metal using a thin film forming process. 68. The temperature switching element as claimed in claim 58, wherein an anti-oxidation film is further formed on the surface of the high melting point metal. 69. The temperature switching element of claim 58, wherein the low-melting-point metal and the high-melting-point metal are alternately stacked in multiple layers. 70. The temperature switching element as claimed in claim 58, wherein the outer periphery, excluding the two opposing end faces of the low-melting-point metal, is covered by the high-melting-point metal. 71. The temperature switching element according to any one of claims 36 to 38, wherein the melting point of either the first fusible conductor or the third fusible conductor is lower than that of the other, and the other fusible conductor melts after the first fusible conductor melts. 72. The temperature switching element according to any one of claims 36 to 38, wherein the thermal conductivity of either the heat conduction path to the first fusible conductor of the first electrode, which functions as a heat transfer component, or the heat conduction path to the third fusible conductor of the third electrode, which functions as a heat transfer component, is higher than that of the other, and after the fusible conductor connected to the first heat conduction path melts, the other fusible conductor connected to the other heat conduction path melts.