TWI715692B - Fuse element - Google Patents

Abstract

Even if the fuse element of the present invention is miniaturized, it can ensure the formation area of the heating element, stably melt the soluble conductor, and ensure the connection area of the package electrode, thereby ensuring the connection strength with the package substrate.

The present invention includes: an insulating substrate 10; a first electrode 11 and a second electrode 12 formed on the surface 10a of the insulating substrate 10; a soluble conductor 13 that is connected across the first and second electrodes 11 and 12; and a heating element 14, which is formed on the back surface 10b of the insulating substrate 10, and fusing the soluble conductor 13 by heating through electricity; and a back electrode 15 which is formed on the back surface 10b of the insulating substrate 10. The heating element 14 and the back electrode 15 overlap with each other through the insulating layer 17.

Description

Fuse element

The invention relates to a fuse element for protecting a circuit by interrupting a power line or a signal line. This application claims priority on the basis of Japanese Patent Application 2015-247288 filed in Japan on December 18, 2015 and Japanese Patent Application 2016-110506 filed in Japan on June 1, 2016, and refers to these applications and uses In this application.

For example, as a fuse element suitable for use in a protection circuit of a lithium ion battery, there is a first electrode formed on an insulating substrate, a heating element extraction electrode connected to a heating element, and a second electrode to connect a soluble conductor to form A part of the current path, which fuses the fusible conductor in the current path by self-heating caused by overcurrent, or energizes the heating element set inside the fuse element by a signal from the outside to be as desired on the circuit side Fuse the fusible conductor at the point in time.

An example of the fuse element is shown in FIG. 30. The fuse element 80 shown in FIGS. 30 to 32 includes: an insulating substrate 85; first and second electrodes 81 and 82 formed on both ends of the surface 85a of the insulating substrate 85; and a heating element 84 laminated on the insulating substrate The back surface 85b of the substrate 85 is covered by the insulating layer 86; the intermediate electrode 88 is laminated on the surface 85a of the insulating substrate 85 and is electrically connected to the heating element 84; and the soluble conductor 83, both ends of which are respectively connected to the first The second electrodes 81, 82, The central part is connected to the intermediate electrode 88.

The first and second electrodes 81 and 82 are connected to the first and second packaged electrodes 91 and 92 provided on the back surface 85 b of the insulating substrate 85 through the through hole 90. In addition, one end of the heating element 84 is connected to the heating element extraction electrode 87 provided on the back surface 85b of the insulating substrate 85, and the other end is connected to the heating element electrode 93 provided on the back surface 85b of the insulating substrate 85. The heating element extraction electrode 87 is connected to the intermediate electrode 88 through the through hole 94. In addition, the soluble conductor 83 is made of a material that can be quickly melted by the heat of the heating element 84, for example, is made of low melting point metal such as solder or Pb-free solder containing Sn as the main component.

In the fuse element 80, when an abnormality such as overcharge or overdischarge is detected, the heating element 84 is energized by the heating element electrode 93 connected to the external circuit. The fuse element 80 melts the soluble conductor 83 by the heat generated by the heater 84, and concentrates the fused conductor on the first and second electrodes 81, 82 and the intermediate electrode 88, thereby blocking the first and second electrodes 81, 82 The current path between.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 2790433

Due to the requirements for miniaturization of machines equipped with lithium-ion batteries, or the need to install multiple lithium-ion batteries for high-current applications such as power tools or electric vehicles, etc., the fuse element is required to be further downsized .

As shown in FIG. 32, the fuse element 80 has a heating element 84, a heating element extraction electrode 87, and first and second structured electrodes 91 and 92 formed on the back surface 85b of the insulating substrate 85. However, when When promoting the miniaturization of the fuse element 80, it can be presumed that there is the following risk: Because the area where the heating element 84 can be arranged in the first and second structured electrodes 91, 92 is narrow, the fusible conductor 83 cannot be quickly fused even by heating up. , Or local overheating and the heating element 84 itself burns out before the soluble conductor 83 melts, and the soluble conductor 83 cannot be melted stably. For example, if the size of the insulating substrate of the fuse element is reduced to 3mm×2mm, the size of the heating element 84 is reduced to 0.8mm×0.8mm, and the size of the soluble conductor that can be blown stably is limited, making it difficult In response to high current applications.

On the other hand, if it is desired to ensure the formation area of the heating element 84 to a certain extent, the heating element extraction electrode 87 or the first and second assembly electrodes 91 and 92 will become smaller, and be captured and formed on the surface 85a of the insulating substrate 85 The intermediate electrode 88 or the first and second electrodes 81, 82 have insufficient space for conduction through castellations or through holes. Or, because the first and second packaged electrodes 91, 92 become narrow, the connection area to the packaged substrate is insufficient, and sufficient connection strength cannot be ensured.

Therefore, the object of the present invention is to provide a fuse element that, even if it is miniaturized, can ensure the formation area of the heating element to stably fuse the soluble conductor, and ensure the connection area of the package electrode, thereby ensuring the connection with the package substrate strength.

In order to solve the above-mentioned problems, the fuse element of the present invention includes: an insulating substrate; a first electrode and a second electrode formed on the surface of the insulating substrate; and a soluble conductor that is connected across the first and second electrodes; A heating element, which is formed on the back surface of the above-mentioned insulating substrate, and fusing the above-mentioned soluble conductor by heating with electricity; and a back electrode, which is formed on the back surface of the above-mentioned insulating substrate. The heating element and the back electrode are overlapped with each other through the insulating layer.

According to the present invention, even when the element is miniaturized, both the effective area of the heating element and the package electrode can be maximized. Therefore, the heat generated by the heating element is also transferred from the overlapping electrodes through the insulating layer, so that the fusing of the soluble conductor is more rapid and stabilized. In addition, the area of the package electrode can be fully ensured, the connection strength with the circuit board can be improved, and the increase of the fuse resistance can be prevented.

1‧‧‧Fuse element

10‧‧‧Insulating substrate

11‧‧‧The first electrode

12‧‧‧Second electrode

13‧‧‧Fusible Conductor

14‧‧‧Heating body

15‧‧‧Extruding electrode of heating element

16‧‧‧Intermediate electrode

17‧‧‧Insulation layer

18‧‧‧The first structure electrode

18a‧‧‧Lower part

18b‧‧‧Upper part

19‧‧‧Second structure electrode

19a‧‧‧Lower Department

19b‧‧‧Upper part

20‧‧‧Through hole

21‧‧‧Through hole

23‧‧‧Heating body electrode

24‧‧‧cover

30‧‧‧Battery pack

31~34‧‧‧Battery unit

35‧‧‧Battery Stack

36‧‧‧Detection circuit

37‧‧‧Current control element

40‧‧‧Charge and discharge control circuit

41、42‧‧‧Current control element

43‧‧‧Control Department

45‧‧‧Charging device

50‧‧‧Fuse element

51‧‧‧The first insulation layer

52‧‧‧Second insulation layer

53‧‧‧Castle contact

55‧‧‧Fuse element

60‧‧‧Fuse element

61‧‧‧The third insulation layer

62‧‧‧4th insulation layer

63‧‧‧Castle contact

65‧‧‧Fuse element

70‧‧‧Fuse element

71‧‧‧Castle contact

72‧‧‧External circuit board

73‧‧‧Packing

74‧‧‧Castle contact

75‧‧‧The first independent terminal

76‧‧‧Second independent terminal

77‧‧‧Castle contact

FIG. 1 is a plan view showing the surface side of an insulating substrate to which the fuse element of the present invention is applied.

Fig. 2(A) is a bottom view showing the back side of an insulating substrate to which the fuse element of the present invention is applied, and Fig. 2(B) is a cross-sectional view of AA' in Fig. 2(A).

Fig. 3 is a circuit diagram showing a configuration example of a battery circuit using the fuse element of the present invention.

Fig. 4 is a circuit diagram of the fuse element to which the present invention is applied.

FIG. 5(A) is a plan view showing the surface side of an insulating substrate to which another fuse element of the present invention is applied, and FIG. 5(B) is a cross-sectional view taken along line AA' of FIG. 5(A).

Fig. 6 is a diagram showing the manufacturing steps of the fuse element shown in Fig. 5, and shows the formation of the heating element extraction electrode, the lower layer portion of the first and second structured electrodes, and the heating element electrode on the back of the insulating substrate. The bottom view of the state where the first insulating layer is formed on the part.

FIG. 7 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 5, and is a bottom view showing a state where the heating element is overlapped with the lower layer by forming the heating element on the first insulating layer.

Figure 8 is a diagram showing the manufacturing steps of the fuse element shown in Figure 5, and is shown in the heating element A bottom view of the state where the second insulating layer is formed on the top.

FIG. 9 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 5, and is a bottom view showing a state where the upper layer portions of the first and second packaged electrodes are formed on the second insulating layer.

FIG. 10(A) is a plan view showing the surface side of an insulating substrate to which another fuse element of the present invention is applied, and FIG. 10(B) is a cross-sectional view of AA' of FIG. 10(A).

Fig. 11 is a diagram showing the manufacturing steps of the fuse element shown in Fig. 10, and is a bottom view showing a state in which heating element lead electrodes and heating element electrodes are formed on the back of the insulating substrate.

FIG. 12 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 10, and is a bottom view showing a state in which a heating element is formed on the back surface of the insulating substrate.

FIG. 13 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 10, and is a bottom view showing a state in which a second insulating layer is formed on the heating element.

FIG. 14 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 10, and is a bottom view showing a state where the upper layer portions of the first and second packaged electrodes are formed on the second insulating layer.

FIG. 15(A) is a plan view showing the surface side of an insulating substrate to which another fuse element of the present invention is applied, and FIG. 15(B) is a cross-sectional view taken along line AA' of FIG. 15(A).

16 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 15, and shows that the heating element extraction electrode, the lower layer of the first and second package electrodes and the heating element electrode are formed on the back of the insulating substrate A bottom view of the body lead electrode and the third insulating layer formed on the lower layer.

FIG. 17 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 15 and is a bottom view showing a state where a heating element is formed on the third insulating layer.

FIG. 18 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 15, and is a bottom view showing a state in which a fourth insulating layer is formed on the heating element.

FIG. 19 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 15 and is a bottom view showing a state where the upper layer portions of the first and second packaged electrodes are formed on the fourth insulating layer.

FIG. 20(A) is a plan view showing the surface side of an insulating substrate to which another fuse element of the present invention is applied, and FIG. 20(B) is a cross-sectional view taken along AA' of FIG. 20(A).

FIG. 21 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 20, and is a bottom view showing a state in which the heating element leading electrode is formed on the back of the insulating substrate.

FIG. 22 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 20, and is a bottom view showing a state where a heating element is formed on the back of the insulating substrate.

FIG. 23 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 20, and is a bottom view showing a state in which a fourth insulating layer is formed on the heating element.

FIG. 24 is a diagram showing the manufacturing steps of the fuse element shown in FIG. 20, and is a bottom view showing a state where the upper layer portions of the first and second packaged electrodes are formed on the fourth insulating layer.

FIG. 25(A) is a plan view of the surface side of the insulating substrate of the fuse element of a modified example without the cover, and FIG. 25(B) is a cross-sectional view of AA' in FIG. 25(A).

Fig. 26 is a BB' cross-sectional view of Fig. 25(A).

Fig. 27 is a cross-sectional view showing the state of being assembled to an external circuit.

FIG. 28 is a plan view of the surface side of the insulating substrate of the fuse element of another modification with the cover omitted.

FIG. 29(A) is a plan view of the surface side of the insulating substrate of the fuse element of the modified example without the cover, and FIG. 29(B) is the BB' cross-sectional view of FIG. 29(A).

Fig. 30 is a plan view showing the surface side of the insulating substrate of the fuse element of the reference example.

Figure 31 is a cross-sectional view taken along line AA' of Figure 30.

Fig. 32 is a bottom view showing the back side of the insulating substrate of the fuse element shown in Fig. 30;

Hereinafter, the fuse element to which the present invention is applied will be described in detail with reference to the drawings. Furthermore, of course, the present invention is not limited to the following embodiments, and various changes can be made without departing from the scope of the present invention. In addition, the drawings are only illustrations, and the ratios of the dimensions may be different from the actual ones. Please refer to the following description to judge the specific dimensions. Moreover, of course, the drawings also include parts with different dimensional relationships or ratios.

The fuse element to which the present invention is applied includes: an insulating substrate; a first electrode and a second electrode formed on the surface of the insulating substrate; a soluble conductor connected between the first and second electrodes; and a heating element formed on The back surface of the insulating substrate is fused to the fusible conductor by heating through electricity; and the back electrode is formed on the back surface of the insulating substrate. The heating element and the back electrode overlap through the insulating layer.

The back electrode overlapping the heating element on the back surface of the insulating substrate is, for example, a heating element extraction electrode connected to the heating element to form an electric path to the heating element. In addition, the back electrode is the first and second packaged electrodes connected to the first and second electrodes and mounted on the circuit board. Or the back electrode is the heating element extraction electrode and the first and second packaged electrodes. In addition, the back electrode may also be an electrode for heat dissipation that is not used for energization or for bonding to a circuit board.

[First Embodiment]

Fig. 1 and Fig. 2 illustrate the fuse element 1 in which the heating element lead electrode as the back electrode overlaps the heating element. The fuse element 1 shown in FIG. 1 includes an insulating substrate 10; a first electrode 11 and a second electrode 12 formed on the surface 10a of the insulating substrate 10; and an intermediate electrode 16 formed on the insulating substrate 10 The surface 10a of the edge substrate 10 is electrically connected to the heating element 14 formed on the back surface 10b; the soluble conductor 13, the two ends of which are respectively connected to the first and second electrodes 11 and 12, and the central part is connected to the middle electrode 16; The heating element lead electrode 15 is laminated on the back 10b of the insulating substrate 10 and is connected to the intermediate electrode 16 and the heating element 14; the heating element 14 is laminated on the heating element lead electrode 15 through the insulating layer 17; and the second structure The electrode 19 is formed on the back surface 10 b of the insulating substrate 10 and is electrically connected to the first package electrode 18 and the second electrode 12 that are electrically connected to the first electrode 11.

The insulating substrate 10 is formed into a substantially square shape by, for example, an insulating member such as alumina, alumina ceramics, glass ceramics, mullite, or zirconia. The insulating substrate 10 can also use materials used for printed wiring substrates such as epoxy glass substrates and phenol substrates. In addition, the fuse element 1 is miniaturized in accordance with the requirements accompanying the miniaturization of the mounted electrical equipment, and for example, the size of the insulating substrate 10 is 3 mm×2 mm and the thickness is 0.3 mm.

[First and second electrodes]

The first and second electrodes 11, 12 are opened by being separately arranged near the opposite side edges on the surface 10a of the insulating substrate 10, and are electrically transmitted through the soluble conductor 13 by mounting the following soluble conductor 13 connection. In addition, the first and second electrodes 11, 12 are caused by the flow of a large current exceeding the rated value in the fuse element 1, and the soluble conductor 13 is fused due to self-heating (Joule heat), or the heating element 14 is energized. Heat is generated and the soluble conductor 13 is fused and blocked.

As shown in FIG. 2(A), the first and second electrodes 11 and 12 are respectively connected to the first and second packaged electrodes 18 and 19 provided on the back surface 10b through the through hole 20 penetrating the insulating substrate 10. Since the through hole 20 connecting the first and second electrodes 11, 12 and the first and second packaged electrodes 18, 19 constitutes a part of the energization path of the fuse element 1 and becomes an element for determining the current rating, it has A predetermined size (e.g. 0.3mm φ) is formed inside to connect the first electrode 11 and the first package The conductive layer of the electrode 18, the second electrode 12 and the second structured electrode 19.

The first and second package electrodes 18, 19 are external connection electrodes connected to a circuit board including a protective circuit of the fuse element 1 and the like. They are separated on the back surface 10b of the insulating substrate 10 and formed on the insulating substrate 10 The first and second side edges 10c, 10d side. The fuse element 1 is connected to a circuit board on which an external circuit is formed through the first and second packaged electrodes 18, 19, and spans the first packaged electrode 18, the through hole 20, the first electrode 11, and the soluble conductor 13. The path of the second electrode 12, the through hole 20, and the second package electrode 19 constitutes a part of the energizing path of the external circuit.

Furthermore, regarding the first and second structured electrodes 18, 19, it is also possible to provide castle-shaped contacts on the first and second side edges 10c, 10d of the insulating substrate 10 instead of the through holes 20 or through the castle-shaped contacts and The through hole 20 is connected to the first and second electrodes 11 and 12 together. In addition, the first and second packaged electrodes 18, 19 have sufficient space to ensure the conduction through the through hole 20 or the castle-shaped contact, expand the connection area to the circuit board, and ensure the connection strength or the predetermined rating. In addition, the resistance of the fuse resistance of the entire device can be reduced (for example, 7mΩ).

The first and second electrodes 11, 12 or the first and second packaged electrodes 18, 19 can be formed using common electrode materials such as Cu or Ag, for example, by printing Ag-Pd paste and firing at 850°C 30min to form. Furthermore, it is preferable to coat the surfaces of the first and second electrodes 11, 12 or the first and second packaged electrodes 18, 19 with Ni/Au plating, Ni/Pd plating, etc. by a known technique such as plating treatment. Coatings such as Ni/Pd/Au plating. Thereby, the fuse element 1 can prevent the oxidation of the first and second electrodes 11, 12 or the first and second packaged electrodes 18, 19, and prevent the variation of the rated value accompanying the increase of on-resistance. In addition, in the case of reflowing the fuse element 1, it is possible to prevent erosion (solder erosion) by melting the connection solder for connecting the soluble conductor 13 or the low melting point metal forming the soluble conductor 13 , The second electrodes 11, 12, and the first and second packaged electrodes can be connected to the The solder for connecting the electrodes of the circuit board is melted to prevent erosion of the first and second packaged electrodes 18, 19.

In addition, on the surface 10a of the insulating substrate 10, an intermediate electrode 16 is laminated between the first and second electrodes 11, 12. The intermediate electrode 16 is connected to the heating element lead electrode 15 laminated on the back surface 10 b of the insulating substrate 10 through the through hole 21. A conductive layer connecting the heating element lead electrode 15 and the intermediate electrode 16 is also formed inside the through hole 21.

[Fusible Conductor]

A soluble conductor 13 is connected across the first electrode 11, the intermediate electrode 16, and the second electrode 12 of the fuse element 1. The soluble conductor 13 is made of a material that can be quickly melted by the heat generated by the heating element 14. For example, a low-melting-point metal such as solder or Pb-free solder mainly composed of Sn can be preferably used. As an example, the soluble conductor 13 can be designed to have Sn:Sb=95:5, a liquidus point of 240°C, and a size of 1mm×2mm.

In addition, the soluble conductor 13 may also use a high melting point metal such as an alloy mainly composed of In, Pb, Ag, Cu or any of these, or may use a low melting point metal for the inner layer and a high melting point for the outer layer Metal laminates. By containing high melting point metal and low melting point metal, in the case of reflowing the fuse element 1, even if the reflow temperature exceeds the melting temperature of the low melting point metal, the low melting point metal is melted and the low melting point metal can be prevented from flowing out Externally, the shape of the soluble conductor 13 is maintained, the predetermined rating can be maintained, and the variation of the interrupting characteristic can be suppressed. In addition, the low melting point metal can also be melted during fusing, and the high melting point metal can be eroded (solder erosion), thereby rapidly melting at a temperature below the melting point of the high melting point metal.

The soluble conductor 13 is connected to the intermediate electrode 16 and the first and second electrodes 11 and 12. The soluble conductor 13 can be easily connected by reflow soldering. As the connection material for connecting the soluble conductor 13, solder can be preferably used. For example, a connection solder paste with Sn/Ag/Cu=96.5/3/0.5 and a melting point of 219°C can be used.

In addition, in order to resist oxidation, improve wettability, etc., the soluble conductor 13 is preferably coated with a flux.

The back surface 10b of the insulating substrate 10 is formed with a heating element 14, heating element extraction electrode 15, first and second package electrodes 18, 19, and heating element electrode 23. The heating element 14 and the heating element extraction electrode 15 overlap through the insulating layer 17 .

[Extracting electrode for heating element]

The heating element lead electrode 15 is formed on the back surface 10b of the insulating substrate 10 from the third side edge 10e of the insulating substrate to the center. In addition, the heating element extraction electrode 15 can be formed using general electrode materials such as Cu or Ag. For example, it can be formed by printing an Ag-Pd paste and firing it at 850°C for 30 minutes. In addition, the heating element lead-out electrode 15 is connected to one end of the heating element 14 and is connected to the intermediate electrode 16 formed on the surface 10 a of the insulating substrate 10 through the through hole 21.

Furthermore, the third side edge 10e of the insulating substrate 10 may be provided with a castle-shaped contact point instead of the through hole 21 or the heating element lead-out electrode 15 and the intermediate electrode 16 can be conducted through the castle-shaped contact point and the through hole 21 together.

[heating stuff]

The heating element 14 is a conductive member that generates heat when energized, and is composed of, for example, W, Mo, Ru, Cu, Ag, or alloys containing these as main components. The heating element 14 can be formed by the following method: using screen printing technology to mix the powder of the alloy or composition, compound with a resin binder, etc., form a paste into a pattern, and then fire it (For example, 850°C for 30 min) and so on. The resistance value of the patterned heating element 14 is set to, for example, 1Ω. In addition, one end of the heating element 14 is connected to the heating element lead electrode 15 and the other end is connected to the heating element electrode 23.

The heating element 14 is constructed by the fuse element 1 on the circuit board and penetrates the heating element The electrode 23 is connected to an external circuit formed on the circuit board. In addition, the heating element 14 can energize and generate heat through the heating element electrode 23 at a predetermined point in which the energization path of the external circuit is interrupted, so that the soluble conductor 13 connected to the first and second electrodes 11 and 12 can be fused. In addition, since the heating element 14 is fused by the soluble conductor 13, its own energization path is also blocked, so the heat generation is stopped.

Here, the fuse element 1 is provided with an insulating layer 17 so as to cover a part of the heating element extraction electrode 15, and the heating element 14 passes through the insulating layer 17 and overlaps the heating element extraction electrode 15. As the insulating material constituting the insulating layer 17, for example, glass with better thermal conductivity can be used. It can be formed by printing and firing glass paste (for example, 850°C for 30 minutes) after forming the heating element to draw the electrode 15. After the insulating layer 17 is formed, the heating element 14 is laminated on the back surface 10b of the insulating substrate 10 and on the insulating layer 17, and overlaps the heating element lead electrode 15 through the insulating layer 17, and overlaps the non-insulated layer 17 of the heating element lead electrode 15 Part of the covering is connected.

The fuse element 1 can be overlapped by the heating element 14 and the heating element lead electrode 15 through the insulating layer 17 so as to ensure a larger forming space for the heating element 14 on the miniaturized insulating substrate 10. Therefore, the fuse element 1 can maximize the effective area of the heating element 14, and the fusible conductor 13 can be melted quickly and stably. For example, if it is assumed that the size of the insulating substrate of the fuse element 1 is reduced to 3 mm×2 mm, the size of the heating element 14 can be increased to, for example, 0.8 mm×1.2 mm. Furthermore, of course, the present invention can form heating elements of all sizes on insulating substrates of all sizes.

Furthermore, it is preferable that the heating element 14 overlaps part or all of the through holes 21 formed in the heating element lead electrode 15. By overlapping the heating element 14 with the through hole 21, the heat of the heating element 14 can also be transmitted to the intermediate electrode 16 and the soluble conductor 13 mounted on the intermediate electrode 16 through the through hole 21, and the soluble conductor 13 is quickly fused.

Moreover, the fuse element 1 can also be further provided with a protective layer (not shown) to protect the heating element 14 Icon). The protective layer can preferably use insulating members such as glass. Thereby, the fuse element 1 can prevent short-circuit with peripheral equipment, etc., and can prevent the abrasion or damage of the heating element 14 and improve the operability.

Furthermore, as shown in FIG. 2(B), the fuse element 1 is mounted on the surface 10a of the insulating substrate 10 with a cover 24 for protecting the inside. Thereby, the fuse element 1 can prevent the melted soluble conductor 13 from scattering, and prevent short circuit with peripheral devices and the like. The cover 24 may be formed of synthetic resin such as nylon or LCP resin (liquid crystal polymer). Furthermore, the size of the cover 24 is formed according to the size of the insulating substrate 10, for example, the size is 2.8×1.8 and the thickness is 0.5 mm.

[How to use the fuse element]

As shown in FIG. 3, such a fuse element 1 is used, for example, integrated into a circuit in a battery pack 30 of a lithium-ion storage battery. The battery pack 30 has, for example, a battery stack 35 composed of battery cells 31 to 34 of a total of four lithium ion storage batteries.

The battery pack 30 includes: a battery stack 35; a charge and discharge control circuit 40 that controls the charge and discharge of the battery stack 35; the fuse element 1 of the present invention is applied to interrupt charging when the battery stack 35 is abnormal; and a detection circuit 36 that detects The voltage of each battery cell 31 to 34; and the current control element 37, which controls the action of the fuse element 1 according to the detection result of the detection circuit 36.

The battery stack 35 is formed by connecting the battery cells 31 to 34 for protection from overcharge and overdischarge control in series, and is detachably connected to the positive terminal 30a and the negative terminal 30b of the battery pack 30 The charging device 45 is applied with a charging voltage from the charging device 45. By connecting the positive terminal 30a and the negative terminal 30b of the battery pack 30 charged by the charging device 45 to an electronic device operating by a battery, the electronic device can be operated.

The charging and discharging control circuit 40 is provided in the flow from the battery stack 35 to the charging device 45 Two current control elements 41, 42 connected in series on the current path, and a control unit 43 that controls the operations of the current control elements 41, 42. The current control elements 41, 42 are, for example, composed of field-effect transistors (hereinafter referred to as FETs), and the gate voltage is controlled by the control unit 43, thereby controlling the conduction and conduction of the charging direction and/or the discharging direction of the current path of the battery stack 35 Occlude. The control unit 43 operates by receiving power supply from the charging device 45, and controls the operation of the current control elements 41, 42 in a manner that interrupts the current path when the battery stack 35 is over-discharged or over-charged based on the detection result of the detection circuit 36 .

The fuse element 1 is, for example, connected to the charging and discharging current path between the battery stack 35 and the charging and discharging control circuit 40, and its operation is controlled by the current control element 37.

The detection circuit 36 is connected to each battery cell 31 to 34, detects the voltage value of each battery cell 31 to 34, and supplies each voltage value to the control unit 43 of the charge and discharge control circuit 40. In addition, the detection circuit 36 outputs a control signal for controlling the current control element 37 when any one of the battery cells 31 to 34 becomes an overcharge voltage or an overdischarge voltage.

The current control element 37 is constituted by, for example, an FET to enable the fuse element 1 to be activated when the voltage value of the battery cells 31 to 34 exceeds a predetermined overdischarge or overcharge state by the detection signal output from the detection circuit 36 The operation is controlled by a method that interrupts the charging and discharging current path of the battery stack 35 without relying on the switching operation of the current control elements 41 and 42.

In the battery pack 30 constructed with the above configuration, the fuse element 1 of the present invention is applied and has the circuit configuration shown in FIG. 4. That is, the circuit configuration of the fuse element 1 is composed of the soluble conductor 13 connected in series through the intermediate electrode 16 and the lead electrode 15, the intermediate electrode 16 and the soluble conductor 13 through the heating element are energized to generate heat to melt the soluble conductor 13 The heating element 14 is constituted. In addition, in the fuse element 1, for example, the soluble conductor 13 is connected in series on the charge and discharge current path, and the heating element 14 transmits The heating body electrode 23 is connected to the current control element 37. One of the two electrodes 11 and 12 of the fuse element 1 is connected to an open end of the battery stack 35, and the other is connected to the positive terminal 30a side of the battery stack 30.

The fuse element 1 constituted by such a circuit configuration is fused by the heat of the heating element 14 to fuse the fusible conductor 13, thereby reliably blocking the current path.

Furthermore, the protection element of the present invention is not limited to the case of a battery pack used in a lithium-ion storage battery, of course, it can also be applied to various applications that require electrical signals to block current paths.

[Second Embodiment]

Next, another embodiment of the fuse element to which the present invention is applied will be described. The fuse element of the present invention can also be used to overlap the first and second packaged electrodes as the back electrode with the heating element. In addition, in the fuse elements 50 and 55 described below, the same reference numerals are given to the same members as the above-mentioned fuse element 1, and detailed descriptions thereof are omitted. The fuse element 50 shown in FIGS. 5(A) and (B) is related to the fuse at the point where the heating element 14 and the first and second packaged electrodes 18, 19 overlap through the first and second insulating layers 51, 52 Element 1 is different.

The first and second package electrodes 18 and 19 of the fuse element 50 respectively have lower layer portions 18a and 19a laminated on the back surface 10b of the insulating substrate 10 and upper layer portions 18b and 19b laminated on the second insulating layer 52. The lower layer portions 18 a and 19 a are separated from the back surface 10 b of the insulating substrate 10 and formed on the first and second side edges 10 c and 10 d sides of the insulating substrate 10. The lower layer portions 18a and 19a can be formed using general electrode materials such as Cu or Ag. For example, they can be formed by printing Ag-Pd paste and firing at 850°C for 30 minutes. In addition, the lower layer portions 18a and 19a are connected to the first and second electrodes 11 and 12 through the through holes 20 penetrating the insulating substrate 10, respectively.

In addition, the lower layer portions 18a and 19a are covered by the first insulating layer 51 except for a part of the insulating substrate 10 on the side of the first and second side edges 10c and 10d. As the insulating material constituting the first insulating layer 51, for example, glass with better thermal conductivity can be used, and it can be formed by printing and firing glass paste (for example, 850°C for 30 minutes).

Furthermore, the lower layer portions 18a, 19a of the first and second packaged electrodes 18, 19 of the fuse element 50 overlap the heating element 14 through the first insulating layer 51. The heating element 14 is laminated on the back surface 10 b of the insulating substrate 10 and connected to the heating element extraction electrode 15 and the heating element electrode 23 formed on the back surface 10 b of the insulating substrate 10. In addition, a second insulating layer 52 is laminated on the heating element 14. The second insulating layer 52 has an area greater than the area of the heating element 14 and covers the entire heating element 14. As the insulating material constituting the second insulating layer 52, for example, glass with good thermal conductivity can be used, and it can be formed by printing and firing glass paste (for example, 850°C for 30 minutes). Furthermore, the upper layer portions 18b, 19b of the first and second packaged electrodes 18, 19 of the fuse element 50 are superposed on the heating element 14 through the second insulating layer 52. The heating element 14 overlaps the first and second structured electrodes 18a, 19a and the upper layer portions 18b, 19b by passing through the first and second insulating layers 51, 52 and the first and second structured electrodes 18, 19 Install electrodes 18 and 19 for insulation.

The upper layer portions 18 b and 19 b are connected to the lower layer portions 18 a and 19 a exposed from the first insulating layer 51. In addition, the upper layer portions 18b and 19b are connected to the external connection electrodes of the circuit board configuring the protection circuit of the fuse element 50 and the like. The fuse element 50 is connected to the circuit board on which the external circuit is formed through the upper portion 18b, 19b of the first and second package electrodes 18, 19, and spans the upper portion 18b, the lower portion 18a, the through hole 20, and the first The path of the electrode 11, the soluble conductor 13, the second electrode 12, the through hole 20, the lower layer portion 19a, and the upper layer portion 19b constitutes a part of the energizing path of the external circuit.

Such a fuse element 50 can use the heating element 14 and the first and second assembly electrodes 18, The upper and lower layers 18a, 18b, 19a, 19b of 19 overlap through the first and second insulating layers 51, 52, and a large space for forming the heating element 14 is secured on the miniaturized insulating substrate 10. Therefore, the fuse element 50 can maximize the effective area of the heating element 14 and can quickly and stably fuse the soluble conductor 13. In addition, the fuse element 50 can ensure a sufficient area of the upper layer portions 18b, 19b of the first and second package electrodes 18, 19, and can maximize the package area for the circuit board, and have the connection strength or the predetermined rating. value.

Furthermore, it is preferable that the heating element 14 overlaps part or all of the through holes 20 formed in the lower layer portions 18a and 19a. By overlapping the heating element 14 with the through hole 20, the heat of the heating element 14 can be transmitted to the first and second electrodes 11 and 12 through the through hole 20 and the soluble conductor mounted on the first and second electrodes 11 and 12 13. Fuse the fusible conductor 13 quickly.

In addition, regarding the lower layer portions 18a, 19a of the first and second packaged electrodes 18, 19, the first and second side edges 10c, 10d of the insulating substrate 10 may be provided with castle-shaped contacts instead of the through holes 20 or through the The castle-shaped contact and the through hole 20 are connected to the first and second electrodes 11 and 12 together.

Furthermore, for the fuse element 50, as shown in FIG. 5(B), the first insulating layer 51 is provided on the lower layer portions 18a, 19a, respectively, and the heating element 14 is overlapped across the first insulating layers 51, but it may be A first insulating layer 51 is provided across the lower layer portions 18 a and 19 a, and the entire heating element 14 is formed on the first insulating layer 51. By also providing the first insulating layer 51 between the back surface 10b of the insulating substrate 10 and the heating element 14, the heat of the heating element can be efficiently transferred to the insulating substrate 10 side.

Such a fuse element 50 can be manufactured by the steps shown in FIGS. 6-9. First, as shown in FIG. 6, on the back surface 10 b of the insulating substrate 10, the heating element extraction electrode 15, the first and second package electrodes 18, 19 lower layer portions 18 a and 19 a and the heating element electrode 23 are formed. Next, a first insulation is formed on the lower layer portions 18a, 19a except for a part of the first and second side edges 10c, 10d of the insulating substrate 10. 缘层51。 Border layer 51.

Next, the heating element 14 is formed as shown in FIG. 7. The heating element 14 is formed on the first insulating layer 51 to overlap the lower layer portions 18a and 19a. In addition, the heating element 14 is connected to the heating element extraction electrode 15 and the heating element electrode 23.

Next, the second insulating layer 52 is formed on the heating element 14 as shown in FIG. 8. The second insulating layer 52 covers the entire heating element 14 and exposes the lower layer portions 18a, 19a except for a part of the first and second side edges 10c, 10d of the insulating substrate 10.

Then, as shown in FIG. 9, the upper layer portions 18 b and 19 b of the first and second packaged electrodes 18 and 19 are formed on the second insulating layer 52. The upper layer portions 18b, 19b are connected to the lower layer portions 18a, 19a at a part of the insulating substrate 10 on the first and second side edges 10c, 10d.

[Third Embodiment]

Furthermore, as shown in FIG. 10(A)(B), the fuse element may not be provided with the first and second package electrodes 18, 19 and the lower layer portions 18a, 19a, and connect the first and the second via the castle-shaped contact 53. 2 Electrodes 11, 12 and upper portion 18b, 19b. The fuse element 55 shown in FIG. 10 is different from the fuse element 50 in that the lower layer portions 18a, 19a of the first and second packaged electrodes 18, 19 are not provided. At this time, it is not necessary to provide the first insulating layer 51 to insulate the heating element 14 from the lower layer portions 18a and 19a, but an insulating layer may be provided between the back surface 10b of the insulating substrate 10 and the heating element 14.

Such a fuse element 55 can be manufactured by the steps shown in FIGS. 11-14. First, as shown in FIG. 11, the heating element extraction electrode 15 and the heating element electrode 23 are formed on the back surface 10 b of the insulating substrate 10. Next, the heating element 14 is formed as shown in FIG. 12. The heating element 14 is connected to the heating element extraction electrode 15 and the heating element electrode 23.

Next, the second insulating layer 52 is formed on the heating element 14 as shown in FIG. 13. 2nd The insulating layer 52 covers the entire heating element 14. Then, as shown in FIG. 14, the upper layer portions 18 b and 19 b of the first and second packaged electrodes 18 and 19 are formed on the second insulating layer 52. The upper portions 18b and 19b are connected to the first and second electrodes 11 and 12 formed on the surface 10a of the insulating substrate 10 through the castle-shaped contacts 53 formed on the first and second side edges 10c and 10d of the insulating substrate 10.

[Fourth Embodiment]

Furthermore, applying the fuse element of the present invention can also make the heating element extraction electrode and the first and second assembly electrodes as the back electrode overlap the heating element. In addition, in the fuse element 60 described below, the same reference numerals are given to the same members as the above-mentioned fuse element 1 and the fuse element 50, and detailed descriptions thereof are omitted. The fuse element 60 shown in FIG. 15(A)(B) overlaps the heating element 14 and the heating element lead electrode 15 through the third insulating layer 61, and the heating element 14 and the first and second package electrodes 18, 19 pass through the third insulating layer. 3. The overlap of the fourth insulating layers 61 and 62 is different from the fuse element 1.

The first and second packaged electrodes 18 and 19 of the fuse element 60 respectively have lower layer portions 18a and 19a laminated on the back surface 10b of the insulating substrate 10 and upper layer portions 18b and 19b laminated on the fourth insulating layer 62.

A third insulating layer 61 is laminated on the heating element extraction electrode 15 and the lower layer portions 18a and 19a. Thereby, the heating element extraction electrode 15 is covered by the third insulating layer 61 except for a part of the third side edge 10e side of the insulating substrate 10, and the lower layer portions 18a, 19a are excluding the first and second side surfaces 10c, 10d of the insulating substrate 10 A part of the outside is covered by the third insulating layer 61. As the insulating material constituting the third insulating layer 61, for example, glass with good thermal conductivity can be used, and it can be formed by printing and firing glass paste (for example, 850°C for 30 minutes). In addition, the heating element extraction electrode 15 of the fuse element 60 and the lower layer portions 18 a and 19 a of the first and second package electrodes 18 and 19 and the heating element 14 overlap with the heating element 14 through the third insulating layer 61.

The heating element 14 is laminated on the third insulating layer 61 and is connected to the heating element extraction electrode 15 not covered by the third insulating layer 61 and the heating element electrode 23 formed on the back surface 10 b of the insulating substrate 10. In addition, a fourth insulating layer 62 is laminated on the heating element 14. The fourth insulating layer 62 prevents short circuit between the heating element 14 and the first and second packaged electrodes 18, 19, and covers at least the heat generated in the area where the upper layer portions 18b, 19b of the first and second packaged electrodes 18, 19 are formed The body 14 preferably covers the entire heating element 14. As the insulating material constituting the fourth insulating layer 62, for example, glass with better thermal conductivity can be used, and it can be formed by printing and firing glass paste (for example, 850°C for 30 minutes).

Furthermore, the upper layer portions 18b, 19b of the first and second packaged electrodes 18, 19 of the fuse element 60 are superimposed on the heating element 14 through the fourth insulating layer 62. The heating element 14 overlaps the lower layer portions 18a, 19a and upper layer portions 18b, 19b of the first and second structured electrodes 18, 19 through the third and fourth insulating layers 61, 62, and thereby overlaps with the first and second structure electrodes. The installed electrodes 18 and 19 overlap with each other in an insulated state.

The upper layer portions 18 b and 19 b are connected to the lower layer portions 18 a and 19 a exposed from the third insulating layer 61. In addition, the upper layer portions 18b and 19b are connected to the external connection electrodes of the circuit board on which the protection circuit etc. of the fuse element 60 are installed. The fuse element 60 is connected to the circuit board on which the external circuit is formed through the upper portion 18b, 19b of the first and second package electrodes 18, 19, and spans the upper portion 18b, the lower portion 18a, the through hole 20, and the first The path of the electrode 11, the soluble conductor 13, the second electrode 12, the through hole 20, the lower layer portion 19a, and the upper layer portion 19b constitutes a part of the energizing path of the external circuit.

Such a fuse element 60 can be overlapped by the heating element 14 and the heating element lead electrode 15 through the third insulating layer 61, and through the third and fourth insulating layers 61, 62 and the first and second packaged electrodes 18, 19 The upper and lower layers 18ab and 19ab overlap, thereby ensuring a larger space for the formation of the heating element 14 on the miniaturized insulating substrate 10. Therefore, the fuse element 60 can maximize the effective area of the heating element 14, and can melt the soluble conductor 13 quickly and stably. For example, if the fuse When the size of the insulating substrate of the element 60 is reduced to 3 mm×2 mm, the size of the heating element 14 can be increased to, for example, 2.5 mm×1.4 mm. In addition, the fuse element 60 can ensure a sufficient area of the upper layer portions 18b, 19b of the first and second packaged electrodes 18, 19, and can maximize the package area for the circuit board to obtain the connection strength or the predetermined rating. Value.

Furthermore, it is preferable that the heating element 14 overlaps part or all of the through holes 20 and 21 formed in the heating element extraction electrode 15 and the lower layer portions 18a, 19a. By overlapping the heating element 14 with the through holes 20, 21, the heat of the heating element 14 can also be transmitted to the first and second electrodes 11, 12, and the intermediate electrode 16 through the through holes 20 and 21 and mounted on the first and second electrodes 11, 12, the soluble conductor 13 on the middle electrode 16 quickly fuse the soluble conductor 13.

In addition, regarding the heating element extraction electrode 15 and the lower layer portions 18a, 19a of the first and second packaged electrodes 18, 19, the first to third side edges 10c to 10e of the insulating substrate 10 may be provided with castle-shaped contacts instead The through holes 20 and 21 or the through holes 20 and 21 are connected to the first and second electrodes 11 and 12 and the intermediate electrode 16 through the castellated contacts and the through holes 20 and 21.

Such a fuse element 60 can be manufactured by the steps shown in FIGS. 16-19. First, as shown in FIG. 16, on the back surface 10 b of the insulating substrate 10, the heating element extraction electrode 15, the first and second package electrodes 18, 19 lower layer portions 18 a and 19 a and the heating element electrode 23 are formed. Next, except for a part on the first and second side edges 10c, 10d side of the insulating substrate 10 on the lower layer portions 18a, 19a, and a part on the third side edge 10e side of the insulating substrate 10 on the heating element extraction electrode 15, a The third insulating layer 61.

Next, the heating element 14 is formed as shown in FIG. 17. The heating element 14 is formed on the third insulating layer 61 to overlap the heating element extraction electrode 15 and the lower layer portions 18a, 19a. In addition, the heating element 14 is electrically connected to a part of the heating element extraction electrode 15 that is not covered by the third insulating layer 61 and the heating element. Pole 23 is connected.

Next, the fourth insulating layer 62 is formed on the heating element 14 as shown in FIG. 18. The fourth insulating layer 62 covers the entire heating element 14 and exposes the lower layer portions 18a, 19a except for a part of the first and second side edges 10c, 10d of the insulating substrate 10.

Then, as shown in FIG. 19, the upper layer portions 18 b and 19 b of the first and second packaged electrodes 18 and 19 are formed on the fourth insulating layer 62. The upper layer portions 18b, 19b are connected to the lower layer portions 18a, 19a at a part of the insulating substrate 10 on the first and second side edges 10c, 10d.

[Fifth Embodiment]

Also, as shown in Figure 20 (A) and (B), the fuse element may not be provided with the first and second packaged electrodes 18, 19 and the lower layer portions 18a, 19a, and the first and second built-in electrodes 18 and 19 are connected through the castle-shaped contact 63 2 Electrodes 11, 12 and upper portion 18b, 19b. The fuse element 65 shown in FIG. 20 is different from the fuse element 60 in that the lower layer portions 18a, 19a of the first and second packaged electrodes 18, 19 are not provided. In this case, it is not necessary to provide the third insulating layer 61 for insulating the heating element 14 from the lower layer portions 18a and 19a, but an insulating layer may be provided between the back surface 10b of the insulating substrate 10 and the heating element 14.

Such a fuse element 65 can be manufactured by the steps shown in FIGS. 21-24. First, as shown in FIG. 21, the heating element extraction electrode 15 and the heating element electrode 23 are formed on the back surface 10 b of the insulating substrate 10. Next, the heating element 14 is formed as shown in FIG. 22. The heating element 14 is connected to the heating element extraction electrode 15 and the heating element electrode 23.

Next, as shown in FIG. 23, a fourth insulating layer 62 is formed on the heating element 14. The fourth insulating layer 62 covers the entire heating element 14. Then, as shown in FIG. 24, the upper layer portions 18b, 19b of the first and second packaged electrodes 18, 19 are formed on the fourth insulating layer 62. The upper portion 18b, 19b is formed through the castle-shaped contacts 63 formed on the first and second side edges 10c, 10d of the insulating substrate 10. The first and second electrodes 11 and 12 on the surface 10a of the insulating substrate 10 are connected.

[Change example]

Here, in order to increase the rated value of the fuse element in response to large currents, not only the low resistance of the soluble conductor 13 itself, but also the first and second electrodes 11, 11 and 11 formed on the surface 10a of the insulating substrate 10 are required. 12 The resistance of the current path to the first and second packaged electrodes 18, 19 formed on the back surface 10b of the insulating substrate 10 is reduced.

Moreover, in the method of connecting the first and second electrodes 11, 12 and the first and second structured electrodes 18, 19 through the castle-shaped contacts provided on the side surface of the insulating substrate 10, it is difficult to fully obtain the castle-shaped contacts. The thickness of the plating layer of the contact and the overall rating of the fuse element are specified by the current path from the first and second electrodes 11, 12 to the first and second packaged electrodes 18, 19, which is difficult to cope with large currents.

Therefore, as described above, in the fuse element to which the present technology is applied, the first and second electrodes 11 and 12 respectively penetrate through the through hole 20 penetrating the insulating substrate 10 and the first and second package electrodes 18 and 19Connect. Because the through holes 20 connecting the first and second electrodes 11, 12 and the first and second packaged electrodes 18, 19 constitute part of the energization path of the fuse elements 1, 50, 60, it becomes the determining current rating The element has a predetermined size (for example, 0.3 mm φ), and a conductive layer connecting the first electrode 11 and the first package electrode 18, and the second electrode 12 and the second package electrode 19 is formed inside.

[Fuse element 70]

In addition, as the fuse element formed with the conductive through hole 20 having a conductive layer, in addition to the above-mentioned fuse elements 1, 50, 60 where the heating element 14 is formed on the back of the insulating substrate 10, as shown in FIGS. 25 and 26 As shown, it can also be applied to a fuse element 70 with a heating element formed on the surface of an insulating substrate. Furthermore, In the description of the fuse element 70 described below, the same reference numerals are given to the same members as the above-mentioned fuse elements 1, 50, 60, and detailed descriptions thereof are omitted.

The fuse element 70 includes: an insulating substrate 10; a heating element 14 laminated on the insulating substrate 10 and covered by an insulating layer 17; a first electrode 11 and a second electrode 12 formed on both ends of the insulating substrate 10; an intermediate electrode 16, which is laminated on the insulating layer 17 in a manner overlapping with the heating element 14; and the soluble conductor 13, the two ends of which are respectively connected to the first and second electrodes 11 and 12, and the central part is connected to the intermediate electrode 16.

[First and second electrodes]

The first and second electrodes 11 and 12 are respectively connected to the first and second packaged electrodes 18 and 19 as external connection electrodes provided on the back surface 10b through the through holes 20 penetrating the insulating substrate 10. Since the through hole 20 connecting the first and second electrodes 11, 12 and the first and second packaged electrodes 18, 19 constitutes a part of the energization path of the fuse element 70, it is an element for determining the current rating, so it has With a predetermined size (for example, 0.3 mm φ), a conductive layer connecting the first electrode 11 and the first package electrode 18, and the second electrode 12 and the second package electrode 19 is formed inside.

[heating stuff]

The heating element 14 can be formed by forming a pattern on the surface 10a of the insulating substrate 10 using a screen printing technique, and performing firing or the like. In addition, one end of the heating element 14 is connected to the heating element lead electrode 15 and the other end is connected to the heating element electrode 23.

The fuse element 70 is provided with an insulating layer 17 so as to cover the heating element 14, and an intermediate electrode 16 is formed so as to face the heating element 14 through the insulating layer 17. In order to efficiently transfer the heat of the heating element 14 to the soluble conductor 13, an insulating layer 17 may be laminated between the heating element 14 and the insulating substrate 10. As the insulating layer 17, for example, glass can be used.

One end of the intermediate electrode 16 is connected to a part of the heating element lead-out electrode 15 exposed from the insulating layer 17 and is continuous with one end of the heating element 14 through the heating element lead-out electrode 15. In addition, the heating element extraction electrode 15 is formed on the third side surface 10e side of the insulating substrate 10, and the heating element electrode 23 is formed on the fourth side surface 10f side of the insulating substrate 10. In addition, the heating body electrode 23 is connected to the external connection electrode 23a formed on the back surface 10b of the insulating substrate 10 through the castellated contact 71 formed on the fourth side surface 10f.

The heating element 14 is mounted on the circuit board 2 by the fuse element 70, and is connected to an external circuit formed on the circuit board 2 through the external connection electrode 23a. Furthermore, the heating element 14 can fuse the soluble conductor 13 connected to the first and second electrodes 11 and 12 by energizing and generating heat through the external connection electrode 23a at a predetermined point in which the energization path of the external circuit is interrupted. In addition, since the heating element 14 is fused by the soluble conductor 13, its own energization path is also blocked, so the heat generation is stopped.

Furthermore, in the fuse element 70, a cover 24 for protecting the inside is also mounted on the surface 10a of the insulating substrate 10.

According to this fuse element 70, since the first and second electrodes 11, 12 are connected to the first and second package electrodes 18, 19 through the conductive vias 20, respectively, they are connected through the conventional castle-shaped contacts. Compared with the case, the thickness of the conductive layer can be sufficiently ensured, and the electric path between the first and second electrodes 11, 12 and the first and second package electrodes 18, 19 can be reduced in resistance. Therefore, the fuse element 70 does not hinder the improvement of the rated value of the energizing path, which is suitable for high current applications.

In addition, in the fuse element 70, the heating element electrode 23, which serves as an electric path to the heating element 14, is connected to the external connection electrode 23a formed on the back surface 10b of the insulating substrate 10 through the castellated contact 71. As a result, as shown in FIG. 27, when the fuse element 70 is soldered to the external circuit board 72, a filler 73 is formed on the castellated contact 71, so it is connected to the external connection electrode 23a. Compared with the shape, the packaging strength for the external circuit board 72 can be improved. In addition, by confirming the filler 73 during the assembly process of the fuse element 70 to the external circuit board 72, it is easy to determine whether the fuse element 70 has been reliably connected by visual inspection or screen inspection.

Furthermore, the fuse element 70 uses the castellated contact 71 to form an electric path between the heating element electrode 23 and the external connection electrode 23a. Compared with the case of forming a conductive through hole, the heating element electrode 23 can be narrowed and the entire element can be realized. The miniaturization.

In addition, the fuse element 70 may be connected to the heating element electrode 23 and the external connection electrode 23a through side electrodes formed on the side surface of the insulating substrate 10 by printing or the like. At this time, as in the case of the connection through the castle-shaped contact 71, by forming the filler 73, the connection strength can be improved or the connection confirmation can be easily performed. Furthermore, compared with the case where conductive vias are formed, the heating body electrode 23 can be made smaller, and the entire element can be miniaturized.

Furthermore, since the energization path to the heating element 14 is different from the energization path of the soluble conductor 13, it is not an element that determines the rating of the fuse element 70, so it can be high resistance compared to the energization path of the soluble conductor 13 (For example, several Ω levels). Therefore, even if the fuse element 70 uses the castellated contact 71 or the side electrode, the improvement of the rating is not impaired. Furthermore, generally speaking, the formation of the castle-shaped contact 71 is higher in construction strength than the case where side electrodes are formed on the side of the insulating substrate 10 by printing, and the manufacturing steps are simple, which is also advantageous in terms of manufacturing cost. On the other hand, in order to form the castellated contact 71, it is necessary to provide recesses in the heating body electrode 23 and the external connection electrode 23a, and the opposite side electrode can form the heating body electrode 23 and the external connection electrode 23a in the minimum required area, which is easy to further Realize miniaturization.

[Castle-shaped contact]

Furthermore, as shown in FIG. 28, the fuse element 70 is based on requirements for miniaturization or manufacturing cost. It is also possible to further form a castle-shaped contact 74 on the first and second electrodes 11 and 12. At this time, in order to ensure the strength, it is preferable to provide the castle-shaped contact 74 and the conductive via 20 at a predetermined interval (for example, more than half of the opening diameter of the conductive via 20). The fuse element 70 is provided with castellated contacts 74 on the first and second electrodes 11, 12 in addition to the conductive through holes 20, which can further reduce the on-resistance and increase the strength of the package through the formation of fillers. The confirmation of the assembly of the external circuit board 72 can be easily performed by confirming the filler.

[Independent electrode]

In addition, as shown in FIG. 29, the fuse element 70 is provided on the surface 10a of the insulating substrate 10 in order to increase the strength of the package for the external circuit board 72, regardless of the conduction of the first and second electrodes 11, 12 and the heating element 14. The first independent terminal 75, and the second independent terminal 76 that is not related to the conduction of the first, second electrodes 11, 12 and the heating element 14 are provided on the back 10b of the insulating substrate 10, and these second independent terminals 76 are connected through the castellated contact 77 1. The second independent terminals 75 and 76.

By providing the first and second independent terminals 75 and 76 connected through the castle-shaped contact 77 to form at least one filler, the fuse element 70 can increase the strength of the assembly of the external circuit board 72.

Furthermore, the fuse element 70 can also be connected to the first and second individual terminals 75 and 76 via side electrodes provided on the side surfaces of the insulating substrate, and fillers can be formed along the side electrodes.

1‧‧‧Fuse element

10‧‧‧Insulating substrate

10a‧‧‧The surface of the insulating substrate 10

10c, 10d‧‧‧The first and second side edges of the insulating substrate 10

11‧‧‧The first electrode

12‧‧‧Second electrode

13‧‧‧Fusible Conductor

16‧‧‧Intermediate electrode

20‧‧‧Through hole

21‧‧‧Through hole

Claims (22)

A fuse element, comprising: an insulating substrate; a first electrode and a second electrode formed on the surface of the insulating substrate; a soluble conductor connected between the first and second electrodes; A heating element formed on the back surface of the insulating substrate to fuse the soluble conductor by heating through energization; and a back electrode formed on the back surface of the insulating substrate; the heating element and the back electrode overlapping through the insulating layer; The back electrode is a heating element extraction electrode connected to the heating element; the heating element extraction electrode is connected to an intermediate electrode formed on the surface of the insulating substrate and connected to the soluble conductor through a conductive through hole penetrating the insulating substrate; The heating element partially or completely overlaps with one of the above-mentioned conductive through holes. For example, the fuse element of the first item of the scope of patent application, wherein the heating element extraction electrode is connected to the intermediate electrode through a castle-shaped contact provided on the side of the insulating substrate. For example, the fuse element of item 1 or 2 of the scope of patent application, wherein the heating element extraction electrode, the insulating layer, and the heating element are sequentially laminated from the back surface of the insulating substrate. For example, the fuse element of the third item in the scope of patent application, wherein the heating element is covered by a protective layer. A fuse element, comprising: an insulating substrate; a first electrode and a second electrode formed on the surface of the insulating substrate; a soluble conductor which is connected across the first and second electrodes; A heating element formed on the back surface of the insulating substrate to fuse the above-mentioned soluble conductor by energization and heating; and a back electrode formed on the back surface of the insulating substrate; the heating element and the back electrode are overlapped through the insulating layer; The back electrode is connected to the first and second electrodes and is mounted on the first and second mounting electrodes of the circuit board. For example, the fuse element of item 5 of the scope of patent application, wherein the first and second structured electrodes respectively penetrate through the conductive through holes penetrating the insulating substrate and the first and second electrodes formed on the surface of the insulating substrate connection. For example, the fuse element of the sixth item in the scope of patent application, wherein the heating element and one of the conductive through holes partially or completely overlap. For example, the fuse element according to any one of items 5 to 7 in the scope of the patent application, wherein the first and second structured electrodes are connected to the first and second electrodes through a castle-shaped contact provided on the side of the insulating substrate connection. For example, the fuse element of any one of items 5 to 7 in the scope of the patent application, wherein the first and second structured electrodes have a lower layer portion provided between the back surface of the insulating substrate and the heating element, and The lower layer portion is connected to and assembled on the upper layer portion of the circuit board; the lower layer portion of the first and second structured electrodes, the first insulating layer, the heating element, and the second insulating layer are sequentially stacked from the back of the insulating substrate Layer, the upper layer portion of the first and second packaged electrodes. For example, the fuse element of item 9 of the scope of patent application, wherein the first insulating layer is formed across the lower layer portions of the first and second structured electrodes; The heating element is formed on the first insulating layer. For example, the fuse element of item 8 of the scope of patent application, wherein the first and second packaged electrodes are connected to the first and second electrodes and are constructed on the upper layer of the circuit board; On the back surface of the substrate, the heating element, the second insulating layer, and the upper layer are laminated in this order. A fuse element, comprising: an insulating substrate; a first electrode and a second electrode formed on the surface of the insulating substrate; a soluble conductor connected across the first and second electrodes; and a heating element A body formed on the back surface of the insulating substrate to fuse the soluble conductor by energization and heating; and a back electrode formed on the back surface of the insulating substrate; the heating body and the back electrode are overlapped through the insulating layer; the back surface The electrodes are heating element extraction electrodes connected to the heating element, and first and second mounting electrodes connected to the first and second electrodes and mounted on the circuit board. For example, the fuse element of item 12 of the scope of patent application, wherein the heating element extraction electrode is connected to an intermediate electrode formed on the surface of the insulating substrate and connected to the soluble conductor through a conductive through hole penetrating the insulating substrate; The first and second packaged electrodes are respectively connected to the first and second electrodes formed on the surface of the insulating substrate through conductive through holes penetrating the insulating substrate. For example, the fuse element of item 13 of the scope of patent application, wherein the heating element and one of the conductive through holes partially or completely overlap. For example, the fuse element of item 13 or 14 of the scope of patent application, wherein the heating element extraction electrode is connected to the intermediate electrode through a castle-shaped contact provided on the side of the insulating substrate; the first and second structured electrodes penetrate A castle-shaped contact provided on the side surface of the insulating substrate is connected to the first and second electrodes. For example, the fuse element of any one of items 12 to 14 in the scope of the patent application, wherein the first and second structured electrodes have a lower layer portion provided between the back surface of the insulating substrate and the heating element, and The lower layer portion is connected to and assembled on the upper layer portion of the circuit substrate; the heating element extraction electrode and the first and second structured electrodes are sequentially stacked from the back surface of the insulating substrate. The lower layer portion, the third insulating layer, and the The heating element, the fourth insulating layer, and the upper layer portion of the first and second packaged electrodes. For example, the fuse element of item 15 of the scope of patent application, wherein the first and second packaged electrodes are connected to the first and second electrodes and are constructed on the upper layer of the circuit board; On the back surface of the substrate, a heating element lead electrode, the heating element, the fourth insulating layer, and the upper layer are laminated in this order. A fuse element, comprising: an insulating substrate; a first electrode and a second electrode formed on the surface of the insulating substrate; a soluble conductor connected between the first and second electrodes; A heating element formed on the insulating substrate to fuse the soluble conductor by energizing heat; and a first external connection electrode and a second external connection electrode formed on the back surface of the insulating substrate; and Either or both of the first electrode and the first external connection electrode, and the second electrode and the second external connection electrode are connected through a conductive through hole penetrating the insulating substrate. For example, the fuse element of item 18 of the scope of patent application, wherein one or both of the first electrode and the first external connection electrode, and the second electrode and the second external connection electrode are connected through a castle Dot or side electrode connection provided on the side surface of the insulating substrate. For example, the fuse element of item 18 or 19 of the scope of patent application, wherein the heating element is formed on the surface of the insulating substrate; the fuse element includes: a heating element lead electrode, which is provided on the surface of the insulating substrate, and The heating element is connected; and an intermediate electrode that overlaps the heating element through an insulating layer between the first and second electrodes, and is connected to the heating element extraction electrode and the soluble conductor; the heating element extraction electrode is provided There are castle-shaped contacts across the back of the insulating substrate. For example, the fuse element of item 18 or 19 of the scope of patent application, wherein the heating element is formed on the back surface of the insulating substrate; the fuse element includes: an intermediate electrode provided between the first and second electrodes, Connected to the above-mentioned soluble conductor; and a heating element lead electrode, which is arranged on the back of the insulating substrate and connected to the heating element; the intermediate electrode and the heating element lead electrode penetrate through the insulating substrate through the lead Electrical vias, castle-shaped contacts, or side electrode connections provided on the side of the insulating substrate. For example, the fuse element of item 18 or 19 of the scope of patent application, wherein a first independent terminal that is not related to the conduction of the first and second electrodes and the heating element is provided on the surface of the insulating substrate; The back side is provided with a second independent terminal irrelevant to the conduction of the first and second electrodes and the heating element; the first and second independent terminals are connected through castellated contacts or side electrodes provided on the side of the insulating substrate.

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