WO2021096224A1 - Fuse element, flexible wiring board, and battery pack - Google Patents

Abstract

[Problem] To provide a fuse element in which a destroyed part of the fuse element formed on a flexible wiring board exhibits stable operation. Alternatively, to provide a stable fuse element that does not impede the functions of parts other than the fuse element formed on the flexible wiring board. [Solution] This fuse element includes a first film, an insulation layer on the first film, a first conductive layer on the insulating layer, and pads spaced apart from each other, electrically connected to the first conductive layer, and having a different material or composition ratio from the first conductive layer.

Description

Fuse element, flexible wiring board and battery pack

One embodiment of the present invention relates to a fuse element, a flexible wiring board, and a battery pack. In particular, embodiments of the present invention relate to a fuse element, a flexible wiring board, and a battery pack formed on a film.

A fuse element is installed to protect each functional element installed in the electric circuit from unintended high current in the electric circuit. The fuse element cuts off the current when a certain or more current flows in order to suppress the destruction of each functional element. In the case of constructing an electric circuit using a conventional printed wiring board, a fuse for mounting a board with a lead wire has been used. Such a mounting fuse is mounted on a printed wiring board using soldering.

In recent years, for example, even in a vehicle electronic device, an electric circuit using a flexible wiring board has been developed in place of the conventional printed wiring board. The flexible wiring board can be thinner and bend compared to a conventional printed wiring board because the substrate can form wiring and functional elements on a flexible film. In the case of forming a fuse element on a flexible wiring board, for example, as shown in Patent Document 1, a chip fuse was formed on the flexible substrate. In Patent Document 1, a chip fuse is mounted on a flexible substrate by solder. However, in, for example, an electronic device for a vehicle, there has been a problem that the chip fuse is detached from the flexible wiring board due to stress caused by vibration or heat while the vehicle is running. In order to solve such a problem, as shown in Patent Document 2, a technique for realizing a fuse element by a pattern of a conductive layer formed on a flexible wiring board has been developed.

(Patent Document 1) [Patent Document 1] Japanese Unexamined Patent Publication No. 2019-033090

(Patent Document 2) [Patent Document 2] Japanese Unexamined Patent Publication No. 2017-204525

In the fuse element described in Patent Document 2, the conductive layer is melted by joule heat generated by a current flowing through the conductive layer. The fuse element is destroyed by melting of this conductive layer to cut off the current (that is, it is melted). However, in the fuse element having the configuration described in Patent Literature 2, there has been a problem that a portion to be destroyed by an overcurrent is not stable. In addition, in the fuse element having the configuration described in Patent Document 2, due to the material of the conductive layer scattered by the spark generated at the time of destruction, the problem of shorting between the insulated wirings, or the parts other than the fuse element due to the spark There was a problem of being damaged.

The present invention has been made in view of the above problem, and an object of the present invention is to provide a fuse element in which a portion of a fuse element formed on a flexible wiring board exhibits a stable operation. In addition, in a fuse element formed on a flexible wiring board, it is an object to provide a highly reliable fuse element that does not impair the functions of parts other than the fuse element.

The fuse element in the embodiment of the present invention is electrically connected to the first film, the insulating layer on the first film, and the first conductive layer on the insulating layer, and has a pad of a material different from the first conductive layer. .

In the embodiment of the present invention, the fuse element is electrically connected to the first film, the insulating layer on the first film, and the first conductive layer on the insulating layer, and has two pads having a composition ratio different from that of the first conductive layer. Have.

The first conductive layer may have a lower resistance than the pad.

The first conductive layer may have a lower melting point than that of the pad.

The first conductive layer may contain silver and copper, and the pad may contain copper.

The first conductive layer and the pad may contain silver and copper.

The ratio of silver in the first conductive layer may be greater than the ratio of silver in the pad.

At least two of the pads are isolated from each other, and the two pads are arranged in a first direction, and the width of the first conductive layer may be smaller than the width of the pad in a second direction orthogonal to the first direction. .

The first conductive layer includes a first region and a second region along the first direction, and in the second direction, the width of the first conductive layer of the first region is the first conductive layer of the second region. It is smaller than the width of the layer, and the width of the first conductive layer may be gradually decreased from the second area toward the first area.

In an embodiment of the present invention, the fuse element is electrically connected to the first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer to be separated from each other in the first direction. The two pads and the first conductive layer have a first region and a second region along the first direction, and in a second direction orthogonal to the first direction, the first conductive layer of the first region The width is smaller than the width of the first conductive layer in the second region, and the width of the first conductive layer gradually decreases from the second region toward the first region.

The first film may include polycyclohexylene dimethylene terephthalate (PCT).

The insulating layer may be an inorganic insulating layer.

The inorganic insulating layer may include one of silicon oxide, silicon nitride, and hafnium oxide, or a stack of two or more of silicon oxide, silicon nitride, and hafnium oxide.

You may further have a primer layer between the insulating layer and the first film.

The flexible wiring board in the embodiment of the present invention is electrically connected to the first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer, and is separated from the first conductive layer. A fuse element with a pad of a different material and a fuse element with a pad of a material different from that of the second conductive layer electrically connected are provided.

The flexible wiring board in the embodiment of the present invention is electrically connected to the first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer, and is separated from the first conductive layer. A fuse element having pads of different composition ratios, a second conductive layer electrically connected to the pad, and a second film on the second conductive layer.

The pad and the second conductive layer contain copper, and the ratio of copper in the pad may be smaller than the ratio of copper in the second conductive layer.

In one embodiment of the present invention, the flexible wiring board is electrically connected to the first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer to each other in a first direction. With at least two pads spaced apart, the first conductive layer has a first region and a second region in the first direction, and the first conduction of the first region in a second direction orthogonal to the first direction The width of the layer is smaller than the width of the first conductive layer in the second region, and the width of the first conductive layer is gradually reduced from the second region toward the first region, There is a second conductive layer connected to each other and a second film on the second conductive layer.

You may further have a conductive adhesive layer between the pad and the second conductive layer.

In one embodiment of the present invention, the battery pack has a battery management system having a battery and a monitoring circuit for monitoring voltage, current, and temperature of the battery, and a flexible wiring board connected to the battery and the battery management system, The flexible wiring board is electrically connected to a first film, an insulating layer on the first film, a first conductive layer on the insulating layer, and the first conductive layer, and includes a pad of a material different from the first conductive layer. A fuse element provided, a second conductive layer electrically connected to the pad, and a second film on the second conductive layer, and the battery management system is installed on the second film, and the monitoring circuit is provided with the second conductive layer. It is connected to the conductive layer.

In one embodiment of the present invention, the battery pack includes a battery management system having a battery and a monitoring circuit for monitoring voltage, current, and temperature of the battery, and a flexible wiring board connected to the battery and the battery management system. The flexible wiring board includes a first film, an insulating layer on the first film, a first conductive layer on the insulating layer, and a pad electrically connected to the first conductive layer, and having a composition ratio different from that of the first conductive layer. A fuse element, a second conductive layer electrically connected to the pad, and a second film on the second conductive layer are provided, the battery management system is installed on the second film, and the monitoring circuit is It is connected to the second conductive layer.

The battery pack in one embodiment of the present invention has a battery management system having a battery and a monitoring circuit for monitoring voltage, current, and temperature of the battery, and a flexible wiring board connected to the battery and the battery management system. The flexible wiring board includes a first film, an insulating layer on the first film, a first conductive layer on the insulating layer, and at least two pads spaced apart from each other in a first direction electrically connected to the first conductive layer, The first conductive layer has a first region and a second region along the first direction, and in a second direction orthogonal to the first direction, the width of the first conductive layer in the first region is the A fuse element that is smaller than the width of the first conductive layer in the second region, and the width of the first conductive layer gradually decreases from the second region toward the first region, and a second conductive layer electrically connected to the pad A layer and a second film are provided on the second conductive layer, the battery management system is installed on the second film, and the monitoring circuit is connected to the second conductive layer.

The electric battery pack is used in an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV).

According to an exemplary embodiment of the present invention, a fuse element in which a portion of a fuse element formed on a flexible wiring board is destroyed may exhibit a stable operation. Further, according to one embodiment of the present invention, in a fuse element formed on a flexible wiring board, it is possible to provide a highly reliable fuse element that does not impair the functions of places other than the fuse element.

1 is a cross-sectional view of a fuse element according to an embodiment of the present invention.

2 is a plan view of a fuse element according to an embodiment of the present invention.

3 is a flowchart showing a method of manufacturing a fuse element according to an embodiment of the present invention.

Fig. 4 is a plan view of a fuse element according to a modification of the embodiment of the present invention.

Fig. 5 is a diagram showing a film thickness profile of a first conductive layer of a fuse element according to a modified example of an embodiment of the present invention.

[Fig. 6] A fuse element according to a comparative example is a diagram showing a film thickness profile of a layer corresponding to the first conductive layer of the fuse element according to the embodiment of the present invention.

Fig. 7 is a plan view of a fuse element according to a modification of the embodiment of the present invention.

Fig. 8 is a plan view of a fuse element according to a modification of the embodiment of the present invention.

9 is a cross-sectional view of a flexible wiring board according to an embodiment of the present invention.

10 is a cross-sectional view of a fuse element according to an embodiment of the present invention.

11 is a cross-sectional view of a flexible wiring board according to an embodiment of the present invention.

12 is a cross-sectional view of a fuse element according to an embodiment of the present invention.

13 is a plan view of a fuse element according to an embodiment of the present invention.

14 is a cross-sectional view of a flexible wiring board according to an embodiment of the present invention.

15 is a functional block diagram of a BMS to which a fuse element according to an embodiment of the present invention is applied.

16 is a cross-sectional view of a battery pack to which a fuse element according to an embodiment of the present invention is applied.

17 is a diagram showing an application example of a battery pack according to an embodiment of the present invention.

Fig. 18 is an optical microscope photograph showing a state after being destroyed in a fuse element according to an embodiment of the present invention.

19 is an optical microscope photograph showing a state after being destroyed in a fuse element according to an embodiment of the present invention.

Fig. 20 is an optical micrograph showing a state after being destroyed in a fuse element according to an embodiment of the present invention.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In addition, the disclosure is only an example. That is, a configuration that can be easily imagined by a person skilled in the art by appropriately changing it while maintaining the knowledge of the invention is, of course, a configuration included in the scope of the present invention. In the drawings, in order to clarify the description, the width, thickness, shape, etc. of each part may be schematically displayed compared to the actual mode. However, these are only examples and do not limit the interpretation of the present invention. In addition, with respect to the present specification and each diagram, the same elements as those described above with respect to the previous diagrams are denoted by the same reference numerals followed by uppercase alphabets, and detailed descriptions can be appropriately omitted.

In the present specification and the claims, when expressing the aspect in which the second member is arranged on the first member, simply "upper" or "upper" is indicated, in particular, when both are arranged and above the first member, further It is defined as including a case in which the second member is disposed through another third member and both. Moreover, the top and bottom of the structure described in this specification may be inverted.

In the present specification, "α includes A, B or C", "α includes any one of A, B and C", "α includes one selected from the group consisting of A, B, and C. The expression "" does not exclude the case where α includes multiple combinations of A to C. Moreover, these expressions do not exclude cases where α includes other elements.

In addition, each of the following embodiments can be combined with each other as long as no technical contradiction occurs.

<First embodiment>

[Configuration of fuse element 10]

The configuration of the fuse element 10 according to the first embodiment will be described with reference to FIGS. 1 to 3. As described below, the fuse element 10 is a fuse having a structure in which a conductive layer (metal layer) is formed on a film, and thus may be referred to as a metal on film (MOF) fuse.

1 is a cross-sectional view of a fuse element according to an embodiment of the present invention. As shown in FIG. 1, the fuse element 10 has a first film 100, an insulating layer 110, a first conductive layer 120, and a pad 130. The insulating layer 110 was installed on the first film 100. The first conductive layer 120 was provided over the insulating layer 110. The insulating layer 110 is in contact with the first conductive layer 120. In other words, the first conductive layer 120 is covered by the insulating layer 110. The pad 130 is provided on each of the insulating layer 110 and the first conductive layer 120. Several pads 130 are installed and placed apart from each other. The first conductive layer 120 is electrically connected to each pad 130. In this embodiment, the pad 130 is provided at the end of the first conductive layer 120 and is in contact with the sidewall and the upper surface of the first conductive layer 120. However, the position of the pad 130 is not limited to the end of the first conductive layer 120.

2 is a plan view of a fuse element according to an embodiment of the present invention. As shown in FIG. 2, two pads 130 are installed, and two pads 130 are arranged side by side in the D1 direction. In the D2 direction orthogonal to the D1 direction, the width w1 of the first conductive layer 120 is smaller than the width w2 of the pad 130. In a region where the first conductive layer 120 and the pad 130 overlap in a plan view, the first conductive layer 120 has a width w3 that is greater than the width w1 and less than the width w2. The ratio of [w1/w2] is 10% or more and 90% or less. The above width ratio may be determined based on the melting point of the first conductive layer 120 and the melting point of the pad 130. The entire area of the first conductive layer 120 having a width w3 overlaps the pad 130 in plan view. However, a part of the area having the width w3 of the first conductive layer 120 does not need to overlap the pad 130 in plan view.

The material of the first conductive layer 120 and the material of the pad 130 are different. Alternatively, the composition ratio of the first conductive layer 120 and the composition ratio of the pad 130 are different. In this embodiment, the resistance of the first conductive layer 120 is lower than that of the pad 130. Also, the melting point of the first conductive layer 120 is lower than that of the pad 130. Specifically, the first conductive layer 120 contains silver and copper. Pad 130 contains copper. More specifically, as the first conductive layer 120, a silver and copper alloy (hereinafter, referred to as "AgCu") is used. For example, as the first conductive layer 120, AgCu (eutectic alloy) of Ag:Cu=9:1 is used. As the pad 130, copper (Cu) is used. For example, as the pad 130, Cu having a purity of 90% or more and 99.99% or less is used.

Here, the melting point of Cu is about 1083°C. In contrast, the melting point of AgCu is about 141°C. Further, the electrical resistivity of Cu is 1.68×10 ^-8 [Ωm]. On the other hand, the electrical resistivity of the AgCu is 3.88 × 10 ^-8 [Ωm]. That is, when Cu and AgCu are compared, the melting point can be lowered without significantly changing the electrical resistivity.

As the insulating layer 110, for example, an inorganic insulating layer is used. Specifically, silicon oxide (SiO2) is used as the inorganic insulating layer. However, as the inorganic insulating layer, in addition to silicon oxide, silicon nitride (SiN), hafnium oxide (HfO2), aluminum oxide (Al2O3), aluminum nitride (AlN), titanium dioxide (TiO2), barium titanate (BaTiO3), titanium zirconate One of yellow (PZT:PbZrTiO3) or a stack of two or more of these insulating layers may be used. As the insulating layer 110, a material harder than the first film 100 may be used.

As the first film 100, a film made of a polycyclohexylene dimethylene terephthalate (PCT) material is used. PCT has high heat resistance and high moisture resistance, so its properties do not change depending on moisture even under high temperature and high humidity environments. However, the material of the first film 100 is not limited to PCT. For example, as the first film 100, PET (Poly Ethylene Terepthalate), PI (Poly Imide), PEN (Poly Ethylene Naphthalate), PPS (Poly phenylene sulfide), or the like may be used.

As described above, according to the fuse element 10 according to the present embodiment, since the melting point of the first conductive layer 120 is lower than that of the pad 130, when an overcurrent flows through the fuse element 10, the first conductive layer 120 is preferentially melted. Accordingly, destruction of the fuse element in an unintended place can be suppressed, and a probability that the destruction of the fuse element 10 occurs in the region of the first conductive layer 120 can be improved. In addition, since AgCu above has a sufficiently low electrical resistivity compared to Cu, the current loss of the fuse element 10 before destruction is not significantly different from the current loss of the fuse element when Cu is used as the first conductive layer 120.

In addition, since the PCT film is used as the first film 100 under the first conductive layer 120 as described above, it is possible to suppress the occurrence of sparks when the first conductive layer 120 is melted by an overcurrent. Therefore, it is possible to suppress a problem in which parts other than the fuse element 10 are damaged by spark. Alternatively, when the first conductive layer 120 is melted, scattering of the first conductive layer 120 due to spark may be suppressed. Therefore, it is possible to suppress the problem of short-circuiting between the insulated wirings.

Also pad 130. You may contain silver and copper. When both the first conductive layer 120 and the pad 130 contain silver and copper, the ratio of silver in the first conductive layer 120 may be different from the ratio of silver in the pad 130. Each of the silver ratios are different, and the melting point of the first conductive layer 120 is lower than that of the pad 130. More specifically, when AgCu is used as the first conductive layer 120 and the pad 130, AgCu of Ag:Cu=9:1 is used as the first conductive layer 120, and as the pad 130, Ag:Cu=85:15-15 :85 AgCu may be used. That is, the ratio of silver in the first conductive layer 120 may be larger than the ratio of silver in the pad 130. However, the ratio of Ag and Cu of the first conductive layer 120 and the pad 130 is not limited to the above example. When the melting point of the first conductive layer 120 is lower than the melting point of the pad 130, the ratio of each Ag may be different from the above ratio.

Further, in the present embodiment, a configuration in which AgCu is used as the first conductive layer 120 and Cu is used as the pad 130 is exemplified, but the configuration is not limited thereto. If the melting point of the first conductive layer 120 is lower than the melting point of the pad 130, materials other than the above combination may be used for the first conductive layer 120 and the pad 130. For example, Cu, Ag, gold (Au), or aluminum (Al) is used as the pad 130, and zinc (Zn), tin (Sn), indium (In), and bismuth (Bi) are used as the first conductive layer 120. These alloys, Cu or Ag, and their alloys may be used.

[Method of manufacturing fuse element 10]

A method of manufacturing the fuse element 10 according to the first embodiment will be described with reference to FIG. 3. 3 is a flowchart showing a method of manufacturing a fuse element according to an embodiment of the present invention. As shown in FIG. 3, the method of manufacturing the fuse element 10 includes the steps of preparing a first film (S141), applying an insulating layer material (S142), printing a first conductive layer (S143), and printing a pad (S144). In this way, since metal is formed as the first conductive layer 120 and the pad 130 by printing, these can be referred to as a metal printed layer. In addition, after each step of S142, S143, and S144, a curing process is performed. In addition, as a curing treatment performed after each step, a heat curing treatment at 120 °C for 20 minutes is performed. However, ultraviolet (UV) curing treatment may be performed as the curing treatment.

In step S141, the first film 100 made of PCT material is prepared. As a film made of a PCT material, for example, a PCT film manufactured by SK Chemicals can be used. Alternatively, the first film 100 may be formed by coating and curing a solution containing PCT on a substrate. When curing the applied PCT, it may be cured using a heat curing treatment or may be cured using a UV curing treatment. In addition, as the first film 100 as described above, materials such as PI, PET, PEN, and PPS may be used instead of PCT.

In step S142, a solution containing silicon oxide is applied on the first film 100. The curing treatment is performed while the solution is applied on the first film 100. An insulating layer 110 containing silicon oxide is formed by this curing treatment. In addition, the solution for forming the insulating layer 110 as described above may contain silicon nitride, hafnium oxide, aluminum oxide, aluminum nitride, titanium oxide, barium titanate, and lead zirconate titanium oxide. In addition, instead of coating, the insulating layer 110 may be formed using a physical vapor deposition (PVD) or a chemical vapor deposition (CVD) method. As PVD, the insulating layer 110 may be formed by using a sputtering method, a vacuum evaporation method, an ion beam evaporation method, or the like. As CVD, the insulating layer 110 may be formed by using plasma CVD, thermal CVD, atomic layer deposition (ALD), organometallic vapor deposition (MOCVD), or the like.

In step S143, an AgCu ink is formed on the first film 100 by a printing method. As the AgCu ink to be printed, for example, AgCu ink of Ag:Cu=9:1 is used. A solvent including polyester can be used as the AgCu ink. The AgCu ink may be one in which an AgCu alloy is dissolved in a solvent, or Ag and Cu may be dissolved in a solvent, respectively. Further, the AgCu ink may be an ink containing AgCu alloy nanoparticles, or may be an ink containing Ag nanoparticles and Cu nanoparticles individually. Further, pattern formation of the first conductive layer 120 may be performed using a mask or may be performed using ink jet. For example, as a pattern forming method of the first conductive layer 120, a plate type printing method such as screen printing (silk printing), offset printing, and gravure printing, or a plateless printing method such as inkjet method, electrostatic method, thermal transfer method, laser method, etc. You can use After the pattern of the first conductive layer 120 is formed, the curing treatment is performed after the pattern of the first conductive layer 120 is formed by the above method.

In step S144, a Cu ink is formed on the first film 100 and the first conductive layer 120 according to the printing method. As the printed Cu ink, for example, a Cu ink containing Cu particles having a purity of 90% or more and 99.99% or less is used. As the Cu ink, a solvent containing polyester can be used. The Cu ink may be an ink in which Cu is dissolved in a solvent, or may be an ink containing Cu nanoparticles. Further, pattern formation of the pad 130 may be performed using a mask or ink jet. After the pattern of the pad 130 is formed by the above method, the above curing treatment is performed.

As described above, the fuse element 10 may be formed according to the steps of S141 to S144. Further, in the above manufacturing method, a manufacturing method in which a curing treatment is performed after each step has been illustrated, but the manufacturing method is not limited thereto. For example, after at least two steps, the members formed in those steps may be cured at once. Further, after each step, a temporary hardening treatment that is weaker than the hardening treatment (hereinafter referred to as the hardening treatment) may be performed, and after at least two steps, the members formed in these steps may be collectively subjected to the main hardening treatment. Here, the temporary hardening treatment weaker than the hardening treatment means, for example, a heat treatment of less than 120°C or less than 20 minutes if the hardening treatment is a heat hardening treatment at 120°C for 20 minutes. Alternatively, if the curing treatment is a UV curing treatment, the roughness or irradiation time of the temporary curing treatment means that the roughness or irradiation time of the curing treatment is weaker or shorter than the roughness or irradiation time of the curing treatment.

As described above, according to the method of manufacturing the fuse element 10 according to the present embodiment, the insulating layer 110, the first conductive layer 120, and the pad 130 can be formed on the first film by coating or printing. Therefore, patterning can be performed at low cost without requiring expensive patterning such as photolithography.

[Modified example of the first embodiment]

A modified example of this embodiment will be described with reference to FIGS. 4 to 8. 4 to 8 are plan views of a fuse element according to a modified example of an embodiment of the present invention. The fuse elements 10A to 10C shown in FIGS. 4 to 8 are similar to the fuse element 10 shown in FIG. 2, but the patterns of the first conductive layers 120A to 120C are different from the patterns of the first conductive layer 120 of FIG. 2, respectively. In the following description, a description of the same features as in FIG. 2 will be omitted, and differences from FIG. 2 will be described.

In the fuse element 10A shown in FIG. 4, the width in the D2 direction of the first conductive layer 120A in a region that does not overlap with the pad 130A in a plan view varies depending on the location. Specifically, the first conductive layer 120A has a first region 151A and a second region 153A. The first conductive layer 120A of the first region 151A has a width w5 in the D2 direction. The first conductive layer 120A in the second region 153A has a width w4 in the D2 direction. The width w5 is less than the width w4. In other words, the width of the first conductive layer 120A in the D2 direction decreases stepwise from the second region 153A toward the first region 151A.

As described above, the width of the first conductive layer 120A in the D2 direction is gradually reduced from the second region 153A toward the first region 151A, so that the melting due to the overcurrent is concentrated in the first region 151A. Accordingly, the fuse element 10A may be melted in the first region 151A with a high probability. In particular, the probability that the melting occurs near the boundary between the first region 151A and the second region 153A is improved. As described above, since the fuse element 10A has a shape in which the width in the direction D2 of the first conductive layer 120A decreases step by step, the position at which the fuse occurs can be controlled according to the shape in which the corresponding width decreases continuously.

5 is a diagram showing a film thickness profile of a first conductive layer of a fuse element according to an embodiment of the present invention. The film thickness profile 121A in FIG. 5 is a film thickness profile when AgCu in the ratio of Ag:Cu=9:1 is used as 120A of the first conductive layer. 5 is a plan view showing only the first conductive layer 120A of FIG. 4. The film thickness profile 121A of FIG. 5 is a film thickness profile measured by scanning from A to A'along the line A-A' in the plan view of FIG. 5. That is, the film thickness profile of FIG. 5 is the film thickness profile of the first conductive layer 120A in the first region 151A where the width in the D2 direction is w5. In other words, the film thickness profile of Fig. 5 is a film thickness profile of a region in the fuse element 10A to be fused. As shown in FIG. 5, the first conductive layer 120A has film thickness peaks 123A and 125A at the end portions of the pattern, and has a concave shape 127A from both ends toward the inside.

6 is a diagram showing a film thickness profile of a layer corresponding to the first conductive layer of the fuse element according to the embodiment of the present invention in the fuse element according to the comparative example. The film thickness profile 121Z in Fig. 6 is a film thickness profile when Cu is used as the first conductive layer 120Z. 6 is a plan view of a fuse element 10Z related to a comparative example. The film thickness profile of FIG. 6 is a film thickness profile measured by scanning from B to B'along line B-B' in the plan view of FIG. 6. As shown in FIG. 6, unlike the first conductive layer 120A of FIG. 5, the first conductive layer 120Z composed of Cu does not have a film thickness peak at the end of the pattern, and has a substantially rectangular shape.

In the fuse element 10A according to the present embodiment, since the first conductive layer 120A has the above-described film thickness profile, the probability of occurrence of the melting in the first conductive layer 120A can be further improved.

Like the fuse element 10A of FIG. 4, the fuse element 10B shown in FIG. 7 has a width in the direction D2 of the first conductive layer 120B in a region that does not overlap with the pad 130B in plan view. Specifically, the first conductive layer 120B has a first region 151B, a second region 153B, and a third region 155B. The first conductive layer 120B of the first region 151B has a width w8 in the D2 direction. The first conductive layer 120B in the second region 153B has a width w7 in the D2 direction. The first conductive layer 120B in the third region 155B has a width w6 in the D2 direction. The first conductive layer 120B overlapping the pad 130B adjacent to the first region 151B in a plan view has a width w9 in the D2 direction. The width w9 is less than the width w3, the width w8 is less than the width w7 and the width w7 is less than the width w6. In other words, the width of the first conductive layer 120B in the direction D2 decreases stepwise from the third area 155B toward the first area 151B. In addition, in the first conductive layer 120B, only one end portion in the D2 direction (the lower end portion in Fig. 7) is gradually reduced from the third region 155B toward the first region 151B. In the example of FIG. 7, the two pads 130B have the same size, but the pad 130B adjacent to the first area 151B may be smaller than the other pad 130B.

As described above, the width in the D2 direction of the first conductive layer 120B gradually decreases from the third region 155B toward the first region 151B, so that the melting due to the overcurrent is concentrated in the first region 151B. In addition, since the stepped portion is formed only at one end of the first conductive layer 120B in the D2 direction, the probability of fusing occurs at the side where the stepped portion of the first region 151B is formed is improved. Therefore, it is possible to further control the location where the fusing occurs.

The fuse element 10C shown in FIG. 8 has a width in the D2 direction of the first conductive layer 120C in a region that does not overlap with the pad 130C in a plan view, similar to the fuse element 10A of FIG. 4. Specifically, the first conductive layer 120C has a first region 161C, a second region 163C, a third region 165C, a fourth region 167C, and a fifth region 169C. Each of the first conductive layers 120C in the first region 161C, the third region 165C, and the fifth region 169C has a width w10 in the D2 direction. Each of the first conductive layers 120C in the second region 163C and the fourth region 167C has a width w11 in the D2 direction. The width w11 is smaller than the width w10. In other words, the width in the D2 direction of the first conductive layer 120C gradually decreases from the first region 161C toward the second region 163C, and gradually decreases from the fifth region 169C toward the fourth region 167C. . Meanwhile, the width of the first conductive layer 120C in the D2 direction is gradually increased from the second region 163C toward the third region 165C and from the fourth region 167C toward the third region 165C.

By having the above configuration, when an overcurrent flows, melting is likely to occur where the width in the D2 direction of the first conductive layer 120C decreases from w10 to w11. That is, the probability that the melting occurs near the boundary of each of the first region 161C, the second region 163C, the third region 165C, the fourth region 167C, and the fifth region 169C is improved. In addition, according to the configuration of FIG. 8, since a plurality of locations with a high probability of occurrence of the above melting can be formed, the probability of occurrence of the melting in the first conductive layer 120C can be improved.

In Fig. 8, a configuration in which each of the first region 161C, the third region 165C, and the fifth region 169C has a width w10 is illustrated, but is not limited to this configuration. For example, the first area 161C, the third area 165C, and the fifth area 169C may have different widths. In addition, although the configuration in which each of the second area 163C and the fourth area 167C has a width w11 has been exemplified, it is not limited to this configuration. For example, the widths of the second area 163C and the fourth area 167C may be different. The width of the second area 163C sandwiched by the first area 161C and the third area 165C may be smaller than the widths of each of the first area 161C and the third area 165C. Similarly, the width of the fourth area 167C, which is sandwiched by the fifth area 169C and the third area 165C, may be smaller than the respective widths of the fifth area 169C and the third area 165C.

4, 7, and 8, in a region that does not overlap with the pads 130A, 130B, and 130C in a plan view, the first conductive layer 120A, 120B, and 120C have a smaller width in the D2 direction than other regions (in FIG. 4). In the case of a configuration having a width w5, a width w8 in FIG. 7, and a width w11 in FIG. 8), when both the first conductive layer 120 and the pad 130 contain silver and copper, the first The ratio of silver and copper in the conductive layer 120 may be the same as the ratio of silver and copper in the pad 130. For example, AgCu of Ag:Cu=9:1 may be used as the first conductive layer 120 and the pad 130. In this case, fusing may occur in an area where the width in the D2 direction is smaller than that of other areas (areas of width w5, width w8, and width w11).

<Second embodiment>

[Configuration of flexible wiring board 20D]

A configuration of the flexible wiring board 20D according to the second embodiment will be described with reference to FIG. 9. 9 is a cross-sectional view of a flexible wiring board according to an embodiment of the present invention. The flexible wiring board 20D shown in FIG. 9 is a fuse element 10D as shown in FIG. 1 connected to the second film 200D on which the second conductive layer 210D is formed. In the following description, a description of the same features as in FIG. 1 will be omitted, and differences from FIG. 1 will be described. The second film 200D is a flammable substrate. The second conductive layer 210D is a wiring installed on the second film 200D.

As shown in FIG. 9, the two pads 130D are electrically connected to different second conductive layers 210D, respectively. Both of the two second conductive layers 210D are installed under the second film 200D. Under the second film 200D, in addition to the second conductive layer 210D, functional elements such as thermistor element 220D, switching element 230D such as transistor, and capacitive element 240D are installed. These functional elements are electrically connected to the second conductive layer 210D through the pad 211D. As described above, the flexible wiring board 20D may be equipped with the functional elements as described above in addition to the fuse element to constitute a circuit having a desired function.

The pad 211D can be formed in the same process as the pad 130D. That is, the configuration of the pad 211D and the configuration of the pad 130D may be the same. Thermistor element 220D, switching element 230D, and capacitive element 240D are composed of a conductive layer, an insulating layer, and a semiconductor layer formed on the first film 100D. For example, these layers may be formed on the first film 100D using a printing method. However, these functional elements may be substrate mounting elements with lead wires.

In this embodiment, a fuse element 10D is provided between the thermistor element 220D and the switching element 230D. When an overcurrent flows through the fuse element 10D, the first conductive layer 120D of the fuse element 10D is fused, and the thermistor element 220D and the switching element 230D are insulated. However, the above configuration is an example, and the position of the fuse element 10D is not limited to the above configuration.

As described above, according to the flexible wiring board 20D according to the second embodiment, the same effects as in the first embodiment can be obtained. In addition, as the fuse element of the flexible wiring board 20D, each of the fuse elements 10 and 10A to 10C may be used. In the flexible wiring board 20D, the fuse element can be formed as a thin film, so that a thin flexible wiring board can be realized.

<Third embodiment>

[Configuration of fuse element 10E]

A configuration of a fuse element 10E according to a third embodiment will be described with reference to FIG. 10. 10 is a cross-sectional view of a fuse element according to an embodiment of the present invention. The fuse element 10E shown in FIG. 10 is similar to the fuse element 10 of FIG. 1, but differs from the fuse element 10 in that a primer layer 170E is provided between the first film 100E and the insulating layer 110E. In the following description, a description of the same features as in FIG. 1 will be omitted, and differences from FIG. 1 will be described.

The primer layer 170E is provided to improve adhesion between the first film 100E and the insulating layer 110E. As the primer layer 170E, an acrylic resin, an ethylene vinyl acetate resin, a urethane resin, and an epoxy resin can be used. Before forming the primer layer 170E on the first film 100E, the surface of the first film 100E may be subjected to UV irradiation treatment or plasma treatment. In particular, when PCT is used as the first film 100E, since the PCT is chemically very stable, it is very difficult to form a film such as an insulating layer 110E on the PCT. That is, the adhesion between the PCT and the insulating layer 110E is poor. Therefore, by forming the primer layer 170E on the PCT and forming the insulating layer 110E on the primer layer 170E, poor adhesion between the PCT and the insulating layer 110E can be improved. In addition, by performing UV irradiation treatment or plasma treatment before forming the primer layer 170E, the adhesion between the PCT and the primer layer 170E can be improved.

As described above, according to the fuse element 10E according to the third embodiment, the same effects as those of the fuse element 10 according to the first embodiment can be obtained. In addition, the respective configurations of the fuse elements 10 and 10A to 10C can be applied to the configuration of the fuse element 10E.

<4th embodiment>

[Configuration of flexible wiring board 20F]

A configuration of the flexible wiring board 20F according to the fourth embodiment will be described with reference to FIG. 11. 11 is a cross-sectional view of a flexible wiring board according to an embodiment of the present invention. The flexible wiring board 20F shown in FIG. 11 is similar to the flexible wiring board 20D shown in FIG. 9, but as in FIG. 10, a primer layer 170F is provided between the first film 100F and the insulating layer 110F, and the pads 130F, 211F and the second. It differs from the flexible wiring board 20D in that a conductive adhesive layer 190F is provided between the conductive layers 210F. In the following description, a description of the same features as in FIG. 9 will be omitted, and differences from FIG. 9 will be described.

Like the primer layer 170E of the fuse element 10E of FIG. 10, the primer layer 170F is provided to improve adhesion between the first film 100F and the insulating layer 110F. As the primer layer 170F, the same material as the primer layer 170E can be used. Further, before forming the primer layer 170F, the surface of the first film 100F may be subjected to UV irradiation treatment or plasma treatment.

As shown in FIG. 11, a conductive adhesive layer 190F was provided between the pad 130F and the second conductive layer 210F. The conductive adhesive layer 190F is provided individually for each of the pads 130F and 211F. However, in the case where the conductive adhesive layer 190F is an anisotropic conductive film having conductivity only in the film thickness direction, the conductive adhesive layer 190F may be continuously provided on the plurality of pads 130F and 211F on the lower surface of the second film 200D.

As described above, according to the flexible wiring board 20F according to the fourth embodiment, the same effects as those of the flexible wiring board 20D according to the second embodiment can be obtained. In addition, as the fuse element of the flexible wiring board 20F, each of the fuse elements 10 and 10A to 10C may be used. Since the fuse element can be formed as a thin film, a thin flexible wiring board can be realized.

<Fifth embodiment>

[Composition of Fuse Device 10G]

A configuration of a fuse element 10G according to a fifth embodiment will be described with reference to FIG. 12. 12 is a cross-sectional view of a fuse element according to an embodiment of the present invention. The fuse element 10G shown in FIG. 12 is similar to the fuse element 10 of FIG. 1, but differs from the fuse element 10 in that a third conductive layer 180G is provided between the first conductive layer 120G and the pad 130G. In the following description, a description of the same features as in FIG. 1 will be omitted, and differences from FIG. 1 will be described.

As shown in FIG. 12, the fuse element 10G has a third conductive layer 180G between the first conductive layer 120G and the pad 130G in addition to the first conductive layer 120G and the pad 130G. The material of the pad 130G, the material of the third conductive layer 180G, and the material of the first conductive layer 120G are different. Alternatively, the composition ratio of the pad 130G, the composition ratio of the third conductive layer 180G, and the composition ratio of the first conductive layer 120G are different. In the embodiment, the resistance of the first conductive layer 120G is lower than that of the third conductive layer 180G. The resistance of the third conductive layer 180G is lower than that of the pad 130G. In addition, the melting point of the first conductive layer 120 is lower than that of the third conductive layer 180G. The melting point of the third conductive layer 180G is lower than that of the pad 130G.

Specifically, for example, the pad 130G may be Cu, the third conductive layer 180G may be AgCu with Ag:Cu=85:15-15:85, and the first conductive layer 120G may be AgCu with Ag:Cu=9:1 . In other words, the fuse element 10G is gradually changing from the pad 130G to the first conductive layer 120G into a material that is easy to melt. If a plurality of conductive layers are provided between the first conductive layer 120G and the pad 130G, a material in which the conductive layer provided on the first conductive layer 120G side is easier to melt than the conductive layer provided on the pad 130G side may be used. Further, in FIG. 12, a configuration in which the third conductive layer 180G sits on the end of the first conductive layer 120G and contacts the sidewalls and the top surface of the first conductive layer 120G is illustrated, but the configuration is not limited thereto. For example, 120G of the first conductive layer may be on the end of 180G of the third conductive layer. That is, 120G of the first conductive layer may be in contact with the sidewall and the top surface of the third conductive layer 180G.

13 is a plan view of a fuse element according to an embodiment of the present invention. 13, in the D2 direction, the pad 130G has a width w12, the third conductive layer 180G has a width w13, and the first conductive layer 120G has a width w14. The width w13 is smaller than the width w12. The width w14 is smaller than the width w13.

As described above, according to the fuse element 10G according to the fifth embodiment, the same effects as those of the fuse element 10 according to the first embodiment can be obtained. In addition, the respective configurations of the fuse elements 10, 10A to 10C, and 10E can be applied to the configuration of the fuse element 10G.

<Sixth embodiment>

[Configuration of flexible wiring board 20H]

A configuration of the flexible wiring board 20H according to the sixth embodiment will be described with reference to FIG. 14. 14 is a cross-sectional view of a flexible wiring board according to an embodiment of the present invention. The flexible wiring board 20H shown in FIG. 14 is similar to the flexible wiring boards 20D and 20F shown in FIGS. 9 and 11, but as in FIG. 12, a third conductive layer 180H is provided between the first conductive layer 120H and the pad 130H. It is different from the flexible wiring board 20D and 20F. Other points are the same as those of the flexible wiring boards 20D and 20F shown in Figs. 9 and 11, so the description is omitted.

When forming the thermistor element 220H, the switching element 230H, and the capacitive element 240H on the first film 100H, a conductive layer of a different material may be formed depending on the use of each functional element. In this case, the first conductive layer 120H and the third conductive layer 180H can be selected to satisfy the characteristics of the fuse element 10G shown in the fifth embodiment.

As described above, according to the flexible wiring board 20H according to the sixth embodiment, the same effects as those of the flexible wiring board 20D according to the second embodiment can be obtained. In addition, each of the fuse elements 10, 10A 10C and 10E may be used as the fuse element of the flexible wiring board 20H. Since the fuse element can be formed as a thin film, a thin flexible wiring board can be realized.

<Seventh embodiment>

In this embodiment, when the fuse elements 10 and 10A to 10H of the first to sixth embodiments or the flexible wiring boards 20D, 20F, and 20H of the second, fourth and sixth embodiments are used in a vehicle. Explain about. Vehicles such as passenger cars, especially hybrid vehicles and electric vehicles, use hundreds of fuse elements in electric systems. The fuse element described above may be used for some of these fuse elements. In particular, the fuse element described above can be used as a fuse element used in an electric circuit installed on a flexible wiring board.

In recent years, the importance of power systems for electric vehicles (EVs), energy storage systems (ESS), and artificial intelligence (AI) servers for efficient use of energy is increasing. Industrialization is in demand worldwide. Vehicle batteries are a key technology for the success of the EV business. The development of battery technology leads to an increase in the application range and a reduction in EV cost.

The battery management system (BMS) is an important component used to monitor the condition or reliable operation of the battery in an EV or ESS. BMS is a monitoring circuit that monitors voltage, temperature and current in order to evaluate the state of the battery such as state of charge (SOC), state of deterioration (SOH), and power limit estimate (PLE). It has 801. In order to make the most of the energy of the battery and to protect the battery from abnormal operation, the BMS needs to accurately monitor the condition of the battery in the module or pack.

15 is a functional block diagram of a BMS to which a fuse element according to an embodiment of the present invention is applied. As shown in FIG. 15, the BMS800 has a measurement block 810, a battery algorithm block 820, a capacity evaluation block 830, a cell equalization block 840, and a thermal management block 850. The function of each block is realized by the monitoring circuit 801. Measurement block 810 stores the ambient temperature as well as the cell voltage, battery current and battery temperature at different points in the battery bank and converts them to digital values. Battery algorithm block 820 evaluates SOC and SOH using battery variables such as battery voltage, current, and temperature. The capacity evaluation block 830 transmits information to the engine control unit (ECU) on the level of the charging current and the pre-discharge current of the battery. The cell equalization block 840 uses cell balancing technology by comparing cell voltages and evaluating the difference between the maximum and minimum cell voltages. The thermal management block 850 measures the ambient and battery temperature and initiates a cooling or heating operation to transmit an emergency signal to the ECU when an abnormal temperature rise occurs.

In order to protect the BMS800 from overcurrent, surge voltage, and electrostatic breakdown, each circuit of the measurement block 810, the battery algorithm block 820, the capacity evaluation block 830, the cell equalization block 840, and the thermal management block 850 is provided with a fuse of the first embodiment to the sixth embodiment. Device 10A is installed.

16 is a cross-sectional view of a battery pack to which a fuse element according to an embodiment of the present invention is applied. As shown in FIG. 16, in the battery pack 30J, a BMS800J and a battery 900J are installed above and below the flexible wiring board 20J. In this embodiment, the BMS800J is installed on the second film 200J, and the battery 900J is installed under the first film 100J. However, the positions of the BMS800J and the battery 900J may be opposite. Incidentally, the flexible wiring board 20J has the same configuration as the flexible wiring board 20D shown in Fig. 9, but is not limited to this configuration.

The fuse element 10J included in the flexible wiring board 20J is electrically connected to the BMS 800J and the battery 900J through a second conductive layer 210J installed on the second film 200J. The second conductive layer 210J and BMS800J may be connected to the outside of the end of the second film 200J by wire bonding, or may be connected by a through electrode provided in a through hole penetrating through the second film 200J. Similarly, the second conductive layer 210J and the battery 900J may be connected to the outside of the end of the first film 100J by wire bonding, or may be connected by a through electrode provided in a through hole penetrating the first film 100J.

17 is a diagram showing an application example of a battery pack according to an embodiment of the present invention. As shown in FIG. 17, the battery pack 30J is mounted on the vehicle 40J. As the vehicle 40J, an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV) is used.

[Example]

18 to 20, the result of an experiment performed by passing a current through the fuse element using the fuse elements 10, 10A, and 10B related to the first embodiment and its modification will be described. 18 to 20 are optical micrographs showing a state after being destroyed in a fuse element related to the present invention. In addition, the fuse elements shown in FIGS. 18 to 20 are sample elements in which a glass substrate is used instead of the first film 100.

When the fuse elements 10, 10A, and 10B are melted by passing current as shown in FIGS. 18 to 20, it is confirmed that the first conductive layers 120, 120A, and 120B are melted in any case. In addition, the melting locations 129, 129A, and 129B in Fig. 18 are portions where the melting has occurred due to an overcurrent. On the other hand, when the layer corresponding to the first conductive layer 120 flows through a fuse element according to the comparative example composed of only Cu and fuse|fuses, it was confirmed that fusing occurred at a random position. It was confirmed that the fuse element according to the comparative example may be melted in the vicinity of the center of a large area corresponding to the pad of the fuse element, so that a stable insulation state cannot be obtained after melting.

As described above, according to the fuse elements 10, 10A, and 10B related to the present embodiment, the fuse occurs in the first conductive layers 120, 120A, and 120B compared to the fuse elements related to the comparative example formed from a single conductive layer (for example, Cu). You can increase the probability.

In the above, the present invention has been described with reference to the drawings, but the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope not departing from the spirit of the present invention. For example, the addition, deletion or design change of appropriate components by a person skilled in the art based on the fuse element of each embodiment is also included in the scope of the present invention as long as the gist of the present invention is met. In addition, each of the above-described embodiments can be appropriately combined as long as there is no contradiction with each other, and technical matters common to each embodiment are included in each embodiment even if there is no explicit description.

In addition, even other effects that are different from those caused by the above-described aspects of the respective embodiments are obvious from the description of the present specification or those that can be easily predicted by those skilled in the art are naturally brought about by the present invention. Is interpreted as being.

Claims (23)

1. With the first film,

   An insulating layer on the first film and

   A first conductive layer on the insulating layer and

   A fuse element electrically connected to the first conductive layer and having a pad of a material different from that of the first conductive layer.
2. With the first film,

   An insulating layer on the first film and

   A first conductive layer on the insulating layer and

   A fuse element electrically connected to the first conductive layer and having two pads having a composition ratio different from that of the first conductive layer.
3. The method according to claim 1 or 2,

   The first conductive layer has a lower resistance than the pad.
4. The method according to any one of claims 1 to 3,

   The first conductive layer has a lower melting point than the pad.
5. The method of claim 1,

   The first conductive layer contains silver and copper,

   The pad is a fuse element containing copper.
6. The method of claim 2,

   The first conductive layer and the pad include silver and copper.
7. The method of claim 6,

   A fuse element in which a ratio of silver in the first conductive layer is larger than a ratio of silver in the pad.
8. The method according to any one of claims 1 to 7,

   At least two pads are installed apart from each other,

   The two pads are arranged in one direction,

   In a second direction orthogonal to the first direction, a width of the first conductive layer is smaller than a width of the pad.
9. The method of claim 8,

   The first conductive layer has a first region and a second region along the first direction.

   In the second direction, the width of the first conductive layer in the first area is smaller than the width of the first conductive layer in the second area, and the width of the first conductive layer is in the second area. A fuse element that gradually decreases toward the area.
10. With the first film,

    An insulating layer on the first film and

    A first conductive layer on the insulating layer and

    It has at least two pads electrically connected to the first conductive layer and isolated from each other in a first direction,

    The first conductive layer has a first region and a second region along the first direction.

    In a second direction orthogonal to the first direction, the width of the first conductive layer in the first area is smaller than the width of the first conductive layer in the second area, and the width of the first conductive layer is The fuse element gradually decreases from the second region toward the first region.
11. The method according to any one of claims 1 to 10,

    The first film is a fuse device including polycyclohexylene dimethylene terephthalate (PCT).
12. The method according to any one of claims 1 to 11,

    The insulating layer is an inorganic insulating layer fuse element.
13. The method of claim 12,

    The inorganic insulating layer is a fuse device including one of silicon oxide, silicon nitride, and hafnium oxide, or a stack of two or more of silicon oxide, silicon nitride, and hafnium oxide.
14. The method according to any one of claims 1 to 13,

    A fuse device further comprising a primer layer between the insulating layer and the first film.
15. A fuse element electrically connected to the first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer, and having a pad of a material different from the first conductive layer,

    A second conductive layer electrically connected to the pad,

    A flexible wiring board having a second film on the second conductive layer.
16. A fuse element electrically connected to the first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer, and having a pad having a composition ratio different from that of the first conductive layer,

    A second conductive layer electrically connected to the pad,

    A flexible wiring board having a second film on the second conductive layer.
17. The method of claim 16,

    The pad and the second conductive layer include copper,

    The flexible wiring board in which the ratio of copper in the pad is smaller than the ratio of copper in the second conductive layer
18. A first film, an insulating layer on the first film, a first conductive layer on the insulating layer, and at least two pads electrically connected to the first conductive layer and isolated from each other in a first direction, and the first The conductive layer has a first region and a second region along the first direction, and a width of the first conductive layer of the second region in a second direction orthogonal to the first direction is the second region of the second region. A fuse element smaller than the second layer of the region, and a width of the first conductive layer gradually decreasing from the second region toward the first region,

    A second conductive layer electrically connected to the pad,

    Flexible wiring board having a second film on the second conductive layer
19. The method according to any one of claims 16 to 18,

    A flexible wiring board further comprising a conductive adhesive layer between the pad and the second conductive layer.
20. Battery and

    A battery management system having a monitoring circuit for monitoring the voltage, current and temperature of the battery;

    It has the battery and a flexible wiring board connected to the battery management system,

    The flexible wiring board

    A fuse element electrically connected to the first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer, and having a pad of a material different from the first conductive layer,

    A second conductive layer electrically connected to the pad,

    Equipped with a second film on the second conductive layer

    The battery management system is provided on the second film, and the monitoring circuit is connected to the second conductive layer.
21. Battery and

    A battery management system having a monitoring circuit for monitoring the voltage, current and temperature of the battery;

    It has the battery and a flexible wiring board connected to the battery management system,

    The flexible wiring board

    A fuse element electrically connected to the first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer, and having a pad having a composition ratio different from that of the first conductive layer,

    A second conductive layer electrically connected to the pad,

    Having a second film on the second conductive layer,

    The battery management system is provided on the second film, and the monitoring circuit is connected to the second conductive layer.
22. Battery and

    A battery management system having a monitoring circuit for monitoring the voltage, current and temperature of the battery;

    It has the battery and a flexible wiring board connected to the battery management system,

    The flexible wiring board,

    The first film, the insulating layer on the first film, the first conductive layer on the insulating layer, and the first conductive layer are electrically connected to have a first region and a second region along a first direction, and the second In a second direction orthogonal to one direction, the width of the first conductive layer is smaller than the width of the first conductive layer in the second area of the second area, and the width of the first conductive layer is in the second area. A fuse element gradually decreasing toward the first region,

    A second conductive layer electrically connected to the pad,

    Providing a second film on the second conductive layer,

    The battery management system is formed on the second film,

    The monitoring circuit is a battery pack connected to the second conductive layer.
23. The method according to any one of claims 20 to 22,

    A battery pack used in an electric vehicle (EV), hybrid electric vehicle (HEV), or plug-in hybrid electric vehicle (PHEV).

Images