CN116783998A

CN116783998A - Pattern fuse and method of manufacturing the same

Info

Publication number: CN116783998A
Application number: CN202280010124.0A
Authority: CN
Inventors: 李昌馥; 郑相恩; 金成圭
Original assignee: LG Energy Solution Ltd
Current assignee: LG Energy Solution Ltd
Priority date: 2021-10-28
Filing date: 2022-10-07
Publication date: 2023-09-19

Abstract

The present application relates to a pattern fuse and a method of manufacturing the same, and in particular, to a pattern fuse and a method of manufacturing the same, the pattern fuse including: a lower film layer; an adhesive layer laminated on the lower film layer; a circuit pattern disposed on the adhesive layer and formed of a conductive material; an upper film layer laminated on the adhesive layer and the circuit pattern and having an opening formed such that the circuit pattern is partially or completely exposed; and a coating layer covering the opening of the upper film layer, wherein the coating layer includes a flame retardant material.

Description

Pattern fuse and method of manufacturing the same

Technical Field

The present application claims the priority rights of korean patent application No.2021-0145980, korean patent application No.2021-0149435, korean patent application No.2021-0150061, korean patent application No. 2022-012597, korean patent application No. 2022-012697, korean patent application No.2021-0149435, korean patent application No. 2021-012597, korean patent application No. 2022-9, and korean patent application No. 2023, which are filed on 10/28 of 2021, and korean patent application No.2021-0149435, each of which is incorporated herein by reference in its entirety.

The application relates to a pattern fuse and a method for manufacturing the pattern fuse. More particularly, the present application relates to a pattern fuse capable of preventing fire due to heat generated during operation of a circuit pattern and guiding cutting of the circuit pattern at a specific position thereof, and a method of manufacturing the pattern fuse.

Background

With the technical development of mobile devices such as smartphones, notebook computers, and digital cameras and the increase in demand therefor, research into secondary batteries capable of charge and discharge is actively being conducted. In addition, secondary batteries have been applied to Electric Vehicles (EVs), hybrid vehicles (HEVs), plug-in hybrid vehicles (P-HEVs), and Energy Storage Systems (ESS) as energy sources that replace fossil fuels causing air pollution.

Among the secondary batteries that are widely used at present are lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, and nickel zinc batteries. Depending on a desired output voltage or charge-discharge capacity, a plurality of unit secondary batteries may be connected in series or parallel with each other to constitute a battery module. Typically, the battery pack is manufactured by adding additional components using at least one battery module.

As needed, various circuit boards, such as a Protection Circuit Module (PCM) board capable of controlling charge and discharge of a battery cell or protecting the battery cell and a sensing board configured to sense a voltage, may be applied to the battery pack.

Generally, such a circuit board is provided with a fuse element configured to prevent the battery pack from catching fire or exploding due to an overcurrent or a short-circuit current. An SMD fuse or a pattern fuse is used as the fuse element.

Fig. 1 is a cross-sectional view of a battery pack including a circuit board on which a conventional fuse pattern is formed.

Referring to fig. 1 shown in patent document 1 (korean patent application laid-open No. 2020-0129161), instead of the fuse element, a fuse pattern having an overcurrent or short-circuit current interruption function is formed on a circuit board.

That is, in the battery pack including the plurality of battery cells C1, C2, and C3, the connection circuit board 20 is interposed between the main circuit board 30 and the battery cells C so as to make connection therebetween, and the connection circuit board 20 is provided with the conductive pattern L including the fuse pattern F and the connection pattern N.

Since the fuse pattern F is located between the electrode tab 22 and the main circuit board 30, there is an advantage in that an operation of installing a separate fuse element or a space for the fuse element is not required. However, the conductive pattern is generally made of metal such as copper, and the melting point of the metal is very high (the melting point of copper is about 1085 ℃), so that very high heat and flame may be instantaneously generated during the operation of the fuse pattern.

The pattern fuse of patent document 1 is configured such that the conductive pattern is buried in the insulating film, and therefore the insulating film may fire when the temperature is high enough to operate the pattern fuse.

Meanwhile, a general pattern fuse is manufactured by: applying an adhesive to the lower film layer; a thermally conductive metal layer is laminated on the adhesive, and a coating agent is applied to the upper film in a state where the upper film is laminated on the metal layer.

Although the circuit pattern is cut off when the temperature is high enough to operate the pattern fuse, it is difficult to predict the region where the circuit pattern is to be cut off, and thus it is difficult to secure the reliability of operation.

(prior art literature)

(patent document 1) Korean patent application laid-open No. 2020-0129761

Disclosure of Invention

Technical problem

The present application has been made in view of the above problems, and an object of the present application is to provide a pattern fuse capable of preventing ignition due to heat generated during operation of a circuit pattern and a method of manufacturing the pattern fuse.

Another object of the present application is to provide a pattern fuse capable of guiding a circuit pattern to be cut at a desired position thereof when an overcurrent occurs and a method of manufacturing the pattern fuse.

Technical proposal

The pattern fuse for achieving the above object according to the present application includes: a lower film layer (100); an adhesive layer (200) that is laminated on the lower film layer (100); a circuit pattern (300) disposed on the adhesive layer (200), the circuit pattern being made of a conductive material; an upper film layer (400) laminated on the adhesive layer (200) and the circuit pattern (300), the upper film layer having an opening (410) formed therein, the opening being configured to allow a portion or all of the circuit pattern (300) to be exposed therethrough; and a coating layer (500) configured to cover the opening (410) of the upper film layer (400), wherein the coating layer (500) comprises a flame retardant material.

In addition, in the pattern fuse according to the present application, the flame retardant material may be a flame retardant material having a flame retardant rating of V-0 according to UL94 standards.

In addition, in the pattern fuse according to the present application, the flame retardant material may include an inorganic-based filler.

In addition, in the pattern fuse according to the present application, the coating layer (500) may be made of a material exhibiting lower thermal conductivity than the upper thin film layer (400).

In addition, in the pattern fuse according to the present application, the coating layer (500) may be made of polyurethane-based or urethane-based materials.

In addition, in the pattern fuse according to the present application, the lower film layer (100) or the upper film layer (400) may include at least one of Polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET).

In addition, in the pattern fuse according to the present application, the circuit pattern (300) may include: a pair of first metal lines (310) facing each other, one side of each of the pair of first metal lines being located under the upper thin film layer (400), the other side of each of the pair of first metal lines being located in the opening (410); and a second metal line (320) configured to electrically connect the pair of first metal lines (310) to each other.

In addition, in the pattern fuse according to the present application, each of the pair of first metal lines (310) may be copper, and the second metal line (320) may be a metal having a lower melting point than copper.

In addition, in the pattern fuse according to the present application, each of the pair of first metal lines (310) may be copper, and the second metal line (320) may be a metal having higher resistivity than copper.

In addition, in the pattern fuse according to the present application, each of the pair of first metal lines (310) may be copper, and the second metal line (320) may be aluminum, tin, or indium.

In addition, the application also provides a circuit board comprising the pattern fuse.

In addition, the application further provides a battery module comprising the circuit board.

In addition, the application further provides a battery pack comprising the battery module.

Further, the pattern fuse manufacturing method according to the present application provides the steps of: first, preparing a lower film layer (100); a second step of forming an adhesive layer (200) on the lower film layer (100); a third step of disposing a circuit pattern (300) on the adhesive layer (200); fourth, stacking an upper film layer (400) having an opening (410); and a fifth step of forming a coating layer (500) so as to cover the opening (410), wherein the coating layer (500) includes a flame retardant material.

In addition, in the pattern fuse manufacturing method according to the present application, the coating layer (500) may be made of a material exhibiting lower thermal conductivity than the upper thin film layer (400).

In addition, in the pattern fuse manufacturing method according to the present application, the coating layer (500) may be made of a polyurethane-based material or a urethane-based material, and the lower film layer (100) or the upper film layer (400) may include at least one of Polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET).

In addition, in the pattern fuse manufacturing method according to the present application, the flame retardant material may be a polyurethane-based material or a urethane-based (urethane-based) material.

Advantageous effects

The pattern fuse and the method of manufacturing the pattern fuse according to the present application have advantages in that a coating layer including a flame retardant material is provided on a circuit pattern, whereby fire can be prevented even if the circuit pattern is heated to a high temperature due to the operation of the pattern fuse.

Further, the pattern fuse and the method of manufacturing the pattern fuse according to the present application have advantages in that a coating layer including a low internal heat material is provided on a predetermined region of a circuit pattern, whereby the circuit pattern can be selectively cut off in a region adjacent to the low internal heat coating layer when the pattern fuse is operated, and thus operational reliability can be improved.

Furthermore, the pattern fuse and the method of manufacturing the pattern fuse according to the present application have an advantage in that the circuit pattern is made of different kinds of metals having different melting points or resistivity, whereby the region to be cut can be more precisely controlled during the operation of the pattern fuse.

In addition, when the pattern fuse according to the present application is mounted on a circuit board, a process of mounting the fuse cut indication device may be omitted, whereby efficiency in manufacturing the circuit board may be improved.

Drawings

Fig. 1 is an exploded perspective view of a battery pack including a circuit board on which a conventional fuse pattern is formed.

Fig. 2 is an exploded perspective view schematically showing a pattern fuse according to a first preferred embodiment of the present application.

Fig. 3 is a cross-sectional view taken along line A-A' of fig. 2.

Fig. 4 is a view illustrating a state in which a coating layer is provided in the cross-sectional view of fig. 3.

Fig. 5 is an exploded perspective view schematically showing a pattern fuse according to a second preferred embodiment of the present application.

Fig. 6 is an exploded perspective view schematically showing a pattern fuse according to a third preferred embodiment of the present application.

Detailed Description

In the present disclosure, it should be understood that the terms "comprises," "comprising," "includes," "including," etc., specify the presence of stated features, amounts, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, amounts, steps, operations, elements, components, or groups thereof.

Moreover, throughout the drawings, the same reference numerals will be used to refer to portions that perform similar functions or operations. In the present specification, where a reference is made to one part being connected to another part, not only can the one part be directly connected to the other part, but also the one part can be indirectly connected to the other part through the other part. Furthermore, the inclusion of a certain element is not meant to exclude other elements, but rather means that the elements may be further included unless otherwise indicated.

Hereinafter, a pattern fuse according to the present application will be described with reference to the accompanying drawings.

Fig. 2 is an exploded perspective view schematically showing a pattern fuse according to a first preferred embodiment of the present application, fig. 3 is a sectional view taken along A-A' line of fig. 2, and fig. 4 is a view illustrating a state in which a coating layer is provided in the sectional view of fig. 3.

When the pattern fuse 100 according to the present application is described with reference to fig. 2 to 4, the pattern fuse may include a lower film layer 100, an adhesive layer 200, a circuit pattern 300, an upper film layer 400, and a coating layer 500.

First, the lower film layer 100 of the layer for insulating the conductive circuit pattern 300 from the outside may be made of various known polymer materials having insulation properties.

In particular, polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET), each exhibiting excellent thermal characteristics, are preferably used as the material of the lower film layer 100. Among them, polyimide (PI) is most preferably used in terms of thermal characteristics.

The adhesive layer 200 located on the lower film layer 100 is a layer configured to allow the circuit pattern 300 to be attached to the lower film layer 100 therethrough. The material of the adhesive layer is not particularly limited as long as the circuit pattern 300 can be adhered.

Here, the circuit pattern 300 is fixed to the top of the lower film layer 100 via the adhesive layer 200; however, a portion of the circuit pattern 300 may be slightly recessed in the adhesive layer 200.

The circuit pattern 300 is designed to facilitate the use of conductive materials, such as copper, to generate heat. The circuit pattern is not limited to the waveform shown in fig. 2, and may be formed to have any of various known shapes.

Further, the circuit pattern 300 may be made of the same material as a pair of wires (not shown) connected to opposite sides of the circuit pattern 300, or may be made of a material of a different kind from that of the opposite wires and having a melting point lower than that of the opposite wires.

Of course, the thicknesses of the circuit pattern 300 and the opposite leads and the length of the circuit pattern 300 may be appropriately designed according to the operating conditions of the pattern fuse.

Next, the upper thin film layer 400 will be described. The upper thin film layer 400 performs a function of insulation from the outside in the same manner as the lower thin film layer 100 described above. Thus, the upper film layer may be made of the same material as the lower film layer 100; however, the present application is not limited thereto, and the upper thin film layer may be made of any one of various polymer materials having insulation properties.

Meanwhile, as shown in fig. 2, an opening 410 is formed in a central portion of the upper thin film layer 400 such that the entire upper thin film layer 400 is exposed. Of course, it is apparent that only a portion of the circuit pattern 300 may be exposed.

The opening 410 is covered with the coating layer 150 (more specifically, a coating layer including a flame retardant material) to prevent ignition due to heat or flame generated from the circuit pattern 300.

When the pattern fuse operates, the temperature of the pattern fuse is raised to a level sufficient to enable the material constituting the circuit pattern 300 to be melted, as described above. In general, the thin film layer covering the circuit pattern 300 exhibits low flame retardancy, and thus a fire is frequently generated.

Of course, it is possible that the thin film layer covering the circuit pattern is made of a material exhibiting high flame retardancy. However, since even a portion without a circuit pattern must be provided, there is a problem of an increase in cost.

Here, it is preferable to use a material having electrical insulation and flame retardancy of a class V-0 based on UL 94V test (which is one of flame retardancy tests for plastic materials) as a material for the coating layer.

The UL 94V test is a test that evaluates the extent to which a flame spreads around a product when applied to the product in a vertical direction, in terms of burning aspects of plastic products. The grades V-0, V-1, and V-2 are set based on the combustion time. Wherein the grade V-0 is the grade having the highest flame retardancy.

Here, the flame retardant material refers to a material formed by adding a flame retardant and various additives to a polymer resin composition in order to improve flame retardancy.

There are various known materials such as polyurethane, urethane, epoxy, and acrylic as the polymer resin that can be a flame retardant material.

Of course, various additives (e.g., glass fiber or spherical silica capable of improving flame retardancy alone or an inorganic-based filler mixed therewith) that are generally used may be further included in the flame retardant material for forming the coating layer.

Meanwhile, if the area of the coating layer 500 is smaller than that of the opening 410, it is impossible to completely block the circuit pattern 300 under the coating layer from the outside. Accordingly, it is preferable that the area of the coating layer is equal to the area of the opening 410 so as to cover only the opening 410, and it is more preferable that the area of the coating layer is slightly larger than the area of the opening 410 so as to overlap with the edge portion of the opening 410 in the case of including the opening 410.

Fig. 5 is an exploded perspective view schematically showing a pattern fuse according to a second preferred embodiment of the present application. Since the second embodiment is identical in configuration to the first embodiment except for the circuit pattern and the coating layer, only a different configuration will be described below.

In the second embodiment of the present application, a specific portion of the circuit pattern 300 (i.e., a position where the circuit pattern is to be cut off) may be controlled manually. That is, as shown in fig. 5, the cutting of the circuit pattern 300 located in a portion of the upper thin film layer 400 (more specifically, the opening 410 of the upper thin film layer 400, which is the area covered by the coating layer 500) may be guided.

When the pattern fuse operates, the temperature of the pattern fuse is raised to a level sufficient to enable the material constituting the circuit pattern 300 to be melted. At this time, the material for the coating layer 500 may be appropriately adjusted so that the circuit pattern 300 located in the opening 410 can be melted and cut first.

In other words, heat is generated from the circuit pattern 300 during operation thereof. At this time, the internal heat and the thermal conductivity of the coating layer 500 covering the circuit pattern 300 may be reduced so that the circuit pattern 300 may be rapidly cut off, and thus, the overcurrent may be interrupted at an early stage.

It is preferable to use a low internal heat and an electrically insulating material exhibiting low thermal conductivity as a material of the coating layer 500 capable of performing the above-described functions.

The low internal heat material refers to a material exhibiting low internal heat. Although any of various known low internal heat materials may be used as the low internal heat material, it is preferable to use a material exhibiting lower internal heat and thermal conductivity than Polyimide (PI), polyethylene naphthalate (PEN), or polyethylene terephthalate (PET), which is suitable for the material of the lower film layer 100 or the upper film layer 400.

Specifically, polyurethane (polyurethane), urethane (urethane), epoxy, and acrylic are used. In particular, a urethane-based material exhibiting low internal heat and low thermal conductivity, a polyurethane-based material exhibiting low internal heat and low thermal conductivity, or a material mainly comprising a mixture of polyurethane and polyacrylic acid is preferably used, a material having thermal conductivity of 0.10W/mK or less is more preferably used, and a material having thermal conductivity of 0.05W/mK or less is most preferably used.

The second embodiment has the advantage that the area to be cut can be adjusted consistently, whereby the reliability of operation as a fuse can be improved. That is, the thermal conduction characteristics may be different depending on the position of the pattern fuse (such as left, middle, or right of the pattern fuse), and thus the interruption operation time at the time of overcurrent may be different depending on which portion of the pattern fuse is cut.

As a result, this means that the operation characteristics are not uniform, and thus the reliability of the fuse is reduced. However, the pattern fuse of the present application is configured to be cut at the same position all the time, whereby the reliability of operation is improved.

Meanwhile, when the coating layer 500 is prefabricated in the form of a film, it is preferable to include air in the film. As an example, the air may be formed using a foaming method, such as a molten foam molding method, a cast foam molding method, or a solid foam molding method.

Fig. 6 is an exploded perspective view schematically showing a pattern fuse according to a third preferred embodiment of the present application. Since the third embodiment is identical in configuration to the second embodiment except for the circuit pattern, only a different configuration will be described below.

In the third embodiment of the present application, the circuit pattern 300 may include a first metal line 310 and a second metal line 320. Specifically, a pair of first metal lines 310 are formed to face each other, one side of each first metal line 310 is located under the upper thin film layer 400, and the other side of each first metal line 310 is located in the opening 410. The second metal line 320 electrically connects the pair of first metal lines 310 to each other.

Here, the first metal line 310 may be copper, and the second metal line 320 may be a metal having a lower melting point than copper. Further, the first metal line 310 may be copper, and the second metal line 320 may be a metal having higher resistivity than copper. Further, the first metal line 310 may be copper, and the second metal line 320 may be aluminum, tin, or indium.

When the first and second metal lines 310 and 320 correspond to any one of the above combinations, the second metal line 320 is first melted or a connection region between the first and second metal lines 310 and 320 is cut off at the time of operation of the pattern fuse, whereby the electrical conduction is interrupted.

Of course, the melting point or the point of time at which the cutting occurs may be further adjusted by adjusting the length or thickness of each of the first and second metal lines 310 and 320.

Next, a method of manufacturing a pattern fuse according to the present application will be described.

The method for manufacturing the pattern fuse includes: first, preparing a lower film layer 100; second, an adhesive layer 200 is formed on the lower film layer 100; third, disposing the circuit pattern 300 on the adhesive layer 200; fourth, an upper thin film layer 400 having an opening 410 is laminated; and a fifth step of forming a coating layer 500.

Meanwhile, the circuit pattern 300 may be formed by disposing a previously prepared pattern on the adhesive layer 200 so as to have a desired shape or by directly forming a desired shape on the adhesive layer 200.

Also, in the fourth step of laminating the upper film layer 400, although the upper film layer 400 may be laminated on the adhesive layer 200 in a state where the circuit pattern 300 is disposed, and then the region corresponding to the opening 410 may be removed so that a portion of the circuit pattern 300 is exposed, it is more preferable to laminate the upper film layer 400 formed with the opening 410 in advance.

In addition, in the fifth step of forming the coating layer 500 in the opening 410, a flame retardant material, a low internal heat material, or a low internal heat material exhibiting low thermal conductivity may be applied to the opening 410 and hardened to form the coating layer 500. Of course, the film-type coating layer 500 containing the above specific materials may be prepared in advance and then may be laminated so as to cover the opening 410.

Here, the material constituting the coating layer 500 may be polyurethane, urethane, epoxy, acrylic or a mixture of polyurethane and polyacrylic acid, as previously described. In addition, each of the lower film layer 100 and the upper film layer 400 may be made of polyimide, polyethylene naphthalate, or polyethylene terephthalate.

The pattern fuse may be formed at a predetermined position on a circuit board such as a Printed Circuit Board (PCB) or a Flexible PCB (FPCB) through the above-described process.

Of course, when the pattern fuse is formed on the circuit board, the circuit pattern 300 may be directly formed on the board without forming a part or all of the lower film layer 100 or the adhesive layer 200 according to circumstances.

Meanwhile, the present application may provide a battery module or a battery pack having a circuit board with a pattern fuse formed thereon and having the circuit board mounted therein. Further, the battery module or the battery pack may be used in various devices.

Although specific details of the application have been described in detail, those skilled in the art will appreciate that the detailed description of the application discloses only preferred embodiments of the application and thus does not limit the scope of the application. Accordingly, it will be understood by those skilled in the art that various changes and modifications are possible without departing from the scope and technical spirit of the present application, and it is apparent that such changes and modifications fall within the scope of the appended claims.

(description of the reference numerals)

100: lower film layer

200: adhesive layer

300: circuit pattern

310: first metal wire

320: second metal wire

400: upper film layer

410: an opening

500: coating layer

Claims

1. A pattern fuse, the pattern fuse comprising:

a lower film layer;

an adhesive layer laminated on the lower film layer;

a circuit pattern disposed on the adhesive layer, the circuit pattern being made of a conductive material;

an upper film layer laminated on the adhesive layer and the circuit pattern, the upper film layer having an opening formed therein, the opening being configured to allow a part or all of the circuit pattern to be exposed therethrough; and

a coating layer configured to cover the opening of the upper film layer, wherein

The coating layer includes a flame retardant material.

2. The pattern fuse of claim 1, wherein the flame retardant material is a flame retardant material having a flame retardant rating of V-0 based on UL94 standards.

3. The pattern fuse of claim 2, wherein the flame retardant material comprises an inorganic-based filler.

4. The pattern fuse of claim 1, wherein the coating layer is made of a material exhibiting lower thermal conductivity than the upper thin film layer.

5. The pattern fuse of claim 4, wherein the coating layer is made of polyurethane-based or urethane-based material.

6. The pattern fuse of claim 5, wherein the lower film layer or the upper film layer comprises at least one of Polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET).

7. The pattern fuse according to claim 1, wherein the circuit pattern comprises:

a pair of first metal lines facing each other, one side of each of the pair of first metal lines being located under the upper thin film layer, the other side of each of the pair of first metal lines being located in the opening; and

and a second metal line configured to electrically connect the pair of first metal lines to each other.

8. The pattern fuse of claim 7, wherein each of said pair of first metal lines is copper, and

the second metal line is a metal having a lower melting point than copper.

9. The pattern fuse of claim 7, wherein

Each of the pair of first metal lines is copper, and

the second metal line is a metal having a higher resistivity than copper.

10. The pattern fuse of claim 7, wherein

Each of the pair of first metal lines is copper, and

the second metal line is aluminum, tin or indium.

11. A circuit board comprising the pattern fuse according to any one of claims 1 to 10.

12. A battery module comprising the circuit board according to claim 11.

13. A battery pack comprising the battery module according to claim 12.

14. A pattern fuse manufacturing method, the pattern fuse manufacturing method comprising the steps of:

a first step of preparing a lower film layer;

a second step of forming an adhesive layer on the lower film layer;

a third step of disposing a circuit pattern on the adhesive layer;

a fourth step of laminating an upper film layer provided with an opening; and

a fifth step of forming a coating layer to cover the opening, wherein

The coating layer includes a flame retardant material.

15. The pattern fuse manufacturing method of claim 14, wherein said coating layer is made of a material exhibiting lower thermal conductivity than said upper film layer.

16. The pattern fuse manufacturing method of claim 14, wherein

The coating layer is made of polyurethane-based or urethane-based material, and

the lower film layer or the upper film layer includes at least one of Polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET).

17. The pattern fuse manufacturing method of claim 14, wherein said flame retardant material is a polyurethane-based or urethane-based material.