KR102187077B1 - Printed Circuit Board - Google Patents

Abstract

An object of the present invention is to provide a printed circuit board including a patterned fuse that implements a circuit pattern that functions as a fuse on a printed circuit board and can easily adjust the capacity of the fuse even within a narrow area of the circuit board,
A first circuit, a second circuit, and a fuse part formed in a conductive pattern having a predetermined width on a substrate, the fuse part, one end and the other end of the pattern are electrically connected to the first circuit and the second circuit, respectively, the The pattern provides a printed circuit board, characterized in that it includes a plurality of bent portions formed to be bent and a plurality of connection portions respectively connecting the bent portions.

Description

Printed Circuit Board

The present invention relates to a printed circuit board including a fuse, and more specifically, to a printed circuit board provided with a fuse as a circuit pattern printed on the substrate and the pattern is destroyed when an overcurrent is applied to the circuit pattern. .

A printed circuit board (PCB) or a flexible printed circuit board (FPCB, Flexible Printed Circuit Board, hereinafter referred to as "printed circuit board" or "PCB") is a standardized way to fix and connect a number of electronic components. It is a circuit board in which the wiring made for the purpose is patterned. The PCB can mechanically and electrically couple a plurality of circuits, thereby reducing the size and weight of electrical products. In addition, circuit characteristics are stabilized, there is no fear of incorrect wiring, and production costs are low. Due to these advantages, PCBs are used in various fields, and recently, they are becoming a core component essential for all electronic devices.

Meanwhile, when a plurality of electric parts are connected and used, if an overcurrent occurs due to a breakdown, malfunction of the electric parts, or external factors, there is a risk that the connected electric parts may be damaged together. Therefore, in order to protect a plurality of electric parts, it is common to install a fuse on the power supply side of a circuit so that the mounted fuse is destroyed when an overcurrent occurs to cut off the current.

1 is a diagram showing that a chip fuse is installed in a conventional FPC. Referring to this, conventionally, a pad for installing surface-mounted components (SMD, Surpace-Mount Devices) on a circuit pattern is formed on the PCB 1, and an SMD-type chip fuse (2) on the pad is formed. Soldered to prevent damage to the circuit pattern or the substrate by overcurrent.

However, when the chip fuse (2) is mounted, the cost of the chip fuse raw material value and the soldering and coating work related to the mounting are required, which increases the cost of the product. In addition, in order to apply the chip fuse, the size of the printed circuit board increases as the space required for the chip fuse and soldering must be secured, resulting in additional cost increases and limitations of miniaturization.

Therefore, research is being conducted on a method to replace the existing chip fuse by omitting the conventional chip fuse land and designing a circuit pattern shape that can function as a fuse, but the fuse part is formed of metal with high resistivity, or the width of the fuse part is increased. Aside from narrowing down, no other plan has been drawn up. However, when the material of the melting part is different, there is a problem that a new process must be added to form a fuse, and there is a problem in setting the fuse capacity because there is a limit to the fine process of narrowing the width of the melting part.

Korean Patent Publication No. 10-0675296 Republic of Korea Patent Publication No. 10-2018-0076572 Republic of Korea Patent Publication No. 10-1082865

The present invention is to solve the problems of the prior art as described above, specifically, a pattern fuse that implements a circuit pattern that functions as a fuse on a printed circuit board, and allows the capacity of the fuse to be easily adjusted even within a narrow area of the circuit board. It is an object of the present invention to provide a printed circuit board comprising a.

Further, an object of the present invention is to provide a printed circuit board that solves the film ignition problem, which has been an obstacle when implementing a fuse with a conventional circuit pattern.

An embodiment of the present invention includes a fuse unit formed on a substrate in a first circuit, a second circuit, and a conductive pattern having a predetermined width in order to solve the above problems, and the fuse unit includes one end and the other end of the pattern. It provides a printed circuit board, characterized in that it is electrically connected to each of the first circuit and the second circuit, the pattern includes a plurality of bent portions formed to be bent and a plurality of connecting portions respectively connecting the bent portions. That is, the total length of the pattern is characterized in that it is formed longer than the distance between the first circuit and the second circuit.

The fuse unit is characterized in that the capacity of the fuse unit is set by adjusting the total length of the pattern by changing the number of bending units and connection units of the pattern. That is, as the number of bent portions and connecting portions increases, the resistance of the fuse portion increases.

Further, the connection portion is formed in a linear shape and is arranged in parallel, and the bending portion is arranged at one end and the other end of the connection portion, and the connection portion and the bent portion are alternately connected, whereby the pattern of the fuse portion is small. It can be formed long enough even within.

In addition, at one point of the pattern, a disconnection guiding portion formed with a width smaller than the width of the pattern is formed, and more specifically, the disconnection guiding portion has a shape of a ring having a hole formed in the center, and the outer side of the ring The difference between the diameter and the inner diameter may be formed to be smaller than the width of the pattern. The inclusion of a ring-shaped disconnection inducing part is to induce a disconnection of the fuse part by forming a point having a higher resistance even within the fuse part.

In addition, the substrate is formed to be flexible, including a copper foil on which the fuse portion is formed and a coverlay covering one or both surfaces of the copper foil, and a portion covering the fuse portion of one or both surfaces of the coverlay is removed, and the It is characterized in that the fuse part is opened. This is to prevent the coverlay from igniting and affecting the surrounding circuit when the fuse is disconnected.

Further, a portion of one or both sides of the coverlay covering the disconnection induction part may be removed, so that the disconnection induction part is opened. By forming so that only the disconnection inducing part is exposed, there is an effect of preventing the coverlay from being fired while maintaining the strength of the substrate.

On the other hand, when the material of the pattern is C1100, and when a current of 1.875A is passed, the characteristics of the present invention for satisfying the condition of disconnection within 5 seconds are as follows. The material of the pattern is all the same, and the current value is directly related to the disconnection time and is excluded because it varies depending on the purpose of installation of the fuse part. That is, the present invention suggests an optimal condition related to the shape of the pattern.

First, the present invention is characterized in that when the width of the pattern is 0.08 mm, the widths of the first and second circuits are 0.3 mm or less, and the length of the pattern is 17.5 mm or more.

In addition, the above condition may be satisfied when a value obtained by dividing the length of the pattern by the width of the pattern is 272.5 or more. In this case, when the width of the pattern is 0.1 mm, the width of the first circuit and the second circuit is 0.3 mm or less.

According to the problem solving means of the present invention as described above, various effects including the following can be expected. However, the present invention is not established when all of the following effects are exhibited.

According to the present invention, the pattern of the fuse part is formed alternately with the bending part and the connection part, so that the pattern length can be sufficiently secured even in a small area on the substrate, so that the device can be miniaturized and the capacity of the fuse can be easily adjusted. In addition, compared to the conventional chip fuse separately mounting, there is an advantageous effect of reducing cost and weight because parts and processes are reduced.

In addition, a position at which the fuse unit is disconnected may be set, including a disconnection inducing unit in which resistance is formed larger than that of other portions of the pattern. If the fuse unit is disconnected near the connected circuit, there is a fear that the connected circuit may suffer secondary damage due to heat when the connected circuit is disconnected. Furthermore, when the disconnection induction part is included, the total resistance of the fuse part is increased, thereby reducing the disconnection time.

In addition, since the coverlay is provided so that the fuse unit or the disconnection inducing unit is exposed, secondary damage that may be inflicted on circuits provided nearby can be prevented by melting or igniting the coverlay when the fuse unit is disconnected.

1 is a view showing that a chip fuse is installed in a conventional FPC;
2 is a plan view of a first embodiment of the present invention,
3 is a plan view showing a modified example in which the coverlay is removed from FIG. 2;
4 is a photographic diagram of an experiment with different pattern lengths in the first embodiment of the present invention;
5 is a plan view of a second embodiment of the present invention;
6 is a plan view illustrating a modification example in which the coverlay is removed from FIG. 5.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. Here, repeated descriptions or detailed descriptions of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted. Embodiments of the present invention are provided to describe the present invention in more detail to those skilled in the art to which the present invention pertains. Therefore, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

The present invention relates to a printed circuit board 3, and the contents described below can be applied not only to a general printed circuit board (PCB), but also to a flexible printed circuit board (FPCB). Therefore, hereinafter, the present invention will be described on the basis of a flexible printed circuit board (FPCB) 3.

2 is a plan view of a first embodiment of the present invention. As shown in Fig. 2, the first embodiment of the present invention is a printed circuit board (3) including a copper foil on which a plurality of circuits having different functions are formed, and a coverlay 40 covering one or both sides of the copper foil. )to be. On the copper foil, the first circuit 20, the second circuit 30, and the fuse part 10 are printed as a conductive pattern 11.

In general, the fuse is installed between the power supply terminal and the electric component to prevent an overcurrent of more than the allowable current from flowing through the electric component, but may be formed between the electric component and the electric component due to the function of the fuse. Therefore, in the present specification, the first circuit 20 and the second circuit 30 may be a circuit for supplying power or a circuit for exerting a practical function, but they are described without distinction.

When the fuse part 10 is electrically connected to the first circuit 20 and the other end to the second circuit 30, the overcurrent flows between the first circuit 20 and the second circuit 30 It is provided to be disconnected. Accordingly, it serves to prevent damage to the first circuit 20 and/or the second circuit 30 connected to the fuse unit 10.

In addition, the width W of the pattern 11 of the fuse part 10 is preferably formed to be smaller than the width H of the first circuit 20 and the second circuit 30. However, if the difference between the width H of the first circuit 20 and the second circuit 30 and the pattern width W of the fuse unit 10 is too large, even if the same power is supplied to the fuse unit 10 Heat is not accumulated and heat is dissipated to the first circuit 20 and the second circuit 30, and thus, a problem in which the fuse unit is disconnected may be longer.

The pattern 11 of the fuse part 10 of the present invention is formed to be longer than the distance between the first circuit 20 and the second circuit 30. The pattern 11 includes a bending portion 11a formed to be bent and a connection portion 11b connected to both ends of the bending portion 11a, respectively. A plurality of bending portions 11a and 11b may be alternately arranged, preferably connecting portions 11b extending in a straight line as shown in the drawing are arranged in parallel, and bending portions at both ends of the connecting portion 11b (11a) is disposed, and the connecting portion 11b and the bent portion 11a may be alternately disposed to be connected.

Therefore, the total length of the pattern 11 can be determined by adjusting the number of the bent portions 11a and the connection portions 11b of the pattern 11, and the fuse portion 10 according to the capacity designed using the length of the pattern 11 ) Resistance can be set. That is, the capacity of the fuse unit 10 can be adjusted by using the fact that the resistance of the fuse unit 10 increases as the number of the bending units 11a and the connection units 11b increases.

The resistance may be determined by the specific resistance according to the material of the pattern 11, the length of the pattern 11, the width of the pattern 11, and the thickness of the pattern 11. Accordingly, the fuse unit 10 can set the fuse capacity by adjusting the resistance size, and has been developed with an emphasis on narrowing the width of the pattern 11 or configuring a material of the fuse to have a large specific resistance. However, if the capacity of the fuse is to be set small, there is a limit to narrowing the width of the pattern 11, and if the material of the pattern 11 is changed, a new process must be added to form the fuse pattern 11, so time and cost There is a problem with this increasing. However, the present invention determines the fuse capacity by increasing the length of the pattern 11, and includes a bending portion 11a and a connection portion 11b so that the pattern 11 can secure a sufficient length even in a narrow space of the substrate, It is possible to reduce the size of the equipment and there is an advantage in that the reliability of the fuse unit 10 is improved.

4 is a photographic view of an experiment by varying the length of the pattern 11 in the first embodiment of the present invention. The applicant of the present invention is based on a copper alloy C1100, a pattern 11 of the fuse part 10 having a thickness of 35 μm and a current of 1.875A, the width H of the first circuit 20 and the second circuit 30, and the fuse part 10 ), the width of the pattern (W) and the length of the pattern 11 were controlled, and the disconnection time was measured. Each experiment result represents the disconnection time (sec), and the disconnection time within 5 seconds is indicated by a shade.

<Experiment 1> Experiment 1: 1st and 2nd circuit width 0.3mm, fuse part pattern width 0.08mm Number of experiments Pattern length (mm) 9.3 13.5 17.5 21.8 25.8 30 One 7.6 3.3 3.5 2.96 2.69 2.49 2 X 4.8 4.8 3.8 3.6 3.3 3 19.1 5.1 4.3 3.1 2.7 2.9 4 X 6.2 5.2 4.3 3.7 3.3 5 16.2 4.6 3.8 3.5 3.2 2.9 6 44.6 8.7 5.3 3.9 3.7 3.8 7 157.9 13.3 6.7 4.9 4.3 3.9

<Experiment 2> Experiment 2: 1st and 2nd circuit width 0.5mm, fuse part pattern width 0.08mm Number of experiments Pattern length (mm) 9.3 13.5 17.5 21.8 25.8 30 One X 13.4 6.8 4.5 4.0 3.8 2 X 14.2 7.1 4.9 3.9 4.2 3 X 14.2 7.1 4.9 3.9 4.2 4 X 10.8 5.5 4.1 3.9 3.3 5 X 17.9 6.9 4.7 4.2 3.9

<Experiment 3> Experiment 3: 1st and 2nd circuit width 2.0mm, fuse part pattern width 0.08mm Number of experiments Pattern length (mm) 9.3 13.5 17.5 21.8 25.8 30 One X 13.1 4.9 3.9 3.5 3.3 2 X X 8.9 5.6 4.9 4.4 3 X 14.3 6.2 3.9 3.5 3.3 4 X 25.2 9.5 4.7 3.9 3.72 5 X 21.3 6.8 4.6 4.0 3.6

<Experiment 4> Experiment 4: 1st and 2nd circuit width 0.3mm, fuse part pattern width 0.1mm Number of experiments Pattern length (mm) 9.3 13.5 17.5 21.8 25.8 30 One X 13.7 9 5.7 4.6 4.3 2 X X 13.9 8.0 6.0 4.5 3 X 15.8 9.1 5.4 5.0 3.7 4 X 25.2 10.7 5.8 5.1 3.7 5 X 13.7 9.0 5.7 4.6 4.3 6 X X 13.9 8.0 6.0 4.5 7 X X 15.8 9.1 5.4 5.0

<Experiment 5> Experiment 5: 1st and 2nd circuit width 0.5mm, fuse part pattern width 0.1mm Number of experiments Pattern length (mm) 9.3 13.5 17.5 21.8 25.8 30 One X 216 35.2 11.0 8.2 5.6 2 X 392 107.2 12.4 9.4 5.6 3 X 600 36.2 10.8 7.3 5.4

<Experiment 6> Experiment 6: 1st and 2nd circuit width 2.0mm, fuse part pattern width 0.1mm Number of experiments Pattern length (mm) 9.3 13.5 17.5 21.8 25.8 30 One X X X 11.9 10.1 6.5 2 X X X 18.6 11.4 6.7 3 X X X 11.4 7.6 5.9

First, in all experiments, it was confirmed that the longer the length of the pattern 11, the shorter the disconnection time. Further, in Experiments 1 to 3, the fuse part 10 pattern width (W) is 0.08 mm, and in Experiments 4 to 6, it is 0.1 mm, and when the fuse part 10 pattern width (W) is 0.08 mm, the pattern ( 11) If the length is more than 21.8mm, it can be seen that the wire breaks within 5 seconds in most experiments. If the width of the pattern 11 is narrow and the length is long, it is judged that the resistance increases and this result is reached. It was confirmed that the fuse part 10 operates reliably when it is more than mm.

In addition, when comparing each experiment in Experiments 1 to 3 and Experiments 4 to 6, it was observed that the disconnection time increases as the widths of the first circuit 20 and the second circuit 30 increase. It is determined that even if the pattern width W of the fuse unit 10 is the same, if the width H of the connected circuit is wide, the heat to be used for melting is lost to the connected circuit, and thus the disconnection time is prolonged. Therefore, when the length of the pattern 11 is 30 mm and the width W of the fuse part 10 is 0.08 or 0.1 mm, the width of the first circuit 20 and the second circuit 30 is preferably formed to be 0.3 mm. I was able to get the result.

In summary, the material of the pattern is C1100, and the shape of the pattern that satisfies the condition of disconnection within 5 seconds when a current of 1.875A is passed is as follows. Here, the material of the pattern is all the same, and the current value is directly related to the disconnection time and is excluded because it varies depending on the purpose of installation of the fuse part. That is, the present invention proposes an optimum condition relating only to the shape of the pattern.

When the length of the pattern is divided by the width of the pattern is 272.5 or more, the above condition may be satisfied. It will be described using the following table.

<Length of pattern / Width of pattern> Pattern width
(W, mm) Pattern length (mm) 9.3 13.5 17.5 21.8 25.8 30 0.08 116.25 168.75 218.75 272.5 322.5 375 0.1 93 135 175 218 258 300

The table above describes the value obtained by dividing the length of the pattern by the width of the pattern. Looking at Experiments 1 to 6, when the pattern width (W) is 0.08 mm, when the pattern length is 21.8 mm or more, the wire is disconnected within 5 seconds, and when the pattern width (W) is 0.1 mm, when the pattern length is 30 mm or more, it is 5 seconds. It is supposed to be disconnected within. This is shown in shades in the table above.

From the table above, it can be seen that disconnection occurs within 5 seconds when the value is over 272.5, and disconnection does not occur within 5 seconds when the value is less than 258.

Furthermore, in this case, when the width of the pattern is 0.1 mm, the width of the first circuit and the second circuit is 0.3 mm or less. This is to use the result of disconnection within 5 seconds only when the width of the first circuit and the second circuit is 0.3 mm in Experiments 4 to 6.

In addition, as another form of the pattern satisfying the above conditions, the present invention is characterized in that when the width of the pattern is 0.08 mm, the width of the first circuit and the second circuit is 0.3 mm or less, and the length of the pattern is 17.5 mm or more. . This is based on the result of Experiment 1 that the value obtained by dividing the length of the pattern by the width of the pattern is 272.5 or less, but even in this case, the disconnection time may be shortened if the widths of the first and second circuits are sufficiently narrow.

3 is a plan view showing a modified example in which the coverlay 40 in FIG. 2 is removed. As described above, the flexible circuit board (FPCB) is formed to be flexible, including the coverlay 40 covering one or both surfaces of the copper foil on which the fuse unit 10 is formed. The coverlay 40 is formed of a polymer film such as polyester (PET, Polyester) or polyimide (PI, polyimide) and has a relatively low smoke point. Accordingly, when the fuse unit 10 is disconnected, the coverlay 40 may ignite or melt, thereby damaging circuits provided around it.

Accordingly, as a modification of the first embodiment of the present invention, as shown in FIG. 3, the coverlay opening 41 is formed so that the coverlay 40 does not cover the part where the fuse part 10 is formed, and thus the fuse part ( 10) may be exposed. The coverlay 40 may be adhered to one side or both sides of the copper foil, and when the coverlay 40 is attached to both sides of the copper foil, the coverlay opening 41 is formed on one or both sides of the fuse part 10 Can be.

The coverlay opening part 41 attaches the coverlay 40 on which the coverlay opening part 41 is formed to the copper foil, or removes only the fuse part 10 after attaching the coverlay 40 to the copper foil. It can be manufactured in a way.

In other words, the coverlay 40 is a configuration necessary for fixing the copper foil and the strength of the substrate in the flexible circuit board, but when the fuse part 10 is implemented as the conductive pattern 11 in the substrate, the coverlay 40 ignites problem. Can occur. In the present invention, by forming the coverlay opening 41 so that the coverlay 40 is opened only in the fuse portion 10, the shape and strength of the flexible circuit board are maintained as in the prior art, and the fuse portion 10 This solved the problem that the coverlay 40 melts or ignites.

Hereinafter, each configuration of the second embodiment of the present invention will be described. The second embodiment is different from the first embodiment in that the fuse unit 110 includes the disconnection induction unit 12, and the same reference numerals are used for the same parts, and the description is omitted.

5 is a plan view of a second embodiment of the present invention, and FIG. 6 is a plan view showing a modification example in which the coverlay is removed from FIG. 5. As shown in these drawings, in the second embodiment of the present invention, at least one disconnection induction part 12 is formed in the middle of the pattern 11. The disconnection induction part 12 is formed as a part of the pattern 11, and is a part having a width W'smaller than that of the other part of the pattern 11, and may be formed at least one. In FIG. 5, one disconnection induction part 12 is formed in the center, and FIG. 6 shows that the disconnection induction part 12 is formed in three places.

Specifically, the disconnection induction part 12 may be formed in the shape of a ring in which a hole 13 is formed in the center. Furthermore, it is preferable that the difference between the outer diameter and the inner diameter of the disconnection induction part 12 is formed smaller than the width W of the other part of the pattern 11. The disconnection induction part 12 is formed to have a smaller width W'than other portions of the pattern 11 and to have a longer length by forming a ring shape. Therefore, since the resistance of the disconnection inducing part 12 increases, it has a characteristic that it is more likely to be disconnected than other parts of the pattern 11 when the same current flows.

Meanwhile, when the fuse unit 110 is disconnected at a portion adjacent to the peripheral circuit, it is preferable to be disconnected at the central portion because there is a risk that the peripheral circuit may be damaged by heat. The second embodiment of the present invention has an effect of preventing secondary damage caused by heat in case of disconnection by allowing the fuse unit 110 to be disconnected at a desired point (disconnection induction unit 12). In addition, when the disconnection inducing part 12 is formed, the total resistance of the fuse part 110 increases, so it goes without saying that there is an effect of shortening the disconnection time of the fuse part 110. Accordingly, when a plurality of disconnection induction units 12 are formed as shown in FIG. 6, the total resistance of the fuse unit increases compared to a case where the disconnection induction unit 12 is formed as one as shown in FIG. 5, and the disconnection time may be shortened.

In general, the point where the disconnection occurs may be formed to have a narrower pattern width than other portions of the fuse unit 110, and in the prior art, it is generally formed in a shape that is recessed from both sides of the pattern toward the center of the pattern. However, there is a limit to reducing the width of the pattern, and it is even more difficult to remove a part from the side of the pattern after forming the pattern.

However, in the present invention, through the method of forming the disconnection guide portion 12 having a wider width than other portions of the pattern 11, and then forming the hole 13 in the center of the disconnection guide portion 12 using a drill, etc., The pattern 11 having a narrow width W'can be implemented, and a process can be easily performed.

Further, as a modification of the second embodiment of the present invention, a portion of the coverlay 40 that covers the disconnection induction part 12 may be removed to form the coverlay opening 141. That is, the fuse part 10 is formed on the copper foil, the coverlay 40 adhered to one or both sides of the copper foil is provided, and covers the disconnection induction part 12 of the coverlay 40 on one or both sides of the copper foil. The portion is formed in a form removed, so that the disconnection induction part 12 is exposed from the coverlay opening 141. In this case, as in the modified example of the first embodiment, there is an effect of preventing the coverlay 40 from being fired while maintaining the strength of the substrate.

In the present specification, each embodiment has been described separately, but an embodiment that can be derived by combining each embodiment is also within the scope of the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains are capable of various modifications and variations without departing from the essential characteristics of the present invention. The scope of protection should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

3: printed circuit board 10, 110: fuse part
11: pattern 11a: bending part
11b: connection part 12: disconnection induction part
13: Hall 20: 1st circuit
30: second circuit 40: coverlay
41, 141: coverlay opening

Claims (10)

A first circuit, a second circuit and a fuse portion formed in a conductive pattern having a predetermined width on the substrate,
The fuse unit, one end and the other end of the pattern are electrically connected to the first circuit and the second circuit, respectively,
The pattern includes a plurality of bending portions formed to be bent and a plurality of connection portions respectively connecting the bending portions,
At one point of the pattern, at least one disconnection induction part formed with a width smaller than the width of the pattern is formed,
The disconnection induction part has a shape of a ring in which a hole is formed in the center, and an outer diameter of the disconnection induction part is larger than a width of the pattern.
The method of claim 1,
The fuse unit is characterized in that the capacity of the fuse unit is set by adjusting the total length of the pattern by changing the number of bent units and connection units of the pattern.
The method of claim 1,
The connection portion is formed in a linear shape and is arranged in parallel and the bending portion is disposed at one end and the other end of the connection portion, and the connection portion and the bending portion are alternately connected to each other.
delete The method of claim 1,
The printed circuit board, characterized in that the difference between the outer diameter and the inner diameter of the ring is formed to be smaller than the width of the pattern.
The method according to any one of claims 1 to 3 and 5,
The substrate is formed to be flexible, including a copper foil on which the fuse part is formed and a coverlay covering one or both surfaces of the copper foil,
A printed circuit board, characterized in that a portion of one or both sides of the coverlay that covers the fuse is removed to open the fuse.
The method of claim 5,
The substrate is formed to be flexible, including a copper foil on which the fuse part is formed and a coverlay covering one or both surfaces of the copper foil,
A printed circuit board, characterized in that a portion of one or both sides of the coverlay that covers the disconnection induction part is removed to open the disconnection induction part.
The method of claim 1,
The printed circuit board, wherein a value obtained by dividing the length of the pattern by the width of the pattern is 272.5 or more.
The method of claim 1,
When the width of the pattern is 0.08mm,
The first circuit and the second circuit has a width of 0.3 mm or less, and a length of the pattern of 17.5 mm or more.
The method of claim 8,
When the width of the pattern is 0.1mm,
The printed circuit board, characterized in that the width of the first circuit and the second circuit is 0.3mm or less.

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