JP2015226011A - Circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board which can inhibit the occurrence of an unintended electric short circuit between conductors adjacent to each other, which is caused by concentration of conductive particles in the case where a connection member composed of a thermosetting resin in which a plurality of conductive particles are mixed is used at the time of electrical connection of conductors among a plurality of substrates.SOLUTION: A circuit board 1 comprises: a plurality of conductors 4 which are electrically connected to a conductor 103 that is another member of another circuit board 101 by using an anisotropically-conductive film F that is a connection member composed of a thermosetting resin Fr in which a plurality of conductive particles Fb are mixed and which extend in parallel with each other; and a particle capture part 4a provided in each conductor, for capturing the particles Fb of the anisotropically-conductive film F.

Description

  The present invention relates to a circuit board.

  Recently, a flexible substrate such as a COF (Chip On Film) in which a semiconductor chip is mounted on a base film is widely used for industrial products. A plurality of flexible substrates called COFs are integrally formed along the longitudinal direction of a base film formed in a tape shape, and become a single unit by being individually punched with a die at a predetermined punching position. For example, Patent Document 1 discloses a conventional technique related to a circuit board having such a flexible board.

  In a conventional circuit board (electronic component mounting board) described in Patent Document 1, a flexible board made of COF and a rigid printed wiring board for surface mounting are electrically connected by thermocompression bonding. For thermocompression bonding, a connecting member called an anisotropic conductive film (ACF) mainly used for electrical connection of a plurality of fine wirings is used. An anisotropic conductive film is a connection member in which a thermosetting resin mixed with a plurality of conductive particles is formed in a film shape.

JP 2004-087938 A

  However, in the above conventional circuit board, when the thermosetting resin of the anisotropic conductive film is melted, the conductive particles of the anisotropic conductive film move and easily concentrate on the end of the flexible board or rigid board. There was concern. And there existed a problem that the electroconductive particle concentrated on the edge part of a board | substrate connected, and there exists a possibility that the electrical short (short) which an unintentional may generate | occur | produce between adjacent conductors may generate | occur | produce.

  The present invention has been made in view of the above points, and uses a connection member made of a thermosetting resin in which a plurality of particles having conductivity are mixed with respect to electrical connection of a conductor between a plurality of substrates. In this case, an object is to provide a circuit board capable of suppressing the occurrence of an unintended electrical short circuit between adjacent conductors due to the concentration of conductive particles.

  In order to solve the above problems, the circuit board of the present invention is a parallel connection that is electrically connected to a conductor of another member using a connection member made of a thermosetting resin mixed with a plurality of conductive particles. And a plurality of conductors extending, and a particle capturing part provided on the conductor for capturing the particles.

  According to this configuration, even when the conductive particles move between adjacent conductors when the thermosetting resin of the connection member is melted, the conductive particles are captured by the particle capturing unit. Therefore, the dispersion amount of the conductive particles in the region between the adjacent conductors is reduced, and the conductive particles are suppressed from concentrating on the end portion of the substrate. As a result, the occurrence of an unintended electrical short circuit between adjacent conductors due to the concentration of conductive particles is suppressed.

  Further, in the circuit board configured as described above, the particle trapping portion is provided on a side surface where the adjacent conductors face each other, and is a recess recessed toward the inside of the conductor in a direction intersecting with the direction in which the conductor extends. Consists of.

  According to this configuration, when the thermosetting resin of the connection member is melted, the conductive particles that move between adjacent conductors can be easily captured by the particle capturing unit. Therefore, the dispersion amount of the conductive particles in the region between the adjacent conductors is further reduced, and it is further suppressed that the conductive particles are concentrated on the edge of the substrate.

  In the circuit board configured as described above, the particle trapping portions provided on the adjacent conductors face each other.

  According to this configuration, a portion where the interval is widened as a particle trapping portion as compared with other portions is formed between adjacent conductors. Therefore, when the thermosetting resin of the connection member is melted, the conductive particles moving between the adjacent conductors are likely to stay in the expanded portion, which is effective when, for example, the interval between the adjacent conductors is relatively narrow. is there.

  In the circuit board configured as described above, the particle trapping portions provided on the adjacent conductors do not face each other.

  According to this configuration, between the adjacent conductors, the particle trapping units are arranged along the direction in which the conductor extends. Accordingly, when the thermosetting resin of the connection member is melted, the chance of encountering the particle trapping portion increases in the process in which the conductive particles move between adjacent conductors. For example, the length of the connection member in the direction in which the conductor extends. This is effective when the length is relatively long.

  In the circuit board configured as described above, the particle trapping portion is provided on the surface of the conductor connected to the conductor of the other member, and includes a recess that is recessed toward the inside of the conductor.

  According to this configuration, when the thermosetting resin of the connection member is melted, the conductive particles that move on the surface of the conductor can be easily captured by the particle capturing unit. Accordingly, the number of conductive particles remaining on the surface of the conductor increases, and the number of conductive particles dispersed in the region between adjacent conductors decreases.

  Further, in the circuit board having the above-described configuration, the particle trapping portion is provided on a side surface where the adjacent conductors face each other, and toward the outside of the conductor in a direction inclined with respect to a direction in which the conductor extends. It consists of projecting branches.

  According to this configuration, when the thermosetting resin of the connection member is melted, the conductive particles that move between adjacent conductors can be easily captured at the branch portions, particularly at the acute angle portions of the branch portions. Therefore, it becomes difficult for the conductive particles to move between the branch portions, and the conductive particles dispersed in the region between the adjacent conductors are reduced.

  According to the configuration of the present invention, when using a connection member made of a thermosetting resin mixed with a plurality of particles having conductivity for electrical connection of conductors between a plurality of substrates, The circuit board which can suppress generation | occurrence | production of the unintended electrical short circuit between the adjacent conductors resulting from concentration can be provided.

It is a fragmentary sectional view which shows the connection state of the circuit board of 1st Embodiment of this invention, and another circuit board. 1 is a schematic plan view of a circuit board according to a first embodiment of the present invention. It is a fragmentary top view of the conductor of the circuit board of 1st Embodiment of this invention. It is sectional drawing which shows the connection location of the conductor of the circuit board of 1st Embodiment of this invention, and the conductor of another circuit board. It is a fragmentary top view of the conductor of the circuit board of 2nd Embodiment of this invention. It is a fragmentary top view of the conductor of the circuit board of 3rd Embodiment of this invention. It is sectional drawing which shows the connection location of the conductor of the circuit board of 3rd Embodiment of this invention, and the conductor of another circuit board. It is a fragmentary top view of the conductor of the circuit board of 4th Embodiment of this invention. It is sectional drawing which shows the connection location of the conductor of the circuit board of 4th Embodiment of this invention, and the conductor of another circuit board. It is a fragmentary top view of the conductor of the circuit board of 5th Embodiment of this invention. It is a partial top view of the conductor of the circuit board of 6th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

<First Embodiment>
First, the outline of the circuit board according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a partial cross-sectional view showing a connection state between the circuit board of the first embodiment and another circuit board, and FIG. 2 is a schematic plan view of the circuit board of the first embodiment.

  As shown in FIG. 1, the circuit board 1 is connected to another circuit board 101 which is another member. The circuit board 1 and the other circuit board 101 are electrically connected to each other using an anisotropic conductive film F.

  The anisotropic conductive film F is a connection member in which a thermosetting resin Fr mixed with a plurality of conductive particles Fb (see FIG. 4) is formed in a film shape. The anisotropic conductive film F is thermocompression bonded to electrically connect the circuit board 1 and the other circuit board 101. At the time of thermocompression bonding, the anisotropic conductive film F is temporarily liquefied by melting the thermosetting resin Fr, and is solidified again at a temperature of, for example, 170 to 180 ° C. to connect the two substrates. At this time, the respective conductors are electrically connected through the particles Fb sandwiched between the respective conductors of the circuit board 1 and the other circuit board 101.

  The circuit board 1 is made of a flexible board such as COF and is attached to the circuit board 101. A plurality of circuit boards 1 are integrally formed on a tape-like base film 2 as shown in FIG. 2, and are individually punched with a die (not shown) at a predetermined punching position 1P (two-dot chain line in FIG. 2). It becomes a simple substance.

  The base film 2 is made of an insulating resin such as polyimide, and is formed in a tape shape extending in the vertical direction in FIG. 2 and is wound around a reel (not shown). Perforations 2a used for feeding the tape pass through and open at both ends of the base film 2 in the width direction (left and right lateral direction, width direction in FIG. 2).

  The circuit board 1 includes a semiconductor chip 3 provided at a substantially central portion thereof, and a conductor 4 whose tip extends from the semiconductor chip 3 to the peripheral edge of the substrate.

  As shown in FIG. 2, the conductor 4 is formed on the base film 2 so as to extend linearly to the outside of the punching position 1 </ b> P to be punched later with a die at the peripheral portion of the circuit board 1. Then, when the circuit board 1 is punched out as a single unit by the mold, the conductor 4 is cut at the leading end at the punching position 1P. A plurality of conductors 4 are provided, and are arranged at a predetermined interval in a direction in which an end surface of the circuit board 1 intersects with a direction in which the conductor 4 extends. Further, the surface of the circuit board 1 is covered with a solder resist 5 which is an insulating film except for the connection portion of the conductor 4 with the circuit board 101 to protect the circuit pattern.

  The circuit board 101 is made of a rigid board such as a glass epoxy board. The circuit board 101 includes a conductor 103 which is provided on the surface of the base material 102 and whose tip extends to the peripheral edge of the board.

  The circuit board 1 and the circuit board 101 are electrically connected to each other through the conductor 4 and the conductor 103. Therefore, a plurality of conductors 103 are provided corresponding to the number of conductors 4 and extend linearly, and are arranged at a predetermined interval in a direction intersecting with the direction in which the conductor 103 extends. Further, the surface of the circuit board 101 is covered with a solder resist 104 which is an insulating film except for the connection portion of the conductor 103 to the circuit board 1 to protect the circuit pattern.

  Subsequently, a detailed configuration of the conductor 4 of the circuit board 1 will be described with reference to FIGS. 3 and 4. FIG. 3 is a partial plan view of the conductor 4, and FIG. 4 is a cross-sectional view showing a connection portion between the conductor 4 and the conductor 103 of the circuit board 101.

  3 is provided in a range where the anisotropic conductive film F is provided at the tip of the conductor 4. The particle capturing portion 4a is provided on the side surface 4S where the adjacent conductors 4 face each other.

  The particle capturing portion 4a is formed of a concave portion that is recessed toward the inside of the conductor 4 in a direction (horizontal direction in the left and right direction in FIG. 3, width direction) that intersects the direction in which the conductor 4 extends (vertical direction and longitudinal direction in FIG. 3). . The particle capturing portion 4a has a rectangular shape having two sides parallel to the direction in which the conductor 4 extends and two sides intersecting with the direction in which the conductor 4 extends, and the conductor 4 is longer than the length in the direction in which the conductor 4 extends. The length in the direction intersecting the extending direction is shorter.

  The particle capturing portion 4a is provided on each of the side surfaces 4S on both sides in the width direction of the conductor 4 with respect to one conductor 4, and each of them is formed at the same position in the direction in which the conductor 4 extends. And each of the particle | grain capture | acquisition part 4a provided in the adjacent conductor 4 opposes each other.

  Here, for example, the width W of the conductor 4 is 20 μm, and the pitch of the adjacent conductors 4 is 35 μm. For example, when the particle size Fb of the anisotropic conductive film F is about 3 μm, the width Wa of the particle capturing portion 4a is 3 μm or more, that is, the particle size of the particle Fb of the anisotropic conductive film F or more. Is preferred. In addition, the numerical value used for the dimension of the conductor 4 described here and the anisotropic conductive film F is an example, and is not necessarily limited to these numerical values.

  When the circuit board 1 including such a conductor 4 and another circuit board 101 are electrically connected to each other using the anisotropic conductive film F, the state shown in FIG. 4 is obtained. In the left and center conductors 4 in FIG. 4, a particle capturing portion 4 a is formed, and the particle capturing portion 4 a captures the particles Fb of the anisotropic conductive film F. In addition, the particle | grains Fb crushed in the up-down direction drawn between the conductor 4 and the conductor 103 have shown the state crushed at the time of thermocompression bonding.

  On the other hand, the other circuit board 101 may be formed as the circuit board according to the present invention with the particle capturing portion 103a formed on the circuit board 101. 4 is formed with the same particle trapping portion 103a as the particle trapping portion 4a of the conductor 4, and the particle trapping portion 103a captures the particles Fb of the anisotropic conductive film F. .

  FIG. 4 shows a state where the thermosetting resin Fr does not enter the particle trapping portions 4a and 103a in order to make it easy to confirm the trapping state of the particles Fb by the particle trapping portions 4a and 103a. However, actually, the thermosetting resin Fr enters the particle trapping portions 4a and 103a when the thermosetting resin Fr is melted. Hereinafter, the same is shown in FIGS. 7 and 9.

  As described above, the circuit board 1 of the first embodiment is another member using the anisotropic conductive film F which is a connection member made of the thermosetting resin Fr mixed with a plurality of conductive particles Fb. A plurality of conductors 4 extending in parallel that are electrically connected to the conductors 103 of the other circuit board 101, and a particle trap for trapping the particles Fb of the anisotropic conductive film F provided on the conductor 4 Part 4a.

  According to this configuration, when the thermosetting resin Fr of the anisotropic conductive film F is melted, the particles Fb are captured even if the particles Fb of the anisotropic conductive film F move between the adjacent conductors 4. It can be captured by the part 4a. Therefore, the dispersion amount of the particles Fb in the region between the adjacent conductors 4 can be reduced, and the particles Fb can be suppressed from concentrating on the edge of the substrate. As a result, it is possible to suppress the occurrence of an unintended electrical short circuit between the adjacent conductors 4 due to the concentration of the particles Fb.

  Moreover, the particle | grain capture | acquisition part 4a is provided in the side surface 4S which the adjacent conductor 4 mutually opposes, and consists of a recessed part dented toward the inner side of the conductor 4 in the direction which cross | intersects the direction where the conductor 4 is extended. According to this configuration, when the thermosetting resin Fr of the anisotropic conductive film F is melted, the particles Fb moving between the adjacent conductors 4 can be easily captured by the particle capturing unit 4a. Therefore, the amount of dispersion of the particles Fb in the region between the adjacent conductors 4 can be further reduced, and the particles Fb can be further suppressed from concentrating on the edge of the substrate.

  Further, in the circuit board 1, the particle capturing portions 4 a provided on the adjacent conductors 4 face each other. According to this configuration, it is possible to form a portion in which the gap is widened between the adjacent conductors 4 as the particle trapping portion 4a as compared with other portions. Therefore, when the thermosetting resin Fr of the anisotropic conductive film F is melted, the particles Fb moving between the adjacent conductors 4 can be easily retained in the expanded portion. Thereby, when the space | interval of the adjacent conductor 4 is comparatively narrow, for example, it is possible to heighten the effect which suppresses generation | occurrence | production of the unintended electrical short circuit between the adjacent conductors 4. FIG.

Second Embodiment
Next, the circuit board of 2nd Embodiment of this invention is demonstrated using FIG. FIG. 5 is a partial plan view of the conductor of the circuit board. Since the basic configuration of this embodiment is the same as that of the first embodiment described above, the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. And

  As shown in FIG. 5, the circuit board 1 according to the second embodiment includes a particle capturing portion 4 a provided at a tip portion of the conductor 4 and in a range where the anisotropic conductive film F is provided. And each of the particle | grain capture | acquisition part 4a provided in the adjacent conductor 4 does not mutually oppose.

  According to this configuration, between the adjacent conductors 4, the particle capturing portions 4 a are arranged along the direction in which the conductor 4 extends. Therefore, when the thermosetting resin Fr of the anisotropic conductive film F is melted, the chance of encountering the particle trapping portion 4a in the process in which the particles Fb move between the adjacent conductors 4 can be increased. Thereby, for example, when the length of the anisotropic conductive film F in the direction in which the conductor 4 extends is relatively long, the effect of suppressing the occurrence of an unintended electrical short circuit between the adjacent conductors 4 is enhanced. Is possible.

<Third Embodiment>
Next, the circuit board of 3rd Embodiment of this invention is demonstrated using FIG.6 and FIG.7. FIG. 6 is a partial plan view of a conductor on the circuit board, and FIG. 7 is a cross-sectional view showing a connection portion between the conductor on the circuit board and the conductor on another circuit board. Since the basic configuration of this embodiment is the same as that of the first embodiment described above, the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. And

  The circuit board 1 of 3rd Embodiment is provided with the particle | grain capture | acquisition part 4b provided in the range which is the front-end | tip part of the conductor 4, and the anisotropic conductive film F is provided, as shown in FIG.6 and FIG.7. The particle capturing part 4b is provided on each side surface 4S on both sides in the width direction of the conductor 4 with respect to one conductor 4, and each of them is formed at a different position with respect to the direction in which the conductor 4 extends. And each of the particle | grain capture | acquisition parts 4b provided in the adjacent conductor 4 is not mutually opposing.

  In the left and center conductors 4 in FIG. 7, a particle capturing portion 4 b is formed, and the particle capturing portion 4 b captures the particles Fb of the anisotropic conductive film F. On the other hand, the particle capturing part 103b may be formed on another circuit board 101. 4 is formed with a particle trapping portion 103b similar to the particle trapping portion 4b of the conductor 4, and the particle trapping portion 103b captures the particles Fb of the anisotropic conductive film F.

  Also in this configuration, between the adjacent conductors 4, the particle trapping portions 4 b are arranged along the direction in which the conductor 4 extends. Therefore, when the thermosetting resin Fr of the anisotropic conductive film F is melted, the chance of encountering the particle trapping portion 4b in the process of moving the particles Fb between the adjacent conductors 4 can be increased.

<Fourth embodiment>
Next, the circuit board of 4th Embodiment of this invention is demonstrated using FIG.8 and FIG.9. FIG. 8 is a partial plan view of a conductor on a circuit board, and FIG. 9 is a cross-sectional view showing a connection point between a conductor on a circuit board and a conductor on another circuit board. Since the basic configuration of this embodiment is the same as that of the first embodiment described above, the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. And

  The circuit board 1 of 4th Embodiment is equipped with the particle | grain capture | acquisition part 4c provided in the range which is the front-end | tip part of the conductor 4, and the anisotropic conductive film F is provided, as shown in FIG.8 and FIG.9. The particle trapping portion 4 c is provided on the surface 4 F of the conductor 4 connected to the conductor 103 of the circuit board 101, that is, on one surface facing the conductor 103, and is composed of a recess that is recessed toward the inside of the conductor 4. The particle trapping portion 4 c is a concave portion shaped like a part of a sphere cut into a round shape.

  In the left and right conductors 4 of FIG. 9, a particle capturing portion 4 c is formed, and the particle capturing portion 4 c captures the particles Fb of the anisotropic conductive film F. On the other hand, the particle capturing part 103 c may be formed on another circuit board 101. 9 is formed with the same particle trapping portion 103c as the particle trapping portion 4c of the conductor 4, and the particle trapping portion 103c captures the particles Fb of the anisotropic conductive film F. .

  According to this configuration, when the thermosetting resin Fr of the anisotropic conductive film F is melted, the particles Fb moving on the surface 4F of the conductor 4 can be easily captured by the particle capturing portion 4c. Therefore, it is possible to increase the number of particles Fb remaining on the surface of the conductor 4 and to decrease the particles Fb dispersed in the region between the adjacent conductors 4.

<Fifth Embodiment>
Next, the circuit board of 5th Embodiment of this invention is demonstrated using FIG. FIG. 10 is a partial plan view of the conductor of the circuit board. Since the basic configuration of this embodiment is the same as that of the first embodiment described above, the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. And

  As shown in FIG. 10, the circuit board 1 according to the fifth embodiment includes a particle capturing portion 4 d provided at a tip portion of the conductor 4 and in a range where the anisotropic conductive film F is provided. 4 d of particle | grain capture | acquisition parts are provided in the side surface 4S which the adjacent conductor 4 opposes mutually.

  The particle trapping portion 4d is composed of a branch-like portion that protrudes toward the outside of the conductor 4 in a direction that is inclined with respect to the direction in which the conductor 4 extends. 4 d of particle | grain capture | acquisition parts are provided in each side 4S of the width direction both sides of the conductor 4 regarding one conductor 4, and each of them is formed so that it may protrude toward the same direction regarding the direction where the conductor 4 is extended. . For example, in FIG. 10, the leftmost particle capturing unit 4 d and the second particle capturing unit 4 d from the right protrude toward the tip side of the conductor 4 (upper side in FIG. 10). In FIG. 10, the rightmost particle trapping portion 4 d and the second particle trapping portion 4 d from the left protrude toward the base side of the conductor 4 (the lower side in FIG. 10).

  According to this configuration, when the thermosetting resin Fr of the anisotropic conductive film F is melted, the particles Fb that move between the adjacent conductors 4 are dispersed at the particle capturing portion 4d, particularly at an acute angle portion of the branch-shaped portion. It can be easily captured. Therefore, it is possible to make it difficult for the particles Fb to move between the branch portions, and to reduce the particles Fb dispersed in the region between the adjacent conductors 4.

<Sixth Embodiment>
Next, the circuit board of 6th Embodiment of this invention is demonstrated using FIG. FIG. 11 is a partial plan view of the conductor of the circuit board. Since the basic configuration of this embodiment is the same as that of the first embodiment described above, the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. And

  As shown in FIG. 11, the circuit board 1 according to the sixth embodiment includes a particle trapping portion 4 e that is provided at the tip of the conductor 4 and in the range where the anisotropic conductive film F is provided. The particle capturing portion 4e is provided on the side surface 4S where the adjacent conductors 4 face each other.

  The particle trapping portion 4e is composed of a branch-like portion that protrudes toward the outside of the conductor 4 in a direction that is inclined with respect to the direction in which the conductor 4 extends. The particle trapping portion 4e is provided on each side surface 4S on both sides in the width direction of the conductor 4 with respect to one conductor 4, and each of them protrudes alternately toward the front end side or the root side in the direction in which the conductor 4 extends. Formed to do.

  Even in this configuration, when the thermosetting resin Fr of the anisotropic conductive film F is melted, the particles Fb moving between the adjacent conductors 4 are captured by the particle trapping portion 4e, particularly at an acute angle portion of the branch-shaped portion. Can be made easier. Therefore, it is possible to make it difficult for the particles Fb to move between the branch portions, and to reduce the particles Fb dispersed in the region between the adjacent conductors 4.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  For example, in the above embodiment, the particle capturing unit is provided only on the circuit board 1 that is a flexible board or on both the circuit board 1 and another circuit board 101 that is a rigid board. A particle capturing unit may be provided only on the substrate 101.

  The first to sixth embodiments can be combined. For example, for one conductor, the particle trapping portion according to the first embodiment may be formed on one side surface in the width direction, and the particle trapping portion according to the sixth embodiment may be formed on the other side surface.

  The present invention can be used in circuit boards.

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Base film 4 Conductor 4a, 4b, 4c, 4d, 4e Particle capture part 4F Surface 4S Side surface 101 Circuit board 103 Conductor 103a, 103b, 103c Particle capture part F An anisotropic conductive film (connection member)
Fb particle Fr thermosetting resin

Claims (6)

A plurality of conductors extending in parallel and electrically connected to a conductor of another member using a connection member made of a thermosetting resin mixed with a plurality of particles having conductivity;
A particle capturing unit provided on the conductor for capturing the particles;
A circuit board comprising:   2. The circuit according to claim 1, wherein the particle trapping portion is formed on a side surface where the adjacent conductors face each other and is recessed toward the inside of the conductor in a direction intersecting with a direction in which the conductor extends. substrate.   The circuit board according to claim 2, wherein each of the particle trapping portions provided in the adjacent conductors faces each other.   The circuit board according to claim 2, wherein the particle trapping portions provided on the adjacent conductors do not face each other.   The said particle | grain capture | acquisition part is provided in the surface of the said conductor connected with the conductor of the said other member, and consists of a recessed part depressed toward the inner side of the said conductor, The claim in any one of Claims 1-4 Circuit board.   The particle trapping part is provided on side surfaces where the adjacent conductors are opposed to each other, and comprises a branch-like part protruding toward the outside of the conductor in a direction inclined with respect to a direction in which the conductor extends. The circuit board according to claim 1.

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