WO2021192073A1 - 回路基板及び電子機器 - Google Patents

回路基板及び電子機器 Download PDF

Info

Publication number
WO2021192073A1
WO2021192073A1 PCT/JP2020/013204 JP2020013204W WO2021192073A1 WO 2021192073 A1 WO2021192073 A1 WO 2021192073A1 JP 2020013204 W JP2020013204 W JP 2020013204W WO 2021192073 A1 WO2021192073 A1 WO 2021192073A1
Authority
WO
WIPO (PCT)
Prior art keywords
ground pattern
ground
circuit board
pattern
electronic device
Prior art date
Application number
PCT/JP2020/013204
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
辰也 山中
佑介 山梶
雄大 米岡
顕次 和田
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2020557354A priority Critical patent/JP6843312B1/ja
Priority to DE112020006584.7T priority patent/DE112020006584B4/de
Priority to CN202080098806.2A priority patent/CN115299184B/zh
Priority to PCT/JP2020/013204 priority patent/WO2021192073A1/ja
Publication of WO2021192073A1 publication Critical patent/WO2021192073A1/ja

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0213—Electrical arrangements not otherwise provided for
    • H05K1/0215—Grounding of printed circuits by connection to external grounding means
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0213—Electrical arrangements not otherwise provided for
    • H05K1/0216—Reduction of cross-talk, noise or electromagnetic interference
    • H05K1/0218—Reduction of cross-talk, noise or electromagnetic interference by printed shielding conductors, ground planes or power plane
    • H05K1/0224—Patterned shielding planes, ground planes or power planes
    • H05K1/0227—Split or nearly split shielding or ground planes
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/16—Printed circuits incorporating printed electric components, e.g. printed resistor, capacitor, inductor
    • H05K1/165—Printed circuits incorporating printed electric components, e.g. printed resistor, capacitor, inductor incorporating printed inductors
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/09—Shape and layout
    • H05K2201/09818—Shape or layout details not covered by a single group of H05K2201/09009 - H05K2201/09809
    • H05K2201/0999—Circuit printed on or in housing, e.g. housing as PCB; Circuit printed on the case of a component; PCB affixed to housing

Definitions

  • This disclosure relates to circuit boards and electronic devices.
  • Such an electronic device includes a circuit board on which a communication circuit is mounted and a connector for connecting a communication cable.
  • Electromagnetic noise that has entered from the connector to which the cable is connected may penetrate inside the electronic device through the pattern of the conductor on the circuit board.
  • Patent Document 1 describes a circuit board in which a slit portion for separating these patterns is arranged between a ground pattern of a housing of an electronic device to be grounded and a ground pattern of a communication circuit.
  • the intruding electromagnetic noise can be reduced by not connecting the ground wiring.
  • the circuit board or the metal device housing is connected by ground wiring. Since such a grounded wiring has residual inductance, residual resistance, etc., it has a high impedance against electromagnetic noise entering from the outside of the circuit board. If electromagnetic noise enters from the communication cable through the ground wiring, it propagates to the communication circuit including the semiconductor element, and the communication circuit may malfunction.
  • the present disclosure has been made in view of the above, and an object of the present disclosure is to provide a circuit board that is not easily affected by electromagnetic noise.
  • the circuit board according to the present disclosure is A circuit board on which a signal line group including a ground line is connected and a communication circuit unit for processing a signal received via the signal line group or a signal transmitted via the signal line group is mounted.
  • the electromagnetic noise in the high frequency band that has entered from the connector to which the communication cable is connected is difficult to propagate to the communication circuit section and is difficult to return to the original path, so that the circuit board is not easily affected by the electromagnetic noise.
  • Electronic devices can be provided.
  • FIG. Perspective view of the electronic device according to the first embodiment Top view of the electronic device shown in FIG. Circuit diagram of the electronic device shown in FIG.
  • Top view of the electronic device according to the second embodiment Circuit diagram of the electronic device shown in FIG. Top view of the electronic device according to the third embodiment Circuit diagram of the electronic device shown in FIG.
  • FIG. Top view of the electronic device according to the fifth embodiment Perspective view of the electronic device according to the sixth embodiment Top view of the electronic device shown in FIG.
  • the electronic device 1 is a circuit in which a metal housing 10 covering a circuit element, wiring, etc., a pin, an element, an integrated circuit, etc. are mounted and has a printed copper foil pattern.
  • the board 21 and the ground wiring 30 electrically connected to the housing 10 are provided.
  • the pattern referred to here refers to a circuit electrode including a conductor foil printed on a circuit board, and does not represent the shape of the foil.
  • the circuit board 21 is arranged on the housing 10.
  • the circuit board 21 is, for example, a single-sided substrate in which a copper foil pattern is arranged only on one side of a dielectric substrate.
  • the grounding wire 30 is, for example, a copper wire connected to a grounding rod embedded in the ground and grounded.
  • the ground wiring 30 will be described as being grounded.
  • the grounding potential is not limited to the absolute potential.
  • the grounding potential broadly includes, for example, the potential of a conductor that is not connected to the grounding rod, serves as a return path for a common mode current, and serves as a reference potential for a plurality of connected electronic devices.
  • the ground wiring 30 is an example of the first ground wire in the claim.
  • the electronic device 1 includes a connector 40 of a communication cable for connecting an external device and a communication circuit unit 50 connected to the connector 40.
  • the connector 40 is a receptacle that accepts a plug or jack of a communication cable.
  • the communication cable includes a signal line, for example, a pair of differential communication wirings DS1 and DS2 and a shield wiring SW.
  • the connector 40 is covered with the connector body B1 and the conductor terminals T1, T2, and T3 which are electrically connected by physically contacting the terminals of the communication cable. , Equipped with.
  • the shield wiring SW of the communication cable and the differential communication wirings DS1 and DS2 are electrically connected to the terminals T1, T2, and T3 of the connector 40, respectively.
  • the shield wiring SW is an example of the ground wire in the claim.
  • the group of the differential communication wiring DS1 and DS2 and the shield wiring SW is an example of the signal line group in the claim.
  • the shield wiring SW may be wiring in which the connector 40 is covered with a conductor, and a metal shield case, a shield sheath, a shield housing, etc. electrically connected to the conductor are connected to the circuit board 21. ..
  • the signal line does not have to be a pair of differential communication wirings DS1 and DS2, and may be a single-ended communication wiring using the shield wiring SW as a current return path.
  • a general noise filter may be provided on the above-mentioned differential communication wiring DS1, DS2 or single-ended communication wiring.
  • the noise filter may be arranged inside the connector 40, or may be arranged between the connector 40 on the circuit board 21 and the communication circuit unit 50.
  • the noise filter generally includes a combination of components that reduce noise, for example, a resistor, a line-to-line capacitor, a ground-to-ground capacitor, a transformer, a normal mode choke coil, a common mode choke coil, and the like.
  • connection portion P1 is a connection point provided on the first ground pattern 60.
  • the connection portion P1 is formed by soldering the first ground pattern 60 to the pin of the terminal T1 protruding from the connector 40.
  • the shield wiring SW and the first ground pattern 60 may be directly connected without passing through the pin of the terminal T1. Further, the metal shield case, shield sheath, shield housing, etc. described above are arranged between the shield wiring SW and the first ground pattern 60, and the shield wiring SW, the shield case, and the first ground pattern 60 are arranged in this order. You may connect.
  • connection units P2 and P3 are connection points provided on the pattern of the signal line extending from the communication circuit unit 50.
  • the connection units P2 and P3 are formed by soldering a pattern of signal lines extending from the communication circuit unit 50 to the pins of terminals T2 and T3 protruding from the connector 40. In the following description, the details of the connector 40 will be omitted. Further, the electrical connection via the pins of the terminals T1, T2, and T3 may be expressed as wiring.
  • the communication circuit unit 50 is equipped with a circuit element including an integrated circuit (IC, Integrated Circuit) for communication, a high frequency transistor, a common mode choke coil, a crystal oscillator, and the like.
  • the communication circuit unit 50 is an electronic circuit that processes a signal received via the differential communication wirings DS1 and DS2 and the shield wiring SW.
  • the ground wiring 30 is electrically connected to the housing 10, and the second ground pattern 70 is electrically connected to the housing 10. Therefore, the housing 10, the ground wiring 30, and the second ground pattern 70 are grounded.
  • the third ground pattern 80 is a pattern of copper foil on the circuit board 21 that provides a reference potential to the communication circuit unit 50.
  • the third ground pattern 80 is electrically connected to the ground terminal of the communication circuit unit 50.
  • the first ground pattern 60, the second ground pattern 70, and the third ground pattern 80 are formed on the surface of the circuit board 21.
  • the first ground pattern 60, the second ground pattern 70, and the third ground pattern 80 are hatched in different patterns to facilitate understanding.
  • the electronic device 1 further includes an inductance element 90 and a capacitance element 100.
  • the first ground pattern 60 and the second ground pattern 70 are connected by an inductance element 90.
  • the second ground pattern 70 and the third ground pattern 80 are connected by a capacitance element 100.
  • the first ground pattern 60 and the third ground pattern 80 are not connected by any of the conductor, the capacitance element, and the inductance element, and are not connected by the connecting member.
  • the fact that none of the conductor, the capacitance element, and the inductance element is connected is referred to as being insulated.
  • Termination including Bob Smith termination may be provided between the differential communication wiring DS1 and the first ground pattern 60, and between the differential communication wiring DS2 and the first ground pattern. Further, a termination including a Bob Smith termination may be provided between the differential communication wiring DS1 and the third ground pattern 80, and between the differential communication wiring DS2 and the third ground pattern 80. In this way, when communication is performed using the differential signal, the ends of the differential communication wirings DS1 and DS2 are connected to the same ground pattern, for example, the first ground pattern 60 or the third ground pattern 80. It is desirable to terminate with. Further, at the end of Bob Smith, noise mixed in the differential communication wirings DS1 and DS2 in the common mode tends to flow.
  • the differential communication wirings DS1 and DS2 are connected to the third ground pattern 80 rather than the differential communication wirings DS1 and DS2. It is desirable to connect to the ground pattern 60 of 1.
  • FIG. 3 is a circuit diagram of the electronic device 1.
  • the noise source is represented by NS
  • the electromagnetic noise generated by the noise source NS acts on the shield wiring SW of the communication cable.
  • the inductance value L of the inductance element 90 is an inductance value L that has high impedance with respect to a high frequency band that is assumed to enter from the connector 40, for example, an electromagnetic noise HN of 1 MHz or more.
  • the inductance element 90 may be an element having both a resistance component and an inductance component and whose characteristics change depending on the frequency, for example, ferrite beads.
  • ferrite beads may be used as the inductance element 90.
  • the residual inductance may be referred to as parasitic inductance, stray inductance, self-inductance, etc., but in the present embodiment, it is referred to as residual inductance.
  • electrostatic discharge, electromagnetic noise in the high frequency band generated by a brush motor or the like is easily affected by a residual inductance component.
  • the impedance of the capacitance element 100 is small with respect to the electromagnetic noise in the high frequency band. Therefore, the electromagnetic noise in the high frequency band penetrates into the circuit board 21.
  • the impedance is high only for a specific high frequency band, so that electromagnetic noise HN in the high frequency band does not easily enter the circuit board 21.
  • ferrite beads having a property of making it difficult for electromagnetic noise having a frequency close to the frequency of the signal used for communication to pass through, it is possible to more effectively prevent malfunction of the communication circuit unit 50.
  • the residual inductance of the inductance element 90, the capacitance element 100, and the ground wiring 30 is a kind of LCL T-type filter circuit.
  • This T-type filter circuit has a property of performing series resonance at a resonance frequency determined by the circuit constant of the inductance element 90 and the circuit constant of the capacitance element 100. Electromagnetic noise having a frequency component close to the resonance frequency propagates from the noise source NS to the communication circuit unit 50 via the inductance element 90 and the capacitance element 100. Therefore, if the frequency of the signal used for communication is close to the resonance frequency, the propagated electromagnetic noise may have a greater influence on the operation of the communication circuit unit 50. Therefore, preferably, the capacitance value C of the capacitance element 100 and the inductance value L of the inductance element 90 are set as values that make the resonance frequency of the T-type filter circuit different from the frequency of the signal used for communication.
  • the inductance element 90 When the frequency band of the signal used for communication in the communication circuit unit 50 is wide, preferably, a ferrite bead having a large resistance component is used as the inductance element 90, and a resistance element arranged in series with the inductance element 90 is used. Use. By doing so, the amplitude of resonance of the T-type filter circuit of the LCL can be reduced, and the amount of electromagnetic noise propagating to the communication circuit unit 50 can be reduced. Further, preferably, the capacitance value C of the capacitance element 100 and the inductance value L of the inductance element 90 are values that make the resonance frequency different from the frequency of the nth harmonic as well as the fundamental frequency of the frequency of the signal used for communication. Set. The case where ferrite beads are used as the inductance element 90 has been described above.
  • the inductance element 90 is arranged on the circuit board 21.
  • the inductance element 90 may be arranged inside the connector 40.
  • the capacitance value C of the capacitance element 100 is a capacitance value C that has high impedance with respect to a low frequency band that is assumed to enter from the connector 40, for example, an electromagnetic noise LN of several hundred kHz or less.
  • the capacitance element 100 arranged between the second ground pattern 70 and the third ground pattern 80 may be two or more capacitors.
  • the specifications of the inductance element 90 and the capacitance element 100 and the arrangement on the circuit board 20 are obtained by, for example, a simulation using a computer.
  • FIG. 5 and 6 show circuit diagrams of electronic devices 2 and 3 according to Comparative Examples 1 and 2 having configurations different from those of the electronic device 1 regarding the behavior when the electronic device 1 having the above configuration is exposed to electromagnetic noise.
  • FIG. 7 showing another circuit diagram of the electronic device 1 according to the first embodiment will be described.
  • Comparative Example 1 Unlike the electronic device 1, the electronic device 2 including the circuit board 22 according to Comparative Example 1 does not include the first ground pattern 60 and the inductance element 90. In the electronic device 2, the shield wiring SW of the connector 40 is directly connected to the second ground pattern 70.
  • FIG. 5 shows a thick arrow indicating the noise propagation path when the electromagnetic noise HN and the electromagnetic noise LN in the low frequency band invade the electronic device 2.
  • the capacitance element 100 has a high impedance and the ground wiring 30 has a low impedance with respect to the electromagnetic noise LN in the low frequency band that has entered from the connector 40. Therefore, the electromagnetic noise LN in the low frequency band escapes from the second ground pattern 70 to the ground through the ground wiring 30. Therefore, the electromagnetic noise LN in the low frequency band does not propagate to the communication circuit unit 50.
  • the capacitance element 100 has a low impedance with respect to the electromagnetic noise HN in the high frequency band invading from the connector 40, but the ground wiring 30 has a high impedance due to the residual inductance component. Therefore, the electromagnetic noise HN in the high frequency band cannot escape to the ground through the ground wiring 30, and propagates from the second ground pattern 70 to the third ground pattern 80 via the capacitance element 100 for communication. It invades the circuit unit 50.
  • Comparative Example 2 In the electronic device 3 including the circuit board 23 according to Comparative Example 2, unlike the electronic device 1, the first ground pattern 60 is not electrically separated from the third ground pattern 80. The first ground pattern 60 and the third ground pattern 80 are connected by a connecting member 130.
  • FIG. 6 shows a thick arrow indicating the noise propagation path when the electromagnetic noise HN and the electromagnetic noise LN in the low frequency band invade the electronic device 3.
  • the connecting member 130 is represented by a capacitance element 130 connected between the first ground pattern 60 and the third ground pattern 80 because it has a capacitance component.
  • the inductance element 90 has a low impedance, and the capacitance element 100 and the connecting member 130 have a high impedance with respect to the electromagnetic noise LN in the low frequency band that has entered from the connector 40. Therefore, the electromagnetic noise LN in the low frequency band escapes to the ground through the first ground pattern 60, the inductance element 90, the second ground pattern 70, and the ground wiring 30.
  • the inductance element 90 has a high impedance and the connecting member 130 has a low impedance with respect to the electromagnetic noise HN in the high frequency band that has entered from the connector 40. Therefore, the electromagnetic noise HN in the high frequency band cannot escape to the ground through the inductance element 90, and propagates from the first ground pattern 60 to the third ground pattern 80 via the connecting member 130 for communication. It invades the circuit unit 50.
  • the electromagnetic noise HN in the high frequency band invades the communication circuit unit 50, which may deteriorate the performance of the communication circuit unit 50.
  • the inductance element 90 has a low impedance with respect to the electromagnetic noise LN in the low frequency band that has entered from the connector 40. Therefore, similarly to Comparative Example 2, the electromagnetic noise LN in the low frequency band escapes to the ground through the first ground pattern 60, the inductance element 90, the second ground pattern 70, and the ground wiring 30.
  • the inductance element 90 has a high impedance with respect to the electromagnetic noise HN in the high frequency band that has entered from the connector 40. Therefore, unlike Comparative Example 1, the electromagnetic noise HN in the high frequency band cannot escape to the ground through the inductance element 90. Further, unlike Comparative Example 2, since the first ground pattern 60 and the third ground pattern 80 are not connected, the electromagnetic noise HN in the high frequency band does not propagate to the third ground pattern 80. Therefore, the electromagnetic noise HN in the high frequency band is reflected by the inductance element 90 and does not propagate to the communication circuit unit 50. If the shield wiring SW is sufficiently long, the electromagnetic noise HN in the high frequency band reflected by the inductance element 90 is attenuated by the loss of the shield wiring SW.
  • the ground wiring 30 When the ground wiring 30 is long, the ground wiring 30 has a high residual inductance with respect to the electromagnetic noise HN in the high frequency band. However, even in this case, according to the electronic device 1, the electromagnetic noise HN in the high frequency band does not propagate to the ground wiring 30, so that it does not invade the communication circuit unit 50.
  • FIG. 8 shows the results of an electromagnetic field simulation comparing the circuit board 21 of the electronic device 1 and the circuit board 22 of the electronic device 2. This simulation is the result of outputting the amount of noise propagating to the differential communication wiring of the communication circuit unit 50 as an S parameter when the electromagnetic noise HN in the high frequency band is applied between the first ground pattern 60 and the ground potential. Is shown.
  • the circuit board 21 shown by the solid line suppresses the amount of noise more effectively than the circuit board 22 shown by the broken line over almost the entire frequency domain. In particular, at around 100 MHz, the circuit board 21 suppresses noise by about 10 dB as compared with the circuit board 22.
  • the housing 10 and the second ground pattern 70 are connected by the ground wiring 30, but the method of connecting the housing 10 and the second ground pattern 70 is limited to this. No.
  • the second ground pattern 70 is electrically connected to the metal convex portion 11 formed by raising a part of the housing 10.
  • the second ground pattern 70 and the housing 10 may be connected by the following method.
  • a screw hole is made on the second ground pattern 70 of the circuit board 29.
  • a convex portion 11 is formed in the housing 10 immediately below the screw hole, and a screw hole is formed in the upper end portion of the convex portion 11.
  • solder leveling the second ground pattern 70 the metal is exposed on the back surface of the circuit board 29.
  • the exposed metal portion is brought into contact with the convex portion 11.
  • a screw is inserted from above the second ground pattern 70, fitted into the screw hole of the convex portion 11, and screwed. By doing so, the second ground pattern 70 is pressed against the convex portion 11 and fixed, so that the contact resistance between the second ground pattern 70, the housing 10, and the ground wiring 30 is reduced.
  • the ground wiring 30 may be a sheet metal, a bus bar, or a combination thereof. That is, if it is a conductor that electrically connects the second ground pattern 70 and the housing 10 and is equal to the ground potential with respect to the direct current that is not affected by the residual inductance, the harness-like one shown in the figure is used. Not limited. Since the ground wiring 30 has a residual resistance component with respect to direct current, a potential difference is generated between the ground potential and the second ground pattern 70 or the housing 10 according to the current flowing through the ground wiring 30. do. Since the residual resistance component of the ground wiring 30 is sufficiently small, it is considered that the potential of the conductor electrically connected via the ground wiring 30 and the ground wiring 30 is equal to the ground potential.
  • the electronic device 4 including the circuit board 24 according to the second embodiment has the same configuration as the electronic device 1 according to the first embodiment, and has the first ground pattern 60, the second ground pattern 70, and the third ground pattern 70.
  • the distance between the ground pattern 80 and the ground pattern 80 has a relationship described later.
  • the shortest distance DA between the first ground pattern 60 and the third ground pattern 80 of the circuit board 24 is the second ground pattern 70 and the third ground pattern 80. Greater than the shortest distance DB.
  • the capacitance value of the capacitance element 100 is C
  • the capacitance value of the parasitic capacitance component 140 generated between the first ground pattern 60 and the third ground pattern 80 is C0.
  • the cross-sectional areas of the first ground pattern 60 and the third ground pattern 80 facing each other are S1 [m 2 ]
  • the cross-sectional areas of the second ground pattern 70 and the third ground pattern 80 facing each other are S2 [m 2]. ].
  • the distance DA is larger than the distance DB.
  • the capacitance value C0 of the parasitic capacitance component 140 is generally C0> C1. However, if DA is made sufficiently larger than DB, the value of C0 can be made sufficiently small. From the above, the capacitance value C0 of the parasitic capacitance component 140 is negligibly small for the electromagnetic noise HN in the high frequency band.
  • the electromagnetic noise HN in the high frequency band that has entered from the connector 40 does not propagate to the third ground pattern 80 via the parasitic capacitance component 140, as shown by the thick arrow. Further, since the inductance element 90 has a high impedance with respect to the electromagnetic noise HN in the high frequency band, the electromagnetic noise HN in the high frequency band does not propagate to the communication circuit unit 50 through the inductance element 90.
  • the electronic device 5 including the circuit board 25 according to the third embodiment has the same configuration as the electronic device 1 according to the first embodiment, and is different from the ground wiring 30.
  • the ground wiring 31 connected to the ground pattern 60 of the above is provided.
  • the ground wiring 30 is electrically connected to the second ground pattern 70 at the ground wiring connection portion 71, and the ground wiring 31 is electrically connected to the first ground pattern 60 at the ground wiring connection portion 61.
  • the ground wiring connection portions 61 and 71 are conductor connection portions provided on the copper foil pattern, and are, for example, metal rings.
  • FIG. 12 shows a thick arrow indicating the noise propagation path when the electromagnetic noise HN and the electromagnetic noise LN in the low frequency band invade the electronic device 5.
  • the inductance element 90 has a low impedance and the capacitance element 100 has a high impedance with respect to the electromagnetic noise LN in the low frequency band that has entered from the connector 40. Therefore, the electromagnetic noise LN in the low frequency band escapes to the ground through the first ground pattern 60, the inductance element 90, the second ground pattern 70, and the ground wiring 30.
  • the electromagnetic noise HN in the high frequency band that has entered the first ground pattern 60 from the connector 40 cannot pass through the inductance element 90.
  • the ground wiring 31 has a residual inductance component like the ground wiring 30. Even so, if the ground wiring 31 is short, the impedance value of the residual inductance component with respect to the electromagnetic noise HN in the high frequency band is relatively small. Therefore, the electromagnetic noise HN in the high frequency band that has entered from the connector 40 escapes to the ground through the ground wiring 31 without returning to the shield wiring SW.
  • the electromagnetic noise HN in the high frequency band does not propagate to the communication circuit unit 50, but also the electromagnetic noise HN in the high frequency band is reflected to other devices connected via the communication cable. Wave propagation can be suppressed. Therefore, it is possible to prevent malfunction of other devices connected to the electronic device 5 via the communication cable.
  • the ground wiring 31 is not limited to a harness-shaped wiring, and may be a plate-shaped wiring such as a sheet metal or a bus bar.
  • the ground wiring 31 is an example of the second ground wire in the claim.
  • the electronic device 5 has two wirings, a ground wiring 30 and a ground wiring 31.
  • the wiring for grounding the first ground pattern 60 and the second ground pattern 70 is one of the ground wirings 30, and the first ground pattern 60 and the second ground pattern 70 are electrically connected to the housing 10.
  • the metal convex portions 11 and 12 are arranged in the housing 10, the first ground pattern 60 is connected to the convex portion 12 with a screw 110, and the second ground pattern 70 is used. May be connected to the convex portion 11 with a screw 110. By doing so, the first ground pattern 60 and the second ground pattern 70 are grounded via the housing 10.
  • the grounding wiring 31 of the electronic device 5 is a wiring that directly grounds the first ground pattern 60, but the configuration for grounding the first ground pattern 60 is not limited to this.
  • the electronic device 6 according to the fourth embodiment includes a ground wiring 32 on the circuit board 26, which is different from the ground wiring 30. Further, the electronic device 6 is electrically connected to the ground wiring 32 and includes a first ground pattern 60, a second ground pattern 70, and a fourth ground pattern 150 different from the third ground pattern 80. There is. Between the first ground pattern 60 and the fourth ground pattern 150, a varistor element 160, which is an element whose resistance value decreases as the applied voltage increases, is arranged.
  • the electronic device 6 has an effect of effectively releasing the electromagnetic noise HHN in the high voltage and high frequency band to the ground. The effect of the electronic device 6 will be described with reference to FIG.
  • the ground wiring 32 is an example of the second ground wire in the claim.
  • the inductance element 90 connected between the first ground pattern 60 and the second ground pattern 70 does not have to be a coil as an individual component.
  • the electronic device 7 including the circuit board 27 according to the fifth embodiment includes a copper foil pattern 91 instead of the inductance element 90.
  • the copper foil pattern 91 is printed in an elongated rectangular shape between the first ground pattern 60 and the second ground pattern 70.
  • the pattern 91 of the copper foil is a conductor having an inductance component with respect to the electromagnetic noise HN in the high frequency band.
  • the specific position, width, length, thickness, etc. of the copper foil pattern 91 can be determined by, for example, using a general strip line, microstrip line, or other method to determine the configuration of the circuit board 27 and the circuit board 27. It is designed based on the material, thickness, etc. of the included dielectric.
  • the inductance element 90 in the electronic device 1 can be formed by the copper foil pattern 91.
  • the degree of freedom in designing the circuit board 27 is improved, and space saving and weight reduction of the electronic device 7 are achieved.
  • the shape of the copper foil pattern 91 is not limited to an elongated rectangle.
  • the copper foil pattern 91 may be, for example, a coil formed by utilizing the layer of the circuit board 27. By doing so, the inductance value of the copper foil pattern 91 can be increased.
  • the electronic device 8 according to the sixth embodiment is different from the electronic device 1 in which the circuit board 20 is composed of a single-sided substrate, the circuit board 28 is composed of a multilayer board 170, and the device is provided with a copper foil pattern inside the multilayer board 170.
  • the multilayer substrate 170 is arranged on the outermost side with two dielectric layers 171 and 172 which are dielectric layers and an inner layer 173 which is a layer sandwiched between the two dielectric layers 171 and 172.
  • a surface layer 174 that mounts a communication circuit unit 50, a first ground pattern 60, a second ground pattern 70, a third ground pattern 80, and the like is provided.
  • the dielectric layer 171 is the first dielectric layer in the claim
  • the dielectric layer 172 is the second dielectric layer in the claim
  • the surface layer 174 is an example of the outermost layer in the claim.
  • a first ground pattern 60, a second ground pattern 70, and a third ground pattern 80 are arranged on the outermost surface layer of the multilayer substrate 170. Further, as shown by the broken line, a fifth ground pattern 81, which is a copper foil pattern, is arranged at a position facing the communication circuit unit 50.
  • the fifth ground pattern 81 is arranged in the inner layer 173 and sandwiched between the dielectric layers 171 and 172.
  • the third ground pattern 80 arranged on the surface layer 174 and the inner layer 173 is electrically connected by a via 180.
  • the via 180 is an example of the connecting conductor in the claim.
  • the electromagnetic noise HN in the high frequency band invades from the connector 40.
  • the electromagnetic noise HN in the high frequency band does not always enter from the connector 40.
  • electromagnetic noise HN in the high frequency band may enter from a path other than the connector 40.
  • a fifth ground pattern 81 arranged to face the communication circuit unit 50 The voltage of is also fluctuated by ⁇ V. Since the third ground pattern 80 and the fifth ground pattern 81 are electrically connected by the via 180, the voltage of the third ground pattern 80 also fluctuates by ⁇ V. Therefore, the voltage of the communication circuit unit 50 and the voltage of the third ground pattern 80 are kept equal.
  • the electromagnetic noise HN in the high frequency band invades the third ground pattern 80 and fluctuates the voltage of the third ground pattern 80 by ⁇ V, it is electrically connected to the third ground pattern 80 by the via 180.
  • the voltage of the fifth ground pattern 81 which is set, also fluctuates by ⁇ V.
  • the voltage of the communication circuit unit 50 arranged to face the fifth ground pattern 81 also fluctuates by ⁇ V. Therefore, the voltage of the communication circuit unit 50 and the voltage of the third ground pattern 80 are kept equal.
  • the voltage of the communication circuit unit 50 and the voltage of the third ground pattern 80 are similarly equal. It is kept at voltage.

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Structure Of Printed Boards (AREA)
PCT/JP2020/013204 2020-03-25 2020-03-25 回路基板及び電子機器 WO2021192073A1 (ja)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2020557354A JP6843312B1 (ja) 2020-03-25 2020-03-25 回路基板及び電子機器
DE112020006584.7T DE112020006584B4 (de) 2020-03-25 2020-03-25 Platine und elektronisches Gerät
CN202080098806.2A CN115299184B (zh) 2020-03-25 2020-03-25 电路基板及电子设备
PCT/JP2020/013204 WO2021192073A1 (ja) 2020-03-25 2020-03-25 回路基板及び電子機器

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2020/013204 WO2021192073A1 (ja) 2020-03-25 2020-03-25 回路基板及び電子機器

Publications (1)

Publication Number Publication Date
WO2021192073A1 true WO2021192073A1 (ja) 2021-09-30

Family

ID=74860856

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/013204 WO2021192073A1 (ja) 2020-03-25 2020-03-25 回路基板及び電子機器

Country Status (4)

Country Link
JP (1) JP6843312B1 (de)
CN (1) CN115299184B (de)
DE (1) DE112020006584B4 (de)
WO (1) WO2021192073A1 (de)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116897484A (zh) * 2021-03-11 2023-10-17 三菱电机株式会社 浪涌保护电路和浪涌保护方法
US12057414B2 (en) 2021-04-06 2024-08-06 Mitsubishi Electric Corporation Printed circuit board

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0384627U (de) * 1989-12-20 1991-08-28
JP2003008153A (ja) * 2001-06-19 2003-01-10 Taiyo Yuden Co Ltd 電子回路装置及びローパスフィルタ
JP2016219553A (ja) * 2015-05-18 2016-12-22 三菱電機株式会社 回路基板

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006261455A (ja) * 2005-03-17 2006-09-28 Fujitsu Ltd 半導体装置およびｍｉｍキャパシタ
JP5063529B2 (ja) 2008-08-22 2012-10-31 キヤノン株式会社 プリント回路板
US8824570B2 (en) 2010-04-06 2014-09-02 Broadcom Corporation Communications interface to differential-pair cabling
WO2018173263A1 (ja) * 2017-03-24 2018-09-27 三菱電機株式会社 回路基板
KR102350154B1 (ko) 2017-06-09 2022-01-11 미쓰비시덴키 가부시키가이샤 프린트 기판

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0384627U (de) * 1989-12-20 1991-08-28
JP2003008153A (ja) * 2001-06-19 2003-01-10 Taiyo Yuden Co Ltd 電子回路装置及びローパスフィルタ
JP2016219553A (ja) * 2015-05-18 2016-12-22 三菱電機株式会社 回路基板

Also Published As

Publication number Publication date
JP6843312B1 (ja) 2021-03-17
JPWO2021192073A1 (de) 2021-09-30
DE112020006584B4 (de) 2024-01-04
DE112020006584T5 (de) 2022-11-10
CN115299184A (zh) 2022-11-04
CN115299184B (zh) 2023-07-14

Similar Documents

Publication Publication Date Title
US11050403B2 (en) Circuit module, network module, and in-vehicle electronic device
KR101999509B1 (ko) 회로 기판
JP2000286587A (ja) 外部ケーブル接続用コネクタ部の電磁シールド構造
US6337798B1 (en) Digital circuit decoupling for EMI reduction
JP6843312B1 (ja) 回路基板及び電子機器
US20140285280A1 (en) Grounding pattern structure for high-frequency connection pad of circuit board
US6016083A (en) Electronic circuit apparatus for suppressing electromagnetic radiation
US10153746B2 (en) Wiring board with filter circuit and electronic device
WO2012039120A2 (en) Printed circuit board
EP1568099B1 (de) Eine schaltung, die ein differenzsignal abgreift
US20200403357A1 (en) Connector
US6933805B1 (en) High density capacitor filter bank with embedded faraday cage
JP2005294511A (ja) コネクタ端子を有する電子回路ユニットおよび回路基板
JP2005150161A (ja) プリント配線板接続構造
US9532442B2 (en) Feed line structure, circuit board using same, and EMI noise reduction method
CN109417846B (zh) 印刷基板
WO2019111645A1 (ja) 電子制御装置
CN110784995A (zh) 电路板结构
JP2001326432A (ja) プリント配線板とケーブルの接続構造及び電子機器
CN110710336A (zh) 印刷基板
TW201306376A (zh) 濾波裝置與濾波電路
JP7497232B2 (ja) プリント回路板、プリント配線板、及び電子機器
JPH11259172A (ja) 電子機器
JP2008172280A (ja) コネクタ端子を有する電子回路ユニットおよび回路基板
JP3408376B2 (ja) フィルタ回路

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2020557354

Country of ref document: JP

Kind code of ref document: A

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20927619

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 20927619

Country of ref document: EP

Kind code of ref document: A1