WO1998002025A1 - Carte a circuit a basse emissivite et connecteur de cable a basse emissivite - Google Patents
Carte a circuit a basse emissivite et connecteur de cable a basse emissivite Download PDFInfo
- Publication number
- WO1998002025A1 WO1998002025A1 PCT/JP1997/002376 JP9702376W WO9802025A1 WO 1998002025 A1 WO1998002025 A1 WO 1998002025A1 JP 9702376 W JP9702376 W JP 9702376W WO 9802025 A1 WO9802025 A1 WO 9802025A1
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- WIPO (PCT)
- Prior art keywords
- low
- emi
- cable connector
- layer
- circuit board
- Prior art date
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- 230000005540 biological transmission Effects 0.000 claims abstract description 42
- 230000002093 peripheral effect Effects 0.000 claims description 13
- 230000005855 radiation Effects 0.000 abstract description 94
- 229910000679 solder Inorganic materials 0.000 abstract description 16
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- 238000007747 plating Methods 0.000 description 3
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- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000004642 Polyimide Substances 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
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- 229920001721 polyimide Polymers 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/552—Protection against radiation, e.g. light or electromagnetic waves
-
- 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
-
- 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
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0007—Casings
- H05K9/002—Casings with localised screening
- H05K9/0039—Galvanic coupling of ground layer on printed circuit board [PCB] to conductive casing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
- H01L2924/161—Cap
- H01L2924/1615—Shape
- H01L2924/16152—Cap comprising a cavity for hosting the device, e.g. U-shaped cap
- H01L2924/16153—Cap enclosing a plurality of side-by-side cavities [e.g. E-shaped cap]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/19—Details of hybrid assemblies other than the semiconductor or other solid state devices to be connected
- H01L2924/191—Disposition
- H01L2924/19101—Disposition of discrete passive components
- H01L2924/19105—Disposition of discrete passive components in a side-by-side arrangement on a common die mounting substrate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/19—Details of hybrid assemblies other than the semiconductor or other solid state devices to be connected
- H01L2924/191—Disposition
- H01L2924/19101—Disposition of discrete passive components
- H01L2924/19106—Disposition of discrete passive components in a mirrored arrangement on two different side of a common die mounting substrate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/30—Technical effects
- H01L2924/301—Electrical effects
- H01L2924/3011—Impedance
Definitions
- the present invention relates to a low EMI circuit board on which circuit elements such as ICs and LSIs are mounted, and more particularly, to a low EMI circuit board and a transmission cable for suppressing radiation from such mounted components centering on a differential mode.
- the present invention relates to a low EMI cable connector that suppresses unnecessary radiation of a cable.
- Such unnecessary radiation can be broadly divided into two types: radiation of common mode caused by resonance caused by potential fluctuation of the power supply layer and duland layer, and radiation of differential mode generated from the signal line layer and mounted components.
- radiation of common mode caused by resonance caused by potential fluctuation of the power supply layer and duland layer
- radiation of differential mode generated from the signal line layer and mounted components In the past, various methods for reducing such unnecessary radiation have been proposed.
- a method using a shield has conventionally been generally used, and specifically, a method of applying a conductive paste containing a resistive material to a substrate surface has been adopted. I have.
- a transmission line such as a coaxial cable is connected to an external transmission source by a connector. I do.
- FIG. 13 schematically shows such a connection state.
- the transmitting source is a transmitting end device 100
- the above-mentioned substrate for receiving a signal from the transmitting end device is a receiving end device 101, and a coaxial cable 102 is connected between them.
- the board as the receiving end device 101 is connected to the coaxial cable 102 by a connector (not shown), and the sending end device 100 is connected to the coaxial cable 102 by a connector (not shown). I have.
- the outgoing line 100a connected to the signal source 100c that generates a pulse-like signal of voltage VO at the frequency ⁇ j is connected to the inner conductor 1 of the coaxial cable 102.
- the return line 100b is connected to the outer conductor 102b of the coaxial cable 102 by a connector (not shown)
- the receiving end device 101 is equivalently ,
- the receiving line 101a is the inner conductor 1 of the coaxial cable 102.
- the return line 101 b are connected to the outer conductor 102 b of the coaxial cable 102 by connectors (not shown), respectively, and the return line at the sending end device 100.
- 100 b and the return line 101 b at the receiving end device 101 are grounded, and the outer conductor 102 b of the coaxial cable 102 is a ground line.
- the outgoing line 100 a, the inner conductor 100 2 a of the coaxial cable 102, the receiving line 101 at the receiving end device 101 The signal path is formed by a, load resistance R, return line 101b, the outer junction body 102b of the coaxial cable 102, and the return line 100b at the sending end device 100.
- the signal output from the signal source 100 c is sent to the inner conductor 102 a of the coaxial cable 102 as a voltage Via and a current i la,
- voltage V lb, current i lb Is received as On the return path of this signal path, the signal of the voltage V2b and the current i2b flows from the receiving end device 101 through the inner surface of the outer conductor 102b of the coaxial cable 102, but not only that.
- current reflection occurs due to equivalent impedance there, and current leakage occurs on the outer surface of the outer conductor 102 b of the coaxial cable 102. Occurs.
- the signal flowing on the inner surface of the outer conductor I 0 2b is the force input to the sending device 100 as a voltage V2a and a current i 2a at the connection point A between the coaxial cable 102 and the sending device 100.
- a current reflection occurs due to the equivalent impedance there.
- a part of the current i 2a leaks to the outer surface of the outer conductor 102 b of the coaxial cable 102 and the coaxial cable 1
- the outer conductor 102 flows through the outer surface of the outer conductor 102b.
- the case of the transmitting end device 100 and the outer surface of the coaxial cable 102 are completely integrated with the outer surface of the coaxial cable 102, and similarly, the case of the receiving end device 101 and the outer conductor of the coaxial cable 102 Complete integration of the outer surface of 102b If the inside of the case 100, the inside of the coaxial cable 102, and the case of the receiving end device 101 could be completely sealed, the above-described leakage current could be eliminated. In practice, it is almost impossible to do so, and the generation of unnecessary radiation as described above cannot be avoided.
- a ferrite core 103a called a common mode core or a common mode chioke is provided at the end of the coaxial cable 102 on the side of the sending end device 100.
- a ferrite core 103 b is also provided at the end of the receiving end device 101.
- the absolute value of the impedance of these ferrite cores 1 ⁇ 3a and 103b is set to about 100 ⁇ from the viewpoint of materials and structure.
- the conductive paste is applied to a relatively flat portion of the substrate surface, and cannot be applied to a mounted component or a portion to which the component is attached.
- the shield layer is opened at the mounting part of the mounted component, and unnecessary radiation leaks from this opening, and resonance occurs at the opening.
- New radiation common-mode radiation
- unnecessary radiation from transmission lines such as coaxial cables connected to the board was not achieved. Radiation can be suppressed to some extent by providing ferrite cores at both ends of the transmission line as described in Fig. 13, but it is not always sufficient.
- the absolute value of the impedance of the ferrite cores 103a and 103b is assumed to be 100 ⁇ . However, if 100 ⁇ is not sufficient, these ferrite cores may be used.
- a large and heavy ferrite core must be used, and using a plurality of ferrites is equivalent to winding the coil a plurality of times, causing a capacitance between them and generating new resonance. There are also problems such as causing problems.
- the clock frequency of the signal to be handled is as low as, for example, about 10 MHz, it is sufficiently lower than 300 MHz, so that the ferrite cores 103 a, 103 b have the permeability ⁇ . Since it can be used in a sufficiently large state, it can sufficiently suppress the fundamental wave and third harmonic of leakage currents i 3 a and i 3 b, which are problems as unnecessary radiation, and the frequency characteristics of the magnetic permeability ⁇ Power that does not become a special problem ⁇ In recent years, for example, the clock frequency of personal computers and the like has become increasingly higher, such as 100 MHz or more and 200 MHz or more.
- An object of the present invention is to provide a low EMI circuit board which can solve such a problem and can effectively suppress radiation mainly in a differential mode.
- Another object of the present invention is to provide a low EMI cable connector which is small in size and simple in configuration and capable of effectively suppressing unnecessary radiation in a signal transmission line. Disclosure of the invention
- the entire board surface including the mounted components is covered with a shield plate, and the shield plate is electrically connected to a ground layer inserted therein.
- unnecessary radiation in the differential mode generated from the mounted components and signal lines is not trapped between the shield plate and the ground layer and does not go outside.
- a loss layer is provided on at least one surface of the conductive layer in the shield plate.
- the periphery of the shield plate is connected to the ground layer at multiple points.
- the resonance frequency of the loop consisting of the shield plate and the roundabout layer can be shifted to a higher frequency band than the frequency region to be suppressed, and the common mode from the side of the substrate using the radiation of the differential mode as a noise source
- the periphery of the shield plate is connected to the ground layer through a matching terminating resistor to suppress potential fluctuations. I do. As a result, it is possible to suppress the common mode radiation from the side surface of the substrate and prevent the leakage to the outside.
- the shield plate is connected at multiple points to the ground layer around a high-speed board mounted component such as an LSI element or a driving IC element. Mounted parts that operate at high speed are likely to generate differential mode radiation. Therefore, by connecting the shield plate to the duland layer at multiple points around the mounted component, the mounted components are individually shielded, so that the radiation in the differential mode from the mounted component is reduced. Even at the periphery of the substrate, since the shield plate is connected to the duland layer at multiple points, the electrical connection structure in the shield is doubled, and the shielding effect is remarkable.
- a short-circuit member surrounding the entire circumference of the transmission cable is provided at the end side of the cylindrical body to form a short-circuit termination line, and a resonance frequency of the short-circuit termination line is defined as a resonance frequency of the transmission cable. Configure to be equal.
- the plurality of tubular bodies forming the short-circuit termination line are coaxially arranged.
- the low EMI cable connector according to the present invention is characterized in that the short-circuit member is configured to be detachable.
- the plurality of tubular bodies forming the short-circuit termination line have a common central axis and are arranged along the central axis.
- the cylindrical bodies forming the short-circuit termination line can be adjusted in position in the direction of the central axis. According to such a configuration, in the short-circuit termination line, the impedance of this line becomes almost infinite at the resonance frequency, and the current of this resonance frequency flowing through this line is suppressed to almost zero. Therefore, by setting the resonance frequency of the short-circuited termination line to be equal to the frequency at which the transmission cable resonates and generates unnecessary radiation, the current that causes such unnecessary radiation can be effectively suppressed.
- the dielectric constant of the dielectric portion is ⁇ ri, and the wavelength of the current flowing through the conductor portion is; Then, in this short-circuited termination line, the wavelength ⁇ ⁇ ′ is i / f £ ri, and the length of the bottomed cylindrical portion of the short-circuited termination line is 1 / f ⁇ ri times shorter than the length of the transmission cable. can do.
- the length of the bottomed cylindrical part can be 1/30 times the length of the transmission cable used, for example, 100 MHz
- the transmission cable has a different fundamental resonance frequency because the outer conductor of the coaxial cable is grounded in the middle, unnecessary radiation is generated according to these fundamental frequencies.
- the current that generates unnecessary radiation for each fundamental resonance frequency can be effectively suppressed by each short-circuit termination line.
- a low EMI cable connector forms a cylindrical body having a dielectric portion surrounding the entire circumference of a transmission cable provided on an inner surface thereof, and a terminal end side of the cylindrical body.
- a resistor serving as a matching termination resistor is provided.
- the length of the cylindrical body is arbitrary, but the above matching terminating resistor matching this is provided.
- An open-ended line is formed with the end of the cylindrical body as an open end, and the resonance frequency of the open-ended line is made equal to the resonance frequency of the transmission cable.
- f i the i-th fundamental resonance frequency of the transmission cable
- ⁇ r i the dielectric constant of the dielectric portion of the i-th cylindrical body.
- the plurality of tubular bodies forming the open terminal line have a common central axis and are arranged along the central axis.
- the tubular body forming the open terminal line is configured to be capable of adjusting the position in the direction of the central axis.
- the open terminal line has a resonance frequency. This is equivalent to a state where a short-circuit termination is provided in the middle position of this line, that is, in the middle position of the cylindrical portion, and the impedance at this time becomes almost infinite. Therefore, by setting this resonance frequency to be equal to the resonance frequency at which unnecessary radiation of the transmission cable occurs, current at a frequency at which unnecessary radiation of the transmission cable is generated can be effectively suppressed.
- the length of the open-ended line that is, the length of the cylindrical portion is twice as long as that of the above-described present invention in which the short-circuited line is used, but the cylindrical portion is still small.
- FIG. 1 is a cross-sectional view showing one embodiment of a low-EMI circuit board according to the present invention
- FIG. 2 is a view showing formation positions of a loss layer in a ground layer and a power supply layer in FIG. FIG.
- FIG. 3 is a cross-sectional view showing one embodiment of the low-EMI circuit board according to the present invention
- FIG. 4 is a cross-sectional view showing one embodiment of the low-EMI cable connector according to the present invention.
- Fig. 5 is an impedance characteristic diagram of the low EMI cable connector shown in Fig. 4.
- Fig. 6 is an installation state of the low EMI cable connector shown in Fig. 4 on the transmitting end device side.
- FIG. 7 is a circuit diagram showing an equivalent circuit in the mounted state shown in FIG. 6, and
- FIG. 8 is a circuit diagram showing an equivalent circuit in the mounted state shown in FIG.
- FIG. 9 is a cross-sectional view showing a mounting state of a low-power connector on a low-EMI circuit board side and an operation thereof.
- FIG. 10 is a sectional view showing another embodiment of the MI cable connector
- FIG. 10 is a sectional view showing still another embodiment of the low EMI cable connector according to the present invention
- FIG. Fig. 12 is a cross-sectional view showing still another embodiment of the low EMI cable connector according to the present invention
- Fig. 12 is a cross-sectional view showing still another embodiment of the low EMI cable connector according to the present invention
- FIG. 13 is an explanatory diagram of generation of unnecessary radiation from a transmission cable.
- FIG. 1 is a sectional view showing one embodiment of a low EMI circuit board according to the present invention, wherein 1 is a multilayer circuit board, 2 is a ground layer, 2a is a loss layer, 3 is a power supply layer, and 3a is Loss layer, 4 is signal line layer, 5 is through hole, 6a to 6n is electrode pattern, 7 is solder, 8 is LSI element, 9 is IC element, 10 is matching termination resistance element, 11 is resistance Element, 12 is a shield plate, 13 is a conductive foil.14 is a loss layer, 15a, 15b, 16 is an insulating layer, 17 is a dielectric layer, In this figure, this embodiment has a configuration in which a shield plate 12 is attached to the surface of a multilayer circuit board 1 on which a ground layer 2, a power supply layer 3, and a signal line layer 4 are provided. .
- the solder 7 used at this time may be made of a conductive adhesive from the viewpoint of heat resistance, particularly when the shield plate 12 is attached.
- a Dalund layer 2 and a power supply layer 3 are provided in a dielectric layer 17 and one signal line layer 4 force ⁇ , ground between one surface layer and the ground layer 2.
- Electrode patterns are provided at predetermined locations on the signal line layer 4 provided on each surface layer, some of which are electrically connected to the ground layer 2 and some of which are electrically connected to the power supply layer 3, respectively. Have been. Here, only the electrode patterns 6a to 6n are shown. Hereinafter, the electrode patterns 6a to 6n will be described. In these, the electrode patterns 6b, 6c, 6e to 6g, 6i to 6k, 6m, 6 ⁇ are electrically connected to the ground layer 2 via the through holes 5. Further, the electrode patterns 6 d and 61 are electrically connected to the power supply layer 3 through the through holes 5.
- the terminals of the resistive element 11 constituting the desired circuit are attached to the electrode pattern 6 d connected to the power supply layer 3 and the electrode pattern 6 c connected to the ground layer 2 by soldering 7.
- a lead of an LSI element 8 molded on the pattern 6 d and the electrode pattern 6 e connected to the ground layer 2 is attached by solder 7, and the electrode pattern 6 1 connected to the power supply layer 3 is formed.
- the electrode pattern 6 k connected to ground layer 2 It is assumed that the leads of the integrated IC element 9 are attached by solder 7. At this time, the IC element 9 may be attached in a bare chip state.
- a shield plate 12 is provided on both sides of the multilayer circuit board 1 so as to cover the entire surface including the LSI element 8, the IC element 9, the resistance element 11 and the like mounted thereon.
- the shield plate 12 has a solid flat surface of a thin plate, and in many cases, many small holes are evenly arranged from the viewpoint of heat dissipation of the IC element and the LSI element.
- the hole diameter (shape) ⁇ shall be ⁇ 60 (or the radiation wavelength) or less in consideration of the suppression area of unnecessary radiation.
- the shield plate 12 and the ground layer 2 suppress radiation centered on the differential mode.
- FIG. 1 shows electrode patterns 6a, 6g, 6h, and 6n as the electrode patterns in the peripheral portion.
- this shield plate 12 is made of a conductive foil (for example, copper foil) provided with a loss layer 14 on the surface of the multilayer circuit board 1, and both sides of the shield 13 are covered with insulating layers 15 a and 15 b.
- the loss layer 14 forms a line having a large attenuation constant ⁇ with the ground layer 2.
- the insulating layer 15a covering the lossy layer 14 side of the conductive foil 13 is made of a heat-resistant insulating film such as polyimide or polyester.
- the insulating layer 15b is not indispensable, and when not provided, the surface of the conductive layer 13 is subjected to an antioxidant treatment. Further, the above insulating film may be used.
- the shield plate 12 is formed so that the conductive foil 13 is connected to the solder 7. And electrically connected to the electrode patterns 6 a, 6 g, 6 h, and 6 ⁇ .
- the loss layer 14 for example, a nickel plating layer or a chrome plating layer having a large resistivity is used.
- the surface of the conductive foil 13 may be made uneven to lengthen the transmission path and equivalently increase the resistance value. In this case, the adhesion between the conductive layer 13 and the insulating film such as polyimide as the insulating layer 15a is improved.
- the shield plate 12 is flexible, and it is desirable that the shield plate 12 be molded in accordance with irregularities due to mounting components on the multilayer circuit board 1. If it is formed in this way, it is easy to mount it on the multilayer circuit board 1, and the mounting portions to the electrode patterns 6a, 6g, 6h, 6n can be easily formed. Since they are arranged close to the electrode patterns 6a, 6g, 6h, and 6n, soldering is simplified.
- the force which is used to confine the radiation of the differential mode generated from the LSI element 8 and the IC element 9 between the shield plate i 2 and the ground layer 2 is simply a shield plate.
- the shield plate 12 is independent of the ground layer 2 only by attaching the 1 2
- a high-speed clock from a high-speed operation component ⁇ differential module by harmonics of the signal processed based on this As a result, energy is accumulated between the shield plate 12 and the durand layer 2 due to the occurrence of a single radiation, thereby causing a potential difference between the shield plate 12 and the ground layer 2 and causing resonance.
- the shield layer 12 and the ground layer 2 are almost parallel lines, they are electrically terminated. By connecting the ends, standing waves are hardly generated in the shield plate 12 and unnecessary radiation from the periphery of the shield plate 12 is suppressed.
- a connection method As a connection method,
- the shield plate 12 is connected to the electrode patterns 6a and 6h provided on the periphery of the surface layer of the multilayer circuit board 1 with solder 7, and this is set so that a termination resistance value close to the matching termination resistance value is obtained.
- the terminal of the chip resistor 10 having a predetermined resistance value is attached to the electrode pattern 6a and the electrode pattern 6 in the peripheral area of the multilayer circuit board 1 connected to the drand layer 2 through the through hole 5 with the solder 7, and
- the terminal of the chip resistor 10 having a predetermined resistance value is soldered to the electrode pattern 6 h and the electrode pattern 6 ⁇ at the peripheral portion of the multilayer circuit board 1 connected to the land layer 2 through the through hole 5. Install it.
- the periphery of the shield plate I2 is connected to the ground layer 2 via the chip resistor 10.
- the pitch determined by the structure of the multilayer circuit board 1 at the periphery of the multilayer circuit board 1 (for example, a size of about A4 size)
- the chip resistors 10 are terminated at approximately equal intervals by connecting a plurality of devices in parallel at a pitch of 25 to 50 mm.
- the inductance component that depends on the structure of the through-hole 5 and the electrode patterns 6a, 6b, 6h, and 6i is set so that the impedance is sufficiently smaller than the terminal resistance value.
- the periphery of the shield plate 12 is connected by solder 7 to the electrode patterns 6 g, 6 n, etc., which are electrically connected to the ground layer 2 through the through holes 5. That is, the shield plate 12 and the ground layer 2 are directly and electrically connected only through the force, the through hole 5, so that the shield plate 12 has the same electric potential as the durand layer 2.
- the radiation of the differential mode is generated from the LSI element 8 and the IC element 9 that perform the high-speed operation and the signal line layer (the high-speed signal line layer) 4 that transmits the high-frequency signal and the clock.
- the mounted components and the high-speed signal line layer 4 are also referred to as high-speed operation components), and such high-speed operation components as radiation sources are shielded so as to be wrapped by the ground layer 2 and the shield plate 12 via the through holes 5.
- the radiation is confined between the ground layer 2 and the shield plate 12, and the shield layer 12 and the ground layer 2 are electrically connected to each other via the through hole 5 to have the same potential. Therefore, even if a standing wave is generated between the shield plate 12 and the ground layer 2, it does not appear outside and effectively suppresses unnecessary radiation from the periphery of the shield plate 12. be able to.
- Short-circuiting the ground layer 2 and the shield plate 12 with the through-holes 5 in this way also shifts the resonance frequency of the loop to a higher frequency range than the unnecessary radiation suppression region. Resonance in this frequency range is suppressed, and unnecessary radiation in this frequency range is reduced. It should be noted that such a frequency shift can be 1 GHz or more, whereby the frequency of the unnecessary radiation can be set in a frequency band outside the regulation. Further, due to the generation of the radiation in the differential mode, a high-frequency current due to the standing wave is generated in a loop including the ground layer 2, the through hole 5, and the shield plate 12.
- the radiation of the differential mode is suppressed and the radiation of the newly generated common mode is suppressed.
- it can be effectively suppressed.
- the LSI element and the driving IC element generate a large amount of radiation particularly in the differential mode.
- Such a circuit element is shielded by providing a double connection region with a shield plate 12.
- the LSI element 8 and the IC element 9 are such elements, as shown in the electrode patterns 6f, 6j, and 6m, the operating frequency and the like around these LSI elements 8 and the IC element 9
- An electrode pattern electrically connected to the duland layer 2 is provided with a suitable pitch, and these electrode patterns are electrically connected to the shield plate 12 with solder. That is, the portions around the LSI element 8 and the IC element 9 on the shield plate 12 are connected to the ground layer 2 at multiple points, and are partially shielded by the shield plate 12.
- unnecessary radiation in the differential mode is confined by the current loop between the shield plate 12 and the ground layer 2 in the shield part, and is suppressed by the loss layer 14.
- the LSI element 8 and IC element 9 generate Differential mode radiation is shielded by the shield plate 12 and the ground layer 2 around them, and is also shielded around the multilayer circuit board 1 to provide double shielding. However, each of them absorbs radiation, and effectively suppresses common mode strong radiation generated from them.
- the interpolated signal line layer 4 is also directly connected to the power supply layer 3 and the ground layer 2 via mounted components, etc., especially when high-speed operation components operate.
- High-frequency current flows through the ground layer 2 and the power layer 3. Then, the high-frequency current also flows around the ground layer 2 and the power supply layer 3, and common mode radiation occurs due to these resonances.
- loss layers 2a and 3a are provided around the periphery of the multilayer circuit board I in the ground layer 2 and the power supply layer 3 so as to attenuate the high-frequency current due to such resonance. I have to.
- the range in which the loss layers 2a and 3a are provided is such that the loss and the signal line layer 4 in the power line layer 3 and the power line layer 3 do not hinder the operation of the components and circuits mounted on the multilayer circuit board 1. It is outside the connection point by through hole 5.
- the loss layers 2 a and 3 a can be the same as the loss layer 14 in the shield plate 12.
- Fig. 2 (a) shows the loss layer 2a in the ground layer 2. Since the roundabout layer 2 is provided on almost the entire cross section of the multilayer circuit board 1, the loss layer 2a is provided on the entire periphery thereof. Can be Fig. 2 (b) shows the power supply layer.
- the loss layer 3a shows a loss layer 3a, in which it is assumed that there are four power layers 3A, 3B, 3C, and 3D having different power voltages.
- the loss layer 3a is provided in a portion corresponding to the peripheral portion of the multilayer circuit board 1 in the power supply layer 3. Therefore, in the case of FIG. 2 (b), the power supply layers 3 A,
- 3B and 3C are provided with a loss layer 3a at a part of the periphery, No loss layer is provided on the power supply layer 3D arranged at the center of the circuit board 1.
- the radiation of the differential mode generated from the mounted components and the signal line layer can be suppressed very effectively.
- the shield plate 12 since the shield plate 12 is fixed to the multilayer circuit board 1 by the solder 7, by removing the solder 7, the shield plate 12 can be easily removed and the mounting parts can be removed. Exchange is easy. Therefore, if one of the mounted components fails, it can be easily replaced and the circuit board can be reused.
- a conductive adhesive for example, Ag (Cu, Au) powder is contained in a thermosetting resin
- the shield plates 12 are provided on both sides of the multilayer circuit board 1.However, when the arrangement is made such that there is a mounting component or a signal line layer which operates at high speed only on one side, the arrangement is made. It is clear that the shield plate 12 needs to be provided only on that surface.
- the multilayer circuit board i as the high-speed signal line serving as a radiation source is arranged in the periphery of the multilayer circuit board 1, the amount of differential mode radiation generated therefrom increases. Therefore, it is preferable to dispose the high-speed signal line in the center of the multilayer circuit board 1.
- FIG. 3 is a sectional view showing another embodiment of the low EMI circuit board according to the present invention, wherein 6 p, 6 q, 6 r are electrode patterns, 18 is a dielectric layer, 19 is a ground layer, Reference numeral 20 denotes a resistance element, and portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted, and reference numerals are partially omitted.
- the radiation of the common mode in addition to the suppression of the radiation of the difference mode, the radiation of the common mode can be newly suppressed. It is.
- another durand layer i 9 is provided between the power layer 3 and the signal line layer 4 on the side opposite to the ground layer 2 with respect to the power layer 3, and A dielectric layer 18 having a dielectric constant ⁇ r different from that of the dielectric layer 17 is provided between the power supply layer 3 and the power supply layer 3.
- C The dielectric layer 1 8, the power supply layer 3, forming a capacitor C to the cod-end layer 1-9 and the electrode are configured to present a sufficiently small Inpidansu against harmonics of the high-speed clock
- a resistance element 20 is connected between the electrode patterns 6p and 6q on one surface layer, and a resistance is formed between the electrode patterns 6m and 6r on the other surface layer. Element 20 is connected.
- These electrode patterns 6 p, 6 r are connected to one of the durand layers 2 via through holes 5, and the electrode patterns 6 q, 6 m are connected to the other durand layer 1 via the through holes 5. Connected to 9.
- the power supply layer 3 and the ground layer 19 are connected via the capacitor C composed of the dielectric layer 18, and the ground layer 19 is connected to the ground layer 2 via the resistance element 20. I have.
- a capacitor C ′ as an interlayer floating capacitance is interposed between the power supply layer 3 and the ground layer 2 by the dielectric layer 17. Since the Q of the capacitor C is high, the mounted components such as LSI elements, IC elements, chip capacitors, etc. have an impedance component of inductance in the harmonic region. In particular, these parallel resonances cause common-mode radiation.
- a series circuit composed of the capacitor C by the dielectric layer 18 and the resistive element 20 is connected in parallel with the capacitor C ′.
- the capacitor C is ignored and the resistance element 20 is connected in parallel with the capacitor C ′.
- the inductance component due to the through-hole 5 and the electrode patterns 6p and 6r generated during mounting is set so that the impedance can be ignored sufficiently compared to the resistance element 20.
- a low Q of the capacitor C ′ can be achieved. As a result, the energy consumption of the resistance element 20 becomes large, and the potential fluctuation in the power supply layer 3 is effectively absorbed by the resistance element 20, and the radiation in the common mode is reduced.
- the capacitor C is a DC cut capacitor, and is used to cut a DC voltage from the power supply layer 3 to the ground layer 19.
- the shield plates 12 on the upper and lower sides of the drawing are connected to the ground layers 2 and 19 by the through holes 5 and the electrode patterns 6 n and 6 q around the multilayer circuit board 1. Have been. Therefore, both surfaces of the substrate 1 are shielded by the shields 12, the ground layers 2, the ground layers 19 and the multiple through holes 5, and the signal line layer 4 disposed inside the shield structure is provided. It also suppresses the radiation of the difference mode due to the mounted components.
- FIG. 4 (a) is a longitudinal sectional view showing a first embodiment of the low EMI cable connector according to the present invention
- FIG. 4 (b) is a cross section taken along the line X--X 'in FIG. 4 (a).
- 2 1 is a base cylindrical portion
- 2 la is a female screw portion
- 2 lb is soldered
- 2 2 is bottomed cylinder
- 2 2a is short-circuited end
- 2 2b is dielectric
- 2 3 is bottomed cylinder
- 2 3a is short-circuited end
- 2 3b Is a dielectric part.
- a bottomed cylindrical portion 22 made of a conductor having a length of 11 is provided on an outer peripheral surface of a base cylindrical portion 21 made of a conductor, and a bottomed cylindrical portion made of a conductor having a length of 12 is further provided on the outer peripheral surface thereof.
- 2 3 strength ⁇ each is overlapped concentrically with each other.
- the bottomed circular cylinder 22 has a closed end at the short-circuit termination portion 22 a, thereby forming a short-circuit terminated line.
- the bottomed cylindrical part 23 is closed at the short-circuit terminating end part 23 a, thereby forming a short-circuit-terminated line.
- the bottomed cylindrical portion 22 is filled with a dielectric having a dielectric constant ⁇ ⁇ to form a dielectric portion 22b.
- the bottomed cylindrical portion 23 also has a dielectric constant The dielectric part 23 b is formed by filling the dielectric of ⁇ r2.
- a coaxial cable is fitted into the inner diameter of the base cylindrical portion 21.
- a female screw portion 21a to be screwed with a male screw portion formed on the outer peripheral surface of the coaxial cable (not shown) is formed.
- an Au plating or the like is applied to an end of the outer peripheral surface of the base cylindrical portion 21 1 opposite to the portion where the bottomed cylindrical portion 22 is provided to form a soldered portion 2 lb.
- FIG. 6 is a diagram showing a state in which the above-mentioned low-EMI cable connector is provided at the end of the coaxial cable 102 on the sending end device 100 side in FIG. 13; Are assigned the same reference numerals.
- the low-EMI cable connector is attached to the end of the coaxial cable 102 such that the open sides of the bottomed cylindrical portions 22 and 23 face the sending end device 100 side.
- this installation is performed by connecting the male screw (not shown) provided at the end of the coaxial cable 102 to the female screw provided at the base cylinder 21 of the low-EMI cable connector. This is done by screwing into the portion 21a, and the soldering portion 21b of the base cylindrical portion 21 is soldered to the case of the sending end device 100 or the like.
- the base cylindrical portion 21 is omitted.
- the current i 2a flowing through the inner surface of the outer conductor 102 b of the coaxial cable 102 toward the transmitting device 100 is At the connection point A between the conductor 10 2 b and the return line 100 b of the sending end device, Some of them leak and try to flow on the outer surface side of the outer conductor 102b.
- the leakage current i 3a can be reduced to almost 0 by the short-circuit termination line composed of the bottomed cylindrical portion 22.
- the leakage current i 4a and i 5a Since there is no resonance in the short-circuited termination line composed of the cylindrical portion 22, although there is a certain degree of attenuation, it passes through the short-circuited termination line composed of the bottomed cylindrical portion 22 with almost the same amplitude. 3 flows into the short-circuit termination line.
- the leakage current i 4a is suppressed by the short-circuited termination line composed of the bottomed cylindrical portion 23.
- the length 12 of the short-circuited termination line composed of the bottomed cylindrical portion 23 is set so that the short-circuited termination line composed of the bottomed cylindrical portion 23 resonates at the frequency of the leakage current i4a. I just need.
- the impedance ⁇ 02 of the short-circuited termination line composed of the bottomed cylindrical portion 23 has the characteristic shown by the broken line in FIG. 5, and the leakage current i 4a at the angular frequency of 2 ⁇ 0, 6 ⁇ , 10 ⁇ 0,. Can be suppressed to almost zero.
- the coaxial cable 102 causes resonance at the fundamental frequency f 0 and an odd multiple thereof, the frequency of the even multiple of the basic frequency f 0 is not a problem. Therefore, in this case, it is not necessary to provide the specially-closed cylindrical portion 23, but the reason for providing the bottomed cylindrical portion 23 will be described later.
- FIG. 7 shows an equivalent circuit of the above configuration, in which 24 is a short-circuited end line composed of a bottomed cylindrical portion 22 of the low EMI cable connector on the sending end device 100 side, and 2 4 ′ is This is a short-circuited terminal line consisting of the bottomed cylindrical part 22 of the low-EMI cable connector on the receiving end device 101, and the bottomed cylindrical part 23 of the low-EMI cable connector on the sending end device 100 side.
- 25 ' is a short-circuited termination line consisting of a bottomed cylindrical portion 23 of the low EMI cable connector on the receiving end device 101 side
- Za and Zb are external parts of the coaxial cable 102. This is the impedance of the conductor 102b.
- the bottomed cylindrical part 2 2, 2 3 There is no problem if the coaxial cable 102 oscillates and generates unnecessary radiation from the short-circuit termination line consisting of the external conductors 102b of the coaxial cable 102b. Outside the bottomed cylindrical portion 23, a short-circuit termination line by the bottomed cylindrical portion for suppressing the current i5a may be provided in the same manner.
- the short-circuit termination lines 24 'and 25' consisting of 22 and 23 are sufficiently suppressed.
- a dielectric material having a large dielectric constant ⁇ rl, sr2 is used as the dielectric material of the dielectric portions 22b, 23b in the bottomed cylindrical portions 22, 23. By doing so, the lengths 11, 12 of the bottomed cylindrical portions 22, 23 can be shortened.
- Strontium titanate-based and barium titanate-based dielectric materials have a dielectric constant of 300 to 100,000.
- the cable connector consisting of short short-circuited termination lines of less than 2 cm makes it possible to reduce the frequency compared to 100 ⁇ when using a conventional ferrite core.
- An extremely high impedance can be obtained, and unnecessary radiation from the coaxial cable 102 can be almost completely suppressed.
- the thickness of the bottomed cylindrical portions 22 and 23 can be such that the short-circuited termination line formed thereby has an infinite impedance at a predetermined frequency, and the matching termination resistance can be set to a specific value. Since it is not required, it can be arbitrarily thinned. Therefore, this embodiment is compact and lightweight, is not bulky, and has a coaxial cable. Generation of unnecessary radiation from the bull 102 can be suppressed sufficiently effectively.
- the bottomed cylindrical portions 22 and 23 may be formed integrally with the base cylindrical portion 21.
- the bottomed cylindrical portions 22 and 23 are respectively electrically inductive. It is a separate cylindrical part having a body part 2 2b, 22 3 b, and a female screw is provided on the inner surface of the bottomed cylindrical part 22, 23, and the outer circumference of the base cylindrical part 21 and the bottomed cylindrical part 22 A male screw is provided on the surface, and by screwing such a screw, the bottomed cylindrical portion 22 is attached to the base cylindrical portion 21, and the bottomed cylindrical portion 23 is attached to the bottomed cylindrical portion 22. You may do so. In this case, the positional relationship of the bottomed cylindrical portion 22 with respect to the base cylindrical portion 21 and the positional relationship of the bottomed cylindrical portion 23 with respect to the bottomed cylindrical portion 22 can be appropriately adjusted.
- the low EMI cable connector can be attached to the coaxial cable 102 with screws, a low EMI cable connector that suppresses different frequencies is provided, and the length of the coaxial cable (accordingly, Depending on the resonance frequency), a desired low EMI cable connector can be appropriately selected and used.
- the coaxial cable 102 is screwed and attached to the base cylindrical portion 2 i by the female screw portion 21 a (this makes it possible to replace the cable, etc.).
- the base cylindrical portion 21 and the coaxial cable 102 may be integrally fixed.
- the dielectric portions 22b and 23b of the bottomed cylindrical portions 22 and 23 are made of a dielectric material having the same dielectric constant. Of course, they have different dielectric constants. A body material may be used. In this case, for example, the dielectric material of the dielectric portion 23 of the bottomed cylindrical portion 23 has a smaller dielectric constant than the dielectric material of the dielectric portion 22 of the bottomed cylindrical portion 22. By using, it is also possible to make the lengths of the bottomed cylindrical parts 2 2 and 23 almost equal. You.
- FIG. 8 is a diagram of FIG. 13 in which the end of the coaxial cable 102 on the side of the receiving device 101 (ie, the low EMI circuit board described in FIGS. 1 to 3) is shown in FIG. It is a figure showing the state where provided the low EMI cable connector shown, and the same reference numerals are given to parts corresponding to the above-mentioned drawings.
- the coaxial cable 102 with the low EMI cable connector attached to the end as described above is connected to the input / output terminals of the low EMI circuit board.
- the inner conductor 102 a of the coaxial cable 102 is electrically connected to the electrode pattern 6 provided on the signal line layer 4 of the low EMI circuit board with solder 7.
- the outer conductor 102b of No. 02 has its tip expanded, and is electrically connected to the ground layer 2 of the low EMI circuit board by the solder 7.
- the entire end of the outer conductor 102b is not soldered, but is generally joined at, for example, four points, and it is very difficult to completely seal the outer conductor.
- the signal current i lb flowing through the inner conductor 102 a of the coaxial cable 102 flows into the signal line layer 4 of the low EMI circuit board via the electrode pattern 6, and
- the return current i 2b flowing on the inner surface of the outer conductor 102 b of the coaxial cable 102 flows through the inner surface of the outer conductor 102 b, but the outer conductor 102 b is soldered at, for example, four points and is not completely sealed.
- the length of the bottomed cylindrical sections 22, 23 in the low EMI cable connector is By appropriately setting and using a dielectric material having an appropriate dielectric constant for these bottomed cylindrical portions 22 and 23, the leakage current i 3b at the frequency that causes unnecessary radiation in the coaxial cable 102 is almost zero. Can be suppressed.
- the current flowing from the low EMI circuit board into the coaxial cable 102 is not limited to the current flowing through the inner surface of the ground layer 2 and the current flowing through the outer surface of the ground layer 2 provided on the substrate surface.
- the low-EM cable connector has a two-stage configuration having two bottomed cylindrical portions 22 and 23.
- Coaxial cable 102 It is the fundamental wave with a fundamental frequency ⁇ 0 and its odd harmonics (2 ⁇ 1) ⁇ ⁇ 0 that generate unnecessary radiation when it resonates. Therefore, as shown by the solid line in FIG. 5, the impedance of the low-frequency I cable connector with respect to the basic frequency ⁇ ⁇ and its odd multiple of 3 ⁇ ⁇ , 5 ⁇ ⁇ ,. Must be infinite.
- a single-stage configuration having only the bottomed cylindrical portion 22 in FIGS. 4 to 8 is sufficient as the low-profile I-cable connector.
- a ground wire is provided at an appropriate location on the outer conductor 102b of the coaxial cable 102, or the outer conductor 102b is connected to the ground line by contact with the ground.
- the coaxial cable 102 is not limited to the coaxial cable 102 itself, but also to the connection of the coaxial cable 102 to the ground wire.
- the line consisting of one city and this ground line Resonance may occur at a frequency 2 ⁇ that is twice the number ⁇ , generating unnecessary radiation. In such a case, as shown in FIGS.
- the bottomed cylindrical portion 23 where the impedance ⁇ 02 becomes infinite at this frequency 2 ⁇ ⁇ outside the bottomed cylindrical portion 22 By providing the short-circuit termination line, it is possible to suppress the generation of unnecessary radiation due to the resonance at the frequency 2 ⁇ 0.
- a single low-power I-cable connector can be used to enclose them together to simultaneously suppress currents that cause unnecessary radiation in these coaxial cables. It can also be used. Also in this case, there is a coaxial cable that resonates at the fundamental frequency ⁇ and an odd multiple of the fundamental frequency ⁇ due to the difference in the length of each coaxial cable, and an even multiple of the fundamental frequency ⁇ . Some may resonate at frequencies. Even in such a case, the low ⁇ Ml cable connector has a two-stage configuration as shown in Fig. 4 to Fig. 8, so that unnecessary radiation as a whole can be prevented. it can.
- FIG. 9 is a longitudinal sectional view showing a second embodiment of the low EMI cable connector according to the present invention, wherein 2 2 ′ is a cylindrical portion, 22 c is a matching terminating resistor, and a portion corresponding to the above-mentioned drawing. Have the same reference numerals.
- a matching termination resistor 22c is provided at the back of a cylindrical portion 2 2 ′ having no bottom. This is the same as the embodiment described with reference to FIGS.
- the length of the cylindrical portion 2 2 c is not important, and by providing a matching terminating resistor 22 c to the line in the line provided with the dielectric portion 22 b in the cylindrical portion 22 ′, Leakage current flowing through this line is not reflected This leakage current is suppressed by flowing through the end resistance 22c and converting it into thermal energy by the matching termination resistance 22c.
- the gap Of the coaxial cable 102 may flow to the outer surface of the outer conductor 102b of the coaxial cable 102.
- matching short-circuit terminations are provided at the short-circuit terminations 2 2 a and 23 a to match the lines formed by the bottomed cylindrical portions 22 and 23, and the current that attempts to leak from the gaps is used for this matching. It can also be made to consume heat by a terminating resistor.
- FIG. 10 is a longitudinal sectional view showing a third embodiment of the low EMI cable connector according to the present invention, in which 22 a ′ is a short-circuit plate, and portions corresponding to the above-mentioned drawings have the same reference numerals. Is attached.
- a lid-shaped short-circuiting plate 22a ' can be detached from a cylindrical portion 22' with a screw or the like.
- this short-circuiting plate 22a ' is attached to the cylindrical member 22', it is the same as the first embodiment shown in FIG. Resonates at odd multiples of that frequency, and the impedance Z 01 becomes infinite at these frequencies.
- the impedance ⁇ 0 ⁇ becomes infinite at the frequency that satisfies.
- This wavelength 01 ' is 1 2 of the above wavelength 01. Therefore, when the short-circuit plate 22a 'is removed, the resonance frequency is twice the resonance frequency when the short-circuit plate 22a' is attached.
- the present invention can be applied to two types of cables having different clock frequencies. Therefore, for example, the same low EMI cable connector can be used for a cable having a mouth frequency of 100 MHz and a cable having a mouth frequency of 200 MHz.
- a two-stage structure can be used, and the short-circuit plate can be detachably attached to each.
- FIG. 11 is a longitudinal sectional view showing a fourth embodiment of a low EMI cable connector according to the present invention, in which 23 ′ is a bottomed cylindrical portion, 23b ′ is a dielectric portion, and 26 is a central axis.
- 23 ′ is a bottomed cylindrical portion
- 23b ′ is a dielectric portion
- 26 is a central axis.
- the same reference numerals are given to portions corresponding to the above-mentioned drawings.
- the base cylindrical portion 21 when a plurality of bottomed cylindrical portions are provided, they are arranged coaxially on the base cylindrical portion 21. ', In the fourth embodiment, as shown in FIG. It is arranged on the base cylindrical portion 21 along the central axis 26 thereof.
- the bottomed cylindrical portion 22 resonates at an odd multiple of the frequency including the basic frequency fO, and the impedance Z01 is almost infinite at the resonance frequency.
- the bottomed cylindrical portion 2 3 ′ resonates at a frequency twice as high as the resonance frequency of the bottomed cylindrical portion 22, and at this resonance frequency, the impedance Z 02 is almost equal to the resonance frequency. It is infinite.
- the bottomed cylindrical portion 22 with a built-in dielectric portion 22b has a frequency fA.
- the low-EMI cable connector shown in FIG. 4 cannot suppress such leakage current i B.
- the leakage current i B flows into the next bottomed cylindrical portion 23 ′, and the current at the frequency f B can be suppressed to almost zero.
- FIG. 12 is a longitudinal sectional view showing a fifth embodiment of a low EMI cable connector according to the present invention, wherein 22 ′ and 23 ′′ are bottomed cylindrical portions, and 22b ′ and 23b ′′ are The dielectric portion, 26, is a central axis, and portions corresponding to the above-mentioned drawings are denoted by the same reference numerals.
- cylindrical portions 2 2 ′ and 2 3 ′′ having no short-circuit termination portion are arranged in a base cylindrical portion 21 along a central axis 26 thereof.
- the low EMI circuit board of the present invention by forming a high-loss shield structure on the low EI circuit board, the suppression (elimination) of differential mode radiation (radiation) and the simultaneous generation of high frequency The suppression and elimination of common mode radiation due to the resonance current can be effectively realized.
- the current generated by the cable from the unnecessary radiation can be suppressed more effectively than the conventional one using a flat core with a small, lightweight and simple configuration.
- the industrial use effect is extremely large.
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Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
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US09/202,926 US6188297B1 (en) | 1996-07-10 | 1997-07-09 | Low-EMI circuit board and low-EMI cable connector |
EP97930733A EP0914032A4 (en) | 1996-07-10 | 1997-07-09 | EMC-CORRECT PCB AND EMC-CORRECT CABLE CONNECTOR |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8180863A JPH1027987A (ja) | 1996-07-10 | 1996-07-10 | 低emi回路基板及び低emiケーブルコネクタ |
JP8/180863 | 1996-07-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998002025A1 true WO1998002025A1 (fr) | 1998-01-15 |
Family
ID=16090680
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/JP1997/002376 WO1998002025A1 (fr) | 1996-07-10 | 1997-07-09 | Carte a circuit a basse emissivite et connecteur de cable a basse emissivite |
Country Status (4)
Country | Link |
---|---|
US (1) | US6188297B1 (ja) |
EP (1) | EP0914032A4 (ja) |
JP (1) | JPH1027987A (ja) |
WO (1) | WO1998002025A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0961321A2 (en) * | 1998-05-29 | 1999-12-01 | Kyocera Corporation | High-frequency module |
Families Citing this family (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6768654B2 (en) * | 2000-09-18 | 2004-07-27 | Wavezero, Inc. | Multi-layered structures and methods for manufacturing the multi-layered structures |
JP2002252506A (ja) | 2000-12-22 | 2002-09-06 | Canon Inc | ケーブル接続構造及び該ケーブル接続構造を有する電子機器 |
US6900383B2 (en) * | 2001-03-19 | 2005-05-31 | Hewlett-Packard Development Company, L.P. | Board-level EMI shield that adheres to and conforms with printed circuit board component and board surfaces |
DE10228981A1 (de) * | 2002-06-28 | 2004-01-15 | Automotive Lighting Reutlingen Gmbh | Vorrichtung zur elektromagnetischen Abschirmung |
US7200010B2 (en) * | 2002-12-06 | 2007-04-03 | Thin Film Technology Corp. | Impedance qualization module |
US6965072B2 (en) | 2003-02-07 | 2005-11-15 | Nokia Corporation | Shielding arrangement |
JP2005086603A (ja) * | 2003-09-10 | 2005-03-31 | Tdk Corp | 電子部品モジュールおよびその製造方法 |
US7354232B1 (en) * | 2003-12-16 | 2008-04-08 | Yeaple Corporation | Individual bookbinding device, system, and associated methods |
JP4049112B2 (ja) * | 2004-03-09 | 2008-02-20 | 株式会社日立製作所 | 電子装置 |
JP4347172B2 (ja) * | 2004-09-14 | 2009-10-21 | 富士通株式会社 | プリント基板ユニットおよび電子機器 |
US7216406B2 (en) * | 2004-09-29 | 2007-05-15 | Intel Corporation | Method forming split thin film capacitors with multiple voltages |
DE102004049485B3 (de) * | 2004-10-11 | 2005-12-01 | Siemens Ag | Elektrische Schaltung mit einer Mehrlagen-Leiterplatte |
DE102006024551A1 (de) * | 2006-05-23 | 2007-11-29 | Siemens Ag | Elektrische Einrichtung mit Abschirmung |
TWI299646B (en) * | 2006-06-06 | 2008-08-01 | Via Tech Inc | A circuit board and manufacturing method thereof |
JP5332164B2 (ja) * | 2006-10-13 | 2013-11-06 | 東レ株式会社 | 電子機器からのノイズの抑制方法 |
IL187101A0 (en) * | 2006-11-20 | 2008-02-09 | Itt Mfg Enterprises Inc | Filter connector with high frequency shield |
US7977583B2 (en) * | 2007-12-13 | 2011-07-12 | Teradyne, Inc. | Shielded cable interface module and method of fabrication |
JP4911321B2 (ja) * | 2008-02-05 | 2012-04-04 | 株式会社村田製作所 | 電磁遮蔽シート及び電磁遮蔽方法 |
US20090283318A1 (en) * | 2008-05-13 | 2009-11-19 | Honeywell International Inc. | Integrated EMI Shield Termination and Cable Support Apparatus |
JP5211948B2 (ja) * | 2008-09-04 | 2013-06-12 | ソニー株式会社 | 集積装置および電子機器 |
US8242375B2 (en) * | 2008-09-18 | 2012-08-14 | United Technologies Corporation | Conductive emissions protection |
JPWO2010053114A1 (ja) * | 2008-11-05 | 2012-04-05 | 日立マクセルエナジー株式会社 | 回路素子 |
EP2237419B1 (en) * | 2009-03-31 | 2015-06-10 | EqcoLogic N.V. | Transceiver for single ended communication with low EMI |
JP6116356B2 (ja) * | 2013-05-15 | 2017-04-19 | 矢崎総業株式会社 | ノイズカット部材 |
US9833235B2 (en) * | 2013-08-16 | 2017-12-05 | Covidien Lp | Chip assembly for reusable surgical instruments |
JP2017212379A (ja) * | 2016-05-26 | 2017-11-30 | 株式会社ジェイテクト | 半導体装置 |
FR3089539B1 (fr) * | 2018-12-10 | 2021-04-09 | Continental Automotive France | Poignée de portière avec des moyens de réduction d’un rayonnement en communication ultra haute fréquence |
KR20220026660A (ko) | 2020-08-25 | 2022-03-07 | 삼성전자주식회사 | 반도체 패키지 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6230400U (ja) * | 1985-08-07 | 1987-02-24 | ||
JPH0137000B2 (ja) * | 1983-03-31 | 1989-08-03 | Tokyo Shibaura Electric Co | |
JPH0246076Y2 (ja) * | 1983-08-15 | 1990-12-05 | ||
JPH0744049B2 (ja) * | 1992-12-09 | 1995-05-15 | 日本電気株式会社 | 通信用シールドケーブル |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3784950A (en) * | 1972-10-26 | 1974-01-08 | R Coffman | Coaxial connector with integral switched terminating resistor |
US4399419A (en) * | 1980-03-20 | 1983-08-16 | Zenith Radio Corporation | Line isolation and interference shielding for a shielded conductor system |
JPS62265796A (ja) | 1986-05-14 | 1987-11-18 | 株式会社住友金属セラミックス | セラミツク多層配線基板およびその製造法 |
DE4142093A1 (de) | 1991-12-19 | 1993-06-24 | Siemens Ag | Kompaktes funkgeraet, insbesondere handfunkgeraet, mit versenkbarer oder umklappbarer antenne |
JP2948039B2 (ja) | 1992-12-28 | 1999-09-13 | 株式会社日立製作所 | 回路基板 |
JPH08330808A (ja) * | 1995-05-29 | 1996-12-13 | Ngk Spark Plug Co Ltd | 誘電体フィルタ |
-
1996
- 1996-07-10 JP JP8180863A patent/JPH1027987A/ja active Pending
-
1997
- 1997-07-09 EP EP97930733A patent/EP0914032A4/en not_active Withdrawn
- 1997-07-09 US US09/202,926 patent/US6188297B1/en not_active Expired - Fee Related
- 1997-07-09 WO PCT/JP1997/002376 patent/WO1998002025A1/ja not_active Application Discontinuation
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0137000B2 (ja) * | 1983-03-31 | 1989-08-03 | Tokyo Shibaura Electric Co | |
JPH0246076Y2 (ja) * | 1983-08-15 | 1990-12-05 | ||
JPS6230400U (ja) * | 1985-08-07 | 1987-02-24 | ||
JPH0744049B2 (ja) * | 1992-12-09 | 1995-05-15 | 日本電気株式会社 | 通信用シールドケーブル |
Non-Patent Citations (1)
Title |
---|
See also references of EP0914032A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0961321A2 (en) * | 1998-05-29 | 1999-12-01 | Kyocera Corporation | High-frequency module |
EP0961321A3 (en) * | 1998-05-29 | 2000-05-17 | Kyocera Corporation | High-frequency module |
US6356173B1 (en) | 1998-05-29 | 2002-03-12 | Kyocera Corporation | High-frequency module coupled via aperture in a ground plane |
Also Published As
Publication number | Publication date |
---|---|
JPH1027987A (ja) | 1998-01-27 |
US6188297B1 (en) | 2001-02-13 |
EP0914032A1 (en) | 1999-05-06 |
EP0914032A4 (en) | 2000-04-12 |
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