WO2010047149A1

WO2010047149A1 - Noise evaluation device

Info

Publication number: WO2010047149A1
Application number: PCT/JP2009/060535
Authority: WO
Inventors: 明博難波; 卓須賀; 敦原; 辰次野間
Original assignee: 株式会社日立製作所
Priority date: 2008-10-24
Filing date: 2009-06-09
Publication date: 2010-04-29
Also published as: JP2010101760A; JP5433202B2

Abstract

Disclosed is a noise evaluation device for the purpose of measuring electrical noise emanating from a device module that is operated by the supply of electrical energy. The noise evaluation device has a module that is operated by the supply of electrical energy, and a noise detection unit that has connection terminals for the purpose of making electrical connections between grounds providing a reference potential, and that detects electrical noise flowing to the grounds through the connection terminals. In addition, the distribution of the noise emanating from the module is measured by arranging the connection terminals and the noise detection unit as an array.

Description

Noise evaluation device

Import by reference

This application claims the priority of Japanese Patent Application No. 2008-273720 filed on Oct. 24, 2008, and is incorporated into the present application by referring to its contents.

The present invention relates to a device for measuring electrical noise generated from a device module that operates by supplying electric energy.

Electromagnetic unnecessary radiation generated from electronic equipment such as information processing equipment and digital AV equipment is a problem. In order to suppress this radiation, it is necessary to suppress the electrical noise of the electronic device that is the radiation source. For this reason, the noise source is often identified by noise source search. As a noise source exploration method, for example, as described in JP-A-11-83918 and JP-A-2004-198232, an electromagnetic field distribution in the vicinity of an electronic circuit board or a cable connecting two or more boards is used. There is a method of measuring with an electromagnetic field sensor.

Further, as a method for measuring electromagnetic radiation from a housing on which a board is mounted, for example, as shown in Japanese Patent Application Laid-Open No. 11-190754, there is a method of measuring radiation current from a closed box containing a board to the ground. . Further, as a method for measuring a propagation path of noise flowing out from the substrate to the housing, there is a joint noise measurement method as disclosed in, for example, Japanese Patent Laid-Open No. 2007-240162.

Japanese Patent Laid-Open No. 11-83918 JP 2004-198232 A JP-A-11-190752 JP 2007-240162 A

However, the measurement methods described in Japanese Patent Application Laid-Open Nos. 11-83918 and 2004-198232 can measure the noise source on the object, but the substrate is not disposed when the substrate is installed in the casing. There is a problem that it is impossible to measure the noise propagation path that propagates from the housing to the housing. In order to suppress unwanted radiation, it is necessary not only to suppress the noise source but also to cut the noise propagation path, and a technique for measuring the noise propagation path is required. In addition, with the measurement method described in Japanese Patent Application Laid-Open No. 11-190752, the electromagnetic radiation of the electrical equipment that houses the substrate can be evaluated, but similarly, the noise propagation path between the substrate and the housing cannot be measured.

The measurement method described in Japanese Patent Application Laid-Open No. 2007-240162 is effective for measuring noise propagated to a joint component such as a screw connecting a housing and a substrate, but noise due to a path other than the joint component cannot be evaluated. Is not enough.

The present invention provides a noise evaluation apparatus that solves the above-described problems. That is, the present invention provides a noise evaluation apparatus that can measure a noise propagation path regardless of the position of a joining component in order to evaluate noise flowing out from a device module that is a noise source to a housing. .

The noise evaluation apparatus according to the present invention has a contact terminal for electrically connecting a module that operates by supplying electric energy and a ground that provides a potential reference. Furthermore, a noise detection unit for measuring electrical noise flowing in the contact terminal is provided. The types of electrical noise include noise current flowing through the contact terminals and noise voltage between the module under measurement and the reference ground.

Furthermore, a plurality of contact terminals and noise detection units are provided as a set, and the noise distribution flowing out from the module is measured by arranging them in an array. Further, the noise distribution is measured by making the contact terminal and the noise detection terminal movable.

The following is a brief description of the outline of typical inventions disclosed in the present application.
(1) A noise evaluation apparatus for measuring electrical noise generated from an apparatus module, which is electrically connected to a ground for providing a potential reference, and is connected to an arbitrary point of the apparatus module. A noise evaluation apparatus comprising: a contact terminal configured to take a noise; and a noise detection unit that measures noise flowing out from the apparatus module to the ground.
(2) The noise evaluation device according to (1), wherein the noise detection unit measures a noise current flowing from the device module to the ground via the contact terminal. .
(3) The noise evaluation device according to (1), wherein the noise detection unit measures a noise voltage between the device module and the ground.
(4) The noise evaluation apparatus according to (1), wherein the ground, the contact terminal, and the noise detection unit are integrally formed of a multilayer printed board.

It is possible to provide an evaluation apparatus capable of measuring the propagation path of electrical noise flowing out from a module that causes electromagnetic radiation.
Other objects, features and advantages of the present invention will become apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is a figure which shows 1st embodiment of the noise evaluation apparatus which concerns on this invention. It is a figure which shows 2nd embodiment of the noise evaluation apparatus which concerns on this invention. It is a figure which shows the example of arrangement | positioning of the contact terminal with a detection part of the noise evaluation apparatus which concerns on this invention. It is a figure at the time of mounting a to-be-measured module on the contact terminal arrange | positioned at array form. It is a figure which shows the 1st form of the noise detection part of the noise evaluation apparatus which concerns on this invention. It is a figure explaining the noise current detection principle by a current detection coil. It is a figure at the time of arrange | positioning a multiple coil as an electric current detection coil. It is a figure which shows the 2nd form of the noise detection part of the noise evaluation apparatus which concerns on this invention. It is a figure which shows the 3rd form of the noise detection part of the noise evaluation apparatus which concerns on this invention. It is a figure which shows the 4th form of the noise detection part of the noise evaluation apparatus which concerns on this invention. It is a figure which shows the 5th form of the noise detection part of the noise evaluation apparatus which concerns on this invention. It is a figure which shows the 1st display example of a noise measurement result. It is a figure which shows the 2nd example of a display of a noise measurement result. It is a figure which shows the 2nd example of a display of a noise measurement result. It is a figure which shows the 1st mounting form of the to-be-measured module in the noise evaluation apparatus which concerns on this invention. It is a figure which shows the 2nd mounting form of the to-be-measured module in the noise evaluation apparatus which concerns on this invention. It is a figure which shows the 3rd mounting form of the to-be-measured module in the noise evaluation apparatus which concerns on this invention.

As shown in FIG. 1, the first embodiment of the noise evaluation apparatus according to the present invention is arranged on a reference ground 3 and one or a plurality (see FIG. In the example, two contact terminals 2 (2a, 2b) and a noise detection unit 1 (1a, 1b) that measures noise flowing in each of the contact terminals 2 (2a, 2b) are appropriately provided. Is done. Here, there may be one or more contact terminals 5 with a detection unit composed of the contact terminals 2 and the noise detection unit 1 (two in the example of FIG. 1: 5a, 5b).

Each contact terminal 2 is electrically connected between the module to be measured 4 and the reference ground 3, and noise flowing out from the module to be measured 4 to the reference ground 3 through the contact terminal 2 is detected by the noise detector 1. The noise detected by the noise detector 1 is measured by the measuring instrument 10. In the case of a noise evaluation apparatus using a plurality of noise detectors 1, a switch 9 is provided, and the switch 9 can select any noise detected by the noise detector 1 and input it to the measuring device 10. According to this method, it is not necessary to provide the same number of measuring devices 10 as the number of noise detection units 1, and it is sufficient to provide fewer measuring devices 10 than the number of noise detection units 1 or a single measuring device 10.・ Cost reduction can be achieved.
In addition, not only this system but the structure which provides the measuring device 10 of the same number with respect to the number of the noise detection parts 1 without using the switch 9 like 2nd embodiment shown in FIG. For example, in the example of FIG. 2, there are two noise detection units 1 (1a, 1b), and the measuring devices 10 (10a, 10b) are provided corresponding to each. According to this method, since a plurality of measuring instruments 10 can be processed in parallel, the measurement process can be speeded up. Further, the contact terminal 2 may be movable by adding a configuration having a spring property or the like in order to make the connection with the target module 4 more reliable.

The control unit 6 controls the measuring instrument 10 and transfers noise measurement control and measured data to the arithmetic processing unit 7. Moreover, the control part 6 also controls the switch 9, when the switch 9 is provided. The arithmetic processing unit 7 corrects the measured data using the sensitivity characteristic of the noise detection unit 1. Moreover, the noise evaluation apparatus of the present invention is provided with a display unit 8 and displays a noise measurement result and a measurement set value.

According to the noise evaluation apparatus according to the present invention, since the noise can be detected by bringing the contact terminal 5 with the detection unit into contact with an arbitrary position of the module 4 to be measured, the display unit 8 displays an arbitrary detection result. The noise spectrum at a point (FIG. 12) and the noise distribution at an arbitrary frequency (FIG. 13) can be displayed to the user. The horizontal axis of the noise spectrum shown in FIG. 12 indicates frequency, and the vertical axis indicates noise intensity. The horizontal and vertical axes of the noise distribution shown in FIG. 13 are the coordinates of the noise evaluation position, and the intensity of the color indicates the noise intensity. As described above, according to the present apparatus, it is possible to specify the frequency of noise to be countermeasured and the position to be a noise propagation path, and therefore, noise evaluation effective for countermeasures against electromagnetic radiation can be performed. For example, the noise distribution shown in FIG. 13 can be obtained in more detail as the number of the contact terminals 5 with the detection unit is increased, and the arithmetic processing unit 7 can obtain the noise distribution based on the obtained noise distribution. By ranking the strength, etc., it is possible to specify the position to be taken.

Next, an arrangement example of the contact terminal 5 with a detection unit of the noise evaluation apparatus according to the present invention will be described. FIG. 3 shows an example in which a plurality of contact terminals 5 with detecting portions are arranged in an array on the reference ground 3. According to this arrangement example, since the noise can be detected by bringing the contact terminal 5 with the detection unit into contact with the entire surface of the module 4 to be measured, the noise propagation path can be specified more accurately. However, the arrangement of the contact terminals 5 with the detection unit is not limited to this, and may be a lattice shape or a staggered shape, and the arrangement interval may be regular or irregular.

As shown in FIG. 4, the module to be measured 4 is placed in contact with the plurality of contact terminals 5 with detection units arranged in this manner, and the noise distribution flowing out from the module to be measured 4 to the reference ground 3 is measured. . In addition, in order to ensure the contact between the contact terminal 5 with the detection unit and the module to be measured, the contact terminal with the detection unit uses a contact terminal having a structure that can be expanded and contracted and that generates a force in the extending direction. May be. Moreover, you may measure the noise distribution which flows out from the to-be-measured module 4 by moving the contact terminal 5 with a detection part.

Next, an embodiment of the noise detection unit 1 and the contact terminal 2 of the noise evaluation apparatus according to the present invention will be described with reference to FIGS.
FIG. 5 shows an example in which the current detection coil 11 is used as a noise detection unit. A magnetic field generated by a noise current flowing out from the measured module 4 toward the reference ground 3 via the contact terminal 2 is detected by interlinking with the current detection coil 11. As shown in FIG. 6, according to the law of electromagnetic induction, the current detection coil 11 generates an induced electromotive force proportional to the noise current intensity. By detecting this induced electromotive force with a voltmeter or the like, the noise current flowing out from the module under measurement 4 is measured. The current detection coil is not limited to this, and a multiple coil as shown in FIG. 7 may be used in order to supplement the magnetic flux due to the noise current.

FIG. 8 shows an example in which the voltage detection probe 12 is used as a noise detection unit. In this embodiment, the voltage detection element 13 is embedded in the contact terminal 2 and the voltage across the voltage detection element 13 is detected by the voltage detection probe 12, whereby the noise voltage flowing out from the module under measurement 4 can be measured. As the voltage detection element 13, a passive element such as a resistor, a capacitor, and an inductor may be used.

As another form, a noise detection unit using an active element may be used. For example, as in the configuration shown in FIG. 9, a noise detection unit 1 for detecting the potential between the module under measurement 4 and the reference ground 3 may be provided. FIG. 9 shows the noise detection unit 1 including a transistor 15 having one end connected to the bias voltage source 17 and an adjustment element 16 connecting the transistor and the ground. The noise detector 1 detects a voltage corresponding to the potential difference between the module under measurement 4 and the reference ground 3. In addition, a noise current detection circuit using an active element or a noise voltage detection circuit may be appropriately configured.

FIG. 10 shows an example in which a noise detection unit, a reference ground, and a contact terminal are integrally formed by a multilayer printed board. In the present embodiment, the current flowing through the contact terminal 2 can be obtained by forming the current detection coil 11 formed in the inner layer of the multilayer printed board in the periphery of the contact terminal 2 formed by the via inside the multilayer printed board. It can be measured by the current detection coil 11. Here, the via is connected to the ground layer which is the reference ground, and is connected to the target module 4 on the surface layer. The induced voltage generated in the current detection coil 11 due to the noise current flowing in the via is guided to the connector installed in the wiring layer via the lead-out wiring of the transmission line structure formed in the wiring layer, and via the high-frequency cable or the like. Detect with measuring instrument. In order to ensure the connection between the via and the target module 4, a contact terminal having a spring property may be provided on the surface layer.
According to this embodiment, since the noise detection unit has a structure integrated with the contact terminal 2, it is difficult to dispose a voltage detection probe or the like on the contact surface between the plurality of contact terminals and the module to be measured 4. It is possible to easily detect noise at a contact location near the center of the surface.

FIG. 11 shows a noise detector that provides a coupling pad 14 in the vicinity of the module to be measured 4 and performs noise measurement by capacitive coupling between the module to be measured 4 and the coupling pad 14. Noise flowing out from the module under measurement 4 flows to the reference ground 3 by capacitive coupling, and the noise can be detected by the noise detector 1. In the case of this embodiment, unlike the other embodiments, the module to be measured is not configured to be electrically connected to the contact terminal, so that problems such as wear of the contact terminal 2 do not occur, and the life of the noise evaluation device can be extended. .

Next, the mounting form of the module to be measured to be mounted on the device casing of the noise evaluation apparatus described so far will be described with reference to FIGS.
FIG. 14 shows a form in which the module to be measured 4 is mounted on the bottom surface of the apparatus housing 31. In the present embodiment, the noise outflow path from the module under measurement 4 to the device housing 31 is the bottom surface of the module under measurement where the module under measurement 4 and the device housing 31 are in contact. 5 is arranged appropriately. Thereby, as shown to FIG. 13A and 13B, the noise which flows out from the module in a module mounting form can be measured.

FIG. 15 shows a module mounting form in which the both side surfaces of the module under measurement 4 and the device casing 31 are in contact with each other. In this case, since the noise outflow path from the module under measurement 4 to the apparatus housing 31 is on both sides of the module under measurement where the module under measurement and the apparatus housing are in contact, the contact terminal 5 with a noise detector is provided on the contact surface 21. Deploy. Thereby, noise flowing out from the module in the module mounting form shown in FIG. 14 can be measured.

FIG. 16 shows a form in which the module under measurement 4 is mounted on the apparatus casing 21 using a stay 32 attached to the side surface of the apparatus casing 31. In this case, the noise outflow path from the module under measurement 4 to the device housing 31 is a place where the module under measurement 4 and the stay 32 are in contact with each other, so the contact terminal 5 with a noise detector is disposed on the contact surface 21. Thereby, noise flowing out from the module in the module mounting form shown in FIG. 15 can be measured.
What is necessary is just to select the above-mentioned mounting form suitably according to the kind of module 4 to be measured. The embodiment is not limited to this, and it is only necessary to arrange the contact terminal 5 with the noise detection unit on the contact surface 21 between the module under measurement 4 and the apparatus housing 31.

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. Not too long. The configurations shown in the embodiments can be replaced and combined without departing from the scope of the invention. For example, the configuration in which the contact terminal 2 is movable is applicable to any embodiment. Moreover, you may comprise one noise evaluation apparatus combining the thing of each different embodiment as the some noise detection part 1. FIG.

Although the above description has been made with reference to embodiments, the present invention is not limited thereto, and it will be apparent to those skilled in the art that various changes and modifications can be made within the spirit of the present invention and the scope of the appended claims.

DESCRIPTION OF SYMBOLS 1 Noise detection part 2 Contact terminal 3 Reference ground 4 Module to be measured 5 Contact terminal with a detection part 6 Control part 7 Arithmetic processing part 8 Display part 9 Switch 10 Measuring instrument 11 Current detection coil 12 Voltage detection probe 13 Voltage detection element 14 Coupling Pad 21 Contact surface 31 Device housing 32 Stay

Claims

A noise evaluation device for measuring electrical noise generated from a device module,
A ground that provides a potential reference;
A contact terminal electrically connected to the ground and in electrical contact with any point of the device module;
A noise detector for measuring noise flowing out from the device module to the ground;
A noise evaluation apparatus.
The noise evaluation device according to claim 1,
The noise detection unit is a noise evaluation device that measures a noise current flowing from the device module to the ground via the contact terminal.
The noise evaluation device according to claim 2,
The noise evaluation device, wherein the noise detection unit is a current detection coil disposed in the vicinity of the contact terminal.
The noise evaluation device according to claim 3,
The current evaluation coil which comprises the said noise detection part is a noise evaluation apparatus which is a multiple coil.
The noise evaluation device according to claim 1,
The noise detection unit is a noise evaluation device that measures a noise voltage between the device module and the ground.
The noise evaluation device according to claim 5,
Between the front end and the rear end of the contact terminal has a voltage detection element,
The noise detection unit is a noise evaluation device that measures a voltage at both ends of the voltage detection element.
The noise evaluation device according to claim 6,
The voltage detection element is a noise evaluation apparatus which is a passive element configured using any one of a resistor, a capacitor, and an inductor.
The noise evaluation device according to claim 1,
The ground, the contact terminal, and the noise detection unit are noise evaluation apparatuses that are integrally formed of a multilayer printed board.
The noise evaluation device according to claim 8,
The contact terminal is formed using a via of the multilayer printed circuit board,
The noise detecting unit is configured by using an inner layer of the multilayer printed board.
The noise evaluation device according to claim 1,
The noise evaluation device, wherein the contact terminal is movable.
The noise evaluation device according to claim 1,
The noise evaluation apparatus in which the contact terminal and the noise detection unit constitute a set, and a plurality of the sets are provided.
The noise evaluation device according to claim 11,
The plurality of sets of contact terminals and noise detection units are noise evaluation devices arranged in an array, a grid, or a staggered pattern.
The noise evaluation device according to claim 11,
Furthermore, the noise evaluation apparatus which has a display part which displays the noise distribution obtained based on the data each obtained by the said multiple sets of contact terminal and a noise detection part.
The noise evaluation device according to claim 13,
Furthermore, the noise evaluation apparatus which has the arithmetic processing part which correct | amends the said data using the sensitivity characteristic of the said noise detection part.
The noise evaluation device according to claim 14, wherein
The arithmetic processing unit is a noise evaluation device having a function of ranking noise intensity in the noise distribution.
The noise evaluation device according to claim 1,
Furthermore, the noise evaluation apparatus which has a measuring device which measures the detection noise obtained by the said noise detection part.
The noise evaluation device according to claim 11,
A noise evaluation apparatus having a plurality of measuring devices electrically connected to each of the plurality of sets of contact terminals and the noise detection unit.
The noise evaluation device according to claim 11,
A switch electrically connected to each of the plurality of sets of contact terminals and the noise detector;
A noise evaluation apparatus comprising: a measuring device that measures detection noise obtained by one noise detection unit selected by the switch.