JP2007049104A - Electromagnetic shielding method and electromagnetic shielding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic shielding raw material that uses a copper iron alloy as a binary alloy or uses a copper iron alloy made by adding cobalt, nickel, manganese, and chromium as dopants added to the binary alloy of copper and iron by smelting processes. <P>SOLUTION: Conventionally, highly conductive metals are used as a method for performing electromagnetic shielding, particularly to shield electric field, while magnetic materials such as iron are used to shield magnetism. Therefore, in order to simultaneously shield electric field and magnetism, it is considered that electromagnetic shielding is performed by preparing a highly conductive metal and iron of high permeability into a binary structure. However, the method is not executed because it is difficult to put it into practice and is due to economic factors. The raw material as the binary alloy of copper and iron or the copper iron alloy made by adding cobalt, nickel, manganese, and chromium to the binary alloy as the dopants exhibits an eutectic condition, and is capable of simultaneously shielding both electric field and magnetism. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the use of an electronic circuit or an electronic component, or in the construction of a shield room, the electromagnetic wave leaking from the electronic circuit or the electronic component, an electric field, a magnetic shield, an unnecessary electromagnetic wave coming from the outside, or an electromagnetic field is increased. The present invention relates to an electromagnetic shielding method or an electromagnetic shielding member that can be performed with a shielding rate.

Conventionally, electromagnetic waves generated from electronic circuits and electronic components have been shielded against interference waves by covering them with an iron plate or a metal plate. Conductive films have also been used. With the development of electronic technology, the reduction of such interference electromagnetic waves has been protected by laws and regulations, and contrivances have been made to reduce mutual interference, malfunction of electronic devices, and the like. However, with the development of electronic technology, facilities and equipment using electronic technology are increasingly used, and those are always being used in close proximity, and the problem of electromagnetic shielding minimizes the impact on the outside world. It is an important factor for improving the performance of electronic circuits and electronic devices, while releasing unnecessary electromagnetic fields to the outside world has a large effect on other electronic devices and equipment. As the situation has become more serious, the need for electromagnetic shielding methods and materials that are higher than conventional electromagnetic shielding rates has increased.
In addition, medical equipment with precise electromagnetic measurement, broadcasting equipment that dislikes electromagnetic wave wrapping, use of electronic equipment in aircraft using advanced electronic technology, electromagnetic measuring device, magnetic head, computer equipment, DC-DC converter In order to minimize the influence on the outside, such as an IC chip, or on the influence of the electromagnetic wave coming from the outside, an electromagnetic shielding technique has been devised. These prior art patent documents are listed below.

JP 2004-137823 A Patent 3338826 JP 07-024352 JP2004-327687 Patent 3591629 JP-A-2005-147822 JP 07-024362 Story of radio wave absorbers Osamu Hashimoto Published by Nikkan Kogyo Shimbun, June 29, 2001 First edition Japanese Patent Application Laid-Open No. 2004-137823 of Patent Document 1 describes the use of electromagnetic shielding concrete in which an elastic joint shielding material provided with a conductive coating is pressed into the joint to prevent radio waves from passing through the wall surface. The shield concrete describes an electromagnetic shield method using electromagnetic shield concrete mixed with magnetite iron ore, iron sand, iron dust, or carbon fiber. However, in this case, complete electrical grounding is not possible, and the electrical resistance is relatively high, so that there is a disadvantage that it is insufficient for transmission of the electromagnetic field.

  Patent Document 2 (Japanese Patent No. 3033826) discloses a shield panel for a shield room and an assembly thereof that can simultaneously and effectively form a magnetic shield and a radio wave shield. In the MRI apparatus, weak resonance generated from the human body due to magnetic resonance is disclosed. Because it is designed to accurately measure the electromagnetic wave and image it, even a slight noise radio wave with a close frequency must be avoided. For this reason, a radio wave shield to strictly shield external radio waves It is described that the room is provided for the entire apparatus (or part of the apparatus). The MRI apparatus is for taking a cross-sectional image of a human body. At the time of photographing, an object to be photographed is exposed to a strong magnetic field of, for example, 0.2 (2000 gauss) to 2 Tesla for a predetermined time, and at the same time, external surroundings. This space is also exposed to the strong magnetic field from the MRI system. For example, even if a magnetic field of about 10 gauss is generated due to magnetic leakage to the surroundings, peripheral precision electronic equipment malfunctions. It is described that there is a great risk that the pacemaker is likely to malfunction when walking near the MRI apparatus in operation. In this case, the shield room assembly work itself has been devised, but a material having high conductivity and high magnetic permeability is required. However, in the past, it was characterized by being formed of an iron plate coated with zinc. However, it is difficult to use a material having high magnetic permeability and high conductivity, high electrical conductivity like copper, and low cost. The material should be used, and it is desirable to use a metal with high permeability such as iron. Therefore, the use of a binary alloy that is an alloy of copper and iron is an optimal material in this respect and is advantageous in the simultaneous shielding of electric and magnetic fields.

  In Japanese Patent Publication No. 07-024352 of Patent Document 3, an electromagnetic wave shielding material that can sufficiently shield electromagnetic waves from communication electromagnetic wave frequencies of various information communication devices used in the building as an electromagnetic wave shielding building is independent of claim 1. Information communication equipment room unit, equipment room unit, etc., which are individually covered, and a communication space which is independently covered with the above-mentioned electromagnetic shielding material and has a power line, a communication line and / or an air conditioning duct inside. An electromagnetic wave shielding building characterized in that a building is constituted by a unit, and communication between the communication space unit and each room unit by wiring or piping is performed through a radio wave leakage prevention device provided in each unit. Is described. According to a third aspect of the present invention, the electromagnetic wave shielding material is an electromagnetic wave reflecting material such as a metal plate such as a galvanized iron plate, a wire net, a metal grid, plating, or a vapor deposition plate / film. Or electromagnetic wave shielding building described in item 2. In this case as well, as in Patent Document 2, a material with high electrical conductivity and low cost such as copper should be used, and the use of a metal with high magnetic permeability such as iron is also used. It is desirable that Therefore, the use of a binary alloy that is an alloy of copper and iron is an optimal material in this respect and is advantageous in the simultaneous shielding of electric and magnetic fields.

  In Japanese Patent Application Laid-Open No. 2004-327687 of Patent Document 4, at least one layer (A layer) of a soft magnetic metal film containing fine crystals having a particle size of less than 100 nanometers is formed by a wet plating method as an electromagnetic interference prevention material. There is a description of a sheet-like electromagnetic interference prevention material. According to claim 4, a metal film layer (B layer) having a better electrical conductivity than the soft magnetic film layer is further formed on or above (and) the A layer by a wet plating method. The sheet-like electromagnetic wave interference preventing material according to any one of claims 1 to 3, which has a layer structure of at least two layers, and in claim 14, the layer B is made of copper or silver, or those The sheet-shaped electromagnetic wave interference preventing material according to any one of claims 4 to 13, wherein the material is composed of one or more selected from an alloy containing selenium. However, in this case, the wet plating method requires a plating tank having an area equivalent to or larger than the electromagnetic interference prevention material in processing, and has a disadvantage that it needs to have a two-layer structure. However, there is a problem that it becomes expensive. Therefore, the use of a binary alloy, which is an alloy of copper and iron, is a situation in which a eutectic of copper and iron forms a multilayer film without forming a double layer, which is also an optimal material in this respect. Convenient for simultaneous shielding of electric and magnetic fields.

  In Patent 3591629 of Patent Document 5, for the electromagnetic shield floor, in claim 1, the fluffy shield material is laid on the floor slab at a ratio sufficient to develop the required electromagnetic shield performance, and the wall side of the fluffy shield material is placed. An electromagnetic shield floor in which an end edge is electrically contacted with a bent lower end of the wall shield material is described, and in claim 9, the conductive fiber is made of copper, brass, stainless steel, iron, It is described that the electromagnetic shield floor is a fiber having a diameter of 40 to 100 μm made of one or more materials selected from the group consisting of a chromium alloy and carbon. Here, a wire made of a material having a high electrical conductivity such as copper and a metal wire having a high magnetic permeability such as iron are used together, but the copper and iron wires are separated from each other. In addition, it is difficult to lay on the floor surface uniformly, and fixing this requires a third material such as a resin, which is difficult in terms of handling and cost. Further, in order to install the terminal completely electrically, caulking work is necessary, but electric corrosion is easily generated when the humidity is accompanied, and there is a problem in terms of durability. Here too, the use of a binary alloy, which is an alloy of copper and iron, is the optimal material in this respect, and the end is easily welded to the copper bar on the other side, brazed with a friend, and screwed easily. It is advantageous in simultaneous shielding of electric and magnetic fields.

  Japanese Patent Application Laid-Open No. 2005-147822 of Patent Document 6 describes the necessity that the first and second metal bodies have an electromagnetic shielding effect and one of them is a metal having high heat conduction. In a switching power supply, which is a DC / DC power supply, conductive and radiated noise, particularly leakage magnetic field noise is generated, and an induction noise voltage is generated by magnetic coupling to a peripheral circuit, particularly a detection system including a panel sensor and an amplifier IC. Problems that affect the quality of the image display device are described. In order to shield leakage electromagnetic field noise from electronic circuits and devices that generate such leakage electromagnetic field noise, it is necessary to seal with electromagnetic shielding material. Therefore, a method is described in which a material having high heat dissipation, that is, a material having high thermal conductivity, such as copper, is used together. Also in this case, there arises a problem for performing the electromagnetic field with high efficiency without giving the two kinds of metals thermal resistance. Therefore, the use of a binary alloy of copper and iron is an optimum material also in this respect, and is advantageous for simultaneous shielding of electric and magnetic fields and releasing heat to the outside.

Also, in the electromagnetic shielding material constituting the electromagnetic shielding blind shown in Japanese Patent Publication No. 07-024362 shown in Patent Document 7, use of a binary alloy of copper and iron is particularly necessary when a high magnetic field shielding rate is required. It is clear that is an effective and optimal material.
Although there are descriptions of various materials and methods for the radio wave absorber in Non-Patent Document 1, there is no description of the use of the binary alloy of copper and iron used in the present invention.

Conventionally, when shielding electromagnetic fields, when shielding electric fields, metals with high conductivity, such as copper, gold, silver, aluminum, etc., are used. For shielding magnetic fields, ferromagnetic materials such as permalloy and iron are used. Has been. However, it is difficult to simultaneously shield the electric field and the magnetic field, and there is no material that shields the electric field and the magnetic field at the same time. Moreover, in order to complete the shielding effect, it is necessary to seal, but at the same time, it is necessary to release heat generated from the sealed electronic device or electronic circuit to the outside. In such a case, a metal having high conductivity, such as copper, gold, silver, or aluminum, is used. However, in this case, there is a problem that the magnetic field shielding effect is lowered as compared with iron or permalloy having high permeability. On the contrary, if iron or permalloy with high magnetic permeability is used, the magnetic field shielding effect is certainly good, but the thermal conductivity is inferior to copper, gold, silver, aluminum, etc., in terms of heat dissipation problems, electric field shielding effect, There are difficulties.
Also, in order to join the copper plate to the iron casing, welding is not possible, and fixing with bolts creates a gap, causing problems when grounding due to leakage of radio waves from the gap or increased contact resistance. It was.

In addition, when using materials that are laminated with iron and copper sheets alternately and pressed together, thin plate processing and rolling processing cannot be performed, and flat plate processing for obtaining a flat plate with a desired thickness and width cannot be performed. there were. On the other hand, a sintered metal obtained by sintering iron and copper powder has a problem that the material is brittle and plate processing such as rolling cannot be performed.
The present invention uses copper as a metal having a high conductivity as a base material, obtains a binary alloy with iron having a high magnetic permeability, realizes electromagnetic shielding with a high electromagnetic shielding effect, and provides electronic equipment, equipment, and buildings. The purpose is to suppress the leakage electromagnetic field emitted from the outside, and to exclude the influence on the sensitive precision instruments, measuring instruments, and medical equipment from the unnecessary electromagnetic field from the outside.

  In the present invention, the binary alloy used as a raw material is made from 3% to 90% of iron and the remaining less than 97% to less than 10% of electrolytic copper by the melting method, or the above binary alloy of copper and iron Copper iron alloy made by adding cobalt, nickel, manganese, and chromium as a trace additive is used, but the binary alloy that is the copper iron alloy has high workability and is easy to roll and draw. It is.

Therefore, it is used in accordance with the electromagnetic shielding purpose for obtaining a flat plate or a thin plate obtained by rolling. On the other hand, the binary alloy that is the copper-iron alloy is easy to be processed into a rod shape or a linear shape, so that it is not limited to a flat plate wave absorber, a linear wave absorber, or a plate shape for electromagnetic shielding, It can be used in a linear form.
In the eutectic alloy of copper and iron, the contained iron is effective for shielding the magnetic field as a ferromagnetic material, and the surrounding copper is a good conductor, so that a high electromagnetic shielding effect is obtained.
Moreover, since iron has a higher electrical resistance than copper, it plays the role of converting the flowing current into heat, and iron is converted into thermal energy as resistance against an alternating magnetic field, both of which function as radio wave absorption.

In addition, the binary alloy of copper and iron effectively shields electromagnetic waves by woven a thin plate, wire, or wire in a net shape as an outer wall material of a shield room that needs to shield radio waves. It can be applied as a material.
In addition, it can be used as a covering material for shielding electromagnetic wave leakage that does not leak out disturbance electric waves transmitted from an electronic circuit, and at the same time, does not give heat to the inside.

The invention described in claim 1 of the present invention uses a binary alloy in which the ratio of electrolytic copper is 60% or more to 90% or less, and the remaining less than 40% to less than 10% by the melting method, or the above There is an electromagnetic shielding method using a copper-iron alloy binary alloy made by adding cobalt, nickel, manganese, and chromium as a trace additive to a copper-iron binary alloy.
Although the copper-iron alloy binary alloy can be composed of 3% to 90% of iron and the remaining less than 97% to less than 10% of copper, the increase of the iron component has the effect of increasing the magnetic permeability. , There is a drawback that the hardness increases and the processing rate cannot be increased.
Therefore, it is necessary to select the component ratio appropriately according to the purpose of use.
Moreover, the effect of the additive has the effect of increasing the magnetic permeability and has a high effect on magnetic shielding.

  In claim 2, by using a binary alloy in which the iron component ratio is decreased and the ratio of electrolytic copper is 30% or more to 60% or less and the remaining less than 70% to less than 40% by the melting method, or the above Describes an electromagnetic shielding method that uses a copper-iron alloy binary alloy made by adding cobalt, nickel, manganese, and chromium as a trace additive to a binary alloy of copper and iron. An electromagnetic shielding member having an improved processing rate is obtained.

  In claim 3, by using a binary alloy in which the iron component ratio is further reduced and the ratio of electrolytic copper is from 3% to 30% and the remaining less than 97% to less than 70% by the melting method, or The electromagnetic shielding method using a copper-iron alloy binary alloy made by adding cobalt, nickel, manganese, chromium as a trace additive to the copper-iron binary alloy is described. It is an improvement. In this case, since the eutectic of iron can be extended further in the rolling direction, the electromagnetic shielding effect on the high frequency side shown in claim 5 can be maintained.

  In Claim 4 of this invention, the electromagnetic shielding method or electromagnetic shielding member which obtains an electromagnetic shielding effect by forming by flat plate or thin plate processing, and covering the to-be-shielded object is described. This is an electromagnetic shielding member according to claims 1 to 3 in which a binary alloy which is an alloy of copper and iron is processed into a flat plate or a thin plate and covers an electromagnetic shielding object, and electromagnetic field leakage is completely prevented. It is an electromagnetic shielding member that shields electromagnetic waves from covering, leakage of electromagnetic fields, or unnecessary electromagnetic fields from the outside.

  Further, as described in claim 5, in claim 4, the eutectic length of iron in copper is adjusted by adjusting the elongation ratio from 1% to 70% in the elongation direction of the eutectic of copper and iron during rolling plate processing. The electromagnetic shielding member is described in which the material flat plate with variable electrical characteristics or the stretch rate variable is used by shifting the direction perpendicular to the electromagnetic field incident direction or obliquely shifting the extension direction. Thus, the shielding of the electromagnetic field is improved by the characteristic obtained by the orientation in which the original material using the electromagnetic shielding characteristic of the flat plate or the thin plate is stretched, and the effect of suppressing the deterioration of the electromagnetic shielding characteristic in the high frequency region is obtained.

  In the case of a high-frequency electromagnetic field, electromagnetic fields called vertical polarization and horizontal polarization have dependency on the incident direction. The binary alloy which is a forged and rolled copper and iron alloy has orientation characteristics related to vertical polarization and horizontal polarization of the high-frequency electromagnetic field shielded by stretching due to the eutectic rolling of iron. In claim 6, the eutectic length of the copper and iron eutectic is adjusted between 1% and 98% during the drawing process, and the eutectic length of iron in copper is varied. In addition, an electromagnetic shielding member having a higher electromagnetic shielding effect can be obtained by using two or a plurality of overlapping linear materials with varying electrical characteristics or varying the stretching ratio at right angles or obliquely shifting the stretching direction. is doing.

  The electromagnetic shielding member according to any one of claims 1 to 5, wherein the processing rate during rolling is changed, the elongate length of the eutectic of iron and copper is changed, and the frequency characteristic of the electromagnetic shielding effect is changed. In particular, the elongation length of the eutectic of iron uses the frequency dependence of the high-frequency current flowing inside the copper-iron alloy binary alloy or through the skin, and the frequency characteristics of the electromagnetic shielding effect are formed in the material design. It is.

  Further, if the sealing is performed to enhance the shielding effect of the electronic circuit or the electronic device, the heat generated from the electronic circuit or the electronic device is confined in the shielding covering, resulting in a problem. As described in claim 8, in order to release the heat of the device together with the electromagnetic shielding, the heat radiation fin or the heat generating part is brought into close contact with the covering of the shielding in order to release the heat of the device together with the electromagnetic shielding. It is an electromagnetic shielding material designed to improve conduction and improve heat dissipation. The binary alloy, which is a copper-iron alloy, has good thermal conductivity. Since the strength is higher than that of aluminum, a thinner material may be used, and heat shielding and electromagnetic field shielding can be performed simultaneously.

  Further, as described in claim 9, the binary alloy which is a copper-iron alloy has an advantage that it can be welded regardless of whether the welding partner is copper or iron. Therefore, in claims 1 to 7, when the casing or other parts or structure is electrically iron or copper, a binary alloy is used regardless of whether the structure is copper or iron. By using or easily welding using iron or copper welding material, the mechanical installation can be made more reliable and the electrical grounding can be done more reliably, which further enhances the electromagnetic shielding effect. It is an electromagnetic shielding material that can be used. For example, in the construction of a shield room, welding to a steel frame or welding to a copper earth bar is easy, thereby making the grounding work more complete. Normally, copper plate and iron cannot be welded, and it is necessary to tighten them with bolts. In the case of the present invention, welding work is easy by using a binary alloy of copper and iron as the welding rod, whether it is iron or copper. It becomes.

  Further, in claim 10, the net-like electromagnetic shielding member described above uses a drawn wire made of a binary alloy of copper and iron, and the drawn binary alloy according to claims 1 to 3 Or using a binary alloy of copper and iron made by adding cobalt, nickel, manganese and chromium as a trace additive to the binary alloy of copper and iron, and woven in a net shape It is an electromagnetic shielding member that can be simultaneously braided with another fiber to form an electromagnetic shielding member, and can be easily used as a covering for an object to be shielded as compared with a processed product of a flat plate or a thin plate. In this case, when it is required that the electromagnetic shielding member is an insulator, a method of using it as an insulator by braiding so that a wire made of a binary alloy that is an alloy of copper and iron that is a core wire is covered with an insulator thread. Easy to implement.

  Furthermore, the binary alloy which is described in claim 11, using the binary alloy which is an alloy of copper and iron, or is the alloy of copper and iron according to claim 1. Using a binary alloy that is an alloy of copper and iron made by adding cobalt, nickel, manganese, and chromium as a trace additive, and fixing or insulating the insulator in a certain direction or unspecified direction. The electromagnetic shielding member solidified in (1) is an electromagnetic shielding member formed by sandwiching a binary alloy, which is an alloy of linear copper and iron, with a resin film, or solidifying with resin to form an electromagnetic shielding member. It can be used for electromagnetic wave leakage, prevention, electromagnetic shielding by forming an indefinite shape cover, or an electromagnetic shielding curtain, or a wall of a shield room. Further, a binary alloy that is an alloy of copper and iron can be drawn from the outer peripheral portion and processed to be grounded.

  The trace additive according to any one of claims 1 to 3, wherein the binary alloy which is an alloy of copper and iron drawn or is used for the binary alloy which is an alloy of copper and iron. As a copper-iron alloy binary alloy made by adding cobalt, nickel, manganese, and chrome, the drawn wire is cut into equal lengths or non-equal lengths, and arranged in the same direction or with regularity. Or an electromagnetic shielding member that is fixed in a certain direction or in a non-specific direction without being regular, or fixed with an insulating material, adjusts to the polarization of electromagnetic waves radiated to the outside, or obtains frequency characteristics. Therefore, the wire rods are cut into equal lengths and arranged with regularity, or do not depend on the polarization of electromagnetic waves, or have non-equal lengths or regularity so as not to have frequency characteristics. Array and electromagnetic It is a member that 蔽. Further, these electromagnetic shielding members are used in an overlapping manner.

In addition, in ordinary electromagnetic shielding, electrical grounding is performed and more complete electromagnetic shielding is performed.In this case, the grounding work is terminated with a copper ground bar or a copper grounding rod. When threaded, the strength is weak and it is not suitable for structures that require more tightening. Also, the earthing rod is driven into the ground to lower the grounding resistance, but copper is weak in strength, so deformation such as bending occurs during the driving operation, and it becomes necessary to replace it with another earthing rod. There was a bug. Therefore, in claim 11 according to claim 13, a small amount is added to a conductor having good conductivity at equal intervals or a binary alloy that is an alloy of copper and iron, or to the binary alloy of copper and iron. A shield member that provides more complete electromagnetic shielding by providing grounding with a grounding wire, grounding bar or grounding rod with a wire using a copper-iron alloy binary alloy made by adding cobalt, nickel, manganese, and chromium as an object Is obtained.
In this case, the electromagnetic shielding member and the ground wire, the ground bar, or the ground bar can be easily connected to each other by screwing, welding, or brazing that can ensure strength compared to copper.

  Furthermore, as described in claim 14, in claim 12, the member that performs electromagnetic shielding by minimizing the length of cut and adhering or mixing the powdered material to an insulator, woven fabric, plastic sheet, or non-woven fabric. Obtainable. Thereby, the wall material of a shield room, the electromagnetic wave absorption member of an anechoic chamber, an electromagnetic shielding curtain, or an electromagnetic shielding covering material is obtained.

  Further, the description of claim 15 is the use of cobalt or nickel as a trace additive in claim 4 using a binary alloy that is an alloy of copper and iron, or a binary alloy that is an alloy of copper and iron. Using the spring property of the plate using a copper-iron alloy binary alloy made by adding manganese and chromium, using the restoring force as a spring, providing a number of specific or unspecified force points to plastically deform, It is an electromagnetic shielding member in which the surface electromagnetic wave reflection angle can be selected by deforming the surface. The good spring property can be used for binary alloys of copper and iron. The original shape due to the spring property is also transformed into a shape as necessary using the restoring force to the shape, but even when the shape of the electromagnetic shielding object is changed and changed, an electromagnetic shielding covering material that can be restored to the original shape is obtained. It is done.

  The configuration of an anechoic chamber, a shield room, or a non-reflecting surface with respect to an electromagnetic wave having a specific wavelength is described in claim 16. In Claim 10 thru | or 13, using the binary alloy which is the said alloy of copper and iron, or adding said cobalt and iron binary alloy as a trace amount additive, adding cobalt, nickel, manganese, and chromium. By utilizing the spring property of the wire using the obtained copper-iron alloy binary alloy, a non-reflective wall member capable of changing the wavelength of the non-reflective characteristic is obtained by utilizing the restoring force as a spring. For example, an electromagnetic wave non-reflective structure with a specific frequency can be formed by providing an actuator that periodically deforms the radio wave absorber or the sheet-like radio wave absorber at a constant period, or by adsorbing it to a structure.

  The copper-iron binary alloy is rolled into a thin plate, forged, or wire-drawn, or the wire-like copper-iron binary alloy is knitted or drawn. Can be cut into a certain length or indefinite length, and this can be hardened or bonded with resin at regular intervals or regularity to achieve electromagnetic shielding with high electric field and magnetic field shielding efficiency. Also, electromagnetic shielding with higher electric field and magnetic field shielding efficiency can be realized by overlapping the forging directions in the same direction, or by making two or more forging directions different in orientation. A radio wave absorber can also be formed by finely cutting or powdering, mixing with a dielectric, and solidifying.

  By realizing electromagnetic shielding with high electric field and magnetic field shielding efficiency, it is possible to realize electronically shielded electronic circuits, electronic application devices, shield rooms, and medical equipment that are smaller and lighter than conventional ones at a low price. Became possible.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the results of measuring the electric field shielding characteristics at each frequency of an electromagnetic shielding member made of a copper and iron alloy processed into a thin plate according to the present invention. CFA90 is a copper-iron binary alloy electric field shielding member 1 of 90% copper and 10% copper, and is a thin plate-like electromagnetic shielding member which is rolled after forging to a thickness of 0.1 mm. The shield / absorber evaluation system is measured by FIG. The electric field shielding member 2 by using the copper-iron binary alloy is used as a laminated electric field shielding member by aligning two 0.1 mm thick thin plates of CFA90 in the rolling direction, and one sheet of 0.1 mm thick thin plate of CFA90 is rolled. And another one is an electric field shielding member obtained by overlapping in a direction orthogonal to the rolling direction, and CFA50 is a copper-iron binary alloy electric field shielding member made of 50% copper and 50% iron, and has a thickness of 0. It is a result obtained by simultaneously measuring three types of electric field shielding members obtained by overlapping two sheets in a direction orthogonal to the rolling direction as 0.07 mm using the electromagnetic wave shielding / absorbing material evaluation system FIG. As can be seen from FIG. 1, at a frequency of 70 MHz or more, a single copper-iron binary alloy electric field shielding member 1 and an electric field shielding member 2 obtained by overlapping use of a copper-iron binary alloy do not depend on the rolling direction, but two layers are stacked. It shows that the electric field shielding characteristic is better, and the electric field shielding member 2 shows substantially the same level of electric field shielding characteristic for all three types. Therefore, the overlay effect is particularly important for electric field shielding.

  In FIG. 2, the electric field shielding effect at each frequency of various copper-iron binary alloys processed into a thin plate according to the present invention is compared with an aluminum foil having a thickness of 12 μm. It can be seen that the copper-iron mixed distribution of the alloy as in FIG. 1 does not cause a difference in electric field shielding. On the other hand, the example of the present invention shown in FIG. 3 shows that it greatly contributes to the copper-iron ratio of the metal component and the electromagnetic shielding effect of superposition perpendicular to the rolling direction.

  FIG. 4 shows the magnetic shielding effect at each frequency of the copper-iron binary alloy processed into a thin plate according to the present invention. In the magnetic shielding effect, a significant improvement in shielding effect is obtained by superimposing the copper-iron binary alloy in a direction perpendicular to the rolling direction, and in a frequency range of 1 MHz to 1 GHz, about 2 times the comparison copper plate. It can be seen that an improvement of the shielding effect close to 30 db can be obtained. Here, a thin CFA 90 sheet having a thickness of 0.1 mm is overlapped in a direction perpendicular to the rolling direction, and the magnetic shielding effect is higher by about 30 db in a frequency region of 1 MHz or more than a copper sheet of 0.2 mm. It shows that.

  In FIG. 5, the magnetic shielding effect in each frequency of the copper-iron binary alloy by which the thin plate process by this invention was carried out is shown. When a thin plate of CFA50 having a thickness of 0.07 mm is stacked perpendicular to the rolling direction, it may be inferior by about 10 db at a frequency of 2 MHz or more compared to the thin plate of CFA90 having a thickness of 0.1 mm used in FIG. Recognize.

FIG. 6 shows a 600 × micrograph of a thin sheet-processed copper-iron binary alloy according to the present invention. It can be seen in the photograph that the black elongate iron eutectic extends in the rolling direction.
In the striped iron eutectic, the stripes also extend in the rolling direction by increasing the processing rate of the rolling process.

  In FIG. 7, it is a schematic diagram of the horizontally polarized wave of the electromagnetic wave according to the present invention, the arrangement of the direction of elongation by eutectic rolling when the electromagnetic shielding member is placed in a form that prevents propagation at right angles to the propagation direction. Show. The high frequency magnetic field is consumed by the eutectic of iron in copper, and a shielding effect can be obtained.

  FIG. 9 shows the configuration of an electromagnetic shielding / absorbing material evaluation system used for measuring the electromagnetic shielding effect of the present invention. The network analyzer 26 transmits a variable frequency electromagnetic wave and sends it to the high frequency director 28 via the high frequency transmission cable 27. The electromagnetic shielding member 30 to be measured has a structure in which both surfaces are sandwiched between measurement metal mask materials 29 to set a measurement region, and at the same time, are pressed against each other to prevent leakage of electromagnetic waves, and further tightened with bolts as necessary. The variable frequency electromagnetic wave that has passed through the electromagnetic shielding member 30 to be measured is received by the lower high-frequency detection probe and waveguide 31, and the leaked electromagnetic wave is detected as an input of the network analyzer 26 by the high-frequency detection cable 32.

Examples of the present invention will be described below.

The binary alloy, which is an alloy of copper and iron used in the present invention, produces a mother alloy by a melting method in which electrolytic copper and pure iron are heated at a high frequency in a high frequency furnace. In carrying out the present invention, a 100 KW high frequency furnace was used.
In addition, the copper-iron alloy produced by the melting method can be further improved in magnetic permeability by adding cobalt, nickel, manganese, and chromium as trace additives to the binary alloy of copper and iron, and the effect as a magnetic shielding material. I was able to increase.
In melting, the mixing ratio of copper and iron is set in accordance with various requirements of the electromagnetic shielding member. For example, in the case of an electromagnetic shielding member that is an electromagnetic shielding member and a heat radiating member and is used as a structural material that requires rigidity, the CFA 50 may be 50% copper and 50% iron.
Unlike the base metal made of sintered metal, the binary alloy that is an alloy made of copper and iron is not brittle and can be easily processed into a plate shape or a round bar shape by hot rolling.

  Copper and iron alloys made by adding cobalt, nickel, manganese, and chromium as trace additives to the copper-iron alloy by the melting method or the binary alloy of copper and iron are formed into a plate, round shape by hot rolling. In addition, the material was further processed into a rod shape, and cold plate processing, rod shape processing, and wire drawing processing were performed to obtain a material metal that would be a plate-shaped, rod-shaped, or linear electromagnetic shielding material.

  Next, as a trace additive to the copper-iron alloy by the melting method or the binary alloy of copper and iron, a binary alloy that is an alloy of copper and iron made by adding cobalt, nickel, manganese, and chromium is heated. The material processed into plate-shaped, round bar-shaped by cold rolling is further subjected to cold plate processing, rod-shaped processing, and wire drawing processing, and the material metal that becomes the plate-shaped, rod-shaped, line-shaped electromagnetic shielding member is heated from 300 to 450 ° C. Heat treatment at 0 ° C. and rapid cooling to obtain an electromagnetic shielding member.

In the example, CFA 50 of 50% copper, 50% iron, 70% copper, CFA 70 of 30% iron, 90% copper and 10% CFA 90 of iron were produced, and the thickness was 0.1 mm and 0.07 mm. The electromagnetic wave shielding / absorbing material evaluation system shown in FIG. It can be seen from FIG. 4 or FIG. 5 that a high electromagnetic shielding effect is exhibited as compared with a copper plate having a thickness of 0.2 mm and CFA50 and CFA90. In FIG. 6, the microscope picture of the binary alloy which is an alloy of copper and iron is shown. It can be seen from FIG. 6 that the eutectic of iron is elongated in the rolling direction during rolling. Therefore, this eutectic iron becomes a resistance against the alternating magnetic field, is consumed as heat, and exhibits a magnetic field shielding effect.
On the other hand, the binary alloy, which is an alloy of copper and iron, can be used more effectively by shielding the electromagnetic field by using the binary alloy in an orthogonal direction or by shifting the eutectic direction. .
FIGS. 1, 2, 3, 4, and 5 have been confirmed to have a binary alloy overlap electromagnetic shielding effect, which is an alloy of copper and iron, in the structure shown in the schematic diagrams of FIGS. .
In FIG. 1, it can be seen that the shielding effect of the high-frequency electric field is remarkable in a high-frequency region of 100 MHz or higher due to the use of a binary alloy which is an alloy of copper and iron. Similarly, in FIG. 2, the binary alloy which is an alloy of copper and iron can confirm the shielding effect of a high frequency electric field compared with an aluminum foil. In addition, with respect to the magnetic shielding effect, the effect of using a single sheet, a plurality of sheets, and the iron eutectic in each rolling extension direction can be confirmed in FIG. 3, FIG. 4, and FIG.
By using these electromagnetic shielding effects and using electromagnetic shielding methods or electromagnetic shielding members, it became possible to realize electromagnetic shielding that was not obtained in the past. The heat radiation generated by the shielded object can also be eliminated by providing heat radiation fins as necessary by using a binary alloy which is an alloy of copper and iron having a high thermal conductivity.
Since the electromagnetic shielding effect is high, it is possible to use a material thinner than that of the conventional member. As a result, it is effective in reducing the size and weight, and the economic efficiency can be improved.
Use of a binary alloy, which is an alloy of copper and iron, improves electromagnetic shielding efficiency, solves heat dissipation problems by sealing the electromagnetic shielding object, and uses linear or mesh electromagnetic shielding at low cost I can do it now.
In addition, a binary alloy which is a linear copper-iron alloy is cut and processed on a powder, so that it can be used as a radio wave absorber without being limited to electromagnetic field shielding.

Binary alloys, which are copper and iron alloys that have been processed into flat plates, are cut or bent to the required dimensions or shape. If they are also thin, they are electromagnetically shielded after rolling, embossing, bending, and cutting. It can be used as an electromagnetic shielding material as a cover for an electronic circuit or electronic equipment that requires the Also, the electromagnetic shielding and the radiation fin can be shared by contacting the heat radiation part of the integrated circuit directly or through an insulator. For example, it can be used for electromagnetic shielding of a circuit with an electromagnetic field such as a DC-DC converter.
If it is a shield room, a flat plate is attached to the wall sequentially, or the adjacent part is welded, brazed, and attached to the wall by screwing, so that it becomes a shield room wall and a shield wall with high electromagnetic shielding efficiency. Available.
For example, it can be used for electromagnetic shielding walls in broadcasting stations or electromagnetic shielding when using wireless LAN in office buildings.
Also, a linear copper-iron alloy is hardened to the required thickness with a resin, or it is sandwiched between a film-like resin or a synthetic resin, or braided into an insulator as a curtain-like electromagnetic shield. Available.
Further, by using a linear copper-iron binary alloy knitted in a net shape, it is possible to construct an irregular electromagnetic shield or an irregular shield space.
Furthermore, in the above utilization, the electromagnetic shielding effect can be enhanced and utilized by overlapping in a direction perpendicular to the extending direction of the iron eutectic or by shifting the direction.
If used in this way, telemeters in the medical field and external or internal electromagnetic shielding can be easily used.
Moreover, it can be used as a radio wave absorber by thinly drawing a copper-iron binary alloy, cutting it short and hardening it with cement or resin.

The electric field shielding effect in each frequency of the copper-iron binary alloy by which the thin plate process by this invention was carried out is shown. In the electric field shielding effect, the effect of using thin plates in a stacked manner is great. The electric field shielding effect in each frequency of the copper-iron binary alloy by which the thin plate process by this invention was carried out is compared with the 12-micrometer-thick aluminum foil. Fig. 4 shows a magnetic shielding effect at each frequency of a thin copper alloy binary alloy according to the present invention. Unlike the electric field shielding effect, it can be seen that the laminated magnetic shielding effect in the rolling direction of the copper-iron binary alloy processed into a thin plate and the direction perpendicular thereto is excellent. The magnetic shielding effect in each frequency of the copper-iron binary alloy by which the thin plate process by this invention was carried out is shown. A CFA90 thin plate with a thickness of 0.1 mm overlapped in the direction perpendicular to the rolling direction shows a higher magnetic shielding effect in a frequency region of 1 MHz or higher compared to a copper plate of 0.2 mm. The magnetic shielding effect in each frequency of the copper-iron binary alloy by which the thin plate process by this invention was carried out is shown. When a thin plate of CFA50 having a thickness of 0.07 mm is stacked perpendicular to the rolling direction, it may be inferior by about 10 db at a frequency of 2 MHz or more compared to the thin plate of CFA90 having a thickness of 0.1 mm used in FIG. Recognize. 1 shows a 600 × micrograph of a thin sheet processed copper-iron binary alloy according to the present invention. It can be seen that the black horizontal stripe iron eutectic extends in the rolling direction. The arrangement | positioning of the direction of the expansion | extension by eutectic rolling at the time of setting an electromagnetic shielding member in the form which blocks | prevents propagation at right angle with respect to the propagation direction of the horizontal polarization of the electromagnetic wave by this invention is shown. This is an electromagnetic shielding member in which a flat plate of a binary alloy, which is an alloy of copper and iron, is overlapped with one in the rolling direction and one in the direction perpendicular to the rolling direction, and the third in the rolling direction. It is an electromagnetic shielding / absorbing material evaluation system using the electromagnetic shielding effect of the present invention for measurement.

Explanation of symbols

1: Copper 90% iron 10% copper iron binary alloy electric field shielding member 2: Electric field shielding member 3 by use of overlapping copper iron binary alloy 3: Aluminum foil electric field shielding member 4: Copper iron binary alloy electric field shielding member 5: 0.1 Milli-thick copper-iron binary alloy shielding member 6: Magnetic shielding member 7 used by overlapping in the direction perpendicular to the rolling direction 7: Magnetic shielding member 8 used by overlapping in the same direction as the rolling direction 8: 50% copper and 50% iron stacked in the rolling direction Magnetic shielding member 9 by use: 90% copper, 10% iron and rolling direction stacked in a cross manner Magnetic shielding member 10: 50% copper 50% iron, rolling direction superimposed in a cross shape 11 Magnetic shielding member 11 by use: 50% copper Magnetic shielding member 12 by using three layers of rolling in a cross shape with iron 50%: 0.2 mm thick copper plate 13: 90% copper 10% iron and rolling direction magnetic shielding member 14: 90% copper 10% direction perpendicular to rolling direction Magnetic shielding member 15: Magnetic shielding member 16 by using 90% copper and 10% iron and rolling directions in a cross shape: Magnetic shielding member 16 made of 0.2 mm thick copper plate 17: Magnetic shielding member with 90% copper and 10% iron in the rolling direction 18: Magnetic shielding member in a direction orthogonal to the rolling direction with 90% iron and 10% copper. 19: Magnetic shielding member by using 50% copper and 50% iron in a cross in a rolling direction. 20: Distribution of iron eutectic in the rolling direction. Electromagnetic shielding member 21: Electromagnetic shielding member in which iron eutectic perpendicular to the rolling direction is distributed 22: Horizontally polarized light incident on the electromagnetic shielding member in which iron eutectic in the rolling direction is distributed 23: Iron eutectic distribution perpendicular to the rolling direction Horizontally polarized light incident on the electromagnetic shielding member 24: Horizontal polarization schematic diagram of electromagnetic wave 25: Three-layer electromagnetic shielding member 26: Network analyzer 27: High frequency transmission cable 28: High frequency director 29: Measurement mask material 30 : Measured Magnetic shielding member 31: high-frequency detecting probe and waveguide 32: high-frequency detecting side cable

Claims (16)

    Using a binary alloy with an electrolytic copper ratio of 60% or more to 90% or less and the remaining less than 40% to less than 10% by the melting method, or as a trace additive to the copper / iron binary alloy An electromagnetic shielding method characterized by using a binary alloy which is a copper-iron alloy made by adding cobalt, nickel, manganese and chromium.     Using a binary alloy with an electrolytic copper ratio of 30% or more to 60% or less of iron and the remaining less than 70% to less than 40% by a melting method, or as a trace additive to the copper / iron binary alloy An electromagnetic shielding method characterized by using a binary alloy which is a copper-iron alloy made by adding cobalt, nickel, manganese and chromium.     Using a binary alloy with a ratio of electrolytic copper of 3% or more to 30% or less and the remaining less than 97% to less than 70% by the melting method, or as a trace additive to the copper / iron binary alloy An electromagnetic shielding method characterized by using a binary alloy which is a copper-iron alloy made by adding cobalt, nickel, manganese and chromium.     4. The electromagnetic shielding member according to claim 1, wherein a binary alloy that is an alloy of copper iron is processed into a flat plate or a thin plate to cover an electromagnetic shielding object.     In Claim 4, at the time of processing a rolled sheet, the elongation rate is adjusted from 1% to 70% in the elongation direction of the eutectic of copper and iron, the eutectic length of iron in copper is varied, and the electrical characteristics are adjusted. An electromagnetic shielding member, wherein the material flat plate having a variable expansion rate is used while being orthogonal to the incident angle of the electromagnetic field or obliquely shifted in the expansion direction.     5. The elongation direction of the eutectic body of copper and iron is adjusted between 1% and 98% at the time of rolling wire drawing, the eutectic length of iron in copper is varied, and electrical characteristics are adjusted. Alternatively, the electromagnetic shielding member is characterized in that two or a plurality of the wire materials having a variable expansion ratio are used in an orthogonal or obliquely shifted extension direction.     6. The electromagnetic shielding member according to claim 1, wherein a processing rate at the time of rolling is changed, an extension length of an eutectic of iron and copper is changed, and a frequency characteristic of an electromagnetic shielding effect is changed.     7. The electromagnetic shielding material according to claim 1, further comprising a heat radiating fin as a member in order to release heat of the device together with the electromagnetic shielding.     In Claim 1-7, when a housing | casing, another component, and a structure are iron or copper electrically, even if those structures are copper or iron, binary alloy is used. Or the electromagnetic shielding member characterized by making earthing more reliable by welding easily using the welding material of iron and copper, and improving the electromagnetic shielding effect by this.     In Claims 1 to 3, copper produced by adding cobalt, nickel, manganese, chromium as a trace additive to the binary alloy obtained by drawing, or as a minor additive to the binary alloy of copper and iron, and An electromagnetic shielding member using a binary alloy of iron and woven in a net shape.     The copper iron produced by adding cobalt, nickel, manganese, and chromium as a trace additive to the binary alloy of copper and iron, using the drawn binary alloy according to claim 1 or claim 3 An electromagnetic shielding member using a binary alloy, which is an alloy, fixed in a certain direction or in an unspecified direction in an insulator or solidified with an insulator.     The copper iron produced by adding cobalt, nickel, manganese, and chromium as a trace additive to the binary alloy of copper and iron, using the drawn binary alloy according to claim 1 or claim 3 Uses binary alloys, and the drawn wires are cut into equal lengths or unequal lengths, arranged in a certain direction or regularity, or in a certain direction in an insulator without regularity Or an electromagnetic shielding member fixed in an unspecified direction or solidified by an insulator.     In Claim 11, cobalt, nickel, manganese, chromium is used as a trace additive to a conductor with good electrical conductivity at equal intervals or the binary alloy of copper and iron, or to the binary alloy of copper and iron. In addition, an electromagnetic shielding member comprising a ground wire, a ground bar, or a ground bar provided with a wire using a copper-iron alloy binary alloy produced in addition.     13. The radio wave absorber according to claim 12, wherein the chopped length is minimized and the powdered material is adhered or mixed and solidified on an insulator, a woven fabric, a plastic sheet, or a non-woven fabric.     5. The copper-iron alloy according to claim 4, wherein the copper-iron binary alloy is used or cobalt, nickel, manganese, chromium is added as a trace additive to the copper-iron binary alloy. Utilizing the spring property of a plate made of a binary alloy, using the restoring force as a spring, providing a number of specific or unfixed force points to plastically deform, and deforming the surface, the electromagnetic wave reflection angle of the surface The electromagnetic shielding member characterized by being able to choose.     The copper formed by adding cobalt, nickel, manganese, chromium as a trace amount additive to the binary alloy of copper and iron or the binary alloy of copper and iron according to claim 10 to claim 13. A non-reflective wall material that makes use of the spring property of a wire that uses a binary alloy, an iron alloy, and makes it possible to change the wavelength of the non-reflective property by utilizing the restoring force of the spring.

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