JP4399768B2 - Magnetic shield panel and magnetic shield room using the same - Google Patents

Description

  The present invention relates to a magnetic shield room for shielding magnetism from outside in the medical field, precision physical measurement field, VLSI manufacturing field, and the like.

The magnetic shield room is a room for magnetically shielding the space inside and outside. Generally, a space to be shielded is surrounded by a high magnetic permeability material such as permalloy, amorphous metal, silicon steel plate, or pure iron so that an external magnetic field does not enter the inside. In order to improve the magnetic shielding performance, a method of using a material with high magnetic permeability, increasing the thickness of the material, or forming a multiple structure such as double or triple is taken. Permalloy is generally used as a magnetic material having a high magnetic permeability. Permalloy is often used as a magnetic material for high-performance magnetic shield rooms because it has a high magnetic permeability and can be manufactured with a large thickness. However, permalloy has the disadvantage that its magnetic properties deteriorate due to deformation and strain of the material. Heat treatment is necessary to bring out the properties, and sufficient care must be taken when handling such as construction after heat treatment. . Recently, materials such as amorphous metals and nanocrystalline alloys have attracted attention. Although the magnetic permeability of these materials is almost the same as that of permalloy, it has an advantage that it is easier to handle than permalloy because the magnetic properties are less deteriorated against deformation and distortion. On the other hand, since these raw materials require the ultra-quenching method in terms of the production method, the shape thereof is flake-like or ribbon-like, and the thickness of 5 to 50 μm is a technical limit. Therefore, a magnetic shield sheet integrated with a resin is provided as a configuration in which a plurality of ribbon-shaped raw materials are arranged in parallel and a part of the end portions are overlapped.
Japanese Patent Laid-Open No. 11-026981 Japanese Patent Laid-Open No. 11-087989 JP-A-11-284388 JP 2000-4094 A

  When assembling a magnetic shield room using these materials, it is advantageous that the size of the magnetic shield panel used for assembly is as large as possible within the range that can be handled because the number of assembling steps can be reduced. As shown in FIG. 4, the magnetic shield panel is a large-area magnetic shield sheet obtained by abutting each magnetic shield sheet together as shown in FIG. 4, and this sheet is supported by a rigid plate member. And made it. If the shield rate is insufficient with a single magnetic shield sheet layer, it is necessary to increase the thickness of the magnetic layer by laminating magnetic shield sheets in order to increase the shield rate. In the conventional laminating method, as shown in FIG. 6, the large area magnetic shield sheet is laminated so that the seams of the respective layers do not overlap. This is because if the positions of the seams of the magnetic shield sheets of the respective layers are matched, the magnetic resistance increases accordingly. However, at the abutting seam, it is difficult to bring the end surfaces of the magnetic shield sheets into close contact with each other with high accuracy, and a gap is likely to occur. Since the magnetic resistance is large in the gap, the magnetic flow in the vicinity of the abutting seam will flow to the adjacent large area magnetic shield sheet avoiding the seam as shown in FIG. One of them is substantially difficult to flow magnetically. For this reason, it is necessary to further increase the thickness of the magnetic layer in order to obtain a predetermined magnetic shield performance.

  As another lamination method, the positions of the seams of the layers can be matched as shown in FIG. In this case, magnetic connection is separately performed by the magnetic shield bonding plate 5 which is a magnetic plate. However, in this case, the magnetic connection is good, but when the magnetic shield panel is formed, irregularities are formed due to the thickness H of the bonding plate, and the appearance is not good, or the panel is thick. is there.

  Therefore, the object of the present invention is to reduce the amount of magnetic material used by suppressing the thickness of the magnetic layer by improving the disadvantages of manufacturing such a large area magnetic shield sheet and eliminating the places where it is difficult to flow magnetism. It is to provide a magnetic shield panel that can be used. Another object of the present invention is to provide a magnetic shield panel in which unevenness of a magnetic connection portion is suppressed.

First invention is formed by superposed with the end of the magnetic shield sheet adjacent the one end of the magnetic shield sheet, superimposed on the end portion of the magnetic shield sheet adjacent the opposite other end on the rear surface of the overlay surface A magnetic shield panel formed by laminating a large area magnetic shield sheet, wherein the position of the overlapping portion of the first large area magnetic shield sheet and the position of the overlapping portion of the second large area magnetic shield sheet are magnetically shielded. The magnetic shield panel is characterized in that the end portions of the magnetic shield sheets of the large-area magnetic shield sheets that are adjacent to each other are stacked while being sequentially shifted by the overlapping width of the sheets. Since the overlapping surfaces can be closely contacted without causing a gap, the magnetic resistance can be reduced, and the formation of a magnetic path passing through each magnetic shield sheet is facilitated. According to the present invention, the occurrence of unevenness can be suppressed and a thin magnetic shield panel can be obtained. In addition, it is preferable because the space factor of the magnetic material in the magnetic shield panel is increased and the magnetic resistance is reduced. In the present invention, when a quadrilateral magnetic shield sheet is overlapped in two directions to increase the area, the corners of the magnetic shield sheet are overlapped by chamfering a width substantially equal to or larger than the overlap width. An increase in the thickness of the corner portion can be suppressed. The thickness of the overlapping corners of the four magnetic shield materials can be two layers at the maximum, and a large area magnetic shield sheet with good magnetic connection and less unevenness can be provided.

  The magnetic material used for the large-area magnetic shield sheet has a structure in which ribbon-shaped soft magnetic materials are arranged in parallel and part of the end portions are overlapped, so that the air gap is Therefore, if the width of the overlapped portion is narrow, good magnetic connection cannot be made. Therefore, an overlap width of 10 mm or more is provided for good magnetic connection, and the size of the chamfered portion is equal to the overlap width. Or it is preferable to make it larger than this so that four magnetic shield materials may not overlap.

In the second invention of the present application, magnetic shield panels formed by sequentially laminating the ends of a plurality of magnetic shield sheets in a step-like manner are arranged so that the end faces face each other with a gap therebetween, corresponding to the shape of the gap Magnetic shield structure that magnetically joins magnetic shield panels using magnetic shield joint plates of the shape to be formed. The magnetic shield joint plate is formed by laminating the same number of magnetic shield sheets as the magnetic shield panels. a magnetic joint structure for causing the magnetic shield sheet of the plane of each layer of the plane and the magnetic shield bonding plate of the magnetic shield sheet of each layer facing each other of the shield panel into contact respectively. According to the present invention, the magnetic shield panels can be magnetically joined without increasing the magnetic resistance at the joint. Further, according to the present invention, the magnetic shield panels can be magnetically bonded without increasing the thickness at the bonded portion.

Third invention is a magnetic shield room, characterized by using the magnetic shield panel of the first aspect of the present invention as a wall member.

  In this invention, the magnetic shield sheet can be enlarged in a large area with good magnetic connection, and the magnetic shield performance is high and the area is increased by adopting a laminated structure that suppresses unevenness in the surface of the magnetic shield sheet. In addition, a magnetic shield sheet having a structure that can be easily laminated can be obtained. Moreover, since the number of units of the magnetic shield sheet can be reduced, the effect of reducing the number of man-hours for construction can be obtained.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these Examples.

FIG. 1 shows the shape of a single magnetic shield sheet used for a large area magnetic shield sheet used to form the magnetic shield panel of the present invention. Its shape is an octagonal shape in which the four corners of the flat plate are chamfered, and the chamfered width is substantially the same as the magnetic shield sheet to be joined, or a slightly larger width in consideration of assembly tolerances. Also, the width should be made as wide as possible so that the magnetoresistance of the seamed portion is sufficiently low. In particular, the magnetic shield sheet used in the present invention has a structure in which a plurality of ribbon-like magnetic bodies are fixed with a resin layer, and an air gap due to the resin layer exists between the magnetic bodies to be joined. Therefore, a wider seaming width is required as compared with direct bonding between magnetic bodies.

FIG. 12 shows the result of evaluating the relationship between the overlap width and the magnetic shield rate. A method for measuring the magnetic shield rate will be described with reference to FIG. The magnetic shield rate S is expressed by the following equation when the external magnetic field strength is Ho and the magnetic field strength inside the shield is Hi.
S = Ho / Hi (S: shield rate, Ho: external magnetic field strength, Hi: internal magnetic field strength)
The magnetic shield box used for the measurement of the magnetic shield rate at this time is one in which each surface of a 450 mm square cube is covered with a magnetic shield sheet. Then, the magnetic field inside the magnetic shield box was measured when a uniform external magnetic field was applied using a coil from a direction perpendicular to one surface of the magnetic shield box. In the magnetic shield box, the magnetic field is prevented from entering the inside by passing the magnetic flux through the magnetic shield sheet arranged in parallel to the applied magnetic field. For this reason, the magnetic shield sheet was placed at the center of the magnetic shield sheet arranged in parallel to the applied magnetic field, and the magnetic shield ratio with respect to the overlap width was measured. As shown in FIG. 12, the effect of superposition is obtained by forming a magnetic circuit even with a superposition width of 5 mm as compared with a state where there is no superposition (abutment). It was found that a sufficient effect was obtained by setting the width to 10 mm or more, and a substantially constant effect was obtained at 20 mm or more. For this reason, the joining width was set to 20 mm.

  FIG. 2 shows a large area magnetic shield sheet obtained by superimposing the magnetic shield sheets. The overlap between the sides is 20 mm. In addition, since the thickness of the corners which has been a problem in the connection between the magnetic shield sheets so far is a shape where the four corners are chamfered, by sequentially joining the magnetic shield sheets in this way, The overlapping thickness of the four sheets generated when the chamfered portion is not provided is not quadrupled, and a satisfactory magnetic connection can be performed while suppressing the thickness to two layers.

  In order to obtain a large magnetic shield effect, one method is to increase the thickness of the magnetic material. In order to increase the thickness of the magnetic material, it is possible to stack the magnetic shield sheets of the above-mentioned large area, but if they are arranged so that the joint portions of the overlapping magnetic shield sheets coincide, the magnetic shield sheet Since the uneven steps of the surface are enlarged, the appearance is deteriorated. Therefore, as shown in FIG. 7, the overlapping magnetic shield sheets are also arranged so as to be shifted by the above-mentioned joining width, so that the plate thickness in the large-area magnetic shield sheet becomes the plate thickness corresponding to the number of stacked layers plus one layer. A large-area magnetic shield sheet can be manufactured, and workability and the like can be greatly improved by finishing the large-area magnetic shield sheet on a single panel.

  By performing magnetic connection for each layer at this time on the magnetic connection surface, the magnetic flow flows through all the magnetic shield sheets as shown in FIG. 5, and a large area and good magnetic connection magnetic shield panel is obtained. I was able to.

  Each side of the magnetic shield panel has a stepped shape. Therefore, as shown in FIG. 8, the magnetic connection between the magnetic shield panels can be easily performed satisfactorily by providing the magnetic shield bonding plate 5 having this shape for the magnetic connection between the panels. FIG. 9 is an enlarged view of a connecting portion of the magnetic shield panel of FIG. A magnetic shield panel formed by sequentially laminating the end portions of a plurality of magnetic shield sheets in a stepwise manner is disposed so that the end surfaces thereof face each other with a gap therebetween. This is a magnetic bonding structure in which magnetic shield panels are magnetically bonded using a magnetic shield bonding plate 5 having a shape corresponding to the shape of the gap. The magnetic shield bonding plate 5 is formed by laminating a plurality of magnetic shield sheets, and the plane of the magnetic shield sheet of the magnetic shield panel and the plane of the magnetic shield sheet of the magnetic shield bonding plate are brought into contact with each other. According to the present invention, the magnetic shield panels can be magnetically joined without increasing the magnetic resistance at the joint. Further, according to the present invention, the magnetic shield panels can be magnetically bonded without increasing the thickness at the bonded portion. FIG. 10 shows the flow of magnetic flux in the connection part.

  As another example, as shown in FIG. 11, a magnetic shield sheet having a maximum length of 100 m can be obtained. Therefore, there is a method of laminating a long type according to a desired dimension of the magnetic magnetic shield room. is there. By forming a magnetic shield panel with such a shape, one side of the magnetic shield can be minimized because the number of joints of the magnetic shield panel can be minimized and the number of parts can be reduced. It is possible to create a magnetic shield panel. In the case of this magnetic shield panel, although the magnetic material is continuous in the longitudinal direction, since the magnetic material is not continuous in the short direction, the magnetic shield performance is higher in the magnetic shield rate in the longitudinal direction. For this reason, it is desirable to make the magnetic shield property isotropic by stacking layers obtained by rotating the longitudinal direction of the magnetic shield sheet described above by 90 °.

  The present invention relates to a method for depositing a metal film and a method for forming a conductor pattern, which are necessary for manufacturing a magnetic device, an electronic device, and an optical device, and more particularly to a method for forming a conductor pattern on a substrate easily and reliably. Can be used for

The top view of the magnetic shielding sheet (one sheet) which is a reference example . The top view and side view of a large area magnetic shield sheet (one layer) which are reference examples . The top view of the conventional magnetic shield sheet (one sheet). The top view and side view of the conventional large area magnetic shield sheet (1 layer). 1 is a partial cross-sectional view of a magnetic shield panel according to the present invention. The partial cross section figure of the conventional magnetic shield panel. The top view and side view of the magnetic shielding panel which concern on this invention. The top view and side view showing the magnetic junction structure concerning this invention. The enlarged side view of the magnetic junction part concerning this invention (before attachment). The enlarged side view of the magnetic junction part which concerns on this invention (after attachment). The top view and side view of a magnetic shield panel of another embodiment according to the present invention. The effect of the width of the magnetic connection surface of the large-area magnetic shield sheet as a reference example . Sectional drawing showing the magnetic connection structure of the magnetic shield panels by the conventional contact plate. It is a figure which shows the measuring method of a shield rate.

Explanation of symbols

1: Magnetic shield sheet 2: Large area magnetic shield sheet 3: Magnetic shield sheet (conventional)
4: Large area magnetic shield sheet (conventional)
5: Magnetic shield bonding plate

Claims (4)

Laminating a large-area magnetic shield sheet with one end of the magnetic shield sheet overlapped with the end of the adjacent magnetic shield sheet and the other end opposed to the end of the adjacent magnetic shield sheet on the back surface of the overlapping surface The position of the overlapping portion of the first large-area magnetic shield sheet and the position of the overlapping portion of the second large-area magnetic shield sheet are equal to the overlapping width of the magnetic shield sheets. A magnetic shield panel, wherein the end portions of the magnetic shield sheets of the large-area magnetic shield sheets adjacent to each other face each other are sequentially stacked. Width substantially the same superposition corners of the magnetic shield sheet or corners thickness magnetic shield panel suppresses claim 1, wherein the increase in the time of overlapped by chamfering a larger width it. A magnetic shield bonding plate having a shape corresponding to the shape of the gap, in which the magnetic shield panels formed by laminating the end portions of a plurality of magnetic shield sheets sequentially in a stepwise manner are arranged so that the end faces face each other through the gap. A magnetic bonding structure for magnetically bonding magnetic shield panels with each other, wherein the magnetic shield bonding plate is formed by laminating a plurality of magnetic shield sheets of the same number as the magnetic shield panel, and each layer of the magnetic shield panel facing each other magnetic junction structure for causing the magnetic shield sheet plane of the magnetic shield bonding plate and a plane of the magnetic shield sheet of each layer in contact respectively. Magnetic shield room, characterized in that used as a wall member to magnetic shield panel according to claim 1 or 2.

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