Shield panel, panel joint, and shield structure

Abstract

This shield panel (10) comprises: a first shield layer (11); a second shield layer (13) which is disposed facing the first shield layer (11) with a spacing therebetween; and an isolation layer (15) which is disposed between the first shield layer (11) and the second shield layer (13), is joined to both the first shield layer (11) and the second shield layer (13) and is made of a non-magnetic material.　The first shield layer (11) has a plane area larger than that of the second shield layer (13), and the first shield layer (11) has a peripheral region protruding outward from the entire peripheral edge of the second shield layer (13) in a plan view.

Description

Shield panels, panel joints and shield structures

[0001] The present invention relates to a shield structure used to block magnetic fields, electromagnetic waves, etc., as well as to magnetic shield panels that constitute the shield structure and panel joints that connect adjacent magnetic shield panels.

[0002] For example, equipment sensitive to magnetic noise requires magnetic shielding to reduce external magnetic noise, and in many cases, magnetic shielding made of soft magnetic materials is used. Advances in technology have made semiconductor device manufacturing equipment, in particular, more vulnerable to magnetic noise. Furthermore, peripheral equipment has become more sophisticated, with an increasing number of different types being installed, and each power cable worsening the magnetic environment, so equipment vulnerable to magnetic noise requires even higher-performance magnetic shielding. Soft magnetic materials used for magnetic shielding include pure iron, electromagnetic steel sheets, and permalloy (an iron-nickel alloy).

[0003] Because soft magnetic materials tend to have improved magnetic properties as they are rolled thinner, magnetic shield panels are typically constructed as plates, e.g., about 1 mm thick. These magnetic shield panels tend to bend easily and are difficult to handle. Patent Document 1, therefore, proposes a magnetic shield panel that integrally comprises an electromagnetic steel sheet and a reinforcing member that contacts or is close to the electromagnetic steel sheet in the thickness direction and extends in the surface direction of the electromagnetic steel sheet. The magnetic shield panel of Patent Document 1 also provides advanced magnetic noise countermeasures by stacking multiple sheets, e.g., electromagnetic steel sheets.

[0004] Japanese Patent Application Laid-Open No. 2021-150507

[0005] As the semiconductor device industry grows, the demand for magnetic shields is also increasing, causing problems for magnetic shield manufacturers in terms of their supply capacity. Magnetic shield rooms, which are installed to magnetically shield the entire semiconductor device manufacturing equipment, are particularly large in scale, and the number of days required for completion determines supply capacity, so there is a demand for manufacturing and construction methods that can further shorten the time required for completion.

[0006] When constructing a magnetic shield in a room within an existing building, it is necessary to attach magnetic shielding panels to one or more of the walls, floors, and ceilings, which takes many days. Furthermore, when high-performance magnetic shielding is required, a multi-layer structure is required, making construction more complicated. This not only lengthens the construction period, but also requires skilled engineers, making it difficult to secure the necessary personnel. While the above example has been given of magnetic fields as a target for shielding, the same situation applies to electromagnetic waves. The present invention solves the problem of shortening the construction period.

[0007] The shielding panel of the present invention comprises: a first shielding layer; a second shielding layer disposed opposite the first shielding layer with a gap therebetween; and an isolation layer made of a non-magnetic material disposed between the first shielding layer and the second shielding layer and bonded to both the first shielding layer and the second shielding layer. The first shielding layer has a larger planar area than the second shielding layer, and the first shielding layer comprises a connection region that protrudes outward from the periphery of the second shielding layer in a plan view.

[0008] It is preferable that the first shielding layer and the second shielding layer are each rectangular, have a similar relationship to each other, and are joined to the isolation layer so that their centers in the planar direction coincide, and that the connection region has a uniform dimension protruding outward from the entire periphery of the second shielding layer.

[0009] Preferably, one or both of the first and second shield layers are made of a soft magnetic material.

[0010] Preferably, both the first and second shield layers are made of a soft magnetic material, and the isolation layer is made of a honeycomb structure made of aluminum or an aluminum alloy.

[0011] Preferably, the first shield layer and the isolation layer are bonded together, and the second shield layer and the isolation layer are bonded together using an epoxy adhesive.

[0012] Preferably, the connecting region corresponds to one or both of a magnetic shield and an electromagnetic wave shield, and the connecting region is preferably inclined so that its tip approaches the second shield layer.

[0013] A panel joint is provided in a gap between a plurality of shielding panels arranged in a lattice with gaps between them, connecting the shielding functions of adjacent shielding panels, the panel joint comprising: a first joint having a shielding function and rectangular in plan view; a second joint having a shielding function and rectangular in plan view and arranged opposite the first joint with a gap between them; and an isolation layer made of a non-magnetic material arranged between the first joint and the second joint and joined to both the first joint and the second joint, wherein both ends of the first joint protrude beyond the isolation layer in a first direction, and both ends of the second joint protrude beyond the isolation layer in a second direction perpendicular to the first direction.

[0014] Preferably, the portion of the second joint that protrudes beyond the isolation layer is inclined so that its tip approaches the first joint.

[0015] The shield structure comprises a plurality of shield panels arranged in a lattice with gaps between them, and panel joints provided in the gaps between adjacent shield panels to connect the shielding functions of the adjacent shield panels, wherein the shield panels are any of the shield panels described above, and the panel joints are any of the panel joints described above.

[0016] Preferably, the first joints contact the connection regions of the adjacent first shield layers, and the second joints contact the adjacent second shield layers at portions thereof that protrude beyond the isolation layer in the first direction.

[0017] According to the present invention, a shielding panel in which the first and second shielding layers are already joined together to form a unit can be attached and fixed to the object to be shielded, such as a wall surface, so that construction can be carried out in a short period of time even without skilled engineers.

[0018] 1A and 1B are plan views (TV), front views (FV), and side views (SV) showing a magnetic shield panel according to an embodiment; a cross-sectional view taken along line II-II in FIG. 1; a plan view (TV), bottom view (BV), front view (FV), and side view (SV) showing a panel joint that magnetically conducts a magnetic shield panel according to an embodiment; a cross-sectional view taken along line IVA-IVA in FIG. 3 and a cross-sectional view taken along line IVB-IVB in FIG. 3; a diagram showing a procedure for attaching and fixing a magnetic shield panel to a wall surface to construct a shield structure, illustrating a step of fixing the magnetic shield panel to the wall surface; a diagram showing a step of fixing a panel joint to a gap between adjacent magnetic shield panels, following FIG. 5; a diagram showing a step of fixing a panel joint to a gap between adjacent magnetic shield panels, following FIG. 6; a diagram showing a step of fixing a panel joint to an intersection of four magnetic shield panels, following FIG. 7; a cross-sectional view showing a step of fixing a panel joint between adjacent magnetic shield panels, following FIG. 7. Fig. 1 is a cross-sectional view showing a step of fixing a panel joint according to a preferred embodiment between adjacent magnetic shield panels; Fig. 2 is a perspective view showing a magnetic shield panel according to a preferred embodiment; Fig. 3 is a diagram showing a procedure for manufacturing a magnetic shield panel according to a preferred embodiment; Fig. 4 is a diagram showing a procedure for connecting magnetic shield panels having four soft magnetic layers with a panel joint.

[0019] An embodiment of the present invention will be described below with reference to the accompanying drawings. The embodiment relates to a shield structure 1 comprising a plurality of shield panels 10 and a panel joint 30 that magnetically connects adjacent shield panels 10. As an example, the shield structure 1 is provided on a wall surface of a magnetically shielded room. The shield structure 1 can also be provided on a ceiling, floor, door panel, or shutter curtain in addition to a wall surface. The magnetic shield structure 1 can also be provided on a framework such as a light steel frame, joists, or sleepers, thereby forming a wall surface, ceiling, or the like. The following describes the shield panels 10, panel joints 30, and shield structure 1, in that order. While the following description uses a magnetic shield as an example, the shield panels 10 and panel joints 30 can also be used for electromagnetic wave shielding.

[0020] [Shield panel 10: see FIGS. 1 and 2] The shield panel 10 includes a first shield layer 11, a second shield layer 13 disposed opposite the first shield layer 11 at a distance, and an isolation layer 15 disposed between the first shield layer 11 and the second shield layer 13 and bonded to both the first shield layer 11 and the second shield layer 13. Because the first shield layer 11 and the second shield layer 13 are both made of flat plate material, the shield panel 10 is also flat. However, the magnetic shield panel of the present invention is not limited to being flat, and may have curved or bent portions.

[0021] [First shield layer 11: FIGS. 1 and 2] <Material of first shield layer 11> The first shield layer 11 is made of a plate made of a soft magnetic material. Examples of soft magnetic materials that can be used include pure iron, electromagnetic steel sheet, permalloy (iron-nickel alloy), amorphous alloy (Fe-based or Co-based), and nanocrystalline alloy. Among these, it is preferable to use a plate made of permalloy, which has low coercive force, high magnetic permeability, and a high magnetic shielding effect, as the first shield layer 11.

[0022] Permalloy is a general term for nickel-iron alloys containing 35 to 80 wt.% nickel (Ni), and JIS C 2531 specifies its chemical composition as "iron-nickel soft magnetic material." JIS C 2531 lists four types: PB, PC, PD, and PF, and of these, PC permalloy, which has magnetic properties of low coercive force and high permeability, is suitable for magnetic shielding. JIS is an abbreviation for Japanese Industrial Standards.

[0023] Permalloy can be heat-treated to adjust its magnetic and mechanical properties. Heat treatments include magnetic annealing, which brings out high magnetic permeability, and stress relief annealing, which improves workability. Magnetic annealing is performed to remove obstacles to magnetic domain movement, facilitating the movement of magnetic domain walls and rotation of magnetic domains due to external magnetic fields, thereby improving soft magnetic properties and especially bringing out high magnetic permeability. Magnetic annealing is performed at high temperatures of 1,000°C or higher in a reducing hydrogen atmosphere. Strain relief annealing is performed to remove residual stress due to processing and thermal history by recrystallizing the material by heating it above the recrystallization temperature. Strain relief annealing is performed at a lower temperature than magnetic annealing.

[0024] <Planar Shape of First Shield Layer 11> The first shield layer 11 has a rectangular, particularly square, shape in plan view. This is because it is suitable for arranging multiple shield panels 10 in a grid pattern to cover the surface to be magnetically shielded, such as a wall surface, without any gaps. However, the planar shape of the first shield layer 11 in the present invention is not limited to a rectangle, and may be a polygon such as a triangle or pentagon, as long as it can cover the surface to be magnetically shielded without any gaps.

[0025] <Dimensions of First Shield Layer 11> The planar dimensions of the first shield layer 11 are arbitrary, but the work of attaching the shield panel 10 to the surface to be magnetically shielded must be taken into consideration. If this work is performed manually, it is necessary to make the area as small as possible so that the shield panel 10 can be held comfortably and reduce the workload due to increased weight. On the other hand, if the area is smaller, the number of times the shield panel 10 must be attached to the same surface to be magnetically shielded increases, which may result in a longer construction period. Considering the above, the planar dimensions of the first shield layer 11, in the case of a square first shield layer 11, are preferably 550 to 750 mm, and more preferably 600 to 700 mm, per side.

[0026] The absolute dimensions of the first shield layer 11 in the planar direction are as described above, but the first shield layer 11 is required to be larger than the second shield layer 13. In other words, the first shield layer 11 has a larger planar area than the second shield layer 13, and the second shield layer 13 has a smaller planar area than the first shield layer 11. This is because, when the first shield layer 11 and the second shield layer 13 are laminated with the isolation layer 15 interposed between them, the peripheral portion of the first shield layer 11 protrudes from the peripheral edge of the second shield layer 13. The function of this protrusion of the first shield layer 11 will be described later.

[0027] The thickness of the first shield layer 11 can also be determined arbitrarily, but considering the need to reduce the burden of manual labor due to the increased weight of the shield panel 10 when attaching it to the surface to be magnetically shielded, it is preferable to use a thickness of, for example, 0.5 to 2.0 mm, and particularly 0.8 to 1.0 mm. This thickness ensures effective magnetic shielding.

[0028] [Second Shield Layer 13] <Material of Second Shield Layer 13> The second shield layer 13 is made of a soft magnetic material having the same chemical composition as the first shield layer 11. However, the second shield layer 13 and the first shield layer 11 do not need to be made of the same material. For example, the first shield layer 11 may be made of permalloy while the second shield layer 13 may be made of an electromagnetic steel sheet, or the first shield layer 11 may be made of PB permalloy while the second shield layer 13 may be made of PC permalloy. When the second shield layer 13 is made of permalloy, magnetic annealing and stress relief annealing are preferably performed.

[0029] <Planar shape of second shield layer 13> As described above, the second shield layer 13 has the same planar shape as the first shield layer 11, except that the second shield layer 13 has a smaller planar area than the first shield layer 11. As an example, the second shield layer 13 and the first shield layer 11 are similar to each other. Like the first shield layer 11, the second shield layer 13 can be formed into a polygonal shape other than a rectangle. However, it is assumed that the second shield layer 13 has the same type of polygonal shape as the first shield layer 11.

[0030] <Dimensions of Second Shield Layer 13> The second shield layer 13 has a smaller plane area than the first shield layer 11. Therefore, the second shield layer 13 has a side length in the range of 550 to 750 mm, or even in the range of 600 to 700 mm, which is smaller than that of the first shield layer 11. The dimension of the second shield layer 13 in the thickness direction is also selected from the same range as that of the first shield layer 11.

[0031] [Isolation layer 15, bonding layers 17A and 17B: see FIGS. 1 and 2] The isolation layer 15 is interposed between the first shield layer 11 and the second shield layer 13, and magnetically separates the first shield layer 11 from the second shield layer 13. Furthermore, the isolation layer 15 secures the first shield layer 11 and the second shield layer 13 on both the front and back sides via the bonding layers 17A and 17B, thereby ensuring the rigidity of the first shield layer 11 and the second shield layer 13.

[0032] The isolation layer 15 is made of a non-magnetic material to magnetically separate the first shield layer 11 and the second shield layer 13. Non-magnetic materials include metallic and non-metallic materials. Metallic materials include aluminum or aluminum alloys, copper or copper alloys, magnesium or magnesium alloys, etc., but aluminum or aluminum alloys, magnesium or magnesium alloys, which have low specific gravities, are preferably used to reduce the weight of the shield panel 10. Non-metallic materials include resin materials, paper, wood, fiber-reinforced plastic (FRP), etc.

[0033] The isolation layer 15 can be a solid structure of the respective materials, but is preferably a lighter structure than a solid member, such as a honeycomb structure as shown in Figure 11. The honeycomb structure can be made of a metal material, such as an aluminum alloy, or can also be made of paper or fiber-reinforced plastic (FRP). Furthermore, as for resin materials, foamed resins such as polyurethane (PUR), polystyrene (PS), and polyolefins (PE, PP, etc.) are preferred for their light weight.

[0034] The isolation layer 15 and the first shield layer 11, and the isolation layer 15 and the second shield layer 13 are bonded together by bonding layers 17A and 17B, respectively. The bonding layers 17A and 17B are preferably made of an adhesive. Bonding the first shield layer 11 and the second shield layer 13 with an adhesive can reduce mechanical stress that deteriorates soft magnetic properties from being applied to the first shield layer 11 and the second shield layer 13. An epoxy adhesive is preferably used as the adhesive. Epoxy adhesives are known to be of two types: a thermosetting type that is hardened by heating and a two-component hardening type that has excellent adhesive strength. The two-component hardening type is preferred. When bonding with the bonding layers 17A and 17B, it is desirable to minimize the application of stress that would deteriorate soft magnetic properties to the first shield layer 11 and the second shield layer 13, which are made of a soft magnetic material, while managing the usable time.

[0035] A front surface 11S, a back surface 11B, a front surface 13S, and a back surface 13B are specified for the first shield layer 11 and the second shield layer 13. The isolation layer 15 is bonded to the front surface 11S of the first shield layer 11 by a bonding layer 17A, and is also bonded to the back surface 13B of the second shield layer 13 by a bonding layer 17B.

[0036] [Relationship between the first shield layer 11, the second shield layer 13 and the isolation layer 15: see Figures 1 and 2] Next, the relationship between the first shield layer 11, the second shield layer 13 and the isolation layer 15, which are integrated by the bonding layers 17A and 17B, will be described.

[0037] The first shield layer 11 and the second shield layer 13, both of which have a square planar shape, are arranged so that their planar centers C1 coincide with each other and their four sides are parallel. Therefore, when the shield panel 10 is viewed from the second shield layer 13 side, the peripheral region of the first shield layer 11 protrudes outward from the periphery of the second shield layer 13. This peripheral region forms a first connection region 11CA that magnetically connects, i.e., conducts, the first shield layer 11 of an adjacent shield panel 10 via a panel joint 30. The front surface 11S of the first shield layer 11, excluding the first connection region 11CA, is covered by an isolation layer 15. This magnetic connection maintains the magnetic shielding function of adjacent shield panels 10.

[0038] The peripheral region of the second shield layer 13 forms a second connection region 13CA where the first shield layer 11 is magnetically connected to the first shield layer 11 of the shield panel 10 that is in contact with the second shield layer 13 via the panel joint 30. The entire front surface 13S of the second shield layer 13, including the second connection region 13CA, is exposed.

[0039] The isolation layer 15 has the same planar area as the second shield layer 13, and the front surface 15S is entirely covered by the back surface 13B of the second shield layer 13, and the back surface 15B is entirely covered by the front surface 11S of the first shield layer 11. In this way, only the side surfaces of the isolation layer 15, excluding the front surface 15S and the back surface 15B, are exposed to the outside.

[0040] In order to fasten the shield panel 10 with screws to, for example, a wall surface that constitutes the shielded room, screw holes 19 are formed in the shield panel 10, penetrating from the front surface 13S of the second shield layer 13 to the back surface 11B of the first shield layer 11. As an example, four screw holes 19 are formed.

[0041] [Unitization of Shield Panels 10] When forming a magnetic shield layer in a magnetically shielded room, a plurality of shield panels 10 are prepared. The plurality of shield panels 10 are unitized with the same specifications such as dimensions and shape.

[0042] 3 and 4, a panel joint 30 that magnetically connects adjacent shield panels 10 will be described. The panel joint 30 includes a first joint 31, a second joint 33 that is disposed opposite the first joint 31 at a distance, and an isolation layer 35 that is disposed between the first joint 31 and the second joint 33 and is bonded to both the first joint 31 and the second joint 33.

[0043] The first joint 31 contacts the first shield layers 11 of adjacent shield panels 10, thereby magnetically connecting the first shield layers 11, and the second joint 33 contacts the second shield layers 13 of adjacent shield panels 10, thereby magnetically connecting the second shield layers 13. The first joint 31 and the second joint 33 magnetically connect the first shield layers 11 and the second shield layers 13, and also function as a magnetic shield between adjacent shield panels 10. Therefore, the first joint 31 and the second joint 33 are made of the same soft magnetic material as the first shield layer 11 and the second shield layer 13. The first joint 31 and the second joint 33 also have the same thickness dimension as the first shield layer 11 and the second shield layer 13.

[0044] [First joint 31, second joint 33: see Figures 3 and 4] <Planar shape and dimensions> The first joint 31 and the second joint 33 are disposed between adjacent shielding panels 10 at a distance from each other, and both have a rectangular shape in a planar view. However, the first joint 31 has a larger longitudinal dimension (L) than the second joint 33, and the second joint 33 has a larger widthwise dimension (W) than the first joint 31. Therefore, when the panel joint 30 is viewed in a planar view, the first joint 31 protrudes more in the longitudinal direction (L) than the second joint 33, and the second joint 33 protrudes more in the widthwise direction (W) than the first joint 31. In the panel joint 30, the longitudinal dimension (L) of the first joint 31 is set to be equal to or slightly shorter than the length of one side of the shielding panel 10. Furthermore, the widthwise dimension (W) of the second joint 33 and the isolation layer 35 is set to be equal to or slightly shorter than the gap between adjacent shielding panels 10. The longitudinal direction (L) corresponds to the first direction in this application, and the width direction (W) corresponds to the second direction in this application, and the two directions are perpendicular to each other.

[0045] [Isolation layer 35, bonding layers 37A and 37B: see FIGS. 3 and 4] The isolation layer 35 is interposed between the first joint 31 and the second joint 33, and magnetically separates the first joint 31 and the second joint 33. The isolation layer 35 also secures the rigidity of the first joint 31 and the second joint 33 by holding the first joint 31 and the second joint 33 on both the front and back sides via the bonding layers 37A and 37B.

[0046] The isolation layer 35 is made of a non-magnetic material to magnetically separate the first joint 31 and the second joint 33. Specifically, the isolation layer 35 is made of the same non-magnetic material as the isolation layer 15 of the shield panel 10.

[0047] The isolation layer 35 and the first joint 31, and the isolation layer 35 and the second joint 33 are respectively bonded by bonding layers 37A and 37B. The bonding layers 37A and 37B are preferably made of the same adhesive as the bonding layers 17A and 17B.

[0048] The first joint 31 and the second joint 33 each have a front surface 31S, a rear surface 31B, a front surface 33S, and a rear surface 33B. The isolation layer 35 is bonded to the rear surface 31B of the first joint 31 by a bonding layer 37A, and is also bonded to the rear surface 33B of the second joint 33 by a bonding layer 37B.

[0049] [Relationship Between First Joint 31, Second Joint 33, and Isolation Layer 35: See FIGS. 1 and 2] Next, the relationship between first joint 31, second joint 33, and isolation layer 35, which are integrated by bonding layers 37A and 37B, will be described.

[0050] The first joint 31 and the second joint 33, both of which have a rectangular planar shape, are arranged so that their centers C2 coincide with each other and their four sides are parallel to each other.

[0051] When the panel joint 30 is viewed from above, both ends of the first joint 31 in the longitudinal direction (L) protrude outward beyond the periphery of the second joint 33 in the longitudinal direction (L). This protruding region covers the wall surface WS. In addition, first connection regions 31CA are formed on both sides of the first joint 31 in the width direction (W) to magnetically connect the first shield layers 11 of adjacent shield panels 10.

[0052] In addition, the second joint 33 contacts the second shield layers 13 of the adjacent shield panels 10, thereby forming a second connection area 33CA that magnetically connects the second shield layers 13 to each other.

[0053] The isolation layer 35 has the same widthwise (W) dimension as the first joint 31 and the same longitudinal (L) dimension as the second joint 33. The front surface 35S is entirely covered by the back surface 31B of the first joint 31, and the back surface 35B is entirely covered by the front surface 33S of the second joint 33. In this way, only the side surfaces of the isolation layer 35, excluding the front surface 35S and the back surface 35B, are exposed to the outside.

[0054] To secure the panel joint 30 to, for example, a wall constituting the shielded room with screws, screw holes 39A are formed in the panel joint 30, penetrating from the front surface 31S of the first joint 31 to the back surface 33B of the second joint 33, and screw holes 39B are formed in both ends of the second joint 33 in the longitudinal direction L, penetrating portions not laminated with the isolation layer 35. As an example, seven screw holes 39A and four screw holes 39B are formed. The reason for the large number of screw holes 39A and 39B formed in the panel joint 30 is as follows: The panel joint 30 is located in the gap between the shield panels 10, where magnetism passes more easily than through the shield panel 10 itself. Therefore, more screw fastening points are provided than for the shield panels 10 to prevent magnetism from leaking out of the gap.

[0055] [Installation Example of Shield Structure 1: See FIGS. 5 to 10] An example of a procedure for installing a plurality of shield panels 10 and a plurality of panel joints 30 to obtain a shield structure 1 will be described with reference to FIGS. 5 to 10. This installation procedure includes a first step (STEP 1: FIG. 5) of fixing the plurality of shield panels 10 to the wall surface of a shielded room, for example, and a second step (STEP 2: FIGS. 6 to 8) of fixing panel joints 30 between adjacent shield panels 10. Note that the following illustrations show four shield panels 10, which are a part of the plurality of shield panels 10 arranged over the entire wall surface.

[0056] [STEP 1: See FIG. 5 ] The required number of shielding panels 10 and fasteners, such as screws SC, for securing the shielding panels 10 to the wall surface WS are prepared. Four shielding panels 10 (10A, 10B, 10C, and 10D) are then secured in parallel with adjacent shielding panels 10 spaced apart from one another. That is, shielding panel 10B is positioned adjacent to shielding panel 10A in the horizontal direction H, and shielding panel 10C is positioned adjacent to shielding panel 10A in the vertical direction V. Shielding panel 10D is positioned adjacent to shielding panel 10B in the vertical direction V and adjacent to shielding panel 10C in the horizontal direction H. That is, shielding panels 10A to 10D are arranged in a matrix layout. Note that shielding panels 10A to 10D are used to distinguish one from the other and have the same specifications.

[0057] Gaps SV1 and SV2 extending in the vertical direction V are provided between shield panels 10A and 10B adjacent to each other in the horizontal direction H, and between shield panels 10C and 10D adjacent to each other in the horizontal direction H, which are necessary for arranging panel joints 30. Gaps SH1 and SH2 extending in the horizontal direction H are provided between shield panels 10A and 10C adjacent to each other in the vertical direction V, and between shield panels 10B and 10D adjacent to each other in the vertical direction V, which are necessary for arranging panel joints 30.

[0058] When the shield panel 10 is fixed to the wall surface WS with the screws SC, the operator performing the construction may hold the shield panel 10, or the shield panel 10 may be temporarily fixed to the wall surface WS using double-sided adhesive tape.

[0059] When the required number of shield panels 10A to 10D, four in this case, have been fixed to the wall surface WS with the screws SC, STEP 1 is completed and the process moves to the second step of fixing the panel joint 30 to the wall surface WS.

[0060] [STEP 2: See FIGS. 6 to 8] Panel joints 30 (30A, 30B, 30C, 30D) corresponding to the number of gaps SV1, SV2, SH1, SH2 between shielding panels 10A to 10D are prepared, along with fasteners, such as screws SC, for attaching the panel joints 30 to the wall surface WS (FIG. 6, STEP 2-1). Seven screw holes 39A and two screw holes 39B are drilled in the panel joints 30, and seven screws SC1 are prepared to fit into the screw holes 39A and two screws SC2 are prepared to fit into the screw holes 39B. The reason why the number of screw holes 39A and 39B formed in the panel joints 30 is greater than the number of screw holes 19 formed in the shielding panel 10 is as described above.

[0061] As an example, the panel joint 30 is installed from the gap SV1 (STEP 2-2 in FIG. 6). Thereafter, as shown in FIG. 7 (STEP 2-3, STEP 2-4) and FIG. 8 (STEP 2-5, 2-6), the panel joints 30 (30A to 30D) are installed and fixed in the order of the gaps SH1, SV2, and SH2.

[0062] FIG. 9 shows the process of the panel joint 30 closing the gap SV1 (to SH2). The panel joint 30 is inserted into the gap SV1 from the side of the first joint 31 (STEP A). When the panel joint 30 is inserted all the way, the first joint 31 comes into contact with both the adjacent first shield layers 11A and 11B, and the second joint 33 comes into contact with both the adjacent second shield layers 13A and 13B (FIG. 9 STEP B). As a result, the first shield layers 11A and 11B, and the second shield layers 13A and 13B, which had previously been magnetically separated, are magnetically connected. As a result, the shield structure 1 can connect the magnetic shielding functions of two layers simply by placing the panel joint 30 between adjacent shield panels 10.

[0063] Even after the four panel joints 30 are fixed, an intersection gap RS remains that cannot be closed by the panel joints 30 (30A to 30D), so this intersection gap RS is closed by a cross joint 40 (FIG. 8, STEPs 2-5 and 2-6). The cross joint 40 is made of a soft magnetic material, just like the first shield layer 11 and the second shield layer 13, and is fixed to the wall surface WS with screws SC while placed on the tip of the second joint 33 of each of the four shield panels 10.

[0064] As described above, each of the four gaps SV1, SH1, SV2, and SH2 is closed by the panel joint 30, and the intersecting gap is also closed by the cross joint 40, so the four shield panels 10 and the wall surface WS closed by the four panel joints 30 are magnetically shielded. The cross joint 40 is magnetically connected to the four first shield layers 11 at the back of the intersecting gap. The gaps SV1, SH1, SV2, and SH2 have the same dimensions in the horizontal direction (H) and vertical direction (V). The gaps SV1, SH1, SV2, and SH2 are sized so that the first joints 31 and the isolation layers 35 of the panel joints 30 can be inserted without any gaps.

[0065] [Effects of the Shield Panel 10, the Panel Joint 30, and the Shield Structure 1] In the shield panel 10, the first shield layer 11, the isolation layer 15, and the second shield layer 13 are joined together to form a unit. Therefore, in on-site work, the number of man-hours required is reduced compared to individually attaching the first shield layer 11, the isolation layer 15, and the second shield layer 13 to, for example, the wall surface WS, and the construction period can be shortened. In addition, because the panel joint 30 is also unitized, the number of man-hours required is reduced compared to individually attaching the first joint 31, the isolation layer 35, and the second joint 33, and the construction period can be shortened.

[0066] Furthermore, by making the specifications of the multiple shielding panels 10 the same, it is possible to prevent workers from getting the shielding panels 10 facing the wrong way around or in the wrong direction when attaching them, thereby eliminating the need for incorrect attachment or reattaching, and wasting time and effort. This also applies to the panel joints 30.

[0067] In the shield panel 10, the first shield layer 11 and the second shield layer 13 have different but similar dimensions. This makes it easy to establish magnetic conductivity by connecting the first shield layer 11A and the first shield layer 11B, and the second shield layer 13A and the second shield layer 13B of adjacent shield panels 10 with the panel joint 30. In particular, the shapes and dimensions of the first joint 31 and the second joint 33 in the panel joint 30 are specified to accommodate the dimensional difference between the first shield layer 11 and the second shield layer 13, making it easy to establish magnetic conductivity.

[0068] While preferred embodiments of the present invention have been described above, the configurations described in the above embodiments may be selected or modified as appropriate without departing from the spirit and scope of the present invention. [Shielding Target] In the above embodiments, both the first shield layer 11 and the second shield layer 13 are constructed of soft magnetic materials for magnetic shielding. However, the shielding of the present invention is not limited to magnetic shielding. For example, electromagnetic waves may also be shielded. Note that radio waves are defined as electromagnetic waves with a frequency of 3 THZ or less in the Radio Act, so the concept of electromagnetic wave shielding here includes radio wave shielding. For example, one of the first shield layer 11 and the second shield layer 13 may be a magnetic shielding layer, and the other of the first shield layer 11 and the second shield layer 13 may be an electromagnetic wave shielding layer. Furthermore, both the first shield layer 11 and the second shield layer 13 may be electromagnetic wave shielding layers. In a shielding structure intended for electromagnetic wave shielding, it is more desirable to seal between components, such as the shield panel 10 and the panel joint 30, than to use a magnetic shield to prevent electromagnetic wave leakage.

[0069] Examples of materials that can be used to form the electromagnetic wave shielding layer include metals, ferrite materials, and conductive polymers, all of which can be used for the shielding layer of the present invention. Metal materials that are highly conductive include copper, copper alloys, aluminum, aluminum alloys, and economically advantageous Galvalume steel sheets (registered trademark). Ferrite materials are a type of magnetic material primarily composed of iron oxide and have excellent electromagnetic wave absorption properties at high frequencies. Conductive polymers are ordinary polymers mixed with conductive particles, making them lightweight and easy to process.

[0070] [Improvement of Contact Pressure of Second Joint 33 Against Second Shield Layer 13: FIG. 10 ] The second joint 33 in the panel joint 30 described above, including the portion protruding from the isolation layer 35 in the width direction (W), is flattened as a whole and parallel to the second shield layers 13, 13. In contrast, as shown in FIG. 10 , the portion protruding from the isolation layer 35 in the width direction (W) is tilted by a small angle. For example, when the panel joint 30 is fully inserted into the gap SV1, the portion protruding from the isolation layer 35 elastically deforms by the amount of the tilt. Then, when the panel joint 30 is fixed with the screw SC, the contact pressure of the second joint 33 against the second shield layers 13, 13 increases, contributing to improved magnetic shielding performance. To improve the contact pressure between the first joint 31 and the first shield layer 11, the first connection region 11CA of the first shield layer 11 can be tilted toward the second shield layer 13. As a result, for example, when the panel joint 30 is inserted all the way into the gap SV1, the first connection region 11CA is elastically deformed by the amount of tilt.

[0071] [Application of Honeycomb Structure to Isolation Layer 15: See Figures 11 and 12] As described above, a honeycomb structure (Figure 11) is used for the isolation layer 15. In this case, when bonding the first shield layer 11 and the second shield layer 13 to the front and back of the isolation layer 15, it is preferable to apply pressure P so that the first and second shield layers 11 and 13 face each other on the front and back sides via the first and second shield layers 11 and 13. If the first and second shield layers 11 and 13 are made of permalloy, heat treatment (magnetic annealing) may cause slight distortion (warping) of the originally flat surfaces. However, by forming bonding layers 17A and 17B made of an adhesive while applying pressure P, the first and second shield layers 11 and 13 can be bonded to the isolation layer 15 without gaps while reducing or correcting the distortion. This is advantageous for achieving high magnetic shielding performance. In Figure 12, the bonding layers 17A and 17B are shown separated from the first shield layer 11, the second shield layer 13, and the isolation layer 15, but they can be applied to the first shield layer 11 and the second shield layer 13 and then bonded to the isolation layer 15, for example.

[0072] [Example of Stacking Three or More Layers: See FIG. 13] While the above-described embodiment has been described as including two shield layers, a first shield layer 11 and a second shield layer 13, the present invention can also provide a shield panel and a shield structure including three or more shield layers. FIG. 13 shows an example including four shield layers. In this example, the shield panel 10 includes a third shield layer 12, a fourth shield layer 14, an isolation layer 16, and an isolation layer 18 in addition to a first shield layer 11, a second shield layer 13, and an isolation layer 15. Furthermore, the panel joint 30 includes a third joint 32, a fourth joint 34, an isolation layer 36, and an isolation layer 38 in addition to a first joint 31, a second joint 33, and an isolation layer 35.

[0073] REFERENCE SIGNS LIST 1 Shield structure 10 Shield panel 11 First shield layer 11S Front surface 11B Back surface 11CA First magnetic connection area 13 Second shield layer 13S Front surface 13B Back surface 13CA Second magnetic connection area 15 Isolation layer 17A, 17B Joining layer 19 Screw hole 30 Panel joint 31 First joint 33 Second joint 35 Isolation layer 37A, 37B Joining layer 39A, 39B Screw hole 40 Cross joint WS Wall surface SC Screw H Horizontal direction V Vertical direction W Width direction L Longitudinal direction SV1, SV2, SH1, SH2 Gap

Claims

1. A shielding panel comprising: a first shielding layer; a second shielding layer disposed opposite the first shielding layer with a gap therebetween; and an isolation layer made of a non-magnetic material disposed between the first shielding layer and the second shielding layer and joined to both the first shielding layer and the second shielding layer, wherein the first shielding layer has a larger planar area than the second shielding layer, and the first shielding layer has a connection region that protrudes outward from the periphery of the second shielding layer in the planar direction.

2. A shielding panel as claimed in claim 1, wherein the first shielding layer and the second shielding layer are each rectangular, have a similar relationship to each other, are joined to the isolation layer so that their centers in the planar direction coincide, and the dimensions of the connection regions protruding outward from the periphery of the second shielding layer are uniform.

3. The shield panel according to claim 1, wherein one or both of the first shield layer and the second shield layer are made of a soft magnetic material.

4. The shield panel according to claim 1, wherein both the first shield layer and the second shield layer are made of a soft magnetic material, and the isolation layer is made of a honeycomb structure made of aluminum or an aluminum alloy.

5. The shield panel according to claim 1, wherein the first shield layer and the isolation layer, and the second shield layer and the isolation layer are joined with an epoxy adhesive.

6. The shield panel according to claim 1, which corresponds to one or both of a magnetic shield and an electromagnetic wave shield.

7. The shielding panel according to claim 1, wherein the connection area is inclined so that its tip approaches the second shielding layer.

8. A panel joint provided in a gap between a plurality of shielding panels arranged in a lattice with gaps between them, connecting the shielding functions of adjacent shielding panels, comprising: a first joint having a shielding function and rectangular in shape in a plan view; a second joint having a shielding function and rectangular in shape in a plan view, arranged opposite the first joint with a gap; and an isolation layer made of a non-magnetic material, arranged between the first joint and the second joint and joined to both the first joint and the second joint, wherein the first joint protrudes beyond the isolation layer at both ends in a first direction, and the second joint protrudes beyond the isolation layer at both ends in a second direction perpendicular to the first direction.

9. A panel joint according to claim 8, wherein the portion of the second joint that protrudes beyond the isolation layer is inclined so that its tip approaches the first joint.

10. A shield structure comprising: a plurality of shield panels arranged in a lattice pattern with gaps between them; and panel joints provided in the gaps between adjacent shield panels to connect the shielding functions of the adjacent shield panels, wherein the shield panels are the shield panels defined in claim 1; and the panel joints are the panel joints defined in claim 8.

11. The shield structure according to claim 10, wherein the first joints contact the connection regions of the adjacent first shield layers, and the second joints contact the adjacent second shield layers at portions that protrude beyond the isolation layer in the second direction.

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