JP7545280B2 - Electromagnetic wave shielding panel and its manufacturing method - Google Patents

Description

The present invention relates to an electromagnetic wave shielding panel and a manufacturing method thereof.

Patent Document 1 discloses an electromagnetic wave shielding housing for shielding electronic components housed within the housing from external electromagnetic waves, or for preventing electromagnetic waves emitted from the electronic components from leaking outside the housing. This electromagnetic wave shielding housing includes a housing molded from a resin material and metal foil adhered to the inner wall surface of the housing.

JP 2001-230586 A

By the way, in order to improve the electromagnetic wave shielding effect of the wall (panel) of an electromagnetic wave shielding enclosure, it is possible to stack multiple metal foils (metal layers) that reflect electromagnetic waves at intervals.

However, even with this type of configuration, if the multiple metal layers are not grounded, sufficient electromagnetic shielding effect cannot be obtained. On the other hand, if each of the multiple metal layers is grounded, the configuration may become complicated.

The present invention was made in consideration of these points, and its purpose is to reliably improve the electromagnetic wave shielding effect with a simple configuration.

To achieve the above object, in this invention, two metal layers adjacent in the stacking direction are brought into conductive contact or bonded to each other, and at least one of the two metal layers is conductively connected to a dischargeable object.

Specifically, the first invention is an electromagnetic wave shielding panel that is composed of a laminate of multiple metal layers and a resin layer, and two of the multiple metal layers that are adjacent to each other in the stacking direction are in contact with or bonded to each other and have a conductive part that can be conductive with each other and a spaced part that is spaced from each other, a resin body is disposed between both metal layers in the spaced part, and at least one of the two metal layers is provided with an earth connection part that is connected to an object that can discharge electricity.

The second invention is the first invention, characterized in that the resin layer is made of a first resin having flame retardancy and is the topmost layer of the laminate, one of the two metal layers is the bottommost layer of the laminate, and the resin body is made of a second resin different from the first resin.

The third invention is characterized in that in the first or second invention, the conductive portion is formed by bonding the two metal layers together with a conductive adhesive.

The fourth invention is any one of the first to third inventions, characterized in that the conductive portion has an adhesive portion where the two metal layers are adhered to each other with an adhesive, and a contact portion where the two metal layers are not adhered to each other with an adhesive.

The fifth invention is a manufacturing method for an electromagnetic wave shielding panel according to the first invention, comprising a preparation step of preparing a plurality of metal foils that are the material for the plurality of metal layers, and a plurality of divided resin materials that are the material for the resin layers and the resin body, which are formed by dividing a sheet-like resin material; an arrangement step of arranging the plurality of metal foils and the plurality of divided resin materials in a lamination direction in a cavity of a molding die; and a compression step of compressing the molding die in a closed state after the arrangement step, wherein the arrangement step is characterized in that the plurality of divided resin materials are arranged at intervals between the two metal foils so that two metal foils corresponding to two adjacent metal layers having the conductive portion and the separating portion have the conductive portion and the separating portion when compressed in the compression step.

According to the first invention, the electromagnetic wave shielding panel is composed of a laminate of multiple metal layers and resin layers, and two of the multiple metal layers adjacent to each other in the stacking direction have a spaced apart portion, so that a higher electromagnetic wave shielding effect is obtained than an electromagnetic wave shielding panel having only one metal layer. In addition, the two metal layers adjacent to each other in the stacking direction have a conductive portion that can conduct electricity to each other, and at least one of the two metal layers is provided with an earth connection portion connected to an object that can discharge electricity, so that both of the two metal layers are earthed. Therefore, the electromagnetic wave shielding effect can be reliably improved with a simple configuration.

According to the second invention, the resin layer is made of a first resin having flame retardancy and is the top layer of the laminate, and one of the two metal layers is the bottom layer of the laminate. Therefore, the electromagnetic wave shielding panel can reliably improve the electromagnetic wave shielding effect with a simple structure, and both the top and bottom sides can be made flame retardant.

According to the third invention, the conductive portion is bonded to the two metal layers by a conductive adhesive so that the two metal layers are not separated from each other in the conductive portion, so that the two metal layers can be reliably made conductive to each other. Therefore, the electromagnetic wave shielding effect can be reliably improved with a simple configuration.

According to the fourth invention, the conductive portion has an adhesive portion where the two metal layers are bonded to each other with an adhesive, and a contact portion where the two metal layers are not bonded to each other with an adhesive. Therefore, even if a non-conductive adhesive is used for the adhesive portion, the metal layers contact each other conductively at the contact portion, and both of the two metal layers are grounded. Therefore, the electromagnetic wave shielding effect can be reliably improved with a simple configuration.

According to the fifth invention, it is possible to manufacture an electromagnetic wave shielding panel that achieves the effects of the first invention.

1 is a schematic cross-sectional view showing an electromagnetic wave shielding box using an electromagnetic wave shielding panel according to a first embodiment. FIG. 2 is an enlarged view of an assembly portion in FIG. 1 . FIG. 2 is an enlarged view of an electromagnetic wave shielding panel portion in FIG. 1 . 3 is a schematic diagram showing the surface of a first metal foil in a preparation process for manufacturing an electromagnetic wave shielding panel. FIG. 11 is a schematic cross-sectional view showing a placement process. FIG. FIG. 4 is a cross-sectional schematic diagram showing a compression process. FIG. 7 is a view equivalent to FIG. 3 of a second embodiment. FIG. 7 is a view equivalent to FIG. 5 of a second embodiment.

The following describes in detail an embodiment of the present invention with reference to the drawings. The following description of the preferred embodiment is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

First Embodiment
In the first embodiment, an electromagnetic wave shielding box 1 that houses a vehicle battery X (housed item) is shown as an application example of an electromagnetic wave shielding panel P1 (hereinafter, sometimes simply referred to as a "panel") according to the present invention. The electromagnetic wave shielding box 1 is for shielding electromagnetic waves directed toward the outside so that electromagnetic waves emitted by the housed battery X do not affect external electronic devices, and for shielding electromagnetic waves directed toward the inside so that electromagnetic waves generated outside do not affect the battery X.

-Electromagnetic wave shielding box-
1 shows an electromagnetic wave shielding box 1 according to this embodiment. In the following, the term "front side" refers to the exterior side of the electromagnetic wave shielding box 1, and the term "rear side" refers to the interior side of the electromagnetic wave shielding box 1.

The electromagnetic wave shielding box 1 comprises a lower case 2 that receives the battery X, and an upper case 3 (electromagnetic wave shielding panel P1) that is attached to the upper side of the lower case 2 and covers the battery X. The lower case 2 and upper case 3 each have recesses 2a, 3a that form a storage space for storing the battery X. The dimensions of the electromagnetic wave shielding box 1 and the thicknesses of the lower case 2 and upper case 3 need only be sufficient to stably store the battery X.

The lower case 2 has a bottom 21 that is rectangular when viewed from the top and bottom, a wall 22 that is provided on the upper side of the bottom 21 at the periphery of the bottom 21, and an outer peripheral flange 23 that surrounds the entire outer periphery of the wall 22 at the assembly part A with the upper case 3 at the upper end of the wall 22. The outer peripheral flange 23 is formed in a plate shape, and both plate surfaces face in the vertical direction. The outer peripheral flange 23 has a through hole 24 for inserting a bolt B. The bottom 21, the wall 22, and the outer peripheral flange 23 of the lower case 2 are all made of metal members made of metals such as iron, aluminum, copper, and stainless steel. The lower case 2 is placed on the vehicle body (not shown) so as to come into contact with the vehicle body. In other words, the lower case 2 is grounded by coming into contact with the vehicle body, which is an object that can discharge electricity.

The upper case 3 has a ceiling portion 31 that is rectangular when viewed in the vertical direction, a wall portion 32 provided on the lower side of the ceiling portion 31 at the peripheral portion of the ceiling portion 31, and an outer peripheral flange 33 that surrounds the entire outer periphery of the wall portion 32 at the assembly portion A where the lower end of the wall portion 32 is attached to the lower case 2. The outer peripheral flange 33 is formed in a plate shape, and both plate surfaces face in the vertical direction.

2 shows an assembly portion A of the lower case 2 and the upper case 3, enlarging the dashed line portion II in FIG. 1. The outer peripheral flange 33 of the upper case 3 is overlapped with the outer peripheral flange 23 of the lower case 2, with its lower surface facing and in contact with the upper surface of the outer peripheral flange 23 of the lower case 2. In this state, the lower case 2 and the upper case 3 are assembled to each other by inserting bolts B into both outer peripheral flanges 23, 33. Nuts N are welded to the portions of the lower case 2's outer peripheral flange 33 where the bolts B are inserted, and both outer peripheral flanges 23, 33 are fixed to each other by fastening the bolts B to the nuts N. There may be several portions of the outer peripheral flanges 23, 33 fixed to each other by the bolts B and nuts N (one each on the left and right sides of the accommodation space is shown in FIG. 1) so that the lower case 2 and the upper case 3 can be stably assembled to each other.

A metallic collar 34 is embedded in the outer peripheral flange 33 of the upper case 3 at the portion where the bolt B is inserted. A through hole 35 is formed inside the collar 34, penetrating in the vertical direction, so that the bolt B can be inserted. The lower end face of the collar 34 is exposed below the outer peripheral flange 33 and is approximately flush with the lower surface of the outer peripheral flange 33, while the upper end face of the collar 34 is exposed above the outer peripheral flange 33 and is flush with the upper surface of the outer peripheral flange 33. The lower end face of the collar 34 is in contact with the upper surface of the outer peripheral flange 23 of the opposing lower case 2, so that the collar 34 can be electrically conductive with the lower case 2.

Between the two outer flanges 23, 33, a groove D is formed along the entire circumference of the outer flange 33, on the inner side of the collar 34, and a gasket G is provided around the entire circumference of the groove D to prevent water from entering the inner side and the storage space from the outside.

-Electromagnetic wave shielding panel-
Fig. 3 is an enlarged view of the dashed line portion III in Fig. 1, showing an electromagnetic wave shielding panel P1 constituting the upper case 3 (the electromagnetic wave shielding panel P1 refers to the upper case 3 itself). This panel P1 is composed of a laminate including a first metal layer 36a, a second metal layer 36b laminated on the front side of the first metal layer 36a, and a resin layer 37 laminated on the front side of the second metal layer 36b.

The first metal layer 36a constitutes the layer on the back side of the panel P1 in the ceiling portion 31 and the wall portion 32. Specifically, the first metal layer 36a is exposed on the back surface (lower surface) of the ceiling portion 31 (see FIG. 3), and then on the back surface (inner peripheral surface) of the wall portion 32 (see FIG. 2). The first metal layer 36a is exposed on the lower surface of the connection portion between the wall portion 32 and the outer peripheral flange 33, and this exposed portion is in contact with the upper surface of the opposing outer peripheral flange 23 of the lower case 2. In other words, the contact portion of the first metal layer 36a with the upper surface of the outer peripheral flange 23 of the lower case 2 constitutes the first earth connection portion E1 that is conductively connected to the vehicle body via the lower case 2 (see FIG. 2).

The second metal layer 36b is embedded in the resin layer 37 of the ceiling portion 31 and the wall portion 32 (see Figures 2 and 3). Specifically, the second metal layer 36b is formed in a wavy shape in cross section so that portions close to the first metal layer 36a and portions distant from the first metal layer 36a are arranged alternately (see Figure 3).

Due to the shape of the second metal layer 36b described above, the two metal layers 36a, 36b have a conductive portion C that can conduct electricity with each other, and a separation portion S that is spaced apart from each other. The conductive portion C has an adhesive portion Ad where the two metal layers 36a, 36b are bonded to each other with an adhesive, and a contact portion Ct where they are not bonded to each other with an adhesive and are simply in contact with each other.

Both metal layers 36a, 36b are made of metal foil such as aluminum, copper, stainless steel, permalloy, etc. The thickness of both metal layers 36a, 36b is preferably 50 μm or more from the viewpoint of enabling panel P1 to exhibit a large electromagnetic wave shielding effect, and is preferably 100 μm or less from the viewpoint of providing appropriate formability for the arrangement process and compression process described below.

The resin layer 37 is made of a first resin having flame retardancy. The resin layer 37 constitutes the topmost layer of the panel P1, and covers the top sides of both metal layers 36a, 36b to prevent corrosion of both metal layers 36a, 36b. In other words, the resin layer 37 is exposed on the surfaces of the ceiling portion 31 and the wall portion 32 and on the upper surface of the outer peripheral flange 33. The first resin is a thermosetting resin, and is specifically made of phenol resin, epoxy resin, etc. A flame retardant is blended into the first resin. The thickness of the resin layer 37 is, for example, 1.5 to 3.5 mm.

A resin body 38a is disposed between the metal layers 36a, 36b in the separation portion S between the metal layers 36a, 36b. The resin body 38a is composed of a second resin that does not have flame retardancy. The second resin is a thermosetting resin, and is specifically composed of a phenolic resin, an epoxy resin, or the like. The second resin differs from the first resin in that it does not contain a flame retardant.

The configuration of the outer peripheral flange 33 of the upper case 3 will be described below with reference to FIG. 2. On the upper side of the first metal layer 36a exposed on the lower surface of the connection between the wall portion 32 of the upper case 3 and the outer peripheral flange 33, a third metal layer 36c having an adhesive portion Ad bonded to the first metal layer 36a and a contact portion Ct in contact with the first metal layer 36a is embedded in the resin layer 37. The third metal layer 36c is formed along the entire circumference of the outer peripheral flange 33. In the third metal layer 36c, a hole penetrating the collar 34 is formed at the portion where the collar 34 is embedded, and the inner peripheral end of this hole is in contact with the outer peripheral surface of the collar 34. In other words, the third metal layer 36c constitutes a second earth connection portion E2 that is conductively connected to the vehicle body via the collar 34 and the lower case 2.

- Manufacturing method for electromagnetic wave shielding panels -
4 to 6 show a method for manufacturing the electromagnetic wave shielding panel P1. The method for manufacturing the electromagnetic wave shielding panel P1 includes a preparation step, a placement step, and a compression step.

--Preparation process--
In the preparation step, the first metal foil M1 which is the material of the first metal layer 36a, the second metal foil M2 which is the material of the second metal layer 36b, the third metal foil M3 which is the material of the third metal layer 36c, a plurality of first divided resin materials R1, R1, ... which are the material of the resin layer 37 formed by dividing a flame-retardant sheet-like resin material (first resin), and a plurality of second divided resin materials R2, R2, ... which are the material of the resin body 38a formed by dividing a sheet-like resin material (second resin) that does not have flame retardancy are prepared. Each of the first divided resin materials R1 and each of the second divided resin materials R2 are formed by dividing and cutting a roll of the sheet-like resin material into long pieces.

The first metal foil M1 and the second metal foil M2 are both formed in a generally rectangular shape with a size that allows them to be provided along the ceiling portion 31 and the wall portion 32, and the third metal foil M3 is formed in a shape that follows the outer peripheral flange 33. Each of the three metal foils M1, M2, and M3 is made of one sheet of the same type of metal. Note that each of the three metal foils M1, M2, and M3 may not be made of a single sheet, but may be made of multiple sheets whose ends are overlapped with each other.

A liquid hot melt adhesive is applied to the surface of the first metal foil M1 and both surfaces of the second metal foil M2 and the third metal foil M3 in order to bond each metal foil to the first resin and the second resin and to form the adhesive part Ad between the two metal layers 36a, 36b. For example, a polyolefin-based, polyester-based, polyurethane-based, or the like is used as the hot melt adhesive. The adhesive is applied by masking so that the application sites (adhesive parts Ad) are spaced apart from each other, as shown in Figures 4 and 5. Note that in Figures 4 and 5, the adhesive is only shown on the surface side of the first metal foil M1. Here, when the two metal layers 36a, 36b are formed in the subsequent process, it is desired that the two metal layers 36a, 36b are reliably bonded by the adhesive part Ad so that they do not peel off from each other at the conductive part C. At the same time, it is desired that the conductive parts C have contact parts Ct that are not bonded to each other so that the conductivity of the conductive part C can be ensured even if the conductivity of the conductive part C is hindered by the adhesive part Ad. From this perspective, at least one adhesive portion Ad is reliably positioned at the position where the two metal foils M1 and M2 are intended to be close to each other, and the width of each adhesive portion Ad and the spacing between adjacent adhesive portions Ad are set so that there are portions without adhesive portions Ad (so that there are contact portions Ct).

-- Placement process --
In the arrangement step, as shown in FIG. 5, the metal foils M1, M2, and M3 and the divided resin materials R1 and R2 prepared in the preparation step are arranged in the cavity of the molding die 40 in a stacking direction.

The molding die 40 is composed of a lower die 41 and an upper die 42. The lower die 41 is formed in a concave shape that is recessed downward corresponding to the shape of the recess 3a of the upper case 3. The upper die 42 is formed in a convex shape that protrudes downward corresponding to the shape of the lower die 41 so that a cavity for molding the upper case 3 is formed between the lower die 41 and the upper die 42. In other words, the lower die 41 and the upper die 42 are configured so that when they are clamped, a cavity for molding the upper case 3 upside down is formed between them. The upper die 42 is formed with a protrusion 42a for forming a groove D for providing a gasket G around the entire circumference along the outer flange 33. The lower die 41 is provided with a set pin 43 that is inserted into the through hole 35 of each collar 34 to position the collar 34 at the part of the outer flange 33 where the bolt B is to be inserted.

In the placement process, the first divided resin materials R1, R1, ... are placed with their respective length directions aligned in the portion that constitutes the cavity of the lower die 41 of the open molding die 40. Each of the first divided resin materials R1 shown in FIG. 5 is placed with its length direction perpendicular to the paper surface. In addition, the collar 34 is placed in the portion of the outer peripheral flange 33 where the bolt B is to be inserted, with the set pin 43 inserted into its through hole 35.

Next, on the back side of the first divided resin material R1, R1, ..., the second metal foil M2 is placed in the areas where the ceiling portion 31 and the wall portion 32 are to be formed, and the third metal foil M3 is placed in the area where the outer peripheral flange 33 is to be formed. Note that the third metal foil M3 has holes formed in the areas where the collars 34, 34 are to be disposed, and these holes are passed through the collars 34, 34.

Next, the second divided resin materials R2, R2, ... are arranged at intervals on the back side of the second metal foil M2, and the first metal foil M1 is arranged on the back side of the second divided resin materials R2, R2, .... Each second divided resin material R2 shown in Figure 5 is arranged with its length direction perpendicular to the paper surface. In addition, the first divided resin material R1 is arranged on the back side of the third metal foil M3 to impart flame retardancy to the outer peripheral flange 33.

In particular, in the arrangement process, the second divided resin materials R2, R2, ... arranged between the first metal foil M1 and the second metal foil M2 are arranged so that adjacent second divided resin materials R2, R2 are spaced apart from each other so that both metal foils M1, M2 have conductive portions C and spaced portions S when compressed in the compression process.

-Compression process-
The compression process is performed after the arrangement process. In the compression process, as shown in FIG. 6, the upper die 42 is lowered, the molding die 40 is closed, and the metal foils M1, M2, M3 and the divided resin materials R1, R2 in the cavity are compressed. At this time, the die is heated in advance to harden the first divided resin materials R1, R1, ... and the second divided resin materials R2, R2, ... which are thermosetting resins. As the die is heated, the divided resin materials R1, R2 are hardened and the hot melt adhesive melts. The hot melt adhesive is hardened by the subsequent temperature drop to form the adhesive portion Ad.

In this compression process, the second metal foil M2 is pressed backward by the first divided resin material R1 between the adjacent second divided resin materials R2, R2 spaced apart from each other, and comes into contact with the first metal foil M1, forming a conductive portion C. At the same time, the second divided resin material R2 hardens between the first metal foil M1 and the second metal foil M2, thereby forming the separation portion S and the resin body 38a.

The compression process forms panel P1 in the cavity of mold 40, and then mold 40 is opened and the formed panel P1 is removed from the cavity.

-Action and Effects-
The electromagnetic wave shielding panel P1 (upper case 3) according to this embodiment is composed of a laminate of a first metal layer 36a, a second metal layer 36b, and a resin layer 37. The two metal layers 36a, 36b have a separation portion S that is spaced apart from each other, so that the two metal layers 36a, 36b provide a high electromagnetic wave shielding effect. The two metal layers 36a, 36b also have a conductive portion C that can be electrically conductive with each other, and the first metal layer 36a is provided with a first earth connection portion E1 and a second earth connection portion E2 that are electrically conductively connected to the vehicle body, which is an object capable of discharging electricity, so that both metal layers 36a, 36b are both grounded. Therefore, the electromagnetic wave shielding effect can be reliably improved with a simple structure.

In addition, in panel P1, the conductive portion C has an adhesive portion Ad where the two metal layers 36a, 36b are adhered to each other with an adhesive, so that the two metal layers 36a, 36b do not peel off from each other. At the same time, the conductive portion C has a contact portion Ct that is not adhered to each other with an adhesive, so that even if the adhesive portion Ad prevents conductivity (i.e., even if a non-conductive adhesive is used for the adhesive portion Ad), the two metal layers can contact each other conductively at the contact portion Ct. In other words, both of the two metal layers 36a, 36b are earthed. Therefore, the electromagnetic wave shielding effect can be reliably improved with a simple configuration.

In addition, the lower half of the storage space of the electromagnetic wave shielding box 1 is covered with the metal member that constitutes the lower case 2, and the upper half of the storage space is covered with the first metal layer 36a and the second metal layer 36b that constitute the upper case 3, so that it can reliably shield electromagnetic waves traveling from the inside to the outside and electromagnetic waves traveling from the outside to the inside.

In the meantime, there are cases where it is desired to make the electromagnetic wave shielding box 1 flame retardant in preparation for a fire inside or outside the electromagnetic wave shielding box 1. Here, the panel P1 has a resin layer 37 made of a first resin having flame retardancy, which is the topmost layer of the panel P1, and a first metal layer 36a which is the bottommost layer of the panel P1. Therefore, both the top and bottom sides can be made flame retardant. In addition, the lower case 2 is a metal member and therefore flame retardant. As a result, the entire electromagnetic wave shielding box 1 can be made flame retardant.

In addition, in panel P1, resin body 38a is composed of a second resin different from the first resin, so the material of resin body 38a is not limited to the first resin having flame retardancy. Even if a second resin that does not have flame retardancy is selected as the material of resin body 38a, the flame retardancy of the front side of panel P1 is not impaired because resin layer 37 constituting the topmost layer has flame retardancy. As described above, it is possible to make both the front and back sides of panel P1 flame retardant while increasing the degree of freedom in selecting the material of resin body 38a.

The manufacturing method of this embodiment makes it possible to manufacture a panel P1 that achieves the above effects.

Second Embodiment
The electromagnetic wave shielding panel P2 according to the second embodiment differs from the panel P1 according to the first embodiment in the configuration of the panel P2 as a laminate. The electromagnetic wave shielding panel P2 according to the second embodiment and its manufacturing method will be described below, but descriptions of the configuration and method common to the first embodiment may be omitted.

Figure 7 shows an electromagnetic wave shielding panel P2 according to the second embodiment. This panel P2 is composed of a laminate including a first metal layer 36a constituting the backmost layer, a second metal layer 36b laminated on the front side of the first metal layer 36a, a fourth metal layer 36d laminated on the front side of the second metal layer 36b, and a resin layer 37 constituting the frontmost layer laminated on the front side of the fourth metal layer 36d. The configurations of the first metal layer 36a and the second metal layer 36b are the same as in the first embodiment, and a resin body 38a is disposed between the metal layers 36a and 36b in the separation portion S between the metal layers 36a and 36b, as in the first embodiment. Hereinafter, in this embodiment, this resin body 38a is referred to as the "first resin body."

The fourth metal layer 36d is formed approximately parallel to the first metal layer 36a, and is provided so as to be in conductive contact with the second metal layer 36b at the portion where the first metal layer 36a and the second metal layer 36b are furthest apart from each other. The second metal layer 36b and the fourth metal layer 36d have a conductive portion C2 that can be conductive with each other and a separated portion S2 that is separated from each other due to the wavy shape of the second metal layer 36b described above. The conductive portion C2 has an adhesive portion Ad2 where the two metal layers 36b and 36d are bonded to each other with an adhesive, and a contact portion Ct2 where they are not bonded to each other with an adhesive and are simply in contact. The material, thickness, and shape of the fourth metal layer 36d are the same as those of the first metal layer 36a.

A second resin body 38b is disposed between the metal layers 36b and 36d at the separation portion S2 between the metal layers 36b and 36d. The second resin body 38b is made of a second resin that is not flame retardant, similar to the first resin body 38a.

Figure 8 shows the arrangement step in the manufacturing method of panel P2 according to this embodiment. In the arrangement step, first divided resin materials R1, R1, ... for forming resin layer 37 are arranged with their respective length directions aligned in the portion constituting the cavity of lower die 41 of molding die 40 in the open state. Each first divided resin material R1 shown in Figure 8 is arranged with its length direction perpendicular to the paper surface. In addition, a collar 34 is arranged in the same manner as in the first embodiment in the portion of outer peripheral flange 33 where bolt B is to be inserted.

Next, on the back side of the first divided resin material R1, R1, ..., the fourth metal foil M4 constituting the fourth metal layer 36d is placed in the area where the ceiling portion 31 and the wall portion 32 are formed, and the second divided resin material R2, R2, ... for forming the second resin body 38b is placed at intervals on the back side of the fourth metal foil M4. On the back side of the second divided resin material R2, R2, ..., the second metal foil M2 constituting the second metal layer 36b is placed in the area where the ceiling portion 31 and the wall portion 32 are formed, and further, the second divided resin material R2, R2, ... is placed at intervals on the back side of the second metal foil M2. Each second divided resin material R2 shown in FIG. 7 is placed with its length direction perpendicular to the paper surface.

Next, the first metal foil M1 that constitutes the first metal layer 36a is placed on the back side of the second divided resin material R2, R2, ....

In addition, the first divided resin material R1, the third metal foil M3, and the first divided resin material R1 are stacked in this order in the area where the outer peripheral flange 33 is formed.

In the arrangement process, the second metal foil M2 is arranged so that the center position of each second divided resin material R2 on the back side of the second metal foil M2 and the center position of each second divided resin material R2 on the front side do not overlap each other when viewed in the stacking direction, so that the first metal foil M1 and the second metal foil M2 have a conductive portion C and a spaced portion S when compressed in the compression process, and the second metal foil M2 and the fourth metal foil M4 have a conductive portion C2 and a spaced portion S2 when compressed in the compression process.

The electromagnetic wave shielding panel P2 according to this embodiment further comprises a fourth metal layer 36d in addition to the first metal layer 36a and the second metal layer 36b, and the second metal layer 36b and the fourth metal layer 36d adjacent in the stacking direction have a separation portion S2 that separates them from each other, so that the electromagnetic wave shielding effect is even higher than that of the panel P1 according to the first embodiment that comprises only the two metal layers 36a and 36b. In addition, the second metal layer 36b and the fourth metal layer 36d have a conductive portion C2 that allows them to be conductive with each other, and the fourth metal layer 36d is also earthed, so that the electromagnetic wave shielding effect can be reliably improved with a simple configuration.

(Modification of the second embodiment)
In the second embodiment, the resin layer 37 is formed by compression molding the first divided resin materials R1, R1, ..., but is not limited to this. For example, the first metal foil M1 having a resin film laminated on the front side by lamination processing may be prepared, and the resin layer 37 may be formed by this resin film.

Third Embodiment
The electromagnetic wave shielding panel (not shown) according to the third embodiment is the same as the panel P1 according to the first embodiment, except that the first resin and the second resin are thermoplastic resins. Specifically, examples of the thermoplastic resins constituting the first resin and the second resin include polypropylene, polyethylene, polyamide, and acrylonitrile-butadiene-styrene copolymer synthetic resin.

In this case, in the arrangement process, the first divided resin material R1, R1, ... and the second divided resin material R2, R2, ... are heated and softened in advance. In the compression process, the molding die 40 is cooled without being heated, to harden the first divided resin material R1, R1, ... and the second divided resin material R2, R2, ....

Other Embodiments
In each of the above-described embodiments, the application of the adhesive to the surface of the first metal foil M1 (or the second metal foil M2) in the preparation step is performed by masking so that the application sites are a plurality of sites spaced apart from each other, but this is not limited to this. For example, the first metal foil M1 (second metal foil M2) may be prepared by applying or laminating a conductive hot melt adhesive (conductive adhesive) to the entire surface of the first metal foil M1 (second metal foil M2), and the hot melt adhesive may be heated once to melt, and then cooled and hardened to form the adhesive portion Ad (Ad2). In this case, the conductive portion C (C2) is composed only of the adhesive portion Ad (Ad2), and does not have the contact portion Ct (Ct2). In addition, the adhesive is not limited to being applied or laminated to the surface of the first metal foil M1 (second metal foil M2), but may be applied or laminated to the back surface of the first metal foil M1 (second metal foil M2) or the front or back surface of another metal foil.

In addition, in each of the above-described embodiments, the conductive portion C (C2) has an adhesive portion Ad (Ad2) and a contact portion Ct (Ct2), but it does not have to have an adhesive portion Ad (Ad2).

In addition, in each of the above-described embodiments, panel P1 (P2) has two or three metal layers, but it may have four or more metal layers. Of the multiple metal layers, two metal layers adjacent to each other in the stacking direction have a conductive portion that can be conductive with each other and a spaced portion that is spaced from each other, and one of the two metal layers is the layer on the back side of panel P1 (P2).

In addition, in each of the above-described embodiments, the first earth connection portion E1 and the second earth connection portion E2 are provided on the first metal layer 36a, which is the layer on the back side, but they may be provided on at least one of the two metal layers having the conductive portion C (C2) and the spaced portion S (S2).

In addition, in each of the above-described embodiments, the adjacent metal layers have a plurality of conductive portions C (C2) that can conduct electricity to each other, but this is not limited to this. It is sufficient that each metal layer has at least one conductive portion C (C2).

In addition, in each of the above-described embodiments, an electromagnetic wave shielding box 1 that houses a vehicle battery X was shown as an application example of the electromagnetic wave shielding panel P1 (P2), but this is not limited thereto, and the panel can be used or applied to anything intended to shield electromagnetic waves. For example, the panel can be used on the bonnet of a vehicle body.

P1, P2 Electromagnetic wave shielding panel X Battery (container)
3. Upper case (electromagnetic wave shielding panel)
36a First metal layer (metal layer)
36b Second metal layer (metal layer)
36c Third metal foil (earth connection part)
36d Fourth metal layer (metal layer)
37 Resin layer 38a First resin body (resin body)
38b Second resin body (resin body)
40 Molding mold C, C2 Conductive portion S, S2 Separation portion Ad, Ad2 Adhesion portion Ct, Ct2 Contact portion E1 First earth connection portion (earth connection portion)
E2 Second earth connection (earth connection)
R1 First divided resin material (divided resin material)
R2 Second divided resin material (divided resin material)
M1 First metal foil (metal foil)
M2 Second metal foil (metal foil)

Claims (5)

The laminate is made of a plurality of metal layers and a resin layer (37),
Among the plurality of metal layers, two metal layers (36a, 36b) adjacent to each other in the stacking direction are
Conductive parts (C) that are in contact with or bonded to each other and can be electrically conductive with each other;
and a spaced portion (S) spaced apart from each other ,
a resin body (38a) is disposed between the two metal layers (36a, 36b) in the spaced apart portion (S);
An electromagnetic wave shielding panel, characterized in that at least one of the plurality of metal layers (36a, 36b) that are capable of conducting electricity with each other via the conductive portion (C) is provided with an earth connection portion (E1, E2) connected to an object capable of discharging electricity. The electromagnetic wave shielding panel (P1) according to claim 1,
the resin layer (37) is made of a first resin having flame retardancy and is the outermost layer of the laminate;
the metal layer on which the earth connection portions (E1, E2) are provided is the rearmost layer of the laminate,
The electromagnetic wave shielding panel, wherein the resin body (38a) is made of a second resin different from the first resin. The electromagnetic wave shielding panel (P1) according to claim 1 or 2,
The electromagnetic wave shielding panel, wherein the conductive portion (C) is formed by bonding the two metal layers (36a, 36b) to each other with a conductive adhesive. In the electromagnetic wave shielding panel (P1) according to any one of claims 1 to 3,
The conductive portion (C) has an adhesive portion (Ad) where the two metal layers (36a, 36b) are adhered to each other by an adhesive, and a contact portion (Ct) where the two metal layers (36a, 36b) are not adhered to each other by an adhesive. A method for producing the electromagnetic wave shielding panel (P1) according to claim 1,
a preparation step of preparing a plurality of metal foils (M1, M2) which are materials for the plurality of metal layers, and a plurality of divided resin materials (R1, R2) which are formed by dividing a sheet-like resin material and are materials for the resin layer (37) and the resin body (38a);
an arrangement step of arranging the plurality of metal foils (M1, M2) and the plurality of divided resin materials (R1, R2) in a cavity of a molding die (40) in a stacking direction;
and a compression step of compressing the molding die (40) in a closed state after the placement step,
a plurality of divided resin materials (R2) are arranged at intervals between two metal foils (M1, M2) corresponding to two adjacent metal layers (36a, 36b) having the conductive portion (C) and the separating portion (S) in the arranging step, so that the two metal foils (M1, M2) have the conductive portion (C) and the separating portion (S) when compressed in the compression step.

Images