Patent Publication Number: US-2023147383-A1

Title: Electromagnetic wave attenuator and electronic device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-182260, filed on Nov. 9, 2021; the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to an electromagnetic wave attenuator and an electronic device. 
     BACKGROUND 
     For example, an electromagnetic wave attenuator such as an electromagnetic shield sheet or the like has been proposed. There is an electronic device that includes the electromagnetic wave attenuator and a semiconductor element. It is desirable that the electromagnetic wave attenuator stably attenuates the electromagnetic wave. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1 A and  1 B  are schematic cross-sectional views illustrating an electromagnetic wave attenuator according to a first embodiment; 
         FIG.  2    is a schematic cross-sectional view illustrating an electromagnetic wave attenuator according to the first embodiment; 
         FIG.  3    is a schematic cross-sectional view illustrating an electromagnetic wave attenuator according to the first embodiment; 
         FIG.  4    is a schematic cross-sectional view illustrating the electromagnetic wave attenuator according to the embodiment; 
         FIGS.  5 A to  5 D  are schematic views illustrating an electronic device according to a second embodiment; 
         FIGS.  6 A to  6 D  are schematic views illustrating parts of the electronic device according to the second embodiment; 
         FIG.  7    is a schematic cross-sectional view illustrating an electronic device according to the second embodiment; 
         FIG.  8    is a schematic cross-sectional view illustrating an electronic device according to the second embodiment; 
         FIG.  9    is a schematic cross-sectional view illustrating an electronic device according to the second embodiment; 
         FIG.  10    is a schematic cross-sectional view illustrating an electronic device according to the second embodiment; 
         FIG.  11    is a schematic cross-sectional view illustrating an electronic device according to the second embodiment; and 
         FIG.  12    is a schematic cross-sectional view illustrating an electronic device according to the second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     According to one embodiment, an electromagnetic wave attenuator includes a stacked member. The stacked member includes a base body including a first surface including unevenness, a first conductive member including Cu, and a first layer provided between the first surface and the first conductive member. The first layer includes Cr and Ti. 
     According to one embodiment, an electronic device includes the electromagnetic wave attenuator described above, and an electronic element. 
     Various embodiments are described below with reference to the accompanying drawings. 
     The drawings are schematic and conceptual; and the relationships between the thickness and width of portions, the proportions of sizes among portions, etc., are not necessarily the same as the actual values. The dimensions and proportions may be illustrated differently among drawings, even for identical portions. 
     In the specification and drawings, components similar to those described previously or illustrated in an antecedent drawing are marked with like reference numerals, and a detailed description is omitted as appropriate. 
     First Embodiment 
       FIGS.  1 A and  1 B  are schematic cross-sectional views illustrating an electromagnetic wave attenuator according to a first embodiment. 
       FIG.  1 A  is an enlarged view of a part of  FIG.  1 B . As shown in  FIGS.  1 A and  1 B , the electromagnetic wave attenuator  10  according to the embodiment includes a stacked member  10 MA. As will be described later, the stacked member  10 MA may include a first planar portion  10   p  and a side surface portion.  FIGS.  1 A and  1 B  illustrate the first planar portion  10   p.    
     The stacked member  10 MA includes a base body  10   s , a first conductive member  10 C, and a first layer  15 . The base body  10   s  includes a first surface  10   f . The first surface  10   f  includes unevenness  10   dp.    
     The first conductive member  10 C includes Cu. The first layer  15  is provided between the base body  10   s  (first surface  10   f ) and the first conductive member  10 C. The first layer  15  includes Cr and Ti. The first layer  15  includes, for example, an alloy including Cr and Ti. 
     As shown in  FIG.  1   , for example, the first conductive member  10 C may be grounded. For example, an electromagnetic wave is incident on the first conductive member  10 C. The electromagnetic wave incident on the first conductive member  10 C is attenuated by the first conductive member  10 C. The electromagnetic wave attenuator  10  can be used as, for example, a shield of an electromagnetic wave. 
     In the electromagnetic wave attenuator  10  according to the embodiment, it is possible to stably attenuate the electromagnetic wave. 
     For example, the first layer  15  is provided in contact with the first surface  10   f  including unevenness of  10   dp . The first conductive member  10 C is provided in contact with the first layer  15 . The electromagnetic wave attenuator  10  (for example, the first conductive member  10 C) functions as, for example, an electromagnetic shielding layer. The first conductive member  10 C including Cu attenuates the incident electromagnetic wave. 
     In a reference example, the first conductive member  10 C is provided in contact with the base body  10   s . In the reference example, the first conductive member  10 C is easily peeled off from the base body  10   s . In the reference example, it may be difficult to stably keep a function of attenuating the electromagnetic wave. 
     In the embodiment, the unevenness  10   dp  is provided on the first surface  10   f  of the base body  10   s . The first layer  15  is provided so as to be in contact with the unevenness of  10   dp . The first conductive member  10 C is provided so as to be in contact with the first layer  15 . In  FIG.  1 A , the unevenness  10   dp  of the first surface  10   f  is omitted. 
     By providing the unevenness  10   dp  on the first surface  10   f , the area in which the base body  10   s  and the first layer  15  are in contact with each other becomes larger than in the case where the unevenness is not provided. High adhesion can be easily obtained. 
     The first layer  15  includes Cr and Ti. The first layer  15  including Cr and Ti is provided between the base body  10   s  and the first conductive member  10 C. The first layer  15  including Cr and Ti has high adhesion to the base body  10   s . The first layer  15  including Cr and Ti has high adhesion to the first conductive member  10 C. The first layer  15  functions as, for example, an under layer for improving adhesion. 
     In the embodiment, peeling-off of the first conductive member  10 C from the base body  10   s  can be suppressed by providing the first layer  15  including Cr and Ti. According to the embodiment, it is possible to provide an electromagnetic wave attenuator capable of stably attenuating the electromagnetic wave. 
     As shown in  FIGS.  1 A and  1 B , a first direction D 1  from the base body  10   s  to the first conductive member  10 C is defined as a Z-axis direction. One direction perpendicular to the Z-axis direction is defined as an X-axis direction. A direction perpendicular to the Z-axis direction and the X-axis direction is defined as a Y-axis direction. 
     As shown in  FIG.  1 B , the unevenness  10   dp  includes a recess  10   fd  and a protrusion  10   fp . The height (or depth) of the unevenness of  10   dp  is defined as a height of  10 H. The height  10 H corresponds to a distance in the first direction D 1  between the recess  10   fd  and the protrusion  10   fp.    
     As shown in  FIG.  1 A , a thickness of the first layer  15  is defined as a thickness t 15 . The thickness t 15  corresponds to a length of the first layer  15  along the first direction D 1 . 
     In the embodiment, the height  10 H of the unevenness  10   dp  is larger than the thickness t 15  of the first layer  15 . The first layer  15  is stacked along the first surface  10   f  including the unevenness  10   pd . High adhesion can be easily obtained due to the thin first layer  15  along the unevenness of  10   dp.    
     In one example, the height  10 H of the unevenness  10   dp  is not less than 1 μm and not more than 100 μm. In one example, the thickness t 15  of the first layer  15  is not less than 1 nm and not more than 30 nm. Due to the unevenness  10   dp  and the first layer  15 , high adhesion can be easily obtained. 
     As shown in  FIG.  1 B , the base body  10   s  includes, for example, multiple particles  17  and a resin  18 . The resin  18  is provided around the multiple particles  17 . The multiple particles  17  include, for example, a first element including at least one selected from the group consisting of silicon and aluminum, and oxygen. In one example, the multiple particles  17  include silicon oxide (e.g., SiO 2 ). The resin  18  may include, for example, at least one selected from the group consisting of epoxy and polyimide. 
     By providing the multiple particles  17 , high mechanical stability can be obtained in the base body  10   s . High insulation and high stability can be obtained. 
     When the base body  10   s  includes the multiple particles  17 , by providing the first layer  15  (foundation layer) including Cr and Ti, particularly high adhesion can be easily obtained. 
     When the base body  10   s  includes the multiple particles  17 , it is considered that the elements included in the first layer  15  are diffused into the base body  10   s . For example, Cr included in the first layer  15  easily diffuses into the base body  10   s . For example, Cr easily binds to multiple particles (for example, silicon oxide particles) included in the base body  10   s . As a result, it is considered that high adhesion can be obtained. 
     For example, Cr included in the first layer  15  diffuses inside the multiple particles  17  and easily binds to the multiple particles  17 . For example, Cr spreads from the first layer  15  to the multiple particles  17 . As a result, high adhesion can be obtained. A concentration of Cr inside the multiple particles  17  may be higher than a concentration of Cr in the resin  18 . 
     In the embodiment, a diameter Dm 1  of at least one of the multiple particles  17  (see  FIG.  1 B ) is, for example, not less than 1 nm and not more than 100 μm. The average diameter Dm 1  of the multiple particles  17  is, for example, not less than 10 nm and not more than 100 μm. 
     As shown in  FIGS.  1 A and  1 B , the stacked member  10 MA may include a second layer  16 . The second layer  16  includes Cr and Ti. The second layer  16  includes, for example, an alloy including Cr and Ti. A first conductive member  10 C is provided between the first layer  15  and the second layer  16 . 
     The second layer  16  functions as, for example, a protective layer. The second layer  16  has high adhesion to the first conductive member  10 C. The second layer  16  suppresses deterioration of the first conductive member  10 C. By providing the second layer  16 , a stable first conductive member  10 C can be obtained. 
     The second layer  16  has a thickness of t 16  (see  FIG.  1 A ). The thickness t 16  may be, for example, not less than 1 nm and not more than 30 nm. The first conductive member  10 C has a thickness of t 10 C (see  FIG.  1 A ). The thickness t 10 C is, for example, not less than 0.5 μm and not more than 100 μm. 
       FIG.  2    is a schematic cross-sectional view illustrating an electromagnetic wave attenuator according to the first embodiment. 
     As shown in  FIG.  2   , in an electromagnetic wave attenuator  10 A according to the embodiment, the first conductive member  10 C includes the first stacked body  10 M. Other configurations of the electromagnetic wave attenuator  10 A may be the same as the configuration of the electromagnetic wave attenuator  10 . In  FIG.  2   , the unevenness  10   dp  of the first surface  10   f  is omitted. 
     The first stacked body  10 M includes multiple first magnetic layers  11  and multiple first non-magnetic layers  11 N. The multiple first non-magnetic layers  11 N includes Cu. One of the multiple first magnetic layers  11  is between one of the multiple first non-magnetic layers  11 N and another one of the multiple first non-magnetic layers  11 N. One of the multiple first non-magnetic layers  11 N is between one of the multiple first magnetic layers  11  and another one of the multiple first magnetic layers  11 . For example, the first magnetic layer  11  and the first non-magnetic layer  11 N are alternately provided. A direction from one of the multiple first non-magnetic layers  11 N to another of the multiple first non-magnetic layers  11 N is along the first direction D 1 . 
     With such a first stacked body  10 M, electromagnetic waves can be attenuated more effectively. In particular, it effectively attenuates electromagnetic waves in the frequency range of not more than 100 MHz. 
     One of the multiple first non-magnetic layers  11 N is in contact with one of the multiple first magnetic layers  11  and another one of the multiple first magnetic layers  11 . 
     The multiple first magnetic layers  11  include, for example, at least one selected from the group consisting of Fe, Ni and Co. The multiple first magnetic layers  11  may further include at least one selected from the group consisting of Cu, Mo and Cr. The multiple first magnetic layers  11  are, for example, soft magnetic layers. In one example, the multiple first magnetic layers  11  are, for example, NiFeCuMo layers. Good soft magnetic properties can be obtained. 
     In the first stacked body  10 M, the number of the multiple first magnetic layers  11  may be the same as the number of the multiple first non-magnetic layers  11 N, may be 1 larger than the number of the multiple first non-magnetic layers  11 N, or may be 1 smaller than the number of the multiple first non-magnetic layers  11 N. For example, the number of the multiple first magnetic layers  11  is, for example, not less than 2 and not more than 200. The number of the multiple first non-magnetic layers  11 N is, for example, not less than 2 and not more than 200. 
     One thickness t 11  of the multiple first magnetic layers  11  is, for example, not less than 20 nm and not more than 1000 nm. One thickness t 11 N of the multiple first non-magnetic layers  11 N is, for example, not less than 20 nm and not more than 1000 nm. A thickness t 10 M of the first stacked body  10 M is, for example, not less than 200 nm and not more than 100 μm. 
       FIG.  3    is a schematic cross-sectional view illustrating an electromagnetic wave attenuator according to the first embodiment. 
     As shown in  FIG.  3   , in an electromagnetic wave attenuator  10 B according to the embodiment, the first conductive member  10 C includes a second stacked body  20 M. Other configurations of the electromagnetic wave attenuator  10 B may be the same as the configuration of the electromagnetic wave attenuator  10 A. In  FIG.  3   , the unevenness  10   dp  of the first surface  10   f  is omitted. 
     The second stacked body  20 M includes multiple second magnetic layers  12  and multiple second non-magnetic layers  12 N. At least one of the multiple second non-magnetic layers  12 N includes at least one selected from the group consisting of Ta, Ti, W, Mo, Nb and Hf. At least one of the multiple second non-magnetic layers  12 N may further includes at least one selected from the group consisting of Cu, Al, Ni, Cr, Mn, Mo, Zr and Si. For example, at least one of the multiple second non-magnetic layers  12 N includes Cr and Ti. For example, at least one of the multiple second non-magnetic layers  12 N includes Ta. 
     One of the multiple second magnetic layers  12  is between one of the multiple second non-magnetic layers  12 N and another one of the multiple second non-magnetic layers  12 N. One of the multiple second non-magnetic layers  12 N is between one of the multiple second magnetic layers  12  and another one of the multiple second magnetic layers  12 . For example, the second magnetic layer  12  and the second non-magnetic layer  12 N are alternately provided. A direction from one of the multiple second non-magnetic layers  12 N to another of the multiple second non-magnetic layers  12 N is along the first direction D 1 . 
     With such a second stacked body  20 M, electromagnetic waves can be attenuated more effectively. For example, it effectively attenuates electromagnetic waves in the frequency domain of not more than 60 MHz. 
     One of the multiple second non-magnetic layers  12 N is in contact with one of the multiple second magnetic layers  12  and another one of the multiple second magnetic layers  12 . 
     The multiple second magnetic layers  12  include, for example, at least one selected from the group consisting of Fe, Ni and Co. The multiple second magnetic layers  12  may further include at least one selected from the group consisting of Cu, Mo and Cr. The multiple second magnetic layers  12  are, for example, soft magnetic layers. In one example, the multiple second magnetic layers  12  are, for example, NiFeCuMo layers. Good soft magnetic properties can be obtained. 
     In the second stacked body  20 M, the number of the multiple second magnetic layers  12  may be the same as the number of the multiple second non-magnetic layers  12 N, may be 1 larger than the number of the multiple second non-magnetic layers  12 N, or may be 1 smaller than the number of the multiple second non-magnetic layers  12 N. For example, the number of the multiple second magnetic layers  12  is, for example, not less than 2 and not more than 200. The number of the multiple second non-magnetic layers  12 N is, for example, not less than 2 and not more than 200. 
     One thickness t 12  of the multiple second magnetic layers  12  is, for example, not less than 10 nm and not more than 500 nm. One thickness t 12 N of the multiple second non-magnetic layers  12 N is, for example, not less than 1 nm and not more than 100 nm. A thickness t 20 M of the second stacked body  20 M is, for example, not less than 200 nm and not more than 100 μm. 
     In the example of  FIG.  3   , the first stacked body  10 M is provided between the first layer  15  and the second stacked body  20 M. In the embodiment, the second stacked body  20 M may be provided between the first layer  15  and the first stacked body  10 M. 
     In the embodiment, as described below, each of the multiple magnetic layers may have an uneven shape. 
     Hereinafter, a case where each of the multiple first magnetic layers  11  has an uneven shape will be described. The following description may be applied to the multiple second magnetic layers  12 . Each of the multiple second magnetic layers  12  may have an uneven shape. 
       FIG.  4    is a schematic cross-sectional view illustrating the electromagnetic wave attenuator according to the embodiment. 
     As shown in  FIG.  4   , each of the multiple first magnetic layers  11  has an uneven shape. The multiple first non-magnetic layers  11 N follow the uneven shape of the multiple first magnetic layers  11 . 
     One of the multiple first magnetic layers  11  includes a first magnetic layer surface  11   fa . The first magnetic layer surface  11   fa  faces one of the multiple first non-magnetic layers  11 N. The first magnetic layer surface  11   fa  includes a first top portion  11   pp , a second top portion  11   pq , and a first bottom portion  11   dp . One direction that crosses the first direction D 1  is defined as a crossing direction De 2 . The crossing direction De 2  is, for example, the X-axis direction. 
     A position of the first bottom portion  11   dp  in the crossing direction De 2  is between a position of the first top portion  11   pp  in the crossing direction De 2  and a position of the second top portion  11   pq  in the crossing direction De 2 . At least a part of the multiple first non-magnetic layers  11 N is between the first top portion  11   pp  and the second top portion  11   pq  in the crossing direction De 2 . A distance along the first direction D 1  between the first top portion  11   pp  and the first bottom portion  11   dp  is, for example, not less than 10 nm. The distance corresponds to the height (depth) of the unevenness. 
     It is considered that magnetostatic interaction of magnetization between one of the multiple first magnetic layers  11  and another one of the multiple first magnetic layers  11  becomes larger by providing such an uneven shape, for example. 
     Second Embodiment 
     The second embodiment relates to an electronic device. The electronic device according to the embodiment includes the electromagnetic wave attenuator according to the first embodiment and an arbitrary electronic element. The electromagnetic wave attenuator according to the first embodiment is, for example, the electromagnetic wave attenuator  10 , the electromagnetic wave attenuator  10 A, the electromagnetic wave attenuator  10 B, or the like. 
       FIGS.  5 A to  5 D  are schematic views illustrating an electronic device according to a second embodiment. 
       FIG.  5 A  is a perspective view.  FIG.  5 B  is a line A 1 -A 2  cross-sectional view of  FIG.  5 A .  FIG.  5 C  is a line B 1 -B 2  cross-sectional view of  FIG.  5 A .  FIG.  5 D  is a plan view as viewed along arrow AA of  FIG.  5 A .  FIGS.  1  to  3    correspond to a line C 1 -C 2  cross section of  FIG.  5 B . 
     As shown in  FIG.  5 A , the electronic device  110  according to the embodiment includes an electronic element  50  and the electromagnetic wave attenuator (in the example, electromagnetic wave attenuator  10 ). A substrate  60  is further provided in the example. The electromagnetic wave attenuator  10  covers at least a part of the electronic element  50 . The electronic element  50  is, for example, a semiconductor element. 
     In the example as shown in  FIG.  5 B , the electronic element  50  includes a semiconductor chip  50   c , an insulating portion  50   i , and a wire  50   w . In the example, an electrode  50   e , a substrate connector  50   f , and a connector  58  are provided at the substrate  60 . The wire  50   w  electrically connects the electrode  50   e  and a part of the semiconductor chip  50   c . The electrode  50   e  and the connector  58  are electrically connected by the substrate connector  50   f . The substrate connector  50   f  pierces the substrate  60 . The connector  58  functions as an input/output portion of the semiconductor chip  50   c . The connector  58  may be, for example, a terminal. The insulating portion  50   i  is provided around the semiconductor chip  50   c . The insulating portion  50   i  includes, for example, at least one of a resin or a ceramic, etc. The semiconductor chip  50   c  is protected by the insulating portion  50   i.    
     The electronic element  50  includes, for example, at least one of an arithmetic circuit, a control circuit, a memory circuit, a switching circuit, a signal processing circuit, or a high frequency circuit. 
     The base body  10   s  of the electromagnetic wave attenuator  10  (referring to  FIG.  1   ) may be, for example, at least a part of the electronic element  50 . The base body  10   s  of the electromagnetic wave attenuator  10  may be, for example, at least a part of the insulating portion  50   i.    
     In the example as illustrated in  FIG.  5 B , the electromagnetic wave attenuator  10  is electrically connected to a terminal  50   t  provided at the substrate  60 . The electromagnetic wave attenuator  10  is set to one potential (e.g., the ground potential) via the terminal  50   t . For example, the electromagnetic wave attenuator  10  attenuates the electromagnetic waves radiated from the electronic element  50 . For example, the electromagnetic wave attenuator  10  functions as a shield. 
     As shown in  FIGS.  5 A to  5 C , the stacked member  10 MA of the electromagnetic wave attenuator  10  includes a first planar portion  10   p  and a first side surface portion  10   a . In the example, the stacked member  10 MA includes first to fourth side surface portions  10   a  to  10   d . A direction from the electronic element  50  to the first planar portion  10   p  is aligned with the first direction D 1  (e.g., the Z-axis direction). 
     As shown in  FIGS.  5 B and  5 C , the electronic element  50  is positioned between the first planar portion  10   p  and the substrate  60  in the first direction D 1 . 
     As shown in  FIGS.  5 C and  5 D , the electronic element  50  is positioned between the first side surface portion  10   a  and the third side surface portion  10   c  in the X-axis direction. 
     As shown in  FIGS.  5 B and  5 D , the electronic element  50  is positioned between the second side surface portion  10   b  and the fourth side surface portion  10   d  in the Y-axis direction. 
     By using the electromagnetic wave attenuator  10 A or the electromagnetic wave attenuator  10 B, for example, electromagnetic waves in the low frequency range of not more than 100 MHz can be attenuated effectively. An electronic device can be provided in which the attenuation characteristics for electromagnetic waves can be improved. 
     For example, the electromagnetic waves emitted from the electronic element  50  can be suppressed. For example, the electromagnetic waves from the outside that reach the electronic element  50  can be suppressed. Stable operations are obtained easily in the electronic element  50 . 
     The first planar portion  10   p  may be, for example, substantially a quadrilateral (including a parallelogram, a rectangle, or a square). 
       FIGS.  6 A to  6 D  are schematic views illustrating parts of the electronic device according to the second embodiment. 
     As shown in  FIG.  6 A , the first side surface portion  10   a  of the electromagnetic wave attenuator  10  includes the multiple first magnetic layers  11  and the multiple first non-magnetic layers  11 N. The stacking direction of the multiple first magnetic layers  11  and the multiple first non-magnetic layers  11 N in the first side surface portion  10   a  is a second direction D 2 . 
     As shown in  FIG.  6 B , the second side surface portion  10   b  of the electromagnetic wave attenuator  10  includes the multiple first magnetic layers  11  and the multiple first non-magnetic layers  11 N. The stacking direction of the multiple first magnetic layers  11  and the multiple first non-magnetic layers  11 N in the second side surface portion  10   b  is a third direction D 3 . 
     As shown in  FIG.  6 C , the third side surface portion  10   c  of the electromagnetic wave attenuator  10  includes the multiple first magnetic layers  11  and the multiple first non-magnetic layers  11 N. The stacking direction of the multiple first magnetic layers  11  and the multiple first non-magnetic layers  11 N in the third side surface portion  10   c  is the second direction D 2 . 
     As shown in  FIG.  6 D , the fourth side surface portion  10   d  of the electromagnetic wave attenuator  10  includes the multiple first magnetic layers  11  and the multiple first non-magnetic layers  11 N. The stacking direction of the multiple first magnetic layers  11  and the multiple first non-magnetic layers  11 N in the fourth side surface portion  10   d  is the third direction D 3 . 
     The first magnetic layers  11  that are included in the first to fourth side surface portions  10   a  to  10   d  each may be continuous with the first magnetic layer  11  included in the first planar portion  10   p . The first non-magnetic layers  11 N that are included in the first to fourth side surface portions  10   a  to  10   d  each may be continuous with the first non-magnetic layer  11 N included in the first planar portion  10   p.    
     Thus, the electronic device  110  according to the embodiment includes the electronic element  50  and the electromagnetic wave attenuator  10  according to the first embodiment. For example, a direction from the electronic element  50  to the electromagnetic wave attenuator  10  is the first direction. 
       FIGS.  7  to  12    are schematic cross-sectional views illustrating electronic devices according to the second embodiment. 
     As shown in  FIG.  7   , an electronic device  111  according to the embodiment includes the electromagnetic wave attenuator  10  and multiple electronic elements (electronic elements  51 ,  51 B,  52 ,  53 ,  53 B,  53 C, etc.). 
     The electronic elements are provided between multiple regions of the electromagnetic wave attenuator  10 . An insulating region (insulating portions  41  and  42 , etc.) may be provided between the electronic element and one of the multiple regions of the electromagnetic wave attenuator  10 . A resin portion (resin portions  511 ,  521 ,  531 , etc.) may be provided between the electronic element and the insulating region (the insulating portions  41  and  42 , etc.). A connection member (connection members  51 N,  52 N,  53 N, etc.) may be provided for each of the multiple electronic elements. For example, the electronic element and the connector  58  may be electrically connected by the connection member. 
     As in an electronic device  112  shown in  FIG.  8   , the connection member  51 N may be sunk into a substrate  55 . In the electronic device  112 , the electromagnetic wave attenuator  10  is provided between the multiple electronic elements. For example, it is suppressed that the electromagnetic waves generated by one of the multiple electronic elements is incident on another one of the multiple electronic elements. 
     As in an electronic device  113  shown in  FIG.  9   , a mounting member  220  may be provided. The mounting member  220  includes the substrate  55  and the electromagnetic wave attenuator  10 . The electronic elements (electronic elements  51  and  51 B) are provided between the mounting member  220  and another electromagnetic wave attenuator  10 . 
     As in an electronic device  114  shown in  FIG.  10   , the electromagnetic wave attenuator  10  may be provided at the side surface of the electronic element  51 . The side surface crosses the X-Y plane. 
     As in an electronic device  115  shown in  FIG.  11   , the electromagnetic wave attenuator  10  may be provided to continuously surround the multiple electronic elements (electronic elements  51  and  52 ). 
     As in an electronic device  116  shown in  FIG.  12   , one of the multiple electronic elements (electronic element  51 ) is provided between the multiple regions of the electromagnetic wave attenuator  10 . Another one of the multiple electronic elements electronic element  52 ) may not be provided between the multiple regions of the electromagnetic wave attenuator  10 . 
     According to the electronic devices  111  to  116  as well, an electronic device can be provided in which the attenuation characteristics for electromagnetic waves can be improved. 
     For example, the embodiments are applicable to an electronic device and an electromagnetic wave attenuator for EMC (Electro Magnetic Compatibility). 
     The embodiments may include the following configurations (e.g., technological proposals). 
     Configuration 1 
     An electromagnetic wave attenuator, comprising: 
     a stacked member, the stacked member including
         a base body including a first surface including unevenness,   a first conductive member including Cu, and   a first layer provided between the first surface and the first conductive member, the first layer including Cr and Ti.       

     Configuration 2 
     The electromagnetic wave attenuator according to Configuration 1, wherein 
     the base body includes a plurality of particles and a resin around the plurality of particles. 
     Configuration 3 
     The electromagnetic wave attenuator according to Configuration 2, wherein 
     the plurality of particles include a first element and oxygen, the first element including at least one selected from the group consisting of silicon and aluminum. 
     Configuration 4 
     The electromagnetic wave attenuator according to Configuration 2, wherein 
     the plurality of particles include silicon oxide. 
     Configuration 5 
     The electromagnetic wave attenuator according to any one of Configurations 2 to 4, wherein 
     a diameter of at least one of the plurality of particles is not less than 1 nm and not more than 100 μm. 
     Configuration 6 
     The electromagnetic wave attenuator according to any one of Configurations 2 to 5, wherein 
     the resin includes at least one selected from the group consisting of epoxy and polyimide. 
     Configuration 7 
     The electromagnetic wave attenuator according to any one of Configurations 1 to 6, wherein 
     a height of the unevenness is larger than a thickness of the first layer. 
     Configuration 8 
     The electromagnetic wave attenuator according to Configuration 7, wherein 
     the height is not less than 1 μm or more and not more than 100 μm. 
     Configuration 9 
     The electromagnetic wave attenuator according to any one of Configurations 1 to 8, wherein 
     a thickness of the first layer is not less than 1 nm and not more than 30 nm. 
     Configuration 10 
     The electromagnetic wave attenuator according to any one of Configurations 1 to 9, wherein 
     the stacked member further includes a second layer including Cr and Ti, and 
     the first conductive member is between the first layer and the second layer. 
     Configuration 11 
     The electromagnetic wave attenuator according to Configuration 10, wherein 
     a thickness of the second layer is not less than 1 nm and not more than 30 nm. 
     Configuration 12 
     The electromagnetic wave attenuator according to any one of Configurations 1 to 11, wherein 
     the first conductive member includes a first stacked body, 
     the first stacked body includes a plurality of first magnetic layers and a plurality of first non-magnetic layers, the plurality of first non-magnetic layers including Cu, and 
     one of the plurality of first magnetic layers is between one of the plurality of first non-magnetic layers and an other one of the plurality of first non-magnetic layers. 
     Configuration 13 
     The electromagnetic wave attenuator according to Configuration 12, wherein 
     the one of the plurality of first non-magnetic layers is in contact with the one of the plurality of first magnetic layers and the other one of the plurality of first magnetic layers. 
     Configuration 14 
     The electromagnetic wave attenuator according to Configuration 12 or 13, wherein 
     the plurality of first magnetic layers include at least one selected from the group consisting of Fe, Ni and Co. 
     Configuration 15 
     The electromagnetic wave attenuator according to Configuration 14, wherein 
     the plurality of first magnetic layers include at least one selected from the group consisting of Cu, Mo and Cr. 
     Configuration 16 
     The electromagnetic wave attenuator according to any one of Configurations 12 to 15, wherein 
     the one of the plurality of first magnetic layers includes a first magnetic layer surface facing the one of the plurality of first non-magnetic layers, 
     the first magnetic layer surface includes a first top portion, a second top portion, and a first bottom portion, 
     a position of the first bottom portion in a crossing direction is between a position of the first top portion in the crossing direction and a position of the second top portion in the crossing direction, the crossing direction crossing a direction from the one of the plurality of first non-magnetic layer to the other one of the plurality of first non-magnetic layers, and 
     at least a part of the one of the plurality of first non-magnetic layers is between the first top portion and the second top portion in the crossing direction. 
     Configuration 17 
     The electromagnetic wave attenuator according to any one of Configurations 12 to 16, wherein 
     the first conductive member further includes a second stacked body, 
     the second stacked body includes a plurality of second magnetic layers and a plurality of second non-magnetic layers, 
     one of the plurality of second magnetic layers is between one of the plurality of second non-magnetic layers and an other one of the plurality of second non-magnetic layers, and 
     the plurality of second non-magnetic layers include at least one selected from the group consisting of Ta, Ti, W, Mo, Nb, and Hf. 
     Configuration 18 
     The electromagnetic wave attenuator according to Configuration 17, wherein 
     at least one of the plurality of second non-magnetic layers further includes at least one selected from the group consisting of Cu, Al, Ni, Cr, Mn, Mo, Zr, and Si. 
     Configuration 19 
     The electromagnetic wave attenuator according to any one of Configurations 1 to 18, wherein 
     the stacked member includes a first planar portion and a first side surface portion, 
     in the first planar portion, a direction from the base body to the first conductive member is along a first direction, 
     in the first side surface portion, a direction from the base body to the first conductive member is along a second direction, and 
     the second direction crosses the first direction. 
     Configuration 20 
     An electronic device, comprising: 
     the electromagnetic wave attenuator according to any one of Configurations 1 to 19; and 
     an electronic element. 
     According to the embodiment, an electromagnetic wave attenuator and an electronic device can be provided in which the electromagnetic wave can be stably attenuated. 
     Hereinabove, exemplary embodiments of the invention are described with reference to specific examples. However, the embodiments of the invention are not limited to these specific examples. For example, one skilled in the art may similarly practice the invention by appropriately selecting specific configurations of components included in electromagnetic wave attenuators such as stacked bodies, magnetic layers, nonmagnetic layers, etc., from known art. Such practice is included in the scope of the invention to the extent that similar effects thereto are obtained. 
     Further, any two or more components of the specific examples may be combined within the extent of technical feasibility and are included in the scope of the invention to the extent that the purport of the invention is included. 
     Moreover, all electromagnetic wave attenuators, and electronic devices practicable by an appropriate design modification by one skilled in the art based on the electromagnetic wave attenuators, and the electronic devices described above as embodiments of the invention also are within the scope of the invention to the extent that the purport of the invention is included. 
     Various other variations and modifications can be conceived by those skilled in the art within the spirit of the invention, and it is understood that such variations and modifications are also encompassed within the scope of the invention. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.