ELECTROMAGNETIC SHIELDING FILM

• Main Authors: TAJIMA HIROSHI, ISHIOKA SOGO, KATSUKI TAKAHIKO, UENO KENJI
• Format: Patent
• Language: English; Japanese
• Published: 22.02.2024
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PRINTED CIRCUITS

To provide an electromagnetic shielding film which has sufficiently high bending resistance and has sufficiently high electromagnetic shielding characteristics even when used in a transmission circuit for transmitting signals in a high frequency region.SOLUTION: In an electromagnetic shielding film including an adhesive layer, a shielding layer laminated on an adhesive layer, and an insulating layer laminated on the shielding layer, a plurality of opening portions 50 with an opening area of 1 to 5000 μm2 is formed in the shield layer. The opening portions include a first opening portion 51 with an opening area of more than 1 μm2 and equal to or less than 300 μm2, and a second opening portion 52 with an opening area of more than 300 μm2 and equal to or less than 5000 μm2. Among the opening portions, a proportion of the number occupied by the first opening portion (a cumulative frequency) is 80% or less, a proportion of the number occupied by the second opening portion (a cumulative frequency) is 20% or more, and the proportion of the number occupied by the first opening portion is higher than the proportion of the number occupied by the second opening portion.SELECTED DRAWING: Figure 2A 【課題】耐屈曲性が充分に高く、かつ、高周波領域の信号を伝送する伝送回路に用いられたとしても電磁波シールド特性が充分に高い電磁波シールドフィルムを提供する。【解決手段】接着剤層と、接着剤層の上に積層されたシールド層と、シールド層の上に積層された絶縁層とからなる電磁波シールドフィルムであって、シールド層には、開口面積が１～５０００μｍ２である複数の開口部５０が形成されており、開口部は、開口面積が１μｍ２を超え、３００μｍ２以下である第１開口部５１と、開口面積が３００μｍ２を超え、５０００μｍ２以下である第２開口部５２とを含み、開口部のうち、第１開口部が占める数の割合（累積頻度）が８０％以下であり、第２開口部が占める数の割合（累積頻度）が２０％以上であり、第１開口部が占める数の割合の方が、第２開口部が占める数の割合よりも高い。【選択図】図２Ａ