Title:
ELECTROMAGNETIC WAVE ABSORBER
Document Type and Number:
WIPO Patent Application WO/2023/243485
Kind Code:
A1
Abstract:
Focusing on the imaginary part of the complex dielectric constant of the dielectric layer used in reflective electromagnetic wave absorbers, the purpose of the present invention is to provide a technology that enables the maintenance of an excellent return loss even if the sheet resistance of the resistive layer is changed. As a consequence, the electromagnetic wave absorber according to the present invention is a laminate comprising a resistive layer, a dielectric layer, and a reflective layer in the indicated sequence. This dielectric layer contains at least one dielectric compound and a resin component and has an imaginary part of the complex dielectric constant of at least 0.5, and the return loss, after a reliability test at 85°C and 85% RH for 700 h, is at least 10 dB. In addition, the real part of the complex dielectric constant of the dielectric layer may be at least 10; the sheet resistance of the resistive layer may be 400 Ω/◻ to 1000 Ω/◻; the resistive layer may be a conductive polymer material having a volume resistivity of 8.0 × 10-5 to 4.0 × 10-3 Ω·m; or the thickness of the resistive layer may be 150 nm to 2000 nm.
Inventors:
SHODA RYO (JP)
NISHIYAMA HIROYOSHI (JP)
IMAI MIHO (JP)
IMAI JUNPEI (JP)
NISHIYAMA HIROYOSHI (JP)
IMAI MIHO (JP)
IMAI JUNPEI (JP)
Application Number:
PCT/JP2023/020961
Publication Date:
December 21, 2023
Filing Date:
June 06, 2023
Export Citation:
Assignee:
TOPPAN HOLDINGS INC (JP)
International Classes:
H05K9/00; B32B7/025; B32B7/12; B32B27/18; H01Q17/00
Domestic Patent References:
| WO2022107797A1 | 2022-05-27 |
Foreign References:
| JP2020167414A | 2020-10-08 |
Attorney, Agent or Firm:
DAI-ICHI INTERNATIONAL PATENT OFFICE, P.C. (JP)
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