• 专利标题:   Electromagnetic interference (EMI) shielding device has dielectric layer and layer of fillers that have volume overlapped with each other when carbon-based materials are self-aligned in presence of magnetic field.
  • 专利号:   US2022165681-A1, CN114554815-A
  • 发明人:   LIU C, LI W C, CHEN X, KWOK C H, LI W, GUO Z
  • 专利权人:   NANO ADVANCED MATERIALS INST LTD, NANO ADVANCED MATERIALS INST LTD
  • 国际专利分类:   C01B032/21, H01F001/00, H01F001/34, H01L023/552, C09K005/14, H05K007/20, H05K009/00
  • 专利详细信息:   US2022165681-A1 26 May 2022 H01L-023/552 202252 English
  • 申请详细信息:   US2022165681-A1 US530483 19 Nov 2021
  • 优先权号:   US118021P, US530483

▎ 摘  要

NOVELTY - Electromagnetic interference (EMI) shielding device comprises a flame retarding, thermal interface material composite with shielding effectiveness of 30-50 dB, a through plane thermal conductivity of no less than 30 W/mK and an in-plane thermal conductivity of no less than 10 W/mK, a dielectric withstanding voltage of no less than 1 kV/mm, the composite comprising: at least a first layer of self-aligned, carbon-based materials formed on at least one dielectric layer having a carbon content of about 85 to 99.9% associated with superparamagnetic particles with magnetic field strength of 60-90 amu/g; amnd at least a second layer of fillers comprising a blend of dielectric isotropic heat transfer materials with a thermal or UV curable polymer or phase change polymer, the first layer comprising ceramic fillers associated with a polymer to form a polymer matrix. USE - The EMI shielding device is useful in integrated circuits (ICs), systems or ultra-fast high-power density tele-communication devices. ADVANTAGE - The EMI shielding device has high heat transfer efficiency, and reduces the contact interface, thus reducing the contact resistance, and has high thermal conductivity in the range of 1-10 W/mK at room temperature. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparing a flame retarding, thermal interface material composite of the device which involves preparing a first mixture of superparamagnetic particles-associated carbon-based materials and a polymer for forming a first layer of aligned carbon-based materials on a dielectric layer; applying a magnetic field of less than 1 Tesla in an angle across the first layer about a horizontal plane of the dielectric layer to orient the carbon-based materials associated with the superparamagnetic particles in a direction substantially the same as the direction of the magnetic field, such that an inclined angle between 90 and 45 degrees is provided between each of the carbon-based materials and the horizontal plane of the dielectric layer; dispersing ceramic fillers through the gaps between the carbon-based materials in the first layer; preparing a second mixture of dielectric isotropic heat transfer materials with a thermal or UV curable polymer for forming a second layer of dielectric isotropic heat transfer materials; applying a magnetic field of less than 1 Tesla across the second layer of dielectric isotropic heat transfer materials in an angle that the dielectric isotropic heat transfer materials in the second mixture align in an orientation substantially the same as that of the aligned carbon-based materials in the first layer; diffusing the ceramic fillers to the first and second layers through the space between each of the aligned carbon-based materials; curing the first and second mixtures until the polymer in both of the mixtures are set.