低温共烧陶瓷(low temperature co-fired ceramic,LTCC)技术是实现电子元件小型化、片式化的一种理想的封装技术,已成为电子元件集成的主要工艺方式,引起了人们的广泛关注。本文详细叙述了LTCC技术的特点、LTCC材料体系、国内外发展现状以及LTCC技术在电子元件集成中的应用。认为利用LTCC技术来实现电源、有源和无源器件的一体化将是今后信息功能陶瓷发展的一个重要方向。我国应该抓住LTCC技术所面临的前所未有的发展机遇,大力开发具有自主知识产权的LTCC技术,整体提升我国在电子集成领域的技术水平和国际竞争力。
The luminescent properties of terbium complex (terbium citrate) by binding to silver nanopartilces in the solution have been reported in this paper.The enhanced luminescence of the complex containing silver nanoparticles was observed at a limited particle concentration region.The nanoparticle concentration dependence of the luminescent intensity was regarded as the result of a delicate balance between an enhancing and a quenching effect of the silver nanoparticles.Furthermore,silver nanoparticles also affected the asymmetric ratio (AS) value of terbium luminescence.We discuss the luminescent properties of the terbium complex in terms of the local electromagnetic field,refractive index,and the ligand field around terbium ion.
WANG Yue-hui ZHOU Ji ZONG Rui-long SHI Shi-kao WANG Ting LI BO
Isotropic negative permeability composite,composed of BST-MgO dielectric cubes with high permit-tivity dispersed in the Teflon substrate with low permittivity,was designed and fabricated based on Mie resonance and the effective medium theory.Measurements and simulations showed that the dielectric composite exhibited a strong sub-wavelength magnetic resonance at the first Mie resonance and possessed isotropic negative permeability,which resulted from the displacement current excited in the cubes.The dielectric particle was equivalent to a magnetic dipole at the magnetic resonance,which could be adjusted by the size and permittivity of the particles.It may provide a convenient method to design isotropic metamaterials and invisible cloak at infrared and visible frequencies.
