Ultralow-permittivity glass /Al2O3 composite for LTCC applications

Authors：Shang, Yong; Zhong, Chaowei^*; Xiong, Huajing; Li, Xinyuan; Li, Hao^*; Jian, Xian

Source：Ceramics International, 2019, 45(11): 13711-13718.

DOI：10.1016/j.ceramint.2019.04.066

• Glass/Al2O3 composite
• Low temperature co-fired ceramic
• Low permittivity
• Dense composite

In the field of low temperature co-fired ceramic (LTCC), it remains a challenge to design the performance of LTCC with low permittivity less than 5. Here, a novel glass mixture of K-Al-B-Si-O (KABS) and Zn-B-Si-O (ZBS) is introduced as a sintering aid of alumina to obtain ultralow-permittivity glass/Al2O3 composite. Meanwhile, the factors of glass mixture component on microstructure, phase structure and dielectric properties of the composites are considered systematically. The crystal structure measured by X-ray diffraction (XRD) shows that pure crystalline phase of ZnAl2O4 spinel can be attained by tailoring the component of the glass mixture. In case of mass ratio of KABS: ZBS equal to 6:4, it favors to efficiently increase the sintering densification of composite, and significantly benefit the low dielectric loss, good mechanical and thermal performances. In detail, the optimal glass/ceramic composites sintered at 850 degrees C for 2 h exhibit the bulk density of 2.89 g/cm3, epsilon(r) of 4.92 at 14 GHz and Q x f of 6873 GHZ, flexural strength of 202 MPa, thermal expansion coefficient of 5.5 ppm/degrees C. The above study provides an effective approach for preparing the novel composites as a promising candidate for LTCC applications.

• Institution
  电子科技大学; hunan univ