Introducing DuPont? GreenTape? 9K5 Low Dielectric Constant, Low Temperature Co-Fired Ceramic (LTCC) Tape System

摘要

Low Temperature Co-fired Ceramic (LTCC) material systems have been successfully used in microwave andmillimeter wave systems for several years. LTCC has very low dielectric loss, high reliability due to inherenthermeticity; high interconnect density, multilayer processing capability leading to true 3D packaging, and bettercost-performance balance. While the medium range dielectric constants (7.00 – 8.00) offered by current tapesystems have advantages, it is generally difficult to realize high speed systems and efficient antennas on LTCC,especially at millimeter wave frequencies. The difficulty arises from the reduced signal propagation velocity in highspeedapplications, and lower radiation efficiency for antennas, both due to higher dielectric constant. To enable andextend applications of LTCC technology to these subsystems, DuPont has developed a new low dielectric constantLTCC system – DuPont? GreenTape? 9K5 - which has a dielectric constant of 5.80 (at 10 GHz) that iscompatible with the commercial DuPont? GreenTape? 9K7 LTCC System. This is achieved withoutcompromising excellent microwave loss properties of the 9KX GreenTape? platform. These materials systemsenable high-speed, high reliability applications while also realizing efficient antennas on LTCC. This paper presentsinitial characterization of the new DuPont? GreenTape? 9K5 LTCC system consisting of low K dielectric tape,gold and silver conductors to evaluate the effects of chemistry, processing conditions, processing latitude,microstructure, and microwave performance. Test coupons with various transmission and resonating structures aredesigned, fabricated, and tested for the evaluation of transmission losses and dielectric properties. Stability of thematerial system over multiple re-fire steps is also examined.