THESIS
2012
1 v. (various paging) : ill. ; 30 cm
Abstract
As the processing speed of the electronic components increased with technology
advances, the overall performance of the system is limited by the propagation delay in
the interconnections, while the propagation speed of signal in interconnections is
depended on the dielectric materials. The current dielectric materials such as silicon
dioxide have dielectric constant of 3.9-4.2. Future generation of electronic devices
require the material to have ultralow dielectric constant below 2. To increase signal
propagation speed and reduce propagation delay, ultralow dielectric constant material
has to be developed. The industry has targeted at the development of ultralow
dielectric materials since 2005 but there is still no available solution.
In this study, porous polyimide (PPI) as an...[
Read more ]
As the processing speed of the electronic components increased with technology
advances, the overall performance of the system is limited by the propagation delay in
the interconnections, while the propagation speed of signal in interconnections is
depended on the dielectric materials. The current dielectric materials such as silicon
dioxide have dielectric constant of 3.9-4.2. Future generation of electronic devices
require the material to have ultralow dielectric constant below 2. To increase signal
propagation speed and reduce propagation delay, ultralow dielectric constant material
has to be developed. The industry has targeted at the development of ultralow
dielectric materials since 2005 but there is still no available solution.
In this study, porous polyimide (PPI) as an ultralow dielectric material for device
application is investigated. Porous polyimide is prepared via a Vapor Induced Phase
Separation (VIPS) method. The porous structure of the film was found to be affected
by the concentration of polyimide (PI) in the casting solution and the processing
conditions. Dielectric measurement showed that dielectric constant is depended on the
porosity of the fabricated films. Microporous polyimide films with 70% porosity and
dielectric constant as low as 1.5 were successfully fabricated.
To evaluate the performance of porous polyimide as a dielectric material, circuits
were built on microporous polyimide substrate with etching process. The dielectric
constant of the microporous substrate was remained stable in value of 1.5 after
exposure to 95% relative humidity for 3 hours. Electrical measurements showed that
the ultralow dielectric constant of the microporous film increased the signal
propagation speed by 35% in the circuits on microporous polyimide substrate than the
circuits on dense polyimide substrate. Impedance tests on copper circuits built on the
substrates showed that a 23% increase in impedance for circuits on microporous
substrate. Considering the same impedance, the ultralow dielectric constant of
microporous polyimide enabled 37% reduction in line spacing. With higher wiring
density, miniaturization of electronic devices can be achieved.
Post a Comment