MATERIAL CHARACTERIZATION AND APPLICATION OF A CARBON-LOADED LIQUID CRYSTAL POLYMER FOR INTERCONNECT DESIGN

Open Access
Author:
Champion, Bruce Allen
Graduate Program:
Electrical Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 03, 2016
Committee Members:
  • Sedig Salem Agili, Thesis Advisor
  • Aldo W Morales, Committee Member
  • Jeremy Joseph Blum, Committee Member
Keywords:
  • Dielectric Absorber
  • Input/Output
  • Insertion Loss
  • Resonance
  • Genetic Algorithm
  • Crosstalk
  • Material Characterization
Abstract:
There is a need for the use of electromagnetic absorbing materials within interconnect designs to eliminate resonances in the throughput and noise parameters, however, a learning curve exists for using these materials in close proximity to high-speed differential pairs commonly used in interconnect applications. This study successfully reduces the Integrated Crosstalk Noise (ICN) of an interconnect by 42% and Insertion Loss Deviation (ILD) by 44% by utilizing a carbon-loaded LCP acting as a dielectric absorber within the interconnect. Current literature characterizes carbon nanotube and carbon black composites acting as dielectric absorbers, however, these studies focus mainly on shielding applications far away from high-speed differential signaling. These studies also did not offer a desirable electrical model conducive for 3D Finite Element Method (FEM) modeling. Conversely, literature which does develop a proper electrical model which can be used in 3D FEM software often develops models for printed circuit board (PCB) materials or other materials with drastically different material characteristics as compared to a dielectric absorber. To date, there has been no study conducted on characterizing a dielectric absorber for use in interconnect applications. To overcome this learning curve this study sets forth a way of understanding the inherent material properties of a Carbon-loaded Liquid Crystal Polymer (LCP) functioning as a dielectric absorber within an interconnect. This study will show why a dielectric absorber is the best choice for interconnect applications. The type of dielectric absorber used in this study is an LCP loaded with 26% volume carbon black powder. In addition, the proper loading of the material above the percolation threshold will be discussed, a Line-Line material characterization test method is presented and validated, a Genetic Algorithm is used to match the material properties to a Multipole Debye Dielectric model, and finally an end application using a dielectric absorber is shown. Using the type of dielectric absorber developed in this study one can significantly reduce the cost and complexity of interconnect designs while increasing performance.