UltraSource Substrate Properties

The substrate is the foundation on which the thin film components are built. The substrate properties have significant influence on the performance of the device. Alumina is still the most common substrate material due to its surface quality, cost, and high frequency performance. For power applications, Aluminum Nitride and BeO substrates are still the choices. Fused silica and quartz are used at very high operating frequencies. Sapphire gets called on for optical window use or when high mechanical strength is a must.

UltraSource is an expert at working with the following substrates:

  • Alumina
  • Quartz/Fused Silica
  • Aluminum Nitride
  • Beryllium Oxide
  • Ferrite/Garnet
  • Titanates
  • Glass
  • Sapphire
  • Silicon
Various thin film substrate materials
Various thin film substrate materials
Material Dielectric Constant (k) Loss Tangent (k) Thermal Conductivity (W/mK) CTE (ppm/K) Dielectric Strength (kV/mm) Polished Surface Finish As-Fired Surface Finish Lapped Surface Finish Available Thicknesses Inch (mm)
99.6% Alumina 9.9 .0001 27 7.0 23 <1u” <4u” <10u” .005-.050 (.127 – 1.27)
99.5% Alumina 9.8 .0001 25 7.0 23 <2u” <5u” <20u” .005-.050 (.127 – 1.27)
96% Alumina 9.6 .0002 25 8.2 19 <4u” <35u” <35u” .010-.120 (.254 – 3.05)
Aluminum Nitride (A1N) 8.9 .001 170, 200, 230 4.5 15 <4u” N/A <20u” .005-.050 (.127 – 1.27)
99.5% BeO 6.6 .003 285 or 325 7.5 14 <4u” N/A <30u” .005-.050 (.127 – 1.27)
Fused Silica 3.8 .0001 1.38 0.5 100 60/40 N/A <30u” .005-.050 (.127 – 1.27)
Sapphire 10 .0001 42 5 48 60/40 N/A <10u” .005-.050 (.127 – 1.27)
Borosilicate Glass 5 .003 3.2 1.2 38 60/40 N/A <10u” .005-.050 (.127 – 1.27)
Ferrites Hundreds of ferrite formulations to choose from <5u” N/A <30u” .010-.050 (.254 – 1.27)