| 摘要 |
A new and improved laminated microwave circuit material (10) comprises a non-woven glass web (5 to 20 vol. %) impregnated with a cyanate ester resin (35 to 68 vol. %) and filled with a low dielectric constant (e.g., silica), high dielectric constant (e.g., titania) filler or other suitable ceramic particulate filler (25-55 vol. %). Intermediate values of dielectric constant may be achieved by filler mixtures of silica, titania and other suitable fillers. Preferably, the filler is coated with a material which renders the filler hydrophobic such as silane, titanate or zirconate coatings. This microwave circuit material (10) of the present invention is preferably formulated to be flame retardant and has many features and advantages relative to prior art and microwave materials including prior art cyanate ester/woven glass materials. For example, the combination of resin, non-woven glass web and filler provides a low dissipation factor (Df) of less than 0.008 thereby permitting the material of the present invention to be used in rellatively demanding consumer and commercial applications (and some less demanding military applications). |
