Abstract:
A dimensionally stable high K' microwave laminate comprises independent control of the K' and CTE (coefficient of thermal expansion) of the fluoropolymer microwave laminates. The laminate comprises a composite having at least two types of ceramic filler. At least one type of ceramic filler exhibits a K' of greater than 30. The two or more fillers are necessary to be able to independently control the K' and the CTE of the composite, thereby achieving a dimensional stability of absolute magnitude less than 0.1% change. The present invention allows the manufacture of microwave laminate with any specified K' (within the achievable range) and the XY CTE of the material nearly matched to that of copper, resulting in good dimensioned stability during circuit fabrication.