Mechanical Properties of Very Thin Polymer Films

The uniaxial and biaxial mechanical properties of five thin film polymers have been measured. Parylenes N, C, and M exhibit uniform properties to thicknesses as low as 0.12 μ; the 4.3 μ polyester (Mylar) and the 2.3 μ polycarbonate (Kimfol) show tensile and elongation properties inferior to those measured on thicker sections. Biaxial rupture strengths were found to vary directly with film thickness and inversely with the half-power of the unsupported area. The measured rupture constant is shown to be a function of the tensile strength and ultimate elongation of the material.