THERMOMECHANICAL STUDIES ON NEWLY DEVELOPED COPOLYESTER THIN-FILMS - PART-1 - THERMAL-EXPANSION COEFFICIENTS

In this paper, the in-plane linear coefficients of thermal expansion ( CTE) (alpha x and alpha y) of a newly developed family of all aromatic and aromatic/aliphatic copolyester thermoset films prepared from spin coating were measured. The volumetric CTEs (beta) were determined by a Pressure-Volume-Temperature (PVT) technique (1). Based on the differ ence between the volumetric CTEs and the sum of the in-plane linear CT Es, the out-of-plane linear CTEs (alpha z) were calculated. The effect s of film processing, including film coating and curing, on the CTEs a re discussed. It was found that the linear CTEs varied significantly w ith the processing conditions, the volumetric CTEs were essentially co nstant, and the out-of-plane linear CTEs (alpha z) of the spin coated films were higher than the in-plane linear CTEs (alpha x,y).