Surface modification of low CTE polyimide

The low CTE (Coefficient of Thermal Expansion) polyimide is modified in chemical solutions and the modified surfaces are well characterized with ISS, XPS, ER, IR and the contact angles. The average depth of modification is measured by a method using an IR absorbance-thickness relationship with ellipsometry and ER IR. Mechanism of the polyimide-polyimide adhesion is well understood from the relationship between depth of modification and adhesion strength.