NEW ASPECTS OF THIN POLYIMIDE FOILS

A series of thin polyimide foils (16-115 mu g/cm(2)) were prepared in a glove-box under a controlled, dry atmosphere. Strengths, as defined by the Chen rupture coefficient, were measured and compared with previ ously published values for foils prepared at about 25% relative humidi ty and were found to be about 50% higher over the whole thickness rang e investigated. The use of a glove-box therefore permits the preparati on of stronger foils, independent of weather conditions (relative humi dity) and with the added advantage of dust-free conditions. The resist ivity of thin carbon layers on polyimide foils was measured for carbon deposits prepared by electron beam evaporation and by laser plasma ab lation. The use of such carbon coated polyimide foils as the cathode i n an electrodeposition process was investigated.