Vacuum Hold-Down System for Heat-Treating Thin Films

In improved furnace concept for heat-treating thin films, vacuum ports in vacuum plate(s) hold films connected together in zones so vacuum applied separately to each zone. Allows material being held to shrink or expand while still being held in place. Unclamped zones expand or contract , relieving local stresses so entire sheet accommades thermally induced changes without cracking. Applications include manufacture of thin semiconductor films for solar cells and of membranes for electrolytic production of oxygen.