Means for supporting a mask

摘要

To prevent tilting or bending of a large mask frame holder and at the same time to prevent distortion when the mask holding frame is attached to a support base by ball plungers in three of the four corner areas of a mask holding frame that engage V groove bodies which face the ball plungers on the surface of the base, compression springs are provided in those three corners which pre-stress the mask holding frame toward the support base while a compression spring is provided between the remaining corner area of the mask holding frame and the base which acts in a direction pressing the mask holding frame away from the support base, thereby preventing the mask holding frame from bending or tilting. As an alternative, in each of the three pre-stressed corner areas of the mask holding frame, instead of a compression spring, an elastic attachment component in the form of a bracket with spring-like legs mounted to the supporting component can be provided.