Apparatus for forming films on substrates

Abstract

A doctor blade assembly for use in combination with apparatus for forming a film on a substrate. The doctor blade assembly includes a doctor blade to be mounted on a programmable robot. The doctor blade has a bottom face and spacers at opposite ends of the body of the doctor blade extending a predetermined distance down below the bottom face of the body for contacting a substrate and spacing the bottom face from the substrate. The spacers are adjustable relative to the doctor blade for adjusting the predetermined distance according to the thickness of film to be formed on the substrate. Other aspects and methods are also disclosed.

What is claimed is: 
     
         1 . Apparatus for forming films on substrates, comprising:
 a doctor blade,   a programmable robot for moving the doctor blade along X, Y and Z axes, the X and Y-axes being generally horizontal and the Z axis being generally vertical, and   a flexible coupling for coupling the doctor blade to the robot, said flexible coupling being configured for exerting a downward force on the doctor blade as it moves along a substrate during the formation of a film on the substrate.   
     
     
         2 . Apparatus as set forth in  claim 1  wherein said downward force is a spring force having a vertical component and a horizontal component. 
     
     
         3 . Apparatus as set forth in  claim 2  wherein said flexible coupling comprises a spring member having a longitudinal axis. 
     
     
         4 . Apparatus as set forth in  claim 3  wherein said spring member is adapted to bend along its longitudinal axis as it exerts said downward force on the doctor blade. 
     
     
         5 . Apparatus as set forth in  claim 3  wherein said spring member has a releasable connection with said doctor blade. 
     
     
         6 . Apparatus as set forth in  claim 3  wherein said doctor blade comprises a body having a bottom face adapted to be spaced a predetermined distance from the substrate to form a gap between the bottom surface and the substrate generally corresponding to the thickness of the film to be formed on the substrate, and wherein said bottom face lies in a plane oblique to the longitudinal axis of the spring member when the spring member is in a relaxed condition. 
     
     
         7 . Apparatus as set forth in  claim 3  wherein said flexible coupling comprises a first pin having a lower end connected to the spring member and an upper end adapted for connection to said robot, and a second pin having a lower end connected to the doctor blade and an upper end spaced from the lower end of the first pin. 
     
     
         8 . Apparatus as set forth in  claim 7  wherein the first and second pins have first and second longitudinal axes, respectively, said axes being generally co-axial with one another when the spring member is in a relaxed condition and skewed relative to one another when the spring member exerts a downward force on the doctor blade during a film-forming operation. 
     
     
         9 . A method of adjusting the gap of a doctor blade to vary a thickness of film formed by the doctor blade, said method comprising:
 providing a doctor blade having a body and opposite ends; and   adjusting spacers at opposite ends of the body to extend a selected distance below the body of the doctor blade, said distance being adjustable according to the thickness of the film to be formed.   
     
     
         10 . A method as set forth in  claim 9  further comprising mounting said doctor blade on a programmable robot after the spacers have been adjusted. 
     
     
         11 . A method as set forth in  claim 9  wherein said robot is movable along X, Y and Z-axes. 
     
     
         12 . A method of forming a film on a substrate, comprising
 moving the doctor blade across a substrate to form a film on the substrate; and   while moving the doctor blade across the substrate, applying a downward force to the doctor blade having both horizontal and vertical force components.   
     
     
         13 . A method as set forth in  claim 12  further comprising mounting a doctor blade on a programmable robot for movement across the substrate.