Apparatus for clamping a planar substrate

Abstract

The disclosure relates to an apparatus for electrostatically adhering grains to a planar substrate comprising: a. an electrostatic chuck having a collection surface with at least one grain collection zone for, when the planar substrate is layered on the collection surface, electrostatically directing charged grains to a corresponding surface on the planar substrate; and b. a pattern of holes through the electrostatic chuck allowing a source of low pressure to act through the electrostatic chuck to adhere the planar substrate.

What is claimed:  
     
         1 . An apparatus for electrostatically adhering grains to a planar substrate comprising: 
 a. an electrostatic chuck having a collection surface with at least one grain collection zone for, when the planar substrate is layered on the collection surface, electrostatically directing charged grains to a corresponding surface on the planar substrate; and    b. a pattern of holes through the electrostatic chuck allowing a source of low pressure to act through the electrostatic chuck to adhere the planar substrate.    
     
     
         2 . The apparatus of  claim 1 , further comprising: 
 d. a low pressure chuck having an adhesion surface having a plurality of holes for aligning with the holes to connect the holes to the source of low pressure.    
     
     
         3 . The apparatus of  claim 2 , wherein the adhesion surface comprises a porous material.  
     
     
         4 . The apparatus of  claim 1 , wherein the electrostatic chuck comprises (i) the collection surface, (ii) a dielectric layer located behind the collection surface, (iii), behind the dielectric layer, one or more attraction electrodes for attracting grains to the collection zones.  
     
     
         5 . The apparatus of  claim 4 , wherein the electrostatic chuck further comprises (iv) one or more shield electrodes for discouraging charged grains from being directed away from the collection zones.  
     
     
         6 . An electrostatic deposition apparatus for electrostatically depositing grains onto a planar substrate comprising: 
 i. at least one low pressure chuck having an adhesion surface having a plurality of holes for conveying low pressure to the adhesion surface;    ii. layered on the collection surface, at least one electrostatic chuck having a collection surface with at least one grain collection zone for, when the planar substrate is layered on the collection surface, electrostatically directing charged grains to a corresponding surface on the planar substrate, the at least one electrostatic chuck having a pattern of holes through the electrostatic chuck allowing the low pressure to act through the electrostatic chuck to adhere the planar substrate; and    iii. a charged grain dispenser for directing charged grains towards the grain collection zones.    
     
     
         7 . The electrostatic deposition apparatus of  claim 6 , further comprising rotatable cluster of a plurality of said low pressure chucks, wherein the low pressure chucks rotate to repeatedly and sequentially present the adhesion surfaces to the charged grain dispenser.  
     
     
         8 . The electrostatic deposition apparatus of  claim 7 , further comprising: 
 iv. a low pressure control mechanism for sequentially applying low pressure to low pressure chucks and sequentially releasing the low pressure from low pressure chucks such that there is a contiguous collection of the low pressure chucks to which low pressure is applied and a contiguous collection of the low pressure chucks with no applied low pressure, thereby allowing a sheet of planar substrate to be presented to the charged grain dispenser while adhered to an electrostatic chuck and low pressure chuck and then released for further processing.    
     
     
         9 . A method of electrostatically applying a grains to a planar substrate comprising: 
 a. adhering the planar substrate to an electrostatic chuck with a pressure differential conveyed to the planar substrate via passages through the electrostatic chuck;    b. applying a voltage to the electrostatic chuck to attract charged grains to at least one grain collection zone defined by the electrostatic chuck;    c. directing charged grains towards the charged grain collection zone; and    d. electrostatically adhering charged grains on a portion of the planar substrate corresponding to the grain collection zone.