Apparatus for clamping a planar substrate

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.

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.