Patent ID: 6592671
Filing Date: 2003-07-15
Classification: A61K,B01J,B05B,H01L,H02N

Abstract:
An apparatus for electrostatically adhering grains to a planar substrate comprising:a. an electrostatic grain-attracting device having a collection surface with a periphery and a collection area within the periphery comprising at least two grain collection zones for, when the planar substrate is adhered to the collection surface, electrostatically directing charged grains to corresponding surfaces on the planar substrate; and b. a pattern of first holes through the electrostatic grain-attracting device allowing a source of low pressure to act through the electrostatic grain-attracting device to facilitate the adherence of the planar substrate; wherein the collection surface and holes are configured and patterned to adhere, with the low pressure, a flexible planar substrate and the electrostatic grain-attracting device is adapted to selectively attract grains to the flexible planar substrate at two or more distinct surface areas corresponding to the two or more grain collection zones, and wherein at least one of the following applies:1. the first holes are at the periphery; or 2. the apparatus further comprises a vacuum chuck comprising a porous support adapted and configured to support the electrostatic grain-attracting device and convey reduced pressure to the first holes, wherein the porous support comprises pores with an average size of 500 microns or less.