Patent ID: 7780787

Claim:
An apparatus for depositing a material on a substrate, comprising: a permeable member configured to be heated to a delivery temperature and to substantially uniformly distribute the material along the length of said permeable member as the material exits said permeable member; a material supply conduit connected to said permeable member for supplying a carrier gas and a material to said permeable member; a secondary gas supply having at least one orifice internal to said permeable member configured to supply a secondary gas to said permeable member, the secondary gas supply configured to provide a uniform gas flow through the walls of said permeable member; and a conveyor configured to convey a substrate adjacent said permeable member, wherein said secondary gas supply has a generally tubular shape and is contained within the permeable member, wherein said permeable member is configured to be connected to a source of electrical power to heat the permeable member to the delivery temperature, and, wherein the material supply conduit includes at least one of a rotary screw or a vibratory feeder and a gas passage into which the rotary screw or the vibratory feeder is configured to introduce a powder of the material for flow with the carrier gas.