Direct Write™ System
View Patent ↗Methods and apparatus for the deposition of a source material ( 10 ) are disclosed. An atomizer ( 12 ) renders a supply of source material ( 10 ) into many discrete particles. A force applicator ( 14 ) propels the particles in continuous, parallel streams of discrete particles. A collimator ( 16 ) controls the direction of flight of the particles in the stream prior to their deposition on a substrate ( 18 ). In an alternative embodiment of the invention, the viscosity of the particles may be controlled to enable complex depositions of non-conformal or three-dimensional surfaces. The invention also includes a wide variety of substrate treatments which may occur before, during or after deposition. In yet another embodiment of the invention, a virtual or cascade impactor may be employed to remove selected particles from the deposition stream.
1. An apparatus comprising:
a material source for supplying a material to be deposited;
an atomizer for producing a plurality of discrete particles from said material source;
a virtual impactor;
a carrier gas for propelling said plurality of discrete particles generally toward a substrate;
a coflowing sheath gas which surrounds said carrier gas for controlling the direction of flight of said plurality of discrete particles; and
a single orifice for narrowing a particle stream comprising said coflowing sheath gas, said carrier gas, and said plurality of discrete particles sufficiently to form a deposited feature comprising a feature size of less than one millimeter on the substrate.
2. The apparatus of claim 1 wherein said coflowing sheath gas forms a boundary layer that prevents said plurality of discrete particles from depositing onto walls of an orifice nozzle.
3. The apparatus of claim 1 wherein said virtual impactor is placed after said atomizer.
4. The apparatus of claim 3 wherein said virtual impactor extracts excess carrier gas without substantially reducing the number of said discrete particles.
5. The apparatus of claim 3 wherein said virtual impactor sorts said plurality of discrete particles by size.
6. The apparatus of claim 3 further comprising two or more virtual impactors placed in series.
7. The apparatus of claim 1 further comprising a laser for processing said discrete particles.
8. A method of direct writing of a material, the method comprising the steps of:
supplying the material to be deposited;
atomizing the material to produce a plurality of discrete particles;
applying a force by employing a carrier gas to propel the plurality of discrete particles generally toward a substrate;
collimating the plurality of discrete particles by surrounding the carrier gas with a coflowing sheath gas to control the direction of flight of the plurality of discrete particles;
subsequently passing the particles through no more than one orifice; and
depositing the plurality of discrete particles on the substrate to form a deposited feature comprising a feature size of less than one millimeter.
9. The method of claim 8 additionally comprising the step of sorting the plurality of discrete particles by size.
10. The method of claim 9 wherein the sorting step comprises employing one or more virtual impactors.
11. The method of claim 8 further comprising the step of the coflowing sheath gas forming a boundary layer, thereby preventing the plurality of discrete particles from depositing onto walls of an orifice nozzle.
12. The method of claim 8 further comprising the step of extracting excess carrier gas without substantially reducing the number of said discrete particles.
13. The method of claim 12 wherein the extracting step comprises employing a virtual impactor.
14. The method of claim 8 further comprising the step of placing two or more virtual impactors in series.
15. The method of claim 8 further comprising the step of processing the discrete particles with a laser.