Rotary reactor for uniform particle coating with thin films
Inventors
Neikirk, Colin C. • Narwankar, Pravin K. • Gangakhedkar, Kaushal • Sivaramakrishnan, Visweswaren • Frankel, Jonathan • ISHIKAWA, David Masayuki • Truong, Quoc • Yudovsky, Joseph
Assignees
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Publication Number
US-12421601-B2
Publication Date
2025-09-23
Expiration Date
Abstract
A reactor for coating particles includes one or more motors, a rotary vacuum chamber configured to hold particles to be coated, wherein the rotary vacuum chamber is coupled to the motors, a controller configured to cause the motors to rotate the rotary vacuum chamber about an axial axis of the rotary vacuum chamber such that the particles undergo tumbling agitation, a vacuum port to exhaust gas from the rotary vacuum chamber, a paddle assembly including a rotatable drive shaft extending through the rotary vacuum chamber and coupled to the motors and at least one paddle extending radially from the drive shaft, such that rotation of the drive shaft by the motors orbits the paddle about the drive shaft in a second direction, and a chemical delivery system including a gas outlet on the paddle configured inject process gas into the particles.
Core Innovation
The method for coating particles uses a rotary vacuum chamber to support a particle bed that enables gas-phase coating. Particles are dispensed into a rotary vacuum chamber, and the chamber is rotated along an axial axis in a first direction to maintain a particle bed formed by a portion of the dispensed particles that remain in a lower portion of the rotary vacuum chamber. Vacuum is applied by evacuating the rotary vacuum chamber through a vacuum port in the rotary vacuum chamber.
A paddle assembly is rotated in a second direction so that a plurality of paddles orbit a drive shaft. Process gas is injected into the particles through a plurality of gas outlets located on the plurality of paddles. Continuously as the plurality of paddles orbit the drive shaft, at least one paddle extends into the particle bed, and at least one gas outlet is located within the particle bed to percolate the process gas through the particles held within the rotary vacuum chamber.
The approach is described in the context of rotary vacuum coating reactor operation for forming thin-film coatings on particles using atomic layer deposition or molecular layer deposition, and optionally chemical vapor deposition. The rotary vacuum chamber architecture includes stationary and rotary vacuum chamber components with vacuum ports and controlled gas injection via paddle-driven outlets, supported by controller-controlled recipe operation and low-temperature operation.
Claims Coverage
The claims describe a core set of inventive features: a rotary vacuum chamber that maintains a particle bed in a lower region, evacuation through a vacuum port, and orbiting paddles with gas outlets that extend into the bed to percolate process gas through the particles. Dependent claims refine gas delivery through the paddle assembly, rotation-speed conditions affecting bed geometry, and coating options including ALD/MLD and an inorganic metal oxide.
Rotary vacuum chamber particle bed with axial rotation
Dispensing particles into a rotary vacuum chamber and rotating the rotary vacuum chamber along an axial axis in a first direction, maintaining a particle bed formed by a portion of the particles dispensed within the rotary vacuum chamber that remain in a lower portion of the rotary vacuum chamber.
Vacuum evacuation through a vacuum port
Evacuating the rotary vacuum chamber through a vacuum port in the rotary vacuum chamber.
Orbiting paddle assembly with in-bed gas outlets
Rotating a paddle assembly in a second direction such that a plurality of paddles orbit a drive shaft, where continuously as the plurality of paddles orbit the drive shaft, at least one paddle extends into the particle bed such that at least one gas outlet of the plurality of gas outlets is located within the particle bed to percolate the process gas through the particles held within the rotary vacuum chamber.
Chemical delivery via chemical supply passages in the paddle assembly
Injecting the process gas into the particles through the plurality of gas outlets located on the plurality of paddles wherein the process gas is delivered via chemical supply passages located within the paddle assembly.
Bed geometry controlled by rotation speed threshold
Rotating a cylindrical portion of the rotary vacuum chamber at a rotation speed greater than a threshold rotational speed such that the particles form a toroidal bed on an inner wall of the rotary vacuum chamber.
Bed maintenance via rotation speed threshold
Rotating the rotary vacuum chamber about the axial axis in the first direction comprising operating at a rotation speed less than a threshold rotational speed such that a portion of the dispensed particles forms a particle bed that remains in the lower portion of the rotary vacuum chamber.
ALD or MLD coating
Coating the particles using atomic layer deposition or molecular layer deposition.
Inorganic metal oxide coating material class
The organic or inorganic coating comprises an inorganic metal oxide.
The claims focus on combining a rotary vacuum chamber that maintains a particle bed with orbiting paddles carrying gas outlets positioned within that bed to percolate process gas through the particles under vacuum, with dependent refinements for gas delivery, rotation-speed-based bed behavior, and coating by ALD/MLD using an inorganic metal oxide.
Stated Advantages
Uniform particle-to-particle coating.
Thinner layers enabling higher API loading.
Scalable high-volume manufacturing.
Documented Applications
Coating API particles (active pharmaceutical ingredients) to form metal oxide thin films and other thin-film coatings, including via atomic layer deposition or molecular layer deposition.
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