This paper will discuss how the Aerosol Jet process is being used to deposit a wide variety of materials onto a wide variety of substrates without conventional masks or thin-film equipment. The process is non-contact, enabling traces to be printed over steps or curved surfaces. Printed features can be less than 10 microns.
Provisional Patent Application Ser. Renn, filed on Jun. Renn, filed on Jan. Renn, filed on Feb. The specifications and claims of all of the above references are hereby incorporated herein by reference.
Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Contract No. NC awarded by the U. Field of the Invention Technical Field The present invention relates generally to the field of direct write deposition.
Background Art Note that the following discussion refers to a number of publications and references. Discussion of such publications herein is given for more complete background of the scientific principles and is not to be construed as an admission that such publications are prior art for patentability determination purposes.
Various techniques may be used for deposition of electronic materials, however thick film and thin film processing are the two dominant methods used to pattern microelectronic circuits. Recently, ink jetting of conductive polymers has also been used for microelectronic patterning applications.
Thick film and thin film processes for deposition of electronic structures are well-developed, but have limitations due to high processing temperatures or the need for expensive masks and vacuum chambers.
Ink jetted conductive polymers have resistivities that are approximately six orders of magnitude higher than bulk metals. Thus, the high resistivity of ink jetted conductive polymers places limitations on microelectronic applications.
One jetting technique, disclosed in U. The minimum feature size attainable with this method was reported to be approximately microns. Deposition of metals onto low-temperature targets is not disclosed.
The process disclosed in U. The apparatus uses ultrasonic atomization and a pressurized chamber ending in an orifice, to form a jet of aerosolized ink entrained in a carrier gas.
Hochberg discloses the use of relatively large exit orifices—the reported orifice diameters range from to microns—and a minimum deposited feature size of 50 microns.
The invention of Hochberg does not use a sheath gas to form an annular flow for the purpose of focusing the aerosol stream and preventing accumulation of material at the exit orifice, is limited to the deposition of ink onto paper, and does not disclose a process for aerosolization and deposition of viscous inks or inks composed of particle suspensions.
The as-deposited line features may be as small as approximately 5 microns, and may be treated thermally or using laser radiation.
The precursor viscosity may range from approximately 1 to centiPoises cPas opposed to ink jetted solutions, which are typically confined to around 10 cP.The QR codes were made using an AutoCAD file and printed with Optomec direct-write aerosol jetting.
The printed QR codes are invisible under ambient lighting conditions, but are readable using a near-IR laser, and were successfully scanned using a smart phone. Aerosol Jet® printing is a direct write technology that was developed through the Defense Agency Research Program Agency (DARPA) Meso Integrated Conformal Electronics (MICE) program.
3 The goal of this program was to create new technologies for the formation of micron-sized electrical circuits while not using the lithographic process. 3 The. Aerosol jetting tends to exhibit higher conductivity than extrusion systems, but are imitated to only being able to print on the exposed surface of the component.
 FIG. 11 is a schematic, side elevation view of an aerosol-jetting deposition apparatus for material depositions.  FIG. 12 is a perspective view, schematically shown, of a general method of laser light treatment of deposited particulates.
By depositing this dispersed suspension as an ink with a direct write printer (aerosol jet) we confirmed the ability to print colloidal crystals with structural color in any pattern. Mike Renn of Optomec, Albuquerque with expertise in Materials Physics.
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