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| Chemical
Mechanical Planarization (CMP) Slurries Containing Nano-abrasive Particles
for Micro-electro-mechanical Systems (MEMS) Applications |
- A high removal rate copper CMP slurry developed specifically
for bulk copper removal for MEMS applications. This slurry provides
a copper removal rate more than 6x that of iCue® 5001 (a
commercial copper CMP slurry used in IC applications).
- A series of high removal rate oxide CMP slurries developed specifically
for bulk silicon dioxide removal for MEMS applications. These
slurries, having controllable and "tunable" removal rates, provide
oxide removal rates of 1.5x to 3x that of Semi-Sperse® 25 (a
commercial colloidal fumed silica CMP slurry used in IC
applications).
- A series of CMP slurries developed specifically for controllable
and "tunable" removal rates on polymeric substrates, especially
polyimide substrates of the type commonly used in microelectronics
applications. CMP removal rates, shown to be highly dependent
upon polyimide structure/property characteristics, were demonstrated
on both blanket and patterned wafers coated with various photosensitive
and standard polyimides manufactured by HD Microsystems; polyimide
product designations: PI-2525, PI-2611, HD-4000, HD-8000).
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| Field
Emitters Based on Low-Cost Carbon Black or Carbon Black/Silica Nanoparticles
or Diesel Exhaust in a Polymer Matrix |
- Inexpensive nanoparticles of carbon black (with optional fumed
silica nanoparticles), dispersed in a polymeric matrix, result
in electrically conducting films that exhibit field emission performance
comparable to that shown by much more expensive carbon nanotubes.
Ordinary diesel exhaust soot in a polymer binder also shows field
emission performance comparable to that of carbon nanotubes. The
carbon black/polymer or diesel exhaust/polymer formulations can
be applied to various substrates by brushing, dipping, spin coating
or spraying. After thermal cure, the resulting field emitter films
are stable under ultra-high vacuum and at temperatures exceeding
450° C. Applications for these patent-pending emitters include:
large area displays and billboards, sensors, microwave amplifiers
and large-area x-ray sources. This emitter technology is based
on the original ideas of Dr. Heinz H. Busta, with supporting technical
contributions from Dr. Ron Myers. See US Patent Application: 20040198892
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| Corrosion
Resistant Coatings for Turbomachinery |
- A patented series of environmentally compliant, chromate-free,
corrosion-resistant coatings are currently used worldwide on power-generating
and turbomachinery components. The SermeTel® Process
2000 coatings are sacrificial aluminum-ceramic compositions consisting
of aluminum powder dispersed in an aqueous, acidic binder. The
sacrificial aluminum-ceramic basecoat is further sealed with a
chemically inert, glassy ceramic topcoat, resulting in an aerodynamically
smooth surface that resists corrosion and fouling. ASTM B117 salt
fog testing of SermeTel® Process 2000 coated at 50 microns
on mild steel substrate, unscribed, shows > 2500 hours
without substrate corrosion. SermeTel® Process 2000
was recognized by the worldwide readership of "Aerospace Engineering"
as being "one of the top ten best new products of 1998". Dr. Myers
led the project team that developed the original SermeTel®
Process 2000 coating systems. See U.S. Patents: 6,368,394;
6,224,657;
6,074,464;
5,968,240.
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| Intumescent
Fire Resistant Coatings |
- Low cost, non-halogenated, ammonium pentaborate (APB) is
shown to be a highly effective intumescent flame retardant
additive for various polymers. APB, at low levels(<10 phr) greatly enhances
char formation and increases burn through resistance of polymer
coatings. A 0.18 cm thick thermoplastic polyurethane coating (Estane®
58202 black) containing 8-10 phr of APB provides 7-10 minutes
of thermal protection to heat sensitive substrates when directly
exposed to a 800° C propane torch flame. In comparison, the Estane® 58202
black control, which is a UL 94 V-O rated polyurethane, provides
less than 1 minute of burn-through resistance under identical
propane torch testing. APB functions as a char-promoting,
intumescent additive and also retards flaming drip and suppresses
char afterglow.
- Low melting, inorganic phosphate-sulfate glasses are shown to
be inexpensive and highly effective, non-halogenated flame and
smoke retardant additives for a variety of organic polymers. These
patented glass/ceramic compositions, when added to polymers such
as polyvinylchloride (PVC), plasticized PVC, polyurethanes, polyamides,
polyolefins, polystyrene, and polyacrylonitriles, show increased
oxygen index values, increased char formation and decreased smoke
generation (relative to controls). The low melting glasses also
exhibit a pronounced intumescent effect, especially in rigid PVC,
polyamides and polyurethanes. The low melting glass additives
strengthen the resulting carbon/glassy ceramic char, providing
a highly effective thermal barrier. Synergistic effects are noted
when the low melting glasses are combined with other flame retardants
such as ammonium pentaborate. See U.S. Patent 4,544,695.
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| Thermal
Management Coatings/Formulations |
- Silicone-based and silicone-free thermal grease formulations,
with Tc > 2 W/mK, are used for heat dissipation in computers
and electronic devices.
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| Preceramic
Polymers |
- Prepared via controlled hydrolytic polycondensation of cyclic
silazanes, these liquid polysilazoxanes provide high yields of
Si-C-O-N ceramic compositions. The preceramic polymers are useful
as composite preform impregnants and densification resins as well
as matrix resins and can be combined with refractory particulates
or fibers to prepare high temperature composites. The preceramic
polymers are especially useful as impregnants and densification
resins for carbon/carbon composites and ceramic matrix composites.
These preceramic polymers show TGA ceramic char yields of 75%
to 85% at 1500° C in air or inert atmosphere. See U.S. Patents
5,256,487
and 5,136,007.
- Silazane-modified phenolic resins are prepared by reacting cyclic
silazanes with phenolic resins, such as SC-1008 phenolic. The
resulting inorganic-organic polymer exhibits thermal stability
substantially greater than that of an unmodified phenolic. The
unmodified phenolic control shows a TGA char yield of only 43
weight % at 1500° C/inert atmosphere, while the silazane-modified
phenolic has char yields of 70-85 weight % under identical TGA
pyrolysis conditions. In addition, the char derived from the unmodified
phenolic consists primarily of carbon, while the silazane-modified
phenolic generates a thermo-oxidatively stable ceramic/carbon
char. These inorganic-organic polymers are useful as: high temperature
adhesives and laminating resins, ablative coatings, and matrix
resins for high temperature composites such as carbon/carbon composites.
See U.S. patent 5,089,552.
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| Inorganic-Organic Hybrid Polymers |
- A reaction product of a cyclic phosphazene and an amine terminated
reactive liquid polymer (Hycar® ATBN). The resulting
product is an elastomer (300% ultimate elongation) that remains
flexible at low temperatures (- 66° C). The phosphazene-modified
ATBN is also inherently flame resistant and self-extinguishing.
See U.S. Patent 4,535,147.
- A reaction product of a cyclic phosphazene and a carboxyl terminated
reactive liquid polymer (Hycar® CTB). The resulting
composition is inherently flame resistant and is hydrophilic,
absorbing more than 3 times its weight in water. See U.S. Patent
4,533,726.
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| Electrically Conducting Polymers |
- Electrically conducting polypyrrole is instantaneously generated
via reaction of pyrrole monomer with transition metal halides,
anhydrous FeCl3 being preferred. The resulting polypyrroles have
room temperature conductivities in the range of 0.001 to 150 S/cm,
depending upon reaction conditions. Organo-substituted pyrrole
monomers result in organic-soluble, electrically conducting polypyrroles.
Also described is a process for converting otherwise electrically
insulating substrates into electrical conductors. Virtually any
porous substrate such as paper, polymers, fabrics, textiles, inorganic
or organic particulates, inorganic or organic fibers and the like
is first exposed to pyrrole monomer and then exposed to initiator/oxidant,
thereby instantaneously forming the conducting polypyrrole as
a coating on and/or impregnant within the porous substrate. This
process has been used to prepare electrically conducting particles
of alumina, silica, zeolites, etc. The process has been used to
prepare lightweight polymer composites having use as aircraft
de-icers, snow/ice melting systems for roofs, and vehicle seat
heaters. See U.S. Patents: 5,407,699;
4,764,573;
4,680,236.
- An electrically conducting polymer blend is formed by in situ
polymerization of pyrrole monomer in a solution of various organic
polymers such as polyurethanes, polyvinylchloride, polyamides,
polyacrylates and the like. The resulting polymer blend can be
further cold pressed or thermoformed, as appropriate, to produce
a polyblend having electrical conductivity in the range of 0.001
to 150 S/cm, depending on reaction conditions. The polyblends
have utility as lightweight resistance heaters (aircraft de-icers,
roof de-icers), anti-static packaging, etc. See U.S. Patent 4,617,353.
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