Adeia Semiconductor Bonding Technologies Inc.

Panasonic Precision Devices Co., Ltd.

Nels Jewell-Larsen

Kenneth Allen Honer

Yan Zhang

Matt Schwiebert

Piyush Savalia

Hongyu Ran

Guilian Gao

Matthew K Schwiebert

Matthew Schwiebert

Ken Honer

Ron Goldman

Surfaces for electromagnetic shielding, retaining electrostatic charge and indeed collecting ion current in EHD fluid mover designs may be formed as or on surfaces of other components and/or structures in an electronic device. In this way, dimensions may be reduced and packing densities increased. In some cases, electrostatically operative portions of an EHD fluid mover are formed as or on surfaces of an enclosure, an EMI shield, a circuit board and/or a heat pipe or spreader. Depending on the role of these electrostatically operative portions, dielectric, resistive and/or ozone robust or catalytic coatings or conditioning may be applied.

Electrohydrodynamic fluid mover techniques for thin, low-profile or high-aspect-ratio electronic devices

Cleaning and/or conditioning electrode surfaces can provide significant performance and operational benefits in EHD devices. In particular, conditioning of emitter electrode surfaces with silver (Ag), silver compositions or silver preparations applied in situ at successive times throughout the operating lifetime of an EHD air mover has been found to significantly reduce ozone production. Structures and techniques are described for in situ conditioning electrode surfaces and, in particular, emitter electrode surfaces of an EHD device such as an air mover or precipitator, with a conditioning material that includes silver.

System and method for in-situ conditioning of emitter electrode with silver

An electrohydrodynamic fluid accelerator includes an emitter electrode and leading surfaces of a collector electrode that are substantially exposed to ion bombardment. Heat transfer surfaces downstream of the emitter electrode along a fluid flow path include a first portion not substantially exposed to the ion bombardment that is conditioned with a first ozone reducing material. The leading surfaces of the collector electrode are not conditioned with the first ozone reducing material, but may include a different surface conditioning. The downstream heat transfer surfaces and the leading surfaces can be separately formed and joined to form the unitary structure or can be integrally formed. The electrohydrodynamic fluid accelerator can be used in a thermal management assembly of an electronic device with a heat dissipating device thermally coupled to the conditioned heat transfer surfaces.

Collector-radiator structure for an electrohydrodynamic cooling system

Small form-factor ion flow fluid movers that provide electrostatically operative surfaces in a flow channel adjacent to an emitter electrode, but upstream of a collector electrode or electrodes, can shape operative electric fields and influence ion flows in ways that accentuate downstream flow while minimizing upstream ion migration. In some cases, dielectric surfaces (or even electrically isolated conductive surfaces) along a flow channel adjacent to an emitter electrode can be configured to collect and retain an initial population of generated ions and thereafter electrostatically repel further ions. Depending on the configuration of such dielectric or electrically isolated conductive surfaces, these repelling electrostatic forces may dissuade ion migration or flow from sensitive but closely proximate components and/or may shape fields to enhance ion flows in a desired downstream direction.

Electrohydrodynamic (EHD) fluid mover with field shaping feature at leading edge of collector electrodes

An electrohydrodynamic fluid accelerator apparatus includes a corona electrode having an axial shape and configured to receive a first voltage. The electrohydrodynamic fluid accelerator apparatus includes a collector electrode disposed coaxially around the at least one corona electrode and configured to receive a second voltage. Application of the first and second voltages on the corona electrode and the collector electrode, respectively, causes fluid proximate to the corona electrode to ionize and travel in a first direction between the corona electrode and the collector electrode, thereby causing other fluid molecules to travel in a second direction to generate a fluid stream. In at least one embodiment of the invention, the ionized fluid proximate to the emitter electrode travels in a radial direction from the corona electrode to the collector electrode, causing the other fluid molecules to travel in an axial direction to thereby generate the fluid stream.

Ionic fluid flow accelerator

Conditioning an electrode is performed with a cleaning device for removing detrimental material from forming electrode surfaces of an electrohydrodynamic device or other ion flow generating device. A conditioning material is deposited on the electrode to at least partially mitigate erosion, corrosion, oxidations, dendrite formation on the electrode or ozone production. The conditioning material can be deposited by a wearable portion of one or more cleaning blocks or wipers. The cleaning blocks may have a composition selected to be hard enough to remove detrimental material under a selected pressure, while soft enough to be wearable to deposit a conditioning layer on the electrode surface. The conditioning material can be applied as a solid or liquid. The applied conditioning material can include at least one of silver, palladium, platinum, manganese, nickel, zirconium, titanium, tungsten, aluminum, oxides or alloys thereof, carbon, and organometallic materials that decompose under plasma conditions.

Electrode conditioning in an electrohydrodynamic fluid accelerator device

Performance of an electrohydrodynamic fluid accelerator device may be improved and adverse events such as sparking or arcing may be reduced based, amongst other things, on electrode geometries and/or positional interrelationships of the electrodes. For example, in a class of EHD devices that employ a longitudinally elongated corona discharge electrode (often, but not necessarily, a wire), a plurality of generally planar, collector electrodes may be positioned so as to present respective leading surfaces toward the corona discharge electrode. The generally planar collector electrodes may be oriented so that their major surfaces are generally orthogonal to the longitudinal extent of the corona discharge electrode. In such EHD devices, a high intensity electric field can be established in the 'gap' between the corona discharge electrode and leading surfaces of the collector electrodes.

Electrohydrodynamic fluid accelerator device with collector electrode exhibiting curved leading edge profile

In thermal management systems that employ EHD devices to motivate flow of air between ventilated boundary portions of an enclosure, it can be desirable to have some heat transfer surfaces participate in electrohydrodynamic acceleration of fluid flow while providing additional heat transfer surfaces that may not. In some embodiments, both collector electrodes and additional heat transfer surfaces are thermally coupled into a heat transfer path. Collector electrodes then contribute both to flow of cooling air and to heat transfer to the air flow so motivated. The collector electrodes and additional heat transfer surfaces may be parts of a unitary, or thermally coupled, structure that is introduced into a flow path at multiple positions therealong. In some embodiments, the collector electrodes and additional heat transfer surfaces may be proximate each other along the flow path. In some embodiments, the collector electrodes and additional heat transfer surfaces may be separate structures.

Electrohydrodynamic fluid accelerator with heat transfer surfaces operable as collector electrode

Reversible flow may be provided in certain EHD device configurations that selectively energize corona discharge electrodes arranged to motivate flows in generally opposing directions. In some embodiments, a first set of one or more corona discharge electrodes is positioned, relative to a first array of collector electrode surfaces, to when energized, motivate flow in a first direction, while second set of one or more corona discharge electrodes is positioned, relative to a second array of collector electrode surfaces, to when energized, motivate flow in a second direction that opposes the first. In some embodiments, the first and second arrays of collector electrode surfaces are opposing surfaces of individual collector electrodes. In some embodiments, the first and second arrays of collector electrode surfaces are opposing surfaces of respective collector electrodes.

Reversible flow electrohydrodynamic fluid accelerator

An apparatus for tandem cleaning of an emitter electrode and collector electrode in electrohydrodynamic fluid accelerator and precipitator devices via movement of a cleaning mechanism including respective cleaning surfaces positioned to frictionally engage the emitter electrode and collector electrode. The cleaning mechanism causes the respective cleaning surfaces to travel along a longitudinal extent of the emitter electrode and, in tandem, over a major dimension of the collector electrode to remove detrimental material from respective electrode surfaces. Alternatively, the electrodes can be transited in tandem in frictional engagement with a fixed cleaning mechanism in the same or opposite directions. A conditioning material is optionally deposited on an electrode to at least partially mitigate ozone, erosion, corrosion, oxidation, or dendrite formation on the electrodes. The conditioning material can include an ozone reducer.

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Campbell, CA, United States of America

Nels Jewell-Larsen