The present disclosure relates to passive electrical components.
The advent of relatively high temperature semiconductor devices, such as silicon-on-sapphire (SOS) and wide-band gap (WBG) semiconductors, has produced devices which can operate at high temperatures from 200° C. to 300° C. base plate temperatures. In comparison, silicon based devices have maximum base plate temperatures of 85° C. to 125° C.
However, not all passive electrical components used with the high temperature semiconductor devices have been optimized for such high temperatures. Current passive electrical components provide significantly reduced efficiency in a 300° C. environment.
Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiment. The drawings that accompany the detailed description can be briefly described as follows:
The capacitor 12 may be formed on a substrate 18. The substrate 18 may be a conductive substrate such as aluminum or a non-conductive substrate deposited with a conductive layer such as silicon carbide (SiC) layered with aluminum. In one non-limiting embodiment, the aluminum may be polished to provide a surface roughness of approximately 20 nm to 85 nm.
The conductor layers 14 may be formed of, for example, aluminum, nickel, copper, gold or other conductive inorganic material or combination of materials. Various aspects of the present disclosure are described with reference to a multiple of inorganic dielectric coating layers 16 and alternating connected conductor layers 14 formed adjacent or on the substrate or upon another layer. As will be appreciated by those of skill in the art, references to a layer formed on or adjacent another layer or substrate contemplates that additional other layers may intervene.
The inorganic dielectric coating layer 16 may be formed of, for example, halfnium oxide, silicone dioxide, silicon nitrides, fused aluminum oxide, Al0.66Hf0.33O3, Al0.8Hf0.2O3, Al0.5Y0.5O3, or other inorganic materials or combination of inorganic materials. In one non-limiting embodiment, the inorganic dielectric coating layer 16 may be deposited to a thickness from approximately 0.6 microns to 10 microns.
The inorganic dielectric coating layer 16 may be applied through a pulsed laser deposition (PLD) process such as that provided by Blue Wave Semiconductors, Inc. of Columbia, Md. USA. The PLD process facilitates multiple combinations of metal-oxides and nitrides on SiC, Si, AN, Al, Cu, Ni or any other suitable flat surface. A multilayer construction of dielectric stacks, with atomic and coating interface arrangements of crystalline and amorphous films may additionally be provided. The inorganic dielectric coating layer 16 provides a relatively close coefficient of thermal expansion (CTE) match to an SiC substrate so as to resist the thermal cycling typical of high temperature operations. The PLD process facilitates a robust coating and the engineered material allows, in one non-limiting embodiment, 3 microns of the inorganic dielectric coating layer 16 to store approximately 1000V.
The PLD process facilitates deposition of the inorganic dielectric coating layer 16 that can provide a flat dielectric constant at approximately 300° C. and the ability to place the inorganic dielectric coating layer 16 in various spaces so as to minimize wasted space. It should be understood that the PLD process facilitates deposition of the inorganic dielectric coating layer 16 on various surfaces inclusive of flat and curves surfaces.
Some factors which may affect the quality of the capacitor include the substrate surface smoothness, the smoothness of the oxide layer, and the thickness and surface area of the inorganic dielectric coating layer 16. A relatively thicker inorganic dielectric coating layer 16 provides a higher breakdown voltage but may facilitate cracks. A relatively larger electrode surface area tends to have more defects and therefore decrease breakdown voltage while a relatively smaller surface area tends to have a higher capacitor density and a higher breakdown voltage.
During development of the passive electrical component of the present disclosure, various material test coupons were evaluated. The operational capabilities of the capacitor are further defined from the following examples.
Referring to
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The inductor 20 may be formed on a substrate 18. The substrate 18 may be a conductive substrate such as aluminum or a non-conductive substrate deposited with a conductive layer such as silicon carbide (SiC) layered with aluminum or other material.
The conductor layers 22 may be formed of, for example, aluminum, nickel, copper, gold or other conductive inorganic material or combination of materials.
The high permeability layers 24 may be manufactured of a permalloy material which is typically a nickel iron magnetic alloy. The permalloy material, in one non-limiting embodiment, includes an alloy with about 20% iron and 80% nickel content. The high permeability layer 24 has a relatively high magnetic permeability, low coercivity, near zero magnetostriction, and significant anisotropic magnetoresistance.
The inorganic dielectric coating layer 26 may be formed by the PLD process as previously described to separate the current flow through each conductor layer 22 and each high permeability layers 24 which travel in opposite directions.
System benefits of the high temperature passive electrical components disclosed herein include reduced weight and robust designs. The combination of high temperature electronic devices with high temperature passive electrical components provide effective operations in temperatures of up to 300° C. with relatively smaller, lighter heat sinks and/or the elimination of active cooling systems.
Although an inductor and capacitor are disclosed as passive electrical components, it should be understood that other passive electrical components such as resistors, strain gauges and others may be manufactured as disclosed herein. The inductor and capacitor may be deposited on the same substrate in various combinations to form power dense filters for power applications and general extreme environment electronic systems.
Referring to
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It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom.
The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims.
The present disclosure is a continuation application of U.S. patent application Ser. No. 12/344570, filed Dec. 28, 2008.
Number | Date | Country | |
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Parent | 12344570 | Dec 2008 | US |
Child | 12829582 | US |