Abstract: A common mode choke includes a plurality of joined together ferrite layers defining a generally rectangular body and comprising a bottom ferrite layer, a top ferrite layer, and at least one intermediate ferrite layer. The at least one intermediate ferrite layer preferably has an opening therein defining a cavity in the generally rectangular body extending from adjacent a first end thereof to adjacent a second end thereof. The choke also preferably includes at least one first pair of interior conductors extending on the at least one intermediate ferrite layer on opposite sides of the cavity. The choke may also include first and second pairs of end conductors on the first and second ends of the body that are connected to the interior conductors. The interior conductors may also have respective side edge portions exposed to the cavity in the body.

Abstract: An inductor, such as for electromagnetic interference (EMI) suppression, comprises a plurality of ferrite layers arranged in stacked relation and joined together to define a ferrite body, and a first electrical conductor extending between a first pair of adjacent ferrite layers. The inductor includes first respective opposing portions of the first pair of adjacent ferrite layers being sintered together, and second respective opposing portions of the first pair of adjacent ferrite layers being in spaced apart relation to define at least one first gap therebetween. Moreover, the device includes a sintering blocking material associated with the at least one first gap. The sintering blocking material causes the gap to form in the ferrite body to selectively block the magnetic path to thereby retain a higher inductance than would otherwise be possible at relatively high currents. In a surface mounting embodiment of the inductor, the ferrite body has a generally rectangular shape.

Abstract: The invention encompasses a method of forming a composition containing an AlN-SiC composite and/or solid solution, the method comprising:a) combining sources of silicon nitride, aluminum, and carbon to form a mixture, andb) heating the mixture whereby the sources react to form an AlN-SiC composite and/or solid solution.The mixture may be shaped before the reacting step. Also, the reacted mixture may be further heated to produce a densified body.

Abstract: Ceramics containing AlN and B.sub.4 C are produced from relatively low cost starting materials. The starting materials are combined and heated whereby they react to form AlN and B.sub.4 C. The reacted mixture can optionally be densified thereafter. The starting materials generally include aluminum metal, boron nitride and carbon.

Abstract: A boron compound, capable of forming boron oxide on hot pressing in an oxygen-containing atmosphere, is used as a densification aid for hot pressing of alumina-containing ceramics in oxygen-containing atmospheres. The boron compound may be incorporated into the material to be hot pressed or may be applied to the surface of that material. Air may be used as the hot pressing atmosphere. The alumina-containing ceramic to be hot pressed may be formed by reaction processing techniques. Boron nitride is a preferred boron compound.

Abstract: The invention encompasses unsintered and sintered compositions comprising boride and alumina. A sintered material containing boride and alumina may be produced by a method comprising:a) combining sources of borate glass frit and aluminum to form a mixture;b) compacting the mixture to form a shape;c) heating the shape, whereby the sources react to form boride and alumina; andd) densifying the reacted shape.Specific embodiments of the invention include the use of rare earth borate glasses such as La.sub.2 O.sub.3. 6 B.sub.2 O.sub.3 glass to form compositions containing rare earth boride.

Abstract: A composition containing MgAl.sub.2 O.sub.4, SiC, and B.sub.4 C is produced by the method comprising:(a) combining sources of magnesium silicate, B.sub.2 O.sub.3, Al and C to form a mixture, and(b) heating the mixture whereby the sources react to form MgAl.sub.2 O.sub.4, SiC, and B.sub.4 C.A sintered material containing MgAl.sub.2 O.sub.4, SiC, and B.sub.4 C, may be produced by the method comprising:(a) combining sources of magnesium silicate, B.sub.2 O.sub.3, Al and C to form a mixture,(b) compacting the mixture into a shape,(c) heating the shape, whereby the sources react to form MgAl.sub.2 O.sub.4, SiC, and B.sub.4 C, and(d) sintering the reacted shape.Possible sources of magnesium silicate are talc, vermiculite and mica.