Abstract: The tantalum chip capacitor of the present invention includes a anode terminal which is substantially flat. The tantalum wire which extends from the tantalum pellet through the insulating material terminates substantially flush with the insulating material, allowing the termination materials to be applied over a substantially flat surface. The tantalum chip capacitors of the present invention are created by methods which include the step of grinding the anode end of the capacitor so that the tantalum wire is flush with the insulating material. Conductive materials can then be applied to the anode end of the capacitor creating a substantially flat anode terminal.
Abstract: A capacitor includes a porous pellet formed from compressed conductive particles. The pellet has a lead receiving external surface. The conductive particles at the lead receiving surface are fused together to create a fused layer on the external surface of the pellet. A lead wire has one of its ends welded to the fused layer on the surface of the pellet. The fused layer is formed by exposing it to high temperatures, preferably by use of a laser beam.
Type:
Grant
Filed:
April 1, 1999
Date of Patent:
April 3, 2001
Assignee:
Vishay Sprague, Inc.
Inventors:
Yuri L. Pozdeev-Freeman, Boris Levi, Semion Akselrod
Abstract: A pellet for use in a capacitor includes a rectangular body formed from compressed and sintered particles of conductive material. The body has an exterior surface which is textured to form a plurality of indentations therein. The profile of the textured surface in cross section is selected from the group including essentially of a curved profile, a sine shape profile, a rectangular shaped profile, a U-shaped profile, and a V-shaped profile.
Abstract: An improved surface mount resistor and method for making the same includes a body comprised of an elongated strip of electrically resistive material and a resistor terminal formed at each end of the resistive material. The resistive material is machined with a laser beam to create a current path having a desired resistance. The pattern cut is determined by partitioning the resistive material into a plurality of squares forming a current path through the resistive material with the correct resistivity. The resistive material is cut primarily with axial cuts so that the beam strength of the resistive material is maintained.
Abstract: Doped tantalum and niobium pellets with nitrogen is described wherein the resulting pellets are substantially free of nitride precipitate on their outer surfaces. The tantalum and niobium pellets are formed by heating the pellets to a temperature of from about 600-1400° C. in a nitrogen gas atmosphere and then in a vacuum which causes nitrogen contacting a pellet to diffuse into the inner portion of the pellet instead of forming a precipitate. The resulting pellets have improved DCL stability and reliability in comparison to prior art nitrogen-doped tantalum and niobium pellets.
Abstract: An improved surface mount resistor and method for making the same includes a body comprised of an elongated strip of electrically resistive material and a resistor terminal formed at each end of the resistive material. The resistive material is machined with a laser beam to create a current path having a desired resistance. The pattern cut is determined by partitioning the resistive material into a plurality of squares forming a current path through the resistive material with the correct resistivity. The resistive material is cut primarily with axial cuts so that the beam strength of the resistive material is maintained.
Abstract: A method of doping tantalum pellets with nitrogen is described wherein the resulting pellets are substantially free of nitride precipitate on their outer surfaces. The method includes the step of heating the pellets to a temperature of from about 1000-1400.degree. C. in a nitrogen gas atmosphere and then in a vacuum which causes nitrogen contacting a tantalum pellet to diffuse into the inner portion of the pellet instead of forming a precipitate. The resulting pellets have improved DCL stability and reliability in comparison to prior art nitrogen-doped tantalum pellets.
Abstract: A method of conformally coating a capacitor with an epoxy layer of the present invention is used to coat the capacitor using fluidized bed techniques. The method includes the use of a chiller bar which is placed against the cathode surface of a capacitor slug which has been heated to 150.degree. C. The capacitor slug and chiller bar are then dipped into the fluidized bed of epoxy powder. The epoxy powder will melt to the capacitor slug on all surfaces except the surface in contact with the chiller bar. After removing the capacitor slug and chiller bar from the fluidized bed and separating the chiller bar from the capacitor, the capacitor will be coated with a layer of epoxy coating on all surfaces except the cathode surface.
Abstract: Doped tantalum pellets with nitrogen is described wherein the resulting pellets are substantially free of nitride precipitate on their outer surfaces. The tantalum pellets are formed by heating the pellets to a temperature of from about 1000.degree.-1400.degree. C. in a nitrogen gas atmosphere and then in a vacuum which causes nitrogen contacting a tantalum pellet to diffuse into the inner portion of the pellet instead of forming a precipitate. The resulting pellets have improved DCL stability and reliability in comparison to prior art nitrogen-doped tantalum pellets.