Bmc Technology Corporation

Aubrey M Burer

Joseph W Crownover

Ben B Meckel

John C Monsees

A method and apparatus for manufacturing electrodes for capacitors having a plurality of thin metal coatings on a ceramic dielectric substrate, with the coated substrates assembled in a monolithic structure. A layer of green ceramic material is formed on a support tape. This green ceramic tape is moved in registration with a stencil web overlying the tape. The stencil web has openings corresponding to the configuration of the conductive coating to be formed on the tape. The sandwich of tape and web is moved through a sputtering chamber in which a selected metal or alloy is sputtered from a target so as to fall on the stencil web, coating the ceramic tape wherever openings are present. The sputtering chamber is arranged so that initially the ceramic tape receives a light, low energy metal coating before being exposed to maximum sputtering. This allows a reflective coating to be formed to reflect thermal energy before the intensity of the thermal radiation reaches a level that would damage an uncoated ceramic. The coated ceramic substrate tape may then be divided and assembled into multi-layer monolithic capacitors. In a related embodiment, the metallic electrodes may be sputtered onto a plastic carrier film to form a transferable layer or decalcomania, with the electrodes later transferred to the surface of the ceramic substrate.

Method for manufacturing electrodes for multilayer ceramic capacitors

A process for producing capacitors having thinner electrodes on dielectric substrates for use in multilayer ceramic capacitors which use less precious metal ink and produce thinner capacitors. Basically, the process begins with coating a support with a mixture of a finely divided ceramic material and a resin to form a green ceramic dielectric substrate of substantially uniform thickness but with a necessarily rough surface. A coating of resin is applied over the green ceramic to form a substantially smooth surface. A desired pattern in an ink comprising precious metal particles in a resin is formed, such as by silk screening, on the coated ceramic to form the electrode. Because of the smooth resin surface and finer metal particles, the ink coating may be relatively thin. The composite may then be fired to produce a capacitor suitable for use in monolithic multilayer capacitors.

Process for producing ceramic capacitors with thinner electrodes

A process of manufacturing thin monolithic multilayer capacitors having improved resistance to delamination. Basically, the process comprises the steps of providing a support sheet having registration indicia, such as a series of registration holes along the support edges, casting a substrate of ceramic particles in a resin binder onto the support, drying the substrate, forming thin electrodes in selected patterns by cathode sputtering, casting an additional substrate on the electrode surface in a vacuum, repeating the drying, electrode formation steps a selected number of times and forming a cover layer of substrate material over the final electrode. Individual capacitors may be cut from the multilayer product in any desired shape using any desired cutting technique. Ordinarily, the electrodes are formed in two alternating patterns in registration on succeeding layers. This process produces thinner multilayer capacitors with improved bonding between succeeding layers so as to increase resistance to delamination during cutting and use.

Growing community of inventors

El Cajon, CA, United States of America

Aubrey M Burer