Abstract: A structure for minimizing resistance between a semi-insulating x-ray detector crystal and an electrically conducting substrate. Electrical contact pads are disposed on the detector crystal and on the substrate with an electrical interconnect between the contact pads formed from a conductive adhesive and washed solder in electrical and mechanical communication with the pads.

Abstract: A flexible, high density decal and the use thereof methods of forming detachable electrical interconnections between a flexible chip carrier and a printed wiring board. The flexible decal has fine-pitch pads on a first surface and pads of a pitch wider than the fine pitch on a second surface, the fine-pitch pads on the first surface designed to electrically connect to a semiconductor device, and the wider-pitch pads on the second surface designed to electrically connect to a printed wiring board or the like. The pads on the first surface are conductively wired to the pads on the second surface through one or more insulating levels in the flexible decal.

Abstract: A flexible, high density decal and the use thereof methods of forming detachable electrical interconnections between a flexible chip carrier and a printed wiring board. The flexible decal has fine-pitch pads on a first surface and pads of a pitch wider than the fine pitch on a second surface, the fine-pitch pads on the first surface designed to electrically connect to a semiconductor device, and the wider-pitch pads on the second surface designed to electrically connect to a printed wiring board or the like. The pads on the first surface are conductively wired to the pads on the second surface through one or more insulating levels in the flexible decal.

Abstract: A circuitized substrate and method of making same in which a first plurality of holes are formed within two bonded dielectric layers and then made conductive, e.g., plated. The substrate also includes third and fourth dielectric layers bonded to the first and second with a plurality of continuous electrically conductive thru holes extending through all four dielectric layers. Conductive paste is positioned within the thru holes for providing electrical connections between desired conductive layers of the substrate and outer layers as well. A circuitized substrate assembly and method of making same are also provided.

Abstract: A method for forming a plated microvia interconnect. An external dielectric layer (EDL) is mounted on a surface of the substrate and is in direct mechanical contact with a conductive element included in the surface. An opening formed in the EDL exposes the conductive element and creates a microvia in the EDL. A sidewall and bottom wall surface of the microvia is treated to promote copper adhesion to the sidewall and bottom wall surfaces. The sidewall and bottom wall surfaces are plated to form a layer of copper thereon. The layer of copper is in direct mechanical and electrical contact with the conductive element. A wet solder paste deposited on the layer of copper overfills a remaining portion of the microvia. The solder paste is reflowed to form a solder bump in and over the remaining portion of the microvia to form the plated microvia interconnect.

Abstract: A metal alloy solder ball comprising a first metal and a second metal, the first metal having a sputtering yield greater than the second metal. The solder ball comprises a bulk portion having a bulk ratio of the first metal to the second metal, an outer surface, and a surface gradient having a depth and a gradient ratio of the first metal to the second metal that is less than the bulk ratio. The gradient ratio increases along the surface gradient depth from a minimum at the outer surface. The solder ball may be formed by the process of exposing the ball to energized ions of a sputtering gas for an effective amount of time to form the surface gradient.

Abstract: A chip carrier structure and method for forming the same having a receptor pad formed therein. The structure comprises a circuitized substrate having a conductive element on the surface, an External Dielectric Layer mounted on the circuitized substrate with an opening positioned above the conductive element to form a microvia. The walls of the microvia are first treated to enhance copper adhesion and then are electroplated to provide a receptor pad. Finally, a solder paste is deposited within the microvia to create a solder deposit or bump.

Abstract: A chip carrier structure and method for forming the same having a receptor pad formed therein. The structure comprises a circuitized substrate having a conductive element on the surface, an External Dielectric Layer mounted on the circuitized substrate with an opening positioned above the conductive element to form a microvia. The walls of the microvia are first treated to enhance copper adhesion and then are electroplated to provide a receptor pad. Finally, a solder paste is deposited within the microvia to create a solder deposit or bump.

Abstract: A metal alloy solder ball comprising a first metal and a second metal, the first metal having a sputtering yield greater than the second metal. The solder ball comprises a bulk portion having a bulk ratio of the first metal to the second metal, an outer surface, and a surface gradient having a depth and a gradient ratio of the first metal to the second metal that is less than the bulk ratio. The gradient ratio increases along the surface gradient depth from a minimum at the outer surface. The solder ball may be formed by the process of exposing the ball to energized ions of a sputtering gas for an effective amount of time to form the surface gradient.

Abstract: A process for altering surface properties of a mass of metal alloy solder comprising a first metal and a second metal. The process comprises exposing the mass to energized ions to preferentially sputter atoms of the first metal to form a surface layer ratio of first metal to second metal atoms that is less than the bulk ratio. The solder may be located on the surface of a substrate, wherein the process may further comprise masking the substrate to shield all but a selected area from the ion beam. The sputtering gas may comprises a reactive gas such as oxygen and the substrate may be an organic substrate. The process may further comprise simultaneously exposing the organic substrate to energized ions of the reactive gas to roughen the organic substrate surface.

Abstract: A process for altering surface properties of a mass of metal alloy solder comprising a first metal and a second metal. The process comprises exposing the mass to energized ions to preferentially sputter atoms of the first metal to form a surface layer ratio of first metal to second metal atoms that is less than the bulk ratio. The solder may be located on the surface of a substrate, wherein the process may further comprise masking the substrate to shield all but a selected area from the ion beam. The sputtering gas may comprises a reactive gas such as oxygen and the substrate may be an organic substrate. The process may further comprise simultaneously exposing the organic substrate to energized ions of the reactive gas to roughen the organic substrate surface.