Abstract: A multilayer ceramic repair process which provides a new electrical repair path to connect top surface vias. The repair path is established between a defective net and a redundant repair net contained within the multilayer ceramic substrate. The defective net and the repair net each terminate at surface vias of the substrate. A laser is used to form post fired circuitry on and in the substrate. This is followed by the electrical isolation of the defective net from the electrical repair structure and passivation of the electrical repair line.

Abstract: A multilayer ceramic repair process which provides a new electrical repair path to connect top surface vias. The repair path is established between a defective net and a redundant repair net contained within the multilayer ceramic substrate. The defective net and the repair net each terminate at surface vias of the substrate. A laser is used to form post fired circuitry on and in the substrate. This is followed by the electrical isolation of the defective net from the electrical repair structure and passivation of the electrical repair line.

Abstract: A method and apparatus are provided for reworking of finishing metallurgy on pads of electronic components. The pads are copper or copper/nickel and have a layer of nickel thereon and an overlying layer of gold. The gold layer is removed first followed by the nickel layer and then the component is treated to remove etch and corrosion products. Media blasting is then used to restore the pads to their original condition as on prime parts. The pads are then replated using conventional nickel and gold plating solutions to form the reworked component.

Abstract: A method and structure to form surface plating metallization on a substrate. Two layers of tape are applied to the surface of the substrate. A first path is cut through both layers of tape exposing the substrate surface. The first path connects at least one conductive via on the top surface of the substrate. A second path is cut through the second layer of tape exposing the first layer of tape. The second path is routed from the first path to an edge of the substrate A seed layer is deposited over the surface of the second layer of tape thereby creating a seeded plating path in the first path and a sacrificial seeded conduction path in the second path. Connecting the sacrificial seeded conduction path to a plating potential at the edge of the substrate creates a plated path on the surface of the substrate. The sacrificial path is removed when the tape is removed.

Abstract: A method and structure to form surface plating metallization on a substrate. Two layers of tape are applied to the surface of the substrate. A first path is cut through both layers of tape exposing the substrate surface. The first path connects at least one conductive via on the top surface of the substrate. A second path is cut through the second layer of tape exposing the first layer of tape. The second path is routed from the first path to an edge of the substrate A seed layer is deposited over the surface of the second layer of tape thereby creating a seeded plating path in the first path and a sacrificial seeded conduction path in the second path. Connecting the sacrificial seeded conduction path to a plating potential at the edge of the substrate creates a plated path on the surface of the substrate. The sacrificial path is removed when the tape is removed.

Abstract: A multilayer ceramic repair process which provides a new electrical repair path to connect top surface vias. The repair path is established between a defective net and a redundant repair net contained within the multilayer ceramic substrate. The defective net and the repair net each terminate at surface vias of the substrate. A laser is used to form post fired circuitry on and in the substrate. This is followed by the electrical isolation of the defective net from the electrical repair structure and passivation of the electrical repair line.

Abstract: A process for cleaning paste from a workpiece, such as a screening mask, which includes the step of electrolytically contacting the workpiece with an aqueous solution containing 0.2 to 2 weight percent TMAH. As an optional prestep, the workpiece may be cleaned nonelectrolytically with an aqueous solution containing 0.2 to 2 weight percent TMAH.

Abstract: A method and apparatus are provided for reworking of finishing metallurgy on pads of electronic components. The pads are copper or copper/nickel and have a layer of nickel thereon and an overlying layer of gold. The gold layer is removed first followed by the nickel layer and then the component is treated to remove etch and corrosion products. Media blasting is then used to restore the pads to their original condition as on prime parts. The pads are then replated using conventional nickel and gold plating solutions to form the reworked component.

Abstract: A semiconductor interconnect connection mechanism for attaching individual surface mounted semiconductor objects to multichip products whereby at least a portion of the electrical pathway between different objects on the top surface of surface mounted devices is not located on the top surface.

Abstract: A semiconductor interconnecting mechanism, having

Abstract: A process for reworking of PGA chip carriers where one or more I/O pins is unplated. The process includes electrolytically etching the I/O pins which removes any corrosion product from the unplated I/O pins and removes the top gold layer from the remaining I/O pins. The etchant includes a metal-providing compound selected from the group consisting of a silver salt, copper cyanide, silver cyanide, gold cyanide or mixtures thereof, at a concentration in the range from about 2.7 to about 4.1 g/l as metal; potassium or sodium carbonate at a concentration in the range from about 10 to about 100 g/l; and potassium or sodium cyanide at a concentration in the range from about 29 to about 35 g/l.

Abstract: A microelectronic structure, having 1) at least one metallic feature situated on a layer of material selected from the group consisting of nonmetallic and semiconductor materials; 2) a layer of a cobalt-phosphorus alloy (Co(P)) covering at least one of the at least one metallic feature; and 3) a layer of a material selected from the group consisting of nickel and palladium covering the area covered by the Co(P) layer.

Abstract: In the manufacture of a microelectronic component having metallic features on a polyimide layer, the metallic features being spaced from one another by gaps, at least some of which gaps have widths in a range from about one micron to about 500 microns, corrosion protection is provided by plating those features by electroless deposition of a nickel-phosphorus alloy forming a layer having a thickness in a range from about 200 .ANG. to about 3000 .ANG., at a rate of about 100 .ANG. per minute, in an aqueous plating bath comprising nickel sulfate hexahydrate in an amount of about 5.5 grams per liter, sodium hypophosphite in an amount of about six grams per liter, boric acid in an amount of about 30 grams per liter, sodium citrate in an amount of about 45 grams per liter, lead acetate in an amount of about one part per million by weight of lead, and a surfactant in an amount of about 0.1 grams per liter. The bath has a temperature of about 72.degree. C. and a pH of about 8.1.

Abstract: The present invention provides a novel method of etching nickle/iron alloy which employs a novel etchant. The novel etchant, which etches nickle/iron alloy but not copper, comprises an aqueous solution of ferric ammonium sulfate, and an acid selected from the group consisting of: sulfuric acid; phosphoric acid; and mixtures thereof.

Abstract: The present invention relates to a method for selectively electroetching a metal from an electrical device having the steps of: immersing the electrical device in an etching solution; immersing a cathode in the etching solution; applying an etching potential to a preselected area of the metal; and maintaining a passivation potential at the metal to remain unetched. The metal to remain unetched is not electrically connected to the preselected area and the passivation potential does not equal the etching potential.The present invention further relates to a method of forming an electrical connection to the inner layers of a multilayer circuit board having a copper foil surface layer and copper containing inner layers.

Abstract: The present invention relates to a method for selectively electroetching a metal from an electrical device having the steps of: immersing the electrical device in an etching solution; immersing a cathode in the etching solution; applying an etching potential to a preselected area of the metal; and maintaining a passivation potential at the metal to remain unetched. The metal to remain unetched is not electrically connected to the preselected area and the passivation potential does not equal the etching potential.The present invention further relates to a method of forming an electrical connection to the inner layers of a multilayer circuit board having a copper foil surface layer and copper containing inner layers.

Abstract: Disclosed is a method of fabricating a microelectronic package having least one layer formed of a Cu-Invar-Cu core encapsulated between a pair of dielectric films. The package is intended to carry surface circuitization on an external surface, with internal circuitization from the surface circuitization passing through the core. The method includes contacting the copper within the Cu-Invar-Cu core with a copper etching aqueous solution of a strong base and a strong oxidizing acid, while maintaining the copper anodic. This electrolytically converts the copper to soluble copper oxides. In a separate step the Invar of the Cu-Invar-Cu core is electrolytically etched with an Invar etching aqueous solution of sodium chloride. This step is carried out under conditions to electrolytically form soluble iron and nickel chlorides while passivating the copper.

Abstract: Disclosed is a method of fabricating a microelectronic package having least one layer formed of a copper-Invar-copper core encapsulated between a pair of dielectric films. The method includes exposing a copper-Invar-copper surface of the copper-Invar-copper core, for example, exposing an edge of the copper-Invar-copper core or drilling a whole through the layer to expose internal copper-Invar-copper. The copper-Invar-copper is then shaped, that is, back etched. This is an electrolytic process where the package is immersed in a substantially pH neutral electrolyte including a counter- electrode. A preferred electrolyte is an aqueous alkali metal nitrate solution. The electrolyte wets the exposed surface of said copper-Invar-copper core. The exposed surface of the copper-Invar-copper core is rendered anodic with respect to the counter-electrode and an electrical potential is applied therebetween. This results in electrochemically etching and shaping the copper-Invar-copper surface.

Abstract: A process and apparatus for electrochemically separating alkali oxides to simultaneously generate oxygen gas and liquid alkali metals in a high temperature electrolytic cell is provided. The high temperature electrolytic cell comprises a cathode in contact with an alkali ion conducting molten salt electrolyte separated from the anode by an oxygen vacancy conducting solid electrolyte. Alkali metals separated in the alkali metal reducing half cell reaction are useful as reducing agents in the direct thermochemical refining of lunar metal oxide ores to produce metallic species and alkali oxides, and the alkali oxides may then be recycled to the high temperature electrolytic cell.