A flexible electronic substrate (FES) includes a metallic layer, a dielectric nanoceramic layer formed by oxidation of a surface of the metallic layer, and an electrical circuit formed on a surface of the dielectric layer. The FES may be used for supporting a device, for example a flexible display, an OLED, an optoelectronic device, or a rf device. The dielectric nanoceramic layer has a crystalline structure consisting of substantially equiaxed grains having an average grain size of 100 nanometers or less, a thickness of between 1 micrometer and 50 micrometers, a dielectric strength of greater than 20 KV mm.sup.1, and a thermal conductivity of greater than 3 W/mK. The FES has a minimum bend radius of lower than 25 cm.

There is provided a roughened copper foil which can significantly improve adhesion to an insulating resin and reliability (e.g., hygroscopic heat resistance). The roughened copper foil of the present invention has at least one roughened surface having fine irregularities composed of acicular crystals, wherein the entire surface of the acicular crystals is composed of a mixed phase of Cu metal and Cu.sub.2O.

A method for producing a metal foil comprising depositing metal onto an oxidizable substrate to form a metal film on the substrate; oxidizing the substrate at an interface between the metal film and the substrate; and removing the metal film from the substrate to yield a metal foil. A method for forming a thin metal film comprising pre-polarizing a single-crystal Si substrate by application of a potential which is negative of a potential at which Si oxidizes, which pre-polarization occurs in the presence of metal ions to form metal growth nucleation sites on the substrate, followed by application of a potential at which both oxidation of Si and electrodeposition of the metal occur to grow the metal film and oxidize the Si to SiOx, which potential is more positive than the potential applied in the pre-polarization step.

A process for manufacturing an electronic component having attaches includes providing a first component having a first attach, forming trenches on a portion of the first attach with a laser to form a solder stop, and providing a second component comprising a second attach. The process further includes providing solder between the first attach and the second attach to form a connection between the first component and the second component, where the trenches contain the solder to a usable area. A device produced by the process is disclosed as well.

A method of establishing conductive connections is disclosed. The method includes providing an integrated circuit die having a plurality of solder balls each of which has an oxide layer on an outer surface of the solder ball. The method also includes performing a heating process to heat at least the solder balls and applying a force causing each of a plurality of piercing bond structures on a substrate to pierce one of the solder balls and its associated oxide layer to thereby establish a conductive connection between the solder ball and the piercing bond structure.

A method of establishing conductive connections is disclosed. The method includes providing an integrated circuit die having a plurality of solder balls each of which has an oxide layer on an outer surface of the solder ball. The method also includes performing a heating process to heat at least the solder balls and applying a force causing each of a plurality of piercing bond structures on a substrate to pierce one of the solder balls and its associated oxide layer to thereby establish a conductive connection between the solder ball and the piercing bond structure.

A process for manufacturing an electronic component having attaches includes providing a first component having a first attach, forming trenches on a portion of the first attach with a laser to form a solder stop, and providing a second component comprising a second attach. The process further includes providing solder between the first attach and the second attach to form a connection between the first component and the second component, where the trenches contain the solder to a usable area. A device produced by the process is disclosed as well.

There is provided a roughened copper foil which can significantly improve adhesion to an insulating resin and reliability (e.g., hygroscopic heat resistance). The roughened copper foil of the present invention has at least one roughened surface having fine irregularities composed of acicular crystals, wherein the entire surface of the acicular crystals is composed of a mixed phase of Cu metal and Cu.sub.2O.

A transparent conductor is provided, including a visible light transparent substrate and metal traces disposed on the substrate, and a layer of a second metal deposited on at least a portion of the metal traces. The transparent conductor further includes a layer of a second metal, which conforms to the surface structure of the metal traces on which it is deposited. Optionally, the transparent conductor also includes a coating layer disposed on a portion of the metal traces and the substrate surface. The coating layer includes a polymer prepared from a polymerizable composition containing at least one ionic liquid monomer. A method of forming a transparent conductor is also provided, including obtaining a visible light transparent substrate having metal traces disposed on the substrate and applying a coating composition on a portion of the metal traces and substrate. The coating composition contains at least one noble metal salt and at least one polymerizable ionic liquid monomer.

A substrate (1, 10) for electrical circuits, comprising at least one metal layer (2,3, 14) and a paper ceramic layer (11), which is joined face to face with the at least one metal layer (2,3, 14) and has a top side and bottom side (11a, 11b), wherein the paper ceramic layer (11) has a large number of cavities in the form of pores. Especially advantageously, the at least one metal layer (2, 3, 14) is connected to the paper ceramic layer (11) by means of at least one glue layer (6, 6a, 6b), which is produced by applying at least one glue (6a, 6a, 6b, 6b) to the metal layer (2,3, 14) and/or to the paper ceramic layer (11), wherein the cavities in the form of pores in the paper ceramic layer (11) are filled at least at the surface by means of the applied glue (6a, 6a, 6b,6b).