Flexible electrical devices comprising electrode layers on softening polymers and methods of manufacturing such devices, including lift-off processes for forming electrodes on softening polymers, processes for forming devices with a patterned double softening polymer layer, and solder reflow processes for forming electrical contacts on softening polymers.

A single-layer circuit board, multi-layer circuit board, and manufacturing methods therefor. The method for manufacturing the single-layer circuit board (10) comprises the following steps: drilling a hole on a substrate (11), the hole comprising a blind hole and/or a through hole (S1); on a surface (12) of the substrate, forming a photoresist layer having a circuit negative image (S2); forming a conductive seed layer on the surface (12) of the substrate and a hole wall (19) of the hole (S3); removing the photoresist layer, and forming a circuit pattern on the surface (12) of the substrate (S4), wherein Step S3 comprises implanting a conductive material below the surface (12) of the substrate and below the hole wall (19) of the hole via ion implantation, and forming an ion implantation layer as at least part of the conductive seed layer.

There is provided a copper foil provided with a carrier exhibiting a high peeling resistance against the developer in the photoresist developing process and achieving high stability of mechanical peel strength of the carrier. The copper foil provided with a carrier comprises a carrier; an interlayer disposed on the carrier, the interlayer having a first surface adjacent to the carrier and containing 1.0 atom % or more of at least one metal selected from the group consisting of Ti, Cr, Mo, Mn, W and Ni and a second surface remote from the carrier and containing 30 atom % or more of Cu; a release layer disposed on the interlayer; and an extremely-thin copper layer disposed on the release layer.

An electrical device, comprising a softening polymer layer, an electrode layer on a surface of the softening polymer layer and a cover polymer layer on the surface of the softening polymer layer. An opening in the polymer cover layer is filled with a reflowed solder, one end of the reflowed solder, located inside the opening, contacts a contact pad site portion of the electrode layer, and another end of the reflowed solder contacts an electrical connector electrode of the device.

A single-layer circuit board, multi-layer circuit board, and manufacturing methods therefor. The method for manufacturing the single-layer circuit board (10) comprises the following steps: drilling a hole on a substrate (11), the hole comprising a blind hole and/or a through hole (S1); on a surface (12) of the substrate, forming a photoresist layer having a circuit negative image (S2); forming a conductive seed layer on the surface (12) of the substrate and a hole wall (19) of the hole (S3); removing the photoresist layer, and forming a circuit pattern on the surface (12) of the substrate (S4), wherein Step S3 comprises implanting a conductive material below the surface (12) of the substrate and below the hole wall (19) of the hole via ion implantation, and forming an ion implantation layer as at least part of the conductive seed layer.

There is provided a copper foil provided with a carrier exhibiting a high peeling resistance against the developer in the photoresist developing process and achieving high stability of mechanical peel strength of the carrier. The copper foil provided with a carrier comprises a carrier; an interlayer disposed on the carrier, the interlayer having a first surface adjacent to the carrier and containing 1.0 atom % or more of at least one metal selected from the group consisting of Ti, Cr, Mo, Mn, W and Ni and a second surface remote from the carrier and containing 30 atom % or more of Cu; a release layer disposed on the interlayer; and an extremely-thin copper layer disposed on the release layer.

A single-layer circuit board, multi-layer circuit board, and manufacturing methods therefor. The method for manufacturing the single-layer circuit board (10) comprises the following steps: drilling a hole on a substrate (11), the hole comprising a blind hole and/or a through hole (S1); on a surface (12) of the substrate, forming a photoresist layer having a circuit negative image (S2); forming a conductive seed layer on the surface (12) of the substrate and a hole wall (19) of the hole (S3); removing the photoresist layer, and forming a circuit pattern on the surface (12) of the substrate (S4), wherein Step S3 comprises implanting a conductive material below the surface (12) of the substrate and below the hole wall (19) of the hole via ion implantation, and forming an ion implantation layer as at least part of the conductive seed layer.

Methods of making metal patterns on flexible substrates are provided. A releasable solid layer is selectively formed on a patterned surface of the flexible substrate by applying a liquid solution thereon. The releasable solid layer is transferred from the patterned surface to a transfer layer where the metal patterns are formed.

A method of manufacturing an electrical device, comprising: forming a patterned inorganic liftoff layer to expose a target electrode site on a softening polymer layer, depositing an electrode layer on the inorganic liftoff layer and on the exposed target electrode site, and removing the inorganic liftoff layer by a horizontal liftoff etch to leave the electrode layer on the exposed target electrode site.

A method produces a multilayer element with a substrate and at least one conductor structure connected in an areal manner to the substrate, which has first regions of electrically conductive material, which is present in accordance with a prescribed pattern, while electrically non-conductive second regions lie between the first regions.