A printed circuit board includes a core layer having a first surface and a second surface opposing the first surface; a first built-up structure disposed on the first surface of the core layer; a second built-up structure disposed on the second surface of the core layer; and a first penetration portion penetrating the first built-up structure and the core layer and penetrating a portion of the second built-up structure. The first penetration portion has a step portion on at least a portion of a wall of the first penetration portion in the region of the first penetration portion penetrating the second built-up structure, and a region including the first penetration portion on a plane is configured as a flexible region.

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

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

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.

A ceramic circuit substrate having high bonding performance and excellent thermal cycling resistance properties, having a circuit pattern provided on a ceramic substrate with a braze material layer interposed therebetween, and a protruding portion formed by the braze material layer protruding from the outer edge of the circuit pattern, wherein: the braze material layer includes Ag, Cu, Ti, and Sn or In; and an Ag-rich phase is formed continuously for 300 m or more, towards the inside, from an outer edge of the protruding portion, along a bonding interface between the ceramic substrate and the circuit pattern, and has a bonding void ratio of 1.0% or less.

A method of manufacturing a flexible electronic circuit is provided. The method may include forming a positive photoresist mold on a flexible polymer substrate having a plurality of metal traces. The method may also include applying a conformal material coating over the positive photoresist mold, the flexible polymer substrate, and the metal traces. The method may further include removing an excess of the conformal material coating by running a blade over the positive photoresist mold. The method may also include removing the positive photoresist mold to reveal a cavity defined by the conformal material coating. The method may further include dispensing an anisotropic conductive paste into the cavity and inserting a chip into the cavity and bonding the chip to the metal traces.

A multi-layer circuit board, successively constituted by surface sticking layer, single-layer circuit board, middle sticking layer, single-layer circuit board, surface sticking layer, said multi-layer circuit board is provided with a hole, a hole wall of said hole is formed with conductive seed layer, and partial outer surface of said surface sticking layer is formed with a circuit pattern layer of conductive seed layer, wherein said conductive seed layer comprises a ion implantation layer implanting below the hole wall of said hole and below partial outer surface of said surface sticking layer.

Methods of making metal patterns on flexible substrates are provided. Releasable solid layer is selectively formed on a patterned surface of the flexible substrate by applying a liquid solution thereon. Metal patterns on the flexible substrate can be formed by removing the releasable solid layer after metallization. In some cases, the releasable solid layer can be transferred from the patterned surface to a transfer layer where the metal patterns are formed.

A flexible conductive track arrangement has a pre-flexing condition in which the arrangement is generally planar. Conductive tracks are formed from a metal layer and they are covered above and below by insulator layers. The elongate conductive tracks are generally planar but locally corrugated perpendicularly to the general plane. This enables improved binding performance, for example to form tight windings using the conductive tracks.